Rotatable die for punching holes in hook-shaped surfaces

Abstract

This utility model discloses a rotatable die for punching back-hook surfaces, belonging to the field of automotive stamping die design and manufacturing technology. It provides a rotatable die for punching back-hook surfaces that ensures stable punching hole positions and significantly reduces the defect rate of punched holes. The rotatable die includes an upper die base, a lower die base, an upper die pressure platen, a profile support punch, an upper die drive block, an upper die nitrogen cylinder, a filling punch, and a trolley. It also includes a back-hook surface punching assembly, which is movably arranged on the lower die base. During the back-hook surface punching process, the corresponding side of the semi-finished blank formed by the back-hook surface punching is stably shaped and positioned by the upper die pressure platen, the profile support punch, and the filling punch in cooperation with the upper and lower die bases. After shaping, the side of the semi-finished blank and the back-hook surface are further stabilized and shaped by the back-hook surface punching assembly, the upper die drive block, and the trolley in cooperation with the driving force output from the upper die nitrogen cylinder and the upper die base, and the hole on the back-hook surface is punched.

Description

Technical Field

[0001] This utility model relates to a rotatable die, and more particularly to a rotatable die for punching holes in the hook surface, belonging to the field of automotive stamping die design and manufacturing technology. Background Technology

[0002] In the automotive stamping die industry, we rarely encounter parts with a hook-shaped surface, often with punched or folded holes. From a conventional stamping die perspective, this functionality is structurally difficult to achieve. To address this, the punch needs to be positioned below the top surface of the product, concealed within the hook surface, to punch holes directly across the top surface. The current forming process for parts with hook surfaces consists of five steps: drawing, trimming and punching, flanging, side flanging, and punching holes in the hook surface, with punching the holes in the hook surface being the final step. To achieve this functionality, the industry typically uses a floating structure for the punch and its fixed components, utilizing the movement of this floating component to propel the punch downwards or diagonally downwards in a straight line. The die sleeve, on the other hand, is usually fixed to the lower die and remains stationary. In this way, although relative movement between the punch and the die sleeve is achieved and punching is realized, the contact sequence between the product and the die is as follows: the top surface and the return surface of the product are simultaneously supported by the lower die—the filling punch is in place, and the side wall of the product is supported by the filling punch—the upper die continues to press down, and the top surface of the product is pressed by the pressure plate—the side cylinder is in place, and the side wall of the product is pressed—the floating punch and the pressure plate move, and the return surface is pressed. This contact sequence between the product and the lower die support surface does not meet the contact sequence requirements for stable part conformity, ultimately leading to unstable or even unqualified punched hole positions. Utility Model Content

[0003] The technical problem to be solved by this utility model is to provide a rotatable die for punching back hook surfaces that can ensure the stability of the punching hole position and significantly reduce the defect rate of the punching hole position.

[0004] The technical solution adopted to solve the above-mentioned technical problems is: a rotatable die for punching back hook surfaces, including an upper die base, a lower die base, an upper die pressure platen, a profile support punch, an upper die drive block, an upper die nitrogen cylinder, a filling punch, and a trolley. The profile support punch, the filling punch, and the trolley are movably arranged on the lower die base, and the upper die pressure platen, the upper die drive block, and the upper die nitrogen cylinder are arranged on the upper die base. The rotatable die also includes a back hook surface punching assembly, which is movably arranged on the lower die base. During the back hook surface punching process, the corresponding side of the semi-finished blank formed by the back hook surface punching is stably shaped and positioned by the upper die pressure platen, the profile support punch, and the filling punch in cooperation with the upper die base and the lower die base. The side of the shaped semi-finished blank and the back hook surface are then stably shaped again by the back hook surface punching assembly, the upper die drive block, and the trolley in cooperation with the driving force output by the upper die nitrogen cylinder and the upper die base, and the hole on the back hook surface is punched.

[0005] Furthermore, the hook-face stamping assembly includes a hook-face clamping assembly and a floating punching assembly. The hook-face clamping assembly and the floating punching assembly are arranged in mutually compatible positions on the lower die base. The side surface and hook-face of the semi-finished blank are stabilized and shaped twice by the floating punching assembly and the hook-face clamping assembly under the cooperation of the driving force output by the upper die nitrogen cylinder and the upper die base. The semi-finished blank that is stabilized and shaped twice is punched with holes on the hook-face by the floating punching assembly.

