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Requirements Of CNC Machining Center For Feed Motion

The feed motion of CNC machine tools is the direct object of digital control. Whether point control or contour control, the final dimensional accuracy (accuracy) and contour accuracy of the workpiece are affected by the transmission accuracy, sensitivity and stability of the feed motion (explanation: stable Stability; no change). To this end, the feed system of CNC machining tools should pay full attention to reducing friction resistance, improving transmission accuracy and rigidity, eliminating transmission gaps, and reducing inertia of moving parts.

1. Reduce frictional resistance

In order to improve the rapid response performance and motion accuracy (accuracy) of the feed system of CNC machine tools (attribute: automatic machine tools), the friction resistance of moving parts and the difference between dynamic and static friction forces must be reduced. CNC machining is a process method for parts processing on CNC machine tools. The process specifications of CNC machine tool processing and traditional machine tool processing are generally the same, but obvious changes have also occurred. Mechanical processing method that uses digital information to control parts and tool displacements. It is an effective way to solve the problems of parts variety, small batch size, complex shape, high precision, etc., and to achieve efficient and automated processing. CNC machining CNC is also known as computer gong, CNCCH or CNC machine tool. It is actually a name from Hong Kong, which greatly reduces the number of tooling. CNC machining of parts with complex shapes does not require complicated tooling. CNC machining is a new type of processing technology and the main work It is to compile the processing program, that is, to convert the original manual to computer programming. If you want to change the shape and size of the part, you only need to modify the part processing program, which is suitable for new product development and modification. To meet the above requirements, ball screw nut pairs, static pressure screw nut pairs, rolling guide rails (TTW guide), static pressure guide rails and plastics (structure: Synthetic resin, plasticizer, stable (explanation: stable and stable; no changes), colorants) guide rail. While reducing frictional resistance, it must also be considered that the transmission components must have appropriate damping to ensure the stability of the system.

2. Improve transmission accuracy (precision) and rigidity

The transmission accuracy (precision) and rigidity of the feed drive system are mainly determined by the mechanical structure from the perspective of the transmission clearance and the accuracy and rigidity of the screw nut pair, worm gear pair (when circumferential feed) and its supporting structure. In numerical control processing, the control system sends out instructions to make the cutter perform various movements that meet the requirements, and expresses the processing of technical requirements and processing requirements such as the shape and size of the workpiece in the form of numbers and letters. It generally refers to the process of processing parts on CNC machine tools. In order to improve production automation, shorten programming time and reduce CNC machining costs, a series of advanced CNC machining technologies have also been developed and used in the aerospace industry. The transmission gap mainly comes from the transmission gear pair, the worm gear pair, the screw nut pair and its supporting parts, and the preload should be applied or measures to eliminate the gap (pointer to the problem). Shortening the transmission chain and setting reduction gears in the transmission chain can also improve the transmission accuracy. Increasing the diameter of the screw and applying preload to the screw nut pair, supporting parts, and the screw itself are effective measures to improve the transmission rigidity. Insufficient rigidity can also cause crawling and vibration of the workbench (or carriage).

3. Reduce the inertia of moving parts

The inertia of moving parts has an effect on the starting and braking characteristics of the servo mechanism, especially the parts that are running at high speed, the influence of the inertia is greater. Therefore, on the premise of satisfying the strength and rigidity of the parts, the mass of the moving parts and the diameter and mass of the rotating parts are reduced as much as possible to reduce the inertia of the moving parts.

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