Reliability Analysis Of MDH80Machining Center

Machining centers are very important equipment in production lines. With the development of our country, machining centers will be used in more industrial area. The quality of machining centers can reflect the comprehensive manufacture level of one country. Because domestic machining centers have too high failure rate, the users of domestic machining centers have to pay more time to repair them and the production efficiency will be reduced. This phenomenon makes domestic machining center manufacturers lose much market share. So improving the reliability level of domestic machining centers can enhance the market competitiveness and brand value of Chinese machine.This research is supported by national science and technology major project. Failure data were collected from16sets domestic MDH80machining centers in one diesel engine body and head production line. In this paper, failure data are analyzed and suggestions to improve the reliability level of machining centers are given. The main contents are as follows:(1) The feature of domestic MDH80machining center is introduced. And the MDH80machining center is divided into ten subsystems based on each subsystem’s function. The ways to collect failure data is introduced. The failure frequency and mean maintenance time of each subsystem are analyzed. This analysis is the basic step to deal with failure data.(2) All failure modes happened in domestic MDH80machining center are analyzed. And these failure modes are classified into different types. The effects of failure modes are analyzed. By criticality analysis method, the criticality of all failure modes and subsystems are calculated. And the weak segments of machining center are found. The result of FMECA can be used in establishing maintenance strategy.(3) The method to establish fault trees of subsystems in MDH80machining center is summarized. After establishing and analyzing fault trees of subsystems, the main reasons of subsystems’failures are found. The measures to solve failures and risk of subsystems are given.(4) The criteria for reliability allocation are given. The reliability block diagram of MDH80machining center is established. An effective allocation method is used to allocate reliability requirement of new machining center into subsystems. This research can be used in design stage to improve the reliability level of machining centers. In this paper, two ways are given to improve the reliability level of domestic MDH80machining center. One is to find reasons of failures and solve them, and the other one is to improve design scheme. The result of this paper can be used in production line.