A hole punching process for thick and high-strength plates

Abstract

A punching process for thick high-strength plates includes the following steps: S1, deep drawing and embossing, wherein the top of the lower punch is provided with a semi-arc-shaped protrusion, the diameter of the semi-arc-shaped protrusion is three-fifths of the hole diameter of the punching hole, and the height is three-tenths of the material, and the bottom of the upper punch is provided with a semi-arc-shaped groove matching the semi-arc-shaped protrusion; S2, deep drawing and embossing; S3, punching; S4, reverse burr pressing, wherein the gap between the punch under the burr pressing and the fixed plate is 0.1mm; S5, punching; S6, shaping. The present invention achieves side wall thickening by changing the shape of the punch in deep drawing and embossing so that the material undergoes flow changes; at the same time, after punching, the reverse burr pressing is performed to squeeze the torn band produced after punching again to make it smooth, so as to ensure that the material edge will not have serious cracking and popcorn cracking shape during the subsequent punching process.

Description

Technical Field

[0001] The invention relates to the technical field of automobile parts processing, in particular to a hole-turning process for thick and high wall panels. Background Art

[0002] Some thick and high-strength plates require some holes, which are either used as riveted bushings or for fastening parts after tapping. The wall thickness, height and R angle of the holes have certain requirements. Only when the wall thickness reaches a certain level can the riveted bushing have sufficient plane support. When tapping to fasten parts, the tooth pitch must be sufficient to ensure that the side wall is not broken after tapping, and the strength reaches torque and thrust within the standard range.

[0003] In the prior art, the conventional method for this kind of hole punching requirement is to draw and convex in two steps, then punch and punch, and finally adjust the height. However, since the thick high-strength plate material is hard and has a large yield resistance, it is easy to become thin and crack during the drawing and convex process. After normal punching and punching, the proportion of hole cracking is relatively large. Once the wall thickness is not thick enough, the bushing will not be riveted tightly; the wall thickness of the tapping will break, causing slipping, and the thrust torque will not meet the requirements.

[0004] Therefore, the prior art needs to be improved and enhanced. Summary of the invention

[0005] In view of the deficiencies in the prior art, the object of the present invention is to provide a punching process for thick and high-strength plates which can still meet functional requirements.

[0006] To achieve the above purpose, the technical solution adopted by the present invention is:

[0007] A punching process for thick high-strength plates comprises the following steps:

[0008] S1, deep drawing and embossing, wherein the top of the lower embossing punch is provided with a semi-arc shaped bulge, the diameter of the semi-arc shaped bulge is three-fifths of the hole diameter of the punched hole, and the height is three-tenths of the material, and the bottom of the upper embossing punch is provided with a semi-arc shaped groove matching the semi-arc shaped bulge;

[0009] S2, deep drawing and embossing;

[0010] S3, punching;

[0011] S4, reverse burr pressing, wherein the gap between the punch and the fixed plate under the burr pressing is 0.1 mm;

[0012] S5, turning the hole;

[0013] S6. Plastic surgery.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] Due to the adoption of the above-mentioned process steps, the side wall is thickened by changing the shape of the punch in deep drawing and embossing so that the material flow changes; at the same time, the burrs are pressed back after punching, and the torn band produced after punching is squeezed smooth again, ensuring that in the subsequent hole-turning process, the edge of the material will not have serious cracks and popcorn cracking shapes. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Attached Figure 1 is a flow chart of the present invention;

[0017] Attached Figure 2 This is a schematic diagram of step 1 of the present invention;

[0018] Attached Figure 3 This is a schematic diagram of step 2 of the present invention;

[0019] Attached Figure 4 This is a schematic diagram of step 3 of the present invention;

[0020] Attached Figure 5 This is a schematic diagram of step 4 of the present invention;

[0021] Attached Figure 6 This is a schematic diagram of step 5 of the present invention;

[0022] Attached Figure 7 This is a schematic diagram of step 6 of the present invention.

