Two-level cooling device and on-board charging device comprising such a cooling device

Abstract

The invention relates to a device (10) for cooling electronic components, the device comprising a housing (11) that comprises: - a first coolant circulation chamber (21); - a second coolant circulation chamber (22), the circulation chambers (21, 22) being stacked, along a stacking plane (P1), on top of one another; - a fluid connection zone (23) between the first circulation chamber (21) and the second circulation chamber (22), so as to form a circulation channel in which the coolant is intended to circulate through the first circulation chamber (21) and then the second circulation chamber (22).

Description

DESCRIPTION Title of the invention: Two-stage cooling device and on-board charging device comprising such a cooling device

[0001] The present invention relates to the field of on-board chargers for electric or plug-in hybrid vehicles and more specifically to a cooling device for electronic components.

[0002] Onboard chargers include various electronic components such as power modules, coils, and capacitors, though this list is not exhaustive. These electronic components generate heat when the onboard charger is in use.

[0003] However, electric vehicles require ever-increasing charging power, particularly to reduce charging times. This increase in charging power is accompanied by a growing heat output during charger operation, necessitating solutions to mitigate thermal stress on charger components.

[0004] For example, power modules can have an operating temperature of 150°C. Power modules are increasingly used in electronic systems because they allow multiple electronic chips to be packed into a small space on a printed circuit board.

[0005] It is known to cool a power module by placing this power module in contact with a wall of a cooling circuit in which a coolant circulates.

[0006] Traditionally, an onboard charging system includes a cooling unit consisting of a receptacle and a sealing plate that define a coolant circuit. This circuit is supplied by a coolant that recovers, through the sealing plate, the heat generated during the operation of the power module mounted on the plate. The shape of the coolant circuit is defined by a circulation channel formed by grooves in the receptacle, designed to channel the coolant under each of the power modules. The circulation channel thus extends between two opposite ends of the cooling unit.It is known to place the power modules along the circulation conduit, with these power modules arranged parallel to the direction of fluid flow in the area where the power module in question is fixed.

[0007] This cooling principle has been improved in an existing solution that features a circulation channel extending not longitudinally between the two opposite ends of the cooling device, but in an annular fashion. This solution offers two advantages: it is compact and provides enhanced cooling. Indeed, due to the annular configuration of the circulation channel, it is possible to place the electronic components in the central part of the cooling device. These components benefit from a large heat exchange surface with a vertical wall of the circulation channel to dissipate the generated heat. Furthermore, because the circulation channel is annular, the coolant inlet and outlet ports are located on the same side.Bringing the coolant inlet and outlet areas together on the same side of the cooling system can facilitate the integration of the cooling system into a vehicle.

[0008] Although already satisfactory, it is desirable to improve existing solutions. Indeed, some electronic components, such as insulated-gate field-effect transistors (or MOSFETs, for Metal-Oxide-Semiconductor Field-Effect Transistors), generate a significant amount of heat that must be dissipated to prevent degrading the power module's operation. However, not all electronic components require this level of cooling.

[0009] The invention falls within this context and proposes a two-level cooling device allowing targeted cooling and which can be easily adapted at the time of design according to the final configuration of the on-board charger.

[0010] To this end, the invention relates to a cooling device for electronic components capable of generating heat, comprising a housing extending at least partially around a cavity suitable for receiving one or more first electronic components, the housing having an upper wall and a side wall, at least one of the upper wall and the side wall being intended to perform a heat exchange with second electronic components, the cooling device being characterized in that the housing comprises: an inlet for introducing coolant into the housing, an outlet for removing coolant from the housing, a first circulation chamber fluidly connected to the inlet, a second circulation chamber fluidly connected to the outlet, one of the first and second circulation chambers being an upper chamber superimposed, according to a superposition plane, on the other of the first and second circulation chambers being the lower chamber, a fluidic connection zone between the first circulation chamber and the second circulation chamber, so as to form a circulation channel in which the coolant is intended to circulate from the inlet to the outlet through the first circulation chamber and then the second circulation chamber.

[0011] The cooling system is physically defined by the generally annular housing. The housing extends around the cavity in which the initial electronic components can be placed. These initial electronic components might be, for example, magnetic components. The housing includes internal walls that form the cavity and through which the initial electronic components can transfer their thermal energy to the coolant. The housing defines a circulation channel for the coolant. The coolant could be, for example, water or a mixture of water and glycol. The circulation channel originates at the housing's inlet and terminates at its outlet.After passing through the inlet, it flows through the first circulation chamber, crosses the fluid connection zone, and passes through the second circulation chamber to reach the outlet. The housing inlet is therefore the entry point for the coolant into the cooling system, and the housing outlet is the outlet point for the coolant from the cooling system.

