FR2977447A1 - Card tray-type electronic cabinet for electronic modules of avionic equipment of aircraft, has interface module arranged on side face and non-parallel to front face of cabinet, and carrying interface connectors to be connected to wiring - Google Patents

Abstract

The cabinet (1) has an interface module arranged on a side face of the cabinet and non-parallel to a front face of the cabinet. The interface module carries a set of interface connectors adapted to be connected to a predetermined aircraft wiring (8). The interface module connects a back panel card to the wiring and comprises an integrated optoelectronic converter. The interface module is integrated into a mechanical structure whose parallel slides guide electronic modules (3) inserted into the structure from the front face. The interface module is accessible from the front face, and removable.

Description

The present invention relates to the field of avionics, and more specifically to the electrical architecture of a set of electronic cards embedded in an aircraft. It relates to a device for connecting these electronic cards vis-à-vis an aircraft interface.

Preamble and prior art In an aircraft, many electronic equipment is located in an area called "avionics bay", located in the lower front of the fuselage, under the cockpit. These electronic devices are in particular in the form of parallelepiped boxes, in which series of electronic cards are, for example but not limited to, arranged vertically, parallel to each other. The avionics bay offers electronic equipment privileged environmental conditions such as a reasonable ambient pressure (pressurized zone of the aircraft), as well as a controlled ambient temperature. To integrate the electronic equipment in the bay, furniture is usually used to fix the electronic equipment, to ventilate it, and to connect it to cables of the aircraft which connect them to various systems of the aircraft. As a technological background, mention may be made here of US Pat. No. 5,253,484 ("High Reliability Avionic Cooling System", Boeing Company, 1991) which describes such a general arrangement. The furniture, which is in question here, consist of shelves, on which we usually find interfaces known to those skilled in the art under the name of "chairs", which perform several functions: - Mechanical maintenance of equipment electronic, - Mechanical maintenance of a connector of the aircraft, - Arrangement of a passage for a flow of ventilation air from the aircraft furniture. It is recalled here that a "chair", in this context, is a mechanical interface mainly comprising a horizontal plate for supporting equipment, a perforated back plate to allow the passage of bundles of cables, and triangulation bars on the two lateral sides. It also includes locking devices of the equipment when it is installed on the chair. This assembly is defined by an international aeronautical standard: ARINC600.

An assembly according to this standard is for example described in US Patent 6,797,879 (Avionics Tray Assembly and Seal Assembly Boeing Company 2002).

For reasons of volume limitations available within the aircraft, it is desirable to reduce as much as possible the volume occupied by these electronic furniture, without substantially modifying the requirements on the rest of the aircraft, so as to be able to adapt, for example, to existing aircraft models.

DESCRIPTION OF THE INVENTION The invention aims in a first aspect at an electronic cabinet for an aircraft, of the type comprising a set of cards called electronic modules, accessible and removable from a so-called front face of said electronic cabinet, said electronic cabinet comprising a set of interface connectors adapted to be connected to a predetermined aircraft wiring. The electronic cabinet is adapted to be installed in the aircraft so that its front face is substantially parallel to the aircraft wiring to which said equipment is connected.

In this electronic cabinet, at least a portion of the set of interface connectors with the aircraft wiring is disposed on an interface module itself disposed on a so-called lateral face, non-parallel (and in practice substantially perpendicular) to the front of the electronic cabinet. The present invention therefore reduces the volume occupied by the routing of the wiring by making the electrical connection between the aircraft and the electronic cabinet by one (or) side (s) side (s) of the latter.

According to a preferred embodiment, the electronic cabinet is of the "card tray" type, and it comprises: a mechanical structure intended to maintain a set of electronic modules, the mechanical structure being in the form of a substantially parallelepipedic housing, the mechanical structure being open on at least a part of a so-called front face for the insertion and extraction of electronic modules, - an electronic card, called "backplane", arranged in one face said rear face of the mechanical structure, opposite to the front face, this backplane card having a series of connectors and being adapted to ensure, via these, the electrical interconnection between electronic modules, once these inserted in the mechanical structure, and the aircraft wiring, - a series of electronic modules.

