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CN-122009328-A - Composite forming process for four-bar linkage suspension subframe of commercial vehicle

CN122009328ACN 122009328 ACN122009328 ACN 122009328ACN-122009328-A

Abstract

The invention provides a composite forming process of a four-bar linkage suspension subframe of a commercial vehicle, which belongs to the technical field of subframe production and manufacturing and comprises the following steps of S1, determining subframe structural parameters based on CAE multi-objective collaborative optimization, S2, manufacturing a left longitudinal beam and a right longitudinal beam by adopting an extrusion forming process, S3, manufacturing a front cross beam by adopting a hydraulic forming process, S4, manufacturing a rear cross beam by adopting a composite structure, S5, positioning and clamping all parts by a clamp, coating structural adhesive, and S6, processing special mounting points of the four-bar linkage suspension subframe on the subframe. According to the invention, through CAE multi-objective optimized driving multi-material composite forming and precise structural adhesive and rivet assembly, the cooperative lifting of the subframe with light weight and high torsional rigidity can be realized, the four-bar suspension is precisely adapted, the NVH performance is improved, the cost is reduced, the synergy is improved, the universalization degree is high, and long-term durability and reliability are ensured.

Inventors

  • TONG JIANMING
  • MENG QINGTING
  • Chang Shiyi
  • SHAO QI

Assignees

  • 中国重汽集团济南动力有限公司

Dates

Publication Date
20260512
Application Date
20260205

Claims (10)

  1. 1. A composite molding process of a four-bar linkage suspension subframe of a commercial vehicle is characterized by comprising the following steps of: S1, determining structural parameters of an auxiliary frame based on CAE multi-objective collaborative optimization, wherein the auxiliary frame is in a butterfly layout and comprises a left longitudinal beam (101), a right longitudinal beam (102), a front transverse beam (103) and a rear transverse beam (105), wherein the left longitudinal beam (101) and the right longitudinal beam (102) are symmetrically arranged and the middle part of the auxiliary frame is converged; S2, manufacturing a left high-strength aluminum alloy longitudinal beam (101) and a right high-strength aluminum alloy longitudinal beam (102) by adopting an extrusion molding process; S3, manufacturing an aluminum alloy front cross beam (103) by adopting a hydraulic forming process, wherein the whole front cross beam (103) is arched; S4, preparing a rear cross beam (105) by adopting a high-strength steel and aluminum alloy composite structure, and processing an assembly groove (1051) in the middle of the rear cross beam during preparation; S41, manufacturing a middle cross beam (104) of the carbon fiber composite structure, which is matched with the assembly groove (1051), by adopting an autoclave molding process; S5, positioning and clamping all parts through a clamp, and coating double-component epoxy resin structural adhesive on overlapping areas of a left longitudinal beam (101) and a right longitudinal beam (102) with a front cross beam (103) and a rear cross beam (105) respectively, wherein the middle cross beam (104) is embedded into an assembly groove (1051) and synchronously coated with adhesive, riveting is adopted for fixing before the structural adhesive is initially solidified, and meanwhile, a connecting joint is reinforced through a connecting cap mechanism and assembled into a whole; S6, processing special mounting points of the four-bar linkage suspension on the assembled auxiliary frame, wherein the mounting points comprise an upper control arm mounting point (110), a lower control arm front mounting point (111), a lower control arm rear mounting point (112) and a stabilizer bar mounting point (113).
  2. 2. The composite forming process of the four-bar linkage suspension subframe of the commercial vehicle according to claim 1, wherein in the step S2, the high-strength aluminum alloy is 6082-T6, the solution treatment and the aging treatment are sequentially carried out after extrusion forming, the solution treatment temperature is 530-550 ℃, and the aging treatment temperature is 160-180 ℃.
  3. 3. The composite forming process of the four-bar linkage suspension subframe of the commercial vehicle according to claim 1, wherein in the step S5, the connecting cap mechanism comprises an upper cap body (301), a lower cap body (302) and a bolt group (303), the upper cap body (301) and the lower cap body (302) are respectively wrapped at all connecting points of the left longitudinal beam (101), the right longitudinal beam (102) and the front cross beam (103) and the rear cross beam (105), and the upper end and the lower end of an assembling connecting point of the middle cross beam (104) and the rear cross beam (105), and the bolt group (303) penetrates through flanges to be fastened.
  4. 4. The composite forming process of the four-bar linkage suspension subframe of the commercial vehicle, which is characterized in that in the step S1, the topological optimization iteration number is not less than 15, the objective function is to maximize static stiffness, the consumption of constraint materials is not more than 30% of a design space, and the first-order natural frequency is not less than 45Hz.
  5. 5. The composite forming process of the four-bar linkage suspension subframe of the commercial vehicle is characterized in that in the step S3, the front cross beam (103) is made of an aluminum alloy 6061-T6 pipe, the middle part of the front cross beam is arched upwards after hydraulic forming, and the arch height meets the avoidance space requirement of a steering system.
  6. 6. The composite molding process of the four-bar linkage suspension subframe of the commercial vehicle according to claim 1, wherein the middle cross beam (104) is in interference fit with the assembly groove (1051), is fixed with rivets through a bi-component epoxy resin structural adhesive after being embedded, and is rigidly connected with the rear cross beam (105).
  7. 7. The composite forming process of the four-bar linkage suspension subframe of the commercial vehicle, which is characterized in that the forming process parameters of an autoclave are that the temperature is 120-180 ℃, the pressure is 0.5-0.7MPa, the carbon fiber composite material is a T700-grade prepreg, and the layering sequence is [0 degree/45 degree/90 degree/45 degree ] s.
  8. 8. The composite forming process of the four-bar linkage suspension subframe of the commercial vehicle according to claim 1 is characterized in that in the step S6, two upper control arm mounting points (110) are arranged, two upper control arm mounting points (110) are respectively arranged at the front parts of a left longitudinal beam (101) and a right longitudinal beam (102), two lower control arm front mounting points (111) are arranged, two lower control arm front mounting points (111) are respectively arranged at the middle parts of the left longitudinal beam (101) and the right longitudinal beam (102), two lower control arm rear mounting points (112) are arranged, two lower control arm rear mounting points (112) are respectively arranged at the rear parts of the left longitudinal beam (101) and the right longitudinal beam (102), two stabilizer bar mounting points (113) are arranged, and two stabilizer bar mounting points (113) are arranged at two ends of a rear cross beam (105).
  9. 9. The composite molding process of the four-bar linkage suspension subframe of the commercial vehicle according to claim 1, wherein the quality detection is carried out after the assembly is completed, and the detection indexes comprise torsional rigidity not lower than 4500N The m/deg, the first-order torsional mode frequency is 45-50Hz, the maximum stress is lower than the yield strength of the material, and the fatigue life coefficient of 100 kilometers is more than or equal to 1.35.
  10. 10. The composite forming process of the four-bar linkage suspension subframe of the commercial vehicle, which is characterized in that in the step S5, automatic riveting equipment is adopted for riveting, the rivet spacing is 15-20mm, and the glue layer thickness is 0.5-1.0mm.

