DE102007036486A1 - Headlamp system with controlled and / or regulated conveyor - Google Patents

Abstract

The invention relates to a headlamp system having at least one headlamp whose interior is delimited at least in regions by means of at least one lens against the environment, with at least one light emitting diode as the light source and at least one arranged within the headlight conveyor. For this purpose, the headlamp system includes a sensor system. The output signal of the sensor system is dependent on a characteristic value of the relative humidity in the interior of the headlight. In addition, the sensor system controls and / or regulates the conveying device by means of the output signal. With the present invention, a headlamp is developed with light-emitting diodes as light sources, in which a deterioration of the luminosity can be eliminated by condensate quickly and with low energy consumption.

Description

The The invention relates to a headlight system with at least one headlight, whose interior at least partially by means of at least one Lens is delimited against the environment, with at least one Light-emitting diode as a light source and at least one within the Headlamps arranged conveyor.

From the DE 10 2005 019 651 A1 Such a headlamp is known. If the desiccant is saturated, the lens may mist and thus affect the illumination of the headlamp. It then takes a long time until the headlamp returns to full brightness.

Of the The present invention is therefore based on the problem to develop a headlamp with light-emitting diodes as light sources, in which an impairment of luminosity eliminated by condensate quickly and with low energy input can be.

These Problem is solved with the features of the main claim. For this purpose, the headlamp system includes a sensor system. The output signal of the sensor system depends on a characteristic value of the relative Humidity in the interior of the headlamp. Furthermore controls and / or controls the sensor system by means of the output signal Conveyor.

Further Details of the invention will become apparent from the dependent claims and the following description of schematically illustrated embodiments.

1 : Headlamp with air cooling and axial fan;

2 : Sensor system with betauter lens;

3 : Sensor system with unbroken lens;

4 : Headlamp with obliquely arranged axial fan;

5 : Headlamp with two heat sinks;

6 : Heatsink;

7 : Headlamp with Peltier element.

The 1 shows a longitudinal section of a headlamp ( 10 ), the z. B. is part of a headlamp system of a motor vehicle. The headlight ( 10 ) comprises a headlamp housing ( 20 ), which in the light emission direction ( 5 ) by means of a, the vehicle contour limiting lens ( 30 ) - in the exemplary embodiment, the lens ( 30 ) the headlight glass ( 30 ) - is closed.

The headlight housing ( 20 ) is for example made of plastic, a composite material, etc. and z. B. cup-shaped. In the open front of this has the 1 illustrated headlight housing ( 20 ) a mounting flange ( 21 ) on which the headlamp lens ( 30 ), the ses consists z. B. glass, plastic, etc., is attached. In the ground ( 22 ) of the headlight housing ( 20 ) sits in this embodiment, an insert plate ( 23 ). This may include a condensate with a drain port not shown here. If necessary, in the headlight ( 10 ) Compensation openings ( 11 ) be provided for air exchange, the total cross-section z. B. is less than 100 square millimeters. The headlight ( 10 ) is thus at least largely closed.

The single headlight ( 10 ), several headlamp housings ( 20 ). Also, the headlight housing ( 20 ) divided into several sections. The headlight housing ( 20 ) can z. B. arranged on its outside cooling elements for dispensing in the headlight ( 10 ) generated heat in the environment ( 1 ) exhibit.

In the interior ( 15 ) of the headlamp ( 10 ) are z. B. three light emitting diodes ( 40 ), z. B. Light emitting diodes as light sources ( 40 ) one above the other in each case in one module ( 90 ) arranged. The modules ( 90 ) serve the mutual positioning of the light sources ( 40 ) and z. B. one of the respective light source ( 40 ) optically downstream lens ( 43 ). Instead of a single lens ( 43 ) can also be arranged a lens system here.

The during operation of the light emitting diode ( 40 ) heated light emitting chip ( 41 ) is at least thermally conductive with a heat sink ( 50 ) connected. The light-emitting chip ( 41 ) sits, for example, on a circuit board ( 42 ), with which he electrically and thermally conductive, z. B. by means of a thermal compound is connected. At the light emitting diodes ( 40 ) facing away from the board ( 42 ) is the heat sink ( 50 ) arranged. This includes, for example, parallel to each other vertically to ordered cooling channels ( 51 ) with z. B. square or rectangular cross-section. He is z. B. manufactured as a cast component or as an extruded profile.

