Research on Slider Pair of Rolling Guide of Machine Tool in Machining Center
The rolling guide has the advantages of high guiding precision, good wear resistance, high rigidity and excellent friction characteristics, and is widely used in machining center machine tools. By studying the development and characteristics of rolling guides, it provides a theoretical basis for the students of secondary vocational schools to study the course design of CNC machine tools, enriches the experimental design content of the course, and lays a solid foundation for the development of high-precision feed mechanisms. Through the calculation of the life of the rolling guide by the first-stage feed, the various factors affecting the life of the guide rail are analyzed and analyzed, and the reference data for the future research of the rolling guide is provided.
The development of the rolling guide of the machining center can be basically divided into four stages. The first stage mainly realizes the excellent characteristics of the rolling guide and can smoothly and unblock the linear guiding motion. In the second stage, due to the new requirements for its installation and use, people began to study the bearing belt cage, the rolling guide pair that does not leak the ball. In the third stage, the application of the rolling guide rail in the rapid field above 35 m/min is gradually increased. When the high-speed motion is reciprocating, the friction and collision between the balls are eliminated, and low noise is realized. In the fourth stage, due to the rapid application of the rolling guide on the heavy-duty, high-precision, high-speed machining center machine tool, the rigidity and bearing capacity of the ball as the circulation body could not be satisfied, and the roller type heavy-duty guide rail was born. It inherits the advantages of the former and truly meets the requirements of the machining center machine tool pair.
The machining center machine has higher requirements on the rolling guide. Firstly, the guiding precision is better. The geometrical accuracy of the rolling guide directly affects the guiding precision of the moving parts. Therefore, in the inspection standard specified by the rolling guide, the straightness of the guide rail and the parallelism of the contact surfaces of the two guide rails are both There are clear regulations. One of the main factors affecting the accuracy is the manufacturing precision, the assembly quality of the rolling guide, and the rigidity and deformation of the rolling guide and its support.
Secondly, the wear resistance of the rolling guide rail is good, and the long-term movement of the moving contact rail surface along the fixed rail surface will cause uneven rolling of the rolling guide rail, thereby destroying the motion guiding precision of the rolling guide rail until the machining precision is affected. The wear resistance of the rolling guide directly affects the machining accuracy of the machine tool. The wear resistance of the rolling guide is the key to the design and manufacture. It is also an important indicator to measure the quality of the machining center. It improves the wear resistance of the rolling guide of the machining center. It is also critical that the small rolling guides wear unevenly and allow for automatic compensation or adjustment after uneven wear.
The rigidity of the re-machining center rolling guide is better. The rolling guide will be deformed after being subjected to an external force, which will affect the relative position between the moving parts and the guiding precision of the moving parts. Therefore, the machining center rolling guide should have good rigidity. The deformation of the rolling guide of the machining center mainly depends on the form of the rolling guide, the size of the rolling guide and the connection mode and force of the rolling guide with the support.
Finally, the friction characteristics of the rolling guide are excellent, the moving parts are easy to crawl when moving at a low speed, and the crawling during the feeding movement will increase the roughness of the surface to be machined, and the crawling during the positioning movement will lower the positioning accuracy. Therefore, it is required that the rolling guide of the machining center should be very stable at low speed. In addition, the friction coefficient of the rolling guide is small to reduce the frictional resistance and the thermal deformation of the rolling guide itself.
The rolling guide of the machining center is mainly composed of a rolling guide block and a linear rolling guide. The rolling guide block of the machining center generally adopts a circulating cylindrical roller, which cooperates with the guide rail of the machine bed, and has the advantage that it is not limited by the stroke length. The rigidity is relatively high.
