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1、<p>  How Car Suspensions Work</p><p>  The ChassisThe suspension of a car is actually part of the chassis, which comprises all of the important systems located beneath the car's body.</p>&

2、lt;p>  These systems include: </p><p>  The frame - structural, load-carrying component that supports the car's engine and body, which are in turn supported by the suspension </p><p>  Th

3、e suspension system - setup that supports weight, absorbs and dampens shock and helps maintain tire contact </p><p>  The steering system - mechanism that enables the driver to guide and direct the vehicle &

4、lt;/p><p>  The tires and wheels - components that make vehicle motion possible by way of grip and/or friction with the road </p><p>  So the suspension is just one of the major systems in any vehi

5、cle. </p><p>  With this big-picture overview in mind, it's time to look at the three fundamental components of any suspension: springs, dampers and anti-sway bars. </p><p>  SpringsToday&#

6、39;s springing systems are based on one of four basic designs: </p><p>  Coil springs - This is the most common type of spring and is, in essence, a heavy-duty torsion bar coiled around an axis. Coil springs

7、 compress and expand to absorb the motion of the wheels. </p><p>  Leaf springs - This type of spring consists of several layers of metal (called "leaves") bound together to act as a single unit. L

8、eaf springs were first used on horse-drawn carriages and were found on most American automobiles until 1985. They are still used today on most trucks and heavy-duty vehicles. </p><p>  Torsion bars - Torsion

9、 bars use the twisting properties of a steel bar to provide coil-spring-like 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

10、 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 alon

11、g its axis to provide the spring force</p><p>  Air springs - Air springs, which consist of a cylindrical chamber of air positioned between the wheel and the car's body, use the compressive qualities of

12、air to absorb wheel vibrations. The concept is actually more than a century old and could be found on horse-drawn buggies. Air springs from this era were made from air-filled, leather diaphragms, much like a bellows; the

13、y were replaced with molded-rubber air springs in the 1930s. </p><p>  While springs by themselves seem like simple devices, designing and implementing them on a car to balance passenger comfort with handlin

14、g is a complex task. And to make matters more complex, springs alone can't provide a perfectly smooth ride. Why? Because springs are great at absorbing energy, but not so good at dissipating it. Other structures, kno

15、wn as dampers, are required to do this.</p><p>  DampersUnless a dampening structure is present, a car spring will extend and release the energy it absorbs from a bump at an uncontrolled rate. The spring wi

16、ll continue to bounce at its natural frequency until all of the energy originally put into it is used up. A suspension built on springs alone would make for an extremely bouncy ride and, depending on the terrain, an unco

17、ntrollable car.</p><p>  Enter the shock absorber, or snubber, a device that controls unwanted spring motion through a process known as dampening. Shock absorbers slow down and reduce the magnitude of vibrat

18、ory motions by turning the kinetic energy of suspension movement into heat energy that can be dissipated through hydraulic fluid. To understand how this works, it's best to look inside a shock absorber to see its str

19、ucture and function.</p><p>  A shock absorber is basically an oil pump placed between the frame of the car and the wheels. The upper mount of the shock connects to the frame , while the lower mount connects

20、 to the axle, near the wheel . In a twin-tube design, one of the most common types of shock absorbers, the upper mount is connected to a piston rod, which in turn is connected to a piston, which in turn sits in a tube fi

21、lled with hydraulic fluid. The inner tube is known as the pressure tube, and the outer tube is known as</p><p>  When the car wheel encounters a bump in the road and causes the spring to coil and uncoil, the

22、 energy of the spring is transferred to the shock absorber through the upper mount, down through the piston rod and into the piston. Orifices perforate the piston and allow fluid to leak through as the piston moves up an

23、d down in the pressure tube. Because the orifices are relatively tiny, only a small amount of fluid, under great pressure, passes through. This slows down the piston, which in turn slows</p><p>  Shock absor

24、bers 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 oc

25、curs 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

26、cycle. </p><p>  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

27、 control all of the unwanted motions that can occur in a moving vehicle, including bounce, sway, brake dive and acceleration squat. </p><p>  Dampers: Struts and Anti-sway BarsAnother common dampening struc

28、ture is the strut -- basically a shock absorber mounted inside a coil spring. Struts perform two jobs: They provide a dampening function like shock absorbers, and they provide structural support for the vehicle suspensio

