Swing arm structure

Abstract

The utility model discloses a swing arm structure which comprises a swing arm upper plate and a swing arm lower plate which are matched with each other. The swing arm upper plate is downwards provided with an upper plate turnup, the swing arm lower plate is upwards provided with a lower plate turnup, and the upper plate turnup and the lower plate turnup are buckled and welded; a ball pin is arranged below the swing arm, a front bushing mounting sleeve is arranged above the swing arm, and a pin shaft matched with the rear bushing is arranged on the side of the swing arm; the ball pin is connected with the swing arm upper plate and the swing arm lower plate through a ball pin connecting seat; the front bushing mounting sleeve is connected with the swing arm upper plate and the swing arm lower plate in a welding manner; the position, close to the pin shaft, of the lower swing arm plate is semicircular, two fins are arranged on the two sides of the lower swing arm plate outwards, and the upper swing arm plate and the lower swing arm plate are connected in a buckled and welded mode and connected with a flange on the pin shaft in a welded mode. And the middle sleeve penetrates through the sleeve holes in the swing arm upper plate and the swing arm lower plate and is connected with the swing arm upper plate and the swing arm lower plate in a welding manner. According to the scheme, the problems that the triangular swing arm is concentrated in stress and cracks in advance are effectively solved, and the product performance is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of automobile structures, and particularly relates to a swing arm structure. Background Art

[0002] With the rapid development of the automobile industry, the performance requirements of automobiles are getting higher and higher. The safety performance of automobiles and the unsprung weight of the chassis are both important design indicators. As the main component in the automobile structure, the performance and weight targets of the chassis are also the key to considering the design parameters of the whole vehicle.

[0003] At present, the front-wheel triangular swing arm assembly of automobiles mainly adopts a welded structure of double-piece steel stampings. It is widely used and can be equipped with MacPherson structures and double-wishbone structures. Strength, stiffness, the fatigue life of the body and welds are used as the main design indicators. Achieving the best performance with the lightest and simplest structure is the ideal state pursued by the design. The stiffness is greatly affected by the cavity of the double-piece stamping, and the strength and fatigue are mainly affected by the structure, material and plate thickness. Usually, when the strength is insufficient and the fatigue life does not meet the requirements, increasing the plate thickness of the stamping or improving the material grade of the steel plate will have obvious improvement, but at the same time, it will increase the weight of the entire swing arm, raise the cost, increase the unsprung mass, and indirectly affect the evaluation of NVH performance.

[0004] The existing swing arm structure usually adopts the upper and lower plates to be buckled, plug welding is carried out with the shaft of the pin shaft, and a circumferential weld is set between the buckling vertical edge and the flange plate of the pin shaft, forming a T-shaped intersection at both left and right sides by four welds, as Figure 5 shown. The T-shaped intersection point is exactly the starting and ending positions of the weld. The stress at the weld intersection is the highest, and the positions of the heat affected zones coincide, which is the weakest place in terms of strength and fatigue life. The results of CAE simulation and experimental verification are consistent, and it is the first cracking position, which greatly affects the overall strength and service life. Summary of the Utility Model

[0005] The purpose of the utility model is to provide a swing arm structure with high strength and fatigue resistance to solve the problems in the prior art.

[0006] The utility model is realized by the following technical scheme: a swing arm structure, characterized in that: the swing arm is in an "r" shape and includes a swing arm upper plate and a swing arm lower plate that cooperate with each other;

[0007] The swing arm upper plate is provided with an upper plate flanging downward, the swing arm lower plate is provided with a lower plate flanging upward, and the upper plate flanging and the lower plate flanging are buckled and welded together;

[0008] A ball pin is arranged below the swing arm, a front bushing installation sleeve is arranged above the swing arm, and a pin shaft cooperating with a rear bushing is arranged on the side of the swing arm;

[0009] The ball pin is connected to the upper swing arm plate and the lower swing arm plate through a ball pin connecting seat; the front bushing mounting sleeve is welded to the upper swing arm plate and the lower swing arm plate;

[0010] The position of the lower swing arm plate near the pin shaft is semi-circular, and there are two fins arranged outward on both sides. The upper swing arm plate and the lower swing arm plate are buckled and welded together and welded to the flange on the pin shaft;

[0011] It also includes a middle sleeve, and the middle sleeve passes through the sleeve holes on the upper swing arm plate and the lower swing arm plate and is welded.

[0012] Furthermore: Reinforcing ribs are provided on the upper swing arm plate and the lower swing arm plate.

[0013] The beneficial effects of the present utility model are as follows: Since the present utility model adjusts the structures of the main components of the swing arm, on the basis of achieving the design goals in terms of hard point positions and parameter performance, through reasonable structural design, the weld length between the lower swing arm plate and the pin flange plate is increased, and a reasonable avoidance is made for the coincidence of the three welds in the heat affected zone. The fin structure at the overlapping position of the lower swing arm plate and the pin shaft changes the weld position between the lower swing arm plate and the pin shaft. The high stress position is led to the distal end of the pin flange plate, thereby improving the strength and fatigue life of the workpiece, reducing the high stress at the connection position between the swing arm and the pin shaft, and greatly enhancing the fatigue life of the swing arm.

