588_重型自卸車設計(底盤設計)（有cad圖）
588_重型自卸車設計(底盤設計)（有cad圖）,重型,卸車,設計,底盤,cad
The English Instruction
Dump Truck
A dump truck or production truck is a truck used for transporting loose material(such as sand,gravel or dirt)for construction.A typical dump truck is equipped with a hydraulically operated open-box bed hinged at the rear,the front of which can be lifted up to allow the contents to be deposited on the ground behind the truck at the site of delivery.In the UK the term applies to off-road construction plant only and the road vehicle is known as a tipper.
A standard dump truck is a full truck chassis with a dump body mounted to the frame.The dump body is raised by a hydraulic ram mounted forward of the front bulkhead,between the truck cab(traction unit)and the dump body (semi-trailer).The tailgate can be configured to swing on hinges or it can be configured in the “High Lift Tailgate” format where in pneumatic rams lift the gate open and up above the dump body.
A standard dump truck has one front axle and one or more rear axles which typically have dual wheels on each side.Common configuration for a standard dump truck include the six wheeler which has one rear axle,the ten wheeler with two rear axles and the tri-axle with three rear axles.These are mainly found in inner cities and in the Deep South.
The short wheelbase of a standard dump truck makes it more maneuverable than the higher capacity semi-trailer dump trucks.
Off-road dump trucks more closely resemble heavy construction equipment or engineering vehicles than they do highway dump trucks.They are used strictly off-road for mining and heavy dirt hauling jobs.
The term ‘Dump’Truck is not generally used by the mining industry or by the manufactures that build these machines.The more appropriate US term for this strictly off road vehicle is ‘Haul’truck.The classification bottom and side for example,describing how the loaded material is discharged once loaded.In the case of the Haul truck illustrated,a Liebherr T 282B the load is discharged to the rear,designing this particular vehicle as an end dump.Bottom dump normally describes a trailer that discharges its load by opening two clam shell doors under the load space,in some examples several trailers(road train)are pulled by one truck mainly these are on road machines.The only remaining example of what is described as a unitized bottom dump coal hauler is manufactured by Kress Corporation.This large capacity truck is used for the transportation of coal from a loading device directly to a power station or bulk storage area.
Many winter service vehicle units are based on dump trucks to allow the placement of ballast to weigh the truck down or to hold salt for spreading on the road.
A semi end dump is a tractor-trailer combination where in the trailer itself contains the hydraulic hoist.A typical semi end dump has a 3-axle tractor pulling a 2-axle semi-trailer.The key advantage of a semi end dump is rapid unloading.A key disadvantage is that they are very unstable when raised in the dumping position limiting their use in many applications where the dumping location is uneven or off level.
Both the tractor and the automobile are complex self-propelled machines consisting of separate interacting machanisms and units that can be combined into certain groups.
The arrangement of the main component parts of the tractor is shown in Fig.2.Irrespective of particular design features,all tractors consist of engine,drive line,running gear,steering mechanism,working attachments and auxiliary equipment.
The drive line comprise a set of mechanisms which transmit the torque developed by the engine to the driving wheels or tracks and change the driving torque both in magnitude and direction,The drive line includes the cluth,flexible coupling,transmission and rear axle.
The cluth serves to disconnect the engine shaft from the transmission for a short period of time while the drivers is shifting gears and also to connect smoothly the flow of power from the engine to the driving wheels or tracks when starting the tractor from rest.
The flexible coupling incorporates elastic elements allowing connecting the cluth shaft and the transmission drive shaft with a slight misalignment
The transmission makes it possible to change the tractor by engaging different pairs of gears.With the direction of rotation of the engine shaft remaining the same,the transmission enables the tractor to be put in reverse.
The rear-axle mechanisms increase the driving torque and transmit it to the driving wheel or tracks at right angles to the drive shaft.In most tractors,the rear also comprises brakes.
