摘要:
An internal combustion is capable of switching, during engine operation, between a low-temperature combustion state in which an intake air with a high EGR rate is burned to operate the engine, and a normal combustion state in which an intake air with a low EGR rate is burned to operate the engine. In the internal combustion engine, a pilot injection is executed in addition to a main fuel injection, and furthermore the execution of the pilot injection is restricted during the engine operation with a combustion state switched to the low-temperature combustion state.
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:
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:
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.
摘要:
A technique is provided that enables reducer concentrations in exhaust gas flowing into an exhaust purification device on the upstream side and an exhaust purification device on the downstream side provided to an exhaust pipe in series to be controlled separately with a simple configuration. Included are the two exhaust purification devices provided to an exhaust passage in series, a bypass passage that bypasses the exhaust purification device on the upstream side, an exhaust control valve provided to the bypass passage, and reducer supply means provided on the upstream side of a branch portion. A reducer is supplied intermittently from the reducer supply means to periodically change the reducer concentration in the exhaust gas, and the exhaust control valve is opened or closed periodically at a predetermined timing with respect to the change in the reducer concentration. Accordingly, the supplied reducer is distributed to be introduced to the exhaust purification device on the upstream side or to be introduced to the exhaust purification device on the downstream side via the bypass passage.
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:
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.