《链接微动特性研究》由会员分享，可在线阅读，更多相关《链接微动特性研究（102页珍藏版）》请在金锄头文库上搜索。
1、 柴油机连杆衬套微动特性研究 摘 要 在发动机运行的过程中， 连杆衬套受到活塞销交变载荷以及连杆自身的惯性力的作用。由于连杆小头和衬套的材料特性不同，其接触面上在承受相同的接触压力时会产生不同程度的变形，导致两接触体在接触面上相互错动，即为微动。微动不但会引起微动磨损，还会引起微动疲劳，这会导致连杆衬套过盈量不足，从而会对发动机造成严重的破坏。因此探寻连杆衬套的微动特性对衬套的使用寿命的提高意义重大。 本文结合某型柴油机连杆小头和衬套的实际工况，利用接触力学理论和有限元方法， 以分析衬套微动特性为目的对其接触过程进行数值有限元模拟分析。 具体工作如下： （1）查阅了大量微动特性分析的文献，详述
2、了微动的发展现状。确定了本文的研究重点、分析方法和需要解决的问题。 （2）总结了连杆衬套的结构和分类。在弹性接触理论的基础上，对常用球和平面接触模型的微动接触过程进行理论分析，得出微动关键参数的理论求解方法。 （3）详述了接触问题的有限元理论和算法。建立包括连杆小头、衬套和活塞销的二分之一实体模型，确立了模型的边界条件。通过有限元求解计算得到了不同衬套过盈量下，连杆小头和衬套爆压时刻的等效应力和变形变化规律。 （4）在过盈量为 0.05mm 时，先分析不同摆角下衬套的微动特性。确定出爆压时刻衬套微动关键参数最大。然后再分析不同过盈量下衬套爆压时刻的微动特性。最后分析过盈量为 0.05mm 时，
3、不同摩擦系数下衬套爆压时刻的微动特性。通过系列的研究工作，总结出连杆摆角、过盈量和摩擦系数对衬套微动关键参数的影响规律。结合衬套的微动特性规律，提出一些减缓衬套微动的措施。 结果表明，爆压时刻衬套的微动最严重。随着过盈量的加大，衬套的摩擦应力、接触压力和摩擦功不断的增大，而微动幅值呈不断减小的趋势。随着摩擦系数的降低，衬套的接触压力变化较小，摩擦应力和摩擦功不断减小，而微动幅值呈不断增大的趋势。 关键词：连杆衬套，微动特性，接触，过盈配合，有限元 Fretting Characteristics Analysis of Connecting Rod Bushing of Diesel Engi
4、ne Abstract The connecting rod is acted upon by the alternating load of piston pin and inertia force of connecting rod during the running process of engine, The contact surface under the same contact pressure can produce the different degree of deformation resulting in two contact bodies mutual slip
5、 in the contact surface because the material character of connecting rod and bushing is different, it is called fretting. The fretting would not only cause fretting wear, but also cause fretting fatigue, which can leads to Interference of connecting rod bushing is insufficient. Insufficient Interfer
6、ence of connecting rod bushing can cause serious damage for engine. So, it is great significance for improving service life of bushing by finding the fretting characteristics of connecting rod bushing. Combined with actual working condition of connecting rod and bushing of a certain type diesel engi
7、ne, this paper simulates the contact process of the connecting rod and bushing by contact mechanics theory and finite element method for analyzing the fretting characteristics of bushing. The specific work is as follows: （1）Access to a large number of literatures of fretting characteristic analysis,
8、 this paper expounds the current status of development of the fretting. The key of research, analysis methods and the problems that need to be solved of this paper are decided. (2) This paper summarizes structure and classification of the connecting rod bushing. On the basis of the elastic contact t
9、heory, this paper analyses the commonly ball and plane contact model to get the theory resolution method of key parameters of fretting. （3） This paper expounds finite element theory and algorithm of the contact problem. One half of the solid model of connecting rod, bushings and piston pin are estab
10、lished, and the boundary conditions of model are ascertained. This paper analyzes the changing regularity of the comprehensive stress and deformation of connecting rod and bushing under different amount of interference of bushing in the detonation pressure moment. (4) Firstly, the fretting character
11、istic of bushing is analyzed under different connecting rod angles when the amount of interference of bushing is 0.05mm. According to analysis, the key parameters of bushing fretting are the largest in the detonation pressure moment. And then the fretting characteristic of bushing is analyzed under
12、different amounts of interference of bushing in the detonation pressure moment. Finally, the fretting characteristic of bushing is analyzed under different friction coefficients when the amount of interference of bushing is 0.05mm. According to the above analysis result, the law of fretting key para
13、meters of bushing is summarized under different connecting rod angles, amounts of interference of bushing and friction coefficients. Combined with the fretting characteristic of bushing, some measures about slowing fretting wear of bushing are proposed. The results show that the fretting of bushing
14、is most serious in the detonation pressure moment. Along with the increase of amounts of interference, contact pressure, friction stress and frictional work of bushing show increasing trends, but fretting amplitude shows reducing trend. With the decrease of the friction coefficient, bushing contact
15、pressure changes a little, friction stress and frictional work show reducing trends, but fretting amplitude shows increasing trend. Key Words: Connecting rod bushing，Fretting characteristic，Contact，Interference fit，Finite element I 目 录 1 引言 1.1 连杆衬套过盈配合微动特性分析的研究背景与意义. 1 1.1.1 微动的基本概念. 1 1.1.2 微动的分类. 1 1.1.3 过盈配合连接的概述. 2 1.1.4 连杆衬套微动的危害. 3 1.2 连杆衬套过盈配合微动特性分析的国内外研究现状 . 3 1.2.1 国外研究现状. 3 1.2.2 国内研究现状. 5 1.3 本文的主要研究内容.
