FR3025294B1 - LIGHTING DEVICE INCORPORATING ENHANCED SEALING - Google Patents

Abstract

The object of the invention is a lighting device comprising an enclosure delimited by a support (16) and a cover which contains an electronic card (12), the lighting device comprising at least one electrical cable passage (64). ) which is characterized in that it comprises: - a seal (68) of deformable material which comprises at least one through conduit in which passes the element comprising at least one electric cable (66) and a side surface (76); ) approximately conical, - a seal support (78) which comprises a bearing face (84) facing the enclosure and which is traversed by a conical conduit (80) configured to receive the seal (68), the conduit ( 80) having a larger section at the bearing face (84), - a compression plate (12) and compression means for compressing the seal (68) between the seal support (78) and the compression plate (12).

Description

LIGHTING DEVICE INCORPORATING ENHANCED SEALING

The present invention relates to a lighting device with light-emitting diodes incorporating improved sealing.

Document WO2010 / 125294 discloses a light-emitting diode lighting device which comprises: a substantially flat support plate; an electronic card fixed on the support plate and on which the light-emitting diodes and other components are implanted; electronic devices for managing the electric power supply of the light-emitting diodes, - a transparent cover which has an optical function and whose peripheral edge is sealingly connected to the support plate so as to enclose the electronic card in a substantially sealed enclosure, - A thermal diffuser in the form of a hollow profile comprising a substantially constant section and stretched in a direction perpendicular to the electronic card, the support plate being attached to one end of said thermal diffuser. Other electronic components are inserted in the housing formed by the thermal diffuser and the support plate.

This device is not fully satisfactory on the following points: - The lighting devices are subjected to significant temperature gradients given the high temperature rise of the light-emitting diodes. In addition, in the case of outdoor lighting, these devices are subject to climatic variations (rain, heat, frost, ....). Even if the contact between the transparent cover and the support plate is in a plane which simplifies the sealing, the latter is not optimal especially at the glands intended to route the power cables into the enclosure delimited by the support plate and the transparent cover. - The dimensions of the section of the profile of the thermal diffuser varying in particular according to the number of light-emitting diodes and therefore the light power emitted by the lighting device, if it is desired to develop a range of lighting devices with powers different lighting it is necessary to provide as many variants of profiles as variants of lighting powers which necessarily has an impact on production costs. - According to another point, these lighting devices generally include presence and brightness sensors for modulating the lighting. According to the design of the prior art, these sensors are located on the electronic card, close to the light emitting diodes, which can impact the operation of the sensors including that of brightness.

The present invention aims to overcome the disadvantages of the prior art by providing a lighting diode device LED improved in terms of sealing. For this purpose, the subject of the invention is a lighting device comprising an enclosure delimited by a support and a cover which comprises a peripheral edge pressed against the support and connected thereto by a sealed connection, said enclosure containing an electronic card which is pressed against the support, the lighting device comprising at least one electrical cable passage configured to allow the passage through the support of an element comprising at least one electric cable.

The lighting device is characterized in that the electrical cable passage comprises: a seal of deformable material which comprises at least one through conduit, through which the element comprising at least one electrical cable, connecting a first end and a second end of the seal and an approximately conical side surface, - a seal support which comprises a bearing face facing the enclosure and which is traversed by a conical duct configured to receive the seal, the duct having a larger cross-section; important at the bearing face, - the seal and the seal support being configured so that in the absence of compression, the seal is protruding from the support face of the seal support when the surface side of the seal is in contact with the seal support, - a compression plate comprising a through hole with a section equal to or slightly greater than that of the electrical cable. ue - compression means for compressing the seal between the seal carrier and the compression plate. Other characteristics and advantages will become apparent from the following description of the invention, a description given by way of example only, with reference to the appended drawings, in which: FIG. 1 is a perspective view of a part of a lighting device according to a variant of the invention without an electronic card and without transparent cover, - Figure 2 is a section illustrating a housing provided at the end of the lighting device of Figure 1, - Figure 3 is a front view of the housing of Figure 2 showing the various elements by transparency, including a seal support shown in strong lines, - Figures 4A and 4B are sections of two seals each provided for the passage of an electric cable with 5 is a sectional view of a portion of the housing of FIG. 3 illustrating a cap with a transparent wall; FIG. 6 is a sectional view of a seal surrounding the cap of FIG. 5; figure 7 is a front view of a transparent cover designed to cover an electronic card comprising at least light-emitting diodes; FIG. 8 is a section of the transparent cover of FIG. 7 attached to a support comprising an electrical cable passage; FIGS. 9A and 9B are sections illustrating in detail the electrical cable passage of FIG. 8 when it is put in place and at the end of its installation, FIG. 10 is a section of a support for a card FIG. 11 is a perspective view of the support of FIG. 10 with a partial cutaway to illustrate the different layers of the support, FIG. 12 is a diagram illustrating a control system of a device of FIG. lighting, and - Figure 13 is a front view illustrating another variant of the invention.

