FR2981824A1 - Avionics equipment for aircraft, has electronic module including through holes to allow passage of external air flow into or out of module, where holes coincide with openings of housings when module is in operative position in cabinet - Google Patents

Abstract

The equipment has a cabinet (10) including a connecting wall (14) connecting two sliding walls (12, 13), and a pair of housings oriented to ensure guiding of an electronic module (20) in the cabinet to an operative position, where the electronic module is connected to an interface connector (141) of the connecting wall. The housings include an opening (123) and another opening. The module includes through holes to allow passage of an external air flow into or out of the module, where the holes coincide with the openings when the electronic module is in the operative position in the cabinet.

Description

The invention relates to the avionics field. More particularly, the invention relates to an avionics equipment intended to remain permanently in an aircraft. In an aircraft, many avionics equipment is located in a space located in the lower front of the fuselage, under the cockpit, and generally called avionics bay. These avionic devices are in particular in the form of substantially parallelepipedic boxes, called cabinets, in which series of electronic cards, intended for the management of different functions in the aircraft, are for example but not limited to, arranged vertically, parallel to each other. other. The avionics bay offers avionics equipment privileged environmental conditions such as a reasonable ambient pressure (pressurized zone of the aircraft), as well as a controlled ambient temperature.

Accessibility to this space is further facilitated by the access door to the hold of the aircraft, generally located nearby. Cabinets are usually placed in furniture on shelves via double-angled elements called chairs. The furniture allows to fix the cabinets in the bay and connect them to the cables of the aircraft. Ventilation for cooling the electronics is provided via the shelves. Forced air circulation is carried out in the shelf and the chair is pierced in its central part thus defining a zone of ventilation under the cabinet. The cabinet has openings facing the vertical of this area and the electronic cards, located vis-à-vis the openings and therefore in the vertical of this area, are thus ventilated. To ensure the tightness of the ventilation system, it is also necessary to provide a seal between the chair and the cabinet, especially around the bore for ventilation provided in the chair. The existing cabinets installed on board an aircraft are specific to him. Cabinets are dedicated to a specific function. They are specifically adapted to insert electronic cards and are thus strategically drilled, for ventilation, at the time of qualification, according to the electronic cards that will be installed. Each opening of the cabinet, facing a card, therefore has a dimension adapted for more or less significant ventilation depending on the type of associated electronic card. In one illustrative example, the opening of the cabinet associated with an electronic supply card thus has a dimension greater than an opening associated with an electronic input / output card because said electronic supply card requires a greater ventilation than the input / output card because it has more electronic components needing to be cooled than the input / output electronic board.

A major disadvantage of these existing avionics equipment appears, during maintenance operations, where said avionics equipment must be removed completely. This requires that they be quickly disconnectable and interchangeable with other avionics equipment with or without the same functions, which requires specific connectors of great technical complexity that penalize the avionics equipment both in terms of cost , volume than weight of the whole. Furthermore, the seal between the chair and the cabinet is requested at each assembly and dismounting of the cabinet, which makes it vulnerable.

The present invention aims to overcome at least one of these disadvantages. More generally, the present invention relates to an improvement of current avionics equipment. The invention proposes for this purpose an avionic equipment of an aircraft, comprising: a cabinet in the form of a substantially parallelepipedal housing, comprising a first and a second sliding wall, and a connecting wall connecting the two sliding walls, - at least one electronic card arranged in the cabinet so as to extend between the two sliding walls, - at least one electronic card included in a support having two solid side walls arranged on either side at least one electronic card, each electronic card and its support forming a set said electronic module. The cabinet comprises at least one pair of receiving housings of an electronic module, a first housing located at the first sliding wall and a second housing located at the second sliding wall, each housing pair being oriented from so as to be able to provide guidance of an electronic module in said cabinet to a so-called operative position in which the electronic module is connected to a connecting interface of the connecting wall.

The cabinet further comprises, for and at each pair of housings, a pair of openings, a first opening in the first sliding wall and a second opening in the second sliding wall. Each electronic module has through orifices adapted to allow the passage of an external air flow in or out of said electronic module, said orifices being determined so that they are in coincidence with a pair of openings of the cabinet when the electronic module is in an operative position in said cabinet. The present invention therefore proposes a modular avionics equipment which no longer requires that the cabinet-electronic module assembly be dismounted at each maintenance. The interchangeability function is moved to the electronic modules. Only electronic modules are removed and then returned or changed. The cabinet may now be permanently attached to the aircraft. In the event of an electronic failure, this allows a modularity refined on the scale of the electronic module and not the whole cabinet, the other electronic modules can continue to operate. On the other hand, this makes it easier and lighter for the repair and maintenance operations for a speaker. This significantly improves the average time between breakdowns of avionics equipment, time known generally as MTBF (Mean Time Between Failures), indicating the reliability of a system.

