EP2156029A1

EP2156029A1 - Module for the cooling circuit of an engine in an automobile

Info

Publication number: EP2156029A1
Application number: EP08736481A
Authority: EP
Inventors: Frédéric Vacca; Alain Farkh
Original assignee: Valeo Systemes Thermiques SAS
Current assignee: Valeo Systemes Thermiques SAS
Priority date: 2007-05-25
Filing date: 2008-04-23
Publication date: 2010-02-24
Also published as: JP5529733B2; US8695542B2; FR2916479A1; FR2916479B1; WO2008145461A1; KR101447306B1; CN101680352A; CN101680352B; JP2010528229A; KR20100017290A; US20100212612A1

Abstract

The invention relates to a module for the cooling circuit of an engine in an automobile, that comprises at least one control valve (18) allowing a flow according to at least one so-called nominal mode. The module further includes a thermal safety device (30) for said circuit, the thermal safety device (30) being capable of authorising a flow according to another so-called short-circuit mode in case of failure of the nominal flow mode. The invention can be used for automobiles.

Description

Module for a cooling circuit of a motor vehicle engine

The invention relates to cooling circuits for motor vehicle engines.

It relates more particularly to a module for a cooling circuit of a motor vehicle engine, comprising at least one control valve for a circulation according to at least one so-called normal mode.

Generally a cooling circuit of this type is traversed by a cooling fluid under the action of a pump and it comprises a control valve having an input adapted to be connected to the motor and a radiator output adapted to be connected to a radiator cooling (see in particular the French patent FR 2,850,726 of 31 January 2003).

In this known cooling circuit, the control valve comprises a clean rotary control member to take different angular positions to control the distribution of the fluid through several outputs which include a radiator output adapted to be connected to a cooling radiator, a heater output clean to be connected to a heater for heating the cabin of the vehicle, and a bypass outlet clean to be connected to a bypass bypassing the cooling radiator. Such a control valve is usually controlled by an electric motor which controls the displacement of the adjustment member according to a chosen law.

The main purpose of the invention is to improve the safety of such a control valve in the event of a failure of external origin, due for example to the vehicle computer or to a control electronics, or of internal origin, due for example to an electric motor, a gearbox or a hydraulic stage.

It is indeed desirable, in such a case, to ensure a safe mode of operation.

One solution is then to direct the cooling fluid to the cooling radiator to prevent overheating and damage to the engine of the vehicle, the engine may be a heat engine, an electric motor, or a hybrid engine.

It is known to incorporate a return spring in a valve, in order to return the rotary adjustment member to a safety position to ensure the opening of the channel corresponding to the radiator output.

However, it is possible to have a failure of the return spring of the valve.

As a result, the rotary adjusting member can remain in a position closing the radiator output. This will cause an uncontrolled rise in temperature of the engine and, eventually, cause damage to it. In addition, the addition of a return spring requires to choose a geared motor capable of permanently defeating the spring force. This has the effect of over-dimensioning the actuating motor of the valve and increasing the cost, the bulk.

The invention improves the situation.

It proposes for this purpose a module for a cooling circuit of a motor vehicle engine, comprising at least one control valve for a circulation according to at least one so-called normal mode.

According to the invention said module further comprises a thermal safety device for said circuit, said thermal safety device being able to allow a circulation according to another so-called short-circuit mode in case of failure of the normal circulation mode.

Thus, in the event of failure of the normal circulation mode, such as an accidental overheating that may be due to a failure of the valve, the thermal safety device then authorizes circulation in a short-circuit mode.

This short circuit mode is primarily intended to prevent any risk of overheating the engine.

Advantageously, the safety device comprises a shutter means controlled by an element sensitive to the detected temperature of a fluid of cooling passing through said cooling circuit, said shut-off means being in a so-called closing position when the detected temperature is below a given threshold and brought into a so-called opening position when the detected temperature exceeds the given threshold, so directing at least a portion of the cooling fluid to a cooling radiator of said cooling circuit by short-circuiting the control valve.

According to another advantageous characteristic, said thermal safety device comprises an input adapted to be connected to a cooling fluid outlet of the engine, a valve outlet adapted to be connected to the input of the control valve and a bypass outlet specific to be connected to a bypass between the inlet and a radiator outlet of the control valve.

