Abstract: A combustion chamber structure in which an installation hole of the injector is improved to realize a rapid combustion and to reduce an unburned hydrocarbon. In the combustion chamber, a leading end of an injector is withdrawn from an upper end of an opening of an installation hole, and an additionally expanded surface area is formed on an upper inner surface of the installation hole from a portion to which the leading end of the injector is situated to an opening end of the installation hole. An angle between the additionally expanded surface area and a joint surface of a cylinder head is narrower than an angle between a center axis of the installation hole and the joint surface.

Abstract: A combustion chamber structure in which an installation hole of the injector is improved to realize a rapid combustion and to reduce an unburned hydrocarbon. In the combustion chamber, a leading end of an injector is withdrawn from an upper end of an opening of an installation hole, and an additionally expanded surface area is formed on an upper inner surface of the installation hole from a portion to which the leading end of the injector is situated. to an opening end of the installation hole. An angle between the additionally expanded surface area and a joint surface of a cylinder head is narrower than an angle between a center axis of the installation hole and the joint surface.

Abstract: A spark-ignition internal combustion engine includes a cylinder head and a piston. A crown surface of the piston includes a central portion, and first outer portions and second outer portions located outside the central portion. The central portion and the first outer portions have a combustion chamber height higher than a predetermined value. The combustion chamber height of the second outer portions is equal to or lower than the predetermined value. The crown surface is composed of a mirror surface region and a rough surface region. The mirror surface region has a surface roughness of less than 0.05 ?m. The rough surface region has a surface roughness of 0.05 ?m or more and 2.5 ?m or less. All of the central portion and the first outer portions are included in the mirror surface region. At least one of the second outer portions is included in the rough surface region.

Abstract: A cylinder head is formed with a pre-chamber surrounded by a thin pre-chamber wall sticking out from the inside wall surface of the cylinder head to the inside of the main combustion chamber. Inside of the pre-chamber, the electrode of a spark plug is arranged. When the spark plug is used to burn the air-fuel mixture in the pre-chamber, jet flames are ejected from the communication holes to the main combustion chamber. The thin pre-chamber wall is formed from a metal material while the overall outer circumferential surface around the communication holes passing through the thin pre-chamber wall is formed by a material with a lower heat conductivity than the thin pre-chamber wall.

Abstract: A cylinder head (3) is formed with a pre-chamber (12) surrounded by a thin pre-chamber wall (11) sticking out from the inside wall surface of the cylinder head (3) to the inside of a main combustion chamber (5). Inside the pre-chamber (12), the electrode of a spark plug (15) is arranged. When the spark plug (15) is used to burn the air-fuel mixture inside the pre-chamber (12), jet flames are ejected from the communication holes (13) to the main combustion chamber (5). The thin pre-chamber wall (11) is formed into a two-layer structure of an outside wall (11a) facing the main combustion chamber (5) and an inside wall (11b) facing the pre-chamber (12). The inside wall (11b) is formed by a material with a higher heat conductivity than the outside wall (11a).

Abstract: A pre-chamber is formed between the front end of a spark plug attached to the cylinder head and a thin pre-chamber wall sticking out from the inside wall surface of the cylinder head to the inside of a main combustion chamber. The communication holes communicating the inside of the pre-chamber and the inside of the main combustion chamber are formed inside the thin pre-chamber wall. The thin pre-chamber wall is formed into a shape with a cross-sectional area gradually decreasing from the inside wall surface of the cylinder head toward the inside of the main combustion chamber such as a conical shape, frustoconical shape, polygonal conical shape, or polygonal frustoconical shape. A ground side electrode portion of the spark plug is positioned inside the gas pocket, and a discharge is caused between the center electrode sticking out from the front end of the center electrode insulator and the ground side electrode portion at the time of ignition.

