Patent Publication Number: US-11397299-B2

Title: Light module for illuminating an outer component of a vehicle, and process for manufacturing such light module

Description:
TECHNICAL FIELD 
     The disclosure concerns a light module for illuminating an outer component of a vehicle. The disclosure also concerns a process for manufacturing such light module. 
     BACKGROUND 
     In the automotive field, it is known to illuminate outer components of a vehicle for aesthetic reasons. For example, the outer components can be strips extending along the profile of the vehicle body, such as strips mounted around lateral doors, rear trunk and/or rear windshield. 
     The illumination can be activated in specific conditions, such as braking, doors locking, night detection, or manual control from the dashboard. The illumination can be activated with a specific program, such as intermittent lighting with a predetermined pattern and at a predetermined tempo, or permanent lighting in darkness. 
     As non-limitative examples, automotive lighting devices are disclosed in documents WO2006086563, WO2015154972 and WO2016112897. 
     SUMMARY 
     The aim of the disclosure is to provide a light module for illuminating an outer component of a vehicle. 
     To this end, the disclosure concerns a light module for illuminating an outer component of a vehicle, the light module comprising: a housing for fastening the light module to the vehicle; a cover mounted on the housing; an inner space delimited between the housing and the cover; a printed circuit board mounted in the inner space; a light source mounted on the printed circuit board and configured for emitting an illumination beam; and a light guide mounted in the housing facing the light source and extending outside the inner space for guiding the illumination beam along the outer component. The light guide includes an optical fiber extending outside the inner space and a lens positioned between the light source and an entry opening of the optical fiber, such that the illumination beam emitted by the light source is focalized toward the entry opening of the optical fiber. 
     The loss of illumination flow between the light source and the optical fiber can be greatly and easily reduced, inducing a lower electric consumption and higher durability of the light source. 
     According to further aspects of the disclosure which are advantageous but not compulsory, such a light module may incorporate one or several of the following features:
         The lens has a specific convergent shape, entirely focalizing the illumination beam on a focus point at the entry opening of the optical fiber.   The lens is transparent, while the housing and the cover are opaque, thus ensuring that the illumination beam it transmitted outside the light module only through the light guide.   The housing and the cover are watertight sealed relative to each other, for example by ultrasonic or laser welding.   The light guide comprises a transparent abutment fastened to the housing and integrating the entry opening of the optical fiber.   The housing comprises an outer protrusion delimiting a hollow recess receiving the abutment.   An outer end of the outer protrusion is provided with retaining means, positioned in retaining contact with the abutment.   The light source is a light-emitting diode.       

     The disclosure also concerns a process for manufacturing a light module as mentioned here-above. The process includes the following steps:
         a) manufacturing the housing,   b) manufacturing the lens,   c) fastening the lens to the housing.       

     In a first embodiment of the process, steps a), b) and c) are performed sequentially. For example, the lens is fastened to the housing by clipping, gluing or welding. 
     In a second embodiment of the process, steps b) and c) are performed simultaneously in a molding operation after step a). In other words, the lens is molded into the housing. 
     In a third embodiment of the process, steps a) and c) are performed simultaneously in an overmolding operation after step b). In other words, the housing is molded over the lens. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Certain embodiments of the invention will now be explained in correspondence with the annexed figures, and as an illustrative example, without restricting the object of the invention. In the annexed figures: 
         FIG. 1  is an upper view of a light module; 
         FIG. 2  is a sectional view of the light module along line II-II of  FIG. 1 ; 
         FIG. 3  is a partial sectional view, at a larger scale, of a detail from  FIG. 2 ; and 
         FIG. 4  is a sectional view of a second embodiment of a light module, along line IV-IV of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
       FIGS. 1 to 3  show a light module  10 . 
     Module  10  is designed for illuminating an outer component  2  of a vehicle  1 , partly and schematically showed only on  FIG. 1  for simplification purpose. 
     Module  10  comprises a housing  20 , a cover  30 , a printed circuit board  50 , a light source  60 , a light guide  70 , and a connection system  80 . Housing  20  and cover  30  delimit a watertight inner space  40  between them. Space  40  receives PCB  50 , on which source  60  is mounted. Guide  70  is mounted in housing  20 , facing source  60 . 
     Housing  20  is designed for fastening module  10  to vehicle  1 , preferably directly to component  2 . Housing  20  is also designed for receiving guide  70 , PCB  50 , then cover  30  to close space  40 . 
