FR2804721A1 - Cooling system for IC engine in car comprises temperature sensors sending information to the control to feed cooling fluid to the circuit branches if the temperature is between two thresholds - Google Patents

Abstract

The fluid circuit comprises temperature sensors (22) for the cooling fluid, sending information to the control (19) to feed cooling fluid to the circuit branches (4-8,44) if the temperature is superior to temperature threshold (T2) and stop if the temperature is inferior to the threshold (T1).

Description

The invention relates to a cooling device of a motor vehicle engine.

The invention relates more particularly to a cooling device comprising a hydraulic coolant coolant circuit, associated with a circulation pump it through the vehicle engine and different branches of the circuit. Thermal equipment of the vehicle can be arranged in the different branches circuit.

The cooling systems are designed to ensure that the motors withstand the thermomechanical stresses resulting from combustion. Furthermore, complementary functions are implemented in addition to the main engine cooling, to improve the overall efficiency or offer and guarantee benefits to vehicle users, such as, for example, the heating of the passenger compartment.

The cooling systems are sized from the operating points at maximum speed and full load of the engine and are therefore oversized in most cases of use of vehicles.

Thus, the operating parameters of the engine are not optimized, which results in a degradation of the performance of the latter, such as increased consumption, a high level of pollutant emission and a reduction in the thermal and acoustic comfort of the engine. vehicle.

An object of the present invention is to provide a cooling device of a motor vehicle engine, overcoming all or part of the disadvantages of the prior art noted above.

This is achieved by the fact that the cooling device of a motor vehicle engine, type comprising a hydraulic circuit coolant coolant, associated with a circulation pump thereof through the vehicle engine and different branches of the circuit, in which are arranged thermal equipment of the vehicle, at least some of the branches of the circuit being provided with electronically controlled actuators for regulating the circulation of the fluid therein, device comprising means for acquiring information relating to the operating conditions of the vehicle connected to actuator operating control means for regulating the volume and the flow rate of fluid circulating in the hydraulic circuit in order to optimize the operation of the engine, the information acquisition means being able to determine the temperature of the cooling liquid, the means of control ensuring the limitation or the stop of the circulation of the fluid in at least some of the branches when the temperature of the fluid is lower than a first threshold temperature determined.

elsewhere, the invention may comprise one or more of the following characteristics the control means at least temporarily provide fluid circulation in at least some of the branches when the fluid temperature is greater than a second predetermined threshold temperature, - when the fluid temperature is between the first and second threshold temperature, the control means at least temporarily provide fluid circulation in at least some of the branches, the volume and / or the flow rate of fluid flowing in said branches being a function of the temperature of the liquid, the second threshold temperature is between approximately 60 and 100 degrees, the first threshold temperature is between approximately 20 and 60 degrees and defines the fluid temperature below which the state of the engine is said to be "in steady state" transient "or" cold ", - the control means cooperate with the means of acqu isition, to calculate on the one hand the average instantaneous power supplied by the engine then on the other hand, the first threshold temperature as a function of the instantaneous average power and a determined modeling of the engine operation defining its cold state (first threshold temperature) as a function of average power, - the information acquisition means are able to detect a possible failure of the electronically controlled actuators, so that when at least one actuator failure is detected and whatever the fluid temperature, the control means ensure the free circulation of the fluid in at least some of the branches, - the circulation pump of the cooling fluid is mechanical pump, - the device comprises a branch provided with an electronically controlled actuator and in which is located recirculating means of at least a portion of the engine exhaust at the emission, or "Exaust Gas Recycling (EGR)", the actuator of 1a cooling branch associated with the exhaust recirculation means being closed when the temperature of the fluid is lower than the first threshold temperature, - the device comprises a branch comprising means for forming a cabin air heater and possibly additional heating means, the device comprises cabin air heater means and possibly additional heating means located in the branch comprising the engine exhaust gas recirculation means, - The branch comprising the heater means is provided with an electronically controlled actuator, the heater means being adapted to provide heating of the passenger compartment to a first target temperature determined by the user of the vehicle and in that the control means cooperate with the means of acquisition, in order to determine the temperature outside the vehicle, and, on the other hand, open, respectively close, the actuator of the air heater branch when outside temperature is lower, respectively higher than the first set temperature, - the branch comprising the heater means is provided with an electronically controlled actuator, the air heater means being able to provide air conditioning of the passenger compartment a second set temperature determined by the user of the vehicle, and in that the control means cooperate with the acquisition means, for on the one hand determine the temperature outside the vehicle, and, on the other hand, close, respectively open, the actuator of the air-heater branch when the outside temperature is lower, respectively higher, than the second set temperature.

