FR3123963A1 - Optical module housing of a motor vehicle lighting and/or signaling device. - Google Patents

Abstract

Housing (1) for an optical module of a lighting and/or signaling device of a motor vehicle, said housing (1) comprising first (2) and second (3) parts of complementary shape obtained after injection molding of a thermoplastic material and of which at least one of the two parts (2 or 3) is partially provided with metallization zones (5), said box (1) comprising a determined cutting profile (P) defining a mechanical assembly interface (4) first (2) and second (3) parts on top of each other; said interface (4) being arranged on at least one of the edges of one of the two parts (2 or 3) provided with a metallization zone (5), in the vicinity of the metallization zone (5) to take account of the stresses molding and metallization. (Figure 1)

Description

Optical module housing of a motor vehicle lighting and/or signaling device.

The invention generally relates to motor vehicle lighting and/or signaling devices and is more particularly concerned with an optical module housing of a lighting and/or signaling device such as a vehicle headlight. automobile.

By optical module, also referred to as an optical unit, is meant a device comprising at least one light source associated with optical means or components such as lenses, reflectors and the like for generating at least one light beam in a determined direction. An optical module is generally contained in a box which itself belongs to, or is attached to, a motor vehicle headlamp. A projector can include one or more optical modules.

To make the visible part of the optical module more attractive while hiding the so-called "technical" parts comprising the internal components of the module, the box can be provided with a stylistic covering giving an attractive appearance to the box and therefore to the optical module in its part. visible to an observer located outside the vehicle in which the optical module is integrated (at the front of the vehicle in the case of a headlight).

The case, which matches the external shape of the module, is in the form of a plastic shell obtained by an injection molding process of a thermoplastic material such as ABS (Acrylonitrile butadiene styrene) or PC (polycarbonate ). These materials are generally dark in color: gray or even black. To decorate the case which is obtained from these materials, it is known to at least partially cover the case with thin layers of aluminum oxide (alumina) according to a known metallization process. A process for the partial metallization of plastic parts is known in particular from document FR2944717A.

The shape, dimensions and volume of the case must meet technical (mechanical strength) and stylistic constraints and must also meet the constraints of the injection molding and partial metallization processes in several distinct areas chosen to amplify the stylistic effect of the optical module.

The aim of the invention is therefore in particular to provide a covering solution making it possible to meet all the constraints set out above.

The first subject of the invention is an optical module housing of a lighting and/or signaling device of a motor vehicle, said housing comprising first and second parts of complementary shape obtained after injection molding of a thermoplastic material and of which at least one of the two parts is partially provided with zones of metallization, said box comprising a determined cutting profile defining a mechanical interface for assembly of the first and second parts one on the other; said interface being arranged on at least one of the edges of one of the two parts provided with a metallization zone, in the vicinity of the metallization zone to take account of the molding and metallization constraints.

According to one characteristic, the case has the general shape of a rectangular parallelepiped; the first and second parts of the case, facing each other, respectively comprise edges extending over the two large side faces of the case, facing each other; said edges belonging to the mechanical assembly interface respectively defining assembly ramps cooperating with each other at the time of assembly of the first and second parts according to a determined assembly direction.

According to another characteristic, the first and second parts comprise axial retaining means and lateral retaining means cooperating respectively with each other to ensure the axial and lateral locking of the assembly of the first and second parts of the case.

According to another feature, the case further comprises a fixing interface arranged on the first and second parts of the case; said fixing interface being able to fix the box on an optical module support in an axial direction of the box.

According to another characteristic, the box further comprises first and second extension parts of the first and second parts of the box; the first and second extension parts extending in the same plane extending perpendicularly to a median plane passing through the longitudinal axis of the casing; the first and second extension parts supporting the fixing interface.

According to another characteristic, the first and second extension parts of the case define a mask vis-à-vis a support intended to receive the fixing interface of the case.

According to another characteristic, the assembly formed by the first and second parts of the case defines a covering shell for an optical module of a lighting and/or signaling device; said shell having areas of metallization and areas devoid of metallization.

A second object of the present invention is an optical block equipped with a box as described above.

A third object of the present invention is a motor vehicle lighting and/or signaling device comprising an optical unit as described above.

Finally, a fourth object of the present invention is a motor vehicle headlamp comprising at least one optical unit as described above.

The advantage of having a box cut into two parts is to make it possible to determine a cutting profile of the box defining an assembly interface which advantageously separates the zones in which the injection molding and metallization processes are not technically compatible. by making it possible to treat these zones separately before the assembly of the two parts of the box.

