Production process of rear seat angle automatic adjuster

Abstract

This invention relates to a production process for an automatic rear seat angle adjuster, belonging to the field of seat component processing technology. It solves the problems of traditional processes, such as difficult welding after electrophoresis, easy corrosion of welds, reduced service life, high cost, and unstable welding quality. The production process includes: welding of the rack and hook after stamping and heat treatment, followed by first-piece metallographic inspection; degreasing, zinc plating, passivation, and electroplating of the rack welds; processing of the steel housing, brass gears, and noise-reducing coating; lock body assembly, riveting, and secondary welding after shell edge reinforcement; overall phosphating and electrophoresis for corrosion protection of the lock body, with temperature control to prevent deformation of plastic parts; assembly of the drive motor; full inspection in a quiet room of noise, running time, and no-load current; multi-point quantitative grease application; final inspection, packaging, and warehousing. This new process, employing welding followed by overall electrophoresis, ensures complete coverage of the weld area with a protective coating, reducing production costs. The finished product features stepless electric adjustment, corrosion resistance, durability, low noise, reliability, convenient operation, and comfortable seating.

Description

Technical Field

[0001] This invention belongs to the field of seat component processing technology, specifically relating to a production process for an automatic rear seat angle adjuster. Background Technology

[0002] The existing manufacturing process for automotive seat angle adjusters is cumbersome. After electrophoresis, the electrophoretic coating inevitably makes welding impossible. Currently, to avoid this problem, the industry often uses methods such as applying a protective film to the spot welding area beforehand or using laser to remove the electrophoretic layer after electrophoresis to achieve metal-to-metal welding. These methods not only increase production costs, but also make the areas not covered by the electrophoretic coating prone to rust, thus affecting the lifespan of the adjuster. Furthermore, the spot welding process has poor weld quality stability, making it difficult to visually assess the weld quality. Therefore, it is necessary to improve the existing manufacturing process for automotive seat angle adjusters. Summary of the Invention

[0003] This invention addresses the aforementioned problems by providing a production process for an automatic rear seat angle adjuster that is simple to operate, improves the lifespan and safety of the adjuster, and reduces production costs.

[0004] The technical solution adopted in this invention is as follows: the production process of the automatic rear seat angle adjuster includes the following steps: Step 1: Stamping and heat treatment of the rack and hook; The angle adjustment rack is made of 42CrMo4 material, and is designed and stamped according to the drawings. It is then heat-treated to meet the hardness requirements of 342 HV10~403 HV10. The lock body ring hook is made of S550MC material, and is stamped according to the drawings. Step 2: The angle adjustment rack and the lock body ring hook are welded together using MAG. At the welding station, the angle adjustment rack and the lock body ring hook are accurately assembled. MAG welding process is used at the weld position required by the drawing. The weld length and penetration depth are strictly controlled according to the process card. Step 3: Electroplating anti-corrosion treatment of the rack and pinion welded parts; The welded angle adjusting rack and lock body ring hook are transferred to the electroplating station and hung on a rack using U-shaped hooks to prevent them from falling off. The angle adjusting rack is first chemically degreased by spraying, and then electrolytically degreased to remove surface oil. Next, the angle adjusting rack is immersed in a weak acid bath with a sulfuric acid volume ratio of 3% to 5% for 15 to 25 seconds for activation treatment to remove the passivation oxide film on the rack surface. Afterward, the angle adjusting rack is placed in an ultrasonic water washing tank with pure water as the medium and a vibration frequency of 35KHz. The process involves washing the rack with water to remove residual acid and impurities from the gaps and edges. The angle-adjusting rack is then placed in an electroplating tank for electroplating to form a uniform zinc coating. Afterward, it undergoes water washing and ultrasonic washing to remove any remaining plating solution. Subsequently, the electroplated angle-adjusting rack undergoes blue-white passivation to enhance its corrosion resistance, followed by another water wash. The rack is then dried in a hot air oven at 70℃~90℃ for 25 minutes. After cooling, the rack is hung for inspection and then stored in the warehouse. Step 4: Machining of the regulator housing, transmission gear, and rack housing; The regulator housing stamping parts are made of S550MC material. They are designed and stamped according to the drawings. They are divided into two types of housing stamping parts: lock body base plate and lock body cover plate. The lock body base plate is a flat plate design with mounting holes for the motor and bolt holes for fixing the motor. The lock body cover plate is a concave design and is inverted on the lock body base plate to form a cavity structure. The transmission gear is made of CW713R high-strength wear-resistant brass. It is precision machined to a machining accuracy of less than 0.1mm and is assembled in the cavity formed by the lock body base plate and the lock body cover plate, providing driven support for the reciprocating motion of the angle adjustment rack. The rack housing is designed to adjust the shape of the rack according to the angle, so as to wrap the rack in the cavity formed by the lock body base plate and the lock body cover plate, to prevent the rack and the adjuster housing from direct metal contact and generating resonance noise, and to reduce metal wear; Step 5: Assemble the lock body; First, fasten the two rack housings onto the outside of the galvanized rack welded parts, using the rack housings to enclose the angle adjustment rack. Place the assembled seat back drive rack assembly into the inverted lock body cover plate. Then, inject 0.2g of grease into the transmission gear and place it at the tail end of the angle adjustment rack. After that, cover the lock body base plate, so that the lock body base plate and the lock body cover plate form a cavity. The rack and the transmission gear are both located in the cavity. The two protruding cover plate positioning insertion elbows of the lock body cover plate extend from the cover plate positioning insertion holes on the edge of the lock body base plate. Step Six: Reinforce the edges of the shell connection points by folding them together; Place the pre-assembled regulator lock body on the bending machine with the two protruding cover plate positioning and insertion elbows at the edge connection of the lock body base plate and the lock body cover plate facing upwards. Start the bending machine and press down the bending machine head to bend the two exposed cover plate positioning and insertion elbows in opposite directions to 90°, further fixing the shells on both sides of the lock body. Step 7: MAG welding of the regulator housing; Place the adjusted lock body with folded edges on the welding fixture and perform MAG welding along the weld seam position required by the drawing; Step 8: Overall electrophoretic corrosion protection treatment of the regulator lock body; The welded regulator lock body is transferred to the electrophoresis line and hung on a rack. First, the regulator lock body undergoes chemical degreasing in a spray line to remove grease. Then, it enters a phosphating tank to form a uniform phosphating film on the surface of the regulator lock body. After cleaning, it is cleaned again to remove acidic impurities. Next, it is placed in an electrophoresis tank for electrophoresis to coat the surface of the regulator lock body. Subsequently, the electrophoretically coated regulator lock body is washed with water and then dried in a high-temperature curing oven. The drying temperature needs to be controlled between 160℃ and 190℃ to avoid deformation of the rack and pinion housing inside the regulator lock body. After inspection, the electrophoretically coated regulator lock body is transferred to the next station. Step 9: Assemble the drive motor; The regulator drive motor, which is used to drive the reciprocating motion of the angle adjustment rack, is installed on the regulator lock body through the drive motor fixing hole provided on the lock body base plate; Step 10: Noise detection; After the regulator is assembled with the drive motor, it is transported to a quiet room. A 12V voltage is connected to the regulator drive motor, and the decibel value of the regulator is measured using a decibel meter at a distance of 20cm. When the ring hook on the side of the angle adjustment rack moves from the left limit position to the right limit position, the sound decibel value must not exceed 55dB, the movement time must not exceed 5 seconds, and the input current under no-load conditions must not exceed 4A. All regulators must be tested, and only those that pass the test can proceed to the next process. Step 11: Quantitative addition of lubricating grease and final inspection and packaging; Apply a measured amount of grease to the positions specified in the regulator drawing using a metering valve; inject 0.2g of grease at the contact point between the angle adjustment rack and the drive motor's driving gear; inject 0.2g of grease at the contact point between the angle adjustment rack and the drive rack's driven gear; inject 0.2g of grease at the contact point between the rack housing and the lock body base plate and lock body cover plate; and inject 0.2g of grease into each of the four pre-drilled oil injection holes on the lock body base plate and lock body cover plate; after lubrication, the regulator undergoes manual re-inspection, is affixed with the factory label, placed in a packaging box, and transferred to the storage area.

