A method for processing punches

Abstract

This invention discloses a method for processing a punch, comprising the following steps: selecting a blank according to the external dimensions of the punch; rough machining the blank to obtain a die blank, the die blank being cylindrical and retaining allowance for wire cutting; heat-treating the die blank; fine-machining the heat-treated die blank to form a cutting edge at one end of the die blank, the cutting edge extending along the axial direction of the die blank; and wire cutting the die blank on the end face opposite to the cutting edge according to the cross-sectional profile of the punch, based on the cutting edge, to obtain the punch. Since the cutting edge is first machined on the die blank, and then the body is formed by wire cutting, multiple cutting edges can be pre-machined depending on the overall strength of the die blank. Based on this die blank integrating multiple cutting edges, multiple independent punches can be cut out at once, significantly shortening the processing cycle and improving production efficiency.

Description

Technical Field

[0001] This invention relates to the field of stamping die technology, and in particular to a method for processing a punch. Background Technology

[0002] Currently, the industry uses stamping processes to process arc-shaped grooves on workpieces. In existing stamping dies, the punches used to stamp arc-shaped grooves have a thin sheet structure and a long and slender shape. At one end, there is also a right-angle step structure for installation and positioning. Such a structure makes the rigidity of the punch poor, and the step part is also prone to stress concentration.

[0003] Based on the structure of the punch, the existing technology obtains the punch by fully milling the blank. This processing method requires the removal of a large amount of material and requires individual cutting, resulting in a long processing cycle. In addition, due to the thin sheet structure of the punch, the vibration generated by the equipment during cutting makes it difficult to stably control the processing dimensions and dimensional accuracy. Furthermore, since the stepped structure needs to be processed last, stress concentration can easily cause the punch to break during processing, increasing unnecessary production costs. Summary of the Invention

[0004] The main objective of this invention is to provide a method for processing punches to solve the problem of low production efficiency in existing punch processing methods.

[0005] To achieve the above objectives, the present invention proposes a method for processing a punch, the punch comprising: a punch body and a reinforcing rib, one end of the punch body having a cutting edge, the projection of the cutting edge on the stamping plane being arc-shaped, the reinforcing rib avoiding the cutting edge to be disposed on the punch body, the side of the reinforcing rib being recessed to form a groove with the punch body, so that the punch can be installed to the outside through the groove; The processing method includes the following steps: The blank is selected according to the outer dimensions of the punch, and the blank is rough machined to obtain the die blank. The die blank is cylindrical and retains the allowance for wire cutting. The mold blank is subjected to heat treatment; The heat-treated mold blank is precision machined to form the cutting edge at one end of the mold blank, the cutting edge extending along the axial direction of the mold blank; Based on the cutting edge, the punch is obtained by wire cutting on the end face of the die blank opposite to the cutting edge according to the cross-sectional profile of the punch.

[0006] Optionally, after the step of finishing the heat-treated mold blank to form the cutting edge at one end of the mold blank, the method further includes: machining a plurality of the cutting edges at one end of the mold blank, the plurality of cutting edges being spaced apart around the center of the mold blank.

[0007] Optionally, the step of heat-treating the mold blank includes: The mold blank is placed in a heat treatment furnace for heating; The mold blank is cooled to room temperature so that the hardness value of the mold blank is HRC58-60; The mold blank is subjected to 2 to 3 tempering processes.

[0008] Optionally, the step of finishing the heat-treated mold blank includes: The shape of the heat-treated mold blank is precision machined. The cutting edge is machined out at one end of the mold blank; The cutting edge is precision ground; The surfaces of the mold blank and the cutting edge are polished.

[0009] Optionally, the step of precision turning the shape of the heat-treated mold blank includes: Determine the positions of the cutting edge and the reinforcing rib on the mold blank; Based on the positions of the cutting edge and the reinforcing rib, a transition slope is machined out on the outer wall of the die blank, and the transition slope is located at the connection between the cutting edge and the reinforcing rib.

