| The auto industry is developing very fast and more and more family have passenger car.People do not just satisfied with getting the destination, passengers pay more attention to the comfort and the control stability of the vehicle.So it gives higher requirement to the vehicle NVH performance.But right now our national’s R&D centers don’t have much knowledge about the NVH and still have much work to do.The suspension hydrobushing work as an important shock absorb component have much better working performance than the rubber bushing,it can absorb the shock and reduce the noise so it is widely used in advanced passenger car.The design and research about hydrobushing in our national is late than foreign country and have much problems about the relevant design principal and it’s performance.This thesis research the project the key technology about the vibration comfort on the passenger car included in the Science and Technology Program of Jilin Province.Build the mathematical model of the hydrobushing,it can calculate the response force more accurately in time domain.Also this model both have frequency relative and amplitude relative.To improve the mechanical performance of hydrobushing the thesis introduce one type invented hydrobushing which can self-adaption it’s inertia track area.The main tasks and responsibilities are as the following :According to the structure characteristic of hydrobushing and compared to the preexisting mathematical model build new mathematical model.Analysis the states of flow and it’s relationship with the pressure lost in the inertia track.To make the model more easier to calculate,firstly simplify the flow state as laminar flow and ignore the throttling loss at entrance and exit.Although this model will lost the amplitude relative,but it still have much significance to the research of hydrobushing.Calculate the dynamic stiffness and lost angel in frequency domain.Use Excel solver module to identity the parameters of the mathematical model.The result fit well with the test result from the test bench MTS831.Also research the sensitivity of parameters in the mathematical model by changing the size of parameters.Ignore the parameter which have less influence to the dynamic property in the following calculation.Using the same method identify the parameters of different amplitude in the simplified model.Analysis the relationship of parameters and the amplitude then fitted curve of them.By all the research results build the new model of hydrobushing by mathematical method.The model can calculate the response force easily in time domain which still both have frequency relative and amplitude relative.Also this model save much calculate time.One type hydrobushing have fixed frequency range of highly efficient vibration isolation.To improve it’s mechanical property designed one type hydrobushing which can change it’s inertia track section area according to the frequency.This project increase the highly vibration isolation efficiency of hydrobushing.This thesis research the mechanical property of hydrobushing, figure out one accurate mathematical model in time domain.Introduce one type hydrobushing. |
