FR2979414A1 - Transparent element for closing case of e.g. headlight for car, has circular openings formed for passage of air flow, where element is traversed by light generated by light source that is installed in case - Google Patents

Abstract

The element (2) has circular openings (5, 5a) formed for a passage of air flow, where the element is traversed by a light beam generated by a light source i.e. LED. The light source is installed in internal volume that is delimited by the transparent element and a case of a lighting and/or signaling device (1). A ventilation device is installed through the openings. The openings are formed at a level of a deformation part of the transparent element. A cover (4) is provided in the deformation part to cover the openings. An independent claim is also included for a car.

Description

TRANSPARENT ELEMENT FOR LIGHTING AND / OR SIGNALING DEVICE, COMPRISING AN AIR PASSAGE PORT The technical sector of the invention is, in general, that of the 5 transparent elements which close the lighting devices and / or or signaling, in particular the front or rear projectors of a motor vehicle. The appearance of condensation on the vehicle headlights is a recent problem. This condensation is created by the temperature difference between the air inside the projector and the air outside the projector, mainly when the outside air temperature is below 10 ° C. The projector glass is then cooled rapidly which promotes the generation of water drops inside the projector and on the same ice. Under conditions where the outside temperature drops below 0 ° C, these drops of water freeze to form a frost layer on the face of the ice facing the interior of the projector. In the past, projectors using incandescent lamps were not as substantially confronted with such an appearance of condensation because the thermal clearance of these lamps evaporated very rapidly drops of water formed on ice. The light sources used in the projectors have also been improved. Incandescent lamps are gradually being supplanted by the use of new technologies that offer much better performance in terms of lighting. However, this improvement in performance is accompanied by a reduction of the heat releases inside the projector, to the point that these new lighting technologies are not enough to evaporate the drops of water present in the projector. US7262388B2 discusses this subject by mounting a heater on the housing of a projector. However, locating the heater relative to the projector glass does not allow the condensation to be effectively removed. This lack of efficiency results in an increase in the time required to perform the function of removing condensation, which is then incompatible with the expectations of the user of the vehicle, because the user wishes to have a lighting system the vehicle is fully operational as soon as it uses the latter. The solution disclosed in this document suffers from another disadvantage. Indeed, the heater embedded in the projector consumes electricity, this consumption can be significant given the distance between the heater of the ice on which it seeks to remove condensation. This power consumption goes against the expectation of car manufacturers seeking to reduce the size of electricity generating components.

The object of the present invention is therefore to solve the disadvantages described above mainly by locating at least one hole through the projector glass to allow a flow of air flow between the inside and the outside of the projector. lighting and / or signaling device. Such an air flow is operated closer to the part of the projector that presents a risk of condensation, that is to say the transparent element through which the lighting beam passes. This or these holes are also covered by a cover or by one or more body parts of the vehicle to protect them and make them invisible from outside the vehicle. The subject of the invention is therefore a transparent element intended to close a housing of a lighting and / or signaling device for a vehicle and able to be traversed by a light beam generated by at least one light source installed in the housing. characterized in that the element comprises at least one orifice for the passage of an air flow. The inventors have been against the practice of not having an opening in the face of the lighting device and / or signaling exposed to bad weather. They have combined a means for evacuating condensation with a cover, possibly decorative, disposed on the transparent element. According to a first characteristic of the invention, the element comprises a front wall and a peripheral skirt capable of being secured to the housing, in which the orifice is formed through the front wall. In this case, the orifice is protected by a hubcap which shares the surface of the transparent element, thereby participating in the formation of a plurality of light beams.

Complementarily or alternatively to the positioning of the orifice mentioned above, it will be noted that the orifice is formed through the peripheral skirt. In such a situation, the peripheral condensation is effectively discharged while the orifices are covered by the body members which overlap the periphery of the transparent element. According to a second characteristic of the invention, the orifice is formed at a deformation of the element. Such a solution improves the aesthetics of the vehicle because the bodywork element can be accommodated in the deformation and thus flush with the outer face of the transparent element.

