How to improve the accuracy of cnc machining center?
As we all know, the error is a major indicator to check the qualification rate of workpiece processing. In the CNC machining center, the accuracy is mainly expressed by the size of the error. The specific accuracy is divided into two types, including static accuracy and dynamic accuracy. So how can we improve the accuracy of the CNC machining center?
1. Selection of cnc machining center. Since the accuracy of the cnc machining center itself is also different, we need to pay attention to the choice of cnc machining center model and accuracy in the selection of cnc machining center. At present, the inspection of the position accuracy of cnc machining center usually adopts the international standard ISO230-2 or national standard GB10931-89 etc. In the selection of cnc machining center, we must pay attention to the standard, because the difference in standard will also cause the difference in accuracy.
2. Control of parts. The cnc machining center of the sliding bearing can use bearings with better wear resistance to ensure the working accuracy of the cnc machining center.
3. Control of the workshop environment. Reducing the heat source: the focus is on the spindle speed, clearance adjustment and reasonable preload. For thrust bearings and tapered roller bearings, due to poor working conditions, the heat is relatively large. If necessary, thrust angular contact ball bearings can be used instead to minimize the friction and heat of some parts. Insulation: Keep the heat source away from the main shaft, such as isolating the motor and transmission, and using separate transmission. Heat dissipation: strengthen lubrication and cooling, adopt oil cooling, air cooling and other methods to accelerate heat dissipation. Reducing the influence of thermal deformation: No matter which method is adopted, it can only reduce thermal deformation and it is difficult to completely eliminate thermal deformation, so measures should also be taken to reduce the influence of thermal deformation.
4. Control of reverse deviation. Because the reverse deviation will cause the accuracy of the equipment to become lower, and as the application time of the cnc machining center is longer, the wear is greater and the error will become larger, which requires the reverse deviation during the application of the cnc machining center Carry out regular inspection and compensation work, so as to reduce errors as much as possible and improve the working accuracy of cnc machining center.
5. Error compensation. Error compensation refers to the corresponding record of the position of the fixed axis during the machining of the cnc machining center. In addition, the relevant recorded data is compared with the actual measurement results to understand the error value and be selected on the axis during operation. Measure the reference point, record the error value during operation, and input it into the relevant control system, so that the axis movement and error time at different points can be well controlled. If the number of measured points is more, it means that the error effect of the pitch compensation needs to be more obvious. The premise of this error compensation technology is established under the cnc machining center coordinate system, and the important parameters to determine the cnc machining center coordinate system are for reference Point, therefore, it must be ensured that the error value of the selected reference point is zero.
6. Compensation for backlash error. Due to the influence of the backlash error in the cnc machining center, the backlash error must be fully paid attention to in the design of the cnc machining center, and effective solutions must be taken. But it is undeniable that there is a gap, so what we have to do is to record the backlash of each point during the operation of the cnc machining center through the pitch error compensation technology, and the reverse movement through the control system of the cnc machining center Directly perform error compensation operations to reduce errors by using parameter settings and system settings.
7. Perfection of technology. With the development of science and technology, the accuracy of cnc machining center is also constantly being improved and improved. The accuracy of cnc machining center has improved from the original micron level to nanometer level. More research and development are needed, especially in bearing technology. Avoiding the lag of bearing technology is one of the development problems. The lag phenomenon is particularly important for the accuracy of positioning. It is found in the research that the hydrostatic bearing technology can solve the mechanical lag phenomenon, so in the high-precision CNC machining center processing Get a lot of applications.
In summary, in the machining work of the cnc machining center, there are many factors that affect the accuracy of the cnc machining center. We need to comprehensively analyze these influences and reduce the error as much as possible from various aspects to achieve an effective improvement in machining accuracy.