发动机配气机构传动系统的频率可靠性分析
Frequency Reliability Analysis for Transmission System in Engine Valve Train

根据发动机配气机构传动系统的固有频率与凸轮激振频率的差绝对值不超过规定槛值的关系准则，定义了配气机构传动系统共振的准失效状态，同时根据摄动理论和可靠性技术推导出参数为正态随机变量时的准失效概率表达式，提出了减小振动的可靠性分析方法。在此基础上，以发动机配气机构振动简化模型为例，分别以所提方法和可靠性分析的Monte Carlo法计算该系统的共振可靠度，数值结果进一步证明了所提方法的可实用性。该方法可用于分析振动影响程度，以避免配气机构的共振失效。
In order to develop the performance of the transmission system of the engine's valve mechanism and to reduce the resonance invalidation，we defined the quasi-failure resonance state of the transmission system based on the rule that absolute value of difference between the natural frequency of the transmission system and the cam vibration frequency cannot go over the specified threshold. According to the perturbation theory and reliability technology，we derived the expression of the probability of the quasi-failure with normal random variables and put forward the analysis method of reliability to decrease the vibration. Finally, we set the simplified model as an example and calculated the reliability of this system with the proposed method and the Monte Carlo method respectively. Numerical results confirmed that practicability of the proposed method which can avoid the resonance invalidation of valve-train by analyzing the effect of vibration.