Angle adjusting component for automobile seat and preparation method of angle adjusting component

Abstract

The invention belongs to the technical field of automobile part manufacturing, and particularly relates to a preparation method of an angle adjusting component for an automobile seat and a product, the process method is based on eight-station cold heading equipment, and one-time forming of the product is achieved by optimizing procedure arrangement and innovating a mold structure. The method specifically comprises the following steps that S1-S2, materials are cut, and the direction of the materials is converted into a vertical state; s3-S4, blank preparation is completed through flattening, shaping and pre-forming procedures; s5, precise forming is completed at a fourth station through a double-trimming die; s6-S9, waste cutting machining, double-face shaping and strong beam trimming of redundant materials are conducted in sequence, and the redundant materials without machining defects are stacked to one side; and S10, carrying out secondary in-mold trimming and final shaping to ensure the dimensional precision. According to the invention, a two-time waste cutting process is designed according to the traditional thought of cutting the waste of the last die, the fourth die cuts most of the waste, then secondary trimming is carried out, in-die trimming and precise shaping are carried out by the eighth die, and the precise shaping processing process of the fifth, sixth, seventh and eighth dies is realized, so that one-time upsetting forming can be realized; a conventional transverse cold heading mode is changed into a vertical cold heading mode, the number of stations is reduced, the product strength is high, the number of machining procedures is small, and efficiency is high.

Description

Technical Field

[0001] This invention relates to the field of automotive parts manufacturing technology, specifically to an angle adjustment component for automotive seats and its preparation method. Background Technology

[0002] With the rapid development of the automotive industry, consumers are increasingly demanding higher levels of comfort and functionality in automobiles. As a key component directly impacting the driving and riding experience, the angle adjustment function of car seats is receiving increasing attention. The eccentric component for car seat angle adjustment, as the core component enabling flexible adjustment of the seat back angle, plays a crucial role in ensuring that the driving and driven wheels of the seat adjustment motor maintain an eccentric state in real time. Its performance and quality directly determine the accuracy, reliability, and service life of the seat angle adjustment. In the current automotive parts manufacturing industry, the processing methods for eccentric components for adjusting the angle of automotive seats mainly employ secondary upsetting forging or powder metallurgy. However, both of these traditional processes have significant limitations in practical applications. (a) Two-stage upsetting process The double upsetting process requires two steps to complete product processing. The first upsetting step mainly trims the raw material to form a blank, laying the foundation for subsequent forming; the second upsetting step is responsible for completing the final shaping of the product. This process has several drawbacks: First, the multiple steps make the production process cumbersome, increasing not only time and labor costs but also reducing overall production efficiency; second, each step requires corresponding equipment and operators, further increasing production costs; in addition, during multiple processing steps, the product is easily affected by external factors between process transitions, posing a risk of difficulty in guaranteeing processing accuracy. Taking the production process of imported Japanese products as an example, the process flow is as follows: 1. Raw material selection; 2. Cold heading and trimming; 3. Polishing; 4. Annealing; 5. Cold heading and shaping; 6. Carburizing heat treatment; 7. Fine polishing; 8. Cleaning and rust prevention. During cold heading, the internal lattice of the raw materials (mostly profiles or materials with large wire diameters) undergoes slippage, resulting in work hardening. To reduce material hardness and refine the internal structure for secondary shaping and to meet product precision requirements, annealing is necessary after cold heading and trimming. This complex process severely restricts production efficiency and cost control. (II) Powder Metallurgy Processing Technology Powder metallurgy is a process that uses metal powders or mixtures of metal and non-metal powders as raw materials to produce products through pressing, molding, and sintering. A typical process flow includes: 1. Raw material (metal powder mixture) preparation; 2. Pressing; 3. Sintering; 4. Secondary pressing; 5. Heat treatment; 6. Fine grinding and polishing; 7. Cleaning and rust prevention. While this process offers advantages in resource utilization due to low or zero waste, it also presents a series of problems that seriously affect product performance and quality. During sintering, the complex physical and chemical changes within the material can easily lead to defects such as shrinkage, porosity, and uneven density. These defects directly affect the mechanical properties of the product, resulting in significantly lower strength compared to upset forging. Furthermore, its surface hardness is lower than that of upset forging after carburizing heat treatment, leading to poor durability and wear resistance, making it difficult to meet the stringent requirements for high surface hardness and high gloss in automotive seat angle adjustment eccentric components. In addition, the production efficiency of powder metallurgy is relatively low, which cannot meet the needs of large-scale, high-efficiency production in the automotive industry.

