FR3071876A1 - VENTILATION DEVICE FOR A HEAT EXCHANGE MODULE OF A MOTOR VEHICLE - Google Patents

Abstract

The invention relates to a ventilation device (2) for generating an air flow in the direction of a heat exchanger (1) of a motor vehicle, the ventilation device comprising ducts (8) intended to be supplied with flow. of air by at least one air propulsion device, each duct (8) having at least one opening (16; 40) for ejecting a flow of air passing through said duct (8), substantially in the direction of said heat exchanger (1), the ventilation device further comprising means adapted to selectively interrupt a fluid communication between at least some ejection openings (16; 40) and said air propulsion device.

Description

VENTILATION DEVICE FOR A MOTOR VEHICLE HEAT EXCHANGE MODULE

The present invention relates to a ventilation device for a heat exchange module and a heat exchange module for a motor vehicle.

A heat exchanger generally comprises tubes, in which a heat transfer fluid is intended to circulate, and heat exchange elements connected to these tubes, often designated by the term "fins" or "spacers".

The fins increase the exchange surface between the tubes and the ambient air. However, in order to increase the heat exchange between the heat transfer fluid and the ambient air, it is frequent that a ventilation device is used in addition to generate a flow of air directed towards the tubes and the fins.

Such a ventilation device most often comprises a propeller fan, which has many drawbacks.

First, the assembly formed by the propeller fan and its motorization system occupies a large volume.

In addition, the distribution of air ventilated by the propeller, often placed in the center of the row of heat pipes, is not uniform over the entire surface of the heat exchanger. In particular, certain regions of the heat exchanger, such as the ends of the heat transfer tubes and the corners of the heat exchanger, are not or only slightly affected by the air flow ventilated by the propeller.

Finally, when it is not necessary to start the ventilation device, in particular when the ambient air flow created by the movement of the motor vehicle is sufficient to cool the heat transfer fluid, the blades of the propeller partially mask the 'heat exchanger. Thus, part of the heat exchanger is not or only slightly ventilated by the ambient air flow in this case, which limits the heat exchange between the heat exchanger and the ambient air flow.

Furthermore, it is known from German patent DE 10 2011 120 865 a motor vehicle having a ventilation device and a heat exchanger, the ventilation device being adapted to generate a flow of air through the heat exchanger. The ventilation device is adapted to create a secondary air flow from a primary flow emitted from one or more annular elements, the secondary air flow being much stronger than the primary air flow. According to this patent, the ventilation device is part of a cooling grid, arranged on the front face of the motor vehicle.

In such a motor vehicle, each annular element is supplied with a primary air flow by a single fan, disposed outside the annular element, via a conduit opening punctually into the annular element. Consequently, the flow of ejected air emitted by the annular element is not homogeneous over the contour of the annular element. On the contrary, the flow of air emitted is all the more important as it is close to the fan. It follows the creation of a secondary air flow passing through the heat exchanger which is also inhomogeneous.

Finally, it is known from the application DE 10 2015 205 415 a ventilation device intended to generate an air flow through a heat exchanger comprising a hollow frame and at least one hollow spacer, dividing the area delimited by the frame into cells. The frame and the spacer (s) are in fluid communication with a turbomachine supplying an air flow. The turbomachine is arranged outside the frame. The frame and possibly the spacer or spacers are further provided with an opening for ejection of the air flow passing through them.

Again, the ventilation device does not generate a homogeneous air flow through the heat exchanger. On the contrary, the air flow emitted by the device is all the more important when it is ejected from the ventilation device near the turbomachine.

The invention aims to provide an improved ventilation device which does not have at least some of the above-mentioned drawbacks.

To this end, the invention provides a ventilation device intended to generate an air flow in the direction of a motor vehicle heat exchanger, the ventilation device comprising ducts intended to be supplied with air flow by at least an air propulsion device, each duct having at least one opening for ejecting an air flow passing through said duct, substantially in the direction of said heat exchanger, the ventilation device further comprising means adapted to selectively interrupt a fluid communication between at least certain ejection openings and said air propulsion device.

Thus, advantageously, the ventilation device can allow, in one configuration, to blow air through certain ejection orifices only.

Preferably, the ventilation device comprises one or more of the following characteristics, taken alone or in combination:

at least one air intake manifold, each duct opening at one of its ends into a separate orifice of the at least one air intake manifold, the conduits being intended to be supplied with an air flow by said at least one air propulsion device, via the at least one air intake manifold, said at least one duct ejection opening being distinct from the ends of the corresponding duct, said at least one opening being located at the 'outside of at least one air intake manifold,

- the means adapted to selectively interrupt a fluid communication between at least certain ejection openings and said at least one propulsion device include means for closing:

o at least some holes in the air collector; and / or o a section of the at least one air collector; and / or o at least certain ejection openings,

- the means adapted to selectively interrupt a fluid communication between at least certain ejection openings and said air propulsion device are passive, the means adapted to selectively interrupt a fluid communication between at least certain ejection openings and said propulsion device preferably being controlled by an air flow and / or an air pressure,

the at least one air intake manifold is of substantially tubular shape, preferably cylindrical, and in which the means adapted to selectively interrupt a fluid communication between at least certain ejection openings and said at least one air propulsion comprise a shutter, the shutter having a section substantially complementary to the cross section of said at least one air intake manifold, the shutter being movable in said at least air manifold,

the shutter is mounted mobile against the action of a return spring, the return spring preferably having a stiffness greater than or equal to 5 N / m and / or less than or equal to 50 N / m,

the means adapted to selectively interrupt a fluid communication between at least certain ejection openings and said air propulsion device comprise at least one valve, preferably a rocker valve, adapted to close at least one orifice of the at least an air manifold, the rocker valve preferably being mounted pivoting against the action of a return spring,

the means adapted to selectively interrupt a fluid communication between at least certain ejection openings and said air propulsion device are active,

the means adapted to selectively interrupt a fluid communication between at least certain ejection openings and said air propulsion device comprise at least one of a solenoid valve and a pneumatic valve, at least certain conduits are pivotable, preferably around a respective longitudinal axis, the conduits preferably also having an oblong section such that the conduits allow the passage of air between the conduits in a first position and that the conduits limit or even prevent the passage of air between the conduits in a second position reached by pivoting the conduits from the first position,

- The conduits are substantially straight tubes, aligned so as to form a row of tubes;

the opening is a slot in an external wall of the duct, the slot extending in a direction of elongation of the duct, preferably over at least 90% of the length of the duct and / or the height of said at least one opening is greater than or equal to 0.5 mm, preferably greater than or equal to 0.7 mm, and / or less than or equal to 2 mm, preferably less than or equal to 1.5 mm;

each conduit has, on at least one section, a geometric section comprising:

o a leading edge;

o a trailing edge opposite the leading edge;

o a first and a second profile, each extending between the leading edge and the trailing edge, said at least one opening of the conduit being on the first profile, said at least one opening being configured so that the flow of ejected air flows along at least part of the first profile,

said at least one opening of the first profile being delimited by an external lip and an internal lip, one end of the internal lip extends, in the direction of the second profile, beyond a plane normal to the free end of the outer lip, the passage section then being defined as the portion of the section of the tube disposed between said end of the inner lip and the trailing edge, on the one hand, and between the first and second profiles, on the other hand;

the maximum distance between the first and the second profiles, in a direction of alignment of the conduits, is downstream of said at least one opening, in the direction of flow of said flow of air ejected through said at least one opening, the maximum distance preferably being greater than or equal to 5 mm, preferably greater than or equal to 10 mm, and / or less than or equal to 20 mm, preferably less than or equal to 15 mm, the maximum distance being even more preferably equal to 11.5 mm;

