Linear guide in the CNC machine tool troubleshooting method analysis
Linear guide as a CNC machine tool to achieve precision movement of the core components, its performance is directly related to the machine tool processing accuracy and productivity. Once the guide fails, it will lead to the decline of processing quality and even stop. Through the organic combination of manual inspection and professional instrumentation, an efficient fault diagnosis system can be built to accurately locate the problem and ensure the continuous and stable operation of the machine tool.
Manual inspection is the basic diagnostic method. Technicians visually inspect the surface of the guide rail to see if there is wear, scratches, corrosion or deformation, and at the same time, observe whether the lubrication pipeline is clogged, oil leakage, lubricant deterioration or insufficient; with a plug ruler to measure the assembly gap between the slider and the guide rail, to determine whether the preload is uniform. Auditory judgment is also very important, manually push the moving parts, listen to any abnormal friction sound, impact sound or ball rolling noise, normal operation should be uniform "rustle" sound, high-speed operation if there is a "buzzing" sound or periodic noise, it may be a ball wear or Guideway parallelism deviation. Can also sense the surface temperature of the guide rail through the sense of touch, after stopping the touch to determine whether the local overheating, manually push the slider to feel whether the movement resistance is uniform, there is no jamming or uneven tightness phenomenon.
Professional instrument testing can realize accurate diagnosis. Laser interferometer is used to detect the straightness, parallelism, perpendicularity and other geometric accuracy of the guideway, the interferometer is fixed in the base of the machine tool, the reflector is mounted on the moving parts, the moving parts record the deviation data and compare it with the national standards or the precision of the machine tool from the factory, such as straightness requirements ≤ 0.01mm / full length . Vibration analyzer by analyzing the guide rail vibration frequency and amplitude to identify the problem, the sensor attached to the guide rail or slider to capture the vibration signal to generate a spectrogram, if there are abnormal peaks, such as the octave component of the frequency of the ball, it may suggest that the ball is worn out or poor contact. Infrared thermal imaging camera can detect the temperature distribution of the rail area, scanning the full length of the rail, under normal circumstances, the temperature should be uniform, if there is a localized high temperature points, may mean poor lubrication, excessive contact stress or cooling system failure . In addition, the coordinate measuring instrument can conduct a full range of size inspection of the guideway to check whether the key dimensions of the guideway due to wear and tear exceeded; ultrasonic detector can detect internal defects in the guideway, to find the naked eye is difficult to detect the cracks and other hidden dangers. A variety of diagnostic methods complement each other, can be comprehensive, accurate judgment linear guide failure, for the repair and maintenance of CNC machine tools to provide a reliable basis.