[0003] Currently, in the Japanese passenger vehicle sector, the eccentric components used for adjusting the angle of automotive seats are either imported from Japan or manufactured using powder metallurgy. Imported products are not only expensive but also have long delivery cycles, making it difficult to meet the rapid market response requirements of domestic automakers. Furthermore, the shortcomings in performance and quality of powder metallurgy products limit their application in high-end automotive seat manufacturing. Therefore, developing a method and process for automotive seat angle adjustment components that overcomes existing technological deficiencies, achieves one-time upsetting, and simultaneously possesses high product strength, fewer processing steps, and high production efficiency has become a pressing technical problem to be solved in the automotive parts manufacturing industry. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide an angle adjustment component for automobile seats and its manufacturing method. By simultaneously improving the process body and fixture, the defects of existing processes can be effectively overcome. The invention employs double edge trimming and vertical cold forging to achieve synergistic gains in efficiency and precision. Through single forging, the product simultaneously possesses the characteristics of high strength, fewer processing steps, and high production efficiency.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A method for preparing an angle adjustment component for an automobile seat, characterized by comprising the following steps: S1. Cutting: The raw material wire rod is cut after being straightened by a cold heading straightening wheel; S2. Material erection: The material cut in S1 is passed through a specially designed clamping mechanism, which changes the material from a horizontal to a vertical position. S3. One-molding flattening and shaping: The material is compressed from a cylindrical shape into a cuboid shape under pressure; S4. Two-stage preforming: The purpose is to extrude the edge contour of the workpiece; S5. Three-stage edge trimming: The purpose is to trim the two sides of the blank into a crescent shape, leaving the waste material in the middle; S6. Scrap Removal from Four-Punch Dies: The die material is conveyed to the four-punch die opening by the rotating clamp. The four-punch ejector pins are pushed out by the small spring (b1). The die moves forward, and the small spring (b1) is compressed to its limit. The four-punch ejector pins make hard contact with the four-punch pad block. The scrap material is squeezed and removed by the cutting edge of the trimming die. After the scrap material is removed, the die moves backward, and the large spring (b2) pushes the scrap push tube to push out the scrap material fitted onto the four-punch ejector pins, completing the next cycle. S7. Five-die in-mold extrusion molding: Upsetting is achieved through in-mold extrusion molding; S8. Six-mold in-mold strong bundle: The strong bundle is sealed inside the mold core and repaired by the strong bundle ligament to eliminate the tear marks of the cut edge and squeeze the excess material to the head.

[0006] S9. Seven-mold shaping of excess waste material at the head: The excess material at the head is squeezed to the optimal cutting edge state through extrusion, which prepares for the next process to cut the edge again and minimizes the cutting edge marks. S10. Eight-mold secondary trimming and shaping: Remove the remaining waste material at the head, extrude it in the mold to the required product size, and push the stripper block with a pusher to remove the waste material; The upper surface of the material-standing mechanism in step S2 is the working surface, which is composed of a horizontal inclined surface and an upward curved arc inclined surface. The angle of the inclined surface is 30°-60°, preferably 45°.

[0007] In step S3, the plastic deformation ratio is 20%-30%.

[0008] The radius (R) of the fillet in step S7 is 0.3mm larger than the design requirement for the finished product, in order to improve the forming process in the next step.

[0009] In step S8, the outline size of the strong ligament is 0.15mm smaller than the die opening, the purpose of which is to extrude the previous process through the strong ligament die.

[0010] The following stations are executed sequentially on the eight-station cold heading machine: Station 1 (S3): Flattening and shaping; Station 2 (S4): Pre-forming; Station 3 (S5): Trimming and shaping; Station 4 (S6): Waste removal; Station 5 (S7): In-mold extrusion forming; Station 6 (S8): Strong bundle trimming; Station 7 (S9): Head shaping; Station 8 (S10): Secondary trimming and shaping.

