Lightweight Design And Experimental Syudy On Mixing Drum Of Concrete Mixer Truck

Concrete mixer truck is the core equipment of concrete transportation industry.In recent years,the national laws and regulations for concrete mixer truck standards and specifications become more stringent,its development direction is no longer the pursuit of large load,but the lightweight as the main direction of its development.On the premise of ensuring the service performance and life of the whole vehicle,the weight of the whole vehicle should be the lightest to realize the maximum loading.The lightweight improvement of concrete mixer truck is generally divided into two aspects:one is the structural optimization of its subframe and other accessories,the other is the lightweight research of mixing drum.The lightweight structure optimization of the sub frame is relatively easy to achieve,while the concrete in the mixing drum is constantly stirred in its working state,and its stress situation is complex.The continuous stirring produces impact force and friction on the inner surface of the mixing drum,resulting in the wear of the inner surface,until the mixing drum fails.Therefore,the best way to realize the lightweight of mixing drum is to carry out the force analysis and wear mechanism research of mixing drum and optimize its structure and parameters.In this paper,the mixing drum of an 8 m~3concrete mixer truck in SINOTRUK Qingdao Heavy Industry Co.,Ltd is taken as the research object,and the research methods of theoretical calculation,simulation,trial production and experimental verification are used to achieve the lightweight optimization design goal of mixing drum,which has certain guiding significance for the lightweight research of mixing drum.The specific research contents are as follows:1.The wear mechanism of mixing drum was studied and the wear characteristics of mixing drum were analyzed.Taking the mixing drum as the research object,the impact and wear characteristics of the concrete mixing process on the mixing drum are analyzed theoretically,and the factors influencing the mixing drum wear under two working conditions are obtained.2.The lightweight optimization design of mixing drum was completed.Based on the integral method,the size of the 8 m3 mixing cylinder is optimized to realize the lightweight of the cylinder with the same volume.Based on the analysis of the spiral angle parameters of the mixing drum,the parameter equation of the logarithmic spiral curve with equivariant angle is derived,and the optimal design parameters of each cone section of the spiral blade are determined.3.The dynamic simulation analysis of mixing drum wear was carried out,and the maximum wear position of mixing drum was determined.The parameters of concrete particles are determined by simulated slump experiment.On this basis,the working state of the mixing drum is simulated and analyzed by using discrete element method.The mixing uniformity of the mixing drum is analyzed by counting the number of particles in the multi grid at different time stages.The simulation results show that the mixing quality of the mixing drum is good.Through the analysis of the force,cumulative contact energy and wear amount of the mixing drum,it is determined that the maximum wear position of the mixing drum is located at the big end of the front cone.4.The coupling simulation method of discrete element and finite element is proposed to analyze the strength of the mixing drum.The method of EDEM and ANSYS Workbench coupling is used to simulate and analyze the stress and deformation of the mixing drum.Through the data analysis of the stress and deformation of the mixing drum,it shows that the strength of the mixing drum after lightweight design meets the work requirements.5.The lightweight mixing drum optimized by simulation was trial-produced and used in QDZ5313GJBZHTX30E1 vehicle and loading experiment was carried out.The loading performance,unloading capacity and residual rate of the mixing drum were tested.The results showed that the stirring quality,loading performance and residual rate of the mixing drum were better than the national standard.The actual wear of the mixing drum was measured.The maximum wear of the mixing drum was 0.04mm after 300 hours,and the error between the maximum wear and the simulation analysis was 2.5%,which verified the accuracy of the simulation analysis.