輕型貨車(chē)車(chē)架設(shè)計(jì)及有限元分析畢業(yè)設(shè)計(jì)論文

輕型貨車(chē)車(chē)架設(shè)計(jì)及有限元分析畢業(yè)設(shè)計(jì)論文,輕型,貨車(chē),車(chē)架,設(shè)計(jì),有限元分析,畢業(yè)設(shè)計(jì),論文 畢 業(yè) 設(shè) 計(jì)（論 文）外 文 參 考 資 料 及 譯 文譯文題目： Automotive safety systems and technology research and analysis 汽車(chē)安全系統(tǒng)技術(shù)研究分析 學(xué)生姓名： 學(xué) 號(hào)： 專(zhuān) 業(yè)： 車(chē)輛工程 所在學(xué)院： 機(jī)電工程學(xué)院 指導(dǎo)教師： 職 稱(chēng)： 年 01 月 15 日說(shuō)明：要求學(xué)生結(jié)合畢業(yè)設(shè)計(jì)（論文）課題參閱一篇以上的外文資料，并翻譯至少一萬(wàn)印刷符（或譯出 3千漢字）以上的譯文。譯文原則上要求打?。ㄈ缡謱?xiě)，一律用 400字方格稿紙書(shū)寫(xiě)） ，連同學(xué)校提供的統(tǒng)一封面及英文原文裝訂，于畢業(yè)設(shè)計(jì)（論文）工作開(kāi)始后 2周內(nèi)完成，作為成績(jī)考核的一部分。Automotive safety systems and technology research and analysisAbstract: auto parts of good and bad will directly affect the safety of the car， are directly related to the people's life safety and security in wealth. This article mainly from the car's active safetytechnology and passive safety technology two aspects elaborated the importance of car parts， and how to improve the safety of the car. Key words: automobile， active safety technology， passive safety technology As traffic tools of the modernization and absolute number increase sharply， traffic accidents are also increasing. Car accident has become severe global social issues. Undoubtedly， advanced auto safety facilities are the driving safety indispensable safeguard. So， we should start， from technology to research and development of high performance， high safety car， also want to strengthen the regular inspection in cars， so timely maintenance investigation， make cars often in good technical status， so as to improve the safety performance of the car. Here we introduced active safety technology and automobile car passive safety technology. Auto safety is according to the traffic accident happened before and after the classified. One is ina traffic accident take safety measures， especially before immediately will produce risk condition， drivers manipulate the steering wheel avoid or emergency brake to avoid traffic accidents. In the car， drive in usually to ensure the basic manipulation stability， drivers on the surrounding environment and to ensure the visual recognition sex drive the car itself， developed the basic performance ant-lock braking system (ABS)， prevent slippery drive system (ASR)，active suspension， power steering and four-wheel drive (4WD)， four-wheel steering (4WS)，lighting system， wiper， the rearview mirror， prevent from rear-end collision car alarm system and laser radar， etc. These security devices and technology， called active safety system， can also be called preventive security system. On the other hand， inorder to reduce