The electronic cabinet further comprises at least one interface module for connecting the backplane board to the aircraft wiring, this interface module being disposed on a side face of the electronic cabinet, and comprising a set of interface connectors compatible with aircraft wiring.

In a particular embodiment, the mechanical structure is provided with an upper plate and a lower plate, the mechanical structure comprising a set of parallel slides arranged under the upper plate and above the lower plate, these slides being intended guiding electronic modules inserted into the mechanical structure from this front face. This arrangement allows insertion and easy extraction of the electronic modules of the equipment. Each interface connector of the interface module advantageously corresponds to a particular connector of the backplane board, said backplane board comprising a set of electrical connections adapted to transmit the electrical signals between the connectors for electronic modules, and the connectors interface. According to a preferred embodiment, the backplane board has at least one connector for an interface module.

According to an advantageous embodiment, at least one interface module is accessible from the front of the electronic cabinet, and removable, thus allowing its interchangeability. In a favorable embodiment, at least one interface module comprises filtering means of the input / output of the backplane board that correspond to its interface connectors, said filtering means being intended for the protection of the equipment and / or the integrity of the processed electrical signals According to a particular embodiment, adapted to reduce the optical data transfer requirements within the electronic cabinet, at least one interface module comprises an integrated optoelectronic converter according to a mode of particular embodiment, the electronic cabinet comprises two interface modules, each located on a lateral face of said electronic cabinet In this case, advantageously, the electronic cabinet benefits from redundant input signals, distributed on two different interface modules, to minus one connector on the backplane board being simultaneously connected to both interface modules. In an alternative embodiment, at least one interface module is integrated into the mechanical structure of the electronic cabinet, so as to reduce the overall manufacturing cost of the electronic cabinet. In another variant, the electronic cabinet comprises separation walls, of shape and material previously chosen according to environmental constraints imposed on the equipment, able to separate the interface modules of the electronic modules. According to a second aspect, the present invention aims at a backplane board for an electronic cabinet as explained above, said backplane board comprising a set of electrical connections adapted to transmit the electrical signals between the connectors for electronic modules, and the interface connectors. According to a third aspect, the invention aims at an interface module for an electronic cabinet as described. According to another aspect, the invention relates to avionic equipment comprising an electronic cabinet as exposed and at least one electronic module. In yet another aspect, the invention is an aircraft comprising an electronic cabinet object of the present invention.

DESCRIPTION OF THE FIGURES The characteristics and advantages of the invention will be better appreciated thanks to the description which follows, description which sets out 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 an electronic cabinet according to one embodiment of the invention; FIG. 2 illustrates this same electronic cabinet, connected to a wiring strand of the FIG. 3 illustrates the lateral interface module, in an alternative embodiment of the electronic cabinet without interchangeable interface modules, FIG. 4 illustrates, in the same way, the module of FIG. side interface, in an alternative embodiment of the electronic cabinet with interchangeable interface modules, - Figure 5 is an illustration of the physical segregation of electronic modules and interface modules, - Figures 6a and 6b illustrate, so schematic, the arrangement of the electronic modules and the aircraft wiring in the case of the prior art (FIG. 6a) and in the case of an electronic cabinet according to the invention (FIG. 6b).

DETAILED DESCRIPTION OF AN EMBODIMENT OF THE INVENTION The description, in no way limiting, which follows, illustrates an embodiment of the invention for an electronic cabinet 1 of the "card tray" type, known per se from the human art. The electronic cabinet is thus distinguished from an electronic equipment, defined as an electronic cabinet in which is installed a set of electronic modules. Said electronic cabinet 1 comprises in the first place a mechanical structure 2. This mechanical structure 2 is dimensioned so as to allow recovery and transfer to the electronic cabinet, structural forces experienced by the electronic cabinet 1 during use of the aircraft . The mechanical structure 2 also maintains a set of electronic modules 3 (see Figure 2) installed within said electronic cabinet, and contributes to the management of thermal stresses.

