Summer Training Report Mahle

A SUMMER TRAINING REPORT ON

PROCESS INVOLVED IN PRODUCTION OF VALVE TAPPET

At

MAHLE ENGINE COMPONENTS INDIA PVT.LTD.PITHAMPUR

SESSION- 2015-2016

MEDICAPS ISTITUTE OF TECHOLOGY AND

MANAGEMENT

SUBMITTED TO- SUBMITTED BY-

Mr.Pramendra Dhebena Pratik Agrawal

(Manager M.S.V.T) Rajat Sharma

7th semester

PREFACE

The theoretical knowledge can be enhanced effectively if it is

supplemented by practical exposure in an organization. A Proper

solution to an engineering problem can be obtained provided that one

is equipped with theoretical as well as practical skills.

Industrial training gives opportunity to relate theory with practical

applications .Hence over all understanding and application of the

concept improves with the industrial exposure.

CERTIFICATE

This is to certify that student Pratik Agrawal & Rajat Sharma of

Medicaps Inst. of Tech. & Mgmt. Indore has successfully completed

their summer training under my guidance on Process involved in

production of Valve Tappet at machine shop of MAHLE ENGINE

COMPONENTS INDIA PVT.LTD.PITHAMPUR.

The duration of the training was 30 days from 08.06.2015 to

04.07.2015.

I have undergone through the report and certify that it has

been prepared to my satisfaction and all the facts mentioned have

been verified to the best of my knowledge.

------------------------------

Mr.Pramendra Dhebena

(Manager M.S.V.T)

ACKNOWLEDGEMENT

Knowledge is power, for an engineering student this power of knowledge is

unattainable unless an element of practical observation and practical

performance is not added. Mechanical Engineering not only calls for a

theoretical knowledge of the subject but also asks for practical

understanding as well.

This opportunity to work at Mahle (M.S.V.T) was an enriching

experience in itself.

We convey our gratitude and sincere acknowledgement to

Mr.B.V.Reddy (G.M Mahle, Pithampur) & Mrs. Neha Jhalani (H.R Mahle,

Pithampur) for permitting us to undergo this vocational training.

We are grateful to our project guide Mr.Pramendra Dhebena

(Manager M.S.V.T) for his excellent guidance and continuous

encouragement thought the course of the project.

We are also grateful to all the other staff members of M.S.V.T who

stepped up to guide us and to share there valuable knowledge & experience

that helped us for in depth understanding.

Also we are thankful to all the technicians and operators who were

ever ready to give all sort of practical knowledge that was required for the

successful completion of this project.

CONTENT

Introduction

Parts Manufactured

Departments

1-FOUNDRY 2-M.S.V.T

Process Flow Chart for Valve Tappet

Process Involved in M.S.V.T

o Nomoco Pre-grinding o Diskus Chill Face Grinding

o Hardness Testing

o 6-Spindle Turning

o Heat Treatment

o Lapping

o Nitriding

o Crack Testing

o Washing

o Final Grinding

o T.C.E Washing

o Phosphating

Project Work

Conclusion

INTRODUCTION

Mahle group is a leading developer of engine components all over the

world. Mahle offers unique systems competence in the combustion

engine and engine peripherals, with its three business units Engine

systems and components, Filtration and Engine Peripherals & Thermal

Management. Mahle group is the soul power which is driving the

automobile industry from generations .The success story begins from

the year 1920 when the pistons made of heavy grey cast iron were

replaced by alloy pistons of aluminum, and this technology went to

reach all over the world and mark the beginning of Mahle group. Then

onwards in 1976 Mahle went to introduce aluminum engine block and

in 1988 the assembled camshaft was developed and was ready for

series production and in 2001 the revolutionary cooling concept for

pistons was also introduced by Mahle group and then from here

Mahle group came up with many more innovations and technologies

for the automobiles. The Mahle group is the only organization having

its production units at over 140 locations around the globe and having

64000 employees working under it.

In 1986 Mahle established a plant named as Mahle Engine

Components India Pvt. Ltd. at Pithampur (M.P) India for the

production of valve tappets and camshafts. In this plant different

types of valve tappets & camshafts are manufactured for different

automotive companies .The plant has mainly two departments one is

foundry for the preparation of raw casting and other is machine shop

for further machining of raw casting into desired product.

