Abstract: A fuel injection valve includes, in part, a pipe, a fixed connector (fixed core), a movable core, a solenoid coil and a needle valve. In the fuel injection valve, a diameter of a fixed action surface of the fixed connector is made smaller than a movable action surface of the movable core. Therefore, magnetic flux around an outer circumferential portion is transmitted from the fixed action surface to the movable action surface substantially in a direction perpendicular to the movable action surface. Thus, an electromagnetic force acting therebetween is efficiently transformed to an attracting force for the movable core.

Abstract: A fuel injection valve includes, in part, a pipe, a fixed connector (fixed core), a movable core, a solenoid coil and a needle valve. In the fuel injection valve, a diameter of a fixed action surface of the fixed connector is made smaller than a movable action surface of the movable core. Therefore, magnetic flux around an outer circumferential portion is transmitted from the fixed action surface to the movable action surface substantially in a direction perpendicular to the movable action surface. Thus, an electromagnetic force acting therebetween is efficiently transformed to an attracting force for the movable core.

Abstract: A fuel injector for an internal combustion engine is provided which includes a valve body, a needle valve, and a hollow nozzle body with a bottom having formed therein spray holes.The needle valve is controlled to be selectively brought into and out of engagement with a valve seat in the valve body to close and open a fuel outlet formed in an end surface of the valve body. The hollow nozzle body is welded to the valve body with the bottom urged into constant engagement with the end surface of the valve body at a given level of pressure which is greater than a maximum fuel injection pressure. This makes it possible to establish the constant engagement of the bottom of the hollow nozzle body with the end surface of the valve body without any clearances even when the maximum fuel injection pressure acts on a portion of the bottom of the hollow nozzle body around the spray holes.

Abstract: An electromagnetic fuel injection valve prevents fuel bubbles from staying at a downstream side of the valve's stopper plate and helps to inject fuel smoothly. The electromagnetic injection valve includes a needle having a valve head opening and closing a valve seat, an electromagnetic coil portion for actuating the needle electromagnetically and a contact portion disposed at the downstream side of the stopper plate on the needle. The stopper plate includes a notch accommodating the needle therein and bubble discharge surfaces made outwardly from the notch to discharge bubbles produced at the downstream side of the contact portion toward the upstream side thereof and help the fuel flow smoothly.

Abstract: A fuel injector comprises, a fuel flow adjustment throttle for determining a flow rate of a fuel passing through the fuel injector, a first member having a cylindrical surface for defining partially the fuel flow adjustment throttle, and a second member including a first surface and a second surface both of which extend toward the first member and join each other at a pointed edge defining the fuel flow adjustment throttle together with the cylindrical surface of the first member, and at least one of which forms a space expanding gradually in a fuel flow direction.

Abstract: A metal elements-resin insert is produced by holding metal elements such as conductive bus bars 8 and the like in a forming cavity 5 of a mold assembly 3, 4 by a support pin 6 projecting in the mold assembly 3, 4. The metal elements 8 embedded in a resin material can overcome problems of corrosion and electrical short-circuit in which the metal elements contact with air or moisture entering through drawn holes 7 formed by support pin 6 into the resin material and can improve the moisture and air proof function.

Abstract: A valve element is slidably disposed in a guide bore in a valve casing, forming a fuel injection valve which is opened or closed by means of a valve seat of the valve casing and a contact portion of the valve element. When the valve element is in the valve open position, a first fuel adjusting passage is formed between the valve seat and the contact portion. A sliding contact portion is provided on the upstream side of the contact portion of the valve element, and a brim portion is provided on the further upstream side thereof. Flat portions are formed on the outer peripheral surface of the sliding contact portion, and adjusting surfaces are formed on the outer peripheral surface of the brim portion. Second fuel adjusting passages are formed between the fuel adjusting surfaces of the brim portion and the guide bore, and third fuel adjusting passages are formed between the flat portions of the sliding contact portion and the guide bore.

Abstract: A fuel injector to be mounted on a branch of an engine intake manifold has a hollow body with an injection orifice therein and a valve member mounted slidably in the body and having a pintle extending from one end of the valve member and slidably received in and extending through the injection orifice. A sleeve member is mounted on the body to cover the injection orifice and defines a pintle-receiving space into which the forward end of the pintle extends. Communication apertures are formed in the outer end of the sleeve member to communicate the pintle receiving space with an engine intake passage. The total of the cross-sectional areas of the communication apertures is smaller than the cross-sectional area of the pintle-receiving space.

Abstract: An electromagnetically-operated fuel injection valve has a magnetic circuit comprising a valve casing, a stator core on which an electromagnetic coil is wound, an armature core, and an air gap between the stator core and the armature core. At least one of the valve casing, the stator core and the armature core is so configuared that the magnetic flux passing therethrough is saturated substantially at the time the armature core is fully attracted to inject fuel. A magnetic restrictor at which the cross-sectional area for the magnetic flux is reduced than that at the other portion is provided at least at a portion of the valve casing, the stator core and the armature core so that the magnetic flux is saturated thereat substantially at the time the armature core is attracted fully.

Abstract: A fuel injection device comprising an injection unit having a back pressure chamber and a fuel chamber which are separated by a diaphragm. The fuel chamber has on its lower end a fuel nozzle. A needle, cooperating with the fuel nozzle, is connected to the diaphragm. A flow control valve is arranged in the fuel feed passage connecting the fuel chamber to the fuel feed pump. The amount of the fuel injected from the fuel nozzle is controlled by the flow control valve so as to be proportional to the amount of the air sucked in. One end of the back pressure chamber is connected, to the pressure reducing chamber of the pressure reducing valve via a restricted opening and, the other end is connected to the fuel tank via the fuel return passage. An electromagnetic valve is arranged in the fuel return passage. An oxygen concentration detector is arranged in the exhaust passage of an engine.

Abstract: A fuel injection device comprising a fuel pump, a constant pressure valve and a fuel nozzle connected to the fuel pump via a fuel feed passage. The constant pressure chamber of the constant pressure valve is arranged in the fuel feed passage. A flow control valve is arranged in the fuel feed passage between the constant pressure chamber and the fuel nozzle. The amount of the fuel injected from the fuel nozzle is controlled by the flow control valve so as to be directly proportional to the amount of the air sucked in. The constant pressure chamber is connected to the fuel nozzle via a bypass passage. An electromagnetic valve is arranged in the bypass passage and opened when an engine is accelerated and before the completion of the warm-up of an engine.