FR3140033A1 - System for assembling a headlight mask for a motor vehicle on a reflector made of thermosetting material - Google Patents

Abstract

The invention relates to a system for assembling a projector mask (40) made of thermoplastic material on a reflector (30) of thermosetting material, said system being characterized in that it comprises: - several elastically deformable clipping members ( 43, 44, 45) arranged in the upper part of said mask being spaced transversely from each other and intended to cooperate by snap-fastening, during the assembly of said mask on said reflector by a longitudinal translation movement, with complementary clipping members respective non-elastically deformable (34, 35) provided along the upper edge of this reflector (30); as well as- several vertical retaining members arranged on said mask each transversely at the level of a corresponding clipping member and below the latter, said vertical retaining members being intended to cooperate by interlocking, during the assembly of said mask, with three respective complementary retaining members provided on said reflector. Figure to be published with the abstract: Fig. 4

Description

System for assembling a headlight mask for a motor vehicle on a reflector made of thermosetting material

The present invention relates generally to the field of headlights for motor vehicles. It relates more particularly to a system for assembling a mask of such a headlight made of thermoplastic material on a reflector made of thermosetting material.

A motor vehicle comprises, in a known manner, optical units mounted at the front of said vehicle and commonly referred to as projectors. The latter make it possible, on the one hand, to illuminate the environment of the vehicle to improve the visibility of the driver, in particular in night conditions, and, on the other hand, to signal the position of the vehicle to other road users.

Such a projector conventionally comprises a hollow housing intended to be fixed to the structure of the vehicle, at least one light module housed fixedly in the housing and capable of providing one or more photometric lighting or signaling functions, as well as an external transparent cover glass fixed to the peripheral edge of the housing and covering the light module.

Each light module typically comprises at least one light source associated with a reflector capable of returning the light rays reaching it towards a space to be illuminated.

Some projectors also have a mask inserted between the reflector and the outer cover glass so that at least its front face is visible from outside the projector.

The function of such a mask is to form a transition between the reflector and the outer cover glass by concealing the edges of certain peripheral walls of this reflector while ensuring part of the style of the projector.

The mask is generally treated, for example by a metallization operation of its visible surface, to present an appearance close to that of the edges of the reflector. It thus contributes largely to the definition of the style of the fire considered.

The mask and the reflector are generally each molded as a single piece in a thermoplastic material such as Polycarbonate (PC), Poly-Methyl Methacrylate (PMMA) or Acrylonitrile Butadiene Styrene (ABS) and assembled to each other by screwing or clipping as disclosed for example in document FR 2 805 596 A1.

When the reflector has large dimensions, the geometric deformations of the part resulting from the demolding of the thermoplastic resin or caused by the heat of the light rays coming from the light source(s) are unfortunately significant enough to significantly impact the optical rendering of the photometric function(s) of the projector and lead to non-compliance with regulatory standards.

To avoid this problem, large reflectors are generally molded from a thermosetting material.

Remaining completely geometrically inert, such a thermosetting material does not present any risk of deformation during the injection process or subsequently in use.

Since thermosetting resin is particularly liquid during injection, the molds used cannot be as complex as those used to mold thermoplastic resins. The use of drawer molds is therefore prohibited in order to avoid infiltration, which does not allow the design of geometrically elaborate assembly interfaces.

The use of such a thermosetting material also does not allow the assembly of the reflector by screwing it onto the mask due to the significant risk of the fixing holes being damaged or the reflector cracking/breaking during the screwing operations.

The installation of clipping tabs on such a thermosetting material is also problematic because there is a high risk of breakage of these tabs during clipping operations.

The present invention aims to facilitate the assembly between a projector mask made of thermoplastic material and a reflector made of thermosetting material.

To this end, it proposes a system for assembling a headlight mask for a motor vehicle made of thermoplastic material on a reflector made of thermosetting material, said system being characterized in that it comprises:
- several elastically deformable clipping members arranged in the upper part of said mask while being transversely spaced from each other and designed to cooperate by snap-fastening, during the assembly of said mask on said reflector by a longitudinal translational movement, with respective complementary elastically non-deformable clipping members arranged along the upper edge of this reflector; as well as
- several vertical retaining members arranged on said mask each transversely at the level of a corresponding clipping member and below the latter, said vertical retaining members being designed to cooperate by interlocking, during the assembly of said mask on said reflector, with three respective complementary retaining members provided on said reflector.