In addition, advantageously, the seal between a cabinet reception chair and the cabinet is no longer requested, which makes the avionics equipment less vulnerable. According to preferred embodiments, the invention furthermore meets the following characteristics, implemented separately or in each of their technically operating combinations. In a completely advantageous manner, all the openings of the cabinet have an identical dimension. Thus, as opposed to existing cabinets where the dimensions of the openings in each housing pair 10 are a function of the electronic card that will be inserted, the cabinet of the invention is a so-called standard cabinet with dimensions of the openings in each pair of housing identical and able to receive and ventilate electronic modules of different functions. In preferred embodiments of the invention, the avionic equipment comprises means for regulating the external air flow passing through the electronic module, said regulating means being disposed in a housing between the electronic module and the cabinet. next to an opening. The addition of a control means advantageously makes it possible to adapt a standard cabinet to the cooling of electronic modules with different and specific electronic functions. Thus, unlike the existing equipment which currently meets the ARINC standard, according to which the distribution of the external air flow is generated at the level of the equipment, the equipment of the invention advantageously makes it possible to report at the level of each module. electronics, the distribution of the air flow and therefore the pressure drop. Preferably, the regulating means is a plate, of a size adapted to fit into a housing, comprising at least one perforation of size and position adapted to direct the flow of external air towards the components of the electronic board of the module. needing to be cool. According to an advantageous characteristic of the regulating means, said regulating means comprises, at one end, a blocking element of the electronic module when inserted into the cabinet. This blocking element also advantageously makes it possible to limit a loss of the external air flow evacuating between the plate and the module, by generating a sinuous path between the plate and the module. In preferred embodiments of the invention, the avionics equipment comprises a plurality of electronic modules and a plurality of associated platelets. Thus, it is possible to obtain a standard cabinet with multiple configurations, depending on the power to be dissipated on each of the electronic modules, by intervening only on the means for regulating the external air flow. This also allows the possibility of reconfiguring a cabinet when said cabinet is already linked to the aircraft in a given configuration, and without resorting to a separation of the cabinet vis-à-vis the aircraft. The invention also relates to a cabinet for avionics equipment as described.

In another aspect, the invention is an electronic module for avionic equipment as described. According to yet another aspect, the present invention relates to an aircraft comprising an avionic equipment object of the present invention. The characteristics and advantages of the invention will be better appreciated thanks to the description which follows, which description exposes the characteristics of the invention through a non-limiting example of application. The description is based on the appended figures in which: FIG. 1 illustrates a perspective view of an avionic equipment 25 according to one embodiment of the invention; FIG. 2a illustrates an electronic module of a compliant avionics equipment; In one embodiment of the invention, FIG. 2b illustrates an exploded perspective view of the electronic module of FIG. 2a. FIG. 3 illustrates a side sectional view of an electronic module in a housing of a cabinet. the avionic equipment, in said operative position, Figure 4 represents an enlargement of Figure 3, Figure 5 shows a truncated longitudinal sectional view of an electronic module in a housing, and illustrating the flow of external air flowing in the electronic module via a flow control means, Figure 6 illustrates examples of flow control means. The following description, which is in no way limiting, illustrates an embodiment of avionic equipment placed in an avionics bay of an aircraft. An avionic equipment, as shown in FIG. 1, comprises a cabinet 10 and a plurality of electronic modules 20. FIG. 1 illustrates by way of nonlimiting example the arrangement of nine electronic modules 20 in the cabinet 10. The electronic cabinet 10 comprises in the first place a mechanical structure 11.

This mechanical structure 11 is dimensioned so as to allow the recovery and transfer, to an electronic furniture, structural forces experienced by the electronic cabinet 10 during use of the aircraft. The mechanical structure 11 also maintains a set of electronic modules 20 and contributes to the management of thermal stresses. The mechanical structure 11 is arranged on shelves (not shown), for example by means of double-angle elements. In the present embodiment, as seen in Figure 1, the mechanical structure 11 is in the form of a housing with three walls, substantially parallelepiped, defining an internal volume for receiving the electronic modules 20. Said housing is provided with two sliding walls 12, 13 substantially parallel and a connecting wall 14 substantially perpendicular to said sliding walls. For the rest of the description, a direct reference is defined relative to this cabinet, the reference comprising: a longitudinal axis X, parallel to a direction of insertion of the electronic modules in the cabinet, that is to say perpendicular to the connecting wall 14, - a vertical axis Z, perpendicular to the longitudinal axis X and located in a plane parallel to the connecting wall 14 of the cabinet, - a transverse axis Y, perpendicular to the two preceding axes. The terms before, back, up, down, on, under, above, below, etc. are defined relative to this marker. Thus, in adequacy with this reference, the mechanical structure 11 comprises a first sliding wall, said upper wall 12, a second sliding wall, said lower wall 13 and the connecting wall, said rear wall 14. The mechanical structure 11 is open at a so-called front face face 15, opposite the rear wall, and two side faces.

