Fuel injection device

Patent metadata

Field	Value
Publication number	US-11067045-B2
Application number	US-201213415960-A
Country	US
Kind code	B2
Filing date	Mar 9, 2012
Priority date	Mar 10, 2011
Publication date	Jul 20, 2021
Grant date	Jul 20, 2021

Abstract

In a fuel injection device, a driving unit structure has a magnetic aperture, in which an inner diameter is gradually enlarged toward the mover side, provided in an inner peripheral surface of the magnetic core. It is possible to reduce magnetic delay time upon valve opening from the supply of the electric current to the coil to the rise of magnetic flux and magnetic delay time upon valve closing from the stoppage of the electric current to the coil to reduction of magnetic flux, by providing a magnetic aperture in the inner peripheral surface of the magnetic core. Thus it is possible to improve the dynamic responsiveness upon valve opening and valve closing.

First claim

The invention claimed is:

1. A fuel injection device comprising:
a valve body;
a mover that performs valve opening and closing operations in collaboration with the valve body, the mover including a first inner diameter enlarged part;
a magnetic core that is excited by energization of a coil and that generates a magnetic force to drive the mover, the first inner diameter enlarged part forming an opening tapering so as to be enlarged in a direction away from the magnetic core; and
a nozzle holder that is a cylindrical member arranged on an outer peripheral side of the magnetic core and the mover so as to surround the mover and at least a part of the magnetic core adjacent to the mover,
wherein the magnetic core has a hole that opens at an end surface opposite to the mover and formed in a direction along an axis of the valve body,
wherein the mover has a slide extension member extending in the axial direction and terminating at a position located intermediate top and bottom surfaces of the mover, the slide extension member projecting within the first inner diameter enlarged part and away from the magnetic core, and
wherein the mover has a fuel passage defined by the first inner diameter enlarged part and the slide extension member.

2. The fuel injection device according to claim 1 ,
wherein the hole forms a second inner diameter enlarged part that is gradually enlarged by being tapered, and
wherein the tapered second inner diameter enlarged part includes sections having different tapers.

3. The fuel injection device according to claim 1 ,
wherein the second inner diameter enlarged part is gradually enlarged by being stepped, and
wherein the stepped second inner diameter enlarged part includes multiple steps.

4. The fuel injection device according to claim 1 ,
wherein the first inner diameter enlarged part defines an outer radial boundary of the fuel passage, and the slide extension member defines an inner radial boundary of the fuel passage.

5. The fuel injection device according to claim 4 , further comprising a spring acting on the mover, the spring located radially outward of the slide extension member and radially inward of the outer radial boundary of the fuel passage.

6. The fuel injection device according to claim 4 , wherein the slide extension member has an outer circumferential surface that faces a tapered inner surface of the first inner diameter enlarged part.

7. The fuel injection device according to claim 5 , wherein the slide extension member has an outer circumferential surface that faces a tapered inner surface of the first inner diameter enlarged part.

Assignees

• Kusakabe Ryo
• Abe Motoyuki
• Ishikawa Tohru
• Maekawa Noriyuki
• Soma Masahiro
• Miyake Takao
• Namaizawa Yasuo
• Hitachi Automotive Systems Ltd

Inventors

• Kusakabe Ryo
• Abe Motoyuki
• Ishikawa Tohru
• Maekawa Noriyuki
• Soma Masahiro
• Miyake Takao
• Namaizawa Yasuo

Classifications

• F02M51/02

  specially for low-pressure fuel-injection ({F02M51/005 takes precedence;} pumpsper se F02M51/04; injectors per se F02M51/08) · CPC title

• F02M51/061 Primary

  using electromagnetic operating means · CPC title

• F02M61/16

  Details not provided for in, or of interest apart from, the apparatus of groups F02M61/02 - F02M61/14 · CPC title

• F02M51/0635

  having a plate-shaped or undulated armature not entering the winding (if entering the winding F02M51/0664) · CPC title

• F02M51/0685

  the armature and the valve being allowed to move relatively to each other or not being attached to each other · CPC title