DE102004025623A1 - Headlight for a motor vehicle - Google Patents

Abstract

Disclosed is a headlight (1) comprising a light emitting diode arrangement (2) with heat-conducting means. Said heat-conducting means is provided with air-conducting means which direct the discharged air flow (5) in a direction that runs parallel to the preferred direction of emission (18) of the generated light. Also disclosed is a headlight comprising a heat exchanger (63) which selectively delivers or withdraws heat to or from the air flow (59) that can enter in contact with the cover pane (50) of the headlight. The invention further relates to a headlight (70) comprising a housing (71) for accommodating two light emitting diode arrangements (72, 77), to each of which one respective cooling element (73, 78) is assigned. A fan (79) is provided for generating an air flow used for cooling the cooling elements (73, 78) while at least one deflection blade (74) is provided that encompasses at least two sections (75, 76), the first section (75) directing a partial air flow onto the first cooling element (73) and the second section (76) deflecting a partial air flow onto the second cooling element (78).

Description

STATE OF TECHNOLOGY

The The present invention relates to a headlight for a motor vehicle according to the generic term of claim 1 or claim 13, and a headlight for a motor vehicle according to the generic term of claim 18.

A headlamp with a light-emitting diode arrangement is for example from the German utility model DE 201 15 772 U1 known. Here, an array of LEDs replaced a conventional halogen lamp.

In In this context, it is further known that particularly powerful LEDs a high heat loss produce, with the efficiency of the LEDs from a certain threshold temperature from about 120 ° C decreases rapidly.

Out For this reason, the light emitting diode arrangement with heat conduction, for example provided a heat sink, the heat the light-emitting diodes can dissipate in a suitable manner.

Now However, there is the problem that, for example, white LEDs produce no infrared radiation, but in conventional Headlamps is generated by the halogen light source and the Defrosting or defrosting the headlight cover disc can be used.

Therefore It is an object of the present invention to provide a headlamp to provide with a light emitting diode array as the main light source, whose headlamp cover disc held ice and fog free can be.

ADVANTAGES OF INVENTION

According to the invention this Task by a headlight with the characterizing features of claim 1. Because of the heat conduction equipped with at least one air-conveying agent suitable for this purpose is the outgoing airflow in a direction parallel to the preferred Direction of directing the emitted light is the specially Heat generated by the LEDs instead of the usual Halogen lamps emitted infrared radiation for de-icing the headlight cover disc exploited, but with essentially no structural changes must be made to the heat, analogous to the infrared radiation of a halogen lamp, always in the direction to transport the preferred emission direction.

In an advantageous embodiment of the present invention can be provided that the heat conduction at least partially has a cylindrical shape, wherein a core is provided, from which cooling fins in the radial direction extend, with the spaces between the cooling fins air ducts form. Such a design of the heat-conducting is compact and is particularly advantageously a heated outgoing Air flow, which is parallel to the preferred direction of radiation the light emitting diode array is aligned.

In an advantageous embodiment of the present invention can be provided that the cooling fins longitudinal of the heat transfer medium extend, with the core over has a recess, which is suitable for receiving the light-emitting diode array. Here is the heat transfer also as receiving means for used the light emitting diode array, resulting in a very compact embodiment of the headlight results.

to Optimization of the air flow can advantageously be provided that the core has a conical shape having. Accordingly, the heat conduction of the tip Side of the core flowed be, which is due to the streamlined shape of the core results in advantageous low-pressure flow behavior.

Also can be advantageously provided that the heat conduction rotatable about its longitudinal axis is and has at least partially a semi-cylindrical shape, with the cooling fins extend in the circumferential direction and the core has a recess, the is suitable for receiving the light-emitting diode array. Such an arrangement is excellent for one For example, rotatable embodiment of the combination of heat sink and LED array. For example, if the heat conduction around its longitudinal axis twisted, so changes the inflow profile of the heat transfer medium not essential, since the cooling fins in Are arranged circumferential direction or in the direction of rotation. To this Way can be a cornering headlight or the tilt adjustment a headlamp at the same time advantageous air flow behavior will be realized.

