Blanking process for achieving full-bright face burr-free cut-off face

Abstract

The invention relates to the field of material blanking, and provides a blanking process for realizing full-bright surface burr-free cut-off surface, which comprises the following steps: primary blanking is performed on a raw material, a first semi-finished product is obtained after a first waste material part is removed, the first semi-finished product is provided with a reserved part, and the reserved part is positioned between the first waste material part and a preset cut-off surface; the local part of the reserved part is subjected to upsetting extrusion, a gap exists between the upsetting extrusion part and the preset cut surface, and a second semi-finished product is obtained; and the second semi-finished product is subjected to secondary blanking along the preset cut-off face, the blanking gap during secondary blanking is smaller than the blanking gap during primary blanking, and a finished product is obtained. The problems that a cut-off surface cannot be a full-bright surface and burrs are prone to being generated are solved.

Description

Technical Field

[0001] This application relates to the field of material stamping, and in particular to a stamping process that achieves a fully bright, burr-free cut surface. Background Technology

[0002] In the field of machining, blanking is a crucial processing method, widely used in numerous industries such as metal products, electronic equipment, and automotive parts. With the continuous development of the manufacturing industry, the requirements for product quality and precision are increasing, and the level of blanking technology is constantly improving. High-quality blanking processes can improve production efficiency, reduce production costs, and help enhance the overall performance and market competitiveness of products. The development of blanking technology has enabled the efficient production of various complex shapes and high-precision parts, driving technological progress in related industries.

[0003] In traditional blanking processes, raw materials are placed on a die and cover its cavity. The punch, entering the cavity, cuts the raw material with its cutting edge. During this process, the cut surface sequentially exhibits a camber, a bright surface, and a fracture layer. A larger blanking clearance (the gap between the punch and the sidewall of the die cavity necessary for smooth entry) results in a larger fracture layer, a larger camber, and a smaller bright surface. A larger camber leads to poorer flatness and substandard product quality. Conversely, a smaller blanking clearance results in a smaller camber, a smaller fracture layer, and a larger bright surface, making it easier to meet requirements. However, this also carries risks: a smaller blanking clearance leads to faster cutting edge wear and a shorter lifespan. A larger bright surface also increases the likelihood of burrs, which can affect the fit and final product performance.

[0004] To address these issues, a new die-cutting method exists: pre-cutting the raw material followed by precision trimming to increase the gloss level. However, this method still cannot achieve a completely glossy finish. While theoretically, reducing the die-cutting gap could further increase the gloss level, this would increase the risk of burrs. Summary of the Invention

[0005] To address the problem that the cut surface cannot achieve a fully smooth finish and is prone to burrs, this application provides a punching process that achieves a fully smooth, burr-free cut surface.

[0006] The punching process for achieving a fully bright, burr-free cut surface provided in this application adopts the following technical solution: A punching process that achieves a completely smooth, burr-free cut surface includes the following steps: The raw material is initially punched to remove the first waste portion, and a first semi-finished product is obtained. The first semi-finished product has a reserved portion, which is located between the first waste portion and the preset cutting surface. The reserved portion is partially pressed, and there is a gap between the pressed portion and the preset cutting surface to obtain a second semi-finished product; The second semi-finished product is punched a second time along the preset cutting surface. The punching gap during the second punching is smaller than the punching gap during the first punching, thus obtaining the finished product.

[0007] By adopting the above technical solution, the first blanking yields a first semi-finished product with a reserved portion, leaving room for subsequent processing; the reserved portion is locally upsetting to flatten it; there is a gap between the upsetting part and the preset cutting surface, thus providing allowance for the second blanking; since the reserved portion has been upsetting, burrs can be avoided during the second blanking, so the blanking gap during the second blanking can be smaller than the first blanking gap, which helps to reduce the collapse angle, increase the bright surface, and make the cut surface fully bright and burr-free, thus improving the blanking quality.

