懸架系統(tǒng)原理 文獻(xiàn)翻譯 題 目 可控并聯(lián)雙筒式減震器設(shè)計(jì) 學(xué)生姓名 專業(yè)班級(jí) 學(xué) 號(hào) 院 （系） 指導(dǎo)教師( 完成時(shí)間 懸架系統(tǒng)原理 Kaoru Aoki, Shigetaka Kuroda, Shigemasa Kajiwara, Hiromitsu Sato and Yoshio Yamamoto Honda R&D Co.,Ltd. 摘要 本文主要研究輕型汽車前獨(dú)立懸架的設(shè)計(jì)分析方法以及輪胎磨損與懸架運(yùn)動(dòng)、前輪定位參數(shù)的關(guān)系。 首先對(duì)雙橫臂獨(dú)立懸架的各主要組成部件如減振器的選型設(shè)計(jì)、橫向穩(wěn)定桿的設(shè)計(jì)校核、扭桿彈簧設(shè)計(jì)以及對(duì)雙橫臂式和麥弗遜式獨(dú)立懸架的運(yùn)動(dòng)進(jìn)行了分析，提出了相應(yīng)的計(jì)算方法，編制了一套具有一定實(shí)用價(jià)值的前獨(dú)立懸架設(shè)計(jì)分析軟件。并且采用前輪定位儀，進(jìn)行了實(shí)驗(yàn)驗(yàn)證。 論文對(duì)雙橫臂獨(dú)立懸架參數(shù)提出以減小輪胎磨損為優(yōu)化目標(biāo)，進(jìn)行了優(yōu)化設(shè)計(jì)。提出了通過(guò)優(yōu)選、調(diào)整懸架初始位置狀態(tài)，以及優(yōu)化確定轉(zhuǎn)向橫拉桿斷開(kāi)點(diǎn)位置的方法，來(lái)減小輪胎磨損。同時(shí)采用正交實(shí)驗(yàn)的方法分析了雙橫臂獨(dú)立懸架各結(jié)構(gòu)參數(shù)和安裝參數(shù)對(duì)懸架性能和輪胎磨損的影響，確定出最大的影響因素及次要因素。 然后從輪胎模型入手分析前輪定位參數(shù)同輪胎磨損的關(guān)系。以輪胎磨損能量作為評(píng)價(jià)指標(biāo)，選取刷子輪胎模型，對(duì)輪胎在穩(wěn)態(tài)縱滑狀態(tài)下、穩(wěn)態(tài)縱滑側(cè)偏狀態(tài)下和邊界條件下的輪胎磨損進(jìn)行了分析研究，確定了量化模型。并以輪胎側(cè)偏角為中間變量，建立了前輪定位參數(shù)同輪胎磨損之間關(guān)系的數(shù)學(xué)模型，進(jìn)行了計(jì)算機(jī)仿真計(jì)算。從而可對(duì)懸架進(jìn)行進(jìn)一步的優(yōu)化設(shè)計(jì)，以減小對(duì)輪胎磨損的影響，提高車輛的行駛性能和使用經(jīng)濟(jì)性。 關(guān)鍵詞：汽車；獨(dú)立懸架；輪胎磨損；定位參數(shù) 懸架系統(tǒng)雖不是汽車運(yùn)行不可或缺的部件，但有了它人們可以獲得更佳的駕駛感受。簡(jiǎn)單的說(shuō)，它是車身與路面之見(jiàn)的橋梁。懸架的行程涉及到懸浮于車輪之上的車架，傳動(dòng)系的相對(duì)位置。就像橫跨于舊金山海灣之上的金門(mén)大橋，它連接了海灣兩側(cè)。去掉汽車上的懸架就像是你做一次冷水潛泳通過(guò)海灣一樣，你可以平安的渡過(guò)整個(gè)秋天，但會(huì)疼痛會(huì)持續(xù)幾周之久。想想滑板吧！它直接接觸路面你可以感受到每一塊磚，裂隙及其撞擊。這簡(jiǎn)直就是一種令人全身都為之震顫的體驗(yàn)。當(dāng)輪子滑過(guò)路面時(shí)，就會(huì)在此產(chǎn)生震動(dòng)，沖擊，這種震動(dòng)的旅程時(shí)對(duì)你的身體和勇氣的檢驗(yàn)。如果你沒(méi)感到隨時(shí)都有被掀翻之勢(shì)，那么你或許會(huì)樂(lè)在其中吧！這就是你會(huì)在沒(méi)有懸架的汽車上將會(huì)體驗(yàn)到的。汽車的懸架分為兩種基本類型：整體和獨(dú)立懸架。 整體懸架（也叫剛性梁，剛性軸）是聯(lián)接車輛上下兩部分的一種主要形式。正如其名，它是用一根金屬材料——軸，來(lái)連接兩側(cè)車輪的。鋼板彈簧在車架之下；在兩半軸中間裝有差速器，允許兩側(cè)的輪子以不同的角速度旋轉(zhuǎn)。 整體式懸架的車輛在行進(jìn)中，由于兩側(cè)的車輪共用一根周因此，當(dāng)某一側(cè)車輪跳動(dòng)時(shí)另一側(cè)也會(huì)隨之運(yùn)動(dòng)。它們的反饋結(jié)果就像是一個(gè)整體?？梢韵胂竦牡剑@不可能有舒適的駕駛體驗(yàn)的。 雖然可以借助于彈簧來(lái)衰減猛烈的震動(dòng)，但仍然存在較強(qiáng)的震動(dòng)。那么，既然如此為什么還要用這種懸架呢？第一，它很堅(jiān)固，由于采用了一體化的結(jié)構(gòu)，固定軸式懸架系統(tǒng)具有著其他方式懸架不可替代的承載能力。它們經(jīng)常應(yīng)用于行駛于較差路況的車輛。你可以在卡車和重載車輛上見(jiàn)到它。 一種由固定軸式懸架變形系統(tǒng)叫做TIB懸架系統(tǒng)（或叫半固定軸式）。在這種結(jié)構(gòu)中，有兩根剛性軸而非一根。這種設(shè)計(jì)可兼得較大的剛性和較好的韌性，通常用于輕卡的前懸。 另外一種基本結(jié)構(gòu)是叫做獨(dú)立懸架的系統(tǒng)。想它的名字一樣，它是由兩個(gè)獨(dú)立存在的“橋”分別連接兩側(cè)的車輪。到目前為止，這種結(jié)構(gòu)可以提供最舒適的乘坐環(huán)境，多見(jiàn)于乘用車，小型貨車和其他的小型車輛。這是目前較為流行的一種懸架系統(tǒng)。如果你喜歡較軟的懸架，那么獨(dú)立懸架無(wú)疑是最佳選擇。除了軸，車輪，輪胎，今天的懸架系統(tǒng)使用的兩個(gè)重要部件是彈簧和減震器，以增強(qiáng)車輛的安全和舒適性。 彈簧： 在一輛車上彈簧是懸架系統(tǒng)的主要部件。有集中不同的彈簧，比如扭桿彈簧，但幾乎所有的車輛都采用螺旋彈簧來(lái)構(gòu)成四輪獨(dú)立懸架系統(tǒng)。許多卡車也用螺旋彈簧，而重載卡車則使用 彈簧安裝于其后懸。 彈簧可以減緩和儲(chǔ)存來(lái)自路面的振動(dòng)，沖擊等能量。它通過(guò)壓縮和伸展來(lái)衰減振動(dòng)。當(dāng)一輛車子的某一個(gè)輪子遇到一個(gè)凸起而向上跳動(dòng)時(shí)，彈簧就會(huì)衰減額外的能量。以此來(lái)保證能量傳遞的連貫性，在此過(guò)程中確保車輪始終與路面保持接觸。 彈簧壓縮或伸展量的大小是由“彈簧剛度”決定的。彈簧剛度以每英寸的變形量是由多少載荷所引起來(lái)表示的。比如,1 inch/pound,所以200磅的負(fù)荷可以產(chǎn)生2 inch的變形量。