Stamping part springback control method
The best time to reduce or eliminate springback is in the product design and mold development stage. With the help of analysis, the springback amount can be accurately predicted, the product design and process can be optimized, and the product shape, process and compensation can be used to reduce springback. In the mold debugging stage, the mold must be tested strictly in accordance with the guidance of process analysis. Compared with ordinary SE analysis, the workload of springback analysis and correction has increased by 30% to 50%, but it can greatly shorten the mold debugging cycle.
Springback is closely related to the drawing forming process. Under different drawing conditions (tonnage, stroke and feed rate, etc.), although there are no forming problems in stamping parts, the springback after trimming will be more obvious. The same software is used for springback analysis and drawing forming analysis, but the key is how to set the analysis parameters and effectively evaluate the springback results.
Springback control of special-shaped parts
During the development of the left and right door sills of the front floor, a 4° springback phenomenon occurred (see Figure 6). Figure 6 marks the springback position and degree of the part. According to the springback position and degree of the part, the countermeasures shown in Figure 7 are made. In the process route, the shaping 4° is also added, and the third shaping sequence is added. At the same time, the mold shaping insert material is Cr12MoV, and the hardness needs to reach HRC58~62.
Springback control of L-shaped parts
L-shaped parts of a certain model swing arm reinforcement plate parts, generally L-shaped parts are developed with the same mold for left and right countermeasures. In order to prevent the existence of lateral force, which causes the formed parts to shift, the springback rectification of L-shaped parts developed symmetrically on the left and right is basically the same as that of U-shaped parts.
U-shaped parts springback control
Generally, U-shaped parts are prone to springback. Figure 1 is a schematic diagram of the front part of the inner plate of the left/right front longitudinal beam of a certain model and the overlap relationship on the whole vehicle. It can be seen from Figure 1 that this part has a springback problem during the development process. Figure 2 shows the springback location and specific springback amount of the part. After repeated analysis and communication with the designer based on its overlap relationship, the part was changed to increase the length of the reinforcing ribs, increase the shaping sequence in the mold itself, and set the shaping of 1~3.5 mm.
The shaping sequence is added to the process sequence, and the entire side wall of the part is shaped to ensure that there is no springback phenomenon in the part. As shown in Figure 5, the shaping insert is added to the side punch sequence after the assembly, and the mold inserts are all made of Cr12MoV material to ensure that the quenching hardness reaches HRC58~62. Finally, this plan was determined, and the mold was changed according to this plan. It was verified on site that there was no springback phenomenon in the formed part.
Based on the experience of developing models in the past, the details of parts that are prone to springback can be determined, and the development process for such parts can be applied.