[0008] Optionally, the step of performing a preliminary punching of the raw materials to obtain a first semi-finished product includes: The raw material is placed on the first concave mold and the mold opening of the first concave mold is covered; The first punch is inserted into the die opening of the first die to remove the first waste material from the raw material, thereby obtaining the first semi-finished product, wherein the width of the reserved portion is 0.2 mm.

[0009] By adopting the above technical solution, the raw material is placed on the first die and covers the die opening of the first die, so that the force on each part is uniform during the initial punching, which can provide a suitable structural foundation for subsequent upsetting and secondary punching, and facilitate subsequent processing. The width of the reserved part is 0.2mm, which provides a suitable processing allowance for subsequent upsetting and secondary punching, and facilitates the modification of the local structure of the reserved part during the upsetting operation, so as to obtain a finished product with a completely bright cut surface and no burrs in conjunction with the secondary punching.

[0010] Optionally, the punching gap between the first punch and the first die is 5%t, where t is the thickness of the raw material.

[0011] By adopting the above technical solution, the punching gap between the first punch and the first die is set to 5% of the raw material thickness during the initial punching process. This allows for reasonable control of material deformation during the initial punching process, providing a suitable first semi-finished product for subsequent upsetting and secondary punching, and helping to achieve a fully bright and burr-free cut surface in the final product.

[0012] Optionally, the step of partially pressing the reserved portion, with a gap between the pressed portion and the preset cut surface, to obtain the second semi-finished product includes: The first semi-finished product is placed on the second cavity mold, and the reserved part is in contact with the second cavity mold; The second punch is brought close to the second die and the reserved portion is pressed, so that the thickness of the pressed portion becomes thinner, the pressing depth is 86%t, and the distance between the pressed portion and the preset cutting surface is 0.03mm, thus obtaining the second semi-finished product.

[0013] By adopting the above technical solution, the first semi-finished product is placed on the second die and the reserved part is attached to the second die, so that the second die can support the reserved part, which facilitates the upsetting and flattening operation of the reserved part; the second punch is brought close to and upsets the reserved part, making the thickness of the upsetting part thinner, and the upsetting depth is 86%t, and the distance between the upsetting part and the preset cutting surface is 0.03mm, which can create favorable conditions for subsequent secondary punching and help the cutting surface achieve a full bright surface without burrs.

[0014] Optionally, the second concave mold has a placement groove, the reserved portion is in contact with the bottom of the placement groove, and the first semi-finished product abuts against the side wall of the placement groove.

[0015] By adopting the above technical solution, the first semi-finished product can be positioned, which facilitates the subsequent pressing and squeezing operation of the reserved part, making the pressing and squeezing position more accurate. The side wall of the placement groove can limit the first semi-finished product, prevent the material from spreading in opposite directions during pressing and squeezing, and help improve the pressing and squeezing quality.

[0016] Optionally, the step of performing a second punching along the preset cutting surface on the second semi-finished product, wherein the punching gap during the second punching is smaller than the punching gap during the first punching, to obtain the finished product includes: The second semi-finished product is placed on the third cavity mold, and the second waste portion of the second semi-finished product is located at the mold opening of the third cavity mold, the second waste portion including the reserved portion; The third punch is inserted into the die opening of the third die and punched along the preset cutting surface to remove the second waste portion, thereby obtaining the finished product.

[0017] By adopting the above technical solution, the raw material is first punched and a portion is reserved, then the reserved portion is partially uptaken, and finally the second semi-finished product is punched a second time along the preset cutting surface. The gap between the second punching and the first punching is smaller, which can make the cutting surface fully bright. Moreover, the internal structural characteristics of the raw material are changed after uptaking, and burrs are not easily generated during the second cutting. The second waste portion of the second semi-finished product is placed in the die opening of the third concave die, and the second waste portion is punched off by the third punch through the die opening, thus completing the second punching to obtain the finished product.

[0018] Optionally, the second waste portion has a first edge that does not cover the edge of the die opening of the third die; the inner side of the die opening of the third die is provided with a material clamping block, and along the secondary punching direction, the projection of the material clamping block overlaps with the projection of the first edge of the second waste portion; The hardness of the clamping block is higher than that of the second waste part, and the third punch is provided with a clearance part for avoiding the clamping block.