In a first variant embodiment, the thermal safety device is adapted to be integrated in a water outlet housing of the engine, adapted to be mounted on the engine.

The engine water outlet housing advantageously comprises a body delimiting a main passage extending between the inlet and the valve outlet and a pipe opening laterally into the main passage and delimiting a secondary passage in which the safety device is mounted. thermal.

Preferably, the water outlet housing of the motor is adapted to be mounted directly on the motor and to directly receive the control valve. In a second variant embodiment, the thermal safety device is adapted to be integrated in a separate equipment, suitable for being mounted between the motor and the control valve.

This separate equipment advantageously comprises a duct delimiting a main passage extending between the inlet and the valve outlet and a pipe opening laterally into the main passage and delimiting a secondary passage in which the thermal safety device is mounted.

In a third variant embodiment, the thermal safety device is integrated in the control valve.

In this third variant, the control valve advantageously comprises a cylindrical body delimiting a cylindrical housing for a control member mounted for rotation about an axis, in which the inlet and the valve outlet of the thermal safety device are aligned coaxially with the cylindrical housing, and wherein the bypass outlet of the thermal safety device is formed by a pipe opening laterally into the cylindrical housing and housing the thermal safety device.

The radiator output of the control valve is advantageously formed by a pipe opening laterally into the cylindrical housing of the control valve. The radiator outlet tubing and the bypass outlet tubing may open at respective locations offset in the axial direction of the control valve.

The radiator outlet tubing and the bypass outlet tubing may also terminate at respective locations offset in the radial direction of the control valve.

In the latter case, the location of the bypass outlet manifold is preferably outside the area of action of the control valve adjusting member.

In the module of the invention, said closure means is preferably a valve.

The term "valve" should be understood in the broad sense to mean any shutter element adapted to be placed in the closed position or the open position mentioned above.

In a first exemplary embodiment, the valve is connected to a thermostatic element capable of moving the valve from the closed position to the open position when the detected temperature exceeds the given threshold, a retaining member being provided to hold the valve in the open position and prevent it from returning to the closed position.

In a second exemplary embodiment, the valve comprises a flap pivotally mounted about an axis and retained in the closed position by a retractable abutment held in abutment position by a material retaining member. eutectic having a melting point corresponding to the given threshold and likely to come into a retracted position to release the valve, when the retaining member has reached its melting point.

In a third exemplary embodiment, the valve is connected to a shape memory alloy element capable of moving said valve from the closed position to the open position when the detected temperature exceeds the given threshold.

The shape memory alloy element may be, for example, a rod capable of elongating, or otherwise retracting, when the sensed temperature exceeds the given threshold.

It may still be a spring, in particular helical, able to elongate, or on the contrary to retract, when the detected temperature exceeds the given threshold.

In another aspect, the invention relates to a cooling circuit of a motor vehicle engine, which comprises a module as defined above.

Other features and advantages of the invention will be better understood on reading the detailed description which follows and with reference to the appended drawings, in which:

FIG. 1 is a diagram of a cooling circuit of a vehicle engine comprising a module comprising a control valve and a thermal safety device according to the invention;

FIGS. 2, 3 and 4 respectively represent three variant embodiments of the module of the invention;

- Figure 5 shows, in side view and partially in section, an engine water outlet housing incorporating a thermal safety device according to the invention, the water outlet housing being adapted to be mounted directly on the motor and to directly receive the control valve;

- Figure 6 is a sectional view of a separate equipment in which is integrated a thermal safety device according to the invention;

- Figure 7 is a partial sectional view of a control valve incorporating a thermal safety device according to the invention;

Figure 8 shows the developed body and the sealing segment of a control valve incorporating a thermal safety device in an alternative embodiment;

- Figure 9 schematically shows a valve connected to a thermostatic element;

- Figure 10 is a partial sectional view of a valve body incorporating a valve in the form of a pivoting flap and retained in the closed position by a retaining member comprising a eutectic material; - Figure 11 is a perspective view of a valve in another embodiment;