[0006] The preferred embodiment of the above scheme is that the floating punch assembly includes at least a side drive cylinder, a side pressure block, a small pressure plate, and a floating slider, and the return hook face clamping assembly includes at least a rotating base, a rotating shaft, and a die sleeve; the side pressure block arranged on the rotating base is driven by the side drive cylinder, the small pressure plate is arranged on the floating slider, the floating slider is arranged on the lower die base through the filling punch, the die sleeve is arranged on the rotating shaft, and the rotating shaft is rotatably arranged on the lower die base around the centering axis through the rotating base. The side and return hook faces of the semi-finished blank are respectively stabilized and shaped under the cooperation of the side drive cylinder, the upper die nitrogen cylinder, and the upper die base output driving force through the trolley, the side pressure block, the small pressure plate, and the die sleeve.

[0007] Furthermore, the hook-face clamping assembly also includes a transmission structure and a return mechanism. The driving force output by the nitrogen cylinder of the upper mold drives the rotating shaft to rotate around the centering shaft through the transmission structure to clamp the hook-face of the semi-finished blank. During the punching process, the rotating shaft is limited to a specific position by the return mechanism. After punching is completed, the rotating shaft is retracted and reset by the return mechanism.

[0008] The preferred embodiment of the above scheme is that the transmission structure includes a transmission plate and a stroke limiting plate. The transmission plate is arranged on the power input end of the rotating shaft through a rotating base. The power output end of the upper mold nitrogen cylinder is pressed onto the transmission plate. The stroke limiting plate is arranged on the rotating base in a position that is compatible with the transmission plate. The rotation return of the rotating shaft is limited by the cooperation of the stroke limiting plate with the transmission plate.

[0009] Furthermore, the return mechanism includes a sensor, a return nitrogen cylinder, a return cylinder mounting plate, a guide sleeve, and a return push rod. The return nitrogen cylinder is arranged vertically on the lower middle part of the rotating base, adapted to the position of the transmission plate, via the return cylinder mounting plate. With the cooperation of the guide sleeve, the return push rod, arranged on the rotating base, vertically pushes against the return nitrogen cylinder and the transmission plate. The sensor is arranged on the rotating base, adapted to the position of the rotating shaft, and the rotation position of the rotating shaft during the rotation process is determined by the sensor.

[0010] The preferred embodiment of the above scheme is that the floating punch assembly also includes a punch, which is arranged on a floating slider. The floating slider is pressed and stabilized on the hook surface with the cooperation of a small pressure plate, and the punch punches holes on the hook surface through the floating slider.

[0011] The beneficial effects of this utility model are as follows: The technical solution provided in this application is based on the existing upper die base, lower die base, upper die pressure platen, profile support punch, upper die drive block, upper die nitrogen cylinder, filling punch, and trolley. It combines the structural features of the profile support punch, filling punch, and trolley being movably arranged on the lower die base, and the upper die pressure platen, upper die drive block, and upper die nitrogen cylinder being arranged on the upper die base. By adding a back-hook surface stamping assembly, the rotatable die of this application is constructed, and then the back-hook surface... The stamping assembly is arranged on the lower die base. During the punching process on the hook surface, the corresponding side of the semi-finished blank formed by the hook surface stamping is first stably shaped and positioned by the upper die pressure plate, the profile support punch, and the filling punch in cooperation with the upper die base and the lower die base. Then, the side of the shaped semi-finished blank and the hook surface are secondarily stabilized and shaped by the hook surface stamping assembly, the upper die drive block, and the trolley in cooperation with the upper die nitrogen cylinder and the upper die base output driving force, and the hole on the hook surface is punched. Because the rotatable die provided in this application performs two stabilization shapings on the semi-finished blank formed by the hook surface stamping before punching on the die, the contact sequence between the semi-finished product and the lower die support surface meets the contact sequence requirements for stable shaping of the part. Therefore, it can be ensured that the semi-finished product can be stably pressed onto the die before punching, and then the punching operation can be performed. This can ensure the stability of the punched hole position and achieve the purpose of significantly reducing the defect rate of punched hole position. Attached Figure Description

[0012] Figure 1 This is a three-dimensional structural schematic diagram of the rotatable die for punching holes in the hook surface according to this utility model;

[0013] Figure 2 This is a schematic diagram of the working structure of the rotatable die for punching back hook surfaces, which is involved in the present invention.

