ELECTRIC PUMP OPERATING STRATEGY

• US 20170356327A1
• Filed: 06/09/2016
• Published: 12/14/2017
• Est. Priority Date: 06/09/2016
• 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., Quelhas, Sergio, Ramappan, Vijay A., Paratore, JR., Michael J.
• Granted Patent: US 10,605,151 B2
• Time in Patent Office: Days
• CPC Class Codes: F01P 2025/08 Temperature
• CPC Class Codes: F01P 7/16 by thermostatic control
• CPC Class Codes: F01P 7/164 by varying pump speed

Abstract

A strategy for controlling an electric pump and control valve in an internal combustion engine cooling system compensates for backpressure variations and maintains system operation within design parameters. The method comprises the steps of measuring the coolant temperature, measuring the electrical current and voltage to the pump motor, determining the pump speed and coolant flow, determining the desired coolant flow, determining a negative correction to the flow control valve and pump if desired flow is less than present coolant flow and determining a positive correction to the flow control valve and pump if desired flow is more than present coolant flow and undertaking this correction to coolant flow. Thus, based upon inferred back pressure in the engine coolant system from the data relating to the pump energy input, proper coolant flow, heat rejection and engine operating temperature can be maintained in spite of variations in system flow restrictions and backpressure.

Claims

1. A method of controlling an electrically driven coolant pump for an internal combustion engine, comprising the steps of:

measuring a coolant temperature in an engine cooling system,

providing a coolant pump driven by an electric motor,

measuring electrical current to said electric pump motor and determining a speed of said electric pump motor,

providing a coolant control valve in said engine cooling system,

determining a coolant flow provided by said coolant pump from said current and speed of said electric pump motor and a position of said coolant control valve,

determining and providing a negative correction signal to said coolant control valve if desired flow is less than present coolant flow and determining and providing a positive correction signal to said coolant control valve if desired flow is more than present coolant flow.

2. The method of controlling an electrically driven coolant pump of claim 1 wherein said coolant temperature measurement is provided to an engine control module.

3. The method of controlling an electrically driven coolant pump of claim 1 wherein said measurement of electrical current are provided to an engine control module.

4. The method of controlling an electrically driven coolant pump of claim 1 wherein said coolant control valve defines a first section which receives coolant from said internal combustion engine and directs said coolant to a radiator or around said radiator.

5. The method of controlling an electrically driven coolant pump of claim 1 wherein said coolant control valve defines a second section which receives coolant from said coolant pump and a turbocharger.

6. The method of controlling an electrically driven coolant pump of claim 5 further including the step of providing an engine oil heater and a transmission oil heater for receiving coolant from said second section of said coolant control valve.

7. The method of controlling an electrically driven coolant pump of claim 1 wherein said electric pump motor is operated at or above 4000 r.p.m.

8. The method of controlling an electrically driven coolant pump of claim 1 wherein said positive correction signal and said negative correction signal are also provided to said electric motor of said coolant pump.

9. A method of operating an electrically driven coolant pump for an internal combustion engine, comprising the steps of:

measuring a coolant temperature in an engine cooling circuit of said internal combustion engine,

providing a coolant pump in said engine cooling circuit driven by an electric motor,

measuring electrical current and voltage to said electric pump motor, determining a speed of said electric pump motor,

determining a coolant flow provided by said coolant pump from said current, voltage and speed of said electric pump motor,

providing a coolant control valve in said engine cooling circuit,

determining and providing a negative correction to said coolant control valve and said electric pump motor if desired flow is less than present coolant flow and determining and providing a positive correction to said coolant control valve and said electric pump motor if desired flow is more than present coolant flow.

10. The method of operating an electrically driven coolant pump of claim 9 including the step of undertaking no further steps if said measured coolant temperature is below a predetermined threshold temperature.

11. The method of operating an electrically driven coolant pump of claim 9 including the step of undertaking no further steps if said determined speed of said electric motor is below a predetermined threshold speed.

12. The method of operating an electrically driven coolant pump of claim 9 wherein said coolant control valve defines a first section which receives coolant from said internal combustion engine and directs said coolant to a radiator or to bypass said radiator.

13. The method of operating an electrically driven coolant pump of claim 9 wherein said coolant control valve defines a second section which receives coolant from said coolant pump and a turbocharger.

14. The method of operating an electrically driven coolant pump of claim 9 further including the step of providing an electronic control module and providing said temperature and electrical measurements to said control module.

15. A method of controlling an electrically driven coolant pump for an internal combustion engine, comprising the steps of:

providing an electronic control module,

measuring a coolant temperature in an engine cooling circuit for said internal combustion engine and providing said measurement to said electronic control module,

providing a coolant pump in said engine cooling circuit driven by an electric motor,

measuring electrical current and voltage to said electric pump motor and providing said electrical measurements to said electronic control module, determining a speed of said electric pump motor in said electronic control module,

determining a coolant flow provided by said coolant pump from said current, voltage and speed of said electric pump motor,

providing a coolant control valve in said engine cooling circuit,

determining and providing a negative correction signal to said coolant control valve from said electronic control module if desired flow is less than current coolant flow and determining and providing a positive correction signal to said coolant control valve from said electronic control module if desired flow is more than current coolant flow.

16. The method of controlling an electrically driven coolant pump of claim 15 wherein said coolant control valve defines a first section which receives coolant from said internal combustion engine and directs said coolant to a radiator or to bypass said radiator.

17. The method of controlling an electrically driven coolant pump of claim 15 wherein said coolant control valve defines a second section which receives coolant from said coolant pump and a turbocharger.

18. The method of controlling an electrically driven coolant pump of claim 15 including the step of terminating said if said measured coolant temperature is below a predetermined threshold temperature.

19. The method of controlling an electrically driven coolant pump of claim 15 including the step of terminating said method if said determined speed of said electric motor is below a predetermined threshold speed.

20. The method of controlling an electrically driven coolant pump of claim 15 wherein said positive correction signal and said negative correction signal are also provided to said electric motor of said coolant pump.