EP1783421A1 - Lampe - Google Patents

Abstract

The lamp has a number of LED`s (5) arranged on a plate (4) as a light source, and a heat sink (1) for cooling the LED`s. The LED`s and the heat sink are locally separated from each other. A heat transfer device (6) is arranged between the LED`s and the heat sink. A stable-form tube is provided as the heat transfer device, where electrical wires are arranged in the tube or the tube serves as electrical wire.

Description

The invention relates to a luminaire according to the preamble of claim 1.

In luminaires equipped with high-performance LEDs (so-called high-power LEDs), it is necessary to operate the LEDs as cool as possible during operation. If the resulting heat loss is not or only insufficiently dissipated, the LED suffers from power losses and in extreme cases even completely destroyed. In addition, the light spectrum changes.

In general, therefore, attempts are made to dissipate the resulting heat as quickly as possible via so-called heat sinks, namely cooling elements. These cooling elements can become very large depending on the power of the LEDs. If a passive cooling element is insufficient, it may be necessary to actively cool it (liquid cooling, fan).

These additional components for cooling the LED's are often perceived as disturbing, since they make up the size of the actual shape-forming elements of the lamp. In addition, a fan, if it is relatively close to the user, be perceived as disturbing. The actual filigree bulb, namely the LED, is thus again a fairly large, conventional-looking bulbs.

On this basis, the invention has for its object, a lamp of the aforementioned kind with an improved cooling for the LEDs to create.

The technical solution is characterized by the features in the characterizing part of claim 1.

The basic idea of the cooling according to the invention for a lamp with LEDs is to decouple the location of the heat generation from the location of the heat dissipation. It is no longer glued as usual, the heat sink directly to the LED board, but the heat sink can be mounted remotely depending on the type of luminaire at a different location, this location can be up to several meters away. Thus, the luminaire head (eg a pendant luminaire) does not require any strongly constructive elements such as heat sinks or fans, since the heat produced in the area of the ceiling can be dissipated in the abovementioned pendant luminaires. The heat transfer device thus serves both the heat conduction and as a holder for the lamp head. Thus, the advantage of the invention is that the heat generated at the light source dissipated and the cooling is performed at a remote location. The heat can be dissipated at almost any location.

A preferred development proposes as a heat transfer device according to claim 2 at least one rod-shaped tube in which a heat transfer medium is located. This tube is a so-called heat pipe. This heat pipe can be located in an outer cladding tube. The heat transfer via these so-called heat pipes means that one or more tube-like structures are available, via which the heat loss to the actual heat sink can be derived. The heat pipes are brought at one end in contact with the heat produced by the LED's, so that then transported away from there through the heat pipe through the heat and the cooling element is supplied. The basic principle of these heat pipes is that at one end the heat pipe defines a heating zone to which the heat of the LEDs is supplied. Within the heat pipe, the evaporation of a medium takes place, so that a vapor stream is formed in capillaries, this vapor stream is supplied by the capillary action to the other end, namely the cooling zone of the heat pipe. Here is a condensation of the steam, which is accompanied by a radiation of heat. The capillary action then causes a reflux of the - again - liquid condensate in corresponding capillaries, so that then a new heat exchange cycle can begin.

The development according to claim 3 has the advantage that the heat is distributed over larger areas. This improves the heat transfer.

The development in claim 4 has the advantage that the heat pipe is also the electric power transmission. For this purpose, in addition to the heat pipe, electrical leads for the voltage supply of the LEDs can preferably run in a cladding tube. At low voltages, the heat pipe can also act as a live element.

In lights with a movable head, the heat pipes can be provided with flexible, bendable sections according to the embodiment in claim 5.

In addition to the above-described heat transfer through the heat pipes, these heat pipes can also be assigned additional functions at the same time. In addition to the dissipation of heat from the LED board to the heat sink, the heat pipe according to claim 6 can serve for suspension of a pendant lamp or according to claim 7 for attaching a lamp. Thus, the lamp head, for example, a pendant lamp comes without strong constituent elements such as heatsinks or fans, since the heat generated in the ceiling can be dissipated. As stated, the heat pipe serves at the same time as a heat pipe and as a pendulum tube. Suspended ceilings can accommodate both the heat sink and a fan or liquid cooling above the ceiling.

In cantilever or table lamps can be used as a cantilever and at the same time as current-carrying elements in the development in claim 7, the heatpipes.

Finally, the development proposes according to claim 8, that the cooling body is associated with a fan. A fan is used when additional active cooling is required. A powerful fan can be accommodated discreetly in a canopy-like enclosure below the ceiling.

Fig. 1a

eine perspektivische Ansicht einer Pendelleuchte;

Fig. 1b

einen Längsschnitt durch die Pendelleuchte in Fig. 1a;

Fig. 1c

eine Draufsicht auf den Kühlkörper der Pendelleuchte in Fig. 1a und 1b;

Fig. 2

eine Prinzipskizze der sogenannten Heatpipe, wie sie bei der Pendelleuchte in Fig. 1a bis 1c verwendet wird;

Fig. 3

eine perspektivische Ansicht einer Auslegerleuchte;

Fig. 4

eine perspektivische Ansicht einer Tischleuchte.