Other features and advantages will appear on reading the description below, with reference to the figures in which - Figure 1 shows schematically the structure and operation of a first embodiment of the cooling device according to the invention FIG. 2 represents a second embodiment of the cooling device according to the invention; FIG. 3 represents, on the same graph, an example of variation over time t of the temperature of the cooling liquid and a first threshold temperature T 1 - FIG. 4 represents an example of a temperature variation Th of the engine lubricating oil as a function of the time t, and the signal representing the opening 0 and closing F conditions of the electronically controlled actuator of the first branch of the circuit - FIG. 5 represents the opening 0 and closing states F of the actuator of the branch 5 shows an example of variation of the period P of the control signal of the actuator of the degassing branch as a function of the temperature T of the cooling liquid, FIG. 7 represents the bypass valve opening state as a function of the coolant temperature T, FIG. 8 schematically represents an example of coupling of the opening of the bypass valve which is a function of the opening of the valve of a radiator, - Figure 9 shows two examples of variation of the speed of rotation of a motorcycle fan unit, depending on the variation of the temperature T of the coolant, Figure 1 represents a preferred embodiment of a cooling device according to the invention. The cooling device comprises a hydraulic circuit 2 containing a cooling heat transfer fluid.

3 hydraulic pump is associated with the circuit 2, to ensure the flow of fluid through the motor 1 and different branches 4, 5, 6, 7, 8, 44 of the circuit 2. Preferably, the pump 3 is a mechanical type pump however, the use of an electric pump can also be considered.

The branches 4, 5, 6, 7, 8, 44 of the circuit 2 are supplied with cooling liquid from a housing 122, or "water outlet housing" (BSE). The housing 122, which is fixed to the engine 1, and preferably to the cylinder head of the engine 1, collects the coolant having circulated in the engine 1. The coolant circulating in the branches recovered meanwhile by a collector water inlet 23 before recirculation in the engine 1.

Advantageously, at least some of the branches 4, 5, 6, 7, 8 of the circuit 2 are provided with respective electronically controlled actuators 14, 15, 16, 17, 1 29 for regulating the circulation of the fluid therein. Electronically controlled actuators are, for example, solenoid valves. Furthermore, the device comprises means 22 for acquiring information relating to the operating conditions of the vehicle. The acquisition means 22 are connected to means 19 for controlling the operation of at least a portion of the actuators 14, 15, 16, 17, 18, 29 to regulate the volume and the flow rate of fluid circulating in the circuit. hydraulic 2 to optimize the operation of the engine.

The control means 19 or information processing unit may comprise any appropriate computer 20, such as, for example, an "Intelligent Service Enclosure" (BSI) of known type. The computer 20 is associated with information storage means 21 comprising, for example, a programmable memory and / or a read-only memory. The computer 20 is also connected to means 22 for acquiring information relating to the operating conditions of the vehicle, comprising, for example, various sensors or other computers such as an engine control computer.

Preferably, the information acquisition means 22 are able to determine at least one of the following parameters: the engine speed, the engine torque, the vehicle speed, the temperature of the engine lubricating oil , the engine coolant temperature, the engine exhaust temperature, the outside air temperature of the vehicle and the temperature inside the passenger compartment. The various information relating to the operating conditions of the vehicle are processed and analyzed by the computer 20, to control the operation of the actuators 14, 15, 16, 17, 18, 29 and possibly that of the pump 3.