- Figure 12 is a partial sectional view of a thermal safety device incorporating the valve of Figure 11;

- Figure 13 shows a partial sectional view of a valve body similar to that of Figure 10 wherein the valve is also formed in the form of a pivoting flap;

FIG. 14 is a perspective view of the valve of FIG. 13;

- Figures 15A and 15B show a valve connected to a shape memory alloy element, here made in the form of a rod, respectively in the closed position and in the open position;

FIGS. 16A and 16B are views similar to FIGS. 15A and 15B in a variant embodiment;

- Figures 17A and 17B illustrate a valve connected to a shape memory alloy element, here made in the form of a spring, respectively in the closed position and in the open position; and

- Figures 18A and 18B are views similar to Figures 17A and 17B in an alternative embodiment. Referring first to Figure 1 which shows a circuit 10 for cooling a motor vehicle engine 12, for example a heat engine, an electric motor or a hybrid engine. The circuit 10 is traversed by a cooling fluid, typically water added with an antifreeze, which circulates under the action of a pump 14. The circuit comprises a cooling radiator 16 in which the cooling fluid gives way. heat to a flow of air set in motion by the speed of the vehicle and / or by a motor-fan unit (not shown),

The circuit comprises a control valve 18 having an input 20 adapted to be connected to an output 22 of the motor, two other outputs 24 and 26 not described in detail and a radiator output 28 adapted to be connected to the cooling radiator 16.

The outlets 24 and 26 may be connected for example to a heater for heating the passenger compartment and a branch bypassing the radiator, in a manner known per se.

In a circuit of this type, the control valve 18 may comprise, for example, a rotary type control member for controlling the distribution of the cooling fluid between the outlets 24, 26 and 28 according to a chosen law, as taught for example by the aforementioned French patent. The regulating member of the control valve is usually controlled by a stepping electric motor or a geared motor. The control valve thus allows circulation according to at least one so-called normal mode. As mentioned above, in the event of malfunction of the valve or its control means, the valve may remain stuck in a position which does not promote cooling of the engine.

However, for safety reasons, it is necessary in this case to favor the cooling of the engine, so pass the cooling fluid in the cooling radiator, to prevent overheating and therefore any engine damage.

The invention provides for this a module comprising the control valve 18 and a thermal safety device 30 adapted to allow circulation according to another so-called short-circuit mode in case of failure of the normal circulation mode. The thermal safety device 30 is installed on a bypass 32 between the inlet 20 of the valve and the radiator outlet 28 of the valve. The device 30 comprises a closure means, in the example a valve

(Not shown), which is normally in a closed position, which closes the bypass 32, when the temperature of the cooling fluid, as detected, is below a given threshold (for example 120 ⁰ C). In this case, the cooling fluid passes from the output 22 of the motor to the inlet 20 of the valve and is then distributed between the channels corresponding to the outlets 24, 26 and 28, as shown by the arrows in solid lines.

In the event of an operating anomaly resulting in an increase in temperature, that is to say when the detected temperature exceeds the aforementioned threshold, the valve of the safety device 30 is automatically, irreversibly or reversibly brought into an open position, which opens the bypass 32. The cooling fluid then passes through the bypass as shown by the arrows in broken lines. Thus, at least a portion of the cooling fluid is directed towards the cooling radiator 16 by short-circuiting the control valve 18. Thus, the thermal safety device 30 is able to allow circulation according to a so-called short-circuit mode. in case of failure of the normal circulation mode.

In the embodiment of Figure 2, the thermal safety device 30 is adapted to be integrated in a water outlet housing 34 of the engine, the housing being adapted to be mounted on the motor and having an inlet 36 specific to be connected to the output 22 of the motor, a valve output 38 adapted to be connected to the inlet 20 of the valve and a bypass outlet 40 adapted to be connected to the bypass 32.

In the variant embodiment of FIG. 3, the thermal safety device 30 is able to be integrated in a separate piece of equipment 42 able to be mounted between the motor 12 and the control valve 18 and comprising an inlet 44 capable of being connected to the output 22 of the motor, a valve output 46 adapted to be connected to the inlet 20 of the valve and a bypass outlet 48 adapted to be connected to the bypass 32.

