Heat sink for a motor vehicle light module and light module for a motor vehicle

Abstract

The invention relates to a heat sink (10) for a motor vehicle light module, the heat sink comprising at least one cooling projection portion (100) extending between a base (110) and a free end (111) in an extension direction and having a thickness (e) in a direction transverse to the extension direction, the thickness of the cooling projection portion decreasing from the base to the free end, characterised in that the cooling projection portion comprises a first portion (101) and a second portion (102), the first portion being located between the base and the second portion, and the second portion being location between the first portion and the free end, the reduced thickness of the cooling projection portion being greater in the second portion than in the first portion. The invention also relates to a light module having such a heat sink.

Description

DESCRIPTION TITLE: Automotive light module heat sink and automotive light module Technical field

[0001] The invention relates to the field of heat sinks for light modules for motor vehicles. It also relates to light modules for motor vehicles comprising such a heat sink, and in particular lighting and / or signaling modules for motor vehicles. Prior art

[0002] Light modules for motor vehicles, in particular lighting and / or signaling modules, include components, such as light sources or elements for controlling light sources, which emit heat when activated. In order to guarantee the performance of the light modules, it is necessary to ensure the cooling of these components. Indeed, overheating of these components, and in particular overheating of the light sources, can degrade the shape of the light beam emitted by the light module.

[0003] To cool the light modules, it is known to use heat sinks. In particular, heat sinks are known comprising a plurality of fins which extend in a direction of extension between a base and a free end and whose thickness taken transversely to the direction of extension decreases continuously from the base towards the free end. This continuous decrease in thickness of the fins from their base towards their free end translates into a constant clearance angle along each of the two transverse sides of the fins, the clearance angle being defined for each of the two transverse sides of the fins by the angle formed between the respective transverse side of the fin and the direction of extension of the fin.

[0004] The draft angle typically has a value greater than or equal to 2°, which allows for a reduction in fin thickness allowing the heat sink to be injected and the heat sink to be easily demolded. However, such a heat sink has the disadvantage of being too bulky to be integrated into certain light modules whose size must be particularly limited.

[0005] It is possible to consider reducing the draft angle to an angle less than 2°, and for example to an angle equal to 1°, while reducing the thickness of the base of the fins and maintaining the spacing between two successive fins at their base. The fins can then be brought closer together, and more fins can be positioned in a smaller volume. The footprint of the heat sink is then reduced, and at the same time, the heat dissipation performance of the heat sink remains similar. However, this poses problems with the injection of the heat sink and the demolding of the heat sink.

[0006] Indeed, it is difficult to ensure that the material forming the fins reaches the free ends of the fins during injection due to the small thickness of their base, and more generally the small thickness of the fins. Consequently, the fins do not take the shape of the mold used during injection well, and therefore do not always have the desired shape. In addition, due to the small draft angle, demolding the heat sink is tricky, and can lead to wear problems on the heat sink or the mold used during injection. Statement of the invention

[0007] The invention aims to overcome at least one of the drawbacks of the aforementioned state of the art. More particularly, the invention aims to propose a compact heat sink, making it possible to dissipate the heat emitted by the components of the light module in which it is intended to be mounted, and easy to manufacture, in particular easy to inject and demould. The invention also aims to propose a light module comprising such a heat sink.

[0008] According to a first object, the invention proposes a heat sink for a light module for a motor vehicle comprising at least one cooling protrusion extending between a base and a free end in a direction of extension, and having a thickness in a direction transverse to the direction of extension, the thickness of the cooling protrusion having a reduction going from the base to the free end. The heat sink is notable in that the cooling protrusion comprises a first portion, and a second portion, the first portion being located between the base and the second portion, and the second portion being located between the first portion and the free end, the reduction in thickness of the cooling protrusion being greater in the second portion than in the first portion.

[0009] The term "reduction in the thickness of the cooling protrusion greater in the second portion than in the first portion" means that, if we consider a part of the first portion of a given height taken in the direction of extension, and a part of the second portion of a height identical to the given height of the part of the first portion, each of the first and second parts having a lower end facing the base of the cooling protrusion and an upper end facing the free end of the cooling protrusion, then the difference between the thickness of the cooling protrusion at the lower end of the part of the first portion and the thickness of the cooling protrusion at the upper end of the part of the first portion, is greater than the difference between,the thickness of the cooling protrusion at the lower end of the part of the second portion and the thickness of the cooling protrusion at the upper end of the part of the second portion.,

[0010] Thus, the reduction in thickness of the cooling protrusion from its base to its free end is not constant. Consequently, it is possible to design a base of the protrusion that is thick enough to ensure the passage of the material forming the heat sink into the mold during injection, while maintaining limited bulk. Indeed, even if the thickness of the base of the protrusion is greater, and therefore more bulky than for a heat sink with a constant draft angle, for example less than 2° all along the transverse sides of the cooling protrusion, having a second portion with a greater reduction in thickness than in the first portion, makes it possible to sufficiently reduce the thickness of the cooling protrusion by moving away from the base.

[0011] According to one embodiment, the heat sink comprises a plurality of cooling protrusions along the transverse direction.

[0012] Thanks to the invention, it is possible to position more cooling protrusions in the same space. Indeed, to position more cooling protrusions in the same space, the distance between two successive cooling protrusions at their base, taken in the transverse direction, is reduced. However, thanks to the reduction in the thickness of the cooling protrusions being greater in the second portion than in the first portion, the distance between two successive cooling protrusions at their second portion is greater than the distance between these two successive cooling protrusions at the first portion.Thus, at the level of the second portion, and therefore approaching the free ends of the cooling protrusions, the distance between the two cooling protrusions is large enough to promote convection between the cooling protrusions and thus promote radiation towards the outside of the heat sink. Indeed, if the cooling protrusions were too close together, this would hinder convection by pressure loss and would cancel outward radiation because the radiation would be captured within the heat sink, between the cooling protrusions. Thanks to the invention, the efficiency of the heat sink is therefore preserved in a smaller footprint than that of the prior art.

[0013] According to a variant, the bases of two successive cooling protrusions are spaced along the transverse direction by the same distance.

[0014] Alternatively, the cooling protrusion is formed by a fin or a spike.

[0015] According to a variant, the cooling protrusion comprises a third portion located between the second portion and the free end, the reduction in the thickness of the cooling protrusion in the third portion being less significant than the reduction in the thickness of the cooling protrusion in the second portion.

[0016] The second portion is then located between the first portion and the third portion.

[0017] For example, the decrease in the thickness of the cooling protrusion in the third portion may be the same as the decrease in the thickness of the cooling protrusion in the first portion.

[0018] Alternatively, the decrease in thickness of the cooling protrusion is constant in the first portion and in the second portion. Optionally, if the cooling protrusion has a third portion, the decrease in thickness of the cooling protrusion may also be constant in the third portion.

[0019] The mold for injecting the cooling protrusion is then simpler to produce.

[0020] According to one variant, the cooling protrusion comprises a first transverse side and a second transverse side, opposite the first transverse side.

[0021] For example, the first and second transverse sides correspond to the edges of the cooling protrusion taken on a section of the cooling protrusion by a plane including the extension direction and the transverse direction.

[0022] Optionally, the first portion comprises a first primary clearance angle formed between the first transverse side of the cooling protrusion in the first portion and the extension direction, and the second portion comprises a second primary clearance angle formed between the first transverse side of the cooling protrusion in the second portion and the extension direction, and the first primary clearance angle is less than the second primary clearance angle. Optionally, if the cooling protrusion comprises a third portion, then the third portion comprises a third primary clearance angle formed between the first transverse side of the cooling protrusion in the third portion and the extension direction, the third primary clearance angle being less than the second primary clearance angle, and possibly identical to the first primary clearance angle.

[0023] Alternatively, the clearance angle along a second transverse side of the cooling protrusion, opposite the first side transverse, is constant. By "constant" we mean that it is identical for each of the portions.

[0024] Alternatively, the first transverse side is symmetrical to the second transverse side about an axis of symmetry parallel to the direction of extension.

[0025] Then, the clearance angle along the second transverse side of the cooling protrusion follows the same evolution as the clearance angle along the first transverse side of the cooling protrusion. In particular, the first portion includes a first secondary clearance angle formed between the second transverse side of the cooling protrusion in the first portion and the extension direction, and the second portion includes a second secondary clearance angle formed between the second transverse side of the cooling protrusion in the second portion and the extension direction. And, the first primary clearance angle is identical to the first secondary clearance angle, and the second primary clearance angle is identical to the second secondary clearance angle.Where applicable, if the cooling protrusion comprises a third portion, then the third portion comprises a third secondary clearance angle formed between the second transverse side of the cooling protrusion in the third portion and the extension direction, and the third primary clearance angle is the same as the third secondary clearance angle.

[0026] In one embodiment, the heat sink comprises at least one upper cooling protrusion and one lower cooling protrusion, and the upper and lower cooling protrusions are aligned and extend in the same direction of extension, in opposite directions.

[0027] In particular, each of the upper and lower cooling protrusions has a base and a free end, and the base of each of the upper and lower cooling protrusions rests on an opposite face along the extension direction of a base of the heat sink. The upper and lower cooling protrusions therefore extend on either side of the base.

[0028] Where appropriate, the upper and lower cooling protrusions each have a height taken along the direction of extension. According to a first variant, the height of the upper cooling protrusion is equal to the height of the lower cooling protrusion. According to a second variant, the height of the upper cooling protrusion is different from the height of the lower cooling protrusion.

[0029] The height of the cooling protrusions is thus adapted to the space available in the light module in which the heat sink is integrated.

[0030] According to one variant, the heat sink comprises a joint plane extending in a longitudinal plane, perpendicular to the direction of extension.

[0031] The parting line corresponds to the area where the two parts of the mold join. In particular, the upper and lower fins extend on either side of the parting line. Preferably, the base of the heat sink is in the parting line.

[0032] According to a second object, the invention proposes a light module for a motor vehicle comprising a heat sink according to the first object of the invention.

[0033] According to one variant, the light module comprises: - at least one light source configured to emit a light beam; - at least one printed circuit board on which the light source is arranged; - at least one optical element configured to deflect and / or project the light beam emitted by the light source; and the heat sink is configured to cool said at least one light source.

[0034] Alternatively, the printed circuit board is arranged on the heat sink. The heat sink is thus in indirect contact with the light source(s), which allows for efficient cooling of the light sources.

[0035] Alternatively, the heat sink joint plane is parallel to the printed circuit board. Brief description of the drawings

[0036] Other characteristics and advantages of the invention will appear more clearly on reading the following description, given as an illustrative and non-limiting example, and the appended drawings among which:

[0037] [Fig. 1] Figure 1 represents a heat sink according to a first object of the invention, comprising a plurality of fins;

[0038] [Fig. 2] Figure 2 shows a sectional view of a rear view of the heat sink shown in Figure 1;

[0039] [Fig. 3] Figure 3 schematically represents the fins of the heat sink of Figures 1 and 2;

[0040] [Fig. 4] Figure 4 schematically represents an alternative of fins of a heat sink according to a variant of the first object of the invention;

[0041] [Fig. 5] Figure 5 represents a light module for a motor vehicle according to a second object of the invention comprising a heat sink as described in Figures 1 to 3, a reflector and a projection lens;

[0042] [Fig. 6] Figure 6 shows the light module of Figure 5 with the reflector removed, revealing a printed circuit board and light sources. Detailed description

[0043] In the remainder of the description, the longitudinal direction L will be understood to mean the direction in which the vehicle is moving, oriented from rear to front, the transverse direction T will be understood to mean the direction extending transversely to the vehicle and which is perpendicular to the longitudinal direction L, and the vertical direction V will be understood to mean the direction extending from bottom to top of the vehicle and which is perpendicular to the longitudinal direction L and to the transverse direction T. These directions are represented by the trihedron L, V, T in the figures.

[0044] Figure 1 shows a heat sink 10 for a light module for a motor vehicle. As will be seen later, the heat sink 10 is intended to be mounted in a light module 20, itself intended to be mounted in a motor vehicle. In the remainder of the description, the longitudinal L, transverse T and vertical V orientations given with reference to the heat sink 10 and the light module 20, correspond to the orientation that the heat sink 10, and the light module 20 have when mounted on the vehicle.

