新型准零刚度空气悬架系统的设计与分析

Design and Analysis of a New Quasi-zero Stiffness Air Suspension System

为提高商用汽车在低频外部激励环境下的隔振性能以及行驶平顺性,基于准零刚度理论,采用正负刚度并联的方式,将负刚度碟形弹簧组与正刚度空气弹簧相结合,设计一种新型准零刚度悬架系统。通过静力学特性分析,建立力位移和刚度位移表达式,得到系统达到准零刚度的参数条件;通过动力学特性分析,建立系统的二自由度模型和简谐力作用下的非线性运动微分方程,得到力传递率特性曲线并对其进行分析。结果表明新结构的低频隔振性能显著提升。基于刚度位移表达式建立2自由度1/4悬架模型,分别对准零刚度系统与传统系统的垂向加速度、悬架动行程和轮胎动载荷等平顺性指标的差异性进行分析,仿真结果表明,该准零刚度系统的平顺性改善效果亦优于传统结构。

In order to improve the vibration isolation performance and ride comfort of commercial vehicles under low-frequency external excitation environment,a new suspension system with quasi-zero stiffness is designed based on the theo-ry of quasi-zero stiffness.In this system,the negative stiffness disc spring group is combined with the positive stiffness air spring by using the parallel connection of positive and negative stiffness.Through the analysis of statics characteristics,the expressions of force displacement and stiffness displacement are established,and the parameter conditions for the system to reach the quasi-zero stiffness are obtained;By analyzing the dynamic characteristics,a 2-DOF model of the system and a nonlinear motion differential equation under the action of harmonic force are established,and the force transfer rate charac-teristic curve is obtained and analyzed.The results show that the low-frequency vibration isolation performance of the new structure is significantly improved.Based on the stiffness displacement expression,a 2-DOF quarter of the suspension model is established to analyze the differences in ride comfort indicators,such as the vertical acceleration,suspension dynamic stroke,and tire dynamic load,between the quasi-zero stiffness system and the traditional system.The simulation results show that the ride comfort improvement effect of the quasi-zero stiffness system is also better than that of the traditional structure.