A punch, a punching device and a punching method for piercing and flanging

Abstract

The application relates to the stamping technical field and discloses a punch for punching and flanging, a stamping device and a stamping method, wherein the punch comprises a punching section, a flanging conical section and a flanging straight section which are sequentially connected; the end face of the punching section comprises intersecting planes and an inclined plane; the intersection of the side surface of the punching section and the planes forms a sharp edge; the intersection of the side surface of the punching section and the inclined plane forms a blunt edge; and the intersection of the planes and the inclined plane forms a blunt edge. After punching and flanging of sheet metal is completed, punching waste can be more stably connected to the back of the sheet metal.

Description

Technical Field

[0001] This invention relates to the field of stamping technology, specifically to a punch, stamping device, and stamping method for punching and flanging. Background Technology

[0002] Currently, in some assembly operations, it is necessary to connect self-tapping screws to sheet metal. Before connecting the self-tapping screws to the sheet metal, it is usually necessary to punch and fold the edges at the connection point between the sheet metal and the self-tapping screw to ensure a stable connection between the self-tapping screw and the sheet metal.

[0003] In related technologies, the punch used for punching and flanging includes a punching section, a flanging tapered section, and a flanging straight section, all integrally formed in sequence. When the operator uses the punch to punch and flanging sheet metal, a die is first placed below the punch, and the punch is then mounted on the stamping end of the press. As the stamping end of the press descends, the punching section punches a hole in the sheet metal, then the flanging tapered section gradually flangs the sheet metal, and finally, the flanging straight section punches the sheet metal to form the final flanging.

[0004] However, after punching and flanging sheet metal, some punching waste will detach from the sheet metal, while some will remain attached. The connection between the punching waste and the sheet metal is weak, with minimal metal material separating them. During subsequent assembly, when self-tapping screws are attached to the sheet metal, the punching waste easily detaches, affecting the assembly area environment and potentially falling into the internal space of the components to be assembled, causing noise. Summary of the Invention

[0005] This application provides a punch, a stamping device, and a stamping method for punching and flanging sheet metal, which enables the punching waste to be more stably attached to the back of the sheet metal after punching and flanging.

[0006] In a first aspect, embodiments of this application provide a punch for punching and flanging, comprising a punching section, a flanging tapered section, and a flanging straight section connected in sequence. The end face of the punching section includes an intersecting plane and an inclined surface. A cutting edge is formed at the intersection of the side surface of the punching section and the plane, and a blunt edge is formed at the intersection of the side surface of the punching section and the inclined surface.

[0007] Through the above implementation method, when punching and flanging sheet metal parts, the portion of the sheet metal part in contact with the cutting edge is first punched by the cutting edge, while the portion in contact with the blunt edge is not punched. Therefore, as the punching section continues to descend, the scrap punched from the cutting edge gradually comes into contact with the inclined surface, and then gradually deflects to one side under the pressure of the inclined surface. After the entire punching stage is completed, the scrap remains attached to the sheet metal part. During the subsequent flanging operation, the flanging tapered section and the flanging straight section have no punching function. Therefore, after the final punching and flanging is completed, the scrap and the side opposite the inclined surface will be firmly attached to the sheet metal part.

[0008] In conjunction with the first aspect, in one embodiment, there is a gap between the edge of the inclined surface closest to the flanged tapered section and the edge of the punched section where the flanged tapered section intersects.

[0009] Through the above implementation method, the complete cylinder between the punching section and the flanged conical section can ensure the strength of the punching section.

[0010] In conjunction with the first aspect, in one embodiment, the gap is smaller than the thickness of the sheet metal part to be punched and flanged.

[0011] The above implementation method can ensure both the strength of the punched section and prevent damage to the waste material formed by punching when the complete cylindrical section moves downward.

[0012] In conjunction with the first aspect, in one embodiment, the cone angle of the flanged tapered segment ranges from 40 to 45°.

[0013] The above implementation method ensures a reasonable guiding transition for the flanged conical section. If the angle of the cone of the flanged conical section is too large, the transition will be too abrupt, which may cause the flange to crack. If the angle of the cone of the flanged conical section is too small, the flange forming stroke will be longer, the entry depth of the flanged conical section will be greater, and the punch will be more prone to breakage.

