Aisan Kogyo Kabushiki Kaisha

Toyota Jidosha Kabushiki Kaisha

Toshiro Makimura

Hiroshi Kawazoe

Hideki Ito

Kaneo Imamura

Takaaki Takagi

Seiji Ii

Hitoshi Takeuchi

Shigetaka Takada

Kenji Kurita

Mamoru Matsubara

Tsuneaki Aoki

Takashi Okada

Motohiro Baba

It is, accordingly, an object of the present teachings to provide fuel injectors that can prevent leakage of noise, which is caused by contact of the valve with the valve seat, to the outside of the fuel injector. a representative injector may comprise a fuel passage, a valve, a valve seat, a jet opening and a jet opening downstream channel. The valve is disposed on the fuel passage and the valve seat receives the valve. The jet opening is formed in the valve seat and through which fuel is exhausted. The jet opening may be opened when the valve is moved apart from the valve seat. The jet opening downstream channel extends downstream from the jet opening through the valve seat and communicates the jet opening to the outside. The diameter of the jet opening downstream channel may be arranged and adapted such that the valve seat has a wall thickness to prevent leakage of noise to the outside through the valve seat. Because the diameter of the jet opening downstream channel is designed to be smaller and the wall thickness of the valve seat is designed to be greater, the representative injector can effectively prevent leakage of noise to the outside through the valve seat.

Fuel injectors

A fuel injection port formed in a seat is opened and closed by a movable valve supported by a flat spring . The movable valve is biased by an elastic force of a coil spring in a direction that closes the fuel injection port . When electric power is supplied to a solenoid coil , the movable valve is moved to a direction that opens the fuel injection port as a result of an electromagnetic attraction force between a magnetic circuit M for generating an electromagnetic attraction force and the movable valve . Air gaps G , G and G are formed within the fuel injection port and permeance ratios between the air gaps may be set to optimal valves.

Electromagnetic fuel injection valve

A fuel injection port formed in a seat is opened and closed by a movable valve supported by a flat spring The movable valve is biased by an elastic force of a coil spring in a direction that closes the fuel injection port When electric power is supplied to a solenoid coil the movable valve is moved to a direction that opens the fuel injection port as a result of an electromagnetic attraction force between a magnetic circuit M for generating an electromagnetic attraction force and the movable valve Air gaps G G and G are formed within the fuel injection port and permeance ratios between the air gaps may be set to optimal values.

A fuel injector of the type in which a valve hole is opened and closed by a valve so as to intermittently inject pressurized fuel from the valve hole includes a distributing adapter fixedly attached to a front end of the valve hole, and an air adapter fixedly attached to a front end of the distributing adapter. The air adapter is formed with a plurality of guide holes directed to a plurality of intake ports of the engine, respectively, and assist air passages each communicating laterally with a corresponding one of the guide holes. The distributing adapter is formed with distributing holes of the same number as the guide holes, each of the distributing holes extending between the valve hole and a corresponding one of the guide holes.

Multi-hole injector with improved atomization and distribution

A fuel injector including an injector casing having a fuel inlet at a side portion thereof; a valve housing having a fuel injection hole at a front end thereof and having a guide hole at an axial central portion thereof, the guide hole being communicated with the fuel inlet; a valve reciprocably accommodated in the guide hole, the valve being adjusted to close the fuel injection hole when advancing and open the fuel injection hole when retracting; a valve driving device for driving the valve to advance and retract the valve; and a fuel strainer mounted on an outer circumference of the injector casing, the strainer comprising a synthetic resin frame having annular portions at front and rear ends thereof and a metal ring connected to at least one of the front and rear end portions of the frame by insert molding of synthetic resin, the metal ring being press-fitted with the injector casing. With this construction, the generation of a gap due to the creep of resin between the injector casing and the strainer can be prevented to thereby prevent entry of a foreign matter into the injector.

Fuel injector with strainer

A fuel injector including a valve housing having a fuel injection hole formed at a front end of the valve housing; a valve movably provided int he valve housing so as to open and close the fuel injection hole; a nozzle fixedly mounted to a front end of the valve housing; and a fuel colliding member provided in the nozzle and positioned in alignment with the fuel injection hole in front thereof. A size of the fuel colliding member is smaller in cross section perpendicular to an axis of the fuel injector than that of the fuel injection hole. Accordingly, a radially inside part of a columnar fuel after collision with the fuel colliding member further collides with a radially outside part of the columnar fuel passing outside the fuel colliding member to accelerate atomization of the fuel without reducing a velocity of flow of the fuel.

Fuel injector

An electromagnetic fuel injector including an injector body, a valve housing mounted in a front portion of the injector body and having an injection hole at a front end thereof, a solenoid coil mounted in a rear portion of the injector body, a valve axially movably received in the valve housing, an armature fixed to a rear end portion of the valve, a spring for normally biasing the valve in a valve closing direction, and a nozzle mounted to the front end of the valve housing and having a plurality of atomizer holes communicated with the injection hole of the valve housing. The valve is reciprocated by a magnetic attraction force due to excitation of the solenoid coil and a reaction force of the spring to thereby intermittently inject fuel from the injection hole. An atomizer plate is provided between the nozzle and the injection hole. The atomizer plate has a fuel colliding portion against which the fuel injected from the injection hole collides.

Nozzle structure in electromagnetic fuel injector

An electromagnetic fuel injector comprising a fixed iron core, a solenoid formed by winding a coil around the fixed iron core, a coil holder fixed to the solenoid, an injector casing surrounding the solenoid and the coil holder and formed of a material having high magnetic permeability, a movable iron core inserted between the fixed iron core and the injector casing, a compression spring normally biasing the movable iron core toward an injection nozzle of the injector, a valve body connected at its base to the movable iron core and formed with a flange at a base portion thereof, a stopper adapted to abut against the flange of the valve body and restrict a movable range, a valve housing incorporated in a front portion of the injector casing and slidably supporting the valve body, the valve housing being formed at its front end portion with a valve seat adapted to abut against the valve body, and a radiation member closely fitted on an outer periphery of the injector casing. A connection member may be provided connecting a plurality of injectors mounted on cylinders in a multi-cylinder engine for radiating heat generated in the injectors.

Electromagnetic fuel injector

Disclosed herein is an electromagnetic fuel injector comprising a fuel outlet opening formed at the front portion of the slide member of the valve body, an annular fuel passage leading from the fuel outlet opening to the valve seat and an annular restricted portion provided at the annular fuel passage. The fuel injector of the invention may compensate decrease in the amount of fuel flow because of decrease in the specific weight of fuel and creation of fuel vapor at the fuel injection nozzle in association with increase in fuel temperature, and may supply an engine with fuel mixture having stable air-fuel ratio to purify exhaust gas during engine operation at high temperatures.

Growing community of inventors

Obu, Japan

Toshiro Makimura