[0005] In step two, during the MAG welding process between the angle adjustment rack and the lock body ring hook, 100% carbon dioxide is used for shielding. The welding current is controlled between 180A and 220A, the voltage between 20V and 26V, the wire feed speed between 5.5m / min and 6.5m / min, and the welding speed between 0.3m / min and 0.5m / min to ensure uniform weld formation and the absence of porosity and incomplete fusion defects. After welding, a 100% visual inspection is performed. When the first piece is welded, the product dimensions are checked using a gauge according to the drawing requirements. If the dimensions are qualified, the weld of the first piece is cut and sent to a metallographic laboratory for weld penetration measurement to confirm that the penetration depth meets the design requirement of ≥0.3mm. If the first piece is unqualified, the dimensions or process parameters are immediately adjusted until it is qualified before mass production begins.

[0006] In step five, the final step of lock body assembly, an 8.5mm diameter rivet conforming to EN 10083-1 and made of C35 material is inserted into the driven gear mounting hole at the center of the housing and the driven gear of the drive rack. After the gear position is restricted, the protruding 1.5mm end is riveted to a height of 1.5mm, forming the initial fixation of the entire regulator's lock body base plate, lock body cover plate, and internal moving rack components.

[0007] In step seven, during the MAG welding of the regulator housing, 100% carbon dioxide is used as the welding shielding gas, the welding current is 140A-150A, the welding voltage is 16V-18V, the wire feed speed is controlled at 5.5m / min-6m / min, and the welding speed is controlled at 0.5m / min-0.6m / min to ensure uniform weld formation and the absence of porosity and incomplete fusion defects. After welding, a 100% visual inspection is performed. When the first piece is welded, the product dimensions are checked using a gauge according to the drawing requirements. If the dimensions are qualified, the weld of the first piece is cut and sent to a metallographic laboratory for weld penetration measurement to confirm that the penetration depth meets the design requirement of ≥0.2mm. If the first piece is unqualified, the dimensions or process parameters are immediately adjusted until it is qualified before mass production begins.

[0008] The automatic rear seat angle adjuster produced by this production process includes a lock body base plate, a lock body cover plate, and an adjuster lock body mechanism that is movably disposed in the hollow cavity formed between the lock body cover plate and the lock body base plate. The drive part of the adjuster lock body mechanism is connected to the output end of an adjuster drive motor disposed on the lock body base plate. A lock body annular hook is also provided on the side of the adjuster lock body mechanism, and the lock body annular hook extends to the outside of the cover plate through an opening in the cover plate. The upper part of the lock body base plate and the lock body cover plate is provided with an adjuster mounting connection hole for mounting the adjuster on the car body.

[0009] The adjuster locking mechanism includes a seat back drive rack assembly. One end of the seat back drive rack assembly meshes with the drive motor drive gear located at the output end of the adjuster drive motor, and the other end meshes with the driven gear of the drive rack. The seat back drive rack assembly includes an angle adjustment rack, with rack covering shells respectively located on the left and right sides of the angle adjustment rack. The rack covering shells are divided into rack covering shell I and rack covering shell II, and rack covering shell I and rack covering shell II are engaged. The angle-adjusting rack is attached to the outside of the housing, with its teeth protruding from the lower side of the housing. The rack-covered housing I has an annular hook clearance hole, a front lubrication groove on the outer side, and a central hole insertion groove and a housing connection groove on the inner side. The rack-covered housing II has two sets of hook connection clearance holes, a central hole insertion protrusion and a housing connection protrusion on the inner side, and a rear lubrication groove on the outer side.

[0010] The angle adjusting rack includes an adjusting tooth plate, with an arc-shaped adjusting tooth on the lower side of the adjusting tooth plate. The adjusting tooth plate also has an annular hook fixing connection hole, and a tooth plate limiting part is provided at the front of the annular hook fixing connection hole. A casing connection hole for connecting the two side casings is provided between the annular hook fixing connection hole and the arc-shaped adjusting tooth. Stress relief grooves are provided at the four corners of the annular hook fixing connection hole on the adjusting tooth plate.

