EP0717233B1 - Reflector made of thermoplastic material for headlamp, in particular for a motor vehicle headlamp with cut off - Google Patents

Reflector made of thermoplastic material for headlamp, in particular for a motor vehicle headlamp with cut off Download PDF

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Publication number
EP0717233B1
EP0717233B1 EP95402779A EP95402779A EP0717233B1 EP 0717233 B1 EP0717233 B1 EP 0717233B1 EP 95402779 A EP95402779 A EP 95402779A EP 95402779 A EP95402779 A EP 95402779A EP 0717233 B1 EP0717233 B1 EP 0717233B1
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EP
European Patent Office
Prior art keywords
aperture
reflector
reflector according
base
headlight
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Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
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EP95402779A
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German (de)
French (fr)
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EP0717233A1 (en
Inventor
Eric Nowak
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Valeo Vision SAS
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Valeo Vision SAS
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21S—NON-PORTABLE LIGHTING DEVICES; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLE EXTERIORS
    • F21S45/00—Arrangements within vehicle lighting devices specially adapted for vehicle exteriors, for purposes other than emission or distribution of light
    • F21S45/40—Cooling of lighting devices
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21S—NON-PORTABLE LIGHTING DEVICES; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLE EXTERIORS
    • F21S41/00—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps
    • F21S41/30—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps characterised by reflectors
    • F21S41/32—Optical layout thereof
    • F21S41/321—Optical layout thereof the reflector being a surface of revolution or a planar surface, e.g. truncated
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21S—NON-PORTABLE LIGHTING DEVICES; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLE EXTERIORS
    • F21S45/00—Arrangements within vehicle lighting devices specially adapted for vehicle exteriors, for purposes other than emission or distribution of light
    • F21S45/10—Protection of lighting devices

