Rexroth PSQ 6000 - RGB Automatyka

Contents 1-1

Rexroth PSQ 6000U/I Regulator

Commissioning, Operating Manual

1070087072Edition 01

1-2 Contents

Title Rexroth PSQ 6000 U/I Regulator

Class of Documentation Commissioning, Operating Manual

Documentation Type DOK-PS6000-UIR********-IB01-EN-P

Intent of the DocumentationThis manual provides information on:• installation• functionality, and• operationof the U/I regulator XQR modul.

This information supplements the respective manual "PSI 6000 Controland I/O Level" and the manual “PSI 6000 Medium-Frequency Inverter".The safety instructions defined in these manuals are applicable.

Follow-Up of ModificationsPrevious editions Status CommentDOK-PS6000-UIR********-IB01-EN-P 08.2006

Note on Industrial Property Rights© Bosch Rexroth Electric Drives and Control GmbH, 2004−2006Unless expressly authorized, any copying of this document and utilizationand disclosure of its content is not allowed. Damages will be payable incase of contravention. All rights are reserved in the event of the grant of apatent or the registration of a utility model or design (DIN 34-1).

Legal ValidityThe data given in this document only intend to describe the product andmust not be understood as guaranteed properties in the legal sense. Anystatement on a specific quality or suitability for a specific applicationcannot be derived from the data given in this document. Such data do notrelieve the user from his duty to make his own assessments and tests.We reserve the right to modify the contents of this Documentation andthe availability of the products.

EditorBosch Rexroth Electric Drives and Control GmbHPostfach 1162D-64701 ErbachBerliner Strasse 25D-64711 ErbachPhone: +49 (0) 60 62/78-0Fax: +49 (0) 60 62/78- 728Dept.: BRC / PAW1

Contents 1-3

1 Contents

1 Contents .................................................................................1-3

2 Safety Instructions.................................................................2-12.1 Intended Use........................................................................... 2-2

2.2 Environmental Protection, Return of Material, Reuse ...... 2-2

2.3 Qualified Personnel ............................................................... 2-3

2.4 Dangerous Magnetic Fields .................................................. 2-4

2.5 Installation and Assembly..................................................... 2-5

2.6 Electrical Connection ............................................................ 2-6

2.7 Modifications by the Operator ............................................. 2-7

2.8 Maintenance, Repair ............................................................. 2-7

2.9 Working Safely ...................................................................... 2-8

2.10 Installation and Retrofit........................................................ 2-9

3 System Design......................................................................3-103.1 Design of the System as a Whole ........................................ 3-10

3.2 Connection ........................................................................... 3-11

3.3 Weld Timer Integration ...................................................... 3-16

3.4 Field of Application ............................................................. 3-16

3.5 Information on Installation and Assembly........................ 3-16

4 Commissioning with BOS 6000 ..........................................4-174.1 First Step .............................................................................. 4-17

4.2 Second Step .......................................................................... 4-17

4.3 Third Step ............................................................................ 4-18

4.4 Forth Step............................................................................. 4-25

5 BOS 6000 with U/I Regulator .............................................5-275.1 Requirements ....................................................................... 5-27

5.2 PSQ Status Display.............................................................. 5-27

5.3 Summary of U/I Operator Functions................................. 5-27

5.4 Programming – Sequence ................................................... 5-28

5.5 PSQ Programming – UIR ................................................... 5-29General: Global UIR Parameters .............................................................5-29

Mode....................................................................................................5-29Expulsion Detection.............................................................................5-30

Referring to UIR Program .......................................................................5-30Measuring ............................................................................................5-30Regulation............................................................................................5-30Monitoring ...........................................................................................5-31Expulsions............................................................................................5-31

5.6 PSQ Programming – UIR Reference ................................. 5-32Load Curve ..............................................................................................5-32

PC ...................................................................................................5-32

1-4 Contents

Reference Sequence Timer .............................................................5-32Actual Curve Timer ........................................................................5-32

Write Curve .............................................................................................5-33 PC ...................................................................................................5-33

Reference Sequence Timer .............................................................5-33Settings ....................................................................................................5-33Zoom........................................................................................................5-33Display.....................................................................................................5-33

5.7 Programming – PSQ – UIR Monitoring............................ 5-33Programming the Monitoring Function ...................................................5-35

Permissible Upper Tolerance Band .....................................................5-36Permissible Lower Tolerance Band .....................................................5-36Conditionally Permissible Tolerance Band..........................................5-36Repetition Factor..................................................................................5-36Acceptance Repetition Factor ..............................................................5-36

Progress Display ......................................................................................5-37Welding Sequence Displayed ..............................................................5-38Update..................................................................................................5-38Settings ................................................................................................5-38Zoom....................................................................................................5-38Actual Desired ................................................................................5-39Export ..................................................................................................5-39Y-Zoom................................................................................................5-39PSQ Status Display..............................................................................5-39

Information on Monitoring ......................................................................5-39Current .................................................................................................5-40PHA (Pulse Width) ..............................................................................5-40Weld Time ...........................................................................................5-41Energy..................................................................................................5-41Process Stability PSF ...........................................................................5-41Process Quality UIP.............................................................................5-42Tolerances............................................................................................5-42

5.8 Diagnostics – Last Sequence ............................................... 5-43

5.9 Diagnostics – PSQ................................................................ 5-45Filter.........................................................................................................5-45

Without ................................................................................................5-45Program................................................................................................5-46Single/Prog. .........................................................................................5-46Stop......................................................................................................5-46

Display.....................................................................................................5-46Cursor 1 ...............................................................................................5-46Cursor 2 ...............................................................................................5-46Min.......................................................................................................5-47Max. .....................................................................................................5-47MV.......................................................................................................5-47

Actual Reference.................................................................................5-47Settings ....................................................................................................5-47Zoom........................................................................................................5-47

5.10 Setup – UIR Setup ............................................................... 5-48Recording Mode ......................................................................................5-49Analysis Mode .........................................................................................5-50

Filter – Program...................................................................................5-50Filter – Actual Curve ...........................................................................5-50Delete Actual Curve.............................................................................5-51Average Curve .....................................................................................5-51Original Curves....................................................................................5-51Reference Sequence Timer .............................................................5-52

PC ...................................................................................................5-52Zoom....................................................................................................5-52

Contents 1-5

5.11 Overview............................................................................... 5-53Overview – General .................................................................................5-53Overview – UIR Mode ............................................................................5-53Overview – PSQ Process Variables.........................................................5-54

Meaning of Table Columns .................................................................5-54Examples: ............................................................................................5-55

5.12 Process Overview................................................................. 5-57

6 Commissioning with BQR...................................................6-586.1 First Step .............................................................................. 6-58

6.2 Second Step .......................................................................... 6-58

6.3 Third Step ............................................................................ 6-59

6.4 Forth Step............................................................................. 6-65

7 BQR User Interface – U/I Regulator..................................7-667.1 Installation and Connection................................................ 7-66

Requirements ...........................................................................................7-66Connection...............................................................................................7-66Installation ...............................................................................................7-66

7.2 Overview of Operating Functions ...................................... 7-67

7.3 Parameterization of the U/I Regulator .............................. 7-67Basic Display ...........................................................................................7-68

All Programs........................................................................................7-68Mode....................................................................................................7-68Expulsion Detection.............................................................................7-69Selected Program .................................................................................7-69UIR Parameter .....................................................................................7-70Supervision Parameters........................................................................7-72Permissible Upper Tolerance Band .....................................................7-72Permissible Lower Tolerance Band .....................................................7-73Conditionally Permissible Tolerance Band..........................................7-73Repetition Factor..................................................................................7-73Q Stop ..................................................................................................7-73

Backup/Restore........................................................................................7-74Display of UI / US Curves (Auto) ...........................................................7-75

All Programs........................................................................................7-76Stop......................................................................................................7-76

Display of Reference Curves (Program)..................................................7-77Source – From PC................................................................................7-77Source – Reference Curves from Timer ..............................................7-77Source – Last Curves from the Timer..................................................7-77Destination – in PC..............................................................................7-78Destination – UIR in Timer .................................................................7-78

Tools, U/I Setup.......................................................................................7-79Comport ...............................................................................................7-79Select Language...................................................................................7-79System Info ..........................................................................................7-79Initialize Data.......................................................................................7-79Load Firmware.....................................................................................7-79U/I setup...............................................................................................7-80

8 Instructions on Commissioning..........................................8-878.1 Defining the Basic Welding Parameters ............................ 8-87

8.2 Making the Reference Weld ............................................... 8-88

1-6 Contents

8.3 Commissioning the Suspension Spot Welders with U/IRegulator......................................................................................... 8-91

8.4 Returning to the CCR Mode............................................... 8-97

9 Comprehending the Resistance characteristics..................9-989.1 Normal Curve ...................................................................... 9-98

9.2 Expulsions ............................................................................ 9-99

9.3 Isolating Materials............................................................. 9-100

9.4 Steps to Optimize the Weld............................................... 9-100General Rules.........................................................................................9-101Elimination of Expulsions .....................................................................9-101

Early Expulsions ................................................................................9-101Late Expulsions .................................................................................9-101Expulsion in the Regulation Mode ....................................................9-102

Optimization in Case of Single-Pulse Welding .....................................9-102Optimization in Case of Preliminary-Pulse Welding.............................9-103

10 Error Messages ............................................................10-104

11 List of Accessories ........................................................11-105

12 Abbreviations, Terms ...................................................12-106

Safety Instructions 2-1

2 Safety InstructionsThe products described in this document have been developed,manufactured, tested and documented in compliance with the safetystandards specified in the EC Machinery Directive. Provided the handlingrules and technical safety instructions described for project planning,assembly and intended use are observed, any personal and/or materialrisks normally do not arise in connection with the product.

But there are still residual risks!

For that reason, please read this manual carefully before assembling,connecting or commissioning the products and before programming thesystem.Keep this manual at a place that is accessible to each and any user atany time.

The contents of this manual refer to• the mechanical design,• the electric connection,• the functionality,• the steps required for commissioning, and• programming of the necessary data by means of the

BOS and BQR user interfaceof the U/I regulator modul.

There are separate manuals for the respectively existing powerunits, weld timer types and welding transformers.These are a supplement to the present manual !

For that reason, please also observe the following documentation:• For PSI 6xxx: Medium-Frequency Inverter, Technical

Information (1070 080 059)• Control and I/O Level, Technical Information (according

to the weld timer type used)• MF Welding Transformers, Technical Information

(1070 087 063)

In addition, the safety instructions in the manuals “PSI 6000 Controland I/O Level” and “PSI 6000 Medium-Frequency Inverter” are alsoapplicable!

2-2 Safety Instructions

2.1 Intended UseThe product described• when used in connection with a suitable weld timer PS 6000 and a

welding transformer suitable for the integrated power section, isintended for- resistance welding of metals,and

• can be used for operation in an industrial environment (emissionclass A, group 2) in accordance with the following regulations:

- EN 50178- EN 50240- EN 60204-1Any use beyond that is no intended use any longer!

DANGERRF interferences may occur!This is a class A resistance welding device.Resistance welding devices of class A are not intended for use inthe public low voltage distribution network supplying f.e. residentialareas, as they may interfere with other devices in the environment.

To utilize class A devices in residential, business and commercialareas and in small enterprises, you need an individual permit by thenational government or test authority; in Germany, this is the‘Bundesnetzagentur (BNetzA)’ with its local agencies.

DANGERAny non-intended use of the devices may cause injury to the user orthird parties, as well as damage to the device, the workpiece to bemachined, or to the environment.For this reason, be sure only to use our products as intended!

To ensure proper and safe operation, the product must be transported,stored, set up, mounted, assembled and operated in a proper, correctand careful manner.

2.2 Environmental Protection, Return of Material, ReuseEnvironmental ProtectionOur products do not contain any hazardous substances which could bereleased when the product is used properly. Under normal conditions, nonegative influences for the environment are to be reckoned with.


Taking back materialThe products manufactured by us can be returned for disposal at nocharge. Requirements for this are:• no buildup of oils, grease or other pollutants• no included inappropriate foreign substances or foreign

components.The packaging material consists of paper, wood and styrofoam.For ecological reasons, a return transport of empty packaging should nottake place. This can be easily put into the recycling bin.The products must be delivered postpaid to the following address:

Bosch Rexroth Electric Drives and Control GmbHBürgermeister−Dr.−Nebel−Strasse 2D-97816 Lohr am Main

RecyclingMain components of our electronic devices:- steel, aluminum, copper, plastic materials.Due to the high proportion of metal, most of our products can berecycled. To achieve optimum metal recovery, dismantling into individualcomponents is necessary.The metals contained in electrical and electronic components can also berecovered by special separation processes. The resulting plastics can bethermally recycled.If batteries or accumulators are contained in the products, these must beremoved before recycling the products and must then be disposed in aproper and environmentally friendly manner.

2.3 Qualified PersonnelThis documentation is designed for especially trained and skilledpersonnel having special knowledge in the field of welding technology.They must have a sound knowledge of the software and hardwarecomponents of the weld timer, the power supply used, and the weldingtransformer.

Project engineering, programming, start and operation as well as themodification of program parameters is reserved to properly trainedpersonnel! This personnel must be able to judge potential hazards arisingfrom programming, program changes and in general from themechanical, electrical, or electronic equipment.

Unless described in the Technical Information, any manipulations to thehardware and software of our products may only be made by technicalpersonnel of Bosch Rexroth GmbH.