The mechanical structure 11 comprises a plurality of housing pairs 121, 131 for receiving electronic modules. Each pair of housings comprises a housing 121 at the top wall 12 and a housing 131 facing at the bottom wall 13. Each housing pair 121, 131 is for guiding an electronically inserted module 20 vertically in the mechanical structure 11 from the open front face 15 to the rear wall 14. More specifically, each pair of housings 121, 131 is oriented so as to be capable of guiding in translation along the longitudinal axis X of a module 20 in said cabinet to a so-called operating position in which said electronic module 20 is connected to a connection interface 141 of the rear wall 14 and locked in a housing 131 of the cabinet, for example via a locking lever 16. A housing 131, on a bottom wall 13 (respectively a housing 121 on the upper wall 12), is in the form of a slide or groove with a cross-section U (respectively inverted U), extending along the longitudinal axis X and comprises two vertical flanks 132 facing each other, substantially perpendicular to the bottom wall 13 (vertical flanks 122 facing each other, substantially perpendicular to the upper wall 12). The housings 121, 131 are substantially parallel to each other on their respective walls 12, 13. In one embodiment, the housings 121, 131 are formed in the mechanical structure 11 of the cabinet 10. Preferably, the two sides of two adjacent housings only form a flank. The reception space of a module defines between the housings 121, 122 of a pair of housings is referred to in the following description slot reception. In the non-limiting example of Figure 1, the cabinet 10 has seventeen slots of receipt. The upper 12 and lower 13 walls of the cabinet 10 each further comprise a plurality of openings 123, 133 able to allow an external air circulation in the internal volume of the cabinet 10 and in the electrical modules 20, as will be described later. More specifically, the cabinet 10 comprises, for each pair of housings 121, 131, a pair of openings 121, 131: - at least a first opening 123 in the upper wall 12, between the two flanks 122 of a housing 121, - At least a second opening 133 in the bottom wall 13, between the two flanks 132 of a housing 131 (shown in Figure 3). In the example of Figure 1, the openings 123 (visible only on the upper wall 12) are shown in the form of slots extending along the longitudinal axis X, parallel to each other. Advantageously, the openings 123, 133 in each housing 121, 131 of the upper wall 12 and lower 13 all have a dimension, in length along the longitudinal axis X and in width along the Y axis, substantially identical to each other. Thus, unlike existing cabinets where the dimensions of the openings in each housing pair are a function of the electronic card that will be inserted into the receiving slot, the cabinet of the invention is a so-called standard cabinet with dimensions of the openings in each pair housing identical and adapted to receive and ventilate electronic modules of different functions. In one embodiment, a ventilation of the electronic modules in the internal volume of the cabinet is provided by the shelf, through the openings 133 of the bottom wall 13, in which forced external air circulation is carried out using an aircraft aeration device available in the avionics bay. The rear wall 14 has, on the side of the housing 121, 131, on the connection interface 141, a plurality of connectors (not shown in the figures) intended to cooperate with the electrical modules 20 when they are in the operative position . The rear wall 14 further comprises a plurality of connectors (not shown in the figures) intended to cooperate with an aircraft wiring (not shown in the figures) leading to the cabinet 10 a distribution of electrical signals from the aircraft.

The rear wall 14 thus ensures, thanks to its various connectors, an electrical interconnection between the electrical modules once they have been operating in the cabinet and the aircraft wiring. In the embodiment described here without limitation of the invention, each electronic module 10 is inserted vertically in the plane XZ, into a receiving slot and connects to the connection interface of the rear wall 14. Each electronic module has a dimension adapted in length, width and thickness to fit vertically, with a close game, between the flanks 122, 132 of a pair of housings 121, 131. In vertical position in the cabinet 10, the electronic module 20 shows: - a length L in a direction extending along the X axis, - a width I in a direction extending along the Z axis, - a thickness e in a direction extending along the Y axis. Each electronic module 20, as illustrated in FIGS. 2a and 2b, comprises: - an electronic card 21 comprising a printed circuit, - a mechanical support 22 of the electronic card, substantially delimiting an external contour of said card. electronic, two solid side walls, said covers 23, arranged on either side of the support, to protect the electronic card and guide the external air flow along the electronic card, as will be explained later. Each electronic module 20 has a substantially identical shape, which fits indifferently into any receiving slot. An electronic module 20 differs from another only at the level of the electronic card 21 which includes all the electronic components necessary to perform an electronic function of said card. Thus, an electronic module 20 is associated with a function, for example, a function of supply, input / output or processor. When the electronic module 20 is in the vertically operating position in the cabinet 10, the electronic module 20 is locked in the receiving slot, at the housing torque 121, 131, by means of a wedge clamp device 30, as shown in FIG. illustrated in Figure 3, acting by clamping on the flanks 122, 132 of the housing 121, 131. This wedge clamping device 30 is of a type known per se and will not be described here.