[0014] In conjunction with the first aspect, in one embodiment, the total length of the punching section is L, and the thickness of the sheet metal part to be punched and flanged is t, wherein L and t satisfy: 4t≤L≤5t.

[0015] The above implementation method can ensure the stability of the punching section. If the total length of the punching section is designed to be too long, the punching section will be thin and prone to breakage; if it is designed to be too short, punching cannot be completed.

[0016] In conjunction with the first aspect, in one embodiment, the punch further includes a connecting section connecting the flange straight segment, the connecting section being provided with a connecting structure for connecting to the stamping end of a press.

[0017] The above-described implementation method facilitates the connection between the punch and the stamping end of the press through the connecting section and connecting structure.

[0018] Secondly, embodiments of this application provide a stamping device, which includes a punch and a die arranged opposite to each other. The die has an inner hole on the side facing the punch, and the inner hole of the die is adapted to the flange straight section of the punch.

[0019] Through the above implementation method, when the operator uses the stamping device to punch and flanging sheet metal parts, a die is first set below the punching section, with the inner hole of the die facing the punching section, and the punch is connected to the stamping end of the press. Then, the sheet metal part is placed on the die, and the stamping end of the press drives the punch to press down, completing the punching and flanging of the sheet metal part. Finally, the stamping end of the press is lifted, and the punch is retracted.

[0020] Thirdly, this application provides a stamping method, which includes setting a die below the punching section, such that the inner hole of the die is opposite to the punching section; the punching section punches the sheet metal part to form a punch cut and waste material of the sheet metal part; the flanging tapered section continues to punch the sheet metal part to gradually form a flanging until the flanging is in place.

[0021] In conjunction with the third aspect, in one embodiment, the punching section punches the sheet metal part to form a cutout and the waste material of the adhered sheet metal part, which includes: the punching section pressing down on the sheet metal part, the sheet metal part being recessed into the inner hole of the die; the punching section continuing to press down on the sheet metal part, the cutting edge punching out a cutout on the sheet metal part, forming waste material; the punching section continuing to descend, the waste material contacting the inclined surface, the waste material deflecting to one side along the inclined surface.

[0022] In conjunction with the third aspect, in one embodiment, the flanging tapered section continues to press the sheet metal part to gradually form a flanging, including: the flanging tapered section pressing down on the sheet metal part, the scrap contacting the flanging tapered section, and the edge of the punching opening contacting the flanging tapered section; the scrap deflecting to one side along the flanging inclined section, and the flanging tapered section pressing the edge of the punching opening gradually downward and simultaneously expanding outward.

[0023] The beneficial effects of the technical solutions provided in this application include:

[0024] Because the punch end face includes both a flat surface and an inclined surface, it forms a cutting edge and a blunt edge, respectively. The cutting edge has a cutting function, while the blunt edge does not. When punching and flanging sheet metal parts, the part of the sheet metal part in contact with the cutting edge is cut by the cutting edge, while the part in contact with the blunt edge is not cut. Therefore, as the punching section continues to descend, the scrap cut from the cutting edge gradually comes into contact with the inclined surface, and then gradually deflects to one side under the pressure of the inclined surface. After the entire punching stage is completed, the scrap remains attached to the sheet metal part. During the subsequent flanging operation, the flanging tapered section and the flanging straight section have no cutting function. Therefore, after the final punching and flanging is completed, the scrap and the side opposite the inclined surface will be firmly attached to the sheet metal part. When the operator subsequently attaches self-tapping screws to the flanged sheet metal, the punching scrap is less likely to fall off the sheet metal. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of the overall structure of the punch in the embodiments of this application;

[0027] Figure 2 for Figure 1 An enlarged schematic diagram of part A in the middle;

[0028] Figure 3 This is a partial dimensional diagram of the punch;

[0029] Figure 4 This is the main view of the punch structure.

[0030] Figure 5 This is a schematic diagram of the extrusion of sheet metal parts during the punching process.

[0031] Figure 6 This is a schematic diagram of a stamped sheet metal part with a punched section;

[0032] Figure 7 This is a schematic diagram of a stamped sheet metal part with a flanged tapered section.

[0033] Figure 8 This is a schematic diagram of a stamped sheet metal part with a straight flange segment.