According to the invention, the flow rate or volume of coolant admitted or not to circulate in the different branches 4, 5, 6, 7, 8, 44 of the circuit 2 is a function of the heating state of the engine 1. By example, it is possible to define three states of the engine 1, a first state in which the engine is said to be "cold", a second in which the engine 1 is said to be "hot", and a third state called "intermediate" between the states hot and cold.

Preferably, the thermal state of the engine is characterized as a function of the temperature T of the coolant, preferably at the output of the engine 1. Thus, when the temperature of the coolant is lower than a first threshold temperature T, determined , the state of the engine 1 is said to be cold. Similarly, when the temperature T of the coolant is greater than a second threshold temperature T2 determined, the state of the engine 1 said hot. Finally, when the temperature of the coolant is between the first T, and second T2 threshold temperatures, the state of the engine 1 is said intermediate.

first T, and / or the second T2 threshold temperature may be fixed or variable values determined according to the type of the engine 1. Preferably, the first T, and / or second threshold temperature T2 are variables depending on the type of the engine 1 and at least one operating parameter of the engine 1. For example, the first T, and / or second T2 threshold temperatures are functions of the average power Pm supplied by the engine 1. That is to say that the means 19 control means cooperate with the acquisition means 22, to calculate the instantaneous average power Pm supplied by the engine 1. The control means 19 then calculate first T, and / or second T2 threshold temperature, depending on the average power Pm instantaneous and of a determined modeling of the operation of the engine 1. The modeling of the engine defines the states cold, hot and intermediate (first T, and second T2 temperatures threshold) according to the average power Pm provided by the latter.

; dans laquelle N est le régime instantané du moteur en tourimin, et C le couple instantané du moteur en N.m. Les valeurs du régime N et du couple C peuvent être mesurées par les moyens 22 d'acquisition de données, c'est-à- dire par des capteurs appropriés. Classiquement, régime N du moteur est compris entre 0 et 6000 tr/min. environ, tandis que le couple C est compris entre 0 et 350 N.m. environ. The instantaneous power P (t) in kiloWatt (kW) supplied <B> .- </ B> by the motor at time t is given by the following relation <B> P </ B> (t) =

; in which N is the instantaneous speed of the engine in turin, and C is the instantaneous torque of the engine in Nm. The values of the speed N and of the torque C can be measured by the data acquisition means 22, that is to say by appropriate sensors. Conventionally, engine speed N is between 0 and 6000 rpm. approximately, while the torque C is between 0 and 350 Nm approximately.

dans laquelle Pm(t-1) est la puissance moyenne à l'instant (t-1). Bien entendu, la puissance moyenne peut être calculée par tout autre formule équivalente, telle que : Pm(t) =

, dans laquelle Pm(t-1) la puissance moyenne à l'instant (t- ), P(t) la puissance instantanée à l'instant t, et c et k des coefficients pondérateurs. The control means 19 then calculate the power P (t) supplied by the engine at time t and the average power Pm (t) supplied by the engine at time t. The average power Pm (t) at time t can be calculated by the following relation Pm (t) =

where Pm (t-1) is the mean power at time (t-1). Of course, the average power can be calculated by any other equivalent formula, such that: Pm (t) =

where Pm (t-1) mean power at time (t-), P (t) instantaneous power at time t, and c and k weighting coefficients.

The computer 19 and / or the information storage means 21 may contain the modeling of the operation of the engine 1, defining its cold, hot and intermediate state (first T, and second threshold temperatures T2) as a function of the average power Pm. That is to say that for a given type of engine, one establishes empirically and / or by calculation of correspondence tables giving the threshold temperatures T, and T2 as a function of the average power Pm of the engine 1. These tables or modelizations , which are a function of the motor type, are for example polynomial functions. The first threshold temperature T, is thus, in general, a decreasing function of the average power.

