柴油動力微型客車設(shè)計（轉(zhuǎn)向系設(shè)計）【含3張CAD圖紙】
柴油動力微型客車設(shè)計（轉(zhuǎn)向系設(shè)計）【含3張CAD圖紙】,含3張CAD圖紙,柴油,動力,微型,客車,設(shè)計,轉(zhuǎn)向,CAD,圖紙
外文資料譯文
The development and forecast of the steering system
1 The steering system of the hydraulic pressure boosts
Along with the vehicles carrying capacity increase as well as the people to the vehicles handling quality enhancement, the simple mechanical type steering system already were unable to meet the need, thereupon the people invented one kind to be able to reduce the pilot to operate the load the hydraulic pressure to boost the steering system, and to 20th century 30's applications on heavy vehicle.
The hydraulic pressure boosts the steering system with the aid of to the motor car engine power actuation oil pump, the air compressor and the generator and so on, by the fluid strength, the physical strength or the electric power increases the pilot to operate the strength which the front wheel changes, enables the pilot to be allowed facilely nimbly to operate steering, reduced the labor intensity, enhanced the travel security.
2 Electrically controlled hydraulic pressure powers steering system
Because the hydraulic pressure power steering system hydraulic pump continuously also revolves along with the engine, has increased the fuel oil consumption, in order to overcome the hydraulic pressure power steering system in fuel oil efficiency insufficiency, increases the electronic control and the functional element in the hydraulic pressure power steering system, (also has the vehicle speed uses vehicle speed and steering wheel rotational speed) introduces in the system, the realization vehicle speed induction boosts the characteristic hydraulic pressure power to change. This kind of system is called the electrically controlled hydraulic pressure power steering system.
The electrically controlled hydraulic pressure power steering system mainly transmits through the vehicle speed sensor the vehicle speed for the electronic component or the microcomputer system, the control electricity liquid switching device change power changes boosts the characteristic, causes the pilot to change the hand power changes according to the vehicle speed and the travel condition change, namely when low speed travel or extreme turn can by very small change the hand power to carry on the operation, when high speed travel can by slightly heavy change the hand power to carry on the stable operation, causes the maneuverability and the stability achieves the most appropriate state of equilibrium. The electrically controlled hydraulic pressure power steering system type are very many, but its basic principle all is through installs the electron implementing agency or the auxiliary unit on the oil pump either the diverter, according to vehicle speed control hydraulic system current capacity or pressure.
At present uses more electrically controlled hydraulic pressure power to change uses the direct current motor to replace the engine drive oil pump, the electric motor supplies power by the accumulator cell. Controller basis vehicle speed signal, steering wheel rotational speed signal control electric motor rotational speed, thus controls the oil pump the current capacity, achieved boosts goal which changes. After uses the direct motor drive oil pump to make the oil pump arrangement to be easy, does not need to arrange nearby the engine when has not changed the operation, the electric motor by the lower rotational speed revolution even stops revolving, thus may reduce the energy consumption.
3. The steering system of electrically and electrically operated boosts (EPS)
3.1 The classification to boost the steering system
Consummates the development along with mechanical and electrical and the control technology, the people invented one kind directly to provide by the electrical machinery boost the steering system, was called electrically operated boosts the steering system. Is different according to the electric motor position, electrically operated boosts the steering system to be possible to divide into three kinds: digress axle boosts the type, the rack boosts the type, pinion boosts the type.
3.2 Electrically operated boosts the steering system the key component
3.2.1 Torque sensor and the vehicle speed sensor
The torque sensor function is surveys the pilot to affect on the steering wheel the moment of force size and the direction, the vehicle speed sensor function surveys the automobile moving velocity. The torque sensor has the contact type and the non- contact type two kinds. The contact type torque sensor electrically operated boosts the steering system to add a twisted bar in digress axle the position, obtains the torque through the survey twisted bar distortion: The non- contact type torque sensor, including a pair of magnetic pole link, its principle is: When between the input axis and output axis has the relative reverse position after a short while, between the magnetic pole link air gap changes, thus causes the electromagnetic induction coefficient change. The non- contact type torque sensor merit is the volume small, the precision is high; The shortcoming is the cost is higher.
