Study On Mechanical Thermal Expansion Forming Process And Fatigue Performance Of Rear Axle Housing Of A Heavy Duty Truck

Cars are one of the best commodities for stimulating domestic demand,and are good carriers for promoting domestic demand and promoting sustained economic and social development.Today,the rapid development of the automobile industry has brought many problems.The emission of automobile exhaust gas causes air pollution,single energy and non-renewable energy,depletion of raw materials,rising costs,etc.,which restricts the development of the automobile industry.One of the most important ways to achieve energy saving and emission reduction.In recent years,new processing technologies,the application of new materials and the forward-looking concept of car have become the target of the automotive industry.Among them,the production method of the drive axle shell has been greatly innovated,and the original cast bridge shell and the flush welded bridge shell process are gradually replaced by the internal high pressure forming process.The former has a cumbersome process,large equipment investment,difficulty in forming a series of products,and low utilization rate of materials.The latter has greatly improved these problems.The internal high pressure forming technology is divided into liquid internal high pressure forming,cold mechanical expansion forming and hot mechanical expansion forming.In most enterprises,cold mechanical expansion stroke technology and liquid internal high pressure forming technology have been applied in batches,but The production capacity is greatly restricted,and automated production cannot be used.The hot mechanical expansion molding technology solves this problem well and combines the advantages of the first two technologies.Therefore,research on the thermal mechanical expansion technology of seamless steel tubes refers to the schedule.The mechanical thermal expansion forming technology of the axle housing body studied in this paper,after 2010,major universities and enterprises have been investedin the research,including the unit where I am located.In the initial design,it is necessary to eliminate the welding of the triangular plate during the molding process of the axle housing body,and form the integral with the body,and it has not entered the mass production mode until now.The paper once again carries out simulation analysis and optimization,optimizes the structure and size of the 457 series axle housing,and meets the process requirements,it can also be suitable for mass production.It can absorb cold bulging experience and replace it with a smaller triangular plate.No triangular plate structure.Firstly,based on the original series of axle shells,this paper confirms the optimized geometry of the axle shell body.After establishing the finite element model,it analyzes and confirms whether it can meet the product design requirements in the software,and analyzes the structural deficiencies.Optimize the structure.Secondly,a multi-pass bulging process scheme was developed with a seamless round pipe as the raw material and satisfying the bulging ratio.The first thing to do in the process is to set the preset hole scheme.In order to ensure the process feasibility,the multiple schemes are analyzed.Combined with Deform-3D finite element analysis software,the process parameters and mold structure are gradually improved and optimized.Reduced development and verification time.Finally,according to the previous argument,the bulging mold was designed and processed,and on-site process verification was carried out.After successfully preparing the sample,compare the previous analysis content,put forward reasonable opinions and risk assessment,and lay the foundation for the subsequent batch production.The bench test of the axle housing assembly was verified to further confirm that the designed product meets the requirements of vertical bending strength and fatigue.