[0034] In the picture:

[0035] 1. Punching section; 11. Plane; 12. Inclined surface; 13. Cutting edge; 14. Blunt edge;

[0036] 2. Flanged conical section;

[0037] 3. Straight line segment of the flange;

[0038] 4. Connecting section; 41. Connecting structure;

[0039] 5. Concave mold; 51. Inner hole;

[0040] 6. Sheet metal parts. Detailed Implementation

[0041] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0042] Currently, in some assembly operations, it is necessary to connect self-tapping screws to sheet metal. Before connecting the self-tapping screws to the sheet metal, it is usually necessary to punch and fold the edges at the connection point between the sheet metal and the self-tapping screw to ensure a stable connection between the self-tapping screw and the sheet metal.

[0043] When punching and flanging sheet metal for relatively large self-tapping screws, it's typically necessary to first punch the sheet metal and then flanging it. This requires a punching die and a flanging die to perform the punching and flanging operations sequentially. The diameter of the punching die's inner hole matches the diameter of the punching punch, and the diameter of the flanging die's inner hole matches the diameter of the flanging punch. Therefore, during the first step of punching, the clearance between the punching die's inner hole and the outer wall of the punching punch is small, and the punching force of the punching punch is relatively large. At this point, the punching waste will smoothly detach from the sheet metal part.

[0044] However, if the size of the self-tapping screw becomes smaller, such as M5 or M6, the diameter of the punch will be relatively smaller, and correspondingly, the diameter of the punch will be smaller. For example, with an M5 self-tapping screw, the diameter of the punch is only about 2.5mm, making it prone to breakage during punching. To solve this problem, existing technologies typically modify the production process, completing the punching and flanging of sheet metal in one operation. This involves using an integrated punching and flanging punch, which comprises a punching section, a flanging tapered section, and a flanging straight section formed sequentially. In this case, the diameters of the die and the flanging straight section are matched. During the punching and flanging operation, the gap between the outer wall of the punching section and the inner wall of the die increases, reducing the punching force of the punching section and decreasing the likelihood of breakage. This allows for small-diameter punching and flanging as well.

[0045] Normally, after the same process described above is completed, the scrap material will fall off the sheet metal part after punching and flanging. However, due to some external unstable factors, such as the parallelism error of the press slide, the precision error of the mold manufacturing, and the shape of the sheet metal part, the gap between the punching section and the inner hole of the die can be uneven. This will cause the gap between one side of the punching section and the inner hole of the die to increase further, resulting in a further decrease in the punching force on that side of the punching section, and thus the scrap material on that side will not be completely punched off. As a result, after the sheet metal part is punched and flanged, some sheet metal parts have no scrap material on them, while others still have scrap material attached.

[0046] When there is scrap material attached to sheet metal, the connection between the punched scrap and the sheet metal is weak due to the limited metal material remaining after punching. During subsequent assembly, when self-tapping screws are attached to the sheet metal, the punched scrap can easily detach, affecting the assembly area and potentially falling into the internal space of the components to be assembled, causing noise.

[0047] Based on the above problems, this application provides a punch, a stamping device, and a stamping method for punching and flanging, which enables the punching waste to be more stably attached to the back of the sheet metal after punching and flanging, and the punching waste is less likely to fall off the sheet metal when workers attach self-tapping screws to the sheet metal later.

[0048] Combination Figure 1 and Figure 2 This application provides an embodiment of a punch for punching and flanging, comprising a punching section 1, a flanging tapered section 2, and a flanging straight section 3 connected in sequence. The end face of the punching section 1 includes an intersecting plane 11 and an inclined surface 12. From the external shape, the punching section 1 is no longer a complete cylinder; the end of the punching section 1 has a notch due to the presence of the inclined surface 12. A cutting edge 13 is formed at the intersection of the side surface of the punching section 1 and the plane 11, and a blunt edge 14 is formed at the intersection of the side surface of the punching section 1 and the inclined surface 12. The cutting edge 13 has a punching function, while the blunt edge 14 does not have a punching function.

[0049] When punching and flanging sheet metal part 6, the portion of sheet metal part 6 in contact with the cutting edge 13 will be punched by the cutting edge 13, while the portion in contact with the blunt edge 14 will not be punched. Therefore, as the punching section 1 continues to descend, the scrap punched from the cutting edge 13 will gradually come into contact with the inclined surface 12, and then gradually deflect to one side under the push of the inclined surface 12. After the entire punching stage is completed, the scrap will still be attached to sheet metal part 6. During the subsequent flanging operation, the flanging tapered section 2 and the flanging straight section 3 have no punching function. Therefore, after the final punching and flanging is completed, the scrap and the side opposite to the inclined surface 12 will be firmly attached to sheet metal part 6.