[0011] The car seat angle adjustment component is manufactured by cold heading using an eight-station cold heading machine. Steps S3 to S10 are performed on the same cold heading machine. Step S3 is performed at the first station, step S4 at the second station, step S5 at the third station, step S6 at the fourth station, step S7 at the fifth station, step S8 at the sixth station, step S9 at the seventh station, and step S10 at the eighth station.

[0012] The car seat angle adjustment component is fastener SWRCH35K.

[0013] A fastener, used for adjusting the angle of an automobile seat, is manufactured using the aforementioned cold heading process. It includes a crescent-shaped body, with one narrow end and the other wide end. The wide end has an arc-shaped recess. The upper and lower ends of the body are flat, and rounded corners are provided at the joints between the surfaces. Specifically, its head has alternating anti-slip textures on the wide and narrow sections, wherein the radius of the arc of the wide section is R5±0.02mm, the length of the straight section of the narrow section is L2.3±0.05mm, and the coaxiality from the bottom surface of the head to the threaded end is ≤0.03mm.

[0014] Compared with the prior art, the beneficial effects of the present invention are: emphasizing " 1. This invention, while meeting the requirements of product strength and durable wear resistance, utilizes an eight-station cold heading machine to achieve one-time forming. It employs double edge trimming plus vertical cold heading to achieve a synergistic gain in efficiency and precision. By moving the edge trimming process to the fourth die, it breaks through the traditional waste removal approach, creating favorable conditions for the subsequent precision shaping in the fifth to eighth processes. Compared to existing technologies, it reduces multiple processes such as secondary annealing, polishing, and secondary cold heading. This significantly shortens the production cycle, substantially improves processing efficiency, reduces enterprise production costs, and enhances the product's price competitiveness in the market. Testing shows improved precision: double edge trimming improves dimensional tolerance from ±0.1mm to ±0.03mm; improved efficiency: production cycle is shortened from 90 seconds / piece to 22 seconds / piece; improved strength: surface hardness reaches HRC58-62, 35% higher than powder metallurgy parts.

[0015] 2. Moving the edge trimming process to the fourth mold changes the traditional molding flow. This allows subsequent precision shaping processes to function more effectively, significantly improving product molding accuracy, ensuring dimensional tolerances remain within a very small range, enhancing product consistency and quality stability, and meeting the stringent high-precision requirements of automotive seat angle adjustment components.

[0016] 3. Adding a material setting mechanism to the cold heading machine enables material orientation change. This innovation effectively reduces the material deformation coefficient and work hardening, reduces material loss during processing, improves material utilization, reduces mold wear, extends mold life, and further reduces the company's overall production costs.

[0017] 4. A spring mechanism is added to the conventional edge-cutting mode. This mechanism enables waste material to fall off automatically, ensuring the continuity of the processing, realizing cyclic processing, reducing manual intervention and downtime for cleaning, improving the degree of automation and production efficiency, and the stable waste material handling mechanism helps to improve the product molding quality and avoid the adverse effects of waste material residue on the product. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the preparation method process according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the material vertical movement structure according to an embodiment of the present invention; Figure 3 This is a mold structure diagram and a molding structure diagram of an embodiment of the present invention; Figure 4 The diagram shows the mold structure and molding structure of the mold according to Embodiment 2 of the present invention. Figure 5 The diagram shows the mold structure and molding structure of the third mold according to embodiment three of the present invention. Figure 6 The diagram shows the mold structure and molding structure of the fourth mold according to embodiment four of the present invention. Figure 7 The diagram shows the mold structure and molding structure of the mold in Embodiment 5 of the present invention. Figure 8 The diagram shows the mold structure and molding structure of the sixth mold according to Embodiment 6 of the present invention. Figure 9 The diagram shows the mold structure and molding structure of the seventh mold according to embodiment seven of the present invention. Figure 10 This is a mold structure diagram and a molding structure diagram of the eighth mold of the present invention.

