HEAT SEAK VENTILATION

Description

[0001] The invention relates to the field of electrical equipment incorporating an acoustic enclosure. BACKGROUND OF THE INVENTION

[0002] Many modern electrical devices incorporate a speaker enclosure, including a subwoofer and a loudspeaker, as well as various electronic components. These devices include "enhanced" set-top boxes, smart speakers, voice assistants, and more.

[0003] The generally very compact design of these devices requires integrating all their functionalities into a reduced volume. In particular, the presence of the acoustic enclosure reduces the volume available to integrate the electronic components of the various functions (acoustic and others). The air volume around the electronic components is therefore reduced, which is detrimental to the cooling of said electronic components and causes significant thermal diffusion problems.

[0004] Devices dedicated to heat diffusion and evacuation, such as radiators or heat sinks, are therefore integrated into electrical equipment. The efficiency of these devices is generally insufficient, especially since the volume devoted to them is also small. The use of a fan seems problematic due to integration constraints and the possible disturbances generated in the audio signals reproduced by the acoustic enclosure.

[0005] Patent document US2020 / 314546 discloses equipment comprising an acoustic enclosure comprising a box, a loudspeaker and a vent.

[0006] Other equipment is also known from documents FR3075546A1, FR2394220A1 and JPH10164680A. SUBJECT OF THE INVENTION

[0007] The object of the invention is to improve heat dissipation in electrical equipment incorporating an acoustic enclosure. SUMMARY OF THE INVENTION

[0008] In order to achieve this goal, equipment according to claim 1 is provided. Such equipment comprises: an acoustic enclosure comprising a cabinet, a loudspeaker and a vent; an electronic component; a heat dissipation device arranged to dissipate heat generated by the electronic component, and comprising the vent and a thermally conductive element which extends from one end of the vent and which is thermally coupled with the electronic component.

[0009] The tubular part of the vent forms an additional dissipation surface in addition to that of the thermal conductive element. In addition, during operation, the surface of the vent is in contact with a significant air flow, which further improves the dissipation of the heat produced by the electronic component.

[0010] We further propose equipment as previously described, in which the thermal conductive element comprises a plate which extends in a plane perpendicular to a longitudinal axis of the vent, and in which the vent flares at said end to open onto said conductive plate.

[0011] We further propose equipment as previously described, in which the electronic component is mounted on an electrical card which extends between the plate and a face of the box, parallel to said plate and to said face.

[0012] Further provided is equipment as previously described, wherein the vent, when viewed in section along a plane perpendicular to a longitudinal axis of the vent, has an oblong shape.

[0013] Further provided is equipment as previously described, wherein the vent includes fins extending from an inner surface of the vent and parallel to a longitudinal axis of the vent.

[0014] We further propose equipment as previously described, in which a distance e between two adjacent fins is such that: e > 2 ∗ h Or h is a height of said fins.

[0015] We further propose equipment as previously described, in which a height of each fin decreases as it approaches the ends of the vent.

[0016] The equipment according to the invention comprises a cable passage formed on or in a fin, or between two adjacent fins, the cable passage extending along a length of said fin(s).

[0017] Further provided is equipment as previously described, wherein the cable passage comprises a groove formed at a surface of a fin, said surface being opposite the inner surface of the vent from which said fin extends.

[0018] Further provided is equipment as previously described, comprising a plurality of vents having parallel longitudinal axes.

[0019] We further propose equipment as previously described, in which the plurality of vents comprises at least two vents each comprising a wall in contact or merged with a wall of the other vent.

[0020] We further propose equipment as previously described, in which the thermal conductive element comprises a plate forming a portion or all of a face of the box.

[0021] Further provided is equipment as previously described, in which the thermal coupling between the thermally conductive element and the electronic component is achieved by a thermal connection means positioned between the thermally conductive element and the electronic component.

[0022] We also propose equipment as previously described, the equipment being a decoder box.

