Rear punching device

Abstract

The invention relates to a rear punching device. The rear punching device comprises a base; the female die is fixed on the base and is provided with a through hole; the guide support and the female die are fixed to the base side by side, a gap is reserved between the guide support and the female die, and a guide hole right opposite to the through hole is formed in the guide support; the punch is arranged in a sliding mode and can slide back and forth relative to the guide hole in the axis direction of the guide hole so as to punch the part to be punched; the driving structure is used for driving the punch to slide towards the female die; moreover, in the punching state, the guide support and the driving structure are both located in the to-be-punched part, the female die is located outside the to-be-punched part, the to-be-punched side wall of the to-be-punched part is located in a gap between the guide support and the female die, and the through hole, the guide hole and the punch are sequentially right opposite to each other. Compared with the prior art, the punching device is small in occupied space, interference between the punching device and the auxiliary frame can be avoided, and the punching precision can be effectively guaranteed.

Description

Technical Field

[0001] This invention relates to the field of automotive chassis component processing, and more particularly to a rear punching device. Background Technology

[0002] Chassis components (such as those with internal cavities) are generally welded together from several stamped steel sheet metal parts. However, welding can lead to significant dimensional variations in the parts. For common chassis components, the tolerance for variations in mounting hole dimensions is sufficient to be ±1mm. However, for some mounting holes on chassis components, the requirements are higher, and the positional tolerance generally needs to be controlled within ±0.5mm.

[0003] Therefore, for mounting points with high requirements, smaller holes need to be punched at the corresponding locations on the stamped parts before welding. After the parts are welded onto the subframe, larger holes of the final size are punched at these high-requirement locations using specialized equipment to meet the stringent positional requirements of the mounting holes. This punching process is called post-punching, and the specialized equipment is called post-punching equipment.

[0004] Furthermore, traditional rear punching equipment typically includes a punching machine body, a rotating clamping head, a punch, and a drive device for driving the punch. However, traditional rear punching equipment is relatively large, and the punching operation is located outside the part to be punched, thus occupying a large space. It also causes significant interference with the subframe during punching, and punching accuracy is difficult to guarantee. Therefore, existing rear punching equipment needs further improvement. Summary of the Invention

[0005] The first technical problem to be solved by the present invention is to provide a rear punching device that can avoid interference with the subframe during punching, in contrast to the prior art.

[0006] The second technical problem to be solved by the present invention is to provide a rear punching device that can avoid interference with the subframe during punching and has high punching accuracy, in contrast to the prior art.

[0007] The third technical problem to be solved by the present invention is to provide a rear punching device that can avoid interference with the subframe during punching and prevent punching waste from remaining inside the part, in contrast to the prior art.

[0008] The technical solution adopted to further solve at least one of the above-mentioned technical problems is: a post-punching device for punching holes inside a part with a cavity and an open side, characterized in that it includes:

[0009] Base;

[0010] A die is fixed on the base and has a through hole;

[0011] A guide support is fixed on the base side by side with the die, with a gap between them, and a guide hole is provided that is directly opposite to the through hole;

[0012] A punch is slidably configured and can slide back and forth relative to the guide hole along the axial direction of the guide hole to punch a hole in the part to be punched.

[0013] A driving structure for driving the punch to slide toward the die;

[0014] Furthermore, in the punching state, the guide support, punch, and drive structure are all located within the part to be punched, the die is located outside the part to be punched, and the punching sidewall of the part to be punched is located in the gap between the guide support and the die, and the through hole, guide hole, and punch are aligned in sequence.

[0015] Furthermore, the diameter of the through hole is greater than or equal to the diameter of the hole to be punched, and during the punching process, the edge of the first end of the through hole along its channel direction always abuts against the outer surface of the part to be punched along the circumferential direction. In this way, the waste generated during punching can be removed through the through hole, avoiding waste remaining inside the part to be punched (if it remains inside the part to be punched, it is difficult to remove).

