Lighting device for a motor vehicle

Abstract

A lighting device for a motor vehicle has a ventilating device for ventilating the interior of the lighting device. The ventilating device has at least one separate component which is connected to a lower housing wall of the lighting device in the region of a ventilation opening in the housing wall, and through which component external air can pass into the interior. The component is embodied as an air-guiding element by which a slip stream can be selectively deflected from the outside onto at least one specific partial region of a lens of the lighting device. The ventilation and therefore the demisting of the lighting device is significantly improved.

Claims

1. A lighting device for a motor vehicle, the lighting device comprising: a housing with an interior and a housing wall, said housing wall having a ventilation opening formed therein, and a lens of the lighting device; a ventilation device for ventilating the interior of the lighting device, said ventilation device having at least one separate component connected to said housing wall in a vicinity of said ventilation opening, said separate component being configured to enable external air from outside to pass into the interior; said component being an air-guiding element configured to selectively deflect a slip stream of air from the outside onto at least one specific partial region of said lens.

2. The lighting device according to claim 1, wherein said component is composed of at least two parts.

3. The lighting device according to claim 1, wherein said component is formed with one air inlet opening and at least two air outlet openings for dividing an air stream entering said component.

4. The lighting device according to claim 1, wherein said at least one separate component is arranged in a front region of a lower housing wall in close vicinity to said lens.

5. The lighting device according to claim 1, which comprises at least one fan in the interior of said lighting device for generating an air flow.

6. The lighting device according to claim 5, wherein said fan is oriented so as to generate a vertical air flow.

7. The lighting device according to claim 5, wherein said fan is oriented so as to generate a horizontal air flow running transversely with respect to a light emission direction or a travel direction of the motor vehicle.

8. The lighting device according to claim 5, which comprises a heat sink and wherein said fan is positioned to generate an air flow that is guided directly through a heat sink.

9. The lighting device according to claim 8, wherein said heat sink has, in cross section, cooling fins which run in a meandering fashion and have clearance distances through which the air flow generated by said fan flows.

10. The lighting device according to claim 8, which comprises a mount supporting said fan and three walls extending from said mount, said three walls being connected to one another in a materially joined fashion and extend along the flow direction of the air flow generated by said fan, and wherein said walls enclose said heat sink, at least for the most part.

11. A motor vehicle, comprising at least one lighting device, the lighting device including: a housing with a housing wall and a lens defining an interior of the lighting device, said housing wall having a ventilation opening formed therein; a light source disposed in said interior of said housing; a ventilation device for ventilating the interior of the lighting device, said ventilation device having an air-guiding element being a separate component connected to said housing wall in a vicinity of said ventilation opening, said air guiding device being configured to enable external air from outside to pass into the interior and to selectively deflect a slip stream of air from the outside onto at least one specific partial region of said lens when the motor vehicle is moving.

12. A lighting device for a motor vehicle, the lighting device comprising: a housing with a housing wall and a lens together defining an interior of the lighting device; said housing wall having a ventilation opening formed therein; a ventilation device for ventilating the interior of the lighting device, said ventilation device having an air-guiding element being a separate component connected to said housing wall in a vicinity of said ventilation opening, said air-guiding element being configured to enable external air from outside to pass into the interior and to selectively deflect a slip stream of air from the outside onto at least one specific partial region of said lens; said air-guiding element having one air inlet opening and at least two air outlet openings for dividing the slip stream of air entering said component.

13. The lighting device according to claim 12, wherein said at least one separate component is arranged in a front region of a lower housing wall in close vicinity to said lens.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

(1) FIG. 1 shows a cross section through a first embodiment of a lighting device according to the invention;

(2) FIG. 2 shows the lighting device according to the sectional profile along the multi-segment line II-II from FIG. 1;

(3) FIG. 3 shows a cross section through second embodiment of the lighting device according to the invention;

(4) FIG. 4 shows the lighting device according to the sectional profile IV-IV from FIG. 3;

(5) FIG. 5 shows a cross section through a third embodiment of the lighting device according to the invention;

(6) FIG. 6 shows an illustration of the lighting device according to the sectional profile VI-VI from FIG. 5;

(7) FIGS. 7A and 7B show perspective and detailed illustrations of the lighting device according to FIGS. 3 and 4, in the region of the fan;