[0010] Optionally, the step of machining the cutting edge at one end of the die blank specifically involves machining two inclined surfaces at an included angle at one end of the die blank, the two inclined surfaces forming the stamping end of the cutting edge.

[0011] Optionally, the cross-sectional profile of the punch includes the cross-sectional profiles of the punch body and the reinforcing rib, and machining allowances are reserved on both sides of the punch body.

[0012] Optionally, after the step of obtaining the punch by wire cutting the end face of the die blank opposite to the cutting edge based on the cross-sectional profile of the punch, the method further includes: opening a pin hole on the punch, the pin hole being disposed away from the cutting edge.

[0013] Optionally, the step of wire cutting the punch according to the cross-sectional profile on the end face of the die blank away from the cutting edge is specifically: using slow wire cutting to cut the cross-sectional profile of the punch in a processing mode of cutting once and finishing three times.

[0014] The present invention also proposes a stamping die, comprising: an upper die, a lower die, and a punch obtained by the above processing method, wherein the upper die and the lower die are disposed opposite to each other, and the punch is disposed on the upper die.

[0015] In the punch processing method of the present invention, the overall strength of the punch is improved by setting reinforcing ribs on the punch and replacing the stepped structure to realize the installation and positioning function. Based on the structural features of the punch, the cutting edge is first processed on the die blank, and then the body is formed by wire cutting. Since the cutting edge is not divided during processing, the workpiece is not in a thin sheet shape. Relying on the overall strength of the die blank, multiple cutting edges can be processed, and there will be no vibration or deformation during processing, which ensures the processing accuracy of the cutting edge. Based on the die blank that integrates multiple cutting edges, multiple independent punches can be cut out at one time. Compared with the existing processing method that can only be milled one by one, the processing cycle is significantly shortened, the production efficiency is improved, and the problem of punch breakage caused by milling is also overcome. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structure of a punch in the prior art; Figure 2 This is a flowchart illustrating the processing of punches in existing technologies. Figure 3 This is a schematic diagram of one structure of the punch of the present invention; Figure 4 for Figure 3 A bottom view; Figure 5 This is a schematic diagram of another structure of the punch of the present invention; Figure 6 A flowchart illustrating one embodiment of the punch processing method of the present invention; Figure 7 A flowchart illustrating another embodiment of the punch processing method of the present invention; Figure 8 This is a flowchart of a specific embodiment of step S3 in the punch processing method of the present invention; Figure 9 This is a flowchart of a specific embodiment of step S5 in the punch processing method of the present invention; Figure 10 for Figure 9 A flowchart of a specific implementation of step S51 Figure 11 A flowchart illustrating another embodiment of the punch processing method of the present invention; Figure 12 This is a schematic diagram of the structure of the finished mold blank in one embodiment of the present invention; Figure 13 This is a schematic diagram of the structure of the die blank after wire cutting in one embodiment of the present invention; Figure 14 for Figure 13 Top view; Figure 15 This is a schematic diagram of the structure of a stamping die according to one embodiment of the present invention; Figure 16 for Figure 15 Top view; Figure 17 for Figure 15 Assembly diagram of the punch and the sliding sleeve; Figure 18 This is a schematic diagram of the finished product.

