Device for improving fillet flanging cracking of automobile stamping part

Abstract

The utility model relates to a device for improving fillet flanging cracking of an automobile stamping part, which comprises an upper die body, a lower die body and a flanging module, a high-frequency magnetic induction coil is arranged on the stamping surface of the flanging module, the device further comprises a cooling spray head, and a nozzle of the cooling spray head faces the flanged position of the part. The high-frequency magnetic induction heating device has the advantages that through high-frequency magnetic induction heating, the temperature of a plate can be rapidly increased, the hardening phenomenon caused by shearing is eliminated, the plasticity of the plate is improved, and flanging cracking caused by reduction of the shearing plasticity is avoided; 2, local flanging heating can release residual stress caused by previous shearing at the shearing edge position of the plate, and flanging cracking caused by stress concentration caused by generated micro holes and micro cracks is avoided; and 3, the cooling nozzle sprays a cooling medium according to the material characteristics to cool and quench the flanged plate, so that the reduction of the material strength caused by heating is avoided, the flanging springback can be reduced, and the forming precision and quality of parts are ensured.

Description

Technical Field

[0001] The utility model belongs to the field of automobile manufacturing, especially the field related to stamping processes, and particularly relates to a device for improving the cracking of fillet flanging of automobile stamping parts. Background Art

[0002] Flanging refers to a forming method in which, on the planar or curved surface part of a stamping part blank, through the action of a die, a straight wall or flange with a certain angle is formed along a closed or unclosed curved edge. However, for parts made of high-strength steel, due to shearing processing, the work hardening of the sheared edge is prominent, the strength increases while the plasticity decreases, and microvoids and microcracks are generated at the sheared edge, resulting in serious cracking problems at the fillet position during the subsequent flanging process of ultra-high-strength automotive steel, which restricts the application of high-strength steel on the vehicle body and limits the lightweight process. At present, the main method to prevent the cracking of the sheared edge during stamping is to remove the sheared edge through secondary cutting, but secondary cutting will reintroduce shearing defects and it is difficult to avoid subsequent flanging cracking.

[0003] Therefore, there is an urgent need for a stamping die to solve the problem of cracking of fillet flanging of high-strength steel in order to achieve the precise forming of the final part. Summary of the Utility Model

[0004] The purpose of the utility model is to provide a device for improving the cracking of fillet flanging of automobile stamping parts, which is used to eliminate the cracking problem of subsequent flanging caused by the defects of the previous sheared edge, and has a simple structure and is easy to form and operate.

[0005] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0006] A device for improving the cracking of fillet flanging of automobile stamping parts includes an upper die body, a lower die body, and a flanging module. A high-frequency magnetic induction coil is arranged at the stamping surface of the flanging module, and a cooling nozzle is also included. The nozzle of the cooling nozzle faces the position after the part is flanged.

[0007] The cooling nozzle is located below the part.

[0008] The cooling nozzles are multiple and are arranged in an arc along the fillet of the part flanging.

[0009] The electromagnetic wave frequency of the high-frequency magnetic induction coil is: 40 - 150 KHz.

[0010] The cooling medium sprayed by the cooling nozzle is water or oil or brine.

[0011] Compared with the prior art, the beneficial effects of the utility model are:

[0012] 1. The utility model can rapidly heat the sheet metal through high-frequency magnetic induction heating, eliminate the hardening phenomenon caused by shearing, increase the plasticity of the sheet metal, and avoid the flanging cracking caused by the reduction of shearing plasticity.

[0013] 2. Local flanging heating can release the residual stress at the sheared edge position of the sheet metal caused by the previous shearing, and avoid the stress concentration caused by the generated micro-holes and micro-cracks, thereby preventing flanging cracking.

[0014] 3. The cooling nozzle sprays the cooling medium according to the material characteristics to cool and quench the flanged sheet metal, avoiding the reduction of material strength caused by heating, and can reduce the flanging springback, ensuring the forming accuracy and quality of the part. Description of the Drawings

[0015] Figure 1 is a three-dimensional schematic diagram of the utility model.