In a preferred embodiment of the present invention, it can be provided that the heat conducting means has a cuboid shape, the heat conducting means having a cover plate departing from the cooling fins, whose interspaces form air guide channels for conducting the outgoing air flow, the cover plate being suitable for receiving the light emitting diode arrangement , wherein an optical deflection means is provided, which is adapted to that of the Leuchtdio to redirect light generated in a direction parallel to the outgoing air flow. In this variant of Wärmeleitmitteltausführung a cuboid heat sink is used, which is easy to edit and inexpensive available in large quantities as a semi-finished product.

It can also be advantageously provided that a housing for Absorption of the heat transfer fluid is provided, which forms a pivot receptacle for the heat conducting in the heat conducting agent is pivotally received, wherein the housing at least partially the heat sink in the area of an opening the to the flow of the heat transfer medium with the incoming air flow is suitable, encloses. By a Such embodiment of the housing, in particular in that the housing encloses the heat sink in the region of the opening can be ensured that the flowed rib surface regardless of Swing angle of the Wärmeleitmittels is.

In a further advantageous embodiment of the present invention can be provided that the heat conduction enclosed by a Wärmeleitmittelgehäuse is which over Holding webs has, for receiving a lens or a shading in front of the light emitting diode array are suitable. Apart from the fact that the air flow continues through the heat conduction housing can be channeled, so carries the arrangement of retaining webs on the Wärmeleitmittelgehäuse continues to a compact design of the headlamp.

Also can advantageously be provided that the recess with is equipped with a reflector and / or has a reflective surface. As a result, a good light output in the direction of the preferred Radiation direction reached.

In an advantageous embodiment of the present invention can be further provided that a heat exchanger is provided, which is suitable for selectively supplying or removing heat from the air flow. hereby can suitably regulate the temperature of the air flow Influence, for example, the air flow to faster warming preheated or in addition at extremely high outside temperatures chilled become.

advantageously, can be provided that the heat conduction is adapted to the outgoing air flow in the direction of the preferred Direction of directing the emitted light to direct.

Corresponding alternatively, it can furthermore advantageously be provided that the headlight is equipped with another heat-conducting agent which is suitable to counteract an outgoing airflow to direct the preferred direction of emission of the emitted light. Accordingly, by a combination of such heat-conducting elements achieved both an air supply and air discharge from the light room become. Such a combination is conceivable, for example, in a headlamp with a dipped beam and a fog light and / or separate high beam is equipped. Here then can the air flow in the manner according to the invention for example about the heat transfer agent the fog lamp dissipated become.

From the EP 0 859 188 A2 a headlamp protection is known, in which an air flow with the headlight disc come into contact and condensation on optical surfaces can be avoided. In an advantageous embodiment of this Scheinwerferbetauungsschutzes a separate heating element, for example, a heating wire to be provided, which can preheat the air flow.

It is also known, the light emitting diode array with a heat conducting Equip and the air flow through the heat emitted by the light emitting diode array to warm up. This makes it possible to dispense with the use of a separate heating element become.

Becomes but the waste heat the light emitting diode array used to heat the air flow, this results in different problems. In particular, the heat source as such can not be regulated, because the main task of the lighting device is still acting as a source of light. Especially at extremely high, but also at extremely low ambient temperatures arise in this case problems, since the bulbs, for example not sufficiently cooled can be or too long to get enough heat to De-icing of the headlight cover disc available too put.

Here employs the present invention and makes it its mission To provide a headlamp that has the above problems can handle.

According to the invention this object is achieved by a headlamp with the characterizing features of claim 13. By providing a heat exchanger adapted to selectively supply or extract heat to the airflow, the airflow being able to contact the headlamp shroud, the air flow temperature is suitably regulated in a suitable manner. For example, the airflow can be faster heating preheated or additionally cooled at extremely high outside temperatures.

Also can in a further advantageous embodiment of the present Be provided that the means for generating a Air flow to a motorized fan is. By this measure can a constant and controllable air flow can be provided.

In a further advantageous embodiment of the headlight can be provided that the air flow between the headlight the heat exchanger and the heat conducting agent circulated. Accordingly, the influence of ambient air largely excluded and the air flow, for example, essential be heated faster.

