(1) Sort by the probability of failure cause In the process of failure analysis, the most likely fault suspect points should be checked in depth, and then the relatively likely fault suspect points should be checked after elimination. The basis for determining the probability of the cause of the failure is as follows.
a. There is a high probability of failure of components with characteristic information related to the cause of the failure. As shown in Figure E, if the movement of the chuck, tool holder and tailstock sleeve is abnormal during the operation of the MJ-50 CNC lathe, you should first suspect whether the common parts of each branch oil circuit - hydraulic oil, filter, hydraulic pump and public pipeline are smooth.
b. Under the same circumstances, first check the components that have been used for a long time, components with a high load ratio, components that have proved to be of poor quality and prone to failure, and components that are sensitive to hydraulic oil contamination. It is also possible to determine the probability of the cause of the failure according to the relevant statistical conclusions, that is, when the failure occurs, according to the statistical conclusions obtained over many years, the fault point with a large probability value is first checked.
(2) Sort by the difficulty of disassembly and observation In the face of a variety of possible causes of hydraulic failure, in the case that the probability of various fault causes is not clear, the detection order should be set according to the difficulty of disassembling and disassembling hydraulic components, that is, first check the components and environmental factors that are easier to observe or disassemble or easy to disassemble (such as oil, electrical system, cooling water, etc.), and then check the components that are more difficult to disassemble, especially the components with large volume and quality; Check the external factors first, and then check the inside of the component; Relatively simple components are checked first, and then components with more complex structural functions and unclear conditions are checked. As far as the components are concerned, the valve should be checked first, then the pump, and finally the hydraulic cylinder and hydraulic motor.