If unqualified manipulations are made to the hardware or software or ifthe warnings provided in the Technical Documentation or attached to theproduct fail to be observed, this may result in severe personal injury orserious material damage.

Only skilled technicians who are familiar with the contents of thisdocumentation are authorized to operate and maintain the productsdescribed.

Such personnel are


• those who, being well trained and experienced in their fieldand familiar with the relevant standards, are able toanalyze the work to be carried out and recognize anyhazards.

• those who have acquired the same amount of expertknowledge through years of experience that wouldnormally be acquired through formal technical training.

Please also note our comprehensive offer of various training courses. Forlatest information on training measures, teachware and training systems,please refer to www.boschrexroth.com/training. For more detailedinformation, please contact ourTraining Center ErbachSAL2Berliner Strasse 25D-64711 ErbachPhone +49 (0) 60 62 78-6 00Fax +49 (0) 60 62 78-8 [email protected]

Danger:

Persons wearing cardiac pacemakers do not belong to the group ofpersons described above!

The strong magnetic fields developing during resistance welding mightimpair the proper functioning of cardiac pacemakers. This may result indeath or considerable injury to the health of the persons affected!

For that reason, such persons must not come near the weldingsystem.

2.4 Dangerous Magnetic FieldsDanger:

In the environment of resistance welding systems, magnetic fieldstrengths have to be expected which are above the limit values specifiedin VDE 0848 Part 4. Especially if manual guns are used, the limit valuesfor extremities may be exceeded. In cases of doubt, you should measurethe field strength and take additional measures to ensure safety andhealth at work. Please comply with regulation BGV B11 of the GermanBerufsgenossenschaft (professional association)”Unfallverhütungsvorschrift elektromagnetische Felder”.

NOTEThe strong magnetic fields developing during resistance welding mightcause permanent damage to wrist watches, pocket watches, floppy disksor magnetic strip identity cards (e.g. credit cards). Please do not carrysuch objects with you while working in the immediate vicinity of thewelding system.


2.5 Installation and AssemblyDANGEROUS ELECTRIC VOLTAGEDanger of life during installation work while systems are switchedon!Make sure that all plant sections undergoing operations during theinstallation are de-energized and sufficiently protected againstaccidental reclosing!

DANGERNon-workmanlike installation or mounting may lead to personalinjury or damage to property. Installation or mounting must becarried out by skilled personnel only.

DANGERDanger of injury and of damage to property through incorrectinstallation!The products, their wirings and control elements, if any, must beinstalled so as to be properly safeguarded against unintentionaloperation or contact.The installation space must be suitable for the degree of protectionspecified.

DANGERDanger of personal injury and damage to property throughinadequate fastening!The place for installing the modules, and their method of fastening,must be suitable for their weight!

DANGERInsufficient degree of protection may be life-threatening or causedamage to property!The degree of protection of the products described is IP 20. Theymust be installed in switchgear cubicles providing a degree ofprotection of no less than IP 54.


2.6 Electrical Connection

DANGERBodily injury and material damage is possible if the electricalinstallation work is not carried out properly.Electrical connection work must therefore be carried out by aprofessional.

DANGERDanger of life through inappropriate EMERGENCY-STOP facilities!EMERGENCY-STOP facilities must be operative in all modes of thesystem. Releasing the EMERGENCY-STOP facility must by nomeans result in an uncontrolled restart of the system! First checkthe EMERGENCY-STOP circuit, then switch the unit on! Pleaseensure that you have checked the E-STOP chain!

DANGEROUS ELECTRIC VOLTAGEDanger to life and limb due to insufficient protective earth system!The devices must be connected to the protective earth (PE) systemof the plant.The continuous connection of the protective earth system must beinspected according to EN 60204 Part 1.

CAUTIONDestruction of assemblies!Do not connect or disconnect any assemblies or connectors whilethey are live!


CAUTIONConnecting lines and signal lines must be laid so as to avoidnegative effects on the function of the units through capacitive orinductive interference!Interference is frequently coupled and decoupled in long cables.Therefore, power and control cables must be routed separately. Theinfluence of interfering cables on cables susceptible to interferencecan be minimized by keeping the following distances:> 100 mm if cables are run in parallel for < 10 m,> 250 mm if cables are run in parallel for > 10 m.Please ensure that all contact surfaces are bright, i.e. free from anypaints, plastic coatings and/or dirt/oxidation.

2.7 Modifications by the Operator

DANGERModifications to the product may have negative effects on the safetyof the unit!The possible consequences include death, severe or light injury(personal injury), damage to property or environmental hazards.Therefore, please contact us prior to making any modifications. Thisis the only way to determine whether changes can be made withoutany problems.

2.8 Maintenance, Repair

DANGEROUS ELECTRIC VOLTAGEPrior to any maintenance work – unless described otherwise – thesystem must always be switched off and sufficiently secured!In the event of necessary measurement or test procedures on theactive system, these have to be performed by skilled electricalpersonnel.


DANGERLithium batteries can cause skin burns or explode in case ofimproper handling!Therefore, do not forcefully open batteries, do not attempt to chargeor heat up batteries over 100 °C!

CAUTIONPlease use only spare parts approved by us!Use only original replacement batteries! In any case, spentbatteries and accumulators should be disposed of ashazardous waste!

2.9 Working Safely

DANGERIf the start signal is present on fault reset (acknowledge), the weldtimer immediately starts the program sequence! Hazardousmachine movements may be the result!Therefore, before fault reset, you should make sure that there are nopersons in the danger zone of the welding equipment!

DANGERDuring operation of the welding equipment welding splashes are tobe expected! They may cause eye injuries or burns. Therefore:− wear protective goggles− wear protective gloves− wear flame-retardant clothes

Note: Please also observe any safety-relevant information essential forhandling the product. Such information can be found in the appropriatemanuals. If unqualified manipulations are made to the hardware orsoftware or if any safety instructions and/or warnings fail to be observed,this may result in severe personal injury or serious material damage.


2.10 Installation and Retrofit

CAUTIONDanger to the module!All ESD protection measures must be observed when using themodule! Prevent electrostatic discharges!

The following protective measures must be observed for modules andcomponents sensitive to electrostatic discharge (ESD)!

• Personnel responsible for storage, transport, and handling musthave training in ESD protection.

• ESD-sensitive components must be stored and transported in theprescribed protective packaging.

• ESD-sensitive components may only be handled at special ESD-workplaces.

• Personnel, working surfaces, as well as all equipment and toolswhich may come into contact with ESD-sensitive components musthave the same potential (e.g. by grounding).

• Wear an approved grounding bracelet. The grounding bracelet must• be connected with the working surface through a cable with an

integrated 1 MΩ resistor.• ESD-sensitive components may by no means come into contact with

chargeable objects, including most plastic materials.

3-10 System Design

3 System Design

3.1 Design of the System as a WholeThe U/I regulator is an modul in double Euroformat. It is inserted in thePSI 6000 weld timer series. Via the internal bus coupling, it is closelyconnected to the weld timer for quick exchange of information. A 32 bitcontroller computes the control algorithm and handles the communicationto the weld timer and the BQR user interface.

The BQR user interface supplements the BOS 5000 user interface foroperation of the U/I regulator.The BOS 6000 user interface version 1.17 and higher already containsoperation of the U/I regulator.The BQR user interface for the U/I regulator is a separate software forPC installation. The interface to the system is realized via a V24/RS232link which is connected either to the regulator modul X3C or to theX1interface on the weld timer. This interface is used to parameterize theregulator and to display the curve slopes of the weld.

Figure:BOS user interface of the weld timer at connector X1; user interface ofthe U/I regulator BQR at the regulator modul connector X3C

U/I regulator modul

BQR user interface

BOS 5000BOS 6000

System Design 3-11

3.2 ConnectionThe electrode voltage cables must be connected as close to theelectrodes as possible. Their contacts can be located at the welding gunarms and must be installed in such a way that the electrode welding guncan move freely. The voltage tap must be placed behind the secondarycables or flexible strips (seen in the direction of the electrodes) to preventfalsification of the measuring by wear or heating.

The contact between the voltage measuring cable and the welding gunarm must be achieved by a screwed connection, permanently and withlow impedance. Connection to the welding gun arm can be achieved atan existing screwed connection by clamping a suitable cable lug.Since only one core has to be connected to each welding gun arm, thecable may be placed without shield across a length of about 1 m in thisarea, with a cross-section ranging from 0.5 to 1.5mm2. Starting at thatpoint and before the voltage cable is running together with other lines, thecable must be provided with a shield across its remaining length. Seecable specification.A plugged or clamped connection is appropriate at this point, in order toallow easy replacement of the unshielded section of the voltage cable incase of wear caused by movements of the welding gun. The shield mustbe provided up to the cabinet / welding box and applied to groundpotential only there, however well-conducting and across a large area, sothat any disturbances are discharged well on the outside.

Where the cable is moved by the welding gun, it must be highly flexible.At such moved spots, the bending radius of the cable must bemaintained. Ensure that strain relief and cable attachment areappropriate.

Welding transformer

Supply line

Highly flexible cable

3-12 System Design

Schematic wiring diagram of the system

Cable Type for Voltage MeasuringUnshielded cable: Single litz wire, type Ölflon FEP from LappShielded cable: 2 x 0.75 mm2, twisted in pairs,in correspondence with BOSCH order no. 1070 913494:2x2x0.75 mm2, LiYCY, 2 twisted pairs of wires for electrode voltage andcurrent sensor.The cable length must not significantly exceed a maximum of 100meters.Single-sided bonding of the shield to chassis, primarily at the input to thecontrol cabinet/welding box. We recommend that a shielded cable beplaced inside the cabinet.

Contacting at the welding gun arm:Solistrand circular welding guns of copper and electrolytically tin-plated,from Tyco Amp, e.g. type 34124

NoteAs the voltage measuring input is dimensioned for low resistance(approx. 500 ohms), no high-resistance cables, connectors or fuses must

X7C

Control cabinet / welding box Welding gun

Weldingtransformer

Welding current

Welding current

Current sensor

CCR U2 V2

X3C

PC

User interface

(1): max. length: 100 m

UIR

USR

X8APSI

(1)

System Design 3-13

be used.

X1SUDM

Pin 2X3CRS232

Pin 3Pin 5

RXTXGND

1

2

24 V Extern0V Extern

Pin 2

X7CCAN-OUT

Pin 3Pin 6Pin 7Pin 9

CAN_LCAN_GND0 V ExternCAN_H24 V Extern

1

2

Usec 1

3

4

Usec 2X8AUIR

PSQ6000XQR

Note:Connector X3C for V24/RS232 of user interface BQR.

Connectors X7C and X1S are used exclusively for the ultrasonic system.

X8A pin assignment:

Pin Signal

1 USEC_1 Electrode voltage, input_1

2 GND Shield

3 USEC_2 Electrode voltage, input_2

4 GND Shield

3-14 System Design

Shield at pin 2 or 4

X3C pin assignment:

Pin Signal

1 DCD

2 RX

3 TX

4 DTR

5 GND

6 DSR

7 RTS

8 CTS

9 n.a.

X1S pin assignment: UDM

Pin Signal

1 24 VDC on

2 0 VDC on

X7C pin assignment:

Pin Signal

1 reserved

2 CAN_L

3 GND_ISO

4 Reserved 24V extern

5 CAN_Shield

6 CAN_GND

7 CAN_H

8 Reserved error line

9 CAN_24VDC

System Design 3-15

LEDs:

Green LED lit:CAN bus communication to dataprocessing module is running.

COM CommunicationRed LED lit:No CAN bus communication todata processing module.

Green LED lit:Modul working without failure.

RUN Operating stateRed LED lit:Modul has detected amalfunction.

3-16 System Design

3.3 Weld Timer IntegrationThe U/I regulator is adapted to the PSI 6000 series weld timer.The regulator is thus optimized for use with an inverter.

When implemented in the various available weld timer types, the U/Iregulator requires adjustments in the weld timer firmware and possibly inthe firmware of the regulation modul. Implementations in other weldtimers from our series are carried out upon customer inquiry or forspecific projects.

3.4 Field of ApplicationThe U/I regulator can be used for the following spot welding tasks:

· with and without slope· single- and multiple-pulse welding with 2nd WLD· pre-heating time with 1st WLD, post-heating time with 3rd WLD in CCR mode· "Repetition" mode is supported.· "Seam" mode is not supported.

Disturbances

Change of power voltageBad fitShuntChange of coatingBad contacts, adhesiveBad tipsThird sheetOther sheet thicknessPower changeElectrode wear

3.5 Information on Installation and Assembly

On delivery, the regulation module is already installed in the weld timer /inverter unit.

In case of retrofitting, the dummy plate has to be removed and theregulation module inserted and screwed tight. Before starting thisprocess, ensure that the supply voltage is switched off!Retrofitting involves the mechanical installation of the regulation modulein addition to updating the firmware of the timer. The weld timer needsthis new firmware to be able to address the regulation device.

An updated version of the BOS user interface is necessary together withthe new firmware because the weld timer firmware represents a new typeof control unit.

Commissioning with BOS 6000 4-17

4 Commissioning with BOS 6000Operation of the U/I regulator with BOS 6000 requires fundamentalknowledge of BOS 6000 interface. The online help integrated in BOS6000 supports you in operating and setting up BOS 6000.For additional information on commissioning, please refer to Chapter 8.For operating the weld timer, BOS 6000 must be set up such that allfunctions required can be executed, such as- welding in the CCR mode,- scaling if necessary, etc.Thereafter, follow the steps below to start up the system.