According to another characteristic of the invention, the element comprises a hubcap housed in the deformation to cover said orifice. Advantageously, the hubcap is a bodywork element of the vehicle, the latter supporting the transparent element according to the invention. According to another characteristic of the invention, the element comprises a ventilation device installed through the orifice, that is to say in the passage of the air flow. This avoids the entry of foreign bodies into the internal volume of the lighting and / or signaling device while effectively suppressing condensation. According to yet another characteristic of the invention, the ventilation device comprises a membrane impermeable to water in the liquid phase and permeable to water in the gas phase. Alternatively or in addition to the membrane presented above, the ventilation device comprises at least two edges, each of which modifies the direction of the air flow. These two edges thus form a baffle which forces the flow of air to effect an "S" circulation. It is understood that the element is transparent since it allows at least 75% of the light beam generated by the light source to pass through. The invention also covers a lighting and / or signaling device comprising at least one light source installed in the internal volume delimited by the housing and by the transparent element as detailed above. Preferably, this wall closes said housing and may be called closing glass. It is advantageous for the light source to be at least one light emitting diode. Indeed, this type of light source is the one that provides the least heat in the beam, which increases the risk of occurrence of condensation. The lighting and / or signaling device is in particular a vehicle headlight, also called vehicle headlight. The lighting and / or signaling device according to the invention may also be a vehicle signaling device, such as a rear light for a motor vehicle. Finally, the invention covers a motor vehicle comprising at least one bodywork element and a lighting and / or signaling device as mentioned above, innovating in that the bodywork element extends to the right of said orifice. to cover the latter. Advantageously, the bodywork element which extends in line with the orifice has a hue identical to the exterior hue of the vehicle. A first advantage according to the invention lies in the circulation of a flow of air between the outside of the projector and its internal volume. The temperature difference is thus significantly reduced which limits the risk of condensation forming on the inner face of the element facing the internal volume of the lighting and / or signaling device. Another significant advantage lies in the fact that the invention does not consume electrical energy to achieve its objective. The efficiency of this system is achieved by the fact that the orifices are made closer to the area of the lighting and / or signaling device which has a risk of condensation. Other characteristics, details and advantages of the invention will emerge more clearly on reading the description given below as an indication in relation to drawings in which: FIG. 1 is a diagrammatic front view of a device for lighting and / or signaling comprising a transparent element according to the invention, - Figure 2 is a sectional view of a lighting and / or signaling device comprising the transparent element according to the invention, - the FIG. 3 is a diagrammatic front view of a lighting and / or signaling device comprising a variant of a transparent element according to the invention, FIG. 4 is a sectional view illustrating the detail of the ventilation device equipping the element according to the invention, - Figure 5 illustrates a variant of the invention.

It should be noted that the figures disclose the invention in detail to implement the invention, said figures can of course be used to better define the invention where appropriate. Figure 1 illustrates a lighting and / or signaling device 1 before for a motor vehicle. The invention also finds a favorable application in a rear light for a motor vehicle, and generally in any device for emitting light in which the formation of condensation can be observed. The lighting and / or signaling device 1 is in particular a vehicle headlight, also called a vehicle headlight. Figure 1 illustrates this lighting and / or signaling device in a front view, that is to say by observing the device from outside the vehicle. This lighting and / or signaling device 1 comprises a transparent element 2 through which one or more beams pass to illuminate the road taken by the vehicle. This is for example a glass ice but this transparent element can also be made from a thermoplastic, for example a transparent polycarbonate. The transparent element is covered on its periphery by a bodywork element 3 belonging to the vehicle. In a central portion of this transparent element 2, there is also a hubcap 4 which is an insert on the transparent element 2. This hubcap 4 is, in particular, a bodywork element 3 in that it forms a participating element. the aesthetic continuity of the bodywork. For example, such continuity is obtained when the outer color of the trim is identical to the color of the vehicle body.

