Improvement of stamping process for rear brake bas

2022-08-16
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Improvement of stamping process of automobile rear brake base plate

Abstract: This paper introduces the stamping process of large multi process stamping parts of thick plate, which is improved from the traditional single process stamping process to the multi station one-time stamping process. The production efficiency is improved and the manufacturing cost is reduced

key words: multi station; Stamping process; improvement; One time pressing

I. Introduction

the rear brake base plate of the automobile (Figure 1) is made of 08f-5gb3275, which is a workpiece with complex shape of medium and thick plate. The production process is blanking - punching - drawing forming - correction pressing - trimming - flanging forming - shaping - punching all holes, a total of seven processes. It has many processes, low production efficiency, high manufacturing costs and unstable product quality. Our company introduced Spanish se press, which has a large worktable (10m × 2m) and high tonnage. Through the improvement of the original process and mold, the multi station, transfer and one-time stamping process production is realized, and remarkable economic benefits are obtained

Figure 1 workpiece figure

II. Improvement measures

1 Traditional process production mode

the original production mode of this product is pressed on JD press, with a total of 7 processes and 7 sets of molds. During production, only one process can be carried out one by one, and one mold can be pressed one by one. See Figure 2 for the mold installation and production mode. The production cycle is long, and there are a lot of phenomena such as manual transfer, product collision and occupation of the production site, which have a negative impact on product quality and production organization

Figure 2 Schematic diagram of original mold installation

1 Machine tool workbench 2 Lower mold 3 Upper mold 4 Machine tool slider

2 The improved process production mode

changes the original single process operation to multi station, transfer production 10, industrial chain production, that is, the original 7 sets of molds are improved and installed on the se press with large worktable to realize the workpiece one-time pressing and forming. High work efficiency, low manufacturing cost and stable product quality

III. key points for improvement

1 The improvement of the mold

mainly solves the problem of the consistency of the sealing height of the seven molds. The static and dynamic detection, increase and decrease, trimming and adjustment of the existing mold sealing height are consistent, and meet the parameter requirements of the se press equipment. Finally, the sealing height is determined to be 1392.4mm. In order to ensure the accuracy, the improved 7 pairs of molds are at the same sealing height, and the simulation debugging is carried out on the JD press to demonstrate the accuracy of the sealing height

2. Determination of the station

the layout of the station should achieve the minimum eccentric load and the shortest transmission of the equipment slider

(1) calculate the stamping load of each process

p1 (blanking and punching) = 3240kn; P2 (drawing forming) = 2580kn; P3 (corrected profiling) = 3200kn; P4 (trimming) = 2260kn; P5 (flanging forming) = 2300kn; P6 (shaping) = 1500KN; P7 (punching all holes) = 1780kn. The total load is p total = 16860kn, and the load rate on Se press is only 42%, meeting the requirements

(2) station layout

in order to be better used on the se press, not only to produce qualified products, but also to ensure the safety performance of the equipment, we must try to avoid eccentric loads and reduce the impact of large stress differences on the equipment. Among the seven processes, the drawing process bears the earliest force and the largest force stroke, which is 44mm, while the working stroke of other molds is relatively small. Therefore, the drawing die is placed in the center of the machine tool workbench, and its station layout is shown in Figure 3 according to the load of each process

Figure 3 Schematic diagram of die installation and station layout after improvement

1 Machine tool slider 2 Upper mold 3 Lower mold 4 Lower mold base plate 5 Workbench

3 The stress state analysis

is shown in Figure 4, on the left Σ P left = 7240kn, right Σ P right = 7040kn, that is, the left side is 200kn more than the right side, which is 0.5% of the nominal pressure. Then calculate the moment of the three forces on both sides to the middle point as m left = -142368kn.m, m right = 145. The project department and the asset manager check 056kn.m, and the sum of the two moments is 2688kn.m (counterclockwise), that is, there is a 200kn eccentric load at the distance of 1.344m from the center, which has little impact on the equipment

Figure 4 stress state diagram

IV. conclusion

(1) the cast aluminum alloy of this process is improved by filling the mold with molten metal, which is different from the traditional progressive die, and changes that the multi station die is generally only used in small and medium-sized sheet metal stamping parts, which creates good conditions for the safe use of thick materials. The improvement of large-scale sheet metal stamping and drawing parts is successful and worthy of promotion. It changes the disadvantages of stamping products with multiple processes, single process production, long processing cycle, large manufacturing cost and so on

(2) the production cycle is greatly reduced. The production cycle of the original process is calculated as 500 pieces, and the production cycle is 15 days. The production of the new process can be completed in one day

(3) reduce energy consumption. JD press total power 55kva; The total power of Se press is 165kva. After calculation, the energy consumption of a single piece is 13.73kw h. The latter is only 2.64kw h. Reduce energy consumption by more than 5 times

(4) the improvement of the stamping process is generally limited by equipment conditions, and it is difficult to implement without large equipment. (end)

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