Disadvantages of the flanging forming die planning; the die is a dual-chamber left/right piece shared, because the content of the process has the shape forming content in addition to the flanging, and the special mess of the workpiece, the curved surface is narrow, and the forming requires the die pressing The core conforms to the forming surface, etc., resulting in a large forming stroke of the mold structural condition and a small pressing area. In planning the initial mold, the planner only considered the feature of the small pressing surface, but ignored the forming stroke of the pressing core.
There is an error in the mold processing parts and the drawing plan; because the pressing material core is a messy surface, the casting surface is machined and then the guiding surface is machined, and there is an empty space error after the processing surface and the concave mold guiding surface are slipped, and the mold works normally. The press core left/right swing occurred during the process. Because the guiding vacant land of this structure is used for debugging and sliding the open space,
Once damaged, there will be no effective adjustment means, which will affect the forming quality of the workpiece for a long time and bring danger. Moreover, the special guide slide plate is not used in the guide portion, but the machined surface mutual guiding structure is adopted, and there is a disadvantage that the empty space is too large to be adjusted, resulting in tearing and tilting behavior of the workpiece.
The forming process parameters are not in place; in the forming process of the part, the process requires that the die, the pressing core and the two parts must be closely attached together, and the press sheet material is plastically deformed to complete the forming when the machine tool slides down. . However, due to the shortcomings such as unstable quality of the stamped parts, it indicates that the machine tool pressure is in an unbalanced pressure jump during the production process. The reason is mainly that the processing technicians did not adjust the machine tool pressure at this stage in time according to the requirements specified by the process, or did not communicate with each other when the operation of each shift did not communicate with the machine pressure stability information, resulting in the quality of the parts. stable.
The accuracy of the press; the accuracy of the press is usually indicated by its static accuracy and rigidity. The accuracy level under static can be divided into special grade, grade 1, grade 2 and grade 3 according to the Japanese JIS press static accuracy index rules. Static rating is a major factor for presses, but the rigidity of the press is an important factor that cannot be ignored. This is the strength of the press.
The press applies a pressure to the data beyond the yield point through the die. Under the nominal pressure, although the press is not damaged, the elastic deformation of the bed and the deflection of the table have a great influence on the press processing. Therefore, it is better to increase the dynamic characteristics of the static precision of the press. Under the action of the punching force, the table top, the crankshaft and the bed are deformed, and the C-type press has an opening, etc., so that the static precision is damaged, and the precision at this time is called Dynamic accuracy. The press level is determined by the quality of the dynamic precision. The dynamic accuracy is directly related to the rigidity of each part of the press, and the high rigidity of the press has high dynamic precision. At present, foreign countries have produced highly rigid presses, and their dynamic accuracy can still be controlled within the static accuracy range. As shown in Table 1, under the static precision of the press, the good rigidity is divided into A special grade, A1 grade, and A2 grade, and the rigidity is generally divided into B grade, B1 grade, and B2 grade.