3.2.2 Electronic controls unit
Electronic control unit (ECU) the function is according to the torque sensor signal and the vehicle speed sensor signal, after carries on the logic analysis and the computation, sends out the instruction, the control motor and the coupling movement. In addition, it also has the safekeeping of security and the self- diagnosis function, ECU through gathers the electric motor the electric current, the generator voltage, the engine operating mode equisignal judges its system working condition whether normal, once the system work will be unusual, boosts automatically cancels, simultaneously ECU will carry on the breakdown diagnostic analysis. The control system and the control algorithm also is one of EPS keys, the control system should have the strong antijamming ability, adapts the automobile changeable travel environment. The control algorithm should fast be correct, satisfies the real-time control the request, and can effectively realize ideal boosts the rule and the characteristic.
3.2.3 Electric motors
Electric motors function is the auxiliary torque which is suitable according to the electronic control unit instruction output, uses not brushes permanent magnetism the direct current motor. EPS has to the electric motor very high requests, not only requests the low rotational speed great torque, to undulate slightly, the rotation inertia small, the size small, the quality light, moreover the request reliability high, is easy to control.
3.2.4 Reduction gears
EPS reduction gear and the electric motor are connected, plays reducing speed increases turns the role. Uses the worm gear endless screw organization, the ball bearing screw rod nut, also has uses the planetary gears. Some EPS also uses for parts the coupling, installs in a reduction gear side, is for guarantee EPS in advance is only establishing in vehicle speed travel scope function. When the vehicle speed achieved when some value, the coupling separates, the electric motor knock off, the steering system transfers manually changes. Moreover, when the electric motor breaks down, the coupling automatically will separate.
3.3 Electrically operated boosted the steering system the merit
.To enhance the fuel oil efficiency;
.Is advantageous to the environment;
.Is easy to realize the product modulation;
.Is independent with the engine, when stalling of engine also can provide boosts;
.Electrically operated boosts the steering system to be opposite to the hydraulic pressure boosts the steering system to have the better low temperature operating performance.
4 Line controls of the steering system
Along with the electronic technology and the control theory development, some researchers make the bold supposition, with changes the steering wheel the wheel through the control signal connection, may use the steering system to change the gain characteristic to compensate the entire vehicle to change the characteristic change, thus reduces pilot's operation burden, improves a person vehicle closed-loop system performance. This kind brand-new changes the control system is the line controls the steering system.
4.1 Line controls of the steering system structure line to control
The steering system by the steering wheel module, change carry out the module and the master control (ECU) three main parts as well as automatically guard against the breakdown system, the power source and so on the auxiliary module are composed.
The steering wheel module including the steering wheel, the steering wheel corner, the moment of force sensor, the steering wheel returns to plus torque the electrical machinery. The steering wheel module main function is changes the pilot the intention (through survey steering wheel corner) to transform the digital signal and transmits for the master control; Simultaneously accepts the moment of force signal which the host controller sends, produces the steering wheel to return plus torque, provides to the pilot the corresponding road feeling information. Changes carries out the module including the front wheel corner sensor, changes carries out the electrical machinery, changes the electrical machinery controller and the front wheel changes composition and so on module. Changes carries out the module function is accepts the host controller the order, the control changes the electrical machinery realization request the front wheel corner, completes the pilot to change the intention.
The master control carries on analysis processing to the gathering signal, distinguished the automobile the state of motion, returns to plus force the electrical machinery to the steering wheel and changes the electrical machinery transmission order, controls two electrical machinery the work. Automatically guards against the breakdown system is the line controls steering system the important module, it including a series of monitorings and the implementation algorithm, makes corresponding processing in view of the different breakdown form and the breakdown rank, maximum limit maintains the automobile in order to the normal speed. The automobile security is a factor which must first consider, is all research foundations, thus the breakdown automatic detection and the automatic reduction are the line controls one of steering system most important composition systems.
