FR2660413A1 - VENTILATED LIGHTING OR SIGNALING DEVICE FOR A MOTOR VEHICLE SUCH AS A PROJECTOR OR SIGNAL LIGHT. - Google Patents

Abstract

Ventilated lighting or signaling device for a vehicle, such as a searchlight or signaling light comprising a communication system, preferably with baffles, between the interior volume of said device and the exterior, characterized by a filter (107) constituted by a cross-linked, open-pore plastic foam disposed within a ventilation channel (102).

Description

The present invention relates to a lighting or lighting device

  ventilated signaling for vehicle

  automobile such as headlamp or signal light.

  We have already tried to make such lighting or signaling devices so that they are

perfectly waterproof.

  But, in addition to requiring special sealing elements specifically adapted to each application, perfect sealing does not generally remain over time due to the severe stresses to which a lighting and signaling device is subjected, in particular during heating and cooling cycles corresponding respectively to the states

on and off of it.

  The lack of sealing generally leads to a presence of moisture in the lighting or signaling device which causes the formation of droplets of condensation inside the lighting or signaling device, which is detrimental, on the one hand, the quality of the light beam emitted by the device and, on the other hand, the good chemical resistance

elements of the device.

  By looking for a perfect seal, in practice you end up with the reverse of the desired result; the entry of air laden with moisture is not prevented, but the evacuation of the resulting moisture is prevented or slowed down. The solutions, which have proven to be the most effective in avoiding the appearance or persistence of condensation in a lighting or signaling device, consist in providing controlled ventilation means which make it possible to establish an air exchange between the interior space of said device and the exterior while preventing liquid penetration

or solid.

  Different types of solutions in this category

have been proposed.

  In particular, patent application FR-A-2 183 934 describes the use of a baffle tube inside which is provided an element permeable to

  air which fixes humidity by adsorption.

  Patent application FR-A-2 254 753 also shows a baffle device, the dimensions of which are determined so as to avoid penetration of liquid inside a headlamp by capillary effect. These different types of solution may have been satisfactory, but they have shown inadequacies and a certain ineffectiveness with regard to the increasingly severe environmental conditions to which a lighting or signaling device can now be exposed. The more severe conditions result from the greater exposure to bad weather and projections of all kinds as well as to the use which is spreading of the cleaning of the engine compartment of the vehicles by jet.

of water under high pressure.

  The object of the present invention is to overcome the

  shortcomings of known solutions.

  A ventilated lighting or signaling device for a vehicle, such as a searchlight or signaling light comprising a communication system, preferably with baffles, between the interior volume of said device and the exterior, is characterized by a filter constituted by a foam. of crosslinked plastic, with open pores, placed inside a ventilation channel. Preferably, said plastic foam is a crosslinked flexible polyurethane foam, the walls of the pore cells of which have been destroyed during crosslinking, so as to leave only

cell edges.

  Advantageously, said foam has a porosity defined by an average number of pores per centimeter of between 9.5 and 14 and preferably

close to 12.

  According to a preferred aspect of the invention, said filter is placed in an upper part of a ventilation duct so that the droplets of liquids which could reach said filter are

  allowed to flow outwards by gravity.

  Thanks to the invention, there is excellent ventilation of a lighting or signaling device which effectively prevents the penetration of liquid and / or solid elements inside such a device while ensuring rapid expulsion. by evaporation of any possible condensation of vapor

  of water inside the device.

  Other features and benefits of

  the invention will appear in the following description

  of an embodiment of the invention and which refers, by way of nonlimiting example, to the projector described in patent application FR-A-2,544,839, the

  description is incorporated into this description for

reference.

  The single figure annexed to this application shows, in section, a detail of the headlight housing of

  motor vehicle fitted with the filter according to the invention.

  A projector housing 1 includes, like and

  with the same references as in the description and

  figure of the aforementioned document, an upper wall 2, a lower wall not shown here, which bears the reference 3 in the aforementioned document, two side walls 4 each of which connects the upper wall 2 and the lower wall, and a bottom wall 5 having an outer periphery by which it is joined to each of the four aforementioned walls, and an inner periphery defining an orifice 6 for access to the interior of the housing 1, normally closed by a cap

hermetic not shown.

  According to one aspect of the present invention, an awning 100 of generally cylindrical shape is placed in the upper part of the projector, coming from the, or fixed on, the external face relative to the housing.

1, from the bottom wall 5.

  As shown, the awning 100 extends beyond

  from the bottom wall 5, the top wall 2.