[0018] Explanation of icon numbers: The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0020] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0021] See Figure 1 The diagram shows a schematic of a punch 10 used in the prior art for stamping arc-shaped grooves. The punch's overall structure is an arc-shaped thin sheet, with a stepped structure at one end and a flat cutting edge at the other. Based on this structure, see [reference needed]. Figure 2The diagram illustrates the existing punch manufacturing process. Specifically, a suitable blank is first selected and heat-treated. Then, the blank is placed on a milling machine, and the main body of the punch is milled out using a milling cutter. Finally, an auxiliary mold is used for positioning, and the stepped structure is milled out. This method can only produce one punch at a time, resulting in a long production cycle and significant material waste due to the large amount of material removed. Furthermore, since the stepped structure is only machined last, the main body of the punch has already been formed. This main body is a thin, elongated sheet, and vibrations from the milling machine and cutter are unavoidable during milling. This leads to increased jitter in the punch as the milling process progresses, causing errors and affecting machining accuracy. Additionally, the connection between the main body and the stepped structure is prone to breakage, especially due to vibrations during machining, increasing unnecessary production costs. In the punch processing method of the present invention, since a reinforcing rib 13 is provided on the punch 10 and replaces the step structure to realize the installation and positioning function, the overall strength of the punch 10 is improved. Based on the structural features of the punch 10, during processing, the cutting edge 12 is first processed on the die blank 70, and then the body is formed by wire cutting. Since the cutting edge 12 has not been divided during processing, the workpiece is not in the form of a thin sheet. Relying on the overall strength of the die blank 70, multiple cutting edges 12 can be processed, and no vibration or deformation will occur during processing, ensuring the processing accuracy of the cutting edge 12. Based on the die blank 70 that integrates multiple cutting edges 12, multiple independent punches 10 can be cut out at one time. Compared with the existing processing method that can only be milled one by one, the processing cycle is significantly shortened, the production efficiency is improved, and the problem of punch breakage caused by milling is also overcome.

[0022] Example 1 See Figures 3 to 5 As shown, the punch 10 structure of the present invention includes a punch body 11 and a reinforcing rib 13. One end of the punch body 11 is a cutting edge 12. Since the punch 10 of the present invention is used to punch out an arc-shaped groove, the cross-section of the cutting edge 12 is arc-shaped. To simplify the processing flow, preferably, in this embodiment, the punch body 11 and the cutting edge 12 are both arc-shaped structures, and the two are an integral structure. A reinforcing rib 13 is provided on the punch body 11, and the reinforcing rib 13 extends along the length direction of the punch body 11. It should be noted that since the punch body 11 is arc-shaped, it has a convex arc surface and a concave arc surface. The reinforcing rib 13 can be provided on the convex arc surface or the concave arc surface according to the actual situation. The structure of the reinforcing rib 13 on the convex arc surface is as follows. Figure 3 As shown, the structure with reinforcing rib 13 set on the concave arc surface is as follows: Figure 5As shown, of course, reinforcing ribs 13 can also be provided on both the convex and concave arc surfaces. It should be noted that the processing steps are the same regardless of which surface the reinforcing ribs 13 are provided on.

[0023] Specifically, such as Figure 4 As shown, the cross-sectional length of the reinforcing rib 13 is smaller than the cross-sectional length of the punch body 11. One or both sides of the reinforcing rib 13 are recessed inward to form a slot 131 structure with the punch body 11. The two side walls of the slot 131 are formed by the side of the reinforcing rib 13 and the surface of the punch body 11, respectively. It can be understood that when the punch 10 is installed in the outside, such as in the sliding sleeve 40 of the mold, the installation can be completed simply by inserting the punch 10 along the extension direction of the slot 131. At the same time, the slot 131 radially limits the punch 10, preventing the slot 131 from shifting to both sides during stamping. The impact force generated during stamping will be absorbed by the side wall of the slot 131, thereby protecting the punch 10. Compared with the existing punch 10 which is positioned and installed through a stepped structure, the punch 10 of the present invention has higher structural strength, will not shift during stamping, and is more stable in installation. Of course, in another embodiment, multiple reinforcing ribs 13 can also be provided, with the multiple reinforcing ribs 13 spaced apart along the width direction of the punch body 11. It can be understood that when multiple reinforcing ribs 13 are provided, the side of the outermost reinforcing rib 13 is recessed to form a groove 131 with the punch body 11. As long as the punch 10 can be installed to the outside through the groove 131, this embodiment is not limited to this, and all of the above are within the protection scope of this invention. Further, in this embodiment, the two back-to-back side walls of the two grooves 131 on the reinforcing rib 13 are arranged at an included angle, preferably 30° to 40°, i.e. Figure 4 As shown in θ1, a stable triangular support structure can be formed. The two back-to-back slots 131 form an anti-rotation structure. When the punch 10 is installed on the slide sleeve 40, the two slots 131 ensure that there is no relative rotation between the slide sleeve 40 and the punch 10, realizing reliable radial positioning, anti-rotation and guidance, and ensuring precision stamping.

