A stamping die having double arc-shaped blade punches

Abstract

The utility model provides a stamping die with double arc blade punch, designs the punch into double arc blade structure, is equivalent to bevel blade blanking but is superior to bevel blade, can greatly reduce the blanking area and is more favorable to the shearing of narrow and long hole, realizes finally the part processing, guarantees product quality. Through the change of the arc section size of punch, this stamping die can process the narrow and long hole of the same kind of different sizes, has good popularization value.

Description

Technical Field

[0001] This utility model belongs to the field of mechanical cold working technology, specifically relating to a stamping die with a double arc-shaped punch. Background Technology

[0002] For a U-shaped part with a narrow, elongated hole (structure such as...) Figure 1a and 1b As shown), its material is No. 10 steel, and its shear strength is 26-34 kgf / mm². 2 The yield strength is 21 kgf / mm. 2 The thickness of the side plate containing the narrow, elongated hole is 4.5mm, the thickness of the bottom plate is 4.0mm, and the thickness of the opposite side plate is 4.0mm. The distance between the opposite end faces of the two side plates is 28mm, and the length of the narrow, elongated hole is 80mm. +0.2 mm, width 4 +0.1 mm, length-to-width ratio 20:1. The main processing methods for narrow, elongated holes include die stamping, milling, laser cutting, and waterjet cutting. For the narrow, elongated holes in the aforementioned U-shaped parts, milling can be used in production, but the disadvantage is that the four corners of the hole need to be cleaned, and the processing efficiency is low, which cannot meet production volume requirements. Therefore, die stamping is the preferred method. The die for punching holes can usually be designed with either a flat blade or a beveled blade. Assuming the punch is designed as a standard flat blade punch, the punching force on the part is the greatest. Calculations show that:

[0003] The blanking force P of the flat-blade punch 平 :

[0004] P 平 =KBtτ=1.3×2×(80+4)×4.5×34=33415.2kgf

[0005] Where K is the correction factor, with a value of 1.3; B is the perimeter of the object being sheared (in mm); t is the thickness of the object being sheared (in mm); and τ is the shear strength of the material, with a value of 34 kgf / mm². 2 .

[0006] The base plate of the U-shaped part is subjected to a force F1:

[0007] F1=(33415.2 / (80×4))×(80 / (2×(80+4.5)))=49.43kgf / mm 2

[0008] Because the stress F1 on the base plate is greater than the yield strength of No. 10 steel (21 kgf / mm²), 2 This can cause the parts to deform.

[0009] The above analysis shows that due to the large quantity of products and the special structure of the parts, both flat-blade and ordinary oblique-blade dies can cause deformation of the parts during processing. Therefore, to punch qualified narrow and long holes, it is necessary to consider reducing the punching area while increasing the shearing force on the bottom plate of the part. Thus, only by designing a special punch structure that balances both aspects can the processing requirements of the parts be met and product quality guaranteed. Utility Model Content

[0010] (a) Technical problems to be solved

[0011] This invention proposes a stamping die with a double-arc-shaped punch to solve the technical problems of how to improve production efficiency, ensure hole processing quality, and prevent product deformation.

[0012] (II) Technical Solution

[0013] To solve the above-mentioned technical problems, this utility model proposes a stamping die with a double arc-shaped blade punch, wherein the punch of the stamping die has a double arc-shaped blade structure.

[0014] Furthermore, the punch is made of Cr12MoV material.

[0015] Furthermore, the centers of the double arcs of the punch fall on the extension lines of the two end faces of the punch, respectively.

[0016] Furthermore, the intersection point of the two arcs of the punch is located on the center line of the punch.

[0017] Furthermore, the stamping die also includes guide pillars, a lower die base, guide sleeves, an upper die base, a die cavity, a fixing plate, and a pressure plate; wherein, the lower ends of the two guide pillars are pressed into the lower die base respectively, and the two guide sleeves are pressed into the upper die base respectively and sleeved on the upper ends of the guide pillars; the die cavity is fixed on the lower die base; the punch is fixed on the fixing plate, and the fixing plate is fixedly connected to the upper die base; the upper die base is installed on the die shank; and a pressure plate is installed on the die cavity.

[0018] Furthermore, the die is fixed to the lower die base by screws and pins.

[0019] Furthermore, the double-arc-shaped punch is pressed into the fixed plate by an interference fit.

[0020] Furthermore, the fixing plate is fixedly connected to the upper mold base by screws.

[0021] Furthermore, the upper mold base is mounted on the mold shank by screws.

[0022] Furthermore, a pressure plate is installed on the die cavity, using the limiting step on the die cavity as a reference.

[0023] (III) Beneficial Effects

[0024] This invention proposes a stamping die with a double-arc-shaped punch. The punch is designed with a double-arc-shaped blade structure, equivalent to but superior to oblique cutting. This significantly reduces the cutting area and is more conducive to shearing narrow, elongated holes, ultimately achieving part processing and ensuring product quality. By changing the size of the arc portion of the punch, this stamping die can process similar narrow, elongated holes of different sizes, making it highly valuable for widespread application. Attached Figure Description

[0025] Figure 1a This is a front view of a U-shaped part with a narrow, elongated hole. Figure 1b This is a side view;

[0026] Figure 2a This is a front view of the double-arc-shaped punch in this utility model. Figure 2b This is a side view;

[0027] Figure 3 This is a schematic diagram of the process of shearing blanks with a double-arc blade punch in this utility model;

[0028] Figure 4 This is a schematic diagram of the stamping die structure with a double-arc-shaped punch according to the present invention. Detailed Implementation

[0029] To make the objectives, contents, and advantages of this utility model clearer, the specific embodiments of this utility model will be described in further detail below with reference to the accompanying drawings and examples.