traffic accidents and company by personnel directly suffer degree， ensure company take staff and pedestrian safety， says the security for passive safety， can also be called conflict safety. When after the accident， in order to prevent disasters， including prevent the expansion of fire and make crew from traffic accident can extricate the security devices and systems， called prevent disaster expand security system. Automobile active security technology ABS braking system Ant-lock Braking System (Braking System， lock do by ABS computers as ABS)，hydraulic device， the wheel speed sensors， brake hydraulic pipeline and electrical wiring etc.Their structures are shown below. ABS tasseled for the car in various driving conditions braking performance and brake safetyparticularly important， especially is emergency braking， can make full use of the peak between tire and road surface adhesion properties， improve performance and reduce automobile fightsideslip braking distance， give full play to the braking performance， but also increase the automobile braking process control. So as to reduce the possibility of car accidents. No installation ABS car， if the driving force trample brake pedal， wheel will rapidly lower speed， and finally wheels stop turning， but body because of inertia remains forward sliding. This phenomenon was at the wheel and pavement occur between larger “slip“， appear this kind of situation， the car tires of automobile lateral spreads almost disappear， so poor force will appear the following phenomena: (1)Steering stability fall: the steering wheel is ineffective， vehicle tail manipulation of curl， serious when vehicle circles or appear folding phenomenon; (2) Handling fall: manipulate the steering wheel and short of steering requirements; (3)Braking distance extended: more than general braking distance. So， we can imagine to have installed ABS system of the car safety is very important. The ASR drive torque control system ABS are used to prevent car braking process wheel lock， will wheel sliding rate control in ideal range， so as to shorten the braking distance， improve automobile braking direction stability and steering control， so as to improve the safety of the car. Along with the increase of vehicle performance requirements， not only in braking process required to prevent wheel lock， and asked the driver to prevent drive roller skating turn in the process， making cars in the direction stability， driving process steering control ability and acceleration performance， so are improved by the car drive torque steering system ASR (Accelerations Regulation) Slip. ASR is the perfect complement and ABS ASR， but most alone is