Abstract: An in-cylinder direct fuel injection engine is disclosed. The engine comprises a fuel injection valve engaged in a fuel injection hole, a cylinder head, and an ignition plug engaged in an ignition hole, The fuel injection valve is attached to the fuel rail and the fuel injection nozzle injects fuel from the fuel rail. The fuel injection hole and the ignition hole are positioned in a central portion of the a roof of the cylinder head so as to be located between an intake and exhaust air ports and are generally aligned along an axis of a crank shaft.

Abstract: A direct-injection internal combustion engine and a combustion method therefore in which fuel injection timing of a fuel injection valve is so configured that (a) the fuel inverted from a cavity in a crown portion of a piston reaches proximity to the discharge electrode portion of a spark plug later than the time of ignition or (b) fuel injection by the fuel injection valve is completed at approximately the same time of ignition. There is no risk of rich combustion at the discharge electrode portion due to the mixed fuel-air mass having a high fuel density, and consequently problems such as wear on the spark plug or smoke generation can be avoided.

Abstract: An in-cylinder direct fuel injection engine is disclosed. The engine comprises a fuel injection valve engaged in a fuel injection hole, a cylinder head, and an ignition plug engaged in an ignition hole, The fuel injection valve is attached to the fuel rail and the fuel injection nozzle injects fuel from the fuel rail. The fuel injection hole and the ignition hole are positioned in a central portion of the a roof of the cylinder head so as to be located between an intake and exhaust air ports and are generally aligned along an axis of a crank shaft.

Abstract: An engine control device is configured to cause an engine to operate at the optimum combustion mode according to the load when warming up of an emissions purification catalyst is required, and to obtain reduced HC discharged from the engine and accelerated warm-up of the catalyst. The engine control device performs stratified combustion with a compression stroke injection in a low-load region according to the engine load, and performs double-injection combustion with an intake stroke injection and a compression stroke injection in an intermediate load region, when warming up of the catalyst is required. In a high-load region, the engine control device performs homogenous combustion with an intake stroke injection.

Abstract: A direct-injection internal combustion engine and a combustion method therefore in which fuel injection timing of a fuel injection valve is so configured that (a) the fuel inverted from a cavity in a crown portion of a piston reaches proximity to the discharge electrode portion of a spark plug later than the time of ignition or (b) fuel injection by the fuel injection valve is completed at approximately the same time of ignition. There is no risk of rich combustion at the discharge electrode portion due to the mixed fuel-air mass having a high fuel density, and consequently problems such as wear on the spark plug or smoke generation can be avoided.

Abstract: An exhaust gas recirculation system is configured to recirculate a large amount of exhaust gas to an engine intake passage while reducing contamination inside the intake passage caused by the recirculated exhaust gas and prevent damage to the intake passage caused by the heat of the recirculated exhaust gas. A first recirculation path recirculates exhaust gas from an upstream section of the exhaust passage located upstream of a catalytic converter unit. A second recirculation path recirculates exhaust gas from a downstream section of the exhaust passage located downstream of the catalytic converter unit. A control unit is provided that controls the switching of a selector valve between the first and the second recirculation paths based on the temperature of the recirculated exhaust gas.

Abstract: A four-stroke cycle in-cylinder fuel injection internal combustion engine (1) comprises a fuel injector (8) which injects fuel directly into a combustion chamber (7), performs stratified charge combustion by means of compression stroke fuel injection, and performs homogeneous combustion by means of intake stroke fuel injection. Upon start-up of the engine (1), intake stroke fuel injection is performed at the first combustion opportunity, and compression stroke fuel injection is switched to from the second combustion opportunity onward. In so doing, switching of the combustion system is performed early and independently of the engine rotation speed.

Abstract: An engine control device is configured to perform optimum combustion control according to environmental conditions when warming up of a catalyst for emission purification is required. The engine control device performs stratified combustion by the compression stroke injection at the time of startup, when warming up of the catalyst is required. However, under conditions of low air density, stratified combustion by compression stroke injection is prevented, and either homogenous combustion by intake stroke injection is performed, or double injection combustion by intake stroke injection and compression stroke injection is performed. Thus, the engine control device maintains starting properties and prevents adverse effects on engine operability.

Abstract: An engine system is capable of switching between a first fuel injection mode, in which fuel is injected from a fuel injection valve 23 directly into a combustion chamber 6 in the compression stroke, and a second fuel injection mode, in which fuel is injected from the fuel injection valve 23 directly into the combustion chamber 6 in the intake stroke. A controller 30 determines the characteristic of the fuel that is supplied to the fuel injection valve 23, selects either the first fuel injection mode or the second fuel injection mode according to the fuel characteristic, and starts an engine 1 in the selected fuel injection mode.

Abstract: An in-cylinder fuel injection internal combustion engine (1) is started up by means of compression stroke fuel injection from the beginning of cranking of the engine (1) to the end of a stratified combustion start-up period TST. If the engine (1) reaches complete combustion during the period, a warm-up operation is begun immediately. If the engine (1) does not reach complete combustion during the period, start-up of the engine (1) is continued using intake stroke fuel injection. By means of this control, stable start-up is assured while suppressing the discharge of unburned fuel during start-up of the engine (1).