4.2 Line controls of the steering system performance characteristic
.Line controls of the steering system are one brand-new concept steering system, because it has cancelled the steering wheel and changes between the wheel the solderless joint, coordinates between them through software the movement relations, may realize a series of traditions steering system to be unable to realize specially energy. Enhances the automobile the maneuverability to change the control aspect in the front wheel to be allowed to realize the velocity ratio wilfully establishment, and to carries on along with the vehicle speed change parameter compensates, causes car to change directoion the characteristic not along with the vehicle speed change. Thus reduced the pilot to bear, enhanced the automobile system changed the input to the pilot the response and "a person vehicle closed-loop system" the initiative security.
.Enhances the automobile the stable performance line to control the steering system to be allowed the control which changes through the front wheel, realizes the DYC control system function, achieves a more ideal effect. Also may with other initiative safety equipment like ABS, the automobile dynamics control, guard against the collision, the single wheel changes, function and so on orbital tracking, automatic lateral navigation as well as self-piloting unifies, realizes to the automobile whole control, enhances the automobile overall stability.
.Improves pilot's road feeling because the steering wheel and changes between the wheel the non- solderless joint, pilot "road feeling" through simulation production. In returns to plus torque the control aspect to be allowed from the signal to propose most can respond the automobile actual travel condition and the road surface condition information, returns as the steering wheel plus torque the control variable, causes the steering wheel merely to provide the useful information to the pilot, thus really provides "the road feeling" for the pilot.
4.3 The steering systems prospects for development forecast
Line controls of the steering system to be able to reduce the pilot to bear, to enhance the entire vehicle initiative security, causes the automobile performance to suit the more amateur pilots' request, has the huge attraction to the general consumers. At present obstructs the line to control a important attribute which the steering system popularizes is its reliable question, now also is unable between the reliability and the cost obtains a very good balance. The world each big development facility is carrying on the union attack on this question, believed very quick can obtain the reasonable solution. Even if uses the clumsiest method that the line which mutually monitors with two sets to control the steering system also to be able to solve well this question, certainly this must take enhance the cost as a price.