[0016] Figure 2 is a schematic diagram of the flanging module of the utility model.

[0017] Figure 3 is a schematic diagram of the part after flanging.

[0018] In the figure: 1 - flanging module, 2 - lower die body, 3 - upper die body, 4 - part before flanging, 5 - cooling nozzle, 6 - part after flanging, 1-1 high-frequency magnetic induction coil, 7 - temperature sensor. Detailed Embodiment

[0019] The following further describes the detailed embodiment of the utility model with reference to the drawings.

[0020] As Figures 1 - 3 shown, a method for improving the fillet flanging cracking of automotive stamping parts includes the following method steps:

[0021] 1) Place the stamping part between the upper die body 3 and the lower die body 2 and clamp and position it;

[0022] 2) Heat the stamping part of the fillet flanging of the part through high-frequency magnetic induction, and the heating temperature is 250 - 800 °C; low-temperature tempering improves the comprehensive performance, medium-temperature improves the elastic-plasticity, and high-temperature improves the hardness and wear resistance.

[0023] 3) Then perform a stamping operation on the stamping part of the fillet flanging of the part;

[0024] 4) After stamping, quickly spray the cooling medium on the flanging position of the part to cool and quench the flanging position.

[0025] The stamping part is a high-strength steel cold stamping part.

[0026] The tensile strength of the high-strength steel is above 780 MPa.

[0027] The cooling medium described above includes water, oil, and brine.

[0028] The electromagnetic wave frequency of the high-frequency magnetic induction described above is: 40 - 150 KHz

[0029] A device used in a method for improving the cracking of the rounded flange of automotive stamping parts includes an upper die body 3, a lower die body 2, and a flanging module 1. A high-frequency magnetic induction coil 1-1 is provided at the stamping surface of the flanging module 1. It also includes a cooling nozzle 5, and the nozzle of the cooling nozzle 5 faces the position after the part is flanged. A temperature sensor 7 is installed on the upper die body 3.

[0030] The cooling nozzle 5 is located below the part.

[0031] The cooling nozzles 5 are multiple and are arranged in an arc along the rounded flange of the part.

[0032] Example 1:

[0033] The strength grade of the steel plate of the stamping part: DP780.

[0034] See Figure 1 , the device for improving the cracking of the rounded flange of automotive stamping parts includes an upper die body 3, a lower die body 2, and a flanging module. A high-frequency magnetic induction coil 1-1 is provided at the stamping surface of the flanging module 1. Multiple cooling nozzles 5 are provided below the part to be stamped, and the cooling nozzles 5 are evenly arranged along the arc direction of the rounded flange of the part, and the nozzles of the cooling nozzles 5 face the position after the part is flanged.

[0035] During stamping, the part 4 before flanging is placed on the lower die body 2, and the upper die body 3 presses the part 4 before flanging against the lower die body 2 to prevent it from moving in space; among them, the high-frequency magnetic induction coil 1-1 is installed on the bottom surface of the outer edge of the working surface of the flanging module 1 and has the same shape as the flanging edge. The flanging module 1 starts to move downwards. When it contacts the part 4 before flanging, the high-frequency magnetic induction coil 1-1 starts to be energized, and the flanging position of the part is quickly heated to 250 °C for low-temperature tempering to improve the comprehensive performance. Subsequently, the flanging module 1 continues to move downwards to perform the part flanging operation. Subsequently, the flanging module 1 returns and lifts, and the cooling nozzle 5 quickly sprays the cooling medium, brine, at the flanging position to cool and quench the flanging position to improve the material strength of the flanging position. In this example, there are no micro-holes, micro-cracks, no flanging cracking, and no flanging springback at the flanging position.

[0036] Example 2:

[0037] The strength grade of the steel plate of the stamping part: 1200 MPa.