Three embodiments of a luminaire according to the invention are described below with reference to the drawings. In these shows:

Fig. 1a

a perspective view of a pendant lamp;

Fig. 1b

a longitudinal section through the pendant lamp in Fig. 1a;

Fig. 1c

a plan view of the heat sink of the pendant lamp in Fig. 1a and 1b;

Fig. 2

a schematic diagram of the so-called heat pipe, as used in the pendant lamp in Fig. 1a to 1c;

Fig. 3

a perspective view of a cantilever lamp;

Fig. 4

a perspective view of a table lamp.

The lamp shown in Figs. 1a to 1c is a pendant lamp, which is suspended from a ceiling.

The upper area of the pendant lamp has, in addition to a suspension device, a heat sink 1 made of radial lamellae. In this heat sink 1, a fan 2 is integrated. The central lower region of the heat sink 1 has a heat chamber 3, which - as will be explained later - should distribute the heat over a larger area.

The lower end of the lamp has a board 4 with LEDs 5 on. Again, a heat chamber 3 is provided above the board 4 for distributing the heat to a larger area.

Between the upper heat sink 1 and the lower board 4 with the LEDs 5 there is a heat transfer device 6, which is to transport the heat that is produced by the LED's 5 to the heat sink 1. The heat transfer device 6 is formed by a tube 7 of a so-called heat pipe. The tube 7 is located in an outer cladding. 8

The operation of the heat transfer device 6 is as follows with reference to FIG. 2:

Heat is generated by the LEDs 5, which collects in the heat chamber 3. In this heat chamber 3, the lower end of the tube 7 of the heat pipe dives. This heat pipe consists of a plurality of capillaries 9, which are arranged longitudinally in the tube 7 made of copper. In addition, located in the tube 7, a heat transport medium.

By indicated in Fig. 2 heat 10, which acts on the lower end of the tube 7, an evaporation of the medium located in the tube 7 takes place. From a physical point of view, the evaporation of a liquid medium requires energy and therefore leads to a cooling effect. The evaporation creates a vapor stream which is transported along the capillary 9 very quickly to the other end of the tube 7 of the heat pipe. There, by condensation, a heat release 11, which is discharged via the heat sink 1 and the fan 2 to the ambient air. The now again liquid condensate flows back through the capillary action of the capillary 9, so that a new cooling circuit can begin.

Fig. 3 shows a lamp in the form of a cantilever lamp. Again, a lamp head 12 is provided with a board 4 with LEDs 5. The other end of the lamp is formed by a heat sink 1. Between the lamp head 2 and the heat sink 1, the tube 7 is a heat pipe, said tube 7 also serves as a boom arm of the lamp.

The operation of this cantilever lamp is according to the pendant lamp, as has been previously described. Ie. the resulting heat in the lamp head 12 is supplied via the heat pipe to the heat sink 1.

Fig. 4 finally shows a table lamp with a lamp head 12 and a pedestal 13. Between the lamp head 12 and the pedestal 13, two tubes 7 a heat pipe are provided. These two heatpipes are used for heat dissipation and as a boom arm. An additional function is as the current-carrying elements for the power supply of the LED's 5. At the rear end of the two tubes 7 is the heat sink. 1

LIST OF REFERENCE NUMBERS

1

heatsink

2

fan

3

warming room

4

circuit board

5

LED's

6

Heat transfer device

7

pipe

8th

cladding tube

9

capillary

10

heat supply

11

heat

12

lamp head

13

pedestal

Claims (8)

lamp
with a plurality of on a circuit board (4) arranged LED's (5) as a light source and
with a cooling body (1) associated with the LEDs (5) for cooling the LEDs (5),
characterized,
that the LEDs (5) and the heat sink (1) are spatially separated from each other and
in that a heat transfer device (6) is arranged between the LEDs (5) and the heat sink (1). Luminaire according to the preceding claim,
characterized,
in that at least one rod-shaped tube (7), in which there is a longitudinally circulating heat transfer medium, is provided as the heat transfer device (6). Luminaire according to one of the preceding claims,
characterized,
that either the one end or both ends of the tube (7) each immersed in an associated heat chamber (3), which is associated with the LED's (5) and / or the heat sink (1). Luminaire according to one of the preceding claims,
characterized,
that in the tube (7) electrical lines are arranged or
that the tube (7) serves as an electrical conductor. Luminaire according to one of the preceding claims,
characterized,
that the tube (7) is bendable. Luminaire according to one of claims 2 to 5,
characterized,
that the tube (7) serves as a suspension device for a pendant lamp. Luminaire according to one of claims 2 to 5,
characterized,
that the tube (7) serves as a boom arm for a cantilever lamp. Luminaire according to one of the preceding claims,
characterized,
that the cooling body (1) is associated with a fan (2).

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