[0016] Furthermore, the diameter of the through hole increases progressively from the first end to the second end. This facilitates the removal of waste material entering the through hole and prevents waste material from remaining in the through hole's channel.

[0017] Furthermore, a cylindrical guide sleeve is inserted into the guide hole. This guide sleeve can move back and forth along the axial direction of the guide hole under the circumferential guidance of its outer circumferential surface and the edge of the guide hole.

[0018] The punch is a cylindrical body that passes through the guide sleeve and can move back and forth along the axis of the guide hole under the circumferential guidance of its outer circumferential surface and the inner circumferential surface of the guide sleeve.

[0019] Furthermore, the diameter of the hole to be punched matches the radius of the punch. During punching, the end face of the first end of the guide sleeve always abuts against the inner surface of the part to be punched circumferentially. Guiding the punch helps it to accurately punch at the desired location, thus better ensuring punching accuracy. In addition, during punching, the part to be punched is held between the guide sleeve and the through hole of the die, allowing for better guidance of the punched waste into the through hole and preventing waste residue from remaining in the part.

[0020] Furthermore, it also includes a punch holder for fixing the punch, which can slide under the drive of the drive structure.

[0021] The second end edge of the guide sleeve extends radially outward in the circumferential direction to form a ring edge. A first spring is fitted on the punch. In the initial state, the first spring is clamped between the punch seat and the ring edge. In the punching state, the punch seat slides towards the die, the first spring is compressed, and the guide sleeve is driven, causing the punch seat to tend to slide away from the area to be punched. This allows the punch seat to smoothly drive the guide sleeve towards the die when it slides. Furthermore, the first spring allows the first end of the guide sleeve to elastically press against the inner surface of the part to be punched, preventing excessive pressure on the guide sleeve at the punching area from affecting the punching effect (rigid pressing may cause tearing at the location adjacent to the punching area during punching). During the punching process, the first spring is compressed and further deformed. On the one hand, this allows the first end of the guide sleeve to be pressed more tightly against the punching location, which not only better prevents waste from falling into the part to be punched, but also assists the punch in punching at the punching location. On the other hand, the elastic force of the first spring can assist the punch seat to reset when the punching ends, in preparation for the next punching.

[0022] Furthermore, one side of the guide support is recessed to form a guide groove with a circular cross-section centered on the guide hole, and this guide groove communicates with the guide hole. The aforementioned annular edge is embedded in this guide groove and can move back and forth within it. By providing a guide groove to guide the annular edge, the guide sleeve can move more smoothly, thereby contributing to the smooth movement of the punch.

[0023] Furthermore, a second spring is fitted onto the guide sleeve, and the second spring is accommodated in the guide groove.

[0024] It also includes a transmission rod that extends along the axial direction of the punch, with one end hinged to the punch seat and the other end fixed to the ring edge.

[0025] During the punching process, the second spring is compressed and clamped between the ring edge and the wall of the guide groove, causing the ring edge to tend to move away from the die. When the punching is finished, the drive structure causes the punch seat to slide, and the guide sleeve slides along with the punch seat via the transmission rod. Simultaneously, the second spring releases its elastic force to assist the guide sleeve in moving with the punch seat, thereby better achieving the reset of the guide sleeve and the punch seat.

[0026] Furthermore, there are two transmission rods, evenly spaced circumferentially along the circumferential edge. The first end of each transmission rod is hinged to the punch seat, while the second end is fixed to the circumferential edge. The outer side of the second end of each transmission rod extends outward to form a first protrusion, which extends radially along the circumferential edge. A second protrusion is protruding from the annular groove wall of the guide groove, corresponding one-to-one with each first protrusion. Initially, each first protrusion abuts against its corresponding second protrusion. By providing two transmission rods, the sliding punch seat can more smoothly drive the guide sleeve to slide synchronously. The first and second protrusions, in conjunction with the first spring, position each transmission rod in the initial state, keeping it extending along the punch's axial direction. This ensures that when punching is finished, the guide sleeve can smoothly slide back to its original position along with the punch seat.

