Cooling device, lighting device for motor vehicle, and motor vehicle

Abstract

The invention relates to a cooling device (6), comprising: a heat sink (7) having at least one heat-conducting surface (8) via which the heat sink (7) can be coupled to a heat source in a heat-conducting manner; the invention relates to a heat sink (7) comprising a heat-conducting surface (8), at least two heat-dissipating fins (10), the heat-dissipating fins (10) projecting from the heat sink (7) on a side surface (9) of the heat sink (7) facing away from the heat-conducting surface (8), each heat-dissipating fin (10) having at least one first chamber (11) and at least one second chamber (12), the second chamber being farther away from the heat sink (7) than the first chamber (11), each chamber being at least partially filled with a phase change material (P).

Description

Technical Field

[0001] This invention relates to a cooling device comprising: a radiator having at least one heat-conducting surface, the radiator being thermally coupled to a heat source via the heat-conducting surface; and at least two heat dissipation fins, wherein the heat dissipation fins protrude from the radiator on a side of the radiator opposite to the heat-conducting surface. The invention also relates to a lighting device for a motor vehicle and a motor vehicle. Background Technology

[0002] Motor vehicles typically have headlights to illuminate lanes and improve their visibility. To enhance brightness and / or provide modern lighting features, such as the ability to display specific illuminated signs, headlights have become increasingly complex and high-performance. Therefore, headlight cooling has become increasingly important.

[0003] In existing technologies, heat dissipation fins are typically installed on headlights for cooling. However, these fins offer only limited cooling capacity, sometimes insufficient for the needs of high-performance headlights. Furthermore, they can only be replaced by active water cooling, which, while improving cooling capacity, is relatively expensive and significantly increases complexity.

[0004] To achieve better cooling capacity even without active water cooling, the use of phase change materials (PCMs) is known in the prior art. These PCMs, also known as latent heat reservoirs, are capable of absorbing a large amount of heat energy during a phase change process. For example, US 2011 / 0303946 A1 discloses an LED lamp with multiple PCM containers disposed thereon. Compared to conventional heat sinks, these containers dissipate more heat energy from the LED lamp due to the phase change of the PCM. The use of PCMs for cooling purposes is also known from EP 4 083 703 A1, in this case, for cooling a projection device in a motor vehicle. Summary of the Invention

[0005] Therefore, the object of the present invention is to provide a design for an improved cooling device, particularly for a lighting device for a motor vehicle.

[0006] To achieve this objective, in a cooling device of the type described at the beginning, according to the invention, each heat dissipation fin has at least one first chamber and at least one second chamber, the second chamber being further away from the heat sink than the first chamber, wherein each chamber is at least partially filled with a phase change material.

[0007] Therefore, the cooling device includes a heat sink with a heat-conducting surface through which heat from a heat source can be absorbed directly or indirectly. On the side facing away from the heat-conducting surface, the cooling device has a plurality of heat dissipation fins, which are preferably plate-shaped or rib-shaped and preferably arranged parallel to each other. The heat dissipation fins preferably protrude vertically from the heat sink, but of course, they can also protrude from the heat sink at different angles. A particularly large amount of heat energy can be absorbed through the chambers of the heat dissipation fins, which are at least partially filled with phase change material. Compared with the prior art, according to the present invention, the heat dissipation fins each have two or more chambers at different distances from the heat sink, which has advantages in cooling performance.

[0008] Due to the varying distances between the chambers and the radiator, when less heat is absorbed through the heat-conducting surface, initially only the phase change material (PCT) of the first chamber (located closer to the heat-conducting surface than the second chamber) may be used for cooling. When more heat is absorbed, i.e., under higher heat loads, the PCT of the second chamber (also located closer to the heat-conducting surface) can be additionally used for cooling, as the radiator fins also heat up in this area, and heat can no longer be absorbed or dissipated solely through the first chamber. This achieves a cascade effect, where only the PCT of the first chamber is used under lower heat loads, such as during normal headlight operation. If the heat input to the radiator increases, causing the second chamber (located further away from the radiator and heat source) to also bear a sufficiently high heat load, the PCT of the second chamber can also be used additionally for overload protection. The PCT of the second chamber is particularly effective at intercepting or compensating for temporary temperature spikes.