[0011] On the lock body base plate, at a position corresponding to the seat back drive rack assembly, a rack assembly support rib is provided. Below the rack assembly support rib, there are respectively a drive gear insertion hole and a driven gear mounting hole, and around the drive gear insertion hole, there are several drive motor fixing holes. A lock body rear oil injection hole is also provided between the rack assembly support rib and the driven gear mounting hole. On the lock body cover plate, at a position corresponding to the lock body annular hook, an annular hook movement avoidance opening is provided. Below the annular hook movement avoidance opening, there are respectively a drive gear mounting hole and a driven gear mounting hole. A lock body front oil injection hole is provided between the annular hook movement avoidance opening and the driven gear mounting hole. Furthermore, a rack assembly contour limiting boss is also provided above the annular hook movement avoidance opening.

[0012] The lock body ring hook has a hook hole in the middle, and a backrest lock abutment is provided on one side of the hook hole. The width of the backrest lock abutment is smaller than the width of the other side of the hook hole. The end of the lock body ring hook is provided with a ring hook fixing foot for connecting to the side of the adjuster lock body mechanism. Furthermore, the overall shape of the lock body ring hook is adapted to the overall curvature of the arc-shaped adjusting tooth on the lower side of the angle adjusting rack.

[0013] The beneficial effects of this invention are as follows: The production process of this automatic rear seat angle adjuster optimizes the structural design and process path, and adopts a new process of welding first and then electrophoresis, which ensures that the weld area is completely covered with a protective coating while reducing the production cost of enterprises; moreover, the angle adjuster integrates a micro drive motor and a precision gear transmission mechanism, which can realize stepless electric adjustment and memory function, greatly improving the ease of operation and riding comfort. Attached Figure Description

[0014] Figure 1 This is a flowchart of the production process of the present invention.

[0015] Figure 2 This is a schematic diagram of a rear seat angle automatic adjuster produced by the method of the present invention.

[0016] Figure 3 yes Figure 2 A schematic diagram of the internal structure (lock body cover removed).

[0017] Figure 4 yes Figure 3 A schematic diagram of a lock body base plate.

[0018] Figure 5 yes Figure 3 A schematic diagram of a split structure of the seat back drive rack assembly.

[0019] Figure 6 yes Figure 3 A schematic diagram of a lock body ring hook structure.

[0020] Figure 7 yes Figure 5 A schematic diagram of a rack-and-tooth shell I.

[0021] Figure 8 yes Figure 5 A schematic diagram of a rack-and-tooth shell II structure.

[0022] Explanation of the numbers in the diagram: 1. Lock body base plate; 2. Lock body cover plate; 3. Adjuster lock body mechanism; 4. Lock body ring hook; 5. Adjuster drive motor; 6. Adjuster mounting connection hole; 7. Adjuster mounting anti-misalignment positioning slot; 8. Seat back drive rack assembly; 9. Drive motor drive gear; 10. Drive rack driven gear; 11. Rack assembly contouring limit boss; 12. Ring hook movement avoidance opening; 13. Drive gear mounting hole; 14. Driven gear mounting hole; 15. Lock body front side oil injection hole; 16. Cover plate positioning insertion bend; 17. Rack assembly support rib; 18. Drive motor fixing hole; 19. Drive gear insertion large hole. 20. Cover plate positioning insertion hole; 21. Lock body rear side oil injection hole; 22. Angle adjustment rack; 23. Rack covering housing I; 24. Rack covering housing II; 25. Adjustment rack; 26. Arc-shaped adjustment rack; 27. Rack limiting part; 28. Cover housing connecting center hole; 29. ​​Ring hook fixing connection hole; 30. Ring hook clearance hole; 31. Front side oil injection lubrication groove; 32. Center hole insertion protrusion; 33. Housing connecting protrusion; 34. Hook connection position clearance hole; 35. Hook hole; 36. Backrest lock hanging part; 37. Ring hook fixing support foot; 38. Center hole insertion groove; 39. Housing connecting groove; 40. Rear side oil injection lubrication groove. Detailed Implementation

[0023] The specific steps of this invention are described in detail. The production process of this automatic rear seat angle adjuster includes: Step 1: Stamping and heat treatment of the rack and hook.

[0024] The angle adjusting rack 22 is made of 42CrMo4 material, and is designed and stamped according to the drawings. It is then heat-treated to meet the hardness requirements of 342 HV10~403 HV10. The lock body ring hook 4 is made of S550MC material, and is stamped according to the drawings.

[0025] Step 2: The angle adjustment rack 22 is welded to the lock body ring hook 4 using MAG welding.

[0026] At the welding station, the angle adjustment rack 22 and the lock body ring hook 4 are accurately assembled. MAG welding process is used at the weld position required by the drawing. The weld length and penetration depth are strictly controlled according to the process card.

[0027] Welding shielding gas uses 100% carbon dioxide. Welding current is controlled between 180A and 220A, voltage between 20V and 26V, wire feed speed between 5.5m / min and 6.5m / min, and welding speed between 0.3m / min and 0.5m / min to ensure uniform weld formation and the absence of porosity and incomplete fusion defects. A 100% visual inspection is performed after welding. Upon completion of the first piece, the dimensions are checked using a gauge according to the drawings. If the dimensions are acceptable, the first weld is cut and sent to a metallographic laboratory for weld penetration measurement to confirm that the penetration meets the design requirement of ≥0.3mm. If the first piece fails to meet the requirements, the dimensions or process parameters are immediately adjusted until acceptable before proceeding with mass production.

[0028] Step 3: Electroplating anti-corrosion treatment of the rack and pinion welded parts.

