Luminaire with air baffles

Abstract

lamp, having a light source (2) extending along a longitudinal axis (L) with a plurality of light emitting elements (3) arranged in a horizontal plane (E), wherein the luminaire has, with respect to the longitudinal axis (L), first through-openings (5) on a first side (re) next to the light source (2) and second through-openings (7) on a second side (li) next to the light source (2), wherein the first and second through-openings (5, 7) are designed for an air flow for cooling the light source (2), wherein the luminaire further comprises a first air guiding surface (6) on the first side (re) next to the first through-openings (5) and below the light source (2) with the light emitting elements (3) arranged in the horizontal plane (E), and a second air guiding surface (8) on the second side (li) next to the second through-openings (7) and below the light source (2) with the light emitting elements (3) arranged in the horizontal plane (E), wherein the two air guiding surfaces (6, 8) are designed in such a way that they form an air inflow region (A) which widens in a funnel shape away from the light source (2), through which air entering the air inflow region (A) from below the light source (2) with the light emitting elements (3) arranged in the horizontal plane (E) is directed to the first and second through-openings (5, 7), and wherein the first through-openings (5) and / or the first air guiding surface (6) are designed as parts of a cooling body (4) which has vertically extending cooling fins (41) on a side opposite the first air guiding surface (6).

Description

[0001] The invention relates to a luminaire with a light source and through openings formed next to the light source for an air flow to cool the light source.

[0002] Light-emitting devices such as light bulbs, fluorescent tubes, LEDs (light-emitting diodes), etc., generally generate heat in the form of heat loss when they are in a state where they emit light. Especially when a light source in a luminaire uses LEDs as light-emitting devices, it is important to ensure that this heat is effectively dissipated for reliable operation. Otherwise, this could lead to damage to the LEDs and / or unintentional changes in their radiation behavior.

[0003] To cool LEDs, heat sinks are typically used, which are connected to the LEDs with good thermal conductivity. An LED downlight with such a heat sink is known, for example, from DE 10 2010 002 235 A1. The heat sink of this downlight features vertically designed cooling fins, which give the heat sink a particularly large surface area and thus enable particularly good heat dissipation to the environment. The cooling fins extend laterally alongside the LEDs, allowing air to flow alongside the LEDs along the cooling fins, thereby forcing heat dissipation from the cooling fins to the environment.

[0004] The document US 2010 / 0097799 A1 also shows a luminaire designed to emit high light intensity. The luminaire has an upper and a lower heat dissipation plate, with the lamps and heat dissipation elements arranged between these two heat dissipation plates. The upper heat dissipation plate has a downward-facing area on the side, in which openings are provided through which heated air is intended to flow. The lower heat dissipation plate has cooling structures on the sides that complement the upper heat dissipation plate.

[0005] The document US 2011 / 0018418 A1 describes a rotationally symmetrical luminaire in the form of an LED spotlight, which has several light sources surrounded by a heat-dissipating housing, wherein the housing is designed in the form of a grid, which is intended to improve air flow and heat dissipation.

[0006] Finally, US 2010 / 0020492 A1 shows a street lighting luminaire in which several channels extend vertically through the housing of the luminaire head. Air flowing through these channels is intended to dissipate the heat generated during operation of the luminaire.

[0007] Highly effective heat dissipation is especially important when the luminaire has a very powerful light source. This is typically the case with luminaires designed to illuminate large rooms or halls, such as so-called "high bay luminaires." These luminaires are designed to be suspended at great heights, for example, approximately 12 m above the floor of a hall. There are luminaires capable of producing a luminous flux output of over 10,000 lm.

[0008] The invention is based on the object of providing a corresponding improved luminaire. In particular, the luminaire should be designed to save material and be characterized by improved thermal behavior.

[0009] This object is achieved according to the invention with the subject matter recited in the independent claim. Particular embodiments of the invention are specified in the dependent claims.

[0010] According to the invention, a luminaire is provided that has a light source with a plurality of light-emitting elements arranged in a horizontal plane. The luminaire has first through-openings on a first side adjacent to the light source and second through-openings on a second side adjacent to the light source. The first and second through-openings are configured for air flow to cool the light source.