[0027] Furthermore, the driving structure includes a driving device mounted on the base, a driving block fixed to the output shaft of the driving device, and the driving device capable of driving the driving block to move back and forth along a first direction, which is perpendicular to the axial direction of the punch.

[0028] Furthermore, the drive block and the punch are respectively arranged on both sides of the punch holder along the axial direction of the punch. The drive block is provided with a drive inclined surface, and the punch holder is provided with a transmission inclined surface. The drive inclined surface extends along the first direction and is inclined towards the punch holder, while the transmission inclined surface can fit into the drive inclined surface.

[0029] In the punching state, the drive block moves under the drive of the drive device, and drives the punch seat to move towards the die direction through the drive inclined surface and the transmission inclined surface.

[0030] In this way, the driving structure can drive the punch holder to slide along the axis of the punch toward the die to achieve the punching action.

[0031] Furthermore, a limiting support is also fixed on the base. In the punching state, the limiting support is located inside the part to be punched.

[0032] Furthermore, a limiting block is fixed on the limiting support. Along the axial direction of the punch, the limiting block is located on the other side of the driving block. Both the limiting block and the driving block have limiting surfaces extending along the first direction, and the limiting surfaces on the limiting block and the driving block always abut against each other along the axial direction of the punch. The limiting block limits the driving block, allowing it to better drive the punch seat to move through interaction with the transmission ramp of the punch seat.

[0033] Compared with the prior art, the advantages of the present invention are as follows: The rear punching device of the present invention includes a base, a die, a guide support, a punch, and a drive structure. In the punching state, the guide support, punch, and drive structure are all located within the part to be punched. Compared with the prior art (where the entire rear punching device is located outside the part to be punched), it occupies less space, thus helping to avoid interference between the rear punching device and the subframe. Furthermore, the die is located outside the part to be punched, and the through hole on the die, the guide hole on the guide support, and the punch are aligned sequentially. This allows for easy adjustment of the die position to ensure that the punch is aligned with the punching location, effectively guaranteeing punching accuracy. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the structure of the post-punching device in the punching state in an embodiment of the present invention;

[0035] Figure 2 for Figure 1 A structural diagram from another direction;

[0036] Figure 3 for Figure 1 A structural diagram in another direction;

[0037] Figure 4 for Figure 2 A cross-sectional view along the AA direction;

[0038] Figure 5 for Figure 3 A cross-sectional view along the BB direction;

[0039] Figure 6 This is a schematic diagram of the punching device in its unused state in an embodiment of the present invention;

[0040] Figure 7 This is an exploded view of the rear punching device in an embodiment of the present invention. Detailed Implementation

[0041] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0042] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention 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. Since the embodiments disclosed in this invention can be arranged in different directions, these terms indicating direction are only for illustration and should not be regarded as limitations. For example, "upper" and "lower" are not necessarily limited to directions opposite to or consistent with the direction of gravity. In addition, features defined with "first" and "second" may explicitly or implicitly include one or more of such features.

[0043] like Figures 1-7 As shown, a rear punching device is used to punch holes inside a part 1 with a cavity and an open side (specifically, an open top in this embodiment), including a base 3, a die 4, a guide support 5, a punch 8, and a drive structure 7.

[0044] Furthermore, the die 4 is fixed on the base 3 and has a through hole 41. The guide support 5 is fixed on the base 3 side by side with the die 4, with a gap between them, and has a guide hole 51 opposite to the through hole 41. The punch 8 is slidably disposed and can slide back and forth relative to the guide hole 51 along the axial direction of the guide hole 51 to punch a hole in the part 1 to be punched. The drive structure 7 is used to drive the punch 8 to slide.

[0045] Furthermore, in the punching state, the aforementioned guide support 5, punch 8, and drive structure 7 are all located within the part 1 to be punched, the aforementioned die 4 is located outside the part 1 to be punched, and the punching sidewall 11 of the part 1 to be punched extends vertically and is located in the gap between the guide support 5 and the die 4, and the aforementioned through hole 41, guide hole 51, and punch 8 are aligned in sequence.