Other characteristics and advantages of the invention will appear on examination of the detailed description below, and of the appended drawing, in which:

illustrates, in a perspective view, an embodiment of a box according to the invention with the two parts of the box assembled;

illustrates the box according to the invention mounted on an optical block, according to a view in longitudinal section;

illustrates, in a perspective view, the box according to the invention before the assembly of the two parts of the box;

illustrates, in a perspective view, the box according to the invention during the assembly of the two parts of the box;

illustrates the box according to the invention with the support of the optical unit, according to a cross-sectional view along the section axis II-II of the ;

illustrates the box according to the invention in a perspective view, seen from the rear of the box, before the assembly of the two parts of the box;

illustrates, in a perspective view, the attachment interface of the case according to the invention;

illustrates in a perspective view, the optical module in its support intended to receive the box according to the invention;

illustrates in a perspective view, the assembly consisting of the optical module in its support and the box according to the invention, fixed to the support;

illustrates the assembly shown in , with a mask attached around the rear part of the case according to the invention;

illustrates, according to a front view, in perspective, a variant of the embodiment of the case according to the ; and

illustrates, according to a rear view, in perspective, the variant of the embodiment of the .

In what follows, the optical module is considered to be part of a motor vehicle headlamp.

The elements represented in the figures are oriented inside the same orthonormal reference frame XYZ and the identical elements are designated by the same alphanumeric references.

For this and unless otherwise specified, reference is made to the orthonormal reference XYZ to identify the directions of extension of the vehicle and the associated relative concepts, including a longitudinal direction (along X), a transverse direction (along Y) and a vertical direction (according to Z). The longitudinal direction X extends between the front and the rear of the vehicle, the transverse direction Y extends between the right and left lateral sides of the vehicle identified with respect to the driver in the driving position of the vehicle, and the vertical direction Z defines the extension of the vehicle in elevation from its rolling plane on the ground. As a result, the front and rear relative notions are identified longitudinally, the lateral notion and the right and left relative notions are identified transversely, the notions like upper and lower or other related relative notions like bottom and top, etc. are defined vertically with respect to the taxiing plan of the vehicle on the ground.

The illustrates, in perspective, an embodiment of an optical module housing 1 according to the invention. In this figure, it is clearly visible that the box 1 defines a kind of shell whose interior size is adapted to closely fit the optical module which in this figure is not shown.

Case 1 has the general shape of a rectangular parallelepiped in two parts. It comprises an upper half-shell 2 and a lower half-shell 3 of complementary shape which are assembled and locked together via a mechanical assembly interface 4, symbolically illustrated in the figure by a line segment in broken lines.

This interface 4 is defined by a so-called cutting profile P which has been determined to take into account the style constraints and the constraints linked to the injection molding and metallization processes as already mentioned above.

In the figure, the cutting profile P has been materialized by a dashed line.

The two half-shells 2 and 3 were obtained by an injection molding process of a thermoplastic material such as ABS or PC which has a basic dark, gray or even black tint as also already mentioned above. In the embodiment described, the material has a black color and consequently the two half-shells 2 and 3 are basically black in color.

The upper half-shell 2 which is the most visible for an observer placed at the front of the vehicle, is provided with facets 5 and 6 substantially in relief with respect to the outer surface of the upper half-shell 2 (the facets 5 are noticeably more in relief than the facets 6). Facets 5 and 6 are obtained directly by the molding process. They form a kind of scales on the outer surface of the upper half-shell 2.

In the embodiment described, the facets 5 (which are the most in relief) are covered with a thin layer of aluminum (alumina). The other facets 6 are for their part devoid of metallization and therefore have a black tint. The metallization has the aesthetic effect of presenting on the outer surface of the upper half-shell 2 shiny zones—zone provided with metallization—alternating with dark (black) zones devoid of metallization.

The partial metallization process, disclosed in particular in the document FR2944717A, implements a masking tool, or marouflage, 7 symbolized on the by its peripheral edges. The smoothing tool 7 has a size (or grip on the part of the part to be metallized) which requires the provision of a sufficiently clear space around the zone to be metallized. The masking tool 7 generally largely covers the periphery of the parts, or parts of parts, to be metallized (here the facets in relief 5). Parallel arrows oriented towards the facets 5 symbolically represent the operation of metallization of the facets 5.

The cutting profile P of the mechanical assembly interface 4 is optimized to pass in the vicinity of the facets 5 (the side edges of the two half-shells 2 and 3 respectively follow this cutting profile P) and thus allows positioning without hindrance of the masking tool 7 for the implementation of the metallization process and this, respecting a configuration imposed by the style.

As illustrated at , according to a view in longitudinal section (following the X axis), the two upper and lower half-shells, respectively referenced 2 and 3, both end in a part advancing towards the front of the case 1 which defines respectively "caps" (or visors) 8 and 9 vis-à-vis the optical lens 10 belonging to the optical module 11 and which closes the optical module 11 at the front of the optical module 11. 8 the cap of the upper half-shell 2, and by "lower cap" 9, the cap of the lower half-shell 3.

