Fuel injection nozzle

Patent metadata

Field	Value
Publication number	US-9556843-B2
Application number	US-201414153559-A
Country	US
Kind code	B2
Filing date	Jan 13, 2014
Priority date	Feb 5, 2013
Publication date	Jan 31, 2017
Grant date	Jan 31, 2017

Abstract

A fuel injection nozzle includes: a nozzle body having a plurality of injection holes; and a needle accommodated in the nozzle body to inject a DME fuel containing dimethyl ether as a main component. The nozzle body has a seat part to which the needle seated or from which the needle separated, and a tip end chamber arranged downstream of the seat part in a flow of the DME fuel to communicate with the plurality of injection holes. The DME fuel in the tip end chamber is heated with combustion heat in a combustion chamber of an internal combustion engine to have a supercritical state.

First claim

What is claimed is:

1. A fuel injection nozzle through which fuel is injected into a combustion chamber of an internal combustion engine, the fuel being a DME fuel containing dimethyl ether as a main component, the fuel injection nozzle comprising:
a nozzle body having a plurality of injection holes; and
a needle accommodated in the nozzle body to open or close the plurality of injection holes, wherein
the nozzle body has
a seat part to which the needle seated or from which the needle separated, and
a tip end chamber arranged downstream of the seat part in a flow of the DME fuel to communicate with the plurality of injection holes,

the DME fuel in the tip end chamber is heated with combustion heat in the combustion chamber to have a supercritical state,
at least one of the plurality of injection holes has a diameter which is smaller than a diameter of the other of the plurality of injection holes, the other of the plurality of injection holes being arranged around the at least one of the plurality of injection holes,
the at least one of the plurality of injection holes is arranged to pass through a tip end part of the nozzle body and to extend on an axis of the nozzle body,
fuel injected from the at least one of the plurality of injection holes is combusted in an area more adjacent to the tip end chamber than fuel injected from the other of the plurality of injection holes,
the at least one of the plurality of injection holes is located at a center of the nozzle body in a radial direction,
the other of the plurality of injection holes is arranged on an outer side of the one small hole in the radial direction at a fixed interval,
the diameter of the at least one of the plurality of injection holes is constant from an end adjacent to the tip end chamber to the other end.

2. The fuel injection nozzle according to claim 1 , further comprising:
a heat receiving portion projected from a tip end of the nozzle body toward the combustion chamber, wherein
the heat receiving portion receives the combustion heat of the combustion chamber and transmits the combustion heat to the tip end chamber.

3. The fuel injection nozzle according to claim 2 , further comprising:
the heat receiving portion is integrally formed with the nozzle body as one-piece element.

4. The fuel injection nozzle according to claim 2 , wherein
the heat receiving portion is formed separately from the nozzle body,
the heat receiving portion is made of a material having a thermal conductivity which is higher than that of the nozzle body, and
the heat receiving portion is assembled to the nozzle body such that a part of the heat receiving portion is exposed in the tip end chamber and that a part of the heat receiving portion is exposed in the combustion chamber.

5. The fuel injection nozzle according to claim 1 , wherein the plurality of injection holes have a Laval nozzle shape.

6. The fuel injection nozzle according to claim 1 , wherein the other of the plurality of injection holes has a Laval nozzle shape.

Assignees

• Denso Corp

Inventors

• Kato Masaaki

Classifications

• F02M21/0248

  Injectors · CPC title

• F02M61/1833

  Discharge orifices having changing cross sections, e.g. being divergent · CPC title

• Y02T10/32

  Cross-Sectional Technologies · mapped topic

• F02M61/1806 Primary

  characterised by the arrangement of discharge orifices, e.g. orientation or size · CPC title

• F02M21/0212

  comprising at least 3 C-Atoms, e.g. liquefied petroleum gas [LPG], propane or butane · CPC title