[0014] The components in the diagram are labeled as follows: 1. Lower die base; 2. Surface support punch; 4. Upper die nitrogen cylinder; 5. Filling punch; 6. Trolley; 7. Semi-finished blank; 8. Side drive cylinder; 9. Side pressure block; 10. Floating slider; 11. Rotating base; 12. Rotating shaft; 13. Die sleeve; 14. Centering shaft; 15. Transmission plate; 16. Stroke limit plate; 17. Sensor; 18. Return nitrogen cylinder; 19. Return cylinder mounting plate; 20. Guide sleeve; 21. Return ejector rod; 22. Punch; 23. Small pressure plate. Detailed Implementation

[0015] like Figure 1 , Figure 2The image shows a rotatable die for punching back-hook surfaces, which can ensure stable punching hole positions and significantly reduce the defect rate of punching hole positions. The rotatable die includes an upper die base, a lower die base 1, an upper die pressure platen, a profile support punch 2, an upper die drive block, an upper die nitrogen cylinder 4, a filling punch 5, and a trolley 6. The profile support punch 2, the filling punch 5, and the trolley 6 are movably arranged on the lower die base 1. The upper die pressure platen, the upper die drive block, and the upper die nitrogen cylinder 4 are arranged on the upper die base. The rotatable die also includes a hook-face stamping assembly, which is movably arranged on the lower die base 1. During the hook-face punching process, the corresponding side of the semi-finished blank 7 formed by the hook-face stamping is stably shaped and positioned by the upper die pressure platen, the profile support punch 2, and the filling punch 5 in cooperation with the upper die base and the lower die base 1. The side of the shaped semi-finished blank 7 and the hook-face are stably shaped and punched on the hook-face by the hook-face stamping assembly, the upper die drive block, and the trolley 6 in cooperation with the driving force output by the upper die nitrogen cylinder 4 and the upper die base. The technical solution provided in this application is based on the existing upper die base, lower die base, upper die pressure platen, profile support punch, upper die drive block, upper die nitrogen cylinder, filling punch, and trolley. It combines the structural characteristics of the profile support punch, filling punch, and trolley being movably arranged on the lower die base, and the upper die pressure platen, upper die drive block, and upper die nitrogen cylinder being arranged on the upper die base. By adding a hook-face stamping assembly, a rotatable die of this application is constructed. The hook-face stamping assembly is then movably arranged on the lower die base. During the hook-face punching process, the corresponding side of the semi-finished blank formed by the hook-face stamping is first stably shaped and positioned by the upper die pressure platen, profile support punch, and filling punch in cooperation with the upper and lower die bases. Then, the side of the shaped semi-finished blank and the hook-face are secondarily stabilized and shaped by the hook-face stamping assembly, upper die drive block, and trolley in cooperation with the driving force output from the upper die nitrogen cylinder and upper die base, and holes are punched on the hook-face. Because the rotatable die provided in this application performs two stabilization molding processes on the semi-finished blank formed by stamping the hook surface on the die before punching, the contact sequence between the semi-finished product and the lower die support surface meets the contact sequence requirements for the stabilization molding of the part. Therefore, it can be ensured that the semi-finished product can be stably pressed onto the die before punching, and then the punching operation can be performed. This can ensure the stability of the punching hole position and achieve the purpose of significantly reducing the defect rate of the punching hole position.

