Research On The Performance Degradation Of Engine Rubber Mount

The NVH of vehicles refers to Noise(noise),Vibration(vibration)and Harshness(acoustic vibration roughness),that is,the vibration and noise of vehicles.At high mileage,the NVH performance of the rubber parts of the automobiles had irreversibly declined.However,due to the complexity of rubber materials and the rubber parts were affected by multiple factors,few people studied their recession.In view of this problem,some basic researches were carried out on the performance degradation of automotive rubber mount in this paper.It was necessary to understand the decline mechanism of the engine rubber mount performance.In this paper,rubber materials and components were analyzed and tested,the purpose was to study the decay mechanism of rubber mount,to predicted mount performance based on material changes,and to give some methods to slow down the performance of rubber mount.Firstly,the stress-strain data ware obtained by basic experiment of rubber material,then the experimental data were fitted by using different constitutive models,and the most suitable constitutive relation was selected according to the actual situation.Then,the viscoelastic model was obtained by using the generalized Maxwell model and the least square method through the experiment of DMA(Dynamic mechanical analysis).Secondly,the paper briefly introduced the mechanism of the deterioration of the rubber material.The important factors affecting the properties of rubber materials are studied through experiments and simulations,and based on changes in material parameters and temperature,the relationship between the static stiffness of rubber mount and these changes is derived.Then,combining with some mount structures commonly used in automobiles,the mechanism of the performance degradation is analyzed according to the rubber mounting work modes at different positions.Finally,a certain domestic pickup rubber mount device was optimized to design,the optimized powertrain natural frequency distribution was reasonable,the energy decoupling rate meets the design requirements.According to the engineering example,a rubber mount dimension design method was used and the size of the rubber mount was analyzed based on the working conditions.,and then The finite element simulation and experimental tests were performed to verify the results.The results showed that this design method can effectively improve the anti-fatigue performance of the mount,slow down the performance degradation of the rubber mount,and solve the contradiction between high performance and low cost of the mount.Then introduced the natural rubber formula and craft,when chooses the rubber formula,must comprehensively consider to the rubber various formulae mechanism and the rubber product working environment,can prolong the life of the rubber product.At last,some physical insulation methods are introduced.By adding a heat shield on the rubber mount,the performance degradation of the rubber suspension can be effectively mitigated.