Doing good maintenance can keep the machining accuracy of the machine in the best state, extend the service life, and adopt the correct startup and commissioning method for the CNC machine tools. In the face of new challenges, it can show a good working state, improve production efficiency and machining results.
CNC machine tool maintenance
There are many types of CNC machine tools, and various types of CNC machine tools have different characteristics due to their different functions, structures, and systems. Its maintenance content and rules also have their own characteristics, and the necessary maintenance system should be formulated and established according to the type, model and actual use of the machine tool, and by referring to the instructions of the machine tool manual. The following are some common maintenance points.
1. Machine tool cleaning: clean the workpieces, jigs, iron chips, etc. in the machine tool, iron chips in the external chip removal machine, wipe out the external sheet metal, and clean the air filter of the electric control box and oil filter of the oil cooler.
2. Anti-rust treatment: clean the workbench and wipe it with rust-proof oil; run the machine slowly for one hour to lubricate the rails; if the cutting fluid needs to be replaced, give priority to anti-rust treatment, and add it when the machine needs to work. Cutting fluid.
3. Do a good job in the workshop to cut off power, gas, and liquid supply: Run the Y-axis of the CNC machine tool to the middle, return the Z-axis to zero, and turn off the machine’s main electrical switch, transformer inlet switch, and air source.
4, waterproof and moisture-proof: close the electrical box for protection.
5. Anti-rat treatment for machine tools: The machine tool also does anti-rat treatment to prevent rats from biting off the wires.
CNC machine tool commissioning
CNC machine tool is a kind of high-tech mechatronics equipment. It is very important to adopt the correct method for commissioning, which largely determines whether the CNC machine tool can play normal economic benefits and itself. Life.
Check before starting: Check the peripheral environment of the machine tool, whether there is any abnormal phenomenon such as water in the electrical box, and whether the oil has deteriorated.
Step-by-step startup: The power voltage of the machine must be detected before the machine is turned on. The power switch of the machine must be turned on after the main power switch has been turned on for about 10 minutes before turning on the power switch of the machine. Then, check whether the voltage is out of phase. Too low, turn on the power of the machine tool without abnormal conditions, and observe whether there is any abnormal phenomenon or air leakage. Do not perform any action when there is no alarm when the machine is turned on, and let the electrical components be energized for 30min.
Slow movement: Check for interference, move the machine with the handwheel all the way, pay attention to any abnormalities, and then perform the origin return step.
Machine tool break-in: Automatically run the machine at a slow speed for a long time, and rotate the spindle at a low speed. Fan failures that often occur on CNC machine tools: The fans in the machine tool can cool and cool the core equipment and effectively prevent equipment from overheating and damage. At the end of the long holiday, the machine fan often “strikes”, which is caused by oil pollution. When the machine stops, the fan inside the machine will also stop. At this time, the oil in the machine tool will flow into the bearings of the fan, causing a short circuit failure of the fan’s circuit, and the fan will alarm or fail to start when the machine is turned on again. The longer the downtime, the greater this risk.
Seal failure: It is necessary to use seals in the hydraulic and pneumatic equipment of the machine tool, in order to ensure the tightness of the device and maintain its normal pressure supply. Seals are generally rubber products, which are prone to aging, especially during long vacations, when the machine tool is not running for a long time and the hydraulic pressure does not flow. This will more easily cause the seals to harden, leading to machine tool oil leakage and insufficient pressure provided by hydraulic devices.
Oil path blocked: The reason for oil path blocked is because the machine tool is stopped for a long time, and the dirt inside the oil path is continuously deposited. Blocking the oil circuit will cause the lubrication system of the machine tool to fail, and the failure of the lubrication system will cause many other serious problems. According to statistics, more than 40% of various common faults of machine tools are related to lubrication faults.
Malfunction of the machine tool travel switch: The machine tool travel switch is an important device that limits the mechanical travel range of the machine coordinate axis. When the moving part of the machine is pressed against the transmission part of the travel switch, its internal contacts act, and the control circuit is turned on, changed or broken. Meet the control requirements of the circuit. A spring is generally installed inside the travel switch. If the spring is not turned on for a long time, it will cause the spring to deform due to long-term force and can no longer return to its original state. The spring will lose its effect and the entire travel switch will become stuck and fail.
Driver, power supply, motherboard and other circuit board failures: In CNC machine tools, the role of circuit boards need not be said much. There are a large number of capacitors on the circuit board. If no power is applied for a long time, these capacitors will age and reduce the capacity, which will cause damage to the machine tool circuit. In addition, the main reason for the failure of the circuit board is that the circuit board will not be at the bottom temperature for a long time, which will cause condensate and cause a short circuit when it is turned on.
Machine tool battery failure: Generally, numerical control systems are equipped with batteries. It should be noted that the battery mentioned here is not the power supply of the entire equipment, but a device that supplies power to some parts. For example, the system battery is used to save system parameters; the battery for the absolute position encoder is used to remember the zero position. Even when not turned on, the power in these batteries will drain slowly. If the machine is not turned on for a long time, it is easy to cause the battery to run out and cause machine data loss.
Avoidance of CNC machine tool failures
1. For machine tools that have been used for a long time, you should not try to turn off the machine during the long vacation. You can take an emergency stop.
2. Regularly check the system fan. If it is contaminated with excessive oil, it should be replaced or cleaned up. If it is used for more than 3a, it must be replaced.
3. Regularly check the hydraulic oil pressure, liquid level and hydraulic impurities in the hydraulic system to ensure smooth oil passage.
4. Regularly clean or lubricate the spring-loaded devices such as the switch, knife arm spring, and hydraulic valve spring.
5. Clean the drive equipment regularly according to the oil contamination.
6. Regularly change the system battery for the machine tool and the desiccant for the electrical cabinet of the machine tool, especially before shutting down on long holidays, this step must not be forgotten.
7, after the long holiday, before restarting, to manually warm up each circuit board of the machine tool, you can use an electric hair dryer to heat each circuit board for a few minutes, just a little temperature.
The degree of automation of CNC machine tools is very high, with the characteristics of high accuracy, high efficiency and high adaptability, but its high and low operating efficiency, equipment failure rate, and length of service life, etc., also largely depend on the correct use of users And maintenance. A good working environment, good use and maintainers will not only greatly extend the trouble-free working time and improve productivity, but also reduce the wear of mechanical parts, avoid unnecessary mistakes, and greatly reduce the burden on maintenance personnel.
