WO2014154820A1

WO2014154820A1 - Deformable heat sink for a lighting device

Info

Publication number: WO2014154820A1
Application number: PCT/EP2014/056188
Authority: WO
Inventors: Piere Angelo FAVAROLO; Sascha Skergeth; Herbert Wessin
Original assignee: Zumtobel Lighting Gmbh
Priority date: 2013-03-27
Filing date: 2014-03-27
Publication date: 2014-10-02
Also published as: EP2984405B1; DE202013101339U1; EP2984405A1

Abstract

The present invention relates to a heat sink (1) for a lighting device (10), which, in particular, takes the form of a fitted light or a downlight. The heat sink (1) can be at least partially deformed such that the length (or height) of the heat sink (1) changes in order to adapt to space (9) available between a false ceiling (7) and a bare ceiling (6). The heat sink (1) consists of a plurality of cooling arms (2) in at least one section of its length, which are designed to extend outwards laterally from the heat sink. The extending of the cooling arms (2) reduces the length of the length section (10) and consequently the total length of the heat sink.

Description

Deformable heat sink for a lighting device

The present invention relates to a deformable heat sink for a

Lighting device. The present invention also relates to a lighting device with a deformable heat sink. In particular, the inventive

Lighting device a recessed light, preferably a downlight. The deformable heat sink is in particular deformable such that changes the length of the heat sink, in particular reduced by the deformation. From the prior art, a recessed light, in particular a downlight is known, which is installed in a mounting hole of a suspended ceiling. The downlight is placed in particular in a space between the suspended ceiling and a raw ceiling. The light source of the recessed luminaire produces heat that has to be dissipated efficiently. This is particularly necessary if one or more LEDs are used as the light source of the recessed luminaire. In order to dissipate the heat generated during operation of the light source, preferably a heat sink is used, which is arranged on the back of the recessed light in order to transport the heat away from the light source and deliver it to the environment.

The depth of the free space between the raw ceiling and the suspended ceiling, in which the recessed light, in particular the heat sink, is installed, but is not fixed, but is only within a certain range. Accordingly, a heat sink is usually used in the prior art, which is adapted to a corresponding recessed luminaire. This means that in particular the length of the heat sink is adapted to the depth of the available free space. For each recessed luminaire, therefore, a heat sink is developed or provided accordingly, resulting in low flexibility and high production costs.

The object of the present invention is to improve the known state of the art. In particular, it is an object of the present invention to achieve greater flexibility in the use of heat sinks. There is one Object of the invention to provide a heat sink that can be used for various recessed lights, regardless of the available space between the raw ceiling and the suspended ceiling. Another object of the present invention is to provide simpler and more mechanically

produce cheaper heat sink. Another object of the present invention is a lighting device, in particular a recessed light

manufacture, which is more flexible, especially in different depths free spaces between suspended ceiling and ceiling can be used. The present invention achieves the above objects according to the independent claims. The dependent claims further advantageously form the core idea of the invention.

The present invention relates to a deformable heat sink for a

Lighting device, wherein at least a longitudinal portion of the heat sink consists of a plurality of cooling arms, which are adapted to laterally auszubpizen from the heat sink to reduce the length of the heat sink.

By virtue of the deformable heat sink according to the invention, greater flexibility is achieved for the use of both the heat sink and a light-emitting device provided with the heat sink than for light-emitting devices of the prior art. In particular, the deformable heat sink according to the invention for recessed luminaires (built-in lighting devices), for example downlight luminaires (downlight luminous devices) is advantageous because the heat sink to an available space between a bare ceiling and a suspended ceiling, which is not fixed, but only within a certain range, can be adjusted. The heat sink according to the invention can in fact deform so that it is narrow enough during installation in the free space to pass through a

Small diameter mounting hole to be introduced into the space, but at the same time in terms of its length (ie, its height when installed in the ceiling) is variable to accommodate the depth of the available space. A lighting device which is equipped with the deformable heat sink according to the invention can thus be installed in free spaces of different depths. A heat sink according to the invention can also be used for different lighting devices to be used. As a result, it is not necessary to produce heat sinks which are individually adapted to the lighting devices, which reduces the production costs. Finally, the installation of a lighting device with the heat sink according to the invention is simplified.

