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 bot tom 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 truc ks 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.
weigh翻译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 distanc e 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 p ower 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,ho od,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 sy stem 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 cloc kwise 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 th
e 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 e ngine 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 an d 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 light
s 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 windshi eld 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 tra nsaxle.
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 sometime s 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

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