The first threshold temperature T may vary between about 20 and 60 degrees, and preferably between 30 and 50 degrees. The second threshold temperature T2 may vary for its part between 60 and 100 degrees approximately. However, the second threshold temperature T2 is generally substantially constant around the value of 80 degrees.

Thus, the control means 19 cooperate with the data acquisition means 22 to compare the temperature T of the coolant with the two threshold temperatures T 1 and T 2.

For the sake of simplification, the value of the first threshold temperature T, can be fixed by the control means 19 as soon as the temperature T measured cooling liquid reaches the first threshold temperature T ,. Indeed, FIG. 3 illustrates, on the same graph, an example of variation over time t: of the temperature T of the coolant, and of the first threshold temperature T, (Pm), which is a function of the average power . By determining these temperatures T and T, (Pm), it can be seen that, for a given average power, from the moment when the temperature T of the fluid reaches the first threshold value T1, this first threshold temperature T varies little around a constant Referring now to Figure 1, the circuit 2 comprises a first branch 8 provided with first electronically controlled actuator 18 and in which is disposed water / oil exchanger 13. Preferably, the first actuator 18 is of the "all or nothing" type ". The control means 19 cooperate with the acquisition means 22 to control the opening or closing of the first actuator 18, so as to accelerate the rate of temperature rise of the oil and, on the other hand, on the other hand, to regulate the temperature of the oil around a determined reference temperature Tr.

More precisely, when the temperature T of the cooling fluid determined by the acquisition means 22 is lower than the first threshold temperature T ,, the driver means 19 tooth, and preferably stop, the flow of fluid in the first branch 8 .

Moreover, when the temperature T of the coolant is greater than the second threshold temperature Tz, the control means 19 regulate the temperature of the oil around the reference temperature Tr. The reference temperature Tr of the oil corresponds to at the optimum operating temperature of the oil. The reference temperature Tr, which depends on the type of oil, is typically between about 120 and 140 degrees, and is preferably about 130 degrees. To do this, the acquisition means 22 comprise means for measuring the temperature of the lubricating oil, such as a suitable sensor.

FIG. 4 illustrates an example of variation of the temperature of the oil Th as a function of time t. On the same graph is represented a square signal symbolizing the opening 0 and closing F of the actuator 18 of the first branch 8. The upper notches of the square signal represent the opening moments 0 of the actuator 18. The lower notches of the square signal represent closing moments F of this same actuator 18.

Thus, when the temperature Th of the oil exceeds the reference temperature Tr by a determined value ATa, the control means 19 ensure the opening of the actuator 18 and thus the circulation of the fluid in the first branch 8. By moreover, when the temperature Th of the lower oil of a value ATa at the reference temperature Tr, the control means 19 close the actuator 18 and thus stop the circulation of the fluid in the first branch 8. The temperature differentials ATa that trigger the O openings and closures F of the first actuator 18 are of the order, for example, from one to six degrees. As shown in FIG. 4, the temperature differentials ATa are preferably equal to two degrees.

In this way, given the thermal inertia of the system, the temperature Th of the oil can be maintained around the reference temperature Tr with a tolerance of about five degrees. Of course, the temperature Th of the oil can be maintained in a larger or smaller range. For this, it suffices to change the threshold differentials ATa of opening and closing of the first actuator 18 around reference temperature Tr.

Advantageously, when the temperature T of the cooling liquid is between the first T 1 and the second threshold temperature T 2, the control means 19 may open the first actuator 18 only when the temperature of the liquid exceeds the temperature of the oil. a second value oTb determined. This second value ATb may be, for example, between about 10 and 20 degrees and is preferably equal to 15 degrees. In this way, the coolant helps to speed up the temperature rise of the oil.

Referring again to FIG. 1, the circuit 2 comprises a second branch 6 called "degassing", provided with an electronically controlled actuator 16 and in which a degassing box 11 is arranged.

