Crawling mainly occurs on the executive parts of the transmission system when running at low speed. Generally speaking, it is not easy to be detected when the crawling degree is slight, and obvious crawling will appear as a large distance jump. Creeping fault can be caused by many reasons, so it is difficult to eliminate it.
1、 Hazard analysis of creeping failure of machine tool
When the machine tool crawls, the guide rail moves unevenly, which reduces the positioning accuracy and sensitivity, which will seriously affect the surface processing quality of the workpiece, and even lead to the scrap of the machined parts; In addition, it will also cause accelerated wear of machine tool moving pairs; When the creeping is serious, the machine tool will lose its processing capacity. Many experts, scholars and colleagues in industry have put forward some hypotheses to explain the reasons for crawling through a large number of experiments and practical experience, but they have different theories about the essence and mechanism of crawling.
For this kind of mechanical processing equipment integrating machine, electricity, hydraulics and other advanced technologies, the factors causing crawling are very complex and comprehensive. Problems in any link of machine, electricity and hydraulics may cause machine tool crawling. How to eliminate crawling faults in actual working conditions has a great relationship with the use and maintenance of machine tools, It is very typical that the metal chips pull the guide rail of the motion pair and the quality of the hydraulic oil, which is the cause of the creeping failure of the machine tool.
2、 Cause analysis of creeping failure of machine tool
When designing and manufacturing machine tools, the rigidity of its transmission mechanism and the bearing capacity of the workbench guide rail can meet the use requirements. In actual work, we mainly consider the factors that are uncontrollable or difficult to control by manpower, which are mainly reflected in the accuracy of the machine tool guide rail pair and the static pressure system.
The poor maintenance of the machine tool during use, such as the damage of the scraping plate, which makes the metal chips directly enter between the two guide rail surfaces, or the hydraulic oil impurities are not filtered completely, is easy to cause the guide rail surface to be strained, and the surface accuracy of the guide rail after wear is not enough. Under the low-speed movement state, the friction increases and the driving force is insufficient, so that the workbench cannot maintain a stable operation and then crawling failure occurs.