4.1 First StepCommissioning the weld timer / inverter unit in the constant currentregulation mode (CCR).

The functioning of the system in the constant current regulation (CCR)mode is an essential prerequisite. The U/I regulator uses the samemechanisms as the CCR. This part of commissioning corresponds to theknown procedures for a PSI 6000 inverter system, so that welding spotscan be produced in the CCR mode.In this context, see the manuals on the PS 6000 regulation system andI/O level, medium-frequency inverter, and welding transformer.

This step also comprises any required force and current scaling.Refer to the corresponding chapters in the manuals.

NoteScaling must not be performed while the U/I regulator is active.

4.2 Second StepPrerequisites regarding welding gun and electrodes

The welding gun must be in excellent condition. The electrodes must beadjusted to ensure that they stand exactly opposite each other and in aright angle to the sheet.

The electrode tips should be dressed and slightly used (approx.20 - 25 spots). Dressing corrects the contact surface of the electrode tips.This results in ambient conditions like those of new tips. However, theremay also be interferences which are caused by dressing. First of all,dressing can create irregularities on the contact surface (e.g. chattermarks); secondly, the plane of the contact surface may not coincide aswell with the joining plane as in the used cap condition.

4-18 Commissioning with BOS 6000

Squeeze time and hold time should be long enough to allow the weldinggun to build up the required force.Force measuring is recommended.

4.3 Third StepGenerating the Reference Curve

Generation of a reference curve requires that welds first be made in theconstant current regulation mode.

Select the welding spots or the programs you wish to use for weldingfrom the BOS 6000 user interface.

Check or set at the BOS 6000 user interfaceSqueeze time Sufficient for this welding jobHold time Sufficient for this welding job1st weld time Possibly as a pilot pulse in the CCR mode (see

Chapter 9.4)2nd weld time andcurrent

Set CCR parameters for this welding job.Possibly, upslope in the 2nd weld time

3rd weld time Possibly for post-heating in the CCR modeCCR mode ONRepetition sequence OFFInhibit monitoring ONReadjusting Heat values to 100%

NoteIf possible, the heat correction should be set to 0% to allow full correctionfunctionality later in the U/I regulation mode.


PSQ Programming – UIRSettings for the U/I regulatorGeneral UIR measuring on

UIR regulation onUIR monitoring on

Referring to UIR program UIR measuring onUIR regulation offUIR monitoring off

Data don't forget the Timer (weld timer).

See chapter 5 "BOS 6000 with U/I Regulator" for a detaileddescription of the operation.


Setting up the Reference Curve

Under U/I Setup, generation of reference curves is supported.Advantage: several welding procedures of a program can be used togenerate a reference curve, irrespective of the sequence of theprograms; this even applies to several weld timers that are used at thesame time. In practice, this considerably simplifies the definition ofreference curves.

Start the recording mode for making the first recording.

Select the weld timers in the recording mode by checking the appropriatecheckboxes.To select a new recording of curves, check the new recording checkbox.This deletes any curves that have already been recorded.If you leave the checkbox unchecked, the last recording will becontinued.


To observe the progress of data recording in the right-hand part of thewindow, click start recording. If the message recording terminatedappears in the status display, click stop recording to stop recording andmove to the analysis mode, provided you have recorded all weldsnecessary for generating the reference curves.


Analysis Mode

Recorded welds of a program

Now, select a program from the filter to view this program's curves. Fromactual curve, select one of these curves; this selected curve is indicatedin red for evaluation.To delete this specific curve, use delete actual curve.Before calculating the reference curve, you can delete any possibleoutliers.

Curves of expulsion welds have to be deleted at any rate.

Expulsions can be recognized from the suddenly falling slope of theresistance characteristic.

Now, click the average curve button to calculate the reference curve for aprogram (on the basis of the curves recorded); the curve is indicated inred. The black curves show the minimum and maximum resistancecharacteristics.


Use original curves to switch back to the original curve screenshot fromthe average curve screenshot.

Appyling the Reference Sequence

Click Reference sequence Timer to save the red curve as a referencesequence in the U/I regulator for this program.

Proceed as described above for the other programs.


Notes

For each combination of sheet thicknesses, we recommend using aseparate program and to determine a separate reference curve.Advantage: In separate programs, all welding parameters can be set inan optimal manner for the respective welding job; there is less extensionof weld time caused by different sheet thicknesses.However, if different sheet thickness combinations must be welded withone program (manual welding gun), the reference curve is determined bymeans of the thinnest sheet combination with the lowest resistance. Incase of coated sheets, it is determined by means of the thinnest sheetswith the thickest coat. Set the force for mean to thick sheet combinations.Please also refer to Chapter 8.3.

Always make the reference weld without adhesive between the sheets, ormake at suitable sheet strips because adhesive is a disturbance variable.

Welding at the component is possible for determination of referencecurves. If strips are used, please note the following:- The curve of the first spot on a sheet should not be used as a

reference curve.- Spots should be welded at a distance of approx. 20 mm (shunt).

If the spot diameter is too small, increase the actual from spot to spotuntil the expulsion limit is reached.If there are expulsions, reduce the actual to the last expulsion-free valueand re-weld. For compensation purposes, it might be necessary toextend the weld time.Only after the weld has been made without expulsions and with the spotdiameter required can this curve be applied as reference curve.

Welding quality cannot be determined through interpretation of thecurves. The evaluation of the curves is limited to the following aspects:- Resistance characteristic: typical course with strong downslope of

resistance at the start (contact is made) and continuous downslopeof resistance towards the end.

- Voltage signal: does a voltage signal exist, and is its curve similar tothe resistance.

Expulsions can also be detected from the suddenly falling slope of theresistance characteristic.Please also refer to Chapter 9.The wear state of the tips should be between 10 and 100 welds.


4.4 Forth StepActivation of the Regulator for this Program:

Under PSQ programming – UIR

Settings for the U/I regulatorGeneral UIR measuring on

UIR regulation onUIR monitoring on

Referring to UIR program UIR measuring onUIR regulation onUIR monitoring off

Weld time prolongation

Weld time prolongation ON permits the U/I regulator to extend the weldtime for this program. The max. weld time prolongation parameter limitsthe weld time prolongation which the U/I regulator needs to compensatefor disturbances. In automated operation, very long weld times may beundesirable.

When this time limit is exceeded, the error message“PSQ maximum weld time reached” is displayed.


Steps 2 to 4 must be repeated for each spot which is to be welded withU/I regulation.This completes the determination of reference curves.

NoteYou can stop the measuring and the regulation for all weld timerprograms in the general field.

Corrections of the reference curve (raise/reduce) can now only beachieved through the heat correction function of the BOS 6000. Weldtime and current setting cannot be changed any more as they are nowdefined by the U/I regulator.For this reason, when activating PSQ actual monitoring, it is important toset sufficiently wide tolerance bands for the current to enable the U/Iregulator to react without signaling of errors.

For a description of monitoring with tolerances, please refer to Chapter5.7.

Use PSQ diagnostics to display the curves of the actual weld.

Visualization of the curve slopes

For a detailed description of operation, please refer to Chapter 5"BOS 6000 with U/I Regulator".

BOS 6000 with U/I Regulator 5-27

5 BOS 6000 with U/I Regulator

5.1 Requirements• Operating system: Windows 2000 / XP with a RAM of at least 512

MB,Windows 2003 server with a RAM of at least1 GB

• At least 2 GHz Pentium• At least 5 GB hard disk drive• Interfaces: Ethernet

RS232/V24 (additionally)• BOS 6000 user interface, version 1.22.x and higher

NoteThe online help integrated in BOS 6000 provides you with basicinformation on how to operate and set up the BOS 6000.

5.2 PSQ Status Display

On some screenshots, the PSQ status display provides information onthe state of the U/I regulator and monitor and, if the system has beenexpanded appropriately, on the state of the US regulator and monitor.

5.3 Summary of U/I Operator Functions

PSQ programmingUIR Parameterization of the U/I regulatorUIR reference Displaying/reading/saving actual and reference

curvesUIR monitoring Monitoring and history values

PSQUIR

USR

Regulation Monitoring

Green: activeYellow: not active

5-28 BOS 6000 with U/I Regulator

DiagnosticsLast sequence Actual values of the last welding sequencePSQ Actual curve

SetupUIR setup Generating reference curves

5.4 Programming – Sequence

The sequence tab allows you to program all basic settings that arerequired for a welding program. This is a preparatory step for the U/Iregulation mode.

NoteProvided the U/I regulation and monitoring functions are activated, someof the parameters/functions provided on the programming – sequencetab can be dimmed or invisible, since they are required in the mode set.


5.5 PSQ Programming – UIRSome of the settings can only be made by users with a specialauthorization level.

General: Global UIR Parameters

These parameters apply to the overall weld timer, covering all electrodesand programs.

This is the location of the activation of measuring, regulation, andmonitoring for the UIR of the overall weld timer.To activate these functions, they must also be activated for the respectiveprogram under referring to UIR program.See Chapter 5.5“Referring to UIR Program”, Measuring, Regulation andMonitoring.

ModeThis list box allows optimization of the activated U/I regulator by means ofadjusted regulator parameters, for the robot – manual welding gun – finespot aplications.The mode function mainly affects the weld time prolongation in case ofdisturbing variables. For example, the manual welding gun optionconsiders that it is not possible to calibrate each sheet thickness


combination separately; the robot option takes into account thatexcessive weld time prolongation should be avoided. A thicker sheetrequires that the regulator react with the appropriate weld timeprolongation.

Expulsion Detection

Changing current due to expulsionUse this parameter to define how the regulator reacts to a detectedexpulsion. The regulator will change the current at the moment of theexpulsion by the programmed percentage. With a positive sign, the valuecan cause an increase of current, and with a negative sign, a reduction ofcurrent.

Expulsion counterClick Reset to reset the expulsion counter and spots counter for allprograms.

For more information on expulsions, please refer to Program-RelatedParameters, Expulsions, and to Chapter 9.2.

Referring to UIR Program

MeasuringClick measuring to turn the U/I measuring on and off.As a precondition for voltage measuring, an electrode voltage cable mustbe connected to the electrode welding gun. U/I measuring is onlyactivated if it is also activated under general!

Regulation

RegulationTurns the U/I regulator for the program selected on and off.To activate the U/I regulator, the following preconditions must be met:♦ The measuring must be activated under general and referring to UIR

program.♦ The U/I regulator must be active under General.♦ The reference curve of the selected program must be saved, and the

respective parameters must be set.

Beginning of regulation phase IIThis value is calculated automatically when the reference curve isgenerated.

Max. current raiseThe max. current raise permits the U/I regulator to raise the current by apercentage in relation to the reference current during the balancing ofdisturbances.


Max. current reductionThe max. rated current reduction permits the U/I regulator to reduce thecurrent by a percentage in relation to the reference current during thebalancing of disturbances.

IMPORTANT

Changing these limits may impair the efficiency of the U/I regulator indealing with disturbances!Do not change these values unless absolutely necessary.

Weld time prolongationWeld time prolongation ON permits the U/I regulator to extend the weldtime for this program.The max. weld time prolongation parameter limits the weld timeprolongation which the U/I regulator needs to compensate fordisturbances. In automated operation, very long weld times may beundesirable.When this time limit is exceeded, the error message"PSQ maximum weld time reached” is displayed.

Example:A weld time prolongation of 100% permits the U/I regulator to double theprogrammed weld time if necessary.

NoteIn the U/I regulation mode, it is no longer allowed to change the weld timeunder programming – sequence – 2nd WLD.When the U/I regulator is switched off, weld time prolongation isdeactivated as well.

MonitoringThe monitoring field turns the monitoring function fo the program selectedon and off in the U/I regulator. Activation of the monitoring functionrequires an activated measuring both under general and referring to UIRprogram.See Chapter 5.7 UIR Monitoring

Expulsions

Spots counterIn the spots counter, the current number of welds (since counter reset)for the program selected is displayed.

Expulsion counterWhen the system detects an expulsion, the expulsion counter is countedup. This allows to read the frequency of expulsions as compared with thespots counter.

Use reset to reset the expulsion counter and spots counter for theprogram selected.


5.6 PSQ Programming – UIR Reference

Display of the progress of current, voltage and resistance of the selectedcurve in a diagram. This option also allows to read and save actual andreference curves.

Load Curve

PCDownloads a reference curve saved in the PC to the display. Clicking thisbutton opens a window for selecting the appropriate file.The extension of these files is rui.

Reference Sequence TimerDownloads the reference curve existing for this program from the weldtimer to the display.Requirement: For this program, a reference curve had to be saved to theweld timer.

Actual Curve TimerDownloads the actual curve of the lastsequence from the weld timer tothe display, irrespective of the program that was run previously. The


associated program data, such as number and date/time, is displayed inthe header of the diagram.Requirement: the U/I measuring is global and has been activated for thisprogram; the weld timer has completed a sequence.

Write Curve

PCSaves the displayed curve to the PC. Clicking this button opens a windowfor selecting the appropriate directory and file name.The extension of these files is rui.

Reference Sequence TimerSaves the curve displayed for this program as a reference curve to theweld timer.Any already existing reference curve will be overwritten!Do not use this functions unless absolutely necessary.

SettingsClicking this button allows you to set the colors of background, raster,font, channel and cursor of this window.