set with ABS combined together， commonly used ABS/ASR says， called antiskid control system. ASR is mainly used to prevent car in the beginning， accelerate the wheels， guarantee slip in the car accelerated rate and improve the stability in bad pavement drive attached conditions. It makes no difference speed in the car lock ice roads and muddy road started and to improve its capacity， also can prevent high in speed by turning cars gliding pavement and rear lateral spreads phenomenon. Anyhow， prevent the wheel because ASR slip， can maximize the engine driving moment of cars had enough， ensure the longitudinal force， lateral force and manipulation of power，make cars in starting， steering and accelerate the process， in gliding and muddy road， in a mountain area downhill process can steadily driving， guarantees the safety， reducing tire wear and fuel consumption， and improves the car driving capability. VDC system ABS/ASR system successfully solves the brake and the car when driven direction stability problem， but cannot solve the vehicle steering stability problem driving direction. For example when steering road， inevitably by lateral and longitudinal force， only local surface can provide full lateral and longitudinal force， the pilot can control vehicles. If the ground adhesion ability lower lateral， will damage cars driving ability predetermined direction. Rainy days cars driving， often high-speed steering lateral sliding out， it is the ground because of insufficient lateral adhesion ability. To resolve the issue， and developed countries automobile industry recently in ABS/ASR system on the basis of the development of dynamic Control system (into car Dynamics Control， the abbreviation VDC Vehicle).The system of the car brake， driving， suspension， steering， engine and so on various mainassembly control system in function， structure organic ground comprehensive together， can make cars in all kinds of bad working conditions， such as ice road pavement， commuting， river bend pavement and took evasive action moving line， braking and acceleration and the downhill for different conditions， such as bearing， different type pressure and different levels of type wear all have good direction stability， to show the best driving performance. VDC applications， in braking， acceleration and steering aspects of driver's fully released request， is the car of active safety driving a new milestone. VDC of steering control system is mainly by driving for each wheel brake control and engine power output control to realize. For example， if the car turn left front wheel for steering the inadequate capacity tend to slip out of the corner， VDC system can measure