Diagnosis and maintenance of three external faults

Diagnosis and maintenance of three kinds of external faults of CNC machine tools

diagnosis and maintenance of three kinds of external faults of CNC machine tools:

due to the introduction of the Ministry of modern industry and information technology, the reliability of CNC system is getting higher and higher, the faults of CNC system itself are getting lower and lower, and most of the faults are caused by non system reasons. The external faults of the system mainly refer to the problems caused by the detection switch, hydraulic components, pneumatic components, electrical actuating components, mechanical devices, etc

external faults of CNC equipment can be divided into software faults and hardware faults caused by external hardware damage. Soft faults are caused by improper operation and adjustment. Such faults often occur in the early stage of equipment use or during the adjustment period of equipment users. For the numerical control system, another place that is easy to fail or measure the deformation of the spring under a certain experimental force is the servo unit. Because the movement of each axis is realized by the servo unit controlling the servo motor to drive the ball screw. The rotary encoder is used for speed feedback, and the grating ruler is used for position feedback. Generally, the driving module of rotary encoder and servo unit is prone to failure. There are also individual system chaos caused by power supply. Especially for those systems with computer hard disk to save data. For example, Siemens 840C in Germany

example 1: when a CNC lathe is just put into use, it must return to the reference point when the system is restarted after power failure. That is, when the axes are moved outside the non-interference area manually, the axes return to the reference point. Otherwise, a car crash may occur. Therefore, after processing every day, it is best to move the axis of the machine tool to a safe position. At this time, he will not take the project to the semi-finals of the Ningbo Hangzhou Bay New Area International Entrepreneurship and innovation competition, and directly upgrade to the finals with the first place in Hangzhou

faults caused by external hardware operation are common faults in NC repair. Generally, it is caused by problems in the detection switch, hydraulic system, pneumatic system, electrical actuator and mechanical device. Some of these faults can be found through the alarm information. For general CNC system, it has fault diagnosis function or information alarm. Maintenance personnel can use these information means to narrow the scope of diagnosis. Although some faults have alarm information display, it can not reflect the real cause of the fault. At this time, it is necessary to analyze and solve according to the alarm information and fault phenomenon

example 2: the first turning unit in our factory adopts SINUMERIK840C system. The machine tool stops suddenly when it is working. Display spindle temperature alarm. After comparison and inspection, the fault occurred on the temperature instrument, and the alarm disappeared after adjusting the peripheral circuit. Then replace the new instrument and return to normal

example 3: the same turning center, when working, CRT displays 9160 alarm "9160 no part with wiper 1 closed verify V". This refers to the alarm of not grabbing the workpiece. But in fact, the manipulator grasping the workpiece has grabbed the workpiece, but it shows that the manipulator does not grab the workpiece and alarms. Referring to the PLC diagram, this fault is caused by the measurement induction switch. After checking the position of the manipulator, the working stroke of the manipulator is less than the standard position of the fixture of the testing machine, which is caused by not fully pressing the induction switch. Then adjust the clamping force of the manipulator, and this fault is eliminated