[0019] In the diagram: 101, First mold material; 103, First ejector pin; 104, First die; 105, First ejector pin; 106, First ejector pin pad; 201, Second mold material; 203, Second ejector pin; 204, Second die; 205, Second ejector pin; 206, Second ejector pin pad; 207, Second mold core; 301, Third mold material; 303, Third ejector pin; 304, Third die; 305, Trimming die; 306, Third ejector pin; 308, Third mold core; 401, Fourth mold material; 402, Fourth ejector pad; 403, B1 small spring; 404, B2 large spring; 405, Fourth ejector pin; 407, Scrap ejector tube; 408, Fourth ejector pin; 410, Trimming die; 501, Five-stage mold material; 601, Six-stage mold material; 604, Six-punch ejector pin; 606, Six-stage ejector pin; 607, Six-stage ejector pin pad; 608, Six-stage mold core; 701, Seven-stage mold material; 704, Seven-punch ejector pin; 706, Seven-stage ejector pin; 707, Seven-stage ejector pin pad; 708, Seven-stage mold core; 801, Eight-stage mold material; 804, Eight-punch ejector pin; 806, Eight-stage ejector pin; 807, Eight-stage ejector pin pad; 808, Eight-stage mold core; Detailed Implementation

[0020] 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.

[0021] Please see Figure 1-10 The present invention provides a method for preparing an angle adjustment component for an automobile seat, which includes the following steps: S1. Cutting: The raw material wire rod is cut after being straightened by a cold heading straightening wheel; S2. Material erection: The material cut in S1 is passed through a specially designed clamping mechanism, which changes the material from a horizontal to a vertical position. The upper surface of the vertical material handling mechanism is the working surface, which consists of a horizontally oriented inclined plane and an upwardly curved arc inclined plane. The angle of the inclined plane is 30°-60°, preferably 45°. A comparison of the technical effects of different horizontal inclined plane angles is shown in Table 1 below.

[0022] Table 1 S3. One-molding flattening and shaping: The material is compressed from a cylindrical shape into a cuboid shape under pressure; Figure 3The forming principle and mold structure of the first mold are as follows: After the operating clamp transports the first mold material 101 to the first mold opening, the first punch 104 begins to press forward. After the first ejector pin 103 pushes the vertical cut material into the first mold core, the operating clamp releases. The first mold material 101 completes the forming of the second mold material 201 under the extrusion of the first ejector pin 103 and the first mold ejector pin 105. Then, the first mold ejector pin pad 106 pushes the first mold ejector pin 105 forward to eject the second mold material 201. At the same time, the operating clamp clamps the second mold material 201 and transports it to the second mold opening.

[0023] The principle of this process is that the die is closed and extruded in the main mold of the first mold. The material is transformed into a square under pressure. The purpose of this process is to flatten the material to achieve the plane required by the subsequent process. Its plastic deformation ratio is 25%. Due to the small deformation, the internal stress and cold work hardening are relatively small, and the hardness change is small. The main purpose of the first mold design is to pre-form the material and control the plastic deformation ratio at 20%-30%.

[0024] S4. Two-stage preforming: The purpose is to extrude the edge contour of the workpiece; Figure 4 Based on the principle of two-mold forming and mold structure, after the operating clamp transports the second mold material 201 to the second mold opening, the second punch 204 begins to press forward. After the second punch ejector pin 203 pushes the second mold material 201 into the second mold core 207, the operating clamp releases. Under the compression of the second punch ejector pin 203 and the second mold ejector pin 205, the second mold material 201 completes the forming of the third mold material 301. Subsequently, the second mold ejector pin pad 206 pushes the second mold ejector pin 205 forward to eject the third mold material 301. At the same time, the operating clamp clamps the third mold material 301 and transports it to the third mold opening.

[0025] The working principle of this process is as follows: the end faces of the two-punch ejector pin 203 and the two-mold ejector pin 205 are made with contoured recesses to pre-form a flat convex chamfer, so as to eliminate the burrs and deformation defects on the edge of the workpiece during the strong binding forming process in the next process. The deformation in this process is small, the internal structure of the workpiece changes slightly, and the hardness does not change significantly.

[0026] The purpose of setting up the second mold is to extrude the edge contour of the workpiece.

[0027] The core design features of this process and the second mold are: Figure 4 The contoured structure of the two-punch ejector pin 203, the two-mold ejector pin 205, and the two-mold core 207 shown is mainly processed by slow wire cutting, electrical discharge machining, heat treatment, fine polishing, and PVD titanium plating.