The control means 19 regulate the cooling fluid circulation so that the quantity of fluid flowing in the second branch 6 is greater when the temperature T of the cooling fluid greater than the first threshold temperature T ,, than when the temperature T of the fluid is lower than this first threshold temperature T 1.

Moreover, the control means 19 regulate the circulation of fluid in the degassing branch 6 so that the quantity of fluid flowing in it is greater when the temperature T of the fluid is greater than the second threshold temperature T2, when when the temperature T of the fluid is lower than this second threshold temperature T2.

In addition, when the temperature T of the fluid is between the first T, and second T2 threshold temperatures, the control means 19 can regulate the flow of fluid in the branch 6 of degassing as a function of the temperature T of the coolant. More specifically, the control means 19 can control the increase of the amount of cooling liquid circulating in the branch 6 of degassing when the temperature T of this liquid increases. The actuator 16 of the degassing branch 6 is preferably of the "all or nothing" type, that is to say with full opening and closing.

As shown in FIG. 5, when the temperature T of the fluid is greater than the second threshold temperature T2, the control means 19 control the opening, preferably the total, of the second actuator 16.

Moreover, when the coolant temperature T is lower than the first threshold temperature T ,, the control means 19 can control the opening of the second actuator 16 as a function of the average power Pm supplied by the engine 1. More precisely , the control means increase the amount of liquid admitted to circulate in the degassing branch 6 when the average power Pm supplied by the engine 1 increases. The branch actuator 16 is controlled, for example, by a variable square signal as a function of the average power Pm supplied by the motor 1. The upper part of the signal represents the actuator's openings <B> 0 </ B> 16, while the lower part represents the closures F of the actuator 16.

When the engine in its cold state (T <T,), the square control signal of the actuator 16 may be periodic. In particular, the opening time To of the actuator 16 may be constant, while the period P of the signal may vary as a function of the average power Pm. That is, the closing times of the valve 16 can decrease, for example linearly, when the average power Pm of the motor increases.

When the engine is in its intermediate state (temperature of the fluid T between the first T, and second T2 threshold temperatures), the control means 19 controlling the opening of the actuator 16 according to a variable square signal as a function of the temperature T coolant. In particular, the opening time To of the actuator 16 may be constant, while the period P of the signal may decrease when the temperature T of the coolant increases.

As shown in FIG. 6, between T 1 and T 2, the period P of the square signal can be inversely proportional to the temperature T of the liquid. Moreover, when the temperature T of the liquid approaches the second threshold temperature T2, the line representative of the evolution of the period P may have a discontinuity, so that the period P remains constant and equals the opening time T.sub.C that is, when the temperature of the liquid reaches, for example, the second threshold temperature T2 minus about five degrees, the decreasing line representing the period P is followed by a horizontal constant portion.

The opening time To of the actuator 16 may be of the order of a few seconds and for example five seconds. The period of the control signal of the actuator 16 can vary, for example, between 5 and 50 seconds. Of course, any other type of appropriate signal can be used to control the second actuator 16. For example, as above, it is possible to vary the opening time To of the valve, in addition to or instead of the time of closing.

As illustrated in FIG. 1, the circuit 2 comprises a third branch 5 provided with an electronically controlled actuator 15 and associated with means 10 forming a direct return of fluid or bypass. The control means 19 can regulate the circulation of the cooling fluid in the bypass branch 5 as a function of the temperature T of this fluid. In particular, the amount of fluid allowed to flow in the bypass branch 5 increases as the temperature of the fluid increases from the first T to the second threshold temperature T2. Preferably, the electronically controlled actuator 15 of the bypass branch is of the proportional type.

As shown in FIG. 7, when the temperature of the fluid T is lower than the first threshold temperature T ,, the control means 19 can limit the flow of fluid in the bypass branch to a determined leakage rate. That is, the actuator 15 of the bypass branch 5 is partially open Of. For example, the partial opening Of of the actuator 15 can provide a leakage flow in the branch 5 pass of between 1 / 50th to About 1 / 5th of the maximum flow of branch 5.

