Housing for an optical module of a lighting and / or signalling device for a motor vehicle

Abstract

The invention relates to a housing (1, 1') for an optical module of a lighting and / or signalling device of a motor vehicle, the housing (1, 1') having first (2, 2') and second (3, 3') parts of complementary shape that are obtained following injection-moulding of a thermoplastic material and of which at least one of the two parts (2, 2' or 3, 3') is provided partially with metallization zones (5), the housing (1, 1') having a predetermined cutting-line profile (P) defining a mechanical interface (4, 4') for the assembly of the first (2, 2') and second parts (3, 3') with one another; the interface (4, 4') being arranged on at least one of the edges of one of the two parts (2, 2' or 3, 3') provided with a metallization zone (5), in the vicinity of the metallization zone (5) in order to take account of moulding and metallization stresses.

Description

[0001] The invention generally relates to lighting and / or signaling devices for motor vehicles and is more particularly concerned with an optical module housing for a lighting and / or signaling device such as a motor vehicle headlight.

[0002] An optical module, also known as an optical unit, means a device comprising at least one light source associated with optical means or components such as lenses, reflectors and others to generate at least one light beam in a given direction. An optical module is generally contained in a housing which itself belongs to, or is attached to, a motor vehicle headlight. A headlight may comprise one or more optical modules.

[0003] 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 housing may be provided with a stylistic covering giving an attractive appearance to the housing and therefore to the optical module in its visible part for an observer located outside the vehicle in which the optical module is integrated (at the front of the vehicle in the case of a projector).

[0004] The casing, 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 enhance the casing obtained from these materials, it is known to at least partially cover the casing with thin layers of aluminum oxide (alumina) using a known metallization process. A process for partial metallization of plastic parts is known in particular from document FR2944717A.

[0005] 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 zones chosen to amplify the stylistic effect of the optical module.

[0006] Furthermore, the state of the art is known from documents US2004042230A1, EP3212992B1, EP3597986A1 and EP3260764A1.

[0007] The invention therefore aims in particular to provide a cladding solution making it possible to meet all the constraints set out above.

[0008] The invention has as its first subject, an optical module housing of a lighting and / or signaling device of a motor vehicle, said housing comprising first and second parts of complementary shapes obtained after injection molding of a thermoplastic material and of which at least one of the two parts is partially provided with metallization zones, said housing comprising a determined cutting profile defining a mechanical interface for assembling the first and second parts on each 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 into account the molding and metallization constraints, said housing further comprising a fixing interface arranged on the first and second parts of the housing;said fixing interface being capable of fixing the housing on an optical module support in a longitudinal direction of the housing. As well as first and second extension parts of the first and second parts of the housing; the first and second extension parts extending in the same plane extending perpendicular to a median plane passing through the longitudinal axis of the housing; the first and second extension parts supporting the fixing interface, characterized in that the first and second extension parts of the housing define a mask with respect to a support intended to receive the fixing interface of the housing.;

[0009] According to one characteristic, the housing has a general shape of a rectangular parallelepiped; the first and second parts of the housing, facing each other, respectively comprise edges extending over the two large lateral faces of the housing, 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.

[0010] According to another characteristic, the first and second parts comprise axial retaining means and lateral retaining means cooperating respectively with each other to ensure axial and lateral locking of the assembly of the first and second parts of the housing.

[0011] According to another characteristic, the assembly formed by the first and second parts of the housing defines a covering shell for an optical module of a lighting and / or signaling device; said shell having metallization zones and zones devoid of metallization.

[0012] The second object of the present invention is an optical unit equipped with a housing as described above.

[0013] The third subject of the present invention is a lighting and / or signaling device for a motor vehicle comprising an optical unit as described above.

[0014] Finally, the present invention has as its fourth object, a motor vehicle headlight comprising at least one optical unit as described above.