In the wheeled tractor,as distinct from its crawler counterpart,the drive line includes the differential which enzbles the wheels to revolve with different speeds when making turns or running over ragged terrain at which time the lefthand and righthand wheels must travel different distance during one and the same time.
The steering mechanism serves to change the direction of movement of the tractor by turing its front wheels of by varying the speed of one of the tracks.
The working attachment of the tractor are used to utilize the useful power of the tractor engine for various farm tasks.They include the power take off shaft,drawbar,implement-attaching system and belt pulley.
The tractor auxiliaries include the driver’s cab with a spring-mounted seat and heating and ventilation equipment,hood,lighting equipment,tell tales horns etc.
The arrangement and purpose of the main component parts of the automobile are in principle the same as those of the wheeled tractor.In the automobile,the drive line,running gear,steering mechanism and brakeing system are referred to collectively as the chasis.The steering mechanism serves to change the direction of traveled the braking system to slow down the running speed of the automobile or to stop it.
The auxiliaries of the automobile include winch,cab heating and ventilation equipment,hitch bar,etc.
The automobile and its engine are controlled and the operation of their mechanisms monitored by means of controls and instrucments located in the cab fort of the driver’s seat.
To start the engine and control its operation,use is made of throttle pedal,radiator shutter control handle,choke button,ignition/starter switch and throttle hand lever.The ignition/start switch is operated by a key which may be placed in one of the following four positions:central position-all current consumers are switched off:first position clockwise-ignition is switched on;first position counter clock wise it is possible to actuate the horn,windshield wiper and heater blower with the ignition circuit switched off.
Before starting the engine,it is necessary to check the radiator coolant level,the engine crankcase oil level and the fule level in the fuel tank.
To start a warm engine,place gear shift lever in neutral and switch on ignition and the starter motor by turning the ignition key clockwise as far as it will go.
To start a cold engine,it is recommended to do the following.Pump up gasoline by using the fule pump hand primer,Close the carburetor choke by pulling chock button outward full distance,Place the gear shift lever in neutral.Disengage the floor,which will decrease drag on the engine and thus ease the operation of the starter motor for in this case the transmission gears will not revolve in thickensed oil during starting.Switch on ignition and the starter motor by turning the ignition key fully clockwise;limit the time the start motor is energized to 5 second.Once the engine has started,switch off the starter motor by releasing the ignition key,open the chock by pushing its button inward one-half its full stroke,increase some what the speed by slightly depressing accelerator pedal and then engage the clutch by releasing its pedal.An engine in good rapair usually can be easily started,if the engine has first or second attempt.In the case of a false start,wait at least 30 second before attempting another start.If the engine has failed to start after the third attempt,check the ignition and fule systems.If the trouble is with the start motor or if the battery is discharged,the engine can be cranked up by your hand.When cranking up ,don’t grasp the crank handle,but keep your fingers on its one side only,so that the hand may not get hurt if the wngine kicks back.
Before starting the engine in low-temperature conditions,shut off the oil cooler,fill the cooling system with hot water and the engine crankcase with hot oil or use the starting preheated.Prior to turning on the ignition switch,close the radiator shutter by pulling handle out ward full distance and crank the engine three to five revolutions with the crank handle.Then perform all the rest operations as recommended for starting the cold engine.
Automobile controls include clutch pedal,brake pedal,throttle pedal,steering wheel,gear shift lever and parking brake lever.
Before starting to drive,warm up the engine at a moderate speed until the coolant temperature reachs 60℃.As the engine gets warmer,gradually open the choke and decrease the engine speed with the choke fully open.Read the dashboard instruments to check on the operation of the engine.
To monitor the operation of engine and the automobile itself,use is made of the following instruments and indicator mounted on the instrument panel in front of the driver’s seat:temperature gauge and temperature warning lamp and oil pressure gauge.