[0029] The angle adjusting rack 22 and lock body ring hook 4, welded together, are transferred to the electroplating station and hung on a rack using U-shaped hooks to prevent them from falling off. The angle adjusting rack 22 is first chemically degreased by spraying, then electrolytically degreased to remove surface oil. Next, the angle adjusting rack 22 is immersed in a weak acid bath with a sulfuric acid volume ratio of 3%–5% for 15–25 seconds for activation treatment to remove the passivation oxide film on the rack surface. Afterward, the angle adjusting rack 22 is placed in an ultrasonic water washing tank with a pure water medium and a vibration frequency of 35 kHz for washing to remove residual acid and impurities from the rack's crevices and edges.

[0030] The angle adjusting rack 22 is placed in an electroplating tank for electroplating to form a uniform zinc plating layer on the surface of the rack. After that, it is washed with water and ultrasonically washed to remove residual plating solution. Then, the electroplated angle adjusting rack 22 is subjected to blue-white passivation to improve its corrosion resistance, and then washed with water again. After that, the rack is put into a hot air oven for drying at a temperature of 70℃~90℃ for 25 minutes. After the rack cools down, it is hung up for inspection and then stored in the warehouse.

[0031] Step four: Machining of the regulator housing, transmission gear, and rack housing.

[0032] The regulator housing stamping is made of S550MC material. It is designed and stamped according to the drawing requirements. It is divided into two types of housing stamping parts: lock body base plate 1 and lock body cover plate 2. The lock body base plate 1 is a flat plate design with mounting holes for subsequent motor installation and bolt holes for fixing the motor on the flat surface. The lock body cover plate 2 is a concave design, which is inverted on the lock body base plate 1 to form a cavity structure.

[0033] The transmission gear is made of CW713R high-strength wear-resistant brass. It is precision machined to a machining accuracy of less than 0.1mm and is assembled in the cavity formed by the lock body base plate 1 and the lock body cover plate 2, providing driven support for the reciprocating motion of the angle adjustment rack 22.

[0034] The rack housing is designed to adjust the shape of the rack 22 according to the angle, so as to wrap the rack in the cavity formed by the lock body base plate 1 and the lock body cover plate 2, to prevent the rack and the adjuster housing from direct metal contact and generating resonance noise, and to reduce metal wear. The rack housing is made of PA66 GF30 material, which can withstand high temperature of 245℃, has good dimensional stability, and is not easy to deform or warp.

[0035] Step 5: Assemble the lock body.

[0036] First, the two rack housings are snapped together and assembled onto the outside of the galvanized rack welded parts, using the rack housings to enclose the angle adjustment rack 22. The assembled seat back drive rack assembly 8 is then placed into the inverted lock body cover plate 2. Next, 0.2g of grease is injected into the transmission gear and placed at the tail end of the angle adjustment rack 22. After that, the lock body base plate 1 is covered, so that the lock body base plate 1 and the lock body cover plate 2 form a cavity, with the rack and transmission gear located inside the cavity. The two protruding cover plate positioning insertion elbows 16 of the lock body cover plate 2 extend from the cover plate positioning insertion holes 20 on the edge of the lock body base plate 1.

[0037] Finally, a rivet with a diameter of 8.5 mm and conforming to the standard EN 10083-1 and made of C35 material is inserted into the driven gear mounting hole 14 in the center of the housing and the driven gear 10 of the drive rack. After the position of the gear is restricted, the protruding 1.5 mm end is riveted to a height of 1.5 mm, thus forming the initial fixation of the entire regulator's lock body base plate 1, lock body cover plate 2 and internal moving rack components.

[0038] Step six: Reinforce the edges of the shell connection area by folding.

[0039] The pre-assembled regulator lock body is placed on the bending machine, with the two protruding cover plate positioning and insertion elbows 16 at the edge connection of the lock body base plate 1 and the lock body cover plate 2 facing upwards. The bending machine is started, and the bending machine pressure head presses down, bending the two exposed cover plate positioning and insertion elbows 16 in opposite directions to 90°, further fixing the housing on both sides of the lock body.

[0040] Step 7: MAG welding of the regulator housing.

[0041] Place the adjusted lock body with folded edges on the welding fixture and perform MAG welding along the weld seam position required by the drawing.

[0042] The welding shielding gas used is 100% carbon dioxide. The welding current is 140A-150A, the welding voltage is 16V-18V, the wire feed speed is controlled at 5.5m / min-6m / min, and the welding speed is controlled at 0.5m / min-0.6m / min to ensure uniform weld formation and the absence of porosity and incomplete fusion defects. A 100% visual inspection is performed after welding. When the first piece is welded, the dimensions are checked using a gauge according to the drawing requirements. If the dimensions are acceptable, the weld of the first piece is cut and sent to a metallographic laboratory for weld penetration measurement to confirm that the penetration depth meets the design requirement of ≥0.2mm. If the first piece fails to meet the requirements, the dimensions or process parameters are immediately adjusted until it meets the requirements before mass production begins.

[0043] Step 8: Overall electrophoretic corrosion protection treatment of the regulator lock body.

[0044] The welded regulator lock body is transferred to the electrophoresis line and hung on a rack. First, the regulator lock body undergoes chemical degreasing in a spray line to remove grease. Then, it enters a phosphating tank to form a uniform phosphating film on the surface. Afterward, it is cleaned again to remove acidic impurities. Next, it is placed in an electrophoresis tank to coat the surface with a coating. Finally, the electrophoretically coated regulator lock body is washed and dried in a high-temperature curing oven at a controlled temperature of 160℃–190℃ to prevent deformation of the internal rack housing.

[0045] After inspection, the electrophoretic regulator lock body is transferred to the next workstation.

[0046] Step nine: Assemble the drive motor.

[0047] The adjuster drive motor 5, which drives the reciprocating motion of the angle adjustment rack 22, is mounted on the adjuster lock body through the drive motor mounting hole 18 provided on the lock body base plate 1, and is fixed with three M5×16 standard bolts conforming to DIN ISO 8992. The drive motor can be a BOSCH AHC 12V model motor, with a rated voltage of 12V, a speed range of 8.4RPM to 12.6RPM, and a maximum torque of 54.7Nm. It is a widely used motor model in the automotive industry, with a high market share and strong stability.

[0048] Step 10: Noise detection.