[0011] Furthermore, the luminaire has a first air guiding surface on the first side next to the first through-openings and below the light source with the light emitting elements arranged in the horizontal plane, and a second air guiding surface on the second side next to the second through-openings and below the light source with the light emitting elements arranged in the horizontal plane, wherein the two air guiding surfaces are designed in such a way that they form an air inflow region which widens out in a funnel shape away from the light source and through which air entering the air inflow region from below is directed to the first and second through-openings. Furthermore, the first through-openings and / or the first air guiding surface are designed as parts of a heat sink, wherein the heat sink has vertically running cooling fins which are arranged on a side opposite the first air guiding surface.

[0012] The airflow area formed by the two air guide surfaces allows air to be directed particularly precisely to the through-holes. This forces airflow through the through-holes, enabling particularly intensive heat dissipation from the surfaces of the through-holes to the environment. This achieves particularly effective cooling of the light source. The design of the first through-holes and / or the first air guide surface as parts of a heat sink enables particularly good heat conduction while maintaining a simple design.

[0013] Preferably, the luminaire is designed such that the first air guide surface is directly adjacent to the first through-openings and / or the second air guide surface is directly adjacent to the second through-openings. This allows air to be directed through the air guide surfaces in a particularly targeted manner to the corresponding through-openings.

[0014] Preferably, the first air guiding surface is designed to be flat or curved, at least in a first approximation, and in particular has a first surface normal which encloses a first angle with a vertical which is between 20° and 85°, preferably between 30° and 70°, particularly preferably between 35° and 60°.

[0015] This enables particularly effective air guidance. Furthermore, the second air guide surface is preferably also designed to be flat or curved, at least to a first approximation, and in particular has a second surface normal that forms a second angle with the vertical, which is between 20° and 85°, preferably between 30° and 70°, particularly preferably between 35° and 60°. This also enables particularly effective air guidance.

[0016] Preferably, the heat sink is designed in such a way that only connecting areas are formed between the cooling fins, the surfaces of which are inclined at least 30°, preferably at least 40° relative to the horizontal, so that a possible deposition of dust or the like during operation of the lamp can be effectively reduced.

[0017] The first air guide surface and / or the second air guide surface are advantageously designed to be reflective, preferably white, in particular painted white. This allows them to act as a reflector for the light emitted by the light source. In particular, this allows the light's emission range to be influenced or limited.

[0018] Preferably, the second air-guiding surface is formed by an outer surface of a housing, wherein the housing is preferably designed to support an operating device of the luminaire. This allows the luminaire to be designed in a particularly material-saving manner while also being thermally advantageous. Furthermore, the luminaire is preferably designed in a thermally advantageous manner such that the housing has an interior space whose vertical projection extends outside the vertical projection of the light source.

[0019] The housing is designed in a profile shape, which is advantageous both thermally and in terms of manufacturing.

[0020] A particularly suitable thermal separation between the housing or the operating device located therein on the one hand and the light source on the other hand can be achieved if the housing is mechanically connected to the heat sink only via a screw connection.

[0021] Preferably, the luminaire also comprises a further light source arranged on the second side next to the housing, wherein the further light source is preferably designed analogously or structurally identically to the first-mentioned light source. The luminaire further preferably comprises a further heat sink for cooling the further light source, which is arranged on the second side next to the housing, wherein the further heat sink is preferably designed analogously or structurally identically to the first-mentioned heat sink.

[0022] A particularly high-performance and technically advantageous luminaire can be achieved if the luminaire is designed symmetrically with respect to a vertical plane of symmetry. The plane of symmetry preferably runs through the housing.

[0023] The invention is explained in more detail below using an exemplary embodiment and with reference to the drawings. They show: Fig. 1 a perspective sketch of a lamp according to the invention from below, Fig. 2 a corresponding sketch from diagonally above, Fig. 3 a view from below, Fig. 4 a cross-sectional sketch and Fig. 5 a sketch in the form of an exploded view of the structure and mounting of the light source on the heat sink.

[0024] In Fig. Figure 1 shows an embodiment of a luminaire according to the invention, sketched obliquely from below. The luminaire shown is a so-called "highbay luminaire," i.e., an indoor luminaire intended for illuminating large rooms or halls and is accordingly powerful. In the example shown, the luminaire is a pendant luminaire intended to be suspended from a ceiling on a pendulum or similar suspension element. Accordingly, the luminaire is designed to be positioned in a room in such a way that it is surrounded by ambient air on all sides.

