Abstract: A fuel injection valve assembly has a construction less expensive in production and applicable for automated assembling. A cylindrical stem portion of a movable core is movably arranged within a movable core guide bore with opposing the rear end thereof with a tip end of a cylindrical core portion of a stationary core and opposing a conical valve head portion to a valve seat. A movable core spring is arranged between the movable core and an inner collar which is arranged within a fuel passage of the housing in pre-loaded fashion. A valve head portion is seated on the valve seat and a gap corresponding to a fully open stroke of said movable core is defined between the rear end of the movable core and the tip end of the cylindrical core portion.

Abstract: Disclosed is an improvement of electromagnetic type fuel injection valve comprising: a cylindrical housing having a stationary core therein; an annular yoke positioned in the vicinity of the opening end of the housing; a coil positioned in the space defined by the housing, the stationary core and the yoke; a valve seat piece having a needle valve put therein, the valve seat piece being positioned ahead of the yoke, and comprising a valve seat and a fuel metering-and-injecting aperture consecutive to the valve seat to be opened and closed by the front end of the needle valve; and a movable plunger integrally connected to the rear end of the needle valve, opposing the end of the stationary core. The fuel injection valve is designed according to the present invention so that the flow rate at which the fuel is injected from the fuel injection valve when fully opened is 20 L/H with the fuel metering-and-injecting aperture having a maximum effective injection area of 0.3 mm.sup.2, and that the product of L.times.

Abstract: In a solenoid type fuel injection valve, outer and inner fuel spray guide devices are coaxially disposed downstream of a fuel injection hole, and a pintle is provided at a tip end of a needle valve and projects to extend through the fuel injection hole and opposed to an upper surface of the inner fuel spray guide device. Thus, fuel passing through the fuel injection hole to collide against a valve head of the pintle is sprayed into an intake port, while being atomized and spread into a cone-like shape. At this time, the fuel is blocked by a support arm which extends radially inwardly from a cap to support the inner fuel spray guide device, thereby causing a fuel spray pattern to be formed into a horse's hoof-like shape having fuel non-spray portions. By forming the fuel non-spray portions in correspondence to a rod portion of an intake valve and/or the like, the deposition of the fuel is prevented.

Abstract: A solenoid type fuel injection valve for injecting fuel into a plurality of intake ports including a pintle provided at a lower end of a needle valve to protrude into a fuel atomizing space formed at a lower portion of a fuel injection hole, so that the fuel is atomized by collision against the pintle after passing through the fuel injection hole, and the atomized fuel is introduced into a fuel distributing space having an inclined wall surface. A pair of fuel spray guides are supported at a lower end of a cap through support arms, and a fuel injection passage having a horseshoe-like cross-sectional shape is formed around an outer periphery of each of the fuel spray guides. A fuel spray colliding against the inclined wall surface is divided into two flows which are conducted into the pair of fuel injection passages and injected equally into a bifurcated intake port.

Abstract: A fuel injection valve comprising a main fuel injection valve body having an inlet opening for fuel and a port for discharge of fuel, a fixed core in the valve body, an electromagnetic coil in the valve body, a movable core attracted magnetically towards the fixed core by the coil and a valve member coupled to the movable core for opening and closing the fuel discharge port. A socket portion is on the valve body to define an end portion for supply of fuel to the inlet opening and the socket portion includes an end flange formed by plastic deformation of the socket portion to dispose the flange radially on the socket portion and provide a radial swarf-free surface on the flange capable of sealed engagement with a connection member having a fuel passage connectible with the fuel inlet. The plastic deformation is achieved by rotating a tool on the edge of the initially straight socket portion to bend an edge portion of the socket portion to form the end flange.

Abstract: A method for producing a smooth finish on the surfaces of a valve seat and a discharge port of a fuel injection valve having a main fuel injection valve body containing an electromagnetic coil, a fixed core, a movable core attracted magnetically towards the fixed core by the coil and a valve rod attached to the movable core and having a valve body for opening and closing a fuel discharge port in a valve seat-forming member attached to the valve body. The fuel discharge port is formed with a smooth surface finish by discharging a honing fluid against the surface. The honing fluid is also discharged against the surface of the valve seat to provide a smooth finish thereon and to provide a rounded corner at the juncture of the seat surface and the fluid discharge port.

Abstract: A fuel injection valve comprising a main fuel injection valve body containing an electromagnetic coil which is operative to displace a movable core having a valve rod attached to the core. The valve rod has an end with a valve body adapted to selectively engage a valve seat-forming member attached to the valve body. The valve seat-forming member has an interior including a guide bore for guiding opening and closing displacement movements of the valve rod. The guide bore has a uniform diameter throughout its entire length and is connected to a valve seat formed at the end of the guide bore in continuation thereof. A fuel discharge port is formed in continuation of the valve seat. The guide bore is straight and has a burnished surface and the valve seat also has a burnished surface for contact by the valve body. The guide bore is connected to the valve seat without any undercut and due to the burnishing, the guide bore and valve seat are connected without flashing.