Fuel injector

Patent metadata

Field	Value
Publication number	US-10480473-B2
Application number	US-201715841036-A
Country	US
Kind code	B2
Filing date	Dec 13, 2017
Priority date	Dec 13, 2017
Publication date	Nov 19, 2019
Grant date	Nov 19, 2019

Abstract

A fuel injector and method are disclosed including an injector body with a fuel sac, and an end positioned into a combustion chamber. A main fuel passage, having a varying cross-sectional area forming a reduced pressure region, fluidically couples the fuel sac to the combustion chamber. One or more additional passages fluidically couple the reduced pressure region with one or both of the fuel sac and the combustion chamber.

First claim

The invention claimed is:

1. A fuel injector comprising:
an injector body;
an end of the injector body configured to be positioned into a combustion chamber;
a fuel sac defined within the injector body;
a main fuel passage to fluidically couple the fuel sac to the combustion chamber, and having a varying cross-sectional area to form a reduced pressure region;
a dome shaped wall disposed over an outlet of the main fuel passage having two or more apertures to allow fuel to pass from the main fuel passage into the combustion chamber; and
an additional passage fluidically coupling the reduced pressure region with one of the fuel sac and the combustion chamber.

2. The fuel injector of claim 1 , wherein the additional passage is a first additional passage, and further comprising a second additional passage wherein the first additional passage couples to the reduced pressure region with the fuel sac and the second additional passage couples to the reduced pressure region with the combustion chamber.

3. The fuel injector of claim 1 , wherein the additional passage terminates at the reduced pressure region in a direction substantially perpendicular to a direction of flow of the main fuel passage.

4. The fuel injector of claim 1 , wherein the main fuel passage is venturi shaped.

5. The fuel injector of claim 3 , wherein the main fuel passage has a venturi shape, and an inlet cone length from 0.8 to 1 mm, an inlet diameter from 1.5 to 2 mm, an outlet diameter from 1.5 to 2 mm, and a diameter at the reduced pressure region from 0.2 to 0.3 mm.

6. The fuel injector of claim 1 , further comprising multiple main fuel passages each with a corresponding additional fuel passage configured similarly and arranged evenly spaced circumferentially around the injector body.

7. The fuel injector of claim 1 , wherein the additional fuel passage is open to the combustion chamber at a location radially outside of a dome shaped wall.

8. A fuel injector comprising:
an injector body;
a fuel sac defined inside the injector body;
an injector needle disposed for movement within the injector body to pressurize fuel within the fuel sac;
one or more venturi shaped nozzle passages from the fuel sac to an outside end of the injector body including a throat region between a nozzle inlet and a nozzle outlet at the outside end;
a wall extending over the nozzle outlet, the wall having two or more spaced apart apertures to allow fuel to pass through the wall; and
one or more flow joining passages fluidically coupling the throat region to one or both of the fuel sac and a side of the nozzle outlet.

9. The fuel injector of claim 8 , wherein the one or more flow joining passages fluidically couples the throat region to the fuel sac and wherein fuel passing through the throat region forms a pressure at a first end of the one or more flow joining passages to force fuel to pass from the fuel sac into the throat region.

10. The fuel injector of claim 8 , wherein the outside end of the injector body is positionable into a combustion chamber of an internal combustion engine, and the one or more flow joining passages couples the throat region to a side of the nozzle outlet wherein passing fuel through the throat region creates a region of low pressure to the side of the nozzle outlet.

11. The fuel injector of claim 8 , wherein the outside end of the injector body is positionable into a combustion chamber of an internal combustion engine, and the one or more flow joining passages couples the throat region to the combustion chamber at a second end thereof wherein passing fuel through the throat region creates a region of low pressure to pull gas from the combustion chamber into the throat region.

12. The fuel injector of claim 8 , further comprising a bulbous wall extending from outside an annular edge of the nozzle outlet outwardly and over the nozzle outlet, the wall having two or more spaced apart apertures to allow fuel to pass through the wall and into a combustion chamber of an internal combustion engine, at least one of the flow joining passages extending from the throat region to a side of the wall radially outside of the annular edge.

13. The fuel injector of claim 8 , further comprising multiple venturi shaped nozzle passages evenly spaced and arranged circumferentially around a central axis of the injector body, each venturi shaped nozzle passage having at least one flow joining passage fluidically coupling respective multiple throat regions to one or both of the fuel sac and a combustion chamber of an internal combustion engine.

14. The fuel injector of claim 8 , wherein the one or more flow joining passage intersects with each throat region substantially perpendicularly.

15. A fuel injector comprising:
an internal cavity to receive fuel and to hold a quantity of fuel for pressurization;
an injection passage through which pressurized fuel is passable from the internal cavity into a combustion chamber, the injection passage having a constricted portion to form a low pressure region in the injection passage; and
a flow joining passage fluidically coupling the constricted portion with the internal cavity, wherein the flow joining passage is a first flow joining passage and further comprising a second flow joining passage, wherein the pressurized fuel flows through the injection passage as a main flow, and some fuel passes from the internal cavity through the first flow joining passage to join the main flow at the low pressure region, and some gas from the combustion chamber passes through the second flow joining passage to join the main flow at the low pressure region to mix with the main flow.

16. The fuel injector of claim 15 , wherein the injection passage is venturi shaped.

17. The fuel injector of claim 15 , wherein the flow joining passage intersects the constricted portion in a direction substantially perpendicular to a direction of flow of the pressurized fuel through the injection passage.

18. The fuel injector of claim 15 , wherein the second flow joining passage fluidically couples the constricted portion with the combustion chamber.

19. The fuel injector of claim 15 , wherein a first portion of the flow joining passage extends substantially perpendicular to the constricted portion and a second portion extends substantially perpendicular to the first portion.

Assignees

• Ford Global Tech Llc

Inventors

• Zhang Xiaogang
• Meinhart Mark
• Yi Jianwen James
• Papaioannou George

Classifications

• F02M69/045

  for injecting into the combustion chamber (F02M69/046 takes precedence) · CPC title

• F02M61/1833 Primary

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

• F02M61/1806

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

• F02M61/10

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

• F02M26/00

  Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems · CPC title