29、n. That means struts deliver a bit more than shock absorbers, which don't support vehicle weight -- they only control the speed at which weight is transferred in a car, not the weight itself. </p><p>  B

30、ecause shocks and struts have so much to do with the handling of a car, they can be considered critical safety features. Worn shocks and struts can allow excessive vehicle-weight transfer from side to side and front to b

31、ack. This reduces the tire’s ability to grip the road, as well as handling and braking performance. </p><p>  Anti-sway BarsAnti-sway bars (also known as anti-roll bars) are used along with shock absorber

32、s 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. </p><p>  When the suspens

33、ion 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. In particular, it combats the roll of a car on its suspension as it co

34、rners. 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. </p><p>  Suspension Types

35、: FrontSo far, our discussions have focused on how springs and dampers function on any given wheel. But the four wheels of a car work together in two independent systems -- the two wheels connected by the front axle and

36、 the two wheels connected by the rear axle. That means that a car can and usually does have a different type of suspension on the front and back. Much is determined by whether a rigid axle binds the wheels or if the whee

37、ls are permitted to move independently. The </p><p>  Front Suspension - Dependent SystemsDependent front suspensions have a rigid front axle that connects the front wheels. Basically, this looks like a sol

38、id bar under the front of the car, kept in place by leaf springs and shock absorbers. Common on trucks, dependent front suspensions haven't been used in mainstream cars for years.</p><p>  Front Suspensi

39、on - Independent SystemsIn this setup, the front wheels are allowed to move independently. The MacPherson strut, developed by Earle S. MacPherson of General Motors in 1947, is the most widely used front suspension syste

40、m, especially in cars of European origin.</p><p>  Suspension Types: Rear</p><p>  Rear Suspension - Dependent Systems</p><p>  If a solid axle connects the rear wheels of a car, th

41、en the suspension is usually quite simple -- based either on a leaf spring or a coil spring. In the former design, the leaf springs clamp directly to the drive axle. The ends of the leaf springs attach directly to the fr

42、ame, and the shock absorber is attached at the clamp that holds the spring to the axle. For many years, American car manufacturers preferred this design because of its simplicity.</p><p>  The same basic des

43、ign can be achieved with coil springs replacing the leaves. In this case, the spring and shock absorber can be mounted as a single unit or as separate components. When they're separate, the springs can be much smalle

44、r, which reduces the amount of space the suspension takes up. </p><p>  Rear Suspension - Independent SuspensionsIf both the front and back suspensions are independent, then all of the wheels are mounted an

45、d sprung individually, resulting in what car advertisements tout as "four-wheel independent suspension." Any suspension that can be used on the front of the car can be used on the rear, and versions of the fron

46、t independent systems described in the previous section can be found on the rear axles. Of course, in the rear of the car, the steering rack -- the assembl</p><p>  The Future of Car SuspensionsWhile there

47、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 in

48、troduction 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 i

49、n automobile suspensio</p><p>  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 t

50、he 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 r

51、esult, an LEM can extend and compress at a much greater speed, virtually eliminating all vibrations in th</p><p>  Unfortunately, this paradigm-shifting suspension won't be available , when it will be of

52、fered 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. </p><p><b>  懸架系統(tǒng)工作原理</b&g

53、t;</p><p><b>  底盤</b></p><p>  汽車懸架實(shí)際上是底盤的一部分,底盤包含了位于車身下方的所有重要系統(tǒng)。</p><p><b>  這些系統(tǒng)包括:</b></p><p>  車架——承載負(fù)荷的結(jié)構(gòu)性部件,用于支撐汽車的發(fā)動(dòng)機(jī)和車身,而它本身車架由懸架支撐 <

54、;/p><p>  懸架系統(tǒng)——用于支撐重量、吸收和消除振動(dòng)以及幫助維持輪胎接觸的裝置 </p><p>  轉(zhuǎn)向系統(tǒng)——使駕駛員能夠操控車輛方向的機(jī)械 </p><p>  輪胎和車輪——利用抓地與路面的摩擦力使車輛能夠運(yùn)動(dòng)起來的部件 </p><p>  因此,懸架在任何車輛中都是主要系統(tǒng)之一。</p><p>  有

