Denso Corporation

Hiroki Kaneta

Masayuki Niwa

Noritsugu Kato

Noritsugu Katou

Yousuke Nakagawa

Sao Yoshidome

Hajime Kataoka

Masahiro Ookuma

Masahiro Okuma

Gen Takai

Yosuke Nakagawa

At least one of nozzle holes is provided as a non-circular nozzle hole where the ratio of the longest diameter to the shortest diameter of an outlet opening portion is greater than 1. A virtual non-circular cone and a virtual circular cone are defined for each of the non-circular nozzle hole and a circular nozzle hole where the ratio of the longest diameter to the shortest diameter of the outlet opening portion is 1. At least two adjacent nozzle holes are formed such that the virtual non-circular cone does not interfere with the virtual circular cone or the virtual non-circular cone.

Fuel injection valve

A nozzle body has an injection hole configured to inject fuel and a fuel passage connecting to the injection hole. A needle is configured to open and close the fuel passage to switch between fuel injection from the injection hole and stop of the fuel injection. An injection hole axis is an imaginary line extending along a center of the injection hole. An injection hole perpendicular cross section is a cross section of the injection hole perpendicular to the injection hole axis. The injection hole perpendicular cross section has a flat shape. The injection hole perpendicular cross section has an area that gradually expands from an inlet of the injection hole to an outlet of the injection hole while maintaining a similar shape.

A needle includes a first seal portion, which is formed at an end portion of the needle located on a side where an injection hole is placed, and a second seal portion, which is formed on a side of the first seal portion where a stationary core is placed. When a boundary between a first outer wall of the first seal portion and a second outer wall of the second seal portion is lifted away from or is seated against an inner wall, the injection hole is opened or closed. Thereby, a seat diameter of the boundary and the inner wall is stabilized, and a change in a fuel injection quantity caused by aging can be reduced. Furthermore, the first outer wall of the first seal portion is shaped into a form of a spherical surface.

In a fuel injector, a first injection holeand a second injection holehaving reference inside diameters Dn, Dndifferent from each other are formed as a plurality of injection holes. In such a configuration, an L/D value obtained by dividing the flow channel length Lnof the first injection holeby the reference inside diameter Dnof the first injection holeagrees to an L/D value obtained by dividing the flow channel length Lnof the second injection holeby the reference inside diameter Dnof the second injection hole

Fuel injector

In a fuel injection valve, a first injection hole and a second injection hole having reference inside diameters Dn, Dndifferent from each other are formed as a plurality of injection holes. In such a configuration, an L/D value obtained by dividing the flow channel length Lnof the first injection hole by the reference inside diameter Dnof the first injection hole agrees to an L/D value obtained by dividing the flow channel length Lnof the second injection hole by the reference inside diameter Dnof the second injection hole.

A fuel injector has a valve nozzle defining a fuel-injection port downstream of a fuel passage. The fuel-injection port is inclined toward a nozzle periphery from a fuel-inlet to a fuel-outlet. A valve needle is capable of moving in a valve-opening direction to open the fuel-injection port so that a fuel flowing into the fuel-inlet from the nozzle periphery is injected into an internal combustion engine. The fuel-injection port has an upstream-portion defining the fuel-inlet, and a downstream-portion defining the fuel-outlet. The downstream-portion is smoothly connected to the upstream-portion at a position most close to a center of the valve nozzle, and the downstream-portion is offset toward the nozzle periphery relative to the upstream-portion, so that the upstream-portion and the downstream-portion forms a step surface therebetween. The step surface is eccentric to a center line of the upstream-portion.

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Kariya, Japan

Hiroki Kaneta