[0049] After the regulator is assembled with the drive motor, it is transported to a soundproof room. A 12V voltage is connected to the regulator drive motor 5, and the decibel level of the regulator is measured using a decibel meter at a distance of 20cm. When the locking ring hook 4 on the side of the angle adjustment rack 22 moves from its left limit position to its right limit position, the sound decibel level must not exceed 55dB, the movement time must not exceed 5 seconds, and the input current under no-load conditions must not exceed 4A.

[0050] All regulators must be tested and pass the test before they can proceed to the next process.

[0051] Step 11: Add grease in measured quantities and perform final inspection and packaging.

[0052] Apply a measured amount of grease to the locations specified in the regulator drawing using a metering valve. 0.2g of grease needs to be injected at the contact point between the angle adjusting rack 22 and the drive motor's driving gear 9; 0.2g of grease needs to be injected at the contact point between the angle adjusting rack 22 and the drive rack's driven gear 10; and 0.2g of grease needs to be injected at the contact points between the rack housing and the lock body base plate 1 and lock body cover plate 2. Furthermore, 0.2g of grease needs to be injected into each of the four pre-drilled oil injection holes on the lock body base plate 1 and lock body cover plate 2. Castrol Optleb GR UF 00 grease can be used, as it has good flow properties, allows for smooth penetration into the gear meshing gap, has good high and low temperature stability, and a long service life.

[0053] After lubrication, the regulator is manually inspected, affixed with the factory label, placed in a box, and transferred to the storage area.

[0054] Furthermore, the automatic rear seat angle adjuster produced by this production process includes a lock body base plate 1, a lock body cover plate 2 covering the lock body base plate 1, and a hollow cavity formed between the lock body cover plate 2 and the lock body base plate 1; an adjuster lock body mechanism 3 is also movably disposed in the hollow cavity between the lock body cover plate 2 and the lock body base plate 1. The adjuster lock body mechanism 3 includes a seat back drive rack assembly 8, one end (drive part) of the seat back drive rack assembly 8 meshes with the drive motor drive gear 9 provided at the output end of the adjuster drive motor 5, and the adjuster drive motor 5 is fixed on the lock body base plate 1; and the other end of the seat back drive rack assembly 8 meshes with the drive rack driven gear 10. Then, the adjuster drive motor 5 drives the drive motor drive gear 9 to rotate, so that the rack assembly can be driven to perform arc-shaped reciprocating motion through the meshing transmission between the drive motor drive gear 9 and one end of the seat back drive rack assembly 8. Meanwhile, the structure in which the other end of the seat back drive rack assembly 8 meshes with the driven gear 10 of the drive rack can limit and constrain the rack assembly by relying on the double meshing of the driving and driven gears, effectively preventing the rack assembly from moving during the movement process, ensuring smooth transmission, and thus driving the seat back to complete the angle adjustment.

[0055] On the lock body base plate 1, at a position corresponding to the seat back drive rack assembly 8, a rack assembly support rib 17 is provided. Below the rack assembly support rib 17, there are a large insertion hole 19 for the drive gear and a driven gear mounting hole 14. Furthermore, several drive motor mounting holes 18 are provided around the large insertion hole 19 for the drive gear. The housing of the adjuster drive motor 5 is connected to the drive motor mounting holes 18 on the lock body base plate 1 by fixing bolts. Two sets of rear-side oil injection holes 21 are also provided between the rack assembly support rib 17 and the driven gear mounting holes 14. Thus, the rack assembly support rib 17 supports the side of the seat back drive rack assembly 8, reducing friction during rack assembly movement and increasing the strength of the housing. The drive motor's driving gear 9 extends into the hollow cavity via the driving gear insertion hole 19 and meshes with the rack assembly. The drive motor fixing hole 18 on the lock body base plate 1 is used to mount and fix the adjuster drive motor 5, while the driven gear mounting hole 14 on the lock body base plate 1 is used to mount the driven gear 10 of the drive rack. At the same time, lubricating grease can be added to the side of the seat back drive rack assembly 8 near the lock body base plate 1 through the oil injection hole 21 on the rear side of the lock body, thereby reducing transmission noise and ensuring the smoothness and reliability of the rack assembly's reciprocating motion.

[0056] The seat back drive rack assembly 8 of the adjuster lock mechanism 3 is also provided with a lock body annular hook 4 on its side. The lock body annular hook 4 has a hook hole 35 in the middle. A backrest lock abutment 36 is provided on one side of the hook hole 35. The width of the backrest lock abutment 36 is smaller than the width of the other side of the hook hole 35. The end of the lock body annular hook 4 is provided with an annular hook fixing support 37 for connecting with the annular hook fixing connection hole 29 on the angle adjustment rack 22 of the seat back drive rack assembly 8. At the same time, the overall shape of the lock body annular hook 4 is adapted to the overall curvature of the arc-shaped adjustment tooth 26 on the lower side of the angle adjustment rack 22. Then, the annular hook fixing support 37 is inserted into the annular hook fixing connection hole 29 of the angle adjustment rack 22, so that the lock body annular hook 4 is assembled on the angle adjustment rack 22. The overall curvature of the lock body annular hook 4 matches the curvature of the arc adjustment tooth 26, so that the lock body annular hook 4 can follow the synchronous arc movement of the angle adjustment rack 22. The hook hole 35 of the lock body annular hook 4 completes the cooperation and traction with the seat lock, thereby driving the backrest to achieve angle adjustment. In addition, the difference in width between the backrest lock hooking part 36 on one side of the hook hole 35 and the width on the other side of the hook hole 35 is to prevent the seat backrest lock buckle from being hooked in the wrong position.

