Provided is a fuel injector that is capable of reducing penetration. The fuel injector of the present invention includes a valve body having a valve body side seat surface, a valve seat side seat surface that abuts on the valve body side seat surface, and an injection hole that is provided downstream of a position at which the valve body side seat surface abuts on the valve seat side seat surface. The valve body has a projection that is formed from the valve body side seat surface toward the injection hole, and the projection is formed to be smaller in a direction of fuel flow between seats than a radius of an upstream opening surface of the injection hole.

A control device for a compression-ignited internal combustion engine includes a nozzle that includes plural injection holes arranged at intervals in the circumferential direction and that directly injects fuel to a combustion chamber, a piston that includes a cavity with an inner circumferential side surface to which a distance from the nozzle varies in the circumferential direction, a first injection hole for injecting fuel to a portion of the inner circumferential side surface to which the distance from the nozzle is the largest out of the plural injection holes, a second injection hole for injecting fuel to a portion of the inner circumferential side surface to which the distance from the nozzle is the smallest out of the plural injection holes, a detection unit that detects a heat release rate in the combustion chamber, and a control unit that determines which of the first and second injection holes is abnormal.

The invention relates to a fuel injector (10), comprising a nozzle body (12) in which a blind hole (19) is formed, wherein at least one injection opening (14) leads off same, comprising a nozzle needle (25; 25a to 25c) that is reciprocatingly movable along a longitudinal axis (18), wherein the nozzle needle (25; 25a-25c) has a valve seat (29) which forms a sealing seat (26) with a seating surface (21) in the nozzle body (12) in a lowered position of the nozzle needle (25; 25a-25c), and comprising at least one borehole (34; 34a-34c) in the nozzle needle (25; 25a-25c), wherein at least some portions of a borehole inlet (36) of the at least one borehole (34; 34a-34c) are located in the region of the seating surface (21) when the sealing seat (26) is formed, and a borehole outlet (40) of the at least one borehole (34; 34a-34c) is located below the valve seat (29) of the nozzle needle (25; 25a-25c) in the direction of the longitudinal axis (18).

A fuel injector configured as a high-pressure injection valve for the direct injection of fuel into a combustion chamber includes: a housing having an housing end face on the combustion chamber side; an actuator; a valve-closure member operable by the actuator; at least one outlet orifice in the housing end face on the combustion chamber side for the fuel, the valve-closure member selectively closing or opening the outlet orifice; and a ring provided round about the outlet orifice in the housing end face on the combustion chamber side.

A holding fixture for an injection device for the injection of a medium into a combustion chamber of an internal combustion engine is provided, the injection device including an injector provided with at least one spray-discharge orifice, from which the medium is spray-discharged; the holding fixture has a first region disposed near the spray-discharge orifice of the injector, and a second region which faces away from the spray-discharge orifice of the injector, the holding fixture having at least one tubular heat conduction device, which extends at least between the first region and the second region.

An internal combustion engine comprises a hydrocarbon feed valve (15) arranged in an engine exhaust passage and a booster pump (60) for boosting an injection pressure of the hydrocarbon feed valve (15). The hydrocarbon feed valve (15) performs NO.sub.X removal injection and clogging prevention injection. A boosting action of the injection pressure by the booster pump (60) and the NO.sub.X removal injection are controlled so that the boosting action of the injection pressure by the booster pump (60) and the NO.sub.X removal injection are not performed simultaneously, and the boosting action of the injection pressure by the booster pump (60) and said clogging prevention injection are allowed to be performed simultaneously.

A cylinder injection valve that injects fuel inside a cylinder and an intake passage injection valve that injects fuel inside an intake passage are provided. When it is determined that deposit greater than or equal to a predetermined amount accumulates, the fuel is forcibly injected by the cylinder injection valve (deposit removing control). The deposit removing control is performed when a pressure of the fuel supplied to the cylinder injection valve is greater than or equal to a predetermined value and an engine load is relatively high. On the other hand, the deposit removing control is not performed when the pressure of the fuel supplied to the cylinder injection valve is greater than or equal to the predetermined value and the engine load is low.

An object of the present invention is to provide a working method of an orifice, which has excellent working accuracy and high productivity in order to work an inclination portion (tapered portion) on the entire circumference of an inner wall of an orifice. Therefore, a working method of an orifice includes a first step of forming an orifice hole 54d in an orifice forming member, a second step of pressing a downstream end surface of the orifice forming member in which the orifice hole 54d opens, in a direction toward an upstream side of the orifice hole 54d by a punch 46 having a cutting blade portion 46a larger than a cross section of the orifice hole 54d. The second step causes a material of the orifice forming member to flow from an entire circumference at the downstream end portion of the orifice hole 54d to an inside of the orifice hole 54d to form a cross-sectional area reduction portion 54s in which a cross-sectional area of the orifice hole 54d is reduced from an upstream side to a downstream side.