Common Faults And Maintenance Of Pneumatic Circuit Of CNC Machine Tools

Common Faults And Maintenance Of Pneumatic Circuit Of Cnc Machine Tools


The main points of CNC machine tool pneumatic system maintenance ensure the supply of clean compressed air. Compressed air usually contains impurities such as moisture, oil and dust. Moisture will corrode pipes, valves and cylinders; oil will deteriorate rubber, plastics and sealing materials, and dust will cause valve body failure. Selecting a suitable filter can remove impurities in the compressed air. When using the filter, the accumulated liquid should be removed in time. Otherwise, when the accumulated liquid is close to the water baffle, the airflow can still roll up the accumulated material.

Make sure the air contains the right amount of lubricating oil. Most pneumatic actuators and controls require moderate lubrication. If the lubrication is poor, the following faults will occur:

  1. Due to the increased frictional resistance, the cylinder thrust is insufficient, and the valve core action fails.
  2. Air leakage due to wear of the sealing material.
  3. The operation and action of the components are out of order due to the raw material.

The method of lubrication is generally to use a lubricator for spray lubrication, and the lubricator is generally installed after the filter and the pressure reducing valve. The oil supply of the oil Power device should not be too much, usually 1ml of oil per 10m3 of free air (ie 40`50 drops of oil). One way to check whether the lubrication is good is to find a clean white paper and put it near the exhaust port of the reversing valve. If the valve has only light and milky spots on the white paper after three to four cycles of operation, then Frog lubrication is good.

Keep the airtightness of the pneumatic system. Air leakage not only increases energy consumption, but also leads to a drop in air supply pressure, and even causes pneumatic components to work. Severe air leakage is easy to detect when the pneumatic system stops running, and the sound caused by air leakage is easy to detect; for minor air leakage, use the instrument or use soapy water to check.

Guarantees the sensitivity of pneumatic moving parts without imitations. The compressed air discharged from the air compressor contains compressor oil particles with a particle size of 0.001`0.008um. Under the high temperature of the exhaust temperature of 120~220 degrees, these oil particles will be rapidly oxidized, and the color of the oil particles will change after oxidation. Deep, viscosity increases, and gradually solidifies from liquid to sludge.

This kind of particles below the um level cannot be filtered out by general filters. When they enter the reversing valve, they are attached to the valve core, so that the sensitivity of the valve is gradually reduced, and even the action fails. In order to remove the sludge and ensure the sensitivity, an oil mist sharer can be installed after the filter of the pneumatic system to share the sludge. In addition, regular valve cleaning can also ensure valve sensitivity.

Ensure that the pneumatic device has suitable working pressure and movement speed. When adjusting the working pressure, the pressure gauge should work reliably and count accurately. After the pressure reducing valve and throttle valve are adjusted, the pressure regulating valve cover or lock nut must be firm to prevent loosening.


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