Abstract:
A lighting module for a motor vehicle, comprising at least one light source; a heat sink able to dissipate the heat produced by the light source or sources; a reflective surface able to reflect the rays from the light source or sources; a lens able to deflect the rays from the reflective surface so as to form a beam of light along an optical axis of the module; a support of the lens and of the reflective surface, the support being mounted on the heat sink. The heat sink and/or the support comprises at least one, and preferably at least two, bosses directed vertically and in contact with the other out of the heat sink and the support so as to maintain a predetermined distance between the heat sink and the support.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority to the French application 1456227 filed Jun. 30, 2014, which application is incorporated herein by reference and made a part hereof. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The invention relates to the field of lighting, more particularly motor vehicle lighting. The invention relates to a lighting module for a motor vehicle headlamp. 
         [0004]    2. Description of the Related Art 
         [0005]    Published patent document EP 2 428 725 A2, which is equivalent to U.S. Patent Publication Nos. 2012/0063156 and 2013/0235606 and to U.S. Pat. Nos. 8,534,888 and 9,039,262, discloses a motor vehicle headlamp lighting module. The lighting module in question comprises a light source of the light emitting diode (LED) type mounted on a mounting plate arranged on a radiator heat sink for cooling the diode. The module also comprises a first reflective surface in the form of a half shell able to reflect the rays emitted by the light source toward a second reflective surface, referred to as a reflector, with an edge for cutting off the lighting beam. The lighting module also comprises a lens positioned in front of the second reflective surface. The rays reflected by the first reflective surface and which pass to the front of the cutoff edge of the reflector encounter the lens and are deflected thereby. The rays that encounter the second reflective surface instead of encountering the lens in the lower part thereof with an angle of incidence that is smaller than the preceding rays, are reflected toward the upper part of the lens at essentially the same angle of incidence. These rays are then deflected by the lens toward the bottom of the beam rather than being deflected upward, thus achieving a cutoff typical of a lighting beam of the “dipped” or “low beam” type. In this module, a main component serves to support the lens, the reflective surface in the shape of a half shell, and the reflector. This component is therefore fixed to the radiator. The latter directly supports the mounting plate with the light source. Relative longitudinal positioning of the main component and the radiator is performed by means of eyelets on the main component collaborating through engagement with posts on the radiator. Fixing screws are then screwed into the posts in order to secure the main component to the radiator. The main component comprises stop surfaces collaborating directly with the radiator for the vertical positioning thereof. This teaching is advantageous in that the main component provides accurate relative positioning between the lens, the reflective surface, the reflector and the radiator. Specifically, the lens is fully supported by the main component. In the case of lenses that are bulky and heavy, that may present certain difficulties in terms of the stability of the lens notably when vibrations are present. In addition, the main component is a complicated component which may moreover have certain manufacturing tolerances that potentially detract from the precision of the assembly. 
       SUMMARY OF THE INVENTION 
       [0006]    It is an object of the invention to alleviate at least one of the disadvantages of the prior art, more particularly of the aforementioned prior art. More specifically, it is an objective of the invention to propose a lighting module use of which is simplified while at the same time maintaining a high degree of precision between the lens and the rest of the module, such as notably the reflective surface and the light source or sources. 
         [0007]    One subject of the invention is a lighting module, notably a lighting and/or signaling module for a motor vehicle, comprising: at least one light source; a heat sink able to dissipate the heat produced by the light source or sources; a reflective surface able to reflect the rays from the light source or sources; a lens able to deflect the rays from the reflective surface so as to form a beam of light along an optical axis of the module; a support of the lens and of the reflective surface, the support being mounted on the heat sink; notable in that the heat sink and/or the support comprises at least one, and preferably at least two, bosses in contact with the other out of the heat sink and the support so as to maintain a predetermined distance between the heat sink and the support. 
         [0008]    According to one advantageous embodiment of the invention, the boss or bosses are directed vertically. 
         [0009]    According to one advantageous embodiment of the invention, the boss or bosses are situated, in the direction of the optical axis, between the reflective surface and the lens. 
         [0010]    According to one advantageous embodiment of the invention, the lens comprises at least one, preferably at least two, lower fixing lugs extending vertically through the support. 
         [0011]    According to one advantageous embodiment of the invention, the support comprises a slot, the lower fixing lug or lugs passing through this slot. 
         [0012]    According to one advantageous embodiment of the invention, the or each of the fixing lugs collaborates by engagement with the heat sink, the engagement preferably having a vertical play of less than 0.5 mm, more preferably a vertical play of less than 0.1 mm, and more preferably still, vertical clamping. 
