平面四桿機(jī)構(gòu)設(shè)計(jì)

平面四桿機(jī)構(gòu)設(shè)計(jì),平面,機(jī)構(gòu),設(shè)計(jì) 平面四桿機(jī)構(gòu)的運(yùn)動(dòng)性能研究 學(xué)生姓名：劉昕 班級(jí)：0781051 指導(dǎo)老師：許瑛 摘要：平面四桿機(jī)構(gòu)是主要的常用基本機(jī)構(gòu)之一,應(yīng)用十分廣泛,也是其他多桿機(jī)構(gòu)的基礎(chǔ)。由于連桿機(jī)構(gòu)的性能受機(jī)構(gòu)上繁多的幾何參數(shù)的影響,呈復(fù)雜的非線性關(guān)系,無(wú)論從性能分析上還是性能綜合上都是一個(gè)比較困難的工作,尚需作進(jìn)一步深入研究。本文基于平面四桿機(jī)構(gòu)的空間模型,將機(jī)構(gòu)實(shí)際尺寸轉(zhuǎn)化為相對(duì)尺寸,在有限的空間內(nèi)表示出無(wú)限多的機(jī)構(gòu)尺寸類型,從而建立起全部機(jī)構(gòu)尺寸類型和空間點(diǎn)位的一一對(duì)應(yīng)關(guān)系,為深入研究平面四桿機(jī)構(gòu)的運(yùn)動(dòng)性能與構(gòu)件尺寸之間的關(guān)系提供了基礎(chǔ)。根據(jù)曲柄搖桿機(jī)構(gòu)、雙曲柄機(jī)構(gòu)、雙搖桿機(jī)構(gòu)、單滑塊四桿機(jī)構(gòu)的不同特點(diǎn),詳細(xì)分析各類機(jī)構(gòu)的運(yùn)動(dòng)性能參數(shù)與構(gòu)件尺寸之間的關(guān)系,指出構(gòu)件尺寸的變化對(duì)機(jī)構(gòu)運(yùn)動(dòng)性能的影響,并繪制相關(guān)的運(yùn)動(dòng)性能圖譜。針對(duì)具有急回特性的Ⅰ、Ⅱ型曲柄搖桿機(jī)構(gòu),通過(guò)深入分析極位夾角與構(gòu)件尺寸之間的內(nèi)在關(guān)系,獲得了Ⅰ型曲柄搖桿機(jī)構(gòu)極位夾角分別小于、等于或大于90°的幾何條件以及Ⅱ型曲柄搖桿機(jī)構(gòu)極位夾角一定小于90°的結(jié)論,揭示了曲柄搖桿機(jī)構(gòu)設(shè)計(jì)時(shí)作為已知條件的極位夾角和搖桿擺角之間應(yīng)滿足的要求。本文得出的圖譜和相關(guān)結(jié)論,為工程應(yīng)用中機(jī)構(gòu)性能分析和機(jī)構(gòu)綜合提供了理論依據(jù)。 關(guān)鍵詞： 平面四桿機(jī)構(gòu) 空間模型 運(yùn)動(dòng)性能 指導(dǎo)老師簽名： Plane four clubs institutions of Sports performance research Student name：Liu Xin Class：0781051 Supervisor: Xu Ying Abstract:The planar four-bar linkages are one type of basic mechanisms, and they are applied very extensively. The performances of the linkages depend on their geometrical parameters and present the complicated non-linear relations. It is necessary to make the further research on them for analysis, synthesis and application of linkages.By using of the three-dimensional models of the planar four-bar mechanisms, the actual sizes of mechanisms are transformed relative ones, and all size types of mechanisms can be figured by spatial coordinates. It is the foundation for research on the relations between the link dimensions and kinematic capability parameters.Aimed at the different characteristics of crank-rocker mechanism, double-crank mechanism, double-rocker mechanism and single-slider mechanism, some inherent relations between the link dimensions and the kinematic capability parameters are deeply analyzed, then the relative kinematic capability diagrams are obtained.Based on deeply analysis of inherent relations between the extreme position angle and the link dimensions of typeⅠand typeⅡcrank-rocker mechanisms with quick return characteristics, the geometrical conditions are put forward in this paper, by which we can judge whether the extreme position angle of typeⅠcrank-rocker mechanisms is less than, equal to or lager than 90°. It is proved that the extreme position angle of typeⅡcrank-rocker mechanism is certainly less than 90°. The relations between the extreme position angle and the angular stroke of the rocker are brought to light, which should be satisfied during the kinematic design of crank-rocker mechanisms.The diagrams and conclusions obtained in this paper provide theoretic foundation for the capability analysis and synthesis of mechanisms. Keyword: Planar four-bar linkage Space model Sports Performance Signature of Supervisor: