DE102004025624A1 - Headlamp with heat exchanger for cooling bulbs - Google Patents

Abstract

A headlight, in particular a motor vehicle headlight, has the following features: the headlight has a compression aggregate (1) for generating a conveying force for a coolant which is conveyed through the headlight for cooling the lighting means (6, 7); the headlight has a heat exchanger (2) for conveying heat from the coolant to the headlight surroundings; and the headlight has means for controlling and/or regulating the compression aggregate (1).

Description

STATE OF TECHNOLOGY

The The invention relates to a headlight, in particular a motor vehicle headlight with the features of the preamble of claim 1.

Such a headlight is for example from the publication with the publication number DE 102 13 680 A1 known. In this document, a cooling circuit is provided, in which the heated air from the lamp by means of a printing unit, it is a fan, is sucked out of the housing of the headlamp and is passed through a heat exchanger to cool the air. At the heat exchanger, the air is then transported back into the housing of the headlamp.

One Disadvantage of the disclosed in the document headlight, that independent from the temperature which the air in the headlight has and regardless of the current cooling capacity of the heat exchanger the printing unit is switched on with the same power. The cooling capacity of the heat exchanger is doing a lot depends on, what temperature and flow velocity the cooling medium has, with the heat exchanger flows against is going to be in the cooling circuit to cool transported air. By the constant Operation of the printing unit requires printing units that have a long life, resulting in increased costs.

Of the Invention is therefore an object of the invention to propose a headlight, where the printing unit is not stressed so much.

ADVANTAGES OF INVENTION

These Task is according to the invention with a Headlamp solved with the features of claim 1. One Such headlight has a means of controlling and / or controlling of the printing unit.

By the means for controlling and / or controlling the printing unit, the Power of the pressure unit according to the temperature of the headlight circulated Air or the secondary side cooling medium and / or according to the flow velocity on the secondary side of the heat exchanger be set.

Advantageous such a headlamp has at least one sensor for the flow velocity and / or a temperature sensor provided with the means for controlling and / or rules. Depending on the flow velocity measured by the sensor or the temperature measured by the temperature sensor is then by the means of controlling and / or regulating the performance adjustable of the printing unit. For example, the secondary side of the Heat exchanger with the ambient air flowed be, the flow rate depending on the Speed of the motor vehicle in which the headlight can be installed, changes. At a high outside temperature and especially at standstill of the vehicle must then the air in the headlight with higher Speed circulated be as for example at lower outside temperatures and very high Speed of the motor vehicle. Temperature sensors can also suitable for it be to directly detect the temperature of the recirculated air, and then to regulate the temperature of this recirculated air to overheat to prevent the bulbs.

The overheating hazard of bulbs is used in modern headlamps especially then Significant if light-emitting diodes are used as light sources. Light-emitting diodes usually tolerate a temperature of about 120 to 130 ° C. Will this temperature, the so-called junction temperature, exceeded, the light-emitting diodes are destroyed.

Preferably can a housing the heat exchanger, a holder for the printing unit and a housing of the printing unit are made of the same plastics like a case the headlight itself. The material may be, for example to trade PP-TV. The housing of the heat exchanger and the case of the blower can integral part of the housing be the headlight. Furthermore, it is advantageous if in the heat exchanger a possibility is provided to in the housing dissipate the headlamp precipitating liquid. A intended for this purpose drainage opening can simultaneously serve as a pressure equalization opening for the headlight housing.

On the secondary side can the heat exchanger to a low-temperature cooling circuit For example, be connected to an air conditioner.

From the prior art, a headlamp is also known, in which the air flow is directed so that it is passed directly to the bulbs and / or heat sinks of the bulbs. As a result, a better dissipation of heat from the lamps and the heat sinks is effected. The headlight, as in the publication DE 198 14 300 A1 is disclosed, has in its housing through openings, which allows an exchange of air between the environment of the headlamp and the headlight interior. So can the headlamps are flowed through, for example during a drive of the motor vehicle by the wind, which then enters the housing of the headlamp, is guided past the bulbs in order to cool them and then exits from further passages again. A disadvantage of this headlight is that through the openings in the housing moisture and dirt can penetrate into the headlight. This is not desirable.

The invention is therefore also the object of the publication DE 198 14 300 train known headlights so that moisture in the headlight housing can no longer occur.