Definitions

  • the present invention relates to reflectors in thermoplastic material for headlamps in particular with cut-off of motor vehicles.
  • the invention also relates to projectors comprising such reflectors.
  • This projector includes a reflector 1 which supports one or more lamps 2 and which is mounted in a housing 3 closed so watertight with glass 4. Other elements may also be mounted in the housing, for example a hubcap 5.
  • the reflector 1 has been more particularly shown in Figure 2. It is molded in one piece thermoplastic polymer and is metallized, so provide the required reflection properties. Function major of reflector 1 is to return the rays light of the lamp (s) 2 according to the direction of the axis optic A of the projector and generate, thanks to its shape - which is calculated for this purpose - the light beam projected onto the road.
  • the reflector 1 has a functional part 1a, for example of parabolic form, which is the part of the reflector which reflects the beam along the axis optic towards the road. It also includes two cheeks, one upper 1b, the other lower 1c, which constitute connecting parts between the bottom of the functional part 1a, the branches thereof and the ice 4.
  • a functional part 1a for example of parabolic form, which is the part of the reflector which reflects the beam along the axis optic towards the road. It also includes two cheeks, one upper 1b, the other lower 1c, which constitute connecting parts between the bottom of the functional part 1a, the branches thereof and the ice 4.
  • Cheeks 1b and 1c do not participate in the development of the optical beam. They constitute connecting parts, which mainly have a role mechanical.
  • the height of the projector is reduced more and more, so that the upper cheek 1b of the reflector 1, located at plumb with the light source constituted by the lamp 2, is very close to said source.
  • thermoplastic reflectors In the case of thermoplastic reflectors, this rise in temperature is accompanied by a thermal expansion tending to increase circumferentially the dimensions of the upper cheek 1b and to deform the functional part 1a of the reflector, especially by removing the branches thereof. This thermal deformation changes the shape of the projected beam and is particularly responsible for the appearance of portions beam in areas that are normally areas where the beam is cut. The rise in temperature of the upper cheek 1b therefore creates a dazzle, which increases with the duration of lighting of the lamp.
  • FIGs 3 and 4 This glare was illustrated in Figures 3 and 4 in the case of a dipped headlight for right-hand drive.
  • the outline of this beam projected has a V-cut at 15 ° perfectly sharp.
  • the Y axis is a vertical axis in the median plane of the projector.
  • the X axis is an axis in the horizontal beam cut-off plane.
  • This projected beam is deformed compared to that of FIG. 2. It has in its left part an Eb portion above the X axis which dazzles.
  • the invention proposes a material reflector thermoplastic for beam projector, more particularly with cut-off comprising a functional reflection part of general shape curvilinear, as well as a lower cheek and an upper cheek which connect the bottom and branches of the functional part, the upper cheek presenting at least one opening, which extends along most of the branch of the functional part which is on the side of said part functional that is likely to reflect glare beams, characterized in that said opening is offset from the area of the upper cheek intended to be in line with the projector lamp.
  • the reflector 10 shown in FIG. 5 is molded from a reinforced thermoplastic polymer material or no.
  • the interior surface of this reflector 10 is metallic.
  • This reflector 10 has a main part functional 11, as well as an upper cheek 12 and a lower cheek which has not been referenced.
  • the functional part 11 presents for example a parabolic shape, with a bottom 11a and two branches arched 11b.
  • Upper cheek 12 and lower cheek each have a parabolic shape matching the upper or lower end contour of the part functional 11.
  • the optical axis of this reflector 10 has been referenced by A.
  • the bottom 11a of the functional part 11 presents an orifice 13 centered on this axis A for the introduction of the projector lamp to which this reflector corresponds.
  • this projector is for example of the type described that with reference to the Figure 1. It includes in particular a box for the reception of the reflector, as well as a window for reflector closing. In Figure 5, only the ice of the projector has been shown. She was referenced by 19.
  • the reflector shown in Figure 5 is a reflector for right-hand traffic.
  • Its upper cheek 12 has on its side which is on the right (when looking at the projector through the rear) an opening 14, which extends along a most of the straight leg llb of the part functional.
  • the opening 14 is therefore directly in look of the optical zone of the reflector which forms the part of the beam likely to generate glare (part of the left beam for its right-hand traffic).
  • This opening 14 makes it possible to minimize the effects of the thermal expansion of the upper cheek 12 on the functional part 11 of reflector 10, for strongly reduce or even eliminate the glare that appears with the reflectors of the prior art, when extended projector operations.
  • Such an opening 14 makes it possible in particular to mechanically decouple the functional part 11 by relative to said upper cheek 12.
  • this opening 14 absorbs part of the dimensional variation of the upper cheek 12 due to thermal expansion of the thermoplastic polymer. To this end, this opening 14 has a geometry which favors the direction of movement of each of the points of the upper cheek 12 towards a point in the center of said opening.
  • This opening 14 advantageously has a contour general triangular, calculated so as not to modify substantially the overall stiffness of the reflector.
  • the outline of the opening 14 is defined by a base 15 parallel to optical axis A and on two sides 16 and 17, which meet at the right end front 18 of reflector 10.
  • Side 16 is defined by the inner contour upper of the right branch 11b of the part functional 11.
  • Side 17 is linear.
  • the base 15 is advantageously located at a distance 15a from the optical axis A equal to 30 to 40% of the half-width of the reflector 10, at its front face.
  • this opening 14 is produced by machining after molding. In variant, it can also be obtained directly by injection outlet.
  • opening 14 is offset relative to the area to the right of the lamp.

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Non-Portable Lighting Devices Or Systems Thereof (AREA)

Description

La présente invention est relative aux réflecteurs en matière thermoplastique pour projecteur en particulier à coupure de véhicules automobiles.The present invention relates to reflectors in thermoplastic material for headlamps in particular with cut-off of motor vehicles.

L'invention concerne également les projecteurs comportant de tels réflecteurs.The invention also relates to projectors comprising such reflectors.

On a représenté schématiquement en coupe sur la figure 1 un projecteur de véhicule automobile conforme à un art antérieur classiquement connu. Ce projecteur comporte un réflecteur 1 qui supporte une ou plusieurs lampes 2 et qui est monté dans un boítier 3 fermé de façon étanche par une glace 4. D'autres éléments peuvent également être montés dans le boítier, par exemple un enjoliveur 5.We have shown schematically in section on the FIG. 1 a motor vehicle headlamp conforming to a classically known prior art. This projector includes a reflector 1 which supports one or more lamps 2 and which is mounted in a housing 3 closed so watertight with glass 4. Other elements may also be mounted in the housing, for example a hubcap 5.

