DE102019200779A1 - Luminaire with a heat sink - Google Patents

Abstract

The invention relates to a lamp (10) with an LED unit (50), at least one optics unit (70), a heat sink (20) and a housing (40). According to the invention, the housing (40) is designed like a trough, the heat sink (20) extending along the longitudinal axis (11) with a constant cross-sectional shape, and having a central section (21) which is transverse to the longitudinal axis between two lateral sections (22) is arranged, the middle section (21) forming a substantially flat contact surface (23) which faces away from the housing (40), the LED unit (50) being fastened to the contact surface (23), the lateral sections (22) each have at least one first web (25), which is oriented substantially perpendicular to the contact surface, being formed in one piece with the central section (21), the first webs (25) each having a first free end (24) of the heat sink (20), which points towards the housing (40), the LED unit (50) and / or the at least one optical unit (70) of the two side sections (22) and the middle section ( 21) is embraced in a U-shape.

Description

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

From the US 7 198 387 B1 a lamp is known which uses LEDs (light emitting diodes) as illuminants. For the purpose of dissipating the waste heat generated in the LEDs, the entire housing is designed in the manner of a heat sink, it having cooling fins.

An LED unit is available from the data sheet, which was available on January 9, 2019 at the Internet address https://www.vossloh-schwabe.com/uploads/tx sbdownloader / LED-Line-SMD-Kit 3R-G DE.pdf known, which each comprises a plurality of LEDs. An optical unit is assigned to the LED unit, which influences the light emitted by the LEDs.

Tub lights for fluorescent tubes are also known, examples being those US 7 083 308 B2 is referred.

An advantage of the present invention is that the luminaire according to the invention can be used as a replacement for the known bath luminaires, which has essentially the same dimensions as a known bath luminaire. The lamp according to the invention is extremely simple. In addition to the above Electronic or lighting components available on the market include only two other components, namely the housing and the heat sink. These two parts are particularly material-saving and therefore inexpensive. The heat sink can be attached to the housing in a particularly simple manner, preferably using only two screws. Nevertheless, the entire lamp is stable in itself. In particular, no deformation of the heat sink due to its own weight can be observed.

According to the independent claim, it is proposed that the housing be trough-shaped, wherein it extends along a longitudinal axis, wherein it has a U-shaped cross-sectional shape with a base and two U-legs in a central region with respect to the longitudinal axis, the heat sink extends with a constant cross-sectional shape along the longitudinal axis, wherein it has a central section which is arranged transversely to the longitudinal axis between two lateral sections, the central section forming a substantially flat contact surface which faces away from the housing, the LED unit on is attached to the contact surface, the lateral sections each having at least one first web, which is aligned substantially perpendicular to the contact surface, wherein it is formed in one piece with the central section, the first webs each forming a first free end of the heat sink, which for Housing indicates wherein the U-legs of the housing each have a second free end, which points towards the heat sink, wherein it rests on an assigned first free end, the LED unit and / or the at least one optical unit from the two lateral sections and the middle section is U-shaped. The housing is therefore similar to the housing of a known bath light. The unit consisting of the heat sink, LED unit and optics unit can be attached to the housing in a similar way to the cover of a known bath light. Due to the high rigidity of the unit mentioned, only very few fastening elements are required for this, preferably only two.

The housing preferably has a constant cross-sectional shape in the central region. The first web primarily serves to increase the surface moment 2nd . Degree of the heat sink with respect to the longitudinal axis. The entire heat sink is preferably formed in one piece. The optical unit can be composed of several optical sub-units, which are assigned to different sections of the LED unit. The parts of the optical unit are preferably attached to the LED unit and / or the heat sink. The LED unit can be composed of several assemblies, preferably comprising a single assembly. The modules mentioned are preferably attached directly to the heat sink. The U-legs are preferably aligned perpendicular to the base. The lateral sections of the heat sink are preferably mirror-symmetrical to one another. The middle section of the heat sink is preferably designed in the form of a flat plate with a constant thickness. The heat sink is preferably made of sheet metal. The first and / or the second free end preferably run parallel to the longitudinal axis. The first free ends preferably lie laterally on the respectively assigned second free end. The first free ends of the heat sink and the second free ends of the first U-legs are preferably flat in the area of the system mentioned. The at least one optics unit is preferably detachably connected to the LED unit, the parts mentioned being most preferably screwed together with the heat sink.

Advantageous further developments and improvements of the invention are specified in the dependent claims.

It can be provided that the two lateral sections each comprise a second web, which is oriented perpendicular to the contact surface, it being arranged between the assigned first web and the contact surface, the second web directly adjacent to the contact surface. The second web is preferably formed in one piece with the first web and the central section. It also serves to increase the bending stiffness of the heat sink. It is further achieved with the second web that the lateral sections of the heat sink comprise the LED and the optics unit in a U-shape, the first free ends of the first webs simultaneously pointing towards the housing.