Abstract: A cylinder head (3) is formed with a pre-chamber (12) surrounded by a thin pre-chamber wall (11) sticking out from the inside wall surface of the cylinder head (3) to the inside of the main combustion chamber (5). Inside of the pre-chamber (12), the electrode of a spark plug (15) is arranged. When the spark plug (15) is used to burn the air-fuel mixture in the pre-chamber (12), jet flames are ejected from the communication holes (13) to the main combustion chamber (5). The thin pre-chamber wall (11) is formed from a metal material while the overall outer circumferential surface around the communication holes (13) passing through the thin pre-chamber wall (11) is formed by a material with a lower heat conductivity than the thin pre-chamber wall (11).

Abstract: A cylinder head (3) is formed with a pre-chamber (12) surrounded by a thin pre-chamber wall (11) sticking out from the inside wall surface of the cylinder head (3) to the inside of a main combustion chamber (5). Inside the pre-chamber (12), the electrode of a spark plug (15) is arranged. When the spark plug (15) is used to burn the air-fuel mixture inside the pre-chamber (12), jet flames are ejected from the communication holes (13) to the main combustion chamber (5). The thin pre-chamber wall (11) is formed into a two-layer structure of an outside wall (11a) facing the main combustion chamber (5) and an inside wall (11b) facing the pre-chamber (12). The inside wall (11b) is formed by a material with a higher heat conductivity than the outside wall (11a).

Abstract: A pre-chamber is formed between the front end of a spark plug (15) attached to the cylinder head (3) and a thin pre-chamber wall (11) sticking out from the inside wall surface of the cylinder head (3) to the inside of a main combustion chamber (5). The communication holes (13) communicating the inside of the sub chamber (12) and the inside of the main combustion chamber (5) are formed inside the thin pre-chamber wall (11). The thin pre-chamber wall (11) is formed into a shape with a cross-sectional area gradually decreasing from the inside wall surface of the cylinder head (3) toward the inside of the main combustion chamber (5) such as a conical shape, frustoconical shape, polygonal conical shape, or polygonal frustoconical shape.

Abstract: An internal combustion engine includes a piston and a fuel injection valve. The fuel injection valve includes a first injection hole, a second injection hole, a first needle configured to open and close the first injection hole, and a second needle configured to open and close the second injection hole. The first injection hole and the second injection hole are configured such that a portion of a fuel spray injected from the first injection hole and a portion of a fuel spray injected from the second injection hole overlap each other at a position apart at a predetermined distance from a side wall of a cavity of the piston. The second needle is configured to start operation in order to open the second injection hole after a predetermined time has elapsed from a point of time when the first needle starts operation in order to open the first injection hole.

Abstract: A fuel injection valve has first injection holes, second injection holes, a first needle that opens and closes the first injection holes, and a second needle. The fuel injection valve is arranged such that a part of fuel injected from the first injection hole and a part of fuel injected from the second injection hole are gathered together at a position spaced from the side wall of the cavity by a predetermined distance. The second needle starts operating to open the second injection holes, after a predetermined time elapses from a point in time at which the first needle starts operating to open the first injection holes.

Abstract: An action of injection of the main injection fuel (QM) from the fuel injector (3) is started within a range of crank angle from 10 degree before the compression top dead center to 10 degree after the compression top dead center. A smaller amount of the auxiliary injection fuel (QN) than the main injection fuel (QM) is made to be injected from the fuel injector (3) before the main injection fuel (QM) so as to make the auxiliary injection fuel (QN) ignite by the premixed charge compression ignition. The injection timing of the auxiliary injection fuel (QN) is controlled to a timing whereby a heat generated by the premixed charge compression ignition of the auxiliary injection fuel (QN) causes the premixed charge compression ignition of the main injection fuel (QM) after the start of injection of the main injection fuel (QM).

