Classifications

• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
  • H05K7/00—Constructional details common to different types of electric apparatus
  • H05K7/20—Modifications to facilitate cooling, ventilating, or heating
  • H05K7/20009—Modifications to facilitate cooling, ventilating, or heating using a gaseous coolant in electronic enclosures
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
  • H05K7/00—Constructional details common to different types of electric apparatus
  • H05K7/20—Modifications to facilitate cooling, ventilating, or heating
  • H05K7/20536—Modifications to facilitate cooling, ventilating, or heating for racks or cabinets of standardised dimensions, e.g. electronic racks for aircraft or telecommunication equipment
  • H05K7/206—Air circulating in closed loop within cabinets wherein heat is removed through air-to-air heat-exchanger

Definitions

• the invention relates to protective covers which are responsible for protecting at least one radiating part of the heat, such as a printed circuit board or PCB (for "Printed Circuit Board”).
• a printed circuit board or PCB for "Printed Circuit Board”
• some parts that radiate heat are relatively fragile and must therefore be protected by a protective cover or by a housing comprising, for example, a base or a support piece and a protective cover secured to one another (possibly by clipping).
• the radiating part of the heat must be evacuated to avoid overheating.
• This solution provides efficient cooling, but it is expensive, cumbersome, noisy and consumes electrical energy.
• aeration means on a main wall of the protective cover, intended, once installed, to be placed facing the room.
• These aeration means are generally in the form of simple openings (or aerators) defined in the main wall. These openings must remain small so that the room can be effectively protected, they leave little external air to penetrate, so that the cooling is not very effective. In fact, most of the surrounding outside air only licks the outer face of the hood's main wall in the vicinity of the openings, and cools the indoor air only when it reaches the outside. outside.
• the invention therefore aims to improve the situation by means of a passive solution (that is to say which does not consume electrical energy).
• a protective cover intended to protect at least one part (for example a printed circuit (or PCB)), which, in operation, can radiate heat, and having a main wall provided with aeration means and intended, once installed in a system, to be placed facing the room and in a vertical direction or an inclined direction.
• at least one part for example a printed circuit (or PCB)
• PCB printed circuit
• This protective cover is characterized in that its aeration means comprise at least one air channeling element protruding above the general level of an outer face of its main wall and having a so-called lower end which is provided with an air inlet communicating with an internal zone located behind an inner face of the main wall, opposite to the outer face, and an upper end which is provided with an air outlet communicating with the internal zone and intended, once the hood is installed, to be located at a level higher than that of the air inlet to induce a suction effect of clean air to promote the evacuation of heat radiated heat convection.
• the protective cover according to the invention may comprise other features that can be taken separately or in combination, and in particular:
• the aeration means may comprise at least two air channeling elements, which may be optionally substantially parallel to each other;
• the air inlet may have an air intake surface greater than the air expulsion surface of the air outlet;
• the air intake area may be at least 40% greater than the air expulsion surface
• each air duct element can be arranged in the form of a cylindrical duct; each air duct element may have a shape suitable for inducing a Venturi type effect;
• each air duct element may comprise a section transverse of substantially rectangular shape
• the air inlet and / or the air outlet can be equipped (s) with a clean grid to limit the entry of foreign bodies.
• the invention also provides a housing comprising a protective cover of the type shown above.
• FIG. 1 schematically illustrates, in a sectional view in a plane containing the vertical direction (DV), an exemplary embodiment of a housing comprising a protective cover according to the invention
• FIG. 2 schematically illustrates, in a front view of the side of the lower side wall, the casing of FIG. 1, and
• FIG. 3 schematically illustrates, in a front view, a lower end of the air duct element provided with a gate at its air inlet.
• the invention aims to provide a protective cover (CP) for protecting at least one piece (Cl) radiating heat.
• the protective cover (CP) is part of a housing (B) intended to house and protect at least one piece (Cl) of printed circuit type ( or PCB). But, the invention is not limited to this type of room. It concerns indeed any type of radiating part of the heat and to be protected by at least one protective cover.
• the protective cover (and thus the housing (B)) is intended to be part of a vehicle, for example of the automotive type (such as example a car). But, the invention is not limited to this application.
• FIG. 1 and 2 show an embodiment of a protective cover CP according to the invention.
• the protective cover CP is secured to a base (or part support (s)) EM with which it constitutes a housing B.
• This connection can be done by any means known to the man of art, and in particular by clipping or screwing.
• the piece Cl here a printed circuit comprising in particular electronic components CE
• the piece Cl can be fixed to the protective cover CP.
