Spring-Loaded Hemming Dies (Feather-Hemming Dies)
Below, we can see a sample Spring-Loaded Hemming (FEV Hem) DXF drawing. An origin reference point will need to be placed at the mounting point on the side profile of the tool.
The upper and lower part of the tool will need to be created on 2 separate layers. This can be seen in the grey and orange colours in the image.
The following text entities are required for a Sash punch:
NAME – This is the name given for the tool.
TONNAGE – This is the tonnage of the tool in kN.
LOWER- This is the lower die valency of the tool.
PIECES – These are the required tool lengths. These are separated by a comma, and if more than one is required, we can use a multiplier to specify the value required.
FLAVOR=SpringHem – This marks the tool as a Spring Hem die.
PARAMS – This text provides some metrics that are required for correct simulation, shown as A, B and C in the image. See the below explanation for more information.
RADIUS – This is the upper die radius used for the tool.
ANGLE – This is the angle of the die to be used.
VWIDTH – This is the width of the die V to be used.
CANFLIP – If the tool can be flipped when mounted, this should be set to 1.
GROUP – This can be used to specify the tool group that this tool would belong to. In this case, it is FEV.
PARAMS Explanation
This die is a two-piece die which has a top part that moves downwards to flatten the hem. Three parameters define the flattening notch.
A – The first parameter is the distance from the centre line of the die for the part during hemming. A +ve value means that it is to the front of the centre line and a -ve value means that it is to the back of the centre line.
B – The second parameter is the location of the flattening notch from the base of the die for the part during hemming.
C – The third parameter is the spring gap which is the height of the notch.
