SHANK: -
Shank is an element of the press tool which acts as connecting link from tool to the press platen and also locates the centre of gravity the tool which aid the tool cutting elements.
Five ways of mounting the shank:-
1.By Riveting
2.By Press fitting
3.By means of threading
4.By making it as integral part of top plate
5.By making flange fastening
Shank is an element of the press tool which acts as connecting link from tool to the press platen and also locates the centre of gravity the tool which aid the tool cutting elements.
Five ways of mounting the shank:-
1.By Riveting
2.By Press fitting
3.By means of threading
4.By making it as integral part of top plate
5.By making flange fastening
1. By Riveting
2.By Press fitting
3.By threading
4.By integral part of top plate
5.By flange fastening
Self aligning type shank:-
The shank permits quick loading and unloading of the press tool on a press. The design of the shank is different from the other types. A TEE coupling mechanism is made in two sections. The Half mounted on the tool is the male member. The half fixed to the press ram is the female member. They are case hardened.
Location of a Shank on a Tool:-
Balancing of the punches is the most important aspect during punching operation.
Un balanced force on the tool may lead to undue wear on punch and die as well as pillars.
The resultant forces of all cutting forces acting on many punches should pass through the shank centre.
The position of the resultant forces of all partially cutting forces can be found by the following methods
By Mathematical calculation.
By Polygon system(Graphical)
By Mathematical calculation:-
shank point location can be found by calculating the X and Y co-ordinates for the point. The formulae used for the calculation are.
X = (l1x1)+l(2x2)+(l3x3)……….+(ln xn)
l1+l2+l3……………….,,,,,+ln
l1+l2+l3……………….,,,,,+ln
Y = (l1y1)+l(2y2)+(l3y3)……….+(ln yn)
l1+l2+l3……………….,,,,,+ln
l1+l2+l3……………….,,,,,+ln
Example :-
The die layout for manufacturing the component is given herewith reference axis. To find the center-point of shank location, proceed by taking X and Y coordinates for each of the section as given below (in the table).
Reference edges for X and Y axis are to be taken from the sides of die plate or from the side of the punch holder.
This is because the position of punches and die are available on these two plates and center axis of punch and die will be same as these two plates. The data pitch 32 is provided to fix "Y" values of each section in the die from the reference edge.
X axis
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Y axis
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Sl. No.
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L x X product
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Sl. No.
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L x X product
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01
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22 x 25 = 550
|
01
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22 x 110 = 2222
|
02
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10 x 30 = 300
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02
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10x 112 = 1120
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03
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12.56 x 37.9 = 476.02
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03
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12.56 x 117.09 = 1470.65
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04
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10 x 48 = 480
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04
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10 x 120 = 120
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05
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11.31 x 57 = 644.67
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05
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11.31 x 116 = 1131.96
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06
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20 x 61 = 1220
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06
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20 x 100 = 2000
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07
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26 x 48 = 1248
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07
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26 x 90 = 2340
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08
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15.71 x 30 = 471.3
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08
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15.71 x 86.815 = 1363.86
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09
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25.136 x 43 = 1080.84
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09
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25.136 x 48 = 1206.52
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10
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15.71 x 30 = 471.3
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10
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15.71 x 26 = 408.46
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By Polygon system(Graphical):-
The centre point of shank location can be determined by graphical method which is also known as polygon system. To construct the polygon force diagram the sequential steps given here have to be followed.
1 Draw the cutting forces to a scale in a straight line on x and y axis at right angle.
2 Draw the arrow heads at the ending points of each force as shown in Fig.9.
3 Draw two more lines at 45° angle from starting and finishing points of the total length of the forces so as to form an isosceles triangle and call the intersecting point as "pole centre".
4 Draw the lines from each arrow head to join the pole point and call them as pole beams.
5 Draw the forces to scale at given distance.
6 Draw the lines parallel to the pole beams, cutting force line graphically as shown in Fig. A
7 The line of action of the resultant goes through that point where those two pole beams intersect.
COMMENTS