Front auxiliary frame structure of automobile

Abstract

The invention discloses a light-weight and high-strength automobile front auxiliary frame structure. According to the structure, the left longitudinal beam, the right longitudinal beam and the cross beam are welded to form an orthogonal bearing type frame, the longitudinal beam is a hollow rectangular tube formed by welding an upper plate and a lower plate which are formed through stamping, and the cross beam is a hollow trapezoidal tube formed by a trapezoidal-groove-shaped upper plate and a trapezoidal-groove-shaped lower plate, so that material redundancy is remarkably reduced. The innovative cleat structure adopts a hollow trapezoidal tubular cleat bracket, a lining positioning tube with a circumferential boss is arranged in a transverse extension part of the cleat bracket, and weldless assembly is realized through clearance fit of the boss and an annular groove, so that welding deformation is effectively eliminated, and the fatigue strength is improved. The front side of the beam is provided with a suspension mounting port, the rear side is provided with a steering engine support, and the middle is additionally provided with a reinforcing support with flanges to connect left and right cleats to form a reinforcing system. According to the structure, modular stamping parts are combined and welded, cost reduction and efficiency improvement are achieved while the performance is guaranteed, and the structure is particularly suitable for the light weight requirement of new energy vehicle models.

Description

Technical Field

[0001] The invention relates to the field of automobile chassis, and in particular to a front auxiliary frame structure of an automobile. Background Art

[0002] The subframe is an extremely important automotive component that is used to connect the body, engine and suspension, and withstand the impact load and vibration from the engine and the road. Therefore, it has extremely high requirements for strength and durability, and must also meet NVH performance.

[0003] Among the existing front subframes, a butterfly-shaped front subframe, also known as a Yuanbao-shaped subframe, is commonly used. The butterfly-shaped front subframe has a simple structure and is easy to manufacture. It is usually composed of an upper plate, a lower plate, a longitudinal connecting plate between the upper plate and the lower plate, and a horn bracket. For example, a front subframe of an automobile disclosed in CN211809838U and a horn structure of an automobile subframe disclosed in CN105882751A are both butterfly-shaped front subframe structures.

[0004] However, the butterfly-shaped front subframe of the prior art has the problems of large size of the upper plate and the lower plate, complex structure, and redundant local materials, and a reinforcement such as a longitudinal connecting plate is provided between the upper plate and the lower plate, as shown in CN211809838U, which results in high cost and high quality. In today's increasingly fierce price competition in the automobile industry, it is particularly important to reduce costs and weight from the front subframe of the automobile.

[0005] Moreover, the side of the body connecting sleeve of the clevis structure of the automobile subframe is fixed to the clevis bracket through a connecting weld. As shown in CN105882751A, the welding and fixing method of the clevis bracket and the bushing positioning tube has a large heat input, high electricity consumption, and high production cost, which is not conducive to social carbon emissions and energy conservation and environmental protection, and is not conducive to the control of vehicle cost. In addition, the welding heat input is large, and the clevis has serious thermal deformation, which will make the subframe dimensional accuracy extremely difficult to control and reduce the quality of the vehicle. At the same time, the stress changes during the welding of the clevis bracket and the bushing positioning tube, and the fatigue damage of the welding position will exceed the standard after long-term use of the vehicle. Summary of the invention

[0006] The purpose of the present invention is to provide a front subframe structure for an automobile in view of the corresponding deficiencies of the prior art. The longitudinal beams and cross beams of the front subframe of the automobile are welded into an H shape, which solves the problem of redundant local materials compared with the traditional butterfly-shaped front subframe, and the longitudinal beams and cross beams are both hollow tubes without internal reinforcements, thus achieving cost reduction and weight reduction; and the horn bracket and the bushing positioning tube adopt clearance fit to prevent stress changes and fatigue damage caused by welding.

