Abstract: A spark ignition engine with a fuel injector for injecting fuel directly into the cylinder comprising a hollow combustion chamber formed on an upper surface of a piston, an ignition plug inserted into the vicinity of the side wall of the combustion chamber at an ignition timing by the movement of the piston, a fuel injector for injecting fuel toward the side wall of the combustion chamber in at least one predetermined engine driving condition, and at least one fuel guide passage for leading fuel injected by the fuel injector into the vicinity of the inserting position, in the combustion chamber, into which the ignition plug is inserted. The fuel guide passage passes through the vicinity of said inserting position. Each wall constructing the fuel guide passage and each extended phantom surface of each wall are arranged not to cross the ignition portion provided at the tip of the ignition plug in spite of the piston position.

Abstract: An engine comprising a first intake valve and a second intake valve that are arranged on each side of a plane including the axis of the cylinder of the engine. A first intake passage and a second intake passage are connected to the combustion chamber via the first intake valve and the second intake valve, respectively and extend along the plane in the same direction. A first fuel injector is arranged in the combustion chamber to inject fuel toward a region of the combustion chamber, which is located on the first intake valve side of the plane. A second fuel injector is arranged in the second intake passage to inject fuel into the second intake passage.

Abstract: An engine comprising a first intake valve and a second intake valve that are arranged on each side of a plane including the axis of the cylinder of the engine. A first intake passage and a second intake passage are connected to the combustion chamber via the first intake valve and the second intake valve, respectively and extend along the plane in the same direction. A first fuel injector is arranged in the combustion chamber to inject fuel toward a region of the combustion chamber, which is located on the first intake valve side of the plane. A second fuel injector is arranged in the second intake passage to inject fuel into the second intake passage.

Abstract: An engine comprising a fuel injector arranged on the inner wall of the cylinder in the vicinity of the intake valve. When the engine is operating under a heavy load, fuel is injected by the fuel injector during the intake stroke toward the rear face of the valve head of the intake valve. At this time, the injected fuel impinges upon the rear face of the valve head of the intake valve and is reflected thereon. Then, the injected fuel flows into the intake port.

Abstract: An internal combustion engine includes fuel injectors which directly inject high pressure fuel into combustion chambers of the engine. Spark plugs are provided in the combustion chambers, a catalytic converter is provided in the middle of the exhaust pipe for purifying the exhaust, and a temperature sensor is provided for detecting the temperature of a catalyst of the catalytic converter. A control unit which receives as input the engine rotational speed, load, and the detection value of the catalyst temperature sensor controls the engine such that, when the temperature of the catalyst is lower than a predetermined target temperature, the fuel injectors inject additional fuel into the combustion chambers during at least one of the expansion stroke and the exhaust stroke to mix the fuel with the exhaust. Thereafter, the exhaust having the additional fuel mixed in is reignited upstream of the catalytic converter to heat the catalyst to the target temperature.

Abstract: A direct fuel injection type spark ignition internal combustion engine includes a piston/cylinder structure including a deep dish portion, a peripheral portion, and a shallow dish portion. The peripheral portion has a depth smaller than the deep dish portion and greater than the shallow dish portion and a diameter larger than the deep dish portion and smaller than the shallow dish portion. At medium engine loads, fuel is injected toward an edge portion defined between the deep dish portion and the peripheral portion and is divided by the edge portion into two portions. One portion flows into the peripheral portion and is evaporated to generate a moderately rich air-fuel mixture which helps to propagate flame from the deep dish portion to the remaining portion of a combustion chamber including the shallow dish portion.

Abstract: A fuel injection valve includes a fuel swirl generation device, a main fuel injection hole having a comparatively large diameter, and a subsidiary fuel injection hole having a comparatively small diameter. The inclination of the main fuel injection hole with respect to an axis of the fuel injection valve is small so that a fuel swirl remains in the fuel injected therethrough. The inclination of the subsidiary fuel injection hole is great so that the swirl operates so as to push out the fuel through the subsidiary fuel injection hole. The fuel injected through the main fuel injection hole spreads due to the centrifugal force acting on the swirling fuel without depending on an intake gas swirl. The fuel injected through the subsidiary fuel injection hole has a strong penetrating force and can reach the vicinity of a spark plug. This improves ignition without depending on an intake gas swirl. Thus, good combustion is obtained over an entire operation range of a direct fuel injection type engine.

Abstract: A fuel injection valve includes a fuel swirl generation device, a main fuel injection hole having a comparatively large diameter, and a subsidiary fuel injection hole having a comparatively small diameter. The inclination of the main fuel injection hole with respect to an axis of the fuel injection valve is small so that a fuel swirl remains in the fuel injected therethrough. The inclination of the subsidiary fuel injection hole is great so that the swirl operates so as to push out the fuel through the subsidiary fuel injection hole. The fuel injected through the main fuel injection hole spreads due to the centrifugal force acting on the swirling fuel without depending on an intake gas swirl. The fuel injected through the subsidiary fuel injection hole has a strong penetrating force and can reach the vicinity of a spark plug. This improves ignition without depending on an intake gas swirl. Thus, good combustion is obtained over an entire operation range of a direct fuel injection type engine.

Abstract: An internal combustion engine comprising a fuel injector for injecting fuel directly into a cylinder and a calculating device for calculating a calculated amount of fuel to be injected on the basis of an engine operating state. The fuel injector injects all of the calculated amount of fuel during a compression stroke when the calculated amount of fuel is smaller than a predetermined first amount of fuel, and injects a part of the calculated amount of fuel during an approximately first half of an intake stroke and injects a remaining part of the calculated amount of fuel during a compression stroke when the calculated amount of fuel is equal to or larger than a predetermined second amount of fuel which is larger than the predetermined first amount of fuel.

Abstract: In a direct fuel injection type spark ignition internal combustion engine, fuel is assisted in evaporation by a squish flow. The engine includes a squish portion for generating the squish flow, a spark plug located adjacent to a center of a cylinder, and a fuel injector. The squish portion is enlarged so as to closely oppose the spark plug at the opening end of the squish portion. The fuel injector is located at a closed end of the squish portion and injects at least one portion of the fuel onto either one of two squish portion defining surfaces defining the squish portion therebetween. Evaporation of the fuel injected onto and adhering to the squish portion defining surface is promoted by the squish flow before being ignited by the spark plug.

Abstract: In a direct fuel injection type spark-ignition internal combustion engine in which a fuel is injected from a fuel injection nozzle into a cylinder onto the surface of the combustion chamber wall and then the fuel adhering to the wall is evaporated so as to generate a combustible mixture gas, the temperature of the combustion chamber wall is controlled so as not to rise excessively in a high engine load range by controlling the flow rate of an oil jet sprayed onto the back surface of the combustion chamber wall in accordance with engine operating parameters. The temperature of the combustion chamber wall in a low engine load range is maintained comparatively high by constructing the wall from a heat insulating structure. Through this control, the maximum combustion pressure at high engine loads can be held small and the cycle-by-cycle variation in rate of combustion at low engine loads can be kept small.