Piercing method with heating

A piercing method for use with a processor and for driving a columnar shaped punch in an axial direction to pierce a hole in a workpiece, the workpiece including:

• (i) a lasering surface, and (ii) a punching surface that a front end of the punch hits, the method comprising successive steps of:
• a local heating step of locally heating the lasering surface of the workpiece in a temperature range that is less than a melting point of the workpiece using a laser generator by emitting a laser beam from the laser generator, the laser beam directly striking the lasering surface of the workpiece;
• an output step of outputting a control signal from the processor to a punch drive that initiates driving of the punch in an axial direction towards the punching surface of the workpiece;
• a laser generator stopping step of stopping the emission of the laser beam by the laser generator such that the laser beam no longer strikes the lasering surface of the workpiece before the punch contacts the punching surface of the workpiece;
• and
• a stamping step of stamping the workpiece by the punch during the driving of the punch such that the punch contacts the punching surface of the workpiece and pierces the hole in the workpiece, the laser generator being positioned during the stamping step such that a central axis of a path on which the laser beam is projectable therefrom is coaxial with a central axis of the punch, wherein
• the processor performs a step of monitoring an elapsed time from a start of the emission of the laser beam such that the workpiece starts to be stamped by the punch after the laser generator stops emission of the laser beam and the laser beam no longer strikes the lasering surface of the workpiece.