Systems and methods for supplying gaseous fuel to an engine

Patent metadata

Field	Value
Publication number	US-9233679-B2
Application number	US-201414260947-A
Country	US
Kind code	B2
Filing date	Apr 24, 2014
Priority date	Apr 24, 2014
Publication date	Jan 12, 2016
Grant date	Jan 12, 2016

Abstract

Systems and methods for supplying gaseous fuel to an internal combustion engine are presented. In one example, a gaseous fuel pump is selectively activated to extend a vehicle's operating range. The methods and systems may be useful for operating an engine that includes directly injected gaseous fuel.

First claim

The invention claimed is:

1. An engine operating method, comprising:
directly injecting a gaseous fuel to an engine in response to a pressure of a gaseous fuel stored in a fuel tank exceeding a threshold pressure; and
activating a gaseous fuel pump only when the pressure of gaseous fuel stored in the fuel tank is less than or equal to the threshold level.

2. The method of claim 1 , where a direct injector is supplied fuel from the fuel tank without the gaseous fuel pump in response to the pressure of gaseous fuel stored in the fuel tank exceeding the threshold pressure.

3. The method of claim 2 , where the direct injector is supplied fuel from the gaseous fuel pump in response to the pressure of the gaseous fuel stored in the fuel tank being less than or equal to the threshold level.

4. The method of claim 3 , further comprising a three-way valve and adjusting a state of the three-way valve in response to the pressure of gaseous fuel stored in the fuel tank.

5. The method of claim 1 , further comprising regulating output of the gaseous fuel pump to a desired pressure.

6. The method of claim 1 , where the threshold pressure is varied with engine operating conditions.

7. An engine operating method, comprising:
directly injecting a gaseous fuel to an engine in response to a pressure of a gaseous fuel stored in a fuel tank exceeding a threshold pressure; and
activating a gaseous fuel pump, adjusting torque converter clutch locking, and adjusting a transmission gear shift schedule in response to the pressure of the gaseous fuel stored in the fuel tank being less than or equal to the threshold pressure.

8. The method of claim 7 , where adjusting the transmission gear shift schedule includes adjusting a vehicle speed at which a transmission shifts gears.

9. The method of claim 8 , where the vehicle speed at which the transmission shifts gears is decreased in response to activating the gaseous fuel pump.

10. The method of claim 7 , where adjusting torque converter clutch locking includes adjusting a vehicle speed at which the torque converter clutch locks.

11. The method of claim 10 , where the vehicle speed at which the torque converter locks is decreased in response to activating the gaseous fuel pump.

12. The method of claim 7 , further comprising adjusting an operating state of a three-way valve that is in fluidic communication with the gaseous fuel pump and the fuel tank.

13. The method of claim 7 , where the gaseous fuel pump supplies fuel to a direct injector.

14. The method of claim 13 , where the direct injector is supplied gaseous fuel via the fuel tank without the fuel passing through the gaseous fuel pump.

15. A vehicle system, comprising:
an engine;
a gaseous fuel tank;
a gaseous fuel pump in pneumatic communication with the gaseous fuel tank; and
a controller including non-transitory instructions for supplying gaseous fuel to the engine and activating the gaseous fuel pump only when a pressure in the gaseous fuel tank is less than a threshold pressure.

16. The vehicle system of claim 15 , further comprising non-transitory instructions for adjusting a torque converter lock-up schedule in response to the pressure in the gaseous fuel tank is less than the threshold pressure.

17. The vehicle system of claim 15 , further comprising a step ratio transmission, and non-transitory instructions for adjusting a transmission shifting schedule in response to the pressure in the gaseous fuel tank being less than the threshold pressure.

18. The vehicle system of claim 15 , further comprising an accumulator positioned downstream of the gaseous fuel pump.

19. The vehicle system of claim 18 , further comprising a pressure regulator positioned downstream of the accumulator.

20. The vehicle system of claim 15 , further comprising a direct gaseous fuel injector coupled to the engine.

Assignees

• Ford Global Tech Llc

Inventors

• Leone Thomas G

Classifications

• B60W10/06

  including control of combustion engines · CPC title

• F02D19/022

  to adjust the fuel pressure, temperature or composition · CPC title

• B60W10/02 Primary

  including control of driveline clutches · CPC title

• B60W10/10

  including control of change-speed gearings · CPC title

• F02M21/0275 Primary

  for in-cylinder direct injection, e.g. injector combined with spark plug · CPC title