DEPARTMENTS

The plant is divided into two main departments:

1-Foundry 2-Machine Shop

FOUNDARY

DRESSING OF CORES

CHAPLET PLACEMENT

ADJUSTMENT

CORE PREHEATING

Core placement (For Hollow Camshaft Only)

and Mould Closing

Molding Material

Procurement (SHELL SAND-

RESIN COATED)

DESIGN AND DRAWING

PATTERN

MAKING

Four station

moulding

Sand

invest

ment

Ejection

&

cleaning

Bakin

g

PRE-

HEATNI

G

CORE MAKING

POURING

SOLIDIFICATION

KNOCKOUT

SHOT-BLASTING

INDUCTION FURNACE

CHARGE PREPARATION

MELTING

NODULARISATIO

N TREATMENT

(FOR SG IRON)

VISUAL

INSPECTION

INTERNAL SHOT

BLASTING and number

punching

FETTLING

In this department casting of valve tappet and camshaft is produced. Both

the types of tappet (mushroom& cylindrical) are cast. Moulds are prepared

by two different sands one is green sand and other is shell sand. Both these

sands have different composition and properties.

M.S.V.T-(Machine Shop Valve Tappet)

The Raw Tappet produced in foundry is sent to machine shop for its further

machining in-order to get the desired shape, size & surface finish. Here different

machining operations are performed sequentially on different machines. The

Nomoco pre- grinding & Cincinnati machine is used for pre-grinding of valve

tappet, the Diskus machine is used for face grinding, 6-spindle turning (Index

machine) is used for turning operations on the tappet & Lapping machine is used

for lapping operation to provide high surface finish. In this machine shop heat

treatment, nitriding, phosphating and washing is also done for the valve tappet.

HEAT TREATMENT (STRESS

RELIEVING ANEALING IF REQUIRED)

FINAL INSPECTION

(ENDOSCOPY, ULTRASONIC

TESTING)

DESPATCH FOR MACHINING OR TO

CUSTOMER IN AS CAST CONDITION

PROCESS FLOW CHART FOR VALVE TAPPET

NITRIDED TAPPET

LAPPING

CRACK TEST

FINAL GRINDING

NITRIDING

INSPECTION

OIL & PACKING

DISPATCH

NON NITRIDED TAPPET

OIL & PACKING

LAPPING

INSPECTION

CRACK TEST

FINAL GRINDING

DISPATCH

HEAT TREATED TAPPET

HEAT TREATMENT

TEMPERING

CRACK TEST

LAPPING

FINAL GRINDING

INSPECTION

PHOSPHATING

PACKING

FINAL INSPECTION

RAW TAPPET

NOMOCO PRE GRINDING M/C

DISKUS M/C

HARDNESS TEST

6-SPINDLE TURNING M/C

Processes Involved In MSVT

Centre less grinding-Centerless grinding is a form of grinding where there is no collet or pair of centers holding the object in place. Instead, there is a

regulating wheel positioned on the opposite side of the object to the grinding

wheel. A work rest keeps the object at the appropriate height but has no

bearing on its rotary speed. The workblade is angled slightly towards the

regulating wheel, with the workpiece centreline above the centerlines of the

regulating and grinding wheel; this means that high spots do not tend to

generate corresponding opposite low spots, and hence the roundness of parts

can be improved. Centerless grinding is much easier to combine with

automatic loading procedures than centered grinding; through feed grinding,

where the regulating wheel is held at a slight angle to the part so that there is

a force feeding the part through the grinder is particularly efficient.

Regulating wheel provides the axial movement to workpiece, both wheels

are having same sense of rotation.

1. Pre-Grinding Process- This process is done in order to remove 1-3 mm material from the given workpiece. The basic purpose of this process is to

remove maximum possible amount of material with in customer

specification. After pre grinding process workpiece is allowed to get its final

finished dimensions by final grinding machines which remove materials in

range of microns.

o Grade of a wheel is defined as a measure of bond strength& it ranges from soft to hard. Soft wheels are used for low material removal rate & grinding

of hard materials, while hard wheels are used for high material removal rate

& grinding of soft materials.

o Feeding motions of workpart can be of 3 types:

1. Traverse feed (Feed motion is parallel to axis of rotation).

2. Plunge Feed (Grinding wheel is fed radially into workpiece).

3. Combination Of both (Grinding wheel is fed at 45deg. & simultaneously

grind cylindrical part of surface).

