CNC machine tool fault diagnosis based on these principles

The cause of abnormal machining accuracy is concealed, and the diagnosis difficulty is relatively large. Five main reasons are summarized: the machine feed unit is changed or changed; the zero offset of the machine axes is abnormal; the axial backlash is abnormal; the motor Abnormal operating conditions, that is, electrical and control parts are abnormal; mechanical failures such as lead screws, bearings, and couplings. In addition, the preparation of the machining program, the selection of the tool and the human factors may also result in abnormal machining accuracy.

First, the principle of fault diagnosis of CNC machine tools

1. The external internal CNC machine tool is a machine tool integrating mechanical, hydraulic and electrical, so the occurrence of faults will be reflected by the three. Maintenance personnel should first check one by one from the outside to the inside, try to avoid unpacking and disassembly at will, otherwise it will expand the fault and make the machine lose precision and reduce performance.

2, the first mechanical and electrical, in general, mechanical faults are easier to detect, and the diagnosis of CNC system faults is more difficult. Before troubleshooting, first pay attention to the elimination of mechanical failures, often can achieve twice the result with half the effort.

3, first static and then move in the static state of the machine power off, through understanding, observation, testing, analysis, confirmed as a non-destructive fault, before the machine can be energized; in the operating conditions, dynamic observation, Verify and test to find faults. For destructive failures, the danger must be removed before powering up.

4, first simple and complicated, when there are multiple faults intertwined and concealed, when there is no way to start, you should solve the easy problem first, and then solve the difficult problem. Often, after a simple problem is solved, a difficult problem may become easier.

Second, commonly used diagnostic methods

1. Intuitive method: (Wang Wen asked) Asked - machine tool failure phenomenon, processing status, etc.; see - CRT alarm information, alarm indicator, capacitor and other components deformation smoke and burn, protector trip, etc.; listening - abnormal sound; -Electric components burnt and other odors; touch - heat, vibration, poor contact, etc.

2, parameter check method: the parameters are usually stored in RAM, sometimes the battery voltage is insufficient, the system will not be powered or external interference for a long time will make the parameters lost or chaotic, should check and correct the relevant parameters according to the fault characteristics.

3, isolation method: some faults, it is difficult to distinguish between the CNC part, or the servo system or mechanical parts, often using the isolation method.