But along with electronic products cost reducing, also has cost reduction to the consumer acceptance degree the possibility. Although the line controls steering system itself the cost to be higher, after but uses the line to control the steering system about, the motor car chassis design does not need to differentiate goes the transportation system steering system, causes the chassis development, the specially globalization multinational corporation's chassis development cost reduces.
Seclect from the car and tractor- one in 2005
汽車轉(zhuǎn)向系統(tǒng)的發(fā)展及展望
1 液壓助力轉(zhuǎn)向系統(tǒng)
隨著車輛載重的增加以及人們對車輛操縱性能的提高，簡單的機械式轉(zhuǎn)向系統(tǒng)已經(jīng)無法滿足需求，于是人們發(fā)明了一種能夠減輕駕駛員操作負荷的液壓助力轉(zhuǎn)向系統(tǒng)，并于20世紀30年代應(yīng)用在重型車輛上。
液壓助力轉(zhuǎn)向系統(tǒng)借助于汽車發(fā)動機的動力驅(qū)動油泵、空氣壓縮機和發(fā)電機等，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，減輕了勞動強度，提高了行駛安全性。
2 電控液壓動力轉(zhuǎn)向系統(tǒng)
由于液壓動力轉(zhuǎn)向系統(tǒng)的液壓泵一直隨發(fā)動機同時運轉(zhuǎn)，增大了燃油消耗，為了克服液壓動力轉(zhuǎn)向系統(tǒng)在燃油經(jīng)濟性上的不足，在液壓動力轉(zhuǎn)向系統(tǒng)中增加電子控制和執(zhí)行元件，將車速(也有采用車速和轉(zhuǎn)向盤轉(zhuǎn)速)引入到系統(tǒng)中，實現(xiàn)車速感應(yīng)型助力特性液壓動力轉(zhuǎn)向。這類系統(tǒng)稱為電控液壓動力轉(zhuǎn)向系統(tǒng)。
電控液壓動力轉(zhuǎn)向系統(tǒng)主要通過車速傳感器將車速傳遞給電子元件或微型計算機系統(tǒng)，控制電液轉(zhuǎn)換裝置改變動力轉(zhuǎn)向的助力特性，使駕駛員的轉(zhuǎn)向手力根據(jù)車速和行駛條件變化而改變，即在低速行駛或急轉(zhuǎn)彎時能以很小的轉(zhuǎn)向手力進行操作，在高速行駛時能以稍重的轉(zhuǎn)向手力進行穩(wěn)定操作，使操縱性和穩(wěn)定性達到最合適的平衡狀態(tài)。電控液壓動力轉(zhuǎn)向系統(tǒng)的種類很多，但其基本原理都是通過在油泵或轉(zhuǎn)向器上加裝電子執(zhí)行機構(gòu)或輔助裝置，根據(jù)車速控制液壓系統(tǒng)的流量或壓力。
目前使用較多的電控液壓動力轉(zhuǎn)向采用直流電動機代替發(fā)動機驅(qū)動油泵，電動機由蓄電池供電?？刂破鞲鶕?jù)車速信號、轉(zhuǎn)向盤轉(zhuǎn)速信號控制電動機轉(zhuǎn)速，從而控制油泵的流量，達到助力轉(zhuǎn)向的目的。采用電動機驅(qū)動油泵后使油泵布置容易，不必布置在發(fā)動機附近 在沒有轉(zhuǎn)向操作時，電動機以較低轉(zhuǎn)速運轉(zhuǎn)甚至停止運轉(zhuǎn)，因而可以降低能量消耗。
3 電動助力轉(zhuǎn)向系統(tǒng)(EPS)
3.1 電動助力轉(zhuǎn)向系統(tǒng)的分類
隨著機電及控制技術(shù)的完善發(fā)展，人們又發(fā)明了一種以電機直接提供助力的助力轉(zhuǎn)向系統(tǒng)，稱為電動助力轉(zhuǎn)向系統(tǒng)。根據(jù)電動機位置不同，電動助力轉(zhuǎn)向系統(tǒng)可分為三類：轉(zhuǎn)向軸助力式、齒條助力式、小齒輪助力式。
3.2 電動助力轉(zhuǎn)向系統(tǒng)的關(guān)鍵部件
3.2.1 轉(zhuǎn)矩傳感器和車速傳感器
轉(zhuǎn)矩傳感器的功能是測量駕駛員作用在轉(zhuǎn)向盤上的力矩大小與方向，車速傳感器的功能是測量汽車行駛速度。轉(zhuǎn)矩傳感器有接觸式和非接觸式兩種。接觸式轉(zhuǎn)矩傳感器的電動助力轉(zhuǎn)向系統(tǒng)在轉(zhuǎn)向軸位置加一扭桿，通過測量扭桿的變形得到扭矩：非接觸式扭矩傳感器，其中有一對磁極環(huán)，其原理是：當輸入軸與輸出軸之間發(fā)生相對扭轉(zhuǎn)位移時，磁極環(huán)之間的空氣間隙發(fā)生變化，從而引起電磁感應(yīng)系數(shù)變化。非接觸式扭矩傳感器的優(yōu)點是體積小、精度高；缺點是成本較高.