In Figures 1 and 8, there is shown a lighting device 10 with light emitting diodes.

This lighting device 10 comprises: - at least one electronic card 12 on which light-emitting diodes 14 and preferably other electronic components are implanted; - an electronic card support 16 which provides mechanical and thermal functions which comprises a surface planar 18 against which is lined the electronic card 12, - a transparent cover 20 which comprises a peripheral edge 22 pressed against the electronic card holder 16 so as to form a chamber 24 "sealed".

The transparent cover 20 is not more detailed because it is known to those skilled in the art. Its geometric and dimensional characteristics vary depending in particular on the optical characteristics sought, the electronic card and the components present on this card.

According to a variant illustrated in Figures 1 to 3, the electronic card support 16 comprises a section 26 with a constant section in a direction 28 (represented by a center line). The section comprises a rectilinear portion which corresponds, along the length of the profile 26, to the flat surface 18 and a plurality of alternating hollow and projecting shapes preferably distributed symmetrically with respect to a median axis perpendicular to the rectilinear portion. .

Unlike the prior art, it is possible to modify the light power by adjusting in particular the length of the profile without the need necessarily to change its section. Thus, from the same die, it is possible to decline several lighting powers.

The section of the section 26 may vary depending on the desired heat exchange.

According to another point, the profile 26 is hollow and comprises inside a conduit 32 which opens at each end 34 of said profile which are in planes approximately perpendicular to the flat surface 18. This conduit 32 can be used to store electrical energy storage means such as batteries, accumulators or others. Since the duct 32 is opening at both ends, naturally a flow of air is obtained which contributes to cooling the means of accumulation of electrical energy.

According to an embodiment illustrated in detail in FIG. 2, the electronic card support 16 comprises two plates 36, one for each end of the profile 26. Each plate 36 is connected to the profile 26 by connecting means 38 and at least one shim 40 is provided to maintain apart the plate 36 and the section 26. According to one embodiment, the connecting means 38 comprise several screws, for each of them, the plate 36 and the wedge 40 each comprising a through hole, and the profile 26 a threaded hole.

According to another characteristic, the lighting device comprises a housing 42 containing at least one sensor 44 among a presence sensor, a brightness sensor, said housing 42 being remote from the electronic card 12 supporting the light-emitting diodes 14. This configuration allows to limit the risks of disturbing the operation of the sensor 44.

Advantageously, the housing 42 is supported by one of the plates 36. This configuration optimizes the operation of the sensors, the housing 42 comprising a first face 46 facing the ground which is adapted for a presence sensor and a second face 48 upward which is suitable for a brightness sensor.

Of course, the invention is not limited to this arrangement. The openings made in the housing 42 for the sensors and the other elements can be grouped on the same face or arranged on different faces. The housing 42 comprises at least one opening on at least one face.

According to this configuration, the plate 36 provides the electronic card support function and comprises a face against which is pressed a second electronic card 50 supporting the sensor or sensors 44 and other electronic components. The housing 42 has a hollow shape and a peripheral edge 52 pressed against the plate 36 so as to delimit with the latter a chamber 54 "sealed" in which is placed the second electronic card 50.

According to this configuration, the lighting device comprises two electronic cards 12 and 50. Thus, it is possible to separate the electronic functions and distribute them on the two plates. Thus, the electronic functions that vary according to the lighting power are implemented on the first electronic card 12 supporting the light-emitting diodes 14 and the electronic functions that do not vary according to the lighting power are implemented on the second card This configuration makes it possible to rationalize the production costs insofar as the second electronic card 50 is identical and common to all the lighting devices.

