Motor vehicle lighting and / or signaling device incorporating a heat shield

Abstract

A lighting and / or signaling device (SSD) for a motor vehicle, comprising a housing (HUD) obtained after injection molding of a first plastic material, said housing (HUD) being open to the outside and hermetically sealed by a glass (GLA); wherein said housing (HUD) comprises at least first and second cavities (CAV1 and CAV2), superimposed vertically and respectively upper and lower when the device (SSD) is mounted on the vehicle, and a heat-emitting light source (HAL) confined in the lower cavity (CAV2), and wherein a partition (ETR), made of a second plastic material, resistant to the heat emitted by the light source (HAL), is attached and fixedly held between the upper (CAV1) and lower (CAV2) cavities so as to define a separating partition to form a thermal shield against the heat emitted by the light source (HAL). (Figure 3)

Description

Title of the invention: Lighting and / or signaling device for a motor vehicle comprising a heat shield

[0001] The invention generally relates to lighting and / or signaling devices for motor vehicles and is more particularly concerned with a lighting and / or signaling device for a motor vehicle comprising a heat shield.

[0002] A motor vehicle lighting and / or signaling device comprises a housing closed by an external glass, or pane. The housing generally contains several light sources and their associated parabolas, arranged in the bottom of the housing to respectively provide the lighting and / or signaling functions expected of a motor vehicle light, in particular a motor vehicle rear light.

[0003] Some of these light sources use halogen incandescent bulbs, more simply referred to as halogen bulbs, or halogen lamps, which give off heat at high temperatures and which coexist with other light sources arranged close to each other in the housing.

[0004] Generally, the size of the upper, horizontal wall, which extends the upper part of the parabola is adapted to the material used. This wall, generally made of the same material as the housing, in addition to its optical function, is also used to delimit the lighting and / or signaling function and create a separation with another adjacent lighting and / or signaling function in the housing sharing the interior space of the housing. Each of the functions is housed in a cavity of reduced volume inside the housing which, itself, is generally of limited size.

[0005] A halogen bulb operates at high temperatures that can reach temperatures of the order of 200 C° (by radiation and convection) in certain lighting functions such as the fog light function, especially if the lighting function is confined in a small space. It is therefore necessary to adapt the type of material used to make the housing, and therefore the wall, in order to withstand these high temperatures.

[0006] Indeed, if a plastic material not suitable for high temperatures is used, such as ABS, PC / ABS for example, to make the walls of a cavity of reduced volume with a halogen bulb, then the heat release at high temperatures will damage the horizontal upper wall extending the parabola (deformation, burning / blackening of the metallized coating which covers the parabola to define a surface reflecting the light), which is of course unacceptable from the point of view of the perceived quality for the vehicle user. We remind you here that the acronyms ABS, PC / ABS correspond respectively to Acrylonitrile Butadiene Styrene (ABS) and Polycarbonate / Acrylonitrile Butadiene Styrene (PC / ABS).

[0007] It is therefore necessary to plan to produce the housing by injection of a plastic material inside a mold, entirely in high temperature resistant material of the PC, PC-HT type, ... for example, but with a consequent increase in the manufacturing cost of the housing of the lighting and / or signaling device, and therefore of the rear light. It is recalled here that the acronyms PC, PC-HT correspond respectively to: Polycarbonate (PC), Heat Resistant Polycarbonate (PC-HT).

[0008] The invention therefore aims in particular to overcome these drawbacks by proposing a simple and economical solution making it possible to manage the proximity of light sources generating high temperatures in operation inside a lighting and / or signaling device housing with limited space requirements.

[0009] To this end, the invention has as its first object a lighting and / or signaling device for a motor vehicle, comprising a housing obtained after injection molding of a first plastic material; said housing being open towards the outside and hermetically closed by a glass, and comprising at least first and second adjacent cavities open towards the outside and superimposed vertically defining respectively upper and lower cavities when the device is mounted on the vehicle;said device further comprising a light source, releasing heat, confined in the lower cavity, and a wall made of a second plastic material resistant to the heat released by the light source, attached and held fixedly between the upper and lower cavities so as to define a separation wall between the upper and lower cavities forming a thermal screen against the heat released by the light source.;

[0010] According to one characteristic, the heat shield when it is attached to the housing, materializes, respectively, the lower and upper faces of the upper and lower cavities by integrating into the style of the housing.

