Abstract: A vehicle continuously passed through speed bumps at a low speed of 10km/h～25km/h after wading in the car body. As the front wheels were lifted, when the front suspension of the vehicle was pulled up by force, a "crunch" sound similar to rubber squeeze can be clearly perceived in the front position. The higher the speed, the more pronounced the sound. After the sound appeared, drive continuously on a bumpy road for about 1km, and the sound would slowly become smaller until it disappeared. However, when the vehicle passed the road in the same condition without wading in water, the sound can not appear. By temporarily modifying the contact position between the bushing and rubber in front of the bushing of the faulty part, the wire was added to increase its interference amount, and it was confirmed that the abnormal sound was caused by the change of friction relationship with the inner casing of the bushing after the rubber wading on the front bushing of the swing arm, resulting in abnormal extrusion slip. The structural analysis, investigation and rectification verification of the front suspension system were carried out to confirm the key factors of abnormal sound caused by the interference between the inner casing of the front swing arm bushing and the flanging rubber. Finally, it was confirmed that the scheme of changing the structure of swing arm bushing from the original structure with flanging rubber to the structure with flange plane was evaluated in batches subjectively, and no abnormal sound was found.

Key words: Front bushing; Speed bump; Control arm; Bushing sound; Vehicle front suspension; Optimization design

摘要： 某车型在下车体涉水后，以低速 10 km/h～25 km/h 连续经过减速带，随着前轮上抬， 车辆前悬挂受力拉升时，车内能明显感知到前部位置出现类似橡胶挤压的“嘎吱嘎吱”异响， 车速越高声音越明显，声音出现后，在颠簸路面上连续行驶约 1 km，该声音会慢慢变小直至 消失。但是当车辆在未涉水情况下以同样工况经过路面时，声音没有出现。通过临时改制对 故障件衬套前套管与橡胶接触位置增加铁丝，加大其干涉量，确认该异响为摆臂前衬套翻边 的橡胶涉水后，与衬套内套管摩擦关系发生变化，产生异常的挤压滑移导致的。对前悬挂系 统结构分析、排查并整改验证，确认摆臂前衬套内套管及其与翻边橡胶的干涉量是导致该异 响的关键因素。将摆臂衬套的结构由原来带橡胶翻边结构更改至法兰平面架构，主观上对其 进行批量评估，均未发现异响。

关键词: 前衬套；减速带；控制臂；衬套异响；车辆前悬挂；优化设计