新型一体式悬架减振支柱行程相关刚度特性研究

Stroke-dependent stiffness characteristics of a new type of integrated suspension strut

提出一种由空气弹簧与单筒式液压减振器组成的新型悬架减振支柱的设计方案,该减振支柱总成刚度与工作行程相关。介绍该减振支柱结构组成和工作原理,基于并联双气室空气弹簧简化物理模型,应用流体力学及热力学理论,建立减振支柱刚度特性数学模型,运用SIMULINK软件对气室压力、总成弹性力及总成刚度与行程的关系进行仿真,结果表明,总成刚度随行程的变化呈非线性变化,有利于抑制不良路面条件下的车轮跳动和"悬架击穿"。通过台架试验测试减振支柱样件的主气室压力及总成弹性力与行程的关系,试验结果与仿真结果基本一致,表明减振支柱刚度特性数学模型正确有效,新型减振器支柱结构方案可行,可简化主动或半主动悬架结构。

The design scheme of a new type of suspension strut consisting of an air spring and a monotube hydraulic shock absorber was put forward, its assembly stiffness characteristic was related to the stroke. The structure and basic working principle of the strut was introduced. According to the simplified physical model of air spring with double gas rooms in parallel, a mathematical model for the stiffness characteristics of the strut was established based on fluid mechanics and thermodynamics. Relationships between stroke and gas room pressure, strut elastic force and its stiffness were simulated by using software SIMULINK. The simulation results indicated that the strut stiffness varies nonlinearly with the stroke ; this property of the strut stiffness helps to restrain wheel bouncing and ＂suspension breakdown＂ under bad road conditions. The strut specimen bench test was conducted to verify the relationships among gas pressure of main air chamber, strut elastic force and stroke. The test results showed good agreement with the simulation ones. It was shown that the established mathematical model of strut stiffness is correct and the design scheme of the new strut is feasible, it can simplify the structure of an active or semi-active suspension.