[0019] By adopting the above technical solution, during the secondary blanking process, the first edge of the second scrap portion does not cover the edge of the die opening of the third die, resulting in a lack of support for the first edge. This can easily affect the blanking quality during the secondary blanking process. By setting a clamping block, the first edge can be temporarily supported during the secondary blanking process. The hardness of the clamping block is higher than that of the second scrap portion, so that when the third punch presses the second scrap portion into the third die, the clamping block can destroy the corresponding part of the second scrap portion, allowing the second scrap portion to move smoothly. At the same time, the avoidance part set on the third punch can avoid interference with the clamping block, ensuring the smooth progress of the secondary blanking process and helping to achieve a fully bright and burr-free cut surface.

[0020] Optionally, the second waste section further includes a non-reserved section; there is a first blanking gap and a second blanking gap between the third punch and the third die, wherein the first blanking gap is the blanking gap between the portions of the third punch and the third die used to blank the reserved section; and the second blanking gap is the blanking gap between the portions of the third punch and the third die used to blank the non-reserved section. The first punching gap is smaller than the second punching gap.

[0021] By adopting the above technical solution, when the second waste section includes a non-reserved section, since the non-reserved section has not been pressed, by setting the first punching gap to be smaller than the second punching gap, burrs can be avoided on the cut surface of the finished product when the non-reserved section is cut off. By setting different punching gaps, the punching requirements of the reserved section and the non-reserved section can be better adapted, and the punching quality can be improved.

[0022] Optionally, the first blanking gap is 0.006 mm; the second blanking gap is 0.05 mm.

[0023] By adopting the above technical solution, setting the first blanking gap to 0.006mm, when the reserved part is cut off, the cut surface of the finished product at the corresponding part of the reserved part can achieve a completely bright surface without burrs; setting the second blanking gap to 0.05mm, when the non-reserved part is cut off, the cut surface of the finished product at the corresponding part of the non-reserved part can achieve a burr-free surface and a relatively large bright surface.

[0024] In summary, this application includes at least one of the following beneficial technical effects: 1. Through the steps of initial blanking, partial pressing of the reserved part, and secondary blanking, the cut surface of the finished product at the corresponding part of the reserved part is made to be completely smooth and burr-free, thereby improving the appearance quality of the product. 2. During the crushing process, the bottom wall of the placement groove can provide support for the reserved part, so that the crushing part can be flattened smoothly. The side wall of the placement groove can limit the reserved part and prevent abnormal flow of the structure during crushing. 3. A clamping block is set up to temporarily support the first edge of the second waste part in the early stage of the secondary cutting, so as to avoid affecting the quality of the secondary cutting. The clamping block has high hardness, so it can cut the second waste part when the second waste part moves relative to it, so that the second waste part can move under the action of the third punch and the third die and finally be cut off. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the punching process that achieves a fully bright, burr-free cut surface provided in this application; Figure 2 This is a three-dimensional structural schematic diagram of the punching device provided in this application; Figure 3 This is an exploded schematic diagram of the punching device provided in this application; Figure 4 This application provides Figure 3 Enlarged view of point A in the middle; Figure 5 This is a partial structural schematic diagram of the punching device provided in this application; Figure 6 This application provides Figure 5 Enlarged diagram of point B in the middle.

[0026] Explanation of reference numerals in the attached figures: 1. First punch; 2. Second punch; 3. Third punch; 31. Clearance section; 4. First die; 5. Second die cavity; 51. Placement groove; 6. Third die cavity; 61. Material clamping block; 200. Raw materials; 210. First semi-finished product; 220. Reserved section; 230. Second semi-finished product; 240. Finished product; 250. Second waste section. Detailed Implementation

[0027] The following is in conjunction with the appendix Figures 1 to 6 This application will be described in further detail.