[0045] The heat sink 10 comprises a plurality of cooling protrusions. In the illustrated example, the cooling protrusions are formed by fins 100. It is understood that other cooling protrusions could be used, such as for example pins. In the remainder of the description, the term fins will be used to refer to the cooling protrusions of the heat sink 100.

[0046] The heat sink 10 comprises a base 11 from which the fins 100 extend. In particular, each fin 100 extends between a base 110 and a free end 111 in a direction of extension E (shown in FIG. 2), the base 110 of the fin being located on the side of the base 11 of the heat sink 10. In the example illustrated, the direction of extension E of the fins 100 corresponds to the vertical direction V.

[0047] The heat sink 10 comprises a joint plane P extending in a longitudinal plane, perpendicular to the direction of extension E. The joint plane P corresponds to the plane in which the two parts of the mold used during the injection of the heat sink 10 are joined. Preferably, the base 11 of the heat sink 11 is in the joint plane P.

[0048] The fins 100 of the heat sink 10 comprise upper fins 100a and lower fins 100b. The base 110 of each of the upper 100a and lower 100b fins rests on an opposite face in the direction of extension E of the base 11 of the heat sink 10. The upper fins 100a and the lower fins 100b thus extend on either side of the base 11 of the heat sink 10.

[0049] In particular, the upper fins 100a extend from their base 110 at an upper face of the base 11 upwards in the vertical direction V to their free end 111, and the lower fins 100b extend from their base 110 at a lower face of the base 11, opposite the upper face of the base 11 in the extension direction E, downwards in the vertical direction V to their free end 111.

[0050] The upper 100a and lower 100b fins are aligned. In other words, each upper fin 100a extends in the same direction of extension E and in an opposite direction as a lower fin 100b. According to a variant covered by the invention, but not shown, an upper fin 100a might not be aligned with a lower fin 100b, and conversely, a lower fin 100b might not be aligned with an upper fin 100a.

[0051] In a variant not shown, the heat sink 10 could comprise only upper fins 100a or only lower fins 100b.

[0052] Each fin 100 comprises a height in the extension direction E. The height of the fins 100 depends on the space available in the light module in which the heat sink 10 is intended to be mounted. Thus, the upper fins 100a and / or the lower fins 100b may all have the same height ha. Alternatively, the upper fins 100a and / or the lower fins 100b may have different heights ha. As illustrated in the non-limiting example shown in Figures 1 and 2, several upper fins 100a have the same height ha, while other upper fins 100a have a different height ha, and all the lower fins 100b have the same height hb, it being understood that some lower fins hb could also have a different height.

[0053] The fins 100, and therefore the upper 100a and lower 100b fins, are distributed along a direction transverse to the extension direction E. In the illustrated example, the direction transverse to the extension direction E corresponds to the transverse direction T.

[0054] Figure 2 shows a rear sectional view in a plane defined by the extension direction and the transverse direction, corresponding in this example respectively to the vertical direction and the transverse direction, of the heat sink 10.

[0055] Each fin 100 has a thickness e in the transverse direction. This thickness e is particularly visible in FIG. 2. This thickness e decreases from the base 1 10 of the fin 100 to the free end 1 1 1 of the fin 100. In particular, the thickness e of each fin 100 is greater near the base 1 10 of the fin 100 than near the free end 1 1 1 of the fin 100.

[0056] The fins 100 comprise a first portion 101, a second portion 102. In the illustrated example, the fins 100 further comprise a third portion 103. The first portion 101 is located between the base 1 10 and the second portion 102, the second portion 102 is located between the first portion 101 and the third portion 103, and the third portion 103 is located between the second portion 102 and the free end 1 1 1. In each of these portions 101, 102, 103, the variation in thickness e of the fin is different.

[0057] The reduction in the thickness e of each fin 100 is greater in the second portion 102 than in the first portion 101. The reduction in the thickness e of the fin 100 in the third portion 103 is less greater than the reduction in the thickness e of the fin 100 in the second portion 102. In the example illustrated, the reduction in the thickness e of the fin 100 in the third portion 103 is identical to the reduction in the thickness e of the fin 100 in the first portion 101.