Abstract: An exhaust gas recirculation system is configured to recirculate a large amount of exhaust gas to an engine intake passage while reducing contamination inside the intake passage caused by the recirculated exhaust gas and prevent damage to the intake passage caused by the heat of the recirculated exhaust gas. A first recirculation path recirculates exhaust gas from an upstream section of the exhaust passage located upstream of a catalytic converter unit. A second recirculation path recirculates exhaust gas from a downstream section of the exhaust passage located downstream of the catalytic converter unit. A control unit is provided that controls the switching of a selector valve between the first and the second recirculation paths based on the temperature of the recirculated exhaust gas.

Abstract: A start-up control device of a direct injection engine has a fuel injector (76) for injecting fuel into the engine; and a controller. The controller is programmed to determine the presence of a learned value for calculating on the basis thereof a fuel injection amount during start-up of the engine (10) by means of a stratified charge combustion operation; calculate the fuel injection amount on the basis of the learned value when the learned value is present, and control the fuel injector (76) to inject fuel in the compression stroke to start up the engine (10) by means of a stratified charge combustion operation; and control the fuel injector (76) to inject fuel in the intake stroke of the engine to start up the engine by means of a homogeneous combustion operation when the learned value is absent, and obtain and store the learned value during the homogeneous combustion operation of the engine.

Abstract: An engine control device is configured to perform optimum combustion control according to environmental conditions when warming up of a catalyst for emission purification is required. The engine control device performs stratified combustion by the compression stroke injection at the time of startup, when warming up of the catalyst is required. However, under conditions of low air density, stratified combustion by compression stroke injection is prevented, and either homogenous combustion by intake stroke injection is performed, or double injection combustion by intake stroke injection and compression stroke injection is performed. Thus, the engine control device maintains starting properties and prevents adverse effects on engine operability.

Abstract: An engine control device is configured to cause an engine to operate at the optimum combustion mode according to the load when warming up of an emissions purification catalyst is required, and to obtain reduced HC discharged from the engine and accelerated warm-up of the catalyst. The engine control device performs stratified combustion with a compression stroke injection in a low-load region according to the engine load, and performs double-injection combustion with an intake stroke injection and a compression stroke injection in an intermediate load region, when warming up of the catalyst is required. In a high-load region, the engine control device performs homogenous combustion with an intake stroke injection.

Abstract: A four-stroke cycle in-cylinder fuel injection internal combustion engine (1) comprises a fuel injector (8) which injects fuel directly into a combustion chamber (7), performs stratified charge combustion by means of compression stroke fuel injection, and performs homogeneous combustion by means of intake stroke fuel injection. Upon start-up of the engine (1), intake stroke fuel injection is performed at the first combustion opportunity, and compression stroke fuel injection is switched to from the second combustion opportunity onward. In so doing, switching of the combustion system is performed early and independently of the engine rotation speed.

Abstract: An engine system is capable of switching between a first fuel injection mode, in which fuel is injected from a fuel injection valve 23 directly into a combustion chamber 6 in the compression stroke, and a second fuel injection mode, in which fuel is injected from the fuel injection valve 23 directly into the combustion chamber 6 in the intake stroke. A controller 30 determines the characteristic of the fuel that is supplied to the fuel injection valve 23, selects either the first fuel injection mode or the second fuel injection mode according to the fuel characteristic, and starts an engine 1 in the selected fuel injection mode.

Abstract: An in-cylinder fuel injection internal combustion engine (1) is started up by means of compression stroke fuel injection from the beginning of cranking of the engine (1) to the end of a stratified combustion start-up period TST. If the engine (1) reaches complete combustion during the period, a warm-up operation is begun immediately. If the engine (1) does not reach complete combustion during the period, start-up of the engine (1) is continued using intake stroke fuel injection. By means of this control, stable start-up is assured while suppressing the discharge of unburned fuel during start-up of the engine (1).

Abstract: A start-up control device of a direct injection engine has a fuel injector (76) for injecting fuel into the engine; and a controller. The controller is programmed to determine the presence of a learned value for calculating on the basis thereof a fuel injection amount during start-up of the engine (10) by means of a stratified charge combustion operation; calculate the fuel injection amount on the basis of the learned value when the learned value is present, and control the fuel injector (76) to inject fuel in the compression stroke to start up the engine (10) by means of a stratified charge combustion operation; and control the fuel injector (76) to inject fuel in the intake stroke of the engine to start up the engine by means of a homogeneous combustion operation when the learned value is absent, and obtain and store the learned value during the homogeneous combustion operation of the engine.

Abstract: A direct fuel injection engine includes a fuel injector so positioned and oriented as to produce a fuel spray whose upper segment reaches the vicinity of a spark plug by a penetrating force of the fuel spray in a low engine speed light load operating region to achieve stratified charge combustion without the aid of tumble. A tumble control valve is operated to strengthen the tumble in a combustion chamber to achieve stratified charge combustion with the aid of tumble in an engine operating region higher in engine speed and/or engine load.

Abstract: A direct fuel injection engine includes a fuel injector so positioned and oriented as to produce a fuel spray whose upper segment reaches the vicinity of a spark plug by a penetrating force of the fuel spray in a low engine speed light load operating region to achieve stratified charge combustion without the aid of tumble. A tumble control valve is operated to strengthen the tumble in a combustion chamber to achieve stratified charge combustion with the aid of tumble in an engine operating region higher in engine speed and/or engine load.