| The development of e-commerce has led to the rapid development of the express logistics industry,but the logistics industry’s transport costs have been high.At the same time,with the rapid development of economy,the problem of environmental pollution and energy shortage is becoming more and more obvious,and the increase in the number of cars has made these problems become more and more serious.Therefore,energy saving,environmental protection,safety and comfort,light weight,low cost has become the pursuit of the goal of the automobile manufacturing enterprises.According to foreign research data show that the quality of the vehicle for each reduction of 100 kg,one hundred kilometers fuel consumption can be reduced by 0.3 to 0.6 liters of vehicle weight per weight loss of10%,fuel consumption can be reduced by 5% ~ 8%.At the same time,light weight can reduce the consumption of raw materials,reduce the cost of parts,increase the income of the enterprise.For the development of a rational structure,the lightest weight of the frame,this topic first by benchmarking in mature lightweight frame structure,according to the commercial vehicle design and development of ideas,select the appropriate size of the longitudinal beam and the cross beam and according to the characteristics of existing products and common failure modes and measures to solve,combined with given vehicle operating conditions and design objectives,application of high strength plate,preliminary optimization scheme is proposed.According to the results of finite element analysis,the maximum stress position of the frame is found,the based car and express logistics vehicle frame longitudinal beam on the maximum stress appeared in the spring support,a cab mounting support near,mainly these positions need to load the assembly or goods to down level transfer,local easy now concentrated load.These positions in the parts of the design should pay special attention to the arrangement of hole position,to avoid the three hole line and the hole distance is too small situation.After completing the theoretical analysis,we verify the correctness of the analysis results and the rationality of the structure by means of electrical test and road test.And analyzes the problems in the process of the test,and puts forward the measures to further ensure the rationality of the product structure and the use of thereliability of the process.Based on the theory of fatigue analysis,the maximum stress and minimum stress were found out by using the rain flow method.The results show that the stress data of all the measuring points are in the range of the limit stress curve of the material,which shows that the fatigue life of the parts of the frame can meet the requirements of the application.In this paper,combined with the finite element analysis,electrical test and road test and other means,through the comparative analysis,the design of the optimal frame structure,and through the test of the reliability of the frame.Through the advanced theory design method is applied to frame design,sublimation previously only depends on experience design method,to avoid the structural design is too conservative,in order to achieve frame weight is lighter,the structure is more reasonable.At the same time,through the combination of electric measurement and finite element analysis,the rationality of the scheme is verified,the reliability of the product is guaranteed,and the verification time of product development is shortened,and the efficiency of product development is improved. |