[0046] In this invention, before welding, a small hole with a smaller diameter is pre-punched at the location to be punched in the part 1 to be punched. Then, the part 1 is welded to the subframe. Finally, the required diameter hole is punched using the rear punching device of this invention, based on the small hole. Furthermore, the rear punching device of this invention includes a base 3, a die 4, a guide support 5, a punch 8, and a drive structure 7. In the punching state, the guide support 5, the punch 8, and the drive structure 7 are all located within the part 1 to be punched. Compared with the prior art (where the entire rear punching device is located outside the part 1 to be punched), this invention occupies less space, thus helping to avoid interference between the rear punching device and the subframe. Moreover, the die 4 is located outside the part 1 to be punched, and the through hole 41, guide hole 51, and punch 8 on the die 4 are aligned sequentially. By adjusting the position of the die 4, the punch 8 located in the part 1 to be punched can be ensured to be aligned with the location to be punched, thereby ensuring the punching accuracy (the punching accuracy of this invention can reach 0.8 mm or higher). In this embodiment, the base 3 is connected to a robotic arm (not shown), so that the position of the base 3 can be adjusted by the robotic arm, thereby adjusting the position of the die 4 and aligning the punch 8 with the hole to be punched.

[0047] Preferably, the diameter of the through hole 41 is greater than or equal to the diameter of the hole to be punched, and during the punching process, the edge of the first end of the through hole 41 along its channel direction always abuts against the outer surface of the part 1 to be punched circumferentially. This allows the waste generated during punching to escape through the through hole 41, preventing waste from remaining inside the part 1 to be punched (which would be difficult to clean if left inside). More preferably, the diameter of the through hole 41 increases from the first end of its channel towards the second end (e.g., ...). Figure 4 and Figure 5 As shown in the figure, this facilitates the removal of waste material entering the through hole 41 and prevents waste material from remaining in the channel of the through hole 41.

[0048] In this embodiment, specifically, the base 3 extends horizontally, and both the die 4 and the guide support 5 are elongated blocks that extend vertically. Their top ends are respectively fixed to the bottom surface of the base 3 (e.g., ...). Figure 4 and Figure 7 (As shown). Furthermore, the aforementioned through hole 41 and guide hole 51 extend horizontally, wherein the lower part of the second end of the through hole 41 is recessed outwards along the extending direction of the through hole 41 (as shown). Figure 4 (As shown), this allows the waste material to be released more smoothly from the second end of the through hole 41.

[0049] Furthermore, such as Figure 4As shown, a cylindrical guide sleeve 6 is inserted into the guide hole 51. Guide sleeve 6 can move back and forth along the axis of guide hole 51 under the circumferential guidance of its outer circumferential surface and the edge of guide hole 51. The punch 8 is a cylindrical column that passes through guide sleeve 6 and can move back and forth along the axis of guide hole 51 under the circumferential guidance of its outer circumferential surface and the inner circumferential surface of guide sleeve 6. Furthermore, the diameter of the hole to be punched matches the radius of punch 8. During punching, the end face of the first end of guide sleeve 6 always abuts against the inner surface of the part 1 to be punched circumferentially. Guiding punch 8 helps it to accurately punch at the desired location, thus better ensuring punching accuracy. In addition, during the punching process, the punching area of ​​the part 1 to be punched is clamped between the guide sleeve 6 and the through hole 41 of the die 4, which allows the punched waste to be better guided into the through hole 41 and better prevents waste from remaining in the part 1 to be punched.

[0050] Furthermore, such as Figure 4 As shown, it also includes a punch seat 81 for fixing the punch 8. The punch seat 81 can slide under the drive of the drive structure 7 to drive the punch 8 to slide. The end edge of the second end of the guide sleeve 6 extends radially outward in the circumferential direction to form an annular edge 61. A first spring 91 is sleeved on the punch 8. In the initial state, the first spring 91 is clamped between the punch seat 81 and the annular edge 61. In the punching state, the punch seat 81 slides towards the die 4, the first spring 91 is compressed and drives the guide sleeve 6, and the punch seat 81 tends to slide away from the punching location.