[0012] The first circulation chamber is located above the second circulation chamber, or alternatively, the second circulation chamber is located above the first circulation chamber. The circulation chamber located above the other is called the upper chamber. The circulation chamber located below the upper chamber is called the lower chamber. It follows from the above that if the first circulation chamber is the upper chamber, the inlet is located above the superposition plane and the outlet below. Conversely, if the second circulation chamber is the upper chamber, the outlet is located above the superposition plane and the inlet below. According to an optional feature, the first chamber is the lower chamber and the second chamber is the upper chamber.The coolant first circulates in the lower chamber, then enters the upper chamber via the fluid connection zone, and finally exits the cooling system through the housing outlet. The top and / or side wall of the housing is designed to facilitate heat exchange with secondary electronic components, such as MOSFETs. MOSFETs generate a significant amount of heat, so substantial heat exchange occurs through the top and / or side wall of the housing. The side wall can be defined as the wall adjacent to the top wall. This could be the side wall facing the cavity or the opposite side wall from the circulation chamber.

[0013] Thanks to these features, the cooling device of the invention operates at two levels of cooling. The first electronic components, located in the central cavity of the cooling device, benefit from a large heat exchange surface formed by the internal walls of the housing. Depending on their shape and positioning, these first electronic components can be in contact with one, two, or three internal walls. The second electronic components are located above the upper chamber. The heat generated by these second electronic components is dissipated through the upper and / or side walls of the housing. This results in an improved cooling device with a larger heat exchange surface compared to prior art solutions.

[0014] According to an optional feature of the invention, the second circulation chamber is fluidically connected to the first circulation chamber in series. This is referred to as series cooling, and it is independent of whether the first circulation chamber is the lower or upper chamber. In this configuration, each circulation chamber has two ends. The inlet fluidically connected to the first circulation chamber is located near one end of the first chamber, and the outlet fluidly connected to the second circulation chamber is located near one end of the second chamber, which is superimposed on the first end of the first chamber. The fluid connection zone is located at the second end of both the first and second circulation chambers. Thus, the coolant is introduced through the inlet and flows through the first chamber.Since the inlet is near the first end of the first chamber, the coolant flows towards the second end of the first chamber, where the fluid connection zone is located. In other words, the coolant flows entirely through the first circulation chamber before entering the second circulation chamber via the fluid connection zone. Then, the coolant flows from the second end of the second circulation chamber back to the first end of the second chamber to reach the outlet. It follows that after passing through the housing inlet, the coolant flows completely through the first circulation chamber, passes through the fluid connection zone, enters the second circulation chamber, and flows completely through the second circulation chamber until it exits the housing through the outlet.The circulation of the coolant from the first chamber to the second chamber is carried out in series.

[0015] According to an optional feature of the invention, the second circulation chamber is fluidically connected to the first circulation chamber in parallel. This is referred to as parallel cooling, and it is independent of whether the first circulation chamber is the lower or upper chamber. In this configuration, the inlet and outlet are located on the same face of the housing, and the fluid connection zone is situated in the circulation channel opposite the inlet and outlet. The coolant is introduced through the inlet and circulates through the first circulation chamber on both sides of the cavity. In other words, the coolant flow splits into two streams, each passing on one side or the other of the cavity. The two streams rejoin at the connection zone.The coolant enters the second circulation chamber and splits again into two streams, each flowing along one side or the other of the cavity before rejoining at the outlet through which the coolant is discharged from the housing. The coolant circulates from the first chamber to the second chamber in parallel.

[0016] According to an optional feature of the invention, in a plane perpendicular to the superposition plane, a cross-section of the upper chamber is smaller than a cross-section of the lower chamber. Reducing the cross-section of the upper chamber increases the velocity of the coolant circulating within it, resulting in improved cooling of the secondary electronic components.

[0017] According to an optional feature of the invention, the cooling device further comprises a separating plate extending in the superposition plane separating the first circulation chamber from the second circulation chamber.

[0018] The separating plate is a flat, open plate with a perforation in its center. This perforation corresponds to the cavity. The discontinuous area of ​​the separating plate represents the fluid connection zone. In other words, the separating plate is positioned within the housing and divides the internal volume of the housing into two chambers. Thus, the separating plate separates the first and second circulation chambers, and its discontinuous area forms the fluid connection zone. The separating plate's shape is therefore complementary to the internal volume of the housing in the plane of superposition.

[0019] In one variant, the separating plate can be attached to the housing using any suitable fastening device, such as rivets or by local material deformation. In another variant, the internal walls of the lower chamber may include, in their upper part, studs oriented towards the interior of the chamber, so that the separating plate rests against these studs to be held in position within the overlapping plane.

[0020] According to an optional feature of the invention, the upper chamber comprises N protrusions extending perpendicularly to the superposition plane, where N is a natural number greater than or equal to 1. It is understood that these protrusions extend from the upper and / or lower wall of the upper chamber. The protrusions thus extend perpendicularly to the streamlines of the coolant flow. This results in an increased contact area between the housing and the coolant, which promotes heat transfer between the housing, itself in contact with the heat-generating electronic components, and the coolant. The protrusions may have a circular cross-section, i.e., a cylindrical shape. The protrusions may also have a rectangular cross-section or any other polygonal cross-section.It should be noted that protrusions may have one type of cross-section, for example, circular, and other protrusions may have a different type of cross-section, for example, octagonal. In other words, the cross-section of the protrusions is in no way a limiting factor of the invention. Advantageously, the protrusions have an elliptical cross-section, with the major axis of the ellipse parallel to the direction of coolant flow in the upper chamber. This configuration of the protrusions ensures an increased contact surface area between the coolant and the housing for improved heat exchange while maintaining a low pressure drop in the upper chamber.

[0021] According to an optional feature of the invention, N protrusions (M) are pins extending from an upper face of the upper chamber, where M is a natural number between 1 and N, from a first cross-section having a first characteristic dimension. A characteristic dimension is defined as a dimension definable according to the cross-section of the pin. For example, for a circular cross-section, a characteristic dimension of the pin is the diameter of its cross-section. For an elliptical cross-section, the characteristic dimension is the length of the side. For an elliptical cross-section, it could be the length of the major axis.

[0022] In this variant, the pins extend from the upper wall of the upper chamber. Since the upper wall of the housing, and therefore of the upper chamber, is designed to exchange heat with secondary electronic components, the pins extending from the top surface of the upper chamber are an extension of this surface into the upper chamber, i.e., into the coolant. This configuration allows the thermal energy from the secondary electronic components to be directed directly into the coolant flowing through the upper chamber. The cooling of the secondary electronic components is thus optimized.

[0023] According to an optional feature of the invention, the M pins have an end of a second cross-section having a second characteristic dimension smaller than the first characteristic dimension, and the separating plate comprises M through-holes with a cross-section substantially equal to the second characteristic dimension of the M pins, the ends of the M pins being inserted into the M through-holes. This means, in the example of pins with a circular cross-section, that the pins have a first diameter from the top face of the upper chamber to a certain distance from the separating plate. Beyond this point, they have a second diameter smaller than the first diameter. Since the separating plate has holes of the second diameter opposite the pins, this allows each pin to be inserted into a through-hole in the separating plate. In other words, the end of each pin is positioned in a through-hole in the separation plate. The interaction between the pin and the separation plate serves a dual purpose: firstly, the insertion of the pins into the holes in the separation plate holds the plate in position, in which case the aforementioned interaction has a mechanical function; and secondly, the insertion of the pins into the holes in the separation plate creates a thermal pathway for the heat generated by the second components. Through thermal conduction, the heat energy from the second components in contact with the upper surface of the housing travels through the housing walls and the pins, then through the separation plate. The heat exchange surface area in the upper chamber is significantly increased, allowing for better cooling of the second electronic components.

[0024] According to an optional feature of the invention, the lower chamber comprises a bottom wall and / or a side wall for heat exchange with third electronic components. N protrusions extend perpendicularly to the superposition plane. M of these N protrusions are pins extending from a lower face of the lower chamber, with a first cross-section being the first characteristic dimension, inserted into M through-holes. In this configuration, a series of electronic components can be arranged below the lower chamber, i.e., below the cooling device, in contact with the bottom wall and / or the side wall. The side wall is to be understood as a lateral wall of the lower chamber. The side wall can be defined as the wall adjacent to the bottom wall.This could be the side wall facing the cavity or the opposite side wall of the lower chamber. The same advantages as those presented with the pins of the upper chamber apply here and are not detailed again.

[0025] According to an optional feature of the invention, the upper chamber includes a projection extending from the separating plate perpendicularly to the superposition plane, the projection defining at least one tortuous passage within it for the coolant. A tortuous passage is understood to mean a passage for the coolant that is not straight. The tortuous passage can be viewed as a tunnel with irregular internal surfaces. The coolant in the upper chamber flows through the tortuous passage of the projection. The heat exchange surface area between the housing and the coolant is increased due to the tortuousness of the passage within the projection.