[0025] The luminaire comprises a light source 2 with several light-emitting elements 3 in the form of LEDs. The LEDs are preferably arranged on an LED board 25.

[0026] In Fig. Figure 3 shows a view of the luminaire from below. In the example shown, the light source 2 is elongated, extending along a longitudinal axis L.

[0027] The LEDs of light source 2 are arranged in an array or matrix. In particular, light source 2 can comprise multiple LEDs, preferably more than 30 LEDs, particularly preferably more than 50 LEDs. This allows the luminaire to generate a correspondingly high luminous flux.

[0028] The LEDs extend over a horizontal LED area that has a length l along the longitudinal axis L and a width b across it. The ratio of l:b can be, for example, between 4:1 and 20:1, particularly preferably between 5:1 and 15:1.

[0029] With reference to the light source 2 or the longitudinal axis L horizontally on a first side re, here to the right of the light source 2, the luminaire has first through openings 5 ​​and on a second side li, here to the left of the light source 2, second through openings 7. In particular, the second side li is directed exactly opposite the first side re.

[0030] The first and second through-openings 5, 7 are designed for air flow to cool the light source 2. The first and second through-openings 5, 7 can be formed by slots. The first and second through-openings 5, 7 are preferably designed as nozzles that increase the velocity of the air flowing through them. This can enhance the cooling effect.

[0031] Preferably, the design is such that the first through-openings 5 ​​extend parallel to the longitudinal axis L and preferably extend over the entire length l of the LED area. In the example shown, the first through-openings 5 ​​are formed in a row, i.e., in a single row, so to speak.

[0032] Furthermore, the first through-openings 5 ​​are preferably formed virtually directly next to the light source 2; for example, it can be provided that a distance d transverse to the longitudinal axis L between the LEDs and the first through-openings 5 ​​is smaller than the width b of the LED area.

[0033] According to the invention, the first through-openings 5 ​​are designed such that air can flow through them from bottom to top. Preferably, the first through-openings 5 ​​are designed such that, viewed in a horizontal cross-section, they are closed on all sides. The design is further preferably such that - viewed in the horizontal cross-section - for each of the first through-openings 5, an inner diameter e transverse to the longitudinal axis L is smaller than the width b of the LED area. The cross-sectional shape of the first through-openings 5 ​​can, to a first approximation, be circular or rectangular, wherein in particular the ratio of an inner diameter f in the direction of the longitudinal axis L to the inner diameter e, i.e. transverse thereto, is between 0.3 and 3, particularly preferably between 0.5 and 2.

[0034] The second through-openings 7 also preferably extend parallel to the longitudinal axis L and thus almost directly adjacent to the light source 2; for example, analogously to the above, it can be provided that a further distance d' transverse to the longitudinal axis L between the LEDs and the second through-openings 7 is smaller than the width b of the LED area.

[0035] In Fig. 2 is a perspective view of the lamp sketched diagonally from above, in Fig. 4 a cross section normal to the longitudinal axis L. As in Fig. As indicated in Figure 4 and already mentioned above, the LEDs or the LED area are arranged in a horizontal plane E.

[0036] The luminaire further comprises a first air guiding surface 6 on the first side (right) next to the first through-openings 5 ​​and below the light source 2 or plane E, and a second air guiding surface 8 on the second side (left) next to the second through-openings 7 and also below the light source 2 or plane E. The two air guiding surfaces 6, 8 are designed such that they form an air flow region A that widens away from the light source 2. In particular, the two air guiding surfaces 6, 8 are designed such that they diverge in a direction away from the light source 2, in particular downwards. The air flow region A formed by the two air guiding surfaces 6, 8 is funnel-shaped - particularly when viewed in a cross-section normal to the longitudinal axis L - and narrows upwards, towards the light source 2.

[0037] The two air guide surfaces 6, 8 ensure that air entering the air flow area A from below is directed specifically to the first and second through-openings 5, 7. This significantly accelerates heat dissipation from the inner walls of the through-openings 5, 7 to the environment.

