Fuel injection device

Patent metadata

Field	Value
Publication number	US-10677208-B2
Application number	US-201615568282-A
Country	US
Kind code	B2
Filing date	Apr 8, 2016
Priority date	Apr 21, 2015
Publication date	Jun 9, 2020
Grant date	Jun 9, 2020

Abstract

Provided is a fuel injector that is capable of reducing penetration. The fuel injector of the present invention includes a valve body having a valve body side seat surface, a valve seat side seat surface that abuts on the valve body side seat surface, and an injection hole that is provided downstream of a position at which the valve body side seat surface abuts on the valve seat side seat surface. The valve body has a projection that is formed from the valve body side seat surface toward the injection hole, and the projection is formed to be smaller in a direction of fuel flow between seats than a radius of an upstream opening surface of the injection hole.

First claim

The invention claimed is:

1. A fuel injector for injection of fuel, comprising:
a valve body having a valve body side seat surface;
a valve seat side seat surface that abuts on the valve body side seat surface; and
an injection hole provided downstream of a position at which the valve body side seat surface abuts on the valve seat side seat surface,
wherein:
a projection is formed on the valve body to project from the valve body side seat surface toward the injection hole,
a distance, in a direction of fuel flow between the valve body side seat surface and the valve seat side seat surface, between a first portion of the projection and a second portion of the projection at which the projection is closest to the injection hole, is smaller than a radius of an opening of the injection hole at an upstream surface of the injection hole,
the valve body is configured to be selectively lifted by one of at least two lift amounts comprising a first lift amount and a second lift amount, the first lift amount being smaller than the second lift amount, such that:
when the valve body opens by the first lift amount, of a plurality of tangent lines formed upstream of the second portion of the projection, a tangent line forming a smallest angle with an injection hole axis of the injection hole intersects with an upstream side of the opening of the injection hole,
when the valve body opens by the second lift amount, the tangent line forming the smallest angle with the injection hole axis of the injection hole intersects with a downstream side of the opening of the injection hole,
when the valve body is lifted by the first lift amount or the second lift amount, the projection is disposed outside of the injection hole, and

the projection has a same height across a region larger than a diameter of the opening of the injection hole.

2. The fuel injector according to claim 1 , wherein the first portion of the projection is located between the injection hole axis and an axis of the of the injection hole edge that is parallel to the injection hole axis.

3. The fuel injector according to claim 1 , wherein the projection is formed annularly on the valve body side seat surface.

4. The fuel injector according to claim 3 , wherein the annularly formed projection has a notch formed in a position not corresponding to the injection hole.

5. The fuel injector according to claim 1 , wherein the smallest angle formed between the tangent line and the injection hole axis is 0°<θ<90°.

6. The fuel injector according to claim 1 , wherein the first portion of the projection is an outer edge of the projection.

7. The fuel injector according to claim 6 , wherein the first portion of the projection is not disposed over the injection hole.

8. A fuel injector for injection of fuel, comprising:
a valve body having a valve body side seat surface;
a valve seat side seat surface that abuts on the valve body side seat surface; and
an injection hole provided downstream of a position at which the valve body side seat surface abuts on the valve seat side seat surface,
wherein a projection is formed on the valve body to project from the valve body side seat surface toward the injection hole,
the projection guides the fuel from upstream of an injection hole edge of the injection hole by a predetermined guide angle and changes a direction of fuel flow to cause the fuel to flow downstream of the injection hole edge,
in a valve open state, among a plurality of tangent lines formed upstream of a downstream end portion of the projection, a tangent line which forms a smallest angle with an injection hole axis of the injection hole intersects with an upstream side of an opening of the injection hole, wherein the injection hole axis of the injection hole is a central axis of the injection hole,
a first portion of the projection located at an outer edge of the projection is located upstream of an upstream end portion of the opening of the injection hole, and a second portion of the projection at which the projection is most projected is located between the upstream end portion of the opening of the injection hole and the central axis of the injection hole, and
the projection has a same height across a region larger than a diameter of the opening of the injection hole.

9. The fuel injector according to claim 8 ,
wherein the valve body is configured to be selectively lifted by one of at least two lift amounts including a first lift amount and a second lift amount, the first lift amount being smaller than the second lift amount.

10. The fuel injector according to claim 9 , wherein when the valve body opens by the second lift amount, the tangent line forming the smallest angle with the injection hole axis of the injection hole intersects with a downstream side of the opening of the injection hole.

Assignees

• Hitachi Automotive Systems Ltd

Inventors

• HOSAKA Tomoyuki
• Ishii Eiji
• Sukegawa Yoshihiro
• Sugii Taisuke
• Yoshimura Kazuki
• ORYOJI Kazuhiro
• Saruwatari Masayuki

Classifications

• F02M61/18

  Injection nozzles, e.g. having valve seats; {Details of valve member seated ends, not otherwise provided for} · CPC title

• F02M61/10 Primary

  Other injectors with elongated valve bodies, i.e. of needle-valve type · CPC title

• F02M61/1873

  Valve seats or member ends having circumferential grooves or ridges, e.g. toroidal · CPC title

• F02M2200/06

  Fuel-injection apparatus having means for preventing coking, e.g. of fuel injector discharge orifices or valve needles · CPC title

• F02M61/162

  Means to impart a whirling motion to fuel upstream or near discharging orifices · CPC title