[0026] According to an optional feature of the invention, the protrusion is formed by a superposition of pairs of adjacent layers, each layer having a plurality of spaced through-holes. A through-hole in one layer is in fluidic connection with at least one through-hole in an adjacent layer, thus forming at least one tortuous passage. The superposition creates a continuous material flow. The tortuous passage is thus formed by the staggered superposition of through-holes on several layers relative to the superposition plane. The tortuous passage can be defined as a plurality of intersecting tunnel segments. This configuration lengthens the distance the coolant must travel to pass through the upper chamber and increases the contact area between the walls of the protrusion, and therefore indirectly of the housing, and the coolant.This results in improved heat exchange between the first and second electronic components and the coolant.

[0027] The invention also relates to an embedded charging device comprising at least one electronic component from among first electronic components, second electronic components, and a cooling device as described above, the first electronic component(s) being arranged in the cavity and the second electronic component(s) being arranged on the top and / or side wall of the housing. As explained above, such an embedded charging device provides optimized cooling of the first and second electronic components. More specifically, it allows for targeted cooling depending on the category of electronic components.The second electronic components, which can be MOSFETs requiring a high level of cooling, are placed on the top wall and / or the side wall of the case, so as to benefit from the advantages of the circulation of the coolant in the upper chamber, according to the different variants of the invention described above.

[0028] According to an optional feature of the invention, the onboard charging device further comprises third electronic components arranged on the bottom wall and / or the side wall. Such a configuration allows for the placement of more electronic components on the cooling device to ensure the dissipation of the thermal energy they generate.

[0029] Other features and advantages of the invention will become apparent from the following description on the one hand, and from several illustrative and non-limiting examples of embodiments given with reference to the attached schematic drawings on the other hand, in which:

[0030] [Fig. 1] represents a cooling device according to the invention,

[0031] [Fig. 2] represents, in perspective, a cross-sectional view along a separation plane of the two levels of the cooling device according to the invention,

[0032] [Fig. 3] represents, in perspective, a cross-sectional view along a plane perpendicular to the plane of separation of the two levels of the cooling device according to the invention,

[0033] [Fig. 4] represents a variant of the circulation channel of the cooling device according to the invention,

[0034] [Fig. 5] represents another variant of the circulation channel of the cooling device according to the invention,

[0035] [Fig. 6] represents an on-board charger device according to the invention.

[0036] The features, variations, and different embodiments of the invention, as described or as they will be presented in the detailed description that follows, can be combined in various ways, provided they are not incompatible or mutually exclusive. In particular, variations of the invention may be conceived comprising only a selection of features, described hereafter in isolation from the other described features, if this selection of features is sufficient to confer a technical advantage and / or to differentiate the invention from the prior art.

[0037] For the sake of clarity, the same elements are designated by the same references in the different figures.

[0038] Figure 1 shows a cooling device 10 according to the invention. The cooling device 10 is intended to cool electronic components that generate heat during operation. Electronic components can be divided into two categories: first, magnetic components, and second, MOSFETs. MOSFETs are characterized by their ability to generate a significant amount of heat, which must therefore be dissipated.

[0039] The cooling device 10 includes a housing 11 that defines an internal volume through which a coolant circulates to cool the first and second electronic components. The housing 11 extends at least partially around a cavity 12. As illustrated, the housing 11 is annular in shape. It thus forms an internal volume that completely surrounds the cavity 12. Alternatively, the housing may form an internal volume that partially surrounds the cavity 12. The cavity 12 is suitable for housing the first electronic components.

[0040] The housing 11 has an upper wall 13. This upper wall 13 is designed to facilitate heat exchange with the second electronic components. It is understood that the second electronic components are arranged above the upper wall 13, in direct contact with this wall or in indirect contact, depending on the chosen configuration. The housing also has a side wall 131, adjacent to the upper wall. The side wall 131 is also designed to facilitate heat exchange with the second electronic components. In other words, the second electronic components can be arranged on the upper wall 13 or on the side wall 131. The side wall 131 extends in a plane intersecting the upper wall 13.

[0041] According to the invention, the housing 11 includes an inlet 14 for introducing a coolant into the housing 11, and an outlet 15 for removing the coolant from the housing 11. The housing also includes two circulation chambers 21, 22 for the coolant. These two circulation chambers are arranged one above the other to constitute a two-level circulation of the cooling device 10. Of these two circulation chambers, a first circulation chamber 21 is fluidly connected to the inlet 14, and a second circulation chamber 22 is fluidly connected to the outlet 15. One of the two circulation chambers 21 or 22 is designated the upper chamber. The upper chamber is superimposed, according to a superposition plane P1, on the other of the first and second circulation chambers, which is then the lower chamber.It follows that, with respect to the superposition plane P1, the lower chamber is below the superposition plane, while the upper chamber is above the superposition plane. In a variant illustrated in Figure 1, the first circulation chamber 21 is the lower chamber and the second circulation chamber 22 is the upper chamber. Consequently, when projected onto a plane perpendicular to the superposition plane, the inlet 14 is located below the outlet 15. In the preceding text, the side wall 131 refers to one or both side walls of the upper chamber.