Furthermore can optimize the flow behavior be provided that the heat conduction cooling fins has, which are aligned approximately parallel to the air flow.

to Intensification of the flow of the heat transfer medium can be advantageously provided that the headlight a casing has, wherein provided within the housing an air flow guide is that as a housing wall designed and adapted to the air flow to the heat conducting medium redirect.

It It is also known that headlamps with multiple light emitting diode arrangements stocked are, a high need for cooling exhibit. On the other hand, the headlight has a compact Represent unit, which are fitted in a limited space got to.

It is accordingly a further object of the present invention, To provide a headlight, in which an optimal cooling of the LED arrays can be ensured, the headlight, however, a same requires little space.

According to the invention this Problem solved by the characterizing features of claim 18. Thereby, that the headlamp has at least one turning vane with at least a first section and a second section, wherein the first section is adapted to a portion of the airflow on the first heat sink too and the second section is suitable for part of Redirect airflow to the second heat sink, can the individual heatsinks the associated light-emitting diode arrangements very targeted and thus effective flows against be, with a comparatively small space is required, For example, only one fan needed becomes.

In an advantageous embodiment may be provided that the Deflection vane is formed as a part of the housing. hereby the turning vane is an integral part of the housing, thereby optimizing, for example, the manufacturing and assembly process can be.

When advantageous and effective embodiment of the turning vane can be provided that the turning vane has an approximately V-shaped cross-section.

DRAWINGS

Further Features and advantages of the present invention will become apparent with reference to the following description of preferred embodiments with reference to the attached figures. Show in it

1 an inventive headlamp in a side sectional view;

2 a heat conducting means of a headlamp according to the invention in a perspective sectional view;

3 an alternative embodiment of a heat conduction in a partially sectioned perspective view;

4 an alternative embodiment of a heat conduction in a partially sectioned perspective view;

5 an inventive headlight;

6 an inventive headlight;

7 a perspective view of a headlamp according to 6 ,

DESCRIPTION OF THE EMBODIMENTS

First, it will open 1 Referenced.

An inventive headlight 1 essentially comprises a cylindrical Wärmeleitmittelgehäuse 8th in which a heat sink 3 with a light emitting diode array 2 is housed. The heat conduction housing 8th is one-sided with retaining bars 16 equipped as a receptacle for a lens 17 or serve a shader, wherein the light of the light emitting diode array 2 over the lens 17 on a headlight cover 6 is projected.

The heat transfer fluid 3 itself has a cylindrical shape with a solid core 13 on, with cooling fins 10 in the radial direction along a longitudinal axis 11 of the heat transfer medium 3 from the massive core 13 extend and in this embodiment together with the Wärmeleitmittelgehäuse 8th a number of air ducts 12 form essentially in the direction of the lens 17 or the headlight cover disc 6 are aligned. The air ducts 12 However, they are also formed when no Wärmeleitmittelgehäuse 8th is provided.

The heat transfer fluid 3 is rotationally symmetrical about its longitudinal axis 11 designed. For receiving the light-emitting diode arrangement 2 has the heat conducting agent 3 a conical recess 14 within the massive core 13 on, with the conical recess 14 in the area of cooling fins 10 can continue. Advantageously, the optical axis of the light-emitting diode arrangement falls 2 with the longitudinal axis 6 of the heat transfer medium 3 together.

During operation, the light emitting diode arrangement gives 2 now heat to the heat transfer fluid 3 from. From a cooling air source, not shown, for example, a fan, reaches the heat sink 3 an incoming cooling air flow 4 passing through the air channels 12 flows and as a heated outgoing airflow 5 the air channels 12 leaves, with the outgoing airflow 5 essentially on the lens 17 or on the headlight cover disc 6 is aligned. Through this heated outgoing airflow 5 becomes the lens 17 and the headlight cover disc 6 warmed up in a suitable manner and thus kept free of ice and mist.

It is further contemplated that the arrangement of heat conducting 3 , Wärmeleitmittelgehäuse 8th , with lens 17 and light emitting diode array 2 pivotable with respect to a support frame 9 is designed. The supporting frame 9 can be part of the headlight 1 be and has an opening 15 on, through which the incoming airflow 4 the heat sink 3 can be forwarded. For pivoting the Wärmeleitmittels 3 is a linkage 7 provided, whereby, for example, a headlamp leveling and / or a cornering lights can be realized.

