EP1915569B1 - Cooling system for a projector - Google Patents

Description

The invention relates to a cooling system for a headlight.

From the WO 2004/029 507 A1 a headlamp is known, which consists of a lamp housing or a one-sided or two-capped light source, which consists of a lamp or a burner, for example a discharge lamp in the form of a metal halide lamp, and a reflector, that of the light source emitted light reflected in the direction of a front opening of the headlamp housing, which is closed by a transparent cover, such as a protective glass or lens disk.

1. a) die Wärmestrahlung wird von den die Lichtquelle umgebenden Bauteilen wie Reflektor, Lichtquellensockel und Zuleitungen zur Lichtquelle sowie vom Scheinwerfergehäuse teilweise absorbiert, die dadurch in ihren Materialeigenschaften negativ beeinflusst werden und selbst als sekundäre Wärmequelle wirken,
2. b) über die elektrischen Kontakte und über den Keramikkörper des Lichtquellensockels findet eine Wärmeleitung statt und
3. c) die Umgebungsluft der Lichtquelle wird aufgeheizt, steigt nach oben und zieht in einem konvektiven Kühlungsprozess kühlere Luft von unten nach.

In addition to the emission of visible light rays, a burning light source generates in its arc or in its filament also in the infrared spectral range invisible heat radiation which is emitted by the following three processes to the environment of the light source:

1. a) the thermal radiation is partially absorbed by the components surrounding the light source such as reflector, light source socket and supply lines to the light source as well as the headlamp housing, which are thereby adversely affected in their material properties and even act as a secondary heat source,
2. b) via the electrical contacts and the ceramic body of the light source socket heat conduction takes place and
3. c) the ambient air of the light source is heated, rises and draws cooler air from below in a convective cooling process.

To support the latter process and to create a headlamp of great light performance with a compact design, this consists of the WO 2004/029 507 A1 known headlight housing of an upper, cylindrical headlight housing part and a lower, cuboid-shaped headlight housing part, are arranged on the ventilation shafts with separate ventilation channels. The ventilation channels are separated by lamellae, which have within the ventilation shaft adjacent to the air inlet openings first fin section and adjacent to the air outlet openings second, opposite the first fin section slit section.

From the US 5,172,975 A is a headlight with a light source, a reflector and a light exit opening in a cylindrical headlight housing known, are also formed on the convective cooling of the environment of the heat-emitting light source circumferential, limited by fins ventilation channels. The slats are bent outside of the cylindrical headlight housing and crimped at their ends, so that on the one hand avoided the leakage of light from the interior of the headlight housing and on the other hand, the air flow is directed perpendicularly away from the headlight housing.

From the US 1 758 290 A is a headlight housing with arranged on the housing walls ventilation ducts with separate ventilation ducts, which are separated by lamellae, so that there are uniform ventilation ducts, flows through the cooling air into the interior of the spotlight housing. The protruding into the interior of the headlight housing ends of the lamellae above and below the optical axis of the headlight are again bent in opposite directions, so that the ends of the above the optical axis arranged lamellae are directed to the bottom of the headlight housing, while the below the optical axis arranged ends of the slats directed to the top of the headlight housing and both sections are interconnected in a central horizontal part, so that an improved cooling air circulation is achieved by the headlight housing by the different orientation of the located inside the headlight housing ends of the slats.

In addition to the heat radiation emitted by the light source is also of other electrical and electronic components such as an ignitor and the electrical Supply lines heat to the interior of the headlamp housing, which is also dissipated by a convective cooling process.

Another problem with heat dissipation from a headlamp housing is that when the headlamp is tilted in relation to the horizontal, the convective air flow is directed to higher parts of the headlamp housing, making it easy for local overheating and consequent damage or destruction of components can come.

In order to give the convective air flow sufficient space and dissipate the heated air better to the environment of the headlamp, the headlamp housing known headlamps are designed voluminous and heavily ribbed on its outer surface to increase the heat-emitting housing surface.