ZoomZoom function of the x-axis to magnify the displayed curves by a factor of2, 5, and 10.You can also move both the x- and the y-axis to view a specific magnifieddetail. To achieve this, left-click while the cursor symbol is a hand.

DisplayDisplays the values of the curve at the movable cursor line:t moment in the curveI current at the cursor positionR resistance at the cursor positionU voltage at the cursor position

5.7 Programming – PSQ – UIR Monitoring

To match the welding job and its quality control, the monitoring functioncan be activated separately for each of the supervision parameters.Depending on the welding job, it may be appropriate to monitor differentvariables.The monitoring result is displayed and recorded by the BOS 6000 andwill be available for evaluations, such as for the statistical process control(SPC).


NoteTo record the monitored values, activate (check checkbox) the currentvalue log function under WT assignment – current value log on startingthe BOS 6000.The UIR monitoring display comprises two main sections:1. The monitoring radio button is activated monitoring is programmedwith tolerance bands, etc.


2. The radio button of a monitored variable is activated the curve of themonitored variable is displayed with tolerance bands.

Programming the Monitoring Function

The monitoring function can be separately turned on and off for eachmonitoring variable.The reference parameters are desired monitoring values for the variousmonitoring variables.The weld timer compares these desired values with the measured actualvalues (displayed in the actual fields) and interprets them• as being “accepted” or “rejected”, based on the tolerance limits of thepermissible upper tolerance band or the permissible lower toleranceband;

• as continuously “worsening”, based on the conditionally permissibletolerance band and repetition factor.Poor actual values initiate an appropriate warning or error message,provided the relevant monitoring function is activated.


Permissible Upper Tolerance BandDefines the maximum permissible positive tolerance in a percentage ofthe reference value.Any actual values exceeding this tolerance limit generate the messagetype “… too high”.

Permissible Lower Tolerance BandDefines the maximum permissible negative tolerance in a percentage ofthe reference value.Any actual values falling below this tolerance limit generate the messagetype “… too low”.

Conditionally Permissible Tolerance BandInput value as a percentage of the reference value.This parameter cooperates with the repetition factor for detecting any“creeping” errors of the system, resulting in a slow and steady“worsening” of the actual values.

Repetition Factor

The repetition factor defines the number of successive welding spots maybe within this conditionally permissible tolerance range.If this value is exceeded, the weld timer emits a message of type“repetition error …”.

NoteThe counter for the repetition factor is incremented, irrespective of whichof the monitored variables is within the conditionally permissible toleranceband. After an accepted weld, the repetition factor counter is reset.

Acceptance Repetition Factor

Defines the number of successive welds within the tolerance band, afterwhich an exceeded tolerance band is reset. This also affects the displayin summary of PSQ process variables.

Conditionally permissible tolerance band, repetition factor 3

"Repetition error..."error or warning

+ upper tolerance in %

X welding current value

100% reference current in kA

cond. perm. tolerancerepetition factor=3

- lower tolerance in %

accepted


Progress Display

This display shows the characteristic of measured values of a supervisionparameter of a program.Activate one of the radio buttons to select one of the availablesupervision parameters. Activate the monitoring radio button to return toprogramming of the tolerances.

By default, the diagram shows the last100 welds. If the record memorycontains a higher number of welds, you can scroll up or down through thedisplay. See welding sequences displayed.Click zoom to view 200, 500 and 1000 welds in the diagram. See zoom.The currently applicable reference value and the currently applicabletolerance bands are displayed as a line.

To view the monitoring values of a specific weld, move the cursor linewhile the cursor symbol is a hand. The parameter fields show the desiredand actual values of the weld selected. The name of the welding spotincluding date and time are displayed at the upper edge of the diagram.

Display of Desired and actual values in the history values field♦ Average values of desired current and actual current♦ Average desired and actual values of the electrode voltage♦ PHA: average desired and actual values of the pulse width (phase

angle)♦ Desired and actual values of the weld time♦ Desired and actual values of the energy♦ Process stability: desired value always 100%. The actual value is

composed of several variables, providing comprehensive informationabout the process by means of a number. Specifies a number for thecurrent process situation in relation to the stable starting situation.

♦ UIP: desired and actual values of the quality factor. The UIP iscomposed of several variables, providing comprehensive informationabout the quality by means of a number. It reaches a statementabout the welding quality on the basis of the curves measured.

♦ Desired and actual values of the heat♦ Average desired and actual values of the resistance


Welding Sequence DisplayedThe diagram shows 100 welds by default. If the memory contains ahigher number of welds, you can scroll up or down through the display.See Zoom.

The number of saved welds is displayed.

UpdateUpdates the display so that the lastwelds are also shown in the diagram.


ZoomThe zoom function increases the number of welds displayed in thediagram to 200, 500 and 1000.

You can also move both the x- and the y-axis to view a specific detail. Toachieve this, left-click while the cursor symbol is shown as a hand.

25th weld value

perm. uppertolerance range

desired =referencevalue

cond. perm.tol. range

perm. lowertolerance range


Actual DesiredApplies the current actual value of the monitoring value selected as thedesired value for monitoring.

ExportThe actual values of the monitoring report are saved to a text file. Toachieve this, you can enter a directory including file or select the“Backup” default directory.The saved actual values can then be further processed or evaluated byexternal parties.

Y-ZoomClicking this button magnifies the actual value in the direction of the Y-axis by a factor of 2, 5 and 10.

PSQ Status DisplayIn addition to actual values, this display also shows the state of the U/Iregulator and monitor at the time when the weld at the cursor positionwas made.

NoteThis display may change from weld to weld.

Information on Monitoring

PSQUIR

USR

Regulation Monitoring

Green: activeYellow: not active


We improved the monitoring quality not only by checking individualphysical variables for compliance with the appropriate desired values, butalso by using expressive criteria from the welding process for calculation.As a result, the process stability PSF and the process quality UIP aremonitored.In practice, the process is further improved by the fact that each andevery welding spot runs through this quality control.

While moving to the reference point, the regulator uses an acceptableweld to learn the relation between its measured values and the quality ofthe welded joint. While the regulated weld processes are in progress, theregulator changes the current setting and the weld time, thuscompensating disturbing variables in order to achieve a consistentwelding quality. The integrated monitoring function supplements theregulation, in order to make a statement about the quality of the jointimmediately after completion of the weld, by using the signal curves inthe production process. The monitoring result is displayed on the userinterface and is additionally saved to the record memory, so that it isavailable for statistic evaluations. Using the programmed tolerancebands, a statement can be made about accepted / rejected welds, withgeneration of an error message if necessary.Expulsion welds are represented as a cross in the monitoring window. Toview the time of expulsion occurrence in the weld time, place the cursoron this cross. Expulsion welds are represented as a cross in themonitoring window. To view the time of expulsion occurrence in the weldtime, place the cursor on this cross.

CurrentHere, it is inappropriate to set the tolerance as tight as possible (as isknown from the CCR regulator), since the U/I regulator must change thecurrent for compensating disturbing variables. When setting the currenttolerances, please keep to the limits of “max. current raise / reduction)”(Chapter 5.5), which are the limits specified for compensation through theregulator.

NoteThe CCR tolerances programmed on the sequence tab do not have anyeffect in the U/I regulation mode. They will be effective only after the CCRmode is active again. See Chapter 8.4.

PHA (Pulse Width)Here as well, tolerance limits should not be tight, because the pulse widthis changed in order to achieve a current raise / reduction. The associatedupper tolerance band can be used to implement a system protectionwhich prevents an excessively high power.

Expuslsion


Weld TimeThe lower tolerance (weld time too short) can be set within tight limits,because the weld time will never be shorter than the reference weld time.An exception here is a premature weld time stop in case of the “nocurrent” error or an external weld time stop. Depending on the type andsize of disturbances, it might be necessary to extend the weld time. Forthat reason, set the upper tolerance value high enough to ensure that theoperational weld time prolongation (e.g. caused by electrode wear) doesnot initiate a message yet.For the weld time, the conditionally permissible tolerance band iseffective in upward direction (contrary to all other monitoring variables).

EnergySince the weld time is included in the energy balance, the lower tolerance(energy too low) can be set within tight limits; the energy included willnever be less than that of the reference weld. An exception here is apremature weld time stop in case of the “no current” error or an externalweld time stop.Depending on the type and size of disturbances, it might be necessary toincrease the energy. For that reason, set the “upper tolerance” value highenough to ensure that the operational increase in energy without anydisturbance does not initiate a message yet.

Process Stability PSFThe process stability is a parameter expressing the degree of complianceof the weld displayed with the reference weld. A process stability value of100% indicates full compliance with the process of the reference weldand, thus, a process that remains stable.For example, a process stability of 70% indicates that the weldingprocess has changed by 30% as compared with the reference weld. Thewelding device has changed, e.g. through wear. Or there was adisturbing variable which had to be compensated by the U/I regulator.Disturbing variables, if occurring only once, are characterized by a singledeviation from the 100% line, e.g. in case of an expulsion or an edgeweld.A continuously increasing deviation indicates wear, mainly of theelectrode tips.A comparison of the running process with the learned reference providesa measure for the state and the safety of the welding process and thewelding device (trend analysis).A change in the process, which is caused by compensation of disturbingvariables through weld time prolongation, is expressed by a worseningprocess stability value. At the same time, the “weld time” parameterassumes a higher value.If manual welding guns are used, it must be noted that the welding ofdifferent sheet combinations actually is a disturbing variable as well, ascompared with the reference weld. This will also result in deviations ofthe process stability if the material used is differing accordingly.

In the CCR/PHA mode, the process stability is displayed only if areference curve has been downloaded.


Process Quality UIPThe process quality results from the exact analysis of the resistancesequence of a weld. Characteristic corner marks and trends of the curveare used for calculation. To achieve this, the resistance sequence issubdivided in several sections. Characteristic marks of the resistancesequence are the start and end resistances as well as the local maximumand minimum. Slopes and tendencies permitting a statement about thewelding quality are derived from between these points. Depending on thesection concerned, the results of the UIP calculation of the individualsections are included in the UIP with varying weighting.

Since the dynamics of the resistance sequence is only weak in somewelding jobs, the UIP calculation is additionally compared with theappropriate sections of the reference sequence and included in thecalculation.

The interpretation of the statement about the quality of manual weldinggun is more difficult if different materials and sheet thicknesses areprocessed with one and the same program.In the CCR/PHA mode, the process quality is displayed only if areference curve has been downloaded.

TolerancesTo determine the tolerance bands for monitoring, you should proceed asfollows:

- First apply the actual values of the reference weld as referencevalues for monitoring.

- Welds are recorded in the display of a curve of a monitored variable.This provides a statement about the limits of the monitored variable.

- Set the tolerances around the reference value such that the majorpart of the welds are within the accepted range. Any outliers will thenbe outside of the tolerance bands.

- Please note that normal manufacturing variations are not outside oftolerance limits (e.g. caused by electrode wear, dressing).

- The curve display shows the programmed tolerances as lines, thusillustrating the potential effect of the tolerance bands.

- After having further observed and optimized the variable, activate themonitoring function for this variable.

- Also verify that the monitoring function is also activated for thisprogram and in the “general” field.


5.8 Diagnostics – Last Sequence

Clicking the diagnostics – last weld) button will display the measuredvalues of the last welding sequence. The display will be refreshedautomatically upon each new sequence. In addition, these values arefiled to the record memory so that they can be tracked later on theProgramming – UIR monitoring tab.

This tab provides you with the following information on the relevant weldtimer:♦ Previously started welding program incl. spot name♦ Date and time of the last weld♦ Wear counter reading of the electrode concerned♦ Dressing counter reading of the electrode concerned♦ Reference current and actual current, splitted by WLD and averaged

across all WLDs in the Standard line♦ Reference time and time actually needed♦ Necessary phase angle, splitted by WLD

PSQ values of the U/I regulator for the 2nd WLD♦ Reference current and actual current♦ Reference and actual values of the electrode voltage♦ Reference and actual values of the pulse width (phase angle)


♦ Reference and actual values of the weld time♦ Reference and actual values of the heat♦ Reference and actual values of the energy♦ Reference and actual values of the resistance♦ Actual value of the process stability♦ Reference and actual values of the UIP quality factor♦ Expulsion time

NoteMinor differences in the values displayed for the average PHA, thecurrent and the weld time between the 2nd WLD and the 2nd WLD PSQresult from the fact that the weld time can be measured with or withoutoverhang.

The reference value is the value specified in the UIR monitoring mode.The U/I monitor compares this value with the actual value taking theprogrammed tolerances into consideration and derives warnings anderror messages from this comparison.Requirement: the U/I measuring is global and has been activated for thisprogram; the weld timer has completed a sequence.


5.9 Diagnostics – PSQ

Clicking the diagnostics – PSQ button will display the measuredvalues of the last welding sequence. The Filter function supportsgeneration of the reference curves.Requirement: the U/I measuring is global and has been activated for thisprogram; the weld timer has completed a sequence.

The program data of the curves displayed, such as number anddate/time, is displayed in the header of the diagram.The course of current, voltage and resistance over time is also displayed.It is also possible to save the actual curve as a reference curve.

Filter

WithoutDownloads the actual curve of the last sequence from the weld timer tothe display, irrespective of the program that was run previously. Thedisplay is refreshed upon each new welding sequence.


ProgramIf program is activated, you can select a program number. This starts thedata display for this program only. This data display will be refreshed witheach sequence of this program.This permits to observe a specific program in automatic systems.