[0023] The numbers in the figure are: (11) upper convex punch, (12) lower convex punch, (21) upper convex punch, (22) lower convex punch, (31) punching punch, (41) burr pressing lower punch, (42) fixing plate, (51) punch for flanging holes, and (61) shaping punch. DETAILED DESCRIPTION

[0024] The invention is further described in detail below in conjunction with the accompanying drawings:

[0025] Example:

[0026] See also Figure 1-7 The present invention provides a punching process for thick high-strength plates, comprising the following steps:

[0027] S1, deep drawing and embossing, wherein the top of the lower embossing punch 12 is provided with a semi-arc-shaped bulge, the diameter of the semi-arc-shaped bulge is three-fifths of the hole diameter of the punched hole, and the height is three-tenths of the material, and the bottom of the upper embossing punch 11 is provided with a semi-arc-shaped groove matching the semi-arc-shaped bulge; when deep drawing and embossing, the upper and lower molds are closed to initially squeeze and thin the bottom of the material into an arc shape in the middle, so that part of the material is squeezed to the side wall;

[0028] S2, deep drawing and embossing, wherein the ends of the upper embossing punch 21 and the lower embossing punch 22 are flat-bottomed, and the bottom of the material is pressed forward and backward again. Due to the inconvenience of the volume of the material, the pressed material is squeezed toward the side wall again, increasing the thickness of the side wall; at the same time, the bottom of the material becomes a thinner plane, and the punching gap is designed according to the thickness of the thinned material in the post-punching process, so that the plane is punched forward and the scraping edge phenomenon will not occur;

[0029] S3, punching;

[0030] S4, reverse burr pressing, where the gap between the burr pressing lower punch and the fixed plate is 0.1mm, so that the burr pressing lower punch can guide the hole by itself, so that the hole opening after the hole turning process is flat and smooth; because after punching, there will be certain burrs and tear bands in the hole, and direct hole turning will cause the side wall to appear jagged or popcorn cracking shape, by adding chamfered burr pressing lower punch, the tear band burrs are squeezed by the reverse force of the burr pressing lower punch to form a very smooth end face

[0031] S5, turning the hole;

[0032] S6. Plastic surgery.

[0033] In this embodiment, punching, drilling and shaping can be performed according to normal procedures.

[0034] The present invention thins the bottom area of ​​the material by embossing in two steps, allowing the bottom area material to be squeezed to the side wall, thereby increasing the wall thickness, and at the same time adding a reverse burr pressing and chamfering process after punching to extrude the torn band produced after punching again to make it smooth, thereby ensuring that during the subsequent hole-turning process, the edge of the material will not have serious cracks and popcorn cracking shapes.

[0035] In summary, the present invention, through the above-mentioned process, well solves the functional requirements of the product after the hole is turned, ensures the use strength requirements of the product, and has the characteristics of reasonable process and good product quality.

Claims

1. A punching process for thick high-strength plates, characterized in that: The following steps are involved: S1. Deep drawing and embossing, wherein the top of the lower embossing punch is provided with a semi-arc-shaped bulge, the diameter of the semi-arc-shaped bulge is three-fifths of the hole diameter of the punched hole, and the height is three-tenths of the material, and the bottom of the upper embossing punch is provided with a semi-arc-shaped groove matching the semi-arc-shaped bulge; when deep drawing and embossing, the upper and lower dies are closed to initially squeeze and thin the bottom of the material into an arc shape in the middle, and a part of the material is squeezed to the side wall; S2, deep drawing and embossing, wherein the ends of the upper embossing punch and the lower embossing punch are flat-bottomed, and the bottom of the material is pressed forward and backward again. Due to the inconvenience of the volume of the material, the pressed material is squeezed toward the side wall again, increasing the thickness of the side wall; at the same time, the bottom of the material becomes a thinner plane; S3, punching; S4, reverse burr pressing, wherein the gap between the punch and the fixed plate under the burr pressing is 0.1 mm; S5, turning the hole; S6. Plastic surgery.

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