- The first profile includes a curved part, the apex of which defines the point of the first profile corresponding to the maximum distance, the curved part being arranged downstream of the opening in the direction of flow of said air flow ejected by said at least an opening ;

- The first profile has a first substantially straight portion, preferably downstream of the curved portion in the direction of flow of said air flow ejected from the at least one opening, in which the second profile comprises a substantially straight portion, s preferably extending over a majority of the length of the second profile, the first rectilinear part of the first profile and the rectilinear part of the second profile forming a non-flat angle, the angle preferably being greater than or equal to 5 °, and / or less than or equal to 20 °, more preferably still substantially equal to 10 °;

the first rectilinear part extends over a section of the first profile corresponding to a length, measured in a direction perpendicular to the direction of alignment of the conduits and to a longitudinal direction of the conduits, greater than or equal to 30 mm, preferably greater or equal to 40 mm, and / or less than or equal to 50 mm;

- The first profile comprises a second rectilinear part, downstream of the first rectilinear part in the direction of flow of the air flow ejected by the at least one opening, the second rectilinear part extending substantially parallel to the rectilinear part of the second profile, the first profile preferably comprising a third straight portion, downstream of the second straight portion of the first profile, the third straight portion forming a non-flat angle with the straight portion of the second profile, the third straight portion extending substantially up to a rounded edge connecting the third straight portion of the first profile and the straight portion of the second profile, the rounded edge defining the trailing edge of the profile of the conduit;

the distance between the second straight part of the first profile and the straight part of the second profile is greater than or equal to 2 mm and / or less than or equal to 10 mm, preferably less than or equal to 5 mm;

the said geometric section of the conduit has a length, measured in a direction perpendicular to the direction of alignment of the conduits and to a main direction of extension of the conduits, greater than or equal to 50 mm and / or less than or equal to 70 mm, preferably substantially equal to 60 mm;

- The ventilation device comprises at least a first and a second duct, the first profile of the first duct being opposite the first profile of the second duct;

- The ventilation device also comprises a third duct, such that the second profile of the second duct is opposite the second profile of the third duct, the distance between the center of the geometric section of the second duct and the center of the geometric section of the third duct preferably being less than the distance between the center of the geometric section of the first duct and the center of the geometric section of the second duct; and

- Each conduit is symmetrical with respect to the plane containing the leading edge and the trailing edge, so that each conduit has two symmetrical openings, respectively on the first profile and on the second profile.

According to another aspect, the invention relates to a motor vehicle heat exchange module comprising:

- a heat exchanger, the heat exchanger having several tubes, called heat transfer tubes, in which a fluid is intended to circulate, and

- a ventilation device as described above in all its combinations, adapted to generate a flow of air towards the heat transfer tubes.

The invention will be better understood on reading the description which follows, given solely by way of example and made with reference to the drawings in which:

- Figure 1 is a perspective view of an example of a heat exchange module with a heat exchanger provided with part of a ventilation device;

- Figure 2 is a schematic sectional view along the plane II-II of an aerodynamic tube of the ventilation device of Figure 1;

- Figure 3 schematically shows a partial section of a manifold of the ventilation device of Figure 1;

- Figures 4a, 4b, 4C are views similar to the view of Figure 3, corresponding to three separate supply pressures of the ventilation device;

- Figures 5a and 5b are views similar to Figure 3 of a variant of the manifold of the ventilation device of Figure 1, corresponding to two supply pressures of the air intake manifold separate;

- Figures 6a and 6b are schematic perspective views of rocker devices that can be implemented to selectively close the orifices of an air manifold of the ventilation device of Figure 1;

- Figures 7 to 10 are views similar to that of Figure 2, of variant tubes of the ventilation device of Figure 1; and

- Figure 11 schematically illustrates a variant of the heat exchange module of Figure 1.

In the various figures, identical or similar elements, having an identical or analogous function, bear the same references. The description of their structure and their function is therefore not systematically repeated.

FIG. 1 shows an example of a heat exchange module 10 with a heat exchanger 1 intended to equip a motor vehicle, equipped with a ventilation device 2 according to a first embodiment example.

The heat exchanger 1 comprises heat transfer conduits 4 in which a fluid is intended to circulate. The fluid here is water or coolant. The heat transfer conduits 4 are here substantially rectilinear and extend in a longitudinal direction. The heat transfer pipes thus form heat transfer tubes 4. The heat transfer tubes 4 are mutually parallel and aligned so as to form a row. The heat transfer tubes 4 are substantially all of the same length.

The heat transfer conduits 4 each extend between a fluid intake manifold 5 and a fluid discharge manifold 6, common to all the heat transfer conduits 4. Preferably, the orifices of the fluid intake manifold 5, in which open the heat transfer conduits 4 are all included in the same foreground. Likewise, the orifices of the fluid evacuation manifold 6, into which the heat transfer conduits 4 open are all included in the same second plane, preferably parallel to said first plane.

More particularly, and conventionally in motor vehicle heat exchangers, each heat transfer tube 4 has a substantially oblong section, and is delimited by first and second planar walls which are connected to heat exchange fins. For reasons of clarity, the fins are not shown in FIG. 1.

The heat exchange module 10 is equipped with a ventilation device 2 comprising a plurality of ventilation ducts 8. The ventilation ducts 8, in the same way as the heat transfer ducts 4, are substantially rectilinear, so as to form ventilation tubes 8. The ventilation tubes 8 are also parallel to each other and aligned so as to form a row of ventilation tubes 8. The ventilation tubes 8 are also of the same length. The length of the ventilation tubes 8 is for example substantially equal to the length of the heat transfer tubes 4.

The ventilation device 2 is intended to generate an air flow in the direction of the heat transfer tubes 4.

The heat transfer tubes 4 and the ventilation tubes 8 can all be parallel to each other, as illustrated in FIG. 1. Thus, the rows of ventilation tubes 8 and heat transfer tubes 4 are themselves parallel. In addition, the ventilation tubes 8 can be arranged so that each of them is opposite a heat-transfer tube 4.

The number of ventilation tubes 8 is adapted to the number of heat transfer tubes 4. For example, for a conventional heat exchanger 1, the ventilation device 2 can for example comprise at least ten ventilation tubes 8, preferably at least fifteen tubes ventilation 8, more preferably at least twenty-four ventilation tubes 8 and / or at most fifty ventilation tubes 8, preferably at most thirty-six ventilation tubes 8, more preferably at most thirty ventilation tubes 8. The heat exchanger 1 can for example comprise between sixty and seventy heat transfer tubes 4.

