DE202012103751U1 - Luminaire with passive cooling - Google Patents

Abstract

Luminaire, in particular interior or exterior luminaire, with a luminaire housing (2) and a transparent cover (3) which define a cavity filled with a fluid, in particular air, wherein an inner side of the luminaire housing (2) partially delimiting the cavity is arched and wherein in the cavity, a carrier (5, 5 ', 5' ', 5' '') is accommodated for at least one lamp, which has a first side for arranging the at least one lighting means and an opposite second side, wherein the carrier within the Cavity is arranged such that generated by the at least one lamp and by the carrier (5, 5 ', 5' ', 5' '') to the second side conducted heat by convection of the fluid at least partially to the inside of the lamp housing (2 ) is dissipatable.

Description

The invention relates to a lamp, in particular a lamp for lighting purposes. The light can be designed in particular as an interior or exterior light.

From the publication WO 03/036159 A1 is a clean room light known, which has a frame and a reflector therein. Above the reflector solid-state light sources are arranged in the frame, which are mounted on a heat sink. The heat sink is adjacent to a cable channel with its upper side and is provided on its underside with a rib structure.

The object of the present invention is to provide a luminaire which allows a simple, efficient cooling of the luminous means.

This object is achieved by a luminaire according to claim 1.

The invention provides a luminaire, in particular an interior or exterior luminaire with a luminaire housing and a transparent cover, which define a cavity filled with fluid, in particular air, wherein an inner side of the luminaire housing which partially bounds the cavity is arched. In the cavity, a support for at least one light source is accommodated, which has a first side for the arrangement of the at least one luminous means and an opposite second side. The carrier is arranged inside the cavity such that heat generated by the at least one light source and conducted through the carrier to the second side can be dissipated by convection of the fluid at least partially to the inside of the light housing.

While in some embodiments, the cavity includes any fluid that may be used for convection, for purposes of simplicity of description, it will be assumed hereinafter that the cavity is filled with air. However, those skilled in the art will recognize that the cavity may alternatively or additionally also be filled with another fluid, in particular with another gas.

According to the invention, the lighting means is in good thermal contact with the carrier. The heat generated by the light source is delivered to the carrier via the first side. By heat conduction through the carrier, the heat reaches its second side, where it is released to the surrounding air. The carrier is arranged inside the cavity of the luminaire in such a way that the air located above the second side of the carrier can transport the heat away from the carrier by means of a convection process. In this way, the heat generated is at least partially dissipated to the lamp housing. This allows efficient cooling of the lamp, without the need for other, in particular active components, such as a fan or a circulation pump. Furthermore, according to the invention no further coolant such. As cooling fins on the carrier, on the lamp housing or other elements of the lamp required. In particular, the first and / or the second side of the carrier may be at least partially smooth and / or flat, so that the fluid can flow unhindered over the first or second side. Preferably, the first and / or the second side of the carrier is unstructured and in particular has no cooling structures such. B. cooling fins on. However, in some embodiments, the support, in particular on the second side, may be provided with cooling fins.

Due to the curvature of the inside, this has a larger surface area, so that the heat can be efficiently delivered to the luminaire housing and the cooling effect is improved. The inside can in particular be curved inward or outward and / or bell-shaped.

The luminaire can be designed, in particular, as a trough luminaire, recessed or surface-mounted luminaire, pendant luminaire, floor lamp, ceiling or wall luminaire. In some embodiments, the luminaire can be designed as an outdoor luminaire, preferably as a decorative outdoor luminaire. It is preferred that the lamp is arranged so that in the mounted state of the lamp, an air flow over at least a portion of an outer side of the lamp housing, in particular in the region of the cavity is made possible. In this way, the heat generated by the lamp can be effectively delivered through the lamp housing to the environment.

The light-emitting means may in particular be a group of LEDs (light-emitting diodes) or OLEDs (organic light-emitting devices).

In some embodiments, the transparent cover has means for directing light, for example a prism structure and / or a lens structure. The means for directing the light can be formed on the cover or arranged as separate components on the cover. The means for directing the light can be arranged on an outer and / or an inner side of the cover.