[0051] Thus, the drive structure 7 drives the punch 8 to slide by driving the punch seat 81. By setting the first spring 91, the first spring 91 has a certain initial deformation in the initial state (under the clamping action of the punch seat 81 and the ring edge 61), so that when the punch seat 81 slides, it can smoothly drive the guide sleeve 6 to slide towards the die 4. Furthermore, the action of the first spring 91 can make the first end of the guide sleeve 6 elastically press against the inner side of the part 1 to be punched, so as to avoid the guide sleeve 6 having too large a pressing force at the punching point, which would affect the punching effect (rigid pressing may cause the part adjacent to the punching point to break during punching). During the punching process, the first spring 91 is compressed and further deformed. On the one hand, this allows the first end of the guide sleeve 6 to be better pressed at the punching location, which not only better prevents waste from falling into the part 1 to be punched, but also assists the punch 8 in punching at the punching location (which is equivalent to having a positioning and guiding effect on the formation of the opening). On the other hand, the elastic force of the first spring 91 can assist the punch seat 81 to reset at the end of the punching process, in preparation for the next punching.

[0052] Furthermore, one side of the guide support 5 is recessed to form a guide groove 52 with a circular cross-section centered on the guide hole 51, and the guide groove 52 communicates with the guide hole 51. The annular edge 61 is fitted into the guide groove 52 and can move back and forth within it. By providing the guide groove 52 to guide the annular edge 61, the guide sleeve 6 moves more smoothly, which in turn helps the punch 8 to move smoothly. Furthermore, a second spring 92 is fitted onto the guide sleeve 6 and is housed in the guide groove 52. A transmission rod 82 is also included, extending along the axial direction of the punch 8, with one end hinged to the punch seat 81 and the other end fixed to the annular edge 61. In this embodiment, specifically, the transmission rod 82 is hinged to the punch seat 81 via a rotating shaft 83.

[0053] Furthermore, during the punching process, the second spring 92 is compressed between the ring edge 61 and the groove wall of the guide groove 52, causing the ring edge 61 to tend to move away from the punching area. When the punching is finished, the drive structure 7 drives the punch seat 81 to slide, and the guide sleeve 6 slides along with the punch seat 81 via the transmission rod 82. Simultaneously, the second spring 92 releases its elastic force to assist the guide sleeve 6 in moving with the punch seat 81, thereby better ensuring the reset of the guide sleeve 6 and the punch seat 81.

[0054] Preferably, there are two transmission rods 82, and the two transmission rods 82 are evenly spaced along the circumferential edge 61. The first end of each transmission rod 82 is hinged to the punch seat 81, and the second end is fixed to the circumferential edge 61. The outer side of the second end of each transmission rod 82 extends outward to form a first protrusion 821. Each first protrusion 821 extends radially along the circumferential edge 61. Furthermore, a second protrusion 521 is protruding on the annular groove wall of the guide groove 52. The second protrusion 521 corresponds one-to-one with each first protrusion 821. In the initial state, each first protrusion 821 abuts against the corresponding second protrusion 521. By setting two transmission rods 82, the sliding punch seat 81 can drive the guide sleeve 6 to slide more smoothly and synchronously. By setting each first protrusion 821 and each second protrusion 521, in the initial state, they cooperate with the first spring 91 to position each transmission rod 82 so that each transmission rod 82 is kept in the state of extending along the axis of the punch 8, so that when the punching ends, the guide sleeve 6 can slide and reset smoothly with the punch seat 81.

