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CN-117444043-B - Fine blanking process for reducing cracking of hole flanging end face

CN117444043BCN 117444043 BCN117444043 BCN 117444043BCN-117444043-B

Abstract

The application relates to the technical field of stamping, in particular to a fine stamping process for reducing cracking of a hole flanging end face, which comprises the following steps of S1, pre-stamping vertical cutting holes on a metal plate which is horizontally placed, synchronously stamping a first-pressure straight chamfer at the position of the metal plate relative to the top of the cutting holes, synchronously stamping a first-pressure circular arc chamfer at the position of the metal plate relative to the bottom of the cutting holes, S2, downwards deforming the position of the top of the metal plate relative to the cutting holes by pressure so as to downwards form a concave at the edge of the cutting holes, S3, continuously downwards deforming the edge of the cutting holes by force so as to downwards fold the edge of the cutting holes to be vertical, folding the cutting faces of the cutting holes to form a lower end face, and S4, applying upwards extrusion force to the lower end face of the cutting holes so as to realize flattening of the lower end face. The application has the advantage of reducing the possibility of generating cracks on the workpiece in the hole flanging process.

Inventors

  • GU XING
  • WANG XU
  • Mao Zhaojiang

Assignees

  • 无锡市泛恩精密机械有限公司

Dates

Publication Date
20260505
Application Date
20231115

Claims (5)

  1. 1. S1, punching a vertical cutting hole (2) in advance on a metal plate (1) which is horizontally placed, synchronously pressing a first-pressure linear chamfer (3) at the position of the metal plate (1) relative to the top of the cutting hole (2), synchronously pressing a first-pressure circular arc chamfer (4) at the position of the metal plate (1) relative to the bottom of the cutting hole (2), wherein the chamfer depth of the first-pressure linear chamfer (3) is larger than that of the first-pressure circular arc chamfer (4), synchronously pressing a transition circular arc surface (5) at the junction of the metal plate (1) relative to the first-pressure linear chamfer (3) and a punching surface, and synchronously pressing a step (6) at the junction of the metal plate (1) relative to the first-pressure circular arc chamfer (4) and the punching surface in the step S1; s2, the top of the metal plate (1) is pressed and deformed downwards relative to the position of the cutting hole (2), so that the edge of the cutting hole (2) is recessed downwards; s3, continuously deforming downwards along the edge of the cutting hole (2) under the stress, so that the edge of the cutting hole (2) is downwards turned to be vertical, and the punching surface of the cutting hole (2) is turned to form a lower end surface; S4, applying upward extrusion force to the lower end face of the hole flanging, and flattening the lower end face.
  2. 2. The fine blanking process for reducing cracking of a hole flanging end face according to claim 1, wherein the height of the punched section of the punching hole (2) is 0.3-0.35 times the thickness of the metal plate (1) after the step S1 is finished.
  3. 3. The fine blanking process for reducing cracking of a hole flanging end face according to claim 1, wherein the height of the punched section of the punching hole (2) is 0.15-0.2 times the thickness of the metal plate (1) after the step S2 is finished.
  4. 4. The fine blanking process for reducing the cracking of the hole flanging end face according to claim 1, wherein in the step S2, the positions of the metal plate (1) relative to the first-pressure straight chamfer (3) and the transitional arc surface (5), the first-pressure arc chamfer (4) and the step (6) are all pressed into a pre-flanging arc chamfer (7).
  5. 5. The fine blanking process for reducing the cracking of the end face of the hole flanging, which is characterized in that in the step S2, the metal plate (1) is S-shaped relative to a pre-flanging circular arc chamfer (7) at the top of the cutting hole (2).

Description

Fine blanking process for reducing cracking of hole flanging end face Technical Field The application relates to the technical field of stamping, in particular to a fine stamping process for reducing cracking of a hole flanging end face. Background Hole flanging refers to a processing technology for turning the edge of a hole into an upright edge. The related art discloses a workpiece hole flanging process, and referring to FIG. 1, the process comprises the steps of (a) punching vertical cutting holes in a horizontally placed metal plate in advance, b) downwards deforming the top of the metal plate relative to the position of the cutting holes under pressure to enable the edges of the cutting holes to be downwards concave, wherein the thickness of the cutting holes is 0.8 times that of the metal plate, c) continuously downwards deforming the edges of the cutting holes under pressure to enable the edges of the cutting holes to be downwards folded to be vertical, folding the cutting holes of the cutting holes to form lower end faces, and d) applying upwards extrusion force to the lower end faces of the cutting holes to flatten the lower end faces. The thickness of the plates in different application scenes is different, for example, the thickness range of the automobile seat adjusting piece is approximately 4mm-6mm, and analysis on the hole flanging process shows that a large number of cracks can be generated in the process of cutting, punching and cutting surfaces are folded to form the lower end surface due to the large thickness of the plates, so that obvious defects exist. Disclosure of Invention In order to solve the problem of cracking in the thick plate hole flanging process, the application provides a fine punching process for reducing cracking of the hole flanging end face. The fine blanking process for reducing the cracking of the hole flanging end face adopts the following technical scheme: A fine punching process for reducing cracking of a hole flanging end face comprises the following steps of S1 punching a vertical cutting hole in advance on a metal plate which is placed horizontally, synchronously pressing a first-pressure straight line chamfer at the position of the metal plate relative to the top of the cutting hole, synchronously pressing a first-pressure arc chamfer at the position of the metal plate relative to the bottom of the cutting hole, S2 enabling the position of the metal plate top relative to the cutting hole to be pressed and deformed downwards to enable the edge of the cutting hole to be downwards formed into a concave, S3 enabling the edge of the cutting hole to be stressed and deformed downwards continuously to enable the edge of the cutting hole to be downwards folded to be vertical, folding a punching face of the cutting hole to be folded to form a lower end face, and S4 applying upward extrusion force to the lower end face of the cutting hole to enable flattening to be achieved. By adopting the technical scheme, when punching out and cutting out the hole, the first-pressure straight line chamfer and the first-pressure circular arc chamfer are pressed out, so that the structural structure of the metal plate near the edge of the cutting out hole can be pressed more tightly, and the possibility of cracking of the part in the hole flanging process is reduced. Optionally, in step S1, the chamfering depth of the first-pressure straight line chamfer is greater than the chamfering depth of the first-pressure circular arc chamfer. By adopting the technical scheme, in the hole flanging process, the part of the metal plate, which is opposite to the cutting and punching surface, is expanded, and the expansion degree is larger as the cutting and punching height is lower, so that the part of the metal plate, which is more compact in the pressed tissue structure, is deviated to the lower position of the cutting and punching surface, and the possibility of cracking of the cutting and punching surface in the hole flanging process is further reduced. Optionally, in step S1, a transition arc surface is pressed synchronously at the junction of the first-pressing straight chamfer and the punching surface of the metal plate. By adopting the technical scheme, the transition arc surface enables the junction of the first-pressure straight chamfer and the punching surface to be smoother, so that the subsequent extrusion of the first-pressure straight chamfer and the punching surface is further realized. Optionally, in step S1, a step is pressed at the junction of the first pressing arc chamfer and the punching surface of the metal plate. Through adopting above-mentioned technical scheme, when the relative cutting and punching hole of metal sheet was extruded, the extrusion direction was not direct towards punching a hole cutter, consequently is difficult to cause the damage to the cutter, and also realizes the pre-compaction for further extrusion afterwards, has reduced the great problem of disposab