The control of the spindle is very important for ensuring the normal operation of the CNC lathe. Both the spindle temperature and the spindle operating speed have specified requirements. If the temperature is too high or too low, it will have a certain impact on the operating efficiency. Moreover, if the speed is too fast, it can easily cause tool biting faults. Today, our CNC lathe manufacturer will explain the detection and analysis of tool biting faults in CNC lathe spindles.
a. Using manual JVC slow running mode, adjust the X and Z axes of the lathe to the origin, restart the machining program, and conduct a test run. When the worktable quickly feeds to the machining position, the spindle still does not rotate, indicating a fault in the AC variable frequency spindle motor speed control system.
b. The analysis shows that the spindle motor is controlled by an AC frequency converter (as the machine tool manufacturer does not provide internal drawings of the AC frequency converter). Therefore, the "mathematical fuzzy maintenance method" is adopted, which considers the internal of the AC frequency converter as a "black box" and only needs to check the status of its external functional interfaces to determine.
c. Firstly, check the LED alarm display content of the AC frequency converter control system.
d. To distinguish between overheating (referring to the motor itself overheating) and overload (referring to the motor carrying excessive load and rotating too heavily) protection, based on experience, the motor casing was already very hot. After using a large fan for forced cooling for a period of time, the motor's heat decreased. Re test, the spindle motor rotates normally; At this point, it is determined that this example is a typical motor overheating fault. After disassembling the spindle motor and carefully inspecting it, it was found that the bearings of the independent cooling fan motor were damaged, resulting in poor heat dissipation and causing the spindle motor to overheat and trigger an alarm. This caused the CNC lathe spindle to suddenly stop rotating during machining operation, resulting in a "tool biting" fault.
e. After replacing the independent cooling fan motor, the CNC lathe operated normally and the fault was resolved.
The above is the detection, analysis, and handling of tool biting faults on CNC lathe spindles. We hope that the above explanation can be helpful for everyone in the future when encountering tool biting faults on CNC lathe spindles.