单选题The working cycle of a four-stroke diesel engine consists of four events:（） (1) compression (2) expansion (3) exhaust (4) suctionThe correct sequence isA(4)-(2)-(3)-(1)B(4)-(3)-(1)-(2)C(4)-(3)-(2)-(1)D(4)-(1)-(2)-(3)
单选题
The working cycle of a four-stroke diesel engine consists of four events:（） (1) compression (2) expansion (3) exhaust (4) suctionThe correct sequence is
A
(4)-(2)-(3)-(1)
B
(4)-(3)-(1)-(2)
C
(4)-(3)-(2)-(1)
D
(4)-(1)-(2)-(3)
参考解析
解析：
暂无解析
相关考题：
Proper lubrication of the main bearings is more easily obtained in a single acting, four-stroke/cycle diesel engine than in a tow-stroke/cycle diesel engine because________.A.The direction of pressure on the journal in four-stroke engine is continuouslyB.positive feed lubricators are installed on all bearings of four-stroke engine, whereas as a splash feed system is used on tow-stroke engineC.four-stroke engines usually utilize a heavier grade of oil than tow-stroke enginesD.Low-stroke engines usually consume less lube oil than four-stroke engines
If all other conditions such as bore, stroke, speed, and mean effective pressures are equal, a two stroke/cycle diesel engine will develop approximatelyA.the same indicated horsepower as a four-stroke/cycle engineB.twice the indicated horsepower as a four-stroke/cycle engineC.one half the indicated horsepower as a four-stroke/cycle engineD.one power stroke for every two crankshaft revolutions
单选题In a four-stroke cycle diesel engine the intake valves open （）Abefore TDC and close after BDCBafter TDC and close after BDCCbefore TDC and close before BDCDafter TDC and close before BDC
单选题The camshaft drive is designed to maintain proper camshaft speed relative to crankshaft speedIn maintaining this relationship, the camshaft drive causes the camshaft to rotate at（）Aone half crankshaft speed in a two-stroke cycle diesel engineBcrankshaft speed in a two-stroke cycle diesel engineCtwo times crankshaft speed in a two-stroke cycle diesel engineDone-fourth times crankshaft speed in a four-stroke cycle diesel engine
单选题Air motion is induced in a four-stroke/cycle diesel engine cylinder to improve air fuel mixing, and is known as（）AsuperchargingBscavengingCturbulenceDswept volume charging
单选题The size of the exhaust valve opening is （）Amost critical in a four-stroke cycle diesel engineBmost critical in a two-stroke/cycle diesel engineCmost critical in a four-stroke/cycle diesel engine if it is turbochargedDof equal importance in a two-stroke/cycle diesel engine as in a four-stroke/cycle diesel engine
单选题Proper lubrication of the main bearings is more easily obtained in a single acting, four-stroke/cycle diesel engine than in a tow-stroke/cycle diesel engine because（）.AThe direction of pressure on the journal in four-stroke engine is continuouslyBpositive feed lubricators are installed on all bearings of four-stroke engine, whereas as a splash feed system is used on tow-stroke engineCfour-stroke engines usually utilize a heavier grade of oil than tow-stroke enginesDLow-stroke engines usually consume less lube oil than four-stroke engines
单选题Proper lubrication of the main bearing is more easily obtained in a single acting four-stroke/cycle diesel engine than in a single acting two-stroke/cycle diesel engine because （）Abearing pressure in a four-stroke/cycle acting single diesel engine is continually reversedBbearing pressure in a two-stroke/cycle single acting diesel engine is continually reversedCthe maximum bearing pressure is higher in a single acting two-stroke/cycle diesel engineDtwo-stoke/cycle diesel engines require more complicated lubrication piping
单选题A disadvantage of a four-stroke/cycle diesel engine is （）Ahigher working temperature of piston and cylinderBthe use of scavenge portsCfewer power strokes per revolution of the crankshaftDpart of the fuel is burned as the piston is moving away from top dead center
单选题Clearance volume scavenging in a turbocharged, four-stroke/cycle diesel engine is accomplished （）.Aduring the valve overlap periodBwith only the exhaust valve openCat a pressure below atmosphericDwithout cooling the cylinders or pistons
