一种可变连杆式VCR发动机结构设计与主要零部件动力学分析

发布时间：2018-01-04 19:09

本文关键词：一种可变连杆式VCR发动机结构设计与主要零部件动力学分析　出处：《重庆交通大学》2015年硕士论文　论文类型：学位论文

【摘要】：日益严重的能源形势和越来越严格的排放规定,让大功率、高性能、低功耗、低污染、多元化、新结构成为当今发动机的特性。然而,既具有良好的动力性能又具有良好的排放性能和燃油经济性在一般发动机中无法同时满足,并且发动机在怠速时、部分负荷时以及启动时因无法完全燃烧导致整体性能差的问题始终得不到很好的解决。因此,研发低功耗、高功率的发动机成为目前市场热点。本文以F1C系列某款发动机为原型,根据导师团队申请的发明专利《可变连杆式VCR发动机连杆机构》的设计思想,对一种可变连杆式VCR(Variable Compression Ratio)发动机机构的结构和动力性能进行了研究。在本次研究中提出了一种可变压缩比机构的设计方案,对其主要零部件的结构进行了计算设计和可靠性验算,并进行了三维建模,最后采用静力学分析和动力学分析,验证了该VCR机构的可行性。本文的主要研究内容如下:①根据课题组申请的国家发明专利《可变连杆式VCR发动机连杆机构》的设计思想和F1C系列某款发动机的结构参数,提出了一种可变连杆长度的VCR发动机。本文主要以该VCR发动机的曲柄连杆机构为研究对象,实现了一种可根据改变连杆长度来实现压缩比变化的设计方案。以液压缸和连杆的运动规律,对压缩比和可变连杆长度之间的变化关系进行了分析与计算。②从理论上分析了该发动机中曲柄连杆机构的工作原理和受力情况,确定了主要零部件的结构尺寸,并进行了强度校核;利用CATIA V5三维设计软件平台,对曲柄连杆机构进行了模型的建立,为仿真研究提供了模型。③利用Ansys Workbench有限元分析软件对可变连杆机构进行了静力学仿真研究,考察了在可变连杆中连杆、活塞杆和液压缸分别受到最大外力时的应力应变变化,验证了该VCR机构方案的合理性和结构的可靠性;④基于ADAMS动力学分析软件,对该VCR发动机机构进行了运动学和动力学仿真,考察了该机构在发动机不同转速和不同负荷下对发动机性能的影响,进一步验证了该VCR机构方案的可行性。研究表明:所提出的可变连杆式VCR机构的方案合理可行,结构稳定可靠,主要零部件的设计满足强度要求,并能实现改善发动机功率和排放的性能。
[Abstract]:The increasingly serious energy situation and the increasingly stringent emission regulations for high power, high performance, low power consumption, low pollution, diversification, the new structure has become the characteristic of modern engine. However, not only has good dynamic performance and excellent emission performance and fuel economy in general can not satisfy the engine and the engine. In the idle, part load and startup due to incomplete combustion leads to poor performance of the problem has not been solved well. Therefore, development of low power consumption, high power engine has become a hot market. In this paper, a series of F1C engine as the prototype, according to the design idea of tutor team patent application < variable connecting rod type VCR engine connecting rod mechanism of a variable >, link type VCR (Variable Compression Ratio) structure and dynamic performance of the engine mechanism were studied in this research. The study presents a variable compression ratio mechanism design scheme, structure of the main parts of the design calculation and reliability calculation, and the 3D modeling, the static analysis and dynamic analysis, verify the feasibility of the VCR mechanism. In this paper, the main research contents are as follows: according to the structural parameters of a the engine's design idea and F1C series research group for the national invention patent "variable VCR engine connecting rod linkage >, proposes a variable link length VCR engine. In this paper the crank connecting rod mechanism of the VCR engine as the research object, realizes a kind of can be changed according to the length of the connecting rod to realize the compression ratio design changes. With the motion law of the hydraulic cylinder and the connecting rod, the relationship between compression ratio and variable link length were analyzed and calculated. Based on the theoretical analysis. The working principle of the engine crank connecting rod mechanism and the stress situation, determine the structure size of the main components, and the strength check; using CATIA V5 3D design software platform of crank mechanism model was established, which provides a model for simulation. The variable linkage mechanism is simulated by statics Ansys finite element analysis software Workbench, examines the link in the variable in the connecting rod, a piston rod and a hydraulic cylinder respectively by the maximum force when the changes of stress and strain, to verify the reliability of the VCR scheme is reasonable and structure; the ADAMS based dynamic analysis software, the VCR engine mechanism of kinematics and dynamics simulation study the mechanism of the influence on engine performance at different engine speed and different loads, to verify the feasibility of this scheme. The research of VCR mechanism It shows that the scheme of the variable link VCR mechanism is reasonable and feasible, and the structure is stable and reliable. The design of the main components meets the strength requirements, and can improve the performance of engine power and emissions.

【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TK403

【参考文献】