[0038] See Figure 1, The device for improving the cracking of the rounded flange of automotive stamping parts includes an upper die body 3, a lower die body 2, and a flanging module 1. A high-frequency magnetic induction coil 1-1 is arranged at the stamping surface of the flanging module 1. A plurality of cooling nozzles 5 are arranged below the part to be stamped. The cooling nozzles 5 are evenly arranged along the arc direction of the flanging radius of the part, and the nozzles of the cooling nozzles 5 face the position after the part is flanged.

[0039] During stamping, the part 4 before flanging is placed on the lower die body 2, and the upper die body 3 presses the part 4 before flanging onto the lower die body 2 to prevent it from moving in space. The high-frequency magnetic induction coil 1-1 is installed at the bottom of the outer edge of the working surface of the flanging module 1 and has the same shape as the flanging edge. The flanging module 1 starts to move downwards. When it contacts the part 4 before flanging, the high-frequency magnetic induction coil 1-1 starts to be energized, quickly heating the flanging position of the part to 300°C to improve the elastic-plasticity at medium temperature. Subsequently, the flanging module 1 continues to move downwards to perform the flanging operation of the part. Then the flanging module 1 returns and lifts. The cooling nozzles 5 quickly spray the cooling medium, which is oil, onto the flanging position to cool and quench the flanging position, improving the material strength of the flanging position. In this embodiment, there are no micro-holes and micro-cracks at the flanging, no flanging cracking, and no flanging springback.

[0040] Example 3:

[0041] The steel strength level of the stamping part: 980 MPa.

[0042] See Figure 1 , The device for improving the cracking of the rounded flange of automotive stamping parts includes an upper die body 3, a lower die body 2, and a flanging module 1. A high-frequency magnetic induction coil 1-1 is arranged at the stamping surface of the flanging module 1. A plurality of cooling nozzles 5 are arranged below the part to be stamped. The cooling nozzles 5 are evenly arranged along the arc direction of the flanging radius of the part, and the nozzles of the cooling nozzles 5 face the position after the part is flanged.

[0043] During stamping, the part 4 before flanging is placed on the lower die body 2, and the upper die body 3 presses the part 4 before flanging onto the lower die body 2 to prevent it from moving in space. The high-frequency magnetic induction coil 1-1 is installed at the bottom of the outer edge of the working surface of the flanging module 1 and has the same shape as the flanging edge. The flanging module 1 starts to move downwards. When it contacts the part 4 before flanging, the high-frequency magnetic induction coil 1-1 starts to be energized, quickly heating the flanging position of the part to 500°C to improve the hardness and wear resistance at high temperature. Subsequently, the flanging module 1 continues to move downwards to perform the flanging operation of the part. Then the flanging module 1 returns and lifts. The cooling nozzles 5 quickly spray the cooling medium, which is oil, onto the flanging position to cool and quench the flanging position, improving the material strength of the flanging position. In this embodiment, there are no micro-holes and micro-cracks at the flanging, no flanging cracking, and no flanging springback.

Claims

1. An apparatus for improving the cracking of the fillet flanging of automotive stamping parts, comprising an upper die body, a lower die body, and a flanging module, characterized in that, A high-frequency magnetic induction coil is provided at the stamping surface of the flanging module, and a cooling nozzle is further included. The nozzle of the cooling nozzle faces the position after the part is flanged.

2. The device for improving the cracking of the fillet flanging of automotive stamping parts according to claim 1, wherein, The cooling nozzle is located below the part.

3. An apparatus for improving the cracking of rounded flanges of automotive stamping parts according to claim 1 or 2, characterized in that, There are multiple cooling nozzles, which are arranged in an arc along the flanging fillet of the part.

4. An apparatus for improving the cracking of the fillet flanging of automotive stamping parts according to claim 1, characterized in that, The electromagnetic wave frequency of the high-frequency magnetic induction coil is: 40 - 150 KHz.

5. The device for improving the cracking of the fillet flanging of automotive stamping parts according to claim 1, wherein The cooling medium sprayed by the cooling nozzle is water or oil or brine.

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