Continuous punch forming method for belleville spring with compression amount of 70%

Abstract

The invention relates to a continuous punch forming method for a disc spring with the compression amount of 70%, which comprises the following steps of: punching a positioning hole, punching an inner hole, chamfering the inner side, pre-stabbing the shape and blanking and forming, namely, pre-stabbing a circular processing area downwards to 60-70% of the thickness of a material belt according to the outline of the outer edge of the disc spring; and in the blanking forming step, the round machining area and the positioning connecting area are punched off, and the disc spring body is formed in the round machining area at the same station. In the pre-stabbing process, a height difference is generated between materials on the two sides of the outline through a mold, and then in the material tearing process, 30-40% of thickness connection can be reserved only when the tearing is not complete, so that the connection strength of the outline part is greatly reduced, but the circular machining area is still connected to the positioning connection area. In this way, the tensile stress in material flowing can be reduced in follow-up machining, and local thinning is avoided. Processing continuity is achieved, and operation efficiency is high. The obtained belleville spring with the compression amount of 70% is high in bearing capacity.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of stamping processing, in particular to a continuous stamping forming method of a 70% compression amount disc spring. BACKGROUND

[0002] The disc spring is also known as Belleville spring washer, disc spring or butterfly washer, which is a washer type spring with a truncated cone section made of sheet metal or a forged blank. The disc spring is a special spring that is conical in the axial direction and bears load. After bearing load deformation, it stores a certain potential energy. When the bolt loosens, the disc spring releases part of the potential energy to maintain the pressure between the flanges to meet the sealing requirements. The stress distribution of the disc spring decreases uniformly from the inside to the outside, which can achieve the effect of low stroke and high compensation force.

[0003] The prior art disc spring generally has only a 50% compression amount. Its production method is to first blanking, that is, to punch out the inner hole and outer circle of the disc spring, and then to stamp forming. The process is more and more, and the production efficiency is low. And the existing disc spring forming die is easy to cause material thinning during processing, and the stress distribution of the product is uneven, which affects the stability of the elastic force performance. CN210788855U discloses a method for processing disc spring washer, which completes disc spring processing through multi-step stamping and forming cooperation, but its material flow control still has limitations, and it is difficult to fully solve the stress concentration problem in the forming process. For a disc spring with a 70% compression amount, its axial size will be larger. If the thickness is not enough, non-elastic deformation will occur. However, if the previous processing technology is blanking first, the conical deformation cannot be continuous, the positioning is not convenient, and the processing efficiency is also affected. If the blanking is after, the edge of the product will be pulled by the material belt, causing the material thickness to be thinned during conical deformation, which cannot meet the load requirement.

[0004] Therefore, it is necessary to design a new forming method to solve the above problems. SUMMARY

[0005] The main purpose of the present application is to provide a continuous stamping forming method of a 70% compression amount disc spring, which can form a large load disc spring with a 70% compression amount, and the process is continuous and the precision is high.

[0006] The present application achieves the above-mentioned purpose through the following technical scheme: a continuous stamping forming method of a 70% compression amount disc spring, the disc spring comprising a disc spring body with a conical surface structure, the disc spring body having a disc spring inner hole with a circular shape inside and a disc spring outer edge with a circular shape outside, the method steps comprising: S1. Punching positioning holes: Prepare a strip of material. The processing unit of the strip includes a positioning connection area and a circular processing area. The circular processing area is arranged in segments along the conveying direction of the strip. Using the beginning and sides of the strip as positioning references, a positioning hole is cut out within the positioning connection area. S2. Punching inner hole: Using the positioning hole as a reference, punch out the inner hole of the disc spring at the center of the circular machining area; S3. Inner chamfer: Using the positioning hole as a reference, the edge of the inner hole of the disc spring is chamfered to remove the burrs caused by punching. S4. Pre-burring of the outer shape: Using the positioning hole as a reference, pre-burring the circular processing area downwards to 60-70% of the material strip thickness according to the outline of the outer edge of the disc spring. S5. Blanking and forming: Using the positioning hole as a reference, the circular processing area and the positioning connection area are punched off and the circular processing area is formed into the disc spring body at the same station.