[0050] In a preferred embodiment of this application, the punching section 1, the flanged tapered section 2, and the flanged straight section 3 are integrally formed. In other embodiments, the three can be fixed together by other fixing methods. To ensure the reliability of the blunt end 14, the edge formed at the intersection of the side surface of the punching section 1 and the inclined surface 12 is rounded to form the blunt end 14, and the edge formed at the intersection of the plane 11 and the inclined surface 12 is rounded to form the blunt end 14.

[0051] Furthermore, refer to Figure 2 There is a gap between the edge of the inclined surface 12 closest to the flanged tapered section 2 and the edge of the punching section 1 where the flanged tapered section 2 intersects. Figure 2 The structure shown illustrates that there is a gap between the leftmost edge of the inclined surface 12 and the rightmost edge of the flanged conical segment 2. That is, the punched segment 1 includes a notched cylinder and a complete cylinder, with the complete cylinder connected to the flanged conical segment 2. Since the strength of the punched segment 1 decreases due to the notch, the presence of a complete cylinder between the punched segment 1 and the flanged conical segment 2 ensures the strength of the root of the punched segment 1. Furthermore, Figure 2 The gap between the leftmost edge of the inclined surface 12 and the rightmost edge of the flanged conical section 2 is less than the thickness of the sheet metal part 6 to be punched and flanged, that is, the length of the complete cylinder is less than the thickness of the plate. With this setting, the strength of the punching section 1 can be guaranteed, and the waste material formed by punching can be prevented from being destroyed when the complete cylindrical section moves downward.

[0052] Furthermore, refer to Figure 3 Assuming the total length of the punching section 1 is L, and the thickness of the sheet metal part 6 to be punched and flanged is t, in this embodiment, L and t satisfy: 4t ≤ L ≤ 5t. This setting ensures the stability of the punching section 1. If the design is too long, the punching section 1 will be thin and prone to breakage; if the design is too short, punching cannot be completed.

[0053] Furthermore, refer to Figure 3The cone angle α of the flanged conical section 2 ranges from 40° to 45°. This setting ensures a reasonable guiding transition for the flanged conical section 2. If the α angle is too large, the transition is too abrupt, which can easily cause flange cracking. If the α angle is too small, it will lead to a longer flange forming stroke and a greater depth of penetration of the flanged conical section 2, making the punch prone to breakage.

[0054] Furthermore, refer to Figure 4 The punch also includes a connecting section 4 that connects to the flanged straight section 3. The connecting section 4 is provided with a connecting structure 41 for connecting to the stamping end of the press. The connecting section 4 and the connecting structure 41 make it convenient for the operator to connect the punch to the stamping end of the press.

[0055] Based on the above-mentioned punch, this application embodiment also discloses a stamping device, which includes a punch and a die 5 disposed opposite to each other. The die 5 has an inner hole 51 on the side facing the punch, and the inner hole 51 of the die 5 is adapted to the flange straight segment 3 of the punch.

[0056] When the operator uses the stamping device to punch and flange the sheet metal part 6, a die 5 is first set below the punching section 1, with the inner hole 51 of the die 5 facing the punching section 1. The punch is then connected to the stamping end of the press. The sheet metal part 6 is then placed on the die 5, and the stamping end of the press drives the punch downward to complete the punching and flangering of the sheet metal part 6. Finally, the stamping end of the press is lifted, and the punch is retracted.

[0057] Based on the above-described stamping apparatus, this application also discloses a stamping method, which includes:

[0058] S1. Set a die 5 below the punching section 1, so that the inner hole 51 of the die 5 is opposite to the punching section 1, and place the sheet metal part 6 on the die 5.

[0059] S2, punching section 1 punches sheet metal part 6, forming punched cuts and waste material of sheet metal part 6;

[0060] S3, the flanging tapered section 2 continues to stamp the sheet metal part 6, gradually forming the flanging until the flanging is in place.