[0028] like Figure 1 As shown in the figure, this application discloses a punching process that achieves a fully glossy, burr-free cut surface, including the following steps: S100: The raw material 200 is initially punched to remove the first waste portion and obtain the first semi-finished product 210. The first semi-finished product 210 has a reserved portion 220, which is located between the first waste portion and the preset cutting surface.

[0029] S200: The reserved part 220 is partially pressed, and there is a gap between the pressed part and the preset cutting surface to obtain the second semi-finished product 230.

[0030] S300: The second semi-finished product 230 is punched twice along the preset cutting surface. The punching gap during the second punching is smaller than the punching gap during the first punching, resulting in the finished product 240.

[0031] Specifically, the raw material 200 can be a strip of material. In the actual punching process, the strip of material can pass through the primary punching station, the upsetting station and the secondary punching station in sequence under the traction of the conventional traction device, thereby completing the primary punching process, the upsetting process and the secondary punching process in sequence, and thus obtaining the finished product 240.

[0032] like Figures 2 to 6 As shown, this embodiment provides a blanking device, which can complete the entire blanking process. The blanking device includes a first punch 1, a second punch 2, a third punch 3, a first die 4, a second die 5, and a third die 6. The initial blanking can be completed with the aid of the first punch 1 and the second die 5, the upsetting process can be completed with the aid of the second punch 2 and the second die 5, and the secondary blanking process can be completed with the aid of the third punch 3 and the third die 6. The first punch 1, the second punch 2, and the third punch 3 can move synchronously, so that the strip can be continuously processed into finished product 240. In this embodiment, an upper die and a lower die can be added. The first punch 1, the second punch 2, and the third punch 3 are all set on the upper die, and the first die 4, the second die 5, and the third die 6 are all set on the lower die. By driving the upper die to move up and down relative to the lower die, the initial blanking process, the upsetting process, and the secondary blanking process can be performed simultaneously.

[0033] like Figures 2 to 4As shown, during the initial punching, the raw material 200 is placed on the first die 4. The first die 4 has a cavity, and the opening of the cavity is its die orifice. The raw material 200 can cover at least a portion of the die orifice of the first die 4, so that when the first punch 1 is inserted into the cavity of the first die 4, a portion of the raw material 200 can be cut off. In this embodiment, the raw material 200 can completely cover the die orifice of the first die 4, and the first waste portion of the raw material 200 can be cut off during the initial punching to obtain the first semi-finished product 210. During the initial cut, it is not cut directly along the preset cutting surface, but a processing allowance is reserved for subsequent processing. In this embodiment, the first semi-finished product 210 has a reserved portion 220, which is located between the first waste portion and the preset cutting surface. The reserved portion 220 facilitates subsequent processing. The width of the reserved portion 220 can be 0.2mm. During the initial punching, the punching clearance between each side wall of the cavity of the first punch 1 and the first die 4 is equal, and the punching clearance can be 5%t. Where t is the thickness of the raw material 200. That is, for a raw material 200 with a thickness of 1.5mm, the punching clearance during the initial punching can be 0.075mm.

[0034] During the upsetting process, the first semi-finished product 210 is first placed on the second die 5. Since the upsetting process only requires partially flattening the reserved portion 220 without cutting it off, the second die 5 does not need to have a cavity. In this embodiment, the second die 5 has a placement groove 51. During upsetting, the reserved portion 220 is in contact with the bottom of the placement groove 51, thereby providing good support for the reserved portion 220 and facilitating improved upsetting quality. The first semi-finished product 210 abuts against the side wall of the placement groove 51, which can limit the first semi-finished product 210, thereby preventing lateral diffusion of the first semi-finished product 210 during subsequent upsetting.

[0035] After placing the first semi-finished product 210, the second punch 2 is brought close to the second die 5 and pressed against the inner side of the reserved portion 220 to obtain the second semi-finished product 230. Pressing reduces the thickness of the pressed portion, making it less prone to burrs during subsequent secondary punching. The pressing depth is 86%t, meaning that if the thickness before pressing is 1.5mm, the thickness after pressing is 0.21mm. During pressing, the entire reserved portion 220 should not be pressed; a certain allowance must be reserved for secondary punching. Therefore, there is a gap between the pressed portion and the preset cut surface, which can be 0.03mm.

