Fault Diagnoses Technology Study Based On HNC-21 CNC Experiment Platform

The CNC machine tool has an important position in modern manufacturing because of its high-efficiency, high-quality, good-flexibility and so on. The CNC machine tools which continuou working for a long time will fial, that will affect the normal production and cause huge economic losses to the enterprise. So the maintenance of CNC machine tools becomes very important. As the market share of CNC machine tools in China market increasing every year, the demand of the high skilled personnel who can repair the CNC machine tool is also increasing. The traditional way of training the high skilled personnel in a company can not meet the market demand. While the higher vocational education also can not train the skilled personnel who can meet the market demands because of lack of the failure diagnosis and maintenance equipment which can do teaching, testing and examining. So, the establishment of a test platform of machine fault diagnosis and maintenance based on numerical control system development becomes particularly important. This is also the main purpose of this paper, in order to meet the demand of market on highly skilled CNC maintenance personnel training requirements, the test platform of fault diagnosis and maintenance is built.In this paper, the demands of highly skilled personnel of the numerical control maintenance in today's society and the current situation of training the highly skilled professionals in higher vocational colleges are analyzed. For Huazhong Numerical Control System having an increasing share in the higher vocational colleges and enterprises and its character of openness and so on, the test platform of fault diagnosis and maintenance based on HNC-21 CNC is proposed.This paper emphatically discussed the elementary knowledge of numerical control system failure diagnosis,studied the causation and the way of diagnosis and the elimination of failure. The HNC-21 numerical control system I/O address assignment, Ladder installation, backup, modification, save and procedure automatic production method is discussed. Through modifying the PLC ladder, how to analyze and eliminate the fault such as emergency stop, positive feed axis overtravel, non-stop turret rotation on the the test platform of NC machine tool failure diagnosis and repair faults are discussed. Finally the application example of PLC in the NC machine tool failure diagnosis and maintenance is introduced and the assumption of building remote fault diagnosis platform is proposed.Finally, the continuous long working will make the transmission parts of CNC machine tools worn, that will affect the machining precision of parts. The method and steps of eliminating the gap between the transmission parts by using pitch error compensation method.In this paper, besides studying and resreaching in theory, it also conducted a specific implementation. The test platform of NC machine tool failure diagnosis and maintenance is great significance for training the CNC high-skilled talents in higher vocational institutions.