Since the heat in the luminaire according to the invention can be delivered flat to the luminaire housing, especially when using bulbs with less Heat generation the luminaire housing is not necessarily made of a material with particularly high thermal conductivity. This allows the designer to select the material in other ways, especially in terms of space requirements, weight or design. For example, the lamp housing can be made of plastic. However, in some embodiments, the light housing may be made of metal, for example, aluminum. In this way, the heat can be better dissipated from the inside of the lamp housing to the outside and the lamps are cooled more efficiently. This is particularly advantageous for bulbs with high heat generation and / or small volume lights. In some embodiments, the housing is made of sheet metal, so that the heat can be dissipated easily to an outside of the lamp housing.

The transparent cover may be made of a transparent plastic, in particular of polymethyl methacrylate (PMMA) or of glass. The cover and the lamp housing may be attached to each other, for. B. by means of a screw, latch or bayonet connection.

In some embodiments, the luminaire has further components, for example light-directing means such as a reflector or lenses, and / or a power supply. One or more of the ingredients may be incorporated into the cavity. It should be noted, however, that the cooling of the carrier by means of convection is still possible.

According to a preferred embodiment, the luminaire housing has a greater distance to the carrier over a central region of the carrier than over a peripheral region of the carrier. In this way, a greater distance to the lamp housing is achieved over a central region of the carrier. This improves the convection.

This is particularly advantageous when the lighting means is arranged at the central region of the carrier. Furthermore, it can be provided that the luminaire housing is arched over the carrier like a fireplace to the outside. This further improves the cooling.

In a preferred embodiment, the transparent cover has a greater distance to the carrier over a central region of the carrier than over a peripheral region of the carrier. Similar to the luminaire housing, this embodiment of the cover improves the convection within the cavity below the carrier and thus provides improved cooling.

According to a preferred embodiment, an inner side of the transparent cover partially delimiting the cavity is arched over a central region of the support and may, in particular, have a trough shape or a shape of a hollow spherical cutout, preferably a hemisphere. This causes a larger surface area of the inside of the cover, so that heat can be efficiently delivered to the cover. This is particularly preferred if the convection also detects a defined by the cover portion of the cavity, z. B. by the carrier has through holes or defines a gap with a border of the cavity.

In a preferred embodiment, the carrier is designed as a carrier plate. In this embodiment, the carrier is flat. This allows the fluid to flow freely over the carrier plate, whereby the convection is further improved. In some embodiments, the second side of the carrier is in particular not convex or not concave curved. According to one embodiment, the carrier is made of a sheet material, for. B. a metal sheet formed. In particular, a bulge is provided on the planar support. The bulge has z. B. a recess on the first side, wherein in the recess preferably at least one light source is added. On the second side an increase is formed according to the bulge.

According to a preferred embodiment, the luminaire housing and the cover abut each other along a plane, the carrier preferably being arranged along the plane. The luminaire housing and the cover can be connected to each other in particular along the plane The concern and in particular the connection of the luminaire housing and the cover along a plane facilitates the mounting of the cover to the luminaire housing. The arrangement of the carrier along the plane makes it easy for a fitter to reach after the transparent cover has been removed. In this way he can easily replace the bulb. Furthermore, this causes a central arrangement of the carrier in the cavity, so that in particular to the lamp housing is sufficient distance to allow efficient convection.

According to a preferred embodiment, the lamp further comprises one or more arranged on a board or on a module lamp, in particular a group of LED and / or OLED, wherein the board or the module on the first side of the carrier and in thermal contact with the Carrier, in particular by means of a thermal paste, a thermally conductive adhesive or a Wärmeleitfolie is attached. The arrangement on a board or a module allows a easier mounting of the light source to the carrier. Further, in this embodiment, the carrier may be made of a metallic material without fear of short circuits of the lighting means. A good thermal connection of the board or the module to the carrier is preferred, since the heat generated by the lamp is dissipated from the board or the module to the carrier. The module may further comprise a cover, by which the lighting means is at least partially covered. The light source can z. B. laterally to the module and / or be arranged in the module.

The carrier may in particular be made of plastic or of metal, in particular of aluminum, steel or copper. These materials are preferred because they have high thermal conductivity so that the heat is efficiently conducted from the first to the second side of the carrier.

