A progressive die for one-step forming of a bridge for a gateway housing lower cover and a method of using the same

Abstract

The present application relates to sheet metal stamping die technical field, especially a kind of continuous die for gateway shell lower cover one-step forming bridge production and its using method, including upper die holder, lower die holder, and the punch module assembly, the outer shape module assembly, bridge forming module assembly and the material distribution module assembly are sequentially arranged along the direction of material belt stepping;Upper die holder and lower die holder are equipped with guiding assembly and limiting assembly, and are provided with misaligned arrangement lifting ring structure.The continuous die is also provided with punch long hole module assembly and shaping module assembly, according to the die step distance required material belt to complete processing after 2 times stepping.The present application realizes the one-step forming of gateway shell lower cover bridge structure by multi-station continuous stamping, avoids the quality risk brought by secondary forming, improves production efficiency and product precision, and improves the reliability, stability and ease of assembly and disassembly of die opening and closing by guiding, limiting and lifting ring structure.

Description

Technical Field

[0001] This invention relates to the field of sheet metal stamping die technology, specifically to a progressive die for one-step forming of a gateway housing lower cover bridge and its usage method. Background Technology

[0002] Progressive dies are cold stamping dies in which multiple stamping processes are completed simultaneously on a single die using several different stations during a single stamping stroke. Each time the die completes a stamping stroke, the sheet material is fed at a fixed distance (called the step amount or feed amount) until the product is finished. Therefore, progressive dies are widely used in the continuous forming of sheet metal parts.

[0003] In the manufacturing of sheet metal parts such as gateway housings and lower covers, bridge structures are common functional features. However, existing processes often cannot meet the requirements for one-step molding of bridge structures, typically requiring secondary molding or step-by-step processing. This processing method is not only inefficient, but also prone to cumulative positioning errors due to multiple positioning and stamping operations, making it difficult to guarantee product dimensional accuracy and posing significant quality risks, such as cracking, deformation, or dimensional deviations in the bridge area. Therefore, there is an urgent need for a progressive die capable of one-step molding of bridge structures to improve production efficiency and ensure product quality. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a continuous mold for one-step molding of the lower cover of a gateway housing and its usage method.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a continuous die for one-step forming of a bridge for the lower cover of a gateway housing, comprising an upper die base and a lower die base, and further comprising a punching die assembly, a cutting die assembly, a bridge forming die assembly, and a separating die assembly arranged sequentially between the upper die base and the lower die base along the material strip stepping direction; a guide assembly and a limiting assembly are provided between the upper die base and the lower die base; wherein, the punching die assembly is used to punch positioning holes near the upper and lower sides of the strip material strip; the cutting die assembly is used to cut out the unfolded shape of the product on the strip material strip, and the upper and lower ends of the cut-out shape holes are respectively aligned with the positioning holes on the same side; the bridge forming die assembly is used to perform one-step forming of a bridge in a designated area of ​​the strip material strip; the separating die assembly is used to separate the formed bridge parts from the material strip.

[0006] In some embodiments, the guide assembly includes lower guide posts installed on the left and right sides of the front and rear sides of the upper mold base, and upper guide sleeves installed on the left and right sides of the front and rear sides of the lower mold base and cooperating with the lower guide posts, wherein the lower guide posts can slide vertically through the upper guide sleeves.

[0007] In some embodiments, the limiting component includes a lower limit position installed on the left and right sides of the front and rear sides of the upper mold base and located next to the inner side of the guide component, and an upper limit position installed on the left and right sides of the front and rear sides of the lower mold base and located next to the inner side of the guide component, so as to improve the stability of the upper mold base and the lower mold base during the mold closing process by means of the cooperation of the upper limit position and the lower limit position.

[0008] In some embodiments, upper lifting ring structures are installed on the left and right sides of both the front and rear sides of the upper die base, and the upper lifting ring structures protrude in a direction parallel to the front-rear direction of the upper die base; lower lifting ring structures are installed on the front and rear sides of both the left and right sides of the lower die base, and the lower lifting ring structures protrude in a direction parallel to the left-right direction of the lower die base; the upper lifting ring structures and the lower lifting ring structures are staggered with each other to improve the ease of assembly and disassembly operations between the upper die base and the lower die base and the external stamping machine.

[0009] In some embodiments, the assembly further includes a punching die assembly and a shaping die assembly installed between the upper die base and the lower die base. The punching die assembly and the shaping die assembly are arranged after the punching die assembly along the material strip stepping direction. According to the die design step distance, the punching die assembly and the shaping die assembly require the sheet material strip to make two steps before they can complete their respective processing.

[0010] In some embodiments, the bridge forming die assembly is used to shape the suspended portion of the strip material and form a bridge structure in one step.

[0011] In some embodiments, the material separating die assembly includes a cutter for cutting the strip material to separate the formed bridge part from the strip material and obtain a complete gateway housing lower cover bridge structure part.

[0012] In some embodiments, the portions of the punching die assembly, the cutting die assembly, the bridging forming die assembly, and the material distribution die assembly that are installed on the upper die base and the portions that are installed on the lower die base respectively engage in a tension-closing fit during the opening and closing of the die to complete the corresponding process.

[0013] In some embodiments, the progressive die is suitable for continuously stamping and forming a sheet-like strip conveyed along the stepping direction. The punching die assembly, the cutting die assembly, the bridging die assembly, and the material separating die assembly are fed sequentially along the stepping direction of the strip, so that the strip completes multiple stamping processes at different stations simultaneously in one stamping stroke.