At the bottom of the heat sink ( 50 ) is a guide channel ( 12 ) connected. This is z. B. three-sided by means of a on the ground ( 22 ) abutting U-shaped profile ( 13 ) limited. The floor ( 22 ) limits the underside of the guide channel ( 12 ). The U-shaped profile ( 13 ) can be made of metal, plastic, be made of a composite material, etc. In the guide channel ( 12 ) is in this embodiment between the ground ( 22 ) and the heat sink ( 50 ) a conveyor device ( 70 ), z. B. an axial fan ( 71 ) arranged. The latter can be attached to the heat sink ( 50 ) or on the headlight housing ( 20 ) be attached.

At the top of the heat sink ( 50 ) is in the direction of the headlight glass ( 30 ) expanding air channel ( 14 ) connected. At the in the representation of 1 upper end of the headlight glass ( 30 ) corresponds to the width of the air duct ( 14 ) at least approximately the width of the headlight glass ( 30 ). This air duct ( 14 ) may have at its headlight glass side outlet nozzles.

In which to the headlight glass ( 30 ) adjacent area of the interior ( 15 ) is a sensor system ( 80 ) arranged. This sits z. B. in the lower part of the headlamp ( 10 ) outside the light exit area of the headlamp ( 10 ). It includes at least one transmitter ( 81 ) and a receiver ( 82 ), see. 2 , The transmitter ( 81 ) is, for example, a light-emitting diode ( 81 ), the z. B. with a normal to the inside ( 32 ) of the headlight glass ( 30 ) includes an angle of, for example, 45 degrees. The recipient ( 82 ), z. B. a photodetector ( 82 ), is mirror-symmetrical to the transmitter ( 81 ), the axis of symmetry being said normal. The angle that the transmitter ( 81 ) and the recipient ( 82 ) with the normal may be greater than the said angle. If necessary, the area of the headlight glass ( 30 ) in which the normal hits, be mirrored.

In the exemplary embodiment, the transmitter ( 81 ) and the recipient ( 82 ) below a blackout cap ( 83 ) arranged. This has an adjacent to the headlight glass opening ( 84 ). By means of this blackout cap ( 83 ), the direct light entry from the light sources ( 40 ) to the recipient ( 82 ) are reduced. For example, the entry of light from the environment ( 1 ), in addition, the lower portion of the headlight glass ( 30 ) z. B. be dark tinted. If necessary, on the blackout cap ( 83 ) are waived.

The sensor system ( 80 ) can, for example, on the inside ( 32 ) of the headlight glass ( 30 ) fastened condensation sensor, the z. B. outputs a signal from an adjustable value of the relative humidity at the headlight glass. That of the sensor system ( 80 ) can also be proportional to the relative humidity.

If a vehicle z. B. for a longer period of time with the headlamps ( 10 ), the interior ( 15 ) of the headlamp ( 10 ) z. B. heated to an operating temperature. The air in the interior ( 15 ) whose absolute humidity z. B. is initially lower than the absolute saturation air humidity at the operating temperature and the air pressure in the interior, absorbs moisture.

After parking the vehicle and switching off the headlights ( 10 ) cools the air in the interior ( 15 ) to the temperature of the environment ( 1 ). The air pressure in the interior ( 15 ) corresponds, for example, to the ambient air pressure ( 1 ). The relative humidity of the air in the interior ( 15 ) increases on cooling. If, during cooling, the relative humidity exceeds the absolute saturation air humidity as a function of the actual temperature - the relative humidity is then 100% - condenses moisture from the air first at the coldest section of the interior ( 15 ) of the headlamp ( 10 ), z. B. on the inside ( 32 ) of the headlight glass ( 30 ). The condensate, for example, penetrates through the opening ( 84 ) in the reflection region of the sensor system ( 80 ).

Will the headlamps ( 10 ) are switched on again, the light-emitting diodes ( 40 ). The light-emitting diodes ( 40 ) generated heat is applied to the heatsink ( 50 ) and from the heat sinks ( 50 ) to the air in the interior ( 15 ) of the headlamp ( 10 ). The heat sinks ( 50 ) act as heat sources ( 50 ). The air temperature in the area of the heat sink ( 50 ) is increasing. With increasing temperature and, for example, constant air pressure, the ability of the air to absorb moisture increases. The ventilator ( 70 ) circulates the air in the interior ( 15 ) in the representation of 1 in the air conveying direction ( 75 ) counterclockwise. At the heat source ( 50 ) - the air flows through the heat sinks ( 50 ), for example through the cooling channels ( 51 ) - the air is heated and above the modules ( 90 ) through the air duct ( 14 ) through to the headlight glass ( 30 ). The air absorbs heat through this forced convection. The heated air can carry moisture from the environment, the z. B. by pressure equalization openings of the headlamp ( 10 ) enters this. The conveyor device ( 70 ) thus promotes heat energy from the heat source ( 50 ) to the headlight glass ( 30 ). By mixing the air inside the headlamp ( 10 ), the absorbed moisture reaches the still cold headlight glass ( 30 ) and can condense there. The by the wind ( 3 ) caused air flow ( 4 ) along the outside ( 31 ) of the headlight glass, which are opposite to the air conveying direction ( 75 ) can increase the condensate accumulation.