单选题Which of the following statements is true regarding the installation of piston rings on two-stroke/cycle, diesel engines as compared to four-stroke/cycle, diesel engines?（）AIn a two-stroke/cycle engine, the rings run hotter, requiring the end gap to be greaterBSome provision must be made in a two-stroke/cycle engine to keep the rings from binding in the portsCNo gap is required to exist between the ends of the ring when cold in a two-stroke/cycle engine, but a small gap is required in a four-stoke/cycle engineDThe gaps should be staggered on either side of a piston in a two-stroke/cycle engine, while staggering is not necessary in a four-stroke/cycle engine
单选题If all other conditions such as bore, stroke, speed, and mean effective pressures are equal, a two-stroke/cycle diesel engine will develop approximately（）Athe same indicated horsepower as a four-stroke/cycle engineBtwice the indicated horsepower as a four-stroke/cycle engineCone half indicated horsepower as a four-stroke/cycle engineDone power stroke for every two crankshaft revolutions
单选题During the power stroke of a four-stroke/cycle diesel engine, most of the side thrust of a trunk-type piston is absorbed by the（）Apiston skirtBpinionCcrossheadDcompression rings
单选题Any increase in the exhaust back pressure of a four-stroke/cycle diesel engine will （）.Areduce engine horsepower outputBaid in silencing the exhaust noiseCincrease the mean effective pressureDcontribute to effective cylinder scavenging
单选题A two-stroke/cycle diesel engine requires less starting air than a four-stroke/cycle diesel engine, of equal displacement, because the two-stroke/cycle diesel engine（）Ahas little or no internal frictionBhas a lower effective compression ratioCoperates with scavenge air under a positive pressureDoperates without energy absorbing intake and exhaust strokes
单选题The speed of the turbocharger for a four-stroke/cycle diesel engine driving a generator at constant speed depends on the （）Aengine speedBkilowatt loadCfuel injection pressureDair intake manifold temperature
单选题If a four-stroke/cycle diesel engine is running at 1550 RPM, the speed of the camshaft will be（）.A525 RPMB775 RPMC1550 RPMD1800 RPM
单选题During which of the listed piston stroke of a four-stroke/cycle diesel engine, is the piston moving downward?（）AIntake strokeBCompression strokeCExhaust strokeDPumping stroke
单选题Fuel oil begins injection into the cylinder of a four-stroke/cycle diesel engine during the （）.Aintake strokeBexhaust strokeCpower strokeDcompression stroke
单选题For a given size engine, the two-stroke/cycle diesel engine will deliver more power than a four-stroke/cycle diesel engine because （）.Ait has a longer power strokeBmore air gets into the cylinder each strokeCit develops twice as many power strokes at the same speedDhigher combustion pressure is developed
单选题If a four-stroke/cycle diesel engine is started by injecting air into the cylinder, the pistons receiving the charge of starting air must be（）Aon the power strokeBon the exhaust strokeCat the end of the power strokeDat the start of the intake stroke
单选题A turbocharged, four-stroke/cycle diesel engine has a larger valve overlap than a naturally aspirated four-stroke/cycle diesel engine, in order to in crease the （）.Atemperature of the exhaust gasesBenergy supplied to the turbochargerCair pressure to the intake manifoldDpurge of exhausted gases from the cylinders
单选题The camshaft on a four-stroke/cycle diesel engine provides a means to operate the （）.Afuel injectorsBexhaust valvesCintake valvesDall of the above
单选题A two-stroke diesel engine exhaust temperature will be lower than a four-stroke diesel engine of the same displacement because the （） (1) scavenging air is cooling the exhaust gases (2) exhaust cycle time is longerA(1) onlyB(2) onlyCboth (1) and (2)Dneither (1) nor (2)
单选题A piston in a four-stroke/cycle diesel engine makes four strokes during each （）.Acrankshaft revolutionBmechanical cycle of operationCperiod of two combustion cyclesDcycle of two events