In the example of FIGS. 3 and 4, the electronic module 20, inserted vertically in the cabinet 10, is blocked at the so-called upper ends 220 and lower 221 of the mechanical support 22 in the pair of housings121, 131. The mechanical support 22 further comprises, at the upper ends 220 and lower 221, in the thickness e of said mechanical support, through holes 222, 223 adapted to allow entry and exit of the external air flow in the electronic module 20. The orifices 222, 223, in the upper ends 220 and lower 221 of the mechanical support 22, are defined, at the mechanical support, so that, when the electronic module 20 is in the operative position in the cabinet 10, the orifices 222 , 223 are found in coincidence with a pair of openings 123, 133 in the cabinet 10. The arrangement vis-à-vis the openings 123, 133 and the orifices 222, 223 advantageously allows the passage of the external air flow 40 in the electronic module 20 for cooling components 211 contained on the electronic card 21 of the electronic module 20. As illustrated in FIG. 3 and 4, when the electronic module 20 is placed in an operative position in the cabinet 10, an external air flow 40 from the shelf thus penetrates through the opening 133 located on the bottom wall 13, passes through the orifices 223 in the lower end 221 of the mechanical support 22 of the electronic module 20, is vertically flush with the electronic card 20 and leaves by the orifices 222 of the upper end 220 of the mechanical support 22 of the electronic module 20 and then through the opening 123 located on the upper wall 12 of the cabinet 10. Preferably, the mechanical support 22 of the electronic module 20 further comprises a gripping means , for example of the handle type 24, on an edge located on the side of the open front face 15 of the cabinet 10, when the electronic module 20 is inserted into the said cabinet. The equipment of the invention thus also differs from the existing equipment in that at present, the gripping means is located at each module to facilitate the extraction of the module out of the cabinet and no longer at the level of cabinet to extract the cabinet from the shelf to which it is attached. Thus, the cabinet can be fixed permanently on the aircraft, only the modules become extractable and interchangeable. Thus, it will be understood that the interchangeability function, as seen more particularly in FIG. 1, is moved to the scale of the electronic module itself, which allows the remaining electronic modules of the cabinet to operate when an electronic module 20 breaks down and is removed for repair. Thus, the maintenance operations are also facilitated. The equipment as hitherto described thus consists of a standardized cabinet 10, which can be permanently fixed in an aircraft, and also standardized electronic modules 20 ventilated, by natural or forced convection, through the implementation of coincidence of the orifices 222, 223 and the openings 123, 133.

In one embodiment of the equipment, depending on the type of electronic card 21 installed in the electronic module 20, the external air flow 40 to cool it may not necessarily be the same. For example, an electronic supply card has many electronic components 211 that need to be cooled, while an electronic input / output card has few electronic components that need to be cooled. The external air flow 40 needed to cool a power supply card must therefore be different, in this case more important than that for cooling an input / output card.

In the example illustrated in FIGS. 3 to 6, in order to modify the external air flow 40 which penetrates and passes through an electronic module 20, the equipment comprises means 50 for regulating the external air flow 40 by forced convection. This regulation means 50, advantageously removable, is disposed in a housing 121, 131, between the flanks 122, 132 of said housing and covers all or part of the opening 123, 133 located in the housing. In an exemplary embodiment, the regulating means is a plate 50 of dimension adapted to fit into a housing, preferably that of the bottom wall 13, between the electronic module 20 and the cabinet 10, covering the entire opening located in the accommodation. The plate 50 has perforations 51 in number, size and position adapted to regulate the flow of external air 40 passing through the electronic module 20. It is clear to those skilled in the art to determine precisely the size, the number and the position of these perforations according to the type of components contained on the electronic card and their positioning on said card. Thus the plate is chosen according to the electronic card. Figure 6 illustrates three examples of non-limiting plates 50 of the invention.