[0030] This embodiment proposes a stamping die with a double-arc-shaped punch. The punch used in this stamping die has a double-arc-shaped blade structure and is made of Cr12MoV material. Figure 2a and 2b As shown. For ease of production and processing, the centers of the double arcs fall on the extension lines of the two end faces of the punch. Since the distance between the opposite end faces of the two side plates is 28mm, the safe distance from the end of the punch stroke to the bottom surface of the workpiece is set at 14mm. The intersection point of the two arcs is located on the center line of the punch. Therefore, it can be calculated using the following formula: (R-14) 2 +40 2 =R 2 Solving for R, we get R = 64.14 mm. Rounding further, R ≈ 64 mm. We then calculate the punching force generated by the double-arc punch:

[0031] P 弧 =KSτ=1.3×(4S 截 +2×4.5×4)×10 -6 ×34×10 7

[0032] Area S 截It is the sum of the areas of the four approximately sector-shaped cross-sections and the two side rectangular cross-sections at the instant the double-arc-bladed punch completely shears off the blank. The maximum single approximately sector cross-sectional area S during stamping is calculated using PROE software. 截 (like Figure 3 (As shown in the shaded area):

[0033] S 截 =59.7709mm 2 ≈60mm 2

[0034] P 弧 =121992 N, at this time the base plate is subjected to a force F2:

[0035] F2=(121992 / 334152)×48.53×10 7 =17.7173×10 7 kgf / mm 2

[0036] Because the stress F2 on the base plate is less than the yield strength of No. 10 steel (21 kgf / mm²), 2 Therefore, the parts will not deform. This demonstrates that the double-arc punch can indeed prevent part deformation while ensuring the quality of the punching.

[0037] When using a stamping die with a double-arc-shaped punch, such as Figure 3 As shown, the lower ends of the two guide pillars 1 are pressed into the lower die base 2, and the two guide sleeves 3 are pressed into the upper die base 4 and fitted onto the upper ends of the guide pillars 1; the die cavity 5 is fixed to the lower die base 2 using screws and pins; the double arc-shaped punch 6 is pressed into the fixing plate 7 by interference fitting, and the fixing plate 7 is fixedly connected to the upper die base 4 by screws; the upper die base 4 is installed on the die shank by screws; using the limiting step on the die cavity 5 as a reference, the pressure plate 8 is installed on the die cavity 5; the upper and lower dies are closed, the pressure and the clearance between the upper and lower dies are adjusted, and after a trial punch, formal processing begins. Before punching, the part is placed on the die cavity 5 and pressed tightly. During operation, the double-arc-bladed punch 6 moves downwards. The tip of the double-arc-bladed punch 6 first contacts the part, pressing the blank inwards, and then punching a double-arc-shaped slit with a shearing surface on each side. The double-arc-bladed punch 6 continues to descend, and due to the action of the die 5 and the bottom plate of the part, the cut gradually expands to both sides along the die 5. When the double-arc part of the arc-bladed punch 6 moves downwards to the cutting edge position of the die 5, it shears the blank, punches a narrow and long hole, and the waste material falls off. The hole cross-section on one side of the bottom plate has slight burrs, which are removed by the process. The other sides are of good quality and do not require processing.

[0038] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A stamping die with a double-arc-shaped punch, characterized in that, The punch of the stamping die has a double arc-shaped blade structure; the stamping die also includes guide pillars, a lower die base, guide sleeves, an upper die base, a die cavity, a fixing plate, and a pressure plate; wherein, the lower ends of the two guide pillars are pressed into the lower die base respectively, and the two guide sleeves are pressed into the upper die base respectively and sleeved on the upper ends of the guide pillars; the die cavity is fixed on the lower die base; the punch is fixed on the fixing plate, and the fixing plate is fixedly connected to the upper die base; the upper die base is installed on the die shank; the pressure plate is installed on the die cavity with the limiting step on the die cavity as a reference.

2. The stamping die with a double-arc-shaped punch as described in claim 1, characterized in that, The punch is made of Cr12MoV material.

3. The stamping die with a double-arc-shaped punch as described in claim 1, characterized in that, The centers of the double arcs of the punch fall on the extension lines of the two end faces of the punch, respectively.

4. The stamping die with a double-arc-shaped punch as described in claim 1, characterized in that, The intersection of the two arcs of the punch is located on the center line of the punch.

5. The stamping die with a double-arc-shaped punch as described in claim 1, characterized in that, The die cavity is fixed to the lower die base by screws and pins.

6. The stamping die with a double-arc-shaped punch as described in claim 1, characterized in that, The double-arc-shaped punch is pressed into the fixed plate by an interference fit.

7. The stamping die with a double-arc-shaped punch as described in claim 1, characterized in that, The fixing plate is fixedly connected to the upper mold base by screws.

8. The stamping die with a double-arc-shaped punch as described in claim 1, characterized in that, The upper mold base is mounted on the mold handle by screws.

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