Fuel injection system and method for a combustion engine

Patent metadata

Field	Value
Publication number	US-9133808-B2
Application number	US-201313775735-A
Country	US
Kind code	B2
Filing date	Feb 25, 2013
Priority date	Feb 25, 2013
Publication date	Sep 15, 2015
Grant date	Sep 15, 2015

Abstract

Apparatus and methods for injecting gaseous fuel into a compression ignition engine are disclosed. A gaseous fuel injector includes a pintle valve and an intensifier. The pintle valve includes a pintle body defining a pintle bore therethrough, a first sealing surface disposed on a distal end of the pintle body, and a pintle disposed within the pintle bore. The pintle includes a shaft, a radially flared portion, and a second sealing surface disposed on a proximal face of the radially flared portion, such that the first sealing surface faces the second sealing surface. The intensifier includes an intensifier body defining a fuel pump chamber therein, the fuel pump chamber being fluidly coupled to a gaseous fuel supply and the pintle bore, a plunger having a distal end disposed in the fuel pump chamber, and an intensifier piston disposed on a proximal end of the plunger.

First claim

What is claimed is:

1. A gaseous fuel injector, comprising:
a pintle valve including:
a pintle body defining a pintle bore therethrough,
a first sealing surface disposed on a distal end of the pintle body, and
a pintle disposed within the pintle bore, the pintle including:
a shaft,
a radially flared portion disposed at a distal end of the pintle,
a second sealing surface disposed on a proximal face of the radially flared portion, such that the first sealing surface faces the second sealing surface, and
a pintle piston disposed at a proximal end of the pintle, the pintle piston having a proximal face in fluid communication with a gaseous fuel supply via a check valve, the proximal end of the pintle being opposite the distal end of the pintle;

an intensifier including:
an intensifier body defining a fuel pump chamber therein, the fuel pump chamber being fluidly coupled to a gaseous fuel supply and the pintle bore,
a plunger having a distal end disposed in the fuel pump chamber, and
an intensifier piston disposed on a proximal end of the plunger; and

an extension tube disposed on the distal end of the pintle body, an internal surface of the extension tube defining an extension tube cavity therein, the extension tube cavity being in selective fluid communication with the pintle bore depending upon a position of the pintle relative to the pintle body.

2. The gaseous fuel injector of claim 1 , further comprising:
a poppet valve fluidly coupled to a hydraulic fluid supply and the intensifier piston; and
a solenoid coupled to the poppet valve.

3. The gaseous fuel injector of claim 1 ,
wherein an end of the extension tube opposite the distal end of the pintle body defines an aperture therethrough.

4. The gaseous fuel injector of claim 3 , wherein an area of the aperture is smaller than a cross sectional area of the extension tube cavity transverse to a bulk flow direction through the extension tube cavity.

5. The gaseous fuel injector of claim 3 , wherein the extension tube includes a frustoconical tube, and an inner diameter of the frustoconical tube decreases in a flow direction away from the pintle valve.

6. The gaseous fuel injector of claim 1 , further comprising:
a first spring member disposed between the intensifier piston and the intensifier body, such that the first spring member biases the intensifier piston away from the fuel pump chamber.

7. The gaseous fuel injector of claim 6 , further comprising:
a second spring member disposed between the pintle and the pintle body, such that the second spring member biases the first sealing surface against the second sealing surface.

8. A combustion engine system, comprising:
an engine cylinder defining a cylinder bore therethrough; and
a gaseous fuel injector fluidly coupled to a gaseous fuel supply and the cylinder bore, the gaseous fuel injector including:
a pintle valve including a pintle body defining a pintle bore therethrough, a first sealing surface disposed on a distal end of the pintle body, and a pintle disposed within the pintle bore, the pintle including:
a shaft,
a radially flared portion disposed at a distal end of the pintle,
a second sealing surface disposed on a proximal face of the radially flared portion, such that the first sealing surface faces the second sealing surface, and
a pintle piston disposed at a proximal end of the pintle, the pintle piston having a proximal face in fluid communication with a gaseous fuel supply via a check valve, the proximal end of the pintle being opposite the distal end of the pintle;

