Fuel injection valve

Patent metadata

Field	Value
Publication number	US-9605634-B2
Application number	US-201314018871-A
Country	US
Kind code	B2
Filing date	Sep 5, 2013
Priority date	Sep 26, 2012
Publication date	Mar 28, 2017
Grant date	Mar 28, 2017

Abstract

A needle has a large-diameter portion, an outer diameter of which is larger than that of a shaft portion of the needle. A needle-side tapered surface is formed at the large-diameter portion on a valve closing side thereof, wherein the needle-side tapered surface is inclined by a needle angle with respect to a center axis of the needle. A core-side tapered surface is formed at a movable core, wherein the core-side tapered surface is inclined by a core angle with respect to the center axis of the needle. The needle and the movable core are brought into contact with each other via the needle-side and the core-side tapered surfaces. The needle angle and the core angle are made to be equal to each other.

First claim

What is claimed is:

1. A fuel injection valve comprising:
a cylindrical housing having an injection port formed at one axial end of the housing for injecting fuel, a valve seat formed adjacent to the injection port, and a fuel passage for passing the fuel to the injection port;
a needle movably accommodated in the housing so as to reciprocate in an axial direction thereof, the needle having a shaft portion of a cylindrical rod shape, the needle having a sealing portion at one axial end of the shaft portion on a side to the valve seat, the needle having a large-diameter portion at the other axial end of the shaft portion on an opposite side to the valve seat, the large-diameter portion being integrally formed with the needle so that the large-diameter portion and the needle are movable as one unit, the large-diameter portion having an outer diameter larger than that of the shaft portion, the needle having a needle-side tapered surface inclined by a needle angle with respect to a center axis of the needle, the needle-side tapered surface being formed at an axial-side surface of the large-diameter portion on a side of a valve closing direction, the injection port being opened or closed when the sealing portion is separated from or seated on the valve seat;
a solenoid coil for generating a magnetic field when electric power is supplied thereto;
a fixed core fixed to an inside of the housing and arranged in a magnetic circuit generated by the solenoid coil;
a movable core formed as a separate part from the needle and movably accommodated in the housing on a side of the fixed core to the valve seat, the movable core having a core-side tapered surface inclined by a core angle with respect to the center axis of the needle, the core-side tapered surface being brought into contact with the needle-side tapered surface, and the movable core reciprocating in the axial direction of the housing together with the needle;
a first biasing member for biasing the needle in a valve closing direction; and
a second biasing member for biasing the movable core in a valve opening direction,
wherein the needle angle and the core angle are identical to each other, so that the needle side tapered surface and the core side tapered surface are in face to face contact with each other, and
wherein the center axis of the needle is in the axial direction, such that the center axis of the needle is a center axis of the cylindrical rod shape of the shaft portion in the axial direction.

2. The fuel injection valve according to claim 1 , wherein
the needle angle is equal to or larger than 45°.

3. The fuel injection valve according to claim 1 , wherein
the needle angle is equal to or smaller than 85°.

4. The fuel injection valve according to claim 1 , wherein
the movable core has a through-hole, through which the needle is movably inserted, and
a recessed portion is formed at an outer wall of the shaft portion of the needle and/or an inner wall of the movable core, to form a damping chamber into which the fuel flows from the fuel passage or from which the fuel flows out to the fuel passage.

5. The fuel injection valve according to claim 1 , wherein
a contacting surface area of the needle-side tapered surface is smaller than the surface area of the core-side tapered surface.

6. The fuel injection valve according to claim 5 , wherein
an inner-peripheral surface portion of the needle-side tapered surface and an outer-peripheral surface portion of the needle-side tapered surface are brought into contact with the core-side tapered surface at the same time, when the needle is in contact with the movable core.

7. The fuel injection valve according to claim 1 , wherein
the large-diameter portion is made as an independent part from the shaft portion of the needle and fixed to the shaft portion so that the large-diameter portion is movable together with the needle as one unit.

Assignees

• Denso Corp
• Kamada Akira
• Murase Eiji
• Komori Keisuke
• Toyota Motor Co Ltd

Inventors

• Yoshimaru Kiyotaka
• Mimura Eiji
• Okamoto Atsuya
• Kamada Akira
• Murase Eiji
• Komori Keisuke

Classifications

• F02M51/066 Primary

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

• F02M51/061

  using electromagnetic operating means · CPC title

• F02M51/0614 Primary

  characterised by arrangement of electromagnets or fixed armature · CPC title