It can be provided that the first and the associated second web are connected to one another in one piece via a connecting section, so that together they form a U-shape. In this way, the heat sink can be realized in a cost-effective manner as a bent sheet metal part. In the corners of the U-shape mentioned, the sheet is preferably bent along a line parallel to the longitudinal axis. The heat sink is preferably made of aluminum. It is preferably formed by several bends from a flat plate with a constant thickness. It is also conceivable to produce the heat sink using the extrusion process. The connecting section is preferably arranged approximately in one plane with a light-emitting surface of the optical unit, and it is most preferably somewhat recessed.

It can be provided that the cross-sectional shape of the heat sink has an essentially constant thickness everywhere.

It can be provided that the second free ends of the U-legs are each provided with a bead, against which in each case an associated first free end of the heat sink rests in such a way that the surfaces of the heat sink and the first U-leg pointing towards the surroundings there are arranged to escape. This prevents dirt and / or moisture from accumulating at the corresponding joint.

It can be provided that the heat sink is attached to the housing only at its two ends pointing away from one another with respect to the longitudinal axis. The heat sink is preferably screwed to the housing there. Preferably, vertically bent fastening tabs are provided in one piece on the heat sink, which directly adjoin the central section. A separate contact disk is preferably arranged between the fastening tabs mentioned and the housing, which reliably establishes an electrically conductive contact between the housing and the heat sink. The contact disk is preferably penetrated by a screw bolt, which also passes through the fastening tab.

It can be provided that the U-shaped cross-sectional shape of the housing is covered with an end plate at both ends of the housing pointing away from one another in the direction of the longitudinal axis, the heat sink being attached exclusively to the two end plates. The end plates are preferably formed in one piece with the remaining housing. The housing can be made by bending from a flat plate with a constant thickness, whereby it is provided at its two edges facing away from each other transversely to the longitudinal axis, each with a bend which forms a first U-leg, while at both of them with respect to the longitudinal axis Ends pointing away from each other are each provided with a bend which forms an end plate, the end plates respectively adjoining both U-legs essentially without a gap. The end plates are preferably firmly connected to the U-legs by means of blind rivets. For this purpose, bent fastening tabs are preferably provided in one piece on the end plates. The housing is preferably made of sheet metal. It is preferably made of steel, which is most preferably painted. The housing can also be made of plastic by injection molding.

It can be provided that the housing, together with the heat sink, encloses a substantially closed cavity, wherein a power supply unit to which the LED unit is electrically connected is arranged in the cavity. The power supply unit is preferably attached to the first base of the housing. The power supply unit is preferably designed in the manner of a constant current driver. The LEDs, which are preferably connected in series, are consequently all supplied with a fixed predetermined current, the voltage at the individual LEDs being adjusted accordingly.

It can be provided that the heat sink consists of aluminum, the housing made of steel or plastic. A heat sink made of aluminum dissipates the waste heat of the LEDs particularly well. The proposed materials for the housing are particularly inexpensive.

It can be provided that the LED unit comprises a circuit board on which a multiplicity of separate LEDs are arranged, the circuit board being fastened to the central section of the heat sink, the optical unit in the area of the LEDs each having a funnel-like reflector which is covered by a transparent or translucent material. The material mentioned is preferably a plastic, most preferably polymethyl methacrylate (PMMA; also called acrylic glass). The circuit board and / or the optical unit is preferably screwed to the heat sink. The LEDs are preferably arranged in a grid pattern on the circuit board.

It goes without saying that the features mentioned above and those yet to be explained below can be used not only in the combination specified in each case, but also in other combinations or on their own without departing from the scope of the present invention.

• 1 eine Explosionsansicht einer erfindungsgemäßen Leuchte; und
• 2 einen Querschnitt der Leuchte nach 1.

The invention is explained in more detail below with reference to the accompanying drawings. It shows:

• 1 an exploded view of a lamp according to the invention; and
• 2nd a cross section of the lamp 1 .

1 shows an exploded view of a lamp according to the invention 10th . The lamp 10th is shown in a position in which the housing 40 is below. This position is during the assembly of the lamp 10th advantageous. The housing is in operation 40 typically arranged at the top, for example being fastened to the basic structure of an assembly work station in order to illuminate a work area.

The housing 40 is in the form of a bent sheet metal part, which is made of sheet steel. But it can also be injection molded from plastic. It is also conceivable that the housing has a base body made of an extruded aluminum profile, the end plates 45 are formed as separate parts which are firmly connected to the base body.