The invention thus makes it possible to carry out, in a simple and economical manner, the assembly without play or almost without play between such a thermoplastic mask and such a thermosetting reflector.

No external support or fixing element is required for this assembly. It should also be noted that the absence of a deformable clipping member on the reflector avoids any risk of cracking or breakage on the reflector made of thermosetting material.

According to preferred characteristics of said assembly system according to the invention:
- this comprises three said clipping members associated with three said complementary clipping members and arranged longitudinally in a staggered manner with respect to each other so as to constitute the three vertices of a first support triangle;
- this comprises three said vertical retaining members associated with three said complementary retaining members and arranged longitudinally in a staggered manner opposite each other so as to constitute the three vertices of a second support triangle extending substantially parallel to said first support triangle below the latter;
- said support triangle(s) point forward;
- at least one of said clipping members is constituted by a tab intended to pass through, during assembly of said mask on said reflector, an oblong hole made on said reflector, said tab having a U-shaped cutout delimiting an elastically deformable clipping tab provided with an inclined ramp extending to a retaining notch and intended to cooperate by snap-fastening with said hole;
- at least one of said clipping members is constituted by an elastically deformable tab having a slot intended to cooperate by snap-fastening, during the assembly of said mask on said reflector, with a tooth provided on said reflector and provided with an inclined ramp extending to a retaining step;
- at least one of said vertical retaining members is constituted by a flat rib extending substantially horizontally and designed to cooperate by fitting, during the assembly of said mask on said reflector, with a corresponding slot of complementary thickness provided on said reflector;
- at least one of said vertical retaining members is constituted by a hollow barrel extending longitudinally towards the rear from a wall of said mask and designed to cooperate by fitting, during the assembly of said mask on said reflector, with a corresponding hole of complementary shape and dimensions made on a wall of said reflector; and/or
- said system comprises a lateral centering lug projecting longitudinally towards the rear from a wall of said mask and designed to cooperate in a form-fitting manner, when assembling said mask on said reflector, with a complementary recess provided in a wall of said reflector.

The invention also aims, under a second aspect, at a headlight for a motor vehicle comprising a hollow housing having an opening closed by a transparent outer cover glass, a light module housed in said housing and provided with a reflector made of thermosetting material, as well as a mask made of thermoplastic material interposed between said reflector and said outer cover glass; characterized in that said mask and said reflector are fixedly assembled to each other by such an assembly system.

The description of the invention will now be continued by the detailed description of an exemplary embodiment, given below for illustrative but non-limiting purposes, with reference to the appended drawings, in which:
- represents a front view of a headlight for a motor vehicle comprising a reflector made of thermosetting material and a mask made of thermoplastic material fixed to the latter by an assembly system according to the invention;
- is a three-quarter front perspective view of the projector reflector of the , provided with fixing elements used in the assembly system according to the invention;
- depicts a three-quarter rear perspective view of the projector mask of the , provided with fixing elements used in the assembly system according to the invention;
- is a top view of the reflector/mask subassembly in assembled configuration;
- , , And represent partial sectional views taken at the level of assembly areas following the vertical transverse planes identified respectively by V, VI, VII and VIII on the ;
- is a rear view of the reflector/mask subassembly in assembled configuration; and
- And represent partial sectional views taken at the level of assembly areas following the vertical transverse planes identified respectively by X and XI on the .

There represents a headlight 1 of a motor vehicle intended to be mounted on the body structure of this vehicle by integrating with the contours of the adjacent body parts and those of the bumper.

In the figures, we define an orthogonal reference XYZ comprising three axes perpendicular two by two, namely:
- an X axis, defining a longitudinal direction, parallel to the longitudinal axis of the vehicle,
- a Y axis, defining a transverse, horizontal direction, which with the X axis defines a horizontal XY plane, and
- a Z axis, defining a vertical direction, perpendicular to the horizontal XY plane.