an intensifier including:
an intensifier body defining a fuel pump chamber therein, the fuel pump chamber being fluidly coupled to a gaseous fuel supply and the pintle valve,
a plunger having a distal end disposed in the fuel pump chamber, and
an intensifier piston disposed on a proximal end of the plunger, the intensifier piston being fluidly coupled to a hydraulic fluid supply; and

an extension tube disposed on a distal end of the pintle body, an internal surface of the extension tube defining an extension tube cavity therein, the extension tube cavity being in selective fluid communication with the pintle bore depending upon a position of the pintle relative to the pintle body.

9. The combustion engine system of claim 8 , further comprising:
a poppet valve fluidly coupled to the hydraulic fluid supply and the intensifier piston; and a solenoid coupled to the poppet valve.

10. The combustion engine system of claim 8 , further comprising an extension tube fluidly coupled to an outlet of the gaseous fuel injector.

11. The combustion engine system of claim 10 , wherein the extension tube includes an elongated cylindrical tube.

12. The combustion engine system of claim 10 , wherein the extension tube includes a frustoconical tube, and an inner diameter of the frustoconical tube decreases in a flow direction away from the pintle valve.

13. The combustion engine system of claim 10 , wherein the extension tube defines at least one aperture therethrough.

14. The combustion engine system of claim 13 , wherein an axis of the at least one aperture is collinear with an axis of a side port defined by the engine cylinder.

15. The combustion engine system of claim 13 , wherein an axis of the at least one aperture is tangent to a circle disposed within the engine cylinder.

16. The combustion engine system of claim 8 , wherein the engine cylinder defines at least one side port through a wall of the engine cylinder, such that the at least one side port is in fluid communication with the cylinder bore,
the combustion engine system further comprises an inlet air jacket disposed around an outer surface of the engine cylinder that includes the at least one side port, the inlet air jacket and the outer surface of the engine cylinder defining an air plenum therebetween, the air plenum being in fluid communication with an air source and the at least one side port, and
wherein an outlet of the pintle valve is in fluid communication with the cylinder bore through the at least one side port.

17. The combustion engine system of claim 16 ,
wherein the extension tube includes an arcuate tube disposed within the air plenum.

18. The combustion engine system of claim 8 , further comprising a liquid fuel injector in fluid communication with the cylinder bore and a liquid fuel supply.

19. A method of injecting a gaseous fuel into a reciprocating combustion engine including a gaseous fuel injector having a plunger disposed in a fuel pump chamber, an intensifier piston coupled to the plunger, the intensifier piston being fluidly coupled to a hydraulic fluid supply, the fuel pump chamber being fluidly coupled to a gaseous fuel supply, and a pintle valve fluidly coupled to the fuel pump chamber, the method comprising:
admitting a gaseous fuel from the gaseous fuel supply into the fuel pump chamber via a check valve;
applying a hydraulic pressure from the hydraulic fluid supply to the intensifier piston;
translating the plunger within the fuel pump chamber, thereby compressing the gaseous fuel against a proximal face of a pintle piston disposed at an end of the pintle valve;
translating a pintle of the pintle valve away from the gaseous fuel injector in response to the compressing the gaseous fuel against the proximal face of the pintle piston disposed at the end of the pintle valve;
flowing the gaseous fuel from an outlet of the pintle valve through an extension tube disposed between the outlet of the pintle valve and a cylinder bore of th

Assignees

• Caterpillar Inc

Inventors

• Fiveland Scott
• Montgomery David
• Stockner Alan

Classifications

• F02M69/04 Primary

  Injectors peculiar thereto · CPC title

• F02M21/0269 Primary

  Outwardly opening valves, e.g. poppet valves · CPC title

• F02B25/04

  Engines having ports both in cylinder head and in cylinder wall near bottom of piston stroke · CPC title

• Y02T10/30

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

• F02M57/025

  hydraulic, e.g. with pressure amplification · CPC title