In all of the cases mentioned, the housing is 40 trough-shaped. In a central area, it extends with a constant cross-sectional shape along a longitudinal axis 11 . The middle area takes up almost the entire length of the housing 40 a. At the two ends of the housing pointing away from each other in the direction of the longitudinal axis 40 is an end plate 45 provided which is perpendicular to the longitudinal axis 11 is aligned. The mentioned cross-sectional shape of the housing 40 is U-shaped with a base (no. 41 in 2nd ) and two U-legs (No. 42 in 2nd ) educated. The housing is preferably 40 executed as a bent sheet metal part. The raw part is accordingly a flat plate of constant thickness, the border of which is cut in a unified manner, for example by means of punching or laser beam cutting. The U-legs and the end plate 45 are each formed by an assigned 90 ° bend. The end plates 45 are preferably each using blind rivets 47 firmly connected to the two U-legs. For this purpose there is preferably a bent fastening tab 46 in one piece on the end plate 45 intended.

At the base of the U-shape is a power supply unit 60 attached, especially screwed. The power supply unit 60 is via the external connection cable 61 connectable to the 230V AC network. It is preferably designed as a constant current driver, which uses one of the AC alternating voltage to operate the LEDs 51 generates suitable direct current with a given current. The protective conductor must be pointed out 62 , over which all metallic parts of the lamp 10th that can be touched from the outside are electrically connected to the protective conductor of the mains supply.

Next is a heat sink 20 provided, which consists of aluminum, wherein it is preferably designed as a bent sheet metal part. The heat sink 20 forms a flat contact surface 23 which are parallel to the longitudinal axis 11 extends. At the of the housing 40 facing contact surface 23 there is an LED unit 50 immediately so that the there in the LED's 51 (light emitting diodes) can be released to the environment with low thermal conductivity. The LED unit 50 is from an optics unit 70 covered. The optics unit 70 is preferably designed so that it is punctiform from the LEDs 51 emitted light is distributed uniformly in the room without the user of the room from the very bright LEDs 51 be dazzled when they go directly to the lamp 10th see.

The optics unit 70 is together with the LED unit 50 using bolts 73 on the heat sink 20 attached. In the present case, the optics unit comprises 70 two optical subunits that are identical to each other 72 . Depending on the length of the lamp 10th will be a suitable number of optics subunits 72 selected. The LED unit 50 in the present case comprises a single circuit board 52 , which with a variety of grid-like arranged LEDs 51 is provided. The LEDs are preferably connected in series, any combination of series and parallel connection being conceivable. The board is with two connection sockets 54 Mistake. The one connection socket 54 is over the first connection cable 53 electrically to the power supply unit 60 connected. The other connection socket 54 is here with a second connection cable 55 short-circuited. There, other identically designed LED units can be connected to one another 1 to realize longer lamp. On the two in the direction of the longitudinal axis 11 Ends pointing away from each other are the optical units 70 with separate end plates 75 closed on the front.

The heat sink 20 is only on its in the direction of the longitudinal axis 11 ends pointing away from each other firmly with the housing 40 connected. There is a fastening tab there 28 on the heat sink 20 provided in one piece, via which it with an associated end plate 45 of the housing 40 is screwed. Between the mounting tab 28 and the end plate 45 is a contact disc 29 arranged, via which a reliable electrical connection between the housing 40 and heat sink 20 will be produced. Beyond this screw connection 30th the heat sink is only frictionally attached to the housing 40 on, in the context of the present invention even a difficult to produce locking engagement can be dispensed with.

2nd shows a cross section of the lamp 10th to 1 . The heat sink 20 includes a middle section 21 , which is transverse to the longitudinal axis between two lateral sections 22 is arranged. The middle section 21 is from the flat contact surface 23 defines at which the LED unit 50 and the optics unit 70 are attached. The investment area 23 points from the housing 40 away so the light of the LED's 51 is emitted to the outside. The two side sections 22 serve to stiffen the heat sink 20 against bending deformation. They are therefore perpendicular to the contact surface 23 executed significantly higher than the middle section 21 . As a result, the side sections 22 a significantly higher area torque 2nd . Degrees than the middle section 21 . In addition, the two side sections summarize 22 and the contact surface the LED unit 50 and the optics unit in a U-shape, so that the overall result is a compact and rigid unit that can be easily and quickly attached to the housing 40 can be attached. Despite the only two fastening points on the end, no noticeable bending deformation can be determined on this assembly due to the weight of the assembly.

The side sections 22 each comprise a first and a second web 25th ; 26 which are perpendicular to the contact surface 23 are aligned. The two bridges 25th ; 26 are via a connecting section 27 , which is essentially parallel to the contact surface 23 is aligned, integrally connected to one another, so that there is a U-shape. At that of the connecting section 27 the opposite end is the second web 26 integral with the middle section 21 connected so that it is the optics unit 70 faces directly to the side. The first footbridge 25th points to that of the connecting section 27 opposite end a first free end 24th on the outside at a second free end 43 an assigned U-leg 42 of the basic body 40 is present. The second free end 43 is with a bead 44 or a recess, so that the outer surfaces of the heat sink 20 and housing 40 are arranged in alignment in the area of mutual contact.