[0016] Accordingly, considering the actual situation of the holes on the hook surface that need to be punched, in order to maximize the realization of punching after secondary shaping, the hook surface stamping assembly of this application includes a hook surface clamping assembly and a floating punching assembly. The hook surface clamping assembly and the floating punching assembly are arranged on the lower die base 1 in mutually adaptive positions. The side surface and hook surface of the semi-finished blank 7 are secondarily stabilized and shaped by the floating punching assembly and the hook surface clamping assembly under the cooperation of the upper die nitrogen cylinder 4 and the upper die base output driving force. The secondarily stabilized semi-finished blank 7 punches the holes on the hook surface through the floating punching assembly. Specifically, the floating punch assembly includes at least a side drive cylinder 8, a side pressure block 9, a small pressure plate 23, and a floating slider 10. The hook-face clamping assembly includes at least a rotating base 11, a rotating shaft 12, and a die sleeve 13. The side pressure block 9, which is arranged on the rotating base 11, is driven by the side drive cylinder 8. The small pressure plate 23 is arranged on the floating slider 10. The floating slider 10 is arranged on the lower die base 1 through the filling punch 5. The die sleeve 13 is arranged on the rotating shaft 12. The rotating shaft 12 is rotatably arranged on the lower die base 1 around the centering shaft 14 via the rotating base 11. The side and hook-face of the semi-finished blank 7 are stabilized and shaped twice by the pulley 6, the side pressure block 9, the small pressure plate 23, and the die sleeve 13 under the cooperation of the side drive cylinder 8, the upper die nitrogen cylinder 4, and the upper die base output driving force.

[0017] Furthermore, to improve control effectiveness and facilitate punch retraction after punching, the hook-face clamping assembly of this application also includes a transmission structure and a return mechanism. The driving force output by the upper die nitrogen cylinder 4 drives the rotating shaft 12 to rotate around the centering shaft 14 via the transmission structure, clamping the hook-face of the semi-finished blank 7. During the punching process, the rotating shaft 12's rotation position is limited by the return mechanism, and after punching, the rotating shaft 12 retracts and resets via the return mechanism. More specifically, the transmission structure includes a transmission plate 15 and a stroke limiting plate 16. The transmission plate 15 is arranged on the power input end of the rotating shaft 12 via a rotating base 11. The power output end of the upper die nitrogen cylinder 4 is pressed against the transmission plate 15. The stroke limiting plate 16 is arranged on the rotating base 11 in a position corresponding to the transmission plate 15. The rotational return of the rotating shaft 12 is limited by the cooperation of the stroke limiting plate 16 with the transmission plate 15. The return mechanism includes a sensor 17, a return nitrogen cylinder 18, a return cylinder mounting plate 19, a guide sleeve 20, and a return push rod 21. The return nitrogen cylinder 18 is vertically arranged on the lower middle part of the rotating base 11, adapted to the position of the transmission plate 15, via the return cylinder mounting plate 19. The return push rod 21, arranged on the rotating base with the cooperation of the guide sleeve 20, vertically abuts against the return nitrogen cylinder and the transmission plate. The sensor 17 is arranged on the rotating base 11, adapted to the position of the rotating shaft 12. During rotation, the rotation position of the rotating shaft 12 is determined by the sensor 17. Correspondingly, the floating punch assembly described in this application also includes a punch 22, which is arranged on a floating slider 10. The floating slider 10, with the cooperation of a small pressure plate 23, presses and stabilizes the return hook surface. The punch 22 punches holes on the return hook surface through the floating slider 10.

[0018] In summary, the technical solution provided in this application also has the following advantages:

[0019] With the above-mentioned rotatable punching die structure, the contact sequence between the product and the die should be as follows: the top surface of the product is supported by the lower die – the filling punch is in place, and the side wall of the product is supported – the upper die continues to press down, and the top surface of the product is pressed by the pressure plate – the side cylinder is in place, and the side wall of the product is pressed – the lower die sleeve is activated, and the hook surface of the product is supported – the floating punch and pressure plate move, and the hook surface is pressed, and finally, the hole is punched. This achieves a stable shape of the semi-finished blank formed by the hook surface stamping, allowing the product to better conform to the die and be pressed firmly before punching, thus more accurately ensuring the punching hole position on the hook surface.