     Housing  20  comprises a main body  21  shaped has an elongated plate. Housing  20  comprises a protrusion  22  formed on the outer side of body  21  and walls  25  formed on the inner side of body  21 . 
     Protrusion  22  has a tubular shape and delimits a hollow recess  23  for receiving part of guide  70 . Recess  23  is open opposite cover  30 , such that guide  70  can extend outside module  10 . Opposite cover  30 , the outer end of protrusion  22  is provided with hooks  24  for retaining guide  70  in recess  23 . 
     Walls  25  extend perpendicular to body  21  and along a square profile having curved angles. Walls  25  delimit space  40  together with body  21  and cover  30 . Inside space  40 , two separate stems  26  extend perpendicular to body  21 . Opposite body  21 , each stem  26  has an end portion forming a lug  27  of reduced diameter. Lugs  27  are designed for tight fitting into complementary apertures  57  formed in PCB  50 , as detailed here-below. 
     Opposed ends of body  21  are provided with fastening means  28  and  29 , namely a bore  28  and a reamed portion  29 . Means  20  are used to fasten housing  20  to a support element, which may belong to component  2 . 
     Cover  30  is mounted on housing  20  for closing space  40 , after PCB  50  has been positioned therein. 
     Cover  30  comprises a main body  31  shaped has an elongate plate, a central boss  32  formed on the outer side of cover  30  and two inner walls  33  and  34  formed on the inner side of body  31 . Each wall  33  and  34  extends along a square profile having curved angles. Between walls  33  and  34  is delimited an assembly path  35  for receiving walls  25 . 
     Housing  20  and cover  30  are watertight sealed relative to each other at the junction of walls  25  and assembly path  35 , for example by ultrasonic or laser welding. 
     PCB  50  is fastened to housing  20  inside space  40 . PCB  50  is provided with conductive tracks and connection holes, not shown for simplification purpose. PCB  50  is designed for mechanically supporting and electrically connecting electronic components, such as source  60  and system  80 . 
     Housing  20  and PCB  50  are provided with complementary indexing means  27  and  57  tightly fitted relative to each other, for directly positioning source  60  mounted PCB  50  relative to guide  70  mounted in housing  20 . 
     Indexing means  27  and  57  allow a precise positioning of source  60  relative to guide  70 , without influence of manufacturing tolerances of housing  20 , cover  30  and PCB  50 , and without influence of eventual assembly shifts between housing  20 , cover  30  and board  50 . The position of source  60  relative to indexing apertures  57  provided on PCB  50  is known with great precision. The position of guide  70  relative to indexing lugs  27  provided on housing  20  is also known with great precision. The indexing means  27  and  57  are fitted without clearance between them. Thus, source  60  can be positioned with great precision relative to guide  70 , in particular to entry opening  73  and focus point  74 . 
     On the examples of the figures, indexing means  27  and  57  have complementary circular transversal sections. Alternately, indexing means  27  and  57 ) can have complementary non-circular transversal sections. 
     According to a particular embodiment not shown, indexing means  27  and  57  can be constituted by only one lug  27  ad one aperture  57 . In this case, indexing means  27  and  57  have non-circular transversal sections. 
     According to another particular embodiment not shown, indexing means  27  and  57  can be constituted by at least one aperture formed in housing  20  and at least one lug belonging to PCB  50 . 
     Light source  60  may be a light-emitting diode. Source  60  is configured for emitting an illumination beam B, for example within a cone having an apex angle of 100 degrees. Source  60  is fixedly mounted on PCB  50 . For example, source  60  is provided with connection pins inserted in holes of PCB  50 . 
     Light guide  70  is mounted in housing  20  facing source  60 . Guide  70  extends at least partly outside space  40  for guiding beam B along component  2 . 
     Guide  70  comprises an optical fiber  72 , an abutment  76  and a lens  78 . 
     Fiber  72  extends outside space  40  for guiding beam B along component  2 . Fiber  72  has a diameter of approximately 2 or 3 millimeters. Fiber  72  has an inner end provided with an entry opening  73  facing source  60 . Fiber  72  has an outer end not shown on the figures for simplification purpose. Beam B enters through opening  73  and is guided along fiber  72 . 
