Cold extrusion die for star flange workpiece and manufacturing method

Abstract

The application discloses a cold extrusion die and a manufacturing method of a star-shaped flange workpiece. The cold extrusion die comprises a first forming die and a second forming die. An end surface of the first forming die is provided with at least two grooves which are distributed in a circumferential array around a central axis of the first forming die. An end surface of the second forming die is provided with at least two extension parts which are distributed in a circumferential array around a central axis of the second forming die. An end surface of the extension part is provided with a guide groove which extends outward along a radial direction of the second forming die to a side surface of the extension part. The flange part of the material is pre-formed by the first forming die, and the grooves on the first forming die push the material to the flange edge while forming the circular contour of the flange. Then, the flange is shaped by the second forming die, the material can flow to the edge along the guide groove on the second forming die and form the flange, the forming precision is higher, and the production efficiency is higher.

Description

Technical Field

[0001] This application relates to a cold extrusion die and manufacturing method for a star-shaped flange workpiece in the field of cold extrusion forming technology. Background Technology

[0002] Flanges for shaft-shaped parts are generally used for axial connections with other parts. Therefore, flanges are usually circular to obtain a larger contact area with other parts and achieve a better connection effect. However, in some specific scenarios, when flanges need to give way to other parts to reduce interference, or when corresponding anti-loosening and anti-rotation structures are required, flanges may also adopt irregular shapes.

[0003] In the automotive manufacturing industry, due to the significant vibrations that occur during vehicle operation, there are requirements for the flange structure to prevent loosening. Therefore, some flanges are designed as star-shaped structures, which have multiple outwardly protruding flanges. The flange structure can be prevented from rotating due to vibration by using other parts to abut against the flanges.

[0004] However, since flange workpieces are metal parts, irregular structures are difficult to process, and cutting processes are time-consuming and costly, making them inconvenient to use. If cold extrusion is used for pressing, the material at the flange will have difficulty flowing, resulting in missing corners and affecting the forming accuracy.

[0005] Application content

[0006] The purpose of this application is to at least solve one of the technical problems existing in the prior art, and to provide a cold extrusion die and manufacturing method for a star flange workpiece, which can improve the forming accuracy of the star flange workpiece at the flange.

[0007] According to a first aspect of this application, a cold extrusion die for a star-shaped flange workpiece is provided, comprising a first forming die and a second forming die, wherein:

[0008] The end face of the first forming mold has at least two grooves, which are arranged in a circular array around the central axis of the first forming mold. The grooves are used to preform the flange of the flange workpiece.

[0009] The end face of the second molding die is provided with at least two extensions, the number of extensions is the same as the number of grooves and they are arranged in a one-to-one correspondence. The extensions are arranged in a circumferential array around the central axis of the second molding die. The end face of the extension is provided with a guide groove, which extends outward along the radial direction of the second molding die to the side of the extension.

[0010] According to a first aspect embodiment of this application, the groove is a V-shaped groove and has a first inclined surface and a second inclined surface, the first inclined surface being close to the middle of the first molding die and the second inclined surface being away from the middle of the first molding die.

[0011] According to a first aspect embodiment of this application, the slope of the first inclined plane is further less than the slope of the second inclined plane.

[0012] According to a first aspect of the present application, the groove is further provided with a rounded chamfer along its edge.

[0013] According to a first aspect embodiment of this application, the extension further protrudes along the radial direction of the second molding die.

[0014] According to a first aspect embodiment of this application, the guide groove is further provided at one end near the middle of the second molding die to the end face of the second molding die.

[0015] According to the first aspect of the embodiment of this application, the second molding die is further provided with a protrusion in the middle for pre-sinking the material.

[0016] According to a second aspect of this application, a method for manufacturing a star-shaped flange workpiece is provided, based on the aforementioned cold extrusion die for the star-shaped flange workpiece, comprising:

[0017] The wire is cut into pieces to obtain materials that meet the length requirements;

[0018] Shaping one end face of the material;

[0019] Flip the material over and shape the other end face;

[0020] The material is subjected to cold extrusion and countersinking treatment;

[0021] The material is cold-extruded using the first forming mold to preform the flange;

[0022] The material is cold-extruded using the second forming die, and the material flows in the guide groove to form the flange.

