indexing jigs and fixture

7/28/2019 indexing jigs and fixture

1/36

INDEXING JIGS ANDFIXTURES OF ROD GUIDE

BUSHBy

KRISHNA KUMAR S.R 31009114036

PRAVEEN KUMAR P 31009114047

GUIDE : MR. A.KUMARAVEL


2/36

WHAT IS JIGS AND

FIXTURES ? JIGS ARE PROVIDED WITH TOOL GUIDING

ELEMENTS WHICH DIRECT THE TOOL TO THE

CORRECT POSITION.

FIXTURES HOLD THE WORK PIECE SECURELY

IN THE CORRECT POSITION WITH RESPECT TO

THE MACHINE/CUTTER OPERATION.


3/36

WHAT IS INDEXING ? INDEXING IS THE PROCESS OF QUICK,

ACCURATE LOCATION OF A WORK PIECE OR

FIXTURE IN A NUMBER OF SPECIFIC

POSITIONS

IT INVOLVES PERIODIC LINEAR OR ROTARYMOVEMENT OF THE INDEXED PART TO THE

NEXT POSITION.


4/36

WHERE ROD GUIDE

BUSH IS USED ?

ROD GUIDE BUSH IS USED IN SHOCK ABSORBER

WHERE THE OIL FLOWS FROM ONE END TO

OTHER THROUGH A TAPER DRILL WHICH IS VERY

ESSENTIAL AND HAS TO BE VERY ACCURATE.


5/36

ROD GUIDE BUSH


6/36

MANDREL


7/36

JIG


8/36

INDEXING PIN


9/36

ANGLE PLATE


10/36

COMPRESSION SPRING


11/36

INDEXING JIGS AND FIXTURE


12/36

MATERIALS USED

MILD STEEL:[C 0.2% Mn 1.65%, Cu 0.6% Si 0.6%]

IT IS THE CHEAPEST AND MOST WIDELY USED

MATERIAL IN JIGS AND FIXTURE.

EN 24 STEEL: [C 0.40% Si 0.25% Mn 0.55%Ni 1.50% Cr 1.20%

Mo 0.30% S 0.05% P 0.05%]

IT IS A POPULAR GRADE DUE TO ITS EXCELLENT

MACHINABILITY & CAN BE FURTHER SURFACE

HARDENED TO ENHANCE WEAR RESISTANCE.


13/36

OHNS STEEL (OIL HARDENEDNON-SHRINKING STEEL)

COMPOSITION

C: 0.95, Mn: 1.15, Cr :0.5, W:0.5, V:0.2

IT IS WIDELY USED FOR MANUFACTURING

DIFFERENT TOOLS FOR MACHINING


14/36

MANUAL VICE


15/36

TRADITIONAL

METHOD THE INDUSTRY USED MANUAL VICE INSTEAD

OF JIGS AND FIXTURES

THE MANUAL VICE HELPS HOLDING THE

WORK PIECE AND DESIRED ANGLE CAN BE

ADJUSTED AND DRILL CAN BE MADE WHICH IS

A SLOW PROCESS.


16/36

DISADVANTAGES OF

MANUAL VICE

LESS PRODUCTIVITY

SKILLED LABOUR REQUIRED

MASS PRODUCTION IS NOT POSSIBLE

HIGH COST


17/36

COMPONENTS OF JIGS ANDFIXTURES

MANDREL


18/36

COMPONENTS OF JIGS ANDFIXTURES

ANGLE PLATE


19/36

INDEXING JIGS AND

FIXTURES

HERE WE USE ROTARY INDEXING WHICH

FACILITATES ACCURATE POSITIONING OF APART AROUND ITS AXIS.

IT CAN BE USED CONVENIENTLY FOR

DRILLING EQUI-SPACED HOLES IN ROUND

WORK PIECES.


20/36

INDEXING JIGS ANDFIXTURES OF ROD GUIDE

BUSH


21/36

WORKING1. THE COMPONENT(ROD GUIDE BUSH)

CLAMPED TIGHTLY IN THE MANDREL.

2. THE INDEXING PIN IS PULLED OUT AND THE

COMPONENT IS ROTATED EITHER

CLOCKWISE OR ANTICLOCKWISE UNTIL IT

GETS LOCKED IN THE HOLE PROVIDED IN

THE MANDREL.


22/36

WORKING CONT..

