Automobile cover oil filler stamping forming die and forming method thereof

Abstract

The application discloses a stamping forming die for a fuel filler of an automobile cover part and a forming method thereof, and the forming die comprises an upper die base, a lower die base, a fuel filler cutter block and an upper die switching mechanism for switching the fuel filler cutter block between a working state and a hidden state, the upper die switching mechanism is arranged on the upper die base, and the fuel filler cutter block is integrated on the upper die switching mechanism through a driving structure for driving the fuel filler cutter block to float up. The forming die effectively makes up for the defects of poor switching flexibility of the existing die, can adapt to a high-speed heavy-load strong-shock operation environment, realizes intelligent switching of the die, eliminates the stop-line debugging process during switching of vehicle models, reduces resource and time consumption, meets the high-precision trimming operation demand in a small space, simplifies production procedures, has stable resetting and accurate repeated positioning capabilities, avoids system distortion problems in stamping operation, guarantees long-term stable operation of an automatic production line, and can provide reliable support for large-scale and efficient production.

Description

Technical Field

[0001] This invention relates to the field of automotive body panel molding technology, and in particular to a stamping die for an automotive body panel fuel filler neck and its molding method. Background Technology

[0002] In traditional mold design, if you want to manufacture parts with and without fuel tank openings using the same mold, you need to install detachable components in the mold. Each time you switch, you need to reinstall and adjust the mold. If you want to achieve high surface quality multi-area trimming and shaping operations in the fuel tank opening area, you need to arrange different processes to operate on multiple parts in a narrow space, which wastes a lot of manpower, material resources and time to reinstall and adjust the mold.

[0003] Although some electric switching technologies exist, the system exhibits poor stability under high-speed, heavy-load, and strong vibration conditions, making it prone to failure. Furthermore, to enable the manufacture of parts with and without oil tank openings using the same mold, some high-end manufacturing research has explored external mechanisms. However, breakthroughs in small-space assembly systems have remained elusive. Additionally, the narrowness of the single-sided guide and its resulting long-term wear resistance issues, along with pressure equalization in confined spaces, have long hindered high-end technological breakthroughs in this area. For example, patent CN114210826A discloses a precision-tuning switching mechanism for the oil filler flange of a side-wall stamping die. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a stamping die for an automotive body panel with a fuel filler neck and a forming method thereof. The die for switching between having and not having a fuel filler neck on the body panel is simple, stable, and reliable.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: This invention provides a stamping die for an automotive body panel fuel filler neck, including an upper die base, a lower die base, a fuel filler neck cutter block, and an upper die switching mechanism for switching the fuel filler neck cutter block to a working state and a hidden state. The upper die switching mechanism is located on the upper die base, and the fuel filler neck cutter block is integrated on the upper die switching mechanism through a drive structure for driving the fuel filler neck cutter block to float.

[0006] Further or preferred: The upper mold switching mechanism includes a mechanism mounting block and a switching support plate. The oil filling port knife block is fixed on the switching support plate, and the switching support plate is mounted on the mechanism mounting block through a driving structure.

[0007] A guide structure is provided between the mechanism mounting block and the switching support plate. The driving structure is a switching return nitrogen spring. The mechanism mounting block is provided with an air connector for connecting the switching return nitrogen spring to an external air source. The air connector is connected to an intelligent switching valve for controlling the switching through an air circuit.

[0008] The mechanism mounting block has a groove, and the switching bearing plate is connected to a stabilizing block that can move within the groove. A guide rod is provided between the stabilizing block and the bottom of the groove.

[0009] The mounting block of the mechanism has a groove opening at the edge, and the edge of the switching bearing plate has a protrusion corresponding to the groove. The switching return nitrogen spring is integrated between the groove and the protrusion.

[0010] The switching support plate is equipped with a built-in pressure core, and the lower part of the upper mold base is equipped with a pressure plate with a notch. The upper mold switching mechanism is set with the notch in accordance with the notch, and the built-in pressure core is adapted to the notch when working.

[0011] The switching bearing plate is provided with an elastic element and a limiting bolt for limiting the movement range of the built-in pressure core.

[0012] The built-in pressure core is provided with a guide hole, and the switching bearing plate is provided with a self-lubricating surrounding guide block that cooperates with the guide hole. The built-in pressure core is provided with a through hole for the extension of the oiling port knife block.

[0013] The oil filler port blade block is a set of trimming blades, and the switching support plate is provided with a blade block positioning plate for positioning the set of trimming blades.

[0014] This invention provides a forming method for stamping and forming a fuel tank opening using the aforementioned automotive body panel fuel filler neck stamping die, comprising the following steps: An upper mold switching mechanism is integrated and installed at the lower part of the upper mold base. Under the control of the upper mold switching mechanism, the oil filling port cutter block can switch between working and hidden states, and work together with the molding mold to complete the molding of a cover part with or without an oil filling port.