[0057] On the lock body cover plate 2, at a position corresponding to the lock body annular hook 4, an annular hook movement avoidance opening 12 is provided, through which the lock body annular hook 4 extends to the outside of the cover plate. Furthermore, on the lock body cover plate 2, below the annular hook movement avoidance opening 12, a drive gear mounting hole 13 and a driven gear mounting hole 14 are respectively provided; two sets of lock body front oil injection holes 15 are provided between the annular hook movement avoidance opening 12 and the driven gear mounting hole 14. Above the annular hook movement avoidance opening 12, a rack assembly contour-guided limiting boss 11 is also provided. Thus, the lock body annular hook 4, connected to the side of the seat back drive rack assembly 8, extends outward through the annular hook movement avoidance opening 12 on the lock body cover plate 2 and reciprocates with the rack assembly. The drive gear mounting hole 13 and the driven gear mounting hole 14 on the lock body cover plate 2 are respectively assembled with the end structure of the corresponding gear shaft. Furthermore, lubricating grease is applied to the seat back drive rack assembly 8 near the lock body cover plate 2 via the oil injection hole 15 on the front side of the lock body, thereby reducing friction noise. In addition, the rack assembly contour limiting boss 11 provided on the lock body cover plate 2 can limit the range of motion of the rack assembly reciprocating and improve the structural strength of the lock body cover plate 2.

[0058] The lower connecting parts of the lock body base plate 1 and the lock body cover plate 2 are respectively provided with matching cover plate positioning insertion holes 20 and cover plate positioning insertion elbows 16 to facilitate the positioning connection of the lock body base plate 1 and the lock body cover plate 2. In addition, the upper part of the lock body base plate 1 and the lock body cover plate 2 is provided with two sets of adjuster mounting connection holes 6 for mounting the entire rear seat back angle automatic adjuster on the vehicle body; and an adjuster mounting anti-misalignment positioning groove 7 is provided between the two sets of adjuster mounting connection holes 6.

[0059] The seat back drive rack assembly 8 includes an angle-adjusting rack 22. Rack-covering housings are respectively provided on the left and right sides of the angle-adjusting rack 22. The rack-covering housings are divided into rack-covering housing I 23 and rack-covering housing II 24. Rack-covering housing I 23 and rack-covering housing II 24 are engaged with the outside of the angle-adjusting rack 22, with the teeth of the angle-adjusting rack 22 protruding from the lower side of the housings. Furthermore, rack-covering housing I 23 and rack-covering housing II 24 are fastened and wrapped around the outside of the angle-adjusting rack 22, allowing the teeth on the lower side of the angle-adjusting rack 22 to protrude from the bottom for meshing with the drive motor drive gear 9 and the drive rack driven gear 10. Therefore, by using the rack housing on both sides, the direct contact between the angle adjustment rack 22 and the metal lock body base plate 1 and lock body cover plate 2 on both sides is isolated, so as to buffer and dampen the impact and eliminate collision noise during the movement of the rack assembly 8 driven by the seat back, and at the same time, it has a self-lubricating effect, making the transmission of the rack assembly smoother.

[0060] The rack housing I 23, which surrounds the angle adjustment rack 22, has an annular hook clearance hole 30. The outer side of the rack housing I 23 has a front lubrication groove 31 that mates with the front oiling hole 15 of the lock body. The inner side of the rack housing I 23 has a central hole insertion groove 38 and a housing connection groove 39. Correspondingly, the rack housing II 24 has two sets of hook connection clearance holes 34. The inner side of the rack housing II 24 has a central hole insertion protrusion 32 and a housing connection protrusion 33. The outer side of the rack housing II 24 has a rear lubrication groove 40 that mates with the rear oiling hole 21 of the lock body. Depending on the application, the rack housing I 23 and rack housing II 24 can be made of hard plastic or similar materials, such as PA66 GF30 double hexagonal nylon (containing 30% glass fiber). Thus, the rack housing I 23 and rack housing II 24 are securely wrapped around the angle-adjusting rack 22 by the mating insertion groove 38 on the inner side of the rack housing I 23 and the mating protrusion 32 on the inner side of the rack housing II 24 within the connecting hole 28 of the housing of the angle-adjusting rack 22, and by the mutual engagement of the corresponding housing connecting protrusion 33 and housing connecting groove 39 on the two rack housings. Furthermore, the annular hook clearance hole 30 and hook connection position clearance hole 34 on the rack housing provide space for the connection and arrangement of the lock body annular hook 4. Simultaneously, the front lubrication groove 31 and rear lubrication groove 40 on the outer sides of the rack housing I 23 and rack housing II 24 respectively can store lubricating oil to continuously lubricate the seat back drive rack assembly 8, reduce friction noise, and ensure smooth transmission.

[0061] The angle adjusting rack 22 is composed of an adjusting rack 25. An arc-shaped adjusting tooth 26 is provided on the lower side of the adjusting rack 25. An annular hook fixing connection hole 29 is also provided on the adjusting rack 25, and a rack limiting part 27 is provided at the front of the annular hook fixing connection hole 29. A housing connection hole 28 for connecting the two side housings is provided between the annular hook fixing connection hole 29 and the arc-shaped adjusting tooth 26. Furthermore, the reciprocating arc-shaped motion is achieved by the meshing transmission between the arc-shaped adjusting tooth 26 on the lower side of the adjusting rack 25 and the drive gear 9 of the drive motor and the driven gear 10 of the drive rack. The fixing foot at the end of the lock body annular hook 4 is assembled at the annular hook fixing connection hole 29 of the adjusting rack 25 and fixed by welding. After welding into a whole, the part of the fixing foot of the lock body annular hook 4 protruding from the adjusting rack 25 is riveted to form a fixing riveting point. Meanwhile, the tooth plate limiting part 27 at the front of the adjusting tooth plate 25, together with the tooth assembly contour limiting boss 11 on the lock body cover plate 2 and other lock body structures, limits the maximum stroke of the angle adjusting tooth rack 22, thereby controlling the backrest adjustment angle. Furthermore, the tooth rack covering shells I 23 and II 24 on both sides are inserted and secured at the covering shell connecting hole 28 in the middle of the adjusting tooth plate 25, achieving overall enclosure of the angle adjusting tooth rack 22, providing buffering and noise reduction. Stress relief grooves are provided at the four corners of the annular hook fixing connection hole 29 on the adjusting tooth plate 25; these grooves disperse the stress generated during the stamping and forming process of the adjusting tooth plate 25, preventing cracking at the hole corners and improving the forming yield and structural strength of the angle adjusting tooth rack 22.

