Reserch On Design Methods Of The Powertrain Mounting System For New Energy Vehicles

With the development of the automobile industry and the highlighting of national energy issues,new energy vehicles such as electric vehicles have ushered in good development opportunities.Consumers’ demands for the overall performance of new energy vehicles continue to increase,and the NVH problem of new energy vehicles has become the focus of attention of various O EMs.Since the internal excitation and structure of new energy vehicles are different from those of traditonal vehicles,the design of new energy vehicle powertrain mounting systems cannot be applied to the design method of traditional vehicles.This paper has carried out research on the pure electric vehicle powertrain mounting system.First of all,this paper should optimize the design of a p ure electric vehicle powertrain mounting system.Considering the differences of the powertrain excitation between pure electric vehicles and traditional diesel vehicles,a 6-degree-of-freedom dynamic model of a pure electric vehicle powertrain is established.The natural frequency and energy distribution of the powertrain are reasonably allocated as optimization targets.The mounting static stiffness and installation position are design variables.The parameters of the mounting system are optimized by Matlab /Isight.After optimization,the natural frequency and energy distribution meet the design requirements.In order to control the displacement of the powertrain centroid of gracity under various working conditions,the stiffness and inflection point of each mounting nonlinear segment are designed.The designed powertrain centroid of gracity displacement meets the displacement control requirements.The accuracy of the centroid displacement of the powertrain calculated in Matlab is verified.Considering the performance fluctuations of the mounting components in the subsequent manufacturing process,this paper evaluates the reliability of the mounting system designSecondly,in order to control the vertical displacement of the powertrain’s centroid under the excitation of the road surface,this paper establishes a 13-degree-of-freedom analysis model for a type of new energy vehicle.After analysis,the vertical displacement of the powertrain’s center of mass exceeds the required value under the condition of overspeed reduction belt,so two of the mounts are designed to be hydraulic mounts.Considering the characteristics of the dynamic characteristics of the hydraulic mounting with frequency,a five-parameter model is used to describe the dynamic stiffness and lag angle of the hydraulic mount.The maximum displacement of the powertrain in the vertical direction of a certain type of vehicle is the design goal.The five p arameters of the hydraulic powertrain mounts mounting are used as design variables,and the maximum displacement of the optimized powertrain meets the design requirements.Thirdly,in order to facilitate the design and calculation of the pure electric vehic le powertrain mounting system.This article developed a user interaction interface software based on Matlab GUI.The software has two main functions,the modal calculation design of the powertrain mounting system and the centroid displacement control design of the powertrain.After the design is completed,a set of calculated mature data is brought into the verification of the ease of use and accuracy of the software development.