3. ONCE THE ROD GUIDE BUSH IS LOCKED IN ITS

POSITION THE DRILL IS MADE THROUGH THE JIG.

4. AFTER DRILLING THE FIRST HOLE , THE WORKPIECE IS

ROTATED IN THE SAME DIRECTION AND THE PROCEDURE

IS REPEATED.


23/36

FISH BONE DIAGRAM


24/36

TIME CALCULATION FOR OURFIXTURE

PROCESS TIME IN SEC

Holds the rod guide bush in the fixture = 4

Tightening the work piece = 3

Locating the drill using indexing pin = 3

Drilling the 1st hole = 12

Locating the drill = 4

Drilling the 2nd hole = 12


Drilling the 3rd hole = 12


Drilling the last hole = 12

Remove the workpiece = 3

TOTAL = 64

T C C T O O


25/36

TIME CALCULATION FOR MANUALVICE

PROCESS TIME IN SEC

Holds the rod guide bush in the fixture = 4

Tightening the work piece = 3

Set to 0deg = 8

Setting the centering bit = 6

Making the centering operation = 8

Removing the centering tool = 6

Setting the drill bit = 6

Making the Drilling operation = 12

Removing the drill tool = 6

Set to 90deg = 8





26/36

CONT..Setting the drill bit = 6



Set to 180deg = 8




lSetting the drill bit = 6



Set to 360deg = 8





27/36

CONT..

Setting the drill bit = 6



Inspecting = 6

Remove the workpiece = 3

TOTAL = 236

SPRING DESIGN


28/36

SPRING DESIGNCALCULATION

Load, P = (Gyd4)/ (8nD3)

= (100.81051.24) / (81237)

=17.14 N

Stiffness , q = load/deflection

= 17.14/10

= 1.714 N/mm

Solid length, LS = n d

=7 1.2

= 8.4 mm

Free length, LF = n d + ymax + 0.15ymax

= 8.4 + 20 + 0.15(20)

=31.4 mm


29/36

Pitch, p = [ (Lf Ls) / n ] + d

= [ (31.4 8.4) / 7 ] +1.2

= 4.48 mm

Torque, Mt = P R

=P (D/2)

=17.14 (12/2)

=102.84 N/mm

Mt = / 16 s 1.23

Shear stress, s = 303.10 N/mm2

Shear stress concentration factor Ks = 1 + (1/2C)

= 1+ [1 / (210)]

= 1.05


30/36

Transverse shear stress , s = load / area of wire

= P / [( /4) d2]

= (4 17.14) / ( 1.22)

=15.15 N/mm2

Resultant shear stress, = s + s

=303.10 + 15.15

= 318.2 N/mm2

The safe shear stress for high carbon steel is 480 N/mm2

so the design is safe


31/36

TIME FOR DRILLING

Time for drilling = (length of drill time)

(feedR.P.M)

= (2060)/(0.042500)

Time for drilling = 12 sec

COST ESTIMATION FOR


32/36

COST ESTIMATION FOROUR METHOD

Total cost = prime cost + overhead cost + selling

and distribution cost

= 71.61 + 14.32 + 4.29

= Rs.90.22

Profit = selling price - total cost

= 110 - 90.22

= Rs.19.78

COST ESTIMATION FOR


33/36

COST ESTIMATION FORMANUAL VICE

Total cost = prime cost + overhead cost + selling anddistribution cost

= 80.61 + 16.32 + 4.86

= Rs.101.77

PROFIT = selling price - total cost

= 110 - 101.77

= Rs.8.44


34/36

PRODUCTION RATE

MANUAL VICE :

TIME FOR 1 COMPONENT=4MIN

NO. OF COMPONENTS

PRODUCED FOR ONE HOUR=60/4

=15NO. OF COMPONENTS

PRODUCED FOR HOUR=15X8

=120


35/36

OUR METHOD

TIME FOR 1 COMPONENT=1MIN

NO. OF COMPONENTS

PRODUCED FOR ONE HOUR=60/1

=60

NO. OF COMPONENTS

PRODUCED FOR HOUR =60X8

=480


36/36

ADVANTAGES1. HIGH PRODUCTIVITY

2. SKILL REDUCTION

3. COST REDUCTION

4. LESS CYCLE TIME

indexing jigs and fixture

Documents

Transcript of indexing jigs and fixture