There are two types of pre grinding machines- A) Tappet Cylindrical Pre-grinding.

Specification of tappet cylindrical pre-grinding machine-

Type of machine- Horizontal through two pass machine

Product process Product/process/Tool specification

Cylindrical tappet type Rough process (Depth of cut- 0.25mm)

Regulating wheel(2 wheel)

Grinding wheel(2 wheel)

300*100*127 ROS 192*40 Grade- A8ORR

Semi-finished process (Depth of cut- 0.17mm)

Regulating wheel(1 wheel)

Grinding wheel(3 wheel)

355*254*152.4 Grade- A8ORR

Dressing Grinding wheel

Regulating wheel

Multi point diamond dresser. Grade- D224047100071754 Frequency- 5000pieces Single point diamond dresser Grade- AAA CLASS 10*35MM/EW2 STUBER Frequency- 15000 pieces.

b) Mushroom Tappet Pre-grinding.

Specification of mushroom tappet pre-grinding machine-

Type of machine- plunger type grinding

Product Process Product/process/Tool specification

Mushroom tappet type Center less process (Depth of cut- 0.5mm) (Cycle time-15 sec) (Machining time-9sec)

Regulating wheel(2 wheel) (speed-17.8 rpm)

Grinding wheel(2 wheel) (speed-

350*60*203ROS260*20 Grade- A80Z1V25/A80RR 400*(60/70)*203ROS260*20 Grade-DA803L5V223/45

Dressing(automatic) Grinding wheel

(Dressing time-2.35min)

Regulating wheel

Blade type diamond dresser. Grade- 1HFAS90-38 Frequency- 45pieces Single point diamond dresser Grade- AAA CLASS 10*35MM/EW2 STUBER Frequency- pieces.

1. DISKUS Chill Face Grinding

Specification of Chill face pre-grinding machine- In this process , the face of

tappet that is head is finished by removing material from range of mm to

microns depends on need.

Before Diskus Operation (chill face) After Diskus Operation (chill face)

Hardness testing process-

It is performed to check the hardness of the mushroom tappet head /cylindrical tappet surface.

2 test points are selected which are 120degree apart.

Load of 150kg is applied on the work piece.

Range of hardness lies from 35HRC to 65HRC (depends upon type of tappet).

Type of machine- DISKUS face grinding machine

Product Process Product/process/Tool specification

Mushroom /Cylindrical tappet

(Depth of cut- 0.45mm) (Cycle time-2.4 sec)

(Machining time-2.4*WIP sec)

Rotating wheel(1 wheel) (speed-1.33 rpm)

Diskus fixture wheel(1 wheel) (speed-27000rpm)

o Grinding segment (Tool ) (no. of segment- 16)

Work holding wheel Cast iron Tool holding device 104/68*75*102 Grade-SG36-2818VS3

Dressing(automatic) Grinding wheel

(Dressing time- ?min)

Cluster type D12 dresser. Frequency- 2min

Diamond indenter is used for test.

Cycle time-10sec.

4. 6- Spindle Turning

a. In this process 6 operations are performed & 6 tools tappets are operated at a

time.

b. This machine is based on Geneva Indexing mechanism.

c. Operations Performed are:

1. Turning: It is the process of removing extra material from workpiece to

generate cylindrical surface.

2. Boring: It is used for enlarging a hole produced by drilling, casting etc.

3. Drilling: It is the process of producing cylindrical hole with the help of drill

bit.

4. Chamfering: It is the operation of beveling the extreme end of a workpiece to

remove burs.

MVT- Mushroom

valve tappet

CVT- Cylindrical

valve tappet

Parameters Specifications MVT CVT

Spindle RPM 600-700 485-540 Cutting Oil ILOCUT 1253 ILOCUT

1253 Total Cycle Time

10.5-12.5sec. 20-22sec.

Indexing Time 2sec. 2sec. Turning Time 8.5-10.5sec. 18-20 sec.

HARDENING-

Hardening is a metallurgical and metalworking process used to increase the

hardness of a metal. The hardness of a metal is directly proportional to the uniaxial

yield stress at the location of the imposed strain. A harder metal will have a higher

resistance to plastic deformation than a less hard.