[0023] Punch holes along the countersunk holes in the material to make it pass through.

[0024] According to a second aspect of the present application, the material is further subjected to pre-sunk hole treatment before countersunk hole and punching.

[0025] According to a second aspect embodiment of this application, the second forming mold is provided with a protrusion in the middle. While the flange is being generated using the second forming mold, the protrusion extrudes the material to complete the pre-sinking process.

[0026] The beneficial effects of this application embodiment include at least the following: This application pre-forms the flange portion of the material using a first forming mold, forming a circular outline of the flange while the groove on the first forming mold pushes the material towards the flange edge; then the flange is shaped using a second forming mold, and the material can flow along the guide groove on the second forming mold to the edge and form a flange, resulting in higher forming accuracy and higher production efficiency. Attached Figure Description

[0027] 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 explained below. Obviously, the described drawings are only a part of the embodiments of this application, and not all of them. Those skilled in the art can obtain other design schemes and drawings based on these drawings without creative effort.

[0028] Figure 1 These are structural schematic diagrams of star flange workpiece 100 and defective products;

[0029] Figure 2 This is a three-dimensional view of the first forming die 200 and the second forming die 300 in the cold extrusion die of the star-shaped flange workpiece according to the first aspect of this application;

[0030] Figure 3 This is a schematic diagram of the material 400 after being cold-extruded by the first forming die 200 in the cold extrusion die of the star-shaped flange workpiece according to the first aspect embodiment of this application;

[0031] Figure 4 This is a schematic diagram of steps S100 to S400 in the manufacturing method of the star-shaped flange workpiece according to the second aspect embodiment of this application;

[0032] Figure 5 This is a schematic diagram of steps S500 to S700 in the manufacturing method of the star-shaped flange workpiece according to the second aspect embodiment of this application.

[0033] Reference numerals: 100-Star flange workpiece, 110-Flange, 200-First forming mold, 210-Groove, 211-First inclined surface, 212-Second inclined surface, 300-Second forming mold, 310-Extension, 311-Guide groove, 320-Protrusion, 400-Material, 410-Protruding part. Detailed Implementation

[0034] This section will describe in detail the specific embodiments of this application. Preferred embodiments of this application are shown in the accompanying drawings. The purpose of the drawings is to supplement the textual description with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of this application, but they should not be construed as limiting the scope of protection of this application.

[0035] In the description of this application, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They 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. Therefore, they should not be construed as limitations on this application.

[0036] In the description of this application, "several" means one or more, "more than" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0037] In the description of this application, unless otherwise expressly defined, terms such as "setup," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this application in conjunction with the specific content of the technical solution.

[0038] Flanges for shaft-shaped parts are generally used for axial connections with other parts. Therefore, flanges are usually circular to obtain a larger contact area with other parts and achieve a better connection effect. However, in some specific scenarios, when flanges need to give way to other parts to reduce interference, or when corresponding anti-loosening and anti-rotation structures are required, flanges may also adopt irregular shapes.

[0039] In the automotive manufacturing industry, due to the significant vibrations experienced by vehicles during operation, flange structures require anti-loosening features; therefore, some flanges are designed with a star-shaped structure. (Refer to...) Figure 1 a. The star-shaped flange workpiece 100 has multiple outwardly protruding flanges 110, which can prevent the flange structure from rotating due to vibration by using other parts to abut against the flanges 110. However, since the flange workpiece is a metal part, its irregular shape is difficult to machine, and the cutting process is time-consuming and costly, making it inconvenient to adopt. Although the cold extrusion process can improve production efficiency, refer to... Figure 1 b. The material at the flange may have difficulty flowing, resulting in missing corners and affecting molding accuracy.

[0040] In response, this application proposes a cold extrusion die and manufacturing method for a star-shaped flange workpiece. The flange portion of the material 400 is pre-formed by a first forming die 200, forming a circular flange outline. At the same time, the groove 210 on the first forming die 200 pushes the material towards the flange edge. Then, the flange is shaped by a second forming die 300. The material can flow along the guide groove 311 on the second forming die 300 to the edge and form a flange 110, which has higher forming accuracy and higher production efficiency.