[0055] Furthermore, the aforementioned drive structure 7 includes a drive device 71 disposed on the aforementioned base 3. A drive block 72 is fixed on the output shaft 711 of the drive device 71, and the drive device 71 is capable of driving the drive block 72 along a first direction (specifically as shown in this embodiment). Figure 4The vertical dashed line in the diagram shows the movement back and forth. This first direction is related to the axis of the punch 8 (specifically, as shown in this embodiment). Figure 4 The drive block 72 and the punch 8 are respectively arranged on both sides of the punch seat 81 along the axial direction of the punch 8. The drive block 72 is provided with a drive inclined surface 721 and the punch seat 81 is provided with a transmission inclined surface 811. The drive inclined surface 721 extends along the first direction and is inclined towards the punch seat 81, while the transmission inclined surface 811 can fit into the drive inclined surface 721. In the punching state, the drive block 72 moves downward under the drive of the drive device 71 and drives the punch seat 81 to move towards the die 4 through the drive inclined surface 721 and the transmission inclined surface 811. When the punching is finished, the drive block 72 moves upward under the drive of the drive device 71, and the punch seat 81 moves away from the die 4 together with the guide sleeve 6 under the action of the first spring 91 and the second spring 92 to reset. Thus, the drive structure 7 can drive the punch holder 81 to slide along the axis of the punch 8 toward the die 4, thereby realizing the punching action. In this embodiment, the drive device 71 can specifically be a hydraulic cylinder, or other feasible drive devices 71.

[0056] Preferably, a limiting support 10 is also fixed on the base 3. In the punching state, the limiting support 10 is located inside the part 1 to be punched. A limiting block 101 is fixed on the limiting support 10. Along the axial direction of the punch 8, the limiting block 101 is located on the other side of the driving block 72. The limiting block 101 and the driving block 72 are respectively provided with limiting surfaces 1011 extending along the first direction, and the limiting surfaces 1011 on the limiting block 101 and the driving block 72 always abut against each other along the axial direction of the punch 8. The limiting block 101 limits the driving block 72, allowing the driving block 72 to better drive the punch seat 81 to move through interaction with the transmission inclined surface 811 of the punch seat 81. In this embodiment, the limiting support 10 is a long strip-shaped block that extends vertically, with its upper end fixed to the bottom of the base 3.

[0057] Furthermore, the rear punching device in this embodiment also includes a housing 2, which is hollow inside. In the non-punching state, except for the die 4 and the corresponding end of the base 3 connected to the die 4, all other parts of the rear punching device are located within the housing 2, such as... Figure 6 As shown, this allows for better avoidance of interference with the subframe during punching operations.

Claims

1. A post-punching device for punching holes inside a part (1) with a cavity and an open side, characterized in that, include: Base (3); A die (4) is fixed on the base (3) and has a through hole (41); The guide support (5) is fixed on the base (3) side by side with the die (4) and there is a gap between it and the die (4), and a guide hole (51) is provided that is directly opposite to the through hole (41); The punch (8) is slidably disposed and can slide back and forth relative to the guide hole (51) along the axial direction of the guide hole (51) to punch a hole in the part (1) to be punched; A drive structure (7) is used to drive the punch (8) to slide toward the die (4); Furthermore, in the punching state, the guide support (5), punch (8) and drive structure (7) are all located in the part to be punched (1), the die (4) is located outside the part to be punched (1), and the punching sidewall (11) of the part to be punched (1) is located in the gap between the guide support (5) and the die (4), and the through hole (41), guide hole (51) and punch (8) are aligned in sequence.

2. The rear punching device as described in claim 1, characterized in that, The diameter of the through hole (41) is greater than or equal to the diameter of the hole to be punched. In the punching state, the edge of the first end of the through hole (41) along its channel direction always abuts against the outer surface of the part to be punched (1) in the circumferential direction.

3. The rear punching device as described in claim 2, characterized in that, The diameter of the through hole (41) increases from the first end of the hole toward the second end.