彈簧變形量是由很多的因素決定的。對(duì)于螺旋彈簧而言，包括有效圈數(shù)，彈簧中徑，彈簧鋼絲直徑。有效圈數(shù)越少，剛度越小。 彈簧的設(shè)計(jì)影響到車輛的舒適性與操縱穩(wěn)定性。由于彈簧衰減了大部分的能量，因而可以提供較好的駕駛環(huán)境。畢竟它可以衰減由于路面產(chǎn)生的能量。但總會(huì)有工程交換的。這種彈簧會(huì)使車輛的重心較高，從而在輪子跳動(dòng)時(shí)導(dǎo)致不穩(wěn)定工況。這種工況的產(chǎn)生是由于彈簧的壓縮和伸展的量不同而引起的。車身的“翻滾”大都發(fā)生在懸架之上。這種“翻滾”叫做載荷轉(zhuǎn)移，是由于某一車輪跳動(dòng)是汽車的重心偏移的離心力所引起的。載荷轉(zhuǎn)移可能導(dǎo)致某一車輪承受較大的附加載荷，這將會(huì)產(chǎn)生有害的拖拽力，不利于操縱穩(wěn)定性。 減振器： 懸架的另外一個(gè)重要部件是減震器。減震器在懸架系統(tǒng)中扮演著衰減振動(dòng)最后防線的角色，而這本是彈簧的職責(zé)。減振器可以衰減由于路面致使彈簧上下跳動(dòng)而產(chǎn)生的振動(dòng)的影響。人們不喜歡限程減振器；他們更喜歡阻尼器。如果不加處理——就是被你，我叫做振動(dòng)衰減器東西。減振器工作中有兩個(gè)行程――壓縮和伸張。壓縮行程發(fā)生在活塞向下運(yùn)動(dòng)，在活塞套筒密閉的內(nèi)室向下擠壓液壓油。伸張行程發(fā)生在活塞向上方的套筒頂部運(yùn)動(dòng)時(shí)，此時(shí)被壓縮的液體將向上充滿套筒。 如果沒(méi)有減振器，彈簧衰減的能量將會(huì)以不可控制的速率釋放。彈簧的慣性將導(dǎo)致它猛烈的彈回和擴(kuò)張。這時(shí)彈簧還可以再次被壓縮，但是又會(huì)被壓縮過(guò)量。此后，彈簧仍舊會(huì)以其自然頻率被彈回直至它的能量被摩擦力損耗完。這種作用十分不利于車輛穩(wěn)定性。 迷惑了吧? 下面是個(gè)模型（來(lái)闡釋這個(gè)概念）。如果你有一個(gè)繃帶 ——并且近日又沒(méi)用它，你可以用它做個(gè)試驗(yàn)。用手拿著它在空中使他壓縮。現(xiàn)在，拿著一端放開(kāi)另一端，繃帶就會(huì)衰減由于地心引力而產(chǎn)生的潛在能量。（就像車上的彈簧衰減路面的振動(dòng)那樣），它會(huì)上上下下的持續(xù)很長(zhǎng)時(shí)間。如果一輛車沒(méi)有減振器的協(xié)作它就會(huì)像這樣。 你可能聽(tīng)過(guò)“支撐桿”這個(gè)單詞，或者更平常點(diǎn)的麥弗遜—支撐桿。這個(gè)桿通常是作為減震器的主要結(jié)構(gòu)部件。對(duì)于支撐桿，減振器是安裝在螺旋彈簧內(nèi)圈的。如此也可減少空間，成本也不高。許多車都用麥弗遜式的結(jié)構(gòu)。振動(dòng)和支撐桿可以幫助控制懸架在允許的范圍內(nèi)快速運(yùn)動(dòng)。這對(duì)于保持輪胎與地面接觸是很重要的。大多數(shù)的減振器在設(shè)計(jì)時(shí)更多的考慮增加彈簧伸展循環(huán)的阻力。這是因?yàn)閿U(kuò)張行程決定著汽車彈簧的重量（通常為懸架重量的50％――100%）。另一方面，壓縮行程決定著車輛的非懸架質(zhì)量（車輪，輪胎，剎車，一半的懸架質(zhì)量）。很明顯，簧上質(zhì)量要遠(yuǎn)大于簧下質(zhì)量。所有現(xiàn)代汽車的減振動(dòng)器都是快速反映類型的――懸架系統(tǒng)運(yùn)動(dòng)的越快，則減振器產(chǎn)生的阻尼力越大。這樣就使車輛適應(yīng)不同的道路狀況，且可使在運(yùn)動(dòng)行的車輛里不希望發(fā)生的運(yùn)動(dòng)得以控制。包括，振動(dòng)，左右搖擺，制動(dòng)前傾，和加速后傾。 橫向穩(wěn)定桿 橫向穩(wěn)定桿（也叫作防止?jié)L動(dòng)桿）是用來(lái)協(xié)同減振器或支撐桿工作的以保持車輛的持續(xù)穩(wěn)定性。橫向穩(wěn)定桿是用金屬做成的圓桿，橫跨車輛中心線，有效的連接在懸架的兩邊。當(dāng)一個(gè)車輪上的懸架上下跳動(dòng)時(shí)，橫向穩(wěn)定桿可以傳遞運(yùn)動(dòng)的能量給另一邊的車輪。這就增加了一個(gè)運(yùn)動(dòng)，而且，減少了車輛的傾斜。具有特殊意義的是：它可以防止在某一單獨(dú)的車輪上的懸架產(chǎn)生較大的傾斜。由于這個(gè)原因，幾乎當(dāng)今所有的乘用車加裝了橫向穩(wěn)定桿，且示為標(biāo)配。如果沒(méi)有，也可以隨時(shí)的裝上—一點(diǎn)不難。 現(xiàn)在，你就知道它—汽車懸架的基本原理。我們只是復(fù)雜的原理簡(jiǎn)單化處理了。 未來(lái)的懸架： 當(dāng)加強(qiáng)和改進(jìn)彈簧和減振器時(shí)，汽車懸架的基本設(shè)計(jì)并沒(méi)有同步進(jìn)行，也沒(méi)有什么重大革命性的發(fā)展。但是這一切都隨著B(niǎo)OSE公司的懸架品牌的引入而發(fā)生改變--就是那個(gè)在聲學(xué)因發(fā)明創(chuàng)造引以為名的公司。一些專家已經(jīng)在說(shuō)—BOSE的懸架是自汽車技術(shù)引入全獨(dú)立懸架以來(lái)在汽車懸架的最重大的進(jìn)步。 它是怎么工作的呢？BOSE的系統(tǒng)是在每一個(gè)車輪上裝一個(gè)線控電磁馬達(dá)（LEM）以控制一組減振器和彈性元件的狀態(tài)。功率放大器提供電力對(duì)馬達(dá)在這種情況下他們的力量再生以系統(tǒng)的各壓縮。 馬達(dá)的主要好處是, 他們因具有慣性，不限制于固有的在常規(guī)基于流體的阻尼特性。所以，一個(gè)LEM可以在任何的速度伸張和壓縮，自然它可衰減乘員艙體的所有振動(dòng)。輪子的運(yùn)動(dòng)可以被很好的控制，因而，在輪子的任何運(yùn)動(dòng)狀態(tài)車體都可以保持可以接受的狀態(tài)。LEM同樣可以在汽車加、減速，轉(zhuǎn)彎時(shí)產(chǎn)生的傾角較小，讓駕駛員以更好的狀態(tài)駕駛汽車。不幸的是，當(dāng)它通常都是出現(xiàn)在高端，甚至是超豪華的車上時(shí)，2009年之前是不可能有這種具有理想變換特性的懸架系統(tǒng)在普通車上見(jiàn)到的。在那以前，駕駛員所能體驗(yàn)到的仍舊是幾個(gè)世紀(jì)以來(lái)的對(duì)付不平路面的方法。 