【摘要】 近年来.一些船用低速柴油机开始采用液压配气机构。本文研究了液压配气机构的工作机理,对其建立了由一维瞬变流和质量—弹簧系统相结合的动力学模型。该模型对应于偏微分方程和常微分方程相结合的方程组,可以用有限差分法或特征线方法求解。文章对机构的复杂边界条件作了简化并用数学方法进行处理,给出了一个算例,得到了气门升程及液压管油压随凸轮转角变化的曲线,计算结果与实测曲线吻合较好。本文还讨论了下列问题:差分格式的步长对计算误差的影响;阻尼对机构稳定性的作用以及机构泄漏对气门运动的影响,并将这些关系用图形显示出来。更多还原

【Abstract】 The working machanisim of a hydraulic valve gears which have beenwidely used in some types of marine diesel engines recently is studied by theauthors and a dynamic model comprising a one-dimensional transient flowand a nonlinear mass-spring vibration system is presented in this paper.The solution of the corresponding partial differential equations is obtainedby using the finite-difference method and the characteristic method whilethe complex boundary conditions are simplified and treated through certainmathmatical functions.The results of the calculation coincide well with thedirect measurement. The effect of the step of difference scheme on the error of the computa-tion,the effect of damping force and leakage on the behavior of valvedynamics are also discussed and shown in the figures.更多还原