Causes

In terms of the machine tool:

Machine tool vibration: Components such as the spindle and motor of the machine tool may generate vibration during operation. This vibration is transmitted to the workpiece and the grinding wheel, which will lead to the appearance of waviness on the surface of the workpiece. For example, wear of the spindle bearing, imbalance of the motor, etc. may all trigger vibration.

Insufficient accuracy of the guide rails: The guide rails are key components for the movement of the machine tool. If the accuracy of the straightness, parallelism, etc. of the guide rails does not meet the standards, the grinding wheel or the workpiece will move irregularly during the movement process, thus forming waviness on the surface of the workpiece.

In terms of the grinding wheel:

Grinding wheel imbalance: There may be an uneven mass distribution in the manufacturing or installation process of the grinding wheel, causing the grinding wheel to generate a centrifugal force during high-speed rotation, which leads to vibration and, in turn, causes waviness on the surface of the workpiece.

Uneven wear of the grinding wheel: After long-term use, the local wear of the grinding wheel may be relatively severe, making the cutting ability of the surface of the grinding wheel inconsistent, and it is likely to generate waviness during the grinding process.

In terms of the workpiece:

Loose clamping of the workpiece: If the workpiece is not firmly clamped during the grinding process, it will displace or vibrate under the action of the grinding force, resulting in the appearance of waviness on the surface.

Uneven material of the workpiece: The uneven hardness, structure, etc. inside the workpiece will make the resistance that the grinding wheel encounters during grinding inconsistent, thus affecting the smoothness of the grinding and generating waviness.

In terms of the grinding parameters:

Inappropriate grinding speed: Both too high and too low grinding speeds may lead to the appearance of waviness on the surface of the workpiece. When the speed is too high, the frictional force and impact force between the grinding wheel and the workpiece increase, and it is easy to cause vibration; when the speed is too low, the grinding process will not be smooth.

Excessive feed rate: If the feed rate is too large, the cutting force of the grinding wheel on the workpiece will also increase, which may cause waviness on the surface of the workpiece.

Solutions

In terms of the machine tool:

Carry out machine tool maintenance and debugging: Regularly check and maintain components such as the spindle and motor of the machine tool, replace the worn bearings in a timely manner, and perform dynamic balance correction on the motor to reduce the vibration of the machine tool. At the same time, adjust the accuracy of the guide rails of the machine tool to make it meet the requirements.

Add shock absorption measures: Shock absorption pads can be installed on the foundation of the machine tool, or vibration isolation devices can be used to reduce the impact of external vibration on the machine tool.

In terms of the grinding wheel:

Balance the grinding wheel: After installing the grinding wheel, use tools such as a balance stand or an electronic balancer to adjust the balance of the grinding wheel to ensure the stability of the grinding wheel during rotation.

Dress the grinding wheel in a timely manner: Dress the grinding wheel regularly to remove the unevenly worn parts and restore the flatness and sharpness of the surface of the grinding wheel.

In terms of the workpiece:

Improve the workpiece clamping method: According to the shape and size of the workpiece, select an appropriate clamping method to ensure that the workpiece is firmly clamped. For example, for slender shaft workpieces, a center rest or a follower rest can be used for auxiliary support.

Pre-treat the workpiece: For workpieces with uneven materials, appropriate pre-treatment, such as heat treatment, etc., can be carried out to improve the uniformity of their internal structure and hardness.

In terms of the grinding parameters:

Optimize the grinding speed: Select an appropriate grinding speed according to factors such as the workpiece material and the characteristics of the grinding wheel. Generally speaking, the optimal grinding speed can be determined through tests and adjustments.

Adjust the feed rate: Appropriately reduce the feed rate to make the grinding process smoother. However, it should be noted that if the feed rate is too small, the machining efficiency will be reduced, and a balance needs to be found between the two.