Design process of high-strength and fracture-resistant car seat slide rail arch bracket mold

Abstract

The present invention discloses a high-strength and fracture-resistant automobile seat slide arch bracket mold design process, which includes using a progressive die to continuously stamp and punch a material strip to form the automobile seat slide arch bracket; the progressive die includes an upper die and a lower die, the upper die includes an upper positioning plate, a plurality of upper pads, an upper template, an upper pad, an upper fixed plate and an upper unloading plate arranged in sequence from top to bottom, and the lower die includes a lower positioning plate, a plurality of lower pads, a lower pad and a lower template arranged in sequence from bottom to top; a lower die insert is provided in clearance fit on the lower template, and an upper unloading plate insert is provided in clearance fit on the upper unloading plate. The present invention fundamentally solves the problem of the firmness of the connection between the arch bracket and the automobile seat slide rail, and avoids the problem that the seat bracket is not firmly fixed, causing it to be subjected to random alternating loads, thereby leading to fatigue fracture failure. The present invention uses a mold forming process and an insert clearance fit to prevent the arch bracket from breaking during continuous stamping.

Description

Technical Field

[0001] The invention relates to a design process for a high-strength, fracture-resistant automobile seat slide rail bow-shaped bracket mold. Background Art

[0002] The seat rail, which connects the seat to the vehicle body and adjusts its fore-aft position, is prone to fracture at its corners, and other areas also experience cracking and damage (similar fractures have also been observed at the bolted connection between the seat rail and the bow bracket). The components on the bracket are all made of SPCC steel (equivalent to 08 steel) with a composition range (wt%) of 0.05-0.12C, 0.35-0.65Mn, and 0.17-0.37Si. This material has low strength but high ductility and toughness, offering excellent stamping, drawing, bending, and welding properties. After stamping, the surface was bluing treated at 180°C for 40 minutes. (Bluing is a material protection technique in which steel is heated in air or immersed directly in a concentrated oxidizing solution to produce an extremely thin oxide film on the surface, also known as blackening. The principle is to create an oxide film on the metal surface that isolates the metal from air and prevents rust.) Analysis revealed that the seat slide failed due to fatigue fracture caused by random alternating loads. The failure mode was fatigue fracture, caused by a loose seat bracket, which exposed it to random alternating loads, leading to fatigue failure. See "Fracture Analysis of the BJ2021 Automobile Seat Slide" by Zhao Aiguo of the Beijing Institute of Aeronautical Materials, published in the journal Materials Engineering (No. 1999). The current solution to this problem is to regularly check the screw holes for tightness and tighten them immediately if they become loose. Additionally, the bolt hole spacing on the slide should be designed to match that on the base as closely as possible. However, this approach requires regular inspection and fundamentally resolves the problem.

[0003] Furthermore, the arched brackets for automotive seat rails are prone to breakage during the continuous stamping process. Designing the progressive stamping die, specifically the progressive die for these brackets, to prevent breakage during the process is another challenge in this field. Patent Publication No. CN203061682U discloses a progressive die mechanism comprising an upper die base, a lower die base, guide pins, guide sleeves, screws, a punch fixing plate, a discharge pad, a spring, a guide pin, a punching punch, a bending die insert, a stop pin, a float block, a gasket, a push rod, a washer, an inner guide pin, an inner guide sleeve, a push block, a receiving plate, an adjustment rod, a sleeve, and a stop sleeve. The guide pins and sleeves are guided by eight inner and outer guide pins and guide sleeves, all using ball bearing guides. The guide pins and sleeves are secured by adhesive, minimizing the accumulation of part machining errors and improving the accuracy of the die's guidance and positioning. The main working parts are designed as small inserts to avoid the problem of rapid wear of the mold working parts due to high-speed stamping. Summary of the Invention

[0004] The present invention aims to overcome the shortcomings of the prior art by providing a high-strength, fracture-resistant mold design process for the arch bracket of an automobile seat slide rail. By tapping threaded holes of the same rotation direction on both sides of the material strip (i.e., the front and back sides of the final arch bracket), or tapping threaded holes of different rotation directions on one side of the arch bracket, the present invention fundamentally improves the secure connection between the arch bracket and the automobile seat slide rail, preventing the seat bracket from being loosely fixed and subjected to random alternating loads, which can lead to fatigue fracture failure. The present invention utilizes a mold forming process and insert clearance fit to prevent the arch bracket from breaking during continuous stamping.

