ass日本风韵熟妇pics男人扒开女人屁屁桶到爽|扒开胸露出奶头亲吻视频|邻居少妇的诱惑|人人妻在线播放|日日摸夜夜摸狠狠摸婷婷|制服 丝袜 人妻|激情熟妇中文字幕|看黄色欧美特一级|日本av人妻系列|高潮对白av,丰满岳妇乱熟妇之荡,日本丰满熟妇乱又伦,日韩欧美一区二区三区在线

To discover the reasons of the strong vibration and unease of a light-bus, the methods of analysis vibration transfer function and road test was used，and found that it was caused by the softer stiffness of engine suspension cushion, which led to the lowest proper frequency of engine suspension system below the allowable value. Two decreasing vibration projects were put forward, which only improved the stiffness of the engine suspension cushion. For project one, the lowest proper frequency of the light-bus engine suspension system was 3.75 Hz which was within permission range. Furthermore, the maximal amplitude value of vibration transfer function descended obviously and the weighting acceleration RMS value was smaller than project two, so it could achieve better effect of isolating vibration.