Identification on modal coupling of a self-excited vibration of an automobile wiper

汽车雨刷扫过玻璃表面后，在几种情况下会引起自激振动。介绍了刮水器自激振动产生的研究工作。对实际雨刷和简化雨刷模型进行了实验研究。为了揭示摩擦振动中的模态数，采用最大李雅普诺夫指数进行评价。通过对雨刷振荡的实验和数值模拟，得出如下结论：1。实际的雨刷有两个自由度。振动方式分为以基座为中心的平移运动和以叶片为中心的俯仰运动。刮水器的振动是由自激振动引起的，振动形式为粘滑运动。刮水器沿玻璃表面和垂直于玻璃表面的运动对刮水器的大振幅振动都有显著的影响。在大振幅振动中，参数激励也会引起相同的响应。在考虑叶片变形影响的刮水器振动实验中，得到了以下结果：雨刮器具有非线性恢复力的特点，包括后屈曲结构。当叶片在接近屈曲载荷的情况下挤压玻璃时，获得了最佳的清扫条件。在实际的雨刷中，如果扫速较慢，则雨刷振动的多种模式会产生复杂的响应。当扫速增加时，响应转变为两个自由度的简化振动。

An automotive wiper swept of glass surface causes a self-excited vibration in several conditions. Research work is presented for a generation of the self-excited vibration of the wiper. Experimental stdies are conducted both of an actual wiper and a simplified wiper model. Toreveal the number of modes in the wipe vibration, evaluation by the maximum Lyapunov exponent is applid. Both in the experiment and the numerical simulation of wiper oscillation, it is found as followings ;1.The actual wiper oscillates with two degrees of freedom. Modes of vibration are classified with translating movement pivoted on the base and the pitching movement centered at the blade.2.The wiper vibration is excited by the self-excited vibration with a type of stick-slip motion.3.Both wiper movements along to the glass surface and perpendicular to the surface has a significant effect on the large amplitude vibration of the wiper. Aresponse by parametric excitation is also induced same in the large amplitude vibration.In the experiment of the wiper vibration taking the effect of blade deforrmation, following results are obtained.1.The wiper blade has characteristics of nonlinear restoring force included a post-buckled configuration.2.When the blade presses the glass in the nearly buckling load, the best sweeping condition is obtained.3.If the sweeping speed is slow in the practical wiper, intricated responses are generated by the many modes of the wiper vibration. When the sweeping speed increases, the response is shifted to a simplified vibration with two degrees of freedom.