The bodywork element 3, including the hubcap 4, is opaque. It therefore forbids the passage of rays coming from one or more light sources installed in the lighting and / or signaling device 1.

The body member 3 is for example a part of a grille fitted to the front of the vehicle, but it may also be a part of a hood or a bumper. Of course, this body element 3 can be achieved by a combination of these three parts of the vehicle body.

The transparent element 2 comprises at least one orifice 5 for the passage of an air flow, this orifice being represented here in dashed line because it is covered by the bodywork element 3 or by the hubcap 4. This orifice 5 is a hole through the transparent element so as to allow a flow of air flow from outside the lighting and / or signaling device 1 to the inside of the latter. Depending on the indoor temperature and the outside temperature, the air flow can also flow in the opposite direction, that is to say from inside the lighting device and / or signaling 1 to the outside of the last. When the transparent element 2 comprises a plurality of orifices 5, these may optionally be arranged in so-called "at risk" zones with regard to the condensation that may form on this element. By way of example, at least a first orifice 5a is formed on the periphery of the transparent element 2 and at least a second orifice 5b is formed at a longitudinal strip which extends substantially in the center, along an axis vertical, of the transparent element 2. The section of these orifices 5a is 5b is for example circular but the invention also covers the case where the section one or the other of these orifices is adapted to facilitate the flow flow of air to limit condensation. By way of example, the second orifice referenced 5b1 located in the center of the transparent element 2 has an ovoid section. FIG. 2 shows a lighting and / or signaling device 1 according to a sectional view AA shown in FIG. 1. The lighting and / or signaling device comprises a housing 6 which can also be called a rear block (or optical block) of the lighting and / or signaling device 1. This housing 6 has several functions. A first function is to serve as a room on which are mechanically reported several functions of the lighting and / or signaling device 1, such as for example the mechanical maintenance of one or more light sources 7, the mechanical maintenance of a mask ( not shown), the mechanical retention of a reflector, etc ... A second function assigned to the housing 6 is to mechanically connect the lighting and / or signaling device 1 to the vehicle. Indeed, this housing 6 comprises a multiplicity of attachment points, for example threads, which ensures a stable mechanical connection with the vehicle. This housing 6 has a bottom 8 and a peripheral strip 9 which extends substantially perpendicular to the plane in which the bottom 8 extends. In other words, the housing 6 has a generally bowl-like shape, a free edge of the peripheral strip. 9 delimiting an edge against which is secured the transparent element 2. It is thus understood that the transparent element 2 closes the housing 6 and thus jointly defines an internal volume 16 in which extends at least one light source 7. This element 2 is transparent in that it allows the passage of at least 85% of the light beam generated by the light source or sources. In other words, the transparent element 2 affects the photometric function of the light source 7 by at most 15%.