         [0013]    According to one advantageous embodiment of the invention, the heat sink comprises a rear portion supporting the light source and a front portion, the boss or bosses being on the front portion. 
         [0014]    According to one advantageous embodiment of the invention, the front portion of the heat sink is set at a lower level than the rear portion of the heat sink. 
         [0015]    According to one advantageous embodiment of the invention, the heat sink has a staircase profile, the front portion forming a first step of the staircase and the rear portion forming a higher second step of the staircase. 
         [0016]    According to one advantageous embodiment of the invention, the support extends along the respective upper surfaces of the front and rear portions of the heat sink, the lens nesting vertically on the support. 
         [0017]    According to one advantageous embodiment of the invention, engagement between the lens and the heat sink is on the front portion of the heat sink. 
         [0018]    According to one advantageous embodiment of the invention, the front portion of the heat sink comprises at least one, preferably at least two, lugs extending forward and collaborating through engagement with an opening in the fixing lugs of the lens respectively. 
         [0019]    According to one advantageous embodiment of the invention, the or each of the lugs of the heat sink forms a stop in the direction of the optical axis for the corresponding fixing lug of the lens. 
         [0020]    According to one advantageous embodiment of the invention, the or each of the lugs of the heat sink has a profile, in the direction of the optical axis, that forms a step. 
         [0021]    According to one advantageous embodiment of the invention, the or each of the lugs of the heat sink comprises at least one rib extending in the direction of the optical axis so as to engage tightly with the corresponding fixing lug of the lens. 
         [0022]    According to one advantageous embodiment of the invention, at least two of the bosses are positioned laterally one on each side of the optical axis of the module. 
         [0023]    According to one advantageous embodiment of the invention, the reflective surface and the support are one and the same component. The reflective surface may be formed on a cavity of the support, for example by metalizing this cavity; if appropriate, the reflective surface and the support form one and the same component. 
         [0024]    According to one advantageous embodiment of the invention, the support comprises means of positioning with respect to the heat sink and in the direction of the optical axis. 
         [0025]    According to one advantageous embodiment of the invention, the positioning means for positioning the support in the direction of the optical axis collaborate with a mounting plate supporting the light source or sources, the mounting plate being positioned on the rear portion of the heat sink. 
         [0026]    Advantageously the light source or sources are of the light emitting diode type. 
         [0027]    Advantageously, the mounting plate comprises a printed circuit, preferably with a connector, the circuit being connected to the light source or sources in order to power same. 
         [0028]    According to one advantageous embodiment of the invention, the positioning means for positioning the support in the direction of the optical axis comprise at least one, preferably at least two, studs, each one of the studs projecting vertically downward into a cavity of the heat sink, the stud or each of the studs collaborating through contact with the edge of an orifice in the mounting plate. 
         [0029]    According to one advantageous embodiment of the invention, the heat sink is made of a molded metallic and/or plastic material, the or at least two of the bosses being formed as an integral part of the heat sink and produced at the time of molding of the heat sink. 
         [0030]    Another subject of the invention is a lighting device for a motor vehicle, comprising a housing and at least one lighting module, notable in that the module or at least one of the modules is in accordance with the invention. 
         [0031]    The measures taken by the invention are advantageous in as much as they make it possible easily and economically to produce a lighting module with precise positioning of the lens with respect to the reflective surface and/or the light source or sources. 
         [0032]    These and other objects and advantages of the invention will be apparent from the following description, the accompanying drawings and the appended claims. 
     
    
     
       BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS 
         [0033]    Other features and advantages of the present invention will be better understood from the description and drawings among which: 
           [0034]      FIG. 1  is a perspective view of a motor vehicle headlamp lighting module according to the invention; 
           [0035]      FIG. 2  is a perspective view of the radiator, of the reflector and of the light source of the module of  FIG. 1 ; 
           [0036]      FIG. 3  is an elevation of the module of  FIG. 1 , showing a line of section IV-IV; 
           [0037]      FIG. 4  is a view in section on IV-IV of the module of  FIG. 3 ; 
           [0038]      FIG. 5  is a perspective view of the radiator provided with the reflector in which this reflector is drawn to show the hidden detail of the ribs used to position the reflector on the radiator; 
           [0039]      FIG. 6  is a view in cross section of the module of  FIG. 1  in the region of the reflector; 
           [0040]      FIG. 7  is an elevation of the module of  FIG. 1 , showing a line of section VIII-VIII; 
           [0041]      FIG. 8  is a view in section on VIII-VIII of the module of  FIG. 7 ; and 
           [0042]      FIG. 9  is a view in section on VIII-VIII of the module of  FIG. 7 , although the view is given in perspective and the section is the opposite to that of  FIG. 8 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0043]      FIG. 1  is a perspective view of a lighting module according to the invention. This lighting module can be mounted in a motor vehicle headlamp. In this particular instance, this module produces a lighting beam with a cutoff such as for a lighting function of the “dipped” or “low beam” type. 