Object of the present invention is to provide a cooling system for a headlamp of the type mentioned, which dissipates the output of a light source and other components of the headlamp even with horizontally inclined headlight with maximum effect with minimal housing dimensions and located inside the headlight housing Cools components effectively.

This object is achieved by the features of claim 1.

The solution according to the invention makes use of both a convective air flow in the interior of the headlight housing and a convection flow extending around the headlight housing and a cooling air flow directed perpendicularly or transversely at least to the convection flow flowing around the headlight housing. While the inner convective flow receives the heat emitted by the light source and the heat generating components, rises and trailing cooler air from below, the convection flow flowing around the headlight housing causes cooling of the headlight housing. The cooling air flow running transversely to these flows carries the heat load in the convection flow partly and in particular even when the headlamp is operated inclined relative to the horizontal.

Another advantage of the solution according to the invention is that the cooling air flow surrounding the convective air flows is significantly cooler than the convective air flows, so that the cooling system according to the invention also ensures improved contact protection.

Accordingly, the cooling system for a headlamp for dissipating the output from a light source and / or optical or current-carrying electrical and electronic components in a headlight housing with a lamp housing and a bottom pan heat with a guided inside the bottom trough and the lamp housing of the headlight housing first convection flow through a first Cooling device for a second convection flow flowing around the lamp housing at least partially in the circumferential direction and a second cooling device for a cooling air flow directed essentially perpendicular to the second convection flow and running parallel to the optical axis of the headlight.

An advantageous embodiment of the solution according to the invention is characterized in that the first cooling device comprises a arranged in the lamp housing sheath current sheet in the interior of the first convection flow is guided and flows around the second Konvektionsströmung, while the second cooling device consists of cooling channels, which are parallel to the optical Axis of the headlamp extending around the sheath current plate and are arranged at a radial distance to the sheath current plate in the lamp housing and the cooling air flow in the longitudinal direction of the headlight housing, wherein the cooling channels are arranged at a small radial distance from the sheath flow sheet and the second convection flow formed by the between the sheath flow sheet and the cooling channels Gap runs.

By arranging a jacket flow sheet, the convection flows and the cooling air flow are deliberately guided, which is strengthened by the formation of a gap between the sheath flow sheet and arranged at a small radial distance to the sheath flow cooling ducts guided around the sheath flow convection and emits a portion of the heat load to the cooling channels ,

Preferably, in the direction of gravity opposite upper portion of the Mantelstromblechs first openings are arranged, which serve the heat removal from the inner convection flow to the outer convection flow or the cooling channels and the environment.

Furthermore, between the substantially parallel to the optical axis extending cooling channels second openings for the passage of the convection flow can be provided, which serve to dissipate the heated air to the environment.

In order to ensure the discharge of the heated air to the environment over the entire length of the headlamp, according to a further feature of the invention, the second openings are formed parallel to the optical axis of the headlamp extending continuously from the front to the back of the headlight housing.

An advantageous development of the invention is characterized in that a plurality of distributed over the circumference of the headlight housing second openings are provided so that the heat dissipated by the convection flow heat to no strong heating of the headlight housing against the gravitational direction, ie from bottom to top.

In order to prevent leakage of stray light from the headlight housing, the first and second openings are arranged offset from one another in the circumferential direction of the headlight housing.

Preferably, the cooling channels form cooling channel openings at the front and rear of the headlight housing, so that a cooling air flow is generated, which is amplified in one or the other direction with a tilt of the headlight and provides for effective heat dissipation, especially in these critical operating conditions of the headlamp.

To increase the heat dissipation, the sheath sheet can be painted with a heat-resistant black lacquer and made of an aluminum casting or die-cast alloy consist. Alternatively, the sheath current sheet may be provided with a low reflection coefficient ceramic coating preferably deposited in a plasma chemical refining process.

By producing a firmly adhering oxide ceramic-metal compound on the sheath sheet a high heat resistance, in particular the low reflection coefficient having coloring of the sheath current sheet is achieved, which does not peel off even under the effect of heat in the long term.