[0028] S5. Three-stage edge trimming: The purpose is to trim the two sides of the blank into a crescent shape, leaving the waste material in the middle; Figure 5Based on the three-mold forming principle and mold structure, after the operating clamp transports the three-mold material 301 to the third mold opening, the three-punch die 304 begins to press forward. Due to the change in the structure of the three molds, the three-mold ejector pin 306 becomes fixed, and the three-punch ejector pin 303 becomes movable. The three-punch ejector pin 303 pushes the three-mold material 301 to the front end of the three-mold ejector pin 306 and fixes it. Then the operating clamp releases, and the three-mold material 301 completes the trimming forming of the fourth mold material 401 under the extrusion of the trimming punch 305 and the three-mold core 308. Subsequently, the formed fourth mold material 401 remains in the trimming punch 305. While the three-punch die 304 retracts, the three-punch ejector pin 303 pushes the fourth mold material 401 forward. The operating clamp simultaneously clamps and transports the fourth mold material 401 to the fourth mold opening.

[0029] The working principle of this process is that the cutting die 305 and the three-die core 308 are designed for double cutting. The three-die ejector pin 306 is designed for positioning and ejection, so that the cutting of the workpiece is mainly completed in the cutting die 305. After the forming is completed, the three-die ejector pin 303 completes the ejection of the workpiece in the cutting die 305. The purpose of designing the three dies is to cut out the blank of the workpiece.

[0030] The core design features of the three-mold mold are: Figure 5 As shown, the three-punch ejector pin 303, the three-mold ejector pin 306, and the three-mold core 308 are square structures, and the processing technology is slow wire cutting, heat treatment, and fine polishing.

[0031] S6. Fourth mold waste removal: Figure 6 Based on the four-die forming principle and mold structure, after the operating clamp transports the four-die mold material 401 to the fourth die opening, the four-punch ejector pin 405 is pushed out by the small spring 403 (b1). The four-punch die begins to press forward. The four-punch ejector pin 405 pushes the four-die mold material 401 to the front end of the four-punch ejector pin 408 and fixes it. Then the operating clamp is released. The small spring 403 (b1) is compressed to its limit due to the forward pressure of the four-punch die, allowing the four-punch pad block 402 to press against the four-punch dies and cause the waste material of the four-die mold material 401 to be processed by the trimming die. The cutting edge of die 410 is subjected to pressure to cut off the waste material, leaving the workpiece of die material 401 at the front end of the die ejector pin 408. After the waste material of die material 401 is cut off, the four-punch die moves backward, the large spring 404 (b2) is released, and the waste push tube 407 is pushed out, ejecting the cut-off waste material of die material 401. At the same time as the four-punch die retracts, the four-punch ejector pin 405 moves forward to eject the workpiece of die material 501. Simultaneously, the operating clamp clamps and transports die material 501 to the fifth die opening. The cutting edge inclination angle of the trimming die 410 is 85°±1°, and the surface roughness Ra≤0.4μm.

[0032] The die material 401 is transported to the die opening by the operating clamp. The four punch ejector pins 405 are pushed out by the small spring 403 of spring b1. The die moves forward and the small spring b1 is compressed to the limit. The four punch ejector pins 405 and the four punch pads 402 make hard contact. The waste material is squeezed and cut off by the cutting edge of the cutting die 410.

[0033] After the scrap is removed, the die moves backward, and the large spring 404 (b2) pushes the scrap ejector tube 407 to push out the scrap fitted onto the four-punch ejector pin 405, thus completing the next cycle. The purpose of the four-die design is to remove scrap.

[0034] After removing 80% of the waste material through the fourth die, the eighth die performs fine cutting of the remaining material, which increases the cutting edge life by 2.3 times. Actual test data shows that the life of a traditional single-edge cutting die is 80,000 pieces, while the embodiment of the present invention can reach 210,000 pieces.

[0035] S7. In-mold extrusion molding: Upsetting is performed by in-mold extrusion molding; the radius R of the corners is 0.3mm larger than the design requirements of the finished product, in order to improve the molding of the next process.

[0036] S8. Six-mold in-mold strong bundle: Strong bundles are sealed inside the mold core and trimmed using strong bundle ligaments to eliminate tear marks at the cut edges and squeeze excess material to the head. Figure 8 Based on the six-mold forming principle and mold structure, after the operating clamp transports the six-mold material 601 to the sixth mold opening, the six-punch die begins to press forward. After the six-punch ejector pin 604 pushes the six-mold material 601 into the six-mold core 608, the operating clamp releases. Under the compression of the six-punch ejector pin 604 and the six-mold ejector pin 606, the six-mold material 601 completes the forming of the seventh mold material 701. Subsequently, the six-mold ejector pin pad 607 pushes the six-mold ejector pin 606 forward to eject the seventh mold material 701. At the same time, the operating clamp clamps simultaneously clamp and transport the seventh mold material 701 to the seventh mold opening.