This further object is achieved by a headlamp according to the invention according to claim 3. Special designs and developments of this headlamp are described in the subclaims 4 to 10. Such a headlamp has, in addition to the features mentioned in the preamble of claim 1, a first air guide section, a second air guide section, a third air guide section, first lighting means and second lighting means. The first air guide is fluidly connected to the pressure side of the pressure unit. The first lighting means are arranged on a first separating element, which has through openings in the region of the first lighting means for the fluidic connection of the first air guiding section to the second air guiding section. Moreover, the first separating element separates the first air guiding section from the second air guiding section. The second lighting means are arranged on a second separating element, which has through openings in the region of the second lighting means for the fluidic connection of the second air guiding section to the third air guiding section. Moreover, the second separating element separates the second air guiding section from the third air guiding section. The third air guide section is also fluidly connected via the heat exchanger with the suction side of the pressure unit. Such a headlight unites on the one hand, the concept of the closed cooling circuit, as it is basically from the document DE 102 13 680 A1 is known with the idea to selectively flow to the cooling lamps and their heat sink with the cooling medium. In this case, the invention makes use of the further knowledge that not all lamps must be cooled in parallel alike cooled by the heat exchanger air. Thus, it is quite possible to group bulbs so that the first bulbs are first flowed, while only after the second bulbs are then flown with the then already warmed by the first bulbs air. In order to implement this concept, the air guiding sections arranged one behind the other are provided in the invention.

The Air ducts can wholly or partly formed by one or more Luftleitkanäle. These air ducts can again be formed by pipes and / or hoses.

The first lighting means and / or the second lighting means can in the passages the first separating element or the second separating element be arranged or protrude into these openings. The first Illuminants and / or the second bulbs can also be connected to a respective heat sink be. Then can the heat sink in the passages be arranged the separating elements or in these passages protrude.

The first separating element and / or the second separating element can be pivoted arranged in the housing be so that it is possible is to pivot the first and / or second bulbs in the housing, for example, the direction of the light emerging from the headlight for one Headlamp leveling to change.

at a particularly advantageous embodiment of the headlamp can also individual bulbs pivotally mounted on the separating elements be. This can be beneficial for a headlamp with a so-called cornering light.

DRAWINGS

embodiments inventive headlight and details of headlights according to the invention are closer to the drawing described. It shows

1 a schematic representation of a first headlamp according to the invention in section,

2 a schematic representation of a second headlamp according to the invention in section,

3 a lamp arranged pivotally in a headlight according to the invention,

4 a heat exchanger of a headlight according to the invention,

5 a heat exchanger of a further headlight according to the invention,

6 a section through an inner tube of a heat exchanger according to 5 in an alternative embodiment and

7 a section through the inner tube of a heat exchanger according to 5 in a further alternative embodiment.

DESCRIPTION THE EMBODIMENTS

The in 1 shown inventive headlight has a housing 13 . 14 on, that from a housing lower part 13 and an upper housing part 14 consists, wherein the upper housing part is transparent and the light emission of the bulbs 6 . 7 generated light from the headlight housing 13 . 14 allows.

In the lower housing part is an outlet opening for a heat exchanger 2 intended. The heat exchanger 2 The purpose of this is to generate the light through the bulbs 6 . 7 generated heat from the housing of the headlamp 6 . 7 dissipate. The heat exchanger 2 is with the suction side of a printing unit 1 , in the present case it is a blower connected. The pressure side of the printing unit 1 is with a first air duct section 3 connected to the headlamp. The air conduction area 3 is through a pipe 11 and first separators 8th limited to the first air duct 3 from a second air duct 4 separate. Only via passages 10 in the first separator 8th is the first air conduction area 3 with the second air conduction area 4 connected.

In the passages 10 are with the first bulbs 6 connected heatsinks 12 arranged, or protrude the heat sink 12 partly in the passages 10 into it. The first bulbs 6 are lenses 15 associated with that of the first bulbs 6 bundle generated light and towards the transparent housing top 14 to steer.

The of the printing unit 1 from the heat exchanger 2 sucked air can during operation of the printing unit via the first air duct 3 through the passages 10 on the heat sinks 12 and the first bulbs 6 over into the second air conduction area 4 be blown. The cool air sweeps the heat sink 12 the first light source 6 and at these bulbs 6 itself over and carries heat from the heat sink 12 or the first light source 6 from.

The air thus heated becomes the heat exchanger 2 fed. This is a third air duct 5 intended. This third air duct 5 is from a pipe 11 and a second separator 9 limited. The second separator 9 points as well as the first separator 8th Through openings 10 on. About this there is a connection to the second air duct 4 , Also in these passages 10 are bulbs, namely second bulbs 7 arranged. These second bulbs are with a heat sink 12 connected, which in the passages 10 of the second separating element 9 protrude.

One of these second bulbs 7 is a reflector 16 associated with that of this second illuminant 7 generated light bundles and directs in a desired direction. The remaining second bulbs 7 are lenses 15 assigned to the light of these bulbs 7 bundle and in the direction of the transparent upper housing part 14 to steer.