Signaling is effected by means of horn button and turn signal switch handle downwards causes the left-hand side of the steering column.Turning the directional signal switch handle downwards causes the left-hand side and tail lights to flash,thus gibing indication of a left turn and turning it upwards actuates the right-hand side and tail lights to indicate a right turns.Whenever either of the turn signal light is switch on turn signal indicator lamp on the instrucment panel starts flashing.The turn signal lights are switched off automatically when the automobile is straightened after turning.
On the left-hand side of the cab floor there is dimmer switch which is used to switch over the head lights from high to low beam and vice versa.Main light switch has three position:1.all lights are off;2.side lights,license plate light,tail maker lights and instrument panel light are switched on;3.side lights,head lights,tail mark lights,instrument panel light and license plate light and license plate lights are switched on.
Mounted on the instrument panel are windshield wiper and heater blower switches blower are switched on by turning their respective switches clockwise.The wiper switch has three positions;off,slow and fast.That of the heater blower also has three position:off ,low air delivery and high air delivery.
Mounted under the instrucment panel are radiation shutter control handle and hood catch handle.Pulling back on handle will close the radiator shutter and pulling back on handle will release the hood catch.There are also two circuits.Breaker button,cowl ventilator handle and ventilator air intake control handle.With handle in the extreme left-hand position,the cowl ventilator is fully open and with the handle in the extreme right-hand position,the air intake door is fully open and when the handle is in the extreme right-hand position,it is fully closed.
1．The last component in the drive train is the axle in a rear wheel drive car axle is in the rear.Engine power is transmitted from the transmission to the axle via the drive shaft.The drive shaft is basically a metal tuber with joints on each end called universal joints.These joints allow the tube to move in relation to the suspension and keep powers flowing to the real.In front wheel drive cars the axle is integrated into the transmission thus the term transaxle.
2. The drive shaft or propeller shaft,connects the transmission output shaft to the differential pinion shaft.Since all roads are not perfectly smooth and the transmission is fixed,the drive shaft has to be flexible to absorb the shock of bumps on the road.Universal or “U-joints”allow the drive shaft to flex(and stop it from breaking)when the drive angle changes.
3. Drive shafts are usually hollow in order to weigh less,but of a large diameter so that they are strong.High quality steel and sometimes aluminum are used in the manufacture of the drive shaft.The shaft must be quite straight and balanced to avoid vibrating.Since it usually turns at engine speeds,a lot of damage can be caused if the shaft is unbalanaced or bent.Damage can also be caused if the U-joints are worn out.
Most power steering systems work by using a hydraulic system to rotate the vehicle’s wheel.The hydraulic pressure is usually provided by a gerotor or rotary vane pump driven by the vehicle’s engine.A double-acting hydraulic cylinder applies a force to the steering mechanism,which in turn applies a torque to the wheels.The flow to the cylinder is countrolled by valves by the steering wheel.There are several common valve.This is done so that the position of the steering wheel corresponds to the position of the vehicle’s wheels.As the pumps employed are of the positive displacement type,the flow rate they deliver is directly proportional to the speed of the engine. This means that at high engine speeds the steering would naturally operate faster than at low engine speeds .Because this would be undersirable,a restricting orifice and flow control valve are used to direct some of the pump’s output back to the hydraulic reservoir at high engine speeds.A pressure when the hydraulic cylinder’s piston reaches the end of the cylinder.
Some modern implementations also include an electronic pressure relief valve which can reduce the hydraulic pressure in the power steering lines as the vehicle’s speed increase(this is known as variable assist power steering).