The tubes and the number of ventilation tubes 8 of the ventilation device 2 can be such that a minimum air passage section between the tubes of the ventilation device, defined in a plane substantially perpendicular to the flow of air through the 'heat exchanger 1, is between 25 and 50% of the surface, defined in a plane perpendicular to the air flow through the heat exchanger, between two extreme heat pipes.

Preferably, the front surface of the ventilation tubes 8, measured in a plane substantially perpendicular to the air flow passing through the heat exchanger 1, is less than 85% of the front surface occupied by the heat transfer tubes 4.

Furthermore, in order to limit the volume occupied by the heat exchange module comprising the heat exchanger 1 and the ventilation device 2, while obtaining heat exchange performance similar to that of a ventilation device. propeller, one can arrange the row of ventilation tubes 8 at a distance less than or equal to 150 mm from the row of heat transfer tubes 4, preferably less than or equal to 100 mm. This distance is preferably greater than or equal to 5 mm, preferably greater than 40 mm. Indeed, a too short distance between the ventilation tubes 8 and the heat transfer tubes 4 may not allow a homogeneous mixing of the air flow ejected from the ventilation tubes 8 with the induced air flow. An inhomogeneous mixture does not allow homogeneous cooling of the heat transfer tubes 4 and induces high pressure drops. Too great a distance may not allow the assembly formed by the ventilation device and the heat exchange device to be put into place in a motor vehicle, without requiring an adapted design of the power unit and / or others components of the motor vehicle present in the vicinity of the heat exchange module.

Likewise, again to limit the volume occupied by the heat exchange module, it can be ensured that the height of the row of ventilation tubes 8 (the term height here referring to the dimension corresponding to the direction in which the ventilation tubes 8 are aligned) is substantially equal to or less than that of the height of the row of heat transfer tubes 4. For example, the height of the row of heat transfer tubes 4 being 431 mm, it can be ensured that the height of the row of ventilation tubes 8 is substantially equal to or less than this value.

The ventilation device 2 further comprises a supply device supplying air to the ventilation tubes 8, not visible in FIG. 1, via an air intake manifold 12, preferably via two intake intake manifolds. air 12.

The air propulsion means are for example a turbomachine, supplying the two air intake manifolds 12, disposed at each end of the ventilation device 1, via a respective port 13. In the example illustrated in the figure 1, the ports 13 are at one longitudinal end of the air intake manifolds 12. Alternatively or additionally, the ports 13 are at the other longitudinal end of each air intake manifold 12 and / or arranged on along the length of the air intake manifolds 12. Alternatively, also, a turbomachine can supply a single intake manifold 12 and not two. One or more turbomachines can also be used to supply each air intake manifold 12 or all of the air intake manifolds 12.

According to another embodiment, also, the turbomachine (s) are received in one or in each air intake manifold 12, in particular in the vicinity of one or each longitudinal end 12a, 12b of the or each manifold d air intake.

Here, however, the air propulsion means are moved away from the ventilation tubes 8, outside the air intake manifolds 12 through which the air propulsion means supply air flow the ventilation tubes 8. The or each turbomachine forming the air propulsion means may not be directly adjacent to the air intake manifolds 12. On the contrary, it may be advantageous to be able to offset the turbomachine (s) remotely ventilation tubes 8, in particular by means of the intake manifolds 12 and, optionally, of an appropriate aeraulic circuit putting the port or ports 13 of the air manifold (s) 12 into communication with one or more turbomachines .

Each air intake manifold 12 can for example be tubular. In the embodiment of Figure 1, the air intake manifolds 12 extend in the same direction, which is here perpendicular to the direction of elongation (or longitudinal direction) of the heat transfer tubes 4 and ventilation 8.

As can be seen in FIG. 1, the air intake manifold 12 comprises a plurality of air ejection orifices 14 each produced at one end of a respective tubular portion, each ejection orifice d the air 14 being connected to a single ventilation tube 8, and more particularly to the end of the ventilation tube 8.

Advantageously, each air intake manifold 12 is devoid of any other opening than the orifices 14 and the abovementioned port or ports 13. In particular, the manifold 12 is preferably devoid of an opening oriented in the direction of the heat exchanger 1, which would in the present case allow the ejection of part of the air flow passing through the air manifold 12, directly in the direction of the heat exchanger 1, without traversing at least a portion of a ventilation tube 8. Thus, all of the air flow created by the turbomachine (s) passing through the air collector (s) 12, can be distributed between substantially all of the ventilation tubes 8. This also allows a more homogeneous distribution of this air flow.

Each ventilation tube 8 has, according to the example of FIGS. 1 and 2, a plurality of openings 16 for the passage of an air flow F2 passing through the tube 8. The openings 16 of the ventilation tubes 8 are located at the 'exterior of the air collectors 12. More specifically, here, the openings 16 are oriented substantially in the direction of the heat exchanger 1, and more precisely still, substantially in the direction of the heat transfer tubes 4, the slots 16 being for example arranged opposite the heat transfer tubes 4 or the fins housed between the heat transfer tubes.

Each ventilation tube 8 opens into an orifice 14 distinct from each manifold 12. Thus, each air collector 12 has as many orifices 14 as it receives ventilation tubes 8, a ventilation tube 8 being received in each orifices 14 of the air collector 12. This allows a more homogeneous distribution of the air flow passing through each air collector 12, in the various ventilation tubes 8.

Furthermore, the air manifold (s) 12 and the ventilation tubes 8 are here configured so that an air flow passing through the air collector (s) 12 is distributed between the various ventilation tubes 8, traverses the different ventilation tubes 8 and is ejected through the openings 16. Thus, the openings 16 being disposed opposite the heat exchanger 1, an air flow F2 is ejected through the openings 16, and passes through the exchanger heat 1.

It should be noted, however, that the air flow F1 passing through the heat exchanger 1 can be significantly different from the air flow F2 ejected through the openings. In particular, the air flow F1 can include, in addition to the air flow F2, an ambient air flow created by the movement of the moving motor vehicle.

In the first example illustrated in FIGS. 1 and 2, and as seen more particularly in FIG. 2, apart from their ends forming an air intake inlet, which have a substantially circular cross section, the ventilation tubes 8 have a substantially oblong cross section, interrupted by the openings 16.

The choice of this shape allows easy manufacture of the ventilation tubes 8 and gives good mechanical strength to the ventilation tubes 8. In particular, such ventilation tubes 8 can be obtained by folding an aluminum sheet for example, but also by molding, overmolding, or by metallic or plastic three-dimensional printing.

More specifically, in the first example shown in Figures 1 to 2, the cross section of the ventilation tubes 8 has a substantially elliptical shape, the small axis of which corresponds to the height of the ventilation tubes 8 and the large axis of the width of the ventilation tubes ventilation 8 (the terms height and width should be understood with respect to T orientation in Figure 2). For example, the minor h axis of the ellipse is about 11 mm.