[0038] In the example shown, the two air guide surfaces 6, 8 are profile-shaped, each extending parallel to the longitudinal axis L. As in Fig. 3, the first air guide surface 8 preferably has a longitudinal extension λ in the direction of the longitudinal axis L, which is at least half as large as the length l of the LED area; preferably, the longitudinal extension λ is at least three-quarters of the length l. As can be seen from Fig. 3, in the example shown, λ, > l applies. The same applies to the corresponding longitudinal extent of the second air guide surface 8.

[0039] The first air guide surface 6 preferably has a surface area that is at least half the surface area of ​​the LED area, particularly preferably at least as large as the surface area of ​​the LED area. The same applies to the surface area of ​​the second air guide surface 8.

[0040] As in Fig. As shown in Figure 6, the first air guide surface 6 extends downwards to a level that is below the plane E by a height difference Δh, wherein this height difference Δh is preferably at least half the width b of the LED area, i.e., Δh > 0.5 b. Preferably, Δh > 0.9 b. The same applies to the second air guide surface 8.

[0041] In the example shown, the design is such that the first air guide surface 6 is directly adjacent to the first through-openings 5. This directs the air directly to the first through-openings 5. The same applies to the second air guide surface 8 and the second through-openings 7.

[0042] The first air guide surface 6 is preferably, at least in a first approximation, flat or curved, in particular concavely curved, wherein it has a first surface normal N1 that forms a first angle α with a vertical V that is between 20° and 85°. Preferably, the first angle α is between 30° and 70°, approximately 45° in the example shown. The same applies again with respect to the second air guide surface 8, which accordingly has a second surface normal N2 that forms a second, correspondingly large angle β with the vertical V.

[0043] A particularly simple design can be achieved if the first through-openings 5 ​​are designed according to the invention as parts of a heat sink 4, wherein the heat sink 4 is designed in particular for cooling the light source 2. As is known from the prior art, the heat sink 4 is connected to the light source 2 in a manner that provides good heat conduction.

[0044] In Fig. Figure 5 shows an exploded view of a slightly modified embodiment. As can be seen from this figure, the heat sink 4 preferably has a horizontal, flat, downward-facing surface 49 on which the light source 2 or the LED board 25 is arranged.

[0045] Optically following the LEDs, an optical element 27 can be provided for influencing the light emitted by the LEDs and / or a translucent cover element for protecting the LEDs. The optical element 27 or the cover element are preferably designed such that they extend toward the first side (right) at most up to the first through-openings 5 ​​and toward the second side (left) at most up to the second through-openings 7.

[0046] For the mechanical mounting of the LED board 25 and, if applicable, the optical element 27 or the cover element, a holding element 29 is preferably provided, which encompasses the aforementioned components from below. The holding element 29 preferably has locking elements 28, which are designed for mechanical connection to the heat sink 4.

[0047] In the example shown, the first air guide surface 6 is advantageously also formed by the heat sink 4. The heat sink 4 preferably consists of a single piece, i.e., is preferably made of one piece. For example, it is made of aluminum.

[0048] Furthermore, according to the invention, the heat sink 4 has cooling fins 41, in particular on a side opposite the first air guide surface 6, i.e. on the first side to the right or right of the first air guide surface 6. This makes it possible to save material by ensuring that between the cooling fins 41 the heat sink 4 only forms connecting regions with surfaces 42 that are inclined relative to the horizontal, preferably at least 30°, particularly preferably at least 40°. In the example shown - particularly saving material - the surfaces 42 to the right of the first air guide surface 6 are inclined at approximately the same angle as the first air guide surface 6, i.e. at approximately 45°. By means of appropriately inclined surfaces 42, the deposits of dust, dirt, etc. can be particularly effectively reduced during operation of the luminaire - compared to a corresponding horizontal surface design.

[0049] In the example shown, the cooling fins 41 are formed parallel to one another, in particular in planes that are oriented normal to the direction of the longitudinal axis L.

[0050] The heat sink 4 advantageously also has further, in particular vertical cooling fins 43, which are designed such that they protrude beyond the light source 2 on the first side (right) and on the second side (left) or left. A region 44 of the further cooling fins 43 protruding on the second side (left) can be designed to form the second through-openings 7, and a region protruding on the first side (right) can be designed to form the first through-openings 5. Like the first-mentioned cooling fins 41, the further cooling fins 43 in the example shown are also designed parallel to one another, in particular in planes oriented normal to the direction of the longitudinal axis L.