In the description which follows and by convention, the terms “front”, “rear”, “lower”, and “upper” will be defined in relation to the mounting position of this headlight 1 on such a motor vehicle.

Furthermore, the use of the term “substantially” will indicate that a slight deviation is permitted from a predetermined nominal position or arrangement, while remaining within the scope of the invention. For example, “substantially vertical” indicates that a deviation of the order of 10° from a strictly vertical orientation is permitted within the scope of the invention.

As illustrated in the , the projector 1 comprises a hollow housing 10 having an opening 10A and containing a light module capable of providing one or more photometric lighting functions (such as the dipped beam and main beam functions) and/or signaling functions (such as the lantern and indicator functions).

The projector 1 also includes a transparent outer cover glass 20, mounted in a sealed manner on the periphery of the opening 10A of the housing 10.

The light module includes three light sources not visible on the and each consisting, for example, of a white power light-emitting diode implanted on a printed circuit board of the PCB type (for “Printed Circuit Board” in English) mounted on a support.

These three light sources are associated with three respective reflecting walls in the shape of a paraboloid 31 coming from the same reflector 30 shown alone in the figure. .

The front exterior face (i.e. the one facing the exterior cover glass 20) of each of these walls 31 is covered with a reflective metallized coating capable of returning the light rays emitted by the light sources towards a space to be illuminated.

The reflector 30 also comprises three skirts 32 each extending longitudinally forward from a lateral edge and the lower edge of a respective reflecting wall 31, these skirts 32 having striated or grained outer faces in order to break up the light rays reaching them so as to avoid the generation of parasitic reflected rays in unwanted and potentially annoying directions.

In order to present excellent geometric stability despite its large dimensions and the heating caused by the absorption of part of the energy of the light rays striking its reflective walls 31, this reflector 30 is molded in a single piece from a thermosetting polymer resin reinforced with natural and/or synthetic fibers (such as in particular the BMC acronym for the English expression “Bulk Molding Compound” and consisting of an unsaturated polyester resin loaded with glass fibers).

The projector 1 also includes a hollow mask 40 interposed between the reflector 30 and the outer cover glass 20 so that at least its front face is visible from outside the projector.

Represented alone on the , the mask 40 forms a transition between the reflector 30 and the external cover glass 20, in particular by concealing the upper edges of the three reflective walls 31 of this reflector 30.

Made from a single-piece molding from a thermoplastic material such as polycarbonate (PC), polymethyl methacrylate (PMMA) or acrylonitrile butadiene styrene (ABS), the mask 40 is rigidly attached to the reflector 30 by means of an assembly system according to the invention.

This assembly system comprises three elastically deformable clipping members 43, 44, 45 extending from the rear edge of an upper wall of the mask 40 while being spaced transversely from each other (see ) and designed to cooperate by snap-fastening, during the assembly of this mask 40 on the reflector 30 by a translational movement from front to back along the longitudinal axis of demolding of this reflector 30, with three respective complementary clipping members 33, 34, 35 non-elastically deformable arranged along the upper edge of this reflector 30 (see ).

Arranged at a first lateral end of the mask 40, the first clipping member 43 is constituted by a first tab intended to cooperate by snap-fastening with an oblong hole 33 formed at the corresponding lateral end of the upper edge of the reflector 30 (see figures 2 to 5).

Extending longitudinally towards the rear along a substantially horizontal mean plane, this tab 43 has a U-shaped cutout delimiting an elastically deformable clipping tab 431 oriented longitudinally and comprising a ramp 431A tilting upwards and forwards from the proximal rear end of this tab 431 to a retaining step 431B (see ).

When assembling the mask 40 on the reflector 30, the rear end of the tab 43 passes through the oblong slot 33 until the inclined ramp 431A of its tab 431 comes to bear against the upper edge of this hole 33.

The continuation of this translational movement causes the progressive pivoting lowering of the tab 431 as the upper edge of this slot 33 slides along the inclined ramp 431A.

As soon as this inclined ramp 431A has completely crossed the hole 33, the tab 431 returns to its initial position, so that the step 431B now facing the perimeter of the hole 33 prevents the withdrawal of the tab 43 by a translational movement from back to front ( ).