Hardening is achieved by following process-

HEAT TREATMENT- It is the heating and cooling of metals to change their physical

and mechanical properties, without letting it change its shape. Heat treatment

could be said to be a method for strengthening materials but could also be used

to alter some mechanical properties such as improving formability, machining,

etc.

Need of Heat Treatment: 1. To releive internal stresses attained after hot & cold

working.

2.To improve hardness.

3.To refine grain size.

4. To improve material magnetic & electrical properties.

5. Reduction in brittleness, resistance to shock & fatigue.

Furnace temperature-920degree centigrade.

Nitrogen is used to create inert atmosphere i.e. to prevent oxidation at such a high temperature.

Flow rate (N2)- 1000nl/Hr , Pressure- 2-3bar.

Cycle time- 13sec.(2product at a time).

Process time- 18min.

Pre heating is done to remove dirt or oil particles from surface of workpiece.

Oil quenching is performed where oil is maintained at 50-60 degree temperature.

Heat exchanger is installed to maintain quenching oil temperature.

ILO quenching oil is used.

Hardness level of 60-65 HRC is achieved by the process.

Process Flow Of Heat Treatment

Tempering- Tempering involves heating steel that has been quenched and hardened for an adequate period

of time so that the metal can be equilibrated. The hardness and strength obtained depend upon

the temperature at which tempering is carried out. Higher temperatures will result into high

ductility, but low strength and hardness. Low tempering temperatures will produce low ductility,

but high strength and hardness. In practice, appropriate tempering temperatures are selected

that will produce the desired level of hardness and strength. This operation is performed on all

carbon steels that have been hardened, in order to reduce their brittleness, so that they can be

used effectively in desired applications.

Furnace temperature from 180-190 degree centigrade(depends on type of tappet).

Tempering is followed by hardening in order to increase toughness and ductility at the

cost of hardness and brittleness.

Capacity-400kg.

Soaking time- 2Hr.

Ambient Cooling is done.

washing with Gardoclean NC 9809

N2 Gas supply in high temp. furnace(980-

1200ltr./hr.)

Quenching in ILO castrol oil upto 50-60

deg.C temp.

Stress relieving- Stress relieving is applied to both ferrous and non-ferrous alloys and is intended to remove

internal residual stresses generated by prior manufacturing processes such as machining, cold

rolling and welding. Without it, subsequent processing may give rise to unacceptable distortion

and/or the material can suffer from service problems such as stress corrosion cracking. The

treatment is not intended to produce significant changes in material structures or mechanical

properties, and is therefore normally restricted to relatively low temperatures.

Furnace temperature from 570, 610 degree centigrade (depends on type of tappet).

Stress relieving is followed by either casting or machining according to requirement in

order to increase machinability and removing residual casting stresses.

Capacity-400 kg

Soaking time- 2-3 Hrs.

Up to 350 degree centigrade cooling is done inside furnace then Ambient Cooling is

done.

Nitriding-

It is one of hardening process that diffuses nitrogen into the surface of a metal to create a case-hardened surface. These processes are most commonly used on low-carbon, low-alloy steels. However, they are also used on medium and high-carbon steels, titanium, aluminum and molybdenum. Recently, nitriding was used to generate unique duplex microstructure (Martensite-Austenite, Austenite-ferrite), known to be associated with strongly enhanced mechanical properties Typical applications include gears, crankshafts, camshafts, cam followers, valve parts, extruder screws, die-casting tools, forging dies, extrusion dies, firearm components, injectors and plastic-mold tools.

Gas nitriding- In gas nitriding the donor is a nitrogen rich gas, usually ammonia (NH3),

which is why it is sometimes known as ammonia nitriding. When ammonia comes into

contact with the heated work piece it disassociates into nitrogen and hydrogen. The

nitrogen then diffuses onto the surface of the material creating a nitride layer. The

thickness and phase constitution of the resulting nitriding layers can be selected and the

process optimized for the particular properties required.

Specification of gas nitriding- Gas composition- N2(40%)+NH3(50%)+CO2(10%)

Two tanks are used-

1. Tank A- Furnace tank.

2. Tank B- Cooling tank

In furnace tank temperature is maintained at 580 degree centigrade.

Nitriding layer (Fe4N) of thickness 8-12 micron is achieved.