With the addition of a perforated plate 50 adapted, it is thus possible to adapt a standard cabinet 10 to the cooling of electronic modules 20 with different and specific electronic function.

In the example of Figure 5 illustrating a longitudinal section of the equipment between two sides 132 of a housing 131, the plate 50 comprises a plurality of perforations 51 for directing the flow to the components 211 of the electronic card 21 requiring to be cool.

Thus, unlike the existing equipment which currently meets the ARINC standard, according to which the distribution of the external air flow is generated at the level of the equipment, the equipment of the invention advantageously makes it possible to report at each slot of reception, the distribution of the air flow and thus the pressure drop.

Thus, a certain advantage of the invention is that, since the pressure drop is brought to the level of each receiving slot of the cabinet, the equipment allows certain reception slots without an electronic module, without modifying or disturbing the balancing . The equipment consequently has an obvious flexibility with respect to existing equipment. For example, during maintenance operations, it is possible to extract an electronic module without disturbing the external air flow circulating in the operational modules. Thus, it is possible to place, in the avionics bays, oversized cabinets with respect to the number of electronic modules to be installed, for subsequent addition of electronic modules, if necessary. In such a case (as well as in the case of a maintenance operation of certain modules), it is possible to place in the opening 123 of the bottom wall 13 a non-perforated plate, to obstruct said opening and maintain an equilibrium. level of losses in the office.

Thus, the cabinet can receive a plurality of electronic modules to which is associated a plurality of plates to allow appropriate regulation of the external air flow in each electronic module installed in the cabinet. In one embodiment, the plate 50 has, at one end 53 in the longitudinal direction X, a locking element 52 of the electronic module. This blocking element plays a dual role. On the one hand, this locking element 52 serves as a stop for the electronic module 20 during its insertion in the cabinet 10. On the other hand, the locking element 52 limits a loss of the external air flow 40 outside the In an exemplary embodiment, as illustrated in FIG. 5, the locking element is a bulge 52 of the plate to which is associated a recess 224 in the lower end 220 of the mechanical support 22 of the electronic module 20. Thus, the external air flow 40, which could be evacuated between the plate and the electronic module, follows a sinuous path, which thus limits its loss. The foregoing description clearly illustrates that by its different features and advantages, the present invention achieves the objectives it has set for itself. In particular, it offers avionics equipment that has a high degree of modularity between the cabinet and the electronic modules that can be associated with it.

Claims (9)

CLAIMS1 - avionics equipment including: - a cabinet (10) in the form of a housing having a first (12) and a second (13) sliding wall, and a connecting wall (14) connecting the two walls of sliding, - at least one electronic card (21) arranged in the cabinet (10) so as to extend between the two sliding walls, characterized in that: - at least one electronic card (21) is included in a support (22) having two solid side walls (23) disposed on either side of the at least one electronic card, each electronic card (21) and its support (22) forming an assembly said electronic module (20), - the cabinet (10) comprises at least one pair of housings (121, 122) for receiving an electronic module (20), a first housing (121) located at the first sliding wall (12) and a second housing ( 131) located at the second sliding wall (13), each neck a plurality of housings being oriented so as to be capable of guiding an electronic module (10) in said cabinet to a so-called operative position in which the electronic module (20) is connected to a connection interface (141) of the connecting wall (14), the cabinet (10) comprises, for each pair of housings (121, 122), a pair of openings (123, 133), a first opening (123) in the first wall of sliding (12) and a second opening (133) in the second sliding wall (13), - each electronic module (20) has through holes (222, 223) adapted to allow the passage of an external air flow in or out of said electronic module, said orifices being in coincidence with a pair of openings (123, 133) of the cabinet (10) when the electronic module 20 is in an operative position in said cabinet. 2 - avionics equipment according to claim 1 wherein all the openings (123, 133) of the cabinet (10) have the same dimension. 3 - avionics equipment according to one of the preceding claims comprising means for regulating (50) the external air flow through the electronic module (20), said regulating means being arranged in a housing (121, 131) between the electronic module (20) and the cabinet (10), facing an opening (123, 133). 4 - avionics equipment according to claim 3 wherein the control means is a plate (50) having at least one perforation (51). 5 - avionics equipment according to one of claims 3 or 4 wherein the control means (50) comprises at one end (53), a locking element (52) of the electronic module (20). 6 - avionics equipment according to one of the preceding claims comprising a plurality of electronic modules (20) and a plurality of associated wafers (50). 7 - electronic module (20) for avionics equipment according to any one of claims 1 to 6. 8 - Cabinet (10) for avionics equipment according to any one of claims 1 to 6. 9 - Aircraft comprising avionics equipment according to one of claims 1 to 6.