[0023] The invention will be better understood in light of the following description of particular non-limiting embodiments of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Reference will be made to the attached drawings, including: [ Fig. 1 ] there figure 1 represents a sectional view, along a vertical plane, of electrical equipment according to one embodiment; [ Fig. 2 ] there figure 2 represents a prior art enclosure without a vent and a prior art enclosure with a vent; [ Fig. 3 ] there figure 3 represents the frequency responses of the speakers of the figure 2 ; [ Fig. 4 ] there figure 4 represents a top view of the housing and the heat dissipation device; [ Fig. 5 ] there figure 5 represents a sectional view of a portion of the vent, along a plane perpendicular to the longitudinal axis of the vent; [ Fig. 6 ] there figure 6 represents a sectional view of a fin and an end of the vent, according to a plane comprising the longitudinal axis of the vent; [ Fig. 7 ] there figure 7 represents a sectional view of a fin and a cable along a plane perpendicular to a longitudinal axis of said fin; [ Fig. 8 ] there figure 8 represents a sectional view, along a vertical plane, of electrical equipment according to another embodiment; [ Fig. 9 ] there figure 9 represents a top view of the housing and the heat dissipation device according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0025] In reference to the figure 1 , the invention is here implemented in a decoder box 1 (or STB, for Set-Top Box ). The decoder box 1 is in this case an “improved” decoder box which comprises, in addition to the electronic components enabling it to implement the usual functions of a decoder box, an acoustic enclosure 2 enabling it to reproduce audio signals to the outside.

[0026] The acoustic enclosure 2 comprises a box 3, a loudspeaker 4 and a vent 5. The loudspeaker 4 is here a bass loudspeaker reproducing low frequencies ( woofer ) .

[0027] The vent 5 extends through the face 6 (upper face of the box 3) which is opposite the face 7 (lower face) at the level of which the membrane of the loudspeaker 4 is integrated.

[0028] The longitudinal axis X of vent 5 is perpendicular to face 6 (and to face 7).

[0029] The vent 5 comprises an end 8 located outside the box 3 and an end 9 located inside the box 3.

[0030] Generally speaking, the low-frequency performance of a loudspeaker is improved by adding such a vent to the enclosure. This is called a "bass-reflex" type enclosure. The air circulating in the vent between the inside of the enclosure and the outside forms a mechanical system that resonates at a specific frequency.

[0031] We see on the figure 2 an enclosure 10 and an enclosure 11, which are prior art enclosures. The enclosure 10 is a sealed enclosure while the enclosure 11 includes a vent. The bass-reflex design improves the enclosure's performance in the low frequencies, without the need for an additional mechanical element (such as a passive radiator) and without requiring excessive dislocation of the speaker membrane (the dislocation being constrained both by the mechanical characteristics of the membrane and by the external design of the equipment).

[0032] In reference to the figure 3 , we see that the response 12 of a bass-reflex design speaker is increased in the low frequencies compared to the response 14 of a so-called "closed load" speaker, i.e. having a closed volume, without a vent.

[0033] The increased low-frequency response is due to the tubular shape of the vent, which, coupled with the internal volume of the enclosure, acts as a Helmholtz resonator. The resonant frequency of this system is given by the following formula: f BassReflex = c 2 π S L + K S . V where c is the speed of sound in air ( c = 340 m . s -1< ), L is the length of the vent (along its longitudinal axis X ), V is the volume of the speaker cabinet, K is an end correction coefficient and S the section (area of ​​the section) of the vent. In the common case of a circular vent, the section is equal to the area of ​​the circle, i.e. S = π . r 2< with r the radius of the circle.

[0034] We return to invention and figure 1 . The decoder box 1 further comprises one or more electrical cards on which electronic components are mounted. Among these electrical cards, the card 15 is mounted outside the box 3 while being positioned parallel to the face 6 against an external wall of said face 6. The card 15 is fixed to the face 6. The card 15 comprises in particular an electronic component 16 which is here a component which heats up relatively significantly during operation. It can be any type of component, and for example an SoC (for System on a Chip, or system on a chip), a processor, a radio transmitter, an amplifier, etc.

[0035] The decoder box 1 further comprises a heat dissipation device 17 which is intended to improve the heat dissipation of the decoder box 1 and, in particular, to dissipate the heat generated by the component 16 in operation.

[0036] The heat dissipation device 17 comprises the vent 5 as well as a thermal conductive element which extends from the end 8 of the vent 5 and which is thermally coupled with the electronic component 16.

[0037] The thermal conductive element is here a rectangular plate 18 which extends in a plane perpendicular to the longitudinal axis X of the vent 5. The vent 5 widens at the end 8 to open onto said plate 18. Here, the vent 5 and the plate 18 form a single piece (but this is not necessarily the case).

