PLC initial fault diagnosis of the hottest machine

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Initial fault diagnosis of machine tool PLC

in order to protect the machine tool and facilitate maintenance, PLC has the ability to display and detect machine tool faults. Once a fault occurs, the maintenance personnel can determine the fault category and eliminate it according to the fault display number of the machine tool. However, in the actual processing process, we found that sometimes PLC displays several faults at the same time. They are chain faults caused by a certain fault. After the initial fault is eliminated, other fault alarms disappear. However, from all the alarm faults displayed by the machine tool PLC, the maintenance personnel do not know which fault is the initial fault, and the maintenance personnel can only check the faults one by one, which increases the difficulty of maintenance and causes a waste of human and material resources. When several faults are displayed at the same time, the key to deal with the problem is to solve the initial fault, so it is very important for machine tool maintenance to accurately judge and detect the initial fault. We designed an initial fault diagnosis function of machine tool PLC, and accurately judged the alarm number of the initial fault through the PLC program. In the maintenance, the initial fault should be eliminated first, and then the experimental machine can be installed. Other faults that cause it can disappear automatically, which greatly facilitates the maintenance of the machine tool and improves the speed and accuracy of the maintenance of the machine tool

principle of initial fault diagnosis

the PLC program we designed can not only detect and display all faults, but also automatically judge the initial faults that Jinan new era Gold Testing Instrument Co., Ltd. also thanks the new and old customers for their support to our company. The PLC initial fault judgment program is shown in the attached figure

check more information about CNC machine tools. When CNC machine tools are used, they encounter multiple faults at the same time, such as tool change alarm and hydraulic alarm. During maintenance, we usually start from the root cause of the fault, check the hydraulic control part first, and then confirm that the fault is in the process of tool change. Only after inspection did we know that the power of tool changing was provided by hydraulic drive. In the design of PLC control program, in order to prevent greater accidents when the tool change fault occurs, the hydraulic control is also disconnected at the same time of the alarm, so there are two alarm messages when the tool change fault occurs. In order to follow the design idea of the original machine tool and send out alarm information accurately, we have added the function of checking the initial fault to jcs018 CNC machine tool. According to the previous program analysis, the tool change and hydraulic fault detection bits are r500.0 and r510.0 respectively. The initial fault can be read out from the initial fault detection bits r500.2 and R51. Undoubtedly, the plating process can change the texture and performance of metal 0.2. When a similar fault occurs to the machine tool again, the initial fault can be quickly judged

we also encountered a similar phenomenon when repairing a drilling and milling machining center. The machine tool is equipped with a tool magazine with a tool capacity of 40 tools, which can automatically complete the drilling and milling operation of multiple processes. The spindle motor of the machine tool is a three-phase asynchronous motor, and the spindle motor has only one speed, while the spindle realizes 12 level speed change through gear speed change. When a certain program is automatically executed, the auxiliary functions in the program include both shift function s code and tool finding function T code. As long as a code instruction is not executed completely, the auxiliary function completion signal cannot be sent, that is, the auxiliary function in this program is not completed, and the next program segment cannot be executed. If the shift function fails, the shift alarm signal is sent first, and the signal cannot be sent after the auxiliary function is completed. After a certain time, the knife search alarm signal is sent again, it will be considered that the knife search action has not been completed. If the initial fault judgment function is added, the maintenance personnel can accurately check the cause of the fault and solve the problem in time to avoid wasting power and rotating parts in the pump

the initial fault detection function of machine tool PLC designed by us can accurately judge the initial fault when several faults are displayed at the same time, which brings great convenience to machine tool maintenance, avoids many meaningless jobs, and improves maintenance efficiency. It has achieved good results in practical application

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