Pre-plating stamping salt mist improved die structure

Abstract

The utility model discloses a pre-plating stamping salt mist improved die structure, and relates to the technical field of punching dies, the die adopts a combined structure of an upper die holder and a lower die holder, symmetrical L-shaped tool bits are arranged at a rough cutting station, a rough cutting reserved groove of 1mm is reserved, a stamping stress concentration area is converted into a controllable transition surface, and the crack occurrence rate of a pre-plating layer is close to zero; and a rough cutting corner collapse area is accurately cut off through a U-shaped tool bit at the accurate cutting station, a zero-defect and full-covering plating layer protection layer is formed, and the salt fog resistance of the edge of the product is greatly improved.

Description

Technical Field

[0001] This utility model relates to the field of punching die technology, specifically to a pre-coated stamping salt spray to improve die structure. Background Technology

[0002] In existing pre-plating stamping processes, traditional mold structures (as shown in the attached image) Figure 1 As shown, a single-station, one-step punching forming scheme is typically adopted, where the upper die holder 1 and the lower die holder 2 are directly mounted on the adjacent surfaces. During production, the product shape is directly formed by the one-step punching of the upper and lower die holders. However, this structure has the following technical defects:

[0003] 1. High risk of pre-plating layer cracking: Because a single punching operation requires complete material severance, the stamping stress is concentrated in the contact area of ​​the cutting edge, causing micro-cracks to form in the pre-plating layer (such as the nickel layer) at corners or edges. Salt spray tests have verified that the propagation rate of such cracks reaches 0.3 mm / h, which is a major cause of salt spray failure.

[0004] 2. High costs associated with salt spray failure: After the pre-coating layer cracks, corrosive media penetrate along the cracks, causing a sharp decline in the product's corrosion resistance, resulting in a customer complaint rate as high as 12%-15%. To meet quality standards, companies need to invest an additional 30%-40% in rework and retesting, including plating removal, repair, and retesting.

[0005] 3. Conflict between mold life and efficiency: In order to reduce the risk of cracking, traditional solutions need to reduce the blade clearance (usually ≤0.05mm), but this leads to increased mold wear and shortens the maintenance cycle to less than 20,000 times, which is contrary to the high-efficiency production requirements of progressive dies. Utility Model Content

[0006] To address the shortcomings of existing technologies, this invention provides a pre-coated stamping salt spray improved mold structure, solving the problems mentioned in the background section.

[0007] To achieve the above objectives, this utility model is implemented through the following technical solution: a pre-plated stamping salt spray improvement mold structure, including an upper mold base and a lower mold base, wherein a roughing upper cutter head and a finishing upper cutter head are respectively installed on the lower part of the upper mold base, and a roughing lower cutter head and a finishing lower cutter head corresponding to the roughing upper cutter head and the finishing upper cutter head are respectively installed on the upper part of the lower mold base; a roughing reserved groove with a width of 1mm is reserved at the corner of both the roughing upper cutter head and the roughing lower cutter head.

[0008] Furthermore, both the upper and lower roughing cutter heads are configured as two symmetrically distributed "L"-shaped cutter head structures, and the upper and lower fine cutting cutter heads are configured as matching "U"-shaped structures.

[0009] Furthermore, the coarse cutting upper blade and the fine cutting upper blade are sequentially fixed to the lower surface of the upper mold base along the product material strip moving direction, and the coarse cutting lower blade and the fine cutting lower blade are sequentially fixed to the upper surface of the lower mold base along the product material strip moving direction.

[0010] Furthermore, the roughing groove is located at the inner corner of the "L"-shaped cutter head structure.

[0011] Furthermore, the width of the "U"-shaped opening of the upper precision cutting blade is 0.2mm-0.5mm smaller than the width of the "U"-shaped opening of the lower precision cutting blade.

[0012] This invention provides a pre-coating method for improving the structure of stamping salt spray molds. Compared with existing technologies, it has the following advantages:

[0013] This pre-coated stamping salt spray improves the mold structure by combining rough pre-forming and fine final forming. In addition, the 1mm rough pre-cut groove buffer design transforms the stress concentration area into a controllable transition surface, ensuring that the interface between the coating and the substrate is free of cracks and peeling risks, completely eliminating the "structural hidden danger" of salt spray corrosion. The fine cutting process precisely peels off the rough cut corner area, forming a zero-defect, fully covered coating protection layer. The salt spray resistance of the product edges breaks through the bottleneck of traditional processes and reaches the industry-leading level. Attached Figure Description

[0014] Figure 1 This is a schematic diagram showing the disassembled structure of a pre-coated stamping salt spray mold in the prior art;

[0015] Figure 2 This is a schematic diagram of the disassembled structure of this utility model;

[0016] Figure 3 This is a structural schematic diagram of the upper mold base in this utility model from a bottom-view perspective;

[0017] Figure 4 This is a top view of the structure of the lower mold base of this utility model;

[0018] Figure 5 This is a schematic diagram of the punching head before and after the improvement in this utility model;

[0019] Figure 6 This is a schematic diagram of the upper and lower precision cutting heads in this utility model.