[0058] In order to illustrate these variations in thickness e of the fins 100, the fins 100 of the heat sink 10 are shown schematically in FIG. 3. On each fin 100, a first part P1 of the first portion 101, a second part P2 of the second portion 102 and a third part P3 of the third portion 103 can be considered, each of these first, second and third parts P1, P2, P3 having a height H, taken along the direction of extension E of the fin 100, which is identical. Each of the first, second and third parts P1, P2, P3 are delimited by an upper end P1 sup, P2sup, P3sup facing the free end 1 1 1 of the fin 100 and a lower end P1 inf, P2inf, P3inf facing the base 110 of the fin 100.Each upper end P1 sup, P2sup, P3sup comprises a thickness e1 h, e2h, e3h taken in the transverse direction, and each lower end P1 inf, P2inf, P3inf comprises a thickness e1 b, e2b, e3b taken in the transverse direction.

[0059] The reduction in the thickness e of each fin 100, which is greater in the second portion 102 than in the first portion 101, is reflected in the fact that the difference between the thickness e1 b of the fin 100 at the lower end P1 inf of the first portion P1 and the thickness e1 h of the fin 100 at the upper end P1 sup of the first portion P1 is greater than the difference between the thickness e2b of the fin 100 at the lower end P2inf of the second portion P2 and the thickness e2h of the fin 100 at the upper end P2sup of the second portion P2.

[0060] The reduction in the thickness e of the fin 100 in the third portion 103, less significant than the reduction in the thickness e of the fin 100 in the second portion 102, is reflected in the fact that the difference between the thickness e2b of the fin 100 at the lower end P2inf of the second portion P2 and the thickness e2h of the fin 100 at the upper end P2sup of the second portion P2 is less than the difference between the thickness e3b of the fin 100 at the lower end P3inf of the third portion P3 and the thickness e3h of the fin 100 at the upper end P3sup of the third portion P3.

[0061] And in particular, in the illustrated example, the reduction in the thickness e of the fin 100 in the third portion 103, identical to the reduction in the thickness e of the fin 100 in the first portion 101, is reflected in the fact that the difference between the thickness e1 b of the fin 100 at the lower end P1 inf of the first portion P1 and the thickness e1 h of the fin 100 at the upper end P1 sup of the first portion P1 is equal to the difference between the thickness e3b of the fin 100 at the lower end P3inf of the third portion P3 and the thickness e3h of the fin 100 at the upper end P3sup of the third portion P3.

[0062] The decrease in thickness e of the fins 100 from their base 1 10 towards their free end 1 10 is therefore not constant, which makes it possible to have a base 1 10 that is sufficiently wide to guarantee the passage of the material forming the heat sink 10 into the mold during injection, while reducing the thickness of the fin 100 more significantly in the second portion 102 in order to obtain a fin 100 that is thinner more quickly as one approaches the free end 1 1 1 of the fin 100. As the fins 100 become thinner more quickly thanks to the greater decrease in thickness in the second portion 102, it is possible to position the fins 100 closer to each other at their base 1 10, because ultimately, the distance between the fins 100 increases more quickly at the second portion 102.Thus, even if it is possible for the fins 100 to radiate heat towards each other at the level of the first portion 101, this radiation phenomenon will then be limited at the level of the second portion 102 and the third portion 103. At the level of the second portion 102 and the third portion 103, convection. is favored and the radiation towards the outside of the heat sink is also favored.

[0063] For each of the first, second and third portions 101, 102, 103, the reduction in the thickness e of the fin 100 is constant. Thus, for the first portion, whatever the first portion P1 of height H considered, the difference between the thickness e1 b of the fin 100 at the lower end P1 inf of the first portion P1 and the thickness e1 h of the fin 100 at the upper end P1 sup of the first portion P1 is identical. Similarly, for the second portion 102, whatever the second portion P2 of height H considered, the difference between the thickness e2b of the fin 100 at the lower end P2inf of the second portion P2 and the thickness e2h of the fin 100 at the upper end P2sup of the second portion P2 is identical.Similarly, for the third portion 103, whatever the third part P3 of height H considered, the difference between the thickness e3b of the fin 100 at the level of the lower end P3inf of the third part P3 and the thickness e3h of the fin 100 at the level of the upper end P3sup of the third part P3 is identical.