[0014] In summary, the present utility model effectively solves the problem of stress concentration in the triangular swing arm and premature cracking, and improves the product performance index. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The following further describes the present utility model with reference to the accompanying drawings.

[0016] Figure 1 is the structural schematic diagram of the present utility model;

[0017] Figure 2 is the exploded structural diagram of the present utility model;

[0018] Figure 3 is the structural schematic diagram of the connection part of the pin shaft of the present utility model;

[0019] Figure 4 is the structural schematic diagram of the connection part of the pin shaft of the present utility model;

[0020] Figure 5 Schematic diagram of the existing swing arm structure;

[0021] Figure 6 is the cross-sectional view of the position of the middle sleeve;

[0022] Figure 7 is the cross-sectional view of the pin shaft position.

[0023] Explanation of the reference numerals in the figure: 1 is the upper swing arm plate, 2 is the lower swing arm plate, 3 is the front bushing mounting sleeve, 4 is the pin shaft, 5 is the middle sleeve, 6 is the rear bushing, 7 is the ball pin, and 8 is the reinforcing rib;

[0024] 11 is the upper plate flange, 21 is the lower plate flange, 22 is the fin; 41 is the flange; 51 is the sleeve hole; 71 is the ball pin connection seat. Detailed implementation manner

[0025] According to Figures 1 to 7 As shown, the present utility model provides a swing arm structure. The swing arm is approximately in the shape of "r", and the main body is formed by welding the upper swing arm plate 1 and the lower swing arm plate 2 that cooperate with each other up and down;

[0026] The upper swing arm plate 1 is provided with an upper plate flange 11 downward (towards the lower swing arm plate direction, or inwards), and the lower swing arm plate 2 is provided with a lower plate flange 21 upward. The upper plate flange and the lower plate flange are buckled and welded to connect and fix the upper swing arm plate 1 and the lower swing arm plate 2. Among them, each flange is located in the main body part of the upper and lower swing arm plates and does not affect the mating connection with other components;

[0027] As Figure 1 shown, taking the overall direction of the swing arm as the reference, a ball pin 7 is provided below the swing arm, a front bushing mounting sleeve 3 is provided above the swing arm, and a pin shaft 4 that cooperates with the rear bushing 6 is provided at the side end of the swing arm;

[0028] The ball pin (including the mounting seat that cooperates with it) is connected to the upper swing arm plate and the lower swing arm plate through the ball pin connection seat 71. The ball pin connection seat is welded to the upper swing arm plate and the lower swing arm plate or integrally formed; the front bushing mounting sleeve is welded to the upper swing arm plate and the lower swing arm plate;

[0029] The position of the lower swing arm plate close to the pin shaft is semi-circular, and two fins 22 are provided outward on both sides. The upper swing arm plate and the lower swing arm plate are buckled and welded and welded to the flange on the pin shaft;

[0030] It further includes a middle sleeve 5. The middle sleeve passes through the sleeve holes 51 on the upper swing arm plate and the lower swing arm plate and is welded to the upper swing arm plate and the lower swing arm plate respectively.

[0031] Preferably: Reinforcing ribs 8 are provided on the upper swing arm plate and the lower swing arm plate by stamping.

[0032] Preferably: The sleeve hole is funnel-shaped. After cooperating with the middle sleeve, a triangular area is formed at the cooperation part as the welding area, increasing the welding area and improving the welding strength.

[0033] Preferably, the sleeve hole is provided with an outward flanging, and the flanging is sleeved with the middle sleeve, so as to increase the contact area between the sleeve hole and the middle sleeve, which not only ensures the stability of the connection, but also makes the weld seam in the thickness direction of the sleeve hole, so that the damage received can be reduced when stressed.

[0034] The structure of the present utility model will be further described below through specific embodiments. Embodiment

[0035] A swing arm structure in this embodiment includes a swing arm upper plate and a swing arm lower plate that cooperate with each other, a front bushing installation sleeve, a rear bushing installation pin, and a middle sleeve. The swing arm upper plate and the swing arm lower plate are both provided with stiffeners. The middle sleeve passes through the swing arm upper plate and the swing arm lower plate and is connected by a circumferential weld, playing a role of stiffness support and swing arm avoidance. The swing arm structure is provided with three connection points. One is the ball pin connection point on the outside of the swing arm; one is that the front bushing sleeve is welded at the front end of the swing arm, and finally a bushing is press-fitted to connect to the subframe; one is that a pin shaft is welded at the rear end of the swing arm, and finally a bushing is press-fitted to connect to the subframe.

[0036] For the swing arm lower plate, the side is welded to the swing arm upper plate, the end is plug-welded to the pin shaft, and an outward-turning structure is adopted at the position wrapping the pin shaft and welded to the pin shaft flange plate. Among them, the swing arm upper plate and the swing arm lower plate are welded and connected. The swing arm upper plate is triangular (or approximately r-shaped), and the swing arm lower plate is also triangular. The flanging of the swing arm lower plate is on the outside, and the flanging of the swing arm upper plate is on the inside. The swing arm upper plate and the swing arm lower plate are overlapped on three sides. The swing arm lower plate is provided with outwardly flared fins and plug-weld holes at the overlapping positions with the swing arm upper plate and the pin shaft.

