Aircraft embedded system electronic board

Abstract

This description relates to an aircraft electronic board (40) comprising: - a first printed circuit board (41) having a slice (411); and - a second printed circuit board (42) having a connection face (420) and mounting means (44) mounted on the connection face, the mounting means being configured to receive the slice of the first printed circuit board so as to lock the first printed circuit board relative to the second printed circuit board. Figure for the abbreviation: Figure 11b

Description

Title of the invention: Electronic board for an aircraft embedded system. Technical field

[0001] The present exposition relates to electronic systems in harsh environments, in particular aircraft embedded systems, especially small form factor electronic boards. STATE OF THE ART

[0002] For reasons of space, some embedded systems are obtained by inserting electronic boards into a small housing, which is notably the case for aircraft embedded systems. Reference may be made to French patent FR 3 080 509, which illustrates an example of such an embedded system.

[0003] However, such embedded systems are difficult to integrate into constrained environments, such as those encountered in the aeronautical field. Indeed, in known embedded systems, the electronic boards are connected to each other by glued or screwed standoffs. This configuration, however, does not allow for compact embedded systems. Furthermore, they are not suitable for the harsh environments encountered in the aeronautical field, whether in terms of resistance to vibration, temperature, or shock. Finally, they are complex to manufacture, install, and repair. GENERAL EXPLANATION

[0004] One aim of this presentation is therefore to improve the mounting of aircraft onboard systems so as to better withstand disturbances within the aircraft, particularly vibrations. Secondarily, an objective of this presentation is to improve the compactness of onboard electronic systems, typically those of aircraft.

[0005] To this end, according to a first aspect of this presentation, an aircraft electronic board is proposed comprising: - a first printed circuit board presenting a slice; and - a second printed circuit board having a connection face and fixing means mounted on the connection face, the fixing means being configured to receive the edge of the first printed circuit board so as to lock the first printed circuit board in relation to the second printed circuit board.

[0006] Some preferred but non-limiting features of the electronic board according to the first aspect are the following, taken individually or in combination: • the first printed circuit board and the second printed circuit board extend in intersecting planes when the edge of the first printed circuit board is inserted into the fastening means of the second printed circuit board; • the fastening means include at least one clamp, the clamp including elastic arms configured to deform when the edge of the first printed circuit board is inserted; • the electronic board includes at least one additional printed circuit board having a slice, the fixing means being further configured to receive the slice of the additional printed circuit board so as to lock the additional printed circuit board relative to the second printed circuit board; • the electronic board further includes a flexible printed circuit board connecting the first printed circuit board to at least one of the second printed circuit board and the additional printed circuit board; • the fixing means are distributed on the connection face of the second printed circuit board so that the first printed circuit board and the additional printed circuit board(s) form a circular arrangement; • the electronic board further includes a third printed circuit board having an additional connection face, and additional fixing means mounted on the additional connection face, the additional fixing means being configured to receive the edge of the first printed circuit board so as to lock the first printed circuit board relative to the third printed circuit board; • the second printed circuit board and the third printed circuit board are connected to the first printed circuit board so that they extend opposite each other or so that the third printed circuit board extends in a plane intersecting a plane that includes the second printed circuit board; and / or • The fastening means are further configured to electrically connect the first printed circuit board and the second printed circuit board.

[0007] According to a second aspect, an electronic module for an aircraft embedded system is also proposed, comprising a housing and an electronic board according to the first aspect, the electronic board being inserted into the housing.

[0008] According to a third aspect, an aircraft onboard system is also proposed comprising: - an electronic module conforming to the first aspect; and - a sensor electrically connected to the module.

[0009] According to a fourth aspect, an aircraft turbomachine is also proposed comprising: - an embedded system according to the third aspect; and - a drive shaft, with the sensor connected to the shaft.