When the temperature of the fluid is greater than the second threshold temperature T2, the control means 19 at least temporarily control the total opening 0 of the bypass actuator 15 (FIG. 7 <B>) </ B>. Furthermore, when the temperature of the fluid is between the first T 1 and second threshold temperature T2, the degree of opening of the actuator 15 may be at least temporarily proportional to the temperature T of the cooling fluid. More precisely, between T 1 and T 2, the opening of the bypass actuator 15 increases as the temperature T of the fluid increases and decreases as the temperature T of the fluid decreases. The variation of the opening of the actuator 15 may be proportional to the temperature of the fluid T.

Advantageously, the curve representative of the opening of the actuator 15 as a function of the temperature T of the fluid can exhibit a hysteresis H. That is to say that the increase in the opening of the actuator 15 begins. after the temperature of the liquid T exceeds the first reference temperature T, by a first value E determined. Likewise, the decrease in the opening of the actuator 5 begins after the temperature T of the liquid becomes lower, from a first determined value E, to the second reference temperature T2. That is to say that the closing openings of the actuator 15 are made shifted with respect to the temperature thresholds T and T2, respectively. The values E of these offsets are, for example, of the order of 5 degrees.

Referring again to Figure 1, the circuit comprises a fourth leg 4 provided with an electronically controlled actuator 14 and provided with means forming a radiator. means 9 radiator can be coupled to a fan motor unit 30, which can also be controlled by the control means 19. The actuator 14 fourth branch 4 proportional type.

Advantageously, when the temperature T of the fluid is greater than the second threshold temperature T2, the control means 19 can control the actuator 15 of the branch 5 by-pass as a function of the opening and closing of the actuator 14 of FIG. the branch 4 radiator.

FIG. 8 illustrates the percentage of opening% O of the actuators 15, 14 of the third and fourth branches 5, 4 as a function of the temperature T of the coolant. As shown in FIG. 8, the control means 19 can close the actuator 15 of the bypass branch 5 when the actuator 14 of the radiator branch 4 is open O. Similarly, the actuator 15 of the branch 5 by-pass is open 0 when the actuator 14 of the radiator branch 4 is closed F. Preferably, the opening of the bypass branch actuator 15 is inversely proportional to the opening of the actuator 14 of the branch 4 radiator.

Furthermore, the closures and openings of the actuator 15 of the branch 5 bypass can be realized with a temperature offset R determined with respect to the openings and closures of the actuator 14 radiator branch 4. The temperature offset R can be of the order of a few degrees, for example five degrees.

As shown in FIG. 9, the control means can control the ventilation means 30 as a function of the temperature of the coolant. More precisely, the speed of rotation of the ventilation means 30 can increase when the temperature T of the cooling liquid increases.

figure 9 illustre deux exemples de droites d1 et d2 représentant la vitesse de rotation du groupe moto ventilateur en fonction de la température T du liquide. Les deux droites d1 et d2 ont des pentes différentes représentatives chacune d'une vitesse de variation

de la température T du liquide de refroidissement. La vitesse de variation

de la température T du liquide de refroidissement peut être calculée par les moyens 19 de pilotage. Preferably, the speed V of rotation of the ventilation means 30 increases in proportion to the speed of variation of the temperature of the coolant.

FIG. 9 illustrates two examples of lines d1 and d2 representing the speed of rotation of the fan motor unit as a function of the temperature T of the liquid. The two straight lines d1 and d2 have different slopes each representative of a speed of variation

the temperature T of the coolant. The speed of variation

the temperature T of the coolant can be calculated by the control means 19.

The cooling circuit 2 shown in Figure 1 also comprises a fifth branch 7 provided with an electronically controlled actuator 17 and in which are arranged means 12 forming a cabin air heater. Conventionally, the heater means 17 may be shaped to provide heating of the passenger compartment at the first set temperature Tc determined by the vehicle user.