[0024] The following details the processing method of the punch of the present invention: See Figure 6 As shown, taking the structure of the reinforcing rib 13 being provided on the outer arc surface of the punch body 11 as an example, a punch processing method of the present invention includes the following steps: S1: Select the blank according to the outer dimensions of the punch 10, perform rough machining on the blank to obtain the die blank 70. The die blank 70 is cylindrical and retains the allowance for wire cutting. S3: Heat treatment of mold blank 70; S5: The heat-treated mold blank 70 is precision machined to form a cutting edge 12 at one end of the mold blank 70, the cutting edge 12 extending along the axial direction of the mold blank 70. S7: Based on the cutting edge 12, wire cutting is performed on the end face of the die blank 70 away from the cutting edge 12 according to the cross-sectional profile of the punch 10 to obtain the punch 10.

[0025] In step S1, the outer dimensions of the punch 10 are determined based on the required size of the arc-shaped groove. A blank is selected according to the dimensions of the punch 10. Specifically, the blank is a mold steel material, such as Cr12MoV or SKD11, which are high-carbon, high-chromium cold work mold steels. These materials have advantages such as good hardenability, wear resistance, and minimal quenching deformation. A section is cut from the bar using a saw or similar equipment to obtain a cylindrical blank. The blank is then rough-machined using a CNC lathe, including turning the outer diameter, drilling or boring the inner hole, and flattening the end face, to obtain a die blank 70. Preferably, the die blank 70 is cylindrical, which provides good rigidity. It is understood that since the punch 10 is arc-shaped, the die blank 70 needs to have a wire EDM machining allowance. That is, the outer diameter of the die blank 70 needs to be larger than the arc diameter of the punch 10, and the inner diameter of the die blank 70 needs to be smaller than the arc diameter of the punch 10, leaving sufficient machining allowance for subsequent wire EDM of the punch 10.

[0026] In step S3, the mold blank 70 is subjected to heat treatment, including quenching and tempering. The quenching process makes the hardness of the mold blank 70 meet the target requirements. Since quenching will generate huge internal stress, in order to eliminate stress and stabilize the structure and prevent deformation or cracking during subsequent processing and use, the mold blank 70 is tempered at high temperature to make the mold blank 70 more stable.

[0027] In step S5, the heat-treated mold blank 70 is precision-machined. Specifically, one end of the mold blank 70 is defined as the cutting edge 12 along its axial direction, and this end is machined into the cutting edge 12 using a lathe or the like. It can be understood that since the mold blank 70 still maintains an integral, highly rigid cylindrical shape, it can effectively resist and suppress vibration during the machining of the cutting edge 12, ensuring the machining accuracy of the cutting edge 12.

[0028] In step S7, based on the position of the cutting edge 12, the cross-sectional profile of the punch 10 is located using the end face of the other end of the die blank 70 as the processing plane. Then, the cutting path of the electrode wire is determined according to the cross-sectional profile, and the preset travel trajectory of the electrode wire is obtained. The wire EDM machine cuts the die blank 70 according to the preset travel trajectory to obtain the punch 10. Finally, the punch 10 is removed from the die blank 70.

[0029] from Figure 3As can be seen, the punch 10 obtained by the processing method of the present invention has a punch body 11 and reinforcing rib 13 as an integral structure formed by wire cutting. There are no weak links in welding or splicing. Compared with the existing punch 10 with stepped structure, the punch 10 of the present invention has good structural integrity, better rigidity and fracture resistance. It will not break during processing. Moreover, when used for stamping, it can effectively resist the bending moment during the stamping process and improve the service life of the punch 10.

