Start-up Debugging of CNC Machine Tool After Returning to Work

Good maintenance can maintain the machining accuracy of the machine tool in the best state, extend the service life, and adopt the correct start-up debugging mode for the CNC machine tool. In the face of new challenges, it can show a good working state and improve the production efficiency and processing effect.

 

Maintenance of CNC machine tool shutdown

There are many kinds of CNC machine tools. Because of their different functions, structures and systems, they have different characteristics. The contents and rules of maintenance also have their own characteristics. The necessary maintenance system shall be formulated and established according to the type, model and actual use of the machine tool, as well as the requirements of the machine tool operation manual. Here are some common maintenance points.

1. Cleaning of machine tool: clean the workpieces, jigs and iron chips in the machine tool, clean the iron chips in the external chip conveyor, wipe the external sheet metal, clean the filter screen of the air conditioner and oil cooler of the electric control box.

2. Antirust treatment: clean and wipe the worktable and apply antirust oil; lubricate the line rail for one hour during the whole slow running of the machine tool; whether the cutting fluid needs to be replaced, give priority to antirust treatment and add cutting fluid when the machine tool needs to work.

3. Do a good job of the total power-off, gas cut-off and liquid supply of the workshop: run the Y-axis of the CNC machine tool to the middle, return the z-axis to zero, turn off the main electrical switch of the machine tool, the incoming switch of the transformer, the air source, etc.

4. Waterproof and moisture-proof: close the electrical box for protection.

5. Anti rat treatment of machine tool: the machine tool shall also be provided with anti rat treatment to prevent the rat from biting the wire.

 

    Start up debugging of CNC machine tool

    CNC machine tool is a kind of mechanical and electrical integration equipment with high technical content. It is very important to start and debug the machine in a correct way, which to a large extent determines whether the CNC machine tool can play its normal economic benefits and its own service life.

Check before startup:

    Check the peripheral environment of the machine tool and the electrical box for abnormal phenomena such as water inflow and oil deterioration.

Step by step:

    Before starting the machine, the power supply voltage of the machine tool must be detected. The power supply switch of the machine tool can only be turned on after the main power switch is turned on for about 10min and the voltage is stable. Then, the other power switches in the electric box can be turned on to check whether the voltage is short of phase and too low. If there is no abnormality, turn on the power supply of the machine bed and observe whether there is any abnormality or air leakage. When there is no alarm when the machine is started, do not perform any action, and let the electrical components power on for 30min.

Slow motion:

    Check whether there is interference, use the hand wheel to move the machine tool all the way, and pay attention to whether there is any abnormal phenomenon, and then perform the steps of origin regression.

Machine running in:

   Long time automatic slow running machine tool, and low-speed rotation of the spindle.

Common faults of CNC machine tools

Fan failure:

The fan in the machine tool can play the role of heat dissipation and cooling for the core equipment, and effectively avoid overheating damage of the equipment. At the end of the long holiday, machine fans often "strike", which is caused by oil pollution. When the machine stops, the fan inside the machine will stop. At this time, the oil in the machine tool will flow into the bearing of the fan, causing the short circuit fault of the fan circuit, and the fan will alarm or fail to start when the machine is turned on again. The longer the downtime, the greater the risk.

Seal failure:

Seals are necessary in hydraulic and pneumatic devices of machine tools, 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 the long holiday period, the machine tool does not start for a long time, and the hydraulic pressure does not flow, which is more likely to cause seal hardening, oil leakage of the machine tool, insufficient pressure provided by the hydraulic device and other problems.

    Blocked oil way:

    The reason for the blockage of the oil way is that the machine tool has been shut down for a long time, and the internal matters in the oil way are continuously deposited. The blocked oil way 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 the common faults of machine tools are related to lubrication faults.

    Machine travel switch failure:

    The travel switch of machine tool is an important device to limit the mechanical travel range of the coordinate axis of machine tool. When the moving parts of the machine are pressed to the transmission parts of the travel switch, its internal contact acts to connect, change or break the control circuit, so as to meet the control requirements of the circuit. Generally, there is a spring inside the travel switch. If the switch is not started for a long time, the spring will not be restored to its original state due to long-term stress deformation. The spring will lose its function, and the whole travel switch will also be stuck and fail.

    Driver, power supply, mainboard and other circuit board faults:

    In the numerical control machine tool, the function of the circuit board need not say much. There are a lot of capacitors in the circuit board. If the circuit board is not electrified for a long time, these capacitors will age, reduce the capacity and damage the circuit of the machine tool. In addition, the main reason for the circuit board fault is that the circuit board will be in the bottom temperature state for a long time without use, which will generate condensation water and lead to short circuit when starting up.

    Machine battery failure:

    Generally, the CNC system is equipped with batteries. It should be noted that the batteries mentioned here are not the power supply of the whole equipment, but the devices that supply power for some parts. For example, system battery is used to save system parameters; absolute position encoder battery is used to remember the zero position. Even when the battery is not turned on, the power in these batteries will be slowly lost. If the machine is not started for a long time, it is easy to make the battery run out of power, resulting in data loss of the machine tool.

    The avoidance of CNC machine failure

1. For machine tools with long service time, try not to shut down the machine during the long holiday, and take pictures of emergency stop.

2. Check the system fan regularly. If there is too much oil contamination, it should be replaced or cleaned. If the service time exceeds 3a, it must be replaced.

3. Regularly check the hydraulic oil pressure, liquid level and hydraulic impurities in the hydraulic system to ensure that the oil circuit is smooth.

4. Regularly clean or lubricate the device with spring, such as feed switch, knife arm spring, hydraulic valve spring, etc.

   5. According to the oil contamination of the drive equipment, clean it regularly.

6. Regularly replace the system battery for the machine tool and the desiccant for the electrical cabinet of the machine tool, especially before the long holiday shutdown, this step should not be forgotten.

7. After the long holiday and before restarting the machine, preheat the circuit boards of the machine tool manually. Use an electric blower to heat each circuit board for a few minutes, with a little temperature.

The automation of CNC machine tools is very high, with the characteristics of high precision, high efficiency and high adaptability, but its operation efficiency, equipment failure rate, the length of service life, to a large extent, also depends on the correct use and maintenance of users. A good working environment, good users 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 of maintenance personnel.