In one embodiment of the solution according to the invention, the headlight housing consists of a substantially cylindrical lamp housing, in which a light source and a reflector are arranged, which reflects the light beams emitted by the light source to a light exit opening of the lamp housing, which is covered with a translucent disc, and a arranged in the direction of gravity below the lamp housing substantially rectangular or polygonal base pan, are arranged in the electrical and electronic components, such as an ignitor, cable feeds and the like, wherein the lamp housing comprises the sheath current sheet and the cooling channels, the bottom pan has air inlet openings for cooling air and in the Bottom pan heated air is directed into the interior of the sheath flow plate of the above the bottom pan arranged lamp housing.

This embodiment of the solution according to the invention ensures an optimized convection flow for dissipating the heat emitted by the electrical and electronic components in the floor pan and the radiant heat emitted by the light source in the lamp housing even with a relative to the horizontal tilted headlights and allows a headlight housing with minimal dimensions at the same time improved contact protection.

Fig. 1

eine perspektivische Frontseitenansicht eines Scheinwerfers für Bühnen-, Studio-, Film-, Fernseh- und Eventbeleuchtung mit einem erfindungsgemäßen Kreuzstrom-Kühlsystem;

Fig. 2

eine perspektivische Rückseitenansicht des Scheinwerfers gemäß Fig. 1;

Fig. 3

einen Querschnitt durch den Scheinwerfer gemäß den Fig. 1 und 2;

Fig. 4

eine Vorderansicht des Scheinwerfergehäuses gemäß den Fig. 1 bis 3;

Fig. 5

einen Längsschnitt durch den das Scheinwerfergehäuse entlang der Linie V-V gemäß Fig. 4 und

Fig. 6

einen Querschnitt durch das Scheinwerfergehäuse entlang der Linie VI-VI gemäß Fig. 5.

Reference to an embodiment shown in the drawing, the idea underlying the invention will be explained in more detail. Show it:

Fig. 1

a front perspective view of a spotlight for stage, studio, film, television and event lighting with a cross-flow cooling system according to the invention;

Fig. 2

a rear perspective view of the headlamp according to Fig. 1 ;

Fig. 3

a cross section through the headlamp according to Fig. 1 and 2 ;

Fig. 4

a front view of the headlight housing according to the Fig. 1 to 3 ;

Fig. 5

a longitudinal section through the headlight housing along the line VV according to Fig. 4 and

Fig. 6

a cross section through the headlight housing along the line VI-VI according to Fig. 5 ,

Fig. 1 shows a perspective front view of a headlight with a headlight housing 1, which consists of a lamp housing 2 and a bottom tray 3. The lamp housing 2 has a front part 4 and a rear part 5, which are usually made of die-cast aluminum. The front part 4 includes a front lens 40 and is connected to a lens mount or attachment 6, which is distributed over the circumference evenly distributed four retaining claws 60 for receiving attachment elements such as diffusers, filter discs, protective screens and the like and a unspecified clamping device with the lamp housing 2 is connected. To connect the headlight housing 1 with a tripod to the stationary arrangement of the headlamp or with a rig to the hanging arrangement of the headlamp, a headband 7 is connected to the lamp housing 2 via a Bügelanlenkung.

The lamp housing 2 surrounds according to the cross-sectional view in FIG Fig. 3 a lamp or a burner 8 and a reflector 9, the light beams emitted by the lamp or the burner 8 in the direction of the front lens 40 according to Fig. 1 reflected.

The lamp housing 2 contains according to the Fig. 1 to 3 . 5 and 6 a jacket flow plate 20 and a plurality of cooling channels 21 to 26 arranged around the jacket flow plate 20, which extend parallel to the optical axis of the headlight and have a profiled but not necessarily ribbed outer surface for enlarging the heat-emitting surface. The cooling channels 21 to 26 are arranged at a short distance from the jacket flow plate 20, so that between the jacket flow plate 20 and the cooling channels 21 to 26, a gap 10 is formed.