Another embodiment of a thermal conduction 20 is in 2 shown. The heat transfer medium used here 20 has a substantially semi-cylindrical shape, wherein the heat conduction 20 also a massive core 24 includes around the cooling fins 23 are arranged radially. The cooling fins 23 however, are in contrast to the heat sink 3 out 1 aligned in the circumferential direction and not in the longitudinal direction. The cooling fins 23 form air channels 25 that from an incoming airflow 4 can be flowed, and the heat conduction 20 in an outgoing airflow 5 leave, essentially on the headlight cover 6 is aligned. In the direction of a longitudinal axis 21 of the heat transfer medium 20 is a recess 22 for receiving the light emitting diode array 2 provided, the optical axis also in the direction of the headlight cover disc 6 is aligned.

In 3 is another embodiment of a thermal interface 30 shown. The heat transfer medium used here 30 is essentially with the in 1 shown heat conduction 3 comparable and includes a massive core 31 that is radial with cooling fins 32 equipped in the longitudinal direction of the heat-conducting 30 run and air ducts 33 form. To generate a low pressure loss possible air flow, the massive core 31 a conical shape, wherein the incoming air flow to the core 31 flows from the sharp side, through the air ducts 25 between the cooling fins 32 is passed through and the heat conduction 30 as outgoing airflow 5 in the direction of the headlight cover disc 6 leaves. Here, too, is the center of the heat transfer 30 a recess 34 provided as a receptacle for the light emitting diode array 2 serves.

Another alternative embodiment of a heat conduction 40 is in 4 shown. The heat transfer fluid 40 has a substantially cuboid shape. on and is with a cover plate 43 Mistake. From the cover plate 43 extend cooling fins 41 , where the spaces between the cooling fins 41 air ducts 42 form. Furthermore, it is provided, the light emitting diode array 2 on the head side of the cover plate 43 to arrange and a mirror 44 or to use a prism, so that the light of the light emitting diode array 2 in the direction of the outgoing airflow 5 can be deflected so that both the light of the light emitting diode array 2 , as well as the heated air flow 5 on the headlight cover 6 can be aligned.

Of course, the heat conduction 20 . 30 . 40 according to the 2 to 4 swivel designed. It is further provided that the respective heat conduction 20 . 30 . 40 at least in sections of the housing 9 is enclosed, the housing 9 one opening each 15 through which the incoming air flow 4 in the air ducts 12 can flow in. By such a design of the air supply, the fin surface can be largely independent of the respective pivot angle of the heat conduction 3 . 20 . 30 . 40 be streamed. Such an advantageous flow is supported for example by a heat conduction 20 to 2 in which the orientation of the cooling fins 23 in terms of incoming airflow 4 despite a pivoting of the heat transfer medium 20 around the longitudinal axis does not change. Alternatively, for example, as in 3 a streamlined configuration of the heat conduction 30 be provided to ensure a possible pressure loss free air flow.

All embodiments of the Wärmeleitmittels 3 . 20 . 30 . 40 Ultimately, it is common that the outgoing airflow 5 in a direction parallel to the preferred radiation direction 18 the light of the light emitting diode array 2 can be steered. In the embodiments shown here, this is done in the direction of the preferred emission direction. However, it is also conceivable that the outgoing air flow against the emission direction 18 is directed, for example, to divert the air from the light space when using a separate fog lamp with a heat transfer medium according to the invention 3 . 20 . 30 . 40 in the same spotlight 1 , Also, it is ensured by the special provisions of the supply of the air flow, that despite a swing of the heat-conducting always the same fin surface is flowing. It may further be provided that the recesses 14 . 22 . 34 are equipped with a reflector and / or a reflective surface, so that the light output in the direction of the headlight cover disc 6 can be improved. Also, of course, alternative geometric shapes instead of the cylindrical or semi-cylindrical shape of the heat-conducting 3 . 20 . 30 . 40 conceivable, as long as this the purpose of the invention can be met.

In 5 is another embodiment of the present inventive headlamp 50 shown. An inventive headlight 50 essentially comprises a headlamp housing 60 with a translucent headlight cover 51 in which a lighting arrangement 61 is housed.

