High-strength claw hoop forming process and forming die

Abstract

The present application relates to the technical field of pipeline connector forming, and discloses a high-strength claw hoop forming process and a forming die, aiming to solve the problem of lack of new high-strength claw hoop forming scheme in the prior art, and the problems of insufficient bending precision, poor forming consistency and low production efficiency in conventional processes. The forming process of the present application sequentially performs plate cutting and intermediate hole punching, tooth strip and edge strip stamping forming, step-by-step bending and setting of tooth strips and edge strips, tooth strip bending structure forming, arc hoop body bending and assembly hole machining processes, realizing the integrated forming of the high-strength claw hoop. The forming die comprises first and second bending dies, which are respectively used for synchronous bending of tooth strips and arc forming of hoop bodies, and the die is provided with matching positioning and avoiding structures to protect the pre-formed tooth strips from being damaged. The present application can effectively reduce the plate forming springback, improve the tooth strip bending precision and product forming consistency, and greatly improve the production efficiency.

Description

Technical Field

[0001] This invention relates to the field of pipe connector molding technology, specifically to a high-strength claw clamp molding process and molding die. Background Technology

[0002] In pipeline laying and connection projects, the reliability and sealing performance of pipeline interfaces directly determine the operational stability of the entire pipeline system. This is especially true in scenarios such as rainwater pipelines, soil transport pipelines, return water area pipelines, roof drainage systems, and wastewater pump transmission pipelines. Once problems such as loosening, leakage, or detachment occur at the pipeline interfaces, they are particularly vulnerable.

[0003] Currently, pipe clamps are commonly used in the industry for fixing and sealing the joints of two pipe sections. Conventional pipe clamps are mostly one-piece or interlocking arc-shaped structures. During use, they are fitted around the outer circumference of the joint between two pipe sections. A locking structure and bolt tightening mechanism achieve radial tightening of the clamp, thus compressing the seal at the pipe joint and achieving coaxial connection and joint sealing of the two pipe sections. However, long-term engineering applications have revealed that these conventional pipe clamps rely solely on the radial clamping force after tightening, lacking additional interlocking and limiting structures. Under conditions such as fluctuating water pressure, media erosion, and external vibration, problems such as clamp loosening, plastic deformation, and axial slippage easily occur. This makes it impossible to maintain the clamping force at the pipe joint for extended periods, leading to joint seal failure, a significant decrease in connection reliability, and difficulty meeting the long-term stable operation requirements of pipeline systems under complex conditions.

[0004] To address the technical defects of conventional pipe clamps, the inventors of this application have innovatively developed a high-strength claw clamp. This high-strength claw clamp, by setting multiple sets of bent teeth on both sides of the clamp body that can interlock with the outer wall of the pipe, combined with a fitting locking edge strip and an end limiting structure, can significantly improve the axial anti-slip capability, radial anti-deformation capability, and interlocking locking force between the clamp and the pipe, fundamentally solving the pain points of conventional pipe clamps being easy to loosen, easy to fall off, and having poor connection reliability.

[0005] However, currently, there is no suitable molding process for this new high-strength claw clamp in the existing technology, nor is there a matching special molding mold. The simple bending and stamping forming process of conventional pipe clamps cannot achieve the step-by-step precise bending, reverse shaping and synchronous bending forming of multiple sets of teeth of the high-strength claw clamp. It also cannot guarantee the forming consistency and structural strength of the tooth structure, arc-shaped clamp body and end limiting structure. When using conventional processing, problems such as insufficient bending accuracy of tooth, structural springback, large forming size deviation and low production efficiency are very likely to occur, which cannot meet the needs of large-scale mass production and performance index requirements of the new high-strength claw clamp.

[0006] Therefore, a new high-strength claw clamp forming process and forming mold are needed to solve the above problems. Summary of the Invention

[0007] To overcome the above-mentioned defects, embodiments of the present invention provide a high-strength claw clamp forming process and forming mold, which solves the technical problems of the lack of a new high-strength claw clamp matching forming scheme in the prior art, insufficient bending accuracy of conventional processes, poor forming consistency, and low production efficiency.

[0008] According to one aspect, at least one embodiment of the present invention provides a high-strength claw clamp forming process, comprising the following steps: S1. Cut the board into a preset size, punch a central hole in the center area of ​​the board; and punch several spaced teeth on both sides of the board, and make the two ends of each side form an unpunched edge strip. S2. Simultaneously bend the edge strip and the toothed strip on the same side of the plate towards the inside of the plate to form an acute angle with the plate; S3. Bend all the teeth in the reverse direction, and then continue to bend the edge strips into the plate until they fit against the plate, and make the teeth after the reverse bending perpendicular to the plate. S4. Bend the middle part of all the toothed strips toward the central axis of the plate, so that each toothed strip forms a bent structure at a preset angle; S5. The plate material that has been bent and shaped by the toothed strip is bent along the length direction into an arc-shaped hoop with a preset arc, and assembly holes are punched at both ends of the arc-shaped hoop.