[0042] The housing 11 further includes a fluid connection zone 23 (not visible in Figure 1, but visible in Figure 2) between the first circulation chamber 21 and the second circulation chamber 22, so as to form a circulation channel in which the coolant is intended to flow from the inlet 14 to the outlet 15 through the first circulation chamber 21 and then the second circulation chamber 22. The fluid connection zone 23 is an opening between the first circulation chamber 21 and the second circulation chamber 22. In other words, the fluid connection zone 23 allows the passage of the coolant from the first circulation chamber 21 to the second circulation chamber 22. The cooling device 10 operates as follows: the cooling device 10 is intended to be connected to a coolant circuit.For this purpose, two hydraulic connectors 16 and 17, shown schematically here, can be used to connect the inlet 14 to the cooling circuit and the outlet to the cooling circuit, respectively. The coolant enters the housing 11 through the inlet 14 and flows into the first circulation chamber 21. The coolant then passes through the fluid connection zone 23 to enter the second circulation chamber 22. The coolant flows through the second circulation chamber 22 to the outlet 14, where it rejoins the cooling circuit.

[0043] As illustrated in Figure 1, the first circulation chamber 21 is the lower chamber and the second circulation chamber 22 is the upper chamber. It should be noted that the invention is not limited to this configuration, and the reverse configuration, i.e., the first circulation chamber 21 being the upper chamber and the second circulation chamber 22 being the lower chamber, is also conceivable within the scope of the invention. In the illustrated embodiment, the coolant enters the housing at the level of the lower chamber. Since the first electronic components can be arranged in the cavity 12 located in the center of the housing 11, the thermal energy from the first electronic components can be transferred to the coolant through the wall of the first circulation chamber 21, which delimits the cavity 12.This transfer of thermal energy between the first electronic components and the coolant can also occur similarly in the upper chamber. As it circulates through the upper chamber, the coolant also exchanges heat with the upper and / or side wall of the housing 11. Since the upper and / or side wall of the housing 11 is in contact with the second set of electronic components, the coolant circulating in the upper chamber absorbs heat from these second electronic components.

[0044] In one embodiment of the invention, the upper chamber may locally include one or more sectional restrictions 18. Such a sectional restriction is defined in a plane perpendicular to the superposition plane P1. This plane is perpendicular to the streamlines of the coolant. By implementing such sectional restrictions, the fluid velocity is locally increased. This results in a local increase in the coolant velocity, thus facilitating the dissipation of thermal energy generated by the electronic components. The upper chamber may include a plurality of successive sectional restrictions 18. As the coolant passes through the plurality of sectional restrictions, it encounters a succession of convergent and divergent sections.This configuration optimizes the contact time between the coolant and the hot walls of the upper chamber, allowing for improved cooling of the electronic components.

[0045] The cooling device of the invention is based on a housing 11 providing coolant circulation in two circulation chambers on two levels, or two stages. Thanks to the superposition of the two circulation chambers, and as will be detailed later, it is possible to apply targeted cooling according to the position of the electronic components and their respective cooling requirements, without any excess material being wasted.

[0046] According to an optional feature of the invention, the cooling device 10 includes a separating plate 24 extending in the superposition plane P1. The separating plate 24 physically separates the first circulation chamber 21 from the second circulation chamber 22. Thanks to the separating plate 24, the coolant is directed first into the first circulation chamber 21 and then into the second circulation chamber 22. The separating plate 24 has a shape complementary to the cross-section of the internal volume of the housing along the superposition plane P1. The separating plate 24 is therefore delimited by the contour of the walls of the housing 11. It is understood that the separating plate is flat. It includes a central opening corresponding to the location of the cavity 12. It also includes a lateral opening corresponding to the fluid connection zone 23.The separation plate 24 physically separates the first from the second circulation chamber, except at its lateral opening to allow the passage of the coolant at the fluid connection zone 23.

[0047] Figure 2 shows, in perspective, a cross-sectional view along a separation plane of the two levels of the cooling device 10 according to the invention. The separation plane of the two levels of the cooling device can be considered equivalent to the superposition plane P1. More precisely, the lower chamber, here the first circulation chamber 21, and the physical separation between the lower and upper chambers are visible. This physical separation can be achieved during the manufacturing of the housing, for example, by stamping. Alternatively, the physical separation between the two chambers can be achieved by the separating plate 24, inserted and fixed between the two chambers. In the following, although the invention is by no means limited to it, the housing 11 will be described in the variant with the separating plate 24.