[0015] Compared with the prior art, the present invention has the following advantages: The stamping die and forming method for the fuel filler neck of the automotive body panel are rationally designed, effectively overcoming the shortcomings of the lack of flexibility in the switching of existing dies. It can adapt to high-speed, heavy-load, and high-vibration operating environments, realize intelligent die switching, eliminate the need for line stoppage and debugging when changing vehicle models, and reduce resource and time consumption. Relying on the pressure balance system to evenly and slowly release the stress, it effectively ensures the forming quality of key parts of the automotive body panel. It meets the needs of high-precision trimming operations in confined spaces, and simplifies the production process. It has stable reset and precise repeatable positioning capabilities, avoids system distortion problems in stamping operations, ensures the long-term stable operation of automated production lines, and can provide reliable support for large-scale and efficient production. Attached Figure Description

[0016] The following is a brief explanation of the contents of each of the accompanying drawings and the markings in the drawings: Figure 1This is a schematic diagram of the mold opening state of the present invention.

[0017] Figure 2 This is a schematic diagram of the closed mold state of the present invention.

[0018] Figure 3 This is a schematic diagram of the upper mold switching mechanism of the present invention in the open state.

[0019] Figure 4 This is a schematic diagram of the upper mold switching mechanism of the present invention.

[0020] Figures 5 to 7 This is a schematic diagram of the upper mold switching mechanism of the present invention without the built-in pressure core.

[0021] Figure 8 This is a schematic diagram of the internal structure of the mounting block of the present invention.

[0022] Figure 9 This is a schematic cross-sectional view of the mechanism of the present invention.

[0023] Figure 10 This is a schematic diagram of the tracheal tube arrangement of the present invention.

[0024] Figure 11 This is a schematic diagram of the mechanism of the present invention arranged on the upper mold base.

[0025] In the picture: 1. Upper die holder, 2. Lower die holder, 3. Upper die switching mechanism, 4. Switching drive structure, 5. Built-in pressure core, 6. Oil filling port cutter block, 7. Self-lubricating surrounding guide block, 8. Limit bolt, 9. Elastic element, 10. Intelligent control conversion valve, 11. Punch, 12. Pressure plate, 13. Guide plate, 14. Guide post, 15. Guide sleeve, 16. Air connector, 17. Air pipe, 18. Mechanism mounting block, 19. Switching bearing plate, 20. Cutter block positioning plate, 21. Guide rod, 22. Stabilizing block. Detailed Implementation

[0026] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings and through the description of the examples.

[0027] Although the invention has been shown and described herein with reference to specific embodiments, it is not intended to be limited to the details shown. Rather, various modifications in detail may be made within the equivalent scope and scope of the claims without departing from the invention. In the drawings, the same item numbers refer to the same elements.

[0028] Throughout this disclosure, various terms are used to describe the physical shape or arrangement of features. Many of these terms are used to describe features conforming to a cylindrical or generally cylindrical geometry with the feature as its radius and a central axis perpendicular to that radius. Unless otherwise specified, the terms are given the following meanings: The terms “longitudinal,” “longitudinal,” “axial,” and “axial” refer to a direction, dimension, or orientation parallel to the central axis. The terms “radial” and “radially” refer to a direction, dimension, or orientation perpendicular to the central axis. The terms “inward” and “inner” refer to a direction, dimension, or orientation extending radially toward the central axis. The terms “outward” and “outer” refer to a direction, dimension, or orientation extending radially away from the central axis.

[0029] In this specification, relative terms such as “horizontal,” “vertical,” “upward,” “downward,” “top,” and “bottom,” and their derivatives (e.g., “horizontal,” “downward,” “upward,” etc.) should be interpreted as referring to the direction described or the direction shown in the accompanying drawings. These relative terms are for ease of description and are not generally intended to require a specific direction.

[0030] like Figures 1 to 11 As shown, this application discloses a stamping die for an automotive body panel fuel filler neck. In this application, unless otherwise defined, all technical terms used in the embodiments have the same meaning as commonly understood by those skilled in the art. Some technical terms appearing in the embodiments of this application are explained below.

[0031] In traditional mold design, if the goal is to manufacture parts with and without fuel tank openings using the same mold, detachable components need to be installed within the mold. Each switch requires reinstallation and adjustment of the mold. Furthermore, achieving high-quality multi-area trimming and shaping of the fuel tank opening area necessitates different processes to operate on multiple parts within a confined space, wasting significant manpower, resources, and time on repeated mold disassembly and adjustment. While some electric switching technologies exist, their stability is poor under high-speed, heavy-load, and strong vibration conditions, leading to system failures. Simultaneously, to achieve the manufacturing of parts with and without fuel tank openings using the same mold, some high-end manufacturing research has explored external mechanisms, but breakthroughs in small-space assembly systems have remained elusive. Moreover, the narrowness of the single-sided guide and its resulting long-term wear resistance issues, along with the pressure equalization problem in confined spaces, have long hindered high-end technological breakthroughs in this area.