[0037] The six-mold material 601 is sealed with a strong bundle within the six-mold core 608. By repairing the bundle, the tear marks at the cut edge during the trimming process are eliminated.

[0038] like Figure 8 As shown, the core of the six molds is designed as a strong-beam mold, and the mold opening profile size is reserved for normal mold clearance. The profile size of the strong-beam ligament is designed to be 0.15mm smaller than the mold opening, in order to extrude the previous process through the strong-beam mold.

[0039] S9. Seven-mold shaping of excess waste material at the head: The excess material at the head is squeezed to the optimal cutting edge state through extrusion, which prepares for the next process to cut the edge again and minimizes the cutting edge marks. Figure 9 Based on the principle and structure of the seven-mold forming process, after the operating clamp transports the seven-mold material 701 to the seventh mold opening, the seven-punch die begins to press forward. After the seven-punch ejector pin 704 pushes the seven-mold material 701 into the seven-mold core 708, the operating clamp releases. Under the compression of the seven-punch ejector pin 704 and the seven-mold ejector pin 706, the seven-mold material 701 completes the forming of the eighth mold material 801. Subsequently, the seven-mold ejector pin pad 707 pushes the seven-mold ejector pin 706 forward to eject the eighth mold material 801. At the same time, the operating clamp clamps the eighth mold material 801 and transports it to the eighth mold opening.

[0040] Through the closed extrusion of the seven-punch ejector pin 704 and the seven-die core 708, the overall height of the workpiece is reduced to achieve flatness on both sides.

[0041] S10. Eight-mold secondary trimming and shaping: Remove the remaining waste material at the head, extrude it in the mold to the required product size, and push the ejector block with the pusher pin to remove the waste material; Figure 10 Based on the principle and structure of the eight-mold forming process, after the operating clamp transports the eight-mold material 801 to the eighth mold opening, the eight-punch die begins to press forward. After the eight-punch ejector pin 804 pushes the eight-mold material 801 into the eight-mold core 808, the operating clamp releases. The eight-mold material 801 completes the product forming under the extrusion of the eight-punch ejector pin 804 and the eight-mold ejector pin 806. Subsequently, the eight-mold ejector pin pad 807 pushes the eight-mold ejector pin 806 forward to eject the product, while the operating clamp simultaneously clamps and transports the product to the product placement area. In this embodiment, the remaining waste material at the head is removed, the in-mold extrusion molding is performed to a dimensional tolerance of ±0.03mm, and the waste material is ejected by the ejector block (806) driven by the hydraulic push rod.

[0042] The 808 mold core is designed with the upper limit of the finished product size, with a grinding allowance. The product precision requirements are met through cold heading and extrusion.

[0043] In this embodiment, the small spring (403) b1 is made of SWOSC-V type spring steel with a stiffness coefficient of 12N / mm; the large spring (404) b2 is a SUS304 stainless steel conical spring with a stiffness coefficient of 42N / mm, and the compression stroke ratio of the two is controlled at 1:2.1-1:2.3 by adjusting the screw.

[0044] The feeding speed of the material-standing mechanism is controlled by a servo motor at 18-25 times / minute, and the motion curve is monitored in real time by an acceleration sensor to ensure that the feeding acceleration is ≤2g; the stiffness ratio of the large spring (404) to the small spring (403) is determined by the following motion parameter formula:

[0045] in, F max The maximum working load is 1200N. F preload The preload is 350N. The meaning and unit of each symbol are shown in Table 2.

[0046] Stiffness ratio constraint: By controlling the stiffness ratio of the two springs ( K b2 / K b1 =3.5), to achieve load distribution optimization and ensure: Preload stage: Small spring dominates deformation (high sensitivity) Working phase: The large spring bears the main load (high stability). Parameter verification results are as follows: when F preload = 350N F max When =1200N: - Small spring ΔL b1 =350N / 12N / mm ≈ 29.17mm - Large spring ΔL b2 =(1200N-350N) / 42N / mm ≈ 20.24mm - Stiffness ratio K b2 / K b1 =42 / 12=3.5, which is consistent with the calculation result of the motion parameter formula.

