Horizontal Force
The horizontal force by which the component jams into the
die opening or by which the pierced component clinges on to the
punch is generally either ignored or underestimated by the tool
designer.
Near to the lower end of the strokes, when the punch penetrates
into the stock, the stock exerts force around the punch. The
force exerted by the stock pressed into the die opening
is naturally slightly different. After the fracture, depending
upon the feature of fracture (either proper clearance or narrow
clearance was applied) and in the stage of push through the forces
act on the punch will naturally lower than in the stage of penetration. In the
absence of available results of experiments , we may suppose, the
variation in the horizontal force is proportional to that of
vertical force
Effects of horizontal force on the Punch & Die
- Friction at the end of downward stroke between the stock
and the die parts. - Wear both an the side of punch and in the die opening.
- Friction when the punch is lifted up during its upstroke
(known as stripping force). - Friction as the jammed component or slug is removed known as
push through force or otherwise termed as ejecting force. - Change in the dimensions of the component ie., swelling of
blanked component and shrinking of pierced hole after
discharging. - Horizontal load on die plate or splits and on inserts, which
tends to shift these component horizontally. - Unbalanced load on punches which does not cut all around
(notching punches, cropping punches, blanking punches which
shear in an earlier partially cut opening).