Description

Composite forming process for four-bar linkage suspension subframe of commercial vehicle Technical Field The invention relates to the technical field of production and manufacturing of auxiliary frames, in particular to a composite forming process of a four-bar linkage suspension auxiliary frame of a commercial vehicle. Background Along with the improvement of energy saving and emission reduction and driving comfort requirements of commercial vehicles, the auxiliary frame with light weight, high torsional rigidity and vehicle type suitability becomes an industry core requirement, and the four-bar independent suspension further highlights the limitation of the existing forming process due to the severe requirements of the auxiliary frame on hard point precision and force flow transmission paths. In the prior art, as disclosed in chinese patent application publication No. CN116331355A, a light-weight sheet metal front subframe of an electric vehicle adopts a sheet metal welded double-beam and Z-shaped two-stage longitudinal beam structure, and weight reduction is achieved by canceling a bent pipe beam, but the process only relies on single sheet metal splicing and welding, does not design a special mounting structure for a four-bar suspension, and lacks a systematic optimization means, so that torsional rigidity and modal performance are difficult to match with heavy load requirements of a commercial vehicle. For example, chinese patent application publication No. CN116968813a discloses a three-beam front subframe of a new energy electric vehicle, which is additionally provided with a middle beam and adopts a front beam of a tube body to improve load adaptability, but still mainly uses a traditional welding process, does not involve multi-material composite forming and precise parameter optimization, and cannot meet the requirements of a four-bar linkage suspension on installation precision and stress dispersion. In addition, the existing auxiliary frame forming process has the defects that firstly, the integration level of materials and processes is low, single steel or common aluminum alloy is mostly adopted, an efficient forming scheme of a carbon fiber composite material and steel-aluminum composite structure is lacked, secondly, design and processes are disjointed, forming parameters are not guided through simulation optimization, so that the weight and performance of a product are difficult to balance, thirdly, the suitability is poor, the modularized installation requirement of a four-bar linkage suspension cannot be responded quickly, the development period is long, and the cost is high. Therefore, a compound forming process based on simulation optimization is needed in the industry to realize the cooperative lifting of the four-bar linkage suspension subframe of the commercial vehicle with light weight, high rigidity and universality so as to solve the technical defects in the prior art. Disclosure of Invention The invention aims to overcome the defects that in the prior art, a four-bar independent suspension is difficult to adapt, the light weight and high torsional rigidity are poor in cooperativity, and a CAE multi-target optimized driving design is lacked, and provides a composite forming process of a sub-frame of a four-bar suspension of a commercial vehicle. The invention is realized by the following technical scheme that the composite forming process of the four-bar linkage suspension subframe of the commercial vehicle comprises the following steps: S1, determining structural parameters of an auxiliary frame based on CAE multi-objective collaborative optimization, wherein the auxiliary frame is in a butterfly layout and comprises a left longitudinal beam, a right longitudinal beam, a front cross beam and a rear cross beam, wherein the left longitudinal beam and the right longitudinal beam are symmetrically arranged and the middle part of the left longitudinal beam and the right longitudinal beam is converged; S2, manufacturing a high-strength aluminum alloy left longitudinal beam and a high-strength aluminum alloy right longitudinal beam by adopting an extrusion molding process, wherein reinforcing rib grids are formed inside the molded left longitudinal beam and right longitudinal beam, and the cross section of the reinforcing rib grids is of a variable-thickness B-shaped structure; s3, manufacturing an aluminum alloy front cross beam by adopting a hydraulic forming process, wherein the whole front cross beam is arched; S4, preparing a rear cross beam by adopting a high-strength steel HG785 and aluminum alloy composite structure, wherein an assembly groove is processed in the middle of the rear cross beam during preparation, and a microporous polyurethane damping material is filled in the rear cross beam; S41, manufacturing a middle cross beam of the carbon fiber composite structure and adapting to the assembly groove by adopting an autoclave molding process; s5, positioning and clamping all