In production, the common accuracy abnormalities mainly include the following aspects:
(1) The feed unit of the machine tool has been changed or changed.
(2) The offset of each axis part of the machine tool is abnormal.
(3) The reverse clearance of the shaft is abnormal.
(4) The operating state (Electrical and control parts) of the electrode is abnormal.
(5) Mechanical (lead screw, bearing, coupling and other components) failure.
(6) Human factors in machining programming and tool selection.
1. System parameters change or change
The system parameters of the machine tool include the feed unit of the machine tool, zero point bias, reverse clearance and so on. In the process of repairing the machine tool, the part offset and clearance changes may be affected. Therefore, it needs to be adjusted and modified after troubleshooting. On the other hand, serious mechanical wear and loose connections may cause changes in the measured parameter values, which need to be modified to meet the accuracy requirements. During disassembly and inspection, it may be found that the bearing is damaged or the ball is disengaged, and it will return to normal after replacing the machine tool.
2. Abnormal machining accuracy caused by mechanical failure
There are three main reasons for abnormal machining accuracy caused by machine tool failure: first, abnormal motor, second, mechanical failure, and third, there is a gap between the lead screws. If you want to further accurately diagnose the fault, you need to separate the motor and the lead screw. Check the motor and machinery. If the inspection result is that the motor operates normally, it is found in the diagnosis of the mechanical part that there is a very obvious sense of vacancy when turning the lead screw by hand. Under normal circumstances, the orderly and smooth movement of the bearing should be felt.
3. The electrical parameters of the machine tool are not optimized, and the motor runs abnormally
If the accuracy of x-axis is abnormal during processing, it is found that there is clearance in x-axis after inspection, and there is instability when the motor is started. There are two main reasons for this situation. First, the reverse clearance of the lead screw is large, and the other is the abnormal operation of the x-axis electrode of the machine tool. The solution is mainly to debug the motor. Compensate for gaps; Or adjust servo gain parameters and pulse suppression function parameters to eliminate X-axis electrode jitter and ensure normal accuracy.