[0007] Specifically, the disc spring body has an inner diameter of 10.60 mm, an outer diameter of 16.5 mm, and a free height of 0.57 mm.

[0008] Furthermore, the disc spring is made of high-temperature alloy steel, and its minimum elastic force is 1350N.

[0009] Specifically, each processing unit includes multiple circular processing areas, and the positioning hole is located at the center of the outer circle of the adjacent circular processing area.

[0010] The beneficial effects of the technical solution of this invention are: 1. Pre-piercing involves using a die to create a height difference between the two sides of the material on the above contour, which then tears the material. However, this tearing is incomplete, leaving 30-40% of the thickness connected. This significantly reduces the connection strength of the contour portion, but the circular processing area remains connected to the positioning connection area. This reduces tensile stress during material flow in subsequent processing, preventing localized thinning. 2. When the circular machining area has an annular structure, the inner and outer circles of the annular structure can maintain good concentricity under the constraint of the positioning hole. Since the circular machining area has not yet been blanked, subsequent steps can still use the positioning hole as the reference and the center of the annular structure as the stamping reference, so that the annular structure becomes a conical surface structure, the machining is continuous and the operation efficiency is high; 3. The load-bearing capacity of a disc spring with 70% compression after processing can be increased to a minimum of 1350N, which is much higher than that of a disc spring with 50% compression. Attached Figure Description

[0011] Figure 1 This is a top-view diagram showing the changing state of the material strip; Figure 2 This is a cross-sectional diagram showing the changes in the material strip structure.

[0012] The diagram is marked as follows: 1-Disc spring, 11-Disc spring body, 12-Disc spring inner hole, 13-Disc spring outer edge; 2-Material strip, 21-Positioning connection area, 211-Positioning hole, 22-Circular processing area, 221-Chamfer. Detailed Implementation

[0013] The present invention will be further described in detail below with reference to specific embodiments.

[0014] Example: like Figure 2 As shown, the disc spring 1 includes a disc spring body 11 with a conical surface structure. The disc spring body 11 has a circular disc spring inner hole 12 inside and a circular disc spring outer edge 13 outside.

[0015] like Figure 1 and Figure 2 As shown, a continuous stamping method for forming a disc spring with 70% compression is used to form the disc spring 1. The process steps include: S1. Punching positioning holes: Prepare a strip 2. The processing unit of the strip 2 includes a positioning connection area 21 and a circular processing area 22. The circular processing area 22 is arranged in segments along the conveying direction of the strip 2. Using the beginning and sides of the strip 2 as references, cut two positioning holes 211 within the positioning connection area 21.

[0016] The position of the positioning hole 211 corresponds to each mold station and is used as a precise positioning reference for subsequent processes.

[0017] In embodiments where the processing unit includes only one circular processing area 22, the two positioning holes 211 are preferably located on both sides of the positioning connection area 21. In some embodiments, the processing unit may have multiple circular processing areas 22 arranged side by side. The positioning holes 211 may also be located at the center of the outer circle of an adjacent circular processing area 22. For example, when the circular processing areas 22 are arranged in a multi-column straight arrangement, the positioning holes 211 may be located at the center of the outer circle of four adjacent circular processing areas 22; if the circular processing areas 22 are arranged in a multi-column staggered arrangement, the positioning holes 211 may be located at the center of the outer circle of three adjacent circular processing areas 22.

[0018] To meet certain heat resistance requirements, high-temperature alloy steel can be selected as the material for strip 2. For example, in automotive engine exhaust gas monitoring, high-temperature alloy steel can withstand an operating environment temperature of 650℃.

[0019] S2. Punching inner hole: Using the positioning hole 211 as a reference, punch out the disc spring inner hole 12 in the center of the circular machining area 22.

[0020] The diameter of the disc spring inner hole 12 is determined according to the product design requirements. Its edges are smooth and burr-free to ensure the smooth progress of subsequent processes. In this embodiment, the inner diameter of the disc spring body 11 (i.e., the diameter of the disc spring inner hole 12) is 10.60 mm, the outer diameter (i.e., the outer diameter of the disc spring outer edge 13) is 16.5 mm, and the free height is 0.57 mm.