In the variant embodiment of FIG. 4, the thermal safety device 30 is integrated in the control valve 18 and more particularly in a housing 50 attached to the control valve and comprising an inlet 52 adapted to be connected to the output 22 of the motor, a valve output 54 connected to the inlet 20 of the valve and a bypass outlet 56 adapted to be connected to the branch 32 .

The variants of FIGS. 2, 3 and 4 are functionally equivalent. They simply differ from each other by the integration mode of the thermal safety device 30 in the module.

Referring now to FIG. 5, which shows in more detail the water outlet housing 34 corresponding to FIG. 2, this housing 34 comprises a body 58 delimiting a main passage 60 which extends between the inlet 36 and the valve outlet 38, and a pipe 62 opening laterally into the main passage 60 and delimiting a secondary passage 64 in which the safety device 30 is mounted. The pipe 62 has an enlarged portion 66 for accommodating the safety device 30 The tubing 62 is advantageously formed in two parts which are connected at this enlarged part to allow the integration of the safety device 30.

In this embodiment, the water outlet housing 34 is adapted to be mounted directly to the motor by a flange 68 and is adapted to directly receive the control valve 18 by means of a flange 70 of the valve.

As can be seen in FIG. 5, the control valve 18 comprises a cylindrical body 72 delimiting a cylindrical housing 74 of axis XX in which is mounted in rotation an adjusting member 76 in the form of a single cylindrical element, for example, hollow with a truncated wall 78. In the valve body laterally open several outlet pipes, only one of which is shown in FIG. 5, namely a tubing 80 which delimits the radiator output 28.

The adjusting member 76 can be brought selectively into different angular positions by means of an electric motor 82 such as a geared motor or a stepper motor which controls the movement of the regulating member through In the event of a malfunction, the safety device 30 is brought into the open position and passes the fluid directly through the tubing 62 as represented by the arrow in broken lines.

Referring now to Figure 6 which further illustrates the separate equipment 42 of Figure 3. This equipment 42 includes a conduit 86 defining a main passage 88 extending between the inlet 44 and the valve outlet 46, and a pipe 90 opening laterally into the main passage and delimiting a secondary passage 92 in which the safety device 30 is mounted.

FIG. 7 illustrates in more detail the embodiment of FIG. 4. The control valve 18 is substantially similar to that of FIG. 5. It comprises a cylindrical body 72 delimiting a cylindrical housing 74 for the adjustment member 76 rotatably mounted about an axis XX. The body 72 of the valve comprises an axial extension 94 to form the inlet 52 and the outlet valve 54 of the safety device. The inlet 52 and the valve outlet 54 are aligned coaxially with the cylindrical housing 74. The bypass outlet 56 of the safety device is formed by a pipe 96 opening laterally into the cylindrical housing and housing the safety device 30.

As in the case of Figure 5, the radiator output 28 of the control valve is formed by a pipe 80 opening laterally into the cylindrical housing of the control valve. The radiator outlet tubing 80 and the bypass outlet tubing 96 open at respective locations offset in the axial direction of the control valve. The pipes are capped by a manifold 98 which is assembled on the pipes 80 and 96 by locking in position the safety device 30. This manifold 98 has an output 100 adapted to be connected to the radiator.

Alternatively, the radiator outlet tubing 80 and the bypass outlet tubing 96 may open at respective locations offset in the radial direction of the control valve.

FIG. 8 shows a sealing segment 102 associated with a rotary control member of a control valve in the aforementioned case. There is shown by a dashed rectangle the developed 104 of the cylindrical valve body. We see that the radiator output 28 of the control valve here has a square shape, while the bypass outlet 56 here has a circular shape and they are angularly offset. This means that the corresponding tubings 80 and 96 (not shown) are offset angularly and not axially as in the case of Figure 7.

It will be noted that in all the embodiments proposed by the present invention, the safety device comprises a bypass outlet adapted to be connected to a shunt between the inlet and a radiator output of the control valve independent of the radiator output of the control valve.

