【正文】 s springing systems are based on one of four basic designs: Coil springs This is the most mon type of spring and is, in essence, a heavyduty torsion bar coiled around an axis. Coil springs press and expand to absorb the motion of the wheels. ? Leaf springs This type of spring consists of several layers of metal (called leaves) bound together to act as a single unit. Leaf springs were first used on horsedrawn carriages and were found on most American automobiles until 1985. They are still used today on most trucks and heavyduty vehicles. 華東交通大學(xué)畢業(yè)設(shè)計(jì) 25 ? Torsion bars Torsion bars use the twisting properties of a steel bar to provide coilspringlike performance. This is how they work: One end of a bar is anchored to the vehicle frame. The other end is attached to a wishbone, which acts like a lever that moves perpendicular to the torsion bar. When the wheel hits a bump, vertical motion is transferred to the wishbone and then, through the levering action, to the torsion bar. The torsion bar then twists along its axis to provide the spring force. European carmakers used this system extensively, as did Packard and Chrysler in the United States, through the 1950s and 1960s. Photo courtesy HowStuffWorks Shopper Torsion bar ? Air springs Air springs, which consist of a cylindrical chamber of air positioned between the wheel and the car39。s look at the parts of a typical suspension, working from the bigger picture of the chassis down to the individual ponents that make up the suspension proper. The Chassis The suspension of a car is actually part of the chassis, which prises all of the important systems located beneath the car39。s ability to steer, brake and accelerate. Minimize the transfer of vehicle weight from side to side and front to back, as this transfer of weight reduces the tire39。s vertical energy is transferred to the frame, which moves in the same direction. In such a situation, the wheels can lose contact with the road pletely. Then, under the downward force of gravity, the wheels can slam back into the road surface. What you need is a system that will absorb the energy of the vertically accelerated wheel, allowing the frame and body to ride undisturbed while the wheels follow bumps in the road. The study of the forces at work on a moving car is called vehicle dynamics, and you need to understand some of these concepts in order to appreciate why a suspension is necessary in the first place. Most automobile engineers consider the dynamics of a moving car from two perspectives: ? Ride a car39。ve evolved over the years and where the design of suspensions is headed in the future. Vehicle Dynamics If a road were perfectly flat, with no irregularities, suspensions wouldn39。 論文的完成是大學(xué)四年學(xué)術(shù)生活的一個(gè)句點(diǎn)，回顧四年以來(lái)，真是感慨碰到了很好的老師、很好的同學(xué)，你們的指導(dǎo)與幫助我會(huì)永遠(yuǎn)銘記！ 何建勛： 雙橫臂獨(dú)立懸架設(shè)計(jì) 20 參考文獻(xiàn) [1] 王望予主編 . 汽車(chē)設(shè)計(jì) [M]. 北京 : 機(jī)械工業(yè)出版社 , 2020 [2] 吉林工業(yè)大學(xué)汽車(chē)教研室編 [M]. 汽車(chē)設(shè)計(jì) . 北京 :機(jī)械工業(yè)出版社 , 1981 [3] 陳家瑞主編 . 汽車(chē)構(gòu)造 [M]. 北京 :機(jī)械工業(yè)出版社 , 2020 [4] 余志生主編 . 汽車(chē)?yán)碚? 第三版 [M]. 北京 :機(jī)械工業(yè)出版社 , 2020 [5] 汪卸建主編 . 汽車(chē)底盤(pán)簡(jiǎn)明教學(xué)圖解 [M]. 北京 :電子工業(yè)出版社 ,2020 [6] 濮良貴 ,紀(jì)名剛主編 . 機(jī)械設(shè)計(jì) 第八版 [M]. 北京 :高等教育出版社 ,2020 [7] 裘文言等主編 . 