Le réflecteur 1 a été plus particulièrement représenté sur la figure 2. Il est moulé d'une pièce en un polymère thermoplastique et est métallisé, de façon à assurer les propriétés de réflexion requises. La fonction majeure du réflecteur 1 est de renvoyer les rayons lumineux de la ou des lampes 2 selon la direction de l'axe optique A du projecteur et de générer, grâce à sa forme - laquelle est calculée à cet effet - le faisceau lumineux projeté sur la route.The reflector 1 has been more particularly shown in Figure 2. It is molded in one piece thermoplastic polymer and is metallized, so provide the required reflection properties. Function major of reflector 1 is to return the rays light of the lamp (s) 2 according to the direction of the axis optic A of the projector and generate, thanks to its shape - which is calculated for this purpose - the light beam projected onto the road.

La qualité et la constance de cette forme sont primordiales.The quality and consistency of this form are essential.

Classiquement, ainsi qu'illustré sur les figures 1 et 2, le réflecteur 1 comporte une partie fonctionnelle 1a, par exemple de forme parabolique, qui est la partie du réflecteur qui assure la réflexion du faisceau selon l'axe optique en direction de la route. Il comporte également deux joues, l'une supérieure 1b, l'autre inférieure 1c, qui constituent des parties de liaison entre le fond de la partie fonctionnelle 1a, les branches de celle-ci et la glace 4.Conventionally, as illustrated in Figures 1 and 2, the reflector 1 has a functional part 1a, for example of parabolic form, which is the part of the reflector which reflects the beam along the axis optic towards the road. It also includes two cheeks, one upper 1b, the other lower 1c, which constitute connecting parts between the bottom of the functional part 1a, the branches thereof and the ice 4.

Les joues 1b et 1c ne participent pas à l'élaboration du faisceau optique. Elles constituent des parties de liaison, qui ont principalement un rôle mécanique.Cheeks 1b and 1c do not participate in the development of the optical beam. They constitute connecting parts, which mainly have a role mechanical.

Dans le but de réduire l'encombrement des projecteurs et également d'améliorer le style du véhicule, la hauteur du projecteur est de plus en plus réduite, de sorte que la joue supérieure 1b du réflecteur 1, située à l'aplomb de la source lumineuse que constitue la lampe 2, est très proche de ladite source. Une fois le projecteur allumé, les effets combinés du rayonnement et de la convection génèrent une importante élévation de température dans la joue supérieure 1b. La température dans la joue 1b peut atteindre plus de 160°C.In order to reduce the size of headlamps and also to improve the style of the vehicle, the height of the projector is reduced more and more, so that the upper cheek 1b of the reflector 1, located at plumb with the light source constituted by the lamp 2, is very close to said source. Once the projector on, the combined effects of radiation and convection generate a significant rise in upper cheek temperature 1b. Temperature in the cheek 1b can reach more than 160 ° C.

Dans le cas des réflecteurs thermoplastiques, cette élévation de température s'accompagne d'une expansion thermique tendant à augmenter circonférentiellement les dimensions de la joue supérieure 1b et à déformer la partie fonctionnelle 1a du réflecteur, notamment en écartant les branches de celle-ci. Cette déformation thermique modifie la forme du faisceau projeté et est notamment à l'origine de l'apparition de portions de faisceau dans des zones qui sont normalement des zones où le faisceau est coupé. L'élévation de température de la joue supérieure 1b crée par conséquent un éblouissement, qui augmente avec la durée d'allumage de la lampe.In the case of thermoplastic reflectors, this rise in temperature is accompanied by a thermal expansion tending to increase circumferentially the dimensions of the upper cheek 1b and to deform the functional part 1a of the reflector, especially by removing the branches thereof. This thermal deformation changes the shape of the projected beam and is particularly responsible for the appearance of portions beam in areas that are normally areas where the beam is cut. The rise in temperature of the upper cheek 1b therefore creates a dazzle, which increases with the duration of lighting of the lamp.

