Factors affecting the dimensional accuracy of numerical control machining
by：QY Precision 2020-04-02
First, the factors that can be avoided to affect the accuracy of CNC machining size 1. Most of the actual processing errors of the processing technology are caused by unreasonable processing technology, which guarantees the basic processing technology (Such as milling CNC machining First coarse and then fine, first face and then hole, first big face and then small face'Or fixture in use Reduce the number of clamping times and try to use combination fixtures'Such as basic processing details) On the basis of the, try to reduce the processing error caused by iron filings on aluminum parts, because the aluminum parts are very soft, and the eliminated iron filings can easily cause processing errors for aluminum parts. For example, in FANUC or central China Processing Center, G83 command is used as far as possible to make deep holes so that iron filings can be discharged instead of G73 command. 2. Numerical calculation in manual programming and automatic programming 3. Three elements of cutting: cutting speed vc, feed f, cutting depth ap and tool compensation. In simple terms, it is the premise of ensuring machining quality and tool wear, the adjustment parameters give full play to the cutting performance of the tool, making the cutting efficiency the highest and the processing cost the lowest. In the CNC lathe, there are also factors such as tool head wear compensation. Since I have not touched the lathe for a long time, I dare not elaborate on it. Please ask the subject to search for it. 4. For the knife, the inaccurate tool is also a factor causing the size error. Therefore, try to choose a good edge finder. If the machine has an automatic tool, it is better. Second, the irresistible factor: 1. The cooling deformation of the workpiece after processing is basically unavoidable. Pay attention to the use of coolant as much as possible during processing, and pay attention to the deformation of the cooled workpiece during in-place measurement. 2. If the stability of the machine tool itself is not a new machine tool or the machine tool has not been debugged after a large amount of processing, the size error caused by the machine tool itself will occur. The error caused by the machine tool itself has the following factors: mechanical aspects: a. Loose between servo motor and screw B. Ball screw bearing or nut wear c. Insufficient lubrication between screw and nut electrical aspects: a. Servo motor failure B. There is dirt inside the grating Ruler c. PMC recovery can be performed on the parameters of the servo amplifier failure system, so it is not mentioned.