In a first and second variant of the deformable heat sink of the present invention preferably has one end of the heat sink on a connecting element for connecting the heat sink with the lighting device, another end of the heat sink has a holding element, wherein the cooling arms respectively

Connecting the connecting element and the holding element together.

The cooling arms are thus fastened in each case with its one end to the holding element and with its other end to the connecting element. Both that

Connecting element and the holding element connect the plurality of cooling arms so each other. If now the cooling arms laterally spread out or bend out of the heat sink, the distance between the connecting element and the holding element is reduced. This reduces accordingly the length of the heat sink. The shortening of the heat sink or the spreading out of the cooling arms can be achieved, for example, by a force acting on the holding element in the direction of the connecting element. Such a force arises, for example, when the heat sink is inserted into the free space and is pressed against the raw ceiling. As a result, when installing the lighting device, the length of the heat sink can be adjusted automatically and does not have to be measured beforehand. Preferably, on an outer side of the holding element is a projecting

Spacer, preferably in the form of a mandrel arranged.

The outside is facing, for example, the raw ceiling. The spacer ensures that a certain minimum distance to the raw ceiling is maintained. This minimum distance is important, for example, when the raw ceiling is not made of concrete, but of wood or a similar material, in particular a heat-resistant material. In the first variant, preferably, the cooling arms are flexible, so that they can bend laterally out of the heat sink.

These cooling arms are particularly easy to produce, since they are formed in one piece. The cooling arms are preferably not only flexible but also elastic. Due to their elasticity, the cooling arms bend back automatically, so that the heat sink is extended again when no force acts in the length direction on the heat sink. As a result, for example, the heat sink can be removed from a mounting opening in a particularly simple manner, since it automatically narrows.

In the second variant, preferably, the cooling arms each consist of several slats arranged one behind the other, which are connected to each other via articulated joints.

The hinged connections are preferably easily detachable from one another and connectable again. The overall cooling arms can then be easily extended or shortened by adding fins to the cooling arms or removing fins from the cooling arms. As a result, the heat sink is even more flexible, since it can be retrofitted or adapted for almost any installation depth.

Preferably, the cooling arms each have a first sipe, which is rotatably mounted with its one end to the connecting element, and have a second sipe, which is rotatably attached with its one end to the holding element, wherein the first and the second sipe with their through the other ends

Articulated connections are rotatably attached to each other.

The rotatable attachment of the slats allows the cooling arms to bend steplessly. Different cooling arms can also bend to different degrees. Thereby, a lighting device with inventive heat sink, for example, be installed in a space between a bare ceiling and a suspended ceiling, even if the two ceilings are not quite parallel to each other are. The heat sink can thus compensate for a slope of the space between the ceilings.

Preferably, the articulated joints are formed by flexible thermally conductive foils.

For example, these slides can be graphene. The joints can thus a good heat transfer between the individual slats

to ensure. This allows heat to be delivered evenly over the entire heat sink.

In a third variant of the deformable heat sink of the present invention, the heat sink preferably has a connection element for connecting the heat sink to the lighting device, wherein the cooling arms are pivotally mounted at one end to the connection element and have a free other end, so that the cooling arms laterally can be deflected to the heat sink.

The mechanics of the heat sink can be simplified again. In particular, the number of components can be reduced. Such is the example

Holding element no longer required. In addition, only one joint per cooling arm is necessary. The third variant also has the advantage that the installation depth additionally decreases, i. the heat sink can be used in even flatter spaces without losing functionality, namely dissipate heat. The cooling arms are preferably designed as lamellae, ie as thin platelets, which are particularly good

Allow heat removal due to their large surface area.

Preferably, the free end of the cooling arms is chamfered.

The slope has the consequence that when inserting the heat sink in the free space, the cooling arms are automatically deflected laterally and accordingly pivot to the side. As a result, the length (or height) of the heat sink is automatically reduced during installation of the heat sink. In all variants of the present invention, the cooling arms are preferably made of a good heat-conducting material, preferably of sheet metal or graphene, which has a thermal conductivity in the range of 100 to 2500 W / mK, preferably in the range of 1000 to 2500 W / mK.

Graphene has a particularly good thermal conductivity and also has a high flexibility. This allows the cooling arms to simply bend laterally. The thickness of the cooling arms can be adjusted according to requirements. Preferably, the cooling arms are thin graphene foils.