The optimum thickness of the carrier depends on various factors, such as the shape and material of the lamp housing, the carrier and the board. Too small a thickness limits the dispersion of heat within the carrier, so that the heat is insufficiently distributed over the second side of the carrier. However, if the thickness is too high, the air is heated over the entire second side of the carrier so that there is a large buoyancy force of the air molecules everywhere, making it difficult to circulate the air in the cavity. In particular, in embodiments in which the support is made of aluminum, the support may have a thickness between 1 mm and 20 mm, in particular between 1 mm and 12 mm, preferably between 2 mm and 10 mm and particularly preferably between 4 mm and 8 mm ,

According to a preferred embodiment, the carrier fills a cross section through a cavity. In this embodiment, the carrier extends through the entire cavity, so that a particularly large surface area is available on the second side of the carrier for emitting the heat and for generating the Konventionstromes.

In a preferred embodiment, at least one gap sized to allow passage of fluid in the cavity between an area above the second side and an area above the first side of the carrier is defined between the carrier and a rim of the cavity. In this embodiment, the convection senses the entire cavity on both sides of the carrier. This allows a better distribution of the heat generated by the bulb in the cavity. Furthermore, in this way the heat can also be delivered to the transparent cover, so that its outside also contributes to the release of heat to the surrounding air.

According to a particularly preferred embodiment, the gap is a gap circulating around the carrier. This embodiment allows the fluid to pass from one side of the carrier to the other over the entire circumference of the carrier. Convection within the cavity is thus improved.

Alternatively or additionally, the carrier may have one or more through-openings to allow passage of fluid from one side of the carrier to another side of the carrier. This improves the heat distribution within the cavity. Through openings in the carrier are particularly advantageous in connection with a gap, since the fluid flowing down through the gap can flow back up through the through openings.

The passage openings and / or the at least one gap may be round and / or angularly shaped.

In a preferred embodiment, the carrier is arranged within a subregion of the cavity defined by the luminaire housing. In this embodiment, the carrier is protected by the lamp housing. This is preferred over other embodiments in which the carrier is arranged within a subregion defined by the transparent cover. In particular, the carrier does not protrude during assembly when the cover is removed, so that accidental damage can be avoided.

According to a preferred embodiment, the luminaire housing and the cover seal the cavity to the outside. In particular, the luminaire housing and the cover can insulate the cavity from the outside so that dust or moisture can not penetrate therein. In this way, the carrier, the lighting means and possibly located in the cavity electronic components is protected. Further, when using a fluid other than air, it is preferable to prevent the fluid from flowing out of the cavity.

Further features and advantages of the present invention will become apparent from the following description of preferred embodiments, wherein like reference numerals designate like features.

1 shows a perspective view of a section of a lamp according to the invention according to a first embodiment.

2 shows a perspective view of a section of a lamp according to another embodiment.

3 shows a perspective view of a section of a lamp according to a third embodiment.

4 shows a cross section through a support of a lamp according to a fourth embodiment.

5 shows a cross section through a support of a lamp according to a fifth embodiment.

1 shows a lamp with a bell-shaped lamp housing 2 and a hemispherical transparent cover attached thereto 3 , The luminaire housing 2 and the cover 3 trap a cavity and surround it completely. The luminaire housing 2 and the transparent cover 3 are connected together along an annular line defining a plane in which a carrier 5 is arranged. The carrier 5 is in the in 1 illustrated embodiment as a separating plate between a through the lamp housing 2 defined portion of the cavity and a through the transparent cover 3 defined sub-area formed. The carrier 5 separates these two parts completely from each other. The carrier 5 is at its edge with the luminaire housing 2 connected.

On a first side of the carrier 5 (Bottom in 1 ) is a circuit board 4 arranged with several LEDs as lighting. During operation, the LEDs generate heat which is transmitted through the board 4 to the carrier 5 is delivered. The heat gets inside the carrier 5 from the first side to an opposite, the luminaire housing 2 directed second side directed. This will over the second side of the carrier 5 heated air, so that a convection starts and an air flow is generated, as in 1 with reference numerals 6 provided arrows is illustrated. The lighting means in particular heat a region of the carrier 5 in an environment of the board 4 , The air heated over the second side rises upwards and reaches the luminaire housing 2 , There the air gives some of its heat to the luminaire housing 2 and flows on the sides of the luminaire housing 2 back down in the direction of the carrier 5 ,

Also in 1 plotted is a separation 7 in the luminaire housing 2 above the carrier 5 , The separation 7 is parallel to the carrier 5 arranged. The separation 7 prevents the heated air from rising too far during the convection process. In this way, the convection movement of the air can be adjusted in order to optimally deliver the heat to the luminaire housing 2 to reach.