[0015] The advantage of having a case cut into two parts is that it allows a case cutting profile to be determined, defining an assembly interface that advantageously separates the areas in which the injection molding and metallization processes are not technically compatible, by allowing these areas to be treated separately before assembling the two parts of the case.

[0016] Other characteristics and advantages of the invention will appear on examining the detailed description below, and the attached drawing, in which: [ Fig.1 ] illustrates, in a perspective view, an embodiment of a housing outside the scope of the invention with the two parts of the housing assembled; [ Fig.2 ] illustrates the housing coming out of the scope of the invention mounted on an optical block, according to a longitudinal sectional view; [ Fig.3 ] illustrates, in a perspective view, the housing outside the scope of the invention before the assembly of the two parts of the housing; [ Fig.4 ] illustrates, in a perspective view, the housing coming outside the scope of the invention during the assembly of the two parts of the housing; [ Fig.5 ] illustrates the housing coming out of the scope of the invention with the support of the optical block, according to a cross-sectional view along the cutting axis II-II of the figure 2 ; [ Fig.6 ] illustrates the case coming outside the scope of the invention according to a perspective view, seen from the rear of the case, before the assembly of the two parts of the case; [ Fig.7 ] illustrates, in a perspective view, the attachment interface of the housing outside the scope of the invention; [ Fig.8 ] illustrates, in a perspective view, the optical module in its support intended to receive the housing outside the scope of the invention; [ Fig.9 ] illustrates in a perspective view, the assembly consisting of the optical module in its support and the housing outside the scope of the invention, fixed on the support; [ Fig.10 ] illustrates the set illustrated in the figure 9 , with a mask added around the rear part of the case coming outside the scope of the invention; [ Fig.11 ] illustrates, in a front view, in perspective, an embodiment of the housing according to the invention; and [ Fig.12 ] illustrates, in a rear view, in perspective, the embodiment of the figure 11 .

[0017] In the following, the optical module is considered to be part of a motor vehicle headlight.

[0018] The elements represented in the figures are oriented within the same orthonormal XYZ reference frame and identical elements are designated by the same alphanumeric references.

[0019] For this purpose and unless otherwise specified, reference is made to the orthonormal reference system 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 (along Z). The longitudinal direction X extends between the front and rear of the vehicle, the transverse direction Y extends between the right and left lateral sides of the vehicle identified in relation to the driver at the vehicle's driving position, and the vertical direction Z defines the extension of the vehicle in elevation from its rolling plane on the ground. Consequently, the relative concepts front and rear are identified longitudinally, the lateral concept and the relative concepts right and left are identified transversely, the concepts such as upper and lower or other related relative concepts such as low and high, ...are defined vertically relative to the vehicle's rolling plane on the ground.

[0020] There figure 1 illustrates, in perspective, an embodiment of an optical module housing 1 outside the scope of the invention. In this figure, it is clearly visible that the housing 1 defines a sort of shell whose internal size is adapted to fit as closely as possible the optical module which in this figure is not shown.

[0021] The housing 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 broken line segment.

[0022] This interface 4 is defined by a so-called cutting profile P which was determined to take into account the style constraints and the constraints linked to the injection molding and metallization processes as already mentioned above.

[0023] In the figure, the cutting profile P has been shown by a broken line.

[0024] 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 color 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.

[0025] 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 which are substantially raised relative to the outer surface of the upper half-shell 2 (facets 5 are substantially more raised than facets 6). Facets 5 and 6 are obtained directly by the molding process. They form a kind of scale on the outer surface of the upper half-shell 2.

[0026] In the embodiment described, the facets 5 (which are the most raised) are covered with a thin layer of aluminum (alumina). The other facets 6 are 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 areas - area provided with metallization - alternating with dark (black) areas devoid of metallization.