These graphene foils are particularly flexible. In addition, when using such graphene films, the material consumption can be kept small. Preferably, the connecting element consists of a good heat-conducting

Material that has a thermal conductivity in the range of 100 - 2500 W / mK,

preferably in the range of 1000 - 2500 W / mK.

Under good thermal conductivity, the present invention understands a

Thermal conductivity in the range of 100 - 2500 W / mK, preferably in the range of 500 - 2500 W / mK, even more preferably in the range of 1000 - 2500 W / mK, most preferably in the range of 1500 - 2500 W / mK. The connecting element is preferably made of sheet metal or another metal. The

Connector can also consist of graphs. The good thermal conductivity of the connecting element promotes the transfer of heat from the

Lighting device on the cooling arms or the heat sink. This allows the entire heat sink to work very effectively. Since the majority of the heat is dissipated through the cooling arms, the connecting element can also be formed from a less thermally conductive material, such as plastics or plastic. This can save costs and / or reduce the weight of the heat sink since plastics and plastics are generally cheaper and lighter than metal.

The present invention further relates to a lighting device, a

Has heat sink as described above. Preferably, the lighting device is a built-in lighting device, in particular a downlight lighting device. Such lighting devices are suitable to be in a space between two

Walls to be installed, for example, between a suspended ceiling and a raw ceiling. The lighting device of the present invention can be flexibly used because it can be installed in clearances of various installation depths. The lighting device can still small through mounting holes

Hole diameter are introduced.

Preferably, the lighting device comprises at least one LED or OLED as a light source. The present invention will now be described in detail with reference to the accompanying drawings. shows a heat sink or a lighting device according to a first variant of the present invention.

2a and 2b show a connecting element and cooling arms of a

Heat sink according to the first variant of the present invention. 3 shows a heat sink or a lighting device according to a second variant of the present invention.

FIGS. 4a and 4b show cooling arms according to the second variant of the present invention

Invention.

5 shows a heat sink or a lighting device according to a third variant of the present invention. 6a to 6c show a connecting element and cooling arms of a

Heat sink according to the third variant of the present invention. Fig. 1 shows a lighting device 10 and a heat sink 1 according to a first variant of the present invention. In the first variant, the heat sink 1 has a plurality of cooling arms 2 that are flexible, i. are made of a flexible material, and therefore designed to be laterally out of the

Bend out heat sink 1 to reduce the length of the heat sink 1.

Fig. 1 shows in general how the lighting device 10 according to the invention is installed in a free space 9 between a bare ceiling 6 and a suspended ceiling 7. In this case, the lighting device 10 is inserted through a mounting opening in the suspended ceiling 7 in the space 9. The mounting opening preferably has a diameter which is just so great that the lighting device 10 fits through it, as long as the cooling arms are not spread out laterally.

The lighting device 10 consists of a deformable heat sink 1 according to the invention and a body 12 of the lighting device 10 to which the deformable heat sink 1 is attached. The body 12 of the lighting device 10 includes a light source 11 and a radiating element 8, for example a reflector 8, which directs the light emitted by the light source 11 away from the suspended ceiling 7 and downwards. For this purpose, the luminous means 11 is preferably inserted into a recess of the radiating element 8. The lighting device 10 is thus - as shown in Fig. 1 - a recessed light, in particular a downlight. The

Lighting device 10 can be installed just as in a free space 9 between a suspended ceiling 7 and a raw ceiling 6, for example, in a space between two walls or two floors or two similar surfaces. The lighting means 11 of the lighting device 10 is preferably at least one LED and / or at least one OLED. The light-emitting means 11 can also consist of a plurality of LEDs or of a plurality of OLEDs or a combination of LEDs and OLEDs. For example, the lighting means 11 may be an LED track or an LED group. If the luminous means 11 comprises a plurality of LEDs or OLEDs, then These either light the same or different color respectively

Deliver color temperature. For example, a red, a blue and a green LED to a white light LED group as the light source 11 of the lighting device 10 may be joined together.

The deformable heat sink 1 according to the invention is preferably via a

Connecting element 3 connected to the body 12 of the lighting device 10. The body 12 of the lighting device 10 preferably carries the radiating element 8 or the lighting means 11. The connecting element 3 can be connected to the body 12 of the lighting device 10, screwed, glued or attached in a similar manner.