[0014] To achieve the above objectives, the present invention also provides the following technical solution: a method for using a continuous mold for one-step molding of a gateway housing lower cover bridge, comprising the following steps: S1. The strip material is conveyed to the punching die assembly station along the stepping direction, and the punching die assembly punches positioning holes near the upper and lower sides of the strip material. S2. The strip is continued to be conveyed to the cutting mold assembly station, where the cutting mold assembly cuts out the unfolded shape of the product on the strip, and the upper and lower ends of the cut-out shape hole are aligned with the positioning hole on the same side. S3. The strip material is continued to be conveyed to the bridge forming mold assembly station, where the bridge forming mold assembly performs one-step forming bridge on the designated area of ​​the strip material. S4. The material strip is continued to be conveyed to the material distribution mold assembly station, where the material distribution mold assembly separates the formed bridge part from the material strip to obtain a complete gateway housing lower cover bridge structure part. Between the punching die assembly and the cutting die assembly, there is also a punching elongation die assembly and a shaping die assembly. According to the die design pitch, the punching elongation die assembly and the shaping die assembly need to make two steps on the sheet material before they can complete their respective processing.

[0015] Compared with the prior art, the beneficial effects of the present invention are: (1) By arranging the punching die assembly, the cutting die assembly, the bridge forming die assembly and the material distribution die assembly in sequence along the material strip stepping direction between the upper die base and the lower die base, the material strip can complete multiple stamping processes at different stations in one stamping stroke, realizing one-step continuous production of the bridge structure of the lower cover of the gateway housing, which significantly improves production efficiency. (2) The one-step forming process of the bridge is used to replace the traditional two-step forming process, which avoids the cumulative positioning error and deformation risk caused by multiple positioning and multiple stamping, effectively ensuring the dimensional accuracy and structural strength of the bridge part and reducing the product defect rate. (3) Through the precise matching and guiding effect of the lower guide post and the upper guide sleeve, the reliability and smoothness of the opening and closing of the upper mold base and the lower mold base are improved; (4) By coordinating the upper and lower limits, the stability of the upper and lower mold bases during the mold closing process is effectively improved, preventing over-explosion of the mold and protecting the mold safety; (5) By staggering the upper and lower lifting ring structures, the ease of assembly and disassembly between the upper and lower die bases and the external stamping machine is further improved. (6) According to the die design pitch, the strip material needs to be stepped twice to complete its respective processing, which ensures the processing quality of the punching and shaping processes and avoids the problem of strip deformation or tearing caused by the process being too concentrated in one step. (7) Each mold component performs opening and closing coordination during the mold opening and closing process, and the actions are coordinated and continuous, ensuring the processing accuracy and molding quality of each process. Finally, the molding bridge parts are separated from the material strip by the material separation mold component to obtain the complete gateway housing lower cover bridge structure parts.

[0016] Details of one or more embodiments of this application are set forth in the following drawings and description to make other features, objects and advantages of this application more readily apparent. The embodiments of this application will provide a detailed description and understanding of this application. Attached Figure Description

[0017] Figure 1 This is a three-dimensional structural schematic diagram of the continuous mold used in the one-step molding of the lower cover of the gateway housing for the production of the bridge according to the present invention; Figure 2 yes Figure 1 A schematic diagram of the exploded three-dimensional structure of the continuous modulus shown. Figure 3 This is a flowchart of the continuous die process of the present invention for one-step forming of the material strip.

[0018] In the diagram: 100, progressive die; 100a, cutter; 200, strip material; 200a, gateway housing lower cover bridge structure part; 10. Upper mold base; 20. Lower mold base; 2. Lower lifting ring structure; 3. Lower guide post; 4. Lower limit switch; 5. Upper lifting ring structure; 6. Upper limit switch; 7. Upper guide sleeve; 15. Punching die assembly; 15a. Elongated hole punching die assembly; 16. Shaping die assembly; 40. Outer profile mold assembly; 60. Bridging molding mold assembly; 70. Material distribution mold assembly; F. Belt stepping direction. Detailed Implementation

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

[0020] Example 1: Overall Structure and Progressive Station Layout of Continuous Die Please see Figures 1 to 3 This embodiment provides a progressive die 100 for one-step molding of a gateway housing lower cover bridge. The die is a progressive cold stamping die, suitable for processing materials along the stepping direction F (e.g., ...). Figure 3The sheet material strip 200 (as indicated by the middle arrow) is continuously stamped to form the bridge structure required for the lower cover of the gateway housing in one step, and finally the complete bridge structure part 200a of the lower cover of the gateway housing is obtained by material separation.

[0021] The continuous die 100 mainly includes an upper die base 10, a lower die base 20, and punching die assembly 15, elongated hole punching die assembly 15a, shaping die assembly 16, outward cutting die assembly 40, bridging forming die assembly 60, and material distribution die assembly 70 arranged sequentially between the upper die base 10 and the lower die base 20 along the material strip stepping direction F. Furthermore, a guide assembly, a limiting assembly, and a lifting ring structure for hoisting and disassembly are also provided between the upper die base 10 and the lower die base 20.