The control means 20 cooperate with the acquisition means to determine the temperature Te outside the vehicle. When the outside temperature Te is lower than the first setpoint temperature Tc, the control means 20 can open the actuator of the branch 7 air heater. In the same way, when the outside temperature Te is greater than the first setpoint temperature Tc, the control means 20 can close the actuator of the branch 7 air heater.

In the same way, the air heater means 12 may comprise an air conditioning function of the passenger compartment at a second setpoint temperature Tr. Thus, when the outside temperature Tc is lower than the second setpoint temperature Tr, the control means 20 may open the door. actuator of branch 7 air heater. Similarly, when the outside temperature Te is greater than the second set temperature Tr, the control means 20 can close the actuator of the branch 7 air heater.

This fifth branch 7 may also optionally comprise additional heating means 160 and / or means 150 for recirculating the exhaust gas from the engine 1 to the inlet. Conventionally, the means 150 forming recirculation of at least a portion of the exhaust gas from the engine 1 to the inlet or "Exaust Recycling (EGR)", allow (I control the temperature of the combustion gases of the engine for, for example , an antipollution treatment.

Finally, the circuit 2 represented in FIG. 1 comprises a sixth branch 44 in which is located means 140 for heating the intake air of the engine 1. This sixth branch 44 is also provided with an electronically controlled actuator 29 controlled by the control means.

FIG. 2 illustrates an alternative embodiment of the cooling device according to the invention. The device shown in FIG. 2 differs from that of FIG. 1 in that the heater means 12 and the heating means 160 are arranged in a seventh branch 45 which is distinct from the sixth branch 7 associated with the means 150 for recirculating the gases. exhaust (EGR). Moreover, the seventh branch 45 is devoid of electronically controlled actuator.

Of course, the invention can not be limited to the exemplary embodiments of FIGS. 1 and 2. In fact, the cooling device may comprise only a portion of thermal equipment 9, 10, 11, 12, 13, 140, 150, 16 and / or branches 4, 5, 6, 7, 8, 44, 45 described above. In addition, one or more branches 4, 5, 6, 7, 8, 44, 45 may be devoid of electronically controlled actuator.

Advantageously, the information acquisition means 22 may be shaped to detect a possible failure in the hands of one of the electronically controlled actuators. In this way, when at least one failure of an actuator is detected and whatever the temperature of the fluid, the control means 19 can ensure the free circulation of the fluid in at least some branches, and preferably in all branches. . That is, when a system failure is detected, all valves in circuit 2 are open.

We therefore conceive. It is easy for the cooling device according to the invention, while being of simple structure, to be able to manage the heat exchanges in real time and in an optimum manner.

 Finally, although the invention has been described in connection with particular embodiments, it includes all the technical equivalents of the means described.

Claims (1)