imminent， just know lateral spreads left rear brake adopt appropriate measures. If at the same corner， because rearwheel tend to slip out of favor of lateral overmuch， VDC system is proper braking to front-right wheel failure， maintain the stability of the vehicle driving. In extreme cases， VDC system can also take reduce engine to reduce the power output， and to reduce the speed of the demand side adhesion ability to maintain the stability of the vehicle driving. Adopt VDC system， automobile in folio pavement or corner of pavement braking distance still can further reduce. CCS cars cruise control system Auto cruise Control System (Cruiser Control System， abbreviation for CCS)is can make automobile work in engine favorable speed range， reduce driver's driving manipulate labor intensity， improve the driving comfort the automatic driving device. Car cruising system (CCS) role is required by the driver: after a normally-closed switch， no speed on the accelerator pedal can automatically keep the speed， make the vehicle with the fixed speed. Using this device， when on the highway after a long time， the driver driving not have to control the accelerator pedal， reduce fatigue ， while reducing unnecessary speed change， can reduce save fuel. Auto cruise control system is the earliest development of the automotive electronic control system. This system USES another speed sensor， will speed signal input engine control microcomputer， by microcomputer control vacuum system work. This system can make use of the server， speed control switch lever and brake pedal on vacuum lift switches etc， its function and basic system the same. In this system， electronic control device can accord change of driving resistance， automatic regulation engine throttle Angle， make the speed constant. Such not only reduce unnecessary speed change， which saves fuel ， also reduced the driver's burden. The electronic cruise control system which is shown in figure 2. Automobile passive safety technology Seat belt Car seat belt is a safety device， it can in car collision or sharp turn， make crew to keep its original position as possible without mobile and rotation， avoid collision with in-car hard parts caused damage. Seat belts and airbags， as modern cars are safety devices， but the long history of the former， popularize the scope. The seemingly simple seat belt actually not “simple“. Attention has been at the forefront of traffic safety， through the analysis of general motors after a car accident found: seat belt not only makes people protect the lives， can be in more than half of the accident to reduce or even eliminate drivers， motorists are the chance of injury. Car