【摘要】：正時(shí)系統(tǒng)是發(fā)動機(jī)配氣系統(tǒng)的重要組成部分，其主要作用是根據(jù)發(fā)動機(jī)的工作順序和工作過程，通過控制氣門開閉的時(shí)刻，準(zhǔn)確的實(shí)現(xiàn)定時(shí)開啟和關(guān)閉相應(yīng)的進(jìn)、排氣門，使充量的可燃混合空氣得以及時(shí)進(jìn)入氣缸，廢氣得以及時(shí)從氣缸排出，實(shí)現(xiàn)換氣過程，以保證發(fā)動機(jī)具有正常、良好的動力輸出表現(xiàn)。為了適應(yīng)汽車發(fā)動機(jī)高速運(yùn)轉(zhuǎn)的需求，越來越多的發(fā)動機(jī)配氣傳動機(jī)構(gòu)采用了正時(shí)齒形鏈系統(tǒng)，然而由于齒形鏈的嚙合機(jī)制欠缺，正時(shí)齒形鏈設(shè)計(jì)方法不明，國內(nèi)的正時(shí)齒形鏈系統(tǒng)長期依賴于國外進(jìn)口，嚴(yán)重制約了國內(nèi)自主品牌的發(fā)展。 論文結(jié)合青島征和工業(yè)有限公司的某一項(xiàng)目，在系統(tǒng)闡述國內(nèi)外正時(shí)齒形鏈系統(tǒng)研究現(xiàn)狀的基礎(chǔ)上，借助現(xiàn)代設(shè)計(jì)方法，提出了某款V型汽車發(fā)動機(jī)正時(shí)齒形鏈系統(tǒng)及其各個(gè)組件的設(shè)計(jì)方法，分析了正時(shí)齒形鏈系統(tǒng)的動態(tài)特性。 論文在系統(tǒng)闡述了汽車發(fā)動機(jī)的換氣過程以及配氣過程的基礎(chǔ)上，分析了影響換氣行程的三個(gè)因素：進(jìn)氣延遲角、排氣提前角和氣門重疊角。其中，進(jìn)氣延遲角對發(fā)動機(jī)性能影響最大。在分析齒形鏈嚙合過程中的不同嚙合機(jī)制的基礎(chǔ)上，比較了不同嚙合機(jī)制的優(yōu)缺點(diǎn)及其適用工況，為正時(shí)齒形鏈系統(tǒng)的設(shè)計(jì)提供堅(jiān)實(shí)的理論基礎(chǔ)。 論文根據(jù)廠商提供的正時(shí)箱體尺寸及相關(guān)參數(shù)，計(jì)算了正時(shí)系統(tǒng)的傳遞功率、有效圓周力以及齒形鏈靜強(qiáng)度安全系數(shù)，設(shè)計(jì)了正時(shí)齒形鏈系統(tǒng)的整體布局，提出了正時(shí)齒形鏈系統(tǒng)及其各個(gè)組件的設(shè)計(jì)和計(jì)算方法。根據(jù)算得數(shù)值選擇了鏈板并設(shè)計(jì)了鏈板的相關(guān)參數(shù)，根據(jù)齒形鏈嚙合原理設(shè)計(jì)了齒形鏈鏈輪。針對齒形鏈系統(tǒng)各邊的松緊程度設(shè)計(jì)了固定導(dǎo)軌和張緊導(dǎo)軌并計(jì)算了各自的曲率半徑。根據(jù)導(dǎo)軌的曲率半徑求得正時(shí)齒形鏈系統(tǒng)的鏈長并圓整取偶數(shù)倍鏈節(jié)，借助Matlab程序重新求得了張緊導(dǎo)軌的轉(zhuǎn)角，根據(jù)松邊的受力情況計(jì)算出張緊器的最大工作行程。 論文分析了主動鏈輪轉(zhuǎn)速為1000r/min、3000r/min和5000r/min三個(gè)工況下正時(shí)齒形鏈系統(tǒng)的動態(tài)特性。著重從齒形鏈的運(yùn)動軌跡分析了正時(shí)齒形鏈系統(tǒng)的多邊形效應(yīng)，提出了從運(yùn)動軌跡來反求正時(shí)系統(tǒng)結(jié)構(gòu)的思路；從齒形鏈的傳動效率方面研究了正時(shí)齒形鏈系統(tǒng)的正時(shí)特性；從鏈節(jié)的張力、鏈板與張緊導(dǎo)軌之間的作用力著手分析了正時(shí)齒形鏈系統(tǒng)的受力情況，，滿足齒形鏈系統(tǒng)的靜強(qiáng)度要求。分析結(jié)果表明，這種V型發(fā)動機(jī)正時(shí)齒形系統(tǒng)滿足設(shè)計(jì)要求。 通過分析表明，論文提出的設(shè)計(jì)方法是科學(xué)可行的，論文的研究成果對于提高我國汽車發(fā)動機(jī)正時(shí)鏈系統(tǒng)的自主創(chuàng)新能力，推動自主化進(jìn)程具有極其重要的現(xiàn)實(shí)意義。
[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.
【學(xué)位授予單位】：吉林大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2012
【分類號】：TH132.45

【引證文獻(xiàn)】

相關(guān)碩士學(xué)位論文 前1條

1 李俊龍;混合動力汽車用齒形鏈傳動系統(tǒng)設(shè)計(jì)及動態(tài)特性分析[D];吉林大學(xué);2013年

本文編號：2209043