The lighting and / or signaling device 1 comprises in this example two light sources 7 but it will either be that the invention covers a lighting and / or signaling device comprising a single light source 7 or more than two light sources 7. This light source 7 comprises a support 10 formed for example by a printed circuit. Such a light source comprises, for example, a discharge lamp, using a Xenon type gas, but the invention finds particular application when this light source 7 comprises at least one light emitting diode 11, advantageously a multiplicity of light emitting diodes. The latter forms the generating component of the light rays constituting the beam projected on the road. The light source 7 further comprises a reflector 12 whose function is to direct the rays emitted by the source towards the transparent element 2, as well as a diopter 13, for example a lens, whose function is to focus the multitude of rays in the same direction. The transparent element 2 consists of a front wall 14 and a peripheral skirt 15 adapted to be secured to the housing 6, at the peripheral edge thereof. The wall 14 is frontal in that it is exposed to the flow of air outside the lighting and / or signaling device 1. For example, this front wall 14 is that visible to a user in front of the door. motor vehicle which comprises the transparent element 2. 10 The peripheral skirt 15 is a portion of the transparent element 2 which extends around the front wall 14 and which is secured to the housing 6. In the example shown in FIG. 2, the front wall 14 comprises a second orifice 5b which passes right through it. This second orifice 5b is masked, in other words covered, by the trim 4, the latter being made in excess thickness with respect to a rectilinear or curved plane in which the front wall 14 fits. The hubcap 4 is then secured to an external face of the front wall by a fastening means, for example by gluing, clipping, complementarity of shape, that comprises the transparent element 2. Exclusively or in addition to the second orifice 5b , the peripheral skirt 15 comprises at least a first orifice 5a which passes right through the transparent element 2. In the upper part of the lighting and / or signaling device 1, the first orifice 5a is covered by the body member 3, for example a cover 17 shown here in part. The lower part of the lighting and / or signaling device 1 comprises a first orifice 5a made at the level of a deformation of the transparent element 2. This deformation is here in particular formed in the peripheral skirt, but it will for such a deformation can also be performed at the front wall 14, as will be detailed below in connection with Figure 4. The deformation 18 is for example a shoulder, or groove, recessed in internal volume direction 16. In the example shown in Figure 2, the deformation 18 comprises a first blank 19 which extends substantially perpendicular to the extension plane of the front wall 14. The deformation 18 comprises a second flank Orthogonal to the first flank 19. The first flank 19 and the second flank 20 each comprise a first orifice 5a which extends along orthogonal axes and through which the air flow can The deformation 18 also serves as receiving housing for the bodywork element 3 which covers the peripheral skirt 15, at the lower part of the lighting and / or signaling device 1. In this embodiment, this bodywork element 3 is a bumper 21 shown only partially.

The deformation 18 can, if necessary, lead through a hole, or a grid, into the bumper 21 so that the air can enter from the outside towards the inside, in the deformation 18. It is understood that the orifices 5a and 5b are protected from external projections by a hubcap 4 or a bodywork element 3. These components thus behave as caches that mask the presence of the orifices 5a and 5b, from outside the lighting and / or signaling device 1. This hubcap 4 and this bodywork element 3 are for example at a minimum distance of the ice of 2 mm, and may have specific shapes to promote the flow of air near the orifices , for example, rays. Moreover, these elements may optionally have holes to facilitate the evacuation of water in the case of play less than 5mm with ice. In the case of the orifice 5b located in the upper part, a conduit of specific shape in the element 17 can be made to ensure the flow of air.

The first orifices 5a formed at the peripheral skirt 15 and / or the second orifices 5b formed at the front wall 14 comprise a ventilation device 23 which will be discussed in detail in the description of FIG. 4. FIG. similar view to Figure 1 and we will refer to the description of the latter to know the structure. The difference lies in the positioning of the second orifices 5b at the level of the front wall 14. Whereas in FIGS. 1 and 2, the orifices 5b extend along a horizontal axis which divides the transparent element 2 into an upper zone traversed by a first beam and a lower zone traversed by a second beam, these second orifices 5b here extend in a vertical direction. The transparent element 2 is thus divided into a first lateral zone 21 and a second lateral zone 22, separated from each other by the hubcap 4. Such a structure makes it possible to arrange the two light sources side by side. 7 according to a substantially horizontal plane. FIG. 4 illustrates an exemplary embodiment of the cooperation between the transparent element 2 and the bodywork element 3. The structure of FIG. 4 is of course also transposable to the cooperation between the transparent element 2 and the hubcap 4 , that it extends horizontally as shown in Figure 1 or vertically as shown in Figure 3. The transparent element 2 comprises a deformation 18 which here takes the form of a groove open to the outside of the device. lighting and / or signaling. The hubcap 4 is housed in the deformation 18 to cover the orifice 5. It is thus understood that the hubcap 4 has an outer face 24 which extends in a plane coinciding with the plane of the outer face of the front wall 14 , or the peripheral skirt, as the case may be.

