Talk about precision machining!

When CNC machine tools process precision mechanical parts in bulk, special attention should be paid to the machining accuracy. What issues should we pay attention to when ensuring accuracy in batch processing

1、 The poor machining accuracy of batch parts is generally due to the improper adjustment of the feed dynamics between each axis during installation and adjustment. Or due to wear and tear during use, there may be changes in the transmission chains of each axis of the machine tool, which can be resolved by readjusting and modifying the gap compensation amount

When the dynamic tracking error is too large and an alarm is triggered, it can be checked whether the servo motor speed is too high, whether the position detection component is in good condition, and whether the position feedback cable connector is in good contact. Whether the corresponding analog output latch and gain potentiometer are in good condition, and whether the corresponding servo drive device is normal

2、 When the machine tool is in motion, overshoot may cause poor machining accuracy, possibly due to short acceleration and deceleration times. The speed change time can be appropriately extended. It may also be due to loose or poor rigidity of the connection between the servo motor and the screw, which can appropriately reduce the gain of the position loop

3、 Roundness deviation during two axis linkage

(1) Axial deformation of a circle

This deformation may be caused by mechanical misalignment and poor positioning accuracy of the shaft. Or improper compensation of the screw clearance can lead to roundness errors when exceeding the limit

(2) Oblique ellipse error

At this point, the position deviation values of each axis should be checked first. If the deviation is too large, the position ring gain can be adjusted to eliminate it. Then, check whether the interface board of the rotary transformer or induction synchronizer is properly adjusted. Then, check whether the mechanical transmission pair clearance is too large and whether the clearance compensation is appropriate

The machining of non-standard precision parts has high precision requirements

The precision of non-standard precision parts processing mentioned here must be strictly processed according to the additional drawings, and the machining dimensions within the allowable range of error are all qualified parts. So the requirement for processing precision components is to strictly follow the theoretical dimensions for processing

The processing of precision components mainly requires dimensional requirements, such as the diameter of a cylinder, which has strict requirements. Positive and negative errors within the specified range are qualified parts, otherwise they are all unqualified parts. There are also specific strict requirements for length, width, and height, and there are also provisions for positive and negative errors. For example, if the diameter of an embedded cylinder is too large and exceeds the allowable range of errors, it will cause it to not be inserted. If the actual diameter is too small and exceeds the lower limit of the allowable negative error value, it will cause the insertion to be too loose and not firm

These are all unqualified products that need to be scrapped or reprocessed, which will inevitably increase costs. Therefore, ensuring the accuracy of non-standard precision parts processing is very important