[0038] This part is made with a rigid material (or materials), such as aluminum or ABS (Acrylonitrile Butadiene Styrene) type plastic, so that the section of the vent 5 remains constant despite pressure variations, and allows good thermal conduction.

[0039] The plate 18 extends outside the box 3 while being parallel to the face 6 of the box 3. The electrical card 15 and the electronic component 16 are positioned between the conductive plate 18 and the face 6 of the box 3. The plate 18 extends over a majority surface of the face 6 of the box 3 and, in particular, covers the entire surface of the component 16.

[0040] The heat dissipation device 17 further comprises a means of thermal connection between the surface of the component 16 and the plate 18, allowing them to be thermally coupled.

[0041] The thermal connection means here comprises a thermal pad 19 which is positioned between the electronic component 16 and the thermal plate 18 while being in contact with these two elements.

[0042] The heat dissipation device 17 therefore makes it possible to dissipate the heat produced by the electronic component 16.

[0043] The vent 5 is used as a dissipation surface. This surface is in direct contact with a significant flow of air, in one direction then in the other, during operation of the loudspeaker 4: the air is moved at high speed in the vent 5 during sound emissions.

[0044] The shape of the vent 5 is designed to maximize the contact surface with the air.

[0045] In reference to the figure 4 , the vent 5 has a cylindrical shape with an oblong section: the vent 5, when seen in section along a plane perpendicular to its longitudinal axis X, has an oblong shape.

[0046] Thus, the contour 20 of the vent 5 has the shape of a rectangle whose widths are rounded and whose lengths are parallel to the length of the decoder box 1.

[0047] This elongated shape of the section of the vent 5, rather than circular, makes it possible to reduce the diameter of the vent 5 in its smallest dimension (“width” of the vent 5), which reduces the depth of the decoder box 1 while increasing the contact surface between the vent 5 and the air for the same volume of air (at constant surface, the perimeter of the vent 5 is increased). This elongated shape therefore makes it possible to improve heat exchanges while reducing the size of the decoder box 1.

[0048] In addition, the periphery of the vent 5 is provided with fins 21. The fins 21 extend from an internal surface 22 of the vent 5 and parallel to the longitudinal axis X of the vent 5. The fins 21 make it possible to further increase the contact surface with the air.

[0049] The reduction in the effective section of the vent 5 caused by the presence of the fins 21 must be compensated by an increase in its dimensions (compared to a vent 5 without fins). The new resonant frequency of the dissipating vent f event is then given by: f event = c 2 π S efficace L + K S efficace . V Or S efficace = S - S ailette .N ailette with S ailette is the section of a fin 21 and N ailette the number of fins 21 integrated in the vent 5.

[0050] The necessary increase in the dimensions of the vent 5 is relatively small, since the presence of the fins 21 has little influence on the section of the vent 5. The fins 21, however, make it possible to obtain a significant increase in the perimeter of the vent 5, and therefore in the exchange surface between the heat dissipation device 17 and the air. However, to maximize the thermal power extracted at the outlet of the vent 5, it is essential that the air circulates properly between the fins 21: the air velocity profile must be as uniform as possible in the section of the vent 5, at the inlet and outlet. Furthermore, if the air does not circulate properly between the fins 21, the effective section of the vent 5 will be reduced and the resonance frequency of the bass reflex will no longer correspond to that which was calculated for the enclosure 2.

[0051] So, with reference to the figure 5 , in order to minimize the influence on the air circulation, the dimensions and position of the fins 21 should preferably be chosen so that the distance e between two adjacent fins 21 is greater than the height h of said fins 21.

[0052] Advantageously, we have: e > 2 * h.

[0053] The width l of each fin 21 must preferably be chosen as small as possible, even if it has very little influence on increasing the perimeter of the vent 5. These criteria also make it possible to avoid acoustic disturbances when the air circulates at high speed between two fins 21 (such disturbances can generate whistling sounds).

[0054] Additionally, it is best to have no sharp edges at the vent inlet and outlet, as sharp edges cause turbulence during airflow.

[0055] In reference to the figure 6 , the height h of the fins 21 decreases as it approaches each of the ends 8, 9 of the vent 5. Each fin 21 comprises, in its length, a central portion of continuous height and two extreme portions whose height decreases towards the relevant end of the fin (and therefore of the vent).

