With the rapid development of modern manufacturing industry, CNC machine tools have become the core force in production lines by virtue of their highly automated characteristics. However, this precise and complex equipment is like a precisely running clock, and long-term operation or improper operation may cause failures. Therefore, mastering scientific and effective daily maintenance methods is the key to ensuring the stable operation and extending the service life of CNC machine tools. Next, let’s reveal the practical tips for daily maintenance of CNC machine tools in detail.
1.Servo Motor and Spindle Motor Section
The servo motor and control system can be regarded as the “heart” and “brain” of CNC machine tools. They are not only the power source for the machine tool operation but also the core components determining the machining accuracy. During daily maintenance, it is necessary to focus on monitoring the noise and temperature rise during their operation.
When the servo axis emits harsh or abnormal sounds during movement, it may be an alarm of mechanical noise caused by the misalignment of the lead screw, coupling, and servo motor. At this time, the motor of the vertical machining center can be separated from the coupling first, and the motor is operated alone.
If the noise still exists, it is necessary to appropriately adjust the speed loop gain and position loop gain to make the motor return to “quiet”; if the noise disappears during single operation, it can be judged that the concentricity of the lead screw and the coupling is deviated. After re – correcting the concentricity and reconnecting it with the motor, the problem can usually be solved.
2.Measurement Feedback Components
Measurement feedback components such as encoders and grating scales are like the “eyes” of CNC machine tools, providing key feedback information for the precise machining of machine tools. In daily maintenance, carefully check whether the connections of these components are firm and whether there are signs of looseness. At the same time, pay attention to whether they are infiltrated by oil or covered with dust, because even fine dust particles and iron filings may cause irreversible damage to these precision components, thereby affecting the machining accuracy of the machine tool.
3.Electrical Control Section
The electrical control section is the “neural network” of CNC machine tools, maintaining the normal operation of the equipment. It is necessary to regularly check whether the external three-phase power supply voltage is stable within the normal range to ensure a stable “energy supply” for the machine tool. At the same time, carefully check whether the connections of electrical components are tight and firm to avoid failures caused by poor contact. With the help of the CRT display diagnostic screen, detect one by one whether all kinds of switches are sensitive and effective, whether the working status of each relay and contactor is normal, and whether the contacts are intact.
Protection components such as thermal relays and arc suppressors should be paid special attention to ensure that they are always in a “standby” state to escort the safe operation of the machine tool. In addition, pay attention to the temperature of the components inside the electrical cabinet to prevent equipment failures caused by excessive temperature.
Once it is found that the contacts of the contactor are in poor contact, the contactor can be carefully disassembled, the oxides generated by high temperature on the surface of the contacts can be carefully filed off with a small file, and then the debris can be carefully wiped with absorbent cotton dipped in alcohol before reassembly. Finally, use a multimeter to conduct a conduction test on the contacts to ensure the repair effect.
4.CNC System Control Section
The CNC system control section covers many key components such as the CNC unit, power module, I/O interface, servo amplifier, spindle amplifier, operation panel, and display, which work together to endow the machine tool with a “smart brain”. In the daily maintenance process, the primary task is to check whether each relevant voltage value meets the specified range to ensure stable system power supply.
At the same time, check whether the connections of electrical components are firm to avoid abnormal signal transmission caused by looseness. In addition, the operation of the fans of each functional module cannot be ignored. Timely remove the dust accumulated on the fans and dust filters to ensure good heat dissipation effect, avoid equipment failures caused by poor heat dissipation, and thus ensure the stable and efficient operation of the CNC system.