英文翻譯
自卸汽車
一輛自卸車或者生產(chǎn)用自卸車是用來運輸建筑用的散料（例如：沙、礫石和垃圾）的汽車。專用自卸車要求后面有液壓傾斜的貨箱，它的前部可以被舉起讓貨物堆放在送貨的汽車后面。在英國，這種汽車只允許在非公路場地用，并且公路車被認為是自卸車。
標準自卸車是在車架上安裝了自卸車箱的整車底盤。車廂被安裝在艙壁前面的液壓缸舉起，液壓缸位于駕駛室（牽引單元）和車廂（掛車）之間。標準的自卸車有一個前橋、一個或者更多每邊都有雙后輪的典型后橋，兩個后橋十個車輪，并且四車軸有三個后橋。這些主要在中部城市和南方見到。
短軸距的標準自卸車比更高的儲存容量半掛車自卸車更具機動性。
非公路自卸車比公路用車更接近與建設設備或工程汽車。它們被嚴格要求運用于采礦和非公路的重型場合。
自卸車并不經(jīng)常被用于采礦業(yè)和建筑業(yè)。在大部分的美國，這種嚴格意義上的非公路汽車是轉運卡車，例如它典型的地步和側面，介紹了當被裝上后的材料是如何被卸載的。在轉運卡車的車廂的說明里，利勃海爾T282b貨車貨物時卸載到后方的，指定這個特別的車輛作為年轉運卡車。有一些例子，幾個拖車（公路列車）是由一輛在道路上行走的卡車牽引。剩下的唯一的例子是被形容為組合煤車hauler是由kress公司制造的。這個大容量的卡車是用來從一個加載裝置直接向電力站或散裝儲存區(qū)運輸煤炭的。
許多冬季服務車輛單位的基礎是自卸卡車，通過布置壓載物來增加卡車的重量或?qū)Ⅺ}散布在道路上。
一個半掛自卸車是一個拖拉機與掛車的組合，其中拖車本身包含液壓啟閉機。一個典型的半掛自卸車有一個3軸拖拉機牽引2軸半掛車。關鍵的優(yōu)勢是一個半掛自卸車可快速的卸載。一個關鍵的缺點是它們在傾卸貨物時很不穩(wěn)定，這限制了它在許多場合的應用，如傾卸的場地是不平的。
拖拉機和汽車都是復雜的自動行走機器，它由不同的相互作用的機械裝置和設備組成，從而形成一定的組合，拖拉機主要由以下部分組成，不考慮專門的設計特征，所有的拖拉機是由發(fā)動機，驅(qū)動機構，汽車傳動，轉向和懸架裝置機構，轉向裝置，工作附件，輔助設備。
發(fā)動機使熱能轉變?yōu)闄C械能。
驅(qū)動機構由一套機械裝置組成，它們能傳遞由發(fā)動機曲軸輸出的扭矩并能在大小和方向上改變轉動扭矩。驅(qū)動機構包括離合器、柔性連機器、變速器和后輪軸。
離合器的作用是使當司機換擋時使發(fā)動機曲軸短時間內(nèi)脫離變速器，同時也是在啟動拖拉機是自如的將能量從發(fā)動機傳到驅(qū)動輪上。
柔性聯(lián)軸節(jié)把彈性元件離合器軸和功率傳動軸連接在一起，并允許它們有輕微的同軸度。
變速器通過嚙合多對齒輪來改變驅(qū)動扭矩和拖拉機的行駛速度，為了發(fā)動機曲軸方向自動保持一致，變速器能幫助拖拉機倒車。后輪裝置可以提高行駛扭矩并能以合適的角度改變扭矩，在大多數(shù)的拖拉機中，后驅(qū)動橋由制動器組成，高速拖拉機與低速拖拉機的區(qū)別是驅(qū)動機構，包括差速器，能使車輪在轉彎時或崎嶇的山路上以不同的角速度轉動。在一定的時間或相同的時間內(nèi)左右車輪可以行駛不同的距離。
汽車的運轉，轉向和懸架機構是拖拉機行走的需要，車輪的轉動與地面有關。