[0009] Overall, this cooling device improves cooling and can sometimes even better adapt to the heat source being cooled. To achieve this, the distance between the chamber of each heat dissipation fin and the heat sink can be appropriately selected. In addition to the first and second chambers, each heat dissipation fin may also have additional chambers. These additional chambers may also be at least partially filled with phase change material and are located further away from the heat sink than the second chamber. It is also conceivable to increase the distance from the heat sink for each additional chamber. Each heat dissipation fin may also have multiple first chambers and / or multiple second chambers and / or multiple additional chambers.

[0010] The distances of the first and second chambers from the heat sink can vary for the multiple heat sink fins. For example, at least a portion of the first chamber of the first heat sink fin and at least a portion of the second chamber of the second heat sink fin can be equidistant from the heat sink, such that the chambers overlap parallel to the heat sink.

[0011] The heat sink can be of any shape, particularly rectangular. The heat-conducting surface can also be of any shape; for example, it can be a planar or curved three-dimensional surface. The chamber can also, in principle, have any cross-section. Rectangular, circular, and especially elliptical or hexagonal cross-sections are conceivable. Preferably, the chamber extends further in the longitudinal direction away from the heat sink than in the direction parallel to the heat sink. The chamber can also taper gradually in the longitudinal direction away from the heat sink.

[0012] Any common phase change material, including water or a mixture of water and ethylene glycol, can be used as a phase change material. The chamber can be completely or partially filled with the phase change material. The latter is advantageous because it can compensate for the volume changes that may occur in the phase change material due to the phase change.

[0013] In a preferred embodiment, one or more heat dissipation fins have a first phase change material in a first chamber and a second phase change material in a second chamber. In other words, the phase change materials in the first and second chambers of a single, multiple, or all heat dissipation fins can be different. Particularly preferably, the first and second phase change materials have different phase change temperatures. This can further improve the cooling gradient already present due to the different distances between the chambers and the heat sink. Therefore, the cooling device has particularly high adjustability.

[0014] A preferred improvement specifies that the phase change temperature of the second phase change material is higher than that of the first phase change material. This better ensures that the first phase change material undergoes a phase change, or phase transition, even under lower heat loads, thus contributing more to cooling, while the phase change of the second phase change material requires a higher heat load. Therefore, not only must heat reach the second chamber further from the heat sink, but more heat is needed overall for the second phase change material to effectively aid in cooling. This allows for effective thermal overload protection in a simple manner. The difference in phase change temperatures of the phase change materials for each heat sink fin can be adjusted as needed. This indicates when the overload protection provided by the second phase change material takes effect.

[0015] Preferably, all phase change materials are selected such that they can undergo two phase changes during cooling: from "solid" to "liquid" and from "liquid" to "gas". Therefore, they can absorb a particularly large amount of heat.

[0016] If the cooling device includes heat dissipation fins with additional chambers besides the first and second chambers, different phase change materials, or either the first or second phase change material, can be used in each of these additional chambers. The corresponding phase change temperatures of all the phase change materials can be different. Alternatively, the same phase change material can be filled in multiple chambers.

[0017] Heat sink fins can be made of metal or plastic. Aluminum is a particularly suitable metal. High-density polyethylene (HDPE) and polyethylene terephthalate (PET) are sometimes considered as plastics. However, in principle, various materials with high thermal conductivity and sufficient heat load capacity for the corresponding application are suitable for manufacturing heat sink fins. To reduce the possibility of heat sink fin damage, such as bending, the heat sink fins can be made of high-strength materials.

[0018] Regarding the structure of the heat dissipation fins, preferably one or more, and preferably all, heat dissipation fins are each composed of at least two interconnected heat dissipation fin semi-fins, wherein the first chamber and the second chamber are cavities, and the at least two heat dissipation fin semi-fins together surround the cavities in the connected state. Heat dissipation fins can be manufactured simply and economically by manufacturing the heat dissipation fin semi-fins and subsequently joining or connecting them. Preferably, each heat dissipation fin is composed of at least two mirror-symmetrically curved, particularly basin-shaped, heat dissipation fin semi-fins. These heat dissipation fin semi-fins can also be understood as half-shells.

[0019] The cross-section of the heat sink fins can vary or remain constant in the axial direction. In the first case, each heat sink fin can be made from only two heat sink fins. In the latter case, the chamber of each heat sink fin can, for example, be defined perpendicular to the axial direction by two interconnected half-shells having a constant cross-section and open on both sides in the axial direction. Then, the heat sink fins can have two or more additional heat sink fins that act as sealing elements to close the chamber at the axial ends.

