(4) concave or convex situation
The upper and lower dimensions of the workpiece are inconsistent. In actual production, this is called a concave heart. The main reason for this is that the servo feed state of the wire and the workpiece is not in a good state during processing. Normal processing should ensure that the servo feed speed of the wire is approximately equal to the erosion speed, and the feed is even and stable. If the servo feed rate is too high (close to short circuit), that is, the servo feed speed of the wire is obviously higher than the erosion speed. When the punch is cut, the bulge will be bad; the servo feed rate will be too slow. In the case of a concave core, the concave mold is reversed. According to this law, the servo feed speed of the machine tool can be adjusted to effectively solve the problem of dimensional accuracy of concave or convex in the mold part.
(5) Large position accuracy error
The accuracy of the cavity position on the stencil is highly dependent on the positioning before machining. In order to achieve high-precision positioning accuracy, the workpiece must have a precise, unambiguous datum. The wire must be subjected to automatic vertical alignment. Do not use the spark correction method because it is difficult to obtain a high precision of verticality, which will affect the positioning accuracy.
Using the positioning method in four sides can achieve higher positioning accuracy, and the sensing errors of the two reference sides can cancel each other out. Positioning and finding the edge should be done several times to check and confirm the positioning accuracy. If there is a large positional accuracy error in the skip processing, check if the machining is deformed. For multi-cavity machining, when programming the process, you can rough-process all the holes first, fully release the stress of the material, and then perform the trimming process uniformly, which can achieve higher precision jump accuracy.
Do not use incremental programming when programming, so as to avoid large differences after error stacking. The shaft of the machine tool should be maintained on time, filled with lubricating oil, and the mechanical precision can be detected and corrected in time to make the machine tool in good precision.