Intelligent Braking System

INTELLIGENT BRAKING SYSTEM

LITERATURE REVIEW

DESIGN

1. Electronic Speed RegulatorMotor is an commutator motor ie, the current to motor is supplied to motor by means of carbon brushes . The power input to motor is varied by changing the current supply to these brushes by the electronic speed variator, thereby the speed is also is changes.

2. Electronic relayThe electronic relay is mounted on the sheet metal panel on the base frame. The electronic relay is connected to the proximity sensor and the motor input circuit. The function of the electronic relay is to cut off power supply when the proximity sensor is operated.

3. Electronic Proximity sensorThe electronic proximity sensor is mounted on the sheet metal panel on the base frame by means of an Z shaped clamp. The proximity sensor as the name suggests senses the proximity of the indexer buttons which acts as stops, such that when they come in front of the proximity sensor the table the relay is operated to stop the table motion. The proximity sensor is connected to the electronic relay and the power source.

4. Inching switchThe inching switch is connected between the electronic relay and the proximity sensor , this switch when operated by-passes the proximity sensor , thereby operating the motor momentarily as long it is kept pressed.

DESIGN METHODOLOGY

DESIGN OF MULTI AXIS WELDING POSITIONER :-

In our attempt to design a special purpose machine we have adopted a very a very careful approach, the total design work has been divided into two parts mainly;

System design Mechanical design

System design mainly concerns with the various physical constraints and ergonomics, space requirements, arrangement of various components on the main frame of machine no of controls position of these controls ease of maintenance scope of further improvement; height of m/c from ground etc.

In Mechanical design the components are categoriesed in two parts.

Design parts Parts to be purchased.

For design parts detail design is done and dimensions thus obtained are compared to next highest dimension which are readily available in market this simplifies the assembly as well as post production servicing work.

The various tolerances on work pieces are specified in the manufacturing drawings. The process charts are prepared & passed on to the manufacturing stage .The parts are to be purchased directly are specified &selected from standard catalogues.

System Design:-

In system design we mainly concentrate on the following parameter

1.System selection based on physical constraints:-

While selecting any m/c it must be checked whether it is going to be used in large scale or small scale industry In our case it is to be used in small scale industry So space is a major constrain .The system is to be very compact. The mechanical design has direct norms with the system design hence the foremost job is to control the physical parameters.

2. Arrangement of various components:-

Keeping into view the space restriction the components should be laid such that their easy removal or servicing is possible moreover every component should be easily seen & none should be hidden every possible space is utilized in component arrangement.

3. Components of system:-

As already stated system should be compact enough so that it can be accommodated at a corner of a room. All the moving parts should be well closed & compact A compact system gives a better look & structure.

Following are some example of this section

Design of machine height Energy expenditure in hand operation Lighting condition of m/c

8. Chances of failure:-

The losses incurred by owner in case of failure of a component are important criteria of design. Factor of safety while doing the mechanical design is kept high so that there are less chances of failure. Periodic maintenance is required to keep the m/c trouble free.

9. Servicing facility:-

The layout of components should be such that easy servicing is possible especially those components which required frequent servicing can be easily dismantled.

10. Height of m/c from ground:-

Fore ease and comfort of operator the height of m/c should be properly decided so that he may not get tired during operation .The m/c should be slightly higher than that the level also enough clearance be provided from ground for cleaning purpose.

11. Weight of machine:-

The total wt of m/c depends upon the selection of material components as well as dimension of components. A higher weighted m/c is difficult for transportation & in case of major break down it becomes difficult to repair.

MOTOR SELECTION

Thus selecting a motor of the following specifications

Single phase AC motor

Commutator motor

TEFC construction

Power = 1/15hp=60 watt

Speed= 0-6000 rpm (variable)

Motor is an Single phase AC motor , Power 60 watt , Speed is continuously variable from 0 to 6000 rpm. The speed of motor is variated by means of an electronic speed variator . Motor is an commutator motor ie, the current to motor is supplied to motor by means of carbon brushes . The power

input to motor is varied by changing the current supply to these brushes by the electronic speed variator, thereby the speed is also is changes. Motor is foot mounted and is bolted to the motor base plate welded to the base frame of the indexer table

Motor Torque

P= 2 П N T

60

T = 60 x 60

2 П x 6000

T = 0.095 N-m

Power is transmitted from the motor shaft to the input shaft of drive by means of an open belt drive,