To increase the flow of air F2 ejected towards the heat exchanger 1 through the openings 16, the openings 16 are formed by slots made in the wall 17 of the ventilation tube 8, these slots 16 extending in the direction elongation of the ventilation tube 8. This slotted shape makes it possible to constitute an air passage of large dimensions, while maintaining a satisfactory mechanical strength of the ventilation tubes 8. Thus, to obtain a larger air passage possible, the openings extend over a large part of the length of the ventilation tube 8, preferably over a total length corresponding to at least 90% of the length of the ventilation tube 8.

The openings 16 are here delimited by guide lips 18 projecting from the wall 17 of the ventilation tube 8.

Due to the fact that they project from the wall 17 of each ventilation tube 8, the guide lips 18 make it possible to guide the air ejected through the opening 16 from the interior of the ventilation tube 8 towards the heat exchanger 1.

The guide lips 18 are preferably planar and substantially parallel. For example, they are spaced from each other by a distance of about 5 mm and have a width of between 2 and 5 mm. The guide lips 18 advantageously extend over the entire length of each opening 16.

The guide lips 18 are preferably made integrally with the ventilation tube 8. The guide lips 18 are for example obtained by folding the wall of the ventilation tube 8.

Furthermore, the openings 16 are also delimited, in the direction of the length of the ventilation tubes 8, by reinforcing elements 20 of the ventilation tubes 8. The reinforcing elements 20 make it possible to keep the width of the openings 16 constant. Here , this is achieved by the fact that the reinforcing elements extend between the two guide lips 18 extending on either side of each opening 16. The reinforcing elements 20 preferably extend in a substantially normal plane in the direction of elongation of the ventilation tubes 8, this in order to maintain the largest possible, the section of the openings 16 allowing the passage of the air flow F2. The reinforcement elements 20 are advantageously distributed regularly over the length of the ventilation tubes 8. In the example illustrated in FIGS. 1 and 2, each ventilation tube 8 comprises seven reinforcement elements 20. Of course, this number is by no means limiting.

Remarkably, the ventilation device 2 is provided with means 100 adapted to selectively interrupt a fluid communication between at least certain ejection openings 16 of the ventilation tubes 8 and the air ejection device or devices supplying the tubes ventilation 8 in air flow. Such means make it possible in particular to eject or not an air flow through certain ejection openings 16, for example as a function of their position. It is thus possible to adapt the flow of air ejected by the ventilation device 2 and, by the same, the flow of air F1 passing through the heat exchanger. For example, again, an air flow F1 can be produced only opposite certain elements to be cooled. This may be more particularly advantageous when the ventilation device 2 is associated with different heat exchangers and / or different elements to be cooled, arranged in defined zones facing the ventilation device 2. By "defined zones" is meant herein zones which can advantageously be distinct, without overlapping.

FIGS. 3 and 4a to 4c illustrate a first example of means 100 adapted to selectively interrupt a fluid communication between at least certain ejection openings 16 of the ventilation tubes 8 and the air ejection device or devices supplying the tubes ventilation 8 in air flow. Here, these means 100 are more particularly adapted to interrupt the communication of fluid between the port 13 of the air intake manifold 12 and the orifices 14 of said intake manifold.

To do this, here, a shutter 102 is mounted free in translation in the air intake manifold 12. The shutter 102 advantageously has a shape substantially complementary to the section of the air intake manifold 12. A seal may also be provided at the periphery of the shutter 102. This gives good airtightness between the shutter 102 and the walls of the air intake manifold 12.

The shutter 102 is here mounted elastically constrained, for example by a spring 104, in the direction of the port 13. Thus, in the absence of air flow coming from the port 13, the shutter 102 is in its lowest position , corresponding to a cut in the fluid communication of all the orifices 14 located above the shutter 102, at port 13. Alternatively, depending on the length 1 min of the spring 104 when empty, that is to say without flow of air supplying the air intake manifold 12, the lowest position of the shutter 102 in the air intake manifold 12 may correspond to a communication of fluid between the port 13 and a minimum of orifices 14, as illustrated in FIG. 4a, or even to a fluid communication between any orifice 14 and the port 13.

In operation of the air ejection device (s), and as visible in FIG. 4b, the shutter is essentially subjected to three forces:

its weight, which in the case of FIGS. 3, 4a to 4c is directed vertically downwards from the air intake manifold 12, that is to say towards the port 13 for supplying air flow from the air intake manifold;

the pressure exerted by the air flow on the lower face of the shutter 102 oriented towards the port 13, partially compensated by the pressure exerted by air at atmospheric pressure on the opposite face of the shutter 102 (a exhaust 106 is provided in the air intake manifold to prevent the shutter from acting as a piston and compressing the air due to its movement);

- The elastic return force of the spring 104 which tends to return the shutter 102 to its position in Figure 4a. The elastic restoring force of the shutter 104 tends to increase with the length 1 _R of the spring 104, up to the length lmax corresponding to the greatest number of orifices 14 in fluid communication with the port 13 and, at the same time , to the greatest force of the return of the spring 104.

Thus, by regulating the pressure of the air flow supplying the air intake manifold 12, the balance of forces applied on the shutter 102 can be shifted. It is then possible to control the position of the shutter 102 in the air intake manifold 12. This position of the shutter 102 thus controls the number of orifices 14 through which the air supplying the air intake manifold 12 is ejected from the intake manifold. air intake 12. In other words, the number of ventilation tubes 8 supplied by the air flow is thus controlled.

The return spring 104 has for example a stiffness greater than or equal to 5 N / m and / or less than or equal to 50 N / m to allow satisfactory control of the position of the shutter 102 as a function of the pressure of the flow d air supplied by the air propelling device.

It is noted that here, the means 100 adapted to selectively interrupt a fluid communication between at least some of the ventilation tubes 8 and the air ejection device are passive. They are controlled directly by the feed air flow itself.

Figures 5a, 5b illustrate a variant of the means 100 adapted to selectively interrupt a fluid communication between at least certain ventilation tubes 8 and the air propulsion device supplying the air intake manifold 12 with air flow . Here these means 100 comprise a spring 104 tending to push the shutter 102 towards the end 12b of the air intake manifold opposite the end 12a of the air intake manifold 12 provided with the port 13 through which the air intake manifold 12 is supplied with air flow by the air propulsion device. The spring 104 compresses when the pressure inside the air intake manifold increases (see FIG. 5b), when the air propulsion device blows air into the manifold 12 via the port 13, then returns to its initial state when the pressure decreases inside the intake manifold 12 (see FIG. 5a).

According to another variant not shown, the means 100 adapted to selectively interrupt a fluid communication between at least certain ventilation tubes 8 and the air propulsion device supplying these tubes with air flow is devoid of elastic return spring. In this case, the position of the shutter is defined by controlling the pressure of the air flow so that it essentially compensates for the weight of the shutter.

