Heater Core Isolation Valve Position Detection

• US 20140110081A1
• Filed: 03/07/2013
• Published: 04/24/2014
• Est. Priority Date: 10/19/2012
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Porras, Angel Fernando
• Granted Patent: US 10,207,567 B2
• Time in Patent Office: Days
• US Class Current: 165/11.1
• CPC Class Codes: B60H 1/004 for vehicles having a combustion engine and electric drive means, e.g. hybrid electric vehicles
• CPC Class Codes: B60H 1/00978 Control systems or circuits characterised by failure of detection or safety means; Diagnostic methods
• CPC Class Codes: B60H 1/034 from the cooling liquid of the propulsion plant and from an electric heating device
• CPC Class Codes: F01P 11/04 Arrangements of liquid pipes or hoses
• CPC Class Codes: F01P 2060/08 Cabin heater

Abstract

A vehicle is disclosed that has multiple coolant paths selected by control of a three-way valve in which the position of the valve is detectable. A method for detecting the valve position during fault conditions is disclosed. The vehicle has a heating system that includes a first coolant loop with a heating source, a water pump, and a heater core. The heating system also has a second coolant loop that includes an engine and a second water pump, in addition to the elements of the first coolant loop. Temperature sensors are located in each coolant loop. A three-way valve fault is detected by monitoring the behavior of the temperature sensors in response to the position of the three-way valve and the status of the heating sources.

Claims

1. A vehicle comprising:

an engine;

a heat exchanger configured to heat a cabin of the vehicle;

an electric heater configured to heat coolant for the heat exchanger; and

a valve system, including a valve, configured to selectively direct coolant from the engine to the heat exchanger and to detect a position of the valve based on a temperature of coolant entering the heat exchanger and a temperature of coolant exiting the engine.

2. The vehicle of claim 1 wherein the valve system is configured to detect a position in which the valve does not direct coolant from the engine to the heat exchanger in response to a temperature increase of the coolant entering the heat exchanger being greater than a temperature increase of the coolant exiting the engine after receiving a command to position the valve to fluidly isolate the engine from the heat exchanger and while the electric heater is on and the engine is off.

3. The vehicle of claim 2 wherein the temperature increase of the coolant entering the heat exchanger is greater than a first threshold and the temperature increase of the coolant exiting the engine is less a second threshold.

4. The vehicle of claim 1 wherein the valve system is configured to detect a fault position in which the valve directs the coolant from the engine to the heat exchanger in response to a temperature increase of the coolant entering the heat exchanger and a temperature increase of the coolant exiting the engine after receiving a command to position the valve to fluidly isolate the engine from the heat exchanger and while the electric heater is on and the engine is off.

5. The vehicle of claim 4 wherein the fault position is detected if the temperature increase of the coolant entering the heat exchanger is less than a first threshold value or the temperature increase of the coolant exiting the engine is greater than a second threshold value.

6. The vehicle of claim 4 wherein the valve system is further configured to generate an output representing a fault in the valve position.

7. A vehicle comprising:

an engine;

a heat exchanger configured to heat a cabin of the vehicle;

an electric heater configured to heat coolant for the heat exchanger; and

a valve system including a valve configured to selectively direct coolant from the engine to the electric heater and to detect a position of the valve based on a change in temperature of coolant exiting the electric heater relative to a change in temperature of coolant exiting the engine.

8. The vehicle of claim 7 wherein the valve system is configured to detect a position in which the valve does not direct coolant from the engine to the electric heater in response to a change in temperature of the coolant exiting the electric heater being greater than a change in temperature of the coolant exiting the engine after receiving a command to position the valve to fluidly isolate the engine from the electric heater and while the electric heater is on and the engine is off.

9. The vehicle of claim 8 wherein the change in temperature of the coolant exiting the electric heater is greater than a first threshold and the change in temperature of the coolant exiting the engine is less than a second threshold.

10. The vehicle of claim 7 wherein the valve system is configured to detect a fault position in which the valve directs the coolant from the engine to the electric heater in response to a change in temperature of the coolant exiting the electric heater and a change in temperature of the coolant exiting the engine after receiving a command to position the valve to fluidly isolate the engine from the electric heater and while the electric heater is on and the engine is off.

11. The vehicle of claim 10 wherein the fault position is detected if the change in temperature of the coolant exiting the electric heater is less than a first threshold value or the change in temperature of the coolant exiting the engine is greater than a second threshold value.

12. The vehicle of claim 10 wherein the valve system is further configured to generate an output representing a fault in the valve position.

13. A method of detecting a valve position comprising:

activating a pump to circulate coolant;

commanding the valve to direct coolant through a heating source and fluidly isolate the heating source from an engine;

activating the heating source; and

in response to the steps of activating and commanding, outputting a signal indicative of a position of the valve based on a change in coolant temperature associated with the heating source and a change in coolant temperature associated with the engine when the engine is off.

14. The method of claim 13 wherein the engine is off for a predetermined period of time prior to detecting the valve position.

15. The method of claim 13 wherein the valve position is detected to be in a fault position in which the valve directs coolant from the engine to the heating source when the change in temperature of coolant associated with the heating source is less than a first threshold or the change in temperature of coolant associated with the engine is greater than a second threshold.

16. The method of claim 13 wherein the valve position is determined to be a position in which the valve does not direct coolant from the engine to the heating source when the change in temperature of coolant associated with the heating source is greater than a first threshold and the change in temperature of coolant associated with the engine is less than a second threshold.

17. The method of claim 13 wherein detecting the valve position is performed when there is an electrical failure detected for the valve.