[0009] Optionally, step S2 includes: S201. Simultaneously bend the toothed strip and the edge strip on the same side of the plate towards the inside of the plate until they are both at a first preset angle to the plate. S202. The edge strip and the toothed strip, which are bent to the first preset angle, are bent inwards towards the inside of the plate so that they are both at a second preset angle to the plate, the second preset angle being greater than the first preset angle.

[0010] Optionally, the toothed strip includes a sheet body and a connecting segment, the sheet body being disposed along the length direction of the plate, and the connecting segment being used to connect the middle part of the plate and the sheet body; In step S303, the sheet is bent in the opposite direction from the middle of the connecting section, and the sheet is perpendicular to the plate.

[0011] Optionally, in step S4, all the strips on the same side of the plate are simultaneously bent toward the central axis of the plate to bend the strips into a V-shape, U-shape or W-shape.

[0012] Optionally, step S4 may be followed by step S401: stamping horizontal stripes on the end face of the sheet away from the plate.

[0013] Optionally, in step S5, after the plate is bent to form an arc-shaped hoop, the end plate of the arc-shaped hoop and its two corresponding edge strips are simultaneously bent back towards the opening direction of the arc-shaped hoop until they overlap.

[0014] A high-strength claw clamp forming mold includes a first bending mold for bending a toothed strip. The first bending mold includes a first upper mold and a first lower mold. The bottom of the first upper mold is provided with a plurality of punches spaced apart, and the top of the first lower mold is provided with a plurality of dies spaced apart. The punches and dies are matched one-to-one, and each set of corresponding punches and dies is used to cooperate with each other to bend the sheet body of the toothed strip.

[0015] Optionally, it also includes a second bending die for bending the sheet metal into an arc-shaped hoop. The second bending die includes a second upper die and a second lower die. The lower surface of the second upper die has an arc-shaped forming cavity. The second upper die is also provided with a blanking part for ejecting the formed arc-shaped hoop. The upper surface of the second lower die is provided with an arc-shaped block that corresponds to and cooperates with the forming cavity. The arc-shaped block has two receiving grooves on its arc surface for accommodating the bent toothed strip.

[0016] Optionally, the first lower mold is provided with a positioning protrusion located between adjacent dies, the positioning protrusion being used to insert into the gap between two adjacent pieces.

[0017] Optionally, the second lower mold is further provided with forming protrusions for forming reinforcing ribs at the connection between the arc-shaped hoop and the end plate. The forming protrusions are located on both sides of the arc-shaped block, and forming grooves that cooperate with the forming protrusions are opened on both sides of the inner wall of the forming cavity of the second upper mold at positions corresponding to the forming protrusions.

[0018] The beneficial effects of this invention are as follows: The high-strength claw clamp forming process of this invention, through continuous and orderly sheet metal pretreatment, stamping of the toothed strip and edge strip, step-by-step bending and shaping, toothed strip bending structure forming, and hoop body arc forming and assembly hole processing, can realize the one-piece forming of high-strength claw clamps, complete the multi-step bending and shaping of the claw clamp interlocking toothed strip, effectively avoid structural springback and dimensional deviation during the toothed strip forming process, ensure the forming accuracy and structural strength of the toothed strip interlocking structure, and at the same time ensure the forming consistency of the arc-shaped hoop body and the locking assembly structure. It fully adapts to the forming requirements of new high-strength claw clamps with interlocking toothed strips, and can realize the stable and efficient processing of this type of claw clamp.

[0019] The high-strength claw clamp forming mold of the present invention, through a first bending mold and a second bending mold separately configured, respectively completes the bending and forming of the high-strength claw clamp toothed strip and the arc forming of the clamp body. The first bending mold, through the one-to-one matching punch and die, can realize the bending and forming of the toothed strip body, ensuring the forming consistency of multiple sets of toothed strips; the second bending mold, through the cooperation of the forming cavity and the arc block, realizes the precise arc forming of the clamp body. The receiving groove on the arc block can provide complete protection for the pre-formed toothed strip during the forming process, avoiding damage to the toothed strip structure. At the same time, the unloading part can realize the convenient unloading of the formed workpiece. The overall mold is fully compatible with the high-strength claw clamp forming process, improving processing efficiency. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are merely some exemplary embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the content of the exemplary embodiments of the present invention and these drawings without any creative effort.

[0021] Figure 1 This is a flowchart of a high-strength claw clamp molding process in one embodiment of the present invention; Figure 2 for Figure 1 A magnified view of a portion at point A in the embodiment; Figure 3 for Figure 1 A magnified view of a portion of point B in the embodiment; Figure 4 for Figure 1 A schematic diagram of the high-strength claw clamp after molding in the embodiment; Figure 5 This is a schematic diagram of the structure of the first bending die in another embodiment of the present invention; Figure 6 for Figure 5 The front view of the first bending die in the embodiment; Figure 7 for Figure 5 A magnified view of a portion of point C in the embodiment; Figure 8 for Figure 5 A schematic diagram of the structure of the second bending die in the embodiment; Figure 9 for Figure 5 The front view of the second bending die in the embodiment; Figure 10 for Figure 5 A schematic diagram of the structure of the second upper mold in the embodiment; Figure 11 for Figure 5A schematic diagram of the structure of the second lower mold in the embodiment.

