6.关联题Passage 1Valve drive mechanismThe valve drive mechanism commands the inlet and exhaust valves at the requiredtiming.第 3 题 The valve drive mechanism consists of an inlet and exhaust cam follower凸轮随动件(8)each suspended in 悬浮在 中 a plunger of the taDDet assembly 挺杆组件(7),two mlrn/ar push rods 空心的推杆(4)with ball joints,two nodular cast iron球墨铸铁 rocker aims 摇臂(2)suspended in a rocker arm bearing bracket,two yokes另箱 5)and a yoke guide pins 导销.See Fig.4-1.The tappet rollers 推杆滚柱fMew the cam profiles and transfer the movementsthrough push rods to the rocker arms.第 4 题 The rocker arms operate the inletand exhaust valves through yokes.Lubrication fbr the rocker arms comes from the engines secondary oil supplymanifold throughdrillings in the cylinder head and rocker arm bracket.第 2 题 The tappet assembly receives lubricating oil via channels in the engineblock f?om the main supply manifold.For the roller and shaft,the oil is suppliedthrough the guiding plunger.第 4 题 To compensate for heat expansion a clearance must exist between therocker arm and yoke.第 1 题 All adjustments have to be done on a cold engine only.Fl.4-1 Valve ckive mnchanisni1.According to the Passage,the best time to adjust the valve clearance is.A.before the engine is started B.when the engine is runningC.after the engine has just been stopped D.when something has gone wrong withthe engine注:根据文章来看,调节阀间隙的最好时间是在发动机启动之前。2.The roller and the tappet assembly are lubricated by means of.A.the main lube system B.the secondary oil systemC.the special pumping system D.the turbine oil system注:滚轮和挺杆组件借助于主润滑系统润滑。3.According to the Passage,the valve drive mechanism does not i n c l u d e.A.tappet rollers B.push rods C.nodular cast iron D.yokes and guide pins注:根据文章来看,阀驱动机构不包括球墨铸铁。(包括杆滚轮、顶杆、吊梁和导销)4.To close valves tightly,which clearance should be inspected according to themaintenance schedule?A.The one between the cam and the tappet roller.B.The one between the pushrods and the ban joints.C.The one between the rocker arms and the yoke D.The one between twotubular push rods.注:依据保养清单,要紧密的关闭阀件,应检查摇臂和吊梁之间的间隙。AACCPassage 2Charge air coolerThe engine is equipped with a charge air cooler.The insert type charge air cooleris mounted in a welded casing(air trunk).The trunk is bolted to the engine block.第 1 题 Standard is a two-stage cooler mounted.The first stage,through which thecharge air flows,is cooled with water from the HT cooling system and cooks thecharge air till approx.90 1000C.The second stage is supplied with water comingfrom the LT water system and cooks the charge air further till the requiredtemperature of approx.500C.第 2 题(B)By controlling the water flow through the LTcooler the charge air temperature can be kept constant at the required temperature.The circulating coolant water should always be under positive pressure andshould be as clean as possible.The operating air temperature should be maintained bycontrolling the coolant inlet temperature.Whilst the engine is running the air and coolant temperatures and pressures atinlet and outlet should be checked and logged periodically.第 3 题 Variations fh)mnoirnal indicate faults developing such as fouling of the film plates or obstruction ofthe water tubes.第 4 题 Check daily,during operation of the engine,the working of the telltalehole at the 什ee end of the charge air receiver.The function of this hole is to inform theoperator the presence of water in the charge air receiver.Under normal condition onlycompressed air should escape from this hole.1.According to the Passage,the expression”HT”probably m e a n s.A.HIGH TANK B.HIGH TEMPERATURE C.HEAT TRANSMISSIOND.HEAT TRANSFER注:根据文章来看,“HT”的意思是:high temperature,高温。2.In order to maintain the change air temperature we should c o n t r o l.A.the coolant inlet temperature coming from the first stage coolerB.the coolant flow coming from the second stage coolerC.the coolant outlet temperature coming from the second stage coolerD.the coolant flow coming from the flint stage cooler注:为维持增压空气的温度,我们应控制来自第二级冷却器的冷却剂流量。3.The charge air temperature departing from normal may indicate t ha t.A.condensate can be formedB.only compressed air should escape from the telltaleC.the film plates are becoming dirty or the water tubes are blocked by scaleD.cooling water may have been carried into the cylinders注:增压空气温度偏离正常表明镀膜变脏或水管被水垢堵塞。4.The function of the telltale hole is to.A.detect whether compressed air has escaped from the holeB.control the coolant inlet temperatureC.determine whether the coolant water is under positive pressureD.inform the operator the presence of water in the charge air receiver注:警报孔或监视孔的作用是同志作业员扫气箱中有水。telltale hole监视孔,指示孔,警报孔;charge air receiver.扫气箱BBCDPassage 3Starting air systemThe engine is started with compressed air of max 30 bar.Minimum pressure requiredis 15 bar.A pressure transmitter PI301 mounted on the starting air line before the mainstarting valve has an indicator in the instrument panel.第 3 题 The supply linefrom the starting air bottles is provided with a non re