[0051] Preferably, the first air guide surface 6 is designed to be reflective, for example, white, in particular painted white. This advantageously influences the light output of the luminaire. In particular, depending on the inclination of the first air guide surface 6, a lateral limitation of the light output can be achieved toward the first side (right). The same applies to the second air guide surface 8 on the second side (left). In other words, this allows an angular range to be defined within which the light is emitted by the luminaire.

[0052] By designing the two air guide surfaces 6, 8 in a correspondingly white manner, it is also achieved that the luminaire, when viewed from below, shows a relatively large, brightly luminous surface through which light is emitted.

[0053] Preferably, the second air guide surface 8 is formed by an outer surface of a housing 9. The housing 9 can be designed, in particular, to support an operating device 10, for example in the form of a converter of the luminaire. In this way, it is advantageous to arrange the operating device 10 laterally next to the light source 2, here on the second side 11 next to the light source 2. This is advantageous because the operating device 10 can thereby be arranged in a manner that is virtually thermally separated from the light source 2. In particular, the design can be such that the operating device 10 is arranged outside the vertical projection of the light source 2, particularly preferably outside the vertical projection of the heat sink 4.

[0054] For this purpose, the housing 9 can have an interior space 19 whose vertical projection runs outside the projection of the light source 2.

[0055] A good thermal separation between the control gear 10 and the light source 2 is important because a control gear generally reacts relatively sensitively to high temperatures.

[0056] The thermal separation between the light source 2 and the operating device 10 is further enhanced in the example shown by the fact that the heat sink 4 is mechanically held to the housing 9 only via a quasi-point-acting connection 11, for example a screw connection. For example, only two - for example in Fig. 2 - screws 12 may be provided. For this purpose, the housing 10 preferably has a flange region 14 projecting toward the first side right, on which the connection 11 is formed, wherein the flange region 14 is located outside the vertical projection of the operating device 10 or the interior space 19.

[0057] For this purpose, the region 44 of the additional cooling fins 43 of the heat sink 4 projecting on the second side 11 is preferably designed such that—at the level of the light source 2—it does not extend all the way to the housing 10, but rather has a distance h from the latter, which is preferably between 1 mm and 10 mm. The second through-openings 7 can thus be formed, on the one hand, by the heat sink 4, more precisely, by the additional cooling fins 43 on the one hand, and the housing 9 on the other.

[0058] The flange region 14 or the connection 11 is preferably formed at a level above the plane E, in particular above the light source 2. The heat sink 4 is advantageously shaped such that it has an upwardly projecting region 45 on the second side 11, at the upper end of which the connection 11 is formed.

[0059] From a fluidic perspective, the heat sink 4 also has a further, upwardly projecting region 46 on the first side (right), which can form, in particular, an upper end region of the first through-openings 5. An upper end region of the first-mentioned cooling fins 41 can also be formed by the further, upwardly projecting region 46.

[0060] In the example shown, the heat sink 4 has a profile-shaped portion 48 which extends along the longitudinal axis L and which - viewed in a cross-section normal to the longitudinal axis L - has two legs, namely a lower leg 48' and an upper leg 48''; the lower leg 48' forms the first air guide surface 6. The upper leg 48'' extends - in particular vertically - upwards and forms the highest point of the further upwardly projecting region 46 of the heat sink 4. This results in a particularly aerodynamically advantageous design of the first through-openings 5.

[0061] The housing 9 is advantageously designed as a profile part that extends parallel to the longitudinal axis L. This enables particularly simple manufacture of the housing 9. Furthermore, this design allows the operating device 10 to be easily inserted into the housing 9 in the direction of the longitudinal axis L for installation.

[0062] A particularly powerful luminaire can be achieved if a further light source 2' is provided on the second side, left or to the left of the housing 9, preferably at the same level as the first-mentioned light source 2. In particular, the further light source 2' can be designed analogously or identically to the first-mentioned light source 2. Accordingly, the luminaire also advantageously has a further heat sink 4' for cooling the further light source 2', which heat sink is preferably designed analogously or identically to the first-mentioned heat sink 4.

[0063] Particularly preferably, the luminaire is designed symmetrically to a vertical plane of symmetry S, which runs in particular parallel to the longitudinal axis L and through the housing 9.