[0022] In the diagram: 1. Plate, 101. Arc-shaped hoop, 102. Assembly hole, 103. End plate, 2. Middle hole, 3. Toothed strip, 31. Sheet, 32. Connecting section, 33. Gap, 4. Edge strip, 5. First bending die, 501. Horizontal stripe, 51. First upper die, 510. Punch, 52. First lower die, 520. Die, 53. Positioning protrusion, 6. Second bending die, 61. Second upper die, 610. Forming cavity, 62. Second lower die, 63. Unloading part, 64. Arc-shaped block, 641. Receiving groove, 65. Forming protrusion, 66. Forming groove, 67. Avoidance cavity. Detailed Implementation

[0023] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it.

[0024] To keep the drawings concise, each drawing only schematically shows the parts relevant to the invention; these do not represent the actual structure of the product. Furthermore, for ease of understanding, in some drawings, only one of components with the same structure or function is schematically shown, or only one is labeled. In this document, "one" not only means "only one," but can also mean "more than one," and "several" includes "two" and "more than two."

[0025] In this document, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0026] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0027] In the description of this embodiment, terms such as "upper," "lower," "left," and "right" are based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of description and simplification of operation, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention.

[0028] Furthermore, in the description of this application, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0029] like Figures 1 to 4 As shown, the molding process and mold provided in this embodiment are used to manufacture the novel high-strength claw clamp previously developed by the applicant. The sheet metal is integrally molded into a high-strength claw clamp using the molding process and mold. Specifically, it should first be noted that the arc-shaped clamp body 101 is made by bending a metal sheet 1 with good plasticity and structural strength. Its radial cross-section is an arc shape that perfectly matches the outer diameter of the pipe to be connected, allowing it to fit completely against the outer circumference of the pipe interface. A through-hole 2 is provided in the central area of ​​the arc-shaped clamp body 101. The through-hole 2 can accommodate the pre-set positioning boss and locking part of the clamp at the pipe interface, achieving circumferential positioning during clamp installation and reducing the overall weight of the clamp body.

[0030] Furthermore, on both sides of the sheet metal 1, multiple sets of equally spaced toothed strips 3 are stamped and formed along the axial direction. Each toothed strip 3 has a T-shaped structure. The toothed strip 3 includes a connecting section 32 integrally connected to the sheet metal 1, and a sheet 31 fixed to the outer end of the connecting section 32. After bending, the sheet 31 forms a V-shaped, U-shaped, or W-shaped bending structure that tightly engages with the outer wall of the pipe. The surface of the sheet 31 facing the outer wall of the pipe is also stamped with dense horizontal lines 501, which can significantly improve the friction coefficient of the interlocking contact surface. A gap 33 is formed between the sheet 31 of two adjacent toothed strips 3, providing sufficient operating space for bending and forming.

[0031] The curved hoop 101, after bending, has end plates 103 integrally extending from both ends. The connection between the end plates 103 and the curved hoop 101 is stamped with longitudinal reinforcing ribs, which significantly improves the end's resistance to deformation. The end plates 103 are bent inwards along a predetermined position in the middle of the hoop to form a U-shaped limiting structure, which provides end support when the claw hoop is locked, preventing end warping when the bolt is tightened. Side strips 4 extend from both sides of the end plates 103. The side strips 4 on the same side are integrally formed with the toothed strips 3 on the side of the curved hoop 101. The side strips 4 at both ends are provided with coaxially corresponding mounting holes 102. The mounting holes 102 include a large-diameter through hole for the locking bolt to pass freely, and a small-diameter internal thread hole formed by tapping.

[0032] The high-strength claw clamp forming process provided in this embodiment includes the following steps: material cutting, punching the central hole, punching the toothed strip, step-by-step bending and shaping, pressing and cold rolling cross-grain, forming the clamp body into an arc, bending and flattening the ends, punching the assembly hole, thread tapping, surface galvanizing, finished product assembly, inspection and packaging.

[0033] Step 1: This is the initial step in the forming process, used to obtain the blank material 1 (plate 1). First, based on the specifications of the high-strength claw clamp to be processed, determine the corresponding material and dimensional parameters of plate 1. Plate 1 can be made of metal plates with good cold bending plasticity and structural strength, such as Q235B galvanized steel plate or 304 / 316 stainless steel plate. The thickness of plate 1 can be flexibly adjusted within the range of 1.5mm-6mm according to the nominal diameter of the claw clamp.

[0034] The cutting process is completed using a CNC shearing machine. First, the entire roll of metal sheet 1 is unrolled and leveled to eliminate residual stress inside the sheet 1, preventing springback and warping during subsequent bending and forming. Then, it is precisely cut according to the preset unfolded dimensions, resulting in a rectangular sheet blank. After cutting, the four sides of the sheet blank 1 are deburred, and the sharp edges and burrs on the cut surfaces are sanded using a belt sander.

