Abstract: The present invention comprises a housing main body, a valve assembly disposed within the housing main body and provided with a valve main body having a large-diameter cylinder portion and a small-diameter cylinder portion, a valve seat having a fuel injection aperture secured within the valve main body and a needle valve for closing and opening the fuel injection aperture, a seal ring held between a cylinder head and a shoulder portion when the valve assembly is inserted into an insertion port in the cylinder for preventing combustion gas in the cylinder from leaking into the housing main body and a welded joint for securing the valve main body to the housing main body disposed between the side of the large-diameter cylinder portion and an engaging portion on the housing main body.

Abstract: A fuel injection system capable of improving the degree of atomization and the combustibility of a fuel, including a fuel swirler, a valve seat having a fuel injection port, an annular fuel swirl chamber formed between the fuel swirler and a valve seat and communicating with plural swirl grooves and a fuel injection port, and a valve body adapted to be moved forward and backward in the interior of the fuel swirler in the axial direction thereof and thereby disengaged from and engaged with the valve seat to open and close a communication passage between the fuel swirl chamber and fuel injection port. Let S1, S2 and S3 equal a minimum cross-sectional area of an opening between the valve body and valve seat in the condition in which the communication passage is fully opened, an area of a cross section of the fuel injection port which is perpendicular to the axis thereof, and an average cross-sectional area of a fuel flow in the fuel injection port, respectively.

Abstract: A fuel injection system capable of improving the degree of atomization and the combustibility of a fuel, including a fuel swirler, a valve seat having a fuel injection port, an annular fuel swirl chamber formed between the fuel swirler and a valve seat and communicating with plural swirl grooves and a fuel injection port, and a valve body adapted to be moved forward and backward in the interior of the fuel swirler in the axial direction thereof and thereby disengaged from and engaged with the valve seat to open and close a communication passage between the fuel swirl chamber and fuel injection port. Let S1, S2 and S3 equal a minimum cross-sectional area of an opening between the valve body and valve seat in the condition in which the communication passage is fully opened, an area of a cross section of the fuel injection port which is perpendicular to the axis thereof, and an average cross-sectional area of a fuel flow in the fuel injection port, respectively.

Abstract: A fuel injection valve includes: a valve seat provided at one end of a hollow valve main body and having an injection hole; a valve body separated/contacted from/with the valve seat to open/close the injection hole; and a swirler for surrounding the valve body to slidably support the valve body and for giving swirling to a fuel flowing into the injection hole, the swirler being produced by metal powder injection molding.

Abstract: An improved fuel injection valve for improving the flow of fuel includes a vortex forming member and a needle valve having a planar surface on its leading end. A valve seat has a fuel injection nozzle formed therein and the needle valve opens and closes the fuel injection nozzle by engaging and disengaging with the valve seat. The vortex forming member provides a vortex motion to the fuel entering the fuel injection nozzle, upstream of a seat portion. The flat portion reduces the amount of surface area in which particles may adhere, thus preventing particles from adhering to the needle valve and reducing interference with the flow of fuel.

Abstract: A cylinder injection type fuel injection valve has a metallic ring 15 of a substantially T-like shape which is disposed inside a solenoid 2 and which has inner and outer sides supported by O-rings 16, 17 in order to seal highly pressurized fuel, whereby a change in a flow rate of fuel, which may be resulted by attaching the fuel injection valve to an internal combustion engine, can be minimized without changing largely a sealing structure for fuel, and deformation of the metallic ring is minimized.

Abstract: A direct injection fuel injection valve includes a valve assembly 6, a hollow housing 14 having a coupling portion 16 coupled to the valve assembly and adapted to be connected to the fuel supply pipe 5, and a solenoid assembly 22 disposed for operating the valve assembly. The housing has an abutting surface 36 disposed at a position radially outward of the coupling portion with respect to the valve assembly and in an opposing relationship relative to a shoulder portion 3 of the fuel injection valve insertion hole 2, and a mounting surface 31 for positioning the housing relative to the cylinder head. A sleeve 40 is provided with one end disposed on the valve assembly in opposition to the shoulder portion of the cylinder head and the other end mounted to the housing in abutment against the abutting surface to bridge across the valve assembly and the housing over the coupling portion.