[0022] The upper die holder 10 and lower die holder 20 are used for fixed connection with the slide and worktable of the press, respectively. Both the upper die holder 10 and lower die holder 20 are made of high-strength steel plates (such as 45# steel or Q235A) welded or integrally cast, then annealed to eliminate internal stress, and finally precision machined. Their flatness is controlled within 0.02mm / 1000mm, and their parallelism is controlled within 0.03mm / 1000mm to ensure that the gap between the punch and die at each station remains uniform throughout its length. The closed height of the upper die holder 10 and lower die holder 20 is designed according to the mold mounting height adjustment range of the adapted press, typically with an adjustment margin of 20mm to 30mm to accommodate the processing requirements of strips 200 of different thicknesses.

[0023] Along the material strip stepping direction F, the functional components are arranged as follows: First, there is the punching die assembly 15 station, which is used to punch positioning holes near the top and bottom of the strip material strip 200, providing a reference for the precise positioning of subsequent stations; then there is the elongation hole punching die assembly 15a station and the shaping die assembly 16 station. These two stations are reserved with empty stations between them and the punching die assembly 15 according to the die design step distance, so that the material strip 200 needs to make two steps to complete the elongation hole punching and shaping processing; next is the shape cutting die assembly 40 station, which is used to cut out the unfolded shape of the product on the material strip 200, and the top and bottom ends of the shape hole are precisely aligned with the positioning holes on the same side; next is the bridging forming die assembly 60 station, which is used to form the suspended part formed after the shape cutting on the material strip 200 in one step; finally, there is the material separating die assembly 70 station, which is used to separate the formed bridging part from the material strip 200 to obtain the complete part 200a.

[0024] The punching die assembly 15, the elongated hole punching die assembly 15a, the shaping die assembly 16, the outward cutting die assembly 40, the bridge forming die assembly 60, and the material distribution die assembly 70, each mounted on the upper die base 10 (usually a punch, cutter, or pressure plate) and on the lower die base 20 (usually a die, cavity, or support plate), engage in opening and closing during the die opening and closing process to complete the corresponding operation. When the press slide moves the upper die base 10 downward, the upper die portion of each assembly moves downward and closes with the lower die portion, stamping the strip 200 located between them. When the press slide moves the upper die base 10 upward, the upper die portion of each assembly opens with the lower die portion, and the strip 200 advances one step under the drive of the feeding mechanism, entering the next station. The opening and closing actions of each assembly are completed synchronously within one stroke of the press, but are spatially distributed at different stations, thereby realizing progressive continuous production.

[0025] The width of strip 200 is determined by the unfolded width of part 200a plus the process overlap, typically ranging from 100mm to 200mm. The die pitch (i.e., the center distance between adjacent stations) is determined based on the external dimensions and number of processes of part 200a; in this embodiment, the pitch is set to 80mm to 120mm. Strip 200 uses cold-rolled low-carbon steel sheet (such as SPCC, SPHC) or galvanized steel sheet (such as SGCC, SECC) with a thickness of 0.8mm to 1.5mm, with a yield strength not exceeding 280MPa and an elongation not less than 30%, to ensure good plastic deformation capacity during the bridge forming process. Before entering the progressive die 100, strip 200 undergoes leveling treatment, with a flatness not exceeding 1mm / 1000mm.

[0026] Example 2: Precision Guiding and Mold Closure Limiting System This embodiment focuses on describing the specific structure and working method of the guide component and the limiting component.

[0027] The guiding assembly is used to ensure precise alignment between the upper die holder 10 and the lower die holder 20 during the die opening and closing process, preventing die misalignment caused by eccentric punching force or lateral force. The guiding assembly includes lower guide posts 3 installed on the left and right sides of the front and rear sides of the upper die holder 10, and upper guide sleeves 7 installed on the left and right sides of the front and rear sides of the lower die holder 20 and cooperating with the lower guide posts 3. In this embodiment, both the upper die holder 10 and the lower die holder 20 are rectangular plate structures, with their front and rear sides referring to the upstream and downstream sides along the material strip stepping direction F, respectively. The upper die holder 10 has two mounting holes on its front and rear sides for fixing the lower guide posts 3, so that the lower guide posts 3 protrude downwards perpendicular to the lower surface of the upper die holder 10. Correspondingly, two upper guide sleeves 7 are provided on the front and rear sides of the lower mold base 20, which correspond to the positions of the lower guide post 3. The upper guide sleeve 7 has a precision guide hole inside, and the lower guide post 3 can slide vertically up and down through the guide hole of the upper guide sleeve 7.

[0028] The lower guide post 3 and the upper guide sleeve 7 are fitted with a precision clearance of H7 / h6 or H6 / h5, with the clearance controlled between 0.01mm and 0.03mm to ensure guiding accuracy. The lower guide post 3 is made of high-quality alloy steel (such as GCr15 or 20Cr), and after carburizing and quenching, its surface hardness reaches HRC58-62, and its surface roughness Ra is no greater than 0.4μm to improve wear resistance and smooth guiding. The upper guide sleeve 7 is made of high wear-resistant copper alloy (such as ZQSn10-1) or a steel-based self-lubricating material inlaid with solid graphite, and its inner hole surface roughness Ra is no greater than 0.8μm to reduce the coefficient of friction and extend service life. The effective guiding length of the lower guide post 3 (i.e., the depth into the upper guide sleeve 7) is no less than 1.5 times the diameter of the lower guide post 3 to ensure good guiding performance throughout the entire mold opening and closing process. Through the precise fit between the lower guide post 3 and the upper guide sleeve 7, the reliability and smoothness of the opening and closing of the upper mold base 10 and the lower mold base 20 can be effectively improved. Even under high-speed stamping conditions (such as more than 200 strokes per minute), good dynamic guiding accuracy can still be maintained.