[0035] After the material is cut, the center hole 2 is punched. A CNC punch press is used in conjunction with a special center hole punching die. The size of the punching die is perfectly matched with the size of the center hole 2. The die clearance is adjusted according to the thickness of the sheet metal 1. Under the normal sheet metal 1 thickness, the clearance on both sides of the die is controlled at 8%-12% of the sheet metal 1 thickness to avoid problems such as corner collapse and excessive burrs on the hole wall after punching.

[0036] Before stamping, place the sheet metal blank 1 on the positioning fixture of the stamping press worktable, using the two adjacent right-angled sides of sheet metal 1 as positioning references to ensure that the center of sheet metal 1 is completely coaxial with the stamping center of the die. After positioning, start the stamping press and stamp a through hole 2 in the center area of ​​sheet metal 1 in one go. After stamping, clean the burrs and iron filings around the hole wall.

[0037] The toothed strips 3 and edge strips 4 are stamped using a progressive die and a high-speed punch press, which can realize the synchronous and continuous stamping of toothed strips 3 on both sides of the sheet 1, ensuring the dimensional consistency and arrangement accuracy of multiple sets of toothed strips 3.

[0038] Before stamping, the pre-formed central hole 2 on the sheet metal 1 is used as the positioning reference to fix the sheet metal 1 on the positioning fixture of the punch press, ensuring that the two opposite sides of the sheet metal 1 are parallel to the punching direction of the die to avoid displacement of the punching position. During the stamping process, the punch of the die punches out several toothed strips 3 with equal intervals along the length of the sheet metal 1 in the middle area of ​​the two opposite sides of the sheet metal 1 in one go. A uniform gap 33 is reserved between adjacent toothed strips 3. After the punching is completed, the two ends of each side of the sheet metal 1 naturally retain the complete area that was not punched, which corresponds to the edge strips 4 used for locking later. The edge strips 4 on the same side are on the same straight line as the toothed strips 3.

[0039] After stamping, the toothed strip 3 has a T-shaped structure, including a connecting section 32 integrally connected to the main body of the plate 1, and a sheet 31 located at the outer end of the connecting section 32.

[0040] Then, the toothed strip and edge strip are bent and shaped in stages. This process mainly reduces the deformation of the metal sheet 1 in a single bend by bending in stages, reduces forming springback, and avoids cracking and structural deformation of the sheet 1 at the bend. This process is completed by bending machine with special bending fixture. The middle hole 2 and the side of the sheet 1 are used as positioning references throughout the process to ensure the positional accuracy of all bending actions.

[0041] This process consists of three consecutive bending steps. Throughout the process, the same surface of board 1 is used as the reference plane for all bending directions to avoid confusion in the positioning reference caused by bending in both directions. The first step is to simultaneously bend the apron 3 and edge strip 4 on the same side of board 1 towards the same board surface to a first preset angle, which is set to 90°. The bending process is carried out along the preset bending mark line on board 1, such as... Figure 1 As shown, the marking line is located on the board material. This effectively thickens the board material after bending, thus increasing the strength of the curved hoop. After bending, both the toothed strip 3 and the edge strip 4 form a 90° angle with the main surface of the board material 1, creating a preliminary vertical edge structure.

[0042] The second step involves bending the edge strip 4 and the toothed strip 3, which have been bent to 90°, further towards the same side of the board 1 to a second preset angle. This second preset angle is set between 120° and 150°, and the specific angle can be adjusted according to the thickness and material of the board 1. The greater the thickness of the board 1, the closer the second preset angle will be to 150°. This step involves a progressive bending process, which significantly reduces the internal stress of a single bend, preventing the metal fibers at the bend from breaking. It also allows for deformation allowance for the subsequent bonding bend of the edge strip 4 and the reverse bend of the toothed strip 3, reducing the springback after forming from the source and facilitating operation on a bending machine.

[0043] The third step is to continue bending the edge strip 4 towards the same side of the plate 1 until the edge strip 4 is completely attached to the surface of the plate 1. The attached edge strip 4 can provide a larger contact support surface when the claw clamp is tightened later, which greatly improves the structural stability after the bolt is tightened and avoids deformation of the edge strip 4 caused by the concentration of tightening force. Then, the toothed strip 3, which is bent to the second preset angle, is bent in the opposite direction to the aforementioned bending direction until the toothed strip 3 and the attached edge strip 4 form a 90° angle perpendicular to each other. During the reverse bending process, the bending position is controlled in the middle of the connecting section 32 of the toothed strip 3. Through the transition deformation of the connecting section 32, the bending force is avoided from acting directly on the connection between the toothed strip 3 and the main body of the plate 1, which prevents structural breakage. At the same time, it is ensured that after the reverse bending, all the pieces 31 of the toothed strip 3 are in the same plane.