[0010] According to a fifth aspect, an aircraft comprising a cell and a turbomachine according to the fourth aspect is also proposed, the turbomachine being fixed to the cell. DESCRIPTION OF THE FIGURES

[0011] Other features, purposes and advantages will become apparent from the following description, which is purely illustrative and not limiting, and which should be read in conjunction with the accompanying drawings on which:

[0012] [Fig.1] [Fig.1] illustrates an aircraft;

[0013] [Fig.2] [Fig.2] illustrates an instrumented aircraft turbomachine;

[0014] [Fig.3] the [Fig.3] a data acquisition device of an embedded system;

[0015] [Fig.4] [Fig.4] illustrates an exploded view of the acquisition device;

[0016] [Fig.5] [Fig.5] illustrates a cross-sectional view of a module;

[0017] [Fig.6] the [Fig.6],

[0018] [Fig.7] the [Fig.7] and

[0019] [Fig.8] the [Fig.8] illustrate examples of electronic boards;

[0020] [Fig.9] [Fig.9] illustrates an example of a module comprising printed circuit boards flexible and rigid and means of fixing by insertion of two rigid printed circuits;

[0021] [Fig. 10] [Fig. 10] illustrates another example of means for fixing two rigid printed circuit boards of an electronic board; and

[0022] [Fig.1 la]

[0023] [Fig. 11b] [Fig. 1a1a] illustrates an unfolded electronic board comprising rigid and flexible printed circuits and [Fig. 11b] illustrates the assembled board of [Fig. 1a1a]. DETAILED DESCRIPTION

[0024] An aircraft 1 is a device configured to rise and move through the air, and may, for example, be a civil or military airplane, or even a helicopter or an airship. According to an example in [Fig. 1] illustrating an aircraft 1 in the case of an airplane, the aircraft 1 comprises an airframe 11 consisting of a fuselage, wings, tail assemblies, control surfaces, and landing gear. The aircraft 1 further comprises a propulsion system 10 to provide it with the thrust necessary for its rise and movement through the air. Of course, the aircraft 1 may comprise a plurality of propulsion systems 10, for example, one propulsion system 10 per wing, as illustrated by way of example in [Fig. 1].

[0025] A turbomachine 10 has a principal direction extending along a longitudinal axis X, and typically comprises, from upstream to downstream in the direction of the flow The turbomachine 10 comprises gases, a fan 102, a primary casing including a compression section that may include a low-pressure compressor 103 and a high-pressure compressor 104, a combustion chamber 105, and a turbine section that may include a high-pressure turbine 106 and a low-pressure turbine 107. In one embodiment, the fan 102 may be shrouded and housed in a retaining casing and includes a nacelle 101 defining an aerodynamic envelope for the engine. Alternatively, the fan may be unshrouded. The airflow entering the turbomachine 10 is divided into a primary flow configured to pass through the primary casing and a secondary flow that bypasses the primary casing and is compressed by the fan 102.

[0026] Furthermore, the turbomachine 10 can be enclosed and comprise more than two bodies.

[0027] The high-pressure turbine 106 is configured to drive the high-pressure compressor 104 via a high-pressure shaft 109.

[0028] The low-pressure turbine 107 is configured to drive the low-pressure compressor 103 via a low-pressure shaft 108. The low-pressure turbine 107 further drives the blower 102, either directly or via a reduction mechanism which may include an epicyclic gear reducer, for example of the epicyclic (“planetary” type or of the planetary (“star” type), which is interposed between the low-pressure shaft 108 and a blower drive shaft.

[0029] The turbomachine includes a sensor 30, typically a speed sensor connected to one of the high-pressure shafts 109 or low-pressure shafts 108 configured to measure the rotational speed of the shaft 109. Other sensors 30 may be connected to the turbomachine, including another speed sensor for the high-pressure shaft 109 or low-pressure shaft 108 that is not already instrumented. If the sensor 30 includes a speed sensor, the sensor may be a tachometer generator or an incremental encoder.

[0030] An electrical harness 31 electrically connects the sensor 30 to a data acquisition device 20. The harness, the sensor and the acquisition device form an on-board system 200 of the aircraft 1.