[0007] The objective of the present invention is achieved by adopting the following scheme: A front subframe structure of an automobile comprises a left longitudinal beam, a right longitudinal beam, a cross beam and a ram's horn, wherein the left longitudinal beam, the right longitudinal beam and the cross beam are welded to form an orthogonal load-bearing frame structure, the left and right longitudinal beams are welded to form a hollow rectangular tube structure by stamping a longitudinal beam upper plate and a longitudinal beam lower plate, and the cross beam is welded to form a hollow trapezoidal tube structure by stamping a cross beam upper plate and a cross beam lower plate; The left and right swing arm front brackets are welded and fixed to the outer sides of the front parts of the left and right longitudinal beams, and the left and right horns are welded and fixed to the upper ends. The left and right steering gear mounting holes are respectively opened at the upper ends of the middle parts of the left and right longitudinal beams, and the left and right stabilizer bar mounting holes are respectively opened at the upper ends of the rear ends of the left and right longitudinal beams. The rear mounting steel sleeves are respectively fixedly arranged in the rear end rectangular tube cavity; A suspension installation opening is provided on the front side wall of the cross beam, a steering gear bracket is welded and fixed at the corners of the rear side of the cross beam and the left and right longitudinal beams, and a steering gear installation hole is provided on the steering gear bracket; The ram horn includes a ram horn bracket and a bushing positioning tube. The ram horn bracket is a hollow trapezoidal tube structure. The front parts of the left and right longitudinal beams are respectively welded and fixed to the fixed ends of the oblique support parts of the left and right ram horn brackets. The oblique support parts of the ram horn brackets are connected to the transverse extension parts through the bending parts. The bushing positioning tube is uprightly arranged in the transverse extension part of the ram horn bracket. The end faces of the bushing positioning tube are provided with axially extending circumferential bosses. The circumferential boss gap is fitted in the annular groove provided on the inner wall of the transverse extension part of the ram horn bracket. Through holes connecting the inner holes of the bushing positioning tube are respectively opened on the upper and lower sides of the ram horn bracket.

[0008] Preferably, the horn bracket is formed by stamping and welding a stamped sheet metal upper body and a stamped sheet metal lower body, the sheet metal upper body is in a trapezoidal groove shape opening downward, and the sheet metal lower body covers the opening of the sheet metal upper body to form a hollow trapezoidal tube structure.

[0009] Preferably, the longitudinal beam upper plate is in the shape of an n-shaped groove opening downward, and the longitudinal beam lower plate covers the opening of the longitudinal beam upper plate to form a hollow rectangular tube structure.

[0010] Preferably, the wing plates on both sides of the web plate of the upper crossbeam plate expand outwards to form a downwardly open groove shape, and the lower crossbeam plate covers the opening of the upper crossbeam plate to form a hollow trapezoidal tube structure.

[0011] Preferably, a strip-shaped reinforcing bracket is welded and fixed to the upper end of the crossbeam, the reinforcing bracket is located between the left and right horns, and both ends of the reinforcing bracket are respectively welded and fixed to the left and right horns.

[0012] Preferably, the upper side edge of the reinforcing bracket is provided with a flange bent forward, and both ends of the flange are respectively welded and fixed to the left and right horns.

[0013] Preferably, the swing arm front brackets are all in the shape of an N-shaped groove opening downward, and the downward openings of the swing arm front brackets are welded and fixed with swing arm front bracket reinforcements, and the left and right swing arm front bracket reinforcements are respectively welded and fixed to the left and right longitudinal beams.

[0014] Preferably, an exhaust pipe bracket extending longitudinally backward is welded and fixed to the crossbeam.

[0015] Preferably, one side edge of the left and right steering gear brackets is welded and fixed to the cross beam, and the other side edge is respectively welded and fixed to the left longitudinal beam and the right longitudinal beam.

[0016] Preferably, the reinforcing bracket is provided with a waist-shaped hole extending axially.

[0017] The beneficial effects of the present invention are as follows: 1. Lightweight structure and cost optimization; the orthogonal load-bearing frame structure is formed by welding the left and right longitudinal beams and the cross beam, which reduces redundant materials and overall weight compared to the traditional butterfly subframe; the longitudinal beams and cross beams are welded into a hollow tubular structure with stamped upper and lower plates, without the need for additional reinforcements, simplifying the process and reducing material costs, thereby achieving cost reduction and weight reduction.

[0018] 2. Improved strength and durability; the hollow rectangular tube longitudinal beam and hollow trapezoidal tube cross beam structure significantly improve the bending and torsional rigidity and enhance the carrying capacity; the horn bracket and the bushing positioning tube are matched through the circumferential boss and the annular groove gap to avoid welding thermal deformation, reduce stress concentration and fatigue damage risks, and extend service life; strengthen the bracket and flange design to further enhance the rigidity of the horn connection area and reduce vibration transmission.