[0032] In response to the above technical issues, such as Figures 1 to 11As shown, this application proposes a novel technical solution. The core of this solution lies in achieving high stability and high precision in multi-station trimming operations within a small space, while ensuring the quality of the surface material, and adapting to high-speed, heavy-load, and strong-vibration environments. By controlling the switching between working and hidden states of the filler port cutter block, it works together with the forming mold to complete the forming of a cover part with or without a filler port, thereby achieving the goal of intelligently manufacturing high-quality automotive body parts using a steady-state innovative structure.

[0033] The automotive body panel fuel filler port stamping die includes an upper die base 1, a lower die base 2, a punch 11, a pressure plate 12, a fuel filler port cutter block 6, and an upper die switching mechanism 3 for switching the fuel filler port cutter block to the working state and the hidden state. The lower die base is located directly below the upper die base. The upper die switching mechanism and the pressure plate are both located on the upper die base 1, and the punch is located on the lower die base 2. The fuel filler port cutter block 6 is integrated into the upper die switching mechanism 3 through a drive structure for driving the fuel filler port cutter block to float.

[0034] The punch on the lower die base and the pressure plate on the upper die base are correspondingly arranged. The lower die base has guide posts 14 on its edge, and the upper die base has guide plates 13 on its edge corresponding to the guide posts. Guide sleeves 15 that cooperate with the guide posts are provided on the guide plates, ensuring stable and reliable operation of the forming mold. The specific structure of the lower die base and the upper die base is a conventional structure in this field and will not be described in detail in this application; the guiding structure between the upper die base and the upper die base also adopts other mold guiding structures in the prior art.

[0035] The main body of the mold adopts a modular split layout, which is compact and facilitates its arrangement and installation on the upper mold base. At the same time, it is equipped with precise guide positioning pairs, guide pillars are set on the side of the lower mold base, and guide plates with guide sleeves are installed at corresponding positions on the upper mold base. Through the precise cooperation of the guide pillars, guide sleeves and guide plates, the opening and closing movement trajectory of the mold is effectively constrained, eliminating the problem of offset and misalignment during the stamping process, and ensuring the stability of the overall mold operation and the forming accuracy.

[0036] The upper mold switching mechanism includes a mechanism mounting block 18 and a switching support plate 19. The oil filling port cutter block is fixed on the switching support plate, and the switching support plate is mounted on the mechanism mounting block via a drive structure. The mechanism mounting block is a hollow structure with an opening at the bottom, and the switching support plate is set accordingly at the lower opening. The mechanism mounting block 18 is a square block, and fixing holes are provided at the four corners of the mechanism mounting block. The entire upper mold switching mechanism is mounted on the lower part of the upper mold base through a set of fixing holes.

[0037] A guide structure is provided between the mechanism mounting block 18 and the switching support plate 19. The oil filling port knife block is integrated on the switching support plate. The oil filling port knife block moves synchronously with the switching support plate. The guide structure ensures stable and reliable switching of the oil filling port knife block state.

[0038] In some embodiments, the hollow structure of the mechanism mounting block 18 forms a groove, and the switching bearing plate is connected to a stabilizing block 22 that can move within the groove. A guide rod 21 is provided between the stabilizing block and the bottom of the groove. The guide structure is integrated inside the hollow structure of the mechanism mounting block, resulting in a compact structure.

[0039] like Figure 8 and Figure 9 As shown, the stabilizing block 22 is a square block. A set of guide rods 21 are provided at the bottom of the groove of the mechanism mounting block. The stabilizing block is provided with guide holes that are compatible with the guide rods. The vertical movement of the filler port knife block is guided by the cooperation of the guide rods and the guide holes. The inner wall of the groove limits the stabilizing block around itself, thereby ensuring that the filler port knife block will not shake when subjected to lateral force, and the structure is reliable.

[0040] In some embodiments, the guide structure between the mechanism mounting block 18 and the switching support plate 19 can also be designed as a slide rail structure; specifically, the hollow structure of the opening of the mechanism mounting block forms a groove, the switching support plate is connected to a stabilizing block that can move in the groove, the inner wall of the groove is provided with a protruding guide bar, and the side of the stabilizing block is provided with a guide groove that matches the guide bar, so that the structure is stable and reliable.

[0041] The switching drive structure 4 is a switching return nitrogen spring. The mechanism mounting block is equipped with an air connector 16 for connecting the switching return nitrogen spring to an external air source. The air connector is connected to the intelligent switching valve 10 for controlling the switching through an air pipe 17. The air pipe is integrated on the upper mold base, and the intelligent switching valve is externally set. The external setting of the intelligent switching valve does not occupy the internal space of the mold, and the external setting of the intelligent switching valve is convenient for operation.