Cet éblouissement a été illustré sur les figures 3 et 4 dans le cas d'un projecteur de croisement pour conduite à droite. Sur la figure 3, on a représenté le faisceau projeté par le projecteur "à froid", sur un plan perpendiculaire à l'axe optique. Le contour de ce faisceau projeté présente une coupure en V à 15° parfaitement nette. Sur cette figure 3, l'axe Y est un axe vertical dans le plan médian du projecteur. L'axe X est un axe dans le plan horizontal de coupure du faisceau.This glare was illustrated in Figures 3 and 4 in the case of a dipped headlight for right-hand drive. In Figure 3, the beam projected by the projector "cold", on a plane perpendicular to the optical axis. The outline of this beam projected has a V-cut at 15 ° perfectly sharp. In this figure 3, the Y axis is a vertical axis in the median plane of the projector. The X axis is an axis in the horizontal beam cut-off plane.

Sur la figure 4, on a représenté le faisceau projeté que réalise le même projecteur à réflecteur thermoplastique, après une certaine durée d'allumage.In Figure 4, the beam is shown projected by the same reflector projector thermoplastic, after a certain ignition duration.

Ce faisceau projeté est déformé par rapport à celui de la figure 2. Il présente en sa partie gauche une portion Eb au-dessus de l'axe X qui réalise un éblouissement.This projected beam is deformed compared to that of FIG. 2. It has in its left part an Eb portion above the X axis which dazzles.

Pour pallier cet inconvénient, il a déjà été proposé dans FR-2 465 949 d'amincir la joue supérieure des réflecteurs.To overcome this drawback, it has already been proposed in FR-2,465 949 to thin the upper cheek of the reflectors.

Cette solution permet de remédier le problème de l'échauffement thermique de la joue supérieure dans le cas de réflecteurs présentant une hauteur importante (supérieure à 100 mm). Elle est toutefois insatisfaisante dans le cas de projecteurs de faible hauteur.This solution solves the problem of overheating thermal of the upper cheek in the case of reflectors having a significant height (greater than 100 mm). However, it is unsatisfactory in the case of low height projectors.

On connaít par ailleurs par EP 0 582 994 un réflecteur présentant une fente de compensation ménagée sur sa portion paraboloïde.We also know from EP 0 582 994 a reflector having a compensation slot formed on its paraboloid portion.

On connaít également par GB 2 093 580 un réflecteur de projecteur de véhicule automobile comportant une fente en forme de fer à cheval s'étendant symétriquement de part et d'autre de son plan médian.We also know from GB 2 093 580 a projector reflector motor vehicle with a horseshoe-shaped slot extending symmetrically on either side of its median plane.

Ces solutions ne sont toutefois pas non plus pleinement satisfaisantes.However, these solutions are also not fully satisfactory.

L'invention propose quant à elle un réflecteur en matière thermoplastique pour projecteur à faisceau plus particulièrement à coupure comportant une partie fonctionnelle de réflexion de forme générale curviligne, ainsi qu'une joue inférieure et une joue supérieure qui relient le fond et les branches de la partie fonctionnelle, la joue supérieure présentant au moins une ouverture, qui s'étend le long d'une majeure partie de la branche de la partie fonctionnelle qui est du côté de ladite partie fonctionnelle qui est susceptible de réfléchir des faisceaux d'éblouissement, caractérisé en ce que ladite ouverture est décalée par rapport à la zone de la joue supérieure destinée à être au droit de la lampe du projecteur.The invention proposes a material reflector thermoplastic for beam projector, more particularly with cut-off comprising a functional reflection part of general shape curvilinear, as well as a lower cheek and an upper cheek which connect the bottom and branches of the functional part, the upper cheek presenting at least one opening, which extends along most of the branch of the functional part which is on the side of said part functional that is likely to reflect glare beams, characterized in that said opening is offset from the area of the upper cheek intended to be in line with the projector lamp.

D'autres caractéristiques et avantages de l'invention ressortiront encore de la description qui suit. Cette description est purement illustrative et non limitative. Elle doit être lue en regard des dessins annexés sur lesquels :

  • la figure 1, qui a déjà été analysée, est une représentation schématique en coupe d'un projecteur de l'art antérieur ;
  • la figure 2 est une représentation schématique en perspective du réflecteur du projecteur de la figure 1;
  • les figures 3 et 4 illustrent la projection sur des plans verticaux que réalisent les projecteurs de l'art antérieur, d'une part, à froid et, d'autre part, après un certain temps d'allumage ;
  • la figure 5 représente en vue de dessus un réflecteur conforme à un mode de réalisation de l'invention.
Other characteristics and advantages of the invention will emerge from the description which follows. This description is purely illustrative and not limiting. It must be read in conjunction with the appended drawings in which:
  • Figure 1, which has already been analyzed, is a schematic sectional view of a projector of the prior art;
  • Figure 2 is a schematic perspective representation of the reflector of the projector of Figure 1;
  • Figures 3 and 4 illustrate the projection on vertical planes that realize the projectors of the prior art, on the one hand, cold and, on the other hand, after a certain time of ignition;
  • Figure 5 shows a top view of a reflector according to an embodiment of the invention.