[0020] Depending on the material of the heat sink fins, different manufacturing and joining methods can be envisioned. Metal heat sink fins can be manufactured, for example, by stamping or deep drawing. Plastic heat sink fins can be manufactured, for example, by injection molding. The joining of heat sink fins can be material-locked, particularly by welding, bonding, or brazing, or by form-locking and / or force-locking, particularly by means of flanging or roll bonding. Additional connecting elements, such as screws or rivets, can also be used. As an alternative to a multi-piece construction, heat sink fins can of course also be manufactured in one piece, for example by means of additive manufacturing.

[0021] To fill and / or empty their chambers, each heat sink fin preferably has at least one sealable inlet and / or at least one sealable outlet. These openings facilitate easy filling and / or emptying of the chambers after the heat sink fins, or cooling device, are manufactured, simplifying manufacturing. They also allow for easy replacement of the phase change material, for example, during maintenance. All inlets and outlets can be conveniently sealed in a liquid-tight and gas-tight manner to prevent accidental leakage of the phase change material from the chambers.

[0022] It is conceivable that the heat dissipation fins have at least one inlet and / or at least one outlet in each chamber. They can be disposed on the side or end face of the respective heat dissipation fins. The cooling device may also have at least one inlet structure and / or at least one outlet structure, which includes at least a portion of the inlet and / or outlet.

[0023] Phase change materials can be filled into the chamber in any physical state, i.e., in solid form, especially via (multiple) inlets. The same applies to venting the chamber, particularly via (multiple) outlets. If the phase change material is already filled into the chamber of the heat sink fins during manufacturing, the inlets and outlets can be completely eliminated.

[0024] In a preferred design, each heat sink fin has a wall thickness of at least 0.1 mm to 2.5 mm between its outer surface and each chamber. Therefore, the wall thickness of each heat sink fin around its chamber is preferably 0.1 mm to 2.5 mm. Even in wall regions not directly adjacent to the chambers, such as between the first and second chambers, each heat sink fin preferably has a corresponding or greater wall thickness, particularly twice the wall thickness.

[0025] The wall thickness can vary depending on the material. Smaller wall thicknesses allow for larger chamber volumes, thus accommodating larger amounts of phase change material. It is important to note that the walls must be thick enough to provide the required strength.

[0026] In a practical design, the cooling device can have at least one pair of heat dissipation fins, wherein the pair comprises two heat dissipation fins arranged, in particular, parallel to each other, and these two heat dissipation fins are securely connected to each other by a connecting section, in particular, a U-shaped bend. Therefore, corresponding two heat dissipation fins can be combined to form a heat dissipation fin pair and connected to the corresponding connecting section. This significantly simplifies manipulation during manufacturing, as it eliminates the need to manipulate each heat dissipation fin individually, requiring only the manipulation of the heat dissipation fin pair.

[0027] The connecting section can be an additional semi-finished product, or formed through a region of one or more heat dissipation fin semi-finished products. It is conceivable that a heat dissipation fin pair is made from two mirror-symmetrical heat dissipation fin semi-finished products, which are specifically U-shaped bent at the center. The bent region then forms the connecting section.

[0028] It is also conceivable that the cooling device has multiple heat dissipation fin groups, each of which includes three or more heat dissipation fins that are interconnected by corresponding connecting sections and extend in parallel with each other.

[0029] Preferably, the heat dissipation fins and / or pairs of heat dissipation fins are fixed to the radiator as prefabricated components. This facilitates the manufacture of the cooling device. The pairs of heat dissipation fins are preferably fixed to the radiator via corresponding connecting sections. In principle, any joining method is feasible, whether or not additional fasteners are used. Therefore, the heat dissipation fins and / or pairs of heat dissipation fins can be fixed to the radiator by welding, brazing, bonding, plugging, or crimping.

[0030] Preferably, the heat dissipation fins and / or pairs of heat dissipation fins are fixed to the heat sink such that there is a sufficiently large gap between each two adjacent heat dissipation fins to prevent them from contacting each other if they expand due to temperature. For this purpose, it is also preferable that there is a correspondingly large gap between the heat dissipation fins in each pair of fins. This prevents the heat dissipation fins from bending due to insufficient space.

[0031] The cooling device may additionally have one or more heat dissipation fins protruding from the heat sink on the side of the radiator away from the heat conduction surface. The one or more additional heat dissipation fins allow for more precise adjustment of the heat dissipation or cooling effect provided by the cooling device.

