FR2788837A1 - MOTOR VEHICLE PROJECTOR WITH IMPROVED SEALING - Google Patents

Abstract

The invention relates to a motor vehicle headlamp, comprising a lens (20), a housing (10) and a seal (300), the lens (20) and the housing (10) forming one groove (26) and for the other a wall (27) intended to penetrate into the groove (26), so that the seal (27) is pinched between the bottom of the groove (26) and a free edge of the wall (27), the crystal (20) and the housing (10) forming, at a location separate from the bottom of the groove (26), two respective faces (263, 277) which extend opposite transversely to the direction of the depth of the groove (26), characterized in that the seal (300) extends between these two faces (263, 277) opposite so as to be compressed between them.

Description

The invention relates to a motor vehicle lighting projector,

  the housing has a light exit opening provided with a transparent cover glass, and comprising between the glass

  and the housing a seal.

  Such headlamps are known which traditionally comprise a groove on the housing and a peripheral marginal zone on the ice coming into the groove and compressing the seal.

  sealing in the bottom of it.

  Document DE 43 41 292 has thus proposed a housing, the peripheral groove of which has a substantially rectangular cross section and also has a rib projecting from an inner lateral edge of this groove. The glass has an inner rib and an outer rib running along its marginal edge. The inner rib of the glass comes to bear against the inner rib of the groove of the housing, while the outer rib of the glass comes to bear against the end of a free lateral wall of the groove. The glass is therefore rigidly supported on the housing at the level of two arrangements belonging respectively to each of the side walls

throat.

  In such a position, the seal adapts by plasticity in the bottom of

  the throat around the end edge of the glass.

  Such a device has a major drawback. When the material of the joint ages, it tends to present geometric modifications, in particular to reduce in volume, and it tends to crack in places. The seal, initially subjected to a pressure formed between the glass and the housing is no longer subjected to any pressure after these geometric modifications due to aging, because the glass and the housing occupy an absolutely fixed mutual position. It then creates between the housing and the glass tiny circulation channels allowing water to enter the projector. This is valid not only for the foam seals described in this prior art, but also for the seals in

elastomer and others.

  The aim of the invention is to solve this problem by proposing a headlamp whose sealing remains effective in the longer term, despite a possible aging of the seal material. For this, the invention provides a motor vehicle headlamp, comprising a window, a housing and a seal, the window and the housing forming for one a groove and for the other a wall intended to penetrate into the groove, in such a way that the seal is pinched between the bottom of the groove and a free edge of the wall, the glass and the housing forming, at a place separate from the bottom of the groove, two respective faces which extend on screw opposite opposite to the direction of the depth of the groove, characterized in that the joint extends between these two opposite faces

  so as to be compressed between them.

  According to advantageous and non-limiting provisions of the invention: the seal is designed to be, in the mounting position, compressed both by the bottom of the groove / free edge of the penetrating wall, and at the

  times by the couple of said opposite faces.

  - one of the facing faces is formed by the end of a wall

lateral throat.

  - one of the facing faces is formed by an extending element

  from one side of the penetrating wall.

  - the said element lateral to the penetrating wall carries an element

  hooking connecting the glass and the housing.

  - the lateral element forms a support arrangement for a staple of

  retaining retaining glass on the housing.

  - the lateral element forms a flexible tab capable of forming, with a

  arrangement carried by the groove, a lug / edge grip couple.

  - the glass forms an attachment arrangement between the glass and the housing having sufficient brittleness to be broken by an operator without

damage the housing.

  - the side element has sufficient fragility to be able to be

  broken by an operator without damaging the housing.

  - one of the two facing faces has a projecting element

  suitable for retaining the seal against sliding on this face.

  - the seal covers the ends of the two side walls of the groove. - The seal carries, on one of its faces, projecting elements capable of elastically fading into the mass of the seal by compression against

  inside the groove or against said penetrating wall.

  Other objects, advantages and characteristics of the invention

  will appear on reading the detailed description which follows made in

  with reference to the accompanying drawings in which: - Figure 1 shows a headlamp according to a first variant of the invention, - Figure 2 shows a detailed longitudinal section of a portion of the headlamp in Figure 1, located in the vicinity of the joint, - Figure 3 shows a detailed longitudinal section of a headlight portion surrounding a joint, according to a second variant of

realization of the invention.

  The headlight of FIG. I has a housing 10, preferably made of plastic, containing a reflector 12 in which a light source 14 is mounted. The housing 10 has a front light outlet opening covered by transparent glass 20. This glass 20 is here made of plastic but can according to the invention be made of glass. At its rear end, the housing has an opening 24 which can be closed off by a

cover 22.