[0044] After completing the above three bending steps, use the first bending die to bend several toothed strips 3 on the same side of the sheet metal in a unified manner. Specifically, first place one side of the toothed strip 3 of the sheet metal between the first upper die and the first lower die of the first bending die, then align the sheet metal with the placement area or align the gap between adjacent sheet metals with the positioning protrusion 53, and the toothed strip 3 can be quickly placed in place. Then, the toothed strip 3 can be stamped into a V shape.

[0045] After the bending and shaping of the toothed rod 3 is completed, the horizontal lines 501 on the surface of the toothed rod 3 sheet 31 are stamped. This process is completed by using a stamping machine with a special horizontal line forming die. Multiple parallel horizontal lines 501 can be stamped in one go on the surface of the sheet 31 facing the outer wall of the pipe.

[0046] Before stamping, the sheet metal 1 is fixed on the positioning fixture to ensure that the sheet metal 31 of the toothed rack 3 is fully embedded in the positioning groove of the mold, so as to avoid the sheet metal 31 from shifting or deforming during stamping. During die-clamping, the toothed punch and die on the mold cooperate to form uniformly deep horizontal grooves 501 on the surface of the sheet metal 31. The tooth depth of the horizontal grooves 501 can be adjusted according to the thickness of the sheet metal 1, and is usually controlled within the range of 0.2mm-0.5mm. The tooth pitch is 1mm-2mm. The arrangement direction of the horizontal grooves 501 is perpendicular to the length direction of the toothed rack 3, which can maximize the axial friction resistance during engagement.

[0047] After the horizontal groove 501 of the toothed strip 3 is stamped, the arc-shaped hoop 101 is bent and formed as a whole. This process is completed using a special second bending die 6, which can bend the flat plate 1 into an arc-shaped hoop 101 that perfectly matches the outer diameter of the pipe to be connected in one go, ensuring the roundness and forming accuracy of the arc.

[0048] Before bending, the sheet metal 1 is placed horizontally on the working surface of the lower die of the second bending die 6. The pre-formed toothed strip 3 is embedded in the receiving groove 641 on the side wall of the die to prevent the toothed strip 3 from being squeezed and deformed by the die during bending. At the same time, the middle hole 2 of the sheet metal 1 is used as the positioning reference to ensure that the length direction of the sheet metal 1 is completely coaxial with the arc forming direction of the die. During the die closing process, the upper die moves downward, and the arc forming cavity 610 of the upper die cooperates with the arc block 64 of the lower die to gradually and evenly bend the flat sheet metal 1 into an arc-shaped hoop 101 with a preset curvature. The holding time is set to 3s-5s to fully release the internal stress of the sheet metal 1 after bending, reduce the amount of springback, and ensure that the curvature of the formed arc-shaped hoop 101 deviates from the design value by no more than ±0.3°, and the roundness tolerance is controlled within ±0.2mm.

[0049] After the mold is opened, the formed arc-shaped hoop 101 is taken out and the forming quality of the arc is checked to ensure that the hoop is free from obvious twisting and warping, the toothed strip 3 structure is free from bumps and deformation, and the tangents at both ends of the arc are parallel.

[0050] After the arc-shaped hoop 101 is formed, the end plates 103 are bent and flattened. This process is completed by using a bending machine with special bending fixtures to bend the end plates 103 at both ends of the arc-shaped hoop 101 into a preset U-shaped limiting structure.

[0051] During the bending process, the end plate 103 is first bent along the bending centerline toward the inner side of the hoop at a bending angle of 90° to form the vertical side of the U-shaped structure. Then, the end of the vertical side is bent 90° toward the outside of the hoop to form the bottom side of the U-shaped structure. Finally, the end plate 103 forms a U-shaped structure with the opening facing the outside of the hoop. After the bending is completed, a flattening fixture is used to press and flatten the U-shaped structure for 2-3 seconds to eliminate bending springback.

[0052] After this process is completed, the connection between the end plate 103 and the arc-shaped hoop 101 forms a double-layer reinforced structure, which can greatly improve the deformation resistance of the hoop end and avoid the problem of end warping and opening when the bolts are tightened later. At the same time, the U-shaped structure can form an end limit when the claw hoop is installed, preventing misalignment and displacement when the two symmetrical claw hoops are tightened.

[0053] After the end bending and shaping is completed, the assembly holes 102 on both end strips 4 are punched, that is, the large diameter through holes and the small diameter threaded bottom holes are punched. This is done by using a CNC punching machine with a special punching die, which can complete the synchronous punching of all the assembly holes 102 on both end strips 4 at one time.

[0054] Before punching, the arc-shaped hoop 101 is fixed on a contour positioning fixture. The contouring surface of the fixture is fully fitted with the outer arc surface of the arc-shaped hoop 101 to prevent deformation of the hoop during punching. At the same time, the middle hole 2 and the U-shaped structure at the end of the arc-shaped hoop 101 are used as positioning references to ensure that the punching position corresponds perfectly with the design position. During the punching process, a large-diameter through hole is punched on the edge strip 4 at one end of the arc-shaped hoop 101. The hole diameter matches the outer diameter of the screw of the matching locking bolt to ensure that the bolt can be freely inserted. A small-diameter threaded bottom hole is punched on the edge strip 4 at the corresponding position at the other end. The diameter of the bottom hole is set according to the national standard requirements based on the thread specification to reserve a precise machining allowance for the subsequent tapping process.

