摘要:
A direct injection internal combustion engine of a compression ignition type in which portions of an injected fuel spray which have not been evaporated are prevented from striking the walls of the combustion chamber, and the fuel spray is prevented from catching up the air around it when moving in the combustion chamber, thereby providing an engine having reduced combustion noise, reduced amount of smoke and noxious emissions, and improved fuel economy. A combustion chamber is formed in the piston substantially in the form of a spherical cavity gradually narrowing towards the opening of the cavity at the top surface of the piston. An air intake mechanism swirls intake air supplied to the combustion chamber. A swirl injector injects a fuel spray substantially in the form of a hollow cone having a velocity component in a direction tangential of the central axis of the nozzle. The nozzle is offset from the central axis of the cavity and inclined with respect to the central axis of the cavity so that the fuel spray is injected in a forward direction of a swirl stream of intake air in the cavity.
摘要:
A direct injection type internal combustion engine has a piston reciprocatably fitted in the bore of a cylinder block defining a combustion chamber together with the cylinder block and a cylinder head. A main recess is formed in the combustion chamber for accelerating the swirl of intake air which is prepared and introduced by an intake device. At least one auxiliary recess is formed in the main recess and is arranged in the direction of the intake air swirl and in the direction of the fuel injection of a fuel injector for generating a secondary swirl different from the intake air swirl and for generating turbulence between the two swirls. Thus, the introduction of air into the fuel droplets fed from the fuel injector is promoted by the intake air swirl and the secondary swirl so that the combustion efficiency of the internal combustion engine is improved.
摘要:
A direct injection internal combustion engine of a compression ignition type uses swirl injection nozzle having relatively small penetration and relies on the combination of an intake swirl and compression squish flow as well as a substantial fuel spray angle to uniformly distribute fuel throughout the interior of a throttled combustion cavity recessed in the piston.
摘要:
A direct injection internal combustion engine of compression ignition type is provided with a piston cavity offset from the piston center and with an injection nozzle which injects a hollow conical fuel spray having a tangential velocity component and relatively weak penetration into a swirl set up in the combustion chamber. The injection geometry and the offset are such that squish and swirl flows interact to form an excellent air-fuel mixture over the whole volume of the cavity without forming local fuel concentrations or wetting the cavity wall.
摘要:
A direct injection type internal combustion engine includes a centrifugal injector having its port facing a recess formed in a combustion chamber. The injector is arranged such that its axis of injection fails to intersect the central axis of the recess but extends at an inclination with respect to the same. In an embodiment typifying the invention, the following relationship is satisfied: ##EQU1## in which: D designates the maximum distance between facing sides of said recess; wherein with respect to a first transverse plane containing the location of the maximum distance D of said recess and a second plane intersecting said first transverse plane at a right angle, being parallel to the axis of sprays of the swirl injector and containing the center of the recess on the first transverse plane, .beta. designates the distance between the axis of sprays of said swirl injector and a second plane intersecting, at a right angle, a first transverse plane containing the location of the maximum distance D of said recess, said second plane being parallel to the axis of sprays of said swirl injector and containing the center of said recess on said first transverse plane; .theta. designates the angle contained between the axis of sprays of said swirl injector and the first transverse plane; and .theta..sub.s designates the angle of sprays of said swirl injector during fuel injection. The practice of the invention prevents the wall surface of the combustion chamber from being wetted with fuel, thereby improving the combustion phenomena and reducing the specific consumption.
摘要:
In an internal combustion engine, an NOX selective reduction catalyst (15) is arranged in an engine exhaust passage, an aqueous urea solution is fed to the NOX selective reduction catalyst (15) and the ammonia generated from the aqueous urea solution is made to be adsorbed at the NOX selective reduction catalyst (15), and the adsorbed ammonia is used to selectively reduce NOX. At the time the engine is stopped, when the ammonia adsorption amount at the NOX selective reduction catalyst (15) is smaller than a predetermined target amount of adsorption, the urea necessary for making the ammonia adsorption amount at the NOX selective reduction catalyst (15) the target amount of adsorption is fed to the NOX selective reduction catalyst (15) at the time the engine is stopped.
摘要:
There is provided a technique which can reduce the NOx stored in an NOx storage reduction catalyst. In case where concentrated reduction is carried out so as to add a reducing agent to the NOx storage reduction catalyst in a concentrated manner when a shift has been made from a state in which reduction of the NOx stored in said NOx storage reduction catalyst is unable to be performed in spite of a request for reduction of the NOx into a state in which reduction of the NOx is able to be performed, the level of concentration upon addition of the reducing agent is changed based on the amount of the NOx stored in the NOx storage reduction catalyst and the temperature of the NOx storage reduction catalyst.
摘要:
Cylinders of a diesel engine 1 are provided with cylinder pressure sensors 29a to 29d for detecting combustion chamber pressures. An electronic control unit (ECU) 20 of the engine selects optimum combustion parameters in accordance with a fuel injection mode of fuel injectors 10a to 10d of the engine and a combustion mode determined by the amount of EGR gas supplied from the EGR valve 35 from among a plurality of types of combustion parameters expressing the combustion state of the engine calculated based on the cylinder pressure sensor output and feedback controls the fuel injection amount and fuel injection timing so that the values of the combustion parameters match target values determined in accordance with the engine operating conditions. Due to this, the engine combustion state is controlled to the optimum state at all times regardless of the fuel injection mode or combustion mode.
摘要:
An exhaust emission purifier is provided and able to suppress overheating of an exhaust emission purifying catalyst and execute fuel addition promptly when fuel addition to the exhaust emission purifying catalyst is requested. In the exhaust emission purifier of an internal combustion engine, exhaust purifying cycles are repeated in order that the exhaust emission purifying catalyst is to be regulated at a target temperature, the cycle being a combination of an addition period during which fuel is added from the fuel addition valve and a halt period during which fuel addition is halted, and the fuel addition valve is manipulated such that the halt period is disposed so as to sandwich the addition period in the cycle.
摘要:
The exhaust purification system for an internal combustion engine according to the present invention includes fuel supply means for supplying fuel to the NOx storage-reduction catalyst from the upstream side thereof, and SOx poisoning recovery control executing means that uses the fuel supply means to supply fuel to the NOx storage-reduction catalyst thereby executing the SOx poisoning recovery control at a predetermined interval during operation of the internal combustion engine. In addition, according to the present invention, the execution of the SOx poisoning recovery control by the SOx poisoning recovery control executing means is prohibited during a predetermined period DELTA Qfen2 starting from a point in time that the operation of the internal combustion engine is initially started. The predetermined period DELTA Qfen2 is longer than a predetermined interval DELTA Qfen1.