Punching machine with controlled punch and die positioning and controlled punch operating stroke

A punching machine, comprising a for an exchangeable die, a supporting face for sheet-type material to be worked, and a punch holder, for an exchangeable punch interacting with the die, the punch holder to be driven at right angles to said supporting face under the influence of a first control device, further comprising:

• a second control device for adjusting the die holder in height relative to the supporting face;
• a first measuring device for producing a first data signal representing the height of the die to be used;
• a second measuring device for producing a second data signal representing the height of the punch to be used;
• a device for producing a third data signal representing the thickness of the material to be worked;
• a data processing device to which the three data signals are fed and comprising first means for producing a first control signal in response to said data signals to be fed to said first control device for controlling the punch holder such that at the end of the operating stroke thereof the end of the punch lines at a predetermined distance below the top surface of the material to be worked, and second means for producing a second control signal in response to said data signals to be fed to the second control device for taking the top surface of the die into a predetermined height setting relative to the supporting face prior to the operating stroke of the punch.