機(jī)械制圖 [M]. 北京 :高等教育出版社 ,2020 [8] 海欣主編 . Pro/Engineer Wildfire [M]. 北京 :電子工業(yè)出版社 ,2020 [9] 肖乾主編 . Pro/Engineer Wildfire [M]. 北京 :中國(guó)電力出版社 ,2020 [10] 趙 洪倫主編 . 軌道車(chē)輛結(jié)構(gòu)與設(shè)計(jì) [M]. 北京 :中國(guó)鐵道出版社 ,2020 [11] 成大先主編 . 機(jī)械設(shè)計(jì)手冊(cè) [M]. 北京 :化學(xué)工業(yè)出版社 ,2020 [12] 張洪欣 . 雙橫臂扭桿獨(dú)立懸架設(shè)計(jì) [J]. 同濟(jì)大學(xué)汽車(chē)工程系 ,1997 [13] 王永寬 . 瑞風(fēng)商務(wù)車(chē)前懸架計(jì)算機(jī)輔助分析 [D]. 安徽工業(yè)大學(xué) ,2020 [14] 洪家娣主編 . 機(jī)械設(shè)計(jì)指導(dǎo) [M]. 江西 :江西高校出版社 ,2020 [15] 劉惟信主編 . 汽車(chē)設(shè)計(jì) [M]. 北京 :清華大學(xué)出版社 ,2020 [16] 劉惟信主編 . 驅(qū)動(dòng)橋 [M]. 北京 :人民交通出版社 ,1987 [17] 張洪欣主編 . 汽車(chē)設(shè)計(jì) [M]. 北京 :機(jī)械工業(yè)出版社 ,1989 [18] 高海波等 . 扭桿彈簧及扭桿彈簧設(shè)計(jì)新方法 [D]. 哈爾濱工業(yè)大學(xué) ,2020 [19] 郭偉 . 輕型汽車(chē)獨(dú)立懸架分析 [D]. 江蘇大學(xué) ,2020 [20] 劉劍 . 汽車(chē)雙橫臂獨(dú)立懸架的運(yùn)動(dòng)學(xué)分析和計(jì)算 [J]. 北京理工大學(xué) ,2020 [21] 胡寧 . 雙橫臂獨(dú)立懸架的運(yùn)動(dòng)學(xué)分析 [D]. 上海工程技術(shù)大學(xué) ,1998 [22] X. L. Bian, B. A. Song, R. Walter. Optimization of steering linkage and doublewishbone suspension via RW multibody dynamic analysis[J]. 2020 [23] 王望予等 . 微型汽車(chē)獨(dú)立懸架轉(zhuǎn)向輪 擺振及其阻尼控制初步研究 [J]. 中國(guó)公路學(xué)報(bào) . 1993 華東交通大學(xué)畢業(yè)設(shè)計(jì) 21 附錄 A 外文 翻譯 原文 部分 How Car Suspensions Work Table of Contents: ? Introduction to How Car Suspensions Work ? Vehicle Dynamics ? The Chassis ? Springs ? Springs: Sprung and Unsprung Mass ? Dampers: Shock Absorbers ? Dampers: Struts and Antisway Bars ? Suspension Types: Front ? Suspension Types: Rear ? Specialized Suspensions: T ? Specialized Suspensions: Formula One Racers ? Specialized Suspensions: Hot Rods ? The Future of Car Suspensions ? Lots More Information ? Compare Prices for Car Suspensions When people think of automobile performance, they normally think of horsepower, torque and zeroto60 acceleration. But all of the power generated by a piston engine is useless if the driver can39。無(wú)論是在論文的選題、構(gòu)思和資料的收集方面，還是在論文的研究方法以及成文定稿方面，我都得到了 李剛 老師悉心細(xì)致的教誨和無(wú)私的幫助，特別是他廣博的學(xué)識(shí)、嚴(yán)謹(jǐn)?shù)闹螌W(xué)精神和一絲不茍的工作作風(fēng)使我受益匪淺，在此表示真誠(chéng)地感謝和深深的謝意。 接頭所連接的兩部分，若其中之一僅是繞某一軸線(xiàn)相對(duì)另一部分轉(zhuǎn)動(dòng)時(shí)，應(yīng)該用何建勛： 雙橫臂獨(dú)立懸架設(shè)計(jì) 18 軸銷(xiāo)式連接，雙橫臂獨(dú)立懸架的上、下橫臂靠近汽車(chē)中部一段的接頭 以及減振器兩端處的接頭都用這種連接，圖 36 所示為軸銷(xiāo)式接頭。接頭所連接的兩部分之間的相對(duì)運(yùn)動(dòng)和傳力特點(diǎn)將影響接頭形式的選擇。 減 振 器的工作缸直徑 D有 20mm、 30mm、 40mm、 (45mm)、 50mm、 65mm等幾種，選取時(shí)按標(biāo)準(zhǔn)選取，根據(jù) QC/T4911999《汽車(chē)筒式減 振 器 尺寸系列及技術(shù)條件》 選取 工作缸直徑為 20mm的減振器。 40mm； ?—— 懸架 振 動(dòng)固有頻率 ，一般為 1～ 。 分析式 39可知：在下橫臂長(zhǎng)度 n不變的條件下，改變減振器在下橫臂上的固定點(diǎn)位置或者減振器軸線(xiàn)與鉛垂線(xiàn)之間的夾角 α，會(huì)影響減振器阻尼系數(shù)的變化。實(shí)際上應(yīng)根據(jù)減振器的布置特點(diǎn)確定減振器的阻尼系數(shù)。 對(duì)于無(wú)內(nèi)摩擦的彈性元件懸架，取ψ =～ ；對(duì)于有內(nèi)摩擦的彈性元件懸架，ψ值取小些。 式 38表明，相對(duì)阻尼系數(shù)ψ的物理意義是：減振器的阻尼作用在與不同剛度 c和不同簧上質(zhì)量 ms的懸架系統(tǒng)匹配時(shí)，會(huì)產(chǎn)生不同的阻尼效果。在沒(méi)有特別指明時(shí)，減振器的阻尼系數(shù)是指卸荷閥開(kāi)啟前的阻尼系數(shù)而言?，F(xiàn)在市場(chǎng)上比較流行雙向作用的減振器，所以本設(shè)計(jì)方案也采用雙向作用式減振器。 20世紀(jì) 50年代單筒式充氣減振器技術(shù)蓬勃發(fā)展起來(lái)，它 采用了浮動(dòng)活塞結(jié)構(gòu)，在浮動(dòng)活塞與缸筒的一端之間形成的補(bǔ)償室內(nèi)充 入 一定量的高壓 ( MPa～ MPa)氮?dú)?，壓縮室內(nèi)油液體積的變化由這部分氣體補(bǔ)償 。我國(guó)在 20世紀(jì) 60年代生產(chǎn)的 BJ21 NJ230汽車(chē)上開(kāi)始采用筒式液阻減振器， 70年代初解放牌汽車(chē)也改用了筒式液阻減振器。 彈簧的有效圈數(shù) n= 9536008 34334 ??? ????FD fGd，取 n=4。 103 Mpa 彈性模量 E=197179。 圖 32 圓柱螺旋彈簧 空載時(shí)彈簧受力為 F1=