55、了這樣一個(gè)總體概念后,下面我們來看所有懸架都具備的三個(gè)基礎(chǔ)部件:彈簧、減振器和導(dǎo)向機(jī)構(gòu)。</p><p><b>  彈簧</b></p><p>  現(xiàn)在的彈簧系統(tǒng)均以下面四種基本設(shè)計(jì)之一為基礎(chǔ):</p><p>  螺旋彈簧——最常見的彈簧類型。它其實(shí)是一個(gè)繞軸盤繞的重型扭桿,通過伸縮來緩沖車輪的運(yùn)動(dòng)。</p><p&g

56、t;  葉片彈簧——由若干綁在一起充當(dāng)一個(gè)單元的金屬層(稱為“葉片”)組成。它最初用在馬車上,直到1985年才用在大多數(shù)美國汽車上?,F(xiàn)在大多數(shù)卡車和重型車輛仍在使用它們。</p><p>  扭桿彈簧——利用鋼棒的扭轉(zhuǎn)特性來提供類似螺旋彈簧的性能。其工作原理是:鋼棒的一端固定在車架上,另一端與一個(gè)A形控制臂相連。A形控制臂的作用就像一個(gè)垂直于扭桿移動(dòng)的杠桿。當(dāng)車輪遇到顛簸路面時(shí),其垂直運(yùn)動(dòng)傳遞至A形控制臂,然后通

57、過杠桿作用傳遞至扭桿。然后,扭桿沿軸發(fā)生扭曲以提供彈力。在二十世紀(jì)的五六十年代,歐洲的汽車制造商普遍使用此系統(tǒng),同樣的還有美國的Packard和克萊斯勒公司。</p><p>  空氣彈簧——由車輪和車身之間的柱狀充氣室構(gòu)成。它利用壓縮空氣減緩車輪震動(dòng)。這一設(shè)計(jì)概念實(shí)際上已經(jīng)出現(xiàn)了上百年,在兩輪馬車上就有它的蹤跡。最初的空氣彈簧由充氣的皮囊制成,很像一個(gè)風(fēng)箱。到二十世紀(jì)三十年代,它們被模壓橡膠空氣彈簧取代。<

58、;/p><p>  雖然彈簧本身看似簡單,但在汽車上設(shè)計(jì)和實(shí)現(xiàn)這些裝置,并在乘客的舒適度與汽車的操縱性能之間取得平衡,將是一項(xiàng)復(fù)雜的任務(wù)。更甚的是,彈簧無法獨(dú)自提供極其平穩(wěn)的行駛感覺。原因何在?因?yàn)閺椈稍谖漳芰糠矫娴男阅軜O佳,但在耗散能力方面要稍差一些。為此,需要使用一種稱為減振器的部件。</p><p><b>  減振器</b></p><p&g

59、t;  如果不使用阻尼結(jié)構(gòu),汽車彈簧將以不可控制的速率彈開并釋放它所吸收的顛簸能量,并繼續(xù)按其自身頻率彈起,直到耗盡最初施加在它上面的所有能量。構(gòu)建在彈簧上的懸架自身會(huì)使汽車根據(jù)地形以彈跳方式行駛且不受控制。</p><p>  讓我們來看看減震器。該設(shè)備也稱為緩沖器,它通過一種稱為阻尼的過程來控制不希望發(fā)生的彈簧運(yùn)動(dòng)。減振器通過將懸架運(yùn)動(dòng)的動(dòng)能轉(zhuǎn)換為可通過液壓油耗散的熱能,來放緩和減弱振動(dòng)性運(yùn)動(dòng)的大小。要了解其

60、工作原理,最好是看看減振器內(nèi)部的結(jié)構(gòu)和功能。</p><p>  減振器基本上是一個(gè)放置在車架與車輪之間的機(jī)油泵。減振器的上支座連接到車架,下支座靠近車輪連接到軸。在雙筒設(shè)計(jì)中,減振器最常見的類型之一是上支座連接到活塞桿,活塞桿連接到活塞,而活塞位于充滿液壓油的筒中。內(nèi)筒稱為壓力筒,外筒稱為儲(chǔ)油筒。 儲(chǔ)油筒存儲(chǔ)多出的液壓油。</p><p>  當(dāng)車輪遇到顛簸路面并導(dǎo)致彈簧壓緊和拉伸時(shí),彈