3.2.2 電子控制單元
電子控制單元(ECU)的功能是根據(jù)扭矩傳感器信號和車速傳感器信號，進行邏輯分析與計算后，發(fā)出指令，控制電動機和離合器的動作。此外，它還有安全保護和自我診斷功能，ECU通過采集電動機的電流、發(fā)電機電壓、發(fā)動機工況等信號判斷其系統(tǒng)工作狀況是否正常，一旦系統(tǒng)工作異常，助力將自動取消，同時ECU進行故障診斷分析?？刂葡到y(tǒng)與控制算法也是EPS的關(guān)鍵之一，控制系統(tǒng)應(yīng)有強抗干擾能力，以適應(yīng)汽車多變的行駛環(huán)境?？刂扑惴☉?yīng)快速正確，滿足實時控制的要求，并能有效地實現(xiàn)理想的助力規(guī)律與特性。
3.2.3 電動機
電動機的功能是根據(jù)電子控制單元的指令輸出適宜的輔助扭矩，采用無刷永磁式直流電動機。EPS對電動機有很高要求，不僅要求低轉(zhuǎn)速大扭矩、波動小、轉(zhuǎn)動慣量小、尺寸小、質(zhì)量輕，而且要求可靠性高、易控制。
3.2.4 減速機構(gòu)
EPS的減速機構(gòu)與電動機相連，起降速增扭作用。采用蝸輪蝸桿機構(gòu)，滾珠螺桿螺母，也有采用行星齒輪機構(gòu)。有的EPS還配用離合器，裝在減速機構(gòu)一側(cè)，是為了保證EPS只在預(yù)先設(shè)定的車速行駛范圍內(nèi)起作用。當車速達到某一值時，離合器分離，電動機停止工作，轉(zhuǎn)向系統(tǒng)轉(zhuǎn)為手動轉(zhuǎn)向。另外，當電動機發(fā)生故障時，離合器將自動分離。
3.3 電動助力轉(zhuǎn)向系統(tǒng)的優(yōu)點
·提高了燃油經(jīng)濟性；
·有利于環(huán)境；
·易實現(xiàn)產(chǎn)品的模塊化；
·與發(fā)動機獨立，在發(fā)動機熄火時也能提供助力；
·電動助力轉(zhuǎn)向系統(tǒng)相對于液壓助力轉(zhuǎn)向系統(tǒng)有更好的低溫工作性能。
4 .汽車線控轉(zhuǎn)向系統(tǒng)
隨著電子技術(shù)和控制理論的發(fā)展，一些研究人員做出大膽假設(shè)，將方向盤與轉(zhuǎn)向車輪通過控制信號連接，就可以利用轉(zhuǎn)向系統(tǒng)的變增益特性補償整車轉(zhuǎn)向特性的變化，從而降低駕駛員的操縱負擔，改善人一車閉環(huán)系統(tǒng)性能。這種全新的轉(zhuǎn)向控制系統(tǒng)就是線控轉(zhuǎn)向系統(tǒng)。
4.1 汽車線控轉(zhuǎn)向系統(tǒng)結(jié)構(gòu)
線控轉(zhuǎn)向系統(tǒng)由方向盤模塊、轉(zhuǎn)向執(zhí)行模塊和主控制器(ECU)3個主要部分以及自動防故障系統(tǒng)、電源等輔助模塊組成。方向盤模塊包括方向盤、方向盤轉(zhuǎn)角、力矩傳感器、方向盤回正力矩電機。
方向盤模塊的主要功能是將駕駛員的轉(zhuǎn)向意圖(通過測量方向盤轉(zhuǎn)角)轉(zhuǎn)換成數(shù)字信號并傳遞給主控制器；同時接受主控制器送來的力矩信號，產(chǎn)生方向盤回正力矩，以提供給駕駛員相應(yīng)的路感信息。轉(zhuǎn)向執(zhí)行模塊包括前輪轉(zhuǎn)角傳感器、轉(zhuǎn)向執(zhí)行電機、轉(zhuǎn)向電機控制器和前輪轉(zhuǎn)向組件等組成。轉(zhuǎn)向執(zhí)行模塊的功能是接受主控制器的命令，控制轉(zhuǎn)向電機實現(xiàn)要求的前輪轉(zhuǎn)角，完成駕駛員的轉(zhuǎn)向意圖。
