Abstract: A fuel injection valve includes: a holder which accommodates a valve body, has a surface magnetically facing the outer periphery of an armature, and is joined to a core; a housing which is press-fitted onto the outer periphery of the holder and accommodates a coil; and a cap which covers the fuel upstream side of the coil in a lid shape and is press-fitted onto the outer periphery of the core. The lower surface of the cap is brought into contact with the upper end surface of the housing in a radially slidable state and then an outer peripheral portion of a contact surface between the cap and the housing is joined by laser welding.

Abstract: A holder of a fuel injection valve is press-inserted to a housing of the fuel injection valve so as to be fixed to the housing, a cap of the fuel injection valve includes a notch portion for notching an annular portion, and is arranged in such a way that an inner circumference surface of the cap is faced to an outer circumference surface of a core of the fuel injection valve via a gap, and an electrode terminal of the fuel injection valve is connected to a terminal of a solenoid of the fuel injection valve via the notch portion of the cap.

Abstract: In a fuel injection valve, a bobbin includes a bobbin main body serving as a part around which a coil is wound, and a terminal housing portion projecting upward from a part of a circumferential direction of the bobbin main body. The terminal housing portion is exposed to the exterior of a cap. A terminal is inserted into the terminal housing portion and electrically connected to the coil. A gap is provided between the core and a housing portion inner surface serving as a core side surface of the terminal housing portion. Resin used to form the connector mold penetrates the gap.

Abstract: A fuel injection valve includes: a holder which accommodates a valve body, has a surface magnetically facing the outer periphery of an armature, and is joined to a core; a housing which is press-fitted onto the outer periphery of the holder and accommodates a coil; and a cap which covers the fuel upstream side of the coil in a lid shape and is press-fitted onto the outer periphery of the core. The lower surface of the cap is brought into contact with the upper end surface of the housing in a radially slidable state and then an outer peripheral portion of a contact surface between the cap and the housing is joined by laser welding.

Abstract: In a fuel injection valve, a bobbin includes a bobbin main body serving as a part around which a coil is wound, and a terminal housing portion projecting upward from a part of a circumferential direction of the bobbin main body. The terminal housing portion is exposed to the exterior of a cap. A terminal is inserted into the terminal housing portion and electrically connected to the coil. A gap is provided between the core and a housing portion inner surface serving as a core side surface of the terminal housing portion. Resin used to form the connector mold penetrates the gap.

Abstract: A holder of a fuel injection valve is press-inserted to a housing of the fuel injection valve so as to be fixed to the housing, a cap of the fuel injection valve includes a notch portion for notching an annular portion, and is arranged in such a way that an inner circumference surface of the cap is faced to an outer circumference surface of a core of the fuel injection valve via a gap, and an electrode terminal of the fuel injection valve is connected to a terminal of a solenoid of the fuel injection valve via the notch portion of the cap.

Abstract: A method of generating a spray by a fluid injection valve is provided. The fluid injection valve includes a valve seat (10), a valve body (8), and an orifice plate (11) having a plurality of orifices (12). The flows in the orifices and the flows directly below the orifices are configured to be substantially liquid film flows. The directions of jet flows (30), (31) from the respective orifices (12) are not necessarily matched to the central axis directions of the orifices and are not necessarily intersected with each other at a downstream position thereof. The sprays are caused to converge by the Coanda effect acting on a plurality of sprays after jet flows from the orifices (12) become sprays at a downstream position farther than a break-up length (a). The convergence of the sprays is continued until the Coanda effect is substantially lost.

Abstract: A method of generating a spray by a fluid injection valve is provided. The fluid injection valve includes a valve seat (10), a valve body (8), and an orifice plate (11) having a plurality of orifices (12). The flows in the orifices and the flows directly below the orifices are configured to be substantially liquid film flows. The directions of jet flows (30), (31) from the respective orifices (12) are not necessarily matched to the central axis directions of the orifices and are not necessarily intersected with each other at a downstream position thereof. The sprays are caused to converge by the Coanda effect acting on a plurality of sprays after jet flows from the orifices (12) become sprays at a downstream position farther than a break-up length (a). The convergence of the sprays is continued until the Coanda effect is substantially lost.

Abstract: A valve seat 14 having an injection hole 14b is fixed at one end of a hollow valve main body 15, a valve body 12 slidably supported so as to be separated from and brought into contact with the valve seat 14 to open and close the injection hole 14b and a swirler 16 for surrounding the valve body 12 to slidably support the valve body 12 and for imparting a swirling motion to fuel flowing into the injection hole 14b are equipped, a swirling groove 16b in the swirler 16 includes a curvature part 16b3 in a groove outlet, and a sectional configuration of the swirling groove 16b is constituted so that the depth of the central part is larger than the depth of the end part.

Abstract: In a fuel injection valve for slanted fuel injection, provided between a conical flow path and an injection port is an intermediate flow path having a cylindrical surface coaxial to the conical flow path, so that the injection port has a portion of the cylindrical surface connected to the conical surface of the conical flow path and another portion of the cylindrical surface connected to the cylindrical surface of the intermediate flow path, whereby generation of stagnation of flow of fuel is suppressed to decrease the formation of the carbon deposit. The intermediate flow path has a tapered conical surface that is connected to a downstream side end portion of said cylindrical surface and that includes a diameter gradually decreases in the direction of flow of fuel to cope with where the injection port diameter is small. A cone apex angle of the conical surface of the intermediate flow path is smaller than a cone apex angle of the valve seat surface.