Motor pulley diameter = 20 mm

IP _ shaft pulley diameter = 110 mm

Reduction ratio = 5

IP_shaft speed = 6000/5 = 1200 rpm

Torque at IP_shaft = 5 x 0.095 = 0.475 Nm

DESIGN OF OPEN BELT DRIVE

Motor pulley diameter = 20 mm

IP _ shaft pulley diameter = 110 mm

Reduction ratio = 5

Coefficient of friction = 0.23

Maximum allowable tension in belt = 200 N

Center distance = 120

= 180 – sin-1 (D-d)/2C

= 180 – sin-1 (110-20)/2x200

= 1360

= 2.37c

Now ,

eμ/sin(θ/2) = e0.2 x 2.37sin (40/2) = 4

width (b2) at base is given by

b2 = 6-2(4 tan 20) = 3.1

Area of cross section of belt = ½{6 + 3.1}x 4

A = 18.2 mm2

Now mass of belt /m length = 0.23 kg/m

V = ПDN/(60 x 1000) = 4.188m/sec

Tc = m V2

Tc = 4.034 N

T1 = Maximum tension in belt – Tc

T1= 195.966 = 196 N

T1 / T2 = eμ/sin(θ/2) =4

T2 = 49 N

Result Table

Tension in tight side of belt (T1) = 196 N

Tension in slack side of belt (T2) = 49 N

DESIGN OF MAIN SHAFT.

MATERIAL SELECTION : -

Ref :- PSG (1.10 & 1.12) + (1.17)

DESIGNATION ULTIMATE TENSILE

STRENGTH

N/mm2

YEILD STRENGTH

N/mm2

EN 24

800 680

ASME CODE FOR DESIGN OF SHAFT.

Since the loads on most shafts in connected machinery are not constant , it is necessary to make proper allowance for the harmful effects of load fluctuations

According to ASME code permissible values of shear stress may be calculated form various relation.

= 0.18 x 800

= 144 N/mm2

OR

fs max = 0.3 fyt

=0.3 x 680 =204 N/mm

considering minimum of the above values ;

fs max = 144 N/mm2

Shaft is provided with key way; this will reduce its strength. Hence reducing above value of allowable stress by 25%

fs max = 108 N/mm2

This is the allowable value of shear stress that can be induced in the shaft material for safe operation.

TO CALCULATE WORM WHEELSHAFT TORQUE

POWER = 2 NT

60

Motor is 60 watt power, run at 6000 rpm, connected to worm shaft by belt pulley arrangement with reduction ratio 1:5

Hence input to worm gear box = 1200 rpm

The worm gear box is the reduction gear box with 1:38 ratio

Hence input speed at the input shaft = 1200/38 =31.5 =32 rpm (approx)

T = 60 x P

2 x x N

= 60 X 60

2 X X 1200

T = 0.477 N-m

T design = 0.48 N-m

CHECK FOR TORSIONAL SHEAR FAILURE OF SHAFT.

Assuming minimum section diameter on input shaft = 16 mm

d = 16 mm

Td = /16 x fs act x d3

fs act = 16 x Td

x d 3

= 16 x 0.48 x 10 3

x (16) 3

fs act = 0.5963 N/mm2

As fs act < fs all

I/P shaft is safe under torsional load

DESIGN (SELECTION OF WORM SHAFT BALL BRG 6003

In selection of ball bearing the main governing factor is the

system design of the drive ie; the size of the ball bearing is of major importance ;

hence we shall first select an appropriate ball bearing first select an appropriate

ball bearing first taking into consideration convinience of mounting the planetary

pins and then we shall check for the actual life of ball bearing .

BALL BEARING SELECTION.

Series 62

ISI NO Brg Basic

Design No

(SKF)

d D

1

D D2 B Basic

capacity

C kgf Co

Kgf

17A

C03

6003 17 19 35 33 10 4650 2850

P = X Fr + Yfa.

Where ;

P=Equivalent dynamic load ,(N)

X=Radial load constant

Fr= Radial load(H)

Y = Axial load contact

Fa = Axial load (N)

In our case;

Radial load FR= BELT TENSION = 196 + 49 N

P= 245 N

L= (C/p) p

Considering 4000 working hours (SPEED = 1200 RPM)

L = 60 n L h = 288 mrev

106

288 = C

245

C = 1617 N

AS; required dynamic of bearing is less than the rated dynamic

capacity of bearing ;

Bearing is safe.

SELECTION OF PNEUMATIC CYLINDER

Y-Axis translation

Standard cylinder (14167)DNU-40-20-PPV-A.

3

Specifications of Standard cylinder (14167)DNU-25-200-PPV-A.

