【溫馨提示】 dwg后綴的文件為CAD圖，可編輯，無水印，高清圖，，壓縮包內(nèi)文檔可直接點開預(yù)覽，需要原稿請自助充值下載，請見壓縮包內(nèi)的文件及預(yù)覽，所見才能所得，請細(xì)心查看有疑問可以咨詢QQ：414951605或1304139763
附錄1
隨著汽車技術(shù)的迅猛發(fā)展,人們對汽車轉(zhuǎn)向操縱性能的要求也日益提高。汽車轉(zhuǎn)向系統(tǒng)已從傳統(tǒng)機(jī)械轉(zhuǎn)向、液壓助力轉(zhuǎn)向(Hydraulic Power Steering ,簡稱HPS) 、電控液壓助力轉(zhuǎn)向( Elect ric Hydraulic PowerSteering , 簡稱EHPS) , 發(fā)展到電動助力轉(zhuǎn)向系統(tǒng)(Elect ric Power Steering ,簡稱EPS) ,最終還將過渡到線控轉(zhuǎn)向系統(tǒng)(Steer By Wire ,簡稱SBW) 。
1 機(jī)械轉(zhuǎn)向機(jī)構(gòu)
1. 1 機(jī)械轉(zhuǎn)向機(jī)構(gòu)的概念
機(jī)械轉(zhuǎn)向系統(tǒng)是指以駕駛員的體力作為轉(zhuǎn)向能源,其中所有傳力件都是機(jī)械的，汽車的轉(zhuǎn)向運動是由駕駛員操縱方向盤,通過轉(zhuǎn)向器和一系列的桿件傳遞到轉(zhuǎn)向車輪而實現(xiàn)的。機(jī)械轉(zhuǎn)向系由轉(zhuǎn)向操縱機(jī)構(gòu)、轉(zhuǎn)向器和轉(zhuǎn)向傳動機(jī)械3 大部分組成。
1. 2 機(jī)械轉(zhuǎn)向機(jī)構(gòu)的分類
通常根據(jù)機(jī)械式轉(zhuǎn)向器形式可以分為:齒輪齒條式、循環(huán)球式、蝸桿滾輪式、蝸桿指銷式。應(yīng)用最廣的兩種是齒輪齒條式和循環(huán)球式(用于需要較大的轉(zhuǎn)向力時) 。在循環(huán)球式轉(zhuǎn)向器中,輸入轉(zhuǎn)向圈與輸出的轉(zhuǎn)向搖臂擺角是成正比的;在齒輪齒條式轉(zhuǎn)向器中,輸入轉(zhuǎn)向圈數(shù)與輸出的齒條位移是成正比的。循環(huán)球式轉(zhuǎn)向器由于是滾動摩擦形式,因而正傳動效率很高,操作方便且使用壽命長,而且承載能力強(qiáng),故廣泛應(yīng)用于載貨汽車上。齒輪齒條式轉(zhuǎn)向器與循環(huán)球式相比,最大特點是剛性大,結(jié)構(gòu)緊湊重量輕,且成本低。由于這種方式容易由車輪將反作用力傳至轉(zhuǎn)向盤,所以具有對路面狀態(tài)反應(yīng)靈敏的優(yōu)點,但同時也容易產(chǎn)生打手和擺振等現(xiàn)象,且其承載效率相對較弱,故主要應(yīng)用于小汽車及輕型貨車上,目前大部分低端轎車采用的就是齒輪齒條式機(jī)械轉(zhuǎn)向系統(tǒng)。
2 液壓轉(zhuǎn)向機(jī)構(gòu)
隨著車輛載重的增加以及人們對車輛操縱性能要求的提高,簡單的機(jī)械式轉(zhuǎn)向系統(tǒng)已經(jīng)無法滿足需要,動力轉(zhuǎn)向系統(tǒng)應(yīng)運而生,它能在駕駛員轉(zhuǎn)動方向盤的同時提供助力,動力轉(zhuǎn)向系統(tǒng)分為液壓轉(zhuǎn)向系統(tǒng)和電動轉(zhuǎn)向系統(tǒng)2 種。其中液壓轉(zhuǎn)向系統(tǒng)是目前使用最為廣泛的轉(zhuǎn)向系統(tǒng)。
2. 1 傳統(tǒng)的液壓動力轉(zhuǎn)向系統(tǒng)(HPS)
液壓轉(zhuǎn)向系統(tǒng)在機(jī)械系統(tǒng)的基礎(chǔ)上增加了液壓系統(tǒng),包括液壓泵、V 形帶輪、油管、供油裝置、助力裝置和控制閥。它借助于汽車發(fā)動機(jī)的動力驅(qū)動液壓泵、空氣壓縮機(jī)和發(fā)電機(jī)等,以液力、氣力或電力增大駕駛員操縱前輪轉(zhuǎn)向的力量,使駕駛員可以輕便靈活地操縱汽車轉(zhuǎn)向,減輕了勞動強(qiáng)度,提高了行駛安全性。