As a variant, all the electronic functions can be grouped together on the same electronic card.

Whatever the variant, the lighting device comprises a "sealed" enclosure 24, 54 delimited by a support 16 or 36 and a cover (the transparent cover 20 or the housing 42) which comprises a peripheral edge pressed against the support and connected to the latter by a connection 56 sealed to air and water, said enclosure containing an electronic card 12 or 50.

To obtain a sealed connection 56, a peripheral seal 58 is interposed between the support 16 or 36 and the cover 20 or 42. For this purpose, the peripheral edge of the cover comprises a groove with a U-shaped cross section towards the support, which extends over the entire periphery and houses the peripheral seal.

According to one characteristic, the "sealed" enclosure 24, 54 comprises at least one opening 60 making it possible to communicate the inside and the outside of said "sealed" enclosure 24, 54, said opening 60 being closed off by a tight wall 62 with water and permeable to air.

According to one embodiment, the wall 62 is a very low-mesh fabric, such as for example a fabric sold by the company "Gore".

The water-tight and breathable wall 62 makes it possible to evacuate the surplus air and to avoid an overpressure when the temperature rises and the air present inside the enclosure " Waterproof 24, 54 expands.

Whatever the variant, the lighting device comprises at least one electrical cable passage 64 for conveying an electrical cable 66 between the inside and the outside of the "sealed" enclosure 24, 54.

In known manner, an electric cable 66 has a circular section.

An electrical cable passage 64 includes a seal 68 (shown in detail in Figures 4A and 4B) of deformable material which includes a through conduit 70 connecting a first end 72 and a second end 74 of the gasket 68 and a side surface 76 approximately conical and concentric to the through conduit 70 and a seal support 78 (shown in detail in Figs. 9A and 9B) traversed by a conical conduit 80 configured to receive the seal 68.

Advantageously, the through conduit 70 of the seal 68 has a convergent portion and a divergent portion from one end to the other, with a reduced section 82 (junction between the convergent and divergent parts).

According to one configuration, as illustrated in FIG. 4A, the reduced section 82 has a diameter equal to the outside diameter of the electric cable 66 to allow the gasket 68 to slide on the electric cable 66.

The seal support 78 comprises a bearing face 84 parallel to the electronic card 12, 50 and oriented towards the latter or towards the enclosure (24, 54). The duct 80 extends from an outer face 86 to the bearing face 84 and has a conical shape with an axis perpendicular to the bearing face 84, the duct 80 having a larger section at the face support 84 only at the outer face 86.

Advantageously, the seal support 78 is pressed against the electronic card 12, 50 or an interposed plate 36. In this configuration, in order to allow the passage of the electric cable 66, the electronic card 12, 50 and the optional interposed plate 36 respectively comprise a through hole 88, 90 with a section equal to or slightly greater than that of the electric cable 66.

In addition to the gasket 68 and the gasket support 78, the electrical cable passage 64 comprises compression means for compressing the gasket 68 between the gasket support 78 and the electronic card 12, 50.

According to one embodiment, these compression means comprise at least one bolt 92 which passes through the joint support 78, a possible interposed plate 36 and the electronic card 12 or 50. Of course, the invention is not limited to this variant for the compression means which may take the form of one or more screws, one or more rivets or one or more other connecting means.

The duct 80 and gasket 68 are dimensioned so that in the absence of compression as illustrated in FIG. 9A, when the lateral surface 76 of the gasket 68 is in contact with the gasket support 78, the gasket 68 is projecting from the bearing face 84 of the seal support 78. Thus, after tightening as illustrated in FIG. 9B, the electronic card 12 or the interposed plate 36 is pressed against the bearing face 84 and exerts a force longitudinal compression (perpendicular to the bearing face 84) on the seal 68 which is positioned in the conduit 80. Given the conical shape of the conduit 80, the seal 68 exerts a centripetal compression force (perpendicular to the longitudinal direction ) on the electric cable 66 which strengthens the seal.

As illustrated in FIGS. 4A and 4B, it is not necessary to modify the entire cable passage to adapt it to different sections of electric cables.

Thus, whatever the diameter of the electric cable 66, the joint support 78 remains unchanged. Only the gasket 68 is adapted to the electric cable. Thus, it is possible to have several sizes for the seals 68, the section of the through duct 70 being different from one format to another, the seals 68 having all the identical side surfaces.