In the present embodiment, as seen in Figure 1, the mechanical structure 2 is in the form of a substantially parallelepipedic housing, having an upper plate and a lower plate. For the rest of the description, a longitudinal axis X is defined, parallel to the lateral faces of the electronic cabinet 1, a transverse axis Y, perpendicular to the preceding one, and parallel to the rear face of the electronic cabinet 1, finally a vertical axis Z, perpendicular to the two previous ones. The terms before, back, up down etc. are defined relative to this marker. The mechanical structure 2 is open on a so-called front face, and comprises a set (about twenty in the case of Figure 1) of parallel rails 7, arranged under the upper plate and above the lower plate, these slides 7 being intended guiding electronic modules 3 inserted into the mechanical structure 2 from this front face. An electronic board, called "backplane" 5, is disposed on the rear face of the mechanical structure 2. This backplane board 5 comprises a series of connectors for electronic modules 9, substantially parallel to each other (see FIG. 1), and ensures, thanks to these, the electrical interconnection between the electronic modules 3, once they have been inserted in the mechanical structure 2, and an aircraft wiring 8 leading to the electronic cabinet 1 the distribution of electrical signals coming from the aircraft .

Unlike the prior art, which proposes a direct connection of the backplane board 5 with the aircraft wiring 8, by the rear face of said backplane board 5 (the outward facing face of the electronic cabinet 1) , the electronic cabinet 1 here described by way of non-limiting example, comprises at least one interface module 4 for connecting the backplane board 5 to the aircraft wiring 8.

This interface module 4 is connected to the backplane board 5 via a connector, possibly similar to the connectors for electronic modules 9 of the 3 "conventional" electronic modules. This interface module 4 carries a set of interface connectors 6 with the aircraft. In the embodiment presented here by way of non-limiting example, each interface connector 6 corresponds to a connector for an electronic module 9. It should however be noted that the interface connectors 6 mainly group signals of the same nature, which can be assigned to different electronic modules 9. The backplane board 5 therefore comprises a set of electrical connections adapted to transmit the electrical signals between the connectors for electronic modules 9 and the interface connectors 6. In the example illustrated in FIG. 1, the electronic cabinet 1 comprises two modules of 4, each located on a side face of said cabinet 1. These interface modules 4 are also inserted into the mechanical structure 2 of the equipment 1 according to the slides 7 of said mechanical structure 2. Each interface module 4 comprises here fourteen interface connectors 6. In the embodiment of Figure 1; the mechanical structure 2 of the electronic cabinet 1 comprises two side walls 12 having a series of recesses arranged in line with the location of the interface connectors 6 on the interface modules 4. In a particular embodiment, when a electronic cabinet 1, as described, comes to replace a previously installed equipment, these interface connectors 6 are identical to the connectors placed on the rear face of the backplane board of the previous equipment, so as not to create requirements modification of connectors at the level of the aircraft wiring 8.

These interface modules 4 are positioned on the lateral faces of the electronic cabinet 1 in order to clear the high and low parts of the electronic cabinet 1 and thus facilitate the flow of ventilation air. As can be seen in FIG. 2, when an electronic cabinet 1 of the type just described is installed on board an aircraft, it is disposed substantially above or just in front of the aircraft wiring 8 on which it depends. Each interface connector 6 is connected by a complementary connector 11 to a cable strand 10 coming from the aircraft wiring 8. The device as described is particularly applicable to electronic cards of electronic equipment located in the "avionics bay", located in the lower front of the fuselage, under the cockpit. It also applies, but not exclusively, to equipment installed in the cargo area.

Advantages The figures 6a and 6b summarize, in schematic top view, the arrangement of the electronic modules and the aircraft wiring in the case of the prior art (FIG. 6a) and in the case of an electronic cabinet according to the invention (FIG. 6b). In the case of the prior art (FIG. 6a), the electronic modules 3 are connected to a first backplane card 5 ', managing the inter-card links. This first 5 'backplane board is connected to a second 5 "backplane board, managing the input / output protection, and then a set of connectors 14 allows the connection of this second 5" backplane board with the harness. aircraft wiring 8.

In some applications, the 5 'and 5 "backplane boards can be replaced by a single board, in which case the connectors 9 are not installed next to the connector 14. In the case of the invention (FIG. the electronic modules 3 and the interface modules 4 are connected to the backplane board 5 via dedicated connectors, the interface modules 4 in particular, in the present nonlimiting example, protecting the inputs / Outputs of the backplane board 5. The interface modules 4 are connected to the aircraft wiring harness 8 by the interface connectors 6.