[0055] After the assembly hole 102 is punched, the internal thread of the threaded bottom hole is machined using a vertical tapping machine with a special tap.

[0056] The entire hot-dip galvanizing process is divided into three stages: pretreatment, hot-dip galvanizing, and post-treatment. The specific steps are as follows: The first stage is pretreatment. First, alkaline degreasing is performed by immersing the workpiece in an alkaline degreasing solution at 50-60℃ for 15-20 minutes to completely remove residual oil and iron filings from the stamping and bending process. After degreasing, the workpiece is rinsed three times with running water to thoroughly remove any remaining degreasing solution. Next, pickling and rust removal are performed by immersing the degreased workpiece in an 8%-10% dilute hydrochloric acid solution for 5-8 minutes to remove oxide scale and rust spots. After pickling, the workpiece is rinsed twice with running water to neutralize any remaining acid and prevent it from affecting the subsequent galvanizing quality. Finally, fluxing is performed by immersing the workpiece in a zinc ammonium fluxing solution at 60-70℃ for 2-3 minutes to form a uniform fluxing film on the workpiece surface. After fluxing, the workpiece is placed in a drying oven and dried at 120℃ for 10 minutes to completely remove surface moisture and prevent zinc explosion during hot-dip galvanizing.

[0057] The second stage is hot-dip galvanizing. The dried workpiece is slowly immersed in molten zinc at a controlled temperature of 435-445℃ using a specialized lifting device. The immersion time is controlled to 1-2 minutes, ensuring that all surfaces of the workpiece, including the inside of threaded holes and the gaps in the toothed strips, are fully in contact with the molten zinc to form a uniform and continuous zinc layer. After immersion, the workpiece is slowly and evenly removed from the molten zinc surface and centrifuged to remove excess molten zinc from the surface, preventing zinc buildup and defects such as drips and zinc nodules.

[0058] The third stage is post-treatment. The dried workpiece is immediately placed in a passivation solution at 30-40℃ for water-cooled passivation treatment for 30-60 seconds. This forms a passivation protective film on the zinc layer surface, further improving the corrosion resistance and surface smoothness of the zinc layer. After passivation, the workpiece surface is rinsed with clean water to remove any remaining passivation solution. Then, it is placed in a drying oven to dry, completing the entire galvanizing process.

[0059] Workpieces that pass the galvanizing inspection enter the finished product assembly process. According to product specifications and customer requirements, the finished claw clamps are assembled. The accessories include locking bolts, spring washers, flat washers, and rubber sealing sleeves can also be used.

[0060] Another embodiment of this application discloses a forming mold for a high-strength claw clamp, used to implement the toothed rod bending process and the clamp body arc forming process in the above forming process. The mold includes a first bending mold 5 for bending the toothed rod 3 and a second bending mold 6 for bending the plate 1 into an arc-shaped clamp body 101.

[0061] like Figures 5 to 7 As shown, the first bending die 5 is used for the bending and forming process of the toothed strip 3 sheet 31 in the forming process. It can complete the synchronous bending of all toothed strip 3 sheets 31 on the same side of the plate 1 at one time, ensuring that the bending angle and forming size of all toothed strips 3 are completely consistent, which greatly improves production efficiency and product consistency.

[0062] The first bending die 5 includes a first upper die 51 that can be fixedly connected to the slide block of the stamping machine, and a first lower die 52 that is fixedly installed on the worktable of the stamping machine. The lower surface of the first upper die 51 is provided with a number of downwardly protruding punches 510 at intervals. The number of punches 510 is exactly the same as the number of toothed strips 3 on one side of the sheet 1. The head shape of the punches 510 matches the preset bending structure. Different shapes of punches 510 can be replaced as needed to bend and form V-shaped, U-shaped or W-shaped sheet body 31 structures. The upper surface of the first lower die 52 is provided with a number of inwardly recessed dies 520 at intervals. The cavity of the die 520 corresponds one-to-one with the shape of the punches 510. When the die is closed, the punches 510 and the dies 520 are aligned vertically to form a complete bending forming cavity. Each set of corresponding punches 510 and dies 520 corresponds to a sheet body 31 of toothed strip 3 to be bent, ensuring that all sheets 31 are bent synchronously when the die is closed.