         [0044]    The lighting module  2  illustrated in  FIG. 1  essentially comprises a radiator, or heat sink  6 , on which there is mounted a mounting plate  16  provided with one or more light sources  12 , preferably of the light emitting diode type. A support  4  depicted to show hidden detail and extending over the entire length of the lighting module  2  is arranged on the radiator  6 . The support is in contact with a lens  8  and comprises a reflective surface  10 . The latter takes the overall shape of a half-shell covering the light source  12 . The profile of the reflective surface  10  may be generally elliptical with two focal points. The light source  12  is situated at the first focal point and a reflective surface  14  is essentially situated in the plane of the light source  12  and with a front edge situated at the second focal point. The reflective surface  14  is commonly referred to as a “reflector” in so far as it reflects some of the rays from the reflective surface  10  toward an upper part of the lens  8 . Indeed, if the reflective surface  14  were absent, the rays passing to the rear of the second focal point would encounter the lens  8  at a low part with a smaller angle of incidence than those passing through the second focal point. These rays would then be deflected by the lens  8  to form the top part of the lighting beam. Reflecting these rays toward a top part of the lens  8  allows this effect to be reversed and the bottom part of the beam to be formed. The front edge of the reflector  14  thus forms a horizontal cutoff of the beam. It may also be noted that the reflective surface of the reflector  14  forms a step in its middle so as to form two different levels of cutoff between the left-hand part and the right-hand part of the lighting beam, in accordance with the vehicle lighting regulations in force in most countries. The use of a reflector to form a lighting beam with a cutoff is well known to those skilled in the art. 
         [0045]    The lighting beam is following a main direction commonly referred to as the optical axis of the lighting module  2 . This axis also essentially corresponds to the longitudinal axis of the lighting module  2 . 
         [0046]    It may be seen in  FIG. 1  that the mounting plate  16  at its rear part comprises a connector  18  so that it can be connected to the electrical network of the headlamp and of the vehicle. 
         [0047]      FIG. 2  illustrates the radiator  6  of the lighting module  2  of  FIG. 1 , the radiator  6  being equipped only with the reflector  14  and with the mounting plate  16 . It may be seen that the radiator  6  comprises a rear portion  6   1  supporting the mounting plate  16  and a front portion  6   2 . The front portion  6   2  is at a lower level than the rear portion  6   1 . The profile of the radiator  6  is similar to that of a staircase, the front portion  6   2  corresponding to a first step and the rear portion  6   1  forming a second step higher than the first. 
         [0048]    The reflector  14  is essentially situated level with the front edge of the rear portion  6   1 . More specifically, the reflector  14  comprises a reflective central portion  14   1  and two lateral portions  14   2  in the form of connecting arms for fixing to the support  4  ( FIG. 1 ). This fixing will be detailed further in relation to  FIG. 6 . The reflector  14  thus has a U-shaped cross transverse profile in which only the central portion  14   1  is optically active. The reflector  14  may be made from a portion of sheet metal, by forming, bending and cutting. 
         [0049]    The front portion  6   2  on its upper surface comprises two bosses  6   3 . These bosses  6   3  are intended to ensure exact positioning of the support  4  in the vertical direction, as will be detailed in conjunction with  FIGS. 3 and 4 . These bosses  6   3  maybe more numerous. There may equally be one or several bosses  6   3  extending transversely, in the manner of a rib. 
         [0050]    The front portion  6   2  also comprises, at its front edge, two lugs  6   4  for attaching the lens  8  ( FIG. 1 ), as will be detailed in conjunction with  FIGS. 3 and 4 . 
         [0051]    As visible in  FIG. 2 , the rear portion  6   1  may comprise one or more pins, in this instance two pins  6   5  which are intended to pass through corresponding orifices in the mounting plate  16 . These pins  6   5  may be generally conical. The mounting plate  16  also has orifices  16   1  intended to accommodate fixing screws and oblong holes  16   2  intended to allow longitudinal positioning, which means to say positioning in the direction of the optical axis, of the support  4  with respect to the mounting plate  16 . 
