Abstract: A hydrocarbon trapping layer (25) is formed by coating a hydrocarbon trapping material onto a carrier (21A). A number of exhaust gas passages (34) are formed in the carrier (21A) and a plurality of slits (22) are formed on the carrier (21A) to cross the passages (24) in a transverse orientation. The slits (22) delay temperature increases in the downstream hydrocarbon trapping layer (25) and delay the release of trapped hydrocarbons therefrom. This is due to blocking the transmission of heat to the downstream hydrocarbon trapping layer (25) from the upstream hydrocarbon trapping layer (25). The slits (22) further produce a turbulent flow in the flow of exhaust gas and promote diffusion of exhaust gas over the entire surface of the carrier (21A).

Abstract: A catalytic converter is interposed in an exhaust passage of an internal combustion engine. In the converter, a plurality of carriers are disposed in series with gaps. Each carrier comprises a hydrocarbon trapping layer, a three-way catalyst layer and a number of passages facing the three-way catalyst layer. The gaps interrupts heat transfer between the carriers in order to retard temperature increase in the hydrocarbon trapping layer and promotes a turbulence in exhaust gas flow in the converter in order to homogenize the exhaust gas dispersion in a radial direction, thereby enhancing the hydrocarbon purification performance of the converter.

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: A fuel property determination system for an internal combustion engine is arranged to determine a fuel property indicative that fuel in use is heavy or light, on the basis of a degree of change of a revolution speed during a period from an expansion stroke of a first fuel injection cylinder at engine start to an expansion stroke of a final fuel injection cylinder in a first round as to all cylinders of the engine.

Abstract: A fuel property determination system for an internal combustion engine is arranged to determine a fuel property indicative that fuel in use is heavy or light, on the basis of a degree of change of a revolution speed during a period from an expansion stroke of a first fuel injection cylinder at engine start to an expansion stroke of a final fuel injection cylinder in a first round as to all cylinders of the engine.

Abstract: The invention comprises at least two independent intake ports 14a, 14b connected to a combustion chamber 15, two intake valves 12a, 12b, and two exhaust valves 13a, 13b. Upper and lower channels 22a, 22b which are defined by a partition wall, and an intake control valve 25 for opening and closing the lower side channel 22b are provided in the interior of the first intake port 14a. An intake control valve 26 for opening and closing the first intake port 14b is also provided. The invention further comprises a controller 50 for controlling the opening and closing of the intake control valves 25 and 26, and the degree of opening of these intake control valves 25 and 26 is controlled in accordance with the operating conditions.

Abstract: The invention comprises at least two independent intake ports 14a, 14b connected to a combustion chamber 15, two intake valves 12a, 12b, and two exhaust valves 13a, 13b. A first fuel injection valve 31a is provided in the first intake port 14a and a second intake control valve 26 is provided for opening and closing the second intake port 14b. When the engine is in the cold condition, the second intake control valve 26 is slightly opened and fuel is injected from the first fuel injection valve 31b. Air-fuel mixture from the first intake port 14a and a smaller amount of fresh air from the second intake port 14b are introduced [into the combustion chamber], and the overall air-fuel ratio inside the combustion chamber is controlled to become slightly lean.

Abstract: A catalytic converter (9) is interposed in an exhaust passage (3) of an internal combustion engine (1). In the converter (9), a plurality of carriers (21A-21D) are disposed in series with gaps (G1-G3). Each carrier (21A-21D) comprises a hydrocarbon trapping layer (25), a three-way catalyst layer (26) and a number of passages (24) facing the three-way catalyst layer (26). The gaps (G1-G3) interrupts heat transfer between the carriers in order to retard temperature increase in the hydrocarbon trapping layer (25) and promotes a turbulence in exhaust gas flow in the converter (9) in order to homogenize the exhaust gas dispersion in a radial direction, thereby enhancing the hydrocarbon purification performance of the converter (9).

Abstract: A hydrocarbon trapping layer (25) is formed by coating a hydrocarbon trapping material onto a carrier (21A). A number of exhaust gas passages (34) are formed in the carrier (21A) and a plurality of slits (22) are formed on the carrier (21A) to cross the passages (24) in a transverse orientation. The slits (22) delay temperature increases in the downstream hydrocarbon trapping layer (25) and delay the release of trapped hydrocarbons therefrom. This is due to blocking the transmission of heat to the downstream hydrocarbon trapping layer (25) from the upstream hydrocarbon trapping layer (25). The slits (22) further produce a turbulent flow in the flow of exhaust gas and promote diffusion of exhaust gas over the entire surface of the carrier (21A).

Abstract: The invention comprises at least two independent intake ports 14a, 14b connected to a combustion chamber 15, two intake valves 12a, 12b, and two exhaust valves 13a, 13b. Upper and lower channels 22a, 22b which are defined by a partition wall, and an intake control valve 25 for opening and closing the lower side channel 22b are provided in the interior of the first intake port 14a. An intake control valve 26 for opening and closing the first intake port 14b is also provided. The invention further comprises a controller 50 for controlling the opening and closing of the intake control valves 25 and 26, and the degree of opening of these intake control valves 25 and 26 is controlled in accordance with the operating conditions.

Abstract: The invention comprises at least two independent intake ports 14a, 14b connected to a combustion chamber 15, two intake valves 12a, 12b, and two exhaust valves 13a, 13b. A first fuel injection valve 31a is provided in the first intake port 14a and a second intake control valve 26 is provided for opening and closing the second intake port 14b. When the engine is in the cold condition, the second intake control valve 26 is slightly opened and fuel is injected from the first fuel injection valve 31b. Air-fuel mixture from the first intake port 14a and a smaller amount of fresh air from the second intake port 14b are introduced [into the combustion chamber], and the overall air-fuel ratio inside the combustion chamber is controlled to become slightly lean.