[0036] like Figures 4 to 6As shown, during the secondary blanking process, the second semi-finished product 230 is placed on the third die 6. The second semi-finished product 230, compared to the final finished product 240, also has a second scrap portion 250. Cutting off the second scrap portion 250 yields the finished product 240. The second scrap portion 250 includes a reserved portion 220. Specifically, the third die 6 also has a cavity. The second scrap portion 250 of the second semi-finished product 230 is placed at the die opening of the cavity of the third die 6. Then, the third punch 3 is inserted into the die opening of the third die 6 and blanked along a predetermined cutting surface to remove the second scrap portion 250, thus obtaining the finished product 240. During the secondary blanking, the blanking gap between the third punch 3 and the third die 6 can be 0.006 mm.

[0037] In some embodiments, the cut surface of the finished product 240 may not need to be fully polished in all areas. For the corresponding areas that do not need to be fully polished, the pressing process may not be required before the secondary punching. That is, the second waste section 250 includes not only the reserved section 220, but also the non-reserved section 220. The non-reserved section 220 has not undergone the pressing process.

[0038] In this embodiment, a first blanking gap and a second blanking gap exist between the third punch 3 and the third die 6. The first blanking gap is the blanking gap between the parts of the third punch 3 and the third die 6 used for blanking the reserved portion 220; the second blanking gap is the blanking gap between the parts of the third punch 3 and the third die 6 used for blanking the non-reserved portion 220. Since the reserved portion 220 has undergone an upsetting process, burrs are less likely to be generated during secondary blanking. However, the non-reserved portion 220 has not undergone an upsetting process, and if the blanking gap is too small during secondary blanking, burrs may be generated, affecting the quality of the finished product 240. Therefore, the first blanking gap is allowed to be smaller than the second blanking gap, so that the cut surface of the reserved portion 220 after secondary blanking can achieve a completely bright surface without burrs. In this embodiment, the first blanking gap is 0.006 mm, and the second blanking gap is 0.05 mm.

[0039] In some embodiments, the second waste portion 250 may not be able to completely cover the die opening of the third die 6, resulting in some areas of the second semi-finished product 230 not being supported by the third die 6. During secondary punching, under the extrusion of the third punch 3, the second semi-finished product 230 may undergo abnormal deformation before the second waste portion 250 is cut off, affecting the quality of the finished product 240. In this embodiment, a retaining block 61 is provided on the inner side of the die opening of the third die 6, which can provide temporary support for the second waste portion 250.

[0040] Specifically, the second scrap portion 250 has a first edge that does not cover the edge of the die opening of the third die 6. Along the secondary punching direction, the projection of the clamping block 61 overlaps with the projection of the first edge of the second scrap portion 250. When the third punch 3 presses the second scrap portion 250, the clamping block 61 can provide support for the first edge. The hardness of the clamping block 61 is higher than that of the second scrap portion 250. When the second scrap portion 250 moves, the clamping block 61 can cut off the part of the second scrap portion 250 that contacts it, ensuring that the second scrap portion 250 can enter the cavity of the third die 6 under the pressure of the third punch 3.

[0041] Along the secondary punching direction, the width of the overlapping portion between the projection of the clamping block 61 and the projection of the first edge of the second scrap portion 250 should not be too large, to avoid excessive resistance from the clamping block 61 to the second scrap portion 250, which would affect the secondary punching process and exacerbate damage to the clamping block 61; of course, the width should not be too small either, to avoid poor support effect of the clamping block 61 on the second scrap portion 250. In this embodiment, this width can specifically be 0.1mm. The clamping block 61 can be triangular in structure, with one corner used to support the second scrap portion 250, and the angle of this corner can be 60°. By reasonably setting the included angle of the clamping block 61, its structural strength can also be improved. In addition, the third punch 3 is also provided with a relief portion 31 for avoiding the clamping block 61.