The lighting arrangement 61 essentially comprises a light-emitting diode arrangement 54 with a fan housing 52 , In front of the light-emitting diode arrangement 54 is a lens 53 attached, by a frame 55 is held. For cooling the light emitting diode arrangement 54 is a heat sink 56 provided in the fan housing 52 protrudes and from a fan 58 is supplied with cooling air. It points. the heat conduction cooling fins 62 on, in the direction of flow along the Wärmeleitmittels 56 extend. It can also be an air flow guide 57 be provided in the form of a housing, with which at least a part of the fan 58 generated air flow to the heat sink 56 is supplied.

The fan 58 is arranged in the preferred embodiment shown here such that a circulating air flow 59 inside the case 60 is generated, the first of the heat sink 56 dissipated heat, then to the headlight cover disc 51 to be cooled. This allows the headlight cover disc 51 despite the lack of infrared light component of the LED arrangement 54 kept ice and fog free.

According to the invention, a heat exchanger 63 for preheating or for cooling the circulating air flow 59 be provided, for example, when the heat conduction 56 its set temperature has not yet reached, or the air temperature is too high to ensure a suitable cooling of the heat conduction. In the embodiment shown here is a circulating air flow 59 shown. It is also conceivable air flow, which is led out at any point from the headlamp, as long as the heat exchanger 63 can act on the air flow in the manner described.

Another embodiment of a headlight according to the invention 70 is in 6 and 7 shown. The headlight 70 includes a housing 71 in which at least one turning vane 75 and a fan 79 is provided. Furthermore, the headlight 70 with a first light emitting diode array 72 with an associated first heat sink 73 and a second light emitting diode array 77 with an associated second heat sink 78 equipped, with both the heatsink assemblies 73 . 78 as well as the air flow of the fan 79 in the case 71 are directed.

To the light-emitting diode arrangements 72 . 77 to cool optimally, is a turning vane 74 provided, which is suitable for the air flow of the fan 79 split into two separate air streams, each one the first heat sink 73 or the second heat sink 78 can be supplied accurately. For this purpose, the turning vane 74 in a first section 75 or a second section 76 split, with the sections 75 . 76 have suitable air guide to make the distribution of the air flow in the manner described above.

Claims (20)