轉向裝置用于通過轉變前輪或改變速度從而改變拖拉機的轉動方向。
工作附件是利用拖拉機的發(fā)動機的可用能量來完成不同的農(nóng)業(yè)工作，它們包括動力輸出軸、拉桿、推動裝置和皮帶輪。
拖拉機的輔助系統(tǒng)包括駕駛室的彈性座椅和加熱通風裝置、發(fā)動機罩、點火裝置、方向指示器、喇叭等。
汽車主要組成部分的布置和目的在理論上與轉動拖拉機的安排在道理上是一樣的，在汽車上，汽車的傳動機構，驅(qū)動機構，汽車的傳動，轉向，懸架機構是用于改變行駛和制動的方向，放慢行駛中的汽車速度直至汽車停下為止。
汽車的輔助裝置包括絞車盤，駕駛室、加熱和通風裝置、牽引桿等。
汽車的控制汽車和它的發(fā)動機的控制和對這些裝置的操作受到駕駛室前面的一些控制件和部件的監(jiān)控。
為了啟動發(fā)動機并控制其旋轉，需要用節(jié)流操作踏板、散熱器百葉窗控制手柄、阻風門按鈕、點火開關和節(jié)氣門操縱拉桿。點火開關由位于以下四個位置的任何一個開關，中間位置——所有的電流消耗被關閉，第一個位置也是點火開關，同樣第二個位置可以打開點火開關和開啟電動機，第一個開關可以按響小喇叭，擦擋風玻璃，同時關閉加熱器和鼓風機的加熱系統(tǒng)。
在啟動發(fā)動機前，有必要檢查指示器里油液的多少，發(fā)動機曲軸箱機油的多少和燃油箱里燃油的多少。
要啟動一個熱的發(fā)動機請把換擋桿至于中間的位置，并打開點火開關，并啟動氣動馬達以使發(fā)動機運轉起來。
要啟動一臺冷的發(fā)動機，建議按如下操作進行：通過啟動液壓泵提高汽油壓力，把阻風門按鈕撥到關閉阻風門，把換擋桿置中，通過踩離合器，將離合器踩至駕駛室地面，這樣就可以減小離合器的阻力，從而以便于啟動發(fā)動機，因為在這種情況下，變速器不會在變濃的機油里攪動。打開點火開關，啟動電動機和發(fā)動機，限制啟動發(fā)動機的時間持續(xù)五秒,如果發(fā)動機被開啟，通過松開點火開關即可關閉發(fā)動機，通過推阻風門按鈕打開阻風門，輕輕踩下加速器踏板在一定程度上能加快發(fā)動機的轉速，同時逐漸放開離合器踏板時離合器結合。一臺狀態(tài)良好的發(fā)動機在一兩次的嘗試下很容易就能啟動。如果啟動失敗，請在另一次啟動前至少等待30秒。如果再試一次仍然無法啟動，請檢查點火裝置和供油系統(tǒng)，如果問題出現(xiàn)在啟動器或電池組上，可以采用手柄的一邊，這樣如果發(fā)動機反轉就不會受傷。
在低溫狀態(tài)下，啟動發(fā)動機前請關閉冷卻器，用熱水灌滿冷卻裝置是發(fā)動機機油箱充滿熱的機油或者使用啟動預熱裝置，在打開點火開關之前請關閉散熱器百葉窗，然后按以下建議打開其余的裝置。
汽車的控制包括離合器踏板、制動器踏板、節(jié)流操作踏板、方向盤、換擋桿和駐車制動桿。
在開始駕駛之前，請以適當?shù)霓D速加熱發(fā)動機直至冷卻液溫度達到60℃，隨著發(fā)動機的變熱，隨著阻風門的全部打開，逐步打開阻風門并降低發(fā)動機的轉速，請閱讀儀表盤儀器以檢測發(fā)動機的運行情況。
為了檢測發(fā)動機的運轉和汽車自身，常使用被安裝在駕駛員座椅前儀表板上的設備和儀表:溫度計、溫度警告燈、燃油油量計、速度計、燃油壓力警告燈、電流表、燃油壓力計。