如果更深入的學(xué)習(xí)你會(huì)接觸到更加專業(yè)的知識(shí)，看看特殊的彈簧和懸架的安裝了解一下它們的優(yōu)，缺點(diǎn)。 多注意路上跑（的車子），并且留心那些懸架的結(jié)構(gòu)，那樣你會(huì)學(xué)到不少的東西。其實(shí)，在我們生活中有許多值得學(xué)習(xí)的，我們應(yīng)該做的就是注意觀察。 參考文獻(xiàn) [1]Aoki, Kaoru, et al.: "Development an Integrated Motor Assist Hybrid System", JSAE No. 98-99 161 [2]Yamaguchi, Tetsuro: "CVT Control in the HONDA Hybrid 'IMA'", No. 9908 JSAE SYMPOSIUM, Latest Motive Power Transmission Technologies '99, p.3740 [3]Ohno, Hiroshi, et al.: "Development of a NOx Adsorptive Reaction Type Three-Way Catalyst", HONDA R&D Technical Review, Vol. 11 No. 2 (October 1999), p.45-50 [4]Fukuo, Koichi, et al.: "Development of the Ultra Low Fuel Consumption Hybrid Car 'Insight'", HONDA R&D Technical Review, Vol. 11 No. 2 (October 1999), p.1-8 [5]Hideki Tanaka, et al .: "The Effect of 0W-20 Low Viscosity Engine Oil on Fuel Economy”, SAE Paper No.1999-01-3468,Fuels and Lubricants meeting and Exposition, Toronto, Ontario, Canada, October 1999. [6]Aoki, Kaoru, et al.: "An Integrated Motor Assist Hybrid System", SAE Paper No.2000-01-2059, Government / Industry Meeting, Washington, D.C., USA Suspension Basics Kaoru Aoki, Shigetaka Kuroda, Shigemasa Kajiwara, Hiromitsu Sato and Yoshio Yamamoto Honda R&D Co.,Ltd. Abstract The method of independem suspension design is studied in detail andthe relation among suspension movement，front wheel alignment parametersand tyre wear is analysed in this paper． Firstly,the big indpendent designmethods of main components of double-linksindependent suspension，including shock absorber’choosing，antiroU bar’scalculation，torque bar spring’s design，are presented and movement ofdouble—links indpendent suspension is analysed．So a soRware which isused to design optimal and analyse independent suspen- sion is programmed．Meanwhile，me experiment to Verifythe result is made with the equipment ofthe front wheel alignment． Then an optimal design t0 mjnimize tyre、vear is perfonlled，whichbrings forward me way to reduce tyre wear throu optimal choosing andmodulating origina ldenpention cture of double-1ink independent suspension andoptimizjng the cut point of track rodill。Future more，the memod oformogonal experiment is used to analyse t11e effect that tlle-stn cture a11d fixparameters of double-1ink indendent suspension have on me suspension performance and tyre wear.And the most impotent factor and second important factor confiemed. KEY WoRDS: automobile，independent suspension，tyre wear， alignment paraeter The suspension system, while not absolutely essential to the operation of a motor vehicle, makes a big difference in the amount of pleasure experienced while driving. Essentially, it acts as a "bridge" between the occupants of the vehicle and the road they ride on The term suspension refers to the ability of this bridge to "suspend" a vehicle's frame, body and powertrain above the wheels. Like the Golden Gate Bridge hovering over San Francisco Bay, it separates the two and keeps them apart. To remove this suspension would be like