Ignition Energy Control for Mixed Fuel Engine

• US 20090114188A1
• Filed: 11/07/2007
• Published: 05/07/2009
• Est. Priority Date: 11/07/2007
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Peters, Mark William, Devries, Jason Eugene, Roth, John M., Hedges, John
• Granted Patent: US 8,584,650 B2
• Time in Patent Office: Days
• US Class Current: 123/406.190
• CPC Class Codes: F02D 2200/503 Battery correction, i.e. corrections as a function of the state of the battery, its output or its type
• CPC Class Codes: F02D 35/025 by determining temperatures inside the cylinder, e.g. combustion temperatures
• CPC Class Codes: F02D 37/02 one of the functions being ignition
• CPC Class Codes: F02D 41/0025 Controlling engines characterised by use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures
• CPC Class Codes: F02D 41/064 at cold start F02D41/067 takes precedence
• CPC Class Codes: F02P 15/08 having multiple-spark ignition, i.e. ignition occurring simultaneously at different places in one engine cylinder or in two or more separate engine cylinders
• CPC Class Codes: F02P 3/00 Other installations
• CPC Class Codes: F02P 5/045 combined with electronic control of other engine functions, e.g. fuel injection in general F02D37/02
• CPC Class Codes: F02P 9/002 Control of spark intensity, intensifying, lengthening, suppression by means of current control in the storage devices F02P3/05, F02P3/09, during starting F02P15/12

Abstract

As one example, an engine system for a vehicle is provided, including an internal combustion engine having at least one cylinder; a fuel system configured to provide a fuel to the cylinder; an ignition system including at least a spark plug; a control system configured to vary a level of ignition energy provided to the cylinder via the spark plug in response to a composition of the fuel provided to the cylinder by the fuel system. A method of operating the engine system by varying a level of ignition energy provided to the engine after a start-up is also provided.

Claims

1. A method of operating an engine system after a start-up of the engine, the method comprising:

during each of a first number of cycles of the engine after a start-up of the engine, delivering a fuel including a mixture of at least gasoline and alcohol to the engine and providing a first level of ignition energy to the engine to ignite the fuel;

during each of a second number of cycles of the engine after the first number of cycles, delivering the fuel to the engine and providing a second level of ignition energy to the engine to ignite the fuel;

where the first level of ignition energy is greater than the second level of ignition energy.

2. The method of claim 1 further comprising, adjusting the first level of ignition energy in response to a concentration of alcohol in the fuel delivered to the engine during the first number of cycles, where the alcohol includes ethanol.

3. The method of claim 2, wherein the first level of ignition energy is adjusted to be higher when the fuel includes a higher concentration of ethanol and the first level of ignition energy is adjusted to be lower when the fuel includes a lower concentration of ethanol.

4. The method of claim 1 further comprising, adjusting the first level of ignition energy in response to a state of charge of a battery provided on-board the vehicle.

5. The method of claim 1, wherein the amount of fuel delivered to the engine during the first number of cycles is greater than the amount of fuel delivered to the engine during the second number of cycles.

6. The method of claim 1, wherein a quantity of the first number of cycles is adjusted in response to a composition of the fuel.

7. The method of claim 1, wherein the quantity of the first number of cycles is adjusted in response to a temperature of the engine at the start-up.

8. An engine system for a vehicle, comprising:

an internal combustion engine having at least one cylinder;

a fuel system configured to provide a fuel to the cylinder;

an ignition system including at least an ignition source;

a control system configured to vary a level of ignition energy provided to the cylinder via the ignition source in response to a composition of the fuel provided to the cylinder by the fuel system.

9. The system of claim 8, further comprising a fuel sensor configured to provide an indication of fuel composition to the control system and wherein the indication of fuel composition provided to the control system by the fuel sensor includes an indication of ethanol concentration.

10. The system of claim 8, wherein the engine system further includes a battery electrically coupled with the ignition system and wherein the control system is further configured to vary the level of ignition energy provided to the cylinder via the ignition source in response to a state of charge of the battery, the control system varying the level of ignition energy responsive to a biofuel composition amount.

11. The system of claim 8, wherein the control system is configured to increase the level of ignition energy provided to the cylinder via the ignition source in response to the concentration of ethanol in the fuel.

12. The system of claim 8, wherein the control system is further configured to vary the level of ignition energy provided to the cylinder via the ignition source in response to a temperature of the internal combustion engine.

13. The system of claim 12, wherein the control system is configured to reduce the level of ignition energy in response to an increase in the temperature of the internal combustion engine.

14. The system of claim 8, wherein the control system is further configured to reduce the level of ignition energy provided to the cylinder via the ignition source as time after a start of the engine increases.

15. The system of claim 8, wherein the control system is configured to adjust the level of ignition energy by adjusting a duration of an ignition spark performed by the ignition source.

16. The system of claim 8, wherein the control system is configured to adjust the level of ignition energy by adjusting a quantity of ignition spark events performed by the ignition source during a cycle of the cylinder.

17. The system of claim 8, wherein the control system is configured to adjust the level of ignition energy by adjusting a magnitude of electrical power of an ignition spark performed by the ignition source.

18. A method of operating an internal combustion engine for a vehicle including at least one cylinder, a fuel system configured to provide fuel to the cylinder and an ignition system configured to provide an ignition spark to the cylinder, the method comprising:

providing a fuel including at least gasoline and ethanol to the cylinder via the fuel system;

providing ignition energy to the cylinder via the ignition system to ignite the fuel; and

adjusting a level of the ignition energy provided to the cylinder in response to a temperature of the engine and a number of combustion events from a start-up of the engine.

19. The method of claim 18 further comprising further varying the level of ignition energy provided to the cylinder in response to a learned concentration of ethanol from previous engine operation, and wherein a higher level of ignition energy is provided to the cylinder when the concentration of ethanol is higher and wherein a lower level of ignition energy is provided to the cylinder when the concentration of ethanol is lower.

20. The method of claim 18, wherein a higher level of ignition energy is provided to the cylinder when the temperature of the engine is lower and wherein a lower level of ignition energy is provided to the cylinder when the engine temperature is higher.