信號是由撥動開關和安裝在轉向柱左邊的信號開關產(chǎn)生的。向下轉動轉向信號開關左轉向燈和車后燈就閃爍起來，這樣指示將要向左轉彎。并且向上轉動使得右邊的燈和車后燈指示右轉彎，不管任何時候開啟任何一個轉向信號燈，安裝在儀表板上的轉向信號指示燈都將閃爍。當汽車轉彎后直線行駛時轉向信號燈自動關閉。
在汽車地板的左邊有腳dimmer開關，它是用來從高到底開啟頂部的燈beam and vice versa 主燈開關有三個位置：1.所以的燈都關 2.邊燈、方向盤燈、后車標燈和儀表板燈都亮 3.邊燈、頭頂燈、后車標燈、儀表盤燈和駕駛方向盤燈都滅。
安裝在儀表盤上的擋風玻璃雨刮器和除霜吹風機開關都可以通過順時針撥動各自的開關來開啟。雨刮器開關有三個位置：關、小流量、和大流量。
安裝在儀表盤下面的是散熱器百葉窗開關控制手柄和車篷手柄。往后拉動手柄可以關上散熱器百葉窗，拉回手柄可以釋放車篷。它們同樣有兩條回路。當手柄到達左邊最大位置時進氣通風口全開，到達右邊最大位置時全閉。當手柄在左邊最大位置時進氣是全開的，當手柄在右邊最大位置時進氣門全閉。
1. 在后輪驅(qū)動的汽車上傳動系的最后部件是后驅(qū)動橋。發(fā)動機功率傳遞，通過傳動軸從變速器傳輸?shù)胶髽颉Ｔ搨鲃虞S基本上是一個兩端都有萬向節(jié)的金屬管。這些萬向節(jié)，使金屬管可以和懸架隨動和保持轉矩不斷地流向后橋。在前輪驅(qū)動的汽車中傳動軸被集成到了變速器，這樣組成了傳動系。
2. 傳動軸或萬向傳動軸，連接變速器輸出軸到差速器輸入軸。因為所有的道路都不能完全平順，并且變速器是固定的，傳動軸必須做成彈性的以吸收坎坷道路引起的震動。一般，當傳動角變化時“u型接頭”允許傳動軸彎曲。
3. 傳動軸通常是中空的，目的是減輕重量，但一個大的直徑，以便他們有足夠的強度。高優(yōu)質(zhì)鋼，有時候鋁都可以用于制造傳動軸。傳動軸必須有很高的直線度和動平衡度，以避免震動。因為它通常是輪流在發(fā)動機速度，如果軸不平衡或彎曲，都可以引起很多的危害，如果u型連接已磨損將引起危害。
大多數(shù)的動力轉向系統(tǒng)是用液壓系統(tǒng)來轉動汽車的輪子的。油液壓力通常由一個由發(fā)動機驅(qū)動的活塞泵或者旋轉葉片泵來提供。一個雙向液壓活塞向轉向機構提供壓力，轉向機構輪流向車輪提供轉矩。液體的流量由方向盤操作來控制。有幾種普通閥雖然較復雜，但是它們都允許轉向輪轉動比開啟一個簡單的必要的閥容易。這樣可以使轉向輪的位置對應汽車車輪的位置。隨著泵的作用輪胎發(fā)生位移，流量直接正比于發(fā)動機的轉速。這就意味著在發(fā)動機高速時需要一個限流閥和流量控制閥被用來引導一部分泵的輸出返回到油液泵。一個泄壓閥也被用來防止當液壓缸活塞到達活塞缸頂部室所建立的壓力引起的危險。
一些現(xiàn)代的調(diào)壓閥也包含一個電子泄壓閥，這個電子泄壓閥可以減小動力轉向系在發(fā)動機轉速上升時油液的壓力（這就是我們眾所周知的可調(diào)式動力轉向）。
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