某SUV动力总成悬置系统引起的振颤问题研究

Research on Vibration of a SUV Caused by Powertrain Mounting System

针对某SUV减速带工况振颤问题,通过仿真分析发现是由动力总成engshake模态与簧下质量模态耦合引起。通过优化动力总成模态频率及解耦率,利用动力总成bounce及pitch耦合,分散动力总成振颤能量,并将pitch设置在簧下质量模态附近,使动力总成作为吸振器,改善振颤问题。通过实车测试,车身振动RMS降低0.19g,问题改善明显,验证了悬置系统模态耦合设计思路的可行性。

Aiming at the deceleration bump vibration of a SUV,the simulation results show that the problem is caused by the coupling of the engshake mode of the powertrain and the under spring mode.By optimizing the frequency and coupling rate of the powertrain system,the vibration energy of the powertrain is dispersed by the coupling of bounce and pitch,and the powertrain is used as the vibration absorber to improve the vibration problem through coupling the pitch with the under spring mode.Through real vehicle test,the RMS vibration of body decreased 0.19g,and the problem is improved obviously.The feasibility of the idea of mode coupling design of the powertrain mounting system is verified.