     Abutment  76  has a cylindrical shape and is made of a transparent material. Inner end and entry opening  73  of fiber  72  are integrated inside abutment  76 , for example by screwing, clipping or overmolding. Abutment  76  is positioned in recess  23 , with hooks  24  in retaining contact with its outer surface. 
     Lens  78  is positioned between source  60  and opening  73 , such that beam B emitted by source  60  is focalized toward opening  73 . Lens  78  may have a specific convergent shape, entirely focalizing beam B on a focus point  74  located at the precise center of opening  73 . Lens  78  is transparent, while housing  20  and cover  30  may be opaque, thus ensuring that beam B it transmitted outside module  10  only through guide  70 . 
     Connection system  80  is designed for connecting PCB  50  to another device outside module  10 , for example the electronic control unit of vehicle  1 . System  80  is described in more details here below in reference to  FIG. 4 . 
     The disclosure also concerns a process for manufacturing module  10 . Said process comprises several steps, including the following steps a), b) and c). 
     Step a) consists in manufacturing housing  20 . Step b) consists in manufacturing lens  78 . Step c) consists in fastening lens  78  to housing  20 . 
     In a first embodiment of the process, steps a), b) and c) are performed sequentially. Steps a) and b) can be performed in any order, while step c) is performed after steps a) and b). In step c), lens  78  can be fastened to housing  20  by clipping, gluing, welding, or any other suitable technique. 
     In a second embodiment of the process, step a) is performed first, then steps b) and c) are performed simultaneously in a molding operation. More precisely, lens  78  is molded into housing  20 . 
     In a third embodiment of the process, step b) is performed first, then steps a) and c) are performed simultaneously in an overmolding operation. More precisely, housing  20  is molded over lens  78 . 
     A second embodiment of module  10  is represented on  FIG. 4 . In this embodiment, elements similar to the first embodiment have the same references and work in the same way. Only the differences with respect to the first embodiment are described hereafter. 
     In this embodiment, module  10  is provided with a heatsink insert  90  integrated to cover  30 , for example by overmolding, or any other suitable technique. While housing  20  and cover  30  are made of plastic materials, insert  90  is made of metal so as to have good heat conduction. Insert  90  may be made of aluminum alloy, for a good compromise between heat conduction, weight and cost. Insert  90  may be a rectangular parallelepiped, easy and cheap to manufacture. 
     Insert  90  has an inner surface  91  positioned in contact with PCB  50  and an outer surface  92  extending outside space  40 , in contact with ambient air. 
     Thus, the heat emitted by source  60  is transferred onto heatsink insert  90  via PCB  50 . This provides cooling of module  10  and prevents source  60  from overheating and overaging. 
     Insert  90  has two lateral portions  93  and  94  separated by a central portion  96 . Portion  93  is encased in a recess  39  of the cover  30 . Said recess  39  forms an abutment opposite PCB  50 . 
     For improved efficiency, source  60  is mounted on PCB  50  precisely opposite insert  90 . Source  60  may be mounted on PCB  50  opposite central portion  96  of insert  90 . 
     System  80  has an inner portion  81  provided with a male configuration and fitted into PCB  50 . System  80  has an outer portion  82  provided with a female configuration, designed to receive a connector plug  100 , schematically and partly shown on  FIG. 4 . 
     System  80  comprises at least one pin  84  extending through cover  30 , between portions  81  and  82 . Pin  84  has a first end  85  projecting in inner portion  81  and connected to PCB  50 . Pin  84  has a second end  86  projecting in portion  82  and located outside cover  30 . As shown on the figures, system  80  may comprise several pins  84  extending through cover  30 . 
     Watertight sealing of cover  30  in the area of system  80  is provided by fitting or overmolding of pins  84  through cover  30 . 
     Alternately, cover  30  can be provided with holes having the dimensions of pins  84 , ready to be traversed by pins  84 , which are then welded on PCB  50 . Consequently, cover  30  is not watertight near pins  84 . 
     In this configuration, watertight sealing of module  10  and space  40  is ensured when plug  100  is fitted into the female socket of portion  82 . Outer ends  86  of pins  84  are received in plug  100 , while outer surfaces of plug  100  are tightly fitted in portion  82 . 
     Other non-shown embodiments of a light module  10  can be implemented within the scope of the invention. In addition, technical features of the different embodiments can be, in whole or part, combined with each other. Thus, light module  10  and its manufacturing process can be adapted to the specific requirements of the application.