Forming die for anti-corrosion fastener

Abstract

The utility model relates to a forming die of an anti-corrosion fastener, the fastener comprises a head part and a rod part, the radial outer edge of the head part towards the end face of the rod part is in R angle smooth transition, the forming die is characterized by comprising an upper die core with an upper die cavity and a lower die core with a lower die cavity, a groove is formed in the periphery of a cavity body of the lower mold cavity in the position, corresponding to the upper mold cavity, of the surface, facing the upper mold core, of the lower mold core, and the radial outer edge of the groove is in R-angle smooth transition; the difference between the diameter of the top of the groove and the diameter of the bottom plane of the groove is smaller than or equal to 1 mm. The fastener manufactured by the forming die is in smooth transition, so that the current concentration of a sharp point of a product during electroplating is avoided, and the salt spray test resistance is improved.

Description

Technical Field

[0001] This utility model relates to the field of molding die technology for automotive parts, specifically to a molding die for corrosion-resistant fasteners with an arc-shaped surface used in automotive assembly. Background Technology

[0002] With the development of science and technology, and the progress and innovation of technology, automobile products are changing rapidly, which also puts forward higher technical requirements for stamped parts and fasteners. Whether the fasteners used in automobile parts are corroded is a decisive factor for the safe driving of vehicles.

[0003] Fasteners, as a type of mechanical part, are cylindrical threaded fasteners fitted with nuts or cylindrical pins with rods. They consist of a head and a rod, and are used to connect two parts with through holes. Fasteners are widely used in various industries, but different industries have different strength requirements for fasteners. Current fastener technology often features sharp corners on the outer edge of the end face of the fastener head, such as... Figure 1 As shown at point A, sharp corners often cause scratches on fasteners during transportation or production, leading to failure in salt spray tests and affecting product lifespan; existing fastener head forming molds, such as Figure 2 As shown, the upper mold core and the lower mold core are connected at an angle, so the resulting shape is a sharp corner.

[0004] Therefore, there is still room for improvement in the forming molds of existing fasteners. Utility Model Content

[0005] The purpose of this invention is to provide a molding die for corrosion-resistant fasteners with an arc-shaped surface for automotive assembly, in order to solve the existing technical problems.

[0006] To achieve the above objectives, this utility model provides a molding die for an anti-corrosion fastener. The fastener includes a head and a rod. The radial outer edge of the end face of the head facing the rod has a smooth R-angle transition. The molding die includes an upper mold core with an upper cavity and a lower mold core with a lower cavity. A groove is formed on the outer periphery of the lower mold core on the surface of the lower mold core corresponding to the position of the upper mold core. The radial outer edge of the groove has a smooth R-angle transition. The difference between the top diameter and the bottom plane diameter of the groove is ≤1mm.

[0007] According to the preferred embodiment of the present invention, the top diameter of the groove is less than or equal to 10 mm, the height difference h between the two ends of the R-angle arc of the groove is 0.2 mm, and R = 4h.

[0008] According to the preferred embodiment of the present invention, the top diameter of the groove is greater than 10 and less than or equal to 20 mm, the height difference h between the two ends of the R-angle arc of the groove is 0.3 mm, and R = 4h.

[0009] The design concept of this application is to change the processing scheme of fasteners and design a molding die for corrosion-resistant fasteners, so as to realize the transition from sharp edges to smooth edges, improve the wear resistance between parts and the impact of collisions on the protective layer; the smooth transition helps to avoid the problem of current concentration at the sharp points of the product during electroplating, and the salt spray test resistance can be improved by 240-480 hours. The fastener structure is reliable, achieving safe production and improving the company's market competitiveness. The bolt fastener designed in this way is suitable for both manual assembly and automated assembly. The smooth transition structure is reliable, and the assembly process effectively controls the problem of collision damage, improving the company's efficiency and reducing production risks.

[0010] Compared with the prior art, the present invention has the following advantages:

[0011] First, the smooth transition of this application helps to avoid current concentration at the product's sharp points during electroplating, thus improving its resistance to salt spray tests.

[0012] Secondly, the fasteners manufactured by the molding die of this application have a reliable structure, achieving safe production and improving the company's market competitiveness.

[0013] Of course, implementing any specific embodiment of the content of this application does not necessarily have all of the above technical effects at the same time. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of existing fasteners;

[0015] Figure 2 This is a schematic diagram of a mold part in the existing technology.

[0016] Figure 3 This is a schematic diagram of the fasteners used in this application;

[0017] Figure 4 This is a schematic diagram of the molding die part of this application;

[0018] Figure 5 for Figure 4 Enlarged diagram of the middle radius (R-angle);

[0019] Figure 6 for Figure 4 Enlarged diagram. Detailed Implementation

[0020] The present invention will be described in detail below with reference to the accompanying drawings.

[0021] Please refer to Figure 3 This application presents a schematic diagram of a fastener. This application modifies the processing scheme of the fastener to achieve a smooth transition from sharp edges, improving the resistance of parts to wear and impact on the protective layer. The smooth transition helps to avoid the problem of current concentration at the product's sharp points during electroplating, and can improve the salt spray test resistance. Such bolt fasteners are suitable for both manual and automated assembly. The smooth transition structure is reliable, and the assembly process effectively controls the problem of collision damage, reducing production risks.