The small thickness of the free end parts of the caps 8 and 9, arranged respectively at the top and at the bottom of the optical lens 10, as imposed by the style, makes it impossible to produce them in a single piece by a molding process by injection for the following reasons:

- the introduction of a thin steel blade into the mold in the internal part of the mold, to produce the end part of the upper cap 8, having an almost closed cavity, makes this top fragile to the pressures applied clearance during the injection step;

- risk of mold breakage may occur when the blade cools;

- an uncontrolled deformation of the blade can lead to uncontrolled changes in thickness and, in the end:

- visual quality problems on the injected part due to uneven cooling may appear.

To circumvent this problem and as illustrated in Figures 2 and 3 in particular, the lower half-shell 3 is extended forwards in its upper part, by an extension 12 which participates in the consolidation of the free end part of the cap upper 8. The free end part of the upper cap 8 is therefore produced by assembling the two half-shells 2 and 3: the outer part of the upper cap 8 is obtained by the upper half-shell 2 and the part inner part of the upper cap 2 (inner part of the free end part) by the extension 12 of the lower half-shell 3. The extension 12 of the lower half-shell 3 with the lower cap 9 of the lower half-shell lower shell 3, define a perforated front face 13 of the case 1 framing the optical lens 10 of the optical module 11. The extension 12 is connected to the lower half-shell 3 by two lateral arms 14 and 15.

The lower half-shell 3 is fully metallized with the exception of the inner surface of the extension 12 which is devoid of metallization. For this purpose, the junctions of the two arms 14 and 15 of the extension 12 with the lower half-shell 3 are locally thinned to create areas of influence of the masking tool 7 intended to mask the surface not to be metallized. .

The lower cap 9 remains one-piece. It advantageously comprises an open cavity 16 ( ) in its lower outer part (therefore not visible to an observer, once the box 1 is installed in the vehicle) making it possible to avoid the molding problems described above.

In general, the cutting profile P of the mechanical assembly interface 4 of the two half-shells 2 and 3 is advantageously arranged to ensure that the smoothing tool 7 always largely covers the periphery of the part. or the part of the part to be metallized (facets 5 and lower half-shell 3).

The cutting profile P of the assembly interface 4 is also advantageously arranged to define guide ramps 16 and 17 ( ) for the respective side edges of the side faces of the two half-shells 2 and 3 during their assembly. The assembly direction (symbolized on the by a double solid arrow 18) is thus done in the general direction of the cutting profile P.

The axial locking (in the direction of assembly 18) of the two half-shells 2 and 3 is ensured by retaining means 19 to 22 distributed respectively, at the front of the case 1 ( and ). The retaining means comprise a stop 19 projecting from the front edge of the extension 12 of the lower half-shell 3 cooperating with a housing 20 arranged in the end part of the upper cap 8. The retaining means further comprise clipping means 21 and 22 arranged behind the means 19 and 20 and respectively distributed over the extension 12 and the free end part of the upper cap 8. The clipping means 21 and 22 cooperate with each other to ensure locking axial of the two half-shells 2 and 3 when the stop 19 comes to the end of its travel in the housing 20.

The lateral locking (along the Y axis) of the two half-shells 2 and 3 is ensured at the rear of the case 1 by two pairs of clipping means 23 and 24 ( ) arranged respectively on the two lateral edges of the two half-shells 2 and 3. These two pairs of clipping means 23 and 24 allow lateral locking by preventing the opening of the two half-shells 2 and 3.

In order to prevent the free end part of the upper cap 8 from collapsing, two ribs 25 and 26 are arranged projecting from the upper lateral edges of the extension 12 of the lower shell 3. These ribs 25 and 26 cooperate respectively with corresponding grooves 27 and 28 arranged in the upper cap 8 of the upper half-shell 2.

Once the two half-shells 2 and 3 are assembled and locked ( ), the box 1 is itself fixed axially (along the axis X) on the rear part of the support 29 ( ) by a fixing interface comprising male clipping means 30, 31, 32, defining three tabs integral with the rear edges of the two half-shells 2 and 3: a tab 30 integral with the upper half-shell 2 and the lugs 31 and 32 integral with the lower half-shell 3.

The male clipping means 30, 31 and 32 ( ), belonging to the fixing interface, cooperate respectively with female clipping means 33, 34, 35 ( ) distributed over a receiving face 36 of the rear part of the support 29, defining a plane extending along YZ to ensure the axial locking of the case 1 on the rear part of the support 29. The female clipping means 33, 34 and 35 respectively define three housings receiving the legs 30, 31 and 32.

As shown in , the two half-shells 2 and 3 are thus held in the rear part of the support 29 and the box 1 is mounted cantilevered in front of the reception face 36.