[0031] The data acquisition device 20 comprises: - an electronic control module 21; and - an electronic measurement module 22 assembled to the electronic control module 21. An example of the device is illustrated in [Fig.3]. In this example, the acquisition device is mounted in the aircraft 1 using flanges 24, for example clamps typically mounted on or in the turbomachine, and the modules are inserted into the flanges.

[0032] The electronic measurement module 22 is configured to collect data from the sensor. The electronic control module 21 is configured to process the data from the electronic measurement module, for example, to send the data to the aircraft network or to a control tower.

[0033] Each module comprises a housing 210, 220 defining a cavity. The modules may have a generally cylindrical shape adapted to reduce the overall size of the device, for example, a cylindrical shape of revolution (tubular). However, the modules 21, 22 may have any other suitable shape, particularly depending on the available space in their area of ​​use. The modules 21, 22 further comprise threads mounted on an external face of the housings 210, 220, and a threaded ring 23 cooperates with the threads so as to lock the modules 21, 22 during assembly and to unlock the modules 21, 22 during separation.

[0034] Each module 21, 22 further comprises at least one electronic card 40 housed in the cavity as illustrated by way of example in [Fig. 5]. Each electronic card 40 has a face 46 comprising conductive tracks. The conductive tracks of face 46 of the electronic control module 21 are electrically connected to the conductive tracks of face 46 of the electronic measurement module 21, for example by contact, when the modules are assembled.

[0035] The electronic modules 21, 22 are small in size, on the order of a few millimeters in width or diameter when they are generally tubular in shape, typically 20 mm, for example 24 mm in diameter, and a few tens of millimeters in length, for example 100 mm in length.

[0036] The electronic board 40 comprises a first printed circuit board 41 and a second printed circuit board 42. In the present application, each printed circuit board 41, 42, 43 comprises a conductive layer (in which case it is a single-sided printed circuit board) or several conductive layers superimposed on each other (in which case it is a multilayer printed circuit board). Each layer has a surface area for printing the conductive tracks and a thickness. The face 410, 420, 430 of the printed circuit board corresponds to the printing surface of the layer, in the case of a single-sided printed circuit board, or of the end layer, in the case of a multilayer printed circuit board. The edge 411, 421, 431 of the printed circuit board corresponds to the surface formed by the thickness of the layer or by the sum of the thicknesses, depending on whether the printed circuit board 41, 42, 43 is single-sided or multilayer.

[0037] The electronic board further includes mounting means 44 mounted on a connection face 420 of the second printed circuit board. A connection face is one of the faces of the second printed circuit board to distinguish it from the face of the second printed circuit board that does not include the mounting means. The 44 fixing means are therefore mounted on only one side of the two sides of the printed circuit board.

[0038] The mounting means 44 are configured to receive the edge 411 of the first printed circuit board 41 so as to lock the first printed circuit board 41 relative to the second printed circuit board 42. Thus, the mounting means 44 achieve bilateral contact by friction with the first printed circuit board 41 to be mounted, resulting in an assembly that is robust against disturbances such as vibrations and shocks in the aircraft. Furthermore, the mounting means 44 allow the first and second printed circuit boards 41, 42 to be assembled orthogonally, thereby enabling highly compact electronic assemblies that are particularly suitable for use in an aircraft.

[0039] The first printed circuit 41 and the second printed circuit 42 can extend in intersecting planes when the edge 411 of the first printed circuit 41 is inserted into the fixing means 44 of the connecting face 420 of the second printed circuit 42.

[0040] Indeed, when the first and second printed circuit boards 41, 42 are mounted together, a first plane comprising the face 410 of the first printed circuit board 41 and a second plane comprising the connection face 420 of the second printed circuit board 42 meet at an intersection. The intersection may, in particular, form a right angle between the two planes when the two planes are orthogonal. In other words, when the first and second printed circuit boards 41, 42 are mounted together, the first printed circuit board 41 protrudes onto the connection face 420 of the second printed circuit board 42.