[0011] According to another characteristic, the housing comprises grooves cooperating respectively with ribs arranged on edges of the screen ensuring the alignment of the screen with the housing when mounting the screen in the housing and holding it in the housing, and fixing means arranged respectively in the bottom of the housing and on an edge of the screen, in contact with the bottom of the housing, cooperating with each other to fix the screen in the housing.

[0012] According to another characteristic, the housing comprises a second lower cavity separated laterally from the first lower cavity by a common partition, and containing another source of light releasing heat, and in which the heat shield covers the two lower cavities, resting on the common partition.

[0013] According to another characteristic, the first plastic material is a plastic material not resistant to high temperatures and the second plastic material is a plastic material resistant to high temperatures.

[0014] According to another characteristic, the first plastic material is chosen from ABS or PC / ABS plastic materials and the second plastic material is chosen from PC or PC-HT plastic materials.

[0015] According to another characteristic, the light source(s) releasing heat at high temperature are halogen bulbs.

[0016] The second subject of the present invention is a motor vehicle rear light comprising at least one lighting and / or signaling device as described above.

[0017] The third subject of the present invention is a motor vehicle comprising at least one lighting and / or signaling device as described above.

[0018] The present invention has as its fourth object, a heat shield for a lighting and / or signaling device as described above, produced separately from the housing of the device by injection molding of a plastic material resistant to the heat given off by a halogen bulb.

[0019] Other characteristics and advantages of the invention will appear on examining the detailed description below, and the attached drawing, in which:

[0020] [Fig-1] illustrates a front view of a motor vehicle rear light comprising a lighting and / or signaling device according to the invention;

[0021] [Fig.2] illustrates a front view of the housing, alone, of the lighting device and / or of signaling according to the invention;

[0022] [Fig.3] illustrates, according to a sectional view along the cutting axis 111-111 of [Fig.l], the lighting and / or signaling device according to the invention;

[0023] [Fig.4] illustrates a perspective view of the lighting and / or signaling device according to the invention; and

[0024] [Fig.5] illustrates a heat shield intended to be fitted into the housing of the lighting and / or signaling device according to the invention.

[0025] In the following, it is considered that the elements represented in the figures are oriented within the same orthonormal reference frame XYZ and identical elements are designated by the same alphanumeric references.

[0026] For this purpose and unless otherwise specified, reference is made to the orthonormal reference frame XYZ to identify the directions of extension of the lighting and / or signaling device as mounted on the vehicle and the associated relative notions, 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 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 in relation to the rolling plane of the vehicle on the ground.

[0027] It is recalled that the objective of the present invention is to provide a multifunction rear light comprising at least one lighting and / or signaling device providing several lighting and / or signaling functions, at a controlled cost.

[0028] For this, the present invention consists of providing a high temperature resistant heat shield in the housing by optimizing its integration in the housing to respect both the style and the perceived quality with a cost remaining compatible with an entry-level rear light.

[0029] Among the functions provided by a lighting and / or signaling device of a rear light, there is in particular at least one function generating high temperatures such as the rear fog light function.

[0030] [Fig.l] illustrates an example of a VHL motor vehicle FAR rear light as mounted on a VHL motor vehicle, seen by an observer positioned at the rear of the VHL vehicle, facing the FAR light (front view).

[0031] The FAR light comprises a lighting and / or signaling device according to the invention DES which provides various lighting functions and which comprises a housing BOI, open to the outside, and which is hermetically sealed by a glass GLA.

[0032] A light, and in particular a rear light, comprises several lighting and / or signaling functions using bulbs, such as a turn signal light function, a reversing light function, a brake light function, a fog light function, etc.

[0033] In the example of [Fig. 1], the glass GLA allows a glimpse through transparency of the bulbs of the lighting and / or signaling functions and the bottom of the case which will be described below, with reference to [Fig. 2], 3 and 4.

[0034] [Fig.2] illustrates the DES lighting and / or signaling box BOI, shown alone, that is to say without the glass GLA closing the box BOI and without the light sources (bulbs) contained in the box BOI, illustrated in figures 3 and 4 described below.

[0035] The BOI case is obtained after injection molding of an ABS type plastic material not designed to withstand high temperatures and which is chosen here for its cost which is lower compared to other types of plastic materials that withstand high temperatures.

[0036] High temperatures are understood to mean temperatures typically around 200°C.

[0037] The BOI box also acts as a mask here to save parts and materials and therefore costs.