[0022] Please refer to Figure 3 , Figure 4 , Figure 5 and Figure 6 This application discloses an anti-corrosion fastener, comprising a head 10 and a shank 20, which are integrally formed. The radial outer edge of the end face of the head 10 facing the shank 20 is smoothly transitioned by an R-angle, which is integrally stamped. The difference between the outer diameter of the head 10 and the diameter of the bottom plane of the head 10 is ≤1mm, and this difference is not 0. In this embodiment, the head 10 is a straight head, so the outer diameter of the head 10 is the same from top to bottom. If the head 10 is not a straight head, then the outer diameter of the head 10 refers to the diameter of the first plane connected to the R-angle, that is, the difference between the plane diameters of the two ends of the arc of the R-angle is ≤1mm. Figure 6 As shown, the value of D1 is larger than the value of D2, and the difference between the two is ≤1mm.

[0023] Regarding the height difference between the planes at both ends of the arc of the R-angle, as follows: Figure 5 and Figure 6 As shown, when the outer diameter of the head 10 is less than or equal to 10mm (D1≤10mm), the height difference h between the two ends of the R-angle arc of the head 10 is 0.2mm, R=4h, that is, R=4x0.2mm=0.8mm, which means the radius of the arc is 0.8mm.

[0024] In another embodiment of this application, regarding the height difference between the two ends of the arc of the R-angle, when the outer diameter of the head 10 is greater than 10mm and less than or equal to 20mm (10mm < D1 ≤ 20mm), the height difference h between the two ends of the arc of the R-angle of the head 10 is 0.3mm, R = 4h, that is, R = 4 x 0.3mm = 1.2mm, which represents that the radius of the arc is 1.2mm.

[0025] Please refer to Figure 4This application presents a schematic diagram of the molding die. The molding die includes an upper mold core 30 with an upper mold cavity 31 and a lower mold core 40 with a lower mold cavity 41. During molding, the rod portion 20 of the workpiece is inserted into the lower mold cavity 41, and the head 10 of the workpiece is placed on the upper surface of the lower mold core 40 to await stamping and forming a rounded radius (R-angle). A groove 42 is formed on the surface of the lower mold core 40 facing the upper mold core 30, corresponding to the position of the upper mold cavity 31, around the cavity of the lower mold cavity 41. The radial outer edge of the groove 42 has a smooth R-angle transition. Figure 5 As shown, the inner edge of the upper mold cavity 31 corresponds to one end of the R-angle of the groove 42. During molding, the inner edge of the upper mold cavity 31 and the groove 42 enclose each other, making the head 10 form a smooth R-angle transition. The difference between the top diameter and the bottom plane diameter of the groove 42 is ≤1mm, and this difference is not 0, that is, the difference between the plane diameters of the two ends of the arc of the R-angle after molding is ≤1mm. Figure 6 As shown, the value of D1 is larger than the value of D2, and the difference between the two is ≤1mm.

[0026] Regarding the height difference between the planes at the two ends of the arc of the R-angle of the groove 42, as follows: Figure 5 and Figure 6 As shown, when the top diameter of the groove 42 is less than or equal to 10mm (D1≤10mm), the height difference h between the two ends of the R-angle arc of the groove 42 is 0.2mm, R=4h, that is, R=4x0.2mm=0.8mm, which means that the radius of the arc of the groove 42 is 0.8mm.

[0027] In another embodiment of this application, regarding the height difference between the two ends of the arc of the R-angle of the groove 42, when the top diameter of the groove 42 is greater than 10mm and less than or equal to 20mm (10mm < D1 ≤ 20mm), the height difference h between the two ends of the arc of the R-angle of the groove 42 is 0.3mm, R = 4h, that is, R = 4 x 0.3mm = 1.2mm, which means that the radius of the arc of the groove 42 is 1.2mm.

[0028] It should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this application.

[0029] In the description of this application, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is usually based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this application and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this application; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0030] At the same time, it should be understood that, for ease of description, the dimensions of the various parts shown in the accompanying drawings are not drawn according to actual scale.

[0031] Compared with the prior art, the present invention has the following advantages:

[0032] First, the smooth transition of this application helps to avoid current concentration at the product's sharp points during electroplating, thus improving its resistance to salt spray tests.

[0033] Secondly, the fasteners manufactured by the molding die of this application have a reliable structure, achieving safe production and improving the company's market competitiveness.

[0034] The above-disclosed embodiments are only a few specific examples of this utility model, but this utility model is not limited thereto. Any variations that can be conceived by those skilled in the art should fall within the protection scope of this utility model.

Claims

1. A forming die for an anti-corrosion fastener, the fastener comprising a head portion and a shank portion, a radially outer extent of an end face of the shank portion being R-anguiy rounded over, characterised in that, The forming die comprises an upper die core with an upper die cavity and a lower die core with a lower die cavity, a groove is opened on the cavity periphery of the lower die cavity corresponding to the position of the upper die cavity on the face of the upper die core towards the upper die core, the radial outer edge of the groove is R angle smooth transition; the difference between the top diameter of the groove and the bottom flat diameter of the groove is ≤1mm.

2. The corrosion-resistant fastener forming die of claim 1, wherein, The top diameter of the groove is less than or equal to 10mm, the height difference h of the R angle arc ends of the groove is 0.2mm, and R=4h.

3. The corrosion-resistant fastener forming die of claim 1, wherein, The top diameter of the groove is greater than 10 and less than or equal to 20mm, the height difference h of the R angle arc ends of the groove is 0.3mm, and R=4h.

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