[0019] 3. Assembly precision and functional integration optimization; the steering gear mounting hole, stabilizer bar mounting hole and rear mounting steel sleeve are integrated into the longitudinal beam, with precise positioning, simplifying the assembly process of the suspension and steering system; the steering gear bracket is welded at the corner of the crossbeam and the longitudinal beam to improve the steering gear installation stability and optimize the force distribution; the exhaust pipe bracket is integrated with the crossbeam to enhance functional integration and save chassis space.

[0020] 4. Manufacturing efficiency and environmental benefits; the clevis bracket, longitudinal beam and cross beam are all stamped, and the upper and lower plates are welded to each other, which reduces the need for complex molds and reduces manufacturing costs; the bushing positioning tube and clevis bracket are welded-free to reduce heat input, reduce energy consumption and carbon emissions, and are in line with the trend of green manufacturing.

[0021] 5. Improved NVH performance; the combination of the orthogonal load-bearing frame, hollow rectangular tube longitudinal beam and hollow trapezoidal tube cross beam effectively disperses vibration energy. The swing arm front bracket reinforcement inhibits local deformation, reduces noise transmission, strengthens the bracket, improves structural strength, relieves assembly stress, and improves the NVH performance of the vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of the present invention; Figure 2 A top view of the present invention; Figure 3 It is a front view of the present invention; Figure 4 This is a schematic diagram of the sheep horn structure in the present invention; Figure 5 It is a schematic diagram of the crossbeam structure in the present invention. DETAILED DESCRIPTION

[0023] like Figures 1 to 5 As shown, a front subframe structure of an automobile includes a left longitudinal beam 11, a right longitudinal beam 12, a cross beam 2, and a horn 3. The left longitudinal beam 11, the right longitudinal beam 12, and the cross beam 2 are welded to form an H shape and an orthogonal load-bearing frame structure. The left longitudinal beam 11 and the right longitudinal beam 12 are parallel to each other, and the left and right longitudinal beams are perpendicular to the cross beam 2.

[0024] The left and right longitudinal beams are welded by stamping the longitudinal beam upper plate 17 and the longitudinal beam lower plate 18 to form a hollow rectangular tube structure. The longitudinal beam upper plate 17 is an n-shaped groove with a downward opening, and the longitudinal beam lower plate 18 has an L-shaped cross section. The longitudinal beam lower plate 18 covers the opening of the longitudinal beam upper plate 17. The longitudinal beam upper plate 17 and the longitudinal beam lower plate 18 are welded to form a hollow rectangular tube structure; the cross beam is welded by stamping the cross beam upper plate 22 and the cross beam lower plate 23 to form a hollow trapezoidal tube structure. The web of the cross beam upper plate 22 is The wing panels on both sides expand outwards to form a downwardly open groove. The slope of the front wing panel expanding outwards is steeper, while the slope of the rear wing panel expanding outwards is gentler. The lower plate 23 of the crossbeam covers the opening of the upper plate 22 of the crossbeam to form a hollow trapezoidal tube structure. An exhaust pipe bracket 6 extending longitudinally backward is welded and fixed to the crossbeam 2. The vertical cross-sectional size of the hollow cavity formed by welding the upper plate 22 of the crossbeam and the lower plate 23 of the crossbeam is positively correlated with the bending mode of the subframe, and the longitudinal cross-sectional size is positively correlated with the torsional mode of the subframe.