[0020] Example 1

[0021] 1) The implementation of the punch return hook surface function and a brief introduction to the mold structure are as follows:

[0022] like Figure 1As shown, the combination of the rotating punching die structure and the floating punch structure assembled in the lower die achieves support and stabilization of the product, and this contact sequence conforms to the product support process and completes the final punching function. The mechanism of the rotating punching die and the floating punch in the lower die, as well as the entire stamping process, are briefly described below:

[0023] a) The mold opens, the robot arm picks up the product from the previous process, and places the product onto the lower mold of this process. The top surface of the product is supported by the convex mold surface.

[0024] b) The upper mold is pressed down, driving the trolley to move along direction A.

[0025] c) The mold continues to press down, and the trolley drives the filling punch to move in direction B until the filling punch reaches its position, supporting the side wall of the product.

[0026] d) The upper die pressure plate presses down to stabilize the top surface of the product, preventing it from moving.

[0027] e) The side cylinder is activated, pushing the pressure block on the cylinder to press down on the side of the product.

[0028] f) The upper mold continues to press down, and the nitrogen cylinder driving the rotating die sleeve contacts the rotating shaft. The rotating shaft rotates along the D direction, and the lower surface of the product's hook surface is supported by the die surface.

[0029] g) The upper die continues to descend, the upper die drive block contacts the floating punch slider and causes the floating slider to slide in direction C. The small pressure plate mounted on the floating block first contacts the product hook surface, and the product hook surface is pressed and stabilized. The floating punch mounted on the floating slider then contacts the product, and finally the punching of the hook surface is achieved.

[0030] 2) The implementation of the rotation function of the rotary punching die and the description of the die structure are as follows:

[0031] like Figure 2As shown, the rotating base is fixed to the lower mold base, serving to support other components and prevent them from shifting. The side drive cylinder is fixed to the rotating base and is driven by factory compressed air. Its start-up time is controlled by the press control program, and it drives the side pressure plate to press the side wall of the product. The upper mold drive nitrogen cylinder is fixed to the upper mold. As the upper press presses downward, the drive nitrogen cylinder contacts the transmission plate, causing the transmission plate and the rotating shaft to rotate clockwise around the centering shaft within the rotating base until the die sleeve surface fixed to the other end of the rotating shaft supports the product's return hook surface. The return ejector is assembled inside the guide sleeve, which is fixed to the rotating base. With the help of the return nitrogen cylinder, the return ejector can move up and down along the guide sleeve. When the upper mold nitrogen cylinder opens upward, the return ejector drives the rotating plate to rotate upward, realizing the return function of the rotating shaft. The stroke limit plate is also fixed to the rotating base, ensuring that the rotating shaft does not exceed its stroke during return. The sensor is also located on the fixed rotating base. When the rotating shaft rotates to the correct position, it sends a signal to the sensor so that the press can press downwards, thus preventing the mold from being damaged due to a malfunction in the rotating shaft.

[0032] The aforementioned rotary punching die structure is a newly improved structure on this set of molds. This structure not only enables punching of hook-type products but also provides support and stabilization for hook-type products according to their springback sequence. When designing this structure, attention must be paid to the starting time of the rotary die's movement to ensure that its movement sequence and stroke are correct with the trolley, filling punch, side pressure cylinder, and floating punch, avoiding stroke conflicts. Simultaneously, attention must be paid to the support surface area of ​​the support and stabilization mechanisms in each direction, ensuring that the rotary driving force of the rotary die sleeve meets the punching requirements. This design concept and structure have been successfully applied to the mold for the rear door outer panel of a Volvo model. The mold has been manufactured and debugged, and qualified parts have been successfully produced.

Claims

1. A rotatable die for punching a hook-shaped surface, comprising an upper die base, a lower die base (1), an upper die pressure platen, a profile support punch (2), an upper die drive block, an upper die nitrogen cylinder (4), a filling punch (5), and a trolley (6), wherein the profile support punch (2), the filling punch (5), and the trolley (6) are movably arranged on the lower die base (1), and the upper die pressure platen, the upper die drive block, and the upper die nitrogen cylinder (4) are arranged on the upper die base, characterized in that: The rotatable die also includes a hook face stamping assembly, which is movably arranged on the lower die base (1). During the hook face punching process, the corresponding side of the semi-finished blank (7) formed by the hook face stamping is stably shaped and positioned by the upper die pressure plate, the profile support punch (2) and the filling punch (5) in cooperation with the upper die base and the lower die base (1). The side of the semi-finished blank (7) after shaping and the hook face are shaped and punched on the hook face by the hook face stamping assembly, the upper die drive block and the trolley (6) in cooperation with the upper die nitrogen cylinder (4) and the upper die base output driving force.