The electronic cabinet 1 as described above has several advantages: - The depth occupied by an electronic cabinet 1 connected to the aircraft wiring 8 is substantially reduced. Indeed, in the prior art, each electronic module 3 (or complete electronic cabinet) is connected to the aircraft wiring 8, by the "bottom" of the chair, that is to say the face opposite to the face by which the electronic modules 3 are inserted. The arrival of the strands from the back of the chair requires a significant space, left free to accommodate the radius of curvature of said strands. The volume occupied by the curvature of the strands is substantial (typically 1/3 of the depth of the electronic cabinet 1) and thus penalizes the space occupation in the aircraft. By interconnecting the strands of the aircraft with the electronic cabinet 1 by one of its lateral faces, the described device makes it possible to reduce the total depth of the electronic cabinet 1 and the aircraft wiring 8. Because of this reduced total depth, the installation of electronic cabinets 1 is made possible in areas of the aircraft today unused because not releasing enough access space, especially for maintenance.

- The intervention of an operator on the aircraft wiring 8 is facilitated. The wiring of the aircraft is, by the installation of an electronic cabinet 1 as described, accessible from the front face of said electronic cabinet 1, instead of being hidden by the rear face of the equipment of the prior art. Access to the aircraft wiring 8 front panel allows an intervention (modification, repair, diagnosis) easy on said wiring. - The distribution of the aircraft electrical signals between the electronic modules 3 (signal mixing) can be changed by changing the interface modules 4. The interface modules 4 brew the signals of the aircraft and distribute them on the card of basket 5, and therefore to the various electronic modules 3, through the interface connectors 6. Different configurations of the aircraft can therefore be managed by the definition of the interface modules 4. However, the modules of interface 4 are, by their arrangement according to the present invention, accessible from the front face of the electronic cabinet 1, and thus are thus interchangeable on the aircraft as all the electronic modules 3 of the electronic cabinet 1. In the prior art, a such modification involved the replacement of the backplane board 5, that is to say in practice the complete disassembly of the electronic cabinet 1. The interface modules 4 offer do nc an easy and fast modification of the mixing of the signals without intervention on the cabling of the aircraft. This feature makes it easier to reconfigure an aircraft, that is to say a different use of the electrical signals provided by the aircraft.

- The interface modules 4 may, in a particular embodiment, include lightning protection (or other) necessary for the protection of the electronic cabinet 1 and / or the integrity of the processed electrical signals.

These components are likely to undergo many electromagnetic attacks and are therefore, in the device as described, advantageously made available to maintenance teams because of their accessibility facilitated. There is then no need for a removal of the complete equipment (electronic cabinet comprising a set of electronic modules) to change these protections. - Technological developments under way in the aeronautical field are showing new types of signals in an aircraft. Thus, fiber optics, Ethernet networks and other innovative technologies require conversions within equipment.

For example, when using an optical signal, an optoelectronic converter must be implemented to allow the electronics of the equipment to process the signal. In the proposed invention, these conversions can be integrated into the interface modules 4 and not penalize the backplane boards 5 in terms of reliability and complexity. The use of optoelectronic converters within the interface modules 4 thus makes it possible to limit the propagation of the optical signal in the equipment and thus simplifies the problem of optical connection within an on-board equipment. - The architecture of the electronic cabinet 1 causes an increase in the average time before failure (MTBF) of the backplane board 5 Indeed, the presence of the interface modules 4 allows to "deport" the electronic components now implanted on the backplane board 5. Thus, the reliability of the backplane board 5 is increased by the invention. The low accessibility of the backplane board 5 makes this improvement 2977447 interesting for maintenance issues.

In one embodiment, the electronic cabinet 1 can benefit from redundant input signals, advantageously distributed over two different interface modules 54. Thus, the replacement of one of the interface modules 4 can be achieved, while retaining some of the functionalities of the electronic cabinet 1 available for the aircraft. These functionalities correspond to the electronic modules 3 whose connector 9 on the backplane board 5 is simultaneously connected to the two interface modules 4. This configuration is not possible today in the case of a dismantling of backplane card 5.

