Control method of an electronic thermostat valve

• US 20030150924A1
• Filed: 02/10/2003
• Published: 08/14/2003
• Est. Priority Date: 02/09/2002
• Status: Active Grant

• Current Assignee: Hyundai Motor Company (Hyundai Motor Group), INZI Controls Co., Ltd.
• Original Assignee: Hyundai Motor Company (Hyundai Motor Group), INZI Controls Co., Ltd.
• Inventors: Peter, Werner Leu
• Granted Patent: US 6,857,576 B2
• Time in Patent Office: Days
• US Class Current: 236/34.5
• CPC Class Codes: F01P 2025/32 Engine outcoming fluid temperature
• CPC Class Codes: F01P 2025/36 Heat exchanger mixed fluid temperature
• CPC Class Codes: F01P 2025/50 using two or more temperature sensors
• CPC Class Codes: F01P 7/167 by adjusting the pre-set temperature according to engine parameters, e.g. engine load, engine speed
• CPC Class Codes: G05D 23/1393 characterised by the use of electric means

Abstract

The present invention relates to a method of controlling an electronic thermostat valve that is based on the driving conditions. The method includes using controlling parameters memorized in an ECU (Electronic Control Unit). A power source to activate the thermostat valve is originated from an expanding force of a thermal element and a change of stroke of an actuating means. A cooling system of a vehicle can be maintained in an optimized state such that fuel consumption and exhaust pollutants are reduced.

Claims

1. A method for controlling an electronic thermostat valve, comprising:

control logic for changing a geometrical volume of a thermal element chamber wherein said control logic sends a controlling signal to an actuator means based on calculation of the optimal coolant temperature(component temperature)in a combustion engine, whereby the coolant temperature at which the thermostat valve opens and controls can be varied within a preferable temperature range.

2. The method of claim 1, wherein said temperature differential calculation comprises:

calculating and outputting a difference (Δ

T_avail) between the temperature of coolant at an outlet of the engine (T_CEO) and the temperature of coolant at an outlet of the radiator (T_RO);

presetting a reference value (Δ

T_ref) between a reference temperature of coolant at the outlet of the engine and a reference temperature of coolant at the outlet of the radiator;

calculating and outputting a difference of Δ

T_ref and Δ

T_avail;

outputting a first control signal by means of an OR gate based at least in part on said Δ

T_ref and Δ

T_avail; and

outputting a second controlling signal by means of an AND gate for selectively controlling said chamber volume based on said first control signal and a current coolant temperature.

3. The method of claim 2, wherein the OR gate further comprising:

receiving the difference Δ

() between a time derivative of the temperature of coolant measured at the outlet of the radiator (dT_RO/dt=_avail) and a reference time derivative of the coolant temperature at the outlet of the radiator (_ref) as an input value; and

outputting said first control signal based on said Δ

()_avail and said Δ

T_ref and Δ

T_avail difference.

4. The method of claim 2, wherein said second signal is further based on a difference (Δ

T_CEO) between the coolant temperature measured at an outlet of an engine (T_CEO) and the reference temperature of coolant at an outlet of an engine(T<sub>CEO −

ref</sub>).

5. The method of claim 2, wherein said second signal is further based on a difference (Δ

T_RO) between the temperature of coolant measured at an outlet of an engine (T_RO) and the reference temperature of coolant at an outlet of an engine (T<sub>RO−

ref</sub>), which is calculated by the forth calculator(comparator).

6. The method of claim 1, wherein a temperature of coolant at which the thermostat valve opens and controls is varied in inverse proportion to a displacement in volume of the chamber.

7. The method of claim 1 and 6, wherein the temperature at which the thermostat valve opens and controls, is changed between about 85 degrees C. and about 105 degrees C. based on driving conditions of the vehicle.

8. The method of claim 1 and 6, wherein the volume of the chamber is changed by displacement of a rod adjusted by changing a ratio of a diameter of the rod to a diameter of a piston.

9. The method of claim 1, wherein an elastic elementis provided for substantially returning the rod to an initial position in case of electric power failure such that the electronic thermostat valve can be automatically configured to a low-temperature level during an electric power failure.

10. A method for controlling an electronic thermostat valve in a vehicle with an engine and radiator, wherein said valve is actuated by a thermal element disposed within a chamber having a volume, said method comprising adjusting responsiveness of the thermal element by changing the volume of the chamber based on determination of a temperature differential across the engine and radiator.

11. The method of claim 10, wherein said temperature differential determination comprises:

determining a first difference between the temperature of coolant at an outlet of the engine and the temperature of coolant at an outlet of the radiator;

setting a reference value between a coolant limit temperature at the outlet of the engine and a coolant limit temperature at the outlet of the radiator;

determining a second difference between said first difference and said reference value; and

outputting a first control signal for selective control of said chamber volume based at least in part on said second difference.

12. The method of claim 11, wherein said temperature differential calculation further comprises:

setting a coolant outlet reference temperature;

determining a third difference between said coolant outlet reference temperature and an actual coolant outlet temperature; and

outputting a second control signal for selectively controlling said chamber volume based on said first control signal and said third difference.

13. The method of claim 12, further comprising determining a fourth difference between a time derivative of the coolant temperature measured at the outlet of the radiator and a reference time derivative of the coolant temperature at the outlet of the radiator, wherein said first control signal is further based in part on said fourth difference.

14. The method of claim 12, wherein said coolant outlet temperature is an engine outlet temperature.

15. The method of claim 12, wherein said coolant outlet temperature is a radiator outlet temperature.

16. A method for controlling an electronic thermostat valve, comprising:

measuring coolant temperature of a vehicle;

calculating a difference between said measured coolant temperature and a predetermined coolant temperature; and

actuating a volume change of a chamber housing a thermal element based on said calculated difference such that a temperature at which the thermal element undergoes a phase change is varied within a desired range.

17. The method of claim 16, wherein said measuring coolant temperature is measured at an outlet of an engine.

18. The method of claim 16, wherein said measuring coolant temperature is measured at an outlet of a radiator.