Le réflecteur 10 représenté sur la figure 5 est moulé en un matériau polymère thermoplastique renforcé ou non. La surface intérieure de ce réflecteur 10 est métallisée.The reflector 10 shown in FIG. 5 is molded from a reinforced thermoplastic polymer material or no. The interior surface of this reflector 10 is metallic.

Ce réflecteur 10 présente une partie principale fonctionnelle 11, ainsi qu'une joue supérieure 12 et une joue inférieure qui n'a pas été référencée.This reflector 10 has a main part functional 11, as well as an upper cheek 12 and a lower cheek which has not been referenced.

La partie fonctionnelle 11 présente par exemple une forme parabolique, avec un fond 11a et deux branches arquées 11b. La joue supérieure 12 et la joue inférieure présentent chacune une forme parabolique épousant le contour d'extrémité supérieur ou inférieur de la partie fonctionnelle 11.The functional part 11 presents for example a parabolic shape, with a bottom 11a and two branches arched 11b. Upper cheek 12 and lower cheek each have a parabolic shape matching the upper or lower end contour of the part functional 11.

L'axe optique de ce réflecteur 10 a été référencé par A. Le fond 11a de la partie fonctionnelle 11 présente un orifice 13 centré sur cet axe A pour l'introduction de la lampe du projecteur auquel ce réflecteur correspond.The optical axis of this reflector 10 has been referenced by A. The bottom 11a of the functional part 11 presents an orifice 13 centered on this axis A for the introduction of the projector lamp to which this reflector corresponds.

A l'exception de son réflecteur, ce projecteur est par exemple du type de celui décrit en référence à la figure 1. Il comporte notamment un boítier pour la réception du réflecteur, ainsi qu'une glace pour la fermeture du réflecteur. Sur la figure 5, seule la glace du projecteur a été représentée. Elle a été référencée par 19.With the exception of its reflector, this projector is for example of the type described that with reference to the Figure 1. It includes in particular a box for the reception of the reflector, as well as a window for reflector closing. In Figure 5, only the ice of the projector has been shown. She was referenced by 19.

Le réflecteur représenté sur la figure 5 est un réflecteur pour circulation à droite.The reflector shown in Figure 5 is a reflector for right-hand traffic.

Sa joue supérieure 12 présente sur son côté qui est à droite (lorsque l'on regarde le projecteur par l'arrière) une ouverture 14, qui s'étend le long d'une majeure partie de la branche droite llb de la partie fonctionnelle. L'ouverture 14 est donc directement en regard de la zone optique du réflecteur qui forme la partie du faisceau susceptible de générer un éblouissement (partie du faisceau gauche pour sa circulation à droite).Its upper cheek 12 has on its side which is on the right (when looking at the projector through the rear) an opening 14, which extends along a most of the straight leg llb of the part functional. The opening 14 is therefore directly in look of the optical zone of the reflector which forms the part of the beam likely to generate glare (part of the left beam for its right-hand traffic).

Bien entendu, dans le cas d'une circulation à gauche, cette ouverture est ménagée sur la partie gauche de la joue du réflecteur.Of course, in the case of traffic at left, this opening is made on the left side the cheek of the reflector.

Cette ouverture 14 permet de minimiser les effets de l'expansion thermique de la joue supérieure 12 sur la partie fonctionnelle 11 du réflecteur 10, pour fortement atténuer, voire supprimer l'éblouissement qui apparaít avec les réflecteurs de l'art antérieur, lors de fonctionnements prolongés du projecteur.This opening 14 makes it possible to minimize the effects of the thermal expansion of the upper cheek 12 on the functional part 11 of reflector 10, for strongly reduce or even eliminate the glare that appears with the reflectors of the prior art, when extended projector operations.