FIGS. 6a, 6b illustrate other means 200 adapted to selectively interrupt a communication of fluid between at least certain ventilation tubes 8 and the air propulsion device supplying air flow to the ventilation tubes. According to the example illustrated in these figures, these means 200 take the form of a rocker valve. The rocker valve 200 essentially comprises a shutter 202 of the orifice 14 for ejecting the air flow from the air intake manifold 12, connected to a control pallet 204 by a lever arm 206 pivotally mounted relative to to an axis of rotation 208. The lever arm 206 can be pivotally mounted against the action of a return spring. Thus, as with the first means 100, it is possible to control the communication of fluid from the ventilation tubes 8 with the air propulsion device controlling the ventilation tubes in air flow: by increasing the pressure of the flow of air supplied by the air propulsion device, it is possible to control the opening or closing of the orifices 14 and, thus, the supply of air flow or not of the corresponding ventilation tubes 8.

FIGS. 7 to 10 illustrate variants of the ventilation device 2 and, more precisely, ventilation tubes 8 of this ventilation device 2.

In what follows, the ventilation tubes 8 are called aerodynamic tubes 8. It can be noted here that the shape of the ventilation tubes 8 is a priori independent of the configuration of the air intake manifolds and / or of the shape of the means adapted to selectively interrupt a fluid communication between at least certain ejection openings and said air propulsion device.

According to the example of FIG. 7, an aerodynamic tube 8 has on at least one portion, preferably over substantially its entire length, a cross section as illustrated with a leading edge 37, a trailing edge 38 opposite the leading edge 37 and, here, disposed opposite the heat transfer tubes 4, and a first and a second profile 42, 44, each extending between the leading edge 37 and the trailing edge 38. The edge of attack 37 is for example defined as the point at the front of the section of the aerodynamic tube 8 where the radius of curvature of the section is minimum. The front of the section of the aerodynamic tube 8 can in turn be defined as the portion of the section of the aerodynamic tube 8 which is opposite - that is to say which is not opposite - of the heat exchanger 1. Similarly, the trailing edge 38 can be defined as the point at the rear of the section of the aerodynamic tube 8 where the radius of curvature of the section is minimal. The rear of the section of the aerodynamic tube 8 can be defined for example as the portion of the section of the aerodynamic tube 8 which is opposite the heat exchanger 1.

The distance c between the leading edge 37 and the trailing edge 38 is for example between 16 mm and 26 mm. This distance is here measured in a direction perpendicular to the direction of alignment of the row of aerodynamic tubes 8 and to the longitudinal direction of the aerodynamic tubes 8

In the example of FIG. 7, the leading edge 37 is free. Also in this figure, the leading edge 37 is defined on a parabolic portion of the section of the aerodynamic tube 8.

The aerodynamic tube 8 illustrated in FIG. 7 also has at least one opening 40 for ejecting a flow of air passing through the aerodynamic tube 8, outside the aerodynamic tube 8 and the air intake manifold 12, in particular substantially towards the heat exchanger 1. The opening or each opening 40 is for example a slot in an external wall 41 of the aerodynamic tube 8, the slot or slots extending for example in the direction of elongation of the aerodynamic tube 8 in which they are made. The total length of the opening 40 or openings can be greater than 90% of the length of the aerodynamic tube. Each opening 40 is distinct from the ends of the aerodynamic tube 8, through which the aerodynamic tube 8 opens into an air manifold 12. Each opening 40 is also outside the air intake manifold 12. The shape in slot makes it possible to constitute a large air passage in the direction of the heat exchanger 1 without excessively reducing the mechanical resistance of the aerodynamic tubes 8.

In the following, only an opening 40 is described, it being understood that each opening 40 of the aerodynamic tube 8 can be identical to the opening 40 described.

The opening 40 is for example arranged near the leading edge 37. In the example of FIG. 7, the opening 40 is on the first profile 42. In this example, the second profile 44 has no opening 40. The opening 40 in the first profile 42 is configured so that the air flow ejected through the opening 40 flows along at least part of the first profile 42.

The aerodynamic tubes 8 of the ventilation device 2 can be oriented alternately with the first profile 42 or the second profile 44 oriented upwards. Thus, alternatively, two neighboring aerodynamic tubes 8 are such that their first profiles 42 are opposite or, on the contrary, their second profiles 44 are opposite. The distance between two neighboring aerodynamic tubes 8 whose second profiles 44 are opposite each other is less than the distance between two neighboring aerodynamic tubes 8 whose first profiles 42 are vis-à-vis. The pitch between two neighboring aerodynamic tubes or the distance between the center of the geometric section of a first aerodynamic tube 8 and the center of the geometric section of a second aerodynamic tube 8, such as the first profile 42 of the first aerodynamic tube 8 either facing the first profile 42 of the second aerodynamic tube 8, measured in the direction of alignment of the aerodynamic tubes 8 is greater than or equal to 15 mm, preferably greater than or equal to 20 mm, and / or less or equal to 30 mm, preferably less than or equal to 25 mm.

For each pair of aerodynamic tubes 8, the openings 40 of which face each other, the air flows ejected through these openings 40 thus create an air passage in which part, called induced air, of the ambient air is entrained. by suction.

It should be noted here that the air flow ejected through the openings 40 runs along at least part of the first profile 42 of the aerodynamic tube 8, for example by Coanda effect. Taking advantage of this phenomenon, it is possible, thanks to the entrainment of ambient air in the created air passage, to obtain a flow of air sent to the heat transfer tubes identical to that generated by a propeller fan. while consuming less energy.

Indeed, the air flow sent to the row of heat transfer tubes 4 is the sum of the air flow ejected through the slots and the induced air. Thus, it is possible to implement a turbomachine of reduced power compared to a conventional propeller fan, generally implemented in the context of such a heat exchange module.

A first profile 42 having a Coanda surface also makes it possible not to have to orient the openings 40 directly in the direction of the heat transfer tubes 4, and thus to limit the size of the aerodynamic tubes 8. It is thus possible to maintain a passage section between the aerodynamic tubes 8, which promotes the formation of a greater induced air flow.

The opening 40 is, in FIG. 7, delimited by lips 40a, 40b. The spacing e between the lips 40a, 40b, which defines the height of the opening 40, can be greater than or equal to 0.3 mm, preferably greater than or equal to 0.5 mm, more preferably greater than or equal to 0.7 mm and / or less than 2 mm, preferably less than or equal to 1.5 mm, more preferably still less than 0.9 mm, more preferably still less than or equal to 0.7 mm. The height of the slit is the dimension of this slit in the direction perpendicular to its length. The lower the height of the slot 40, the greater the speed of the air flow ejected through this slot. A high speed of the ejected air flow results in a high dynamic pressure. This dynamic pressure is then converted into static pressure in the mixing zone of the air flow ejected through the slot 40 and the induced air flow. This static pressure makes it possible to overcome the pressure drops due to the presence of the heat exchanger downstream of the ventilation device, in order to ensure a suitable air flow through the heat exchanger. These pressure drops due to the heat exchanger vary in particular as a function of the pitch of the heat transfer tubes and the pitch of the fins of the heat exchanger, as well as according to the number of heat exchange modules which can be superimposed in the heat exchanger. However, a too low slot height induces high pressure losses in the ventilation device, which implies using one or more oversized air propelling device (s). This can generate an additional cost and / or create a space incompatible with the space available in the vicinity of the heat exchange module in the motor vehicle.