The heat sink 1 further includes a holding element 4, which is arranged at a certain distance from the connecting element 3, wherein this distance determines the length of the heat sink 1. Between the connecting element 3 and the holding element 4, the plurality of cooling arms 2 are arranged. In this case, each cooling arm 2 connects the connecting element 3 with the holding element 4. The cooling arms 2 thus form a longitudinal section of the heat sink 1. The cooling arms 2 are preferably parallel to each other in the length direction of the heat sink 1, that is from the connecting element 3 to holding element 4, respectively.

The holding element 4 is preferably provided on its upper side, that is to say on a side of the heat sink 1 facing the blanket 6, with a spacer 5, which is advantageously designed as a mandrel or as a projection or the like. By this spacer 5 ensures that always a

Minimum distance between the heat sink 1 and the raw ceiling 6 is maintained when the lighting device 10 is inserted into the space 9. This

Minimum distance is important if, for example, the raw ceiling 6 made of wood or a similar material that may be damaged if too much heat development of the lighting device 10 or heating of the heat sink 1. In addition, by this minimum distance, the resulting heat better

be transported away. As already described above, the plurality of cooling arms 2 in the first variant of the heat sink 1 according to the invention are preferably flexible, so that they can bend laterally out of the heat sink. The cooling arms 2 are thus formed of a flexible, preferably even of an elastic material. The cooling arms 2 can bend laterally out of the heat sink 1, that is, they bend into one

Direction out, perpendicular to the length direction of the heat sink 1. The cooling arms 2 bend when a force on the support member 4 in the direction of

Connecting element 3 or vice versa acts. Such a force acts, for example, when the heat sink 1 abuts the raw ceiling 6. This has the consequence that the cooling arms 2 are bent outwards and the length (height in Fig. 1) of the heat sink 1 is changed, namely reduced. Thus, the heat sink 1 can also be used in free spaces 9 with low installation depth. In particular, the

Heatsink initially when inserted into the free space 9 still narrow enough to be pushed through the mounting hole in the suspended ceiling 7, since the cooling arms 2 still rest on the heat sink 1. In Fig. 1 is indicated by dotted lines, as the cooling arms 2 bend during installation laterally from the heat sink 1, namely, when the heat sink abuts the raw ceiling 6, and so the length of the heat sink 1 is reduced by an amount AL. As a result, the reduction of the installation depth is possible.

Fig. 2a shows the connecting element 3 of the heat sink 1 of the first variant of the present invention. The connecting element 3 is advantageously designed as a screw, preferably in the form of a gear. To the

Connecting element 3 is preferably for each cooling arm 2 a receptacle 3 a provided. In the receptacles 3 a, the cooling arms 2 can be inserted and secured to the connecting element 3. The cooling arms 2 are preferably designed as lamellae, which means thin, preferably flat platelets, even more preferably as graphene lamellae. These slats can be inserted into thin slits, which serve as the receptacles 3 a. Fig. 2a shows four such receptacles 3 a, that is, it can be mounted on the connecting element 3 exactly four cooling arms 2. Fig. 2b shows accordingly an example of four cooling arms 2, which are each offset by 90 ° around the circumference of the connecting element 3 around and thus in four different directions, which are perpendicular or parallel to each other, from the heat sink 1 can bend. It can, however, too more than four cooling arms 2 are used. These multiple cooling arms 2 can then be attached to the connecting element 3, for example at different angles to each other, evenly or non-uniformly distributed around the connecting element 3.

Fig. 3 shows a second variant of the lighting device 10 and the heat sink 1 of the present invention. The lighting device 10 is designed except for the heat sink 1 exactly as in the first variant. The heat sink 1 is constructed similarly as in the first variant, but now has cooling arms 2, which consist of a plurality of successively arranged sections, preferably a plurality of successively arranged slats 2a, 2b, which are connected to each other via articulated joints 2c. The connection of the individual lamellae 2a, 2b can take place via special joints 2c. However, it is also a connection on flexible and thermally conductive films, which are made for example of graphene conceivable. It should be advantageously ensured that takes place at the joints 2c good heat transfer, so that the heat can be discharged uniformly over the entire heat sink 1.