主控制器對采集的信號進行分析處理，判別汽車的運動狀態(tài)，向方向盤回正力電機和轉(zhuǎn)向電機發(fā)送命令，控制兩個電機的工作。自動防故障系統(tǒng)是線控轉(zhuǎn)向系的重要模塊，它包括一系列的監(jiān)控和實施算法，針對不同的故障形式和故障等級做出相應(yīng)的處理，以求最大限度地保持汽車的正常行駛。汽車的安全性是必須首先考慮的因素，是一切研究的基礎(chǔ)，因而故障的自動檢測和自動處理是線控轉(zhuǎn)向系統(tǒng)最重要的組成系統(tǒng)之一。
4.2 汽車線控轉(zhuǎn)向系統(tǒng)性能特點
汽車線控轉(zhuǎn)向系統(tǒng)是一種全新概念的轉(zhuǎn)向系統(tǒng)，由于其取消了方向盤和轉(zhuǎn)向車輪之間的機械連接，通過軟件協(xié)調(diào)它們之間的運動關(guān)系，可以實現(xiàn)一系列傳統(tǒng)轉(zhuǎn)向系統(tǒng)無法實現(xiàn)的特殊能。
·提高汽車的操縱性
在前輪轉(zhuǎn)向控制方面可以實現(xiàn)傳動比的任意設(shè)置，并對隨車速變化的參數(shù)進行補償，使汽車轉(zhuǎn)向特性不隨車速變化。從而減輕駕駛員負擔，提高了汽車系統(tǒng)對駕駛員轉(zhuǎn)向輸入的響應(yīng)和“人一車閉環(huán)系統(tǒng)”的主動安全性。
·提高汽車的穩(wěn)定性能
線控轉(zhuǎn)向系統(tǒng)可以通過前輪轉(zhuǎn)向的控制，實現(xiàn)DYC控制系統(tǒng)的功能，達到更為理想的效果。且可以與其它主動安全設(shè)備如ABS、汽車動力學控制、防碰撞、單個車輪轉(zhuǎn)向、軌道跟蹤、自動側(cè)向?qū)Ш揭约白詣玉{駛等功能相結(jié)合，實現(xiàn)對汽車的整體控制，提高汽車整體穩(wěn)定性。
·改善駕駛員的路感
由于方向盤和轉(zhuǎn)向車輪之間無機械連接，駕駛員“路感”通過模擬生成。在回正力矩控制方面可以從信號中提出最能夠反應(yīng)汽車實際行駛狀態(tài)和路面狀況的信息，作為方向盤回正力矩的控制變量，使方向盤僅僅向駕駛員提供有用信息，從而為駕駛員提供更為真實的“路感”。
4.3 汽車轉(zhuǎn)向系統(tǒng)發(fā)展前景展望
汽車線控轉(zhuǎn)向系統(tǒng)能夠減輕駕駛員負擔、提高整車主動安全性，使汽車性能適合更多非職業(yè)駕駛員的要求，對廣大消費者有著巨大的吸引力。目前阻撓線控轉(zhuǎn)向系統(tǒng)普及的一個重要因素是其可靠性問題，現(xiàn)在還無法在可靠性與成本之間取得一個很好的平衡。世界各大研究機構(gòu)正在就這一問題進行聯(lián)合攻關(guān)，相信很快能夠得到合理的解決。即使采用最笨拙的方法——用2套相互監(jiān)控的線控轉(zhuǎn)向系統(tǒng)也能夠?qū)⑦@一問題很好地解決，當然這要以提高成本為代價。
但是隨著電子產(chǎn)品成本的降低，將成本降低到消費者接受的程度也是有可能的。雖然線控轉(zhuǎn)向系統(tǒng)本身的成本較高，但是采用線控轉(zhuǎn)向系統(tǒng)后，汽車底盤設(shè)計就不必區(qū)分左右行駛交通系統(tǒng)的轉(zhuǎn)向系統(tǒng)，使底盤開發(fā)，特別是全球化跨國公司的底盤開發(fā)費用降低。
摘自 汽車拖拉機-2005年1期
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