Inside the orifice 5, there is the ventilation device 23. The function of this device is to prohibit the penetration of water in the liquid phase inside the internal volume 16. The ventilation device 23 obstructs the the entire orifice. It authorizes the circulation of the air flow illustrated by the arrow 25 in the two directions mentioned above. By this means, it allows the gaseous phase of the water to escape from the internal volume 16. FIG. 4 shows the ventilation device 23 according to two exemplary embodiments, these examples being able to be used alone or in combination with one another. with the other.

The first embodiment is a membrane 26 impermeable to water in the liquid phase and permeable to water in the gas phase. This membrane 26 also prevents the penetration of dust. Its diameter is for example 3 mm. According to a second embodiment of the ventilation device 23, the latter comprises at least two edges arranged transversely to the flow direction of the air flow in the orifice 5 in order to modify this direction at least twice. A first edge 27 partially blocks the passage of the air flow 25. A second edge 28 is positioned opposite to the first edge 27. The air flow 25 thus follows a rough path that tends to retain water in the liquid phase . In other words, this first edge 27 and this second edge 28 delimit a baffle that retains the particles or dust and water in the liquid phase, which can come from outside. The invention also covers a motor vehicle which comprises a lighting and / or signaling device 1 as described above. In such a situation, it is advantageous that the bodywork element extends to the right of said orifice 5 to cover the latter, in particular by overlapping it. It is understood from this that the body member 3 or the hubcap 4 covers the entire section of the orifice 5 concerned. According to a feature of the invention, the trim 4 has an outer shade identical to that of the bodywork elements 3, or different to create a distinctive style This allows to share harmoniously the same lighting device and / or signaling giving the impression that they are two separate devices. This also makes it easy to hide the orifices and the ventilation devices located in the central zones of the transparent element where condensation may form. In the embodiment of Figure 5, the hubcap 4 is absent.

Claims (11)

REVENDICATIONS1. Transparent element (2) for closing a housing (6) of a lighting and / or signaling device (1) for a vehicle and capable of being traversed by at least one light beam generated by at least one light source (7) ) installed in the housing (6), characterized in that the transparent element (2) comprises at least one orifice (5, 5a, 5b, 5b1) for the passage of an air flow (25). 2. Element according to claim 1, comprising a front wall (14) and a peripheral skirt (15) adapted to be secured to the housing (6), wherein the orifice (5), called first orifice (5b, 5b1). is formed through the wall 1 o front (14). 3. Element according to claim 1, comprising a front wall (14) and a peripheral skirt (15) adapted to be secured to the housing (6), wherein the orifice (5), called second orifice (5a) is provided through the peripheral skirt (15). 15 4. Element according to any one of claims 1 to 3, wherein the orifice (5, 5a, 5b, 5b1) is formed at a deformation (18) of the transparent element (2). 5. Element according to claim 4, wherein there is provided a hubcap (4) housed in the deformation (18) to cover said orifice (5, 5a, 5b, 5b1). 20 6. Element according to any one of the preceding claims, wherein is installed a ventilation device (23) through the orifice (5, 5a, 5b, 5b1). An element according to claim 6, wherein the venting device (23) comprises a gas phase water-permeable liquid phase waterproof membrane (26). 8. Element according to any one of claims 6 or 7, wherein the ventilation device (23) comprises at least two edges (27, 28) which each changes the direction of the air flow (25). 9. A lighting and / or signaling device (1) comprising at least one light source (7) installed in an internal volume (16) delimited by a housing (6) and by a transparent element (2) according to the any of the preceding claims. 10. Device according to claim 9, characterized in that the light source (7) is at least one light emitting diode. Motor vehicle comprising at least one bodywork element (3, 4) and a lighting and / or signaling device (1) according to any one of claims 9 to 10, characterized in that the bodywork element (3, 4) extends to the right of said orifice (5, 5a, 5b, 5b1) to cover the latter.