基于高次方程的凸轮优化设计.doc

基于高次方程的凸轮优化设计
Design of cam according to the high index number equality optimization

摘    要
配气机构是内燃机的重要组成部分，配气凸轮是决定配气机构工作性能的关键零件，如何设计和加工出具有合理型线的凸轮是整个配气系统设计中最为重要的问题。
文章首先对凸轮进行分段设计，然后利用最大速度和最大加速度位置基于高次方程凸轮运动规律设计通过Matlab软件进行凸轮型线的优化设计，根据摇臂比计算气门运动规律，然后通过变摇臂比对凸轮运动规律进行反求，借鉴高次方程的凸轮设计经验，得出一种凸轮设计的新方法，对气门运动规律进行优化设计，将新设计凸轮型线与原始凸轮型线进行对比，分析出新设计比原设计上在升程、速度和加速度方面所得到的提高，据此得出新设计对配气机构乃至整车所发挥的作用。

关键词：凸轮；高次方程；变摇臂比；优化设计

 
ABSTRACT
It is the importance of the internal combustion engine to constitute part to go together with to annoy organization, go together with to annoy a cam is to decide to go together with the key spare parts of annoying the organization work function, how design and process to submit the cam of having the reasonable type line is the most important problem in the whole design that go together with to annoy system.
The article carries on a cent to the cam first segment design, then make use of the biggest speed and the biggest acceleration position exercises according to Gao power distance cam the regulation design carry on a cam type through a Matlab software line of excellent turn a design, according to shaking an arm ratio to compute air valve sport regulation, then pass and change and shake arm compare exercise to the cam the regulation carry on anti- beg, draw lessons from Gao power distance of cam design experience, get a kind of cam design of new method, to air valve sport the regulation carry on excellent turn a design, will lately design a cam type the line and original cam type line carry on contrast and analyze lately design ratio original design up gain in the aspects of rising distance, speed and acceleration of exaltation, on these grounds get a new design to go together with to annoy organization is to the whole car develop of function.

Key words: cam; high index number equality; proportion of changing; optimization design
 
目    录
1绪论 1
1.1配气凸轮结构形式及特点 1
1.1.1等加速凸轮 1
1.1.2组合多项式型 2
1.1.3高次方凸轮 2
1.1.4多项动力凸轮 2
1.2配气机构动力特性计算模型 3
1.2.1单质盆模型 3
1.2.2二质量模型 3
1.2.3多自由度模型 3
1.2.4有限元模型 3
1.3配气凸轮型线设计国内外研究现状 4
1.4配气凸轮优化设计方法 5
1.4.1静态优化设计 6
1.4.2动态优化设计 6
1.5凸轮优化设计总结 7
1.6课题研究主要内容 8
2基于高次方程凸轮型线设计 9
2.1普通高次多项式凸轮型线的设计 9
2.1.1缓冲曲线的设计 10
2.1.2工作段运动曲线设计 12
2.2高次多项式凸轮的新型设计方法 14
2.3汽油发动机凸轮型线的改进设计 15
2.3.1汽油机配气凸轮型线设计的原则 15
2.3.2发动机进气凸轮的改进设计 16
2.3.3改进凸轮型线设计的MATLAB实现 17
2.4本章小结 19
3基于高次方程的气门理想运动规律计算 20
3.1气门设计理论基础 20
3.2气门运动规律要素 20
3.2.1气门有准确的配气相位 20
3.2.2良好的充气性能 20
3.2.3工作平稳 20
3.3气门运动规律的设计 21
3.4本章小结 21
4利用变摇臂比反求凸轮型线 22
4.1计算变摇臂比 22
4.1.1摇臂的运动学分析 22
4.1.2摇臂比的计算 23
4.2确定凸轮的升程函数 24
4.3分析原设计与变摇臂比设计 24
4.4本章小结 26
5总结与展望 28
5.1总结 28
5.2展望 28
参考文献 30
致    谢 32