[0029] The limiting assembly is used to limit the mold closing depth of the upper mold base 10 and the lower mold base 20, preventing the mold from over-extending and damaging the molding parts or the mold itself, while improving the stability during the mold closing process. The limiting assembly includes lower limit positions 4 installed on the left and right sides of the front and rear sides of the upper mold base 10, and upper limit positions 6 installed on the left and right sides of the front and rear sides of the lower mold base 20. The lower limit position 4 is located next to the inner side of the lower guide post 3, that is, the installation position of the lower limit position 4 is closer to the center area of ​​the mold than the lower guide post 3; the upper limit position 6 is located next to the inner side of the upper guide sleeve 7, that is, the installation position of the upper limit position 6 is closer to the center area of ​​the mold than the upper guide sleeve 7.

[0030] In this embodiment, both the lower limit 4 and the upper limit 6 adopt a cylindrical limiting post structure. The lower limit 4 is fixedly installed on the lower surface of the upper mold base 10 and protrudes downward; the upper limit 6 is fixedly installed on the upper surface of the lower mold base 20 and protrudes upward. When the lower mold base 20 and the upper mold base 10 are closed to the designed position, the lower end face of the lower limit 4 abuts against the upper end face of the upper limit 6, thereby preventing the upper mold base 10 from continuing to move downward. The abutting end faces of the lower limit 4 and the upper limit 6 are precision ground, and the flatness is controlled within 0.005mm to ensure that all limiting points contact simultaneously when the mold is closed, avoiding the mold from tilting due to uneven limiting. The lengths of the lower limit 4 and the upper limit 6 are precisely calculated according to the mold closing height and the working stroke required for the molding process. Typically, the limiting components begin to function after the forming punch enters the die to a depth of about 0.5mm to 1.0mm, thereby ensuring that the molding is in place and avoiding excessive extrusion that could lead to excessive material thinning or mold edge breakage. By coordinating the upper limit 6 and the lower limit 4, the stability of the upper mold base 10 and the lower mold base 20 during the mold closing process can be significantly improved, ensuring that the gap between the punch and die at each station is uniform and consistent, thereby guaranteeing the processing accuracy of each process.

[0031] To further improve the limiting and buffering performance, the limiting component in this embodiment can also adopt a composite structure combining elasticity and rigidity. Specifically, a nitrogen spring or polyurethane elastomer can be embedded inside the lower limit 4 or the upper limit 6. When the mold approaches closure, the elastic limiting part first contacts and absorbs part of the impact energy, and then the rigid part performs the final limiting. This composite limiting method can effectively buffer the impact of the upper die holder 10 on the lower die holder 20 during high-speed stamping, reduce mold vibration and noise, and protect the press slide guide and worktable.

[0032] Example 3: Misaligned lifting ring assembly and disassembly structure This embodiment elaborates on the specific construction of the lifting ring structure and the principle behind its improved ease of assembly and disassembly.

[0033] The lifting ring structure includes an upper lifting ring structure 5 installed on the upper mold base 10 and a lower lifting ring structure 2 installed on the lower mold base 20. An upper lifting ring structure 5 is installed on each of the left and right sides of the front and rear sides of the upper mold base 10, and the upper lifting ring structure 5 protrudes along a direction parallel to the front-rear direction of the upper mold base 10 (i.e., the material strip stepping direction F). In this embodiment, the upper mold base 10 has a total of four upper lifting ring structures 5, located near the four corners of the upper mold base 10. Each upper lifting ring structure 5 includes a lifting ring seat fixedly connected to the upper mold base 10 and a lifting ring body rotatably installed on the lifting ring seat. The rotation axis of the lifting ring body is parallel to the left-right direction of the upper mold base 10, so as to allow the hook to be inserted from different angles and adapt to different lifting postures.

[0034] Lower lifting ring structures 2 are installed on the front and rear sides of both the left and right sides of the lower mold base 20. The lower lifting ring structures 2 protrude in a direction parallel to the left and right of the lower mold base 20. In this embodiment, the lower mold base 20 has a total of four lower lifting ring structures 2, which are located in the middle of the four sides of the lower mold base 20. The lower lifting ring structure 2 also includes a lifting ring seat and a rotatable lifting ring body, but its protruding direction is perpendicular to the upper lifting ring structure 5.

[0035] Because the upper lifting ring structure 5 protrudes along the front-to-back direction, while the lower lifting ring structure 2 protrudes along the left-to-right direction, the two are staggered. This staggered design has the following technical advantages: First, during hoisting and installation, the upper lifting ring structure 5 and the lower lifting ring structure 2 will not interfere with each other. Whether using a crane to vertically hoist from above the upper mold base 10 or to pull horizontally from the side, there is ample operating space, and the lifting slings will not collide with adjacent lifting rings. Second, when the upper mold base 10 and the lower mold base 20 are closed for storage or transportation, the staggered lifting ring structure makes the overall shape of the mold more compact, facilitating the stacking and storage of the mold and saving storage space. Third, when installing the mold on the press, operators can operate the upper lifting ring structure 5 of the upper mold base 10 from the front and rear sides of the mold, and operate the lower lifting ring structure 2 of the lower mold base 20 from the left and right sides, which conforms to the principles of ergonomics and reduces the labor intensity of assembly and disassembly.