Single/Prog.If single/prog. is activated, you can select a program number. This startsthe data display for this program only. Only one sequence of this programwill be recorded.To restart the data display, select Stop and then single/prog. again.In automatic systems, this function prevents the curves displayed frombeing overwritten by a new sequence.

StopThis option stops the data display until it is released by one of the otherfilter functions.In automatic systems, this function prevents the curves displayed frombeing overwritten by a new sequence.For example, this is required when the reference curve is saved withACTUAL reference).

DisplayDisplays the values of the curve at the movable cursor line:t moment in the curveI current at the cursor positionU voltage at the cursor positionR resistance at the cursor positionRref resistance of the reference curve at the cursor position

Cursor 1Cursor 1 is active by default. That means that the curve values aredisplayed at the position of cursor 1.

Cursor 2To display the curve values at the position of cursor 2, select cursor 2.


Min.Select this radio button to display the minimum value between the twocursors.

Max.Select this radio button to display the maximum value between the twocursors.

MVSelect this radio button to display the average value between the twocursors.

Actual ReferenceIf you intend to use a recorded weld for generating the reference curve,stop data recording with stop to ensure that the curves displayed will notbe overwritten by a new sequence.

Click the actual reference button to save the curve displayed as thereference curve to the U/I regulator. To achieve this, enter the programnumber and acknowledge the message that appears with OK.


ZoomZoom function (magnification) of the time axis of the displayed curves bya factor of 2, 5, and 10.You can also move both the x- and the y-axis to view a specific magnifieddetail. To achieve this, left-click while the cursor symbol is shown as ahand.


5.10 Setup – UIR Setup

Allows for comfortable setting of reference curves, above all in automatedproduction.

Start the recording mode and select one or more weld timers. From nowon, the resistance characteristics of your welds are recorded andassigned to the corresponding program. The sequence in which theprograms are executed is not important. It is advisable to weld somecomponents before completing data recording. Now, you have someresistance characteristics for each program that has been run. From thisdata, a average curve can now be calculated for each program andsaved to the U/I regulator as a reference curve for this program. As amatter of course, this requires that the welding quality of the curvesrecorded is satisfying. To this effect, determine e.g. the spot diameter.Outliers in the curve slopes caused e.g. by expulsion must be deletedbefore calculation.

In practice, this mode considerably simplifies the definition of referencecurves.


Recording Mode

Select the weld timers in the recording mode by checking the appropriatecheckboxes at the beginning of the line. If you check the topmostcheckbox, you can select/deselect all connected weld timers as a whole.To select a new recording of curves, check the new recording checkbox.This deletes any curves that have already been recorded.

Recording has been started.

The BOS is now ready to record data and is waiting for the firstsequence.

The welds performed now are displayed as resistance characteristics.Important: The sequence in which the programs are welded is of nosignificance – they can be executed in "any" sequence (e.g. Prg 15, Prg4, Prg 6, etc.).

The progress of data recording can be viewed in the right-hand section ofthe window. If the message recording complete appears in the statusdisplay, click stop recording to stop recording and move to the analysismode, provided you have recorded all welds necessary for generating thereference curves.


Start recording with new recording.

This starts recording of new data. If there are any previously recordedcurves, they are deleted, and the resistance characteristics of the mostrecent welding program are saved.

Start recording without new recording (Continue)Unintentional or intentional exiting of the window does not result in loss ofthe recorded data. If you start recording without checking the newrecording checkbox, you can continue recording.

Analysis Mode

Filter – ProgramAny previously recorded curve slopes can be viewed in dependence onthe respective program. All recorded curves of this program aredisplayed.

Filter – Actual CurveUse this function to switch between the individual curves of the currentlyselected program and to select one curve. The currently selected curve isshown in red.


Delete Actual CurveClicking the delete actual curve button will delete the curve selected.Before calculating the reference curve, you can delete any possibleoutliers.



Average CurveClicking the Average Curve button will calculate the reference curve for aprogram; the curve is indicated in red. The black curves show theminimum and maximum resistance characteristics of this program.

Original CurvesClicking the original curves button will switch back to the original curvescreenshot from the average curve screenshot.


Reference Sequence TimerClick the reference sequence Timer button to save the red curve asthe reference curve to the U/I regulator.

PCClicking PC will save the red curve as the reference curve to adirectory of the PC. To do this, a directory must have been selectedbeforehand.

Corrections of the reference curve (raise/reduce) can now only beachieved through the heat correction function of the BOS 5000/6000.Weld time and current setting cannot be changed any more as they arenow defined by the U/I regulator. For this reason, when activating PSQcurrent monitoring, it is important to set sufficiently wide tolerance bandsto enable the U/I regulator to react without signaling of errors.

ZoomZoom function (magnification) of the time axis of the displayed curves bya factor of 2, 5, and 10.


5.11 Overview

Overview – GeneralThe overview tab allows you to select a parameter from the list. Thecurrent state of this parameter is listed for all programs of the weld timerselected. This provides a quick overview of the state of the system.

Overview – UIR Mode

Active = Not active =

NoteThe measuring is displayed as being active only if it is global and ON forthis program.

Regulation is displayed as being active only if the measuring is globaland ON for this program, if the regulation is global and ON for thisprogram and if a valid curve is saved for this program.

Program number


Monitoring is displayed as being active only if the measuring is global andON for this program, if monitoring is global and ON for this program and ifat least one of the supervision parameters is ON.

Overview – PSQ Process Variables

The PSQ process variables screen of the overview tab allows you toselect the process stability or UIP parameter. The current state of thesesupervision parameters is listed for all programs of the weld timerselected. This provides a quick overview of the state of the qualitycontrol. This requires that tolerances have been specified and monitoringbeen activated in programming – UIR monitoring.

Only those programs (Prog.) / spot names are displayed, where n.i.o.spots are existing.

Meaning of Table Columns

Spot nameIf there is no spot name, the message “ no spot name!” will be displayed.If the spot name is shown on a colored background, there are spotscorresponding with this program. Place the cursor on the spot name toshow a tool tip text which displays the corresponding spots with severalspot names being assigned to one program.

Program number


A program number associated with the above spot name.

NoteClick on the program number to open the UIR monitoring window whichshows the UIP and/or process stability of the program concerned.

N.i.o.Number of welding spots which are Not OK (n.i.o.), i.e. which haveexceeded the conditionally permissible or the permissible lower toleranceband.

The number of i.O. (OK) spots can be defined on programming – PSQ –UIR monitoring screen. This number is defined under acceptancerepetition factor = UIR monitoring limit, which indicates the number of i.O.(OK) spots have to follow in order to reset an exceeded tolerance.

TotalDisplay of the totel of all welding spots for this program number that havebeen completed since the last time errors were reset on this screen.

Max. status: % displayPercentage value of the rejected (n.i.o.) welds in relation to the total ofwelds.

Status bar:• Green: the programmed number of successive accepted

welds (acceptance repetition factor) has been reached,i.e. the tolerance band has not been exceeded, and thepercentage value of the n.i.o. welds is below thepercentage specified under Status Max. %.

• Yellow: at least one welding spot was rejected.• Red: the display range of the bar was exceeded,

depending on the setting under Status Max. %.

Status Max: % ParameterAllows setting of the display range of the bar to 1%, 2% or 5%. Beyondthis range, the bar will become red.

UpdateDestined for reading in of the current data and refreshing of the display.Whenever the screen is called up, the display is refreshed automatically.

Reset errorsResets the error display of the process variables.Counting of n.i.o. spots and total spots is restarted.This option does not reset any sequence errors!To sort the columns, just click on the header of the particular column.

Examples:

4 out of 81 welds have exceeded a tolerance band a short time ago. Thebar becomes yellow because the Status max. is set to 5%.


4 out of 71 welds have exceeded a tolerance band. The bar becomes redbecause the Status max. of 5% has been exceeded.

3 out of 70 welds have exceeded a tolerance band. The bar, however, isgreen because the last welds – set under programming – PSQ – UIRmonitoring – acceptance repetition factor – did not exceed any toleranceband and the Status max. of 5% has not been exceeded either.


5.12 Process Overview

Clicking the button will provide an overview of the process stateof the connected weld timers.

The following items can be selected:• Process stability• UIP• Q stop (depending on the type of weld timer)

Green barPercentage value of all programs enabled for a WT, which did not exceedany conditionally permissible tolerance band nor any permissible lowertolerance band.Yellow barPercentage value of all programs enabled for a WT, which exceeded aconditionally permissible tolerance band or a permissible lower toleranceband in the last 10 welding spots.Red barPercentage value of all programs enabled for a WT, which initiated a Q-stop error.The Q-stop function is not available for all weld timers. Please refer to thedescription of the Q-stop function in the WT documentation.The sequence inhibition of enabled programs is OFF.

The display is sorted such that the worst value is shown at the top.

UpdateClick update to refresh the display.

Double-click on a WT to open the overview – PSQ – process variableswindow with the appropriate UIR process variable, which provides anoverview of the process state of the various programs of this WT.

6-58 Commissioning with BQR

6 Commissioning with BQRFollowing the installation of all components, the system can becommissioned step by step.For additional information on commissioning, please refer to Chapter 8.

6.1 First StepCommissioning the weld timer / inverter unit in the constant currentregulation mode (CCR).

The functioning of the system in the constant current regulation (CCR)mode is an essential prerequisite. The U/I regulator uses the samemechanisms as the CCR. This part of commissioning corresponds to theknown procedures for a PSI 6000 inverter system, so that welding spotscan be produced in the CCR mode.In this context, see the manuals on the PS 6000 regulation system andI/O level, medium-frequency inverter, and welding transformer.

This step also comprises any required force and current scaling.Refer to the corresponding chapters in the manuals.

NoteScaling must not be performed while the U/I regulator is active.

6.2 Second StepPrerequisites regarding welding gun and electrodes

The welding gun must be in excellent condition. The electrodes must beadjusted to ensure that they stand exactly opposite each other and in aright angle to the sheet.

The electrode tips should be dressed and slightly used (approx. 20–25spots). Dressing corrects the contact surface of the electrode tips. Thisresults in ambient conditions like those of new tips. However, there mayalso be interferences which are caused by dressing. First of all, dressingcan create irregularities on the contact surface (e.g. chatter marks);secondly, the plane of the contact surface may not coincide as well withthe joining plane as in the used cap condition.

Squeeze time and hold time should be long enough to allow the weldinggun to build up the required force.Force measuring is recommended.

Commissioning with BQR 6-59

6.3 Third StepGenerating the Reference Curve

Select the desired welding program at the BOS 5000/6000 user interface.To generate a reference curve, first make some welds in the constantcurrent regulation mode until you have reached a sufficient spotdiameter.

Check or set at the BOS5000/6000 user interfaceSqueeze time sufficient for this welding jobHold time sufficient for this welding job1st weld time Possibly as a pilot pulse in the CCR mode (see

Chapter 9.4)2nd weld time andcurrent

set for this welding job. Possibly, upslope in the2nd weld time

3rd weld time Possibly for post-heating in the CCR modeCCR mode ONRepetition sequence OFFInhibit monitoring ONReadjusting Heat values to 100%

NoteIf possible, the heat correction should be set to 0% to allow full correctionfunctionality later in the U/I regulation mode.


Settings at the BQR user interface of the U/I regulatorAll programs UIR measuring ONSelected program UIR measuring on

UIR regulation offUIR monitoring off

Data don't forget the timer (weld timer).

See chapter 7 "BQR User Interface U/I Regulator" for a detaileddescription of the BQR operation.


Setting the reference curve

Under Setting of tools - U/I, generation of reference curves is supported.Advantage: several welding procedures of a program can be used togenerate a reference curve, irrespective of the sequence of theprograms. In practice, this considerably simplifies the definition ofreference curves.

Press the New key in Data recording to start data recording.

A welding process has been recorded.

All executed welding processes are indicated. View - Program filtershows the program number of the program executed last, and View -Actual curve the current number of the last welding process.


If the welding processes which are to be used to generate the referencecurve have been recorded, data recording can be stopped now.

Now, chose a program in View - Program filter to see this program'scurves. In View - Actual curve select one of these curves; this selectedcurve is indicated in red for evaluation.To delete this specific curve, use Delete actual curve.

Before calculating the reference curve, you can delete any possible

outliers.



expulsion


Now, click the Average curve button to calculate the reference curve for aprogram; the curve is indicated in red. The black curves show theminimum and maximum resistance characteristics.

Click original curves to switch back to the original curve screenshot fromthe average curve screenshot.

Confirm reference curve

Use actual curve reference curve to save the red curve as thereference curve to the U/I regulator.

Minimum resistancesaverage curve

maximum resistances


Notes

For each combination of sheet thicknesses, we recommend using aseparate program and to determine a separate reference curve.Advantage: In separate programs, all welding parameters can be set inan optimal manner for the respective welding job; there is less extensionof weld time caused by different sheet thicknesses.However, if different sheet thickness combinations must be welded withone program (manual welding gun), the reference curve is determined bymeans of the thinnest sheet combination with the lowest resistance. Incase of coated sheets, it is determined by means of the thinnest sheetswith the thickest coat. Set the force for mean to thick sheet combinations.

Please also refer to Chapter 8.3.

Always make the reference weld without adhesive between the sheets, ormake at suitable sheet strips because adhesive is a disturbance variable.