  The housing 10 has, along its front edge surrounding

  the light outlet opening 18, a peripheral groove 26.

  The glass 20 is formed of a main part transverse to the direction of light propagation, extended towards the rear of the headlight by a wall substantially parallel to the direction of light propagation, called the ice base. The rear edge 27 of this wall describes a

  closed contour capable of coming to bear on the housing.

  The rear edge 27 of this wall is introduced into the groove 26 of the housing so that this rear edge circulates along the entire contour

  front of the housing 10 inside the groove 26.

  The rear edge of the window closes in several places of the tabs 280 which first extend towards the outside of the glass and then return to extend parallel to the foot of the glass. The ice forms, in these places, each time a U, which extends transversely to the direction of the rear edge of the ice. A branch of this U is formed by the rear edge of the glass and another branch is formed by the outer tab of the glass. The outer branch 280 of the U therefore extends outside the groove

  26 by covering the external lateral wall of this groove 26.

  As can be seen in FIG. 2, this outer branch 280 of the U formed by the glass 20, extends towards the rear of the headlamp beyond the groove 26. This outer branch 280 also forms another through passage 282 of which a rear edge forms a hook edge for a lug

265 integral with the throat 26.

  Such a lug 265 extends towards the outside of the housing from the external lateral wall of the groove 26. The external tab 280 of the glass, made integrally with the glass, is flexible enough towards the outside to slide on one side oblique front of lug 265 when mounting the glass on the housing. Thus, it suffices to bring the glass 20 closer to the housing 10 so that the tab 280 slides on the lug 265 and the lug comes into the orifice 282, pressing against the rear edge of the orifice 282. Between the border rear 27 of the glass and the bottom of the groove 26 is disposed a seal 300

  circulating around the entire contour of the projector.

  In cross section, this seal 300 has the shape of a U surrounding the rear marginal portion 27 of the glass. This seal 300 can be drawn or molded. This seal is here an elastic rubber seal whose shape is chosen to be substantially complementary and slightly larger than the space between the rear marginal edge of the glass and the bottom of the groove 26. The branches of the U formed by the seal point so towards

the front of the projector.

  According to the invention, this joint 300 extends at the end of the branches of the U it forms, overlapping one end

  263 of the outer side wall 262 of the groove 26.

  More specifically, this external lateral wall 262 has a free end pointing towards the front of the projector and forming a face turned substantially towards the front of the projector, that is to say transverse to

  the vehicle's direction of travel.

  As mentioned above, the marginal portion 27 of the glass and the tab 280 form the branches of a U, the bottom of which is constituted by a wall 275 substantially transverse to the main direction of lighting. A rear face 277 of this wall 275 is opposite the

  front end face 263 of the external wall 262 of the groove 26.

  This wall 275 is not limited to the location of the tab 280, but circulates over the entire contour of the foot of the glass, facing in

  any place towards the rear of the projector.

  The rear end arrangements of the glass 20 and the geometry of the groove 26 and of the lug 265 are such that when the lug 265 is in abutment against the rear edge of the orifice 282, there is a spacing between the

  front face 263 of the groove 26 and the rear face 277 of the wall 275.

  According to the invention, the joint 300 extends in this space, by one end 320 of a branch of the U formed by this joint 300. The outer branch of the U formed by the joint therefore extends transversely to the main direction lighting between these two elements 275 and 263 facing each other at any point of junction between the glass and the housing. The U formed by the seal 300 thus has at the end of its branches, a lateral extension 320 towards the outside, substantially perpendicular to the

branches of the U formed by it.

  Preferably, the thickness of this extension 320 is greater than the space between the two faces 277 and 263 in the mounting position. Thus, the joint is, in this part 320, compressed between these two faces 277 and 263 which it repels by elasticity in compression, one by

compared to each other.

  The geometry of the seal 300, of the rear part of the glass and of the groove 26 is such that in this mounting position, the seal 300 undergoes compression simultaneously at the bottom of the groove, between the end of the rear edge 27 and the bottom of the groove 26, and at its extension 320 between the element 275 and the front end 263 of the wall

lateral throat 26.

  Such a double compression of the seal over the entire rear contour of the glass produces a particularly reliable sealing of the headlight and particularly stable over time. Of course, this arrangement of junction between the glass and the housing can, according to the invention,

  be adopted only on part of the contour of the ice.

  Thanks to this arrangement, the water does not penetrate anywhere between the seal 300 and the interior of the groove 26 or even between the seal 300 and the rear of the glass 20, so that no water infiltration , which could possibly be helped by temperature variations, is only possible with the device of the invention. Such a geometry of joints therefore guarantees

  a perfect seal against a labyrinth effect.