The outer lip 40a here consists of the extension of the wall of the aerodynamic tube 8 defining the leading edge 37. The inner lip 40b is constituted by a curved part 50 of the first profile 42. One end 51 of the inner lip 40b can extend, as illustrated in FIG. 11, towards the second profile 44, beyond a plane L normal at the free end of the external lip 40a. In other words, the end 51 of the inner lip 40b can extend, in the direction of the leading edge 37, beyond the plane L normal to the free end of the outer lip 40a. The end 51 can then help direct the air flow circulating in the aerodynamic tube 8 towards the opening 40.

The opening 40 of the aerodynamic tube 8 can be configured so that a flow of air circulating in this aerodynamic tube 8 is ejected through this opening 40, flowing along the first profile 42 substantially to the trailing edge 38 of the aerodynamic tube 8. The flow of the air flow along the first profile 42 can result from the Coanda effect. It is recalled that the Coanda effect is an aerodynamic phenomenon resulting in the fact that a fluid flowing along a surface at a short distance from it tends to be flush with it, or even to cling to it.

To do this, here, the maximum distance h between the first 42 and the second 44 profiles, measured along an alignment direction of the aerodynamic tubes 8, is downstream of the opening 40. The maximum distance h can be greater than 10 mm, preferably greater than 11 mm and / or less than 20 mm, preferably less than 15 mm. Here, by way of example, the maximum distance h is substantially equal to 11.5 mm. A height h that is too small can cause significant pressure drops in the aerodynamic tube 8, which could make it necessary to implement a more powerful and therefore more bulky turbomachine. For the same value of the distance between the aerodynamic tubes 8, measured according to the direction of alignment of the aerodynamic tubes, a height h that is too large limits the passage section between the aerodynamic tubes for the induced air flow. The total air flow to the heat exchanger is also reduced.

The first profile 42 here comprises a curved portion 50 whose apex defines the point of the first profile 42 corresponding to the maximum distance h. The convex part 50 can be arranged downstream of the opening 40 in the direction of ejection of the air flow. In particular, the curved part 50 can be contiguous with the internal lip 40b delimiting the opening 40.

Downstream of the convex part 50 in the direction of ejection of said air flow through the opening 40, the first profile 42 of the aerodynamic tube 8 of the example in FIG. 7 comprises a first part 52 which is substantially straight. The second profile 44 comprises, in the example illustrated in FIG. 7, a substantially rectilinear part 48, preferably extending over a majority of the length of the second profile 44. In the example of FIG. 7, the length 1 of the first rectilinear part 52, measured in a direction perpendicular to the longitudinal direction of the aerodynamic tube 8 and to the direction of alignment of the row of aerodynamic tubes, may be greater than or equal to 30 mm, preferably greater than or equal to 40 mm, and / or less than or equal to 50 mm. A relatively large length of this first rectilinear part is desired in particular to ensure the guiding of the flow of air ejected from the opening 40, which makes it possible to ensure greater air intake. The length of this first rectilinear part is however limited due to the corresponding size of the ventilation device and its consequences on the packaging of the ventilation device or of the heat exchange module.

In this case, the first rectilinear part 52 of the first profile 42 and the rectilinear part 48 of the second profile 44 can form a non-flat angle Θ. The angle Θ thus formed can in particular be greater than or equal to 5 °, and / or less than or equal to 20 °, more preferably still substantially equal to 10 °. This angle of the first rectilinear part 52 relative to the rectilinear part 48 of the second profile 44 makes it possible to accentuate the relaxation of the air flow ejected through the opening 40 and undergoing the Coanda effect forcing it to follow the first profile 42 , this enhanced relaxation making it possible to increase the induced air flow. An angle Θ too large, however, may prevent the Coanda effect from being achieved, so that the air flow ejected through the opening 40 may not follow the first profile 42 and, therefore, not be oriented correctly towards the heat exchanger 2.

The first profile 42 may comprise, as illustrated in FIG. 7, a second rectilinear part 38a, downstream of the first rectilinear part 52, in the direction of ejection of the air flow, the second rectilinear part 38a extending substantially parallel to the straight part 48 of the second profile 44. The first profile 42 can also include a third straight part 54, downstream of the second straight part 38a of the first profile 42. The third straight part 54 can form a non-flat angle with the rectilinear part 48 of the second profile 44. The third rectilinear part 54 can extend, as illustrated, substantially up to a rounded edge connecting the third rectilinear part 54 of the first profile 42 and the rectilinear part 48 of the second profile 44. The edge rounded can define the trailing edge 38 of the cross section of the aerodynamic tube 8.

The rectilinear part 48 of the second profile 44 extends in the example of FIG. 7 over the majority of the length c of the cross section. This length c is measured in a direction perpendicular to the longitudinal direction of the aerodynamic tubes 8 and to the direction of alignment of the row of aerodynamic tubes 8. This direction corresponds, in the example of FIG. 11, substantially to the direction of the flow of the induced air flow. In this first embodiment, the length c of the cross section (or width of the aerodynamic tube 8) may be greater than or equal to 50 mm and / or less than or equal to 70 mm, preferably substantially equal to 60 mm. In fact, the inventors have found that a relatively large length of the cross section of the aerodynamic tube makes it possible to more effectively guide the air flow ejected through the opening 40 and the induced air flow, which mixes with this ejected air flow. However, too long a length of the cross section of the aerodynamic tube 8 poses a packaging problem for the ventilation device 2. In particular, the size of the heat exchange module can then be too large compared to the space which is available in the motor vehicle in which it is intended to be mounted. The packaging of the heat exchange module or the ventilation device can also be problematic in this case.

Furthermore, as illustrated in FIG. 7, the second rectilinear part 38a of the first profile 42 and the portion 38b of the rectilinear part 48 of the second profile 44 which faces it, are parallel. For example, the distance f between this second rectilinear part 38a and the portion 38b of the rectilinear part 48 of the second profile 44 can be greater than or equal to 2 mm and / or less than or equal to 10 mm, preferably less than or equal to 5 mm.

FIG. 7 also illustrates that the cross section (or geometric section) of the aerodynamic tube 8 defines a passage section S for the air flow passing through the aerodynamic tube 8. This passage section S is here defined by the walls of the aerodynamic tube 8 and by the segment extending in the direction of alignment of the aerodynamic tubes 8 between the second profile 44 and the tip of the end 51 of the internal lip 40b. This passage section may have an area greater than or equal to 150 mm ² , preferably greater than or equal to 200 mm ² , and / or less than or equal to 700 mm ² , preferably less than or equal to 650 mm ² . A section for the passage of the air flow in the aerodynamic tube 8 makes it possible to limit the pressure drops which would have the consequence of having to oversize the turbomachine used to obtain a flow of air ejected through the desired opening 40. However, a large passage section induces a large bulk of the aerodynamic tube 8. Thus, with fixed pitch aerodynamic tubes, a larger passage section may harm the passage section of the induced air flow between the aerodynamic tubes 8 , thus not making it possible to obtain a satisfactory total air flow rate, directed towards the heat transfer tubes 4.