collision or unexpected emergency braking force generated great inertia， will allow the driver and passenger and car windscreen， steering wheel， seat， collision happened objects such as secondary to drive is caused extremely easily crew serious damage， even drive occupant seats or threw the apex， seat belts can will ride in the seat. Bondage personnel When has the accident， which can effectively prevent the collision， and its buffer role can absorbs a great deal of kinetic energy， reduce rides personnel extent of the injuries. Fasten your seat belt airbags play our role is also an important condition. Because the airbagto maximize role for the ride in the impact of the physical location， sitting instant action have extremely strict and the requirements. Otherwise， the airbag started strong instantaneous wallops to head are fragile site， may cause serious damage， especially for children， this damage can be fatal. Even the most ordinary three belts， try a can timely in crash that lived rides the bundle， ensure the upper part of a ride in the airbag fully extended range， make the airbag most effectively play efficacy. Accordingly， must not because the car is equipped with airbags and feel carefree seat belt fastened， only to reduce or eliminate the traffic accident happen. The airbag When the front collision happened strong， because inertia， who rides the body forward fast moving， then seat belts and will try to “pull“ rides on person the body， absorb some of theimpact energy， while the airbag with “the eyepiece trend“ inflatable and completely open; Then the rides the upper body will sink to airbags， gas also began from the vent air uniform escaping， and absorbed most of the impact energy; Subsequently， the ride back seat and return to the body. Above the whole process is almost always happens in a flash， who rides the completelyin passive situation， in this case， the passive rely on auxiliary occupant protection system is the only option. Airbags development design is based on the protection on seat belt Co.， LTD; they cooperate with each other to ride the play the auxiliary protective effect. Seat belt usage in under the condition of the crew， balloon help reduce chest， head and facial injuries in the seriousness of the collision. When car collision happened before， the first isthe car to stop motion， car under the action of inertial force crews to go forward with the original speed still sport. Not wearing a seatbelt crews will and steering dish， front windscreen together， so it can be severely hurt; Wearing a seatbelt as car stop the crew can stop moving forwardmovement and gradually. If collision violent， crew forward movement