61、簧的能量通過上支座傳遞到減振器,并經(jīng)由活塞桿向下傳遞到活塞?;钊洗蛴锌祝?dāng)活塞在壓力筒內(nèi)上下運(yùn)動(dòng)時(shí),液壓油可通過這些小孔滲漏出來。因?yàn)檫@些孔非常微小,所以在很大的壓力下也只能有很少的液壓油通過。這樣就減緩了活塞的運(yùn)動(dòng)速度,從而使彈簧的運(yùn)動(dòng)緩慢下來。</p><p>  減振器的工作包括兩個(gè)循環(huán)——壓縮循環(huán)和拉伸循環(huán)。壓縮循環(huán)是指活塞向下運(yùn)動(dòng)時(shí)壓縮其下面的液壓油;拉伸循環(huán)指活塞向上運(yùn)動(dòng)到壓力筒頂部時(shí)其上方的液壓油

62、。對(duì)于典型的汽車或輕型卡車,其拉伸循環(huán)的阻力要比其壓縮循環(huán)的阻力大。</p><p>  所有現(xiàn)代的減振器都帶有速度傳感功能——懸架的運(yùn)動(dòng)速度越快,減振器提供的阻力越大。這使得減振器能夠根據(jù)路況進(jìn)行調(diào)整,并控制行駛的車輛中可能出現(xiàn)的所有不希望發(fā)生的運(yùn)動(dòng),包括彈跳、側(cè)傾、制動(dòng)俯沖和加速后仰等。</p><p><b>  滑柱和防橫搖穩(wěn)定桿</b></p>

63、<p>  另一個(gè)常見阻尼結(jié)構(gòu)是滑柱——即安裝在螺旋彈簧內(nèi)部的減振器。滑柱完成兩項(xiàng)工作:一是提供與減振器類似的阻尼功能,二是為車輛懸架提供結(jié)構(gòu)支撐。也就是說,滑柱的功能要略多于減振器(不支撐車輛重量)——但它們只控制重量在汽車中轉(zhuǎn)移時(shí)的速度,而不控制重量本身。</p><p>  因?yàn)闇p振器和滑柱與汽車操控性能的關(guān)系如此密切,我們可以將其視為非常重要的安全性能。已磨損的減振器和滑柱會(huì)使過多的車身重量向

64、前后左右轉(zhuǎn)移。這會(huì)降低輪胎的抓地性能以及操控和制動(dòng)性能。</p><p>  防橫搖穩(wěn)定桿(也叫防側(cè)傾桿)與減振器或滑柱配合使用,以便為行駛中的汽車提供附加穩(wěn)定性。防橫搖穩(wěn)定桿是一個(gè)橫跨整個(gè)車軸的金屬桿,將懸架的兩側(cè)有效地連接在一起。</p><p>  當(dāng)一個(gè)車輪上的懸架上下移動(dòng)時(shí),防橫搖穩(wěn)定桿會(huì)將移動(dòng)傳遞給其他車輪。 這樣可以使行駛更平穩(wěn),并減少了車輛的傾斜度。尤其是它能抵消轉(zhuǎn)彎時(shí)懸架

65、上的汽車的側(cè)翻趨勢。有鑒于此,今天幾乎所有汽車都將防橫搖穩(wěn)定桿作為標(biāo)準(zhǔn)配備;即使不是如此,也可使用相應(yīng)的工具隨時(shí)、輕松地安裝。</p><p><b>  前懸架的類型</b></p><p>  到目前為止,我們的討論都是集中在彈簧和減振器對(duì)任意給定車輪的作用上。但是,一輛汽車的四個(gè)車輪是在兩個(gè)獨(dú)立系統(tǒng)上協(xié)同工作的——兩個(gè)車輪通過前軸連接,另外兩個(gè)通過后軸連接。也就

66、是說,汽車可以并且通常在前后軸上具有不同的懸架類型。更確切地說,車輪可以通過剛性軸連接在一起,也可以各自獨(dú)立運(yùn)動(dòng)。前一種稱為非獨(dú)立系統(tǒng),后一種稱為獨(dú)立系統(tǒng)。</p><p><b>  非獨(dú)立前懸架</b></p><p>  非獨(dú)立式前懸架具有一個(gè)連接兩個(gè)前輪的剛性前軸。 它看起來像是車前部下方由葉片彈簧和減振器固定就位的一個(gè)實(shí)心桿。非獨(dú)立式前懸架在卡車上很常見,但