According to a first variant illustrated in Figures 8, 9A and 9B, when the support 16 has a sufficient thickness to accommodate the conduit 80, the seal support 78 and the support 16 are a single piece. This solution reduces the number of parts and therefore the costs.

According to a second variant illustrated in FIG. 2, when the support has a small thickness, as in the case of a plate 36, the joint support 78 and the plate 36 are two separate parts, the plate 36 being inserted between the support of seal 78 and the electronic card 50. To reduce the number of parts, according to this second variant, the seal support 78 also performs the function of wedge 40. In this case, as illustrated in Figure 3, the seal support 78 has a cylindrical shape and comprises at least one branch 94, in this case three branches 94 which each comprise at their ends a ring 96 which forms a spacer and which is traversed by the connecting means 38.

Advantageously, the seal 68 has a Shore A hardness of the order of 50 to obtain a good radial compression of the electric cable 66. According to one embodiment, the seal 68 is made of thermoplastic elastomer, such as SEBS.

According to other configurations, the electronic card 12 or 50 can be shifted with respect to the cable passage 64 and does not include passage holes 88, 90. In this case, the lighting device comprises a compression plate distinct from the electronic board for compressing the gasket 68. Whatever the variant, the lighting device comprises at least one compression plate which may be the electronic card 12 or 50, the plate 36 or another plate, said compression plate comprising a through hole 88 with a section equal to or slightly greater than that of the electric cable 66.

In addition, the one or more electrical cables can be inserted into a tube, the gasket 68 being compressed against the outer wall of the tube in which the electric cable or cables pass. Therefore, the invention is not limited to the passage of at least one electrical cable. Thus, the invention allows the passage of at least one element comprising at least one electrical cable, this element being either the electric cable or a tube containing at least one electric cable.

Depending on the case, the seal 68 comprises a single through conduit 70 or more conduits 70 each intended for the passage of an element comprising at least one electrical cable.

The cable passage according to the invention allows its mounting from a single face, namely the face on which the light emitting diodes are reported. Thus, it is possible to obtain a perfectly tight cable passage even if it is difficult to access such as for example if it is remote from the ends of a profile 26 or if the support 16 is already fixed and its rear face (opposite to that receiving the cover 20) is no longer accessible.

According to another characteristic, the housing 42 has an opaque wall and comprises an opening 98 intended for the presence sensor, visible in detail in FIG. 5. This opening 98 is closed by a cap 100. According to one embodiment, the cap 100 comprises a cylindrical duct 102 surmounted by a head 104.

The cylindrical duct 102 has a diameter that increases slightly from its end connected to the head 104 to its other end intended to come inside the casing 42.

The head 104 comprises a cylindrical lower portion 106 surmounted by a dome 108 of a transparent material for the light. The cylindrical lower portion 106 of the head has a diameter greater than that of the cylindrical duct 102. Thus, the cylindrical duct 102 is connected to the cylindrical lower part 106 of the head by a radial wall 110 which extends in a plane perpendicular to the axes of the cylindrical duct 102 and the cylindrical lower portion 106 of the head.

To improve the seal, the lighting device comprises a seal 112 interposed between the cap 100 and the edge 114 of the wall of the housing 42 defining the opening 98.

This seal 112 is illustrated in detail in FIG. 6. It comprises a cylindrical base 116 surmounted by a cylindrical head 118 which has an outside diameter greater than that of the cylindrical base which has a diameter approximately equal to that of the cylindrical base. opening 98. The cylindrical base 116 comprises outside and at its lower end a flange 119 whose outside diameter is greater than that of the opening 98. This flange 119 is separated from the head 118 by a distance approximately equal to the thickness of the edge 114 of the housing wall. Preferably, the flange 119 has a conical shape to promote its passage through the opening 98. When the seal 112 is fitted into the opening 98, only the head 118 remains outside the housing.

The base and the head are traversed by a conduit 120 configured to house the cap 100. This conduit 120 comprises in the upper part a countersink 122 whose inner diameter is equal to that of the head 104 of the cap 100.

The conduit 120 comprises under the countersink 122 a median portion 124 with a diameter which is reduced to an end portion 126 which has a constant diameter.