After nitriding layer steam is passed through same tank in order to achieve oxidation

layer of thickness 1.5 micron which works as lubricating layer during start of engine.

Holding time- 4 Hours.

Capacity of furnace- 400kg.

Flow rate-

a) N2 (during heating)= 1800 to 2200Lt/Hr.

b) N2 (during holding)= 1300 to 1700Lt/Hr.

c) NH3 = 1300 to 1700Lt/Hr.

d) CO2 = 200 to 400Lt/Hr.

Steam pressure- 1 to 6bar.

Lapping and Chamfering process- It is final chill face grinding process in which we provide convex profile on tappet head in order

to increase its life cycle and chamfering is done in order to provide proper stress distribution.

Cycle time-4 to 8 sec.

Cutting oil-Macron 295 F5.

Lapping roughing wheel-

a) Size- 110*60*94mm / 194*82*175mm.

b) Grade-AA7A 80 H9V3703/AA7A 100 HO 370.

c) Length-15mm.

Lapping finishing wheel-

a) Size- 110*60*94mm / 194*82*175mm.

b) Grade-4A400 N5 BA YOY03/01-EKR-350-LBK.

c) Length-15mm.

Chamfering Wheel-

a) Size- 18.5*26*8 mm.

b) Grade- AA 5021.

c) Length-10 mm.

Convexity 0+0.008.

Chamfer on chill face- 0.4+0.2/-0.0 * 45 degree.

Surface roughness-Ra 0.07

Crack Testing-

As the tappets are subjected to high wear during their opearation. It is not tolerable

to have even a hint of crack on specially chill face to ensure that it may lead to a

major failure.For this, surface of tappets are carefully observed for cracks .In this

process crack which are developed during any of the surface operations are

examined in UV rays by passing it through a particular solution ,so that powder

present in solution gets stuck into the cracks .

Magnetisation of Tappet

(Generation of north-south pole)

Passing through oil+ Magnaflux

fluoroscent powder solution

Identification of cracks in UV Rays.

This method uses UV blacklights for use in conjunction with fluorescent dye penetrants and magnetic particles for highlighting defects in metals and ceramics.

Examples include; hairline cracks in aircraft landing gear, automotive steering systems and many other safety critical components on which our lives may depend.

Defects literally jump out at the inspector due to the dramatic contrast between the bright glowing image of a defect against a dull background

Steps to perform:-

1. Magnetizing the tappet up to min. 3 gauss.

2. Magnetized tappets are to be passed through the test oil mixed with powder.

3. Check the tappets for cracks and foundry defects under the ultra violet light generated

by UV lamp in the dark room.

4. Pass the tappet through demagnetizer to reduce intensity up to 1 gauss.

5. Gauze meter is used to check if the tappet is demagnetized or not.

Ultra Violet lamp intensity- 1500micro watt/cm2.

Test oil- 16gm uniflux powder mixed in make ferro chem. Oil.

Phosphating Phosphate coatings are a crystalline conversion coating that is formed on a ferrous metal

substrate. Phosphate coating is employed for the purpose of pretreatment prior to coating or

painting, increasing corrosion protection and improving friction properties of sliding

components. In other instances, phosphate coatings are applied to threaded parts and top

coated with oil (P&O) to add anti-galling and rust inhibiting characteristics.

Process is carried in seven separate tanks-

1) Tank 1- Perform degreasing process.

a) Solution used-water (150 lit.) + gardoclean 4 chemical (750 gm).

b) Working temperature-75-80 degree centigrade.

c) Holding time- 5-6 min.

2) Tank 2- Water rinsing (soft water).

a) Solution used-water

Visual Inspection

under UV rays.

A VOCATIONAL TRAINING REPORT ON

PROCESS INVOLVED IN PRODUCTION OF VALVE TAPPET

At

MAHLE ENGINE COMPONENTS INDIA PVT.LTD.PITHAMPUR

SESSION- 2014-2015

SUBMITTED TO- SUBMITTED BY-

Mr.Pramendra Dhebena Aakar Gangrade

(Manager M.S.V.T ) Apurv Gupta

(5thsem. Medicaps Institute of

Tech. & Mgmt. Indore )

b) Holding time- 1-2 min.