67、多年以來一直沒有用在主流汽車上。</p><p><b>  獨(dú)立前懸架</b></p><p>  在獨(dú)立式前懸架系統(tǒng)中,前輪可以獨(dú)立移動(dòng)。通用公司的厄爾·S·麥弗遜在1947年開發(fā)的麥弗遜式滑柱是使用最廣泛的前懸架系統(tǒng),特別是在歐洲原產(chǎn)汽車中。</p><p><b>  后懸架類型</b><

68、/p><p><b>  非獨(dú)立后懸架</b></p><p>  如果用實(shí)心軸連接汽車的后輪,那么懸架通常很簡單——以葉片彈簧或螺旋彈簧為基礎(chǔ)。 在第一種設(shè)計(jì)中,葉片彈簧直接夾在驅(qū)動(dòng)軸上,末端直接與車架相連,減振器附著在將彈簧固定到軸上的夾具上。曾經(jīng)有好幾年,美國的汽車制造商都傾向于采用這種設(shè)計(jì),因?yàn)樗芎唵巍?lt;/p><p>  用螺旋彈簧替換

69、葉片彈簧可獲得相同的基本設(shè)計(jì)。在這種情況下,彈簧和減振器既可作為一個(gè)裝置安裝,也可作為單獨(dú)的部件分別安裝。分別安裝時(shí),彈簧可以更小,可以減少懸架占用的空間。</p><p><b>  獨(dú)立后懸架</b></p><p>  如果前后懸架都是獨(dú)立式的,那么所有車輪都將獨(dú)立安裝并連接彈簧,也就是汽車廣告中所吹捧的“四輪獨(dú)立懸架”。在汽車前軸上使用的任何懸架都可用于汽車后

70、軸,前一節(jié)所述的獨(dú)立式前懸架系統(tǒng)的不同版本也可在后軸上找到。當(dāng)然,在汽車后部沒有轉(zhuǎn)向機(jī)齒條——這是包含小齒輪導(dǎo)向的裝配,使車輪能夠從一側(cè)轉(zhuǎn)向另一側(cè)。這意味著后軸獨(dú)立式懸架可以是前軸獨(dú)立懸架的簡化版本,盡管其基本原理保持不變。</p><p><b>  未來的汽車懸架</b></p><p>  雖然針對(duì)彈簧和減振器已經(jīng)有了許多改進(jìn),但在過去的若干年中,汽車懸架的基本

71、設(shè)計(jì)仍未有重大突破。但所有這一切可能會(huì)隨著Bose全新的懸架設(shè)計(jì)理念的引入而發(fā)生變化。有些專業(yè)人士甚至表示,Bose懸架是自全獨(dú)立式設(shè)計(jì)面世以來汽車懸架領(lǐng)域的最大進(jìn)步。</p><p>  那么Bose系統(tǒng)的工作原理是什么?Bose系統(tǒng)在每個(gè)車輪處使用一個(gè)線性電磁馬達(dá)(LEM)取代了傳統(tǒng)的減振器和彈簧裝置。 放大器以隨著系統(tǒng)的每次壓縮重新產(chǎn)生動(dòng)力的方式向馬達(dá)提供電力。這種馬達(dá)的主要優(yōu)點(diǎn)是它們不受傳統(tǒng)液壓式減振器固

72、有的慣性限制。因此,LEM能夠以更快的速度伸縮,從而幾乎完全消除了車廂的震動(dòng)。車輪的運(yùn)動(dòng)可以控制得如此之好,以至于不管車輪發(fā)生什么情況,車身都能保持平穩(wěn)。LEM還可以抵消汽車加速、制動(dòng)和轉(zhuǎn)彎時(shí)的車身運(yùn)動(dòng),為駕駛員提供更美妙的操控體驗(yàn)。</p><p>  不幸的是,這一具有里程碑式意義的懸架在尚不會(huì)面世。即便到那時(shí),也只會(huì)裝配在一兩款高端豪華車上。在此之前,駕駛員們?nèi)员仨氁蕾噹讉€(gè)世紀(jì)以來為我們掃平崎嶇路面的各種久

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