Une telle ouverture 14 permet en particulier de découpler mécaniquement la partie fonctionnelle 11 par rapport à ladite joue supérieure 12.Such an opening 14 makes it possible in particular to mechanically decouple the functional part 11 by relative to said upper cheek 12.

Egalement, cette ouverture 14 absorbe une partie de la variation dimensionnelle de la joue supérieure 12 due à la dilatation thermique du polymère thermoplastique. A cet effet, cette ouverture 14 présente une géométrie qui favorise la direction des déplacements de chacun des points de la joue supérieure 12 vers un point au centre de ladite ouverture.Also, this opening 14 absorbs part of the dimensional variation of the upper cheek 12 due to thermal expansion of the thermoplastic polymer. To this end, this opening 14 has a geometry which favors the direction of movement of each of the points of the upper cheek 12 towards a point in the center of said opening.

Cette ouverture 14 a avantageusement un contour général triangulaire, calculé de façon à ne pas modifier substantiellement la rigidité globale du réflecteur.This opening 14 advantageously has a contour general triangular, calculated so as not to modify substantially the overall stiffness of the reflector.

Dans la variante préférentielle représentée sur la figure 5, le contour de l'ouverture 14 est défini par une base 15 parallèle à l'axe optique A et par deux côtés 16 et 17, qui se rejoignent au niveau de l'extrémité droite avant 18 du réflecteur 10.In the preferred variant shown in the Figure 5, the outline of the opening 14 is defined by a base 15 parallel to optical axis A and on two sides 16 and 17, which meet at the right end front 18 of reflector 10.

Le côté 16 est défini par le contour intérieur supérieur de la branche droite 11b de la partie fonctionnelle 11. Le côté 17 est linéaire.Side 16 is defined by the inner contour upper of the right branch 11b of the part functional 11. Side 17 is linear.

La base 15 est avantageusement située à une distance 15a de l'axe optique A égale à 30 à 40 % de la demi-largeur du réflecteur 10,au niveau de sa face avant.The base 15 is advantageously located at a distance 15a from the optical axis A equal to 30 to 40% of the half-width of the reflector 10, at its front face.

La dimension de cette base 15 est choisie de façon que la surface de l'ouverture 14 soit au moins égale à s où : s = 2SαΔ (2 + αΔ), où

  • S est la surface globale de la joue supérieure 12 (y compris la surface s de l'ouverture 14),
  • Δ est la différence de température maximale attendue pour ladite joue supérieure,
    et
  • α est le coefficient d'expansion thermique du matériau thermoplastique.
    • The dimension of this base 15 is chosen so that the surface of the opening 14 is at least equal to s where: s = 2SαΔ (2 + αΔ), or
  • S is the overall surface of the upper cheek 12 (including the surface s of the opening 14),
  • Δ is the maximum temperature difference expected for said upper cheek,
    and
  • α is the coefficient of thermal expansion of the thermoplastic material.

    • Selon une caractéristique avantageuse, cette ouverture 14 est réalisée par usinage après moulage. En variante, elle peut également être obtenue directement en sortie d'injection.According to an advantageous characteristic, this opening 14 is produced by machining after molding. In variant, it can also be obtained directly by injection outlet.

    On notera qu'une autre caractéristique avantageuse de l'invention tient en ce que l'ouverture 14 est décalée par rapport à la zone au droit de la lampe.It will be noted that another advantageous characteristic of the invention is that the opening 14 is offset relative to the area to the right of the lamp.

    La solution consistant à pratiquer l'ouverture directement à l'aplomb de la source lumineuse ne permet d'abaisser la température que localement, la quantité de chaleur ainsi évacuée pouvant dans certains cas se reporter sur le reste de la joue supérieure.The solution of practicing openness directly above the light source does not allow to lower the temperature only locally, the amount of heat thus evacuated which can in certain cases transfer to the rest of the upper cheek.