In order to obstruct the flow of air towards the heat-transfer tubes 4 and the fins as little as possible, the ventilation device 2 provided with such aerodynamic tubes 8 is advantageously arranged so that each aerodynamic tube 8 is opposite. screw of the front face 4f connecting the first 4a and second 4b flat walls of a corresponding heat transfer tube 4. More particularly, the trailing edge 38 of each aerodynamic tube 8 is included in the volume delimited by the first and second longitudinal plane walls of the corresponding heat transfer tube 4.

Preferably, the second rectilinear part 38a of the first profile and the rectilinear part 48 of the second profile 44 are contained respectively in the same plane as the first longitudinal plane wall and the second plane longitudinal wall of the corresponding heat transfer tube 4.

In particular, the distance f separating the second rectilinear part 38a from the first profile 42 and the portion 38b from the rectilinear part 48 of the second profile 44 which faces it, is substantially equal to the distance separating the first longitudinal wall and the second longitudinal wall of the heat transfer tube 4 opposite which the aerodynamic tube 8 is disposed. For example, this distance f is greater than or equal to 2 mm and / or less than or equal to 10 mm, preferably less than or equal to 5 mm.

In other embodiments, the distance f separating the second straight portion 38a of the first profile 42 and the portion 38b of the straight portion 48 of the second profile 44, which faces it, may however be less than the distance separating the first longitudinal wall and the second longitudinal wall of the heat transfer tube opposite which the aerodynamic tube 8 is disposed.

Two heat transfer tubes 4 can be contained in the volume delimited by the air passage defined by two aerodynamic tubes 8 neighbors. It can however be envisaged that a single heat transfer tube 4, or even three or four heat transfer tubes 4 are contained in this volume. Conversely, it is conceivable that an aerodynamic tube 8 is arranged opposite each heat-carrying tube 4.

In the examples of FIGS. 8, 9 and 10, the aerodynamic conduits 8 are substantially rectilinear, mutually parallel and aligned so as to form a row of aerodynamic tubes 8. However, the first and second profiles 42, 44 of each aerodynamic tube 8 are, according to these examples, symmetrical with respect to a plane CC, or chord plane, passing through the leading edge 37 and the trailing edge 38 of each aerodynamic tube 8.

As the first and second profiles 42, 44 are symmetrical, each of these profiles 42, 44 is provided with an opening 40. Thus, at least a first opening 40 is produced on the first profile 42, which is configured so that a air flow leaving the first opening 42 flows along at least part of the first profile 42. Likewise, at least one second opening 40 is present on the second profile 44, which is configured so that a air flow leaving the second opening 40 flows along at least part of the second profile 44. As for the example in FIG. 7, this can be achieved here by implementing the Coanda effect.

For the same reasons as those given for the example of FIG. 7, the distance c between the leading edge 37 and the trailing edge 38 can also, in these examples, be greater than or equal to 50 mm and / or less or equal to 80 mm. In particular, the length c can be equal to 60 mm.

The openings 40 are similar to those of the example in FIG. 7. In particular, the distance e separating the internal 40b and external 40a lips from each opening 40 may be greater than or equal to 0.3 mm, preferably greater than or equal to 0.5 mm, more preferably greater than or equal to 0.7 mm, and / or less than or equal to 2 mm, preferably less than or equal to 1.5 mm, more preferably less than or equal to 0.9 mm and more preferably still less than or equal to 0.7 mm.

The fact that the profiles 42, 44 are symmetrical with respect to the chord plane CC passing through the leading edge 37 and the trailing edge 38 of the aerodynamic tube 8 makes it possible to limit the obstruction to the air flow between the device ventilation 2 and the heat pipes 4, while creating more air passages in the volume available in front of the heat pipes 4.

In other words, unlike the embodiment of FIG. 7, an air passage entraining the ambient air is created between each pair of neighboring aerodynamic tubes 8, produced according to one of FIGS. 8 to 10.

The pitch between two neighboring aerodynamic tubes 8 can, in this case, be greater than or equal to 15 mm, preferably greater than or equal to 20 mm, more preferably still greater than or equal to 23 mm and / or less than or equal to 30 mm, preferably less than or equal to 25 mm, more preferably less than or equal to 27 mm. Indeed, if the pitch between the aerodynamic tubes 8 is lower, the induced air flow is limited by a passage section between the weak aerodynamic tubes. On the contrary, if the pitch is too large, the ejected air flow does not allow an induced air flow to be created over the entire pitch between the neighboring aerodynamic tubes.

The pitch between two neighboring aerodynamic tubes 8 can in particular be defined as the distance between the center of the cross section of two neighboring aerodynamic tubes 8 or, more generally, as the distance between a reference point on a first aerodynamic tube 8 and the point corresponding to the reference point, on the nearest aerodynamic tube 8. The reference point can in particular be one of the leading edge 37, the trailing edge 38 or the top of the convex part 50.

The distance between the aerodynamic tubes 8 and the heat transfer tubes 4 can in particular be chosen greater than or equal to 5 mm, preferably greater than or equal to 40 mm, and / or less than or equal to 150 mm, preferably less than or equal to 100 mm . In fact, the speed peak of the air speed profile in the vicinity of the profile tends to reduce as it moves away from the opening 40 in the aerodynamic tube. An absence of peak indicates a homogeneous mixture of the air flow ejected through the opening 40 and the induced air flow. It is preferable that such a homogeneous mixture is produced before the air flow arrives on the aerodynamic tubes. Indeed, an incident air flow on the heat transfer tubes, heterogeneous, does not allow optimal cooling of the heat transfer tubes and induces higher pressure drops. However, the distance between the aerodynamic tubes and the heat transfer tubes is preferably contained to limit the size of the cooling module.

In the example illustrated in FIG. 8, the trailing edge 38 is formed by the top joining two rectilinear symmetrical portions 60 of the first profile 42 and the second profile 44 of each aerodynamic tube 8. According to the variant of FIG. 8, the trailing edge 38 is the point of the cross section of the aerodynamic tube 8 located closest to the heat exchanger. In other words, the angle formed by the two rectilinear portions 60 is less than 180 °, in particular less than 90 °.

On the contrary, in the variant of FIG. 9, the trailing edge 38 is arranged between the two rectilinear portions 38a, 38b of the first and second profiles 42, 44. In other words, the angle a formed by the rectilinear portions 60 is here greater than 90 °, in particular greater than 180 °.

