The Vibration Isolation Mechanism Research And Design Of Hydraulic Engine Mount With Powertrain Of Construction Vehicle

As large vehicles used in national construction,the working environment of construction vehicles are relatively poor.With the increasing demand for driving comfort,the traditional rubber isolator has been unable to meet the requirements of vibration isolation performance.At present,the hydraulic engine mount(HEM)is mainly used in some top-grade cars in China,and the internal liquid flow structure is relatively simple,so it cannot give full play to its excellent vibration isolation performance.In this paper,the floating-decouple hydraulic engine mount is taken as the research object,the evaluation index,modeling method,identification of structure parameters of floating-decouple HEM,and the HEM under different conditions of Mount dynamic characteristics are mainly studied,the main research work is as follows:1?Research on the lumped parameter modeling method of HEM.Based on the study of the working mechanism of floating-decouple HEM,the evaluation index is established,including the dynamic stiffness and equivalent damping coefficient.The lumped parameter model of the floating-decouple HEM is established under two different conditions:the low frequency,large amplitude and the high frequency and small amplitude.The formulas for calculating the dynamic stiffness and damping coefficient of the floating-decouple HEM under different working conditions are derived,and the characteristic points of the dynamic characteristics of the HEM are obtained,which provides the theoretical guidance for the design of the floating-decouple HEM.2?The key parameters of the floating-decouple HEM are identified based on the fluid-structure interaction finite element theory.The finite element method was used to identify the key physical parameters such as the rubber spring,the flow damping coefficient of the damping hole and the decoupling device with ADINA finite element software,which provides a new method for identifying the structural parameters of the floating-decouple HEM.3?Dynamic characteristics of the floating-decouple HEM are simulated with MATLAB.Based on the lumped parameter model,and the effects of key parameters on the dynamic characteristics are analyzed.Through the finite element simulation of a complete fluid-structure interaction finite element model,the relationship between the dynamic reaction force and displacement excitation is obtained,and the dynamic characteristics are analyzed and evaluated by the geometric drawing method.4?Analysis application of the floating-decouple HEM in the loader powertrain.The target of the vibration optimization is defined through the vibration test and analysis of the powertrain system.Through the analysis of the harmonic response of the original rubber vibration isolator,the main reason of the poor vibration isolation performance of the rubber isolator is obtained.In this paper,the structural parameters of the floating-decouple HEM are designed for the loader power assembly system,and the dynamic characteristics of the system are verified by the simulation analysis,which provides the theoretical support for the application of the floating-decouple HEM in the construction vehicle.