Substantially identical and arranged respectively at a second lateral end of the mask 40 and at a zone laterally distant from the two ends of this mask 40, the clipping members 44 and 45 are constituted by elastically deformable tabs designed to cooperate by snap-fastening with two corresponding teeth 34, 35 formed respectively at the corresponding lateral end of the upper edge of the reflector 30 and at the separation zone between two reflecting walls 31 (see figures 2 to 4, 6 and 7).

Extending longitudinally towards the rear along a substantially horizontal mean plane, each leg 44, 45 has a rectangular light 44A, 45A formed near its free rear end.

As illustrated in Figures 6 and 7, each tooth 34, 35 includes a ramp 34A, 35A sloping upwardly and rearwardly from its forward end to a retaining step 34B, 35B.

When assembling the mask 40 on the reflector 30, the rear end of each of these legs 44, 45 comes to bear against the ramp 34A, 35A of a corresponding tooth 34, 35.

Continuing this translational movement in the assembly direction causes the progressive pivoting lifting of these legs 44, 45 as their rear ends slide along the inclined ramps 34A, 35A, then the insertion of these ramps through the slots 44A, 45A which causes the legs 44, 45 to return to their initial positions. The notches 34B, 35B, now facing the rear edges of the slots 44A, 45A, therefore prevent the legs 44, 45 from being withdrawn by a translational movement from back to front (Figures 6 and 7).

It will be noted with reference to the that the three legs 43, 44, 45 of the mask 40 as well as the three complementary clipping members 33, 34, 35 provided on the reflector 30 are arranged longitudinally in a staggered manner opposite each other so as to constitute the three vertices of a first support triangle pointing forward and of which the central leg 44 as well as the clipping member 34 form the front point.

In reference to the , the assembly system according to the invention also comprises three vertical retaining members 46, 47, 48 each extending transversely at the level of a corresponding clipping tab 43, 44, 45, but below and in front of the latter.

These three vertical retaining members 46, 47, 48 are designed to cooperate by interlocking, during the assembly of this mask 40 on the reflector 30, with three respective complementary retaining members 36, 37, 38 arranged in the upper part of this reflector 30 (see ).

Arranged respectively at the two lateral ends of the mask 40, the retaining members 46, 48 are constituted by two flat ribs extending substantially horizontally and designed to cooperate by fitting with two corresponding slots of complementary thicknesses 36, 38 formed respectively at the two lateral ends of the reflector 30 (see figures 5 and 8).

Arranged transversely at the level of the clipping tab 44, the retaining member 47 is constituted in this case by a hollow cylindrical barrel extending longitudinally towards the rear from a substantially vertical wall of the mask 40 and designed to cooperate by fitting with a corresponding drilling of complementary shape and dimensions 37 made on a wall of the reflector 30 (see ).

It will be noted with reference to Figures 2 and 3 that the three vertical retaining members 46, 47, 48 of the mask 40 as well as the three complementary retaining members 36, 37, 38 provided on the reflector 30 are arranged longitudinally in a staggered manner with respect to each other so as to constitute the three vertices of a second support triangle pointing forward and extending substantially parallel to the first support triangle below the latter, with the central member 47 as well as the complementary member 37 which form its front point.

The action of these two support triangles offset vertically and longitudinally from each other thus ensures excellent stability of the mask 40 on the reflector 30 after its assembly, without risk of pivoting of one relative to the other.

It will also be noted in reference to the that the form-fitting cooperation between the hollow cylindrical barrel 47 and the bore 37 also makes it possible to ensure the lateral centering of the mask 40 with respect to the reflector 30.

As illustrated by the and in order to ensure even more precise lateral centering, the assembly system according to the invention also advantageously comprises a lug 49 (also visible on the ) projecting longitudinally rearward from a wall of the mask 40 near the tab 45 and designed to cooperate in a form-fitting manner, when assembling this mask 40 on the reflector 30, with a complementary recess 39 (also visible on the ) arranged in a wall of the reflector 30 near the tooth 35.

According to embodiment variants not shown, the number and/or the conformation of the clipping and/or vertical retaining members provided on the mask may differ. The same applies to the number and/or the conformation of the complementary clipping and/or retaining members.