To increase the heat dissipation, the jacket flow sheet 20 is painted with a heat-resistant black lacquer and is preferably made of an aluminum casting or die-cast alloy. Alternatively, to increase the heat resistance, the sheath lamination sheet 20 may be provided with a low-reflection cohesive ceramic coating applied in a plasma-chemical finishing process. The plasma-chemical process takes place in special aqueous-organic electrolytes in which the sheath current plate 20 is connected as an anode, so that the metal is partially melted by the action of the oxygen plasma generated in the electrolyte on the surface of the sheath flow plate 20 and a firmly adhering oxide ceramic metal composite arises on the sheath current sheet 20, which has good scattering properties.

The jacket flow plate 20 is open to the bottom pan 3 and has the cross-sectional view corresponding to Fig. 3 an omega cross-sectional shape. On its upper side opposite the bottom trough 3, the sheath lamination plate 20 contains a plurality of lenghts arranged side by side in the direction of the optical axis of the headlamp, both in cross-section Fig. 3 as well as the longitudinal section according to Fig. 5 to be taken first openings 11, 12, 13, which on the outside cooling channels 22, 23, 24, 25 at a distance of the gap 10 face.

Between the cooling channels 21 to 26 and between the outer circumferential cooling channels 21 and 26 and the bottom pan 3 second openings 14 to 19 are formed, flows through the cooler ambient air or heated air.

In the cross-sectional view according to Fig. 3 are symbolically registered arrows that characterize the various air currents in the interior and on the outer surface of the jacket flow plate 20. Via not shown air inlet openings in the bottom pan 3 gets cooler outside air into the bottom pan 3 and leads there from the located in the bottom pan 3 electrical and electronic components, such as the ignitor of the headlamp and electrical cables and controls, heat released into the interior 200th of the completed by the sheath plate 20 lamp housing 2 from. The heat radiation emitted by the lamp or the burner 8 further heats the inner or first convection flow K1 circulating in the interior 200 of the jacket flow plate 20 of the lamp housing 2 and gives some of the heat to the jacket flow plate 20 and over the upper area of the jacket flow plate 20 first openings 11, 12, 13 in the formed between the sheath louver 20 and the cooling channels 21 to 26 gap 10 from.

Via the openings 14, 19, which are formed between the circumferentially outer cooling channels 21, 26 and the bottom pan 3, air for the outer or second convection K2 is sucked, which is guided around the jacket flow plate 20 and the heat load partially to the cooling channels 21st to 26 or through the second openings 15, 16, 17, 18 emits to the environment.

Perpendicular to the inner and outer or first and second convection flows K1 and K2 guided inside the jacket flow plate 20 and around the jacket flow plate 20, a cooling air flow K3 is guided in the cooling channels 21 to 26, which are arranged in accordance with FIG Fig. 4 via front cooling channel openings 41 to 46 of the cooling channels 21 to 26 and according to Fig. 2 are guided over the rear cooling channel openings 51 to 56. The cooling air flow K3 guided through the cooling channels 21 to 26 is used as inlet openings to the rear cooling channel openings 51 to 56 as inlet openings to the rear side cooling channel openings 41 to 46 and downwards from the rear cooling channel openings 51 to 56 as inlet openings directed to the front side cooling channel openings 41 to 46 as outlet openings.

In addition, in the back part 5 of the headlight housing 1, openings 50, 57, 58, 59 can be arranged on the outer periphery of the back part 5, via which, with the headlight inclined, the outer convection flow K2 guided on the outside of the jacket flow plate 20 is discharged through the rear part 5 to the environment becomes.

Furthermore, 5 covered air outlet slots 501, 502, 503 can be provided in the region of the central surface of the rear part, is discharged through the in the interior 200 of the lamp housing 2, that is located within the jacket flow plate 20 heated air, especially with tilted headlights.

It is also within the scope of the present invention, laterally arranged on the floor pan 3 cooling boxes according to the cited above WO 2004/029507 A1 provide and provide with straight or bent blades for targeted air flow guidance for a convection flow.