In 2 is another embodiment of a lamp with a bell-shaped lamp housing 2 and a hemispherical transparent cover 3 shown. From the in 1 illustrated embodiment, which differs in 2 illustrated embodiment in particular by the carrier used 5 , This fills in 2 not the complete cross section through the cavity. Rather, it is between the carrier 5 and the through the luminaire housing 2 defined border of the cavity a circumferential gap 8th educated. Further, the carrier has 5 several angular openings 9 on. Through the gap 8th as well as through the passage openings 9 can air between a subarea above the carrier 5 and a portion below the carrier 5 circulate within the cavity. In particular, the flows on the lamp housing 2 cooled air through the gap 9 in through the cover 3 defined portion of the cavity. There she reaches the cover 3 and gives another part of the heat to this. Subsequently, the air flows through the through holes 9 back to the upper portion of the cavity defined by the luminaire housing. Through the gap 8th and the openings 9 the heat can be better distributed in the cavity and except the luminaire housing 2 also to the transparent cover 3 be delivered. In this way, a larger area of the outer surface of the lamp is available for heat dissipation.

In the illustrated embodiment, the light can be used in particular with a 50 W light source. In this case, the lamp housing can be made of plastic. Due to the bell shape of the luminaire housing 2 the heat is released over a large area of this, so that no particularly good heat conducting material such. B. aluminum is required. In this way, the production cost of the lamp can be lowered and the lamp is easier to manufacture. Further, in this embodiment, a thickness of the carrier is sufficient 5 in the area of the board between 4 mm and 8 mm, the carrier 5 made of aluminum.

In 3 a further alternative embodiment of a lamp is shown, wherein the parts corresponding to the previous embodiments with the same reference numerals are provided. The alternative embodiment differs by the carrier element 5 ' which in this case is a bulge 10 having. The bulge 10 forms a depression on the first side and an elevation on the second side. In the recess on the first page is on a circuit board 4 arranged the light source. The bulge 10 came to be adapted to the shape of the bulb. The bulge 10 can also be adapted to the shape of a light-emitting module, which comprises a separate housing in which lighting means, and optionally a circuit board, an integrated reflector and / or a transparent cover, which may also act refractive, are included. The bulb module can be replaceable in the bulge 10 be mounted, for better thermal connection between the housing of the lamp module and the bulge 10 Means for improving the thermal conductivity, z. B. a heat paste can be provided. Preferably, the bulge extends 10 as shown in the figure, in a direction over the entire cross section of the carrier 5 ' , Due to the bulge, among other things, the stability of the flat support element 5 ' elevated. Furthermore, a better thermal contact is given in the case of a positive connection of the lighting means or the lighting module.

The 4 and 5 show cross sections through two further embodiments of the carrier. In 5 is a carrier 5 '' represented, which has a bulge 10 having in cross-section so wide that it has two boards 4 or light modules can record side by side. In 5 are in the carrier 5 ''' next to each other two bulges 10 provided, which each have a board 4 or pick up a bulb module. It should be understood that the protrusions extend over preferably the entire diameter of the carrier 5 '' respectively. 5 ''' extend, as it does in 3 for the embodiment of the carrier 5 ' is shown with a bulge.

Modifications of the described embodiments are possible according to the invention. In particular, the luminaire housing and / or the cover can be trough-shaped.