The height of the middle and end portions 124 and 126 is smaller than the height of the cylindrical duct 102 of the cap 100 so that the latter protrudes from the gasket 112 when the radial wall 110 of the cap 100 comes against the bottom 128 of the counterbore 122. In addition, the cylindrical duct 102 of the cap 100 has, at its lower end, an outside diameter greater than that of the end portion 126 so that the cap 100 is held in the seal 112.

According to one feature, the wall 129 of the seal head 112 surrounding the counterbore 122 has a thin thickness of the order of 1 to 3 mm.

The seal 112 is made of deformable material. It has a Shore A hardness of the order of 40. According to one embodiment, the seal 112 is made of thermoplastic elastomer, such as for example in SEBS.

Advantageously, the bottom 128 of the countersink 122 comprises a circular rib 130 projecting which surrounds the duct 120. This rib 130 has a height of the order of 0.5 to 1 mm and a thickness of the order of 0.5 to 1 mm. . It is spaced from the conduit 120 by a distance of less than 1 mm.

This circular rib 130 promotes the maintenance of the cap 100 in the seal 112 and improves the seal between these two elements. Thus, when the cap 100 is fitted into the seal 112, the radial wall 110 of the cap crushes the circular rib 130. The crushing of this circular rib 130 causes the deformation of the wall 129 of the seal head 112 whose end upper deforms towards the inside of the seal as illustrated by the arrows 132. Thus, the seal 112 exerts a compressive force on the head of the cap 100 which improves the seal.

The seal 112 may also be used to improve the seal between a cap and the edge of an opening in the transparent cap 20.

According to another variant illustrated in Figures 10 to 13, the support 16 is a panel 134 which comprises a honeycomb structure 136 interposed between two plates 138, 138 'planar. The sandwich structure of the panel 134 gives it high mechanical properties.

This panel 134 is metallic, for example aluminum alloy.

The honeycomb structure 136 comprises a plurality of ducts having axes parallel and perpendicular to the plates 138, 138 '. Each duct is delimited by at least one wall 140 perpendicular to the plates 138, 138 '.

According to the example illustrated in FIG. 11, the honeycomb structure 136 is a honeycomb structure. However, the invention is not limited to this hexagonal form. Thus, the ducts of the honeycomb structure may have circular, square or other sections. Unlike a support of the prior art, the panel 134 has two flat parallel faces which improves its integration.

A first face 138F on which is reported an electronic card 148 covered with its cover as shown in Figure 11 or several electronic cards each covered by a cover as shown in Figure 13.

According to an important point, the electronic card 148 is pressed against a first face 138F of one of the two plates 138 in contact with the cellular structure 136 which contributes to the heat transfer. In this way, the plate 138 is interposed between the honeycomb structure 136 and each electronic card 148. Thus, as illustrated in FIG. 10, the plate 138 being completely flat, the surface contact between the electronic card 148 and the plate 138 ensures optimal heat transfer between the electronic card 148 and the panel 134. The walls 140 of the cellular structure 136 provide heat transfer between the two plates 138,138 '. Finally, the heat calories are evacuated via the plate 138 '.

In one configuration, the walls 140 have a thickness of the order of 0.2 to 2 mm.

The plates 138, 138 'have a thickness of the order of 0.5 to 3 mm.

The panel 134 has a thickness of 10 to 50 mm depending on its area.

Finally, the ducts of the honeycomb structure 136 each have an area of the order of 1 cm 2. Generally the supports of the prior art are designed to have a significant thermal inertia to evacuate the heat generated by the light emitting diodes. With against feet, the support of the invention has a low thermal inertia which gives it a great reactivity to evacuate the calories.

In another aspect, the panel 134 is industrially produced in large quantities because it is intended for other applications. Therefore, its cost is lower than a support of the prior art.

In addition, the honeycomb structure is perfectly connected to the plates 138, 138 'so that the cells are sealed.

It can be cut and machined easily. Thus, it is possible to drill as shown in Figure 10 so as to insert an electric cable. In addition, it is possible to adjust the dimensions of the panel according to the number of electronic cards positioned on the panel.