The third air conduction area 5 is not just with the second air duct 4 but also - as already stated - with the heat exchanger 2 , This creates a closed circuit for the air. From one side of the heat exchanger 2 the cold air is passed through the pressure unit through the first air conduction area 1 at the first bulbs 6 over into the second air conduction area 4 transported. It takes the air from the first bulbs 6 generated heat. From the second air conduction area 4 then the air at the second bulbs 7 passing through the passages 10 in the third air conduction area 5 transported. This deletes the already from the first bulbs 6 heated air at the second bulbs 7 and in these second bulbs 7 associated heatsinks 12 and also takes heat from these bulbs 7 on. About the third air duct 5 then the heated air reaches the other side of the heat exchanger 2 , In the heat exchanger 2 the heat is withdrawn from the air, so that on the cold air side of the heat exchanger again cold air is available in sufficient quantity to bring the bulbs to the desired operating temperature.

The bulbs are according to the representation of the 1 In order to light-emitting diodes, in principle, however, such a headlight is also conceivable with other light sources.

The Indian 2 illustrated inventive headlamp has features that according to the features of the headlamp according to at least in their function 1 correspond. These features are in the 2 Therefore, provided with the same reference numerals as in 1 , So the headlight according to 2 in particular a heat exchanger 2 , a printing unit 1 , a first air conduction area 3 , a second air conduction area 4 , a third air duct 5 , first bulbs 6 , second bulbs 7 , the illuminants associated heatsink 12 and lenses 15 , as well as a first separating element 8th and a second separator 9 on.

Unlike the headlight according to 1 is the first air conduction area 3 and the second air conduction area 4 but not limited by a pipe. Rather, the first air duct is 3 as well as the third air conduction area 5 through the housing 13 as well as the first separating element 8th or the second separating element 9 limited. A third separating element 23 . 24 further adjoins the first air duct 3 against the third air duct 5 off and vice versa.

The first separating element 8th , the second separating element 9 and a first part 23 of the third separating element 23 . 24 are integrally connected. This so formed total separation element 8th . 9 . 23 is in a pivot 18 rotatable on the housing lower part 13 of the housing 13 . 14 appropriate. This allows, for example, a headlight range adjustment of the headlight. By pivoting the entire separating element 8th . 9 . 23 with the first bulbs attached thereto 6 , second bulbs 7 , Heat sinks 12 and lenses 15 it is possible to change the direction of the transparent upper housing part 14 Set emerging light beam.

By sealing areas 17 between the first separator 8th or the second separating element 9 on the one hand and the lower housing part 13 on the other hand, and by a sliding connection between the first part 23 and a second part 24 of the third separating element 23 . 24 it is ensured that even after or during a pivoting of the entire separating element 8th . 9 . 23 with the associated attachments the desired path of the air from the first air duct 3 to the second air duct section 4 further into the third air duct section 5 is predetermined and a fluidic short circuit, for example, between the first Luftleitabschnitt 3 and the third air guiding section 5 is excluded, as well as a direct transition of the air from the first Luftleitabschnitt 3 in the second air duct section 4 , or from the second air duct section 4 in the third air duct section 5 bypassing the passage openings 10 , This causes the constant flow of heat sink 12 or the first light source 6 and the second light source 7 secured.

That in the 3 shown detail of a headlight according to the invention shows a first or second light source 6 . 7 pivotable in a first and second separating element, respectively 8th . 9 is arranged. On the separator 8th . 9 are two opposing tabs 25 provided, the both sides of the passage opening 10 of the separating element 8th . 9 are arranged. At these tabs 25 is the heat sink 20 . 21 , the bulbs 6 . 7 is associated, rotatably mounted. To this heat sink 20 . 21 is then both the light source 6 . 7 as well as the lamp associated with the lamp 15 appropriate.

The heat sink 20 . 21 . 26 has a sleeve-like left section 26 on top of a sealing area 27 close to the separator 8th . 9 is applied. The sealing area 27 between the separator 8th . 9 and the left section 26 is by a ball or cylinder surface around the pivot axis 19 formed of the heat sink. This ensures that air passing through the passages 10 passes through the left section 26 of the heat sink, and not between the separator 8th . 9 and the left section 26 of the heat sink can pass. In the left section 26 of the heat sink 20 . 21 . 26 are radial webs 21 intended. At a core in the center of the heat sink is the bulb 6 . 7 attached. To the left section 26 Close in a right section of the heat sink holding webs on which the lens 15 is attached.

At the left end of the lower section 26 the heat sink is a pivoting lever 22 hingedly mounted, via which a force can be exerted on the heat sink to the heat sink with the attachments attached thereto about the pivot axis 19 to pivot. This makes it possible to change the direction of the light source 6 . 7 generated light by an actuation of the pivot lever 22 to change. This may be necessary, for example, in motor vehicle headlights for the dynamic cornering light.