In Fig. 3, a preferred embodiment of the second variant is shown, in which each cooling arm 2 each consists of a first blade 2a and a second blade 2b. The two lamellae 2a and 2b are rotatably attached to each other via the joint 2c and also rotatably attached to the holding element 4 and the connecting element 3, respectively. More specifically, the first fin 2a is attached to the holding member 4 at one of its ends and attached to the second fin 2b at the other end thereof. The second sipe 2b is correspondingly attached at one of its ends to the first sipe 2a and attached to the connecting element 3 with another of its ends. In order to change the length of the heat sink 1, that is to say bring about a change in length AL, the lamellae 2a or 2b can rotate as indicated by the dotted lines, both at the joints which they connect to the connection or holding element 3, 4, as well as between the slats 2a, 2b

arranged joint 2c. As a result, the cooling arms 2 are deflected laterally out of the heat sink 1. As a result, the installation depth can be reduced as in the first variant. Fig. 4a shows an example of the design of the first blade 2a and its profile. Fig. 4b shows an example of the configuration of the second blade 2b and its profile. Both lamellae 2a, 2b are preferably stamped to obtain the profile shown. The second blade 2b shows in its profile two bulges. These can also be embossed on the lamella. The first sipe 2a shows a corresponding receptacle into which the bulge of the second sipe 2b can be inserted to produce the hinged connection 2c between the sipes 2a, 2b. Fig. 5 shows a third variant of the lighting device 10 and the

Heat sink 1 of the present invention. Again, the lighting device 10 is the same except for the heat sink 1 as in the other two variants described above. The heat sink 1 consists in the third variant of a plurality of cooling arms 2, which are connected only at their lower sides articulated to the connecting element 3. The tops of the cooling arms 2, however, are free-standing, so not connected to a holding element or each other. Since there is no holding member 4 in the third variant, the number of components can be reduced.

The cooling arms 2 are preferably thin, wing-like lamellae, which preferably consist of graphene. The freestanding upper sides of the cooling arms 2 are preferably bevelled, so that the cooling arms 2 are automatically deflected laterally out of the heat sink 1 when the heat sink 1 is installed in the free space 9 when they abut the raw ceiling 5. Here, the cooling arms 2 rotate as indicated in Fig. 5 around the joint 2 d, via which the cooling arms 2 are hinged to the connecting element 3. As a result, the length of the heat sink 1 changes by the amount AL. The Längenäderung depends on the angle by which the cooling arms 2 rotate about the hinge 2d. This angle is continuously variable.

Fig. 6a shows in detail the connecting element 3 in a plan view. The

Connecting element 3 is formed with receptacles 3a, in which, as shown in Fig. 6c, the cooling arms 2 can be inserted. For this purpose, the cooling arms 2 are preferably provided as thin lamellae with an embossment which protrudes slightly and with the corresponding receiving element 3 c of the receptacle 3 a a hinged

Connection 2d produces. Fig. 6b is a side view of the connecting element 3 at the third variant. The connecting element 3 is therefore preferably as

Receiving ring designed and designed for a plurality of cooling arms 2, which are arranged along the circumference of the receiving ring, preferably evenly. For the three described variants of the heat sink 1 and the

Lighting device 10, the cooling arms 2 are made of a good thermal conductivity material, preferably made of sheet or graphene. Preferably, the

Thermal conductivity of the cooling arms 2 in the range of 100 - 2500 W / mK, preferably in the range of 500 - 2500 W / mK, even more preferably in the range of 1000 - 2500 W / mK, most preferably in the range of 1500 - 2500 W / mK , Graphene is a special type of carbon that can be produced in two-dimensional films. The cooling arms 2 are therefore preferably graphene films which have a very good thermal conductivity. Graphene as a material is particularly advantageous because it additionally has the required flexibility, so that the cooling arms, for example, as shown in the first variant, can flex. The thickness of the graphene sheets used as the cooling arms 2 may be adjusted as necessary, but is preferably in a range of 0.1 to 2 mm, more preferably 0.1 to 1 mm. In all variants, the connecting element 3 is formed as a good thermally conductive material, such as sheet metal, another metal or graphene.