It is further noted that the sealing segment 102 has a portion 106 of greater width which controls the radiator output 28 and the output 24 corresponding to the heater and the outlet 26 corresponding to the radiator bypass. The sealing segment 102 also has a narrower portion 108 which permanently disengages the bypass outlet 56. Thus, this outlet is in a dead zone, which is spared by the sealing segment 102, regardless of the angular position. of the regulator of the valve. As a result, the location of the tubing 96 of the bypass outlet 56 is outside the area of action of the control member of the control valve.

We will now describe in more detail different embodiments of the safety device 30, and more particularly its valve.

In the embodiment of FIG. 9, the safety device 30 comprises a valve 110 made in the form of a plate which is connected to a thermostatic element 112, for example of the type with an expandable wax capable of moving the valve of the position. closure shown in phantom solid in the open position shown in broken lines. A retaining member formed of a plurality of resilient tongues 114 is provided to hold the valve in the open position and prevent it from returning to the closed position. The resilient tabs 116 have respective ends 116 which are spaced radially by the valve 110 in the closed position. When the valve is moved axially in its open position, the ends 116 of the tongues 114 can move radially inwards to retain the valve as shown in phantom in Figure 9. As a result, the valve remains maintained in the open position to favor the cooling of the engine.

Referring now to Figure 10 which shows a water outlet housing 34 defining a main passage 60 axially aligned with the cylindrical housing 74 of a control valve 18. The water outlet housing 34 also defines a passage secondary 64 in which is mounted a valve 152 of the safety device. On the body of the valve is reported a base 120 having a connector 122 fitted into the radiator outlet 28 of the valve and a connector 124 aligned with the secondary passage 64 of the valve body. On the base 120 is mounted a housing 126 forming a tube 128 adapted to be connected to the cooling radiator and delimiting a chamber 130 adapted to be powered or not by the cooling fluid depending on whether the valve 152 is in the open position or in the closed position. This chamber 130 communicates with the interior of the tubing 128. The valve 152 of the safety member 30 is in the form of a flap pivotally mounted about an axis 154 and retained in the closed position by a retractable stopper 156, which is held in its abutment position by a member retainer 158 made of eutectic material. This retaining member is placed against a plate 160 integral with the abutment 156, and against which comes to rest a helical spring return 162.

The principle of operation of the retaining member is based on the use of a eutectic material, that is to say a phase-transforming material which can pass from a solid phase to a liquid phase to a liquid phase. very precise temperature depending on the composition of the material. In other words, this eutectic material has a melting point which corresponds to the threshold given to release the valve when the detected temperature corresponds to this threshold.

In the normal position, the eutectic material 58 is in the solid state and holds the stopper 156 in its extended position, against the restoring force exerted by the spring 162. The valve is held against the abutment 156 under the spring. effect of the pressure P of the fluid. On the other hand, as soon as the detected temperature exceeds the given threshold, the eutectic material melts and the stop comes to retract in the direction of the arrow F1, which makes it possible to release the valve which will pivot about its axis in the direction of the arrow

F2 under the effect of the pressure P of the fluid. The fluid can then reach the radiator bypassing the control valve.

The valve 164 shown in FIGS. 11 and 12 is here a pivoting flap of rectangular shape and comprises two flanges 166 for delimiting a pivot axis. The valve 164 is provided with a seal 168 at its periphery, as seen in FIG.

In the alternative embodiment of Figures 13 and 14, the valve 170 is a generally circular pivoting flap provided with two flanges 172 defining an axis of rotation which extends substantially along the diameter of the flap. Again, the flap is provided with two flanges 172 similar to the flanges 166 of Figure 11. This flap is surrounded by a seal 174. The axis of the flap is secured to a torsion spring, not shown.

In the case where a eutectic material is used to form a retaining member, it is possible to very precisely choose the composition of this material to obtain the chosen melting point.

It is particularly preferred to use alloys of the tin-bismuth type. For example, to obtain a melting point 130 ^° C., it is possible to choose an alloy comprising 40% tin, 56% bismuth and 4% zinc, these percentages being expressed by weight. In such alloys, materials such as cadmium and lead are prohibited to avoid any pollution problem.

Referring now to Figures 15A and 15B which show a valve 176 made in the form of a soft rubber-type seal adapted to cooperate with an opening 178 formed in a wall 179. The valve 176 is mounted at the end of an element 180 made of shape memory alloy and here having the shape of a rod. The other end of the element 180 bears on a fixed wall 182.