[0048] As explained previously, the coolant enters the housing 11, flows through the first circulation chamber 21, passes through the fluid connection zone 23, and flows into the second circulation chamber 22. Two scenarios are possible, corresponding to the two illustrations in Figure 2. In the first scenario, as shown on the left of the figure, the lateral opening of the separating plate 24 is located opposite the inlet 14 of the housing 11. The flow of the coolant within the housing is schematically represented by arrows. The coolant, corresponding to a flow F, passes through the inlet 14 and is divided into two flows, F1 and F2. As illustrated, flow F1 flows clockwise and flow F2 flows counterclockwise in the first circulation chamber 21.The two flows F1 and F2 converge at the fluid connection zone 23 and pass through the lateral opening of the separating plate 24 to enter the second circulation chamber 22 (not shown). Similar to what occurs after passing through the inlet 14, the coolant flow F splits into two flows. One flow passes through one side of the second circulation chamber 22 while the other flows through the other side of the second circulation chamber 22 to converge at the outlet 15 of the housing where the coolant leaves the cooling device 10. The second circulation chamber 22 is said to be fluidically connected to the first circulation chamber 21 in parallel.

[0049] In the variant illustrated on the right of the figure, the separating plate 24 has its lateral opening positioned on a face adjacent to the face of the inlet 14. The flow F of coolant which enters the housing 11 through the inlet 14 circulates entirely through the entire first circulation chamber 21 before entering the second circulation chamber 22 through the fluidic connection zone 23. The second circulation chamber 22 is said to be fluidically connected to the first circulation chamber 21 in series.

[0050] Figure 3 shows, in perspective, a cross-sectional view along a plane perpendicular P2 to the separation plane, or superposition plane P1, of the two levels of the cooling device 11 according to the invention. This view shows the cavity 12, which can house the first electronic components. The cavity 12 may be a single cavity (as shown in Figure 1) or it may comprise several sub-cavities, as shown in Figure 3. Two sub-cavities are separated by a rigid wall, which notably helps to hold the first electronic components in position within it.

[0051] In the plane P2 perpendicular to the superposition plane P1, a section S1 of the upper chamber is smaller than a section S2 of the lower chamber. The difference in cross-section between the upper and lower chambers results in a higher velocity for the coolant circulating in the upper chamber. This higher circulation velocity leads to improved cooling, particularly of the second electronic components 50 located on the upper wall 13 and / or the side wall 131 of the housing 11.

[0052] Figure 4 shows a variant of the circulation channel of the cooling device 10 according to the invention. As a reminder, the circulation channel is formed by the first and second circulation chambers and constitutes the path that the coolant takes through the cooling device 10.

[0053] According to an optional feature of the invention, the upper chamber comprises N protrusions 30 extending perpendicularly to the superposition plane P1, N being a natural number greater than or equal to 1. At the top of Figure 4, section AA is shown, representing eleven protrusions. In this case, N is equal to eleven. Of course, the invention applies similarly for any integer N that is at least equal to 1. The extension of one or more protrusions 30 through the upper chamber increases the contact area between the coolant and the housing walls to achieve more efficient heat exchange between the heat sources and the coolant.

[0054] In the general view of the cooling device, it can be seen that some of the protrusions 30 are pins extending from an upper face 25 of the upper chamber. The pins have a first cross-section with a first characteristic dimension d1. The characteristic dimension corresponds to a principal dimension of the pin's cross-section. In the illustrated case, the pins are cylinders, the cross-section is circular, and the characteristic dimension d1 is the pin's diameter. Although any cross-section is applicable to the pins, a circular cross-section is preferred to allow good flow of the coolant around them. Advantageously, the cross-section of the pins is elliptical, with the major axis coinciding with the streamlines of the coolant in the upper chamber.Thus, in addition to increasing the heat exchange surface between the case and the coolant, the circular or elliptical cross-section pins generate little or no pressure loss in the flow of the coolant.

[0055] According to an optional feature of the invention, the pins have an end 31 of a second cross-section having a second characteristic dimension d2 smaller than the first characteristic dimension d1. In the example of the pin with a circular cross-section, the diameter d2 of the pin's end is smaller than the diameter d1 of the pin's body. Furthermore, the separating plate 24 includes through holes 26 with a cross-section substantially equal to the second characteristic dimension d2 of the pins. These features allow the ends 31 of the pins to be inserted into the through holes 26 of the separating plate. Inserting the pins into the separating plate 24 helps to maintain the position of the separating plate within the internal volume of the housing 11. In other words, each pin has a shoulder that provides axial support for the separating plate 24.Furthermore, since the pins extend from the upper face 25 of the upper chamber to the separating plate 24, they form a thermal path to dissipate the thermal energy stored at the upper face 25 to the separating plate by thermal conduction. The pins and the separating plate together form an enlarged contact surface with the coolant, ensuring efficient dissipation of the thermal energy generated by the electronic components.