Abstract: An object of the present invention is to further improve the characteristic of the fuel spray of a fuel injection valve which has a plurality of stepped injection holes having a hole diameter of an outlet side injection hole larger than a hole diameter of an inlet side injection hole and which injects fuel from the stepped injection holes into a cylinder of an internal combustion engine. A cutout portion, which guides a flow of gas flowing into an outlet side injection hole from a lateral position of a fuel outlet of the outlet side injection hole during fuel injection, in a circumferential direction of the outlet side injection hole, is provided for at least one of both lateral portions between which the fuel outlet is interposed along with an arrangement direction of a plurality of injection holes, on a circumferential edge of the fuel outlet of the outlet side injection hole, in relation to at lease some of the injection holes of a fuel injection valve having the plurality of stepped injection holes.

Abstract: An internal combustion engine includes a piston and a fuel injection valve. The fuel injection valve includes a first injection hole, a second injection hole, a first needle configured to open and close the first injection hole, and a second needle configured to open and close the second injection hole. The first injection hole and the second injection hole are configured such that a portion of a fuel spray injected from the first injection hole and a portion of a fuel spray injected from the second injection hole overlap each other at a position apart at a predetermined distance from a side wall of a cavity of the piston. The second needle is configured to start operation in order to open the second injection hole after a predetermined time has elapsed from a point of time when the first needle starts operation in order to open the first injection hole.

Abstract: A fuel injection valve has first injection holes, second injection holes, a first needle that opens and closes the first injection holes, and a second needle. The fuel injection valve is arranged such that a part of fuel injected from the first injection hole and a part of fuel injected from the second injection hole are gathered together at a position spaced from the side wall of the cavity by a predetermined distance. The second needle starts operating to open the second injection holes, after a predetermined time elapses from a point in time at which the first needle starts operating to open the first injection holes.

Abstract: An action of injection of the main injection fuel (QM) from the fuel injector (3) is started within a range of crank angle from 10 degree before the compression top dead center to 10 degree after the compression top dead center. A smaller amount of the auxiliary injection fuel (QN) than the main injection fuel (QM) is made to be injected from the fuel injector (3) before the main injection fuel (QM) so as to make the auxiliary injection fuel (QN) ignite by the premixed charge compression ignition. The injection timing of the auxiliary injection fuel (QN) is controlled to a timing whereby a heat generated by the premixed charge compression ignition of the auxiliary injection fuel (QN) causes the premixed charge compression ignition of the main injection fuel (QM) after the start of injection of the main injection fuel (QM).

Abstract: A condensed water treatment device for an internal combustion engine is provided. The condensed water treatment device may include a condensed water tank, a condensed water supply device, and a condensed-water generation quantity controlling device. The condensed water treatment device may further include a computer. The computer by executing a computer program may function as a storage-water-quantity decrease controlling device and a storage-water-quantity increase controlling device.

Abstract: The condensed water treatment device increases the EGR quantity (S16, S17) so as to be larger than the EGR quantity (Qe) calculated based on the operating state, when within a specific time period (S13) from a moment when execution of filter regeneration control is started to a moment after predetermined time has elapsed following the end of the execution, and also in a case where (S15) the storage water quantity (Qw) of a condensed water tank storing condensed water generated in an EGR cooler is smaller than a normative water quantity (Qwt).

Abstract: The condensed water treatment device obtains (S1) the storage water quantity (QW) of a condensed water tank, and drains (S4) condensed water in the condensed water tank when the storage water quantity (QW) is larger than a threshold value (tu) and also urea water is supplied to an exhaust passage for a selective-reduction type NOx catalyst. Thereby, the condensed water is neutralized and then drained to the outside of an internal combustion engine through the exhaust passage.

Abstract: The condensed water processing device determines (S2) whether the pH of condensed water stored in the condensed water tank is smaller than a threshold value (t). When the pH of condensed water is smaller than the threshold value (t), the supply quantity of urea water being supplied to the upstream side of the NOx catalyst is increased (S7) so that the supply quantity is larger than that in normal control (S4) executed when the pH of the condensed water is equal to or more than the threshold value (t).