As the core equipment for precision machining, high-precision cylindrical grinding machines directly determine the product accuracy level based on the roundness index of the machined parts. Failure to meet roundness standards not only affects production efficiency, but may also lead to batch product scrap. Therefore, establishing a scientific diagnostic process and adopting targeted solutions are crucial for ensuring processing quality.
Fault diagnosis should follow the core principle of "from simplicity to complexity, from surface to interior", and be carried out in an orderly manner in three steps. The first step is to verify the basic status. Firstly, check the fixture to confirm whether the workpiece is firmly clamped and whether the fit between the top and the center hole is tight. If there are gaps or clamping deviations, it may cause the workpiece to move during processing. Next, check the condition of the grinding wheel and observe whether there are any imbalances, passivation, or improper adjustments. If the radial runout of the grinding wheel exceeds the tolerance, it will be directly transmitted to the surface of the workpiece. Finally, check the cutting parameters. Excessive feed rate or deep cutting depth may cause vibration and affect roundness.
The second step is the detection of core components. Focus on investigating the spindle system. Wear, excessive clearance, or insufficient preload of the spindle bearings can lead to a decrease in spindle rotation accuracy, which is a key cause of roundness deviation. The radial runout of the main shaft can be detected through a dial gauge to determine the bearing condition. Simultaneously checking the accuracy of the guide rail, wear or straightness errors of the bed guide rail can cause the movement trajectory of the drag plate to deviate, thereby affecting the relative position accuracy between the grinding wheel and the workpiece. In addition, it is necessary to confirm whether there is any clearance in the transmission system. Wear of transmission components such as gears and belts can cause unstable motion transmission.
The third step is environmental and process review. Environmental vibration is a often overlooked factor, and the vibrations generated by the operation of peripheral equipment can be transmitted to the grinding machine through the foundation, interfering with the machining process. It is necessary to detect the vibration value of the processing environment to determine whether it exceeds the allowable range of the equipment. At the same time, review the process steps to confirm the cleanliness and cooling effect of the grinding fluid. Excessive impurities or insufficient cooling can exacerbate grinding wheel wear and workpiece thermal deformation, indirectly affecting roundness.
Accurate solution strategies need to be adopted for different causes of faults. If it is a clamping problem, the center of the tip should be recalibrated, and worn chucks or tips should be replaced to ensure clamping rigidity. The spindle system malfunction requires replacement of worn bearings, re adjustment of preload force, and restoration of spindle rotation accuracy. The wear of the guide rail can be repaired by scraping or sticking plastic to restore its straightness. The transmission clearance requires replacement of worn parts, adjustment of gear mesh clearance or tensioning of belts. Environmental vibration problems can be solved by installing vibration isolation pads and adjusting equipment layout; In terms of process, it is necessary to regularly replace grinding fluid, optimize cutting parameters, and reduce vibration and thermal deformation.
In summary, the diagnosis of roundness faults in high-precision cylindrical grinders requires a systematic investigation of the basic state, core components, and environmental processes. Targeted measures should be taken to restore equipment accuracy, and a regular maintenance mechanism should be established to reduce the occurrence rate of faults from the source.