The causes of abnormal machining accuracy are hidden and difficult to diagnose. Five main reasons are summarized: the machine tool feed unit is changed or changed; The zero point offset of each axis of the machine tool is abnormal; Abnormal axial reverse clearance; Motor operation status is abnormal, that is, electrical and control parts are abnormal; Mechanical failure, such as lead screw, bearing, coupling and other components. In addition, the preparation of machining program, the selection of tools and human factors may also lead to abnormal machining accuracy.
1、 Causes of abnormal machining accuracy.
The causes of abnormal machining accuracy are hidden and difficult to diagnose. Five main reasons are summarized: the machine tool feed unit is changed or changed; The zero point offset of each axis of the machine tool is abnormal; Abnormal axial reverse clearance; Motor operation status is abnormal, that is, electrical and control parts are abnormal; Mechanical failure, such as lead screw, bearing, coupling and other components. In addition, the preparation of machining program, the selection of tools and human factors may also lead to abnormal machining accuracy.
2、 Judgment standard of NC machine tool failure.
The external to internal CNC machine tool is a machine tool integrating mechanical, hydraulic and electrical functions, so the occurrence of its failure will be reflected by these three factors. The maintenance personnel shall check one by one from the outside to the inside, and try to avoid random unsealing and disassembly, otherwise the fault will be expanded, and the accuracy of the machine tool will be lost and the performance will be reduced.
Generally speaking, mechanical faults are easy to detect, while NC system faults are more difficult to diagnose. Before troubleshooting, pay attention to eliminating mechanical faults first, which can often achieve twice the result with half the effort.
The machine tool can be powered on only after it is confirmed as a non-destructive fault through understanding, observation, testing and analysis under the static state of power off of the machine tool; Dynamic observation, inspection and test shall be carried out under operating conditions to find faults. For destructive faults, the power can be switched on only after the danger is eliminated.
First simple then complex When multiple faults are intertwined and covered up, and there is no way to start at the moment, the easy problems should be solved first, and then the difficult problems should be solved. Often, after simple problems are solved, difficult problems may become easy.