[0064] Each fin 100 comprises a first transverse side 120 and a second transverse side 130, opposite the first transverse side 120. In particular, the first and second transverse sides correspond to the edges of the fin 100 taken on a section of the fin 100 by a plane comprising the direction of extension E and the transverse direction T, corresponding to the section plane of FIG. 2, and to the plane in which the fins 100 are represented schematically in FIG. 3.

[0065] The first transverse side 120 is symmetrical to the second transverse side 130 with respect to an axis of symmetry S parallel to the direction of extension

[0066] The reduction in the thickness e of the fin 100 constant in each of the first, second and third portions 101, 102, 103 results in the fact that the first and second transverse sides 120, 130 are formed by a straight line segment for each of the first, second and third portions. Thus, the first portion 101 comprises a first primary clearance angle 11 formed between the first transverse side 120 of the fin 100 in the first portion 101 and the extension direction E, the second portion 102 comprises a second primary clearance angle i2 formed between the first transverse side 120 of the fin 100 in the second portion 102 and the extension direction E, and the third portion 103 comprises a third primary clearance angle i3 formed between the first transverse side 120 of the fin 100 in the third portion 103 and the extension direction E.

[0067] The first primary clearance angle i1 is less than the second primary clearance angle i2, and the third primary clearance angle i3 is less than the second primary clearance angle i2, and in particular, in the illustrated example, the third primary clearance angle i3 is identical to the first primary clearance angle i1.

[0068] By symmetry, the clearance angle along the second transverse side 130 of each fin 100 follows the same evolution as the clearance angle along the first transverse side 120 of the fin. In particular, the first portion 101 comprises a first secondary clearance angle i1' formed between the second transverse side 130 of the fin 100 in the first portion 101 and the direction of extension E, the second portion 102 comprises a second secondary clearance angle i2' formed between the second transverse side 130 of the fin 102 in the second portion 102 and the direction of extension, and the third portion 103 comprises a third secondary clearance angle i3' formed between the second transverse side 130 of the fin in the third portion 103 and the direction of extension E.

[0069] The first primary clearance angle il is identical to the first secondary clearance angle il ', the second primary clearance angle i2 is identical to the second secondary clearance angle i2', and the third primary clearance angle i3 is identical to the third secondary clearance angle i3'.

[0070] Figure 4 schematically represents an alternative shape of the fins 100 of the heat sink 10. The fins 100 shown in Figure 4 differ from those shown in the other figures only by the fact that the reduction in thickness e of the fin 100 in the first portion 101 and in the second portion 102 is not constant. In the example illustrated, the reduction in thickness e of the fins 100 is constant for the third portion 103.

[0071] Only the decrease in thickness e is not constant in the first portion 101 and the second portion 102 will be explained in the rest of the description, it being understood that otherwise, the description of the fins 100 made with reference to figures 1 to 3 applies to the fins 100 of figure 4, and in particular, the description made of the third portion 103.

[0072] Since the reduction in thickness e of the fins 100 is not constant, for the first portion 101, the difference between the thickness e1 b of the fin 100 at the lower end P1 inf of the first part P1 and the thickness e1 h of the fin 100 at the upper end P1 sup of the first part P1 is different depending on the first part P1 considered. Similarly, for the second portion 102, the difference between the thickness e2b of the fin 100 at the lower end P2inf of the second part P2 and the thickness e2h of the fin 100 at the upper end P2sup of the second part P2 is different depending on the second part P2 considered.

[0073] The non-constant decrease in the thickness e of the fins 100 in the first portion 101 and in the second portion 102 also results in the fact that the first and second transverse sides 120, 130 are formed by a continuous curve for the first and second portions.