[0042] In some embodiments, such as Figures 4 to 8 As shown, the groove opening edge of the mechanism mounting block 18 is provided with a slot, and the slot on the edge is a square slot structure. The edge of the switching bearing plate is provided with a protrusion corresponding to the slot. The switching return nitrogen spring is integrated between the slot and the protrusion.

[0043] Specifically, the mounting block has mounting holes in the groove on its side. The lower end of the switching return nitrogen spring is fixed in the mounting holes. The bottom of the mounting holes has air holes that communicate with the switching return nitrogen spring. The mounting block has an integrated internal air passage with connecting air connectors and air holes. The internal air passage is integrated into the mounting block, eliminating the need for separate external air passages. The structure is compact and the operation is stable and reliable.

[0044] The switching return nitrogen spring is fixed in the side groove of the mechanism mounting block. The extension of the side of the switching bearing plate is provided with a connecting hole. The end rod of the switching return nitrogen spring passes through the connecting hole and is positioned by fasteners. Furthermore, two switching return nitrogen springs are integrated in the groove on each side of the mechanism mounting block. The switching return nitrogen springs on both sides of the mechanism mounting block are symmetrically arranged, and the force is stable and reliable.

[0045] The upper die switching mechanism of this application enables free switching between the working and hidden states of the oil filling port cutter block, breaking through the limitations of the traditional fixed cutter block structure. This mechanism mainly consists of a mechanism mounting block and a switching support plate. The oil filling port cutter block is directly fixed to the switching support plate and can move synchronously with the support plate. The position of the cutter block is switched through the mechanism drive, flexibly adapting to the forming requirements of different stamping processes and improving the mold's adaptability and versatility.

[0046] The mechanism mounting block adopts a square hollow block structure with an open bottom and fixing holes at the four corners. It can be quickly and securely assembled to the lower part of the upper mold base with fasteners such as bolts. The installation and positioning are convenient and the fixing strength is high, providing a reliable base for the stable operation of the entire switching mechanism.

[0047] To ensure the smoothness and accuracy of the switching between the fuel filler port cutter block states, an integrated guide structure is incorporated within the mechanism, completely resolving the issues of cutter block swaying and offset under force. For vertical guidance, a stabilizing block that slides within the groove of the mechanism's mounting block is connected to the switching bearing plate. Guide rods are positioned at the bottom of the groove, and corresponding guide holes are provided on the stabilizing plate. Through the precise cooperation of the guide rods and guide holes, the vertical lifting and lowering trajectory of the cutter block is accurately constrained, ensuring linear motion accuracy. For lateral limiting, the stabilizing block is omnidirectionally limited by the inner wall of the groove in the mechanism's mounting block, effectively counteracting the lateral forces borne by the cutter block during stamping, preventing cutter block offset and swaying, and significantly improving the accuracy of forming dimensions and structural reliability. Simultaneously, the entire guide structure is integrated within the hollow interior of the mechanism's mounting block, with no external redundant structures, resulting in a compact and orderly overall layout.

[0048] The mold uses a switching return nitrogen spring as the tool block lifting drive structure, replacing the traditional mechanical drive structure, resulting in smooth driving, precise return, and stable response. The nitrogen spring adopts an embedded integrated installation method, with a square slot opened on the edge of the mounting block groove, and a corresponding extension set on the switching bearing plate. The nitrogen spring is compactly arranged between the slot and the extension, and the concealed installation greatly saves mold space.

[0049] In some embodiments, the switching support plate 19 is provided with a built-in pressure core 5, that is, the lower part of the upper mold base is provided with a pressure plate 12, the pressure plate is provided with a notch, the upper mold switching mechanism is set with the notch, and the built-in pressure core is adapted to the notch when working; the built-in pressure core adopts a self-pressure source balanced position clamping system to ensure high precision of the forming area and stability of the surface quality.

[0050] The switching bearing plate 19 is equipped with an elastic element 9 and a limiting bolt 8 for limiting the movement range of the built-in pressure core. The elastic element 9 is a pressure stabilizing source. Preferably, the pressure stabilizing source is composed of a set of nitrogen springs connected in series. Through its series connection mode, it can achieve its own pressure and distribute the pressure evenly. It can also automatically adjust to a balanced state under the working off-center load pressure.

[0051] The built-in pressure core 5 is provided with a guide hole, and the switching bearing plate is provided with a self-lubricating surrounding guide block 7 that cooperates with the guide hole. The built-in pressure core is provided with a through hole for the extension of the oiling port knife block. Through the surrounding self-lubricating guide control structure, high-precision, multi-area and associated dimensional chain joint control of the trimming process is realized.