[0032] The heat dissipation fins, or at least one of them, may have only one chamber at least partially filled with phase change material. Therefore, the cooling device may also include heat dissipation fins, each having only one chamber containing phase change material. Alternatively or supplementarily, the heat dissipation fins, or at least one of them, may be formed as a solid body. In other words, at least one conventional heat dissipation fin formed as a solid body may also be provided, which does not have a chamber containing phase change material.

[0033] In addition to the cooling device, the present invention also relates to a lighting device for a motor vehicle, the lighting device having at least one lighting element and at least one cooling device according to the invention, wherein each cooling device is thermally connected to one or more, particularly all, lighting elements via a corresponding heat-conducting surface, the connection being formed either directly by the heat-conducting surface abutting against the corresponding lighting element, or indirectly, particularly via an additional heat-conducting element. The cooling device according to the invention exhibits its advantage precisely in cooling one or more, particularly high-performance, lighting elements. All features and advantages described in conjunction with the cooling device according to the invention also apply to the lighting device according to the invention, and vice versa.

[0034] At least one cooling device can be thermally coupled to the lighting element through direct physical contact via its (multiple) heat-conducting surfaces. Alternatively, it can be thermally coupled to the lighting element indirectly via a thermally conductive agent, particularly thermally conductive paste.

[0035] The lighting device can be a headlight, particularly an LED headlight. Alternatively or supplementarily, at least one lighting element can be provided to provide low beam. Preferably, the lighting device, particularly the headlights of a motor vehicle, has multiple high-performance LED lighting elements. Even under conditions of significant heat generation, effective cooling of the LED lighting elements can be ensured using a cooling device. The lighting device can also be a taillight of a motor vehicle or various arbitrary, particularly high-performance, luminaires, such as omnidirectional warning lights.

[0036] Finally, the present invention also relates to a motor vehicle having at least one cooling device according to the invention and / or at least one lighting device according to the invention. The features and advantages described above regarding the cooling device and lighting device according to the invention also apply to the motor vehicle according to the invention, and vice versa. The motor vehicle preferably has two high-performance headlights, particularly matrix LED headlights, each having a plurality of high-performance LED lighting elements and one or more cooling devices according to the invention for cooling the LED lighting elements. Attached Figure Description

[0037] Other advantages and details of the present invention will now be described with reference to the accompanying drawings and embodiments. The drawings are schematic diagrams and illustrate:

[0038] Figure 1 A top view of an embodiment of a motor vehicle according to the invention, having a lighting device according to the invention, is shown;

[0039] Figure 2 Show Figure 1 A perspective view of the cooling device according to the invention for the central lighting device;

[0040] Figure 3 Show Figure 2 A cross-sectional view of the cooling device. Detailed Implementation

[0041] Figure 1 An embodiment of a motor vehicle 1 according to the invention is shown in top view. This vehicle has two structurally identical lighting devices 2 according to the invention, configured as headlights 3, specifically matrix LED headlights. Each headlight has multiple high-performance lighting elements 4 in the form of LEDs 5, configured to generate or provide low beam in a standard operating mode and high beam in a high-performance operating mode. Each lighting device 2 includes a cooling device 6 according to the invention for cooling the lighting elements 4. Figure 1 The cooling device is shown only schematically. Figure 2 and Figure 3 Using perspective views respectively Figure 2 ) and the cross-sectional view along line III-III ( Figure 3The cooling device 6 is shown in detail.

[0042] like Figure 2 and Figure 3 As shown, the cooling device 6 includes a radiator 7 having a heat-conducting surface 8 and a plurality of heat-dissipating fins 10. These fins are arranged parallel to each other on the side 9 of the radiator 7 opposite to the heat-conducting surface 8 and protrude from the radiator 7 along the longitudinal axis L. The heat-dissipating fins each have a first chamber 11 and a second chamber 12, wherein the second chamber 12 is further away from the radiator 7 than the first chamber 11. Both chambers 11 and 12 are almost completely filled with a phase change material P. The radiator 7 may also have a plurality of heat-conducting surfaces 8, particularly those spatially spaced apart from each other.

[0043] exist Figure 1 In this embodiment, the cooling device 6 is installed in the lighting device 2 such that its heat-conducting surface 8 is directly in contact with the corresponding lighting element 4, i.e., physically in contact with the lighting element and thus thermally coupled with it. To achieve thermal coupling, a thermally conductive agent, such as thermal paste, can be placed between the lighting element 4 and the heat-conducting surface 8.