4. The post-punching device as described in any one of claims 1 to 3, characterized in that, A cylindrical guide sleeve (6) is inserted into the guide hole (51). The guide sleeve (6) can move back and forth along the axis of the guide hole (51) under the circumferential guidance of its outer circumferential surface and the edge of the guide hole (51). The punch (8) is a cylindrical column that passes through the guide sleeve (6) and can move back and forth along the axis of the guide hole (51) under the circumferential guidance of its outer circumferential surface and the inner circumferential surface of the guide sleeve (6). Furthermore, the diameter of the hole to be punched is matched with the radius of the punch (8). During the punching process, the end face of the first end of the guide sleeve (6) is always circumferentially abutted against the inner side surface of the part to be punched (1).

5. The rear punching device as described in claim 4, characterized in that, It also includes a punch holder (81) for fixing the punch (8), which can slide under the drive of the drive structure (7). The end edge of the second end of the guide sleeve (6) extends radially outward in the circumferential direction to form a ring edge (61). A first spring (91) is sleeved on the punch (8). In the initial state, the first spring (91) is clamped between the punch seat (81) and the ring edge (61). In the punching state, the punch seat (81) slides toward the die (4), the first spring (91) is compressed and drives the guide sleeve (6), and the punch seat (81) has a tendency to slide away from the die (4).

6. The rear punching device as described in claim 5, characterized in that, The guide support (5) has a recessed side to form a guide groove (52) with a circular cross-section centered on the guide hole (51), and the guide groove (52) communicates with the guide hole (51). The aforementioned ring edge (61) is embedded in the guide groove (52) and can move back and forth in the guide groove (52).

7. The rear punching device as described in claim 6, characterized in that, A second spring (92) is fitted onto the guide sleeve (6), and the second spring (92) is housed in the guide groove (52). It also includes a transmission rod (82) that extends along the axial direction of the punch (8), with one end hinged to the punch seat (81) and the other end fixed to the ring edge (61). In the punching state, the second spring (92) is compressed between the ring edge (61) and the groove wall of the guide groove (52) so that the ring edge (61) tends to move away from the die (4).

8. The rear punching device as described in claim 7, characterized in that, There are two transmission rods (82), and the two transmission rods (82) are evenly spaced along the circumferential edge (61). The first end of each transmission rod (82) is hinged to the punch seat (81), and the second end is fixed to the circumferential edge (61). The outer side of the second end of each transmission rod (82) extends outward to form a first protrusion (821). Each first protrusion (821) extends radially along the circumferential edge (61). Furthermore, a second protrusion (521) is protruding on the annular groove wall of the guide groove (52). The second protrusion (521) corresponds one-to-one with each first protrusion (821). In the initial state, each first protrusion (821) abuts against the corresponding second protrusion (521).

9. The post-punching device according to any one of claims 5 to 8, characterized in that, The drive structure (7) includes a drive device (71) mounted on the base (3). A drive block (72) is fixed on the output shaft (711) of the drive device (71), and the drive device (71) can drive the drive block (72) to move back and forth along a first direction, which is perpendicular to the axial direction of the punch (8). Furthermore, the drive block (72) and the punch (8) are respectively arranged on both sides of the punch holder (81) along the axial direction of the punch (8), and the drive block (72) is provided with a drive inclined surface (721) while the punch holder (81) is provided with a transmission inclined surface (811). The drive inclined surface (721) extends along the first direction and is inclined toward the punch holder (81), while the transmission inclined surface (811) can fit into the drive inclined surface (721). In the punching state, the drive block (72) moves under the drive of the drive device (71), and drives the punch seat (81) to move toward the die (4) through the drive inclined surface (721) and the transmission inclined surface (811).

10. The rear punching device as described in claim 9, characterized in that, A limiting support (10) is also fixed on the base (3). In the punching state, the limiting support (10) is located inside the part (1) to be punched. Furthermore, a limiting block (101) is fixed on the limiting support (10). Along the axial direction of the punch (8), the limiting block (101) is located on the other side of the driving block (72). The limiting block (101) and the driving block (72) are respectively provided with limiting surfaces (1011) extending along the first direction. The limiting surface (1011) on the limiting block (101) and the limiting surface (1011) on the driving block (72) always abut against each other along the axial direction of the punch (8).

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