[0036] Both the upper lifting ring structure 5 and the lower lifting ring structure 2 are forged from high-strength alloy steel (such as 40Cr or 35CrMo) and tempered. Their rated lifting load is not less than three times the total weight of the mold to ensure lifting safety. The lifting ring seat is fixed to the mold base with four high-strength internal hexagonal screws, and a triangular reinforcing rib is added between the lifting ring seat and the mold base. The thickness of the reinforcing rib is the same as that of the lifting ring seat, thereby increasing the tensile load-bearing capacity of the lifting ring seat by about 50%. The lifting ring body is machined from forgings, with continuous internal fiber structure and no casting defects. Its safety factor (the ratio of breaking load to rated load) is not less than 6.

[0037] Example 4: Design of Idle Station Stepping and Process Interval This embodiment focuses on the design of the stepping interval between the punching die assembly 15a, the shaping die assembly 16 and the preceding and following processes, and their role in ensuring processing quality.

[0038] The punching die assembly 15a and the shaping die assembly 16 are arranged after the punching die assembly 15 along the material strip stepping direction F. According to the die design step distance, the punching die assembly 15a and the shaping die assembly 16 require the sheet material strip 200 to make two steps before they can complete their respective processing. Specifically, an empty station is reserved between the punching die assembly 15 station and the punching die assembly 15a station (i.e., this station does not have any punching punch or die, but only a guide plate and a floating pin), and another empty station is reserved between the punching die assembly 15a station and the shaping die assembly 16 station.

[0039] The punching die assembly 15a includes a punching punch and a punching die, used to punch elongated process holes or mounting holes in the strip 200. The length direction of the elongated hole can be parallel to or perpendicular to the strip's stepping direction F, depending on the specific structural design of the lower cover of the gateway housing. The punching punch is made of high-speed tool steel W6Mo5Cr4V2 or cemented carbide YG15, and its lower end has a sharp cutting edge with an angle of 118° to 120°. The punching die has a blanking hole corresponding to the punch, and the single-sided clearance between the blanking hole and the punch is 5% to 8% of the thickness of the strip 200.

[0040] The shaping die assembly 16 includes a shaping punch and a shaping die, used to flatten and shape the area on the strip 200 after punching or elongating holes, eliminating burrs, warping, or local deformation generated during the punching process, and providing a flat reference surface for subsequent cutting and bridging forming. The working surfaces of the shaping punch and the shaping die are precision ground, with a surface roughness Ra of no more than 0.4 μm. The shaping gap is controlled between 90% and 95% of the thickness of the strip 200 to ensure that the strip is flattened without excessive compression that would cause the material to become thinner.

[0041] Because the punching and shaping processes significantly alter the local stress state of the strip 200, continuous operation at the same or adjacent stations can easily lead to stress concentration, causing tearing, warping, or severe deformation of the strip 200, affecting the positioning accuracy and forming quality of subsequent processes. This embodiment addresses this by setting empty stations before and after the punching die assembly 15a and the shaping die assembly 16, allowing sufficient time for the strip 200 to release punching stress during the two-step conveying process. In the empty stations, the strip 200 is continuously supported and guided by the guide plate and floating pins. The floating pins, under spring action, lift the strip 200 to the height of the die's reference surface, while the guide plate restricts the lateral displacement of the strip 200, ensuring the strip 200 maintains the correct conveying posture while releasing stress. This two-step interval arrangement effectively avoids deformation and tearing of the strip 200 caused by excessive process concentration, ensuring the processing quality of the punching and shaping processes, and thus guaranteeing the dimensional accuracy of the final part 200a.

[0042] Example 5: One-step forming bridge and precision material distribution This embodiment elaborates in detail the structural principles of the cutting mold assembly 40, the bridge forming mold assembly 60, and the material distribution mold assembly 70, as well as the technical advantages of one-step forming bridge.

[0043] The cutting die assembly 40 is used to cut out the unfolded shape of the product on the strip 200, and the upper and lower ends of the cut-out shape hole are aligned with the positioning holes on the same side. The cutting die assembly 40 includes a cutting punch and a cutting die. The outline of the cutting punch is consistent with the planar unfolded outline of the bridge structure part 200a of the gateway housing lower cover, but does not yet include the three-dimensional forming outline of the bridge part. The cutting edge clearance of the cutting punch and the cutting die is determined according to the material thickness and material of the strip 200. For cold-rolled steel sheet or galvanized steel sheet with a thickness of 0.8mm to 1.5mm, the clearance on one side is 6% to 10% of the thickness of the strip 200.

[0044] When the cutting die assembly 40 cuts out the outline, the upper and lower ends of the outline (i.e., the positions near the upper and lower edges of the strip 200) are precisely aligned with the positioning holes on the same side, with an alignment accuracy controlled within ±0.05mm. This alignment is ensured through precision machining during die manufacturing, specifically, the positional tolerance between the cutting edge of the cutting die and the positioning hole cutting edge of the punching die is controlled within ±0.02mm. This alignment ensures that during the subsequent forming die assembly 60, the bridge position relative to the edge of the strip 200 and the positioning hole is accurate, thereby ensuring that the final part 200a's dimensions meet the assembly requirements of the gateway housing lower cover. The cutting die assembly 40 is equipped with a floating unloading device and an ejector device to ensure that the strip 200 after cutting can continue to be smoothly conveyed.