(8) FIG. 8 shows a sectional illustration according to the sectional profile VIII-VIII from FIG. 7A;

(9) FIG. 9 shows an air-guiding component in isolation;

(10) FIG. 10 shows a partial detail of a further embodiment of a lighting device in the region of an air-guiding component; and

(11) FIG. 11 shows a motor vehicle having lighting devices according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

(12) Referring now to the figures of the drawing in detail and first, particularly, to FIGS. 1 and 2 thereof, there is shown a lighting device 1 according to the invention. The lighting device 1 has a housing 10 in which two light modules LM1 and LM2 are accommodated.

(13) Each of the light modules LM1 and LM2 is embodied as a projection module and has at least one light source 14, also referred to as lighting means 14, whose light beams (not illustrated) are reflected by a reflector 13 in the direction of a projection lens 15. The light source 14 can preferably be embodied as light-emitting diodes (LEDs) or as LED circuit boards. However, other types of light sources are conceivable. The light modules LM1 and LM2 can also be embodied as pivoting modules and can be moved by means of a suitable pivoting device (not illustrated) in such a way that beam width adjustment and/or a cornering light can be generated.

(14) A heat sink 16 having cooling fins is connected in a thermally conductive fashion to each of the light modules LM1 and LM2.

(15) The housing 10 has lateral walls 10a and 10c, a rear wall 10b, an upper wall 10d and a lower wall 10e.

(16) In a light emission direction LA, which corresponds in the mounted state of the lighting device 1 to a conventional travel direction F of a motor vehicle K (cf. FIG. 11), the housing 10 is closed by means of a lens 11. The rear wall 10b has two access openings 10f and 10g, via which mounting operations or repair operations are possible. The access openings 10f, 10g are closed by covers 12.

(17) From the figures it is also apparent that the lower wall 10e, which therefore forms the floor of the lighting device 1, is provided with a ventilation opening 21a, and the lateral wall 10c is provided with a ventilation opening 21b in the region near to the floor. In the region of the ventilation openings 21a, 21b, separate components 22 and 23 are connected to the walls 10c and 10e, respectively. The components 22 and 23 are embodied, in particular, as air-guiding elements and are latched to the walls 10c, 10e, which permit them to be mounted easily.

(18) The components 22 and 23 are embodied in such a way that a slip stream FW penetrating the ventilation openings 21a, 21b passes into the components 22, 23, and is deflected in a flow S1 (component 23) or S2 (component 22) selectively to at least one specific partial region B1 or B2 and B3 of the lens 11.

(19) The regions B1, B2 and B3 are intended to illustrate regions which can only be ventilated very inadequately with an air flow which is known in the prior art. However, with the illustrated selective ventilation from the slip stream, these regions can be ventilated very effectively.

(20) Ventilation openings, through which air which penetrates the housing 10 can also escape again, are indicated by dashed lines with 21c.

(21) Referring to FIGS. 3 and 4, a second exemplary embodiment of a ventilation device 2 will now explained in which, in contrast to the ventilation device 1, there is an active ventilation device in the region of the rear wall 10b. The active ventilation device is composed of a heat sink 19 which is thermally coupled to the light module LM1 and above which a fan 17 is arranged. The fan 17 is positioned above the heat sink 19 by means of a mount 18. The mount 18 has walls 18a which enclose the heat sink 19 from the outside, at least for the most part. As a result, an air flow S3, which is generated by the fan 17, and which runs from top to bottom, can be guided through the heat sink 19 without appreciable losses.

(22) As is apparent, the air flow S3 which is generated by the fan 17 produces a circuit which is directed downward in the region of the fan 17 and upward in the region of the lens 11. In particular, in this way heat which is generated by the lighting means 14, for example by LED circuit boards, is transported downward via the heat sink 19 by the fan 17. This increases the protection of the lighting means 14 against overheating and the safeguarding of the light performance. In addition, as a result warm air is moved through the relatively cool regions of the lighting device and can pick up moisture there (demisting). It is to be noted that the fan 17 is also operated when the motor vehicle K is stationary (cf. FIG. 11), with the positive effects as described above.

