V型发动机正时齿形链系统设计与动态特性分析
发布时间：2018-08-28 09:56
【摘要】：正时系统是发动机配气系统的重要组成部分，其主要作用是根据发动机的工作顺序和工作过程，通过控制气门开闭的时刻，准确的实现定时开启和关闭相应的进、排气门，使充量的可燃混合空气得以及时进入气缸，废气得以及时从气缸排出，实现换气过程，以保证发动机具有正常、良好的动力输出表现。为了适应汽车发动机高速运转的需求，越来越多的发动机配气传动机构采用了正时齿形链系统，然而由于齿形链的啮合机制欠缺，正时齿形链设计方法不明，国内的正时齿形链系统长期依赖于国外进口，严重制约了国内自主品牌的发展。 论文结合青岛征和工业有限公司的某一项目，在系统阐述国内外正时齿形链系统研究现状的基础上，借助现代设计方法，提出了某款V型汽车发动机正时齿形链系统及其各个组件的设计方法，分析了正时齿形链系统的动态特性。 论文在系统阐述了汽车发动机的换气过程以及配气过程的基础上，分析了影响换气行程的三个因素：进气延迟角、排气提前角和气门重叠角。其中，进气延迟角对发动机性能影响最大。在分析齿形链啮合过程中的不同啮合机制的基础上，比较了不同啮合机制的优缺点及其适用工况，为正时齿形链系统的设计提供坚实的理论基础。 论文根据厂商提供的正时箱体尺寸及相关参数，计算了正时系统的传递功率、有效圆周力以及齿形链静强度安全系数，设计了正时齿形链系统的整体布局，提出了正时齿形链系统及其各个组件的设计和计算方法。根据算得数值选择了链板并设计了链板的相关参数，根据齿形链啮合原理设计了齿形链链轮。针对齿形链系统各边的松紧程度设计了固定导轨和张紧导轨并计算了各自的曲率半径。根据导轨的曲率半径求得正时齿形链系统的链长并圆整取偶数倍链节，借助Matlab程序重新求得了张紧导轨的转角，根据松边的受力情况计算出张紧器的最大工作行程。 论文分析了主动链轮转速为1000r/min、3000r/min和5000r/min三个工况下正时齿形链系统的动态特性。着重从齿形链的运动轨迹分析了正时齿形链系统的多边形效应，提出了从运动轨迹来反求正时系统结构的思路；从齿形链的传动效率方面研究了正时齿形链系统的正时特性；从链节的张力、链板与张紧导轨之间的作用力着手分析了正时齿形链系统的受力情况，，满足齿形链系统的静强度要求。分析结果表明，这种V型发动机正时齿形系统满足设计要求。 通过分析表明，论文提出的设计方法是科学可行的，论文的研究成果对于提高我国汽车发动机正时链系统的自主创新能力，推动自主化进程具有极其重要的现实意义。
[Abstract]:Timing system is an important part of engine valve distribution system, its main function is according to the working sequence and working process of the engine, by controlling the opening and closing time of the valve, the timing of opening and closing the corresponding intake and exhaust valve can be accurately realized. So that the combustible mixed air can enter the cylinder in time, the exhaust gas can be discharged from the cylinder in time, and the air exchange process can be realized, so as to ensure the engine has normal and good power output performance. In order to meet the need of the automobile engine running at high speed, more and more engine valve transmission mechanisms adopt the timing tooth chain system. However, due to the lack of meshing mechanism of the gear chain, the design method of the timing tooth chain is not clear. The domestic timing chain system depends on foreign imports for a long time, which seriously restricts the development of domestic independent brands. Based on a project of Qingdao Zhenghe Industrial Co., Ltd., this paper systematically expounds the present situation of the research on the system of timing tooth chain at home and abroad, and makes use of the modern design method. In this paper, the design method of a V-engine timing tooth chain system and its components are presented, and the dynamic characteristics of the timing tooth chain system are analyzed. On the basis of systematically expounding the air exchange process and the valve distribution process of the automobile engine, three factors affecting the ventilation stroke are analyzed: the intake delay angle, the exhaust advance angle and the valve overlap angle. Among them, the inlet delay angle has the greatest effect on engine performance. Based on the analysis of different meshing mechanisms in the meshing process of toothed chain, the advantages and disadvantages of different meshing mechanisms and their applicable working conditions are compared, which provides a solid theoretical basis for the design of timing tooth chain system. According to the dimension of timing box provided by the manufacturer and relevant parameters, the transfer power, effective circumference force and static strength safety factor of the timing system are calculated, and the overall layout of the timing gear chain system is designed. The design and calculation method of the timing tooth chain system and its components are presented. According to the numerical value, the chain plate is selected and the relevant parameters of the chain plate are designed, and the tooth chain sprocket is designed according to the mesh principle of the tooth chain. The fixed guide rail and the tension guide rail are designed and their curvature radii are calculated according to the tightness degree of each side of the tooth chain system. According to the curvature radius of the guide rail, the chain length of the system is obtained and the chain joint is rounded to an even number, and the rotation angle of the tensioning guide is re-calculated by using Matlab program, and the maximum working stroke of the tensioner is calculated according to the stress on the loose edge. In this paper, the dynamic characteristics of the timing tooth chain system are analyzed under three operating conditions: the speed of the active sprocket is 1000r / min and the speed of the active sprocket is 3000r / min and 5000r/min. In this paper, the polygon effect of the timing tooth chain system is analyzed from the motion trajectory of the tooth chain, and the train of thought of inverse seeking the timing system structure from the motion path is put forward, and the timing characteristic of the timing tooth chain system is studied from the transmission efficiency of the tooth chain. Based on the tension of the chain joint and the force between the chain plate and the tensioning guide rail, the stress of the timing tooth chain system is analyzed, which meets the static strength requirement of the tooth chain system. The analysis results show that the V-engine timing gear system meets the design requirements. The analysis shows that the design method proposed in this paper is scientific and feasible. The research results of this paper are of great practical significance to improve the independent innovation ability of the timing chain system of automobile engine in China and to promote the process of autonomization.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH132.45