[0045] The bridge forming die assembly 60 is used to perform one-step bridge forming on a designated area of ​​the strip material 200. The bridge forming die assembly 60 includes a bridge forming punch and a bridge forming die. The bridge forming punch is fixedly installed on the lower surface of the upper die base 10, and its lower end is provided with a forming surface that matches the desired bridge shape; the bridge forming die is fixedly installed on the upper surface of the lower die base 20, and its upper end is provided with a forming cavity that mates with the bridge forming punch. When the press drives the upper die base 10 downward, the bridge forming punch presses the suspended portion of the strip material 200 after its shape has been cut into the cavity of the bridge forming die, and the planar strip material 200 can be partially formed into a three-dimensional bridge structure through a single stamping action.

[0046] The suspended portion refers to the area on the strip 200 that, after being shaped, remains partially connected to the main body of the strip and is not yet completely separated. This area is suspended after the shaped section, facilitating plastic deformation during the bridging forming process. The bridging forming mold assembly 60 further shapes the suspended portion during the forming process, ensuring smooth sidewalls, rounded corners, and consistent height of the bridging section. This one-step bridging structure avoids positional deviations caused by repositioning in traditional two-stage forming processes, and also avoids the risk of material thinning and cracking due to repeated bending or stretching. This results in a dimensional accuracy of ±0.05mm and an angular accuracy of ±0.5° for the bridging section.

[0047] To accommodate the varying height, width, and shape requirements of different gateway housing covers, the bridge forming mold assembly 60 can employ a modular insert structure. The bridge forming punch consists of a base and replaceable bridge forming inserts. The base is fixedly mounted on the lower surface of the upper mold base 10, and its lower surface has a T-slot or dovetail groove. The bridge forming insert is fixed to the T-slot or dovetail groove of the base using screws and pins. The lower surface of the bridge forming insert is machined with a profile matching the required bridge shape, including the bridge top surface, bridge sidewalls, and transition fillets connecting the bridge to the main body of the part. For semi-circular, rectangular, or trapezoidal bridges, only the corresponding bridge forming insert needs to be replaced; the entire punch base does not need to be replaced, significantly reducing mold changeover time. The working surfaces of the bridging forming punch and bridging forming die are polished, with a surface roughness Ra of no more than 0.8μm. They are made of high wear-resistant cold work die steel such as Cr12MoV or SKD11, and after quenching and deep cryogenic treatment, the hardness reaches HRC60-64 to ensure service life in high-speed continuous production.

[0048] The material separating die assembly 70 is used to separate the formed bridge part from the material strip 200 to obtain a complete gateway housing lower cover bridge structure part 200a. The material separating die assembly 70 includes a cutter 100a and a material separating die. The cutter 100a is fixedly installed on the lower surface of the upper die base 10, and the material separating die is fixedly installed on the upper surface of the lower die base 20. The cutting edge profile of the cutter 100a is consistent with the final outer contour of the part 200a. Based on the outer contour cut by the outer contour cutting die assembly 40, the remaining connecting part between the part 200a and the material strip 200 is completely cut off. The cutter 100a adopts an interlocking structure, composed of multiple blades, which facilitates individual replacement after local wear and reduces maintenance costs. The material distribution die assembly 70 is also equipped with a part ejection device and a guide and support device for the strip 200. After the cutter 100a completes the separation, the ejection device pushes the part 200a upward from the material distribution die, while the support device supports the strip 200, allowing the part 200a to separate smoothly from the strip 200. The separated part 200a is collected by a slide or conveyor belt located below the die, while the waste portion of the strip 200 is collected by a waste winding device or after being cut.

[0049] Example 6: Usage Method and Process Control This embodiment provides a method for using a progressive die for one-step molding of a gateway housing lower cover bridge, employing a progressive die 100 as described in any one of embodiments one to five, and including the following steps: S1. Punching Positioning Holes: The strip material 200 is conveyed along the stepping direction F to the punching die assembly 15 station, where the punching die assembly 15 punches positioning holes near the top and bottom edges of the strip material 200. Specifically, the strip material 200 is unwound and leveled from the roll by an automatic feeder or servo feeder, and then fed into the progressive die 100 with constant tension and speed. The feeder's feeding accuracy is controlled within ±0.05mm, and the step distance accuracy is controlled within ±0.03mm. The strip material 200 first enters the punching die assembly 15 station, where the punching punch moves downward under the drive of the press slide, cooperating with the punching die to symmetrically punch positioning holes on the top and bottom edges of the strip material 200. The number and position of the positioning holes are determined according to the positioning requirements of subsequent stations; typically, two positioning holes are set on each side, with a diameter of 3mm to 6mm and a center distance of 60mm to 100mm. After punching is completed, the upper die holder 10 moves upward, the stripper plate peels the strip 200 off the punching punch, and the feeder moves the strip 200 forward by one step.

[0050] S2. Cutting the Outline: The strip 200 continues to be conveyed step-by-step to the cutting outline die assembly 40 station. The cutting outline die assembly 40 cuts the unfolded outline of the product onto the strip 200, and the upper and lower ends of the cut outline holes are aligned with the positioning holes on the same side. During the process of the strip 200 stepping from the punching die assembly 15 station to the cutting outline die assembly 40 station, the strip 200 is supported and guided by the floating pins and guide plates set in the die. After the strip 200 enters the cutting outline die assembly 40 station, the cutting outline punch descends and cooperates with the cutting outline die to cut off the excess part on the strip 200 along the unfolded outline of the part 200a. After cutting the outline, the unfolded outline of the part 200a is formed on the strip 200, but the part 200a is still connected to the main body of the strip 200 through a partial connecting belt for continued conveying.

