Performance Analysis And Optimization For Minibus Powertrain Mounting System

The powerstrain is one of the most important vibration sources in the automobile.To improve the riding comfort and reduce the transmission of engine vibration to the body,the use of engine mounting system connection powerstrain and frame are important means of isolating vibrations.Mounting system support powerstrain and isolate vibration sources,play an important role in the vehicle NVH performance.Design reasonable engine mounting system can significantly reduce the vibrations of the vehicle powertrain and body,improve the NVH performance,and improve the ride comfort.In the process of the development of the mounting system performance,the problems of layout,structure and stiffness are found and optimized to enhance the market competitiveness.This paper present development case of a domestic brand mounting system,the vibration isolation performance of the system is analyzed,and the dynamic model establishment,analysis,optimization and sensitivity analysis of the powertrain mounting system are completed.The main research contents are listed as follows:First,this paper expounds the source,research significance and purpose of the project,summarizes the function,ideal characteristics and system design requirements of the mounting system,and introduces the development history and the present situation of the research and development.The characteristics of the powertrain mounting system are studied,including layout theory,ideal characteristics,design requirements and dynamic mathematical model,the vibration isolation theory of mounting system and the commonly used design theory are evaluated.Second,the physic parameters,bushing stiffness and damping,location parameter of mounting system are obtained,which prepare for the rigid modal analysis.Finally,this paper establishes the mechanical model of rubber mounts,describes the powertrain coordinates and relative coordinates,and establishes the rigid engine mounting system with six degrees of freedom dynamic model.Then based on Lagrange equation and the theory of vibration,establish the powertrain mounting system mathematical model,which completed the modal and decoupling analysis.Based on the design of the decoupling rate,the design variable of bushing stiffness have been optimized,and DOE analysis are taken into account,which will help to improve the efficiency in the early development and matching products.