[0042] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A punching process that achieves a fully glossy, burr-free cut surface, characterized in that, Includes the following steps: The raw material (200) is initially punched to remove the first waste portion and a first semi-finished product (210) is obtained. The first semi-finished product (210) has a reserved portion (220) located between the first waste portion and the preset cutting surface. The reserved portion (220) is partially pressed, and there is a gap between the pressed portion and the preset cutting surface to obtain the second semi-finished product (230). The second semi-finished product (230) is punched twice along the preset cutting surface. The punching gap during the second punching is smaller than the punching gap during the first punching, to obtain the finished product (240).

2. The punching process for achieving a fully smooth, burr-free cut surface according to claim 1, characterized in that: The step of performing initial punching on the raw material (200) to obtain the first semi-finished product (210) includes: The raw material (200) is placed on the first cavity (4) and covers the opening of the first cavity (4); The first punch (1) is inserted into the die opening of the first die (4) to remove the first waste portion from the raw material (200) to obtain the first semi-finished product (210), and the width of the reserved portion (220) is 0.2 mm.

3. The punching process for achieving a fully smooth, burr-free cut surface according to claim 2, characterized in that: The blanking gap between the first punch (1) and the first die (4) is 5%t, where t is the thickness of the raw material (200).

4. The punching process for achieving a fully smooth, burr-free cut surface according to claim 2, characterized in that: The step of performing a partial upsetting of the reserved portion (220), with a gap between the upsetting portion and the preset cutting surface, to obtain the second semi-finished product (230) includes: The first semi-finished product (210) is placed on the second cavity mold (5), and the reserved part (220) is attached to the second cavity mold (5); The second punch (2) is brought close to the second die (5) and the reserved part (220) is pressed, so that the thickness of the pressed part becomes thinner, the pressing depth is 86%t, and the distance between the pressed part and the preset cutting surface is 0.03mm, thus obtaining the second semi-finished product (230).

5. The punching process for achieving a fully smooth, burr-free cut surface according to claim 4, characterized in that: The second die (5) has a placement groove (51), the reserved part (220) is in contact with the bottom of the placement groove (51), and the first semi-finished product (210) abuts against the side wall of the placement groove (51).

6. The punching process for achieving a fully smooth, burr-free cut surface according to claim 1, characterized in that: The step of performing a second punching on the second semi-finished product (230) along the preset cutting surface, wherein the punching gap during the second punching is smaller than the punching gap during the first punching, to obtain the finished product (240) includes: The second semi-finished product (230) is placed on the third cavity (6), and the second waste portion (250) of the second semi-finished product (230) is located at the mold opening of the third cavity (6), the second waste portion (250) includes the reserved portion (220). The third punch (3) is inserted into the die opening of the third die (6) and punched along the preset cutting surface to remove the second waste part (250) and obtain the finished product (240).

7. The punching process for achieving a fully smooth, burr-free cut surface according to claim 6, characterized in that: The second waste section (250) has a first edge that does not cover the edge of the die opening of the third die (6); the inner side of the die opening of the third die (6) is provided with a material clamping block (61), and along the secondary punching direction, the projection of the material clamping block (61) overlaps with the projection of the first edge of the second waste section (250); The hardness of the clamping block (61) is higher than that of the second waste part (250), and the third punch (3) is provided with a relief part (31) for avoiding the clamping block (61).

8. The punching process for achieving a fully smooth, burr-free cut surface according to claim 6, characterized in that: The second waste section (250) also includes a non-reserved section (220); there is a first blanking gap and a second blanking gap between the third punch (3) and the third die (6), the first blanking gap being the blanking gap between the parts of the third punch (3) and the third die (6) used to blank the reserved section (220); the second blanking gap being the blanking gap between the parts of the third punch (3) and the third die (6) used to blank the non-reserved section (220); The first punching gap is smaller than the second punching gap.

9. The punching process for achieving a fully smooth, burr-free cut surface according to claim 8, characterized in that: The first blanking gap is 0.006 mm; the second blanking gap is 0.05 mm.

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