[0030] Example 2 See Figure 7 The diagram shown is a flowchart of another embodiment of the processing method of the punch 10 of the present invention.

[0031] In this embodiment, the main difference from Embodiment 1 is that, after performing finishing on the heat-treated mold blank 70 to form a cutting edge 12 at one end of the mold blank 70, the following steps are also included: S6: Multiple cutting edges 12 are machined out at one end of the mold blank 70, and the multiple cutting edges 12 are spaced apart around the center of the mold blank 70.

[0032] It should be noted that, based on the structural features of the die blank 70 and the punch 10, multiple cutting edges 12 can be divided on the die blank 70 to allow multiple punches 10 to be wire-cut in a single operation. Specifically, the machining process of forming the cutting edges 12 in step S5 is repeated to machine multiple cutting edges 12. As an example, in this embodiment, six identical cutting edges 12 are divided on the die blank 70. The six cutting edges 12 are arranged in a circular array around the central axis of the die blank 70, at a preset angle and radius. It can be understood that, since six cutting edges 12 are machined in this step, in the subsequent step S7, based on the number of cutting edges 12, six independent punches 10 can be wire-cut in a single operation, such as... Figure 13 As shown in the figure, the die blank 70 after wire cutting six punches 10 is shown. Three notches are filled with the punches 10 that have not yet come out, while the other three notches have removed the punches 10. It should be noted that the number of cutting edges 12 depends on the size of the punches 10 and the die blank 70, and can be determined according to the actual situation. This embodiment is not limited to this, and all of the above are within the protection scope of this invention. Thus, on the one hand, multiple cutting edges 12 are machined on the die blank 70 in one processing cycle, so that the subsequent wire cutting process can cut multiple punches 10 at one time, further improving processing efficiency. On the other hand, the multiple cutting edges 12 make full use of the die blank 70, reducing material waste and saving production costs.

[0033] Example 3 See Figure 8As shown, further, in this embodiment, step S3 includes the following steps: S31: Place the mold blank 70 into a heat treatment furnace for heating; Specifically, the mold blank 70 is placed in a vacuum heat treatment furnace for heating. Using a vacuum furnace can effectively prevent the mold blank 70 from oxidizing and decarburizing at high temperatures, ensuring good surface finish and stable composition. It should be noted that the heating temperature and holding time depend on the material of the mold blank 70. For example, when using SKD11 mold steel, it is heated to 1000-1050℃ and held for a sufficient time to allow the core to be completely austenitized.

[0034] S32: Cool the mold blank 70 to room temperature so that the hardness value of the mold blank 70 is HRC58~60; Specifically, after the mold blank 70 is heated, it is rapidly cooled. This can be done by oil cooling, high-pressure gas, liquid nitrogen, or other methods to quickly reduce its temperature to room temperature, thereby stabilizing the hardness value of the mold blank 70 within the range of HRC58 to 60. This hardness range allows the mold blank 70 to achieve a good balance between wear resistance and toughness.

[0035] S33: Temper the mold blank 70 2 to 3 times; Specifically, the quenched mold blank 70 contains significant internal structural and thermal stresses. To ensure the stability and service life of the mold blank 70, preferably, this embodiment performs 2 to 3 tempering treatments after quenching to fully eliminate internal stresses and improve the toughness of the mold blank 70. As an example, each tempering is performed at a low temperature of 180–200°C, with each holding time being 2–3 hours.

[0036] Example 4 See Figure 9 As shown, further, in this embodiment, step S5 includes the following steps: S51: Perform precision turning on the outer shape of the heat-treated mold blank 70; Specifically, the outer circle and end face of the mold blank 70 are micro-cut by a lathe to correct the minor deformation that may be caused by heat treatment, and to provide a precise positioning reference for subsequent processes.