In the example illustrated in FIG. 10, the first and second profiles 42, 44 of the aerodynamic tube 8 converge towards the trailing edge 38 so that the distance separating the first and second profiles 42, 44 strictly decreases towards the edge of leak 38 from a point of these first and second profiles 42, 44 corresponding to the maximum distance h between these two profiles, these points of the first and second profiles 42, 44 being downstream of the openings 40 in the direction of flow of the air flow ejected through the opening 40. Preferably, the first and second profiles 42, 44 each form an angle of between 5 and 10 ° with the cord CC of symmetry of the cross section of the aerodynamic tube 8.

Therefore, unlike the example of Figure 8, the aerodynamic profile of Figure 8 does not include a portion delimited by first and second opposite planar walls parallel. This has the advantage of limiting the drag along the aerodynamic profile of the aerodynamic tube 8.

For example, the maximum distance h between the first profile 42 and the second profile 44 may be greater than or equal to 10 mm and / or less than or equal to 30 mm. In particular, this maximum distance h can be equal to 11.5 mm.

Finally, FIG. 11 schematically illustrates a variant of the heat exchange module 10 of FIG. 1. According to this variant, the heat exchange device 1 comprises three separate radiators 1a, 1b, such as, while the radiators la and lb are superimposed substantially, the third radiator is compact and extends only in the lower part of the heat exchange device 1. In this case, it may be advantageous to combine the absence of ejection of an air flow through certain conduits 8 at a position of these conduits 8 limiting or even preventing air from passing through these conduits 8. To do this, the conduits 8 advantageously have an oblong shape. The conduits 8 are pivotable about a respective longitudinal axis between a first effective position, in which the conduits are oriented so that the air which they eject is directed towards the heat exchange device and allowing a passage of air between the conduits 8 so as to form an induced air flow. On the contrary, in a second position, reached by pivoting from the first position, the conduits 8 limit or even prevent the passage of air between them, in the direction of at least part of the heat exchanger. Thus, advantageously, the ventilation device can be configured so that in its part facing the heat exchanger most in need of cooling is most often, or even always, in the position where the openings of the conduits 8 are oriented towards this part of the heat exchanger 1, the conduits 8 then being supplied with air by the air propulsion device, via the air intake manifold 12. On the contrary, the part of the heat exchanger placed opposite the ventilation device, can correspond to that which is not supplied with air by the ventilation device when the flow and / or pressure of the air flow emitted by it this is relatively small. In this case, where these conduits are not supplied with air, they can be pivoted to limit or even prevent the passage of air through between the conduits, so as to improve the aerodynamic properties of the vehicle on which the exchange module of heat has risen.

The invention is not limited to the embodiments presented and other embodiments will be apparent to those skilled in the art. In particular, the different examples can be combined, as long as they are not contradictory.

Furthermore, the examples given of means for selectively interrupting a fluid communication between at least certain conduits and the air propulsion device make it possible to interrupt this fluid communication in an air intake manifold. Alternatively, however, fluid communication can be selectively interrupted in each tube. In particular, the means for selectively interrupting a communication of fluid between at least certain ejection orifices and the air propulsion device can consist of means for closing the section of a ventilation tube, the position of which in the tube can be controlled in a manner substantially similar to what has been described opposite the shutter in the air intake manifold. According to another variant, a shutter for the ejection orifices of the ventilation tubes can be provided which is selectively moved to control the communication of fluid between the ejection orifices and the air propulsion device.

Also, in the examples described, the means for selectively interrupting the communication of fluid between at least certain ejection orifices and the air propulsion device are passive. Such a solution is preferred because it requires neither electrical power nor complex connection. As a variant, these means are active. Such an active solution can in particular make it possible to control the communication of fluid between the ejection orifices and the air propulsion device, independently of the pressure of the air flow supplied by the air propulsion device. The active means can take the form of one or more solenoid valves and / or one or more pneumatic valves.

Finally, according to an embodiment not illustrated, the air propulsion device can be received in one of the air intake manifolds or in each air intake manifold.

Claims (10)

1. Ventilation device (2) intended to generate an air flow towards a heat exchanger (1) of a motor vehicle, comprising ducts (8) intended to be supplied with air flow by at least one air propulsion device, each duct (8) having at least one opening (16; 40) for ejecting an air flow passing through said duct (8), substantially in the direction of said heat exchanger (1), the ventilation device further comprising means adapted to selectively interrupt a fluid communication between at least certain ejection openings (16; 40) and said air propulsion device. 2. A ventilation device according to claim 1, further comprising at least one air intake manifold (12), each opening duct (8) by one of its ends in an orifice (14) separate from the at least one manifold. air intake (12), the conduits (8) being intended to be supplied with an air flow by said at least one air propulsion device, via the at least one air intake manifold (12), said at least one ejection opening (16; 40) of the conduits being distinct from the ends of the corresponding conduit, said at least one opening (16; 40) being situated outside the at least one collector of air intake (12). 3. Ventilation device according to claim 1 or 2, in which the means adapted to selectively interrupt a fluid communication between at least certain ejection openings (16; 40) and said at least one propulsion device comprise means for closing off : - at least some orifices (14) of the air collector; and or - a section of the at least one air manifold (12); and or - at least some ejection openings (16; 40). 4. Ventilation device according to one of the preceding claims, in which the means adapted to selectively interrupt a fluid communication between at least certain ejection openings (16; 40) and said air propulsion device are passive, the means adapted to selectively interrupt a fluid communication between at least certain ejection openings (16; 40) and said propulsion device being preferably controlled by an air flow and / or an air pressure. 5. Ventilation device according to claim 4, in which the at least one air intake manifold (12) is of substantially tubular shape, preferably cylindrical, and in which the means adapted to selectively interrupt a communication of fluid between at least some ejection openings (16; 40) and said at least one air propulsion device comprise a shutter (102), the shutter (102) having a section substantially complementary to the cross section of said at least one manifold air intake (12), the shutter (102) being movable in said at least one air collector (12). 6. Ventilation device according to claims 5, wherein the shutter (102) is movably mounted against the action of a return spring (104), the return spring (104) preferably having a greater or equal stiffness at 5 N / m and / or less than or equal to 50 N / m. 7. Ventilation device according to any one of the preceding claims, in which the means adapted to selectively interrupt a fluid communication between at least certain ejection openings (16; 40) and said air propulsion device comprise at least a valve (202), preferably a rocker valve, adapted to close at least one orifice (14) of the at least one air manifold (12), the rocker valve preferably being mounted pivotally against the action of a return spring. 8. Ventilation device according to claim 1 or 3, wherein the means adapted to selectively interrupt a fluid communication between at least certain ejection openings (16; 40) and said air propulsion device are active. 9. A ventilation device according to claim 8, in which the means adapted to selectively interrupt a fluid communication between at least certain ejection openings and said air propulsion device comprise at least one of a solenoid valve and a valve. pneumatic. 10. Ventilation device according to any one of the preceding claims, in which at least certain conduits (8) are pivotable, preferably around a respective longitudinal axis, the conduits (8) preferably also having an oblong section such that the conduits (8) allow the passage of air between the conduits in a first position and that the conduits (8) limit or even prevent the passage of air between the conduits (8) in a second position reached by pivoting 5 of the conduits (8) from the first position.