    Claims (10)

    1. A reflector of thermoplastic material, for a headlight and more particularly for a headlight giving a cut-off beam, the reflector including an operative reflecting portion (11) of generally curvilinear form, together with a lower part and an upper part (12) which join the base portion (11a) and the branches (11b) of the operative portion (11), the upper part (12) having at least one aperture (14) which extends along a major part of the branch (11b) of the operative portion (11) which is on the side of the said operative portion (11) that is adapted to reflect dazzling beams, characterised in that the said aperture (14) is offset with respect to the zone of the upper part (12) which is disposed in line with the lamp of the headlight.
    2. A reflector according to Claim 1, characterised in that the said aperture (14) has a form which causes points on the upper part (12) to be displaced towards the centre of the said aperture (14) during thermal dilation of the said upper part (12).
    3. A reflector according to Claim 2, characterised in that the said aperture (14) is of generally triangular form.
    4. A reflector according to Claim 3, characterised in that the said aperture (14) has a contour defined by a base (15) which is substantially parallel to the optical axis (A) of the reflector, and two sides (16, 17) which extend from the said base (15) and are joined together in the region of the front end of the branch (11b) of the operative portion (11) along which the said aperture (14) extends.
    5. A reflector according to Claim 4, characterised in that one (16) of the sides that extend from the base (15) is defined by the branch of the operative portion along which the aperture (14) extends, the other side (17) being linear.
    6. A reflector according to Claim 4 or Claim 5, characterised in that the base (15) is spaced away from the optical axis by a distance of 30 to 40% of the half width of the reflector.
    7. A reflector according to one of the preceding Claims, characterised in that, α being the coefficient of thermal expansion of the material, Δ the maximum temperature attained, and S the general surface area of the upper part (12), the surface area of the aperture (14) is greater than or equal to s, where s is given by: s = 2S αΔ (2+ αΔ).
    8. A reflector according to one of the preceding Claims, characterised in that the aperture (14) is formed therein by machining after moulding.
    9. A reflector according to one of Claims 1 to 7, characterised in that the aperture (14) is formed in a moulding operation.
    10. A motor vehicle headlight including a reflector according to one of the preceding Claims.
    EP95402779A 1994-12-12 1995-12-11 Reflector made of thermoplastic material for headlamp, in particular for a motor vehicle headlamp with cut off Expired - Lifetime EP0717233B1 (en)

    Applications Claiming Priority (2)

    Application Number Priority Date Filing Date Title
    FR9414917A FR2728056A1 (en) 1994-12-12 1994-12-12 REFLECTOR IN THERMOPLASTIC MATERIAL FOR PARTICULAR PROJECTOR WITH CUT-OFF OF MOTOR VEHICLES
    FR9414917 1994-12-12

    Publications (2)

    Publication Number Publication Date
    EP0717233A1 EP0717233A1 (en) 1996-06-19
    EP0717233B1 true EP0717233B1 (en) 2001-02-07

    Family

    ID=9469701

    Family Applications (1)

    Application Number Title Priority Date Filing Date
    EP95402779A Expired - Lifetime EP0717233B1 (en) 1994-12-12 1995-12-11 Reflector made of thermoplastic material for headlamp, in particular for a motor vehicle headlamp with cut off

    Country Status (3)

    Country Link
    EP (1) EP0717233B1 (en)
    DE (1) DE69520065T2 (en)
    FR (1) FR2728056A1 (en)

    Families Citing this family (2)

    * Cited by examiner, † Cited by third party
    Publication number Priority date Publication date Assignee Title
    DE10300415A1 (en) * 2003-01-09 2004-07-22 Hella Kg Hueck & Co. Headlights for vehicles
    JP6195747B2 (en) 2012-10-22 2017-09-13 株式会社小糸製作所 Lamp unit and vehicle lamp

    Family Cites Families (2)

    * Cited by examiner, † Cited by third party
    Publication number Priority date Publication date Assignee Title
    DE3106319A1 (en) * 1981-02-20 1982-09-16 Westfälische Metall Industrie KG Hueck & Co, 4780 Lippstadt MOTOR VEHICLE HEADLIGHTS
    JPH0617007U (en) * 1992-08-12 1994-03-04 スタンレー電気株式会社 Resin reflector

    Also Published As

    Publication number Publication date
    FR2728056B1 (en) 1997-03-07
    FR2728056A1 (en) 1996-06-14
    DE69520065T2 (en) 2001-08-23
    DE69520065D1 (en) 2001-03-15
    EP0717233A1 (en) 1996-06-19

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