To stiffen the assembly of the box 1 on the front part of the support 29 containing the optical module, 10, 11, longitudinal ribs 37, 38 and 39 ( ), are arranged along the entire length of the front part of the support 29 of the optical module 10, 11 extending along the axis X. These same ribs 37, 38 and 39 form support stops, here numbering three, arranged around the support 29 so as to form an isostatic system ( ). The is a cross section (along Y) of the assembly formed by the support 29 and the box 1: the section being considered along the section axis II-II of the . Thus, the box 1 can no longer move either vertically (along the Z axis) or transversely (along the Y axis) relative to the front part of the support 29.

Finally, with reference to the , to mask the rear part of the support 29 and its associated technical parts (in particular the fixing interface), an additional mask 40 extending substantially along a vertical plane (along YZ), parallel to the receiving face 36 of the case 1, can be added around the box 1 in its rear part leaving visible, for an outside observer located at the front of the vehicle, only the box and the lens 10 of the optical unit 11.

Alternatively and with reference to Figures 11 and 12, the mask can be an integral part of the box 1 '. The mask is then divided into two parts 41 and 42: a first part 41 is made in one piece with the rear part of the upper half-shell 2' and a second part 42 is made in one piece with the rear part of the lower half-shell 3 '. Mask 41, 42 extends in a YZ plane parallel to host face 36 of support 29.

With reference to the , additional clipping means 43 and 44 are provided, at the mechanical assembly interface of the two half-shells 2' and 3', respectively on the first and second mask parts 41 and 42. They cooperate with each other to ensure the locking of the rear part of the two half-shells 2' and 3' and of the two mask parts 41 and 42 in an inclined direction corresponding to the assembly direction 18 ( ).

Three fixing lugs, referenced 45, 46 and 47 respectively, extend in the same direction (along X) perpendicular to the YZ plane in which the two mask parts 41 and 42 extend. rear face of the first mask part 41 and the two tabs 46 and 47 are integral with the rear face of the second mask part 42. There is substantially the same distribution of the tabs 45, 46 and 47 at the rear of the case 1' than those of legs 30, 31 and 32 of the .

Claims (10)

Housing (1) for an optical module of a lighting and/or signaling device of a motor vehicle, said housing (1) comprising first (2) and second (3) parts of complementary shape obtained after injection molding of a thermoplastic material and of which at least one of the two parts (2 or 3) is partially provided with metallization zones (5), said box (1) comprising a determined cutting profile (P) defining a mechanical assembly interface (4) first (2) and second (3) parts on top of each other; said interface (4) being arranged on at least one of the edges of one of the two parts (2 or 3) provided with a metallization zone (5), in the vicinity of the metallization zone (5) to take account of the stresses molding and metallization. Case (1) according to the preceding claim, having the general shape of a rectangular parallelepiped; the first (2) and second (3) parts of the case (1), facing each other, respectively comprise edges extending over the two large side faces of the case (1), facing the one another; said edges belonging to the mechanical assembly interface (4) respectively defining assembly ramps (16, 17) cooperating with each other when the first (2) and second (3) parts are assembled in a direction d determined assembly (18). Case (1) according to the preceding claim, in which the first (2) and second (3) parts comprise axial retaining means (19-22) and lateral retaining means (23, 24) cooperating respectively with each other to ensure the axial and lateral locking of the assembly of the first (2) and second (3) parts of the box (1). Case (1) according to one of the preceding claims, further comprising a fixing interface (30-32) arranged on the first (2) and second (3) parts of the case (1); said fixing interface (30-32) being capable of fixing the box (1) on an optical module support in an axial direction (X) of the box (1). Box (1') according to the preceding claim, further comprising first (41) and second (42) extension parts of the first (2') and second (3') parts of the box (1'); the first (41) and second (42) extension parts extending in the same plane (YZ) extending perpendicularly to a median plane passing through the longitudinal axis (X) of the box (1'); the first (41) and second (42) extension parts supporting the fixing interface (45-47). Box (1') according to the preceding claim, in which the first (41) and second (42) extension parts of the box (1') define a mask vis-à-vis a support intended to receive the interface fixing (45-47) of the box (1'). Case (1; 1') according to one of the preceding claims, in which the assembly formed by the first (2; 2') and second (3; 3') parts of the case (1; 1') defines a shell covering for an optical module of a lighting and/or signaling device; said shell having metallization zones (5) and zones (6) devoid of metallization. Optical unit (10, 11) fitted with a box (1; 1') according to one of the preceding claims. Motor vehicle lighting and/or signaling device comprising an optical unit (10, 11) according to the preceding claim. Motor vehicle headlamp comprising at least one optical unit (10, 11) according to claim 8.