(23) A third exemplary embodiment of a lighting device 3 will now be described with reference to FIGS. 5 and 6. In contrast to the lighting device 2, the fan 17 is arranged here together with the mount 18 in such a way that the fan 17 generates a horizontal air flow S4 which runs transversely with respect to the light emission direction LA at least in the region of the fan 17.

(24) This has the advantage that the air flow S4 which is generated by the fan 17 also flows directly through the heat sink 16 of the second light module LM2, which is not equipped with a fan, and therefore an effective dissipation of the heat generated by the lighting means 14 of all the light modules LM1/LM2 is achieved.

(25) A view of a partial region of the lighting device 2 will now be considered once more with reference to FIGS. 7A and 7B. In said figures, the fan 17 can be seen together with the mount 18 in detail. Here, the cover 12 of the rear opening 10f was removed. The mount 18 itself is mounted on a mounting element 20 above the heat sink 19.

(26) In specific terms, FIG. 7A shows the fan 17 in its installation position, and FIG. 7B shows it in a nonmounted position. It is apparent that the fan 17 is attached from above with the mount 18. In this context it projects somewhat into surrounding walls of the mount 18. In the downward direction, that is to say along or parallel to the air flow S3 which is generated, the mount 18 is lengthened by three walls 18a which are connected to one another in a materially joined fashion. In the mounted position, the heat sink 19 is surrounded by the walls 18a for the most part.

(27) In this way, the air flow S3 which is generated by the fan 17 can flow through the heat sink 19, in particular through clearance distances a between cooling fins 19a, without appreciable losses (cf. also FIG. 8).

(28) As becomes apparent, in particular, from FIG. 8, the cooling fins 19a run in a meandering fashion in the horizontal cross section. As a result, an extremely good thermal efficiency level of the heat exchange can be achieved.

(29) In FIG. 9, the component 22 is shown once more in isolation. It is apparent that the component 22 is composed of an upper part 22a and a lower part 22b. The lower part 22a and the upper part 22b are joined via latching means 22c. The component 22 can be latched to the housing 10 of a lighting device 1, 2, 3 in the region of the ventilation opening 21a using latching means 22d. The component 22 has an air inlet opening E and two air outlet openings A1 and A2, through which an entering air flow can be divided. There can also be more than two air outlet openings.

(30) A partial detail of a further embodiment of a lighting device 4 can be seen in FIG. 10. Here, a separate component 24 is latched to the lower wall of a housing 10 in the region of a ventilation opening 21a. The component 24 also has an upper part 24a and a lower part 24b, which are connected to one another by latching means 24c and by which a ventilation duct is formed. An inlet opening E, which is approximately rectangular in cross section, is positioned above the ventilation opening 21a. Furthermore, the upper part 24a is lengthened with a canopy-like extension 24d above the inlet opening E. In this way, a slip stream FW which penetrates the ventilation opening 21a can pass particularly easily into the ventilation duct of the component 24, and an air flow S5 at an air outlet opening A can exit again selectively in the direction of a partial region B4 of a lens 11 which is difficult to access.

(31) Finally, FIG. 11 illustrates a motor vehicle K which is equipped with two lighting devices 2 according to the invention in the form of headlights. Instead of the lighting devices 2, it is, of course, also possible for the lighting devices 1, 3 or 4 to be mounted.

(32) The following is a summary list of reference numerals and the corresponding structure used in the above description of the invention: 1 Lighting device 2 Lighting device 3 Lighting device 4 Lighting device 10 Housing 10a Lateral wall 10b Rear wall 10c Lateral wall 10d Upper wall 10e Lower wall 10f Access opening 10g Access opening 11 Lens 12 Cover 13 Reflector 14 Light source, lighting means 15 Projection lens 16 Heat sink 17 Fan 18 Mount 18a Wall 19 Heat sink 19a Cooling fins 20 Mounting element 21a,b Ventilation openings 21c Venting openings 22 Separate component 22a Upper part 22b Lower part 22c, d Latching means 23 Separate component 24 Separate component 24a Upper part 24b Lower part 24c Latching means 24d Canopy-like extension a Distances A, A1, A2 Air outlet openings B1-B4 Partial regions of the lens E Air inlet opening F Travel direction FW Slip stream K Motor vehicle LA Light emission direction LM1, LM2 Light modules S1-S5 Air flows