         [0052]      FIG. 3  is a view in elevation of the module of  FIG. 1 .  FIG. 4  is a depiction in section on the line IV-IV of  FIG. 3 . It may be seen that the support  4  comprises several portions, in this instance a rear portion  4   1  in contact with the mounting plate  16  on the rear portion  6   1  of the radiator  6 , an intermediate portion  4   2  and a front portion  4   3  which is arranged above the front portion  6   2  of the radiator  6  and on its bosses  6   3 . 
         [0053]    It may be seen in  FIG. 4  that the lens  8  comprises two fixing lugs  8   1  extending from a lower edge towards the lugs  6   4  of the radiator  6 . More specifically, these lugs  8   1  pass through openings  24  in the front portion  4   3  of the support  4 . These lugs  8   1  may have cavities, or through-passages, fitting over the ends of the lugs  6   4 . As may be seen in  FIG. 4 , the front portion  4   3  of the support  4  rests, via its lower face, on the bosses  6   3  and, via its upper face, on the lens  8 . The front portion  4   3  is thus exactly vertically positioned with respect to the radiator  6  and with respect to the lens  8 . 
         [0054]    The fit between the lugs  6   4  of the radiator  6  and the orifices or cavities of the fixing lugs  8   1  of the lens  8  is practically free of play, more particularly a tight clamping fit. With reference to  FIG. 2 , it may be seen that the lugs  6   4  of the radiator  6  may at their ends have longitudinal ribs intended to clamp slightly against the fixing lugs  8   1  of the lens. As the material of the lens  8  is preferably a translucent or transparent plastics material, such as polycarbonate for example, the fixing lugs  8   1  may deform a little as they are fitted onto the lugs  6   4 , in order to prevent any mechanical clearance and uncertainty as to the vertical positioning of the lens  8 . 
         [0055]    As far as the longitudinal positioning of the lens  8  is concerned it may be seen from  FIG. 4  and from  FIG. 2  that the lugs  6   4  form an S-shaped profile, namely a profile with a step, this step forming a stop surface in the longitudinal direction of the lighting module  2 . Longitudinal positioning of the fixing lugs  8   1  of the lens  8  is thus also afforded. 
         [0056]    Still in  FIG. 4 , it may be seen that the reflector  14 , more specifically the central and optically active portion  14   1  thereof, rests against a rib  6   6  of the radiator  6 , which rib  6   6  will be detailed further in relation to  FIGS. 5 and 6 . 
         [0057]      FIG. 5  illustrates the radiator  6  of the lighting module  2  of  FIG. 1 , equipped only with the lens  8  and with the reflector  14 , the latter being depicted to show hidden detail. It may be seen that the radiator  6  comprises H-shaped ribs  6   6  in the longitudinal direction of the lighting module  2 . These ribs  6   6  act as bearing surfaces for the reflector  14  because it is important for the reflector  14  and, more particularly, the reflective central portion  14   1  thereof to be parallel to the upper surface of the rear portion  6   1  of the radiator  6 . This is because any misalignment of the reflecting surface of the reflector  14  is liable to alter appreciably the photometry of the light beam of the module. It is therefore important to be able to position the reflector  14  very precisely not only translationally in the longitudinal direction but also vertically and in terms of rotation about a transverse axis. The ribs  6   6  provide vertical positioning and positioning for rotation about a transverse axis of the reflector  14 . They also make it possible to avoid any light leaking out between the lower face of the central portion  14   1  and the upper face of the rear portion  6   1  of the radiator  6 . 
         [0058]    It may also be seen from  FIG. 5  that the rear portion  6   1  of the radiator  6  comprises two cavities  6   7  the function of which will be detailed in relation to  FIGS. 8 and 9 . 
         [0059]    Fixing screws  20  and  22  of the mounting plate supporting the light source and of the support are visible in  FIG. 5 . 
         [0060]      FIG. 6  is a view in cross section of the module of  FIG. 1 , the section being taken in the region of the reflector  14 . This view illustrates how the reflector  14  is fixed and positioned. It may be seen that the central portion  14   1  of the reflector does indeed rest against the transverse ribs  6   6  of the radiator  6 . It may also be seen that the fixing arms  14   2  of the reflector collaborate through engagement with orifices in the support  4 . These arms  14   2  may for this purpose comprise retaining tabs intended to allow the arms  14   2  to be inserted into the orifices and to prevent them from leaving these orifices. Other fixing and/or retaining means may be contemplated. 
