Hem Punches
Below, we can see a sample Hem punch DXF drawing. To the left, we have the side view profile of the tool. To the right, we have any ear tools that are required for this tool. We can specify the number of ear tools by putting a multiplier value inside the drawing. In this example, we can see that it is 2x. An origin reference point will need to be placed at the mounting point on the side profile of the tool.
The punch has a flat surface that can be used for flattening a bend on top of a seaming die.
The following text entities are required for a Hem punch:
NAME – This is the name given for the tool.
TONNAGE – This is the tonnage of the tool in kN.
UPPER – This is the upper punch 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=HemPunch – This text is required to mark this as a hemming punch tool.
PARAMS= 1,12.15,70 – This text entry provides some metrics that are required for correct simulation. See below for the PARAMS explanation.
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 Pointed.
PARAMS Explanation
There are three parameters required to define the hemming process. These can be seen as the A, B and C values in the image above.
A – The first (1mm in this example) defines how far behind the bending line the flat vertical face of the punch is.
B – The second parameter (12.15mm here) defines how far ahead of the bending line the hemming tip is.
C – The final parameter (70mm here) is the vertical distance from the punch tip to the hemming tip point.