A condensation of moisture on the headlight glass ( 30 ) can also be done if the Vehicle enters a cool parking garage, a tunnel, etc.

By switching on the ignition or the headlight ( 10 ), the sensor system ( 80 ) switched on. The light emitting diode ( 81 ) emits light ( 85 ) in the direction of the headlight glass ( 30 ). This light ( 85 ) is added to both the condensed water droplets ( 86 ) as well as the headlight glass ( 30 ) reflected. The recipient ( 82 ) receives a diffused, z. B. faint signal. The sensor system ( 80 ) thus communicates with the inside ( 32 ) of the headlight glass ( 30 ).

The recipient ( 82 ) is connected to the control of the fan ( 70 ) connected. If, for example, the price of the recipient ( 82 ) received light signal z. B. adjustable lower threshold level level, causes the output signal of the sensor system ( 80 ) turning on the fan ( 70 ) or an increase in its speed. The by means of the fan ( 70 ) delivered volume flow is amplified. The conveyed air flows -. B. under heat absorption at the heat sink ( 50 ) - on the headlight lens ( 30 ). The air flow hits at least approximately in the entire width of the headlamp ( 10 ) on the headlight glass ( 30 ) in the upper area. At the headlight glass ( 30 ) along the air flow down towards the bottom ( 22 ) guided. Here, the on the headlight glass ( 30 ) condensed moisture displaced and / or carried along by the air flow. For example, the higher the volume flow and / or the pressure and / or the temperature of the conveyed air, the higher is the deaeration.

The control of the fan ( 70 ) may have a timer. For example, after a z. B. adjustable duration of 15 seconds from the receiver ( 82 ) is still below the lower threshold, the controller can set the speed of the fan ( 70 ) z. B. increase by one more level. A dew formation on the inside ( 32 ) of the headlight glass ( 30 ) can thus be removed quickly.

As soon as the signal level at the receiver ( 82 ) after first switching on or raising the fan ( 70 ) exceeds an upper threshold, the headlamp lens ( 30 ) free of condensate, cf. 3 , The upper threshold may be equal to the lower threshold. The output signal of the sensor system ( 80 ) maintains or decreases the speed of the fan ( 70 ). If the speed is maintained, this is, for example, the speed required for further operation, which now follows the maximum permissible operating temperature of the light-emitting diodes (FIG. 40 ). This minimum cooling capacity is required so that the continuous operating temperature of the LEDs ( 40 ) z. B. does not exceed 85 degrees Celsius. If the speed of the fan ( 70 ), the amount of energy consumed per unit of time is also reduced. For example, the conveyor device ( 70 ) by means of the sensor system ( 80 ) and controlled by means of the maximum permissible continuous operating temperature or vice versa. Also, a control and / or control by both parameters is conceivable.

It is also conceivable, by means of the sensor system ( 80 ) from the recipient ( 82 ) to measure received signal level. The speed control of the fan ( 70 ) can then z. B. continuously. Even with an emerging risk of condensation, the volume flow of the conveyor ( 70 ) increase.

Is the insert plate ( 23 ) formed as a condensation plate, the air flows in the guide channel ( 12 ) along this condensation plate. In this case, the edge region of the air flow is cooled. The relative humidity - at least in the edge area of the air flow - exceeds the saturation limit, which depends on the temperature and the pressure. Moisture condenses on the condensation plate from the air flow. The condensation takes place for example as a film condensation. The absolute and relative moisture content of the headlamp ( 10 ) conveyed air is thereby reduced. In the case of a high amount of condensation, the condensation can also take place as dropwise condensation. The resulting condensate is then, for example, through a drain opening into the environment ( 1 ) guided.

If necessary, in the headlight ( 10 ) may be arranged a separate heat source. For example, the fan ( 70 ) heat the recirculated air.

As a fan ( 70 ) may be held in conjunction with the 1 described axial fan ( 71 ) a radial fan can be used. Also, a reversal of the conveying direction ( 75 ) conceivable. Here, the air along the inside ( 32 ) of the headlight glass ( 30 ) in the same direction as the one on the outside ( 31 ) of the headlight glass ( 30 ) flowing along, through the wind ( 3 ) generated air flow ( 4 ). The ventilator ( 70 ) can be above or below the heat sink ( 50 ) can be arranged. It is also possible to have a separate fan ( 70 ) only to remove the condensate. The heat dissipation of the light sources ( 40 ) can then z. B. by means of another conveyor, the inside or outside of the headlight housing ( 20 ) can be arranged. Also, one with the light sources ( 40 ) thermally connected heat sink outside the headlight housing ( 20 ) can be arranged.