LIST OF REFERENCE NUMBERS

2

luminaire housing

3

transparent cover

4

circuit board

5, 5 ', 5' ', 5' ''

carrier

6

airflow

7

separation

8th

gap

9

Through opening

10

bulge

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• WO 03/036159 A1 [0002]

Claims (15)

Luminaire, in particular interior or exterior luminaire, with a luminaire housing ( 2 ) and a transparent cover ( 3 ), which define a cavity filled with a fluid, in particular with air, wherein a cavity partially delimiting the inner side of the luminaire housing (FIG. 2 ) and wherein in the cavity a support ( 5 . 5 ' . 5 '' . 5 ''' ) is received for at least one light source, which has a first side for arranging the at least one light source and an opposite second side, wherein the carrier is arranged within the cavity such that generated by the at least one light source and by the carrier ( 5 . 5 ' . 5 '' . 5 ''' ) guided to the second side heat by convection of the fluid at least partially to the inside of the lamp housing ( 2 ) is dissipatable. Luminaire according to claim 1, wherein the luminaire housing ( 2 ) over a central area of the carrier ( 5 . 5 ' . 5 '' . 5 ''' ) a greater distance to the carrier ( 5 . 5 ' . 5 '' . 5 ''' ) than over a peripheral region of the carrier ( 5 . 5 ' . 5 '' . 5 ''' ). Luminaire according to one of the preceding claims, wherein the transparent cover ( 3 ) over a central area of the carrier ( 5 . 5 ' . 5 '' . 5 ''' ) a greater distance to the carrier ( 5 . 5 ' . 5 '' . 5 ''' ) than over a peripheral region of the carrier ( 5 ) Luminaire according to one of the preceding claims, wherein a cavity partially delimiting the inside of the transparent cover ( 3 ) over a central area of the carrier ( 5 . 5 ' . 5 '' . 5 ''' ) is curved and in particular a trough shape or a shape of a hollow spherical cutout, preferably a hemisphere. Luminaire according to one of the preceding claims, wherein the support ( 5 ) is designed as a support plate. Luminaire according to one of claims 1 to 4, wherein the carrier ( 5 ' . 5 '' . 5 ''' ) is formed flat and in particular one or more bulges ( 10 ) for receiving the bulbs on the first side. Luminaire according to one of the preceding claims, wherein the luminaire housing ( 2 ) and the cover ( 3 ) abut each other along a plane, whereby preferably the carrier ( 5 ) is arranged along the plane, or sections of the carrier ( 5 ' . 5 '' . 5 ''' ) are arranged along the plane. Luminaire according to one of the preceding claims, which further comprises one or more arranged on a board or a module lamp, in particular a group of LED and / or OLED, wherein the board or the module on the first side of the carrier ( 5 . 5 ' . 5 '' . 5 ''' ) and in thermal contact with the carrier ( 5 . 5 ' . 5 '' . 5 ''' ), in particular by means of a thermal paste, a thermally conductive adhesive or a Wärmeleitfolie is attached. Luminaire according to one of the preceding claims, wherein the support ( 5 . 5 ' . 5 '' . 5 ''' ) has a thickness between 1 mm and 20 mm, in particular between 1 mm and 12 mm, preferably between 2 mm and 10 mm and particularly preferably between 5 mm and 8 mm. Luminaire according to one of the preceding claims, wherein the support ( 5 . 5 ' . 5 '' . 5 ''' ) fills a cross section through the cavity. Luminaire according to one of claims 1 to 9, wherein between the support ( 5 . 5 ' . 5 '' . 5 ''' ) and a border of the cavity at least one gap ( 8th ) which is dimensioned to permit passage of fluid in the cavity between an area above the second side and an area above the first side of the carrier ( 5 . 5 ' . 5 '' . 5 ''' ) to allow. Luminaire according to claim 11, wherein the gap ( 8th ) one around the carrier ( 5 . 5 ' . 5 '' . 5 ''' ) is circumferential gap. Luminaire according to one of the preceding claims, wherein the support ( 5 . 5 ' . 5 '' . 5 ''' ) one or more passage openings ( 9 ) to permit passage of fluid in the cavity between an area above the second side and an area above the first side of the carrier (10). 5 . 5 ' . 5 '' . 5 ''' ) to allow. Luminaire according to one of the preceding claims, wherein the support ( 5 . 5 ' . 5 '' . 5 ''' ) within a through the lamp housing ( 2 ) defined portion of the cavity is arranged. Luminaire according to one of the preceding claims, wherein the luminaire housing ( 2 ) and the cover ( 3 ) seal the cavity to the outside.

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