液壓助力轉(zhuǎn)向系統(tǒng)從發(fā)明到現(xiàn)在已經(jīng)有了大約半個世紀(jì)的歷史,可以說是一種較為完善的系統(tǒng),由于其工作可靠、技術(shù)成熟至今仍被廣泛應(yīng)用。它由液壓泵作為動力源,經(jīng)油管道控制閥向動力液壓缸供油,通過活塞桿帶動轉(zhuǎn)向機(jī)構(gòu)動作,可通過改變缸徑及油壓的大小來改變助力的大小,由此達(dá)到轉(zhuǎn)向助力的作用。傳統(tǒng)液壓式動力轉(zhuǎn)向系統(tǒng)一般按液流的形式可以分為:常流式和常壓式2 種類型,也可根據(jù)控制閥形式分為轉(zhuǎn)閥式和滑閥式。
隨著液壓動力轉(zhuǎn)向系統(tǒng)在汽車上的日益普及,人們對操作時的輕便性和路感的要求也日益提高,然而液壓動力轉(zhuǎn)向系統(tǒng)卻存在許多的缺點: ①由于其本身的結(jié)構(gòu)決定了其無法保證車輛在任何工況下轉(zhuǎn)動轉(zhuǎn)向盤時,都有較理想的操縱穩(wěn)定性,即無法同時保證低速時的轉(zhuǎn)向輕便性和高速時的操縱穩(wěn)定性; ②汽車的轉(zhuǎn)向特性受駕駛員駕駛技術(shù)的影響嚴(yán)重; ③轉(zhuǎn)向傳動比固定,使汽車轉(zhuǎn)向響應(yīng)特性隨車速、側(cè)向加速度等變化而變化,駕駛員必須提前針對汽車轉(zhuǎn)向特性幅值和相位的變化進(jìn)行一定的操作補(bǔ)償,從而控制汽車按其意愿行駛。這樣增加了駕駛員的操縱負(fù)擔(dān),也使汽車轉(zhuǎn)向行駛中存在不安全隱患;而此后出現(xiàn)了電控液壓助力系統(tǒng),它在傳統(tǒng)的液壓動力轉(zhuǎn)向系統(tǒng)的基礎(chǔ)上增加了速度傳感器,使汽車能夠隨著車速的變化自動調(diào)節(jié)操縱力的大小,在一定程度上緩和了傳統(tǒng)的液壓轉(zhuǎn)向系統(tǒng)存在的問題。
系統(tǒng)是未來轉(zhuǎn)向系統(tǒng)的發(fā)展趨勢，但由于其取消了方向盤和轉(zhuǎn)向車輪之間的機(jī)械連接，可靠性成為阻撓線性控制轉(zhuǎn)向技術(shù)普及的一個重要因素，現(xiàn)在仍然處于研究階段。相比而言，液壓助力轉(zhuǎn)向系統(tǒng)應(yīng)用的時間較長，技術(shù)已經(jīng)比較成熟，而且在成本上有著巨大的優(yōu)勢，同時具有助力大、轉(zhuǎn)向感覺平順、安全可靠的優(yōu)點，對于中等功率（500-1000W）和大功率的伺服機(jī)構(gòu)，液壓方案仍為最佳的選擇。
附錄2
Along with the rapid development of automobile technology, people on the vehicle steering control performance requirements are increasing. Steering system has turned from the traditional mechanical and Hydraulic Steering (Hydraulic Power Steering, referred to as HPS), electric Hydraulic Steering (Elect ric Hydraulic PowerSteering, referred to as EHPS), the development of electric Power Steering system (Elect ric Power Steering, referred to as EPS), finally will also transition to the Wire Steering system (who, By Wire SBW referred to).