[0021] S3. Inner chamfer: Using the positioning hole 211 as a reference, the edge of the inner hole 12 of the disc spring is chamfered in the circular machining area 22 to remove the burrs caused by punching.

[0022] The angle and depth of chamfer 221 are precisely calculated to avoid material weakening due to excessive chamfering or affecting the subsequent forming quality due to insufficient chamfering.

[0023] S4. Pre-burring of the outer shape: Taking the positioning hole 211 as the reference, pre-burring the circular processing area 22 downwards to 60~70% of the material strip thickness according to the outline of the outer edge 13 of the disc spring.

[0024] Pre-burring is essentially a process where a height difference is created between the two sides of the material on the contour using a die, causing the material to tear. However, this tearing is incomplete, leaving 30-40% of the thickness connected. This significantly reduces the connection strength of the contour portion, but the circular machining area 22 remains connected to the positioning connection area 21. This reduces tensile stress in the material flow during subsequent processing, preventing local thinning. At this point, the circular machining area 22 is essentially just a ring structure. Under the constraint of the positioning hole 211, the inscribed circle and circumscribed circle of the ring structure maintain good concentricity. Because the circular machining area 22 has not yet been blanked, subsequent steps can still use the positioning hole 211 as a reference and the center of the ring structure as the stamping reference, transforming the ring structure into a conical surface structure. This ensures continuous processing and high work efficiency.

[0025] S5. Blanking and forming: Taking the positioning hole 211 as the reference, the circular processing area 22 and the positioning connection area 21 are punched off and the circular processing area 22 is formed into the disc spring body 11 in the same station.

[0026] The pre-punching of the outer shape has basically separated the circular processing area 22 from the positioning and connecting area 21. Therefore, the mold in this step only needs to apply a little pressure to completely separate the material. The material on the outer side of the outline will not pull the material on the inner side. At the same station, the circular processing area 22 is pressed from the flat sheet structure into a conical surface, which is equivalent to center positioning. Therefore, it can be directly formed when blanking to ensure that the material thickness is evenly distributed. When the mold is opened, the already formed disc spring 1 will automatically slide out.

[0027] The disc spring 1 with 70% compression, after being processed in this way, can have a minimum load capacity of 1350N, which is much higher than that of a disc spring with 50% compression (maximum load capacity of 1100N).

[0028] The above descriptions are merely some embodiments of the present invention. Those skilled in the art can make various modifications and improvements without departing from the inventive concept of the present invention, and these all fall within the scope of protection of the present invention.

Claims

1. A continuous stamping method for a disc spring with 70% compression, the disc spring comprising a disc spring body with a conical surface structure, the disc spring body having a circular inner hole and a circular outer edge, characterized in that... The method steps include: S1. Punching positioning holes: Prepare a strip of material. The processing unit of the strip includes a positioning connection area and a circular processing area. The circular processing area is arranged in segments along the conveying direction of the strip. Using the beginning and sides of the strip as positioning references, a positioning hole is cut out within the positioning connection area. S2. Punching inner hole: Using the positioning hole as a reference, punch out the inner hole of the disc spring at the center of the circular machining area; S3. Inner chamfer: Using the positioning hole as a reference, the edge of the inner hole of the disc spring is chamfered to remove the burrs caused by punching. S4. Pre-burring of the outer shape: Using the positioning hole as a reference, pre-burring the circular processing area downwards to 60-70% of the material strip thickness according to the outline of the outer edge of the disc spring. S5. Blanking and forming: Using the positioning hole as a reference, the circular processing area and the positioning connection area are punched off and the circular processing area is formed into the disc spring body at the same station.

2. The continuous stamping forming method for a 70% compression disc spring according to claim 1, characterized in that: The disc spring body has an inner diameter of 10.60 mm, an outer diameter of 16.5 mm, and a free height of 0.57 mm.

3. The continuous stamping forming method for a 70% compression disc spring according to claim 1, characterized in that: The disc spring is made of high-temperature alloy steel and has a minimum spring force of 1350N.

4. The continuous stamping method for a 70% compression disc spring according to claim 3, characterized in that: Each processing unit includes multiple circular processing areas, and the positioning hole is located at the center of the outer circle of the adjacent circular processing area.

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