Abstract: In a fuel injection valve for slanted fuel injection, provided between a conical flow path and an injection port is an intermediate flow path having a cylindrical surface coaxial to the conical flow path, so that the injection port has a portion of the cylindrical surface connected to the conical surface of the conical flow path and another portion of the cylindrical surface connected to the cylindrical surface of the intermediate flow path, whereby generation of stagnation of flow of fuel is suppressed to decrease the formation of the carbon deposit. The intermediate flow path has a tapered conical surface that is connected to a downstream side end portion of said cylindrical surface and that includes a diameter gradually decreases in the direction of flow of fuel to cope with where the injection port diameter is small. A cone apex angle of the conical surface of the intermediate flow path is smaller than a cone apex angle of the valve seat surface.

Abstract: A moving iron core that reciprocates in axial direction in response to a fuel injection signal is provided with a radial recess of a predetermined width and a predetermined depth on the outer circumference at a position facing a magnetic characteristic change portion produced in a yoke due to heat generated when a sleeve and the yoke are welded together. As a result, it is possible to suppress the variation in injection quantity characteristic of the products caused by the magnetic characteristic change portion of the yoke due to the heat generated at the time of welding the sleeve and the yoke together.

Abstract: A valve seat 14 having an injection hole 14b is fixed at one end of a hollow valve main body 15, a valve body 12 slidably supported so as to be separated from and brought into contact with the valve seat 14 to open and close the injection hole 14b and a swirler 16 for surrounding the valve body 12 to slidably support the valve body 12 and for imparting a swirling motion to fuel flowing into the injection hole 14b are equipped, a swirling groove 16b in the swirler 16 includes a curvature part 16b3 in a groove outlet, and a sectional configuration of the swirling groove 16b is constituted so that the depth of the central part is larger than the depth of the end part.

Abstract: A moving iron core that reciprocates in axial direction in response to a fuel injection signal is provided with a radial recess of a predetermined width and a predetermined depth on the outer circumference at a position facing a magnetic characteristic change portion produced in a yoke due to heat generated when a sleeve and the yoke are welded together. As a result, it is possible to suppress the variation in injection quantity characteristic of the products caused by the magnetic characteristic change portion of the yoke due to the heat generated at the time of welding the sleeve and the yoke together.

Abstract: A fuel injection valve of low collision noise includes a housing (3), a core (4) secured internally of the housing (3), an electromagnetic coil (5) disposed externally around the core (4), a valve body (13) secured to the housing (3), a rod-like valve element (9) disposed reciprocatively movably within the valve body (13), an armature (10) secured to the valve element (9) at one end and attracted to the core (4) upon energization of the electromagnetic coil (5), and a valve seat (11) disposed at one end of the valve body (13) and having a seat portion (11a) and a fuel injection port (11b). A variable gap (A) is formed between an end face of the armature (10) and that of the valve body (13) such that flow path area of the gap (A) diminishes as the valve element (9) moves toward the valve seat (11).

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: To generate the effective damping relative to the change of fuel pressure when a needle valve is closed and to decrease the generation of after-dripping right after injection (spray), a rubber ring is provided between a core and a sleeve adapted to seal the fuel.

Abstract: A fuel injection valve for reducing carbon deposit on a passage portion between a seat portion and an injection port. The fuel injection valve includes an injection port 13 for injecting a fuel that is arranged to face a combustion chamber of an internal combustion engine. A seat portion H, where a valve element 8 comes in contact with a face of a valve seat 11 to intermit fuel injection, is arranged at a place upstream the injection port 13. The valve element 8 is conical at a portion downstream the seat portion H to an inlet of the injection port 13. The sectional area of the passage between the valve element 8 and the face of the valve seat 11 at the time of fully opening the valve element 8 is arranged so that the sectional area of the passage downstream of the vicinity of the seat portion H is larger. A tapered face 17 having a bore not more than 1/2.5 of an inner diameter of a swirl chamber 16 of a swirler 10 is formed on the face of the valve seat 11 which is downstream the seat portion H.

Abstract: There is provided a fuel injection valve in which an operation sound at the time of an operation of the fuel injection valve is lowered, and durability of parts is improved. A flat surface 4a of a valve body 4 is provided at a lower surface side of a shoulder portion 3a provided at a needle valve 3, and when the needle valve 3 moves in a valve closing direction, a portion B in which fuel is confined is compressed at a place between a lower surface of the shoulder portion 3a and the flat surface 4a, so that a damping effect of fluid is obtained and an operation sound is lowered.

Abstract: A fuel injection control system of low cost for a cylinder injection type internal combustion engine, which system is capable of preventing degradation of fuel injection quantity accuracy which may be brought about by disturbances such as change of a battery voltage, change of resistance of a plunger coil of the fuel injection valve (1) and change of the fuel pressure (Fp) acting on the fuel injection valve (1) which may occur in the course of overexcitation driving of the fuel injection valve (1) at a battery voltage, to thereby allow the fuel injection quantity control to be secured for the fuel injection valve (1) over an extended range.