[0037] S52: A cutting edge 12 is machined out at one end of the mold blank 70; Specifically, after the finishing of the outer shape is completed, the geometric shape of the cutting edge 12 is machined at one end of the mold blank 70 by a lathe. The cutting edge 12 can be a flat cutting edge or a raised pointed cutting edge, depending on the actual situation. This embodiment is not limited to this, and all of the above are within the protection scope of the present invention.

[0038] S53: Fine grinding of the cutting edge 12; Specifically, the cutting edge 12 is finely ground by a grinding machine to obtain higher dimensional accuracy and lower surface roughness than turning. This can remove the tiny tool marks and surface deterioration layer generated during hard turning, making the cutting edge 12 sharper.

[0039] S54: Polish the surfaces of the die blank 70 and the cutting edge 12; Specifically, the surface of the cutting edge 12 is polished to a mirror finish using a polishing machine to further reduce its surface roughness. As a result, when the punch 10 is stamping, the smooth cutting edge 12 results in very little friction between it and the stamped part, preventing material from adhering to the cutting edge 12, thereby improving the cross-sectional quality of the stamped part, reducing burrs, and further extending the cycle of punch 10 needing to be re-grind due to wear, thus increasing the service life of punch 10.

[0040] Example 5 See Figure 10 As shown, further, in this embodiment, step S51 includes the following steps: S511: Determine the positions of the cutting edge 12 and the reinforcing rib 13 on the mold blank 70; Specifically, the axial direction of the die blank 70 is defined as the length direction of the punch 10. The positions of one or more cutting edges 12 are determined on the die blank 70, as well as the length of the cutting edges 12 on the die blank 70, i.e. the proportion of the cutting edges 12 on the punch 10, and then the extension length of the reinforcing rib 13 on the punch 10 is determined.

[0041] S512: Based on the positions of the cutting edge 12 and the reinforcing rib 13, a transition slope 132 is machined out on the outer wall of the mold blank 70. The transition slope 132 is located at the connection between the cutting edge 12 and the reinforcing rib 13. Specifically, see Figure 12 Based on the positions of the cutting edge 12 and the reinforcing rib 13, a transition slope 132 is machined on the mold blank 70, so that the mold blank 70 presents a structure that transitions from a large cylinder to a small cylinder, with the two cylinders connected by the transition slope 132; combined with Figure 13 After the punch 10 is cut out, the transition slope 132 also serves as the connection point between the reinforcing rib 13 and the cutting edge 12.

[0042] Example 6 Furthermore, in this embodiment, step S52 specifically involves machining two inclined surfaces 121 at an included angle at one end of the die blank 70. The two inclined surfaces 121 form the stamping end of the cutting edge 12. By precision machining, two inclined surfaces 121 at a preset included angle are machined at one end of the die blank 70, forming an inverted triangular structure. The intersection of these two inclined surfaces 121 forms the stamping end of the cutting edge 12. Preferably, in this embodiment, the included angle formed by the two inclined surfaces 121 is 120°. It should be noted that the smaller (sharper) the included angle of the stamping end, the smaller the punching force of the cutting edge 12. However, conversely, the sharper the stamping end, the farther its distance from the reinforcing rib 13, i.e., the longer the cutting edge 12. This will affect the overall rigidity, leading to poor dimensional accuracy, and is also not conducive to material removal. It will also increase the cost of the die. Therefore, setting the included angle to a suitable obtuse angle can strengthen the strength of the stamping end and extend its service life.