[0038] The BOI housing is shaped to define several cavities, five cavities CAV1-CAV5 in the example considered, arranged in the bottom of the FDB housing. The cavities CAV1-CAV5 extend over the entire bottom of the FDB housing and are delimited, respectively, by lateral separating partitions CLS extending in a substantially vertical general direction (along Z) and upper and lower partitions, substantially horizontal, extending in a general direction (along Y), made of the same material as the BOI housing and extending transversely from the bottom of the FDB housing towards the front of the BOI housing as far as the closing glass GLA of the BOI housing when the latter closes the BOI housing.

[0039] The bottom of the FDB housing also forms the bottom faces FDC ([Fig.3]) of each cavity CAV1-CAV5 with a parabola shape, or portion of a parabola, to define a reflection surface for the light emitted by the light sources SOL (figures 3 and 4).

[0040] Some of these cavities, and in particular the adjacent cavities CAV1 and CAV2, are vertically superimposed on each other and share one or more separating partitions CLS. The lower cavity CAV2 contains a halogen bulb HAL (figures 3 and 4).

[0041] The dimensioning of the CAV1-CAV5 cavities responds to the size, the shape of the FAR light, the number of functions provided by the DES lighting and / or signaling device and the type of function.

[0042] As a result, the dimensioning (the size) of the cavities CAV1-CAV5 is highly constrained, resulting in reduced heights for some of these cavities CAV1-CAV5, as is particularly the case for the lower cavity CAV2 containing the fog light function. The halogen bulb HAL, which is the lighting source SOL for this function, is therefore confined inside a cavity CAV2 with reduced height.

[0043] Given the high temperatures released by the HAL halogen bulb, it might have seemed sensible to choose a plastic material resistant to these high temperatures to produce the entire BOI housing, for example a material of the PC, PC-HT, etc. type already mentioned above.

[0044] However, the cost of this type of high temperature resistant plastic material, compared to the cost of ABS plastic material, makes it unsuitable to achieve the imposed objective of producing a low-cost rear light, especially since the heating caused by the HAL halogen bulb (figures 3 and 4), remains located inside the BOI housing at the interface between the upper and lower cavities CAVI and CAV2.

[0045] Indeed, when the fog light function is activated, the heat released by the halogen bulb HAL, is directed, by natural convection, towards the top of the housing BOI and heats the lower surface of the horizontal separating partition CLS arranged between the upper cavities CAV1 and lower cavities CAV2. The release of heat can then cause local deformation of the housing BOI, which is made of an ABS type material chosen for its low cost but which is not resistant to high temperatures.

[0046] The solution implemented by the present invention consists in producing the horizontal separation partition CLS, separating the upper and lower cavities, respectively CAV1 and CAV2, separately from the BOI housing, from a material resistant to high temperatures, then placing it in the BOI housing before closing the BOI housing by the GLA glass.

[0047] The CLS partition wall is therefore an ETR added wall which is obtained by molding like the BOI housing but from a material resistant to high temperatures. The ETR added wall behaves as a heat shield with respect to the upper cavity CAV1. It has the general shape of a horizontal plate (when the BOI housing is mounted in the VHL vehicle) whose surface is substantially uneven.

[0048] The ETR thermal screen, when it is attached to the BOI housing, materializes, respectively, the lower and upper faces of the upper and lower cavities CAV1, CAV2.

[0049] In the example considered, two adjacent lower cavities CAV2 and CAV3 are arranged in the housing BOI, each containing a light source SOL, HAL releasing heat at high temperature and confined in their respective cavities CAV2, CAV3. They are separated laterally from each other by a common, vertical partition CLV. The cavity CAV1, greater than the second and third cavities, respectively CAV2 and CAV3, covers them completely. According to this arrangement ([Fig. 4]), the two lower cavities CAV2 and CAV3 share the same thermal screen ETR which is positioned and maintained above the two lower cavities CAV2 and CAV3 on the one hand, by the common partition CLV and, on the other hand, by a lateral rib NRV (Figures 4 and 5) of the screen ETR cooperating with a groove GRG of the housing BOL

[0050] Other constraints added to the cost and to be respected by the ETR heat shield are the style and the perceived quality. The ETR heat shield must be assembled without play in the BOI case and visually integrate optimally into the style of the BOL case

[0051] This is what justifies the choice of using an ETR heat shield obtained by molding a plastic material that is easy to conform and assemble optimally on a housing also obtained by molding a plastic material. For an observer, the ETR heat shield appears visually as coming from the same material as the BOL housing.

[0052] To respect the style of the BOI case, the upper face of the ETR screen is covered with a metallized coating supporting a decorative MOT pattern in the same style as that of the rest of the BOI case, in the form of gadroons as in the example described.