         [0061]    The ribs  6   6  illustrated in  FIGS. 5 and 6  are preferably formed as integral parts of the radiator  6 . The latter is preferably made of a metallic or plastics material that can be molded, such as, for example, aluminum or thermoplastics that have heat conduction properties. It is therefore advantageous for these ribs to be produced directly at the time of producing the radiator. 
         [0062]    It should be noted that the shape of these ribs may deviate from that illustrated in  FIGS. 5 and 6 . Specifically, they could for example comprise two transverse ribs parallel to and distant from one another. They could also have a U-shaped or even rectangular profile. They could equally take the form of a number of isolated bosses. 
         [0063]      FIG. 7  is an elevation of the module of  FIG. 1 . Unlike  FIG. 3 ,  FIG. 7  illustrates the module provided with the fixing screws  20  and  22  which are visible notably in  FIG. 5 . As can be seen in  FIG. 7 , the line of section VIII-VIII passes through an oblong hole  4   5  of the support  4  and through one of the pins  6   5  of the radiator  6 . The head of the fixing screw  22  passing through this oblong hole is fully housed by the hole, meaning that this screw does not press against the support  4  but does indeed press only on the mounting plate  16 . 
         [0064]      FIG. 8  is a section on VIII-VIII of  FIG. 7 .  FIG. 9  is a view in section on VIII-VIII of the lighting module  2  of  FIG. 7  although the view is in perspective and the view point for the section is the opposite of that of  FIG. 8 . 
         [0065]    There it may be seen that the support  4  comprises two studs  4   4 , one on each side of the longitudinal or optical axis of the lighting module  2 . Each of these studs  4   4  extends from the rear portion  4   1  of the support toward a cavity  6   7 , namely essentially vertically downward. Each of the studs  4   4  also passes through an oblong hole  16   2  made in the mounting plate  16  and rests in the longitudinal direction against the edge of the hole  16   2 . In this particular instance, the bearing force is directed rearward, namely that it is the rear portion of the edge of the oblong hole  16   2  that is in contact with the stud  4   4 . However, it must be understood that this bearing force could be directed forward in an alternative. 
         [0066]    The cavities  6   7  may be dimensioned to allow the studs  4   4  to move freely therein as the support  4  is being positioned. For that purpose the cavity may extend beyond the edge of the oblong hole  16   2  against which the stud  4   4  abuts. 
         [0067]    The mounting plate  16  is fixed by the screw  22  passing through the oblong hole  4   5  in the support  4 . The mounting plate  16  may be positioned on the radiator  6  by two pins  6   5  of the radiator  6  which collaborate with corresponding orifices of the mounting plate  16 . As the support  4  is being fitted, after having positioned and possibly fixed the mounting plate  16 , the rear portion  4   1  of the support  4  is placed against the mounting plate  16  taking care to ensure that the studs  4   4  enter the oblong holes  16   2  of the mounting plates  16  and the corresponding cavities  6   7  of the radiator  6 . Oblong holes  4   6  may be provided for collaborating with the pins  6   5  while at the same time allowing the support  4  some movement. When the rear portion  4   1  of the support  4  is in contact with the mounting plate  16 , the support  4  can then be moved essentially in the longitudinal direction so as to bring each of the studs  4   4  into contact with the corresponding edge of the oblong holes  16   2  of the mounting plate  16 . The fixing screws  20  pressing against the support  4  may then be fitted and tightened in order to fix the support  4  and the mounting plate  16  to the radiator  6 . 
         [0068]    The use of the studs  4   4  as stop means in the longitudinal direction acting between the support  4  and the mounting plate  16  means that the relative positioning of the reflective surface  10 , supported by the support  4 , and of the light source  12  can be ensured. 
         [0069]    It should be noted that the studs  16   2  and the oblong holes  16   2  of the mounting plate  16  with which they collaborate may be designed to provide positioning not only in the longitudinal direction but also in the transverse direction, namely positioning in the plane of sliding between the mounting plate  16  and the rear portion of the support  4 . To do that, the edges of the oblong holes  16   2  and/or the corresponding stud  4   4  may be profiled in such a way as to center the corresponding stud  4   4 . 
         [0070]    While the system, apparatus, process and method herein described constitute preferred embodiments of this invention, it is to be understood that the invention is not limited to this precise system, apparatus, process and method, and that changes may be made therein without departing from the scope of the invention which is defined in the appended claims.