[0037] Specifically, the swing arm upper plate and the swing arm lower plate are welded and formed by overlapping through three flangings; the front bushing sleeve is welded to the circular contour formed by the buckled side edges at the front ends of the swing arm upper and lower plates; after the swing arm upper plate and the swing arm lower plate are buckled, two semi-circles are formed at the rear end to surround one end of the pin shaft. One end of the pin shaft is plug-welded to the swing arm upper plate and the swing arm lower plate. The vertical edge where the swing arm upper plate and the swing arm lower plate are buckled contacts the pin shaft flange plate, and the contact position is fixed by a weld seam.

[0038] The swing arm upper plate 1 and the swing arm lower plate 2 are fixed in position through two main and auxiliary positioning holes. When overlapping, the three flangings of the swing arm upper plate 1 are on the inside, and the three flangings of the swing arm lower plate 2 are on the outside. The flangings of the upper and lower plates overlap by 5 mm and are buckled and welded. The front bushing sleeve 3 overlaps with the circular contour formed by the buckled side edges at the front ends of the swing arm upper plate 1 and the swing arm lower plate 2, and the overlapping position is fixed by a weld seam. Two semi-circular shapes are formed at the rear end after the swing arm upper plate 1 and the swing arm lower plate 2 are buckled to surround one end of the pin shaft 4. The pin shaft 4 is connected to the swing arm upper plate 1 and the swing arm lower plate 2 by plug welding. The rear end vertical surfaces of the swing arm upper plate 1 and the swing arm lower plate 2 abut against the pin shaft flange plate to form a fillet weld overlap. The middle sleeve 5 passes through the middle of the swing arm upper plate 1 and the swing arm lower plate 2 respectively to form a circular full-weld connection and fixation.

[0039] After the front bushing sleeve 3 is press-fitted with the bushing, it is connected to the subframe; after the pin shaft 4 is press-fitted with the rear bushing 6, it is connected to the subframe; the outer spherical ball pin 7 of the swing arm is connected to the steering knuckle.

[0040] In this embodiment, different plate thicknesses and different materials can be selected for each component according to different forces. The position where the lower plate of the swing arm is fitted with the pin shaft adopts a fin structure with an eight-character outward turn, and is welded and fixed to the flange plate of the pin shaft along the fin structure. During welding, the weld is located on the outer circular side of the upper and lower plates of the swing arm. The fin structure keeps the weld away and no longer forms a T-shaped structure with the weld between the upper and lower plates of the swing arm, avoiding the concentration of the starting and ending positions of welding arcs, so that this structure is firm and reliable. The strength of the swing arm is improved, and this swing arm structure meets the target requirements of modal, static stiffness, static strength, dynamic stiffness, and fatigue damage.

[0041] The structure of the present utility model optimizes the structure of the swing arm to achieve the purpose of improving performance, controlling weight, and saving costs. The structures of the upper plate and the lower plate of the swing arm are reasonably designed to increase the connection length between the upper plate and the lower plate of the swing arm and the flange plate of the pin shaft and avoid the concentration of the starting and ending positions of welding arcs. The design strength and fatigue life of the product are further improved. Without increasing the thickness of the upper and lower plates of the swing arm, the stress is reduced by about 100 MPa, and the fatigue life is increased by more than 30%, effectively improving the design and service life of the product; secondly, due to the reduction of the plate thickness, the product weight is controlled, the unsprung mass is reduced, which contributes to the adjustment of misoperation conditions and NVH performance. The steel plate grade is reduced, the material cost is controlled, and the effect of saving materials and reducing costs is achieved.

Claims

1. A swing arm structure, characterized in that: The swing arm is in an "R" shape, and comprises a swing arm upper plate and a swing arm lower plate that cooperate with each other; The upper plate of the swing arm is provided with an upper plate flange downward, and the lower plate of the swing arm is provided with a lower plate flange upward, and the upper plate flange and the lower plate flange are buckled and welded together; A ball pin is arranged below the swing arm, a front bushing mounting sleeve is arranged above the swing arm, and a pin shaft matching with the rear bushing is arranged on the side of the swing arm; The ball pin is connected to the upper plate and the lower plate of the swing arm through the ball pin connecting seat; the front bushing mounting sleeve is welded to the upper plate and the lower plate of the swing arm; The position of the swing arm lower plate near the pin shaft is semicircular, and two fins are arranged outward on both sides. The swing arm upper plate and the swing arm lower plate are welded together and are welded to the flange on the pin shaft. It also includes a middle sleeve, which passes through sleeve holes on the swing arm upper plate and the swing arm lower plate and is welded and connected.

2. A swing arm structure according to claim 1, characterized in that: Reinforcing ribs are arranged on the upper plate and the lower plate of the swing arm.

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