  Attached to, or alternatively from, the bottom wall 5 and housed inside the volume delimited by the canopy 100, there is provided a hollow nozzle 101 contributing to form a ventilation channel 102 between the interior of the

housing 1 and the exterior.

  As shown, the hollow tip 101 came

molding the bottom wall 5.

  The hollow end piece 101 has a radial shoulder

  103 parallel to the bottom wall 5.

  On the hollow endpiece 101 is mounted, bearing on the radial shoulder 103, a tube 104 in which the said ventilation channel 102 is extended and which is advantageously bent and which opens outwards through an orifice 105 facing the wall background 5 and

  located inside the awning 100.

  Preferably, and as shown, the tube 104 is entirely disposed inside of

the awning 100.

  Thanks to the above arrangements, the ventilation channel 102 is particularly well protected with respect to the projections of liquids and / or solids to which the projector housing 1 may be subjected.

mounted on a motor vehicle.

  According to another aspect of the invention, the ventilation channel 102 opens inside the housing 1 in a cup 106 which, as shown, has come from molding

of the back wall 5.

  The above provisions help to form

  a very efficient baffle communication system.

  According to the invention, inside the channel of

  ventilation 102 is placed a buffer 107 forming a filter.

  The pad 107 is, according to a characteristic of the invention, constituted by a foam of material

  cross-linked plastic with open pores.

  Preferably, said plastic foam is a crosslinked flexible polyurethane foam, the walls of the pore cells of which have been destroyed during crosslinking, so as to leave only

cell edges.

  Advantageously, said foam has a porosity defined by an average number of pores per centimeter of between 9.5 and 14 and preferably

close to 12.

  In the example shown, a polyurethane foam sold by the company TRAMICO was used under the name "TRAMOPEN" and under the reference 3 OPPI, that is to say corresponding to a number of pores

  average of 11.8 per centimeter (30 per "Inch").

  Thanks to the invention, excellent ventilation of the lighting or signaling device is ensured while effectively preventing the penetration of elements.

  liquids and / or solids inside said device.

  In addition, any condensation of water vapor that may occur inside the device is quickly expelled to the outside when the

  headlamp or the traffic light is on.

  Surprisingly, particularly severe tests have shown that even in the event of complete immersion in a liquid of the ventilated lighting or signaling device according to the invention, this liquid is not allowed to penetrate

inside said device.

Claims (10)

  1) Ventilated lighting or signaling device for a vehicle, such as a searchlight or signaling light, comprising a communication system, preferably with baffles, between the interior volume of said device and the exterior, characterized by a filter (107) consisting of a cross-linked, open-pored foam of plastic, placed inside a ventilation channel (102).   2) Device according to claim 1, characterized in that said filter (107) is in the form of a pad (107) consisting of a foam   cross-linked plastic with open pores.   3) Device according to claim 2, characterized in that said plastic foam is a crosslinked flexible polyurethane foam, the walls of the pore cells of which were destroyed during crosslinking, so as to leave only cell edges.   4) Device according to claim 3, characterized in that said foam has a porosity defined by an average number of pores per centimeter   between 9.5 and 14, and preferably close to 12.   5) Device according to any one of   previous claims comprising a housing (1)   formed in particular of an upper wall (2) and a bottom wall (5), characterized by a canopy (100) of generally cylindrical shape originating from, or fixed to, the external face, relative to the housing 1, of said bottom wall (5), inside which is housed a system of communication (101,102,104,105).   6) Device according to claim 5, characterized in that said communication system (101,102,104,105) comprises a hollow nozzle (101) helping to form a ventilation channel (102) between   inside the housing (1) and outside.   7) Device according to claim 6, characterized in that said communication system (101,102,104,105) comprises a bent tube (104) opening outwards through an orifice (105) facing the bottom wall (5) and opening out to the inside said awning (100).   8) Device according to claim 6 or claim 7, characterized in that said filter (107) is in the form of a pad (107) placed at   the interior of said ventilation channel (102).   9) Device according to any one of   claims 4 to 7, characterized in that said system   of communication (101,102,104,105) leads to the interior   of the housing (1) in a cup (106).   ) Device according to any one of   claims 4 to 8, characterized in that said awning   (100) has been molded from said bottom wall (5) and   extends said upper wall (2) of said housing (1).   11) Device according to any one of   claims 4 to 9, characterized in that said tip   (101) and said cup (106) are molded from said bottom wall (5).