[0044] By using the phase change material P in chambers 11 and 12—a mixture of water and ethylene glycol—which undergoes two phase changes for cooling, the heat dissipation performance of the cooling device 6 is significantly improved compared to conventional heat dissipation fins. Furthermore, by placing the second chamber 12 further from the heat source formed by the illumination element 4 compared to the first chamber 11, a stepped cooling effect is achieved in the cooling device 6.

[0045] If in Figure 1 If the temperature rise of the lighting element 4 in the standard operating mode is lower than that in the high-performance operating mode, then cooling is achieved solely or primarily through the first chamber 11, for example, through the phase change of the phase change material P disposed therein. If the cooling device 6 absorbs more heat in the high-performance operating mode of the lighting element 4, then at least a portion of the cooling is additionally achieved through the second chamber 12. This heat is subsequently also absorbed by the phase change material P disposed further away in the second chamber 12. Therefore, the second chamber 12 is primarily used for cooling under special load conditions, i.e., as a so-called overload protection when the cooling effect through the first chamber 11 is no longer sufficient.

[0046] To achieve a particularly good cooling effect using the cooling device 6, the first chamber 11 contains a first phase change material P, while the second chamber 12 contains a second phase change material P, wherein the phase change temperature of the first phase change material P is lower than that of the second phase change material P. The advantage of this is that the first phase change material P undergoes a phase change significantly earlier than the second phase change material P, i.e., with less heat absorption. Based on the difference in phase change temperatures between the two phase change materials P, the cooling effect gradient of the cooling device 6 can be adjusted with particular precision. Therefore, it is advantageous to predetermine from what level of heat absorption the second chamber 12 will make a significant contribution to cooling.

[0047] like Figure 2 and Figure 3 As shown, each heat dissipation fin 10 is composed of six interconnected heat dissipation fin semi-fins K, which together surround the corresponding chambers 11 and 12. Two of the mirror-symmetrical half-shells H have recesses 18 (see...). Figure 3 These recesses, after engaging with each other, laterally define chambers 11 and 12. Additionally, four end pieces E are provided as additional heat dissipation fin semi-finished products K (see [link to end piece]). Figure 2 The end piece also closes chambers 11 and 12 along the axial direction A.

[0048] Here, the heat dissipation fins are made from aluminum heat dissipation fin semi-fins K by roll bonding, which enables particularly economical manufacturing. They can also be made from plastics with good thermal conductivity, such as high-density polyethylene (HDPE) or polyethylene terephthalate (PET).

[0049] Each heat dissipation fin 10 has a wall thickness W of 1.5 mm between its outer surface 19 and each of its chambers 11, 12. This allows for a large volume of chambers 11, 12, thus accommodating a large amount of phase change material P, thereby improving heat dissipation performance. Simultaneously, the walls of the heat dissipation fins 10 are sufficiently robust to provide good stability. Depending on the material and manufacturing method, the minimum wall thickness W is preferably between 0.1 mm and 2.5 mm. In the intermediate region 13 not directly adjacent to chambers 11, 12, the heat dissipation fins 10 can have a larger wall thickness W, for example, from 3 mm to 8 mm.

[0050] To fill and empty the phase change material P in chambers 11 and 12, the heat sink fins 10 are provided with inlets 14 and outlets 15 in each chamber 11 and 12, which can be sealed liquid-tightly and gas-tightly. This simplifies manufacturing by allowing the phase change material P to be filled into chambers 11 and 12 only after the heat sink fins 10, or cooling device 6, has been manufactured. It also allows for easy replacement of the phase change material P. During the filling and emptying process, the phase change material P can be in any state of matter.

[0051] Here, the heat dissipation fins 10 are not individually fixed to the radiator 7, which is conceivable in principle. Instead, multiple pairs of heat dissipation fins 16 are provided, each pair having two heat dissipation fins 10, which are securely connected to each other by U-shaped connecting sections 17. This facilitates operation and reduces the number of joints required on the radiator 7. Furthermore, to facilitate the fixing of the heat dissipation fin pairs 16, the radiator 7 includes partial protrusions 20, to which the heat dissipation fin pairs 16 are securely fixed by their respective connecting sections 17. In principle, any suitable connection technique is feasible here, including welding, brazing, bonding, plugging, or crimping.

[0052] The heat dissipation fins 16 are fixed to the radiator 7 as prefabricated components, which simplifies the manufacturing of the cooling device 6. All heat dissipation fins 10 are arranged such that there is a sufficiently large gap between each two adjacent heat dissipation fins 10 to prevent adjacent heat dissipation fins 10 from contacting each other and potentially bending or being damaged due to temperature-induced expansion.