[0074] The first portion 101 comprises a first primary clearance angle 11 formed between the tangent to the first transverse side 120 of the fin 100 in the first portion 101 and the direction of extension E, the second portion 102 comprises a second primary clearance angle 12 formed between the tangent to the first transverse side 120 of the fin 100 in the second portion 102 and the direction of extension E. The first primary clearance angle 11 and the second clearance angle 12 change along the first transverse side 120. In particular, the first primary clearance angle 11 and the second primary clearance angle 12 increase as the tangent to the first transverse side 120 considered moves away from the base 11 of the heat sink 10.

[0075] The third primary clearance angle i3 is less than the second primary clearance angle i2. In particular, the second portion 102 may be defined by a portion in which all of the second primary clearance angles i2 are less than the third primary clearance angle i3. The portion then located between the second portion 102 thus defined and the base 110 of the fin 100 then forms the first portion 101.

[0076] By symmetry, the clearance angle along the second transverse side 130 of each fin 100 follows the same evolution as the clearance angle along the first transverse side 120 of the fin.

[0077] Figures 5 and 6 show a light module 20 for a motor vehicle in which the heat sink 10 is mounted. This light module 20 is intended to be mounted in a motor vehicle headlight.

[0078] The light module 20 comprises a plurality of light sources 201 configured to emit a light beam, as well as a printed circuit board 202 on which the light sources 201 are arranged. The heat sink 10 makes it possible to cool the light sources 201. The printed circuit board 202 rests on the heat sink 10. In this example, the joint plane P of the heat sink 10 is parallel to the printed circuit board 202.

[0079] The light module 20 comprises a first optical element in the form of a reflector 203 and a second optical element in the form of a projection lens 204. The reflector 203 is intended to receive the light beam emitted by the light sources 201 and to reflect this light beam towards the projection lens 204. The projection lens 204 makes it possible to project the light beam reflected by the reflector 203 onto the road on which the vehicle is traveling.

Claims

CLAIMS [Claim 1.] Heat sink (10) for a light module for a motor vehicle comprising at least one cooling protrusion (100) extending between a base (110) and a free end (111) in a direction of extension, and having a thickness (e) in a direction transverse to the direction of extension, the thickness of the cooling protrusion having a decrease going from the base to the free end, characterized in that the cooling protrusion comprises a first portion (101), and a second portion (102), the first portion being located between the base and the second portion, and the second portion being located between the first portion and the free end, the decrease in the thickness of the cooling protrusion being greater in the second portion than in the first portion. [Claim 2.] A heat sink according to any preceding claim comprising a plurality of cooling protrusions (100) along the transverse direction. [Claim 3.] A heat sink according to claim 1 or 2, wherein the cooling protrusion is formed by a fin (100) or a spike. [Claim 4.] Heat sink according to one of claims 1 to 3, in which the cooling protrusion comprises a third portion (103) located between the second portion and the free end, the reduction in the thickness of the cooling protrusion in the third portion being less significant than the reduction in the thickness of the cooling protrusion in the second portion. [Claim 5.] Heat sink according to one of claims 1 to 4, wherein the reduction in the thickness of the cooling protrusion is constant in the first portion (101) and in the second portion (102). [Claim 6.] Heat sink according to one of the preceding claims, in which the cooling protrusion comprises a first transverse side (120) and a second transverse side (130), opposite the first transverse side, the first transverse side being symmetrical to the second transverse side with respect to an axis of symmetry (S) parallel to the direction of extension. [Claim 7.] A heat sink according to any preceding claim, comprising at least one upper cooling protrusion (100a) and one lower cooling protrusion (100b), and wherein the upper and lower cooling protrusions are aligned and extend in the same direction of extension, in opposite directions. [Claim 8.] Heat sink according to one of the preceding claims, comprising a joint plane (P) extending in a longitudinal plane, perpendicular to the direction of extension. [Claim 9.] Light module (20) for a motor vehicle comprising a heat sink (10) according to one of the preceding claims. [Claim 10.] A light module (20) according to the preceding claim further comprising: - at least one light source (201) configured to emit a light beam; - at least one printed circuit board (202) on which the light source is arranged; - at least one optical element (203, 204) configured to deflect and / or project the light beam emitted by the light source; and wherein the heat sink is configured to cool said at least one light source.

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