  In the embodiment described here, the seal 300 also covers a front end face 264 of the side wall of the groove

  26 which is inside the projector by an extension 322.

  The seal 300 therefore generally has the shape of a Q whose

  basic dashes are formed by extensions 320 and 322.

  The external surface of the seal, or surface intended to come into contact with the interior of the groove 26, is provided with a set of projections formed by molding with the seal 300, referenced 330. These elements 330 form small rubber points small enough to be in position

  of assembly, completely crushed in the total mass of the joint.

  Thus, these projecting elements 330 which are erased in the mounting position so that the external surface of the seal is in its entirety in contact and pressing against the groove, provide a slight elastic thrust when the glass is separated from the housing, tending to peel off the seal from the inside of the groove 26. By the action of these elements 330, during such a

  disassembly, the seal therefore remains secured to the glass and not to the housing.

  As shown in FIG. 2, the elements 330 are distributed in a substantially uniform manner over the seal 300, in particular in a cross section of the seal. Thus, an element 330 is arranged on a rear face of each of the extensions 320 and 322 intended to come to bear on the front edges of the side walls of the groove 26. The fact that the seal remains integral with the glass and not with the housing during dismantling the box has a particular advantage. Indeed, the fact that the seal is detached from the rest of the projector at the same time as the glass during a replacement operation of the glass ensures that the operator will spontaneously also change the seal 300 and does not leave in place a

seal possibly damaged.

  The fact of having flexible projecting elements 330 on the external face of the seal also allows the seal to be placed in the groove without excessive friction between the rubber and the interior of the groove 26 so that the seal cannot be accidentally deviated from his

  location chosen during this installation.

  To change the lens 10, it is not necessary to disassemble the projector. It suffices to push the flexible outer tab 280 away from the housing 10 to separate it from the lug 265 or even to strike this outer tab 280 lightly at its junction with the main body of the glass 10, for example using of a screwdriver, to break this tab 280. It is then enough to pull the glass 10 towards the front of the

  vehicle to separate it from the rest of the housing simultaneously with the gasket 300.

  Advantageously, the tab 280 forms at its junction with the main body of the glass a portion extending in a direction slightly oblique to the direction of the light beam, slightly

leaning back.

  Thus, when the glass is placed on the housing, and that the tab 280 slides on the lug 265, the bottom of the U formed by the tab 280 with the rear edge of the glass comes to bear against the seal 300 at the level of this oblique part leaning backwards. This oblique geometry gives the tab 280, despite its predetermined fragility at its base, a particular resistance against any damage due to this thrust of the seal 300 on the bottom of the tab 280. This bottom, formed by the wall 275, is more precisely provided on its rear face with a slightly protruding plate forming a parallel flat face and facing the front face 263 of the edge

throat 26.

  There is shown in Figure 3, a second embodiment in which the groove 26 has a shape generally similar to that of the previous embodiment and in which the seal 300 is identical to that presented above. The glass 20 has, in its rear part, a foot of glass 25 of substantially cylindrical shape with a main axis coincident with that of light propagation. On its rear end marginal portion, referenced 27, the foot of the glass forms an extension 272 projecting transversely outwards, along a main plane perpendicular to the direction of projection of the light. The cylindrical portion formed by the glass base 25 therefore has, slightly in front of its rear end, a projecting plate 272 forming a flat rib, which runs along the entire contour of the cylindrical part 25, it is at

  say the entire rear contour of the ice.

  This planar rib 272 extends from the cylindrical body 25 at a distance substantially equal to the half-width of the joint 300. Thus, this planar rib 272 covers the assembly with a basic dash of the Q formed by the

seal 300.

  By its face facing the rear of the projector, the planar rib 272 is parallel to the front face 263 formed by the front end of the edge

throat 26.

  In the same way as for the embodiment of FIG. 1, the seal 300 extends by a lateral extension 320 between this planar extension

  272 and the front face 263 of the outer edge of the groove 26.

  The flat rib 272 has, on its rear face and at its edge remote from the main body 25, a flange 273 extending projecting from this rear face. This element 273 forms a joint retaining rim 300 against a possible sliding of the joint away from the glass 20. The rim 273 therefore prevents a possible detachment of the branch of the joint

  300 with respect to the marginal border 27.

  1 * r -1 Between this rim 273 and the outer face of the foot of glass 25, there is a distance equal to the width of the end portion of the outer branch of the joint 26 or basic dash of the omega. Thus, the seal 26 extends over the entire transverse extent of the planar rib 272 between the rim 273 and the marginal edge 27, so that the seal 26 is in contact over the entire

flat rib 272.