[0047] Table 2 The cold heading forming of the automotive seat angle adjustment component is performed sequentially on an eight-station cold heading machine, with the following steps: Station 1 (S3): flattening and shaping; Station 2 (S4): pre-forming; Station 3 (S5): three-die trimming and forming; Station 4 (S6): waste removal; Station 5 (S7): in-mold extrusion forming; Station 6 (S8): tension trimming; Station 7 (S9): head shaping; Station 8 (S10): secondary trimming and shaping. When manufacturing using an eight-station cold heading forming machine, steps S3 to S10 are performed on the same cold heading machine. Step S3 is performed at the first station, step S4 at the second station, step S5 at the third station, step S6 at the fourth station, step S7 at the fifth station, step S8 at the sixth station, step S9 at the seventh station, and step S10 at the eighth station.

[0048] The car seat angle adjustment component is fastener SWRCH35K.

[0049] A fastener, used for adjusting the angle of an automobile seat, is manufactured using the aforementioned cold heading process. It includes a crescent-shaped body, with one narrow end and a wide end, the wide end having a rounded recess. The upper and lower ends of the body are flat, and the joints between the surfaces are rounded. For details, see [link to details]. Figure 3 Its head has anti-slip textures that alternate between wide and narrow sections, with the wide section having a radius of radius R5±0.02mm and the narrow section having a straight section length L2.3±0.05mm. The coaxiality from the bottom surface of the head to the threaded end is ≤0.03mm.

[0050] To verify the range of deformation rate parameters, the following comparative experiments were conducted using multiple examples: Example 1: With a deformation rate of 20%, slight cracks appeared in the threaded portion of the resulting workpiece; Example 2: Deformation rate 25%, complete molding and surface finish Ra0.8; Example 3: Deformation rate 28%, material utilization rate increased by 15%, but an additional annealing process is required; Example 4: With a deformation rate of 30%, a mold temperature rise exceeding 120°C resulted in a 40% reduction in lifespan. Test results show that the overall benefits are best within the deformation rate range of 20%-30%.

[0051] The tensile strength of the workpiece produced by the double-edge cutting process in Embodiment 2 of this invention is 1250 MPa, which is much greater than the 980 MPa of the traditional process. Other comparative test results are shown in Table 3 below.

[0052] Table 3 The key feature of the above embodiments of the present invention lies in the design of the inclined structure (30°-60° adjustable angle + gradient radius R) of the upright material mechanism and the collaborative control method of the double-edge cutting die (parameter matching of the fourth die for rough cutting + the eighth die for fine cutting). Under the premise of meeting the strength and durable wear resistance of the fastener product, it uses an 8-station cold heading machine for one-time forming, reducing processing steps and improving processing efficiency. The process method of the present invention is based on an eight-station cold heading machine, achieving one-time forming of the product through optimized process layout and mold structure innovation. Specifically, it includes the following steps: S1-S2 cutting the material and changing its orientation to an upright state; S3-S4 completing the blank preparation through flattening, shaping, and pre-forming processes; S5 completing precision forming at the fourth station using a double-edge cutting die; S6-S9 sequentially performing waste material removal, double-sided shaping, and strong binding trimming of excess material to eliminate processing defects and stack the excess material to one side; S10 final shaping with secondary in-die edge cutting to ensure dimensional accuracy. This invention departs from the traditional approach of removing waste material in the final die. Instead, it designs a two-stage waste removal process. After removing most of the waste material in the fourth die, a second edge trimming is performed, followed by precision shaping in the eighth die. This achieves precision shaping in the fifth, sixth, seventh, and eighth dies, enabling one-time upsetting and forging. It changes the conventional horizontal cold upsetting method to a vertical cold upsetting method, reducing workstations, resulting in higher product strength, fewer processing steps, and higher efficiency.

[0053] Based on actual testing, its key improvements include at least the following three points: The improvement of the cold heading method has shifted the edge trimming process from the traditional approach of removing waste material in the last mold to the fourth mold, enabling precise shaping in the fifth, sixth, seventh, and eighth processes. The improvement to change the material orientation in cold heading, changing the conventional horizontal cold heading method to a vertical cold heading method, is mainly achieved by adding a vertical material feeding mechanism to the cold heading machine to change the material orientation. The mold structure has been improved. Instead of the conventional edge-cutting mode, a spring mechanism has been added to allow waste material to fall off and complete the cyclic processing.

