xd474汽油机凸轮设计x474汽油机凸轮设计xd474汽油机凸轮设计xd474汽油机凸轮设计.doc

摘要 随着我国经济不断的发展，汽车在国内的发展前景越来越好。打破国外汽车在国内的优势对我国汽车产业的发展至关重要。随着人们生活水平不断的提高，人们对汽车综合性能的要求也越来越高，安全、舒适、低耗油、低噪声、低排放是现代汽车发展的趋势。 XD474汽油发动机是四冲程发动机，采用了整体四缸的结构，采用水冷方式。本设计参考了LJ474汽油发动机。XD474汽油机有重量轻、尺寸小和低温起动性能好、转速高、结构简单、紧凑的特点，采用立式结构、直喷燃烧室。由于其重量轻，尺寸小，起动性能好，转速高等特点，被广泛用于中小型汽车上。 在该设计中，涉及到了XD474汽油机的基本参数的选择、总体设计、热力学计算，重点是凸轮轴的设计。在专题设计中，凸轮采用高次方多项凸轮，介绍了凸轮轴的一些典型加工工艺、热处理、磨损、强度计算。 [关键词]：汽油机 凸轮轴 热力学计算 凸轮型线 The Design of the type of XD474 Gasoline Engine Abstract Along with our country economy development，the prospect of the development of car is getting better and better in the domestic. Breaking the advantage of foreign car in China is very important to the development of Chinas automotive industry. With the improvement of living level, peoples requirement for the comprehensive performance of vehicle is getting higher and higher，the trend of the development of the modern car is safe , comfortable ,low fuel consumption, low noise, low emission. XD474 petrol engine is four-stroke engine, using the overall structure of the multi-cylinder, have four cylinder, using hydrocooling. It reference to the LJ474 gasoline engine. XD474 gasoline engine has light weight, small size and low-temperature start-up performance and high speed, simple structure, compact characteristics. It uses vertical structure and DI chamber. Because of its light weight, small size, good starting performances, high speed, are widely used in small and medium-sized vehicles. In this design, related to XD474 gasoline engine selection of basic parameters, general design, thermodynamic calculation, this paper focuses on the cam shaft design. In the project design, cam using high order multiple cam, this paper introduces some typical camshaft processing technology heat treatment ,wear ,strength calculation. Key words : gasoline engines camshafts thermodynamic Calculation cam profile 目录 前言 第一章 XD474汽油机的主要技术参数 1 第一节　设计目的 1 第二节　设计原则 2 第三节　XD474汽油机主要参数的选择 3 第二章 XD474整体设计 9 第一节 机体与