[0020] In the diagram: 1. Upper die holder; 11. Upper punch cutter head; 2. Lower die holder; 21. Lower punch cutter head; 3. Roughing upper cutter head; 31. Roughing pre-cut groove; 4. Fine cutting upper cutter head; 5. Roughing lower cutter head; 6. Fine cutting lower cutter head; 7. Product strip. Detailed Implementation

[0021] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0022] Please see Figure 2-6 This utility model provides a technical solution: a pre-plating stamping salt spray improvement mold structure, including an upper mold base 1 and a lower mold base 2 arranged correspondingly. A coarse cutting upper cutter head 3 and a fine cutting upper cutter head 4 are sequentially fixedly installed on the lower surface of the upper mold base 1 along the product strip movement direction. A coarse cutting lower cutter head 5 and a fine cutting lower cutter head 6 are sequentially fixedly installed on the upper surface of the lower mold base 2 along the corresponding direction. The coarse cutting upper cutter head 3 and the coarse cutting lower cutter head 5 constitute a coarse cutting station, and the fine cutting upper cutter head 4 and the fine cutting lower cutter head 6 constitute a fine cutting station.

[0023] In the specific structure, both the upper roughing cutter head 3 and the lower roughing cutter head 5 adopt two symmetrically distributed "L"-shaped cutter head structures, and a roughing reserved groove 31 with a width of 1mm is provided at the right-angle inner corner.

[0024] The upper precision cutting head 4 and the lower precision cutting head 6 adopt a matching "U"-shaped structure, wherein the opening width of the upper precision cutting head 4 is 0.3mm smaller than that of the lower precision cutting head 6. This dimensional difference forms the shearing gap during precision cutting, and together with the double-sided cutting edge of the "U"-shaped structure, it can achieve a smooth cut of the product edge;

[0025] During the stamping process of the product strip 7, with the 1mm wide rough cutting pre-reserved groove 31, when the upper rough cutting head 3 cuts the product strip, it is equivalent to the cutting position being offset by 1mm. The stamping corner collapse crack will be within the range of 1mm. Then, relying on the fine cutting treatment of the lower rough cutting head 5 and the lower fine cutting head 6, the corner collapse crack is just cut off. The resulting product is crack-free and will not have corrosion problems after subsequent salt spray testing.

Claims

1. A pre-plating press salt fog improvement die structure comprising an upper die shoe (1) and a lower die shoe (2), characterized in that: The lower part of the upper die holder (1) is respectively equipped with a roughing upper cutter head (3) and a fine cutting upper cutter head (4), and the upper part of the lower die holder (2) is respectively equipped with a roughing lower cutter head (5) and a fine cutting lower cutter head (6) corresponding to the roughing upper cutter head (3) and the fine cutting upper cutter head (4); a roughing reserved groove (31) with a width of 1mm is reserved at the corner of the roughing upper cutter head (3) and the roughing lower cutter head (5).

2. A pre-plated press salt fog improvement mold structure according to claim 1, wherein The upper roughing cutter (3) and the lower roughing cutter (5) are both set as two symmetrically distributed "L"-shaped cutter structures, and the upper fine cutting cutter (4) and the lower fine cutting cutter (6) are set as matching "U"-shaped structures.

3. A pre-plated stamping salt mist improvement mold structure according to claim 1, wherein The coarse cutting upper cutter head (3) and the fine cutting upper cutter head (4) are sequentially fixed to the lower surface of the upper mold base (1) along the product material strip moving direction, and the coarse cutting lower cutter head (5) and the fine cutting lower cutter head (6) are sequentially fixed to the upper surface of the lower mold base (2) along the product material strip moving direction.

4. A pre-plated stamping salt mist improvement mold structure according to claim 1, wherein The roughing groove (31) is located at the inner corner of the "L"-shaped cutter head structure.

5. A pre-plated stamping salt mist improvement mold structure according to claim 1, wherein The width of the "U"-shaped opening of the upper precision cutting head (4) is 0.2mm-0.5mm smaller than the width of the "U"-shaped opening of the lower precision cutting head (6).

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