Fan control system and method

• US 9,752,492 B2
• Filed: 03/06/2015
• Issued: 09/05/2017
• Est. Priority Date: 03/06/2015
• Status: Active Grant

• Current Assignee: Deere & Company
• Original Assignee: Deere & Company
• Inventors: Sheidler, Alan D.
• Primary Examiner(s): Holbrook, Tea
• Application Number:
  US14/640,539
• Publication Number:
  US 20160258338A1
• Time in Patent Office: 914 Days
• Field of Search: 123 4101, 123 4111, 123 4112, 123 4139
• CPC Class Codes: F01P 2023/08 Microprocessor; Microcomputer
• CPC Class Codes: F01P 7/04 by varying pump speed, e.g. by changing pump-drive gear ratio

Abstract

A method for controlling a fan. The method includes determining an actual air flow over an engine of a vehicle at a current time, and determining a necessary air flow over the engine for maintaining an appropriate engine coolant temperature. The actual air flow is associated with the vehicle traveling in a first direction. The method further includes estimating a future air flow over the engine that is associated with the vehicle travelling in a second direction. The method also includes controlling a fan operating characteristic based on the actual, necessary, and future air flows.

Claims

1. A method for controlling a fan, the method comprising:

determining an actual air flow over an engine of a vehicle at a current time, the actual air flow being associated with the vehicle traveling in a first direction;

determining a necessary air flow over the engine for maintaining an appropriate engine coolant temperature;

estimating a future air flow over the engine, the future air flow being associated with the vehicle travelling in a second direction; and

controlling a fan operating characteristic based on the actual air flow, the necessary air flow, and the future air flow, and wherein the controlling comprises maintaining a fan provided air flow if;

the necessary air flow is greater than the actual air flow;

the future air flow is greater than the necessary air flow; and

a length of time to reach a vehicle direction change, from the first direction to the second direction, is less than a length of time to reach an engine coolant overheating temperature.

2. The method of claim 1, wherein the estimating the future air flow comprises assuming that a future fan provided air flow associated with the second direction is the same as a current fan provided air flow associated with the first direction.

3. The method of claim 1, wherein the first direction and the second direction are opposite directions relative to one another and parallel relative to one another.

4. The method of claim 1, wherein the first direction and the second direction are opposite direction relative to one another and overlapping one another.

5. The method of claim 1, wherein the controlling comprises increasing a fan provided air flow if:

the necessary air flow is greater than the actual air flow; and

the necessary air flow is greater than the future air flow.

6. The method of claim 1, wherein the controlling comprises maintaining a fan provided air flow if:

the necessary air flow equals the actual air flow; and

the necessary air flow equals the future air flow.

7. The method of claim 1, wherein the controlling comprises decreasing a fan provided air flow if:

the actual air flow is greater than the necessary air flow; and

the future air flow is greater than the necessary air flow.

8. The method of claim 1, further comprising:

receiving a wind signal; and

estimating the future air flow based on the wind signal and the second direction.

9. The method of claim 8, wherein the wind signal comprises a wind speed signal and a wind direction signal.

10. The method of claim 1, further comprising:

determining a rate at which an engine coolant temperature will rise; and

basing the length of time to reach the engine coolant overheating temperature on the rate at which the engine coolant temperature will rise.

11. The method of claim 1, further comprising basing the length of time to reach the engine coolant overheating temperature on the length of time to reach the vehicle direction change from the first direction to the second direction.

12. The method of claim 1, wherein the controlling comprises increasing the fan provided air flow if:

the necessary air flow is greater than the actual air flow;

the future air flow is greater than the necessary air flow; and

the length of time to reach the vehicle direction change, from the first direction to the second direction, is greater than the length of time to reach the engine coolant overheating temperature.

13. The method of claim 12, further comprising:

determining a rate at which an engine coolant temperature will rise; and

basing the length of time to reach the engine coolant overheating temperature on the rate at which the engine coolant temperature will rise.

14. The method of claim 1, wherein the controlling comprises decreasing the fan provided air flow if:

the actual air flow is greater than the necessary air flow;

the necessary air flow is greater than the future air flow; and

a sum of the length of time to reach the vehicle direction change, from the first direction to the second direction, and a length of time that the vehicle will be in the second direction is less than the length of time to reach the engine coolant overheating temperature.

15. The method of claim 14, further comprising:

determining a rate at which an engine coolant temperature will fall before the vehicle direction change from the first direction to the second direction; and

basing the length of time to reach the engine coolant overheating temperature on the rate at which the engine coolant temperature will fall.

16. The method of claim 14, further comprising basing the length of time to reach the engine coolant overheating temperature on the length of time the vehicle is in the second direction.

17. The method of claim 1, wherein the controlling comprises maintaining the fan provided air flow if:

the actual air flow is greater than the necessary air flow;

the necessary air flow is greater than the future air flow; and

a sum of the length of time to reach the vehicle direction change, from the first direction to the second direction, and a length of time that the vehicle is in the second direction is greater than the length of time to reach the engine coolant overheating temperature.

18. The method of claim 17, further comprising:

determining a rate at which an engine coolant temperature will fall before the vehicle direction change from the first direction to the second direction;

determining a rate at which the engine coolant temperature will rise in the second direction; and

basing the length of time to reach the engine coolant overheating temperature on the rate at which the engine coolant temperature will fall and the rate at which the engine coolant temperature will rise.

19. A method for controlling a fan, the method comprising:

determining an actual air flow over an engine of a vehicle at a current time, the actual air flow being associated with the vehicle traveling in a first direction;

determining a necessary air flow over the engine for maintaining an appropriate engine coolant temperature;

estimating a future air flow over the engine, the future air flow being associated with the vehicle travelling in a second direction; and

controlling a fan operating characteristic based on the actual air flow, the necessary air flow, and the future air flow, and wherein the controlling comprises maintaining a fan provided air flow if;

the actual air flow is greater than the necessary air flow;

the necessary air flow is greater than the future air flow; and

a sum of a length of time to reach a vehicle direction change, from the first direction to the second direction, and a length of time that the vehicle is in the second direction is greater than a length of time to reach an engine coolant overheating temperature.