The optics unit 70 includes for each LED 51 a funnel-shaped reflector 71 . Next is a plate-like cover 76 made of transparent or translucent material.

Reference list

10th

lamp

11

Longitudinal axis

12th

cavity

20

Heatsink

21

middle section

22

side section

23

Contact surface

24th

first free end

25th

first footbridge

26

second web

27

Connecting section

28

Mounting tab

29

Contact washer

30th

Bolts

40

casing

41

Base

42

U-leg

43

second free end

44

Surround

45

End plate

46

Mounting tab

47

Blind rivet

50

LED unit

51

LED

52

circuit board

53

first connection cable

54

Connection socket

55

second connection cable

60

Power supply unit

61

Connection cable

62

Protective conductor

70

Optics unit

71

reflector

72

Optics subunit

73

Bolts

75

End plate

76

cover

QUOTES INCLUDE IN THE DESCRIPTION

This list of documents listed by the applicant has been generated automatically and is only included 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.

Patent literature cited

• US 7198387 B1 [0002]
• US 7083308 B2 [0004]

Claims (10)

Luminaire (10) with an LED unit (50), at least one optics unit (70), a heat sink (20) and a housing (40), the LED unit (50) comprising a plurality of separate LEDs (51), it being attached to the heat sink (20) in such a way that waste heat from the LEDs (51) can be dissipated at least indirectly to the surroundings via the heat sink (20), the optical unit (70) being connected to the LED unit (50) in this way is connected in that it influences the light that can be emitted by the LEDs (51), characterized in that the housing (40) is trough-shaped, it extends along a longitudinal axis (11), in one with respect to the longitudinal axis (11) middle region has a U-shaped cross-sectional shape with a base (41) and two U-legs (42), the heat sink (20) with a constant cross-sectional shape extending along the longitudinal axis (11), wherein it has a central portion (21) which is transverse to the longitudinal axis between two lateral sections (2nd 2) is arranged, the middle section (21) forming a substantially flat contact surface (23) which faces away from the housing (40), the LED unit (50) being fastened to the contact surface (23), the lateral sections (22) each have at least one first web (25), which is oriented essentially perpendicular to the contact surface, being formed in one piece with the central section (21), the first webs (25) each having a first free end ( 24) of the heat sink (20) which faces the housing (40), the U-legs (42) of the housing each having a second free end (43) which faces the heat sink (20), whereby it an associated first free end (24) abuts, the LED unit (50) and / or the at least one optical unit (70) being encompassed in a U-shape by the two lateral sections (22) and the central section (21) . Luminaire according to one of the preceding claims, characterized in that the two lateral sections (22) each comprise a second web (26) which is oriented perpendicular to the contact surface (23), being between the assigned first web (25) and the contact surface (23) is arranged, the second web (26) directly adjoining the contact surface (23). Afterglow Claim 2 , wherein the first and the associated second web (25; 26) are integrally connected to one another via a connecting section (27), so that together they form a U-shape. Luminaire according to one of the preceding claims, wherein the cross-sectional shape of the heat sink (20) has a substantially constant thickness everywhere. Luminaire according to one of the preceding claims, wherein the second free ends (43) of the U-legs (42) are each provided with a bead (44), against which an associated first free end (24) of the heat sink (20) rests in this way that the surfaces of the heat sink (20) and the first U-leg (42) facing the surroundings are arranged in alignment. Luminaire according to one of the preceding claims, wherein the heat sink (20) is attached to the housing (40) exclusively at its two ends pointing away from one another with respect to the longitudinal axis (11). Luminaire according to one of the preceding claims, wherein the U-shaped cross-sectional shape of the housing (40) is covered at both ends of the housing (40) pointing away from one another in the direction of the longitudinal axis (11) with an end plate (45), the heat sink (20 ) is only attached to the two end plates (45). Luminaire according to one of the preceding claims, wherein the housing (40) together with the heat sink (20) encloses a substantially closed cavity (12), wherein in the cavity (12) a power supply unit (60) is arranged to which the LED Unit (50) is electrically connected. Luminaire according to one of the preceding claims, wherein the heat sink (20) consists of aluminum, the housing (40) made of steel or plastic. Luminaire according to one of the preceding claims, wherein the LED unit (50) comprises a circuit board (52) on which a plurality of separate LEDs (51) is arranged, the circuit board (52) at the central portion of the heat sink (20) is attached, the optical unit (70) in the area of the LEDs (51) each having a funnel-like reflector (71) which is covered by a transparent or translucent material.

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