Automatic start-up of an auxiliary power unit

• US 7,290,517 B2
• Filed: 07/28/2005
• Issued: 11/06/2007
• Est. Priority Date: 07/28/2005
• Status: Expired due to Fees

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Orr, David C., Marchand, David G., Bernardi, John J., Borgeson, Jon B.
• Primary Examiner(s): Cronin; Stephen K.
• Assistant Examiner(s): Castro; Arnold
• Application Number:
  US11/191,138
• Publication Number:
  US 20070022995A1
• Time in Patent Office: 831 Days
• Field of Search: 123/179.3, 123/179.19, 123/DIG.8, 123/142.5
• US Class Current: 123/179.3
• CPC Class Codes: F01P 2060/08 Cabin heater
• CPC Class Codes: F01P 2060/18 Heater
• CPC Class Codes: F02B 37/02 Gas passages between engine outlet and pump drive, e.g. reservoirs
• CPC Class Codes: F02B 63/04 for electric generators
• CPC Class Codes: F02D 25/04 by cutting-out engines
• CPC Class Codes: F02N 11/0803 characterised by means for initiating engine start or stop F02N11/0814 takes precedence
• CPC Class Codes: F02N 11/0862 characterised by the electrical power supply means, e.g. battery
• CPC Class Codes: F02N 19/10 by heating of engine coolants
• CPC Class Codes: F02N 2200/061 Battery state of charge [SOC]

Abstract

An auxiliary power unit automatic start-up system is configured to assist a main engine start of a machine. The auxiliary power unit automatic start-up system may include an auxiliary power unit and a controller. The controller may monitor a parameter of the machine, automatically start the auxiliary power unit if the parameter is outside a first predetermined range, and bring the parameter within a second predetermined range using the auxiliary power unit.

Claims

1. An auxiliary power unit automatic start-up system configured to assist a main engine start of a machine, comprising:

an auxiliary power unit assembly configured to supply a variable level of output; and

a controller configured to;

monitor a parameter of the machine;

automatically start the auxiliary power unit assembly if the parameter is outside a first predetermined range; and

bring the parameter within a second predetermined range using the auxiliary power unit assembly.

2. The system of claim 1, wherein the parameter affects the starting of the main engine.

3. The system of claim 1, wherein the auxiliary power unit assembly is configured to supply charge to a battery, and the parameter is indicative of a voltage of the battery.

4. The system of claim 1, wherein the auxiliary power unit assembly is configured to warm a coolant of a cooling system of the machine, and the parameter is indicative of a temperature of the coolant.

5. The system of claim 4, wherein the auxiliary power unit assembly shares coolant with the main engine.

6. The system of claim 1, wherein the first predetermined range and the second predetermined range are different.

7. A method for automatically starting an auxiliary power unit assembly to assist a main engine start of a machine, the method comprising:

monitoring a first parameter of the machine;

monitoring a second parameter of the machine;

automatically starting the auxiliary power unit assembly to operate in a first mode if the first parameter falls outside a first predetermined range before the second parameter falls outside a second predetermined range; and

automatically starting the auxiliary power unit assembly to operate in a second mode if the second parameter falls outside the second predetermined range before the first parameter falls outside the first predetermined range.

8. The method of claim 7, wherein the first and second parameters affect the starting of the main engine.

9. The method of claim 7, wherein the first parameter is indicative of a voltage of the battery, and the second parameter is indicative of a temperature of a coolant.

10. The method of claim 7, wherein the first mode is a battery charging mode.

11. The method of claim 7, wherein the second mode is a coolant warming mode.

12. The method of claim 7, wherein the auxiliary power unit assembly is prevented from starting when the main engine is cranking.

13. The method of claim 7, wherein operating in the first mode includes bringing the first parameter within a first target range.

14. The method of claim 13, wherein the first predetermined range and the first target range are different.

15. The method of claim 7, wherein operating in the second mode includes bringing the second parameter within a second target range.

16. The method of claim 15, wherein the second predetermined range and the second target range are different.

17. A work machine comprising:

a main engine; and

an auxiliary power unit automatic start-up system, comprising;

an auxiliary power unit assembly configured to supply a variable level of output when assisting a main engine start of the machine; and

a controller configured to;

monitor a parameter of the machine;

automatically start the auxiliary power unit assembly if the parameter is outside a first predetermined range; and

bring the parameter within a second predetermined range using the auxiliary power unit assembly.

18. The work machine of claim 17, further including a battery configured to assist in starting the main engine.

19. The work machine of claim 17, further including a cooling system configured to circulate a coolant through the main engine and the auxiliary power unit assembly.

20. The work machine of claim 17, wherein the first predetermined range and the second predetermined range are different.

21. The work machine of claim 17, further including:

a battery voltage sensor configured to provide information to the controller; and

a coolant temperature sensor configured to provide information to the controller.