[0053] As illustrated in [Fig. 3], by a cross-sectional view along the section axis III-III of [Fig. 1], the ETR screen extends transversely (along X) relative to the bottom of the FDB housing between the upper and lower cavities CAV1 and CAV2, from the bottom of the FDB housing towards the GLA glass, bearing on the vertical lateral partitions CLV of the BOI housing ([Fig. 4]) and on an inner wall PGL of the GLA glass forming a RED recess, once the GLA glass is fixed to the BOL housing

[0054] As illustrated in [Fig.5], the ETR screen comprises two NRV ribs arranged respectively on the right lateral edge BLA of the ETR screen and under the ETR screen, being substantially centered under the ETR screen; the two NRV ribs extending transversely (along X) relative to the front edge B AV of the ETR screen.

[0055] The BOI housing comprises ([Fig.4]) grooves GRG cooperating respectively with the ribs NRV of the ETR screen ensuring the alignment of the ETR screen with the BOI housing when mounting the ETR screen in the BOI housing and then holding it in the BOL housing.

[0056] Means for fixing the ETR screen to the bottom of the FDB housing ([Fig. 3]) comprise two pairs of clipping tabs CLP, arranged ([Fig. 5]) on the rear edge BAR of the ETR screen, cooperating with two FNT slots arranged in the bottom of the FDB housing (figures 3 and 4).

[0057] The profile of the rear edge BAR of the ETR screen is shaped to optimally fit, without play, the bottom of the FDB housing when the ETR screen is fixed in the BOL housing.

[0058] The profile of the front edge BAV of the ETR screen ([Fig.5]) is shaped to match the curve of the inner wall of the PGL glass ([Fig.3]).

[0059] A support stop B AP is arranged on the front edge BAV of the ETR screen ([Fig.5]) to rest against the RED indent of the inner wall of the PGL window ([Fig.3]).

Claims

Claims

1. Lighting and / or signaling device (DES) for a motor vehicle (VHL), comprising a housing (BOI) obtained after injection molding of a first plastic material; said housing (BOI) being open to the outside and hermetically closed by a glass (GLA), and comprises at least first and second adjacent cavities (CAV1 and CAV2), open to the outside and superimposed vertically, defining respectively upper and lower cavities when the device (DES) is mounted on the vehicle (VHL);said device (DES) further comprising a light source (HAL), releasing heat, confined in the lower cavity (CAV2), and a wall (ETR) made of a second plastic material resistant to the heat released by the light source (HAL), attached and held fixedly between the upper (CAV1) and lower (CAV2) cavities so as to define a separating wall between the upper and lower cavities (CAV1, CAV2) forming a heat shield against the heat released by the light source (HAL), characterized in that the housing (BOI) comprises a second lower cavity (CAV3) separated laterally from the first lower cavity (CAV2) by a common partition (CLV), and containing another light source (HAL) releasing heat, and in which the heat shield (ETR) covers the two lower cavities (CAV2, CAV3) by resting on the common partition (CLV).;

2. Device according to the preceding claim, in which the thermal screen (ETR) when it is fitted in the housing (BOI) materializes, respectively, the lower and upper faces of the upper and lower cavities (CAV1, CAV2) by integrating into the style of the housing (BOI).

3. Device (DES) according to one of the preceding claims, in which the housing (BOI) comprises grooves (GRG) cooperating respectively with ribs (NRV) arranged on edges of the screen (ETR) ensuring the alignment of the screen (ETR) with the housing (BOI) during the mounting of the screen (ETR) in the housing (BOI) and its retention in the housing (BOI), and fixing means (CLP, FNT) arranged respectively in the bottom of the housing (FDB) and on

4.

5.

6.

7.

8. an edge of the screen (FDB), in contact with the bottom of the housing (FDB), cooperating with each other to fix the screen (ETR) in the housing (BOI). Device (DES) according to one of the preceding claims, in which the first plastic material is a plastic material not resistant to high temperatures and the second plastic material is a plastic material resistant to high temperatures. Device (DES) according to the preceding claim, in which the first plastic material is chosen from ABS, or PC / ABS plastic materials and the second plastic material is chosen from PC or PC-HT plastic materials. Device (DES) according to one of the preceding claims, in which the light source(s) (SOL) releasing heat at high temperature are halogen bulbs (HAL). Rear light (FAR) of a motor vehicle (VHL) comprising at least one lighting and / or signaling device (DES) according to one of claims 1 to 6. Motor vehicle (VHL) comprising at least one lighting and / or signaling device (DES) according to any one of claims 1 to 6.

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