[0052] The self-lubricating surrounding guide block is fixed in the middle of the switching bearing plate. The self-lubricating surrounding guide block is a square block with fixing holes. The surface of the self-lubricating surrounding guide block forms a stepped hole corresponding to the fixing hole. It is fixed to the switching bearing plate with bolts, and the structure is reliable.

[0053] The center of the built-in pressure core has a hollow hole, and the edge of the hollow hole matches the side wall of the self-lubricating surrounding guide block. A set of pits is provided on the side surface of the self-lubricating surrounding guide block, and the pits contain graphite structures to form a self-lubricating surrounding guide structure.

[0054] In some embodiments, the oil filling port cutter block 6 is a set of trimming cutters, and the switching support plate 19 is provided with a cutter block positioning plate 20 for positioning the set of trimming cutters, which is stable and reliable; the built-in pressure core is provided with a hollow area for the trimming cutter to extend, and the guide block is located in the middle position of the built-in pressure core, which is integrated and compact.

[0055] In some embodiments, such as Figure 9 As shown, the main blade of the trimming knife has an L-shaped structure, with the end of the main blade forming a cutting edge; the horizontal part of the L-shaped main blade forms a blade positioning plate, and the edge of the blade positioning plate is provided with a groove. Other blades are fixed on the switching bearing plate and located in the groove, making the structure stable and reliable.

[0056] This mold features an integrated self-adaptive clamping core and a high-precision guiding structure, significantly improving the quality and dimensional accuracy of the molded surface. The switching support plate integrates the integrated clamping core structure, with matching notches on the upper mold clamping plate. The upper mold switching mechanism is arranged to match these notches, ensuring precise clamping of the clamping core during operation. The clamping core is equipped with a self-pressure source equalizing clamping system, using a series-connected nitrogen spring assembly as the pressure source. The series structure enables autonomous pressure supply and uniform pressure distribution. Even under uneven load conditions, it automatically and adaptively adjusts the pressure, completely resolving molding defects caused by uneven local pressure and ensuring the stability of dimensional accuracy and surface quality in the oil filler port molding area.

[0057] To ensure stable movement and controllable stroke of the pressure core, the support plate is equipped with elastic elements and limiting bolts. The elastic elements provide continuous and stable pressure, while the limiting bolts precisely limit the vertical movement of the pressure core, preventing structural interference and forming errors caused by overtravel. A surrounding self-lubricating guide structure is also incorporated. The pressure core has guide holes, and the support plate is fitted with matching self-lubricating surrounding guide blocks. Through omnidirectional surrounding guidance and constraint, high-precision positioning in the trimming process is achieved, enabling joint and precise control of multi-area, interconnected dimensional chains, adapting to complex trimming and forming conditions. The pressure core has reserved working through holes and hollow areas for the cutting tool, providing dedicated space for the extension of the trimming tool at the oil filler port. The guide blocks are integrated into the center of the pressure core, resulting in a compact overall structure.

[0058] The mold trimming cutter assembly adopts a positioning integrated installation structure, ensuring high positioning accuracy and structural stability. The oil filler cutter block is an integral part of the trimming cutter assembly structure, achieving precise assembly and positioning based on the cutter block positioning plate on the switching support plate, eliminating cutter block working deviation. The core main cutter block adopts a dedicated L-shaped structure, with the L-shaped horizontal section integrally formed as the cutter block positioning plate. The positioning plate has a dedicated groove on its edge, and the remaining auxiliary cutter blocks are precisely embedded and fixed inside the groove, forming an integral cutter assembly structure. This integrated positioning structure can effectively distribute the trimming cutting force, preventing individual cutter blocks from loosening or shifting under force, ensuring structural stability and good forming consistency throughout the trimming operation.

[0059] This invention provides a forming method for stamping and forming a fuel tank opening using the aforementioned automotive body panel fuel filler neck stamping die, comprising the following steps: An upper mold switching mechanism is integrated and installed at the lower part of the upper mold base. Under the control of the upper mold switching mechanism, the oil filling port cutter block can switch between working and hidden states, and work together with the molding mold to complete the molding of a cover part with or without an oil filling port.

[0060] The stamping die and forming method for the fuel filler neck of the automotive body panel are rationally designed, effectively overcoming the shortcomings of the lack of flexibility in the switching of existing dies. It can adapt to high-speed, heavy-load, and high-vibration operating environments, realize intelligent die switching, eliminate the need for line stoppage and debugging when changing vehicle models, and reduce resource and time consumption. Relying on the pressure balance system to evenly and slowly release the stress, it effectively ensures the forming quality of key parts of the automotive body panel. It meets the needs of high-precision trimming operations in confined spaces, and simplifies the production process. It has stable reset and precise repeatable positioning capabilities, avoids system distortion problems in stamping operations, ensures the long-term stable operation of automated production lines, and can provide reliable support for large-scale and efficient production.