It is known that the ^shape memory alloys are materials that can resume their original preset shape triggered by heating, this process being reversible and can be repeated several times. As shape memory alloys that can be used in the invention, mention may be made by way of example of nitinol which is a nickel-titanium alloy material, copper-aluminum-nickel alloys and copper alloys -aluminium-zinc.

In the example of FIGS. 15A and 15B, the element 180 is able to lengthen when the detected temperature exceeds the given threshold.

Thus, when the detected temperature is below the given threshold, that is to say below the trigger threshold of the shape memory alloy, the valve 176 closes the opening 178 as shown in FIG. 15A, where the detected temperature exceeds the above threshold, the device is actuated and the element 180 extends so that the rubber seal passes through the opening 178 and is placed on the other side of the corresponding wall as shown Figure 15B. This device offers the advantage of being reversible. Thus, when the temperature drops below the trigger threshold of the shape memory alloy, the valve returns to its normal position of closure.

Figures 16A and 16B show a variant in which the element 184 of shape memory alloy is a rod capable of retracting when the detected temperature exceeds the given threshold. Here, the valve 186 is a shutter provided with a seal 188 adapted to bear against the wall 179 in which the opening 178 is formed.

When the temperature exceeds the given threshold, that is to say the trigger threshold of the shape memory alloy, the element 184 retracts, which also causes the valve 186 and the seal 188 to move away from the wall 179 as shown in Figure 16B. The valve then moves to the open position.

In the embodiment of FIGS. 17A and 17B, the valve 186 provided with a gasket 188, the presence of which is not essential, is urged in the closed position by a support spring 190, Furthermore, the valve 186 is connected to a shape memory alloy element 192 which is formed in the form of a spring, in the helical example, one end of which is fixed to the valve and the other end of which is fixed. on the bottom wall 182. In the closed position of FIG. 17A, the valve is biased against the wall 179 to close the opening 178.

When the detected temperature exceeds the given threshold, that is to say the threshold of the element 192, the latter retracts to clear the opening 178 as seen in Figure 17B.

In the embodiment of FIGS. 18A and 18B, the valve is plated in its closed position by a helical spring 190 similar to that of FIGS. 17B. The valve 186 is connected to a shape memory alloy element 194 made in the form of a spring, in the helicoidal example, interposed between the wall 179 and the valve, unlike the preceding embodiment. shape memory element 194 is able to elongate when the detected temperature exceeds the given threshold. Thus, in case of exceeding this threshold, the element 194 elongates which causes the displacement of the valve 186 in the opening direction as seen in Figure 18B.

It is of course possible to design other shape memory alloy elements to control the movement of the valve in the direction of opening when the detected temperature exceeds the threshold mentioned above which corresponds to the trigger threshold of the alloy to shape memory used.

The invention finds particular application to the cooling circuits of motor vehicle engines, in particular thermal engines, but also electric motors or hybrid engines.

Claims

claims

1. Module for a cooling circuit of a motor vehicle engine, comprising at least one control valve (18) allowing a circulation according to at least one so-called normal mode,

characterized in that said module further comprises a thermal safety device (30) for said circuit, said thermal safety device (30) being able to allow a circulation according to another so-called short-circuit mode in case of failure of the mode normal circulation.

2. Module according to claim 1, wherein said thermal safety device (30) comprises an inlet (36; 44; 52) adapted to be connected to a cooling fluid outlet of the engine, a valve outlet (38; 46; 54) adapted to be connected to the inlet (20) of the control valve (18) and a bypass outlet (40; 48; 56) adapted to be connected to a bypass (32) between the inlet (20) and a radiator output (28) of the control valve (18).

3. Module according to claim 1 or 2, wherein the safety device comprises a shutter means (110; 152; 164; 170; 176; 186) controlled by a sensed element to the detected temperature of a cooling fluid. traveling through said cooling circuit, said shut-off means being in a so-called closed position when the detected temperature is below a given threshold and brought into a so-called opening position when the detected temperature exceeds the given threshold, so as to direct at least a portion of the cooling fluid to a cooling radiator (16) of said cooling circuit by shorting the control valve (18).