of the seat belts， evenfaster in the complete stop before motion， still and in-car things together. If this fashion in steering the disk or within the popup balloon inflated dash， it can protect the occupant reduce the possibility of car together with things， more uniform dispersion head， chest， absorb the impact energy of movement， thus crew has added effect of seat belts. In addition to seat belts and airbags outside car passive safety technology includes car bumper， automobile safety glass， security body， occupant head and neck protection system (WHIPS)， etc. These vehicles to improve the safety performance has very important contribution.汽車(chē)安全系統(tǒng)技術(shù)研究分析摘要：汽車(chē)各部件的好與壞將直接影響汽車(chē)行駛的安全性，直接關(guān)系著人們的生命安全和產(chǎn)財(cái)安全。本文主要從汽車(chē)的主動(dòng)安全技術(shù)和被動(dòng)安全技術(shù)兩方面來(lái)闡述汽車(chē)各部件的重要性，并如何改善汽車(chē)行駛的安全性。 關(guān)鍵詞：汽車(chē)、主動(dòng)安全技術(shù)、被動(dòng)安全技術(shù) 隨著交通工具的現(xiàn)代化和絕對(duì)數(shù)量的急劇增長(zhǎng)，車(chē)禍也不斷增加。汽車(chē)交通事故已成為嚴(yán)峻的全球性社會(huì)問(wèn)題。毋庸置疑，先進(jìn)的汽車(chē)安全設(shè)施是行車(chē)安全不可缺少的保障。所以，我們要從技術(shù)上入手，努力研究開(kāi)發(fā)高性能、高安全性的汽車(chē)，同時(shí)也要加強(qiáng)對(duì)在用汽車(chē)的定期檢查，以便及時(shí)維修調(diào)查，使汽車(chē)經(jīng)常處于良好的技術(shù)狀況，以提高汽車(chē)行駛的安全性能。 這里我們重點(diǎn)介紹汽車(chē)主動(dòng)安全技術(shù)和汽車(chē)被動(dòng)安全技術(shù)。汽車(chē)的安全性是按交通事故發(fā)生的前后加以分類(lèi)的。一方面是在交通事故發(fā)生之前采取安全措施，特別當(dāng)即將發(fā)生危險(xiǎn)狀態(tài)時(shí)，駕駛者操縱方向盤(pán)避讓或者緊急制動(dòng)以避免交通事故發(fā)生。汽車(chē)在通常的行駛中，為確保駕駛者的基本操縱穩(wěn)定性，對(duì)周?chē)h(huán)境的視認(rèn)性和確保汽車(chē)本身的基本行駛性能，開(kāi)發(fā)了防抱死制動(dòng)系統(tǒng)(ABS)、防滑驅(qū)動(dòng)系統(tǒng)(ASR)、主動(dòng)懸架、動(dòng)力轉(zhuǎn)向、四輪驅(qū)動(dòng)(4WD)、四輪轉(zhuǎn)向 (4WS)、燈光照明系統(tǒng)、刮水器、后視鏡、防止車(chē)輛追尾的車(chē)距報(bào)警系統(tǒng)和激光雷達(dá)等。這些安全裝置和技術(shù)稱(chēng)為主動(dòng)安全系統(tǒng)，也可稱(chēng)為預(yù)防安全系統(tǒng)。另一方面，為了盡量減少交通事故和司乘人員直接受害程度，保證司乘人員和行人的安全，稱(chēng)這種安全性為被動(dòng)安全，也可稱(chēng)為沖突安全。當(dāng)事故發(fā)生后，為了防止災(zāi)害的擴(kuò)大，包括防止火災(zāi)和使乘員能從事故車(chē)輛中解脫出來(lái)的安全裝置和系統(tǒng)，稱(chēng)為防止災(zāi)害擴(kuò)大的安全系統(tǒng)。 汽車(chē)主動(dòng)安全技術(shù) ABS 防抱死制動(dòng)系統(tǒng) 防抱死制動(dòng)系統(tǒng)(Anti-lock Braking System，簡(jiǎn)稱(chēng) ABS)由 ABS 電腦、液壓裝置、車(chē)輪轉(zhuǎn)速傳感器、制動(dòng)液壓管路及電器配線等組成。 ABS 系統(tǒng)對(duì)于汽車(chē)在各種行駛條件下的制動(dòng)性能及制動(dòng)安全尤為重要，特是緊急制動(dòng)，能夠充分利用輪胎和路面之間的峰值附著性能，提高汽車(chē)抗側(cè)滑性能并縮短制動(dòng)距離，充分發(fā)揮制動(dòng)效能，同時(shí)增加了汽車(chē)制動(dòng)過(guò)程中的可控性。從而減少了汽車(chē)事故發(fā)生的可能性。 沒(méi)有安裝 ABS 的汽車(chē)，如果在行駛中用力踩踏制動(dòng)踏板，車(chē)輪會(huì)急速降低轉(zhuǎn)速，最后車(chē)輪停止轉(zhuǎn)動(dòng)，但車(chē)身由于慣性依然保持向前滑動(dòng)。這種現(xiàn)象在車(chē)輪與路面之間發(fā)生較大的“滑移” ，出現(xiàn)這種狀況時(shí)，汽車(chē)輪胎對(duì)路面的側(cè)滑摩差力幾乎消失，于是會(huì)出現(xiàn)下述現(xiàn)象： （1）轉(zhuǎn)向穩(wěn)定性下降：方向盤(pán)操縱不靈，車(chē)輛尾部上翹，嚴(yán)重時(shí)車(chē)輛打轉(zhuǎn)或出現(xiàn)折疊現(xiàn)象； （2）操縱性下降：操縱方向盤(pán)而達(dá)不到轉(zhuǎn)向要求； （3）制動(dòng)距離延長(zhǎng)：超過(guò)一般的制動(dòng)距離。 