[0043] Example 7 See Figure 14 As shown, further, in this embodiment, the cross-sectional profile of the punch 10 includes the cross-sectional profiles of the punch body 11 and the reinforcing rib 13, and machining allowances are reserved on both opposite sides of the punch body 11. It should be noted that, since the outer profiles of the punch body 11 and the cutting edge 12 are consistent, when wire cutting the punch body 11 and the reinforcing rib 13, to avoid the electrode wire scraping and damaging the already treated surface of the cutting edge 12, machining allowances are reserved on the two opposite surfaces of the punch body 11. Preferably, a machining allowance of 0.3 mm is reserved. Figure 4 The structure of the punch 10 shows that the punch body 11 has a reserved layer 14 protruding on both sides, and the reinforcing rib 13 is provided on one of the reserved layers 14. The reserved machining allowance refers to the reserved layer 14.

[0044] Example 8 See Figure 11 The diagram shown is a flowchart of another embodiment of the processing method of the punch 10 of the present invention.

[0045] In this embodiment, the main difference from Embodiment 1 is that, after step S7: based on the cutting edge 12, wire cutting is performed on the end face of the die blank 70 away from the cutting edge 12 according to the cross-sectional contour of the punch 10 to obtain the punch 10, the following steps are also included: S8: A pin hole 15 is provided on the punch 10, and the pin hole 15 is located away from the cutting edge 12.

[0046] Specifically, the end of the punch body 11 that is away from the cutting edge 12 is defined as the mounting end, such as... Figure 3As shown, a through hole, or pin hole 15, is provided radially through the punch 10 near the mounting end. The pin hole 15 can be formed by drilling or EDM machining. When installing the punch 10, a pin 50, shaft, or other components pass through the pin hole 15 to mount the punch 10 to the outside. Combined with the reinforcing rib 13, this achieves axial and radial positioning of the punch 10. It can be understood that compared to the existing method of positioning the punch 10 using a stepped structure, the pin hole 15 avoids stress concentration caused by the stepped structure, improving the service life of the punch 10. Furthermore, the hole is simple to machine, simplifying the machining process and improving machining efficiency.

[0047] Example 9 Furthermore, in this embodiment, step S7 specifically involves using slow wire EDM to cut the cross-sectional contour of the punch 10 in a processing mode of one cut and three finishing cuts. The first cut is a rough cut using a large discharge energy to form the basic contour of the punch body 11 and the reinforcing rib 13. The subsequent three finishing cuts progressively reduce the discharge energy. Specifically, the first finishing cut can eliminate the large processing marks and surface hardening layer generated during the rough cut. The second finishing cut further improves the dimensional accuracy and surface finish. The third finishing cut achieves high surface quality, ultimately resulting in a surface roughness of the punch 10 below Ra0.2 and a dimensional accuracy of 0.01 mm. Further, after obtaining the punch 10 through wire EDM, the punch 10 can be tempered twice to eliminate cutting stress. After tempering, the surface of the punch 10 is polished and coated with a titanium layer to further improve its wear resistance. This embodiment is not limited to these steps, and all of the above are within the protection scope of this invention.

[0048] Example 10 See Figures 15 to 18 As shown, this embodiment provides a stamping die 100, including: an upper die 20, a lower die 30, and a punch 10 obtained by the above processing method. The upper die 20 and the lower die 30 are arranged opposite to each other, and the punch 10 is disposed on the upper die 20.

[0049] It should be noted that in the stamping die 100 of this embodiment, the punch 10 is installed on the upper die 20 to form a punch, and the lower die 30 has a stamping chamber inside to form a die. The upper die 20 and the lower die 30 are arranged opposite to each other. In use, the upper die 20 can be fixed and the lower die 30 can move toward the upper die 20; or the lower die 30 can be fixed and the upper die 20 can move toward the lower die 30. The specific arrangement depends on the product requirements and processing method, and is not limited here. Specifically, as shown... Figure 15As shown, the stamping die 100 of this embodiment is provided with multiple punches 10, which are inserted into the sliding sleeve 40. The punches 10 are fixed in the upper die 20 by the sliding sleeve 40. Correspondingly, the lower die 30 has multiple grooves that match the shape of the punches 10, so that when the stamping is in place, the cutting edges 12 of the multiple punches 10 can be inserted into the corresponding grooves. Taking the processing of a pulley workpiece as an example, the pulley to be processed is placed in the lower die 30. When the upper die 20 approaches the lower die 30, it drives the cutting edges 12 of the punches 10 to press against the pulley, thereby stamping out the arc-shaped groove. The structure of the finished workpiece 60 after stamping is as follows. Figure 18 As shown, the inner and outer ring arc grooves of the finished workpiece 60 are long and narrow, with high processing accuracy. Since the punch 10 processed by the processing method of the present invention has high strength and high processing accuracy, the punch 10 is stamped by the stamping die 100 of this embodiment, ensuring the processing accuracy of the arc groove while ensuring that the punch 10 will not easily break.