Headlights ( 1 ) for a motor vehicle, comprising - a light emitting diode array ( 2 ) with a preferred emission direction ( 18 ) of the emitted light, - a heat conducting agent ( 3 . 20 . 30 . 40 . 56 ) for exchanging heat between the light emitting diode array ( 2 ) and a stream of air ( 4 . 5 . 59 ), wherein the heat conduction from an incoming air flow ( 4 ) and from an outgoing air stream ( 5 ) is left, - a translucent headlamp lens ( 6 . 50 ), which in a preferred direction of radiation ( 18 ) of the light, characterized in that the heat conducting means ( 3 . 20 . 30 . 40 . 56 ) is equipped with at least one air-conveying means adapted to remove the outgoing airflow ( 5 ) in a direction parallel to the preferred radiation direction ( 18 ) to direct the emitted light. Headlamp, according to claim 1, characterized in that the heat conducting means ( 3 . 20 . 30 . 40 . 56 ) at least in sections has a cylindrical shape, wherein a core ( 13 . 24 . 31 ) is provided, from which cooling fins ( 10 . 23 . 32 ) extend in the radial direction, wherein the interstices of the cooling fins Luftleitkanäle ( 12 . 25 . 33 ) form as an air guide. Headlamp according to claim 2, characterized in that the cooling fins ( 10 . 23 . 32 ) in the longitudinal direction of the heat conduction ( 3 . 20 . 30 . 40 . 56 ), the core ( 13 . 24 . 31 ) via a recess ( 14 . 22 . 34 ) arranged to receive the light emitting diode array ( 2 ) suitable is. Headlight according to claim 2 or 3, characterized in that the core ( 31 ) has a conical shape. Headlamp according to claim 2, characterized in that the heat conducting means ( 20 ) is rotatable about its longitudinal axis and at least partially has a semi-cylindrical shape, wherein the cooling fins ( 23 ) extend in the circumferential direction and the core ( 24 ) has a recess for receiving the light emitting diode array ( 2 ) suitable is. Headlamp according to claim 1, characterized in that the heat conducting means ( 40 ) has a cuboid shape, wherein the heat conduction ( 40 ) via a cover plate ( 43 ), from the cooling fins ( 41 ) whose interspaces air ducts ( 42 ) for conducting the outgoing airflow ( 5 ), wherein the cover plate ( 43 ) for receiving the light-emitting diode arrangement ( 2 ) is provided, wherein an optical deflection means is provided, which is adapted to that of the light emitting diode array ( 2 ) generated light in the direction of the outgoing air flow ( 5 ) to divert. Headlamp according to one of claims 1 to 6, characterized in that a housing ( 9 ) for receiving the heat transfer medium ( 3 . 20 . 30 . 40 . 56 ) is provided, which is a swivel mount for. forms the heat conduction, in which the heat conduction is pivotally received, wherein the housing ( 9 ) enclosing the heat conducting medium at least in sections and wherein the housing ( 9 ) with an opening ( 15 ), which is responsible for the flow of heat to the incoming air stream ( 4 ) suitable is. Headlamp according to one of claims 1 to 7, characterized in that the heat conducting means ( 3 . 20 . 30 . 40 . 56 ) of a heat conduction housing ( 8th ) is enclosed, which over holding webs ( 16 ) for receiving a lens ( 17 ) or a rake in front of the light emitting diode array ( 2 ) are suitable. Headlamp according to one of claims 3 to 8, characterized in that the recess ( 14 . 22 . 34 ) is equipped with a reflector and / or has a reflective surface. Headlamp according to one of claims 1 to 9, characterized in that a heat exchanger ( 63 ) is provided, which is adapted to the air flow ( 4 . 5 ) optionally heat or withdraw heat. Headlamp according to one of claims 1 to 10, characterized in that the heat conducting means ( 3 . 20 . 30 . 40 . 56 ) is suitable for controlling the outgoing airflow ( 5 ) in the direction of the preferred radiation direction ( 18 ) to direct the emitted light. Headlamp according to one of claims 1 to 11, characterized in that the headlamp with a further heat conducting means ( 3 . 20 . 30 . 40 . 56 ), which is adapted to the one outgoing air flow ( 5 ) against the preferred radiation direction ( 18 ) to direct the emitted light. Headlamp according to the preamble of claim 1, characterized in that a heat exchanger ( 63 ) is provided, which is adapted to the air flow ( 59 ) optionally heat or extract heat, wherein the air flow ( 59 ) with the headlight cover disc ( 50 ) can come into contact. Headlamp according to claim 13, characterized in that it is in the means for generating the air flow ( 59 ) around a motorized fan ( 58 ). Headlight according to claim 13 or 14, characterized in that the air flow ( 59 ) between the headlight cover disc ( 50 ), the heat exchanger ( 63 ) and the heat conducting agent ( 56 ) circulates. Headlamp according to one of claims 13 to 15, characterized in that the heat conducting means ( 56 ) Cooling fins ( 62 ), which is approximately parallel to a section of the airflow ( 59 ) are aligned. Headlight according to one of Claims 13 to 16, characterized in that the headlight is a housing ( 60 ), wherein within the housing ( 60 ) an air flow guide ( 57 ) is provided, which is designed as a housing wall and is adapted to the air flow ( 59 ) on the heat conducting agent ( 56 ) to divert. Headlights ( 70 ), comprising - a housing ( 71 ) for receiving at least one first light-emitting diode arrangement ( 72 ) and a second light-emitting diode arrangement ( 77 ), wherein - each light-emitting diode arrangement ( 72 . 77 ) a first ( 73 ) and a second heat sink ( 78 ), wherein - a fan ( 79 ) for generating an air flow for cooling the heat sinks ( 73 . 78 ) is provided, characterized in that at least one turning vane ( 74 ) with at least a first section ( 75 ) and a second section ( 76 ), the first section ( 75 ) is suitable for a part of the air flow to the first heat sink ( 73 ) and the second section ( 76 ) is adapted to a part of the air flow to the second heat sink ( 78 ) to divert. Headlamp according to claim 18, characterized in that the deflecting blade ( 74 ) as a part of the housing ( 71 ) is trained. Headlamp according to claim 18 or 19, characterized in that the deflecting blade ( 74 ) has an approximately V-shaped cross-section.