[0056] In one embodiment of the invention, the lower chamber may include a bottom wall and / or a side wall for heat exchange with third electronic components. In other words, the third electronic components may be arranged below the cooling device 10. The lower chamber may then include N protrusions extending perpendicularly to the superposition plane P1, and M of these N protrusions are pins extending from a lower face of the lower chamber. Similar to the pins of the upper chamber, the pins of the lower chamber have a first cross-section where the first characteristic dimension is d1, and they are inserted into the M through-holes 26 of the separation plate 24. The same advantages of increased heat exchange without generating pressure losses and mechanical support of the separation plate, as described above, result from this configuration.The end 31 of a pin from the upper chamber and the end of a pin from the lower chamber can thus be inserted into the same through hole in the separating plate, provided that the separating plate 24 is thick enough to accommodate a portion of each end.

[0057] Figure 5 shows another variant of the circulation channel of the cooling device 10 according to the invention. In this variant, the upper chamber includes a projection 40 extending from the separating plate 24 perpendicularly to the superposition plane P1. The projection 40 defines one or more tortuous passages 41 within it for the coolant. The tortuous passages 41 are composed of multidirectional channels for the circulation of the coolant. The projection 40 is intended to increase the contact area between the coolant and the housing 11.

[0058] The protrusion 40 can be formed, in particular, by a superposition of layers 41, 42, 43, 44 placed in pairs adjacent to each other, each layer having a plurality of through-openings 410, 420, 430, 440 spaced apart. For example, layer 41 is arranged on the separating plate 24. Layer 41 comprises several oblong through-openings 410. Each opening 410 extends at a distance and parallel to the opening adjacent to it on layer 41. Layer 42 is arranged on layer 41. Layer 42 comprises several oblong through-openings 420. Each opening 420 extends at a distance and parallel to the opening adjacent to it on layer 42. Each opening 420 is oriented differently from an opening 410. And a through-opening 410 of layer 41 is in fluidic connection with at least one through-opening 420 of layer 42. Similarly, layer 43 is arranged on top of layer 42. Layer 43 comprises several oblong through-openings 430. Each opening 430 extends at a distance and parallel to its adjacent opening on layer 43. Each opening 430 is oriented differently from an opening 420, and may, for example, be oriented in the same way as a through-opening 410. And a through-opening 420 of layer 41 is in fluidic connection with at least one through-opening 430 of layer 43. The same principle applies to layer 44. The fluidic connection between the different through-openings allows the tortuous passage(s) 41 to be formed.

[0059] In the preceding text, the through-holes were described as having an oblong shape. Naturally, the invention applies similarly to other shapes of through-holes. Furthermore, the formation of the tortuous passage 41 was described using superimposed layers to aid understanding. This does not imply anything about the manufacturing method of the protrusion. Indeed, such a protrusion can be obtained by superimposing and assembling prefabricated layers, or it can be produced by additive manufacturing, in which case the superposition of the layers forms a continuous material.

[0060] The convoluted passage 41 forms a circulation volume for the coolant. This circulation volume is shown at the bottom of the figure. It is therefore understood that this is the volume available for the coolant to circulate through the protrusion. As can be seen, the convoluted passage is composed of a network of channels extending in several directions, corresponding to the orientations of the through-holes described above. The convoluted passage 41 implies a longer distance for the coolant to travel compared to an upper chamber in the protrusion, and a larger heat exchange surface between the housing and the coolant, contributing to efficient dissipation of thermal energy from the electronic components.

[0061] In one variant of the invention, the overlapping through openings 410, 420, 430, 440 can form the through holes 26 for the insertion of the pins.

[0062] Figure 6 shows an on-board charger device 500 according to the invention, the on-board charger comprising at least one electronic component from among first electronic components, second electronic components, for example MOSFETs, and a cooling device 10 as described in this document. The on-board charger device 500 includes a housing 510 on which the cooling device 10 is disposed. A cavity 12 is defined by the cooling device 10 within which electronic components are disposed. The first electronic component(s) are disposed in the cavity 12. Although not shown, one or more second electronic components 50 may be disposed on the upper wall 13 and / or the side wall 131 of the housing 11.Thanks to the innovative design of the cooling system, the onboard load device benefits from optimized cooling tailored to its operating requirements. Coolant is introduced into and drained from the cooling system 10 via hydraulic connectors 16 and 17. The circulation of coolant through the two circulation chambers 21 and 22 guides the coolant within the housing 11, enhancing heat exchange where cooling is most critical, particularly in the upper chamber which houses MOSFET electronic components. Cooling can be further improved by adapting the configuration of the upper chamber using protrusions 30 and projections 40. Their number and shape can be customized according to the type of onboard load device.The invention thus enables two-stage cooling for targeted cooling. Furthermore, the cooling level can be adapted during the design phase according to the final configuration of the onboard charger.

