Analysis of a kind of integrated punching and overturning mechanism for automobile side wall die
This paper mainly introduces the process of punching and turning the auxiliary positioning hole at the rear wing of the side panel stamping parts. Aiming at the strength of the rear bumper of the side panel die and the accuracy requirements of the hole, a new type of punching and turning integrated mechanism is put forward in the development of the automobile side panel die. This mechanism can not only meet the needs of high-speed production, but also can not be affected by the environment It has the strength of the body and improves the accuracy of the positioning hole of the side wall pair.
During the trial assembly process of a certain project vehicle, the poor consistency and inheritance of the positioning holes on the welding fixture are caused by the quality defects of the plate hole accuracy, which directly affects the welding delivery progress and project node. After several rounds of debugging, the poor precision consistency of the auxiliary positioning holes of some parts can not be completely eliminated. Therefore, it is of great significance to study the causes and preventive measures in the process of punching to improve the quality of stamping parts.
We know that improving product quality and reducing manufacturing costs are the two most effective ways to improve competitiveness. In the manufacturing process of stamping die, simplifying the working procedure can directly reduce the cost. However, after reducing the working procedures, the punching and flanging originally processed in different sequences must be completed in the same sequence. This makes the traditional die structure not only can not fully meet the application requirements, but also the quality of the processed sheet metal can not be guaranteed.
Structure is usually used
As shown in Figure 1, the die in the figure is composed of upper die seat-1, punching and flanging structure-2, pressing core-3, flanging concave die-4, lower die body-5, sheet metal part-6 and punching scrap-7.
This structure has the following disadvantages.
Figure 1 mold is usually used
(1) when punching, there is no punching edge under the part, and there will be continuous scrap punching during the punching process.
(2) when punching, the part will be deformed and burr will be produced after punching.
(3) when punching, the hole is suspended below the punching boundary, the hole position is not accurate, and the hole edge is prone to deformation, resulting in inconsistent flanging length after flanging, and the hole diameter position changes, which can not meet the subsequent fixture positioning and plug installation.
(4) after the hole flanging, the flanging part of the workpiece is close to the die, and there is no ejection device, so it is difficult to take out the parts automatically.
(5) the accuracy of the hole diameter position is poor, which needs to be adjusted many times before it can meet the requirements, which increases the debugging cycle and cost of the mold.
To sum up, this structure can not fully meet the production requirements in the processing process, which affects the quality of the processed sheet metal parts, but also increases the manufacturing cost of the mold.
Fig. 4 mechanism regression diagram
Working principle of punching mechanism
As shown in Fig. 3, the punching punch 2 moves down with the upper die holder under the action of the slide block of the machine tool to contact the processed sheet metal part 6. At this time, the multi-functional ejector supports the sheet metal under the sheet metal to ensure that the sheet metal does not deform during punching, and the punching position is accurate; in addition, the inner ring of the multifunctional ejector is provided with a section of piercing edge matching with the edge of the piercing punch to make the punch continue to move down The moving punching process becomes a conventional punching process, eliminating the phenomenon of punching burr. After punching, the punch and flanging punch continued to go down, and the flanging process was completed by the flanging contour part and punching and flanging concave die 4. At the same time, the end of the flanging contour pressed the top of the multifunctional ejector and moved down for a certain distance, and the punching waste also entered the inner cavity of the multifunctional ejector.
As shown in Fig. 4, after the part forming, the punching punch moves up and back with the upper die seat under the action of the machine tool slider. If the punching waste 7 is adsorbed on the punch, it will be blocked when passing through the lower end of the piercing edge of the multi-functional ejector to separate it from the punch and fall off smoothly. After the punching punch exits the female die, the pressing plate will leave the sheet metal immediately. At this time, under the action of the auxiliary spring 9, the top of the multi-functional ejector pushes tightly the edge of the sheet metal after flanging and moves up a certain distance, so that the sheet metal which is locked in the die no longer has the clamping force with the die, so the sheet metal can be easily taken out of the lower die after processing, thus improving the production efficiency. The whole process meets the production requirements of punching and flanging in the same sequence, and also ensures the quality of parts after forming.
It has been proved by experiments that the structure can effectively solve the problems in the process of punching and turning holes in the same process: (1) continuous cutting of waste materials. (2) deformation of sheet metal. (3) waste material jumps back. (4) punching burr. (5) the punching position is not accurate. (6) the punching edge is deformed. (7) it is difficult to take parts. The actual production proves that the punching position of the structure is accurate, the consistency is high and the inheritance is good.
Conclusion
To sum up, this structure can not only fully meet the production requirements, improve the quality and precision of sheet metal, but also reduce the manufacturing cost of the die, which is of great significance to improve the quality of stamping parts.
2020-12-17