[0056] Each end of the fin 21, when viewed in section along a plane comprising the longitudinal axis X of the vent 5, therefore has the shape of a slope which descends towards the end closest to the vent 5. Each fin 21 is therefore profiled and becomes thinner at the inlet and outlet of the vent 5, which makes it possible to avoid turbulence. The chamfer thus formed makes it possible to prevent the fin 21 from acting as an obstacle to the flow of air.

[0057] In reference to the figure 7 , at least one of the fins 21 comprises a cable passage which extends along a length of said fin 21 and which makes it possible to accommodate a cable 23. Several fins 21 in this case each comprise a cable passage.

[0058] The cables 23 here connect, for example, the loudspeaker 4 to an amplifier located outside the subwoofer 3.

[0059] This is not mandatory, however: the cable(s) 23 could perfectly well connect components other than a loudspeaker and an amplifier.

[0060] Each cable passage comprises in this case a groove 24 formed at the level of the upper surface 25 of the fin, that is to say the surface opposite the internal surface 22 of the vent 5 from which said fin extends.

[0061] The groove 24 allows the cable 23 to be inserted along the entire length of the vent 5. The groove 24 holds the cable 23 by pinching. This allows the cable 23 to be passed through the vent 5, so as not to have to manage the passage of the cable 23 through the box and thus avoid sealing problems.

[0062] The cable 23, smooth or rough, must be sufficiently flexible to fit into the groove 24 and be held there securely. The material of the vent 5 as mentioned above ensures that the fin 21 is sufficiently strong to hold the cable without deforming. Finally, the extension of the heat dissipation device 17 at the vent outlet 5 can be used to guide the cable 23 to the component located outside the box 3 and to which it is connected.

[0063] The groove 24 here has a narrowing at its exit (and possibly at its entry), in order to eliminate the risks of the cable 23 “coming out” during normal use of the product.

[0064] It is noted that, when the cable 23 extends in the groove 24, the surface area of ​​the “full” section of the fin 21 along a plane perpendicular to the longitudinal axis of the fin 21, that is to say the sum of the surface area of ​​the section of the fin 21 and the surface area of ​​the section of the cable 23, is almost equal to the surface area of ​​the section that the fin 21 would have without the groove 24. Thus, the presence of the groove 24 and of the cable 23 does not modify the formula for the resonant frequency of the vent 5 provided previously, which facilitates the dimensioning and design of the heat dissipation device 17.

[0065] Many variations are possible.

[0066] In reference to the figure 8 , the vent 5 could extend through another face of the box 3, and for example through the rear face 26.

[0067] The component 16 to be cooled and the electrical card 15 on which it is mounted may be located on top of the box 3. In this case, the vent 5 is extended in its external part by a first plate 18a then by a second plate 18b perpendicular to the first plate 18a, the second plate 18b completely covering the surface of the component 16. The first plate 18a and the second plate 18b (and the vent 5) may be formed by a single piece, but this is not necessarily the case.

[0068] The plate(s) 18 could form a portion (or all) of one or more faces of the box 3.

[0069] In another variant, the height of the fins 21 can also be extended to have several pipes whose sum of sections is equal to the section of the initial vent.

[0070] In reference to the figure 9 , the enclosure 2 thus comprises a plurality of vents.

[0071] The vents can be "jointed" (for example by one of their walls), or can be non-jointed.

[0072] Here, the enclosure comprises four vents 5a, 5b, 5c, 5d. The longitudinal axes X of the vents 5 are parallel to each other and are perpendicular to the plane in which the plate 18 extends.

[0073] As before, the section of each vent 5 along a plane perpendicular to its longitudinal axis X is oblong. The contour 20 of each vent 5 has the shape of a rectangle whose widths are rounded and whose lengths are parallel to the length of the decoder box 1.

[0074] The vents are aligned and extend successively so that the longitudinal axes Y of their contours 20 are aligned and parallel to the length of the decoder box 1.

[0075] The vents are positioned so that the outer walls of two adjacent vents are in contact at the width of their contour 20: vent 5a is in contact with vent 5b which is also in contact with vent 5c which is also in contact with vent 5d.

[0076] The walls, which can be confused at the location of the contact surface, play the role of the fins presented earlier.

[0077] This configuration makes it possible to maximize the exchange surfaces with the air. This variant can be used in the case where the installation of the fins 21 is too complex, for example if the material is too flexible or if the machining of fins is not possible.

[0078] Of course, the invention is not limited to the embodiments described but encompasses any variant falling within the scope of the invention as defined by the claims.