1 mechanical steering mechanism
1 1 mechanical steering mechanism of concept
Mechanical steering system refers to the driver's physical energy, including all as to force all is mechanical, automobile steering movement by the steering wheel is, through the steering and a series of bar transmission to the steering wheel. Mechanical steering system, steering gear control mechanisms by turning and steering transmission machinery 3 major components.
1. 2 mechanical steering mechanism of classification
Usually based on mechanical redirector form can be divided into: super-modulus gear and circular ball type, worm and worm wheel type to pin type. One of the most widely used two is super-modulus gear and ball type (used to need cycle of steering force). In the cycle of ball type redirector, input and output of turning circle to radial angular is proportional to the, In rack-and pinion steering gear-component, input and output of steering laps is proportional to the displacement of the rack. Ball type redirector cycle because it is rolling friction forms, so is the transmission efficiency high, convenient operation and long service life, and bearing capacity, widely used in automotive. Super-modulus gear steering gear-component with circular ball type, characteristic is rigid, compact structure, light weight, and low cost. Because this way by the wheel will easily reaction to the steering wheel, so has the sensitive reaction of pavement condition, but also easy to produce goons and shimmy and its carrying such phenomena as relatively weak efficiency, it is mainly used in cars and vans, most low-end cars USES is super-modulus gear type mechanical steering system.
2 hydraulic steering mechanism
With the increase of vehicle load and people to improve vehicle handling performance requirements, simple mechanical steering system has been unable to satisfy needs, power steering system, it can also provide the driver turned the steering wheel, power steering system into hydraulic steering system and power steering system of two. One hydraulic steering system is the most widely used steering system.
2 one of traditional hydraulic steering system (HPS)
Hydraulic steering system in mechanical system on the basis of the hydraulic system, including increased pump, v-shaped belt wheel, tubing and oil-supplied device, booster device and valves. With the help of a car engine driving pump, air compressors, generators, hydraulic, pneumatic or electric increases the power of the front wheel steering, the driver can lightweight flexible steering control and reduce the labor intensity, improve the driving safety.
Hydraulic steering system from the invention to now has a history of about half a century, is a relatively complete system, due to its reliable work, mature technology still has been widely used. It consists of a power source, the pump valve oil pipeline to power supply and hydraulic cylinder piston driven by steering mechanism, by changing the size of the hydraulic cylinder size and to change the size of the power steering, thus achieve the effect. Traditional hydraulic power steering system according to the general form of fluid flow can be divided into: often flow and atmospheric type two kinds, also can turn into the form according to the control valve type and rotary type.
With hydraulic steering system in the bus to the increasing popularity of the operation, and the way of portability, but also increasing hydraulic power steering system has many disadvantages: (1) because of its own structure determines its cannot assure vehicles in any conditions when turning steering wheel, and has better stability, namely can also guarantee the high portability and turned the steering stability, 2 the car by driving technology to the serious influence, 3 automotive steering transmission fixed, steering response speed and lateral acceleration with such changes, the driver must advance in automotive steering amplitude and phase change of operation, thus controlling automobile compensation according to its will. This increases the driver's burden, also make the car to drive the safe hidden trouble, And then appeared electric hydraulic booster systems, it is in the traditional hydraulic steering system based on increased speed sensor, which can automatically adjust the speed of change with the size of the force control in a certain extent, alleviated the traditional hydraulic steering system.