Abstract: An in-cylinder injection type internal combustion engine is provided, which first fires a first spark plug and thereafter fires a second spark plug when a required load is low and which first fires the second spark plug and thereafter fires the first spark plug when the required load is high.

Abstract: A direct cylinder injection-type spark ignition internal combustion engine is disclosed. The engine comprises a spark plug, a cavity formed in the top surface of a piston, and a fuel injection valve for injecting fuel into the cavity in nearly the shape of a fan having a relatively small thickness. When the fuel injected in nearly the shape of a fan from the fuel injection valve is considered by being divided into a plurality of fuel segments in a radial direction, a side wall of the cavity has a first fuel deflection passage 82a and a second fuel deflection passage 82b for so deflecting at least two of the plurality of fuel segments as to pass near the spark plug. The side wall of the cavity is at least partly provided with a return portion 83 that protrudes toward the inside of the cavity.

Abstract: A direct fuel injection-type spark-ignition internal combustion engine is disclosed. The engine comprises a fuel injector for injecting fuel as a spray in nearly the shape of a fan having a relative small thickness, a spark plug and a cavity formed on the top surface of a piston. The cavity has a long and narrow groove-like shape. The spray is injected by the fuel injector such that the spray is almost parallel with the center axis of the piston, and impinges in the cavity. The spark plug is arranged in the upper portion of the cylinder to face the cavity.

Abstract: A direct cylinder injection-type spark ignition internal combustion engine is disclosed. The engine comprises a spark plug, a cavity formed in the top surface of a piston, and a fuel injection valve for injecting fuel into the cavity in nearly the shape of a fan having a relatively small thickness. When the fuel injected in nearly the shape of a fan from the fuel injection valve is considered by being divided into a plurality of fuel segments in a radial direction, a side wall of the cavity has a first fuel deflection passage 82a and a second fuel deflection passage 82b for so deflecting at least two of the plurality of fuel segments as to pass near the spark plug. The side wall of the cavity is at least partly provided with a return portion 83 that protrudes toward the inside of the cavity.

Abstract: A direct cylinder injection-type spark ignition internal combustion engine is disclosed. The engine comprises a spark plug, a cavity formed in the top surface of a piston, and a fuel injection valve for injecting fuel into the cavity in nearly the shape of a fan having a relatively small thickness. When the fuel injected in nearly the shape of a fan from the fuel injection valve is considered by being divided into a plurality of fuel segments in a radial direction, a side wall of the cavity has a first fuel deflection passage 82a and a second fuel deflection passage 82b for so deflecting at least two of the plurality of fuel segments as to pass near the spark plug. The side wall of the cavity is at least partly provided with a return portion 83 that protrudes toward the inside of the cavity.

Abstract: An in-cylinder injection type internal combustion engine is provided, which first fires a first spark plug and thereafter fires a second spark plug when a required load is low and which first fires the second spark plug and thereafter fires the first spark plug when the required load is high.

Abstract: A direct cylinder injection-type spark ignition internal combustion engine is disclosed. The engine comprises a spark plug, a cavity formed in the top surface of a piston, and a fuel injection valve for injecting fuel into the cavity in nearly the shape of a fan having a relatively small thickness. When the fuel injected in nearly the shape of a fan from the fuel injection valve is considered by being divided into a plurality of fuel segments in a radial direction, a side wall of the cavity has a first fuel deflection passage 82a and a second fuel deflection passage 82b for so deflecting at least two of the plurality of fuel segments as to pass near the spark plug. The side wall of the cavity is at least partly provided with a return portion 83 that protrudes toward the inside of the cavity.

Abstract: A direct-fuel-injection-type spark-ignition internal combustion engine has an ignition plug, a cavity formed in an upper wall of a cylinder, a fuel injection valve that injects fuel so that most of the fuel strikes a side wall of the cavity at an acute angle with respect to a tangent to the side wall at the point where the fuel strikes it, and a fuel guide portion that is provided in the side wall of the cavity and that guides most of the fuel to the vicinity of the ignition plug. The direct-fuel-injection-type spark-ignition internal combustion engine is able to realize a good stratified charge combustion by reliably positioning a major portion of combustible mixture in the vicinity of the ignition plug at the time of ignition.

Abstract: A direct cylinder injection-type spark ignition internal combustion engine is disclosed. The engine comprises a spark plug, a cavity formed in the top surface of a piston, and a fuel injection valve for injecting fuel into the cavity in nearly the shape of a fan having a relatively small thickness. When the fuel injected in nearly the shape of a fan from the fuel injection valve is considered by being divided into a plurality of fuel segments in a radial direction, a side wall of the cavity has a first fuel deflection passage 82a and a second fuel deflection passage 82b for so deflecting at least two of the plurality of fuel segments as to pass near the spark plug. The side wall of the cavity is at least partly provided with a return portion 83 that protrudes toward the inside of the cavity.

Abstract: A direct-fuel-injection-type spark-ignition internal combustion engine has a fuel injection valve which directly injects fuel into a cylinder. A nozzle hole of the fuel injection valve directs fuel toward an impingement portion of the cylinder bore located opposed to the nozzle hole in a lower section of the cylinder bore so that fuel can be injected into a cavity formed in a top face of a piston from an upper section of the cylinder bore during the latter half of a compression stroke. A cooler located at least in the neighborhood of the impingement portion in the lower section of the cylinder bore has a lower cooling capacity than a cooler located in the neighborhood of the upper section of the cylinder bore. Thus, fuel injected during the latter half of an intake stroke that adheres to the cylinder bore can be effectively gasified.

