The positioning of the CNC machine axes is done by the position servo system. Position servo systems generally use closed loop or semi-closed loop control. The characteristic of closed-loop control is that failure of any link may result in inaccurate, unstable or invalid system positioning. Diagnosing and locating faults becomes the key to maintenance. According to the control principle of the servo system and the characteristics of the system interface, it is an effective method to decompose and judge the system. This paper introduces the position loop and speed loop diagnostic methods in combination with maintenance examples. Position loop fault diagnosis If the position feedback and speed feedback of the position servo system use a feedback device, the position loop can be disconnected and the speed loop can be operated separately to determine whether the fault is from the position loop or the speed loop. To disconnect the position loop, two methods can be used: mechanical disconnection, ie disconnecting the drive connection between the position feedback encoder and the servo motor. Electrical disconnection, that is, disconnecting the position feedback encoder from the system. If the position feedback disconnection alarm is required, when the maintenance test is performed in the position open loop state, any way of moving the command to the tested axis is not allowed, otherwise the servo motor will be out of control. Since the X-axis servo system has two encoders for position feedback and speed feedback, the mechanical connection between the position feedback encoder and the servo motor can be disconnected for further judgment. At this time, the motor is turned to a certain fixed angle, and there is always a doping phenomenon. Therefore, it can be considered that the speed loop is basically stable, which may be caused by a short circuit of the commutator at a certain angle, causing the speed to drop instantaneously, thereby causing the motor to be beaten. After carefully cleaning the motor commutator and brush, the motor runs smoothly. Since the shaft servo motor speed feedback signal is sent to the CNC main board by the motor tail position feedback encoder signal, it is obtained after the F/V conversion of the hybrid IC module, and the system always has no position feedback alarm, so the preliminary judgment is the CNC to servo amplifier cable and There is a problem with the contact of the control panel. (Finish)

The Engine Parts cover all the brand engine parts in China. Our main product cover: WEICHAI/FAWDE/SDEC/DEUTZ/YUCHAI/CUMMINS/QUANCHAI/PERKINS/CHANGCHAI and also some gearbox brand like QIJIANG/FAST/QJGT/ZF. We can provide you the realiable quality and best price truck parts to maintance your after market service. Our main product: