Common problems and solutions in grinding of centerless grinder

What is centerless grinding?

Centerless grinding is a kind of grinding processing. There are two grinding wheels: a regulating wheel and acenterless grinding wheel. The regulating wheel drives the cylindrical workpiece to rotate on the cushion iron, and the grinding wheel grinds the workpiece.

Centerless grinding wheel with large feed and excellent workpiece support are helpful to increase the margin removal rate and achieve high productivity.

With centerless cylindrical grinding, the workpiece does not need to be clamped at both ends, but is located in the grinding gap formed by the grinding wheel, regulating wheel and workpiece bracket. The workpiece bracket uses the CNC height adjustment function to minimize the changing time, while the grinding process is optimized by automatically adjusting the grinding clearance geometry. In addition, the tilt bed design also ensures maximum dimensional accuracy.

Centerless grinding machine is a kind of grinding machine that does not need to use the axis grinding of workpiece. It is composed of cneterless grinding wheel, regulating wheel and bracket. Common grinding defects of centerless grinding machine are as follows:

The reasons for parts not being round include:

1. The introduction does not fix the circle.Should rebuild guide wheel, wait for introduction to repair circle and stop.

2. The ellipse of the original workpiece is too large, the tool size is small, and the grinding times are not enough. Grinding times should be appropriately increased.

3. The grinding wheel is blunt. Reset the grinding wheel.

4. Too much grinding or too much cutting. Reduce grinding and cutting speed.

Part polygons occur for the following reasons:

1. The part center is not high enough.The center of the forward parts should be accurate.

2. The axial thrust of the parts is too large, which causes the parts to press the block pin tightly, resulting in the uneven rotation. Reduce the grinder introduction tilt Angle to 0.5 degrees or 0.25 degrees.

3. The grinding wheel is unbalanced. Grinding wheel to be balanced.

4. The part center is too high. Lower the center height of the part properly.

The reasons for the vibration marks on the surface of parts are as follows:

1.machine tool vibration caused by unbalanced grinding wheel. The grinding wheel should be balanced.

2. the advance of the part center makes the workpiece jump. The workpiece center should be lowered appropriately.

3. the grinding wheel is blunt or the surface of the grinding wheel is too smooth. Only the grinding wheel or increase the dressing speed of the grinding wheel.

4. if the rotation speed of the adjustment wheel is too fast, the selection speed of the adjustment wheel should be reduced appropriately.

The workpiece has a taper:

1. If the grinding wheel dressing is not correct, it will have taper.

2.the surface of grinding wheel and regulating wheel has been worn. Replacement of non – wear regulating wheel or grinding wheel is available.

3. the tilt Angle of the front and rear guide plates is too large or too small. The front guide plate should be moved into the guide plate properly and adjusted to be parallel to the guide wheel bus. The guide surface of the adjusted policy is parallel to the regulating wheel bus and in a line.

The reason why the workpiece center is large and the two ends are small:

1.The front and rear guide plates tilt evenly to one side of the grinding wheel. Elimination method: the front and rear guide plates should be adjusted.

2. dressing the grinding wheel into a waist drum shape. Elimination method: the grinding wheel should be modified. The allowance for each modification should not be too large.

Cause of grinding a small piece off the front end of the workpiece:

1. The front guide plate is protruding from the surface of the guide wheel. The front guide plate should be moved back a bit.

2. the front end face of the adjustment wheel and the grinding wheel is not in the same line, and the difference is too big. The longest of the two should be replaced or modified.

3. excessive grinding at the grinding entrance.The amount of grinding at the grinding entrance should be reduced appropriately.

The cause of insufficient surface finish of the workpiece:

1. The tilting Angle of the guide wheel is too large, which makes the workpiece go too fast. The tilt Angle should be reduced appropriately.

2. Grinding wheel modification speed is too high, and the surface dressing of grinding wheel is not bright. The dressing speed should be reduced and the grinding wheel should be modified again.

3. The regulating wheel is too thick. The regulating wheel should be rebuilt.