[0063] On the first die 52, an upwardly protruding positioning ridge 53 is provided on the die platform between adjacent die 520s. The width of the positioning ridge 53 perfectly matches the width of the gap 33 between adjacent toothed strip 3 pieces 31. When the die is closed, the positioning ridge 53 can be inserted into the gap 33 between two adjacent toothed strip 3 pieces 31 on the sheet 1, realizing the lateral positioning of the sheet 1 and preventing the sheet 1 from shifting during bending. At the same time, it can limit the lateral deformation of adjacent pieces 31 during bending, ensuring the dimensional accuracy of the pieces 31 after bending. The die platform between adjacent positioning ridges 53 forms a positioning placement area for placing the pieces 31 to be bent, ensuring that the pieces 31 to be bent are completely laid flat in the placement area and the bending starting position is completely consistent.

[0064] The working process of the first bending die 5 is as follows: In the open state, the pre-formed sheet 1 is placed on the working surface of the first lower die 52, so that all the toothed strips 3 pieces 31 on the same side of the sheet 1 are placed in the positioning area one by one, and the positioning protrusions 53 are inserted into the gaps 33 between adjacent pieces 31 to complete the positioning; then the press drives the first upper die 51 to move down and close the die, the punch 510 presses down and pushes the pieces 31 into the cavity of the die 520, and completes the synchronous bending and forming of all pieces 31 at one time, and holds the pressure for 2s-3s to release the internal stress; after the pressure is held, the first upper die 51 moves up and opens the die, and the sheet 1 is taken out, completing the entire bending process.

[0065] like Figures 8 to 11 As shown, the second bending die 6 is used in the overall forming process of the arc-shaped hoop 101 in the forming process. It can complete the arc bending of the flat plate 1 in one go, and at the same time, it can completely protect the pre-formed toothed strip 3 structure during the bending process to avoid structural damage. Furthermore, while bending the main body of the plate 1, it can also complete the bending of the end plates, so that the end plates and the bottom surface of the arc-shaped hoop are on the same horizontal plane. Moreover, it can directly form reinforcing ribs at the connection between the arc-shaped hoop and the end plates.

[0066] Specifically, the second bending die 6 includes a second upper die 61 that can be fixedly connected to the slide block of the hydraulic press, and a second lower die 62 that is fixedly installed on the worktable of the hydraulic press. The lower surface of the second upper die 61 is provided with an inwardly recessed arc-shaped cavity 610. The curvature of the cavity 610 matches the outer arc surface of the arc-shaped hoop 101 to be processed. The top of the second upper die 61 is also provided with a feeding component 63. The feeding component 63 adopts a structure of top plate and return spring. The lower end of the top plate extends to the inner wall of the cavity 610. When the die is opened after forming, the top plate can be pushed out downward under the elastic force of the spring, automatically pushing out the arc-shaped hoop 101 stuck in the cavity 610, realizing automatic feeding, reducing the intensity of manual operation, and improving processing efficiency.

[0067] The upper surface of the second mold 62 is provided with an upwardly protruding arc-shaped block 64. The outer arc surface of the arc-shaped block 64 matches the inner arc surface of the arc-shaped hoop 101. The arc-shaped block 64 and the forming cavity 610 are coaxially aligned, forming a complete arc-shaped bending cavity when the mold is closed. Two inwardly recessed receiving grooves 641 are respectively provided on the two axial side walls of the arc-shaped block 64. The receiving grooves 641 match the structure of the pre-formed toothed strip 3. When the mold is closed, the pre-formed toothed strip 3 on the plate 1 can be completely embedded in the receiving grooves 641, preventing the toothed strip 3 from being squeezed and deformed by the upper and lower molds during the mold closing process, ensuring that the forming structure of the toothed strip 3 is not damaged. The inner bottom wall of the receiving groove 641 is also provided with an inwardly extending clearance cavity 67. The clearance cavity 67 can accommodate the raised structure of the horizontal ridge 501 on the bottom surface of the toothed strip 3 plate 31, further preventing the horizontal ridge 501 on the surface of the plate 31 from being bumped or worn during bending, ensuring the product's interlocking performance.

[0068] The upper surface of the second lower mold 62 is also provided with an upwardly protruding forming protrusion 65. The forming protrusion 65 is located at both ends of the arc-shaped block 64. On both sides of the inner wall of the forming cavity 610 of the second upper mold 61, inwardly recessed forming grooves 66 are provided at positions corresponding to the forming protrusion 65. The forming grooves 66 and the forming protrusion 65 are perfectly matched in shape. When the mold is closed, the forming protrusion 65 and the forming groove 66 are precisely matched, and longitudinal reinforcing ribs can be stamped at the connection between the arc-shaped hoop 101 and the end plate 103 in one go, which greatly improves the structural strength of the hoop end and avoids fatigue deformation and cracking at the connection during long-term use of the claw hoop.

[0069] The working process of the second bending die 6 is as follows: In the open state, the pre-formed plate 1 is placed horizontally on the upper surface of the arc block 64, so that the teeth 3 on both sides of the plate 1 are fully embedded in the receiving groove 641 on the side wall of the arc block 64, thus completing the positioning of the plate 1; then the hydraulic press drives the second upper die 61 to move down and close the die, the forming cavity 610 cooperates with the arc block 64, and gradually bends the flat plate 1 into an arc hoop 101 with a preset curvature. At the same time, the forming protrusion 65 cooperates with the forming groove 66 to stamp and form reinforcing ribs at both ends of the hoop. After the die is closed, the pressure is held for 3s-5s to release the bending internal stress of the plate 1 and reduce springback; after the pressure is held, the second upper die 61 moves up and opens the die, and the unloading part 63 pushes the formed arc hoop 101 out from the forming cavity 610, thus completing the entire arc forming process.

