A new type of automobile suspension swing arm

Abstract

A novel automotive suspension control arm includes a control arm body. The upper and lower ends of the control arm body are respectively connected and fixed to a ball joint pin assembly and a bushing assembly. The middle section of the control arm body is connected and fixed to a central bushing assembly. The control arm body is an integral arc-shaped hydroformed tubular component. The height of the tubular body at both ends is less than the height of the middle section. The cross-section of the end connected to the bushing assembly is a variable cross-section, wider at both ends and thinner in the middle. The control arm body is manufactured using bending, shrinking, pre-forming, internal high-pressure forming, and laser cutting processes, resulting in a structure different from traditional stamping and welding. This control arm product offers stable dimensional accuracy, a simple manufacturing process, and solves the problem of ensuring welding gap in stamping and welding structures.

Description

Technical Field

[0001] This invention relates to the field of automobile manufacturing technology, specifically to a novel automobile suspension control arm. Background Technology

[0002] The suspension control arm is a core load-bearing component of the chassis. Its structural strength, lightweight level, and manufacturing process directly affect the vehicle's safety, handling stability, and production cost. With the development of the automotive industry, especially the increasing demands for lightweighting, compactness, and NVH performance from new energy vehicles, higher standards have been set for the design and manufacturing processes of the control arm.

[0003] Traditional suspension arms mostly employ a stamped and welded structure, formed by welding together multiple stamped parts. This process involves numerous steps, significant welding deformation, insufficient structural rigidity, and low lightweighting levels. Furthermore, material utilization is only around 65%, and long weld lengths result in low production efficiency and high costs. To address the lightweighting issue, some suspension arms utilize conventional hydroforming processes. However, conventional hydroforming struggles to achieve composite forming involving large cross-sectional changes and end diameter reduction / expansion. The cross-sectional change rate is typically below 10%, making it impossible to simultaneously complete expansion and contraction within a single mold. This leads to low forming accuracy, low material utilization, and poor matching between structure, materials, and processes, making it difficult to simultaneously meet the high strength and lightweighting requirements of the suspension arm.

[0004] In the prior art, patent document CN113400876A discloses a front lower control arm of a car made of tubular forming parts. Although it reduces some welds, it is only a simple tube welding process without hydraulic composite forming process, and the cross-sectional change rate does not break through the conventional level. Patent document CN107128140B discloses a stamped control arm assembly, which still relies on stamping and welding, which is complicated and heavy. Other swing arm related technologies focus on structural cross-section optimization, without innovation in hydraulic forming process, and cannot solve the core technical problem of asynchronous tube shrinking and expansion.

[0005] Therefore, traditional swing arms can no longer meet the multiple demands of modern automobiles, especially new energy vehicles, for high performance, lightweight, compact size, and excellent manufacturability of subframes, and a new structure and process are urgently needed to solve this problem. Summary of the Invention

[0006] The purpose of this invention is to address the shortcomings of existing technologies by providing a novel automotive suspension control arm. This control arm offers stable dimensional accuracy, a simple manufacturing process, and solves the problem of ensuring welding gaps in stamped and welded structures.

[0007] The objective of this invention is achieved through the following solution: a novel automotive suspension control arm, comprising a control arm body, the upper and lower ends of which are respectively connected and fixed to a ball joint pin assembly and a bushing assembly, the middle section of which is connected and fixed to a central bushing assembly, the control arm body being an integral arc-shaped tube, the height of the tubes at both ends of the control arm body being less than the height of the tubes in the middle, and the cross-section of the end connected to the bushing assembly being a variable cross-section that is wide at both ends and thin in the middle, the control arm body being manufactured by tube bending, tube shrinking, preforming, internal high-pressure forming and laser cutting processes.

[0008] The ball joint pin assembly is welded and fixed to the main body of the swing arm, and the ball joint in the ball joint pin assembly is installed in a sunken convex structure.

[0009] The bushing assembly is fixed to the swing arm body by bolts, and the center bushing assembly is fixed to the swing arm body by welding.

[0010] The main body of the swing arm is shrunk in a hydraulic mold.

[0011] The cross-sectional change rate between the middle and end sections of the swing arm body can reach 25%.

[0012] The main body of the swing arm is made of QSTE420TM-QSTE650TM material.

