How to reduce the machining error of CNC lathe? In order to improve the machining accuracy of CNC lathe, error compensation method and error prevention method can be used.
1. Error compensation method
Error compensation method is a method to improve the accuracy of CNC lathe by using the compensation function of CNC lathe system to compensate the existing error of lathe. Through the error compensation technology, high precision parts can be processed with lower precision on CNC lathe. The realization of error compensation can be completed by hardware or software.
This programming method can realize the interpolation processing of CNC lathe when the mechanical parts remain unchanged and the low-speed unidirectional positioning reaches the interpolation starting point. In the interpolation process, when the feed is reversed, the formal interpolation of the gap value can meet the tolerance requirements of the parts. Other types of CNC lathes can provide multiple addresses in the memory of CNC equipment to be used as a dedicated storage unit to store the reverse clearance value of each axis. When the axis of CNC lathe is indicated to change the movement direction, the numerical control device of CNC Lathe will read the reverse clearance value of the shaft from time to time, compensate and correct the coordinate displacement command value, and accurately position the lathe at the specified position according to the requirements, so as to eliminate or reduce the influence of reverse deviation on the machining accuracy of parts.
For CNC lathe with semi closed loop servo system, the positioning accuracy and repeated positioning accuracy of lathe are affected by reverse deviation, which further affects the machining accuracy of parts. In this case, the compensation method can be used to compensate the reverse deviation and reduce the precision error of machining parts. Nowadays, the positioning accuracy of many CNC lathes in China's mechanical processing industry is more than 0.02mm. This kind of lathe generally has no compensation function. In some cases, programming method can be used to realize unit positioning and clear reverse clearance.
2. Other methods
For the machining accuracy error caused by the geometric parameters of turning tool, the following methods can be used to solve the problem: during the programming process, the trajectory of the tool tip should be consistent with the machining contour of the part and the ideal contour, that is, before programming, the actual required arc-shaped tool tip trajectory can be converted into the imaginary tool tip trajectory through human calculation, so as to achieve zero error in theory. At the same time, it is very important to take the center of the tool tip arc as the tool location in the programming process, because the drawing of the center track of the tool tip arc and the calculation of its characteristic points are complicated, and a little error will cause great error. In order to avoid and reduce the error, this operation can be completed by using the drawing function of isometric line and the coordinate query function of points in CAD software Make. However, when using this method, it is necessary to check whether the value of the tool tip arc radius is consistent with the value in the program, and the value should be taken into account when setting the tool.
On 2018-08-08 11:45:46