4. Module according to claim 3, wherein said shutter means is a valve.

5. Module according to claim 4, wherein the valve (110) is connected to a thermostatic element (112) adapted to move said valve from the closed position to the open position when the detected temperature exceeds the given threshold, a retainer (114) being provided to hold the valve in the open position and prevent it from returning to the closed position.

6. Module according to claim 4, wherein the valve comprises a flap (152; 164; 170) pivotally mounted about an axis and retained in the closed position by a retractable stop (156) held in abutment position by an organ retaining eutectic material having a melting point corresponding to the given threshold and likely to come into a retracted position to release the valve, when the retaining member has reached its melting point.

7. Module according to claim 4, wherein the valve (176; 186) is connected to a shape memory alloy element (180; 184; 192; 194) capable of moving said valve from the closed position to the opening position when the detected temperature exceeds the given threshold.

8. Module according to claim 7, wherein the shape memory alloy element is a rod (180) capable of elongation when the detected temperature exceeds the given threshold.

9. Module according to claim 7, wherein the shape memory alloy element is a rod (184) capable of retracting when the detected temperature exceeds the given threshold.

10. Module according to claim 7, wherein the shape memory alloy element is a spring (194), in particular helical, capable of extending when the detected temperature exceeds the given threshold.

11. Module according to claim 7, wherein the shape memory alloy element is a spring (192), in particular helical, capable of retracting when the detected temperature exceeds the given threshold.

12. Module according to one of claims 2 to 11, wherein the thermal safety device (30) is adapted to be integrated in a water outlet housing (34) of the engine, adapted to be mounted on the engine ( 12).

The module according to claim 12, the connection of claim 12 to claim 3 being taken in its connection to claim 2, wherein the water outlet housing (34) of the engine comprises a body (58) defining a main passage (60) extending between the inlet (36) and the valve outlet (38) and a manifold (62) opening laterally into the main passage (60) and delimiting a secondary passage (64) in which is mounted the thermal safety device.

14. Module according to one of claims 12 and 13, wherein the water outlet housing (34) of the motor is adapted to be mounted directly on the motor (12) and directly receive the control valve (18). .

15. Module according to one of claims 2 to 11, wherein the thermal safety device (30) is adapted to be integrated in a separate equipment (42), adapted to be mounted between the motor (12) and the valve of control (18).

Module according to claim 15, the connection of claim 15 to claim 3 being taken in its connection to claim 2, wherein the separate equipment (42) comprises a conduit (86) delimiting a main passage (88). extending between the inlet (44) and the valve outlet (46) and a pipe (90) opening laterally into the main passage and delimiting a secondary passage (92) in which the thermal safety device (30) is mounted.

17. Module according to one of claims 2 to 11, - wherein the thermal safety device (30) is integrated in the control valve (18).

18. Module according to claim 17, the connection of claim 17 to claim 3 being taken in its connection to claim 2, wherein the control valve (18) comprises a cylindrical body (72) delimiting a cylindrical housing (74). ) for an adjusting member (76) rotatably mounted about an axis (XX), in wherein the inlet (52) and the valve outlet (54) of the thermal safety device are aligned coaxially with the cylindrical housing (74), and wherein the bypass outlet (56) of the thermal safety device (30) is formed by a tubing (96) opening laterally into the cylindrical housing (74) and housing the thermal safety device (30).

19. Module according to claim 18, wherein the radiator output (28) of the control valve (18) is formed by a pipe (80) opening laterally into the cylindrical housing (74) of the control valve (18).

The module of claim 19, wherein the radiator outlet tubing (80) and the bypass outlet tubing (96) open at respective locations offset in the axial direction of the control valve (18).

The module of claim 19, wherein the radiator outlet tubing (80) and the bypass outlet tubing (96) open at respective locations offset in the radial direction of the control valve.

The module of claim 21, wherein the location of the bypass outlet manifold (96) is outside the action area of the control valve adjusting member.

23. Cooling circuit of a motor vehicle engine, characterized in that it comprises a module according to one of claims 1 to 22.