[0041] The electronic card 40 may further comprise at least one additional printed circuit board 4L

[0042] The fastening means 44 are further configured to receive the edge 410 of the additional printed circuit 41 so as to lock the additional printed circuit 41 relative to the second printed circuit 42. Several printed circuits 41 then extend in projection from the same connection face 420.

[0043] According to a first embodiment, notably illustrated in [Fig. 6], the electronic board 40 comprises several additional printed circuit boards 4L. The fastening means 44 are arranged on the connection face 420 of the second printed circuit board 42 so as to form several superimposed rows, and the edge 411 of each additional printed circuit board 41 is mounted on one of the rows formed by the fastening means 44. The additional printed circuit boards 41 are then spaced apart from each other in a direction normal to the face 410 of the first printed circuit board 4L. The electronic board 40 then has the shape of a "shelf" sufficiently compact to be inserted into the housing 210, 220.

[0044] The electronic card 40 may further include a third printed circuit board 43 having an additional connection face 430, and additional fixing means 44 mounted on the additional connection face 430 of the third printed circuit board 43.

[0045] In a manner analogous to the fastening means, the additional fastening means 44 are configured to receive the slice 411 of the first printed circuit board 41 so as to block the first printed circuit board 41 with respect to the third printed circuit board 43.

[0046] The second printed circuit board 42 and the third printed circuit board 43 can in particular be connected to the first printed circuit board 41 so as to extend opposite each other

[0047] According to one embodiment, notably illustrated in [Fig. 6], the connection face 430 of the third printed circuit board 43 and the connection face 420 of the second printed circuit board 42 are symmetrically opposite with respect to a plane of symmetry intersecting the face 410 of the first printed circuit board 41. The edge 411 of the first printed circuit board is inserted into the mounting means 44 of the second printed circuit board 42 and the third printed circuit board 43 simultaneously. The edge 411 of the first printed circuit board 41 then separates the connection faces 420, 430 of the second and third printed circuit boards 42, 43.

[0048] Alternatively, the second printed circuit 42 and the third printed circuit 43 can in particular be connected to the first printed circuit 41 so that the third printed circuit 43 extends in a plane intersecting with a plane comprising the second printed circuit 42.

[0049] According to one embodiment, notably illustrated in [Fig. 7], a first plane comprising the connection face 420 of the second printed circuit board 42 and a second plane comprising the connection face 430 of the third printed circuit board 43 intersect. The connection face 420 of the second printed circuit board 42 and the connection face 430 of the third printed circuit board 43 then form a wedge. The edge 411 of the first printed circuit board 41 is inserted into the fastening means 44 mounted on the connection face 420 of the second printed circuit board 42 and into the fastening means 44 mounted on the connection face 430 of the third printed circuit board 43.

[0050] The fastening means 44 can be distributed on the connection face 420 of the second printed circuit 42 so that the first printed circuit 41 and the additional printed circuit(s) 41 form a circular arrangement.

[0051] According to an embodiment illustrated in [Fig. 8], the fastening means 44 mounted on the connection face 420 of the second printed circuit board 42 form several rows distributed along a circular line belonging to the connection face 420 of the second printed circuit board 42. Starting from the first printed circuit board 41, The edge 411 of the first printed circuit board 41 and the edge 411 of each additional printed circuit board 41 are inserted in a row. The additional printed circuit boards 41, circumferentially adjacent to each other or to the first printed circuit board 41, are then separated at the connection face 420 of the second printed circuit board 42 by a constant angular distance measured between two rows. The electronic board 40 then has a "crown" shape sufficiently compact to be inserted into the enclosure 210, 220.