[0079] The electrical equipment in which the invention is implemented is not necessarily a decoder box, but can be any equipment comprising an acoustic speaker and electronic components: connected speaker, voice assistant, television, etc.

[0080] Of course, the dissipation plate 18 can be thermally coupled with several electronic components.

[0081] The plate may optionally be fitted with ribs / fins to increase the dissipation surface.

[0082] The plate and the component to be cooled could be located inside the box; in this case, the plate extends from the end 9 of the vent 5.

[0083] The heat dissipation device could include two plates each extending from a separate end of the vent: one plate positioned outside the enclosure and another inside the enclosure, each plate being thermally coupled with at least one electronic component.

[0084] The thermally conductive element, which extends from one end of the vent, is not necessarily a plate but can be of any shape.

[0085] The vent and the thermal conductive element can be designed as several separate parts, linked by a suitable thermal bond (direct contact or thermal bonding means, for example, a thermal pad). It is then possible to have different materials between these two parts, such as aluminum or copper for the heat sink, and ABS plastic for the vent. This reduces the overall manufacturing cost compared to an all-metal solution (ABS plastic being easier to machine for complex shapes).

[0086] The thermal medium that can thermally couple the component to be cooled and the thermally conductive element is not necessarily a pad: it could be, for example, thermal paste or even thermally conductive epoxy resin.

[0087] The cable passage associated with a fin is not necessarily a groove. It could be, for example, a tubular conduit formed inside the fin, or fixing means such as hooks positioned on one face of the fin.

[0088] The cable passage is not necessarily associated with a single fin. The cable passage may be formed on or in a (single) fin, or between two adjacent fins, the cable passage extending along a length of said fin(s). The cable passage may thus, for example, consist of two closely spaced fins allowing the cable to be gripped between the two fins. The faces of these fins located on the cable insertion side may optionally be ribbed to help hold the cable.

Claims

1. Equipment (1) comprising: · a speaker enclosure (2) comprising a chamber (3), a loudspeaker (4), and a vent (5); • an electronic component (16); and • a heat sink device (17) arranged to dissipate the heat generated by the electronic component and comprising both the vent (5) and also a thermally conductive element (18) that extends from an end (8) of the vent and that is thermally coupled with the electronic component, the vent comprising fins (21) projecting from an inside surface (22) of the vent and extending parallel to a longitudinal axis (X) of the vent, the equipment being characterized in that it comprises a cable (23) and a cable passage formed on or in a fin or between two adjacent fins, the cable passage extending along the length of said fin(s).

2. Equipment according to claim 1, wherein the thermally conductive element comprises a plate (18) lying in a plane perpendicular to the longitudinal axis (X) of the vent, and wherein the vent flares at said end and opens out in said plate.

3. Equipment according to claim 2, wherein the electronic component is mounted on a circuit card (15) that lies between the plate and a face (6) of the chamber, extending parallel to said plate and to said face.

4. Equipment according to any preceding claim, wherein when seen in section on a plane perpendicular to its longitudinal axis (X), the vent (5) presents a shape that is oblong.

5. Equipment according to any one of claims 1 to 4, wherein two adjacent fins (21) are spaced apart by a distance e such that: e > 2 ∗ h where h is a height of said fins (21).

6. Equipment according to any one of claims 1 to 5, wherein each fin (21) is of a height that decreases on approaching the ends (8, 9) of the vent (5).

7. Equipment according to any one of claims 1 to 6, wherein the cable passage comprises a groove (24) formed in a surface (25) of a fin, which surface is remote from the inside surface (22) of the vent from which said fin projects.

8. Equipment according to claim 7, wherein the cable (23) is inserted in the grove (24) along the entire vent length, the grove (24) maintaining the cable by pinch.

9. Equipment according to any preceding claim, including a plurality of vents (5a, 5b, 5c, 5d) having respective longitudinal axes (X) that are parallel.

10. Equipment according to claim 9, wherein the plurality of vents includes at least two vents, each having a wall in contact with or coinciding with a wall of the other vent.

11. Equipment according to any preceding claim, wherein the thermally conductive element comprises a plate forming an entire face of the chamber, or a portion thereof.

12. Equipment according to any preceding claim, wherein the thermal coupling between the thermally conductive element (18) and the electronic component (16) is provided by thermal connection means positioned between the thermally conductive element and the electronic component (16).

13. Equipment according to any preceding claim, the equipment being a set-top box (1).