本文编号：2209043
[Abstract]:Timing system is an important part of engine valve distribution system, its main function is according to the working sequence and working process of the engine, by controlling the opening and closing time of the valve, the timing of opening and closing the corresponding intake and exhaust valve can be accurately realized. So that the combustible mixed air can enter the cylinder in time, the exhaust gas can be discharged from the cylinder in time, and the air exchange process can be realized, so as to ensure the engine has normal and good power output performance. In order to meet the need of the automobile engine running at high speed, more and more engine valve transmission mechanisms adopt the timing tooth chain system. However, due to the lack of meshing mechanism of the gear chain, the design method of the timing tooth chain is not clear. The domestic timing chain system depends on foreign imports for a long time, which seriously restricts the development of domestic independent brands. Based on a project of Qingdao Zhenghe Industrial Co., Ltd., this paper systematically expounds the present situation of the research on the system of timing tooth chain at home and abroad, and makes use of the modern design method. In this paper, the design method of a V-engine timing tooth chain system and its components are presented, and the dynamic characteristics of the timing tooth chain system are analyzed. On the basis of systematically expounding the air exchange process and the valve distribution process of the automobile engine, three factors affecting the ventilation stroke are analyzed: the intake delay angle, the exhaust advance angle and the valve overlap angle. Among them, the inlet delay angle has the greatest effect on engine performance. Based on the analysis of different meshing mechanisms in the meshing process of toothed chain, the advantages and disadvantages of different meshing mechanisms and their applicable working conditions are compared, which provides a solid theoretical basis for the design of timing tooth chain system. According to the dimension of timing box provided by the manufacturer and relevant parameters, the transfer power, effective circumference force and static strength safety factor of the timing system are calculated, and the overall layout of the timing gear chain system is designed. The design and calculation method of the timing tooth chain system and its components are presented. According to the numerical value, the chain plate is selected and the relevant parameters of the chain plate are designed, and the tooth chain sprocket is designed according to the mesh principle of the tooth chain. The fixed guide rail and the tension guide rail are designed and their curvature radii are calculated according to the tightness degree of each side of the tooth chain system. According to the curvature radius of the guide rail, the chain length of the system is obtained and the chain joint is rounded to an even number, and the rotation angle of the tensioning guide is re-calculated by using Matlab program, and the maximum working stroke of the tensioner is calculated according to the stress on the loose edge. In this paper, the dynamic characteristics of the timing tooth chain system are analyzed under three operating conditions: the speed of the active sprocket is 1000r / min and the speed of the active sprocket is 3000r / min and 5000r/min. In this paper, the polygon effect of the timing tooth chain system is analyzed from the motion trajectory of the tooth chain, and the train of thought of inverse seeking the timing system structure from the motion path is put forward, and the timing characteristic of the timing tooth chain system is studied from the transmission efficiency of the tooth chain. Based on the tension of the chain joint and the force between the chain plate and the tensioning guide rail, the stress of the timing tooth chain system is analyzed, which meets the static strength requirement of the tooth chain system. The analysis results show that the V-engine timing gear system meets the design requirements. The analysis shows that the design method proposed in this paper is scientific and feasible. The research results of this paper are of great practical significance to improve the independent innovation ability of the timing chain system of automobile engine in China and to promote the process of autonomization.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH132.45
【引证文献】
相关硕士学位论文 前1条
1 李俊龙;混合动力汽车用齿形链传动系统设计及动态特性分析[D];吉林大学;2013年
本文编号：2209043
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