[0061] This application addresses the issue of external intelligent control of the fuel tank opening area functional device in the stamping process of automotive body panels. It utilizes a self-pressure source balanced positioning clamping system to ensure high precision and surface quality stability in the forming area. A surrounding self-lubricating guide control structure enables high-precision, multi-area, and interconnected dimensional chain joint control of the trimming process. A switching return nitrogen spring achieves repeatable reset of the precise positioning system. This results in a mold-embedded trimming device that can seamlessly switch product states, ensure high surface and product precision, and achieve multi-station trimming operations in a small area under high-speed, heavy-load, and high-vibration conditions without the need for electronic components in the working area.

[0062] The core of this solution lies in achieving high stability and high precision in multi-station trimming operations within a confined space, adaptable to high-speed, heavy-load, and high-vibration environments while ensuring regional surface quality. This enables the intelligent manufacturing of high-quality automotive body panels using a stable, innovative structure. The specific technical solution primarily needs to meet the following key requirements: 1. Structural optimization under high-speed, heavy-load, and high-vibration conditions: stable mechanical structure conversion of intelligent control signals under these conditions; 2. High-precision pressing technology: built-in self-pressure type all-around high-precision pressing technology for situations with insufficient processes; 3. Stable forming structure design: a stable forming structure design for high stability and high precision multi-region trimming operations in confined spaces; 4. High-stability rapid reset system: repeatable reset of a precise positioning system achieved by switching return nitrogen springs. By utilizing a stable, innovative structure in a confined and complex production environment, high stability and high precision multi-station trimming operations are achieved while ensuring regional surface quality, providing a reliable and economical technical solution for the stamping production of high-quality outer body panels.

[0063] The preferred embodiment of this application is as follows: The present invention application embodiment is a stamping die for a high-precision repair punching device for the fuel filler port of an intelligent automotive body panel mold. Its structure includes: an upper die switching mechanism, a switching return nitrogen spring, an internal pressure core, a trimming knife, a self-lubricating surrounding guide block, a limit bolt, a stabilizing pressure source, and an intelligent control conversion valve (this mechanism is a commonly used standard part in the industry, and its main function is to control the air intake direction of the gas source, and it is usually used in conjunction with the switching mechanism).

[0064] Figure 1 This is the mold-opening state of the device of the present invention. In this state, the device is required to achieve both working state and hidden reset state under the control of the upper mold switching mechanism. At the same time, it is required to achieve rapid and highly repeatable working state reset and hidden state hiding under the action of the nitrogen spring during the switching return. Figure 2 This is the closed mold state of the device of the present invention. In the closed mold state, the device can intelligently switch between working and hidden states through the upper mold switching mechanism.

[0065] The installation method and specific working method of this application are as follows: Installation steps and initial state: The upper mold switching mechanism is installed at the upper mold mounting position; the switching return nitrogen spring is installed in the upper and lower sliding grooves of the upper mold switching mechanism, and can complete the floating work according to the up and down drive of the upper mold switching mechanism (the descent work needs to be done after the upper mold switching mechanism switches to the floating state; the pre-pressure generated when the switching return nitrogen spring moves relative to the mold pressure core pushes it back); the trimming knife, self-lubricating surrounding guide block, and stabilizing pressure source are fixed to the switching bearing plate mounting surface in the middle of the switching return nitrogen spring with mounting screws; the built-in pressure core forms four guide surfaces through the square hole structure in its middle, passes through the self-lubricating surrounding guide block and slides up and down on it, and is in a floating state under the support of the stabilizing pressure source; the limit bolt passes through the through hole of the built-in pressure core and is fixed in the corresponding mounting hole on the switching return nitrogen spring to limit the overall movement stroke and position of the built-in pressure core; the intelligent control conversion valve is installed outside the mold and connected to the upper mold switching mechanism through the air pipe to control the upper mold switching mechanism; At this time, the upper mold switching mechanism is in a sunken state without air supply, the switching return nitrogen spring is in a sunken state, and the nitrogen spring above it has no pre-pressure because it is not in contact with the pressure core. The built-in pressure core is in a floating state under the initial pressure of the stable pressure source, and the whole device forms the initial state.

[0066] The intelligent control switching valve enables the device to float and retract via an air source: when an automotive body panel with an oil tank opening is needed, the intelligent control switching valve drives the control switch to connect to the air source; the air pressure is transmitted to the upper mold switching mechanism through the air pipe, and the upper mold switching mechanism drives the entire device to float up to the working position, so that the entire device is in a waiting-to-work state.

[0067] The pressure-stabilizing self-pressure source consists of a set of nitrogen springs connected in series. This series connection achieves self-pressure and distributes it evenly. It automatically adjusts to a balanced state even under off-center load. An internal pressure core is mounted above the pressure-stabilizing self-pressure source and its movement is limited by limit bolts, ensuring controllable movement. The center of the internal pressure core features a self-lubricating surrounding guide block. This sliding surface controls the movement of the internal pressure core along this guide block. The self-lubricating surrounding guide block is a copper structure inlaid with graphite dots, enabling long-term, high-wear-resistant, and stable movement while providing self-lubrication. Its four-sided surrounding structure ensures high precision and stability of the internal pressure core's movement, thus preparing the entire device for trimming operations.

