阻尼匹配是制约钢板弹簧悬架系统减振器设计的关键问题。根据1/4车辆二自由度行驶振动模型，利用随机振动理论，建立了悬架系统最优阻尼比及悬架动挠度和振动速度均方根值数学模型。在此基础上，通过分析、处理钢板弹簧加载-卸载试验所测得的载荷及变形数组数据，建立了在实际行驶工况下的钢板弹簧等效阻尼数学模型；根据悬架系统最优阻尼比及钢板弹簧的等效阻尼，得到了所需匹配减振器在悬架系统中应承担的最佳阻尼比；利用平安比及双向比，建立了钢板弹簧悬架系统最佳阻尼匹配减振器的速度特性，并通过仿真分析和实车行驶平顺性试验验证了钢板弹簧悬架系统减振器最佳阻尼匹配设计方法的正确性及有效性，利用该设计方法匹配减振器后的车身垂直振动加速度均方根值与传统经验法相比降低了6.72%，能够有效改善车辆的乘坐舒适性。该研究可为钢板弹簧悬架系统减振器的设计提供参考。%Damping matching is the key problem of shock absorber design for leaf spring suspension system, and there is no optimal matching theory to resolve this problem at present, which seriously restricts the improvement of ride comfort and driving safety. So, in order to make the leaf spring suspension system achieve the optimal damping matching so that the vehicle has good ride comfort and driving safety, in this paper, based on the quarter vehicle model and random vibration theory, taking the minimum of body vertical vibration acceleration as the target, a mathematical model of optimal damping ratio of suspension based on ride comfort was established; taking the minimum of wheel dynamic load as the target, a mathematical model of optimal damping ratio of suspension based on driving safety was established; then, according to the golden section, a mathematical model of optimal damping ratio of suspension based on ride comfort and driving safety was built. Based on this, the root mean square value of suspension dynamic deflection was taken as the leaf spring vibration amplitude, which was obtained under actual road conditions for vehicle driving, and the root mean square value of suspension vibration velocity obtained under actual road conditions for vehicle driving was combined with the principle of energy conservation; by analyzing and processing the load and deformation array data of leaf spring loading-unloading test, the equivalent damping of leaf spring under certain work condition and the damping ratio provided by leaf spring for the suspension were built. Then, combining the optimal damping ratio of suspension based on ride comfort and driving safety with the damping ratio provided by leaf spring, using the displacement superposition principle, the optimal damping ratio, which should be provided by shock absorber matching to the optimal damping of leaf spring suspension, was built. Based on this, using the smoothness-safety ratio and the two-way ratio, a mathematics model of velocity characteristic of shock absorber matching to the optimal damping of leaf spring suspension was built. With a practical example, the optimal damping ratio and the velocity characteristic of shock absorber for leaf spring suspension system were designed, and the optimal damping matching method was validated by the simulation. The result showed that using the theoretical design method for the shock absorber, the root mean square value of body vertical vibration acceleration was reduced by 7.67% compared with the traditional experience method. Furthermore, in order to further verify the correctness of the result, the optimal damping matching method was validated by the vehicle ride comfort test. The result showed that using the theoretical design method for the shock absorber, the root mean square value of body vertical vibration acceleration was reduced by 6.72% compared with the traditional experience method. Therefore, the results showed that the optimal damping matching method of shock absorber for leaf spring suspension system was correct, and it could significantly improve the ride comfort of vehicle and make the vehicle have good driving safety. This study has significant value of theory research and practical application for shock absorber design of leaf spring suspension system.
展开▼
