Fuel injector for directly injecting fuel into a combustion chamber of an engine

Patent metadata

Field	Value
Publication number	US-9651010-B2
Application number	US-201214364073-A
Country	US
Kind code	B2
Filing date	Sep 6, 2012
Priority date	Dec 9, 2011
Publication date	May 16, 2017
Grant date	May 16, 2017

Abstract

Provided is a direct spray fuel injector including a bundle of opening/closing valves, wherein the bundle of opening/closing valves includes: a valve needle that is disposed within a valve housing; an electromagnetic coil that is installed at a side opposite to the spray hole of the valve needle; an armature that is coaxially mounted on an outer circumferential surface of the valve needle to be slidable in an axial direction; and a pressurizing spring that is installed to pressurize the valve needle toward the spray hole and causes the valve needle to close the spray hole in normal times, and the bundle of opening closing valves is configured to pressurize the valve needle by the armature so that bounce generated when the valve needle in an open state approaches the spray hole so as to close the spray hole is able to be attenuated.

First claim

What is claimed is:

1. A fuel injector for directly injecting fuel into a combustion chamber of an engine, comprising:
a valve needle that is disposed within a valve housing that constitutes an exterior of the fuel injector in a lengthwise direction and that opens and closes a spray hole opened to one side of the valve housing;
an electromagnetic coil that is installed at a side opposite to the spray hole and causes a spray hole opening/closing operation of the valve needle to be performed;
an armature that is coaxially mounted on an outer circumferential surface of the valve needle to be slidable along the outer circumferential surface of the valve needle in an axial direction so as to be positioned between the valve needle and the electromagnetic coil;
a pressurizing spring that is installed to pressurize the valve needle toward the spray hole and causes the valve needle to close the spray hole in normal times;
a stop ring that is fixed to an upper side of the valve needle and pressurized by the pressurizing spring; and
a stop sleeve that is fixed to a lower side of the valve needle;
wherein the armature is slidably movable along the valve needle between the stop ring and the stop sleeve;
wherein the armature is pressurized toward the stop sleeve by a buffer spring so that when the spray hole is closed by the valve needle, a buffer gap is formed between the armature and the stop ring, and the armature is in direct contact with the stop sleeve; and
wherein the buffer spring has a smaller elastic coefficient than the pressurizing spring and is configured to attenuate and suppress a bounce of the valve needle.

2. The fuel injector of claim 1 , wherein a spring seat is formed on the surface of the armature facing the stop ring, and the armature is pressurized toward the stop sleeve by the buffer spring mounted on the spring seat.

3. The fuel injector of claim 1 , wherein a plurality of attenuation holes pass through the stop sleeve on a support plate contacting the armature so that a shock generated when the armature contacts the support plate is able to be alleviated.

4. The fuel injector of claim 3 , wherein a plurality of attenuation holes each has a tapered nozzle shape in which each of diameters of the attenuation holes decreases as getting to an opposite side to the armature.

5. The direct spray fuel injector of claim 2 , wherein a plurality of attenuation holes pass through the stop sleeve on a support plate contacting the armature so that a shock generated when the armature contacts the support plate is able to be alleviated.

6. The fuel injector of claim 5 , wherein the plurality of attenuation holes each have a tapered nozzle shape in which each of diameters of the attenuation holes decreases as getting closer to an opposite side to the armature.

Assignees

• Kim Hyoung Jin
• Lee Kang Hun
• Hyundai Kefico Corp

Inventors

• Kim Hyoung Jin
• Lee Kang Hun

Classifications

• F02M51/061 Primary

  using electromagnetic operating means · CPC title

• F02M61/20

  Closing valves mechanically, e.g. arrangements of springs or weights {or permanent magnets; Damping of valve lift} · CPC title

• 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

• F02M2200/304

  using hydraulic means · CPC title

• F02M2200/306

  using mechanical means · CPC title