[0051] Between the punching die assembly 15 and the cutting die assembly 40, there is also a long hole punching die assembly 15a and a shaping die assembly 16. According to the die design pitch, the long hole punching die assembly 15a and the shaping die assembly 16 require the strip material 200 to make two steps before they can complete their respective processing. Specifically, after the strip material 200 completes punching at the punching die assembly 15 station, it first steps into the long hole punching die assembly 15a station, where the long hole punching punch and long hole punching die work together to punch out the long hole; then the strip material 200 steps into the shaping die assembly 16 station for the second time, where the shaping punch and shaping die flatten and shape the strip material 200. Between the two steps, the strip material 200 passes through an empty station, where no stamping process is set up; only the guide plate and floating pin support and guide the strip material 200, allowing sufficient time for the strip material 200 to release the punching stress and return to flatness.

[0052] S3. One-Step Bridging: The strip 200 continues to be conveyed step-by-step to the bridging forming die assembly 60 station, where the bridging forming die assembly 60 performs one-step bridging forming on a designated area of ​​the strip 200. The strip 200 steps from the cutting die assembly 40 station to the bridging forming die assembly 60 station, passing through the support and guidance of the floating pin and guide plate. After entering the bridging forming die assembly 60 station, the pressure plate first contacts the strip 200 and presses it tightly. Then, the bridging forming punch descends, pressing the suspended portion of the strip 200 after cutting into the cavity of the bridging forming die. During the forming process, the suspended portion undergoes plastic deformation, changing from a planar state to a three-dimensional bridging state. The forming force is calculated based on the material, thickness, and bridging height of the strip 200, typically ranging from 500N to 1500N per millimeter of strip width. The forming speed (i.e. the downward speed of the press slide within the forming zone) is controlled between 100 mm / s and 300 mm / s to avoid material breakage due to excessive speed or excessive material springback due to excessive speed.

[0053] S4. Material Separation: The material strip 200 continues to be conveyed step-by-step to the material separation die assembly 70 station. The material separation die assembly 70 separates the formed bridge part from the material strip 200, obtaining the complete gateway housing lower cover bridge structure part 200a. The material strip 200 steps from the bridge forming die assembly 60 station to the material separation die assembly 70 station. After entering the material separation die assembly 70 station, the cutter 100a descends and cooperates with the material separation die to completely cut off the remaining connecting part between the part 200a and the material strip 200. After separation, the ejector device ejects the part 200a upwards. Under the action of gravity or with the help of compressed air, the part 200a falls into the collection chute or part box below the mold. The waste part of the material strip 200 continues to be conveyed forward or is cut off and collected by the waste cutting device.

[0054] In this embodiment, the press is an open or closed mechanical press. The nominal pressure is determined based on the total punching force of the progressive die 100, typically ranging from 200kN to 1000kN. The press's slide stroke is determined based on the die's closing height and unloading stroke, typically ranging from 100mm to 200mm. The press is equipped with an automatic feeding mechanism, a waste collection mechanism, and a parts counting device, achieving fully automated production. The production speed (i.e., strokes per minute) is set based on the complexity of the part 200a and the material characteristics of the strip 200, typically ranging from 60 to 150 strokes per minute.

[0055] During mass production, the die undergoes a cutting edge inspection and lubrication maintenance every 5,000 to 10,000 stamping cycles. This includes checking for chipping, wear, or dulling of the cutting edges of each punch and die, and promptly re-sharpening or replacing any damaged parts. Every 500,000 to 1,000,000 stamping cycles, a comprehensive overhaul of the die is performed, including checking the clearance of guide pillars and bushings, verifying the height of limit components, testing the elasticity of elastic elements, and checking the anti-loosening properties of all fasteners, to ensure long-term stable operation of the die.

[0056] In addition, the progressive die 100 can be equipped with safety detection devices, including a strip 200 end detection sensor, a part discharge detection sensor, and a die overload protection device. The strip 200 end detection sensor is installed at the feed end. When it detects that the strip 200 is about to run out, it automatically issues an alarm signal and stops the machine to prevent dry-punching and damage to the die. The part discharge detection sensor is installed at the part collection chute below the distribution die assembly 70. When it detects that part 200a has not been discharged normally, it automatically stops the machine and issues an alarm to prevent stacked material from causing die damage during punching. The die overload protection device is installed between the press slide and the upper die holder 10. When the punching load exceeds a set value (such as 110% of the nominal pressure), the protection device automatically cuts off the press power to protect the die and press from damage.

[0057] This technology uses a one-step continuous die 100 to form a one-step 200a structure from sheet material conveyed in the direction of the F-side arrow. Specifically, it includes an upper die holder 10, a lower die holder 20, a punch for punching through holes 90 near the upper and lower sides of the strip material for positioning the subsequent step distance on the strip material, a 95 positioning for shaping the convex hull of 96, and the upper and lower ends respectively aligned and guided with the through holes 90 on the same side for the step distance, a punching assembly 97 for completing the subsequent work on the sheet material, continuing to punch 90 and positioning the 95 step distance according to the design step distance for feeding the sheet material and the upper edge of the outer shape 98 for cutting the outer shape assembly, continuing to form the edge of the suspended part 99 and shape 99a with the suspended part, continuing to form the bridge structure of 101 in one step on the strip material, and using a 100a cutter to cut to obtain part 200a.

