Keihin Corporation

Koji Kitamura

Akira Arioka

Gaku Sato

Eishi Matsumoto

A fuel injection valve is provided that includes a valve seat member () having provided therein a conical valve seat () and a valve seat hole () communicating with the downstream end of the valve seat (), a flat fuel diffusion chamber () radially extending from the valve seat hole (), the fuel diffusion chamber () being formed between the valve seat member () and an injector plate (), and a plurality of fuel injection holes () bored in the injector plate () so as to open in the fuel diffusion chamber (), wherein the fuel injection holes () are arranged so as to be radially outwardly separated from the valve seat hole (), and when the height of the fuel diffusion chamber () is tand the length of the valve seat hole () is t, t/t&#x2267;2. It is thereby possible to atomize injected fuel effectively by logically setting the relationship between the length of the valve seat hole and the height of the fuel diffusion chamber, and the relative positional relationship between the valve seat hole and the fuel injection holes.

Fuel injection valve

In a fuel injection valve including a flat fuel diffusion chamber provided between a valve seat member and an injector plate to widen radially outwards from an outer end edge of a valve seat bore, an annular step is formed on a ceiling surface of the fuel diffusion chamber so that a level of the ceiling surface is gradually lowered radially outwards, and fuel injection orifices are disposed immediately below the step and at a distance from an inner peripheral wall of the fuel diffusion chamber. Thus, a fuel spread radially in the fuel diffusion chamber is allowed to collide with the annular step, leading to an enhancement in fuel diffusing effect, so that it is possible to further promote the atomization of the fuel injected from the fuel injection orifices and to form more stable fuel spray forms.

A fuel injection valve includes a valve seat member having a valve seat and a valve bore provided through a central portion of the valve seat, and an injector plate coupled to an outer end face of the valve seat member and having a plurality of fuel injection bores arranged in an annular shape surrounding an axis of the valve bore. A fuel diffusion chamber is defined between the valve seat member and the injector plate, and faced by the valve bore and all the fuel injection bores. The plurality of the fuel injection bores are formed in parallel to the axis of the valve bore, and the spreading angle of a fuel spray foam formed by the fuel injected from the fuel injection bores is determined depending on an axis distance between the valve bore and each of the fuel injection bores. Thus, it is possible to determine the spreading angle of the fuel spray foam as desired.

A fuel injection valve includes a valve seat member having a valve bore, and an injector plate coupled to an outer end face of the valve seat member. A fuel diffusion chamber is defined between the valve seat member and the injector plate. The injector plate is provided with a plurality of fuel injection bores which are parted on a plane including an axis of the valve bore into primary and secondary groups for injecting fuel toward primary and secondary intake ports. When a direction of arrangement of the primary and secondary intake ports is represented by X, and a direction perpendicular to the direction of arrangement is represented by Y, the fuel injection bores of the primary and secondary groups are formed so that they are inclined to a side opposite from the axis of the valve bore only in a direction X toward a downstream side.

Growing community of inventors

Miyagi, Japan

Koji Kitamura