| Since the 21 st century,with the support of government policies and the joint efforts of various industries,China's automobile industry has developed rapidly.At the same time,the pressure of energy saving and emission reduction is increasing.The state clearly proposes to build a "resource-saving,environment-friendly" society.By2020,the overall fuel consumption target of passenger cars in China should reach 5liters/100 kilometers,and 4 liters/100 kilometers by 2025.To achieve this goal,vehicle lightweight is an inevitable trend of development.Sub-frame is an important part of front axle or rear axle.It can prevent vibration and noise from entering the carriage and improve ride comfort.At the same time,the sub-frame can improve the stiffness of the car.It can Integrated chassis parts and improve the convenience of assembly.However,the relatively large sub-frame will increase the weight of the car,this is not conducive to achieving lightweight goals.If aluminum alloy is used,the problem can be solved easily.The forming process of aluminium alloy is various,and extruding aluminium alloy is one of the solutions.Firstly,based on the principle of multi-rigid-body system dynamics,the force distribution at the hard point where the sub-frame connects to the body and chassis is obtained according to the different motion conditions of the vehicle.On this basis,this paper develops the research of progressive space topology optimization technology.With the load under different working conditions as input,the sub-frame as the object of research,analysis and optimization design,under the constraints of design space,and on the premise of satisfying the modal and strength of assembly,the initial structure of automobile aluminum alloy sub-frame is obtained,and combined with manufacturing technology and connecting technology.Connect process and other constraints to obtain the final structure.Then,through the finite element simulation,the strength,modal and other performance were checked to confirm that the structure of the sub-frame assembly can meet the design performance requirements.Finally,the aluminium alloy material and its extrusion process are fully studied,the connection process and its quality assurance method are studied,which supports the development work from the manufacturing aspect,and simple manufacturing and connection verification are carried out within the allowable range.In a word,compared with other processes,extrusion process has greaterflexibility in processing.Compared with processing costs,die cost of extrusion process is lower,time-consuming and high efficiency.Extruded aluminium alloy has been widely used in automotive anti-collision beams,but rarely in sub-frame.Based on the development process of traditional automotive parts,this paper establishes a topological mechanics model to realize progressive spatial iteration.Combining with extrusion process requirements,the performance-based aluminium alloy sub-frame is optimized.New material,new structure and new technology are applied in automobile design to meet the requirements of lightweight design. |
PDF Full Text Request