Preferably, the thermal conductivity of the connector is in the range of 100 - 2500 W / mK, preferably in the range of 500 - 2500 W / mK, more preferably in the range of 1000 - 2500 W / mK, most preferably in the range of 1500 - 2500W / mK. As a result, the heat which is emitted by the luminous means 11 of the lighting device 10 can be transmitted to the heat sink 1 in a particularly efficient manner. The dissipated heat is released mainly via the cooling arms 2 of the heat sink 1. Therefore, for example, in the first and second variant of the invention, the holding element 4 are made of a less thermally conductive material such as plastic or other plastic. The

Retaining element 4 does not necessarily have to serve the cooling. This can make it cheaper and possibly easier. However, of course, the holding element 4 may consist of a good heat conducting material. In summary, the present invention provides a heat sink 1 for a lighting device 10, in particular a recessed luminaire, wherein the

Heatsink 1 can at least partially deform, so that the length (or height) of the heat sink 1 at the standing for clearance 9 between

Suspended ceiling 7 and raw ceiling 6 can adjust.

The heat sink 1 according to the invention consists in at least a portion of its length of a plurality of cooling arms 2, which are adapted to laterally auszubpreizen from the heat sink. Due to the bending of the cooling arms 2, the length of this length section is reduced and thus also the overall length of the heat sink 1 is reduced.

Claims

claims

1. Deformable heat sink (1) for a lighting device (10), wherein at least one longitudinal portion of the heat sink (1) consists of several cooling arms (2), which are adapted laterally from the heat sink (1) auszuspreizen or bend to to reduce the length of the heat sink (1).

2. Deformable heat sink (1) according to claim 1, wherein

an end of the heat sink (1) has a connecting element (3) for connecting the heat sink (1) to the lighting device (10);

another end of the heat sink (1) has a holding element (4);

wherein the cooling arms (2) each have the connecting element (3) and the

Connecting holding element (4) together.

3. Deformable heat sink (1) according to claim 2, wherein on an outer side of the holding element (4) a projecting spacer (5), preferably in the form of a mandrel, is arranged.

4. Deformable heat sink (1) according to claim 2 or 3, wherein

the cooling arms (2) are flexible, so that these laterally from the heat sink

(1) can turn out.

5. deformable heat sink (1) according to claim 2 or 3, wherein

the cooling arms (2) each consist of a plurality of laminations (2a, 2b) arranged one behind the other, which are connected to one another via articulated connections (2c).

6. Deformable heat sink (1) according to claim 5, wherein

the cooling arms (2) each have a first lamella (2a) which is rotatably mounted with its one end on the connecting element (3), and a second lamella (2b) which rotatably with its one end to the holding element (4) is attached, wherein the first and the second blade (2a, 2b) with their other ends by the hinge joints (2c) are rotatably attached to each other.

7. Deformable heat sink (1) according to claim 5 or 6, wherein the

Articulated joints (2c) are formed by flexible heat-conducting foils.

8. A deformable heat sink (1) according to claim 1, comprising

a connecting element (3) for connecting the heat sink (1) to the

Lighting device (10);

wherein the cooling arms (2) are hinged at one end to the connecting element (3) and have a free other end, so that the cooling arms (2) can be laterally deflected out of the heat sink (1).

9. Deformable heat sink (1) according to claim 8, wherein the free end of the cooling arms (2) is chamfered.

10. Deformable heat sink (1) according to one of claims 1 to 9, wherein the cooling arms (2) made of a highly thermally conductive material, preferably of sheet metal or

Graphene, which has a thermal conductivity in the range of 100 - 2500 W / mK, preferably in the range of 1000 - 2500 W / mK.

11. Deformable heat sink (1) according to one of claims 1 to 10, wherein the cooling arms (2) are thin graphene foils.

12. Deformable heat sink (1) according to one of claims 2 to 11, wherein the connecting element (3) consists of a highly thermally conductive material having a thermal conductivity in the range of 100 - 2500 W / mK, preferably in the range of 1000 - 2500 W / mK.

13. Lighting device (10) having a heat sink (1) according to one of claims 1 to 12.

14. Lighting device (10) according to claim 13, which is a recessed light, in particular a downlight.

15. Lighting device according to claim 13 or 14, which comprises at least one LED and / or an OLED as a light source (11).