[0050] Furthermore, such as Figure 17 As shown, the reinforcing ribs 13 are respectively provided on the convex or concave arc surfaces of the two types of punches 10, which are connected together by pins 50 passing through their respective pin holes 15. The upper die 20 has a slot for limiting the pins 50. After the die is installed, the pins 50 are limited in the upper die 20. In this way, the pins 50 cooperate with the slots 131 to provide axial and radial constraint forces for the punches 10. Compared with the prior art of fixing by setting a stepped structure, stress concentration can be reduced, the service life of the punches 10 can be improved, and the processing of the pin holes 15 is simple and the cost is lower.

[0051] The above description is merely an optional embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A method for processing a punch, characterized in that, The punch includes: a punch body and a reinforcing rib. One end of the punch body is formed with a cutting edge. The projection of the cutting edge on the stamping plane is arc-shaped. The reinforcing rib avoids the cutting edge and is disposed on the punch body. The side of the reinforcing rib is recessed to form a groove with the punch body so that the punch can be installed to the outside through the groove. The processing method includes the following steps: The blank is selected according to the outer dimensions of the punch, and the blank is rough machined to obtain the die blank. The die blank is cylindrical and retains the allowance for wire cutting. The mold blank is subjected to heat treatment; The heat-treated mold blank is precision machined to form the cutting edge at one end of the mold blank, the cutting edge extending along the axial direction of the mold blank; Based on the cutting edge, the punch is obtained by wire cutting on the end face of the die blank opposite to the cutting edge according to the cross-sectional profile of the punch; The step of finishing the heat-treated mold blank includes: The shape of the heat-treated mold blank is precision machined. The cutting edge is machined out at one end of the mold blank; The cutting edge is precision ground; The surfaces of the mold blank and the cutting edge are polished; The step of precision turning the shape of the heat-treated mold blank includes: Determine the positions of the cutting edge and the reinforcing rib on the mold blank; Based on the positions of the cutting edge and the reinforcing rib, a transition slope is machined out on the outer wall of the die blank, and the transition slope is located at the connection between the cutting edge and the reinforcing rib.

2. The processing method as described in claim 1, characterized in that, The step of heat-treating the mold blank includes: The mold blank is placed in a heat treatment furnace for heating; The mold blank is cooled to room temperature so that the hardness value of the mold blank is HRC58-60; The mold blank is subjected to 2 to 3 tempering processes.

3. The processing method as described in claim 1, characterized in that, The cross-sectional profile of the punch includes the cross-sectional profiles of the punch body and the reinforcing rib, and machining allowances are reserved on both sides of the punch body.

4. The processing method as described in claim 1, characterized in that, After the step of obtaining the punch by wire cutting the end face of the die blank opposite to the cutting edge according to the cross-sectional profile of the punch based on the cutting edge, the method further includes: opening a pin hole on the punch, the pin hole being located away from the cutting edge.

5. The processing method as described in claim 1, characterized in that, The step of wire cutting the punch according to the cross-sectional profile on the end face of the die blank away from the cutting edge is specifically: using slow wire cutting, cutting the cross-sectional profile of the punch in a processing mode of cutting once and finishing three times.

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