Krishna Kumar Mishra

Nikhil yadav

Rohit Kumar Bind

PROJECT SUPERVISOR: Dr. P.K Mishra

STANDERD FLAT WASHER SIZE

CUTTING FORCEForce required to penetrate the stock material with the punch is the Cutting Force.

F = perimeter*thickness*Shear Strength = pi*D*t*S(for Circular Cross section)= 2(L+B)*t*S (for Rectangular Cross Section)

NOMINAL SIZE

INSIDEDIAMETER(mm)

OUT SIDE DIAMETER(mm)

THICKNESS(mm)

10 10.77 20 2.2

CUTTING FORCE

Alloy’s Shear Strength(Mpa)

PunchingForce(kN)

Blanking Force(kN)

A02010 269.1 20.02 37.178

A02040 175.0 13.02 24.178

A02950 143.65 10.68 19.846

A03280 111.8 8.31 15.446

A03550 134.55 10.01 18.589

Aluminium Alloys:

CUTTING FORCE

ALLOYS SHEAR STRENGTH (MPa)

PUNCHINGFORCE (kN)

BLANKING FORCE (kN)

COLD DRAWN 216.88 16.135 29.964

PHOSPHOROUS DEOXIDIZED

140.25 10.434 19.326

ZR COPPER 288.88 21.486 39.900

BRONZE 172.52 12.835 23.835

RED BRASS 181.03 13.468 25.011

NAVEL BRASS 283.65 21.103 39.189

NI AL BRONZE 453.48 33.738 62.652

Copper Alloys:

STAINLESS STEEL

SEAR STRENGTH(MPa) PUNCHING FORCE(kN) BLANKING FORCE(kN)

450 33.479 62.172

CLEARANCEC= .0032*t*sqrt(S) S : Shear strength of stock material t : Thickness of the strip

CLEARANCE FOR ALUMINIUM ALLOYS

Alloy Clearance

A0201 0.115

A0240 0.093

A02950 0.0843

A03280 0.0744

A03550 0.0816

CLEARANCE FOR COPPER ALLOYS

ALLOYS CLEAREANCE (mm)

COLD DRAWN 0.103

PHOSPHOROUS DEOXIDIZED 0.083

ZR COPPER 0.119

BRONZE 0.092

RED BRASS 0.094

NAVEL BRASS 0.118

NI AL BRONZE 0.150

DESIGN OF PIERCING PUNCH:

WASHER MATERIAL : STAINLESS STEEL

ISO7089 ; Nominal size - 10

Internal Diameter (mm)

Outer Diameter (mm) Thickness (mm)

10.77 20 2.2

Size of Punch = Max. Diameter = 10.77 mmSize of Die = Max. Diameter + 2c = 11.0686 mm

Punch length :Maximum Permissible free length of circular Punches to be safe against Buckling.

Maximum Length of Punch :L = (pi*d/4)*((E*d)/(S*t))^1/2 ;

Modulus of elasticty = 207 GPa

PUNCH LENGTH =197.178 mm

DESIGN OF PUNCH FOR ALUMINIUM ALLOYS

Alloy Size of Punch(mm) Size of Die(mm)

A02010 10.77 11

A02040 10.77 10.956

A02950 10.77 10.938

A03280 10.77 10.918

A03550 10.77 10.933

DESIGN OF PUNCH FOR COPPER ALLOY

ALLOYS SIZE OF PUNCH (mm) SIZE OF DIE (mm)

COLD DRAWN 10.77 10.976

PHOSPHOROUS DEOXIDIZED

10.77 10.936

ZR COPPER 10.77 10.008

BRONZE 10.77 10.954

RED BRASS 10.77 10.958

NAVEL BRASS 10.77 11.006

NI BRONZE 10.77 11.070

DESIGN FOR BLANKING PUNCH:

Size of Punch = Max. Diameter – 2c = 19.7014 mmSize of Die = Max. Diameter = 20 mm

Aluminium Alloy Size of Punch (mm) Size of die (mm)

A02010 19.77 20

A02040 19.814 20

A02950 19.8314 20

A03280 19.8512 20

A03550 19.8368 20

COPPER ALLOYS SIZE OF PUNCH(mm) SIZE OF DIE (mm)

COLD DRAWN 19.790 20.000

PHOSPHOROUS DEOXIDIZED

19.830 20.000

ZR COPPER 19.762 20.000

BRONZE 19.816 20.000

RED BRASS 19.812 20.000

NAVAL BRASS 19.764 20.000

NI AL BRONZE 19.700 20.000

DIMENSIONS OF STRIPCalculated amount of distance has to be given between blanks and edge of strip to prevent scrap from twisting and wedging between punch and die.