所以，可想而知有無(wú)裝設(shè) ABS 系統(tǒng)對(duì)汽車(chē)行駛的安全性是非常重要的。 ASR 驅(qū)動(dòng)防滑控制系統(tǒng) ABS 用于防止汽車(chē)制動(dòng)過(guò)程中車(chē)輪抱死，將車(chē)輪的滑移率控制在理想的范圍內(nèi)，以縮短制動(dòng)距離，提高汽車(chē)制動(dòng)時(shí)方向穩(wěn)定性和轉(zhuǎn)向操縱性，從而提高汽車(chē)行駛的安全性。隨著對(duì)汽車(chē)性能要求的提高，不僅要求在制動(dòng)過(guò)程中防止車(chē)輪抱死，而且要求在驅(qū)動(dòng)過(guò)程中防止驅(qū)動(dòng)輪滑轉(zhuǎn)，使汽車(chē)在驅(qū)動(dòng)過(guò)程中的方向穩(wěn)定性、轉(zhuǎn)向控制能力和加速性能都得到提高，因此采用了汽車(chē)驅(qū)動(dòng)防滑轉(zhuǎn)向系統(tǒng) ASR（Accelerations Slip Regulation） 。ASR是 ABS 的完善和補(bǔ)充，ASR 可單獨(dú)設(shè)置，但大多數(shù)是與 ABS 組合一起，常用 ABS/ASR表示，稱(chēng)為防滑控制系統(tǒng)。 ASR 主要用來(lái)防止汽車(chē)在起步、加速時(shí)車(chē)輪的滑轉(zhuǎn)，保證汽車(chē)在加速過(guò)程中的穩(wěn)定性并改善在不良路面上的驅(qū)動(dòng)附著條件。它可以使無(wú)差速鎖的汽車(chē)在冰雪路面和泥濘道路上起步并改善其通行能力，還可以防止在車(chē)速較高并通過(guò)滑溜路面又轉(zhuǎn)彎時(shí)汽車(chē)后部的側(cè)滑現(xiàn)象。 總之，ASR 由于防止了車(chē)輪的滑轉(zhuǎn)，便可最大限度地利用發(fā)動(dòng)機(jī)的驅(qū)動(dòng)力矩，保證汽車(chē)有足夠的縱向力、側(cè)向力和操縱力，使汽車(chē)在起動(dòng)、轉(zhuǎn)向和加速過(guò)程中，在滑溜和泥濘路面上、在山區(qū)上下坡過(guò)程中都能穩(wěn)定地行駛，既保證了行車(chē)安全，減少輪胎磨損和燃油消耗，又改善了汽車(chē)的驅(qū)動(dòng)性能。 VDC 系統(tǒng) ABS/ASR 系統(tǒng)成功地解決了汽車(chē)在制動(dòng)和驅(qū)動(dòng)時(shí)的方向穩(wěn)定性問(wèn)題，但不能解決汽車(chē)轉(zhuǎn)向行駛的方向穩(wěn)定性問(wèn)題。例如當(dāng)汽車(chē)轉(zhuǎn)向行駛時(shí)，不可避免地受到側(cè)向和縱向力的作用，只有當(dāng)?shù)孛婺軌蛱峁┏浞值膫?cè)向和縱向力時(shí)，駕駛員才能控制住車(chē)輛。如果地面?zhèn)认蚋街芰Ρ容^低，就會(huì)損害汽車(chē)按預(yù)定方向行駛的能力。雨天汽車(chē)高速轉(zhuǎn)向行駛時(shí)，常常側(cè)向滑出，就是地面?zhèn)认蚋街芰Σ蛔愕木壒?。為解決此問(wèn)題，最近汽車(chē)工業(yè)發(fā)達(dá)國(guó)家又在 ABS/ASR 系統(tǒng)的基礎(chǔ)上發(fā)展成汽車(chē)動(dòng)態(tài)控制系統(tǒng)（Vehicle Dynamics Control，簡(jiǎn)稱(chēng) VDC） 。這個(gè)系統(tǒng)把汽車(chē)的制動(dòng)、驅(qū)動(dòng)、懸架、轉(zhuǎn)向、發(fā)動(dòng)機(jī)等各主要總成的控制系統(tǒng)在功能上、結(jié)構(gòu)上有機(jī)地綜合在一起，可使汽車(chē)在各種惡劣工況下，如冰雪路面上、對(duì)開(kāi)路面上、彎道路面上以及采取規(guī)避動(dòng)作移線、制動(dòng)、加速和下坡等工況時(shí)，對(duì)不同承載、不同輪胎氣壓和不同程度的輪胎磨損都有良好的方向穩(wěn)定性，表現(xiàn)出最佳的行駛性能。VDC 的應(yīng)用，在制動(dòng)、加速和轉(zhuǎn)向方面完全解脫對(duì)駕駛員的要求，是汽車(chē)的主動(dòng)安全行駛方面的一個(gè)新的里程碑。 VDC 系統(tǒng)對(duì)轉(zhuǎn)向行駛的控制主要是借助于對(duì)各個(gè)車(chē)輪的制動(dòng)控制和發(fā)動(dòng)機(jī)功率輸出控制來(lái)實(shí)現(xiàn)的。例如汽車(chē)左轉(zhuǎn)彎時(shí)，若前輪因轉(zhuǎn)向能力不足而趨于滑出彎道，VDC 系統(tǒng)即可測(cè)知側(cè)滑即將發(fā)生，就采取適當(dāng)制動(dòng)左后輪的辦法。若在同一彎道上，因后輪趨于側(cè)向滑出而轉(zhuǎn)向過(guò)多，VDC 系統(tǒng)即采取適當(dāng)制動(dòng)右前輪的辦法，維持車(chē)輛的穩(wěn)定行駛。在極端情況下，VDC 系統(tǒng)還可采取降低發(fā)動(dòng)機(jī)功率輸出的辦法降低行駛車(chē)速，減少對(duì)地面?zhèn)认蚋街芰Φ男枨髞?lái)維持車(chē)輛的穩(wěn)定行駛。采用 VDC 系統(tǒng)后，汽車(chē)在對(duì)開(kāi)路面上或彎道路面上的制動(dòng)距離還可進(jìn)一步縮短。 CCS 汽車(chē)巡航控制系統(tǒng) 汽車(chē)巡航控制系統(tǒng)（Cruised Control System，縮寫(xiě)為 CCS）就是可使汽車(chē)工作在發(fā)動(dòng)機(jī)有利的轉(zhuǎn)速范圍內(nèi)，減輕駕駛員的駕駛操縱勞動(dòng)強(qiáng)度，提高行駛舒適性的汽車(chē)自動(dòng)行駛裝置。 