According to an important point, since the panel has a low thermal inertia, the lighting device comprises a system for regulating the heat emitted by the light-emitting diodes. For this purpose, the lighting device comprises a control 142 ensuring the regulation of the supply current of the light-emitting diodes 144 and a temperature sensor 146 implanted in the vicinity of the light-emitting diodes 144 which is connected to the control 142. Thus, the control 142 regulates the supply current of the light-emitting diodes 144 so that the temperature measured by the temperature sensor 146 remains below a threshold temperature. As an indication, this threshold temperature is lower than the maximum operating temperature of the light emitting diodes. By way of example only, the threshold temperature is of the order of 65 °.

According to one embodiment, the temperature sensor 146 is fixed on the electronic card 148 supporting the light-emitting diodes 144.

Claims (9)

1. Lighting device comprising an enclosure (24, 54) delimited by a support (16, 36) and a cover (20, 42) which comprises a peripheral edge pressed against the support (16, 36) and connected thereto by a sealed connection (56), said enclosure (24, 54) containing an electronic card (12, 50) which is pressed against the support (16, 36), the lighting device comprising at least one electrical cable passage ( 64) configured to allow passage through the support (16, 36) of an element comprising at least one electrical cable, characterized in that the electrical cable passage (64) comprises: - a seal (68) of deformable material which comprises at least one through conduit (70), through which the element comprising at least one electrical cable (66), connecting a first end (72) and a second end (74) of the seal (68) and a side surface (76) approximately conical, the through conduit (70) of the gasket (68) a converging portion and then a diverging portion with a reduced section (82) having a diameter equal to the outer diameter of the member comprising at least one electrical cable (66), - a joint support (78) which comprises a face d support (84) directed towards the enclosure (24, 54) and which is traversed by a conical conduit (80) configured to receive the seal (68), the conduit (80) having a larger section at the face (84), - the gasket (68) and the gasket support (78) being configured so that, in the absence of compression, the gasket (68) protrudes from the bearing surface ( 84) of the seal support (78) when the side surface (76) of the seal (68) is in contact with the seal support (78), - a compression plate (12, 50, 36) including a through hole (88) with a section equal to or slightly greater than that of the electric cable (66), - compression means for compressing the seal (68) between the s seal holder (78) and the compression plate (12, 50,36). 2. Lighting device according to claim 1, characterized in that the support (16) and the joint support (78) are a single piece. 3. Lighting device according to claim 2, characterized in that it comprises a plate (36) interposed between the electronic card (50) and the seal support (78). 4. Lighting device according to claim 3, characterized in that the joint support (78) comprises at least one branch (94) which comprises at its end a ring (96) which forms a spacer and which is traversed by connecting means (38) connecting the plate (36) and the support (16). 5. Lighting device according to one of the preceding claims, characterized in that the through conduit (70) has a section adapted to that of the element comprising at least one electrical cable (66), the seals (68) having all an identical lateral surface (76). 6. Lighting device according to one of the preceding claims, characterized in that the seal (68) has a Shore A hardness of the order of 50. 7. Lighting device according to one of the preceding claims, characterized in that the enclosure (24, 54) comprises at least one opening (60) for communicating the inside and outside of said enclosure (24). , 54), said opening (60) being closed by a wall (62) impervious to water and permeable to air. 8. Lighting device according to one of the preceding claims, characterized in that it comprises a seal (112) interposed between a cap (100) and the edge of an opening (98) formed in the cover (20, 42). 9. Lighting device according to claim 8, characterized in that - the cap (100) comprises a cylindrical duct (102), a head (104) and a radial wall (110) which extends between the head (104). ) and the cylindrical duct (102), and in that - the seal (112) is made of a deformable material and comprises a cylindrical base (116) surmounted by a cylindrical head (118), the cylindrical base (116) comprising the outside and at its lower end a collar (119) for holding the seal (112) fitted into the opening (98), the cylindrical base and the cylindrical head being traversed by a conduit (120) which comprises in part a counterbore (122) having an inside diameter equal to that of the head (104) of the cap (100), the wall (129) of the seal (112) surrounding the counterbore (122) having a thin thickness to be deformable , and in that the bottom (128) of the counterbore (122) comprises a projecting circular rib (130) which oure the duct (120) and which is configured so that when the radial wall (110) of the cap (100) is pressed against the bottom (128) of the countersink (122) and crushes said circular rib (130) this causes the deformation from the wall (129) to the interior of the seal (112).