[0027] The partial metallization process, disclosed in particular in document FR2944717A, uses a masking tool, or marouflage, 7 symbolized on the figure 5 by its peripheral edges. The marouflage tool 7 has a size (or footprint on the part of the part to be metallized) which requires providing a sufficiently clear space around the area to be metallized. The marouflage tool 7 generally covers a large part of the periphery of the parts, or parts of parts, to be metallized (here the raised facets 5). Parallel arrows oriented towards the facets 5 symbolically represent the metallization operation of the facets 5.

[0028] The cutting profile P of the mechanical assembly interface 4 is optimized to pass in the vicinity of the facets 5 (the lateral edges of the two half-shells 2 and 3 respectively follow this cutting profile P) and thus allows the positioning without hindrance of the marouflage tool 7 for the implementation of the metallization process, while respecting a configuration imposed by the style.

[0029] As illustrated in the figure 2 , according to a longitudinal sectional view (along the X axis), the two upper and lower half-shells, respectively referenced 2 and 3, both end with a part advancing towards the front of the housing 1 which respectively define “caps” (or visors) 8 and 9 with respect to 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. The term “upper cap” 8 will designate the cap of the upper half-shell 2, and the term “lower cap” 9 will designate the cap of the lower half-shell 3.

[0030] The small thickness of the free end portions of the caps 8 and 9, arranged respectively at the top and bottom of the optical lens 10, as imposed by the style, makes it impossible to produce them in a single piece by an injection molding process 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 it very fragile to the pressures brought into play during the injection step; risks of breakage of the mold can occur when the blade cools; uncontrolled deformation of the blade can lead to uncontrolled changes in thickness and, ultimately: visual quality problems on the injected part due to heterogeneity of the cooling can appear.

[0031] To work around this problem and as illustrated in figures 2 And 3in particular, the lower half-shell 3 extends forward in its upper part, by an extension 12 which participates in the consolidation of the free end part of the upper cap 8. The free end part of the upper cap 8 is therefore produced by the assembly of 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 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 3, define an openwork front face 13 of the housing 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.

[0032] 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 gripping areas for the marouflage tool 7 intended to mask the surface not to be metallized.

[0033] The lower cap 9 remains a single piece. It advantageously includes an open cavity 16 ( Fig. 1 ) in its lower external 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.

[0034] Generally speaking, 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 marouflage 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).

[0035] The cutting profile P of the assembly interface 4 is also advantageously arranged to define guide ramps 16 and 17 ( Fig. 4 ) for the respective lateral edges of the lateral faces of the two half-shells 2 and 3 during their assembly. The assembly direction (symbolized on the figure 4 by a double solid arrow 18) is thus done in the general direction of the cutting profile P.

[0036] The axial locking (along the assembly direction 18) of the two half-shells 2 and 3 is ensured by retaining means 19 to 22 distributed respectively, at the front of the housing 1 ( Fig. 2 And Fig. 6 ). 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 distributed respectively 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 the axial locking of the two half-shells 2 and 3 when the stop 19 reaches 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 housing 1 by two pairs of clipping means 23 and 24 ( Fig. 6 ) 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 while preventing the two half-shells 2 and 3 from opening.

[0037] In order to prevent the free end portion of the upper cap 8 from sagging, two ribs 25 and 26 are provided 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 provided in the upper cap 8 of the upper half-shell 2.

[0038] Once the two half-shells 2 and 3 are assembled and locked ( Fig. 7 ), the box 1 is itself fixed longitudinally (along the X axis) on the rear part of the support 29 ( Fig. 8 ) 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 tabs 31 and 32 integral with the lower half-shell 3.

[0039] The male clipping means 30, 31 and 32 ( Fig. 7 ), belonging to the fixing interface, cooperate respectively with female clipping means 33, 34, 35 ( Fig. 8 ) distributed on 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 housing 1 on the rear part of the support 29. The female clipping means 33, 34 and 35 respectively define three housings receiving the tabs 30, 31 and 32.

[0040] As illustrated in the figure 9 , the two half-shells 2 and 3 are thus held in the rear part of the support 29 and the housing 1 is mounted cantilevered in front of the receiving face 36.