Claims

1. A production process for an automatic rear seat angle adjuster, characterized in that, Includes the following steps: Step 1: Stamping and heat treatment of the rack and hook; The angle adjustment rack is made of 42CrMo4 material, and is designed and stamped according to the drawings. It is then heat-treated to meet the hardness requirements of 342 HV10~403 HV10. The lock body ring hook is made of S550MC material, and is stamped according to the drawings. Step 2: The angle adjustment rack and the lock body ring hook are welded together using MAG. At the welding station, the angle adjustment rack and the lock body ring hook are accurately assembled. MAG welding process is used at the weld position required by the drawing. The weld length and penetration depth are strictly controlled according to the process card. Step 3: Electroplating anti-corrosion treatment of the rack and pinion welded parts; The welded angle adjusting rack and lock body ring hook are transferred to the electroplating station and hung on a rack using U-shaped hooks to prevent them from falling off. The angle adjusting rack is first chemically degreased by spraying, and then electrolytically degreased to remove surface oil. Next, the angle adjusting rack is immersed in a weak acid bath with a sulfuric acid volume ratio of 3% to 5% for 15 to 25 seconds for activation treatment to remove the passivation oxide film on the rack surface. Afterward, the angle adjusting rack is placed in an ultrasonic water washing tank with pure water as the medium and a vibration frequency of 35KHz. The process involves washing the rack with water to remove residual acid and impurities from the gaps and edges. The angle-adjusting rack is then placed in an electroplating tank for electroplating to form a uniform zinc coating. Afterward, it undergoes water washing and ultrasonic washing to remove any remaining plating solution. Subsequently, the electroplated angle-adjusting rack undergoes blue-white passivation to enhance its corrosion resistance, followed by another water wash. The rack is then dried in a hot air oven at 70℃~90℃ for 25 minutes. After cooling, the rack is hung for inspection and then stored in the warehouse. Step 4: Machining of the regulator housing, transmission gear, and rack housing; The regulator housing stamping parts are made of S550MC material. They are designed and stamped according to the drawings. They are divided into two types of housing stamping parts: lock body base plate and lock body cover plate. The lock body base plate is a flat plate design with mounting holes for the motor and bolt holes for fixing the motor. The lock body cover plate is a concave design and is inverted on the lock body base plate to form a cavity structure. The transmission gear is made of CW713R high-strength wear-resistant brass. It is precision machined to a machining accuracy of less than 0.1mm and is assembled in the cavity formed by the lock body base plate and the lock body cover plate, providing driven support for the reciprocating motion of the angle adjustment rack. The rack housing is designed to adjust the shape of the rack according to the angle, so as to wrap the rack in the cavity formed by the lock body base plate and the lock body cover plate, to prevent the rack and the adjuster housing from direct metal contact and generating resonance noise, and to reduce metal wear; Step 5: Assemble the lock body; First, fasten the two rack housings onto the outside of the galvanized rack welded parts, using the rack housings to enclose the angle adjustment rack. Place the assembled seat back drive rack assembly into the inverted lock body cover plate. Then, inject 0.2g of grease into the transmission gear and place it at the tail end of the angle adjustment rack. After that, cover the lock body base plate, so that the lock body base plate and the lock body cover plate form a cavity. The rack and the transmission gear are both located in the cavity. The two protruding cover plate positioning insertion elbows of the lock body cover plate extend from the cover plate positioning insertion holes on the edge of the lock body base plate. Step Six: Reinforce the edges of the shell connection points by folding them together; Place the pre-assembled regulator lock body on the bending machine with the two protruding cover plate positioning and insertion elbows at the edge connection of the lock body base plate and the lock body cover plate facing upwards. Start the bending machine and press down the bending machine head to bend the two exposed cover plate positioning and insertion elbows in opposite directions to 90°, further fixing the shells on both sides of the lock body. Step 7: MAG welding of the regulator housing; Place the adjusted lock body with folded edges on the welding fixture and perform MAG welding along the weld seam position required by the drawing; Step 8: Overall electrophoretic corrosion protection treatment of the regulator lock body; The welded regulator lock body is transferred to the electrophoresis line and hung on a rack. First, the regulator lock body undergoes chemical degreasing in a spray line to remove grease. Then, it enters a phosphating tank to form a uniform phosphating film on the surface of the regulator lock body. After cleaning, it is cleaned again to remove acidic impurities. Finally, it is placed in an electrophoresis tank for electrophoresis to coat the surface of the regulator lock body. Subsequently, the electrophoretic parts of the regulator lock body after washing are placed in a high-temperature curing oven for drying. The drying temperature needs to be controlled between 160℃ and 190℃ to avoid deformation of the rack and shell inside the regulator lock body. After inspection, the electrophoretic regulator lock body is transferred to the next station. Step 9: Assemble the drive motor; The regulator drive motor, which is used to drive the reciprocating motion of the angle adjustment rack, is installed on the regulator lock body through the drive motor fixing hole provided on the lock body base plate; Step 10: Noise detection; After the regulator is assembled with the drive motor, it is transported to a quiet room. A 12V voltage is connected to the regulator drive motor, and the decibel value of the regulator is measured using a decibel meter at a distance of 20cm. When the ring hook on the side of the angle adjustment rack moves from the left limit position to the right limit position, the sound decibel value must not exceed 55dB, the movement time must not exceed 5 seconds, and the input current under no-load conditions must not exceed 4A. All regulators must be tested, and only those that pass the test can proceed to the next process. Step 11: Quantitative addition of lubricating grease and final inspection and packaging; Apply a measured amount of oil at the location specified in the regulator drawing using the metering valve; 0.2g of grease needs to be injected at the contact point between the angle adjustment rack and the drive motor's drive gear; 0.2g of grease needs to be injected at the contact point between the angle adjustment rack and the driven gear of the drive rack; 0.2g of grease needs to be injected at the contact points between the rack housing and the lock body base plate and lock body cover plate; and 0.2g of grease needs to be injected into each of the four pre-drilled oil injection holes on the lock body base plate and lock body cover plate; after lubrication, the regulator is manually inspected, affixed with the factory markings, placed in a packaging box, and transferred to the storage area.