taking a cool dive from the Golden Gate: you might survive the fall, but the impact would leave you sore for weeks. Think of a skateboard. It has direct contact with the road. You feel every brick, crack, crevice and bump. It's almost a visceral experience. As the wheels growl across the paveme nt, picking up a bump here, a crack there, the vibration travels up your legs and settles in your gut. You could almost admit you were having fun, if you didn't feel like you were gonna toss your tacos at any second.This is what your car would feel like without a suspension system.Before we get into the individual components that make up a vehicle's ride support, let's take a look at a basic principle of design: solid axle vs. independent suspension. Solid axle suspension (also known as rigid beam, or rigid axle) is the most elementary form of connecting the upper and lower halves of a vehicle. As the name implies, it utilizes a single piece of metal -- a common axle for both wheels -- sprung beneath the car's undercarriage. Pivots located between the axle and the wheel spindles allow the wheels to swivel on each end. In solid axle suspension, because both wheels share the same axle, the up or down movement of one wheel causes a like movement in the other wheel. They respond as one unit. As you can imagine, this doesn't make for the most comfortable ride. Even though solid axle designs utilize springs to soften their inherently harsh ride characteristics (more on different spring setups below), they still bump along like a brick outhouse. So why use them at all? Well, strength, for one. Because of the unitized construction, solid axle suspension systems offer incredible load bearing capacity. They also handle uneven roads superbly. You'll find them in trucks and offroad vehicles[1]. A modified form of the solid axle design is called Twin-I-beam suspension, or semi-rigid axle. In this setup, two rigid axles -- one for each wheel -- take the place of a single axle. This design offers many of the strengths of the solid axle design, with a slightly softer ride. You'll find it used primarily in the front end of light trucks. The other main design is called independent suspension. As the name suggests, independent suspension assemblies offer a separate "bridge" for each wheel. They deliver the best ride characteristics by far, and are found most frequently in passenger cars, minivans, and other street vehicles. This is the most popular kind of suspension system in use today. If you like the "smoothness" of your car's ride, we can almost guarantee it has independent suspension. In addition to axles, wheels and tires, today's suspension systems utilize two other components that are critical to safe and comfortable driving: springs and shock absorbers. Springs A car's springs are the central part of the suspension. There are different designs of springs, such as torsion bars and leaf springs, but nearly all of today's passenger cars use coil