Embodiments 15 In an alternative embodiment illustrated in FIG. 3, the interface modules 4 'are integrated into the mechanical structure 2 of the electronic cabinet 1. All the advantages mentioned above are retained except for the reconfiguration of the stirring, which can not then be performed without removing the cabinet 1. This concept is more economical and can be interesting in some configurations.

In another embodiment, illustrated in FIGS. 4 and 5, the interface modules 4 are separated from the electronic modules 3 of the equipment by separation walls 13. This segregation makes it possible, by choosing a particular type of separation wall 13 (or a particular spacing between the electronic modules 3 and the interface modules 4), to facilitate the management of environmental constraints imposed on the electronic cabinet 1 (thermal, electromagnetic and mechanical). It should be noted that the description was made in the particular case of an electronic cabinet type card tray, but the use of electronic modules side, accessible from the front, and serving as an interface between the card basket and aircraft wiring, can be adapted to any type of electronic cabinet mounted in an aircraft.

Claims (4)

REVENDICATIONS1. Electronic cabinet (1) for an aircraft, of the type adapted to house a set of cards called electronic modules (3), accessible from a so-called front face of said electronic cabinet, said electronic cabinet (1) comprising a set of interface connectors ( 6) adapted to be connected to a predetermined aircraft wiring, characterized in that at least a portion of the set of interface connectors (6) with aircraft wiring (8) is disposed on an interface module (4). ), not parallel to the front of the cabinet. 2. Electronic cabinet (1) according to claim 1, characterized in that it is an electronic cabinet (1) type "card tray", said electronic cabinet (1) comprising: - an electronic card, said "backplane" (5), comprising a series of "connectors for electronic modules" (9) and being able to ensure, via them, the electrical interconnection between electronic modules (3), once they are inserted in the electronic cabinet (1), and the aircraft wiring (8), the electronic cabinet (1) further comprising at least one interface module (4) for connecting the backplane board (5). ) to the aircraft wiring (8), this interface module (4) being disposed on a lateral face of the electronic cabinet, and comprising a set of interface connectors (6) compatible with the aircraft wiring (8). 3. Electronic cabinet (1) according to claim 2, characterized in that each interface connector (6) of the interface module (4) corresponds to a particular connector 9 of the backplane board (5), said card backplane (5) having a set of electrical connections adapted to transmit the electrical signals between the connectors for electronic modules (9) and the interface connectors (6). 4. Electronic cabinet (1) according to any one of claims 2 to 3, characterized in that the backplane board (5) comprises at least one connector adapted to the connection of an interface module (4). Electronic cabinet (1) according to any one of claims 2 to 4, characterized in that at least one interface module (4) is accessible from the front of the electronic cabinet (1), and removable. 6. Electronic cabinet (1) according to any one of claims 2 to 5, characterized in that at least one interface module (4) comprises means for filtering the input / outputs of the backplane board (5). ) which correspond to its interface connectors (6), said filtering means being intended for the protection of the electronic cabinet (1) and / or the integrity of the processed electrical signals. 7. Electronic cabinet (1) according to one of any of claims 2 to 6, characterized in that at least one interface module (4) comprises an integrated optoelectronic converter. 8. Electronic cabinet (1) according to any one of claims 2 to 7, characterized in that it comprises two interface modules (4), each located on a side face of said electronic cabinet (1). 9. Electronic cabinet (1) according to claim 8, characterized in that at least one connector for electronic module (9) on the backplane board (5) is connected simultaneously to the two interface modules (4). 10. Electronic cabinet (1) according to any one of claims 2 to 9, characterized in that at least one interface module (4) is integrated in the mechanical structure (2) of the electronic cabinet (1). Electronic cabinet (1) according to one of Claims 2 to 10, characterized in that the interface modules (4) are separated from the electronic modules (3) of the electronics cabinet (1) by partition walls ( 13) of shape and material previously chosen according to environmental constraints imposed on the electronic cabinet. 12. Backplane board (5) for electronic cabinet (1) according to any one of claims 3 to 11. 13. avionics equipment, characterized in that it comprises an electronic cabinet (1) according to one of claims 1 at 11, and at least one electronic module (3). 14. Aircraft comprising an electronic cabinet (1) according to any one of claims 1 to 11.