Criterion Feature

Stroke 25

Piston diameter 16

Piston rod thread M6

Cushioning Pneumatic cushioning, adjustable at both ends (PPV)

Assembly position Any

Conforms to standard ISO 6431

Piston-rod end Male thread

Design structure Piston

Piston rod

Position detection With proximity sensor

Variants Single-ended piston rod

Operating pressure 0.3 - 12 bar

Mode of operation Double-acting

Operating medium Dried compressed air, lubricated or un-lubricated

Corrosion resistance classification CRC

2

Ambient temperature -20 - 80 °C

Authorisation Germanischer Lloyd

Cushioning length 30 mm

Theoretical force at 3 bar, return stroke

30 N

Theoretical force at 3bar, advance stroke

50N

Additional weight per 10 mm stroke

76 g

Basic weight for 0 mm stroke 2662 g

Mounting type With accessories

Pneumatic connection G3/8

Materials information for cover Aluminium

Materials information for seals TPE-U(PU)

Materials information for piston rod

High alloy steel

Materials information for cylinder barrel

Materials information for cylinder barrel

Anodised

Theoretical force at 3 bar when advancing of piston = 50 N

Piston rod threading end = M16 x 1 pitch

Design of piston rod

Material selection:

Ref :- (PSG – 1.12)

Designation Tensile Strength

N/mm2

Yield

Strength

N/mm2

EN9 600 380

Direct Tensile or Compressive stress due to an axial load :-

fc act =

fc act =

fc act = 2.54 N/mm 2

W

50

(/4 ) x 5 2

As fc act < fc all ; Piston rod is safe in compression.

2. Shear stress in threaded end due to axial load :-

fs act =

t = width thread at root = p/2

t= 0.5 mm

W

n dc t

n = No of threads in contact = 12/1 =12

fs act =

fs act = 0.5305 N/mm 2

As ; fs act < fs all , the screw threads are safe in shear.

50

x12x5 x 0.25

Stresses due to buckling of piston rod :-

According to Rankine formula,

Where

Wcr =

Where ; Wcr = Crippling load on screw (N)

A = Area of c/s at root (mm2)

A= constant

Le= Equivalent unsupported length of screw (mm)

decided by end conditions.

K= Radius of gyration = dc/4 (mm)

Fc= Yield stress in compression (N/mm2)

le = 0.707L;as one end of screw are considered to be fixed

and other free(Ref . PSG Design Data Pg. No. 6.8)

Here transverse of the piston is 50 mm, total length of piston rod

=172 mm

le = 0.707 x 72 = 50.94 mm

300 x (/4 x 102)

fc A

Wcr =

1+(1/7500)( 50.94/ (10/4))2

Wcr =23.56x10 3 N

As, The critical load causing buckling is high as compared to

actual compressive load of 0.240 kN the piston rod is safe in

buckling .

PART NAME : INPUT SHAFT

Sr.

No

Description of Operation

Tools Time in minutes

Jigs & Fixture

M/c

Tools

Cutting

Tools

Measuring Instrument

Setting

Time

M/c

Time

Total

Time

1 Clamp stock Three jaw chuck

Lathe - - 20 - 20

2 Facing Both side to total length 242mm

Three jaw chuck

Lathe Facing

tool

Vernier - 5 5

MATERIAL SPECIFICATION : EN24

RAW MATERIAL SIZE: 30X 250

3 Turning OD Ø 21 mm through length

Turning tool

5 10 15

4. StepTurning OD to Ø 17mm through length 197

Centers supports & carrier

Lathe Turning tool

Vernier - 14 14

5. StepTurning OD to Ø 14mm through length187


Lathe Turning tool

Vernier - 8 8



Lathe Turning tool

Vernier - 4 4



Lathe Turning tool

Vernier - 6 6

PART NAME : LH_BRG_HSG

Sr.

No

Description of

Operation


Jigs & Fixture

M/c Cutting Measuring Instrumen

Setting

M/c Total

MATERIAL SPECIFICATION : EN 9

RAWMATERIAL SIZE: 50X50X20

Tools Tools t Time Time Time

1. Clamp stock M/C Vice Milling - - 15 - 15

2. Facing All Sides Sq. to total length 40x12x40mm

--”-- --”-- Facing cutter

Vernier 5 44 49

3. Clamp stock on lathe

4 jaw chuck

Lathe - - 25 25

4. Drilling Ø 18.5 through thickness

--”-- --”-- Twist drill Vernier 15 10 25

5. Boring Ø 28through thickness

--”-- --”-- Boring tool

Vernier 15 10 25

6. Counter Boring Ø 32 through 10 thickness


Vernier 15 10 25

PART NAME : RH_BRG_HSG

Sr.