The of the light sources ( 40 ) generated heat can also be by means of a water cooling z. B. by means of a heat exchanger derived. Such a constructed headlight ( 10 ) then has, for example, a separate fan ( 70 ), which by means of a sensor system ( 80 ) depending on the Kondensatsbefalls the headlight glass ( 30 ) is driven. If necessary, an additional heat source in this headlight ( 10 ) by means of the sensor system ( 80 ).

In the 4 is a headlight ( 10 ) with an axial fan ( 71 ), z. B. is arranged inclined by 45 degrees. The diameter of the axial fan ( 71 ) is z. B. 40% larger than the diameter of the in the 1 represented fan ( 10 ). With the same external dimensions of the headlamp ( 10 ) can such a conveyor ( 70 ) are used, which - compared to the embodiment according to 1 - Promotes a higher flow rate at the same speed. The functions of the sensor system ( 80 ) and the conveyor device ( 70 ) correspond to the functions of these devices, as used in connection with the embodiment of 1 are described.

The 5 shows a headlight ( 10 ) with z. B. six modules ( 90 ) and two heat sinks ( 50 . 52 ). Three modules each ( 90 ) are on one of the two z. B. arranged at right angles to each other heat sink ( 50 . 52 ) arranged. Between the two heat sinks ( 50 . 52 ) is used as a conveying device ( 70 ) a radial fan ( 72 ) arranged. The centrifugal fan ( 72 ) conveyed air can therefore by means of the first heat source ( 50 ) already preheated.

In this embodiment, the second heat sink ( 52 ) z. B. in two parts from a lower ( 53 ) and an upper heat sink part ( 54 ) built up. These two heatsink parts ( 53 . 54 ) enclose, for example, eight air ducts ( 56 ). In an arrangement of the second heat sink ( 52 ) at the roof ( 24 ) of the headlight housing ( 20 ) may optionally be applied to the upper heat sink part ( 54 ) are waived.

All modules ( 90 ) can also be on a common, z. B. curved board ( 42 ) can be arranged. The heat sinks ( 50 . 52 ) can each other z. B. by means of a bypass, the fan ( 70 ), be connected.

In the 6 is z. B. the lower heat sink part ( 53 ) of the second heat sink ( 52 ). The cross section of the individual air ducts ( 56 ) widens from the entrance side ( 57 ) to the exit side ( 58 ) steadily up. The side surfaces of the individual ribs ( 59 ) are z. B. parabolic surface sections.

The 7 shows a headlight ( 1 ), which is similar to the structure in the 1 illustrated headlights. The here as heat sink ( 60 ) insert plate ( 23 ) is a condensation plate ( 61 ) with an electric cooling element ( 65 ), z. B. a Peltier element. During operation of this electrical cooling element ( 65 ), for example, the inner surface ( 62 ) of the condensation plate ( 61 ) z. B. tempera ture difference of 10 K cooler than the temperature of the interior ( 15 ). The minimum temperature of the heat sink ( 60 ) is the temperature of the triple point of water in which all three phase states coexist. At temperatures below the triple point no condensation occurs. Is the temperature of the environment ( 1 ) below this specific temperature, the risk of condensation on the headlight glass increases (even if the outside temperatures continue to fall). 30 ) do not continue.

During operation of the conveyor device ( 70 ), the condensation takes place, as in connection with the embodiment of 1 described. This reduces the absolute amount of moisture in the air delivered to the headlamp, which also reduces the relative humidity in the interior atmosphere ( 15 ) is reduced.

The condensate, for example, on the inner surface ( 62 ), flows into the condensate drain ( 63 ). This is for example a labyrinth ( 64 ), a gas permeable membrane, etc. connected to the environment, so that the condensate from the headlight ( 10 ).

The Peltier element ( 65 ) can be switched off electrically as soon as the relative humidity in the interior ( 15 ) is below a threshold. When approaching this threshold or when exceeding this threshold, the Peltier element ( 65 ) are switched on again to reduce the amount of moisture in the headlight ( 10 ) to reduce.

The sensor system ( 80 ) and the conveyor device ( 70 ), as related to the 1 described.

To the Measuring the humidity can also be a commercial one Moisture sensor can be used.

