CNC punch timely grinding can effectively extend the service life of the mold

2021-04-25

CNC punch timely grinding can effectively extend the service life of the mold

If the workpiece has excessive burrs or abnormal noise during stamping, the mold may be passivated. Check the punch and the lower die, when the edge wear produces an arc with a radius of about 0.10mm, it will be sharpened. Practice has shown that regular micro-grinding rather than wait until the grinding can not be grinding, not only will maintain a good quality of the workpiece, reduce the blanking force, but also can make the mold life more than doubled.

In addition to knowing when the mold is sharpened, it is especially important to master the correct sharpening method. Die grinding procedures are as follows:

1) Use sintered alumina grinding wheel, hardness D ~ J, abrasive grain size 46~60, preferably suitable for high-speed steel grinding wheel.
2) When sharpening, the punch is vertically clamped in the V-groove or fixture of the magnetic chuck of the surface grinder, and the grinding amount is 0.03~0.05mm each time. The grinding is repeated until the punch is sharp, and the maximum grinding amount is generally 0.1~0.3mm.
3) When the grinding force is large or the mold is close to the grinding wheel, adding coolant can prevent the mold from overheating and cracking or annealing. High-quality multi-purpose coolant should be selected according to the manufacturer's requirements.
4) The downward feed of the grinding wheel is 0.03~0.08mm, the transverse feed is 0.13~0.25mm, and the transverse feed rate is 2.5~3.8 m/min.
5) After sharpening, polish the cutting edge with oilstone to remove burrs and grind out rounded corners with a radius of 0.03~0.05mm to prevent the cutting edge from cracking.
6) The punch is demagnetized and sprayed with lubricating oil to prevent rust.