[0058] In summary, this invention integrates multiple processes such as punching, punching elongated holes, shaping, cutting the outer shape, bridge forming, and material distribution into a single progressive die. It is further enhanced by a precise guiding and limiting system, a staggered lifting structure, and a scientific stepping design for empty workstations. This enables efficient, high-precision, one-step continuous production of the bridge structure of the gateway housing lower cover, effectively overcoming the quality risks and low production efficiency problems of existing secondary forming processes.

[0059] The above embodiments merely illustrate several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

[0060] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A continuous mold for one-step molding of a gateway housing lower cover bridge, comprising an upper mold base and a lower mold base, characterized in that, It also includes a punching die assembly, a cutting die assembly, a bridging die assembly, and a separating die assembly arranged sequentially between the upper die base and the lower die base along the material strip's stepping direction; a guide assembly and a limiting assembly are provided between the upper die base and the lower die base; wherein, the punching die assembly is used to punch positioning holes near the upper and lower sides of the strip material strip; the cutting die assembly is used to cut out the unfolded shape of the product on the strip material strip, and the upper and lower ends of the cut-out shape holes are respectively aligned with the positioning holes on the same side; the bridging die assembly is used to perform one-step forming bridging on a designated area of ​​the strip material strip; the separating die assembly is used to separate the formed bridging parts from the material strip.

2. The continuous modulus as described in claim 1, characterized in that, The guide assembly includes lower guide posts installed on the left and right sides of the front and rear sides of the upper mold base, and upper guide sleeves installed on the left and right sides of the front and rear sides of the lower mold base and cooperating with the lower guide posts. The lower guide posts can slide vertically up and down through the upper guide sleeves.

3. The continuous mold as described in claim 1 or 2, characterized in that, The limiting component includes a lower limiting position installed on the left and right sides of the front and rear sides of the upper mold base and located next to the inner side of the guide component, and an upper limiting position installed on the left and right sides of the front and rear sides of the lower mold base and located next to the inner side of the guide component, so as to improve the stability of the upper mold base and the lower mold base during the mold closing process by means of the cooperation of the upper limiting position and the lower limiting position.

4. The continuous modulus as described in any one of claims 1-3, characterized in that, The upper die base has upper lifting ring structures installed on both the left and right sides of its front and rear sides, with the upper lifting ring structures protruding in a direction parallel to the front-rear direction of the upper die base; the lower die base has lower lifting ring structures installed on both the front and rear sides of its left and right sides, with the lower lifting ring structures protruding in a direction parallel to the left-right direction of the lower die base; the upper lifting ring structures and the lower lifting ring structures are staggered to improve the ease of assembly and disassembly between the upper die base and the lower die base and the external stamping machine.

5. The continuous modulus as described in claim 1, characterized in that, It also includes a punching die assembly and a shaping die assembly installed between the upper die base and the lower die base. The punching die assembly and the shaping die assembly are arranged after the punching die assembly along the material strip stepping direction. According to the die design step distance, the punching die assembly and the shaping die assembly need the sheet material strip to make two steps before they can complete their respective processing.

6. The continuous modulus as described in claim 1, characterized in that, The bridge forming mold assembly is used to shape the suspended part of the strip material and form a bridge structure in one step.

7. The continuous modulus as described in claim 1, characterized in that, The material distribution mold assembly includes a cutter, which is used to cut the strip material to separate the formed bridge part from the strip material and obtain a complete gateway housing lower cover bridge structure part.

8. The continuous modulus as described in claim 1, characterized in that, The punching die assembly, the cutting die assembly, the bridge forming die assembly, and the material distribution die assembly, each mounted on the upper die base and the lower die base respectively, engage in a tension-closing cooperation during the opening and closing of the die to complete the corresponding process.

9. The continuous modulus as described in claim 1, characterized in that, The continuous die is suitable for continuously stamping and forming sheet-like strips conveyed along the stepping direction. The punching die assembly, the cutting die assembly, the bridging forming die assembly, and the material separating die assembly are fed sequentially along the stepping direction of the strip, so that the strip can complete multiple stamping processes at different stations simultaneously in one stamping stroke.

10. A method of using a continuous mold for one-step molding of a gateway housing lower cover bridge, characterized in that, The continuous modulus as described in any one of claims 1-9 is employed, and the following steps are included: S1. The strip material is conveyed to the punching die assembly station along the stepping direction, and the punching die assembly punches positioning holes near the upper and lower sides of the strip material. S2. The strip is continued to be conveyed to the cutting mold assembly station, where the cutting mold assembly cuts out the unfolded shape of the product on the strip, and the upper and lower ends of the cut-out shape hole are aligned with the positioning hole on the same side. S3. The strip material is continued to be conveyed to the bridge forming mold assembly station, where the bridge forming mold assembly performs one-step forming bridge on the designated area of ​​the strip material. S4. The material strip is continued to be conveyed to the material distribution mold assembly station, where the material distribution mold assembly separates the formed bridge part from the material strip to obtain a complete gateway housing lower cover bridge structure part. Between the punching die assembly and the cutting die assembly, there is also a punching elongation die assembly and a shaping die assembly. According to the die design pitch, the punching elongation die assembly and the shaping die assembly need to make two steps on the sheet material before they can complete their respective processing.

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