Punch Processing Technology

The punch plays a very important role in the mold. Its design shape, dimensional accuracy and material hardness directly affect the blanking quality, service life and accuracy of the stamping parts. In actual production and processing, due to the residual stress deformation inside the workpiece blank and the thermal stress deformation caused by discharge, the threading hole should be processed first for closed cutting, and deformation caused by open cutting should be avoided as much as possible. If closed cutting cannot be performed due to the size of the workpiece blank, for square blanks, attention should be paid to selecting the cutting route (or cutting direction) when programming. The cutting route should be conducive to ensuring that the workpiece is always kept in the same coordinate system with the fixture (clamping support frame) during the processing process to avoid the influence of stress deformation. The fixture is fixed at the left end, and the cutting is performed in a counterclockwise direction from the left side of the gourd-shaped punch. The entire blank is divided into left and right parts according to the cutting route. As the material connecting the left and right sides of the blank is cut smaller and smaller, the right side of the blank gradually separates from the fixture, and cannot resist the internal residual stress and deforms, and the workpiece is also deformed. If the cutting is done in a clockwise direction, the workpiece is left on the left side of the blank, close to the clamping part. Most of the cutting process keeps the workpiece and the fixture in the same coordinate system, with good rigidity, avoiding stress deformation. In general, a reasonable cutting route should arrange the cutting section where the workpiece is separated from the clamping part at the end of the total cutting program, that is, the pause point (support part) is left near the clamping end of the blank.
The medium-speed wire cutting machine is suitable for processing various complex-shaped dies and single-piece gears, splines, and sharp-angle narrow slit parts. It has the advantages of fast speed and short cycle, and its application is very popular. The electrode wire of the high-speed wire cutting machine is mainly molybdenum wire. The electrode wire movement speed is usually 8~12 mm/s, and it is a two-way reciprocating cycle. It is easy to break the wire during the processing. If the wire breaks several times during the cutting process of the workpiece, it will not only cause certain economic losses, but also bring the trouble of rewinding the wire; it will not only delay time, but also produce wire break marks on the workpiece, affecting the processing quality, and seriously causing the workpiece to be scrapped.