The lathe has the characteristics of machine, electricity, and liquid in one, technology-intensive and knowledge-intensive, and is an advanced processing equipment with a high degree of automation, a complicated and expensive structure. In order to give full play to its benefits and reduce the occurrence of failures, daily maintenance work must be done. Therefore, maintenance personnel of CNC lathes should not only have knowledge of machinery, processing technology, and hydraulic and pneumatic aspects, but also have electronic computers, automatic control, drive, and measurement. Knowledge, such as technology, in order to fully understand, master CNC lathes, and do a good job in maintenance.1. Contents of the main daily maintenance work of CNC machine tools: Choose an appropriate environment: The environment (such as temperature, humidity, vibration, power supply voltage, frequency, and interference, etc.) of the CNC lathe will affect the normal operation of the machine tool, so install the machine tool. It should be strictly required to meet the installation conditions and requirements specified in the machine manual. Under conditions permitting economic conditions, CNC lathes should be installed separately from ordinary mechanical processing equipment to facilitate repair and maintenance.2. CNC lathes should be equipped with specialized personnel for programming, operation and maintenance of CNC systems: These personnel should be familiar with the mechanical parts, numerical control systems, strong electrical equipment, hydraulic pressure, air pressure, etc. of the machine tools used, and the use environment and processing conditions. Correctly use the CNC lathe according to the requirements of the machine tool and system manual.3. Long-term maintenance of CNC lathes: When CNC lathes are not used, they should be powered by the CNC system often. When the machine tool is locked, it can be run empty. In the mild rainy season when the air humidity is high, the electricity should be energized every day. The electrical components themselves are used to generate heat to drive off the moisture in the CNC cabinet to ensure the stable and reliable performance of the electronic components.4. Maintenance of the hardware control part of the CNC system: Have an experienced maintenance electrician inspect it once a year. Check whether the relevant reference voltage is within the specified range, such as the output voltage of the power module, the reference voltage of the numerical control unit, etc. If it is abnormal and remove the dust, check whether the connection of the electrical components in the system is loose; check the function modules using the fan Check whether the connection of the external regenerative discharge unit used by the servo amplifier and the spindle amplifier is reliable and remove dust. Check whether the voltage of the memory backup battery used by each function module is normal or not. It should be replaced regularly according to the manufacturer’s requirements. For long-term deactivated machine tools, the machine should be turned on for 4 hours per month, which can extend the service life of CNC machine tools.5. Maintenance of the machine tool part: After the end of each shift, the operator should clean the chips scattered on the pallets, guide rails, etc.; pay attention to check whether the chip remover is normal in the work so as to avoid the accumulation of chips and damage the guide rail accuracy. The life of the ball screw and the guide rail is compromised; before the work is completed, the servo shaft should be stopped after it is returned to the origin.6. Maintenance of machine spindle motor: The maintenance electrician should check the servo motor and spindle motor once a year. Focusing on checking its operating noise and temperature rise, if the noise is too large, the cause should be ascertained. It is the problem of bearing or other mechanical problems or the parameter setting of the amplifier that matches it, and corresponding measures should be taken to solve it. For DC motors, their brushes, commutators, etc. should be inspected, adjusted, repaired, or replaced to make them work well. Check if the cooling fan at the end of the motor is running properly and clean the dust; check if the motor connection plugs are loose.7. Maintenance of machine feed servo motor: For the servo motor of CNC lathe, maintenance should be carried out in 10 to 12 months. The machine that accelerates or decelerates frequently changes should perform maintenance in 2 months. The main contents of maintenance include: using dry compressed air to blow off the dust from the brush and checking the wear of the brush. If it needs to be replaced, the brushes with the same specifications should be used. After the replacement, it should be run for a certain period of time to replace it. The surface of the commutator is matched; check the cleaning armature commutator to prevent short circuit; if it is equipped with a speed measuring motor and pulse encoder, check and clean it. The DC servo motor in the CNC lathe shall be inspected at least once a year. Generally, the inspection shall be carried out under the condition that the CNC system is powered off and the motor is completely cooled; remove the rubber brush cap and unscrew the brush cover with a screwdriver. Take out the brush; measure the length of the brush. For example, if the brush of FANUC DC servo motor is worn from 10mm to less than 5mm, the same type of brush must be replaced; carefully check the arcuate contact surface of the brush for deep grooves and cracks, and Whether there is no spark on the brush spring. If the above phenomenon occurs, it is necessary to consider whether the operating conditions of the motor are excessive or whether the motor itself has a problem. Compressed air containing no metal powder and moisture is introduced into the brush hole of the brush, and the brush powder adhered to the wall of the brush hole is blown clean. If it is difficult to blow, clean it gently with the tip of the screw until the wall is completely clean, but be careful not to touch the surface of the commutator. Get a new brush and tighten the cover. If a new brush is replaced, run the motor for a period of time so that the brush surface matches the commutator surface.
Fonte: Meeyou Carbide