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.
& emsp; Troubleshooting and Fault Diagnosis Method for CNC Machine Tool Accuracy Reduction
& emsp; 1. Function program test method: write some small programs for all commands of G, M, S, T and functions, and run these programs when diagnosing faults to judge the lack of functions.
& emsp; 2. Parameter inspection method: parameters are usually stored in RAM. Sometimes the battery voltage is insufficient, the system is not powered for a long time or external interference will cause parameter loss or confusion. Relevant parameters should be checked and calibrated according to the fault characteristics.
& emsp; 3. Intuitive method: (looking, hearing, inquiring) Question – the fault phenomenon and processing condition of the machine tool; Check the CRT alarm information, alarm indicator, capacitor and other components for deformation, smoke burning, protector tripping, etc; Hearing – abnormal sound; Smell – burning smell of electrical components and other peculiar smell; Touch – heating, vibration, poor contact, etc.
& emsp; 4. In the same kind of exchange method, replace the suspected faulty template with a standby board with the same function, or exchange the templates or units with the same function.
& emsp; 5. Isolation method: For some faults, it is difficult to distinguish whether they are caused by the numerical control part, the servo system or the mechanical part, so the isolation method is often used.