According to other embodiments not shown, the mask and the reflector may be devoid of specific centering means such as the lug 49 and the recess 39.

Finally, it is recalled that the present invention is not limited to the embodiments described and shown, but also encompasses all variants of execution within the reach of those skilled in the art.

Claims (10)

System for assembling a mask (40) of a projector (1) for a motor vehicle made of thermoplastic material on a reflector (30) made of thermosetting material, said system being characterized in that it comprises:
- several elastically deformable clipping members (43, 44, 45) arranged in the upper part of said mask (40) while being transversely spaced from each other and designed to cooperate by snap-fastening, during the assembly of said mask (40) on said reflector (30) by a longitudinal translational movement, with respective complementary elastically non-deformable clipping members (33, 34, 35) arranged along the upper edge of this reflector (30); as well as
- several vertical retaining members (46, 47, 48) arranged on said mask (40) each transversely at the level of a corresponding clipping member (43, 44, 45) and below the latter, said vertical retaining members (46, 47, 48) being designed to cooperate by interlocking, during the assembly of said mask (40) on said reflector (30), with three respective complementary retaining members (36, 37, 38) provided on said reflector (30). Assembly system according to claim 1, characterized in that it comprises three said clipping members (43, 44, 45) associated with three said complementary clipping members (33, 34, 35) and arranged longitudinally in a staggered manner opposite each other so as to constitute the three vertices of a first support triangle. Assembly system according to claim 2, characterized in that it comprises three said vertical retaining members (46, 47, 48) associated with three said complementary retaining members (36, 37, 38) and arranged longitudinally in a staggered manner opposite each other so as to constitute the three vertices of a second support triangle extending substantially parallel to said first support triangle below the latter. Assembly system according to one of claims 2 or 3, characterized in that said support triangle(s) point forward. Assembly system according to one of claims 1 to 4, characterized in that at least one of said clipping members (43, 44, 45) is constituted by a tab (43) intended to pass through, during the assembly of said mask (40) on said reflector (30), an oblong hole (33) formed on said reflector (30), said tab (43) having a U-shaped cutout delimiting an elastically deformable clipping tab (431) provided with an inclined ramp (431A) extending to a retaining step (431B) and intended to cooperate by snap-fastening with said hole (33). Assembly system according to one of claims 1 to 5, characterized in that at least one of said clipping members (43, 44, 45) is constituted by an elastically deformable tab (44, 45) having a slot (44A, 45A) intended to cooperate by snap-fastening, during the assembly of said mask (40) on said reflector (30), with a tooth (34, 35) formed on said reflector (30) and provided with an inclined ramp (34A, 35A) extending to a retaining step (34B, 35B). Assembly system according to one of claims 1 to 6, characterized in that at least one of said vertical retaining members (46, 47, 48) is constituted by a flat rib (46, 48) extending substantially horizontally and designed to cooperate by fitting, during the assembly of said mask (40) on said reflector (30), with a corresponding slot of complementary thickness (36, 38) formed on said reflector (30). Assembly system according to one of claims 1 to 7, characterized in that at least one of said vertical retaining members (46, 47, 48) is constituted by a hollow barrel (47) extending longitudinally towards the rear from a wall of said mask (40) and designed to cooperate by fitting, during the assembly of said mask (40) on said reflector (30), with a corresponding hole of complementary shape and dimensions (37) formed on a wall of said reflector (30). Assembly system according to one of claims 1 to 8, characterized in that it comprises a lateral centering lug (49) projecting longitudinally towards the rear from a wall of said mask (40) and designed to cooperate in a form-fitting manner, when assembling said mask (40) on said reflector (30), with a complementary recess (39) formed in a wall of said reflector (30). Headlight for a motor vehicle (1) comprising a hollow housing (10) having an opening (10A) closed by a transparent outer cover glass (20), a light module housed in said housing (10) and provided with a reflector made of thermosetting material (30), as well as a mask made of thermoplastic material (40) interposed between said reflector (30) and said outer cover glass (20); characterized in that said mask (40) and said reflector (30) are fixedly assembled to each other by an assembly system according to one of claims 1 to 9.