[0041] Reference Figure 2 The cold extrusion die for the star-shaped flange workpiece in the first aspect embodiment of this application includes a first forming die 200 and a second forming die 300. The first forming die 200 is used to pre-form the flange portion of the star-shaped flange workpiece 100 and push the material to the edge to reduce the occurrence of corner defects in the flange 110 after subsequent cold extrusion. The second forming die 300 is used to shape the flange portion of the star-shaped flange workpiece 100 and guide the material to form the flange 110, so that the flange 110 is full and meets the design requirements.

[0042] Specifically, refer to Figure 2 a. The end face of the first forming mold 200 has at least two grooves 210. The grooves 210 are arranged in a circular array around the central axis of the first forming mold 200. The grooves 210 are used to preform the flanges 110 of the star-shaped flange workpiece 100. It is easy to understand that the number of grooves 210 is determined by the number of flanges 110 of the star-shaped flange workpiece 100. In this embodiment, the star-shaped flange workpiece 100 has 4 flanges 110. The number and position of the grooves 210 can also be adjusted according to the actual situation. Further, the groove 210 is a V-shaped groove and has a first inclined surface 211 and a second inclined surface 212. The first inclined surface 211 is close to the middle of the first forming mold 200, and the second inclined surface 212 is far away from the middle of the first forming mold 200. Moreover, the slope of the first inclined surface 211 is less than the slope of the second inclined surface 212. During the cold extrusion process, refer to Figure 3 When the material 400 is compressed, its end face deforms, and the flowing material flows into the groove 210 along the first inclined surface 211. During this process, the material also spreads outward and concentrates in each groove 210. The second inclined surface 212 is used to prevent the material from overflowing further, keeping it within the groove 210. After removing the first forming mold 200, the end face of the material 400 forms the approximate outline of the flange and several convex portions 410. The convex portions 410 will deform again during the subsequent cold extrusion process to form flanges 110.

[0043] Furthermore, the edge of the groove 210 is provided with a rounded chamfer, which makes it easier for the flowing material to enter the groove 210, and also reduces the stress concentration of the first molding die 200 at the corner of the groove 210, thus extending the die life.

[0044] Reference Figure 2 b. The end face of the second forming mold 300 is provided with at least two extensions 310. The number of extensions 310 is the same as the number of grooves 210 and they are arranged in a one-to-one correspondence. They are distributed in a circumferential array around the central axis of the second forming mold 300. The end face of the extension 310 is provided with a guide groove 311. The end of the guide groove 311 near the middle of the second forming mold 300 smoothly transitions to the end face of the second forming mold 300, so that the pressurized material can more easily flow into the guide groove 311. The guide groove 311 extends outward along the radial direction of the second forming mold 300 to the side of the extension 310, so that the guide groove 311 can guide the material to the edge of the material 400. When the second forming mold 300 extrudes the material 400, the flange portion of the material 400 can be further shaped so that its contour meets the design requirements; at the same time, the convex portion 410 deforms under pressure, and the flowing material is guided by the guide groove 311 to the edge, thereby forming the flange 110 of the star-shaped flange workpiece 100.

[0045] Furthermore, the extension 310 protrudes in the radial direction of the second forming mold 300, thereby enabling the material in the guide groove 311 to be transported further, fully filling and forming the flange 110, making the flange 110 fuller and reducing the occurrence of corner defects.

[0046] Furthermore, the second forming mold 300 has a protrusion 320 in the middle for pre-sinking the material 400.

[0047] A method for manufacturing a star-shaped flange workpiece according to a second aspect embodiment of this application, based on the cold extrusion die of the star-shaped flange workpiece, includes the following steps:

[0048] S100.Reference Figure 4 a. Cut the wire into pieces to obtain material 400 that meets the length requirements;

[0049] S200.Reference Figure 4 b. Shape one end face of material 400 to facilitate subsequent countersinking and punching processes;

[0050] S300.Reference Figure 4 c. Flip the material 400 and shape the other end face of the material 400 to facilitate subsequent countersinking and punching processes;

[0051] S400.Reference Figure 4 d. Perform cold extrusion countersinking on material 400;

[0052] S500.Reference Figure 5e. Use the first forming mold 200 to cold extrude the material 400 to preform the flange;

[0053] S600.Reference Figure 5 f, The material 400 is cold-extruded using the second forming mold 300, and the material 400 flows in the guide groove 311 to generate the flange 110;

[0054] S700. Reference Figure 5 g. Punch holes along the countersunk hole of material 400 to open it up, and finally obtain star flange workpiece 100.