2. The production process of the automatic rear seat angle adjuster according to claim 1, characterized in that: In step two, during the welding process of the angle adjustment rack and the lock body ring hook MAG, 100% carbon dioxide is used for welding protection gas. The welding current is controlled at 180A to 220A, the voltage is controlled at 20V to 26V, the welding wire feeding speed is controlled at 5.5m / min to 6.5m / min, and the welding speed is controlled at 0.3m / min to 0.5m / min to ensure that the weld is uniform and free from porosity and incomplete fusion defects. After welding is completed, a 100% visual inspection is carried out. When the first piece is welded, the product dimensions are checked using a gauge according to the drawing requirements. If the dimensions are qualified, the weld of the first piece is cut and sent to a metallographic laboratory for weld penetration measurement to confirm that the penetration meets the design requirement of ≥0.3mm. If the first piece is unqualified, the dimensions or process parameters are adjusted immediately until it is qualified before mass production begins.

3. The production process of the automatic rear seat angle adjuster according to claim 1, characterized in that: In step five, the final step of lock body assembly, an 8.5mm diameter rivet conforming to EN 10083-1 and made of C35 material is inserted into the driven gear mounting hole at the center of the housing and the driven gear of the drive rack. After the gear position is restricted, the protruding 1.5mm end is riveted to a height of 1.5mm, forming the initial fixation of the entire regulator's lock body base plate, lock body cover plate, and internal moving rack components.

4. The production process of the automatic rear seat angle adjuster according to claim 1, characterized in that: In step seven, during the MAG welding process of the regulator housing, the welding shielding gas is 100% carbon dioxide, the welding current is 140A to 150A, the welding voltage is 16V to 18V, the wire feeding speed is controlled at 5.5m / min to 6m / min, and the welding speed is controlled at 0.5m / min to 0.6m / min to ensure that the weld is uniformly formed and free from porosity and incomplete fusion defects. After welding is completed, a 100% visual inspection is carried out. When the first piece is welded, the product dimensions are checked using a gauge according to the drawing requirements. If the dimensions are qualified, the weld of the first piece is cut and sent to a metallographic laboratory for weld penetration measurement to confirm that the penetration meets the design requirement of ≥0.2mm. If the first piece is unqualified, the dimensions or process parameters are adjusted immediately until it is qualified before mass production begins.

5. The automatic rear seat angle adjuster produced according to the production process of the automatic rear seat angle adjuster as described in claim 1, characterized in that: The device includes a lock body base plate, on which a lock body cover plate is provided. An adjuster lock body mechanism is movably disposed within a hollow cavity formed between the lock body cover plate and the lock body base plate. The drive unit of the adjuster lock body mechanism is connected to the output end of an adjuster drive motor disposed on the lock body base plate. A lock body annular hook is also provided on the side of the adjuster lock body mechanism. The lock body annular hook extends to the outside of the cover plate through an opening in the cover plate. An adjuster mounting connection hole for mounting the adjuster on the vehicle body is provided on the upper part of the lock body base plate and the lock body cover plate.

6. The automatic rear seat angle adjuster according to claim 5, characterized in that: The regulator locking mechanism includes a seat back drive rack assembly. One end of the seat back drive rack assembly meshes with the drive motor drive gear located at the output end of the regulator drive motor, and the other end of the seat back drive rack assembly meshes with the drive rack driven gear. The seat back drive rack assembly includes an angle adjustment rack. Rack housings are provided on both the left and right sides of the angle adjustment rack. Each rack housing is divided into rack housing I and rack housing II. Rack housing I and rack housing II are engaged with the outside of the angle adjustment rack, with the teeth of the angle adjustment rack protruding from the lower side of the housing. Rack housing I has an annular hook clearance hole, a front lubrication groove on its outer side, and a central hole insertion groove and a housing connection groove on its inner side. Rack housing II has two sets of hook connection clearance holes, a central hole insertion protrusion and a housing connection protrusion on its inner side, and a rear lubrication groove on its outer side.

7. The automatic rear seat angle adjuster according to claim 6, characterized in that: The angle adjusting rack includes an adjusting tooth plate, with an arc-shaped adjusting tooth on the lower side of the adjusting tooth plate. The adjusting tooth plate also has an annular hook fixing connection hole, and a tooth plate limiting part is provided at the front of the annular hook fixing connection hole. A casing connection hole for connecting the two side casings is provided between the annular hook fixing connection hole and the arc-shaped adjusting tooth. Stress relief grooves are provided at the four corners of the annular hook fixing connection hole on the adjusting tooth plate.

8. The automatic rear seat angle adjuster according to claim 5, characterized in that: On the lock body base plate, at a position corresponding to the seat back drive rack assembly, a rack assembly support rib is provided. Below the rack assembly support rib, there are respectively a drive gear insertion hole and a driven gear mounting hole, and around the drive gear insertion hole, there are several drive motor fixing holes. A lock body rear oil injection hole is also provided between the rack assembly support rib and the driven gear mounting hole. On the lock body cover plate, at a position corresponding to the lock body annular hook, an annular hook movement avoidance opening is provided. Below the annular hook movement avoidance opening, there are respectively a drive gear mounting hole and a driven gear mounting hole. A lock body front oil injection hole is provided between the annular hook movement avoidance opening and the driven gear mounting hole. Furthermore, a rack assembly contour limiting boss is also provided above the annular hook movement avoidance opening.

9. The automatic rear seat angle adjuster according to claim 5, characterized in that: The lock body ring hook has a hook hole in the middle, and a backrest lock abutment is provided on one side of the hook hole. The width of the backrest lock abutment is smaller than the width of the other side of the hook hole. The end of the lock body ring hook is provided with a ring hook fixing foot for connecting to the side of the adjuster lock body mechanism. Furthermore, the overall shape of the lock body ring hook is adapted to the overall curvature of the arc-shaped adjusting tooth on the lower side of the angle adjusting rack.

Images