The centerless grinding machine is a kind of grinding machine that does not need to use the axial grinding of the workpiece. It is composed of three mechanisms: the grinding wheel, the guide wheel, and the bracket. There are centerless grinding defects as follows:

1. The reasons for the non-round parts are:

• The guide wheel does not dress round. The guide wheel should be rebuilt until it is round.
• The ellipticity of the original workpiece is too large, and the amount of feed is small, and the grinding time is not enough. Should increase the grinding times.
• The grinding wheel is blunt and is re-dressed.
• The grinding stock and the amount of feed is too large. Reduce the grinding stock and the feeding speed.

 

2. The reasons for part polygons are:

• The axial thrust of the part is too large, which making the part pressed against the pin and the rotation cannot be even. Reduce the inclination angle of the guide wheel to 5° or 0.25°.
• The grinding wheel is not balanced. Should balance the grinding wheel.
• The center of the part is too high. It is good to reduce the height of the center of the part properly.

3. The reasons for the vibration marks on the surface of the parts are:

• The imbalance of the grinding wheel causes the machine to vibrate. The grinding wheel should be balanced.
• The center of the workpiece should be lowered appropriately.
• The grinding wheel is blunt or the surface of the grinding wheel is dressed too much light. Just increase the grinding wheel dressing speed.
• If the adjustment wheel rotates too fast, should reduce the adjustment wheel speed appropriately.

 

4. The workpiece has tapered.

• The grinding wheel is not dressed correctly and it has the taper.
• The surface of the grinding wheel and the guide wheel are worn. Replace the wear-free guide wheel or grinding wheel.
• The inclination angle of the front and rear guides is too large or small.　

5. The reasons for the large center and the small head of the workpiece.

• The front and rear guides are evenly inclined to one side of the grinding wheel. Elimination method: adjust the front and rear guides.
• The grinding wheel is dressed into the waist drum shape. Elimination method: modify the grinding wheel, and the amount of each modification should not be too large.

 

6. The reasons for a small piece on the front end of the workpiece ground out

• The front guide protrudes from the surface of the guide wheel, and the front guide should be moved backward a little.
• The adjustment wheel and the front end of the grinding wheel are not in a straight line and the difference is too large. Replace or modify the longest of the two.
• Grinding too much at the grinding inlet. Reduce the grinding stock at the grinding inlet appropriately.

 

Conclusion of centerless grinding defects:

There are centerless grinding wheels with different materials, such as diamond and CBN centerless grinding wheels, or silicon carbide centerless grinding wheels. In the process of actual processing, there are different centerless grinding defects. Need to continuously summarize the experience in the practice process and find the right solutions.