[0041] To stiffen the assembly of the housing 1 on the front part of the support 29 containing the optical module, 10, 11, longitudinal ribs 37, 38 and 39 ( Fig. 8 ), are arranged along the entire front part of the support 29 of the optical module 10, 11, extending along the X axis. These same ribs 37, 38 and 39 form support stops, here three in number, arranged around the support 29 so as to form an isostatic system ( Fig. 5 ). There figure 5 is a cross-section (along Y) of the assembly formed by the support 29 and the housing 1: the section being considered along the cutting axis II-II of the figure 2 . 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.

[0042] Finally, with reference to the figure 10 , 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 housing 1, can be attached around the housing 1 in its rear part leaving visible, for an external observer located at the front of the vehicle, only the housing and the lens 10 of the optical unit 11.

[0043] In one embodiment of the invention and with reference to figures 11 et 12 , the mask is an integral part of the housing 1'. The mask is divided into two parts 41 and 42: a first part 41 is made of the same material as the rear part of the upper half-shell 2' and a second part 42 is made of the same material as the rear part of the lower half-shell 3'. The mask 41, 42 extends in a plane YZ parallel to the receiving face 36 of the support 29.

[0044] In reference to the figure 12 , 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 ( Fig. 4 ).

[0045] Three fixing lugs, referenced respectively 45, 46 and 47, extend in the same direction (along X) perpendicular to the YZ plane in which the two mask parts 41 and 42 extend. The lug 45 is made of the same material as the rear face of the first mask part 41 and the two lugs 46 and 47 are made of the same material as the rear face of the second mask part 42. The lugs 45, 46 and 47 are found at the rear of the housing 1' in substantially the same distribution as those of the lugs 30, 31 and 32 of the figure 7 .

Claims

1. An optical module housing (1 ') of a lighting and / or signaling device of a motor vehicle, said housing (1 ') comprising first (2 ') and second (3 ') parts of complementary shapes obtained after injection molding of a thermoplastic material and at least one of the two parts (2 ' or 3 ') of which is partially provided with metallization zones (5), said housing (1 ') comprising a determined cutting profile (P) defining a mechanical interface (4 ') for assembling the first (2 ') and second (3 ') parts one on top of the 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 molding and metallization constraints, said casing further comprising a fixing interface (30 - 32) arranged on the first (2 ') and second (3 ') parts of the casing (1 '); said fixing interface (45 - 47) being able to fix the casing (1 ') on an optical module support in a longitudinal direction (X) of the casing (1 '), as well as the first (41) and second (41) 42) extension parts of the first (2') and second (3') housing parts (1'); the first (41) and second (42) extension parts extending in a same plane (YZ) extending perpendicularly to a median plane passing through the longitudinal axis (X) of the housing (1'); the first (41) and second (42) extension parts supporting the attachment interface (45-47), the first (41) and second (42) extension parts of the housing (1') defining a mask facing the housing an optical module holder for receiving the attachment interface (45-47) of the housing (1').

2. Case (1') according to the preceding claim, having a 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 lateral faces of the case (1'), facing each other; said edges belonging to the mechanical assembly interface (4') respectively defining assembly ramps (16, 17) cooperating with each other at the moment of assembly of the first (2') and second (3') parts in a determined assembly direction (17) 8).

3. 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 one another to ensure the axial and lateral locking of the assembly of the first (2') and second (3') parts of the case (1').

4. The case (1') according to claim 1, wherein the assembly formed by the first (2') and second (3') parts of the case (1') defines a cover shell for an optical module of a lighting and / or signaling device; said shell having metallization zones (5) and zones (6) devoid of metallization.

5. Optical unit (10, 11) equipped with a housing (1 ') according to one of the preceding claims.

6. Motor vehicle lighting and / or signaling device comprising an optical unit (10, 11) according to the preceding claim.

7. Motor vehicle headlamp comprising at least one optical unit (10, 11) according to claim 5.

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