• the protective cover CP comprises for example a main wall PP, a so-called lower side wall PLI, a so-called upper side wall PLS, and two complementary side walls secured to each other.
• the main wall PP is provided with ventilation means MAi and intended, once the protective cover CP has been installed in a system (here a car), to be placed opposite the room Cl (here a printed circuit) and in a vertical direction DV or an inclined direction.
• the main wall PP is placed in a plane that contains the vertical direction DV. But, it could be placed in a plane inclined relative to this vertical direction DV.
• the angle of inclination must be strictly less than +/-
• the ventilation means MAi comprise at least one air channeling element which protrudes above the general level of an outer face FE of the main wall PP, opposite to an internal face F1 oriented towards the piece C1.
• the invention is not limited to this number (3) of air channeling elements MAi. It requires in fact that the main wall PP is provided with at least one air channeling element.
• the ventilation means MAi may comprise one or two salient air channeling elements MAi, or even more than three (for example four or five).
• the air channeling elements MAi are substantially parallel to each other, and moreover substantially identical. But, this is not mandatory. They could indeed be different from each other and / or be oriented in slightly different ways. Thus, at least one of their dimensions along the three directions of space could vary.
• Each air duct element MAi has two ends
• the lower end E1 is provided with an air inlet EA which communicates with an internal zone Z1 which is located behind the inner face Fl of the main wall PP and which contains the piece C1.
• the upper end E2 is provided with an air outlet SA which also communicates with the internal zone Z1.
• the air outlet SA of an air duct element MAi is located at a level which is higher than that of the EA air inlet of the same air duct element MAi. There is therefore a pressure difference between the air outlet SA and the air inlet EA which induces an air suction effect similar to that which exists in a chimney.
• the fresh outside air enters the internal zone Z1 with each air inlet EA, absorbs by thermal convection the calories carried by the internal air which has been heated by the radiation produced by the piece C1, and is expelled as heated air out of the protective cap CP, via each air outlet SA.
• the inlet EA air has an air intake surface greater than the air expelling surface of the air outlet SA.
• the air expulsion surface of the air outlet SA is shown in dotted lines because this figure is a front view of the side of the lower side wall PLI (and therefore on the side of the EA air inlet). It will be understood that this surface difference between the input EA and the output SA is intended to create a vacuum which induces an aspiration (and therefore an acceleration of the air flow).
• the air inlet area of the air inlet EA may be at least 40% greater than the air expelling surface of the air outlet SA. Preferably, it is chosen greater than at least 50%.
• the EA air inlet and the SA air outlet are not necessarily placed substantially one above the other (i.e. substantially vertically aligned once installed) as shown. Indeed, we can consider that they are slightly offset in a substantially horizontal direction. Thus, it may be advantageous for the air outlet SA to be shifted forward with respect to the air inlet EA.
• each air duct element MAi is arranged in the form of a cylindrical duct of rectangular cross section.
• the transverse section may have other shapes than the rectangular shape (for example square or semi-circular or semi-elliptical), and an air channeling element MAi may not be cylindrical (its shape may indeed to be curvilinear, for example).
• the largest side of the rectangle has an extension much greater than the smaller side of this rectangle. For example, an extension ratio of between about 2 and about 5 may be envisioned.
• each air duct element MAi may optionally have a shape suitable for inducing a Venturi type effect.
• each air duct element MAi may have at least one narrowing located between its lower ends E1 and upper E2. Such a narrowing is intended to induce an acceleration of the air flow.
• each grid G may be an insert or may be an integral part of an EA air inlet or an air outlet SA.
• This grid can be in any form since it allows to intercept foreign bodies whose size is less than a chosen threshold.
• the grid G comprises a square grid, but it could comprise a rectangular grid or diamond, or include circular holes or elliptical.
• the protective cover CP according to the invention may advantageously be made of plastic or synthetic material, for example by molding by means of a mold (the complexity of which may be limited when the air channeling elements have relatively simple shapes, for example of the type illustrated in Figures 1 to 3).

Landscapes

• Engineering & Computer Science (AREA)
• Microelectronics & Electronic Packaging (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Aviation & Aerospace Engineering (AREA)
• Cooling Or The Like Of Electrical Apparatus (AREA)
• Ventilation (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=41010849

Family Applications (1)

Country Status (5)

Families Citing this family (1)

Family Cites Families (4)

• 2009
  • 2009-02-13 FR FR0950922A patent/FR2942367B1/fr not_active Expired - Fee Related
• 2010
  • 2010-02-09 WO PCT/FR2010/050213 patent/WO2010092294A1/fr active Application Filing
  • 2010-02-09 BR BRPI1005954A patent/BRPI1005954A2/pt not_active IP Right Cessation
  • 2010-02-09 EP EP10708313A patent/EP2397021A1/de not_active Withdrawn
  • 2010-02-09 CN CN2010800078044A patent/CN102450114A/zh active Pending

Non-Patent Citations (1)

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