[0005] To achieve the above-mentioned purpose, the technical solution of the present invention is to design a high-strength and anti-fracture automobile seat slide rail bow bracket mold design process, including using a progressive die to continuously stamp and punch the material strip to form the automobile seat slide rail bow bracket;

[0006] The progressive die consists of an upper die and a lower die. The upper die consists of, from top to bottom, an upper positioning plate, several upper feet, an upper template, an upper backing plate, an upper fixing plate, and an upper stripper plate. The lower die consists of, from bottom to top, a lower positioning plate, several lower feet, a lower backing plate, and a lower template. The lower template has a clearance fit on the lower die insert, while the upper stripper plate has a clearance fit on the upper stripper plate. Through the die forming process, the clearance fit of the inserts prevents the arch bracket from breaking during continuous stamping.

[0007] A further technical solution is that the continuous stamping process comprises the following process steps in sequence: punching a guide hole, punching one, punching two, fine punching one, trimming one, idle step one, fine punching two, idle step two, trimming two, idle step three, idle step four, idle step five, idle step six, idle step seven, chamfering one, idle step eight, idle step nine, idle step ten, idle step eleven, idle step twelve, bending downward one, idle step thirteen, idle step fourteen, bending downward two, idle step fifteen, idle step sixteen, idle step seventeen , empty step 18, empty step 19, shaping and side shaping 1, empty step 20, empty step 21, empty step 22, empty step 23, side punching, empty step 24, empty step 25, empty step 26, empty step 27, shaping and side shaping 2, empty step 28, empty step 29, empty step 30, empty step 31, punching 3, empty step 32, edge cutting 3, empty step 33, chamfering 2, empty step 34, shaping, empty step 35, empty step 36, cutting.

[0008] A further technical solution is to provide a tapping process after the first and / or second downward bending processes; the lower die is provided with a tapping machine. This enables automatic tapping during continuous stamping. The tapping machine on the lower die allows tapping during the continuous stamping process and also creates threaded holes during the blanking process. This allows threaded holes to be created during the stamping of the bow-shaped bracket, eliminating the need for a separate tapping process after blanking, thereby improving efficiency.

[0009] A further technical solution involves also installing a tapping machine on the upper die; the taps on both the upper and lower dies have the same rotation direction, and there is only one tapping machine on each die. This allows two threaded holes to be machined simultaneously during stamping, and the threaded holes are machined simultaneously on both sides of the arch bracket. This fundamentally solves the problem of loosening screw holes caused by loose tightening, and prevents fatigue fracture of the seat slide or arch bracket under random alternating loads.

[0010] A further technical solution is to have two tapping machines on the lower die, with the tapping machines rotating in opposite directions. This arrangement allows for both left-hand and right-hand threaded holes to be provided on one surface of the bow-shaped bracket. When the bow-shaped bracket is connected to the car seat rail, two bolts with different rotation directions are used to secure the two.

[0011] A further technical solution is to also install a tapping machine on the upper die; the tapping machines on the upper and lower dies have the same rotation direction, but the number of tapping machines on the upper and lower dies is different. This arrangement allows different numbers of threaded holes to be provided at different points where the arch bracket connects to the car seat rail, further preventing the possibility of loosening of the screw holes.

[0012] A further technical solution is that two tapping machines are provided on the upper die, and three or four tapping machines are provided on the lower die.

[0013] A further technical solution is that the diameter of the tap on the tapping machine is smaller than the diameter of the threaded hole on the arched bracket of the formed automobile seat slide rail;

[0014] After the continuous stamping process is complete, the seat rail and bow bracket are aligned and initially connected by welding. Then, a tapping machine is used to directly tap and drill holes in the connected rail and bow bracket. By setting the tap on the tapping machine to a diameter smaller than the threaded hole, a small hole is initially machined in the material strip. Any mismatch between the bolt hole spacing on the seat rail and the bow bracket can be corrected through subsequent processing.