2. The rotatable die for punching holes in the hook surface according to claim 1, characterized in that: The hook-face stamping assembly includes a hook-face clamping assembly and a floating punching assembly. The hook-face clamping assembly and the floating punching assembly are arranged in a mutually compatible manner on the lower die base (1). The side surface and hook-face of the semi-finished blank (7) are stabilized and shaped twice by the floating punching assembly and the hook-face clamping assembly under the cooperation of the upper die nitrogen cylinder (4) and the upper die base output driving force. The semi-finished blank (7) that has been stabilized and shaped twice is punched with holes on the hook-face by the floating punching assembly.

3. The rotatable die for punching holes in the hook surface according to claim 2, characterized in that: The floating punch assembly includes at least a side drive cylinder (8), a side pressure block (9), a small pressure plate (23), and a floating slider (10). The hook-face clamping assembly includes at least a rotating base (11), a rotating shaft (12), and a die sleeve (13). The side pressure block (9) arranged on the rotating base (11) is driven by the side drive cylinder (8). The small pressure plate (23) is arranged on the floating slider (10). The floating slider (10) is driven by the filling punch (5). The die sleeve (13) is placed on the lower die base (1) and arranged on the rotating shaft (12). The rotating shaft (12) is rotatably arranged on the lower die base (1) around the centering shaft (14) via the rotating base (11). The side and back hook surfaces of the semi-finished blank (7) are stabilized and shaped twice by the pulley (6), the side pressure block (9), the small pressure plate (23) and the die sleeve (13) under the cooperation of the side drive cylinder (8), the upper die nitrogen cylinder (4) and the upper die base output driving force.

4. The rotatable die for punching holes in the hook surface according to claim 3, characterized in that: The hook-face clamping assembly also includes a transmission structure and a return mechanism. The driving force output by the upper die nitrogen cylinder (4) drives the rotating shaft (12) to rotate around the centering shaft (14) through the transmission structure to clamp the hook-face of the semi-finished blank (7). During the punching process, the rotating shaft (12) is limited to a specific position by the return mechanism. After punching is completed, the rotating shaft (12) is retracted and reset by the return mechanism.

5. The rotatable die for punching holes in the hook surface according to claim 4, characterized in that: The transmission structure includes a transmission plate (15) and a stroke limiting plate (16). The transmission plate (15) is arranged on the power input end of the rotating shaft (12) through the rotating base (11). The power output end of the upper mold nitrogen cylinder (4) is pressed onto the transmission plate (15). The stroke limiting plate (16) is arranged on the rotating base (11) in a position corresponding to the transmission plate (15). The rotation return of the rotating shaft (12) is limited by the cooperation of the stroke limiting plate (16) on the transmission plate (15).

6. The rotatable die for punching a hook-shaped surface according to claim 4 or 5, characterized in that: The return mechanism includes a sensor (17), a return nitrogen cylinder (18), a return cylinder mounting plate (19), a guide sleeve (20), and a return push rod (21). The return nitrogen cylinder (18) is arranged vertically in the lower middle part of the rotating base (11) in accordance with the position of the transmission plate (15) through the return cylinder mounting plate (19). With the cooperation of the guide sleeve (20), the return push rod (21) arranged on the rotating base is vertically connected between the return nitrogen cylinder and the transmission plate. The sensor (17) is arranged on the rotating base (11) in accordance with the position of the rotating shaft (12). During the rotation process, the rotating shaft (12) determines its rotation position through the sensor (17).

7. The rotatable die for punching a hook-shaped surface according to claim 3, 4 or 5, characterized in that: The floating punch assembly also includes a punch (22), which is arranged on a floating slider (10). The floating slider (10) presses the hook surface in place with the cooperation of a small pressure plate (23). The punch (22) punches holes on the hook surface through the floating slider (10).

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