Back Scrap (a)= t + .015d =2.5 mm ; t= thicknessScrap Bridge (b) = t = 2.2 mm d= diameter of blank

MATERIAL UTILISATION

It is defined as Ratio of Area of Blank to be cut to Area of material available.

M= (pi*d^2)/(4(d+b)(d+2a)) ;

STRIPPER PLATE THICKNESS

Stripper Plate Thickness is given as :T = (w/3+16t)/8 w= width of stock

strip t= thickness of

strip

DIE BLOCK THICKNESS

The Die Block is the female half of two mated tools which carries the cutting edges.

Die thickness = 19 mm ,Blank Perimeter <=75Die thickness = 25 mm , Blank Perimeter = 70 mm to 250 mmDie Thickness = 30 mm , Blank Perimeter > 250 mm

ALUMINIUM ALLOYS

StripperForce(kN)

Material utilization

Blank perimeter(mm)

Die Block Thickness(mm)

A02010 3.7178 0.5657 62.8 19

A02040 2.4178 0.5657 62.8 19

A02950 1.984 0.5657 62.8 19

A03280 1.544 0.5657 62.8 19

A03550 1.858 0.5657 62.8 19

STRIPPER FORCE ;MATERIAL UTILIZATION;BLANK PERIMETER;DIE BLOCK THICKNESS:

COPPER ALLOYS Stripper Force (kN)

Materialutilization

Die block Perimeter(mm)

Die blockThickness(mm)

COLD DRAWN 2.996 0.5657 62.800 19

PHOSPHOROUS DEOXIDIZED

1.937 0.5657 62.800 19

ZR COPPER 3.990 0.5657 62.800 19

BRONZE 2.380 0.5657 62.800 19

RED BRASS 2.501 0.5657 62.800 19

NAVEL BRASS 3.918 0.5657 62.800 19

NI AL BRONZE 6.265 0.5657 62.800 19

STRIPPER FORCE ;MATERIAL UTILIZATION;BLANK PERIMETER;DIE BLOCK THICKNESS:

DESIGN OF SPRING

MATERIAL OF SPRING:STAINLESS STEEL

Let no. of springs be 4Maximum force spring can exert (Fs)=(Stripper Force)/(No.of Springs);Wahl facto(K)=1.4;Diameter of wire(d)=K*sqrt((8*Fs*D)/(S*d));Spring Index=D/d=4;Movement of stripper = (t+2) mm;Spring Deflection=(3*movement of stripper);Compressed Length(l)=(1.1*n*d)+D;Free Length(L)=compressed Length +Spring Deflection;

Stripper Force = 6.2172 kNMaximum force spring can exert(Fs)= 2.3314 kNMovement of Stripper = 4.2 mmSpring Deflection = 12.6 mmDiameter of wire = 18 mmDiameter of coil (D) = 72.08 mmCompressed Length(l) = 31.5 cmFree Length = 32.76 cm

Design of Components

Washer Dimension:Internal Diameter : 10.77 mmOutside Diameter : 20 mmThickness : 2.2 mm

PunchingPunch Diameter : 10.77 mmDie Diameter : 11.0686 mm

MATERIAL : AUSTENITIC STAINLESS STEEL

BLANKING

BLANKING PUNCH DIAMETER : 19.7014mmBLANKING DIE DIAMETER : 20.0000mm

SPRING DESIGN

Let No. of spring. = 4Diameter of wire (d) =18 mmDiameter of coil = 72.08mm

STRIPPER PLATE

Stripper plate thickness = 5.233mm

CUTTING FORCE = pi*D*t*S

Blanking force = 62.172mmPunching force = 33.479mm

Thank You