[0068] After the trimming preparation is complete, the upper die structure begins to descend. At this time, the built-in pressure core floats up first under the action of the stabilizing pressure source to prioritize pressing the material, ensuring the surface accuracy of the forming area and the stability of the trimming and punching. The die continues to descend, and the stabilizing pressure source is compressed to generate pressure force to press the workpiece. Then, the upper slide continues to descend, and the trimming cutter continues to descend under the drive of the upper die base to complete high-precision trimming. During this process, the nitrogen spring on the return nitrogen spring is affected by the descent of the overall die's pressure core to form pre-tightening pressure.

[0069] After the trimming is completed, the upper slide moves upward. At this time, the trimming blade disengages from the workpiece. Under the influence of the pressure from the stabilizing pressure source, the built-in pressure core maintains pressure and performs a slow-release pressure movement to ensure the surface quality of the forming area. At the same time, the entire device enters the next forming judgment stage of the stamping system. If the next workpiece still needs to undergo oil tank opening trimming, the intelligent control switching valve does not work. The pre-tightening pressure formed by the nitrogen spring on the return nitrogen spring is automatically released as the upper die continues to move upward. Then, the upper slide continues to move upward, and the entire device disengages from the mold forming area. The built-in pressure core returns to the floating state under the influence of the stabilizing pressure source. At this time, the entire device returns to the trimming operation preparation state, ready to perform the next oil tank opening trimming operation.

[0070] If the next part does not require trimming, during the next forming judgment stage of the stamping system, the conversion command controls the intelligent conversion valve to receive the conversion signal, the internal air pressure direction is reversed, the upward limit of the upper die switching mechanism is removed, the pre-tightening pressure formed by the nitrogen spring on the switching return nitrogen spring pushes the switching return nitrogen spring to sink, causing the entire device to sink, pushing the entire mechanism to the non-working hidden state, completing the hidden state switch, and the entire device returns to the initial state.

[0071] The key feature of this mold design is its steadily switchable upper mold switching mechanism, which overcomes the limitations of traditional fixed cutter block structures. Utilizing an external intelligent control switching valve and an integrated switching return nitrogen spring, it achieves intelligent and seamless switching between the working and concealed states of the fuel filler trimming cutter group without the need for electronic components in the work area. This allows the same mold to be compatible with stamping automotive body panels with and without fuel filler ports, completely eliminating the need for downtime disassembly and debugging during vehicle model switching, significantly saving manpower, resources, and time. The mold adopts a modular, compact layout, featuring precise guide pillars and guide sleeves, and an integrated guide rod or sliding rail omnidirectional guiding structure within the mechanism. Combined with the lateral limiting constraint of square stabilizing blocks, it effectively prevents cutter block offset and wobbling during stamping, ensuring structural stability and motion accuracy under high-speed stamping conditions. Meanwhile, the mold integrates a built-in pressure core structure and is equipped with a self-pressure source equalization and stabilization system consisting of series nitrogen springs. This system can adaptively level the pressure under off-center load conditions, achieving precise pressure equalization and slow release in the forming area, thus solving forming defects caused by uneven local pressure. The matching surrounding graphite self-lubricating guide structure has high wear resistance and self-lubricating properties, enabling high-precision joint control of multiple areas and interconnected dimensional chains in confined spaces, adapting to complex trimming forming conditions. In addition, the oil filler cutter assembly adopts an integrated installation structure with an L-shaped main cutter block and an integrated positioning plate, ensuring uniform force distribution and precise positioning, effectively preventing the cutter block from loosening or shifting, and ensuring the consistency of forming in mass production.

[0072] During operation, the mold can intelligently switch working conditions according to production needs. When producing parts with oil filler ports, the mechanism rises and drives the cutter group into position, and the pressure core prioritizes stabilizing and pressing the material before completing high-precision trimming. When producing parts without oil filler ports, the mechanism automatically sinks and hides the cutter group, returning to the initial standby state. This technical solution effectively solves the problems of cumbersome processes, inefficient switching, unstable precision, and easy failure of electric mechanisms in traditional molds. With its excellent adaptability to working conditions, forming accuracy, and operational stability, it is suitable for high-speed automated stamping production lines. While improving the surface quality and production efficiency of key product areas, it simplifies production processes and reduces equipment maintenance and production costs.