[0025] The left and right swing arm front brackets 13 are welded and fixed to the outer sides of the front parts of the left and right longitudinal beams, and the left and right horns 3 are welded and fixed to the upper ends. The left and right steering gear mounting holes 14 are respectively opened at the upper ends of the middle parts of the left and right longitudinal beams, and the left and right stabilizer bar mounting holes 15 are respectively opened at the upper ends of the rear ends of the left and right longitudinal beams. The outer side walls are opened with swing arm rear placement bracket mounting ports, and the rear installation steel sleeves 16 are respectively fixedly arranged in the rear end rectangular tube cavity; A suspension mounting opening 21 is provided on the front side wall of the crossbeam 2, and a steering gear bracket 4 is welded and fixed at the corners between the rear side of the crossbeam 2 and the left and right longitudinal beams. A second steering gear mounting hole 41 is provided on the left and right steering gear brackets 4. The left and right steering gear brackets 41 are both triangular in shape, with one edge welded and fixed to the crossbeam 2, and the other edge welded and fixed to the left longitudinal beam 11 and the right longitudinal beam 12 respectively. The welding range and torsional mode of the left and right steering gear brackets 41 and the longitudinal beams are positively correlated, and the left and right steering gears are respectively fixed through the steering gear mounting hole 14, the second steering gear mounting hole 41, and the third steering gear mounting hole provided at the upper end of the crossbeam 2 in a three-point mounting manner.

[0026] The ram horn 3 includes a ram horn bracket 31 and a bushing positioning tube 32. The ram horn bracket 31 is a hollow trapezoidal tube structure. The front parts of the left and right longitudinal beams are respectively welded and fixed to the fixed ends of the oblique supporting parts of the left and right ram horn brackets 31. The fixed ends of the oblique supporting parts of the ram horn brackets 31 are also welded to the front bracket 13 of the swing arm. The horizontal and longitudinal welding lengths between the ram horn bracket 31 and the front bracket 13 of the swing arm are proportional to the front mounting point stiffness of the swing arm.

[0027] The oblique supporting portion of the horn bracket 31 is connected to the transverse extension portion through a bending portion, and a bushing positioning tube 32 is uprightly arranged in the transverse extension portion of the horn bracket 31. Both end faces of the bushing positioning tube 32 are provided with axially extending circumferential bosses, and the circumferential boss clearance fits in the annular groove provided on the inner wall of the transverse extension portion of the horn bracket 31. Through holes 33 connecting to the inner hole of the bushing positioning tube 32 are respectively provided on the upper and lower sides of the horn bracket 31.

[0028] The horn bracket 31 is formed by welding a stamped sheet metal upper body 311 and a sheet metal lower body 312. The sheet metal upper body 311 is in the shape of a trapezoidal groove opening downward, and the sheet metal lower body 312 covers the opening of the sheet metal upper body 311 to form a hollow trapezoidal tube structure.

[0029] A strip-shaped reinforcing bracket 5 is welded and fixed to the upper end of the crossbeam 2, and the reinforcing bracket 5 is located between the left and right horns 3. The two ends of the reinforcing bracket 5 are respectively welded and fixed to the left and right horns 3. The reinforcing bracket 5 is provided with an axially extending waist-shaped hole 52, and the upper side edge of the reinforcing bracket 5 is provided with a forward-bent flange 51, and the two ends of the flange 51 are respectively welded and fixed to the left and right horns 3. The suspension installation point is adjusted by adjusting the vertical height of the reinforcing bracket 5. The vertical stiffness of the reinforcing bracket 5 is proportional to the dynamic stiffness of the front installation point of the swing arm, and the longitudinal extension length of the flange 51 is proportional to the static stiffness of the front installation point of the swing arm.

[0030] The swing arm front bracket 13 is in the shape of an N-shaped groove opening downwards, the thickness of the front swing bracket is proportional to the dynamic stiffness of the front mounting point of the swing arm, and proportional to the static stiffness of the front mounting point of the swing arm, the downward opening of the swing arm front bracket 13 is welded and fixed with a swing arm front bracket reinforcement 131, the left and right swing arm front bracket reinforcements 131 are welded and fixed to the left and right longitudinal beams respectively, and the welding extension length of the swing arm front bracket reinforcement 131 and the longitudinal beam is proportional to the dynamic stiffness of the front mounting point of the swing arm.