springs at all four corners. A lot of trucks use coil springs too, with leaf springs for heavier load capacity typically found on a truck's rear suspension system. Springs absorb and store road shock caused by bumps, dips, cracks, and so forth (remember the skateboard analogy). They absorb this shock by either compressing or extending. When a car's wheel goes over a bump and gets pushed upward, the spring absorbs that additional load, keeps the road shock from reaching the chassis, and makes sure the tire maintains contact with the pavement[3]. ng compresses or extends is determined by its "spring rate." Spring rate is measured in pounds per inch of deflection; for example, 100 pounds per inch. So, say a load of 200 pounds is applied, the spring will deflect 2 inches. Spring rate comes from various factors. For a coil spring, this includes the number of active coils, the diameter of the coils, and the diameter of the spring wire. The fewer coils a spring has, the higher the spring rate it will have. The design of a spring affects how well the vehicle will ride and handle. A spring that absorbs lots of energy will generally offer a comfortable ride. After all, it can absorb most of the road shock (energy) that is being generated by the road surface. But there are always engineering trade-offs. This kind of spring generally requires a higher vehicle ride height, which will cause the vehicle to feel unstable during cornering. This instability is because the more distance a spring compresses or extends, the more the vehicle "rolls" around on its suspension. This rolling is called weight transfer, and it is caused by centrifugal force acting on the weight of the vehicle as it goes around a corner. Weight transfer can overload a tire's grip, which ultimately hurts traction, and therefore handling[1]. Shock Absorbers The other main part of a car's suspension is the shock absorber. Contrary to its name, a shock absorber plays a minimal role in absorbing impacts taken by the suspension. That's the spring's job. A shock absorber dampens road impacts by converting the up and down oscillations of the spring into thermal energy. Shock absorbers work in two cycles -- the compression cycle and the extension cycle. The compression cycle occurs as the piston moves downward, compressing the hydraulic fluid in the chamber below the piston. The extension cycle occurs as the piston moves toward the top of the pressure tube, compressing the fluid in the chamber above the piston. A typical car or light truck will have more resistance during its extension cycle than its compression cycle. With that in mind, the compression cycle controls the motion of the vehicle's unsprung weight, while extension controls the heavier, sprung weight[2]. People who live and breathe shock absorbers don't like the term shock absorbers; they prefer "dampers." The unwashed masses -- that's you and me -- just call them shock absorbers. Without a shock absorber, a spring