The conveyor device ( 70 ) can remove air from the environment ( 1 ) of the headlamp ( 10 ). For example, the intake is connected to the engine pre-heating of the motor vehicle. Thus, filtered air enters the interior ( 15 ) of the headlamp ( 10 ). Optionally, the air after flowing along the lens ( 30 ) back to the surroundings ( 1 ).

The headlamp system may be located outside the headlamp ( 10 ) arranged sensor system. This sensor system can be arranged, for example, on the bumper of the motor vehicle. By means of this sensor system, for example, from the temperature, the air pressure, the absolute or relative humidity in the environment ( 1 ) and optionally a correction factor determines a characteristic value. The correction factor - it can be nonlinear or linear to change the measured parameters - takes into account B. a difference in the humidity of the interior ( 15 ) to the humidity of the environment ( 1 ). The output signal of the sensor system is then z. B. depending on the thus determined characteristic value of the relative humidity in the interior of the headlamp ( 10 ). Depending on this characteristic, the sensor system controls and / or regulates the conveying device. Such a headlamp system can have multiple headlamps ( 10 ), whose conveying devices are controlled and / or regulated by means of a common sensor system.

At least on the motor-facing outside of the individual headlight ( 10 In addition, shielding can be arranged against the heat radiation of the engine. These shielding plates can also be parts of the body and / or a front module.

The Embodiments of the individual embodiments can also be combined with each other.

1

Surroundings

3

wind

4

Air flow along ( 31 )

5

light emission

10

headlights

11

compensation openings

12

guide channel

13

U-shaped profile

14

air duct

15

inner space

20

headlamp housing

21

mounting flange

22

ground

23

insert plate

24

top, roof

30

Headlight glass, Lens

31

outside

32

inside

40

Light source Light emitting diode, light emitting diode

41

light emitting chip

42

boards

43

lenses

50

Heat source heatsink

51

cooling channels

52

heatsink

53

lower Heatsink member

54

upper Heatsink member

56

Air guide channels

57

entry page

58

exit side

59

ribs

60

heat sink

61

condensing plate

62

palm

63

Condensate drain, condensate drain

64

labyrinth

65

electrical Cooling element, Peltier element

70

Conveyor, fan

71

Axial

72

centrifugal fan

75

Air flow direction

80

sensor system

81

Transmitter, Light emitting diode, light emitting diode

82

Receiver, Photodetector, optical receiver

83

Abdunkelungskappe

84

opening

85

light

86

Waterdrop

90

modules

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• DE 102005019651 A1 [0002]

Claims (9)

Headlamp system with at least one headlamp ( 10 ), whose interior ( 15 ) at least partially by means of at least one lens ( 30 ) against the environment ( 1 ) is delimited, with at least one light emitting diode ( 40 ) as a light source ( 40 ) and at least one inside the headlight ( 10 ) arranged conveying device ( 70 ), characterized in that - the headlamp system is a sensor system ( 80 ), - that the output signal of the sensor system ( 80 ) depends on a characteristic value of the relative humidity in the interior ( 15 ) of the headlamp ( 10 ) and that the sensor system ( 80 ) the conveying device ( 70 ) is controlled and / or regulated by means of the output signal. Headlight system according to claim 1, characterized in that in the headlight ( 10 ) with the inside ( 32 ) of the lens ( 30 ) communicating sensor system ( 80 ) and that the output signal of the sensor system ( 80 ) depends on the relative humidity of the inside ( 32 ) of the lens ( 30 ). Headlight system according to claim 2, characterized in that the sensor system ( 80 ) a light emitting diode ( 81 ) and an optical receiver ( 82 ). Headlight system according to claim 3, characterized in that the lines of action of the light-emitting diode ( 81 ) and the optical receiver ( 82 ) include an angle whose vertex on the inside ( 32 ) of the lens ( 30 ) lies. Headlight system according to claim 1, characterized in that in the interior ( 15 ) a heat source ( 50 ) arranged with the light source ( 40 ) is connected at least thermally conductive. Headlamp system according to claim 5, characterized in that the conveying device ( 70 ) Heat energy from the heat source ( 50 ) to the lens ( 30 ) promotes. Headlight system according to claim 1, characterized in that at a relative humidity of the inside ( 32 ) of the lens ( 30 ), which is greater than an adjustable threshold, the output signal of the sensor system ( 80 ) the conveying device ( 70 ) controls such that the volume flow of the conveyor ( 70 ) is increased. Headlamp system according to claim 1, characterized in that the conveying device ( 70 ) a fan ( 70 ). Headlamp system according to claim 1, characterized in that the conveying device ( 70 ) Ambient air ( 1 ) of the headlamp ( 10 ) sucks.