The in 4 illustrated heat exchanger of a headlight according to the invention has first channels 31 and second channels 32 on, which are alternately guided side by side through the heat exchanger. The second channels 32 serve to transport the circulated in the headlight air, while the first channels 31 serve to receive air from outside. The air taken in from outside becomes countercurrent to that in the headlight and the second channels 32 circulated air passed through the heat exchanger. By dividing it into a multitude of first channels 31 and second channels 32 becomes the surface between the first channels 31 and the second channels 32 increases, which allows efficient heat exchange between the channels 31 . 32 in a small space allows. Between the channels very thin-walled metal sheets or plastic walls may be used to minimize the heat transfer resistance.

The in 5 illustrated heat exchanger of a heat exchanger according to the invention has a first channel 31 through which the outside air is passed, through which a second channel 32 to cool guided air circulated in the headlight. The first channel 31 is formed by a tube (inner tube), which is covered concentrically by a second tube. This second tube is at his Widened ends and is also close to the first tube tight. Over side sockets 32a . 32b For example, the air circulated in the headlight is conveyed into and out of the clearance between the first pipe and the second pipe. The air flows through the first channel 31 and the second channel 32 are transported in countercurrent, so that an efficient cooling of the circulated in the headlight air is possible.

Instead of the first tube, the separation between the first and the second channel 31 . 32 also be formed by a ribbed, extruded hollow profile, as in 6 is shown in section. In this extruded hollow profile, the surface between the first channel and the second channel is increased, which allows a more efficient heat exchange.

Likewise, a tube folded from sheet metal can be used as it is in 7 is shown in section.

Claims (10)

Headlamps, in particular motor vehicle headlamps, having the following features: - the headlamp comprises a printing unit ( 1 ) to generate a transport force for a cooling medium through the headlamp for cooling bulbs ( 6 . 7 ); - the headlamp comprises a heat exchanger ( 2 ) for transporting heat from the cooling medium into an environment of the headlamp, characterized in that the headlamp is a means for controlling and / or regulating the printing unit ( 1 ). Headlamp according to claim 1, characterized in that the headlamp comprises at least one pressure sensor and / or a temperature sensor which is connected to the means for controlling and / or regulating, and that depending on the pressure measured by the pressure sensor, or by the temperature sensor measured temperature by the means for controlling and / or regulating the power of the printing unit ( 1 ) is controllable. Headlamp, having the features of the preamble of claim 1, in particular according to claim 1 or 2 and with the following further features: - the headlamp comprises a first air guide section ( 3 ), a second air duct section ( 4 ), a third air duct section ( 5 ), first bulbs ( 6 ) and second illuminants ( 7 ); - the first air duct section ( 3 ) is connected to the pressure side of the pressure unit ( 1 ) fluidly connected; - the first bulbs ( 6 ) are connected to a first separating element ( 8th ), which in the region of the first lighting means ( 6 ) Passages ( 10 ) to the fluidic connection of the first air duct section ( 3 ) with the second air duct section ( 4 ) and, moreover, the first air guide section (FIG. 3 ) from the second air guiding section ( 4 ) separates; The second illuminants ( 7 ) are connected to a second separating element ( 9 ), which in the region of the second light source ( 7 ) Passages ( 10 ) for the fluidic connection of the second air duct section ( 4 ) with the third air duct section ( 5 ) and the rest of the second air duct section ( 4 ) from the third air duct section ( 5 ) separates; The third air duct section ( 5 ) is via the heat exchanger ( 2 ) fluidically with the suction side of the pressure unit ( 2 ) connected. Headlamp according to claim 3, characterized in that the first air duct section ( 3 ) and / or second air duct section ( 4 ) comprises one or more air ducts. Headlamp according to claim 4, characterized in that the air ducts through pipes ( 11 ) and / or tubes are formed. Headlamp according to one of claims 3 to 5, characterized in that the first lighting means ( 6 ) and / or the second lighting means ( 7 ) in the passage openings ( 10 ) of the first separating element ( 8th ) or of the second separating element ( 9 ) are arranged or in these passages ( 10 protrude). Headlamp according to one of claims 3 to 6, characterized in that the first lighting means ( 6 ) and / or the second lighting means ( 7 ) each with a heat sink ( 12 ) are connected. Headlamp according to claim 7, characterized in that the heat sinks ( 12 ) in the passage openings ( 10 ) of the first separating element ( 8th ) or of the second separating element ( 9 ) are arranged or in these passages ( 10 protrude). Headlamp according to one of claims 3 to 8, characterized in that the first separating element ( 8th ) and / or the second separating element ( 8th ) pivotable in the housing ( 13 . 14 ) is arranged. Headlamp according to one of claims 3 to 9, characterized in that the first lighting means ( 6 ) and / or the second lighting means ( 7 ) at least partially pivotable on the separating elements ( 8th . 9 ) are stored.