乘用车仪表板螺栓软连接紧固衰减规律研究

Study on the Decay Law of Bolt Soft Connection Fastening of Passenger Car Instrument Panel

以乘用车仪表板螺栓软连接为对象,对螺栓软连接发生松动的影响因素进行理论分析,确定其主要影响因素;根据实际服役环境条件(自然环境和道路载荷)设计仪表板台架试验,通过台架试验获取不同工况下螺栓软连接点的拧紧力矩和预紧力的衰减程度,验证了软连接松动的主要影响因素分析结果的正确性。基于螺栓松动主要影响因素和失效机制,建立了螺栓软连接预紧力随环境振动的反比例衰减模型和随高低温循环的指数衰减模型,提出了增加连接件强度、缩小安装孔、调整连接点安装方向等防松建议。

This paper takes the soft connection of passenger car instrument panel bolts as the object.To determine the main influencing factors for the occurrence of loosening of the bolted soft joints by conducting theoretical analysis of them.Design the instrument panel bench test according to the actual service environment conditions,including natural environment and road load.To obtain the tightening torque and the degree of decay of the preload force of the bolted soft connection points under different service conditions through the bench test,which verified the correctness of the results of the analysis of the main influencing factors of soft joint loosening.Based on the main influencing factors and failure mechanism of bolt loosening,the inverse proportional decay model of bolt soft connection preload force with environmental vibration and the exponential decay model of bolt soft connection preload force with high and low temperature cycles are established.Loosening prevention suggestions such as increasing the strength of the connection,reducing the mounting hole,and adjusting the mounting direction of the connection point are put forward.