[0013] The advantages of this invention are: 1. It combines the shrinking and expanding processes, breaking through the limitation of cross-sectional change rate. The swing arm combines the extrusion of the tube by the mold with the internal high-pressure liquid filling and forming. The cross-sectional change rate of the middle and end of the swing arm body reaches 25%, which far exceeds the cross-sectional change rate level of less than 15% of conventional hydraulic forming, enabling the production of hydraulic tubes with large cross-sectional change rate. 2. Significantly lightweight, balancing high strength and low material cost: Using QSTE420TM-QSTE650TM steel pipes as raw materials, compared with the high-strength steel FB780 of traditional stamping and welding process products, the material grade is reduced and the cost is lower; the number of welds is reduced by 17%, and the first mode is improved by 77HZ. The buckling strength and structural strength of the swing arm meet the requirements of the whole vehicle, achieving a balance between lightweight and high strength. 3. Simplified production process, improved production efficiency and reduced costs: The swing arm processing eliminates the multi-part stamping, fastening and welding processes in traditional stamping and welding. The production process is: bending tube → shrinking tube → pre-forming → internal high pressure forming → laser cutting → welding, which is simple. Moreover, the swing arm body is formed in one piece, and only the bracket and sleeve need to be welded. The weld length is greatly reduced, which reduces welding costs and welding deformation. The mold structure is relatively simple, and the debugging time is greatly shortened, which is suitable for rapid product iteration and adaptable to large-scale mass production. 4. High forming precision and good product consistency: The internal high-pressure forming process is precisely controlled by the mold. The synergistic effect of high-pressure liquid and axial thrust makes the tube wall fit tightly into the mold cavity, resulting in high dimensional accuracy of the swing arm body. Laser cutting further ensures the dimensional accuracy of the installation part, effectively improving the consistency of the finished swing arm and reducing subsequent assembly errors. 5. Optimized structural design to improve the performance of the control arm: The ball joint of the finished control arm is designed with a sunken convex structure, which improves the structural strength of the ball joint and avoids stress concentration; the control arm body is a one-piece tubular hydroformed structure without stamped and spliced ​​sections, which has high structural rigidity and can effectively withstand longitudinal, lateral and vertical forces during vehicle operation, thereby improving the handling stability and driving safety of the whole vehicle. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a side view of the present invention; Figure 3 This is a sectional view of BB. Figure 4 This is a sectional view along the DD direction; Figure 5 This is a schematic diagram of the ball head pin assembly structure; Figure 6 This is a schematic diagram of the rate of change of the cross section. Detailed Implementation

[0015] like Figures 1 to 6 As shown, a novel automotive suspension control arm includes a control arm body 1. The upper and lower ends of the control arm body 1 are respectively connected and fixed to a ball joint pin assembly 4 and a bushing assembly 2. The ball joint pin assembly 4 is welded and fixed to the control arm body 1, and the ball joint in the ball joint pin assembly 1 has a recessed convex structure. The bushing assembly 2 is bolted and fixed to the control arm body 1, and the central bushing assembly 3 is welded and fixed to the control arm body 1. The middle section of the control arm body 1 is connected and fixed to the central bushing assembly 3. The control arm body 1 is an integral arc-shaped tube, and the height of the tube body at both ends of the control arm body 1 is less than the height of the tube body at the middle. The cross-section of the end connected to the bushing assembly 2 is a variable cross-section that is wide at both ends and thin in the middle. The control arm body 1 is manufactured by tube bending, tube shrinking, preforming, internal high-pressure forming, and laser cutting processes. The control arm body 1 is made of QSTE420TM-QSTE650TM material, which is easy to form, easy to process, and has a low cost. The first-order mode elevation is 77 Hz, and both buckling and strength meet the requirements. The cross-sectional change rate of the middle and end sections of the swing arm body 1 can reach 25%.

[0016] The following is the manufacturing process of the suspension control arm: Select steel pipes made of QSTE420TM-QSTE650TM material with an outer diameter of 73mm and a wall thickness of 2.0-3.5mm, and cut them to the predetermined length; pre-bend them into an arc shape using a pipe bending machine; place them in a hydraulic mold for mold compression, reducing the local pipe diameter to facilitate placement in the next process mold; pre-form to ensure local deformation for placement in the next process mold; place them in a liquid-filling molding mold, and after mold closing, inject high-pressure liquid (pressure 80-150MPa) while simultaneously axially advancing the pipe end to make the pipe wall fit the mold cavity, creating a variable cross-section with wide ends and a thin middle, forming a bushing mounting sleeve at one end and a ball head pin support at the other end; after demolding, machine the mounting area; and weld the bracket.

[0017] It eliminates multiple stamping, fastening, and welding processes, shortening the manufacturing process; it achieves optimal material distribution through variable cross-section design; it reduces weld length and lowers welding costs; and its relatively simple mold structure significantly shortens debugging time, making it suitable for rapid product iteration.

[0018] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications made to the present invention by those skilled in the art without departing from the spirit of the present invention shall fall within the protection scope of the present invention.

Claims

1. A new type of automobile suspension swing arm, comprising a swing arm body (1), the upper and lower ends of the swing arm body (1) are respectively connected and fixed with a ball pin assembly (4) and a bushing assembly (2), and the middle section of the swing arm body (1) is connected and fixed with a center bushing assembly (3), characterized in that: The main body of the swing arm (1) is an integral arc tube. The height of the end tubes at both ends of the main body of the swing arm (1) is less than the height of the middle tube. The end section connected to the bushing assembly (2) is a variable cross section that is wide at both ends and thin in the middle. The main body of the swing arm (1) is made by bending, shrinking, preforming, internal high-pressure forming and laser cutting processes.

2. The novel automotive suspension swing arm as claimed in claim 1, wherein: The ball head pin assembly (4) is welded and fixed to the swing arm body (1), and the ball head installation position in the ball head pin assembly (1) is a sunken convex structure.

3. The new type of automobile suspension swing arm according to claim 1, characterized in that: The bushing assembly (2) is fixed to the swing arm body (1) by bolts, and the center bushing assembly (3) is fixed to the swing arm body (1) by welding.

4. The new type of automobile suspension swing arm according to claim 1, characterized in that: The swing arm body (1) is shrunk in a hydraulic mold.

5. The new type of automotive suspension swing arm according to claim 1, characterized in that: The cross-sectional change rate of the middle and end sections of the main body (1) of the swing arm can reach 25%.

6. The novel automotive suspension control arm according to claim 1, characterized in that: The main body of the swing arm (1) is made of QSTE420TM-QSTE650TM material.

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