Method and device for cooling a motor vehicle engine

• US 20030196612A1
• Filed: 01/06/2003
• Published: 10/23/2003
• Est. Priority Date: 03/17/2000
• Status: Active Grant

• Current Assignee: Peugeot Citroen Automobile SA (Stellantis NV)
• Original Assignee: Peugeot Citroen Automobile SA (Stellantis NV)
• Inventors: TOMASSELI, LUDOVIC, Le Lievre, Armel
• Granted Patent: US 6,880,495 B2
• Time in Patent Office: Days
• US Class Current: 123/41.1
• CPC Class Codes: F01P 2007/143 using restrictions
• CPC Class Codes: F01P 2007/146 using valves
• CPC Class Codes: F01P 2023/00 Signal processing; Details thereof
• CPC Class Codes: F01P 2025/08 Temperature
• CPC Class Codes: F01P 2025/13 Ambient temperature
• CPC Class Codes: F01P 2025/60 Operating parameters
• CPC Class Codes: F01P 2025/62 Load
• CPC Class Codes: F01P 2025/64 Number of revolutions
• CPC Class Codes: F01P 2025/66 Vehicle speed
• CPC Class Codes: F01P 2060/02 Intercooler
• CPC Class Codes: F01P 2060/04 Lubricant cooler
• CPC Class Codes: F01P 7/048 using electrical drives
• CPC Class Codes: F01P 7/164 by varying pump speed
• CPC Class Codes: F01P 7/167 by adjusting the pre-set temperature according to engine parameters, e.g. engine load, engine speed

Abstract

A method for cooling a motor vehicle engine consists in regulating the volume and the flow rate of a coolant fluid in a hydraulic circuit provided with a branch equipped with an electronically controlled actuator and means forming radiator. The method comprises a step of determining the temperature of the cooling liquid, a step of comparing the temperature of the cooling liquid with a specified threshold temperature from which the engine is said to be hot, and, when the temperature of the fluid is higher than the threshold temperature, the flow rate in the radiator branch is regulated so as to maintain the temperature of the cooling fluid around a specified setpoint value. The curve representing the opening of the thermostat valve based on the temperature of the cooling fluid exhibits an hysteresis around the setpoint temperature. The invention also concerns a device for cooling a motor vehicle engine.

Claims

1. Method for cooling a motor vehicle engine, consisting in regulating the volume and the flow rate of a cooling fluid in a hydraulic circuit (2) provided with a branch (4) equipped with an electronically controlled actuator (14) and provided with means (9) forming radiator, the method comprising a first step of determining the temperature (T) of the cooling fluid, a step of comparing this temperature with a specified threshold temperature (T₂) from which the engine (1) is referred to as “

hot”

, and, when the temperature (T) of the fluid is higher than the threshold temperature (T₂), the flow rate in the radiator branch (4) is regulated so as to maintain the temperature (T) of the cooling liquid around a specified setpoint value (Tc), characterized in that the curve representative of the opening (O) of the thermostatic valve (4) as a function of the temperature (T) of the cooling fluid exhibits an hysteresis (h1, h2) around the setpoint temperature (Tc1, Tc2), so as to regulate the temperature (T) of the cooling fluid at said setpoint temperature (Tc1, Tc2).

2. Device for cooling a motor vehicle engine, of the type comprising a hydraulic circuit (2) of a cooling fluid, associated with a pump (3) for circulating this fluid through the engine (1) of the vehicle and different branches (4, 5, 6, 7, 8, 44) of the circuit, in which are arranged thermal equipment (9, 10, 11, 12, 13, 140, 150, 160) of the vehicle, at least some of the branches (4, 5, 6, 7, 8, 44) of the circuit (2) being equipped with electronically controlled actuators (14, 15, 16, 17, 18, 29) to regulate the circulation of the fluid in these branches, the device comprising means (22) for collecting information relating to the operation conditions of the vehicle, connected to means (19) for controlling the operation of the actuators (14, 15, 16, 17, 18, 29), in order to regulate the volume and the flow rate of fluid circulating in the hydraulic circuit (2) so as to optimize the operation of the engine (1), the circuit (2) comprising a branch (4) equipped with an electronically controlled actuator (14) and provided with means (9) forming radiator, the information collecting means (22) being adapted to determine the temperature (T) of the cooling fluid, so that, when the temperature (T) of the fluid is higher than a specified threshold temperature (T₂) from which the engine (1) is referred to as “

hot”

, the control means (19) regulate the flow rate in the radiator branch (4) so as to maintain the temperature (T) of the cooling liquid around a specified setpoint value (Tc), characterized in that the actuator (14) of the radiator branch (4) is constituted by a thermostatic valve adapted to be electronically controlled, and in that the curve representative of the opening (O) of the thermostatic valve (4) as a function of the temperature (T) of the cooling fluid exhibits an hysteresis (h1, h2) around the setpoint temperature (Tc1, Tc2), so as to regulate the temperature (T) of the cooling liquid at said setpoint temperature (Tc1, Tc2).

3. Device according to claim 2, characterized in that the setpoint temperature (Tc) is between 60 and 120 degrees approximately.

4. Device according to any of claims 2 or 3, characterized in that the control means (19) cooperate with the information collecting means (22), in order to determine the temperature (Ta) of the intake air of the engine (1), so as to increase the flow rate in said branch (4) when the temperature (Ta) of the intake air of the engine (1) increases beyond a specified first threshold (S1).

5. Device according to claim 4, characterized in that the control means (19) increase the flow rate in the radiator branch (4) when the temperature (Ta) of the intake air of the engine (1) increases, so as to ensure a maximum flow rate in the branch (4) when the temperature (Ta) of the intake air of the engine (1) reaches a specified second threshold (S2).

6. Device according to any of claims 2 to 5, characterized in that the control means (19) cooperate with the information collecting means (22), in order to determine the speed of the vehicle, so as to increase the flow rate in said branch (4) when the speed of the vehicle increases beyond a specified first threshold.

7. Device according to claim 6, characterized in that the control means (19) increase the flow rate in the radiator branch (4) when the speed of the vehicle increases, so as to ensure a maximum flow rate in the branch (4) when the speed of the vehicle reaches a specified second threshold.

8. Device according to any of claims 2 to 7, characterized in that it comprises ventilation means (3), or “

Motor Ventilation Group”

, adapted to cooperate with the means (9) forming radiator, the control means (19) ensuring a control of the ventilation means (30) as a function of the temperature (T) of the cooling liquid, so that the rotational speed (V) of the ventilation means (30) increases when the temperature (T) of the cooling fluid increases.

9. Device according to claim 8, characterized in that the increase of the rotational speed (V) of the ventilation means (30) is controlled as a function of the speed of variation

10. Device according to claim 9, characterized in that the rotational speed of the ventilation means (30) as a function of the temperature (T) of the cooling liquid follows a line whose slope is proportional to the speed of variation

11. Device according to any of claims 8 to 10, characterized in that the ventilation means (30) are started when the temperature (T) of the cooling fluid is higher than the setpoint temperature (Tc) and the flow rate of the cooling liquid in the radiator branch (4) is substantially maximum.

12. Device according to any of claims 8 to 11, characterized in that the control means (19) cooperate with the information collecting means (22), in order to determine the temperature of the air located under the vehicle hood, so as to start the ventilation means when the temperature of the air located under the hood is higher than a specified threshold.