COOLANT CONTROL SYSTEMS AND METHODS FOR WARMING ENGINE OIL AND TRANSMISSION FLUID

• US 20140261254A1
• Filed: 03/14/2013
• Published: 09/18/2014
• Est. Priority Date: 03/14/2013
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: GONZE, EUGENE V., Claypole, George M., Chen, Yue-Ming
• Granted Patent: US 9,581,075 B2
• Time in Patent Office: Days
• US Class Current: 123/41.08
• CPC Class Codes: F01P 11/08 Arrangements of lubricant coolers in lubrication apparatus F01M

Abstract

A coolant control system of a vehicle includes a target pressure module and a thermostat valve control module. The target pressure module determines a target pressure of coolant in a coolant path between a thermostat valve and at least one of an engine oil heat exchanger and a transmission fluid heat exchanger. The thermostat valve control module closes the thermostat valve and blocks coolant flow out of an engine when a temperature of coolant within the engine is less than a predetermined temperature. When the temperature is greater than the predetermined temperature, the thermostat valve control module controls opening of the thermostat valve to the coolant path based on the target pressure.

Claims

1. A coolant control system of a vehicle, comprising:

a target pressure module that determines a target pressure of coolant in a coolant path between a thermostat valve and at least one of an engine oil heat exchanger and a transmission fluid heat exchanger; and

a thermostat valve control module that closes the thermostat valve and blocks coolant flow out of an engine when a temperature of coolant within the engine is less than a predetermined temperature and that, when the temperature is greater than the predetermined temperature, controls opening of the thermostat valve to the coolant path based on the target pressure.

2. The coolant control system of claim 1 further comprising a coolant valve control module that closes a coolant valve and blocks coolant flow into the engine when the temperature is less than the predetermined temperature and that opens the coolant valve when the temperature is greater than the predetermined temperature.

3. The coolant control system of claim 1 further comprising a pump control module that disables a coolant pump when the temperature is less than the predetermined temperature and that, when the temperature is greater than the predetermined temperature, controls a speed of the coolant pump based on the target pressure.

4. The coolant control system of claim 3 wherein the pump control module controls the speed of the coolant pump further based on a coolant flowrate through the engine, the engine oil heat exchanger, and the transmission fluid heat exchanger.

5. The coolant control system of claim 1 wherein the thermostat valve control module controls the opening of the thermostat valve to the coolant path further based on a coolant flowrate through the engine.

6. The coolant control system of claim 1 wherein the thermostat valve control module further closes the thermostat valve and blocks coolant flow to a second coolant path between the thermostat valve and a radiator when at least one of an engine oil temperature is less than a first predetermined temperature and a transmission fluid temperature is less than a second predetermined temperature.

7. The coolant control system of claim 6 wherein the thermostat valve control module further opens the thermostat valve and allows coolant flow to the second coolant path when the engine oil temperature is greater than the first predetermined temperature and the transmission fluid temperature is greater than the second predetermined temperature.

8. The coolant control system of claim 1 further comprising:

a heat rejection module that determines a heat rejection rate of the engine to coolant within the engine; and

a maximum coolant flow module that determines a maximum coolant flowrate through the engine oil and transmission fluid heat exchangers based on the heat rejection rate,

wherein the target pressure module determines the target pressure based on the maximum coolant flowrate.

9. The coolant control system of claim 8 wherein the heat rejection module determines the heat rejection rate based on an engine speed, an engine load, and at least one of a first temperature of coolant at an inlet of the engine and a second temperature of coolant at an outlet of the engine.

10. The coolant control system of claim 8 wherein the maximum coolant flow module determines the maximum coolant flowrate further based on a predetermined coolant temperature increase between an inlet of the engine and an outlet of the engine.

11. A coolant control method for a vehicle, comprising:

determining a target pressure of coolant in a coolant path between a thermostat valve and at least one of an engine oil heat exchanger and a transmission fluid heat exchanger;

closing the thermostat valve and blocking coolant flow out of an engine when a temperature of coolant within the engine is less than a predetermined temperature; and

,

when the temperature is greater than the predetermined temperature, controlling opening of the thermostat valve to the coolant path based on the target pressure.

12. The coolant control method of claim 11 further comprising:

closing a coolant valve and blocking coolant flow into the engine when the temperature is less than the predetermined temperature; and

opening the coolant valve when the temperature is greater than the predetermined temperature.

13. The coolant control method of claim 11 further comprising:

disabling a coolant pump when the temperature is less than the predetermined temperature; and

,

when the temperature is greater than the predetermined temperature, controlling a speed of the coolant pump based on the target pressure.

14. The coolant control method of claim 13 further comprising controlling the speed of the coolant pump further based on a coolant flowrate through the engine, the engine oil heat exchanger, and the transmission fluid heat exchanger.

15. The coolant control method of claim 11 further comprising controlling the opening of the thermostat valve to the coolant path further based on a coolant flowrate through the engine.

16. The coolant control method of claim 11 further comprising closing the thermostat valve and blocking coolant flow to a second coolant path between the thermostat valve and a radiator when at least one of:

an engine oil temperature is less than a first predetermined temperature; and

a transmission fluid temperature is less than a second predetermined temperature.

17. The coolant control method of claim 16 further comprising opening the thermostat valve and allowing coolant flow to the second coolant path when the engine oil temperature is greater than the first predetermined temperature and the transmission fluid temperature is greater than the second predetermined temperature.

18. The coolant control method of claim 11 further comprising:

determining a heat rejection rate of the engine to coolant within the engine;

determining a maximum coolant flowrate through the engine oil and transmission fluid heat exchangers based on the heat rejection rate; and

determining the target pressure based on the maximum coolant flowrate.

19. The coolant control method of claim 18 further comprising determining the heat rejection rate based on an engine speed, an engine load, and at least one of a first temperature of coolant at an inlet of the engine and a second temperature of coolant at an outlet of the engine.

20. The coolant control method of claim 18 further comprising determining the maximum coolant flowrate further based on a predetermined coolant temperature increase between an inlet of the engine and an outlet of the engine.