Abstract: A direct fuel injection-type spark-ignition internal combustion engine is disclosed. The engine comprises a fuel injector for injecting fuel as a spray in nearly the shape of a fan having a relative small thickness, a spark plug and a cavity formed on the top surface of a piston. The cavity has a long and narrow groove-like shape. The spray is injected by the fuel injector such that the spray is almost parallel with the center axis of the piston, and impinges in the cavity. The spark plug is arranged in the upper portion of the cylinder to face the cavity.

Abstract: In a direct fuel injection-type spark ignition internal combustion engine including a spark plug and a fuel injector for injecting fuel directly into the cylinder, the engine can carry out stratified charge combustion by the fuel injection in the compression stroke and uniform charge combustion by the fuel injection in the intake stroke. The engine includes a mechanism which can make a tumbling stream formed in the cylinder in the intake stroke in the stratified charge combustion weaker than that in the uniform charge combustion.

Abstract: A direct cylinder injection-type spark ignition internal combustion engine is disclosed. The engine comprises a spark plug, a cavity formed in the top surface of a piston, and a fuel injection valve for injecting fuel into the cavity in nearly the shape of a fan having a relatively small thickness. When the fuel injected in nearly the shape of a fan from the fuel injection valve is considered by being divided into a plurality of fuel segments in a radial direction, a side wall of the cavity has a first fuel deflection passage 82a and a second fuel deflection passage 82b for so deflecting at least two of the plurality of fuel segments as to pass near the spark plug. The side wall of the cavity is at least partly provided with a return portion 83 that protrudes toward the inside of the cavity.

Abstract: A direct fuel injection, spark-ignition internal combustion engine wherein fuel mainly proceeds toward a spark plug side wall of a cavity along a bottom wall, is deflected by the spark plug side wall and is led to the vicinity of a spark plug. In the engine, the spark plug side wall of the cavity is provided with a deflecting portion inclined toward the inside of the cavity. A first part of the deflecting portion provided on both sides of the spark plug side wall functions to lead the fuel to the vicinity of the spark plug. A second part of the deflecting portion on the central portion of the spark plug side wall functions to lead the fuel to a region neighboring the side of the fuel injection valve from the vicinity of the spark plug.

Abstract: A direct fuel injection-type spark ignition internal combustion engine is disclosed. The engine comprises a spark plug arranged in the upper wall of the cylinder, a fuel injector for directly injecting fuel into the cylinder, and a cavity formed in the top surface of the piston. The cavity has a bottom wall and a spark plug side wall. Fuel injected into the cavity from the fuel injector in the latter half of the compression stroke proceeds on the bottom wall of the cavity so as to be deflected by the spark plug side wall and led to the vicinity of the spark plug. In the engine, the fuel injector injects fuel in the shape of a fan having a relatively small thickness. The cavity has guide walls for preventing fuel from excessively spreading in the direction of width of the fan shape as it proceeds on the bottom wall.

Abstract: A direct cylinder injection-type spark ignition internal combustion engine is disclosed. The internal combustion engine comprises a spark plug 6, a cavity 8 formed in the top surface of the piston, and a fuel injection valve 7 for injecting fuel into said cavity in nearly the shape of a fan having a relative small thickness. A side wall 8b of the cavity opposed to the fuel injection valve for leading the fuel to the vicinity of the spark plug, has a horizontal arcuate shape which is nearly symmetrical to a first vertical plane (N1). The first vertical plane is separated away from a vertical center plane (Nc) at the center of the fuel and is nearly parallel with the vertical center plane.

Abstract: A combustion chamber of an engine comprising a pair of exhaust valves arranged on one side of an inner wall of a cylinder head. A pair of intake valves are arranged on the other side of the inner wall of the cylinder head. Inflow suppressing walls for suppressing the inflow of the intake air from the openings of the intake valves are formed along the peripheral portions of the intake valves positioned opposite to the exhaust valves and positioned between the intake valves. The parts of the inner wall of the cylinder head around the peripheral portions of the intake valves positioned opposite to the exhaust valves and positioned opposite to the other intake valves are expanded outward from the cylinder bore.

Abstract: An intake device of an engine comprising an intake passage which is common to a first intake valve and a second intake valve. The intake passage is divided into a first straight passage and a second straight passage by a dividing wall which extends toward a point upstream of the intake passage from a position between the first intake valve and the second intake valve. A downwardly projecting separating wall is formed on the upper wall of the intake passage. The separating wall extends from a position upstream of the upstream end of the dividing wall toward a point upstream of the intake passage along the axis of the first straight passage. An intake control valve is arranged between the separating wall and the side wall of the intake passage, which is located on the second straight passage side.

Abstract: In an internal combustion engine cylinder head for being clamped to a cylinder block for defining therewith a plurality of combustion chambers arranged in a row, the cylinder head is formed with three parallel coolant passages along the row of combustion chambers, a first, a second and a third one of those passages successively passing by intake ports, exhaust ports and roofs of the row of combustion chambers, respectively, each passage being independently connected at one end thereof with a coolant jacket of the cylinder block to receive coolant therefrom, so that three parallel coolant flows of a favorable triple distribution of flow rates are optionally established according to certain relative magnitudes of flow resistance of the three coolant passages.

Abstract: An internal combustion engine has a cylinder block formed with first and second cylinder bores, and first and second pistons are fitted in the bores and reciprocate in them. A cylinder head is affixed to the cylinder block and defines first and second combustion chambers in cooperation with the first and second pistons and cylinder bores. This cylinder head is formed with a portion which in cooperation with a portion of the first piston defines a squish area of the first combustion chamber, with a cylinder fixing bolt hole boss being located between the first portion and the second portion of the cylinder head, and being disposed towards the side of the cylinder head on the side of the squish area. Further, the cylinder head is formed with a side wall defining one side of a coolant passage which substantially follows through the cylinder head proximate to the squish area so that a first portion of the coolant passage directly cools the squish area.