[0070] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A high-strength claw clamp forming process, characterized in that, Includes the following steps: S1. Cut out a plate (1) according to the preset size, and punch a central hole (2) in the central area of ​​the plate (1); and punch several spaced toothed strips (3) on both sides of the plate (1), and make the two ends of each side form unpunched edge strips (4). S2. Simultaneously bend the edge strip (4) and the toothed strip (3) on the same side of the plate (1) toward the inside of the plate (1) to form an acute angle with the plate (1); S3. Bend all the toothed strips (3) in the opposite direction, and then bend the edge strip (4) into the plate (1) until it fits against the plate (1), and make the toothed strip (3) after the reverse bending perpendicular to the plate (1); S4. Bend the middle part of all the toothed strips (3) toward the central axis of the plate body, so that each toothed strip (3) forms a bent structure at a preset angle; S5. The plate (1) after the toothed strip (3) has been bent and shaped is bent along the length direction into an arc-shaped hoop (101) with a preset arc, and assembly holes (102) are punched at both ends of the arc-shaped hoop (101).

2. The high-strength claw clamp forming process according to claim 1, characterized in that, Step S2 includes: S201. Simultaneously bend the toothed strip (3) and the edge strip (4) on the same side of the plate (1) toward the inside of the plate (1) until they are both at a first preset angle to the plate (1); S202. The edge strip (4) and the toothed strip (3) bent to the first preset angle are bent toward the inside of the plate (1) to form a second preset angle with the plate (1), the second preset angle being greater than the first preset angle.

3. The high-strength claw clamp forming process according to claim 2, characterized in that, The toothed bar (3) includes a sheet (31) and a connecting section (32). The sheet (31) is arranged along the length direction of the plate (1), and the connecting section (32) is used to connect the middle part of the plate (1) and the sheet (31). In step S303, the sheet (31) is bent in the opposite direction from the middle of the connecting section (32), and the sheet (31) is perpendicular to the plate (1).

4. The high-strength claw clamp forming process according to claim 3, characterized in that, In step S4, the sheet bodies (31) of all the toothed strips (3) on the same side of the plate (1) are simultaneously bent toward the central axis of the plate (1) so that the sheet bodies (31) are bent into a V-shape, U-shape or W-shape.

5. A high-strength claw clamp forming process according to claim 3 or 4, characterized in that, Step S4 is followed by step S401: stamping cross stripes (501) on the end face of the sheet (31) away from the plate (1).

6. The high-strength claw clamp forming process according to claim 1, characterized in that, In step S5, after the plate (1) is bent to form an arc-shaped hoop (101), the end plate (103) of the arc-shaped hoop (101) and its two corresponding edge strips (4) are simultaneously bent back to overlap in the opening direction of the arc-shaped hoop (101).

7. A high-strength claw clamp forming mold, characterized in that, The first bending die (5) includes a first upper die (51) and a first lower die (52). The bottom of the first upper die (51) is provided with a plurality of punches (510) spaced apart, and the top of the first lower die (52) is provided with a plurality of dies (520) spaced apart. The punches (510) and the dies (520) are matched one-to-one, and each set of corresponding punches (510) and dies (520) is used to cooperate with each other to bend the sheet (31) of the toothed strip (3).

8. The high-strength claw clamp forming mold according to claim 7, characterized in that, It also includes a second bending die (6) for bending the sheet (1) into an arc-shaped hoop (101). The second bending die (6) includes a second upper die (61) and a second lower die (62). The lower surface of the second upper die (61) is provided with an arc-shaped forming cavity (610). The second upper die (61) is also provided with a blanking part (63) for ejecting the formed arc-shaped hoop (101). The upper surface of the second lower die (62) is provided with an arc-shaped block (64) that corresponds to and cooperates with the forming cavity (610). The arc surface of the arc block (64) is provided with two receiving grooves (641) for accommodating the bent toothed strip (3).

9. A high-strength claw clamp forming mold according to claim 7, characterized in that, The first lower mold (52) is provided with a positioning protrusion (53) located between adjacent concave molds (520), and the positioning protrusion (53) is used to insert into the gap (33) between two adjacent pieces (31).

10. A high-strength claw clamp forming mold according to claim 7, characterized in that, The second lower mold (62) is also provided with a forming protrusion (665) for forming a reinforcing rib at the connection between the arc-shaped hoop (101) and the end plate (1). The forming protrusion (65) is located on both sides of the arc-shaped block (64). The inner walls of the forming cavity (610) of the second upper mold (61) are provided with forming grooves (66) that cooperate with the forming protrusion (65) at positions corresponding to the forming protrusion (65).

Images