that has absorbed energy will release it by oscillating at an uncontrolled rate. The spring's inertia causes it to bounce and overextend itself. Then it recompresses, but again travels too far. The spring continues to bounce at its natural frequency until all the energy originally put into the spring is used up by friction. This effect can be quite detrimental to the stability of a vehicle[3]. Confused? OK, here's an analogy. If you have a Slinky lying around -- and who doesn't these days? -- you can use it as an example[2]. Hold up a compressed Slinky in the air with your hand. Now hold just one end and let the other drop. The Slinky will absorb the potential energy caused by gravity (just like how a car's spring absorbs road shock) and then bounce up and down, up and down (aka: oscillate), for a long time. This what an automotive spring does if it doesn't have a shock absorber attached to it. Perhaps you've heard the word "strut," or, more formally, MacPherson strut. Struts are simply shock absorbers used as major structural members. For struts, the shock absorber is placed inside the coil spring. In addition to saving space, it often costs less. Many cars use a strut design.Shocks and struts help control how fast the suspension is allowed to move, which is important for keeping the tires in contact with the road. Most shock absorber designs have more resistance during the extension (rebound) cycle than the compression cycle[6]. This is because the extension cycle controls the motion of the vehicle's sprung weight (half of the suspension and everything else above the suspension) [4]. The compression cycle, on the other hand, controls the motion of unsprung weight (wheels, tires, brakes, and half of the suspension). Obviously, there is a lot more weight in the upper part of the car than unsprung weight in the lower part of the car. All modern shock absorbers are velocity-sensitive -- the faster the suspension moves, the more resistance the shock absorber provides. This enables shocks to adjust to road conditions and to control all of the unwanted motions that can occur in a moving vehicle, including bounce, sway, brake dive and acceleration squat. Anti-sway Bars Anti-sway bars (also known as anti-roll bars) are used along with shock absorbers or struts to give a moving automobile additional stability. An anti-sway bar is a metal rod that spans the entire axle and effectively joins each side of the suspension together. When the suspension at one wheel moves up and down, the anti-sway bar transfers movement to the other wheel. This creates a more level ride and reduces vehicle sway[5]. In particular, it combats the roll of a car on its suspension as it corners. For this reason, almost all cars today are fitted with anti-sway bars as standard equipment, although if they're not, kits make it easy to install the bars at any time. So there you have it -- the basics of automotive suspension. We realize this is a simplistic view