Welding at the component is possible for determination of referencecurves. If strips are used, please note the following:- The curve of the first spot on a sheet should not be used as a

reference curve.- Spots should be welded at a distance of approx. 20 mm (shunt).

If the spot diameter is too small, increase the current from spot to spotuntil the expulsion limit is reached.If there are expulsions, reduce the current to the last expulsion-free valueand re-weld. For compensation purposes, it might be necessary toextend the weld time.Only after the weld has been made without expulsions and with the spotdiameter required can this curve be applied as reference curve.

Welding quality cannot be determined through interpretation of thecurves. The evaluation of the curves is limited to the following aspects:- Resistance characteristic: typical course with strong downslope of

resistance at the start (contact is made) and continuous downslopeof resistance towards the end.

- Voltage signal: does a voltage signal exist, and is its curve similar tothe resistance.

Expulsions can also be recognized from the suddenly falling slope of theresistance characteristic.Please also refer to Chapter 9.The wear state of the tips should be between 10 and 100 welds.


6.4 Forth StepActivation of the Regulator for this Program:

Settings at the BQR user interface of the U/I regulatorAll programs UIR regulation ONSelected program UIR regulation ON

NoteThrough all programs, the measuring, monitoring and regulation for allweld timer programs can be switched off.

Steps 2 to 4 must be repeated for each spot which is to be welded in theU/I regulation mode.

This completes the determination of reference curves.

Corrections of the reference curve (raise/reduce) can now only beachieved through the heat correction function of the BOS 5000/6000.Weld time and current setting cannot be changed any more as they arenow defined by the U/I regulator. For this reason, when activating PSQcurrent monitoring, it is important to set sufficiently wide tolerance bandsto enable the U/I regulator to react without signaling of errors.

Use to indicate the curves of the current welding.

Visualization of the curve slopes

For a detailed description of operation, please refer to Chapter 7"BQR User Interface – U/I Regulator".

7-66 BQR User Interface – U/I Regulator

7 BQR User Interface – U/I Regulator

The BQR user interface can be used for parameterization anddiagnostics of the U/I regulator on site and for supplementing the BOS5000. The current versions of the BOS 6000 interface also contain thefunctions of the separate BQR user interface. The BQR user interface forthe U/I regulator can only be operated via the V24/RS232 interface onthe regulator modul X3C or the weld timer X1. It automatically adjusts toone of the two Baud rates of 19,200 Bd or 57,600 Bd. The GUI isdimensioned for a fixed screen resolution of 1024 * 768 points.

In the same way as in BOS 5000 / BOS 6000, up to 256 weldingprograms (0–255) and 32 electrodes (0–31) are supported.

The BQR user interface is only used for commissioning or diagnostics.After initial setup, the regulator works independently.

7.1 Installation and Connection

Requirements

• Operating system: Windows 2000/NT/XP• Screen resolution: 1024 x 768• Serial interface COM1 or COM2 (with at least 57,600 bauds)• Min. Pentium II 233 MHz• Min. 1 GB space on the hard disk drive• Min. 64 MB random access memory• CD Rom drive

Connection

For connection, a V24/RS232 connection cable is required between thePC and the regulator modul, e.g. BOSCH order number 1070 066749.For more information on the connection cable, please refer to the RexrothManual “PSI 6xxx.000 Control and I/O Level”, Technical Information,index entry “programming unit” or “X1”.

InstallationDepending on your operating system, select one of the followingdirectories:• Windows 2000 and NT• Windows XP

and start the Setup program.

BQR User Interface – U/I Regulator 7-67

7.2 Overview of Operating Functions

Operation of the U/I regulator is subdivided in the areas described in thefollowing. These areas are reflected in the menu structure.

File View Tools ?Backup U/I/US curves

(auto)Comport Help

Restore Referencecurves(program)

Selectlanguage

Info

End Weld timeridentificationPSI settingsExpert modeInitialize dataLoad firmwareSet up U/I

Table: Menu structure of the user interface

7.3 Parameterization of the U/I Regulator

All parameters for U/I regulation are stored in the regulation device. Adistinction is made between parameters for

· "all programs": applicable to all electrodes and all programs· "selected program": applicable to program numbers 0 to 255


To achieve the desired welding results, all parameters must be setcorrectly. To ensure simple application, all parameters are preset withdefault values that will generate a functioning welding in most cases.

All parameters are monitored with regard to a permissible entry range, orthe entry is limited to the permissible range. Before a parameter isloaded, the default vales are indicated.

Basic Display

All Programs

All programs means for the overall weld timer, covering all electrodes andprograms.This is the location of the activation of measuring, regulation, andmonitoring for UIR.

ModeThis list box allows optimization of the activated U/I regulator by means ofadjusted regulator parameters, for robot – manual welding gun – fine spotapplications.The “mode” function mainly affects the weld time prolongation in case ofdisturbing variables. For example, the manual welding gun optionconsiders that it is not possible to calibrate each sheet thicknesscombination separately; the robot option takes into account that


excessive weld time prolongations should be avoided. A thicker sheetrequires that the regulator react with the appropriate weld timeprolongation.

Expulsion DetectionCurrent changeUse this parameter to define how the regulator reacts to a detectedexpulsion. The regulator will change the current at the moment of theexpulsion by the programmed percentage. With a positive sign, the valuecan cause an increase of current, and with a negative sign, a reduction ofcurrent.Smooth areaPreset with default value. Changes are only allowed as per instruction.

Selected Program

First, select a program with

Here, measuring, regulation and monitoring for a selected program isactivated.

Click measuring on to turn the U/I measuring on and off.As a precondition for voltage measuring, an electrode voltage cable mustbe connected to the welding gun. To activate the U/I measuring, it mustalso be activated under "All Programs”!

Click regulation on to turn the U/I regulator on and off.To activate the U/I regulator, the following preconditions must be met:a) the U/I regulation mode must be active under "All Programs;b) the reference curve of the selected program must be stored, and therespective parameters must be set.

U/I regulation ready

Here, the operating condition of the regulator is indicated:

U/I regulator ready

U/I regulator not ready

A U/I-regulated welding sequence can only be carried out if a validreference curve for the selected program has been loaded, and if the U/Iregulator has been activated globally as well as for the selected program.

Weld time prolongation


Weld time prolongation ON permits the U/I regulator to extend the weldtime for this program.The maximal parameter limits the weld time prolongation which the U/Iregulator needs to compensate for disturbances. In automated operation,very long weld times may be undesirable.When this time limit is exceeded, the error message“SQ maximum weld time reached" is displayed.

Example:A weld time prolongation of 100% permits the U/I regulator to double theprogrammed weld time if necessary.

NoteIn the U/I regulation mode, it is no longer allowed to change the weld timeunder programming – sequence – 2nd WLD)When the U/I regulator is switched off, weld time prolongation isdeactivated as well.

Spots counterIn the spots counter, the current number of welds (since counter reset)for the program selected is displayed.

Expulsion counter

If the U/I regulator detects an expulsion, the expulsion counter isincremented. This allows to read the frequency of expulsions ascompared with the spots counter.

Click the reset button to reset the expulsion counter and spots counter forthe program selected.Click reset all to reset the expulsion counter and spots counter for allprograms.

CopyClick this button to copy the parameters of the selected program to otherprograms.

NoteBy double-clicking a parameter field (left mouse button), only theparameter selected can be copied to several programs.

UIR Parameter


Limit values

The max. current raise permits the U/I regulator to raise the current by apercentage in relation to the reference current during the balancing ofdisturbances.

The max. current reduction permits the U/I regulator to reduce the currentby a percentage in relation to the reference current during the balancingof disturbances.

IMPORTANT

Changing these limits may impair the efficiency of the U/I regulator indealing with disturbances!Do not change these values unless absolutely necessary.

Period II

This value is calculated automatically when the reference curve isgenerated.


Supervision Parameters

To match the welding job and its quality control, the monitoring functioncan be activated separately for each of the supervision parameters.Depending on the welding job, it may be appropriate to monitor differentvariables. Please also refer to Chapter 5.7, Information on Monitoring.

The monitoring function can be separately turned on and off for eachmonitoring variable (checkbox).The reference parameters are provided as desired monitoring values forthe various monitoring variables.The weld timer compares these desired values with the measured actualvalues and interprets them• as being “accepted” or “rejected”, based on the tolerance limits of thepermissible upper tolerance band or the permissible lower toleranceband;

• as continuously worsening, based on the conditionally permissibletolerance band and repetition factor.Poor actual values initiate an appropriate warning or error message,provided the relevant monitoring function is activated.

Permissible Upper Tolerance BandDefines the maximum permissible positive tolerance in a percentage ofthe reference value.


Any actual values exceeding this tolerance limit generate the messagetype “… too high”.

Permissible Lower Tolerance BandDefines the maximum permissible negative tolerance in a percentage ofthe reference value.Any actual values falling below this tolerance limit generate the messagetype “… too low”.

Conditionally Permissible Tolerance BandInput value as a percentage of the reference value.This parameter cooperates with the repetition factor) for detecting any“creeping” errors of the system, resulting in a slow and steady“worsening” of the actual values.

Repetition FactorThe repetition factor defines the number of successive welding spots thatmay be within this conditionally permissible tolerance range.If this value is exceeded, the weld timer emits the message type“repetition error …”.

NoteThe counter for the repetition factor is incremented, irrespective of whichof the monitored variables is within the conditionally permissible toleranceband. After an accepted weld, the repetition factor counter is reset.

Q Stop

This function depends on the type of weld timer and is described in theassociated documentation.

For more information on how to monitor and define tolerancebands, please refer to Chapter 5.7.

"Repetition error..."error or warning

repetition factor = 3

cond. perm. tolerance

- lower tolerance in %

Conditionally permissible tolerance band, repetition factor

+ upper tolerance in %

X welding current value

100% reference current in kAaccepted


Backup/Restore

The menu item File provides the Backup and Restore functions.

Use the Backup function to store the data of the regulation modul to thePC (or network).

Having selected the data source "regulator card”, you must determine afile directory and name. Through actuation of the Start button, theregulation modul creates a backup of the parameters and referencecurves of the individual programs.

Use the Restore function to transfer saved data back to the regulationmodul.

Having selected "regulator card”, you must determine a file directory andname. Through actuation of the Start button, the parameters andreference curves of the individual programs are downloaded from thebackup file to the regulation modul.


Display of UI / US Curves (Auto)

This display shows the curve slops of the last weld.Program number, date and time of the last sequence are also shown.

In the diagram, the current curve slope is shown:• Voltage blue• Current red• Resistance green• Reference resistance black

The weld time is plotted on the x axis in milliseconds.

On the curves, individual moments in time (in milliseconds) can beselected via mouse click. Then, the corresponding measured values ofthe selected spot are indicated in the diagram frame.


Use

to select the individual curves.

All Programs

This button in the display field starts the request to the regulator modul;the signal area turns green.

If a new welding sequence has taken place, current curve slopes aredownloaded and displayed automatically. A new sequence is detected bythe time specification.

Stop

Use Stop to stop data transfer; the signal area turns red.


Display of Reference Curves (Program)

Here, reference and actual curves can be downloaded to the display andsaved as reference curves.

Source – From PCDownloads a reference curve stored in the PC into the display. To thisend, select the directory (default directory:C:\EinrichtenUI\Referenzkurven) and the file on the PC.The reference curve can be saved to one of the targets.

Source – Reference Curves from TimerDownloads a reference curve from the weld timer to the display. To thisend, a program number must be entered.The reference curve can be saved to one of the targets.

Source – Last Curves from the TimerDownloads the actual curve of the most recent weld from the weld timerto the display. To this end, a program number must be entered.The curve can be stored in one of the targets.


Destination – in PCThe currently displayed curve is saved as a reference curve to the PCdirectory (default directory: C:\EinrichtenUI\Referenzkurven). A file namemust be entered.

Destination – UIR in TimerThe currently displayed curve is saved as a reference curve to the weldtimer. A program number must be entered.

IMPORTANT

Changing the reference curve may impair the function of the U/Iregulator!Do not use this functions unless absolutely necessary.


Tools, U/I Setup

ComportSpecification of the comport number of the computer where the serialinterface V24/RS232 is connected. Having entered a new port number, anew initialization of the interface is performed; after successfulcompletion, the comport number is shown in the left bottom corner andshaded in green. A red field indicates that the interface is not ready.

Select LanguageGerman and English can be selected here.

System InfoTo identify the weld timer and / or the regulation module, the versionidentification of the device where the user interface is connected via theserial interface can be displayed.

When the BQR user interface is connected to the regulator modul X3C,the version identification of the regulator modul is displayed.

When the BQR user interface is connected to the weld timer (X1interface), the weld timer type and its version number are displayedadditionally.

Initialize Data• Delete reference curve: this requires entry of the curve number

= program number.• Initialize modul parameters: deletes all parameters and resets

the U/I regulator modul to its basic state.

Load FirmwareUse this function to load new firmware to the regulator modul.– Open file: the extension of the file is "hex".– Observe the messages on the screen.

The firmware version can be viewed under Tools – System info.

CAUTIONWhile the firmware download is in progress, no welding sequence can beperformed!


U/I setup

Allows for comfortable setting of reference curves, above all inautomated production.