[0015] A further technical solution is that a guide post is also provided in the progressive die, and the guide post includes a guide post body and a graphite layer covering the circumferential side of the guide post body, and an aluminum alloy protective layer is fixedly sleeved on the outside of the graphite layer. An annular graphite layer and an annular aluminum alloy protective layer are provided outside the guide post. When the progressive die is used multiple times, the aluminum alloy protective layer protects the guide post and other components of the progressive die (such as pads, templates, etc.) in the early stage. When the aluminum alloy protective layer is worn, the graphite layer plays the role of protection in the next stage, and also has a prompting function. When the graphite layer is completely worn out in the later stage, the surface of the stamped part will no longer have graphite ash, which serves as a reminder to the worker that the guide post needs to be replaced. On the one hand, it can solve the problem of rapid wear of the working parts of the mold due to high-speed stamping, and it can also serve as a reminder when the guide post body is worn out (of course, the graphite layer and the aluminum alloy protective layer are not thick to avoid the guide post failing to guide after the graphite layer is worn out).

[0016] A further technical solution is that the upper part of the guide column passes through the upper fixed plate and the upper unloading plate, and the lower part of the guide column passes through the lower pad and the lower template.

[0017] The advantages and benefits of the present invention lie in that by tapping threaded holes of the same rotation direction on both sides of the material strip (i.e., the front and back sides of the final bow-shaped bracket), or tapping threaded holes of different rotation directions on one side of the bow-shaped bracket, the secure connection between the bow-shaped bracket and the vehicle seat rail is fundamentally improved, thus preventing the seat bracket from being loosely fixed and subjected to random alternating loads, which can lead to fatigue fracture and failure. The present invention utilizes a mold forming process and insert clearance fit to prevent the bow-shaped bracket from breaking during continuous stamping.

[0018] Automatic tapping is achieved during continuous stamping. The tapping machine installed on the lower die can realize tapping during the continuous stamping process, and also process threaded holes during the blanking process. It can realize the processing of threaded holes during the stamping process of the bow bracket, without the need for additional tapping process to process threaded holes after blanking, thus improving efficiency.

[0019] Tapping machines are installed on both the upper and lower dies, so that two threaded holes are processed simultaneously during stamping, and the threaded holes are processed on the front and back sides of the bow bracket at the same time. This fundamentally solves the problem of loosening of screw holes due to loose tightening, and avoids fatigue fracture of the seat slide or bow bracket caused by random alternating loads.

[0020] Left-handed and right-handed threaded holes are simultaneously arranged on one surface of the arched bracket. When the arched bracket is connected to the car seat slide rail, two bolts with different rotation directions are used to achieve a fastening connection between the two.

[0021] Different numbers of threaded holes are provided at different connection points between the arch-shaped bracket and the car seat slide rail, thereby further preventing the possibility of the screw holes being loose.

[0022] By setting the tap on the tapping machine to a diameter smaller than the size of the threaded hole, a small hole is initially machined on the material strip. If the bolt hole spacing on the car seat slide rail does not match the bolt hole spacing on the bow bracket, this problem can be solved through subsequent processing.

[0023] An annular graphite layer and an annular aluminum alloy protective layer are set outside the guide pillar. When the progressive die is used multiple times, the guide pillar and other components of the progressive die (such as pads, templates, etc.) are protected by the aluminum alloy protective layer in the early stage. When the aluminum alloy protective layer is worn, the graphite layer plays the role of protection in the next stage, and also has a reminder function. When the graphite layer is worn out in the later stage, there will be no graphite ash on the surface of the stamped parts, which reminds workers that the guide pillar needs to be replaced. On the one hand, it can solve the problem of rapid wear of the mold working parts due to high-speed stamping, and it can also serve as a reminder when the wear reaches the guide pillar body. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of a progressive die in the design process of a high-strength, fracture-resistant automobile seat slide rail arch bracket mold of the present invention;

[0025] Figure 2 yes Figure 1 An enlarged schematic diagram of the lower half;

[0026] Figure 3 yes Figure 1 An enlarged schematic diagram of the upper part;

[0027] Figure 4 yes Figure 1 An enlarged schematic diagram of the center guide post body and its vicinity;