[0031] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modification 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 front subframe structure of an automobile, comprising a left longitudinal beam (11), a right longitudinal beam (12), a cross beam (2), and a clevis (3), characterized in that: The left longitudinal beam (11), the right longitudinal beam (12), and the cross beam (2) are welded to form an orthogonal load-bearing frame structure; the left and right longitudinal beams are welded to form a hollow rectangular tube structure by stamping a longitudinal beam upper plate (17) and a longitudinal beam lower plate (18); and the cross beam is welded to form a hollow trapezoidal tube structure by stamping a cross beam upper plate (22) and a cross beam lower plate (23); The left and right swing arm front brackets (13) are respectively welded and fixed to the outer sides of the front parts of the left and right longitudinal beams, and the left and right horns (3) are respectively welded and fixed to the upper ends. The left and right steering gear mounting holes (14) are respectively opened at the upper ends of the middle parts of the left and right longitudinal beams, and the left and right stabilizer bar mounting holes (15) are respectively opened at the upper ends of the rear ends of the left and right longitudinal beams. The rear mounting steel sleeves (16) are respectively fixedly arranged in the rear end rectangular tube cavity. A suspension mounting opening (21) is provided on the front side wall of the cross beam (2), a steering gear bracket (4) is welded and fixed at the corners of the rear side of the cross beam (2) and the left and right longitudinal beams, and a second steering gear mounting hole (41) is provided on the steering gear bracket (4); The horn (3) comprises a horn bracket (31) and a bushing positioning tube (32); the horn bracket (31) is a hollow trapezoidal tube structure; the front portions of the left and right longitudinal beams are respectively welded and fixed to the fixed ends of the oblique support portions of the left and right horn brackets (31); the oblique support portions of the horn bracket (31) are connected to the transverse extension portion via a bent portion; a bushing positioning tube (32) is vertically arranged in the transverse extension portion of the horn bracket (31); both end surfaces of the bushing positioning tube (32) are provided with axially extending circumferential bosses; the circumferential bosses are gap-fitted in an annular groove provided on the inner wall of the transverse extension portion of the horn bracket (31); and through holes (33) communicating with the inner hole of the bushing positioning tube (32) are respectively provided on the upper and lower sides of the horn bracket (31).

2. The automobile front subframe structure according to claim 1, characterized in that: The horn bracket (31) is formed by welding a stamped sheet metal upper body (311) and a stamped sheet metal lower body (312); the sheet metal upper body (311) is in the shape of a trapezoidal groove opening downward, and the sheet metal lower body (312) covers the opening of the sheet metal upper body (311), forming a hollow trapezoidal tube structure.

3. The automobile front subframe structure according to claim 1, characterized in that: The longitudinal beam upper plate (17) is in the shape of an n-shaped groove opening downward, and the longitudinal beam lower plate (18) covers the opening of the longitudinal beam upper plate (17) to form a hollow rectangular tube structure.

4. The automobile front subframe structure according to claim 1, characterized in that: The wing plates on both sides of the web plate of the crossbeam upper plate (22) expand outwards to form a downwardly open groove shape, and the crossbeam lower plate (23) covers the opening of the crossbeam upper plate (22) to form a hollow trapezoidal tube structure.

5. The automobile front subframe structure according to claim 1, characterized in that: A strip-shaped reinforcing bracket (5) is welded and fixed to the upper end of the crossbeam (2); the reinforcing bracket (5) is located between the left and right horns (3); and both ends of the reinforcing bracket (5) are respectively welded and fixed to the left and right horns (3).

6. The automobile front subframe structure according to claim 5, characterized in that: The upper edge of the reinforcing bracket (5) is provided with a flange (51) bent forward, and both ends of the flange (51) are respectively welded and fixed to the left and right horns (3).

7. The automobile front subframe structure according to claim 1, characterized in that: The swing arm front brackets (13) are all in the shape of an n-shaped groove opening downwards, and a swing arm front bracket reinforcement member (131) is welded and fixed to the downward opening of the swing arm front bracket (13), and the left and right swing arm front bracket reinforcement members (131) are respectively welded and fixed to the left and right longitudinal beams.

8. The automobile front subframe structure according to claim 1, characterized in that: An exhaust pipe bracket (6) extending longitudinally backwards is welded and fixed to the crossbeam (2).

9. The automobile front subframe structure according to claim 1, characterized in that: One side edge of the left and right steering gear brackets (41) is welded and fixed to the cross beam (2), and the other side edge is respectively welded and fixed to the left longitudinal beam (11) and the right longitudinal beam (12).

10. The automobile front subframe structure according to claim 5, characterized in that: The reinforcing bracket (5) is provided with a waist-shaped hole (52) extending axially.

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