汽車(chē)巡航系統(tǒng)（CCS）的作用是：按司機(jī)所要求的速度閉合開(kāi)關(guān)后，不用踩油門(mén)踏板就可以自動(dòng)地保持車(chē)速，使車(chē)輛以固定的速度行駛。采用了這種裝置，當(dāng)在高速公路上長(zhǎng)時(shí)間行車(chē)后，司機(jī)就不用再去控制油門(mén)踏板，減輕了疲勞，同時(shí)減少了不必要的車(chē)速變化，可以減省燃料。 汽車(chē)巡航控制系統(tǒng)是最早開(kāi)發(fā)的汽車(chē)電子控制系統(tǒng)之一。這種系統(tǒng)使用另外的車(chē)速傳感器，將車(chē)速信號(hào)輸入發(fā)動(dòng)機(jī)控制微機(jī)，由微機(jī)控制真空系統(tǒng)工作。這種系統(tǒng)也要使用伺服器、車(chē)速控制開(kāi)關(guān)桿和制動(dòng)踏板上的真空解除開(kāi)關(guān)等，其功能和基本系統(tǒng)相同。 在這個(gè)系統(tǒng)中，電子控制裝置可根據(jù)行駛阻力的變化，自動(dòng)調(diào)節(jié)發(fā)動(dòng)機(jī)油門(mén)開(kāi)度，使行駛車(chē)速保持恒定。這樣既減少了不必要的車(chē)速變化，從而節(jié)省了燃料，同時(shí)也減輕了駕駛員的負(fù)擔(dān)。電子巡航控制系統(tǒng)的方框圖如圖 2 所示。 汽車(chē)被動(dòng)安全技術(shù) 安全帶 汽車(chē)安全帶是一種安全裝置，它能在汽車(chē)發(fā)生碰撞或急拐彎時(shí)，使乘員盡可能保持原有的位置而不移動(dòng)和轉(zhuǎn)動(dòng)，避免與車(chē)內(nèi)堅(jiān)硬部件發(fā)生碰撞而造成傷害。安全帶與安全氣囊一樣，都是現(xiàn)代轎車(chē)上的安全裝置，但是前者的歷史悠久，普及范圍廣。 看似簡(jiǎn)簡(jiǎn)單單的安全帶其實(shí)并不“簡(jiǎn)單” 。一直處在關(guān)注行車(chē)安全最前沿的通用汽車(chē)公司，通過(guò)分析大量意外事故后發(fā)現(xiàn)：汽車(chē)安全帶不但能使人保住性命，更能在超過(guò)半數(shù)的事故中減低甚至消除駕車(chē)者、乘車(chē)者受傷的機(jī)會(huì)。汽車(chē)發(fā)生碰撞或遇到意外緊急制動(dòng)時(shí)產(chǎn)生的巨大慣性作用力，會(huì)使駕駛員、乘客與車(chē)內(nèi)的方向盤(pán)、擋風(fēng)玻璃、座椅靠背等物體發(fā)生二次碰撞，極易造成對(duì)駕乘員的嚴(yán)重傷害，甚至將駕乘員拋離座位或拋出車(chē)外，而安全帶能將駕乘人員束縛在座位上。發(fā)生意外時(shí)，它能有效防止二次碰撞，并且其緩沖作用能吸收大量動(dòng)能，減輕駕乘人員的傷害程度。 系好安全帶也是安全氣囊發(fā)揮作用的一個(gè)重要條件。因?yàn)榘踩珰饽乙l(fā)揮最大作用，對(duì)于駕乘者在撞擊瞬間的身體位置、坐姿以及動(dòng)作有著極為嚴(yán)格的要求。否則，安全氣囊展開(kāi)時(shí)強(qiáng)大的瞬間沖擊力對(duì)于頭部等較為脆弱的部位，可能造成嚴(yán)重的傷害，尤其對(duì)于兒童，這種傷害可能是致命的。即便是最普通的三點(diǎn)試安全帶，在撞車(chē)瞬間也可及時(shí)束住駕乘者的上半身，確保駕乘者處于安全氣囊完全展開(kāi)的范圍內(nèi)，使安全氣囊最有效地發(fā)揮功效。因此，千萬(wàn)不要因?yàn)檐?chē)中配備了安全氣囊而感到高枕無(wú)憂，只有系好了安全帶才能減輕或消除車(chē)禍的發(fā)生。安全氣囊 當(dāng)汽車(chē)前部發(fā)生強(qiáng)烈的碰撞時(shí)，由于慣性，駕乘者的身體向前快速移動(dòng)，這時(shí)安全帶便會(huì)盡力“拉住”駕乘者的身體，吸收部分沖擊能量，同時(shí)安全氣囊以“迅雷不及掩耳之勢(shì)”充氣并完全打開(kāi)；接著駕乘者的身體上部便沉向安全氣囊，氣體也開(kāi)始從氣囊的排氣口勻速逸出，并吸收了大部分沖擊能量；隨后，駕乘者身體向后并回到座椅上。以上整個(gè)過(guò)程幾乎都是發(fā)生在一瞬間的，駕乘者完全處于被動(dòng)的局面，在這種情況下，被動(dòng)的依靠輔助乘員保護(hù)系統(tǒng)是唯一的選擇。安全氣囊的開(kāi)發(fā)設(shè)計(jì)就是基于安全帶有限的保護(hù)作用之上的，它們互相配合發(fā)揮對(duì)駕乘者的輔助保護(hù)作用。 在乘員使用安全帶的情況下，氣囊有助于減輕胸、頭和面部在碰撞時(shí)受傷的嚴(yán)重性。當(dāng)汽車(chē)發(fā)生前碰撞時(shí)，首先是汽車(chē)要停止運(yùn)動(dòng)，車(chē)內(nèi)乘員的慣性力作用下仍以原速度繼續(xù)向前運(yùn)動(dòng)。不系安全帶的乘員將會(huì)與轉(zhuǎn)向盤(pán)、前擋風(fēng)玻璃相碰，因而可能受到嚴(yán)重傷害；系安全帶的乘員可以隨著汽車(chē)停止運(yùn)動(dòng)而逐漸停止向前運(yùn)動(dòng)。如果碰撞劇烈，乘員向前運(yùn)動(dòng)更快，即使系了安全帶，在完全停止運(yùn)動(dòng)前，仍會(huì)與車(chē)內(nèi)物相碰。如果此時(shí)裝在轉(zhuǎn)向盤(pán)或儀表板內(nèi)的氣囊充氣彈出，它就可以保護(hù)乘員減少其與車(chē)內(nèi)物相碰的可能性，更均勻的分散頭、胸的碰撞力，吸收乘員的運(yùn)動(dòng)能量，從而起到補(bǔ)充安全帶效果的作用。除了安全帶和安全氣囊外汽車(chē)被動(dòng)安全技術(shù)還包括汽車(chē)保險(xiǎn)杠、汽車(chē)安全玻璃、安全車(chē)身、乘員頭頸保護(hù)系統(tǒng)（WHIPS）等。這些對(duì)提高汽車(chē)行駛的安全性能都有著非常重要的貢獻(xiàn)。