No

Description of

Operation


Jigs & Fixture

M/c Cutting Measuring Instrumen

Setting

M/c Total

MATERIAL SPECIFICATION : EN 9

RAWMATERIAL SIZE: 50X50X20

Tools Tools t Time Time Time

1. Clamp stock M/C Vice Milling - - 15 - 15

2. Facing All Sides Sq. to total length 40x12x40mm

--”-- --”-- Facing cutter

Vernier 5 44 49

3. Clamp stock on lathe

4 jaw chuck

Lathe - - 25 25

4. Drilling Ø 18.5 through thickness

--”-- --”-- Twist drill Vernier 15 10 25

5. Boring Ø 28through thickness


Vernier 15 10 25

6. Counter Boring Ø 32 through 10 thickness


Vernier 15 10 25

BILL OF MATERIALS:-

SR

NO.

PART CODE DESCRIPTION QTY MATERIAL

1. WK -1 ENGINE 01 STD

2. WK -2 BELT 01 STD

3. WK -3 REDUCTION PULLEY 01 MS

4. WK -4 INPUT SHAFT 01 EN24

5. WK -5 LH_BRG_HOUSING 01 EN9

6. WK -6 DRVER GEAR 01 EN9

7. WK -7 PLANET GEAR 02 EN9

8. WK –8 PLANET GEAR

SHAFT

02 EN24

9. WK –9 PGS_BRG_HSG 02 EN9

10. WK –10 COUPLER SHAFT 02 EN24

11. WK –11 COUPLER CLUTCH 02 EN24

12. WK –12 PLANET CONE 02 EN24

13. WK –13 SPHERICAL BUSH 02 GM

14. WK –14 GM_BUSH HOLDER 02 EN9

15. WK –15 DRIVEN HUB 01 EN24

16. WK –16 OUTPUT SHAFT 01 EN24

17. WK –17 SPRING 01 STD

18. WK –18 SPRING HOLDER 01 EN9

19. WK –19 THRUST BEARING 01 STD

20. WK -20 THRUST BRG

HOLDER

01 EN9

21. WK -21 LOCK NUT-1 01 EN9

22. WK -22 LOCKNUT-2 01 EN9

23. WK -23 RH_BRG_HOUSING 01 EN9

24. WK -24 TRASMISSION RING 01 EN9

MATERIAL PROCUREMENT

Material is procured as per raw material specification and part quantity. Part process planning is done to decide the process of manufacture and appropriate machine for the same.

GENERAL MATERIAL USED

EN24- ALLOY STEEL

EN9- PLAIN CARBON STEEL

MS-MILD STEEL

STD- STANDARD PARTS SELECTED FROM PSG DESIGN DATA/MANUFACTURER CATALOGUE

RAW MATERIAL COST

The total raw material cost as per the individual materials and

their corresponding rates per kg is as follows,

Total raw material cost = Rs4400/-

MACHINING COST

OPERATION RATE

Rs /HR

TOTAL TIME

HRS

TOTAL COST

Rs/-

LATHE 80 30 2400

MILLING 90 18 1620

DRILLING 60 4 240

HOBBING - - 1380

TOTAL 5640

MISCELLANEOUS COSTS

OPERATION COST(Rs)

FABRICATION 200

SAWING 120

TOTAL 320

COST OF PURCHASED PARTS :-

SR

NO.

DESCRIPTION QTY COST

1. ENGINE 01 2450

2. BELT 01 110

3. GRUB SCREW 09 36

4. BEARINGS 10 1400

The cost of purchase parts = Rs 3996

TOTAL COST

TOTAL COST = Raw Material Cost +Machine Cost +

Miscellaneous Cost + cost of Purchased Parts +Overheads

Hence the total cost of machine = Rs 14556/-

BRAKE APPLICATION ---PNEUMATIC ARRNGEMENT

PNEUMATIC ARRANEGEMENT

1. Double acting cylinder : The double acting cylinder IS connected end to end , and cylinder piston rods is clamped to the shifter for the dis-engagement

2. 5/2 way direction control valve : These are lever type (detent) valves that suppy compressed air to the either cylinder. The lever on the respective valve acts as the gear shifting button.

Working

The pneumatic circuit is as shown , the motor is started to drive the main shaft by means of belt and pulley arrangement, initially the gear box is in neutral ie, the output shaft doesnot rotate. When the 5/2 way direction control valve -1 is operated the cylinder -operates the piston to move in the right hand direction thereby bringing the clutch into dis- engagement.

REFFERENCES

1. Mechanisms & Mechanical Linkages – I A Chironis2. Performance Investigations of Novel Rolling Traction CVT

Akehurst S , et al, SAE Technical Paper 20001-01-0874.

3. PSG Design Data4. Design of Machine Elements – V B Bhandari5. Machine Design – R S Khurmi

Documents

Intelligent Braking System