  On its front face, the rib 272 also has a projection at its end remote from the foot of glass 25, so that this

  front face forms a receiving cavity for a retaining clip 400.

  This retaining clip 400 extends in this cavity and also away from the glass foot 25 towards the rear of the projector, beyond the groove 26, to come to bear at the rear of this groove 26 against a cavity

external formed thereon.

  The clip 400 is here a metal clip extending at its front end, towards the outside of the projector, in a substantially rectilinear portion, which makes it possible to grasp the clip by hand or to push it back with a

  screwdriver from the front of the vehicle to separate it from the glass 20.

  Thus, it is not necessary to disassemble the projector to change the glass. The geometries of the clip 400 and of the seal 300 are chosen so that the pressure exerted by the clip is conveyed from the glass to the housing only through the seal 300. Thus, in this embodiment as in the embodiment previous embodiment, the glass 20 comes to bear against the housing 10 only through the joint 320. In other words, in no

  the glass 20 does not come into direct contact with the housing 10.

  In this way, even if the seal 300 undergoes a volumetric variation due to its aging or to thermal expansion for example, it remains permanently under pressure since the gripping force of the fixing means is transmitted from the glass to the housing only by through the gasket 300. We therefore obtain a positioning of the glass on the housing

adaptive to the shape of the joint.

  Thus, in the case described here, a narrowing of the seal results in a slight approximation between the glass and the case, sufficiently weak to

  do not modify the shape of the light beam.

  More precisely, whatever the age of the seal or its thermal expansion or contraction, the glass and the housing pinch the seal both at the bottom of the groove 26 and at the portion of the seal

  covering the end of a side wall of the groove.

  Additional metallic or plastic springs may be provided guaranteeing constant pressure once the glass or

  the transparent attached to the case and despite temperature changes.

  Of course, the invention is not limited to the examples described here.

  We can in particular modify the geometry of the groove forming the seat of the seal or the geometry of the arrangements of the glass, bearing the seal. We can also reverse the arrangements described here by applying the seal or the groove on the housing and not on the glass, or by making tabs

  fixing on the case and not on the glass.

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Claims (12)

  1. Motor vehicle headlamp, comprising a window (20), a housing (10) and a seal (300), the window (20) and the case (10) forming for one a groove (26) and for the other a wall (27) intended to penetrate into the groove (26), so that the seal (27) is pinched between the bottom of the groove (26) and a free edge of the wall (27) , the crystal (20) and the shoemaker (10) forming, at a location separate from the bottom of the groove (26), two respective faces (263, 277) which extend opposite transversely to the direction of the depth of the groove (26), characterized in that the seal (300) extends between these two faces (263, 277) opposite so as to be compressed between them.   2. Projector according to one of the preceding claims, characterized   in that the seal (300) is designed to be, in the mounting position, compressed both by the bottom of the groove (26) / edge of the wall (27) pair   penetrating, and at the same time by the pair of said faces (263, 277) opposite.   3. Projector according to claim 1 or 2, characterized in that one of the faces (263, 277) facing each other is formed by the end (263) of a   side wall (262) of the groove (26).   4. Projector according to one of claims 1, 2 or 3, characterized in   that one of the facing faces (263, 277) is formed by an element (272,   275) extending from one side of the penetrating wall (27).   5. Projector according to claim 4, characterized in that said lateral element (272, 275) to the penetrating wall (27) carries an element   attachment (280, 400) connecting the glass (20) and the housing (10).   6. Projector according to claim 5, characterized in that the lateral element (280, 400) forms a support arrangement for a clip   (280) holding retaining the glass (20) on the housing (10).   7. Projector according to claim 5, characterized in that the lateral element (275) forms a flexible tab (280) capable of forming, with an arrangement (265) carried by the groove (26), a lug / edge couple hook (265, 280).   8. Projector according to one of the preceding claims, characterized   in that the glass (20) forms an attachment arrangement between the glass (20) and the housing (10) having sufficient brittleness to be broken by   an operator without damaging the housing (10).   9. Projector according to one of claims 5 to 7, in combination   with claim 8, characterized in that the lateral element (275) has sufficient fragility to be able to be broken by an operator without damaging the housing (10).   10. Projector according to one of the preceding claims,   characterized in that one of the two opposite faces comprises a projecting element (273) capable of retaining the seal (300) against a sliding on this face (277).   11. Projector according to one of the preceding claims,   characterized in that the seal (300) covers the ends of the two walls sides of the throat (26).   12. Projector according to one of the preceding claims,   characterized in that the seal (300) carries, on one of its faces, projecting elements (330) capable of being elastically erased in the mass of the seal (300) by compression against the interior of the groove (26) or against said penetrating wall (27).