[0055] The transfer of material at position 400 and the flipping of its posture are both completed by the robotic arm.

[0056] Furthermore, before countersinking and punching, the material 400 is pre-countersinked. A recess is first cold-extruded onto the end face of the material 400, reducing the stretching effect at the hole edge during subsequent countersinking or punching, thus resulting in a more precise and complete hole profile. To improve production efficiency, in some embodiments, a protrusion 320 is provided in the middle of the second forming mold 300. While the flange is being formed using the second forming mold 300, the protrusion 320 extrudes the material 400 to complete the pre-countersinking process, thereby saving steps.

[0057] The punch used for punching has raised ribs on its side to machine grooves on the inner wall of the hole for assembly with other parts. During the scrap removal process, material protrusions and burrs remain in these grooves, so CNC machining is used to clean the defects and burrs inside the holes of material 400. For the outer surface of material 400, vibratory grinding is used to remove burrs.

[0058] The above is a detailed description of the preferred embodiments of this application. However, the present invention is not limited to the embodiments described. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of this application. All such equivalent modifications or substitutions are included within the scope defined by the claims of this application.

Claims

1. A cold extrusion die for a star-shaped flange workpiece, characterized in that, It includes a first molding die (200) and a second molding die (300), wherein: The end face of the first forming mold (200) is provided with at least two grooves (210), the grooves (210) are arranged in a circular array around the central axis of the first forming mold (200), and the grooves (210) are used to preform the flange (110) of the star flange workpiece (100). The end face of the second molding die (300) is provided with at least two extensions (310), the number of extensions (310) is the same as the number of grooves (210) and they are arranged in a one-to-one correspondence. The extensions (310) are arranged in a circumferential array around the central axis of the second molding die (300). The end face of the extension (310) is provided with a guide groove (311), which extends outward along the radial direction of the second molding die (300) to the side of the extension (310).

2. The cold extrusion die for the star-shaped flange workpiece according to claim 1, characterized in that: The groove (210) is a V-shaped groove and has a first inclined surface (211) and a second inclined surface (212). The first inclined surface (211) is close to the middle of the first molding die (200), and the second inclined surface (212) is far away from the middle of the first molding die (200).

3. The cold extrusion die for the star-shaped flange workpiece according to claim 2, characterized in that: The slope of the first inclined plane (211) is less than the slope of the second inclined plane (212).

4. The cold extrusion die for the star-shaped flange workpiece according to claim 1, characterized in that: The groove (210) has a rounded chamfer along its edge.

5. The cold extrusion die for the star-shaped flange workpiece according to claim 1, characterized in that: The extension (310) protrudes in the radial direction of the second molding die (300).

6. The cold extrusion die for the star-shaped flange workpiece according to claim 1, characterized in that: The guide groove (311) smoothly transitions to the end face of the second molding mold (300) at one end near the middle of the second molding mold (300).

7. The cold extrusion die for the star-shaped flange workpiece according to claim 1, characterized in that: The second forming mold (300) has a protrusion (320) in the middle for pre-sinking the material (400).

8. A method for manufacturing a star-shaped flange workpiece, based on a cold extrusion die for the star-shaped flange workpiece according to any one of claims 1 to 7, characterized in that, include: The wire is cut to obtain material (400) that meets the length requirements; Shaping one end face of the material (400); Flip the material (400) and shape the other end face of the material (400); The material (400) is subjected to cold extrusion countersinking treatment; The material (400) is cold-extruded using the first forming mold (200) to preform the flange; The material (400) is cold-extruded using the second molding die (300), and the material (400) flows in the guide groove (311) to form the flange; Punch through the countersunk hole in the material (400) to make it pass through.

9. The method for manufacturing a star-shaped flange workpiece according to claim 8, characterized in that: Before countersinking and punching, the material (400) is pre-countersinked.

10. The method for manufacturing a star-shaped flange workpiece according to claim 9, characterized in that: The second forming mold (300) has a protrusion (320) in the middle. While the flange is being generated using the second forming mold (300), the protrusion (320) extrudes the material (400) to complete the pre-sinking treatment.

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