[0063] Of course, the invention is not limited to the examples just described, and many modifications can be made to these examples without departing from the scope of the invention. In particular, the features of different embodiments of the invention can be combined to carry out the invention, provided that these embodiments are not incompatible with each other.

Claims

DEMANDS 1- Cooling device (10) for electronic components capable of generating heat, comprising a housing (11) extending at least partially around a cavity (12) suitable for receiving one or more first electronic components, the housing (11) having an upper wall (13) and a side wall (131), at least one of the upper wall and the side wall being intended to perform heat exchange with second electronic components, the cooling device (10) being characterized in that the housing (11) comprises: an inlet (14) for introducing coolant into the housing (11), an outlet (15) intended to drain the coolant from the housing (11), a first circulation chamber (21) fluidly connected to the inlet (14), a second circulation chamber (22) fluidly connected to the outlet (15), one of the first and second circulation chambers (21, 22) being a superimposed upper chamber, according to a superposition plane (P1), to the other of the first and second circulation chambers being the lower chamber, a fluidic connection zone (23) between the first circulation chamber (21) and the second circulation chamber (22), so as to form a circulation channel in which the coolant is intended to circulate from the inlet (14) to the outlet (15) through the first circulation chamber (21) and then the second circulation chamber (22). 2- Cooling device (10) according to claim 1, in which the second circulation chamber (22) is fluidly connected to the first circulation chamber (21) in series. 3- Cooling device (10) according to claim 1, in which the second circulation chamber (22) is fluidly connected to the first circulation chamber (21) in parallel. 4- Cooling device (10) according to any one of claims 1 to 3, wherein, in a plane (P2) perpendicular to the superposition plane (P1), a section (S1) of the upper chamber is less than a section (S2) of the lower chamber. 5- Cooling device (10) according to any one of claims 1 to 4, further comprising a separation plate (24) extending in the superposition plane (P1) separating the first circulation chamber (21) from the second circulation chamber (22). 6- Cooling device (10) according to any one of claims 1 to 5, in which the upper chamber comprises N protrusions (30) extending perpendicularly to the superposition plane (P1), N being a natural integer greater than or equal to 1. 7- Cooling device (10) according to claim 6, in which M of the N protrusions (30) are pins extending from an upper face (25) of the upper chamber, M being a natural integer between 1 and N, of a first section having a first characteristic dimension (d1). 8- Cooling device (10) according to claim 7 in combination with claim 5, wherein the M pins have an end (31) of a second section having a second characteristic dimension (d2) less than the first characteristic dimension (d1), and the separating plate (24) comprises M through orifices (26) of a cross section substantially equal to the second characteristic dimension (d2) of the M pins, the ends (31) of the M pins being inserted into the M through orifices (26). 9- Cooling device (10) according to claim 8, in which the lower chamber comprises a lower wall and / or a side wall intended to carry out heat exchange with third electronic components, N protrusions extending perpendicularly to the superposition plane (P1), M of the N protrusions are pins extending from a lower face of the lower chamber, of a first section being the first characteristic dimension (d1), inserted into the M through orifices (26). 10- Cooling device (10) according to any one of claims 6 to 9 in combination with claim 5, wherein the upper chamber comprises a projection (40) extending from the separating plate (24) perpendicularly to the superposition plane (P1), the projection (40) defining at least one tortuous passage (41) within it for the coolant. 11- Cooling device (10) according to claim 10, wherein the projection (40) is formed by a superposition of layers (41, 42, 43, 44) adjacent in pairs, each having a plurality of through-openings (410; 420; 430; 440) spaced apart, a through-opening (410; 420; 430; 440) of a layer (41, 42, 43, 44) being in fluidic connection with at least one through opening (420; 410; 430; 440) of an adjacent layer, so as to form at least one tortuous passage (41). 12- On-board charging device (500) comprising at least one electronic component from among first electronic components, second electronic components and a cooling device (10) according to any one of claims 1 to 11, the first electronic component(s) being disposed in the cavity (12) and the second electronic component(s) being disposed on the upper wall (13) and / or the side wall (131) of the housing (11). 13- On-board charging device (500) according to claim 12 and comprising the cooling device (10) according to claim 9, further comprising third electronic components arranged on the lower wall and / or the side wall.

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