[0028] Figure 5 yes Figure 4 an enlarged schematic diagram of the upper end portion of ;

[0029] Figure 6 It is a step diagram of continuous stamping of the present invention;

[0030] Figure 7 yes Figure 6 Side view of the middle material belt;

[0031] Figure 8 yes Figure 6 Schematic diagram of the 21-step sequence;

[0032] Figure 9 yes Figure 6 Schematic diagram of the 24-step sequence;

[0033] Figure 10 Schematic diagram of an arch-shaped bracket formed by continuous stamping of the present invention;

[0034] Figure 11 yes Figure 10 Side view of

[0035] Figure 12 yes Figure 11 A top view of

[0036] Figure 13 This is a schematic diagram of the connection between the punched bow-shaped bracket and the car seat slide rail of the present invention;

[0037] Figure 14 yes Figure 13 A three-dimensional view of a car seat slide.

[0038] In the figure: 1. Material strip; 2. Bow-shaped bracket; 3. Upper positioning plate; 4. Upper foot; 5. Upper template; 6. Upper pad; 7. Upper fixing plate; 8. Upper unloading plate; 9. Lower positioning plate; 10. Lower foot; 11. Lower pad; 12. Lower template; 13. Lower mold insert; 14. Upper unloading plate insert; 15. Tapping machine; 16. Threaded hole; 17. Car seat slide rail; 18. Guide column body; 19. Graphite layer; 20. Aluminum alloy protective layer. DETAILED DESCRIPTION

[0039] The following embodiments are further described in conjunction with the accompanying drawings and examples. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention.

[0040] like Figures 1 to 14 As shown, the present invention is a high-strength and fracture-resistant automobile seat slide arch bracket mold design process, which includes using a progressive die to continuously stamp and punch a material strip 1 to form a car seat slide 17 arch bracket 2; the progressive die includes an upper die and a lower die, the upper die includes an upper positioning plate 3, a plurality of upper pads 4, an upper template 5, an upper pad 6, an upper fixed plate 7 and an upper unloading plate 8 arranged in sequence from top to bottom, and the lower die includes a lower positioning plate 9, a plurality of lower pads 10, a lower pad 11 and a lower template 12 arranged in sequence from bottom to top; a lower die insert 13 is provided on the lower template 12 with a clearance fit, and an upper unloading plate insert 14 is provided on the upper unloading plate 8 with a clearance fit.

[0041] The continuous stamping process is carried out in the following order: punching guide hole, punching 1, punching 2, fine punching 1, trimming 1, idle step 1, fine punching 2, idle step 2, trimming 2, idle step 3, idle step 4, idle step 5, idle step 6, idle step 7, chamfering 1, idle step 8, idle step 9, idle step 10, idle step 11, idle step 12, downward bending 1, idle step 13, idle step 14, downward bending 2, idle step 15, idle step 16, idle step 17, idle step 18 , Empty Step 19, Shaping and Side Shaping 1, Empty Step 20, Empty Step 21, Empty Step 22, Empty Step 23, Side Punching, Empty Step 24, Empty Step 25, Empty Step 26, Empty Step 27, Shaping and Side Shaping 2, Empty Step 28, Empty Step 29, Empty Step 30, Empty Step 31, Punching 3, Empty Step 32, Trimming 3, Empty Step 33, Chamfering 2, Empty Step 34, Shaping, Empty Step 35, Empty Step 36, Cutting. After the downward bending 1 and / or downward bending 2 processes, a tapping process is provided; a tapping machine 15 is provided on the lower die. A tapping machine 15 is also provided on the upper die; the tapping of the tapping machines 15 on the upper and lower dies has the same direction of rotation, and there is one tapping machine 15 on each of the upper and lower dies. The tapping machine 15 has a tapping diameter smaller than the diameter of the threaded hole 16 in the arch bracket 2 of the formed car seat slide 17. After the continuous stamping is completed, the car seat slide 17 and the arch bracket 2 are aligned and initially connected by electric welding. The tapping machine 15 then directly taps and drills holes in the connected car seat slide 17 and arch bracket 2. The progressive die also includes a guide post, which includes a guide post body 18 and a graphite layer 19 covering the circumference of the guide post body 18. The graphite layer 19 is fixedly sheathed with an aluminum alloy protective layer 20. The upper half of the guide post extends through the upper fixing plate 7 and the upper stripper plate 8, while the lower half extends through the lower pad 11 and the lower mold plate 12.