[0064] The luminaire can thus be constructed in a modular manner, with a central module comprising the housing 9 with the operating device 10, and an LED module with associated heat sink 4, 4' arranged on both sides, right and left, next to the central module. These modules are preferably connected to one another only via the screw connections mentioned above for mechanical support.

[0065] The luminaire according to the invention can generate luminous fluxes of more than 10,000 lm. The luminaire is also suitable, for example, for being connected to another, identically constructed luminaire, so that the two luminaires are aligned one behind the other along the longitudinal axis L. The luminous flux emitted by these two luminaires together is then correspondingly twice the luminous flux of either of them.

Claims

[1] Lamp, comprising a light source (2) extending along a longitudinal axis (L) with a plurality of light emitting elements (3) arranged in a horizontal plane (E), wherein the luminaire has, with respect to the longitudinal axis (L), first through-openings (5) on a first side (re) next to the light source (2) and second through-openings (7) on a second side (li) next to the light source (2), wherein the first and second through-openings (5, 7) are designed for an air flow for cooling the light source (2), wherein the luminaire further comprises a first air guiding surface (6) on the first side (re) next to the first through-openings (5) and below the light source (2) with the light emitting elements (3) arranged in the horizontal plane (E), and a second air guiding surface (8) on the second side (li) next to the second through-openings (7) and below the light source (2) with the light emitting elements (3) arranged in the horizontal plane (E), wherein the two air guiding surfaces (6, 8) are designed in such a way that they form an air inflow region (A) which widens in a funnel shape away from the light source (2), through which air entering the air inflow region (A) from below the light source (2) with the light emitting elements (3) arranged in the horizontal plane (E) is directed to the first and second through-openings (5, 7), and wherein the first through-openings (5) and / or the first air guiding surface (6) are designed as parts of a cooling body (4) which has vertically extending cooling fins (41) on a side opposite the first air guiding surface (6). [2] Luminaire according to claim 1, which is designed such that the first air guiding surface (6) is directly adjacent to the first through openings (5) and / or the second air guiding surface (8) is directly adjacent to the second through openings (7). [3] Luminaire according to claim 1 or 2, in which the first air guiding surface (6) is designed to be flat or curved, at least in a first approximation, and preferably has a first surface normal (N1) which encloses a first angle (α) with a vertical (V) which is between 20° and 85°, preferably between 30° and 70°, particularly preferably between 35° and 60°. [4] Luminaire according to claim 3, in which the second air guiding surface (8) is designed to be flat or curved, at least in a first approximation, and preferably has a second surface normal (N2) which encloses a second angle (β) with the vertical (V) which is between 20° and 85°, preferably between 30° and 70°, particularly preferably between 35° and 60°. [5] Luminaire according to one of the preceding claims, in which the cooling body (4) is designed such that only connecting regions are formed between the cooling fins (41), the surfaces (42) of which are inclined at least 30°, preferably at least 40°, relative to the horizontal plane (E). [6] Luminaire according to one of the preceding claims, in which the first air guiding surface (6) and / or the second air guiding surface (8) are designed to be reflective, preferably white, in particular painted white. [7] Luminaire according to one of the preceding claims, in which the second air guiding surface (8) is formed by an outer surface of a housing (9), wherein the housing (9) is preferably designed to support an operating device (10) of the luminaire. [8] Luminaire according to claim 7, which is designed such that the housing (9) has an interior space (19) whose vertical projection extends outside the vertical projection of the light source (2). [9] Luminaire according to claim 7 or 8, wherein the housing (9) is profile-shaped. [10] Luminaire according to one of claims 7 to 9, with the features mentioned in claim 5, in which the housing (9) is mechanically connected to the heat sink (4) only via a screw connection. [11] Luminaire according to one of claims 7 to 10, still exhibiting a further light source (2') which is arranged on the second side (li) next to the housing (9), wherein the further light source (2') is preferably designed analogously or identically to the first-mentioned light source (2). [12] Luminaire according to claim 11, still exhibiting a further heat sink (4') for cooling the further light source (2'), which is arranged on the second side (li) next to the housing (9), wherein the further heat sink (4') is preferably designed analogously or identically to the first-mentioned heat sink (4). [13] Luminaire according to claim 11 or 12, which is designed symmetrically with respect to a vertical plane of symmetry (S), wherein the plane of symmetry (S) preferably runs through the housing (9).

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