Start data recording. From now on, the resistance characteristics of allweldings are recorded and assigned to the corresponding program. Thesequence in which the programs are executed is not important. It isadvisable to weld some components before completing data recording.Now, you have some resistance characteristics for each program thathas been run. From this data, a average curve can be calculated for eachprogram and saved to the U/I regulator as a reference curve for thisprogram. As a matter of course, this requires that the welding quality ofthe curves recorded is satisfying. To this effect, determine e.g. the spotdiameter.Outliers in the curve slopes caused e.g. by expulsions must be deletedbefore calculation.In practice, this mode considerably simplifies the definition of referencecurves.

Start recording with New.

NewThis starts a new data recording. Any previously recorded curves will bedeleted. Each welding process performed from now on will be stored inthe BQR and displayed in correspondence with the respective program.


ContinueUnintentional or intentional exiting of the window does not result in loss ofthe recorded data. Click Continue to re-start at the point you left the datarecording window.The recorded curves are filed in the PC under C:\EinrichtenUI\P001,...\P002, etc.

Program FilterAny previously recorded curve slopes can be viewed in dependence onthe respective program. Only the curves for the selected program areshown.

Actual CurveUse this function to switch between the individual curves of the currentlyselected program and to select one curve.

Recording has been started.


The BQR is now ready to record data and is waiting for the firstsequence.

Stop stops the recording.

In the record mode, entries cannot be made in the program filter andactual curve boxes.

Display - program filter shows the program number of the programexecuted last, and display – actual curve the current number of the lastwelding process.


Record mode

The welds performed now are displayed as resistance characteristics.The most recent curve is indicated in red.Important: The sequence in which the programs are welded is of nosignificance – they can be executed in "any" sequence (e.g. Prg 15, Prg4, Prg 6, etc.).However, all last curves and the actual curve are always output for theprogram welded last.

The actual curve box shows the number of processes executed with theactual program.

The program number, date and time of the last sequence are shown inthe header.The footer provides further information on readjustment and electrodestate:♦ Dressing counter♦ Wear counter♦ The current correction factor shows the currently effective power

readjustment in percent of the basic power.


Zoomed curvesRight-click to zoom the curves in their amplitude. Left-click to return thecurves to standard representation.


Recording complete

After termination of recording with Stop, select the curves of the desiredprogram with program filter. All recorded curves of this program aredisplayed.

Use actual curve to switch between the curves of a program and selectthe curve desired. The actually selected curve is shown in red.

To delete the curve selected, use delete actual curve.

In the above illustration, Program 3 has been selected with program filter.10 curves have been recorded; one of these can be selected throughactual curve to have it shown in red. This provides for betterrepresentation and evaluation of the individual curves.


Average reference curve

Now, click the average curve button to calculate the reference curve for aprogram; the curve is indicated in red. The black curves show theminimum and maximum resistance characteristics of this program.

Click original curves to switch back to the original curve screenshot fromthe average curve screenshot.

Applying the reference curve

Use actual curve reference curve to save the red curve as thereference curve to the U/I regulator.

Using In PC, the red curve is saved as the reference curve to the PCdirectory C:\EinrichtenUI\Referenzkurven.

Corrections of the reference curve (raise/reduce) can now only beachieved through the heat correction function of the BOS 5000/6000.Weld time and actual setting cannot be changed any more as they arenow defined by the U/I regulator. For this reason, when activating PSQactual monitoring, it is important to set sufficiently wide tolerance bandsto enable the U/I regulator to react without signaling of errors.

minimum resistancesmaximum resistances

Minimum resistancesaverage curve

Instructions on Commissioning 8-87

8 Instructions on Commissioning

Commissioning of the U/I regulator requires a quality weld (= referenceweld) which will form the basis of regulation and monitoring.

There are different cases:

Initial startup (new materials, new systems, new components, etc.)• As quickly and easily as possible• Parameters have not been optimized yet• Wide monitoring limits• Only certain supervision parameters are reasonable

Optimization (increase in piece numbers, stable bulk production, etc.)• System optimization (robot positioning, cooling, forces,

scaling, etc.)• Welding parameter optimization• Tight monitoring limits

The reference weld must be a problem-free weld of the particularwelding job, with a result that exceeds the minimum requirements. Thespot diameter should be just above the nominal diameter, but below theexpulsion limit. The result must be verified by means of a destructivetest. In addition, the curve slopes should be checked / interpreted, forexample to detect expulsions or edge welds.

The definition of the quality weld as a reference weld requirescompliance with further requirements:

• The electrode tips must be worked in, but not worn toostrongly approx. 20 spots

• The welding gun force must be stable and reproducible:verify by repeated measurings

• Cooling state okay: check flow volume and cooling tube

8.1 Defining the Basic Welding ParametersThe basic welding parameters for a welding spot to be set up can beobtained from various sources:

• Apply the welding parameters from a system which isrunning in a stable state and performs the same weldingjob

• Results of laboratory tests• DMS table values

8-88 Instructions on Commissioning

• Manufacturer’s specific inhouse standard• Calculation programs• Welding parameters database• Simulation programs

8.2 Making the Reference Weld

Variant 1: Weld a spot on the original component in the productionshop.

• Safest method for regulation and monitoring• Requires optimized welds• Requires a low number of expulsions• Dressing cycle must be incorporated• Relatively work-intensive as compared with variants 2

and 3• Results in a relatively large volume of testing scrap

(components)• Suitable for retrofitting of existing systems

Sequence for each sheet combination (don’t forget special items, such asadhesives):

• CCR weld with basic parameters on the component withoriginal welding gun

• Subject components to a destructive test• If the spot diameter is OK, make several welds on

various components to create defined marginalconditions

• Define referencing from superimposed curves (seeChapter 5.10) and save the reference curve

• Make a weld on the component using the U/I regulator• Copy the reference curve to all spots with the processed

sheet combination and activate the regulator• Observe the monitoring result• Weld the component using the U/I regulator• Destructive test• Second recursion for optimization


Variant 2: Weld sheet strips at the welding gun in the production shop.

• Less work-intensive than variant 1• As compared with variant 1, the regulator is involved to a

greater extent, since the individual special features of thespots on the component are not taken into consideration

• Poorer basis for the process stability and process qualitymonitoring variables

Please observe the following:• Effect of dressing cycle, welding gun replacement,

adhesives, special steels and coatings• The first welding spot on the sheet strip is of no

relevance

Details on variant 2:

On startup of a new system (new vehicle model)

• Few existing components for setup welding• Extraordinarily expensive components• Components fail to be custom-fit

Variations in the welding sequence, which have to be compensated bythe regulator:

• Robot positioning• Fitting problems• Shunt• Wear• Material variants

Sequence for each sheet combination (don’t forget special items, such asadhesives):

• CCR weld with basic parameters on the sheet strip withoriginal welding gun.

• Subject sheet strips to a destructive test• If the spot diameter is OK, make several welds on

various sheet strips to create defined marginal conditions• Define referencing from superimposed curves (see

Chapter 5.10) and save the reference curve• Make a weld on the sheet strip using the U/I regulator• Copy the reference curve to all spots with the processed

sheet combination and activate the regulator• Observe the monitoring result• Weld the component using the U/I regulator• Destructive test


• Second recursion for optimization

Variant 3: Weld sheet strips in the laboratory.

• Least work-intensive• The regulator is involved to a very high extent, since

individual special features of the spots and the weldingdevice are not taken into consideration

• Optimization required for close monitoring• Suitable for initial parameterization• Poorer basis for the process stability and process quality

monitoring variables

Details on variant 3:

Problems which may occur on transition from the welding gun in thelaboratory to the welding gun in the production shop:

Which are the differences between the welding guns?- Resistance of the secondary circuit- Force development- Slipping behavior- Inductive influences- Electrode tips

Theoretically, the influence exercised by the welding gun can beeliminated by tapping the voltage directly at the electrode. In other words,the voltage tap should be placed as near to the electrode as possible, inorder to be able to generalize welding parameters, reference curves andmonitoring limits.


8.3 Commissioning the Suspension Spot Welders with U/IRegulator

Basic requirements for commissioning the Suspension SpotWelders with U/I regulator:

• Measuring instruments for scaling of current andforce

• Cap dressing device (or file)• Sheet strips of all sheet combinations used• Tools for testing the welding quality of the sheet

strips (e.g. manual ultrasonic device, hammer andchisel, shear tension machine)

1. Checking / scaling of force and currentProper scaling of force and current is an important requirement foroptimal functioning of the U/I regulator.

2. Preparing the electrode tips- Dress the tips initially.

Since there are welding guns which do not allow dressing of thetips, the necessary working surface of the cap should beachieved by filing or grinding. Above all, this minimizes slipping ofthe welding gun if the tips are applied at an angle.

- Work in the tips (approx. 20 spots).

3. Checking the sheet combinations- Define the sheet packets, i.e. thinnest / thickest sheet combination (e.g. for a total sheet thickness ranging from 1.5 mm to 4.5 mm)- Check the strength of the sheets (e.g. soft, micro alloy, high strength, ultra-high strength)- Analyze the coatings of the sheets used (e.g. organic, anodized or hot-dip galvanized)- Check critical sheet combinations, 3-sheet weld (e.g. 0.7 mm DC04+ZE + 2 mm Usibor + 2 mm H320LA)


4. Defining the welding parameters for the reference curve(see table: Basic parameters for the U/I regulator)

- ForceThe force should be defined for the thicker sheet combinations, with thestrength of the sheets taken into account. The maximum force of thewelding gun also plays an important role. Sometimes, the forces that canbe reached with manual welding guns range only up to 3 kN. In this case,the force should be set to approx. 2.8 kN, in order to reduce the wear ofthe welding gun.

- CurrentThe current should be set such that the maximum resistance develops inthe 1st third of the weld time. The strength and coating of the sheetswelded with the welding gun must also be taken into consideration. If,e.g., only hot-dip galvanized sheets are welded, the current for thereference curve should already be adjusted to galvanizing.

Observe the following recommended values:• Electrolytic coating and hot-dip galvanization: current increase

of 0.5 to 1.0 kA in addition to the value specified in the table• Higher-strength steels: current must be reduced by up to

1.0 kA

- Weld timeThe weld time should be within the range of the average sheet packet(e.g. sheets ranging from 1.5 mm to 4.5 mm WLD: ranging from 210ms to 710 ms according to table WLD: set approx. 450 ms).We recommend an upslope of 50 ms to 100 ms especially in case offitting problems, thicker sheet packets and adhesives.

The squeeze time should be selected such that the programmed force iscompletely built up on start of the weld time (see figure force built-up).The example clearly shows that the maximum force has only been builtup after approx. 300 ms. A squeeze time of at least 1000 ms isrecommended for manual welding guns.However, the squeeze time should be separately checked for each typeof welding gun. Particularly where large welding guns and high forces areconcerned, an extended squeeze time may improve welding quality.

The hold time may be dependent on the sheet combination.Tests have shown that the hold time should range from 100 to 200 ms.


Force built-up during the squeeze time:

Resistance characteristic with correct and insufficient squeezetimes:

Resistance characteristics with correct squeeze time and two shortsqueeze time:

Basic parameters for the U/I regulatorIf adaptive regulators are used, the welds must be made withinthe scope of one current pulse.For soft deep-drawing steels with an additional organic coating,the basic parameters are as follows if pairs of F16 electrode tipsare used:

Force built-up: Lap welding gun with 3,0kN

0

500

1000

1500

2000

2500

3000

3500

0 100 200 300 400 500 600

Time / ms

Force / N

Resistance characteristics with different squeeze times

200

250

300

350

400

450

0 10 20 30 40 50 60 70 80 90 100Time / ms

Force 3,0kNSqueeze: 300ms

Force 3,0kNSqueeze: 150ms

Forc

e / N

R /

µOhm


Table: Basic parameters for the U/I regulator

Total sheet Upslope Weld time Current Forcethickness [mm] [ms] [ms] [kA] [kN]

1.2 - 200 9.0 2.0

1.3 - 200 9.0 2.1

1.4 - 200 8.9 2.1

1.5 - 210 8.8 2.1

1.6 - 230 8.7 2.2

1.7 - 240 8.7 2.2

1.8 - 250 8.6 2.2

1.9 - 270 8.6 2.3

2.0 100 350 8.5 2.3

2.1 100 360 8.5 2.4

2.2 100 380 8.4 2.4

2.3 100 390 8.4 2.5

2.4 100 400 8.3 2.5

2.5 100 410 8.3 2.6

2.6 100 430 8.2 2.6

2.7 100 440 8.2 2.7

2.8 100 450 8.2 2.8

2.9 100 470 8.1 2.9

3.0 120 500 8.1 3.0

3.1 120 510 8.1 3.1

3.2 120 530 8.0 3.2

3.3 120 540 8.0 3.3

3.4 120 550 8.0 3.4

3.5 120 560 7.9 3.5

3.6 120 580 7.9 3.6

3.7 120 590 7.9 3.6

3.8 120 600 7.8 3.7

3.9 120 620 7.8 3.7

4.0 120 630 7.8 3.8

4.1 120 640 7.8 3.9

4.2 120 660 7.8 4

4.3 120 670 7.8 4.1

4.4 120 680 7.8 4.2

4.5 150 710 7.8 4.3

4.6 150 730 7.8 4.4

4.7 150 740 7.8 4.5

4.8 150 750 7.8 4.6

4.9 150 770 7.8 4.6

5.0 150 780 7.8 4.7

5.1 150 790 7.8 4.8

5.2 150 800 7.8 4.8

5.3 150 820 7.8 4.9

5.4 150 830 7.8 5

5.5 150 850 7.8 5.1

5.6 150 860 7.8 5.2

5.7 150 870 7.8 5.3

5.8 150 880 7.8 5.4

5,.9 150 900 7.8 5.5

6.0 150 910 7.8 5.5


5. Evaluating the reference curve by means of an example

To generate the reference curve for all optimized welding guns, thefollowing sheet combination was used in tests:

1.75 mm H320LA + 0.8 mm DC04 OC=> sheet packet of 2.55 mmFrom table: I = 8.3 kA; STZ (WLD) = 410 ms

Example:Welding gun with Fmax: 3.9 kN

Thinnest sheet combination: sheet packet of 1.54 mm0.7 mm DC04 ZE + 0.84 mm ZEFrom table: I = 8.8 kA; STZ (WLD) = 210 ms

Thickest sheet combination: sheet packet of 4.85 mm1.5 mm H320LA + 2.0 mm Usibor + 1,25 mm UsiborFrom table: I = 7.8 kA; STZ (WLD) = 750 ms

Welding parameters selected for reference:Force: 3.5 kN (because of Fmax of the welding gun)Upslope: 3.0 kA / 100 ms (adhesive is used)2. STZ (WLD): 7.6 kA (less current because of Usibor) and450 ms(The time corresponds approximately to the average value of thetimes for the thickest and the thinnest sheets.)