of a complex system. The Future of Car Suspensions ，While there have been enhancements and improvements to both springs and shock absorbers, the basic design of car suspensions has not undergone a significant evolution over the years. But all of that's about to change with the introduction of a brand-new suspension design conceived by Bose -- the same Bose known for its innovations in acoustic technologies. Some experts are going so far as to say that the Bose suspension is the biggest advance in automobile suspensions since the introduction of an all-independent design.[3] How does it work? The Bose system uses a linear electromagnetic motor (LEM) at each wheel in lieu of a conventional shock-and-spring setup. Amplifiers provide electricity to the motors in such a way that their power is regenerated with each compression of the system. The main benefit of the motors is that they are not limited by the inertia inherent in conventional fluid-based dampers. As a result, an LEM can extend and compress at a much greater speed, virtually eliminating all vibrations in the passenger cabin. The wheel's motion can be so finely controlled that the body of the car remains level regardless of what's happening at the wheel. The LEM can also counteract the body motion of the car while accelerating, braking and cornering, giving the driver a greater sense of control. Unfortunately, this paradigm-shifting suspension won't be available until 2009, when it will be offered on one or more high-end luxury cars. Until then, drivers will have to rely on the tried-and-true suspension methods that have smoothed out bumpy rides for centuries[4]. If you learn more , you'll get a little more technical and a little more specific, looking at particular spring and suspension setups, and the advantages and disadvantages of each. until then, keep your eye on the road, and watch out for those pothole,then you will learn more good knowledge .In the fact ,there are many thing can be learn in our life ,the only thing what you should do is observation. REFERENCES [1]Aoki, Kaoru, et al.: "Development an Integrated Motor Assist Hybrid System", JSAE No. 98-99 161 [2]Yamaguchi, Tetsuro: "CVT Control in the HONDA Hybrid 'IMA'", No. 9908 JSAE SYMPOSIUM, Latest Motive Power Transmission Technologies '99, p.3740 [3]Ohno, Hiroshi, et al.: "Development of a NOx Adsorptive Reaction Type Three-Way Catalyst", HONDA R&D Technical Review, Vol. 11 No. 2 (October 1999), p.45-50 [4]Fukuo, Koichi, et al.: "Development of the Ultra Low Fuel Consumption Hybrid Car 'Insight'", HONDA R&D Technical Review, Vol. 11 No. 2 (October 1999), p.1-8 [5]Hideki Tanaka, et al .: "The Effect of 0W-20 Low Viscosity Engine Oil on Fuel Economy”, SAE Paper No.1999-01-3468,Fuels and Lubricants meeting and Exposition, Toronto, Ontario, Canada, October 1999. [6]Aoki, Kaoru, et al.: "An Integrated Motor Assist Hybrid System", SAE Paper No.2000-01-2059, Government / Industry Meeting, Washington, D.C., USA