[0053] In an alternative embodiment, the cooling device 6 may additionally have one or more heat dissipation fins protruding from the radiator 7, particularly on its side 9. These heat dissipation fins may be conventional, solid heat dissipation fins. However, these heat dissipation fins may also have only one chamber, which is at least partially filled with a phase change material P. With the aid of the appropriate heat dissipation fins, the heat dissipation performance of the cooling device 6 can be more precisely adjusted for the specific application.

[0054] Cooling device 6 can also be used for cooling Figure 1 The taillights or any other lighting device 2 of the vehicle 1. Each lighting device 2 may also include multiple cooling devices 6, which each cool only a portion of the lighting element 4.

Claims

1. A cooling device (6) comprising: a radiator (7) having at least one heat-conducting surface (8), the radiator (7) being thermally coupled to a heat source via said at least one heat-conducting surface; and at least two heat dissipation fins (10), wherein, The heat dissipation fins (10) protrude from the heat sink (7) on the side (9) away from the heat conduction surface (8). Its features are, Each heat sink fin (10) has at least one first chamber (11) and at least one second chamber (12), the second chamber being further away from the heat sink (7) than the first chamber (11), wherein each chamber is at least partially filled with a phase change material (P).

2. The cooling device (6) according to claim 1. Its features are, One or more heat dissipation fins (10) have a first phase change material (P) in a first chamber (11) and a second phase change material (P) in a second chamber (12), wherein the first phase change material (P) and the second phase change material (P) have different phase change temperatures.

3. The cooling device (6) according to claim 2. Its features are, The phase transition temperature of the second phase change material (P) is higher than that of the first phase change material (P).

4. The cooling device (6) according to any one of the preceding claims. Its features are, One or more—preferably all—heat dissipation fins (10) are each composed of at least two interconnected heat dissipation fin semi-fin products (K), wherein the first chamber (11) and the second chamber (12) are cavities, and the at least two heat dissipation fin semi-fin products (K) together surround the cavities in the connected state.

5. The cooling device (6) according to any one of the preceding claims. Its features are, The heat dissipation fins (10) are made of metal or plastic.

6. The cooling device (6) according to any one of the preceding claims. Its features are, Each heat dissipation fin (10) has a wall thickness (W) of at least 0.1 mm to 2.5 mm between its outer surface (19) facing outward and each chamber (11, 12).

7. The cooling device (6) according to any one of the preceding claims. Its features are, Each heat dissipation fin (10) has at least one inlet (14) and / or at least one outlet (15) that can be closed in order to fill and / or empty its chamber (11, 12) – particularly on each chamber (11, 12).

8. The cooling device (6) according to any one of the preceding claims. Its features are, The cooling device (6) has at least one pair of heat dissipation fins (16), which includes two heat dissipation fins (10) arranged in parallel with each other, and the two heat dissipation fins are firmly connected to each other by a U-shaped connecting section (17).

9. The cooling device (6) according to any one of the preceding claims. Its features are, The heat dissipation fins (10) and / or the heat dissipation fin pairs (16) are fixed to the radiator (7) as prefabricated components.

10. The cooling device (6) according to any one of the preceding claims. Its features are, The cooling device (6) additionally has one or more heat dissipation fins protruding from the heat dissipation fins on the side (9) of the heat sink (7) away from the heat conduction surface (8), wherein the heat dissipation fins or at least one of the heat dissipation fins have only one chamber at least partially filled with phase change material (P), and / or wherein the heat dissipation fins or at least one of the heat dissipation fins are formed as a solid body.

11. A lighting device (2) for a motor vehicle, the lighting device having at least one lighting element (4) and at least one cooling device (6) according to any one of the preceding claims, wherein, Each cooling device (6) is thermally connected to one or more—in particular all—lighting elements (4) via a corresponding heat-conducting surface (8), the connection being formed either directly by abutting the heat-conducting surface (8) against the corresponding lighting element (4) or indirectly, in particular, via additional heat-conducting elements.

12. The lighting device (2) according to claim 11. Its features are, The lighting device (2) is a headlight (3), particularly an LED headlight, and / or the at least one lighting element (4) is provided for providing low beam.

13. A motor vehicle (1) having at least one cooling device (6) according to any one of claims 1 to 10 and / or at least one lighting device (2) according to any one of claims 11 to 12.

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