Actual curve:

Course of refernce current

0

1

2

3

4

5

6

7

8

9

0 50 100 150 200 250 300 350 400 450Time / ms

I / k

A

I_Ref


Resistance characteristic:

In the resistance characteristic, the maximum should develop relativelyearly after the upslope.

6. Checking the welding qualityTo check the welding quality, U/I-regulated welds should be made on thesheet strips, using the critical sheet combinations (thinnest combination,thickest combination or 3-sheet combination).If the welding quality proves to be satisfactory, the welding gun can beused for manufacture.If there are expulsions or spots that are too small, the weldingparameters should be adjusted by optimizing the actual and weld timeparameters.

Course of refernce resistance

100

150

200

250

300

350

0 50 100 150 200 250 300 350 400 450Time / ms

R /

µO

hm

R_Ref


8.4 Returning to the CCR Mode

If switching back from the U/I regulation mode to the CCR modebecomes necessary, it is essential that the CCR parameters have alsobeen optimized. In this case, the programmed actual value (in kA) willagain become decisive for the welding quality.The reference actual parameters including tolerances and repetitionfactor are effective for CCR (actual) monitoring.

The heat correction function is still effective and can be used to adjust thevalue of the current. In most cases, the current in the CCR mode shouldbe set higher than that in the U/I regulation mode.In the U/I regulation mode, the heat does not have to be corrected,because the heat adjustment is programmed to be 100%. Switching backto the CCR mode, however, might require a heat correction, in order tocompensate for electrode wear.

9-98 Comprehending the Resistance characteristics

9 Comprehending the Resistance characteristics

To execute its regulation task, the U/I regulator utilizes a great deal ofdata from the welding process. For calculating the actual and weld timecontrol variables, the U/I regulator uses various measuring variables atdifferent times during the welding sequence. In addition to the current, italso uses the values of energy and resistance. It also includesinformation about expulsion events and the time course of the variousvariables in its calculation.

To become familiar with the process of a welding job, it is recommendedto comprehend the resistance characteristics. These curves arevisualized on the user interface, together with the actual curves. In theconstant-current (CCR) mode, this visualization allows observation ofchanges in the process after welding parameters have been varied, sothat this knowledge can be used for optimization. In the U/I regulatormode, comprehension of the resistance characteristics helps torecognize interventions of the regulator and changes in the processsituation.

9.1 Normal CurveThe figure below shows the “normal” course of a curve. At the beginningof the weld, the values are relatively high; then the resistance decreasesbecause the sheets are heated and, thus, better abutting. This phase iscalled the coupling or heating phase. After a relative minimum, theresistance again rises to a relative maximum, because the steel starts toliquefy in the weld spot. Once the maximum value has been reached, thematerial in the weld spot is liquid. While the weld time is elapsing, theresistance value continuously decreases. In this phase, the welding spotincreases until it reaches the spot diameter desired.

Stromzeit[ms]

normal curve

coupling /heating phase

fusing phase, spot increases

maximum

weld time [ms]

Comprehending the Resistance characteristics 9-99

Here, it must be noted that the sequence shown represents an idealcurve. There may be sheet combinations where the minimum andmaximum positions are expressed only weakly, so that the curve has avery flat behavior. For example, this applies to very thin sheetcombinations. There may even be cases where the resistancecharacteristic starts with a high initial value and then decreases withoutany noticeable extreme values until the weld time has elapsedcompletely. This can be observed with thin electrolytically galvanizedsheets. The regulator is suitable for such curves, although theirinterpretation is more difficult. Dynamic resistance characteristics, i.e.changes in resistance of approx. 100 µOhms, are usually developing withthick sheet combinations.

9.2 ExpulsionsIn the resistance characteristic, an expulsion can be identified by asudden change towards lower resistance values. In the example shownbelow, the expulsion occurs at 105 ms of the weld time. The measuresfor elimination of the expulsion strongly depend on the time of expulsionoccurrence, as will be illustrated in more detail below.

Resistance characteristic with expulsion at 105 ms

weld time [ms]

expulsion

expulsion


9.3 Isolating MaterialsIsolating layers between the sheets to be welded are particularly incurredwhere adhesives are used in the body assembly shop. If properlyapplied, such materials do not impair the weld. However, their isolatingeffect must be eliminated before the welding process is started. Thefigure below shows the variation in the resistance characteristic. At thestart of the weld time, the resistance remains high until the isolating layeris displaced or burnt away. The duration of this phase depends on thematerial used and the forces at the welding gun and on other factors.Once the isolation has been eliminated, the welding process will berunning normally with the resistance characteristics being defined by thesheet combination.

Resistance characteristic in case of welds with adhesive

9.4 Steps to Optimize the Weld

The curves of the process variables visualized by the user interface canbe used to easily optimize the welding parameters.

weld time [ms]

Normal course

adhesive

adhesive causes delayed startof the heating phase


General Rules

• The special features of the particular welding job must always beincluded in optimization (material, coating, adhesives, etc.).

• The welding device and the parts to be joined must always bechecked for being suitable for the welding job (forces, positioning,cooling, flange width, etc.).

• Any disturbing variables of the welding device must be minimized.• Using the scales of the graphs, the voltage and resistance conditions

of the machine / welding gun can be checked roughly.• Before generating the reference weld, defined starting conditions

must be created for the electrode cap (see Chapters 4.2 and 6.2).• Resistance characteristics should be dynamic with a relatively large

variation in resistance. Such curves indicate a stable processsituation and can be observed easily.

Elimination of Expulsions

At first, the time of expulsion occurrence must be determined.

Early Expulsions

An expulsion occurring before approx. two thirds of the weld time haveelapsed indicates an early expulsion time. When early expulsions areincurred, it must be expected that the ratio of current to force is notcorrect. If a check shows that the force has the proper value, the currentmust be reduced.

There are other disturbing variables in the welding process which may bethe cause of expulsions. If the spot position results in an edge weld, itmust be eliminated. Often, fitting problems will cause expulsions. Apartfrom eliminating the cause, an improved coupling can be reached by acurrent upslope.

Late Expulsions

An expulsion occurring in the last third of the weld time indicates a lateexpulsion time. In case of late expulsions, the disturbing variables in thewelding process must be minimized as well. A known problem is a poorslipping behavior of the welding device.

Expulsions occurring shortly before the weld time has elapsed completelycan often be eliminated by slightly shortening the weld time. This appliesparticularly to hot-dip galvanized material.


Expulsion in the Regulation Mode

Although the regulator largely balances disturbances caused bydisturbing variables, welding expulsions may nevertheless occur in theregulation mode. This can be attributed to the fact that the disturbingvariable is so strong that it cannot be regulated any longer or that severaldisturbing variables are effective at the same time.

The response of the regulator to expulsions can be adjusted with regardto the welding current (see Chapters 7.3 and 5.5). In case of expulsions,the activated regulator automatically extends the weld time to a certaindegree, in order to compensate for the energy that has been lost with thematerial.

The regulator provides the additional possibility of varying the energyintroduced by means of the “heat correction” function. It is also possibleto reduce the energy in order to eliminate expulsions.

Optimization in Case of Single-Pulse Welding

In association with the force, current and weld time must be dimensionedsuch that the relative maximum of the resistance characteristic ispositioned before half of the weld time has elapsed. The coupling phasefor hot-dip galvanized material is longer, so that the maximum of theresistance characteristic may also be positioned in the second third of theweld time.


Optimization in Case of Preliminary-Pulse Welding

Where preliminary-pulse welding is concerned, the preliminary pulsemust be dimensioned such that there is no fusing yet. This can beachieved by setting the appropriate current and pulse duration and, ifnecessary, the cool time. In the preliminary pulse, the resistancecharacteristic must not reach its maximum yet. The falling edge of theresistance characteristic must be positioned entirely in the main pulse.

Dimensioning a preliminary pulse

preliminary pulse

weld time [ms]

10-104 Error Messages

10 Error Messages

The weld timer will inform you of any events occurring during operationwhich are of relevance for it.Primarily, a distinction is made between• errors and• warnings.

In case of an error• no welding sequence can be started,• the READY LED at the front of the weld timer turns dark (see

documentation of the weld timer),• the output signal "Weld Timer Ready" at the PSI 6000 is reset.

In case of a warning• welding processes are still permissible.

Whether an event is interpreted as error or as warningdepends on the parameterization of the weld timer (BOS; errorassignment).Errors as well as warnings can be "self-acknowledging".“Self-acknowledging” means that such events are automatically clearedby the weld timer after the cause of error or warning has been eliminated.In this case, a manual “Fehler rücksetzen (error reset)” is not required.

Examples for self-acknowledging errors:- Stop circuit open /no 24 V- Supply voltage off / too low

Together with information on error causes and errorelimination, all error and status messages concerning the PS6000 and the U/I regulator can be found in the “Error List PS5000 / PS 6000” (No.: 1070 087001).

For the acknowledgement of errors, please refer to theappropriate weld timer manual.

DANGERAfter an error has been reset, the machine might immediately startthe welding procedure!

If an error is reset (acknowledged) while the start signal is present,the weld timer immediately starts the program run! This may resultin dangerous movements of the machine! For that reason, pleaseensure that no-one is staying in the danger zone of the weldingdevice, before resetting the error!

List of Accessories 11-105

11 List of Accessories

Component Order numberV24/RS232: 9-pin D socket 1070 912981V24/RS232: protective cover for 9-pin D socket 1070 313723V24/RS232: cable set, 1.5 m in length 1070 066749Sensor cable: 2 x 2 x 0.75 mm2 LiYCY 1070 913494

Table: List of accessories including order numbers

12-106 Abbreviations, Terms

12 Abbreviations, Terms

BOS (UIW) User interface weldingBQR User interface U/I regulatorCAN Controller Area Network: data busE/A (I/O) Input / output (Eingang / Ausgang)ED (ON) ON time: ratio of weld time to idle intervalESZ (EST) End slope time, current ramp at the end of the 2nd WLDExt. External, e.g. +24-V voltage for signal elements

(switches) and controlling elements (valves) outside ofthe weld timer.

FK (SEC) Step enable contact, completed message contactkA Kiloamperes (current intensity)kN Kilonewtons (force)KSR (CCR) Constant current regulation. Keeps the current in the

secondary circuit constant through regulation.KUR (CVR) Constant voltage regulation. Balances line fluctuations.LAN Local Area Network: general networkLT (PU) Power unit (thyristor or inverter)LST (POW) (G)Current in SKT (scale values/pulse width) or kAMV (SV) Solenoid valve, activation of the cylinders, for closing the

electrodes.PG (PU) Programming unit / welding processor.PHA Phase anglePSG Transformer-rectifier unit for the PSU/PSI inverter seriesPSL PS power unitPSI Medium frequency power unit (1000 Hz)PSQ Quality assurance systemPST Thyristor power unit (50/60 Hz)PSS PS power unitPSU Welding current inverter (medium frequency)PSZ (CT) Cool time, time between the current pulses/blocks (1st,

2nd, 3rd CT).SKT Scale values. Measures of an electric phase angle or

pulse width.Slope Current tramp from an initial to a final current valueSST Timer (WT) Weld timer, also referred to as timer, or

resistance weld timer.SSZ (UST) Upslope time, current ramp at the start of the 2nd WLDStepper Current stepping for compensation of electrode wearSTZ (WLD) Weld time2. STZ (2nd WLD) Second weld time, main weld time, can form a

block with individual pulses; only this 2nd WLD can work with current increase and current decrease (slope)

Temp TemperatureUDM Ultrasonic data processing module (front end)

Abbreviations, Terms 12-107

UIR U/I regulatorUS UltrasonicUSE Ultrasonic sensorsUSP Intersecting point between compensating line / x axisUSR USR regulation moduleUSW NEXUM recording of operating data and statistics

softwareÜK (MC) Monitoring contact.

E.g. for monitoring the pressure inside the cylinder (whichcloses the electrodes) or monitoring of the electrode position(e.g. “welding gun closed”).

VHZ (SQZ) Squeeze time that elapses before the weld time. Theelectrodes squeeze together the parts to be welded.

XQR Regulator modulZdg. (Weld/No weld) Ignition, firing pulses for triggering the power are

switched on and off

12-108 Abbreviations, Terms

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