<B> <U> CLAIMS </ U> </ B>. Cooling device for a motor vehicle engine, of the type comprising a hydraulic circuit (2) for coolant, associated with a pump (3) circulation thereof through the engine (1) of the vehicle and different branches (4, 5, 6, 7, 8, 44, 45) of the circuit in which thermal equipment 10, 12, 13, 140, 150, 160) of the vehicle are arranged, in the hands of some of the branches (4, 5, 6 , 7, 8, 44) of the circuit (2) being provided with electronically controlled actuators (14, 15, 16, 17, 29) regulating the circulation of the fluid in those of the device comprising means (22) for acquisition of information relating to the operating conditions of the vehicle, connected to means (19) for controlling the operation of the actuators (14, 15, 16, 17, 18, for regulating the volume and the flow rate of fluid circulating in the circuit hydraulic system (2) in order to optimize the operation of the engine, characterized in that the means (22) for acquiring information are capable of determining the temperature of the cooling liquid, the control means (19) ensuring the limitation or the stoppage of the circulation of the fluid in at least some of the branches (4). , 5, 6, 7, 8, 44) when the fluid temperature is lower than a first threshold temperature (T,) determined. 2. Device according to claim 1 characterized in that the control means (19) provide at least temporarily fluid circulation in at least cnrtane :: branches (4. 5, 6, 7, 8, 44) when the temperature fluid is greater than a second threshold temperature (T2) determined. 3. Apparatus according to i evendica'io @ is 1 and 2 characterized in that, when the temperature of I..Aide is cor.- Taken ent: e lus first (T,) and second; (T2; terr: threshold threshold, the means ue piloting (19) provide at least temporarily fluid circulation in at least some (4, 5, 6, 7, 8, 44) branches, volume and / or flow of fluid flowing in said branches (4, 5, 6, 7, 8, 44) depending on the temperature of the liquid 4. Device according to claim 2 or 3, characterized in that the second threshold temperature (T2) is included between 60 and 100 degrees C. 5. Device according to any one of claims 1 to 4, characterized in that the first threshold temperature (T) is between approximately 20 and 60 degrees and defines the fluid temperature below which the state of the engine (1) is said to be "transient" or "cold" 6. Device according to claim 5, characterized in that the control means (20) cooperate with the acquisition means (22), for calculate on the one hand the instantaneous mean power (Pm) supplied by the motor (1) then, on the other hand, the first threshold temperature (T) as a function of the instantaneous mean power (Pm) and a determined modeling of the operation of the engine (1) defining its cold state (first threshold temperature (T)) in average power function (Pm). 7. Device according to any one of claims 1 to 6, characterized in that the means (22) for acquiring information are able to detect a possible failure of the actuators 15, 16, 17, 18, 29), so that when at least one failure of an actuator (14, 15, 16, 17, 18, 29) is detected and whatever the temperature of the fluid, the control means (19) ensure the free circulation of the fluid in at least some of the branches (4, 5, 6, 7, 8, 44). 8. Device according to any one of the preceding claims, characterized in that the pump (3) for circulating the cooling fluid es-: a mechanical pump. Device according to any one of the preceding claims, characterized in that it comprises a branch (7) provided with an electronically controlled actuator (17) and associated with means (150) for recirculating at least part of the gases of exhaust of the engine (1) at the intake, or "Exaust Gas Recycling (EGR)", the actuator (17) of the branch (7) of cooling associated with the exhaust gas recirculation means being closed when the fluid temperature is lower than the first threshold temperature (T,). Device according to any one of the preceding claims, characterized in that it comprises a branch comprising means (12) forming a cabin air heater and possibly additional heating means (160). 11. Device according to claim 9, characterized in that it comprises means (12) forming a cabin heater and optionally additional heating means (160) located in the branch (7) comprising the means (150) for recirculation. exhaust gases from the engine (1). 12. Device according to claim 10, characterized in that the branch (7, 45) comprising the means (12) heater is provided with an electronically controlled actuator ically, the heater means being adapted to ensure heating of the passenger compartment. a first target temperature (Tc) determined by the user of the vehicle, and in that the control means (20) cooperate with the acquisition means (22), in order firstly to determine the outside temperature (Te) at the vehicle on the other hand, opening, respectively closing, the actuator of the branch (7, 45) heater when the outside temperature (Te) is lower, respectively higher, at the first set temperature (Tc). 13. Device according to claim 10 or 12, characterized in that the branch (7, 45) comprising the means 2) heater is provided with acticnneur electronically controlled, the heater means being able to ensure an air-conditioning of the passenger compartment at a second setpoint temperature (Tr) determined by the user of the vehicle, and in that the control means (20) cociperate with the acquisition means (22), for a part to determine the external temperature (Te) to the vehicle, on the other hand, closing, respectively opening, the actuator of the branch (7, 45) heater when the external temperature (Te) is lower, respectively greater than the second set temperature ( Shoot).