Engine and engine control method

• US 7,464,681 B2
• Filed: 02/28/2006
• Issued: 12/16/2008
• Est. Priority Date: 02/28/2006
• Status: Active Grant

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Withrow, Michael Paul, Rockwell, Andrew Duncan
• Primary Examiner(s): Cronin; Stephen K.
• Assistant Examiner(s): Castro; Arnold
• Application Number:
  US11/362,813
• Publication Number:
  US 20070199534A1
• Time in Patent Office: 1,022 Days
• Field of Search: 123/179.16, 123/701, 123/104, 123/113
• US Class Current: 123/179.1
• CPC Class Codes: F02D 2200/0414 Air temperature
• CPC Class Codes: F02D 41/064 at cold start F02D41/067 takes precedence

Abstract

A method of operating an engine is provided. The engine may include a combustion chamber and a working member positioned adjacent the combustion chamber. The method may include providing a source of fuel for the engine. The method may also include starting the engine producing power by combusting fuel in the combustion chamber to drive the working member. Additionally, the method may include selectively controlling delivery of the fuel to the combustion chamber at least partially as a function of an air temperature in response to achieving at least one predetermined condition involving the air temperature. The air temperature may be at least one of an ambient air temperature and an intake air temperature.

Claims

1. A method of operating an engine, the engine having a combustion chamber, a working member positioned adjacent the combustion chamber, and engine controls, the method comprising:

providing a source of fuel for the engine;

starting the engine producing power by combusting fuel in the combustion chamber to drive the working member;

controlling fuel delivery to the combustion chamber with the engine controls, including selectively controlling delivery of the fuel to the combustion chamber at least partially as a function of an air temperature in response to achieving at least one predetermined condition involving the air temperature and, in at least some circumstances, changing with the engine controls the relative significance of the air temperature and an engine temperature as factors in controlling fuel delivery to the combustion chamber, wherein the air temperature is at least one of an ambient air temperature and an intake air temperature.

2. The method of claim 1, wherein the at least one predetermined condition involving the air temperature includes the air temperature being below a reference temperature.

3. The method of claim 2, wherein the at least one predetermined condition involving the air temperature includes existence of a predetermined relationship between an engine temperature and the air temperature.

4. The method of claim 2, wherein controlling the delivery of the fuel to the combustion chamber at least partially as a function of the air temperature includes controlling the delivery of the fuel to the combustion chamber in such a manner to compensate for cold conditions to promote successful combustion.

5. The method of claim 1, wherein the at least one predetermined condition involving the air temperature includes existence of a predetermined relationship between an engine temperature and the air temperature.

6. The method of claim 1, wherein the circumstances of changing with the engine controls the relative significance of the air temperature and an engine temperature as factors in controlling fuel delivery to the combustion chamber include changing with the engine controls the relative significance of the air temperature and an engine temperature as factors in controlling fuel delivery to the combustion chamber subsequent to starting the engine producing power.

7. The method of claim 6, wherein changing with the engine controls the relative significance of the air temperature and the engine temperature as factors in controlling the delivery of the fuel to the combustion chamber subsequent to starting the engine producing power includes increasing the relative significance of the engine temperature.

8. The method of claim 1, wherein:

the air temperature is the ambient air temperature; and

controlling the delivery of the fuel to the combustion chamber at least partially as a function of the air temperature is done only in response to achieving the at least one predetermined condition involving the air temperature, the at least one predetermined condition involving the air temperature including the air temperature being below a predetermined reference temperature and a predetermined relationship between the air temperature and an engine temperature.

9. An engine, comprising:

a combustion chamber;

a working member positioned adjacent the combustion chamber;

engine controls operable to cause the engine to produce power by combusting fuel in the combustion chamber to drive the working member;

the engine controls being operable to, when starting the engine and before the engine has reached an idle speed, in response to achieving at least one first predetermined condition involving an air temperature, execute a cold-start algorithm for controlling fuel delivery to the combustion chamber;

wherein the air temperature is at least one of an ambient air temperature and an intake air temperature; and

wherein executing the cold-start algorithm for controlling fuel delivery to the combustion chamber includes delivering fuel to the combustion chamber in a manner to compensate for cold conditions and promote successful combustion.

10. The engine of claim 9, wherein the at least one first predetermined condition includes the air temperature having a predetermined relationship to the engine temperature.

11. The engine of claim 9, wherein the engine controls are further configured to, when starting the engine, in response to achieving the at least one first predetermined condition, control fuel delivery to the combustion chamber at least partially as a function of the air temperature.

12. The engine of claim 9, wherein:

the engine is a compression ignition engine utilizing heat and pressure generated by the working member compressing air in the combustion chamber to initiate combustion of fuel in the combustion chamber; and

executing the cold-start algorithm for controlling fuel delivery to the combustion chamber includes controlling an initial timing and a time pattern of fuel delivery into the combustion chamber during each power cycle in a manner to compensate for cold conditions and promote successful combustion.

13. The engine of claim 9, wherein the engine controls are further operable to, when starting the engine, in response to achieving at least one second predetermined condition that includes an engine temperature being below a reference engine temperature, execute the cold-start algorithm for controlling fuel delivery to the combustion chamber.

14. An engine, comprising:

a combustion chamber;

a working member positioned adjacent the combustion chamber;

engine controls operable to cause the engine to produce power by combusting fuel with air in the combustion chamber to drive the working member;

the engine controls being further operable to

in at least some circumstances, control fuel delivery to the combustion chamber at least partially as a function of an air temperature, the air temperature being at least one of an ambient air temperature and an intake air temperature,

in at least some circumstances, control fuel delivery to the combustion chamber at least partially as a function of an engine temperature, and

while causing the engine to produce power, change the relative significance of the air temperature and the engine temperature as factors in controlling fuel delivery to the combustion chamber.

15. The engine of claim 14, wherein:

controlling fuel delivery to the combustion chamber at least partially as a function of the air temperature includes, in at least some circumstances, controlling fuel delivery to the combustion chamber at least partially as a function of the air temperature when starting the engine producing power; and

changing the relative significance of the air temperature and the engine temperature as factors in controlling fuel delivery to the combustion chamber includes, subsequent to starting the engine producing power, increasing the significance of the engine temperature with respect to the significance of the air temperature.

16. The engine of claim 14, wherein controlling fuel delivery to the combustion chamber at least partially as a function of the air temperature in at least some circumstances includes

selectively controlling fuel delivery to the combustion at least partially as a function of the air temperature when starting the engine producing power.

17. The engine of claim 16, wherein changing the relative significance of the air temperature and the engine temperature as factors in controlling fuel delivery to the combustion chamber includes

subsequent to controlling fuel delivery to the combustion chamber at least partially as a function of the air temperature when starting the engine producing power, gradually phasing out the air temperature as a factor in control of fuel delivery to the combustion chamber while gradually increasing the significance of the engine temperature as a factor in control of fuel delivery to the combustion chamber.

18. The engine of claim 14, wherein controlling fuel delivery to the combustion chamber at least partially as a function of the air temperature in at least some circumstances includes

when starting the engine producing power, in response to at least one predetermined condition that includes an engine temperature having a predetermined relationship to the air temperature, controlling fuel delivery to the combustion chamber at least partially as a function of the air temperature.

19. The engine of claim 14, wherein controlling fuel delivery to the combustion chamber at least partially as a function of the air temperature in at least some circumstances includes

when starting the engine producing power, in response to achieving at least one predetermined condition that includes the engine temperature having a predetermined relationship to the air temperature, controlling fuel delivery to the combustion chamber at least partially as a function of the air temperature.