毕业论文移动版

摘要配气机构是船用柴油机的重要组成部分，配气机构的好坏对柴油机性能指标有着很重要的影响。配气凸轮是决定配气机构工作性能的关键零件，如何设计和加工出有合理型线的凸轮轴是整个配气系统设计中最为重要的问题。其设计合理与否直接关系到柴油机的动力性能、经济性能、排放性能及工作的可靠性、耐久性。多学科优化是九十年代以来在国外迅速发展的一门科学，它可以有效地解决大规模复杂工程系统的设计问题。本文正是以此为契机，对船用配气机构的凸轮型线进行了多学科设计优化。43623

本文建立了某柴油机配气机构单自由度模型，构造出其凸轮和推杆在基本段的六项式动力升程函数；又在多刚体运动学理论的基础上，用ADAMS软件对配气机构进行仿真建模。为确保配气机构在工作过程中有良好的换气性能，以最大丰满系数为优化目标，气门的最大正负加速度、最小接触应力和最小曲率半径等为约束条件，应用多学科优化软件ISIGHT进行优化计算，对得出的优化结果进行分析，从而实现对配气凸轮的多学科优化分析。

毕业论文关键词：多学科优化、配气凸轮、凸轮型线、丰满系数、NLPQL算法

Abstract Gas distribution mechanism is an important part of marine diesel engine, so the quality of it has a very important impact on diesel engine. Gas distribution cam is a key part to determine the performance of gas distribution. Its design is reasonable or not directly related to the diesel power performance, economic performance, emission performance, reliability and durability. Multidisciplinary optimization is developed rapidly in foreign countries in ninety times. It can solve the problem of large-scale complex engineering effectively. This article is chance with this, optimize the profile of cam.  

The dynamic model of a diesel engine valve train is built, and then constructs the six power lift function of the push rod when it works on the basic segments. Good ventilation performance in the course of their work to ensure that the gas distribution agencies with the greatest fullness coefficient as the optimization objective, the largest positive and negative acceleration and minimum radius of curvature constraints, the application ISIGHT software integration of ADAMS, use NLPQL algorithm to optimize calculation, the optimization results derived in order to achieve the analysis of multi-disciplinary optimization of gas distribution cam.

Keywords: multidisciplinary optimization, Valve cam, cam profile, the fullness coefficient NLPQL algorithm

目录

第1章  绪论 1

1.1 选题背景 1

1.2 多学科优化设计的发展与现状 2

1.3 配气机构动力学研究 4

1.4 本课题的主要研究内容 5

1.5 本章小结 6

第2章  配气机构传统动力学分析 7

2.1 配气凸轮的设计准则 7

2.1.1 准确的配气相位 7

2.1.2良好的换气性能 7

2.1.3工作平稳，振动和噪声较小 8

2.1.4挺柱与凸轮间的接触应力不宜过大 8

2.2 配气机构动力学计算模型 11

2.3 单自由度模型参数的确定 14

2.4 配气凸轮基本段型线的分类及特点 16

2.4.1组合式 (责任编辑：qin)