In the field of screw machining, the machining quality of screw grinders directly affects the performance and service life of products. Among them, the generation of vibration patterns and poor surface roughness are common quality problems. This article will explore in depth how to effectively reduce vibration patterns and improve surface roughness on machine tools.

1、 Machine tool self optimization

1. Rigid Enhancement:Screw grinderInsufficient rigidity can easily cause vibration and generate vibration patterns. The overall rigidity can be improved by enhancing the structural design of the bed body, using high-quality cast iron materials, and arranging the internal ribs reasonably. For example, increasing the wall thickness and number of support columns in key areas can effectively resist deformation caused by cutting forces and reduce vibration patterns caused by machine tool shaking.

2. Improvement of spindle accuracy: High precision spindle runs smoothly, which is crucial for reducing vibration patterns. Regularly inspect and maintain the spindle bearings, select appropriate lubrication methods such as grease lubrication or oil air lubrication, and ensure that the bearing clearance is in optimal condition. At the same time, perform dynamic balance correction on the spindle to reduce the amount of imbalance during high-speed rotation and avoid the formation of vibration patterns on the workpiece surface due to spindle vibration transmission.

3. Restoration of guide rail accuracy: The wear of the guide rail will damage the motion accuracy, resulting in unstable movement of the grinding wheel frame and worktable and the generation of vibration patterns. Using high-precision guide rail grinders to repair worn guide rails, or adopting new technologies such as plastic coated guide rails, can improve the wear resistance and motion stability of the guide rails, ensure the relative positional accuracy between the grinding wheel and the workpiece, and help improve surface roughness.

2、 Grinding wheel and process parameter adjustment

1. Grinding wheel selection and dressing: Choose the appropriate grinding wheel according to the material, pitch, and accuracy requirements of the screw. For example, for hard alloy screws, diamond grinding wheels can be used; For ordinary steel screws, aluminum oxide grinding wheels are more commonly used. Regularly adjust the grinding wheel to maintain its sharpness and correct shape. By using a diamond roller dresser and setting the dressing parameters, the abrasive particles on the surface of the grinding wheel are evenly distributed and have good cutting edges, thereby improving grinding efficiency and reducing vibration patterns caused by wheel passivation.

2. Grinding parameter optimization: Reasonably set parameters such as grinding speed, feed rate, and grinding depth. Excessive grinding speed may result in short contact time between the grinding wheel and the workpiece, insufficient grinding, and the generation of vibration patterns; Excessive feed rate and grinding depth will increase cutting force and cause machine tool vibration. The optimal parameter combination is determined through experiments, generally using a smaller grinding depth and moderate feed rate, combined with a higher grinding wheel line speed, which can reduce vibration patterns and improve surface roughness while ensuring processing efficiency.

3、 Fixtures and Fixture Improvements

1. Fixture design optimization: Design a dedicated screw fixture to ensure accurate positioning and reliable clamping of the screw during the grinding process. Using fixtures such as elastic clamps or vacuum suction cups to ensure uniform force distribution on the screw and avoid deformation and vibration caused by local stress concentration. For example, for slender screws, a center frame or a follower frame can be used as auxiliary support to enhance their rigidity and reduce vibration caused by bending deformation.

2. Clamping force control: Excessive clamping force may cause plastic deformation of the screw, affecting machining accuracy and inducing vibration patterns; If the clamping force is too small, it will cause the screw to loosen during the grinding process. Determine the appropriate clamping torque or pressure through experiments to prevent adverse effects caused by excessive clamping while ensuring stable clamping of the screw.

In summary, in order to reduce vibration patterns and improve surface roughness in screw grinding machine processing, comprehensive measures need to be taken from multiple aspects such as the rigidity and precision maintenance of the machine tool itself, the selection and optimization of grinding wheels and process parameters, as well as the fixture and clamping links, in order to achieve high-quality screw grinding processing.