连续可变气门升程机构的动力学特性分析

发布时间：2018-03-13 07:31

本文选题：连续可变气门升程机构　切入点：VALDYN软件　出处：《辽宁工业大学》2016年硕士论文　论文类型：学位论文

【摘要】：发动机中配气机构的主要作用是控制气缸内的进排气过程。传统配气机构的配气相位和气门升程是固定的,只能保证发动机某一工况下的最佳性能,难以兼顾所有工况对配气相位的要求。而可变配气机构能够通过控制气门正时、气门升程以及气门持续开启时间使发动机能够在其适合的工况下运行,从而提高了发动机的综合性能。可变配气机构现已取得广泛应用。本论文以一新型连续可变气门升程机构为研究对象,基于VALDYN软件,对该配气机构的动力学特性进行仿真分析,来验证该机构的实用性。主要工作概况如下:深刻了解连续可变气门升程机构的结构特点和工作原理,在VALDYN软件中建立动力学模型,并对模型进行运动学分析。分析结果表明,在凸轮轴转速较低时,气门升程运动学曲线与气门升程动力学仿真曲线完全吻合,因而,可验证模型的准确性以及模型中相关参数的准确性。在不同气门升程下,针对不同的凸轮轴转速对连续可变气门升程机构进行动力学特性分析,研究气门升程、气门速度、气门加速度以及配气机构中部件所受载荷力的仿真曲线特征,并讨论了载荷曲线的载荷丢失现象和气门弹簧受力情况,推算了配气机构的固有频率范围。在不同气门升程下,针对不同凸轮轴转速,基于试验数据对配气机构进行动力学特性分析,结果表明,配气机构在整个发动机转速范围内对气门正时和气门运动都能保持合适的性能,从而体现了该配气机构实用价值。
[Abstract]:The main function of the valve distribution mechanism in the engine is to control the intake and exhaust process in the cylinder. The phase of the valve and the valve lift of the traditional valve distribution mechanism are fixed, which can only ensure the optimal performance of the engine under a certain working condition. It is difficult to take into account the requirements of the valve phase in all working conditions. The variable valve valve mechanism can make the engine run in its suitable working condition by controlling the valve timing, valve lift and valve continuous opening time. Therefore, the comprehensive performance of the engine is improved. The variable valve mechanism has been widely used. In this paper, a new type of continuous variable valve lift mechanism is taken as the research object, and the dynamic characteristics of the valve valve mechanism are simulated and analyzed based on VALDYN software. The main work is as follows: deeply understand the structure characteristics and working principle of the continuous variable valve lift mechanism, set up the dynamic model in VALDYN software, and carry on the kinematics analysis to the model. When the speed of camshaft is low, the kinematics curve of valve lift is in good agreement with the simulation curve of valve lift dynamics. Therefore, the veracity of the model and the accuracy of relevant parameters in the model can be verified. The dynamic characteristics of continuous variable valve lift mechanism are analyzed for different camshaft speeds, and the simulation curve characteristics of valve lift, valve velocity, valve acceleration and the load force of components in valve distribution mechanism are studied. The load loss phenomenon of the load curve and the stress situation of valve spring are discussed, and the natural frequency range of valve distribution mechanism is calculated. Based on the experimental data, the dynamic characteristics of the valve train are analyzed. The results show that the valve timing and valve motion of the valve can be maintained in the whole engine speed range, which reflects the practical value of the valve valve mechanism.
【学位授予单位】：辽宁工业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U464.134.4

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