3) Tank 3- Surface conditioning.

a) Solution used- water (150 lit.) + pyrolite VMA (450 gm) or

pyrolite VMC (450 gm) depends on type of tappet.

b) Working temperature- 45-49 degree centigrade.

c) Holding time- 2-6 min.

4) Tank 4- Phosphating.

a) Solution used- water (150 lit.) +gardobond-30 9.5 lit. by

volume+ steel wool to provide iron upto 4-6 %.

b) Working temperature- 96 to 99 degree centigrade.

5) Tank 5- Water rinsing.

a) Holding time-1-2 min.

6) Tank 6- Dewatering.

a) Solution used- gardorol DW- 36.

b) Holding time-1-2 min.

7) Tank 7-Antirust coating.

a) Solution used- Fuchs anticorit 6120/42e.

b) Holding time- 1-2 min.

PHOSPATING TANK

Primary+secondary

washing

Gardoclean-104

Surface

conditioning+

water rinsing soft

water.

Surface Conditioning

Gardolene

(VMA+VMC)

Phosphating

Gardobond-30 steel

wool+ water rinsing.

Project work-

SLIDE 1-

Conclusion :-Trial lot should be pre-grind 0.1 mm under size ( i.e. 38.00 -0.15/-0.25 ) against Specification of Nomoco pre grinding Process. ( Within Customer

Specification )

36% Head Diameter over size found after Heat Treatment Process with Existing Nomoco Pre grinding Specification ( 2840 Nos over size out off 7706 Nos )

Specification at

Pre Grinding

Before Heat

Treatment Head

Diameter Size

Observed

After Heat

Treatment Head

Diameter Size

Observed

Expansion

Observed after

Heat Treatment

38.00 -05/-0.150 37.78 to 37.83 37.11 to 38.23 Max 0.42 mm

Customer Spec 38.00 0.250 ( VT 8003 ISBe ) Result- Following are the dimensions achieved-

Heat Treatment Process thermal expansion-

NOTE- Data regarding above observation is attached here.

MAHLE Engine Components India Pvt. Ltd. Dept. Quality Assurance & Systems2

Valve Tappets -Head Diameter Over Size

AugTotal 2013

Problem Description : Head Diameter Over Size ( Specification : 38 0.25 mm )36% Head Diameter over size found after Heat Treatment Process with Existing

Nomoco Pre grinding Specification . 38.00 -0.05/-0.15

( 2840 Nos over size out off 7706 Nos )

Model: Valve Tappet 8003 IS

Possible Cause Identified :

Head Diameter Ground oversize at pre- Grinding Operation .

Expansion of Head Diameter after Heat Treatment Process.

Gather Data & Corrective Action :

Pre Grinding Process Study :- Inspect one Dressing Cycle Component 100

Nos , Dressing frequency-50. Status :-Done

Heat Treatment Process Study :- Check 500 Tappets before & after Heat

Treatment Process . Status :- Done.

Valve Tappets - Head Diameter Over Size

Corrective Actions-(a)Study of nomoco pre-grinding process.


In Min-32.84 Max-32.87

Out Min-32.84 Max-32.87

Variation 0.03 0.03

Conclusion

As per above observations variation(0.03mm) of the process is only 6% of tolerance under customer specification that is 0.5mm.

As per standard norms the variation should be less than 10% for process to be correct.

Hence no corrections are required in nomoco pre grinding process.

NOTE- Data regarding above observation is attached.

Corrective Actions : (b) Heat Treatment Process Study

Specification at

Pre Grinding

Before Heat

Treatment Head

Diameter Size

Observed

After Heat

Treatment Head

Diameter Size

Observed

Expansion

Observed after

Heat Treatment

38.00 -05/-0.150 37.78 to 37.84 37.87 to 38.24 Max 0.42 mm


Conclusion :- We have taken Trial Batch Qty 500 Tappets.

This tappets Head Diameter grind at Cincinnati Pre Grinding m/c because of Grinding wheel not available at Nomoco pre Grd. m/c .

Trial lot grind 0.05 mm under size ( i.e. 38.00 -0.2/-0.3 ) against Specification of Nomoco pre grinding Process. ( Within Customer Specification )

3.68% Head Diameter over size found after Heat Treatment Process with Existing Nomoco Pre grinding Specification ( 18 Nos over size out off 500 Nos )

NOTE- Data regarding above observation is attached.

Documents

Summer Training Report Mahle