[0042] Here’s how it works:

[0043] Simultaneous tapping of threaded holes during stamping improves efficiency. Threaded holes with different rotation directions or on different surfaces are designed to prevent loosening. Differing the number and rotation directions of threaded holes in diagonal or relative locations ensures a secure connection. This prevents loose seat brackets from being subjected to random alternating loads, leading to fatigue fracture. An annular graphite layer and an annular aluminum alloy protective layer are applied to the guide posts. During repeated use of the progressive die, the aluminum alloy protective layer initially protects the guide posts and other die components (such as backing plates and mold plates). Once the aluminum alloy protective layer wears away, the graphite layer takes on the next stage of protection and also serves as a reminder. When the graphite layer is completely worn away, the surface of the stamped part will no longer be covered with graphite dust, alerting workers to the need to replace the guide posts. This mitigates the rapid wear of die working parts caused by high-speed stamping and also serves as a warning when wear reaches the guide post itself.

[0044] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. High-strength anti-fracture automobile seat slide rail bow bracket mold design process, characterized by: The method includes using a progressive die to continuously stamp and punch a material strip to form a bow-shaped bracket for a car seat slide rail; The progressive die includes an upper die and a lower die. The upper die includes an upper positioning plate, a plurality of upper pads, an upper template, an upper pad, an upper fixing plate and an upper stripper plate, which are arranged in sequence from top to bottom. The lower die includes a lower positioning plate, a plurality of lower pads, a lower pad and a lower template, which are arranged in sequence from bottom to top. A lower die insert is provided on the lower template with a clearance fit, and an upper stripper plate insert is provided on the upper stripper plate with a clearance fit. The continuous stamping process comprises the following process steps which are carried out in sequence: punching a guide hole, punching one, punching two, fine punching one, trimming one, idle step one, fine punching two, idle step two, trimming two, idle step three, idle step four, idle step five, idle step six, idle step seven, chamfering one, idle step eight, idle step nine, idle step ten, idle step eleven, idle step twelve, bending downward one, idle step thirteen, idle step fourteen, bending downward two, idle step fifteen, idle step sixteen, idle step seventeen, idle step ten 8. Empty Step 19, Shaping and Side Shaping 1, Empty Step 20, Empty Step 21, Empty Step 22, Empty Step 23, Side Punching, Empty Step 24, Empty Step 25, Empty Step 26, Empty Step 27, Shaping and Side Shaping 2, Empty Step 28, Empty Step 29, Empty Step 30, Empty Step 31, Punching 3, Empty Step 32, Trimming 3, Empty Step 33, Chamfering 2, Empty Step 34, Shaping, Empty Step 35, Empty Step 36, Cutting; A tapping process is provided after the first downward bending process and / or the second downward bending process; a tapping machine is provided on the lower die; The lower die is provided with two tapping machines, and the rotation directions of the two tapping machines are opposite; the diameter of the taps on the tapping machines is smaller than the diameter of the threaded hole on the arched bracket of the formed automobile seat slide rail; After the continuous stamping is completed, the car seat slide rail and the bow-shaped bracket are aligned and initially connected by electric welding, and then the car seat slide rail and the bow-shaped bracket that have been connected as one are directly tapped and drilled by a tapping machine; the progressive die is also provided with a guide column, which includes a guide column body and a graphite layer covering the circumferential side of the guide column body, and an aluminum alloy protective layer is fixedly sleeved on the outside of the graphite layer; the guide column is protected by the aluminum alloy protective layer in the early stage, and when the aluminum alloy protective layer is worn, the graphite layer plays a protective role in the next stage and also has a prompt role.

2. The high-strength anti-fracture automobile seat slide rail arch bracket mold design process according to claim 1 is characterized in that: The upper part of the guide column passes through the upper fixing plate and the upper unloading plate, and the lower part of the guide column passes through the lower pad and the lower template.

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