[0073] The implementation of this design effectively solves the problem of insufficient mold flexibility in existing technologies and the increase in manufacturing costs caused by insufficient processes, while improving production efficiency. Its main advantages can be described from the following four aspects: 1. Significantly improves production efficiency: It solves the problem of intelligent switching of the mold system under high-speed, heavy-load, and strong vibration conditions, thereby solving the long-standing problem of needing to stop the line to switch and perform functional and precision debugging when producing different styles of automotive body panels with the same mold, resulting in a large waste of manpower, material resources, and time; 2. Improves the surface quality of key areas: Through the balancing self-pressure system, a pressure release system with load equalization and slow release is formed; high-precision surface quality assurance is achieved in key areas of automotive body panels; 3. Saves costs: It realizes self-lubricating, high-precision, multi-area, small-space trimming operations; while ensuring high precision, it reduces the amount of processes used, improves product precision, and reduces the maintenance costs of the equipment; 4. Precise control of production scenarios: Steady-state reset and rapid high-precision repeatable positioning enable long-term stable intelligent control of production during the operation of high-speed automated production lines, while solving the system distortion failure problem of the electric switching system in the high-speed, heavy-load stamping process; providing equipment support for large-scale rapid manufacturing.

[0074] In the various embodiments listed in this application, if there are no mutual constraints or conflicts between the technical features, these technical features can be freely combined and applied according to actual application needs and scenarios. This flexibility aims to ensure that the technical solution can better adapt to various practical application environments, thereby improving its applicability and effectiveness.

[0075] The above description is merely an illustration of preferred embodiments of the present invention, and the above technical features can be arbitrarily combined to form multiple embodiments of the present invention.

[0076] The present invention has been described above by way of example with reference to the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any non-substantial improvements made using the concept and technical solution of the present invention, or the direct application of the concept and technical solution of the present invention to other occasions without modification, are all within the protection scope of the present invention.

Claims

1. A stamping die for an automotive body panel fuel filler neck, comprising an upper die base, a lower die base, and a fuel filler neck cutting block, characterized in that: It also includes an upper mold switching mechanism for switching the oil filling port cutter block between the working state and the hidden state. The upper mold switching mechanism is located on the upper mold base, and the oil filling port cutter block is integrated on the upper mold switching mechanism through a drive structure for driving the oil filling port cutter block to float.

2. The stamping die for the fuel filler neck of an automotive body panel as described in claim 1, characterized in that: The upper mold switching mechanism includes a mechanism mounting block and a switching support plate. The oil filling port knife block is fixed on the switching support plate, and the switching support plate is mounted on the mechanism mounting block through a driving structure.

3. The stamping die for the fuel filler neck of an automotive body panel as described in claim 2, characterized in that: A guide structure is provided between the mechanism mounting block and the switching support plate. The driving structure is a switching return nitrogen spring. The mechanism mounting block is provided with an air connector for connecting the switching return nitrogen spring to an external air source. The air connector is connected to an intelligent switching valve for controlling the switching through an air circuit.

4. The stamping die for the fuel filler neck of an automotive body panel as described in claim 3, characterized in that: The mechanism mounting block has a groove, and the switching bearing plate is connected to a stabilizing block that can move within the groove. A guide rod is provided between the stabilizing block and the bottom of the groove.

5. The stamping die for the fuel filler neck of an automotive body panel as described in claim 4, characterized in that: The mounting block of the mechanism has a groove opening at the edge, and the edge of the switching bearing plate has a protrusion corresponding to the groove. The switching return nitrogen spring is integrated between the groove and the protrusion.

6. The stamping die for the fuel filler neck of an automotive body panel as described in claim 2, characterized in that: The switching support plate is equipped with a built-in pressure core, and the lower part of the upper mold base is equipped with a pressure plate with a notch. The upper mold switching mechanism is set with the notch in accordance with the notch, and the built-in pressure core is adapted to the notch when working.

7. The stamping die for the fuel filler neck of an automotive body panel as described in claim 6, characterized in that: The switching bearing plate is provided with an elastic element and a limiting bolt for limiting the movement range of the built-in pressure core.

8. The stamping die for the fuel filler neck of an automotive body panel as described in claim 7, characterized in that: The built-in pressure core is provided with a guide hole, and the switching bearing plate is provided with a self-lubricating surrounding guide block that cooperates with the guide hole. The built-in pressure core is provided with a through hole for the extension of the oiling port knife block.

9. The stamping die for the fuel filler neck of an automotive body panel as described in claim 8, characterized in that: The oil filler port blade block is a set of trimming blades, and the switching support plate is provided with a blade block positioning plate for positioning the set of trimming blades.

10. A forming method for stamping and forming a fuel tank opening using a stamping die for a fuel filler neck of an automotive body panel as described in any one of claims 1 to 9, characterized in that: The molding method includes the following steps: An upper mold switching mechanism is integrated and installed at the lower part of the upper mold base. Under the control of the upper mold switching mechanism, the oil filling port cutter block can switch between working and hidden states, and work together with the molding mold to complete the molding of a cover part with or without an oil filling port.

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