Fuel injector with co-axial control valve members and fuel system using same

Patent metadata

Field	Value
Publication number	US-9228505-B2
Application number	US-201213563836-A
Country	US
Kind code	B2
Filing date	Aug 1, 2012
Priority date	Aug 1, 2012
Publication date	Jan 5, 2016
Grant date	Jan 5, 2016

Abstract

A dual fuel injector utilizes first and second control valves to open and close first and second nozzle outlet sets to inject a first fuel and a second fuel, respectively. The first and second control valves have concentric lines of action. The two fuels may differ in at least one of chemical identity, matter phase and pressure.

First claim

What is claimed is:

1. A fuel injector comprising:
an injector body defining a first fuel inlet, a second fuel inlet, a first nozzle outlet set, a second nozzle outlet set, a first drain passage, and a second drain passage, and defining therein a first control chamber and a second control chamber;
a first check valve member with a closing hydraulic surface exposed to fluid pressure in the first control chamber, and being movable between a closed position in contact with a first seat to fluidly block the first fuel inlet from the first nozzle outlet set, and an open position out of contact with the first seat to fluidly connect the first fuel inlet to the first nozzle outlet set;
a second check valve member with a closing hydraulic surface exposed to fluid pressure in the second control chamber, and being movable between a closed position in contact with a second seat to fluidly block the second fuel inlet from the second nozzle outlet set, and an open position out of contact with the second seat to fluidly connect the second fuel inlet to the second nozzle outlet set;
a first control valve member positioned in the injector body and being movable along a common centerline between a first position at which the first control chamber is fluidly blocked from the first drain passage, and a second position at which the first control chamber is fluidly connected to the first drain passage; and
a second control valve member positioned in the injector body and being movable along the common centerline between a first position at which the second control chamber is fluidly blocked from the second drain passage, and a second position at which the second control chamber is fluidly connected to the second drain passage,
an axis of the first control valve member being coaxial with an axis of the second control valve member.

2. The fuel injector of claim 1 wherein one of the first control valve member and the second control valve member is intersected by the common centerline, and
an other of the first control valve member and the second control valve member defines a bore therethrough that is concentric with the common centerline.

3. The fuel injector of claim 1 further comprising:
a first armature operably coupled to move the first control valve member;
a second armature operably coupled to move the second control valve member; and
a shared stator separating the first armature from the second armature.

4. The fuel injector of claim 1 wherein the first control valve member is in contact and out of contact with a first valve seat at the first position and the second position, respectively,
the second control valve member is in contact and out of contact with a second valve seat at the first position and the second position, respectively, and
one of the first valve seat and the second valve seat is a flat seat.

5. The fuel injector of claim 4 wherein an other of the first valve seat and the second valve seat is a conical seat.

6. The fuel injector of claim 1 wherein the second control valve member is trapped to move between a conical seat and a second flat seat, and
the first control valve member is trapped to move between a first flat seat and a stop.

7. The fuel injector of claim 1 wherein the first check valve member and the second check valve member move along a first line and a second line, respectively, that are each parallel to, but spaced apart from, the common centerline.

8. The fuel injector of claim 1 wherein the first control chamber is fluidly connected to one of the first fuel inlet and the second fuel inlet through two orifices that are fluidly in parallel when the first control valve member is in the first position, such that the two orifices share a common fluid inlet and a common fluid outlet when the first control valve member is in the first position.

9. The fuel injector of claim 1 wherein each of the first control chamber and the second control chamber is fluidly connected to one of the first fuel inlet and the second fuel inlet when the first control valve member and the second control valve member are in the respective first positions.

10. A fuel system comprising:
a plurality of fuel injectors, each fuel injector of the plurality of fuel injectors including
an injector body defining a first fuel inlet, a second fuel inlet, a first nozzle outlet set, a second nozzle outlet set, a first drain passage, and a second drain passage, and defining therein a first control chamber and a second control chamber;
a first check valve member with a closing hydraulic surface exposed to fluid pressure in the first control chamber, and being movable between a closed position in contact with a first seat to fluidly block the first fuel inlet from the first nozzle outlet set, and an open position out of contact with the first seat to fluidly connect the first fuel inlet to the first nozzle outlet set;
a second check valve member with a closing hydraulic surface exposed to fluid pressure in the second control chamber, and being movable between a closed position in contact with a second seat to fluidly block the second fuel inlet from the second nozzle outlet set, and an open position out of contact with the second seat to fluidly connect the second fuel inlet to the second nozzle outlet set;
a first control valve member positioned in the injector body and being movable along a common centerline between a first position at which the first control chamber is fluidly blocked from the first drain passage, and a second position at which the first control chamber is fluidly connected to the first drain passage;
a second control valve member positioned in the injector body and being movable along the common centerline between a first position at which the second control chamber is fluidly blocked from the second drain passage, and a second position at which the second control chamber is fluidly connected to the second drain passage;
a source of a first fuel fluidly connected to the first fuel inlet;
a source of a second fuel fluidly connected to the second fuel inlet; and
an electronic controller in control communication with each fuel injector of the plurality of fuel injectors,

the first fuel differing from the second fuel in at least one of chemical identity, matter phase, and pressure, and
an axis of the first control valve member being coaxial with an axis of the second control valve member.

11. The fuel system of claim 10 wherein the source of the first fuel includes a first common rail, and the source of the second fuel includes a second common rail.

12. The fuel system of claim 11 wherein the first fuel is natural gas,
the second fuel is liquid diesel fuel,
the first common rail is at a first pressure, and
the second common rail is at a second pressure that is greater than the first pressure.

13. The fuel system of claim 12 wherein the injector body of each fuel injector includes a common conical seat through which the first fuel inlet and the second fuel inlet open.

14. The fuel system of claim 13 wherein one of the first control valve member and the second control valve member is intersected by the common centerline, and
an other of the first control valve member and the second control valve member defines a bore therethrough that is concentric with the common centerline.

15. The fuel system of claim 14 wherein each fuel injector includes a first armature operably coupled to move the first control valve member, a second armature operably coupled to move the second control valve member, and a shared stator separating the first armature from the second armature,
wherein the first c

Assignees

• Mittal Mayank
• Brasche Adrienne M
• Caterpillar Inc

Inventors

• Mittal Mayank
• Brasche Adrienne M

Classifications

• F02D19/10

  peculiar to compression-ignition engines in which the main fuel is gaseous · CPC title

• F02D19/06 Primary

  peculiar to engines working with pluralities of fuels, e.g. alternatively with light and heavy fuel oil, other than engines indifferent to the fuel consumed · CPC title

• Y02T10/36

  Cross-Sectional Technologies · mapped topic

• Y02T10/30

  Use of alternative fuels, e.g. biofuels · CPC title