3. Machining accuracy problem
Slow wire cutting can handle high-precision mold parts. In actual production, due to improper operation or unreasonable process, the processing accuracy may cause problems. Generally, the following situations may occur.
(1) Large shape error
In general, machining deformation is the main reason for the large shape error, and can be improved from the processing technology by referring to the above related introduction.
The pressure of the spark channel in the process produces a large back thrust to the wire, which causes a slight bending of the wire, and the hysteresis of the wire is likely to cause the corner to collapse when the corner is cut. In order to improve the corner cutting accuracy, the corner control function of the machine tool can be used to improve the corner accuracy problem. When machining to the corner position, the machine automatically reduces the machining energy, reduces the flushing pressure, reduces the servo advance, and uses a delay to control the corner accuracy. The corner strategy is divided into an inner corner and an outer corner, and their protection strengths can be set separately. The corner strategy should be applied flexibly according to the corner accuracy requirements.
For microfinishing of small rounded corners, narrow slits, and fine parts, filaments can be cut to obtain a smaller inner corner radius. The corners processed using galvanized wire have high precision, especially the shape error of the sharp corners is significantly improved compared to the brass wire.
If the tension of the wire is too small, the rushing pressure is too high, and the wire is shaken, the processing is unstable, resulting in an increase in geometric error, and reasonable control is required to reduce the shape error.