[0061] Furthermore, in combination Figure 5 and Figure 6 Step S2 specifically includes:

[0062] S21, the punching section 1 presses down on the sheet metal part 6, and the sheet metal part 6 is recessed into the inner hole 51 of the die 5. At this time, the sheet metal part 6 has not yet been punched out.

[0063] S22, the punching section 1 continues to press down on the sheet metal part 6, and the cutting edge 13 punches out the blank on the sheet metal part 6, forming waste material.

[0064] S23, the punching section 1 continues to descend, the scrap comes into contact with the inclined surface 12, and the scrap deflects to one side along the inclined surface 12.

[0065] Furthermore, in combination Figure 7 and Figure 8 Step S3 specifically includes:

[0066] S31, the flanged tapered section 2 presses down on the sheet metal part 6, the scrap material contacts the flanged tapered section 2, and the edge of the punched cut contacts the flanged tapered section 2.

[0067] S32. The waste material is tilted to one side along the inclined section of the flange. The edge of the flange conical section 2 is squeezed downward and expanded outward at the same time until the flange is finished. The flange straight section 3 enters the inner hole 51 of the flange and the flange is connected at part of the flange.

[0068] In the description of this application, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0069] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0070] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A punch for piercing and flanging, characterized in that, The assembly includes a punching section (1), a flanged tapered section (2), and a flanged straight section (3) connected in sequence. The end face of the punching section (1) includes an intersecting plane (11) and an inclined surface (12). A cutting edge (13) is formed at the intersection of the side surface of the punching section (1) and the plane (11). A blunt edge (14) is formed at the intersection of the side surface of the punching section (1) and the inclined surface (12). A blunt edge (14) is formed at the intersection of the plane (11) and the inclined surface (12). The edge of the inclined surface (12) closest to the flanged tapered section (2) has a gap with the edge of the punching section (1) where the flanged tapered section (2) intersects with the edge of the punching section (1). The gap is smaller than the thickness of the sheet metal part (6) to be punched and flanged.

2. A punch for piercing and flanging according to claim 1, characterised in that The cone angle of the flanged tapered section (2) ranges from 40 to 45°.

3. A punch for punching and flanging according to claim 1, characterized in that, The total length of the punching section (1) is L, and the thickness of the sheet metal part (6) to be punched and flanged is t. The L and the t satisfy: 4t≤L≤5t.

4. A punch for punching and flanging according to claim 1, characterized in that, The punch also includes a connecting section (4) that connects the flange straight section (3), and the connecting section (4) is provided with a connecting structure (41) for connecting the punching end of the press.

5. A stamping device based on the punch according to any one of claims 1-4, characterized in that, The stamping device includes a punch and a die (5) arranged opposite to each other. The die (5) has an inner hole (51) on the side facing the punch, and the inner hole (51) of the die (5) is adapted to the flange straight section (3) of the punch.

6. A stamping method based on the stamping apparatus of claim 5, characterized in that, include: A die (5) is provided below the punching section (1) such that the inner hole (51) of the die (5) is opposite to the punching section (1); The punching section (1) punches the sheet metal part (6), forming a punched notch and a piece of waste material that adheres to the sheet metal part (6); The tapered section (2) continues to stamp the sheet metal part (6) to gradually form the flanging until the flanging is in place.

7. The stamping method according to claim 6, characterized in that, The punching section (1) punches the sheet metal part (6), and the waste material forming the punched notch and the bonded sheet metal part (6) includes: The punching section (1) presses down on the sheet metal part (6), and the sheet metal part (6) is recessed into the inner hole (51) of the die (5); The punching section (1) continues to press down on the sheet metal part (6), and the cutting edge (13) punches out a cut on the sheet metal part (6) to form waste material; As the punching section (1) continues to descend, the waste material comes into contact with the inclined surface (12), and the waste material deflects to one side along the inclined surface (12).

8. The stamping method according to claim 6, characterized in that, The flanged tapered section (2) continues to stamp the sheet metal part (6), gradually forming a flange including: The flanged tapered section (2) presses down on the sheet metal part (6), the waste material contacts the flanged tapered section (2), and the edge of the punching opening contacts the flanged tapered section (2); The waste material is deflected to one side along the flanged conical section (2), and the flanged conical section (2) squeezes the edge of the punching opening downward and expands outward at the same time.

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