[0054] 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 method for manufacturing an angle-adjustable component for an automobile seat, characterized in that, It adopts a cold heading process, including the following steps: S1. Cutting: The raw material wire rod is cut after being straightened by a cold heading straightening wheel; S2. Material erection: The material cut by S1 is passed through the material erection mechanism by a specially designed operating clamp, changing the material from a horizontal to an vertical state. S3. One-time flattening and shaping: The material is compressed from a cylindrical shape into a rectangular shape under pressure; S4. Two-stage preforming: The purpose is to extrude the edge contour of the workpiece; S5. Three-mold edge trimming: The purpose is to trim the two sides of the blank into a crescent-shaped blank, leaving the waste material in the middle; S6. Four-die scrap removal: The die material is transported to the four-die opening by the operating clamp. The four-punch ejector pin (405) is pushed out by the small spring (403) of spring b1. The die moves forward and the small spring (403) of b1 is compressed to the limit. The four-punch ejector pin (405) and the four-punch pad block (402) make hard contact. The scrap is squeezed and cut off by the cutting edge of the trimming die (410). After the scrap is removed, the die moves backward and the spring (404) pushes the scrap push tube (407) to push out the scrap sleeved on the four-punch ejector pin (405) to realize the next cycle. S7. Five-die in-mold extrusion molding: Upsetting is achieved through in-mold extrusion molding; S8. Six-mold in-mold strong bundle: The strong bundle is sealed inside the mold core and repaired by the strong bundle ligament to eliminate the tear marks of the cut edge and squeeze the excess material to the head. S9. Seven-mold shaping of excess waste material at the head: The excess material at the head is squeezed to the optimal cutting edge state through extrusion, which prepares for the next process to cut the edge again and minimizes the cutting edge marks. S10. Eight-mold secondary trimming and shaping: Remove the remaining waste material at the head, extrude it in the mold to the required product size, and push the ejector block with the pusher to remove the waste material.

2. The method for preparing the angle adjustment component for an automobile seat according to claim 1, characterized in that, The upper end face of the material-standing mechanism in step S2 is the working end face, which is composed of a horizontal inclined surface and an upward curved arc inclined surface. The angle of the inclined surface is 30°-60°.

3. The method for preparing the angle adjustment component for an automobile seat according to claim 1, characterized in that, In step S3, the plastic deformation ratio is 20%-30%.

4. The method for preparing the angle adjustment component for an automobile seat according to claim 1, characterized in that, The radius (R) of the fillet in step S7 is 0.3mm larger than the design requirement for the finished product, in order to improve the forming process in the next step.

5. The method for preparing the angle adjustment component for an automobile seat according to claim 1, characterized in that, In step S8, the outline size of the strong ligament is 0.15mm smaller than the die opening, the purpose of which is to extrude the previous process through the strong ligament die.

6. The method for preparing an angle-adjustable component for an automobile seat according to any one of claims 1-5, characterized in that, The following stations are executed sequentially on the eight-station cold heading machine: Station 1 (S3): Flattening and shaping; Station 2 (S4): Pre-forming; Station 3 (S5): Trimming and shaping; Station 4 (S6): Waste removal; Station 5 (S7): In-mold extrusion forming; Station 6 (S8): Strong bundle trimming; Station 7 (S9): Head shaping; Station 8 (S10): Secondary trimming and shaping.

7. The method for preparing the angle adjustment component for an automobile seat according to claim 1, characterized in that, The car seat angle adjustment component is fastener SWRCH35K.

8. A fastener, characterized in that, It is an angle adjustment component for automobile seats, made using the method described in any one of claims 1-7, comprising a crescent-shaped body, one end of which is narrow and the other end is wide, the wide end of which has an arc-shaped recess, the upper and lower ends of which are flat, and the joints between the surfaces are rounded.

9. The fastener according to claim 8, characterized in that, Its head has anti-slip textures that alternate between wide and narrow sections, with the wide section having an arc radius of R5±0.02mm, the narrow section having a straight section length of L2.3±0.05mm, and the coaxiality from the bottom surface of the head to the threaded end being ≤0.03mm.

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