大学毕设论文__发动机可变配气装置设计.doc

本科毕业设计（论文） 发动机可变配气装置设计 摘要 汽车发动机配气机构是发动机的重要组成部分，它根据气缸的工作次序，定时开关进、排气门，保证气缸吸入新鲜空气和排除废气。本研究主要针对小型汽车上使用的汽油机进行配气机构设计，并对配气机构中的凸轮进行运动分析，以保证发动机获得充分的空气供给。? ????配气机构由气门组、气门传动组、凸轮轴传动机构三部分组成。气门组主要由：气门、阀座、气门导管、气门弹簧和连接键组成，195B型柴油机采用不带阀壳气门组气门的开启和关闭是靠传动机构来实现的，传动机构可分为机械和液压传动机构。195B型柴油机采用下置式传动形式，由凸轮、挺柱、推杆、摇臂、摇臂座、摇臂轴、调整螺钉等组成。凸轮轴与曲轴之间的传动机构与柴油机的型式、凸轮轴与曲轴的相对位置、气门传动机构的型式等有关，一般有齿轮传动和链传动。195B型柴油机采用齿轮传动，柴油机曲轴与凸轮轴的传动比为2：1。 本次配气机构的设计，主要包括凸轮、凸轮轴、推杆、摇臂、挺柱、气门组、气门弹簧的材料、结构的选择，尺寸的确定以及相关数据的计算。还包括了各个零件的热加工方法、损坏形式以及预防办法。最后介绍了现代配气机构的可变技术，有利于节能减排、环境保护。 配气机构控制着发动机进排气的过程，它直接影响着发动机的性能，是衡量发动机可靠性的标准之一。 关键词　发动机配气机构； 凸轮轴； 气门组； 可变技术 Abstract Automobile Engine Valve is an important part of the engine, it is based on the work order of the cylinder, timer switch intake and exhaust valves to ensure that the cylinders breathe fresh air and Exhaust air. This study focused on the use of small cars gasoline engine valve train design, and valve train cam motion analysis to ensure that the engine get adequate air supply. ???? Valve set by the valve, the valve transmission group, camshaft drive mechanism consists of three parts. Valve Group consists of: valves, valve seats, valve guides, valve springs and linkages composition, 195B diesel engine without using the opening and closing valve valve housing valve group is achieved by the drive mechanism, the drive mechanism can be divided into mechanical and hydraulic actuators. 195B-type diesel engine mounted under the form of transmission, cam, tappet, push rod, rocker arm, rocker seat, rocker shafts, adjusting screws and other components. Type, position of the camshaft relative to the crankshaft, and other types of transmission and diesel engine camshaft and crankshaft between a valve drive mechanism, generally a gear transmission and chain drive. 195B diesel engine gear transmission, diesel engine crankshaft and camshaft gear ratio of 2: 1. The design of the air distribution organization, mainly including the cam, the cam shaft, the push rod, the rocker arm, the qu