LIST OF REFERENCE NUMBERS

1

headlamp housing

2

lamp housing

3

floor pan

4

front part

5

rear part

6

front attachment

7

headband

8th

Lamp or burner

9

reflector

10

gap

11 - 13

first openings

14 - 19

second openings

20

Jacket flow guide plate

21 - 26

cooling channels

40

front lens

41 - 46

Front openings

51 - 59

back openings

60

retaining claws

200

inner space

501 - 503

Air outlet slots

K1

First convection flow

K2

Second convection flow

K3

Cooling air flow

Claims (11)

1. A cooling system for a projector for dissipating the heat output by a light source (8) and/or optical components or electric and electronic components through which current flows in a projector housing (1) with a lamp housing (2) and a base tray (3), with

   - a first cooling device (11-20) in which a first convection flow (K1) is guided through the interior space (200) of the base tray (3) and the lamp housing (2) and around which a second convection flow (K2) circulates which circulates around the lamp housing (2) at least partially in the circumferential direction, and

   - a second cooling device (21-26) for a cooling air flow (K3) which is directed substantially perpendicularly to the second convection flow (K2) and runs parallel to the optical axis of the projector.
2. The cooling system as claimed in claim 1,
   characterized in that the first cooling device (11-20) comprised of a jacket flow plate (20) which is arranged in the lamp housing (2), in whose (upper) section first openings (11-13) are arranged, which (upper) section is counter to the direction of gravity, and in that the second cooling device comprises cooling ducts (21-26), which are arranged in the lamp housing (2) around the jacket flow plate (20) and radially spaced apart from the jacket flow plate (20) wherein they extend parallel to the optical axis of the projector and which guide the cooling air flow (K3) in the longitudinal direction of the projector housing (1), and in that second openings (14-19) of the cooling ducts (21-26) for the passage of the first and second convection flows (K1, K2) are provided between the cooling ducts (21-26) which cooling ducts extend substantially parallel to the optical axis of the projector.
3. The cooling system as claimed in claim 2,
   characterized in that the cooling ducts (21-26) are arranged at a small radial spacing from the jacket flow plate (20) and in that the second convection flow (K2) flows through the gap (10) formed between the jacket flow plate (20) and the cooling ducts (21-26).
4. The cooling system as claimed in claim 2 or 3, characterized in that the second openings (14-19) extend substantially parallel to the optical axis such that they lead through from the front face to the rear face of the lamp housing (2).
5. The cooling system as claimed in one of claims 2 to 4, characterized in that the first and second openings (11-13; 14-19) are arranged offset with respect to one another in the circumferential direction of the lamp housing (2).
6. The cooling system as claimed in at least one of the preceding claims 2 to 5, characterized in that the cooling ducts (21-26) form cooling duct openings (41-46; 51-56) at the front and rear faces of the lamp housing (2).
7. The cooling system as claimed in at least one of the preceding claims 2 to 6, characterized in that the jacket flow plate (20) is painted with a heat-resistant black lacquer.
8. The cooling system as claimed in at least one of the preceding claims, characterized in that the jacket flow plate (20) comprises an aluminum cast or pressure diecast alloy.
9. The cooling system as claimed in at least one of the preceding claims, characterized in that the jacket flow plate (20) has a ceramic coating with low reflection coefficient, which is applied in a plasma-chemical finishing process.
10. The cooling system as claimed in at least one of the preceding claims, characterized in that in the substantially cylindrical lamp housing (2) which comprises the jacket flow plate (20) and the cooling ducts (21-26), a light source (8) and a reflector (9) are arranged, which reflector reflects the light beams emitted by the light source (8) to a light exit opening of the lamp housing (2), the light exit opening being covered by a transparent plate (40), and in that in the substantially cuboid or polygonal base tray (3) which is arranged in the direction of gravity beneath the lamp housing (2), electric and electronic components, such as an ignitor, cable leads and the like are arranged.
11. The cooling system as claimed in claim 10,
    characterized in that the base tray (3) has air entrance openings for cooling air and the air heated by the functional elements in the base tray (3) is directed into the interior space (200) of the jacket flow plate (20) of the lamp housing (2) arranged above the base tray (3).

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