[0052] The fastening means 44 may be clamps. Each clamp comprises elastic arms 441, 442 configured to deform upon insertion of the slice 411 of the first printed circuit board 41. According to an exemplary embodiment illustrated in [Fig. 9], the clamp comprises a support 440, mounted on the face 420, 430 of the second or third printed circuit board 42, 43, and two rows of two arms 441, 442 facing each other and extending from the support. Moving away from the support 440 along a direction normal to the support 440 to the tips of the arms 441, 442, the facing arms 441, 442 are spaced at a constant distance, then meet along a line of contact, and then move apart again. Each branch 441, 442 then has a first flat portion 443 and a second concave portion 444 connected to the first portion, the first and second portions 443, 444 being deformable during the insertion of the slice.

[0053] Thus, when the first printed circuit board 41 or the additional printed circuit board 41 or one of the additional printed circuit boards 41 comes into contact with the clamp 44, the first printed circuit board 41 or the additional printed circuit board 41 or one of the additional printed circuit boards 41 pushes against the arms 441, 442, causing the arms 441, 442 to separate only at the second portions 444, then the first printed circuit board 41 or the additional printed circuit board 41 or one of the additional printed circuit boards 41 is inserted into the clamp 44 until it comes to a stop against the support 440. The first printed circuit board 41 or the additional printed circuit board 41 or one of the additional printed circuit boards 41 is then held in place by friction between the second portions 444 of the arms in contact with the first printed circuit board 41 or the additional printed circuit board 41 or one of the additional printed circuit boards 41

[0054] Such means, including the gripper 44, are generally known and have a standard geometry, which makes it possible to improve the repeatability of the cards, reduce manufacturing costs and facilitate the maintenance and assembly of the card 40, in particular in an automatic, typically robotic way.

[0055] The clips 44 may also be made of a material suitable for welding to the conductive tracks, typically an aluminum or copper alloy.

[0056] Furthermore, as illustrated by way of example in [Fig.10], the printed circuits 41, 42, 43 assembled by the clips 44 may have conductive tracks 413, 423, 433 in contact with the clips. To establish an electrical connection between two printed circuit boards mechanically linked by clips 44, each clip is soldered to the conductive trace 423, 433 of the second and / or third printed circuit board 42, 43 and is in contact with the conductive trace 413 of the first printed circuit board 41 or of an additional printed circuit board 41. Thus, the clips 44 provide both a mechanical and an electrical connection, further increasing the compactness of the electronic board 40. The electrical connection also ensures electrical continuity within the electronic board 40, notably to create a common ground between the printed circuit boards 41, 42, 43.

[0057] The electronic board 40 may further include a flexible printed circuit board 45 connecting two printed circuit boards 41, 42, 43. According to an example illustrated in [Fig. 11b], the electronic board 40 comprises flexible printed circuit boards 45 connecting two superimposed printed circuit boards 41 and printed circuit boards 42, 43 extending in intersecting planes. The term "flexible printed circuit board" here refers to a printed circuit board on a substrate that can be deformed by hand. Therefore, the flexible printed circuit boards 45 can be bent, which further increases the compactness of the electronic board. Indeed, the addition of flexible printed circuit boards 45 increases the overall size of the printed circuit board of the electronic board 40 for the same overall volume of the electronic board 40.

[0058] Of course, this description can be applied to other harsh environments than that of an aircraft without departing from the scope of this application.

Claims

Demands

1. Aircraft electronic board (40), the electronic board comprising: - a first printed circuit board (41) having a slice (411); and - a second printed circuit board (42) having a connection face (420) and fixing means (44) mounted on the connection face, the fixing means being configured to receive the slice of the first printed circuit board so as to lock the first printed circuit board relative to the second printed circuit board.

2. Electronic card (40) according to claim 1, wherein the first printed circuit board (41) and the second printed circuit board (42) extend in intersecting planes when the edge (411) of the first printed circuit board is inserted into the fastening means (44) of the second printed circuit board.

3. Electronic board (40) according to any one of claims 1 and 2, wherein the fastening means (44) comprise at least one clip, the clip comprising elastic arms (440, 441) configured to deform upon insertion of the wafer (411) of the first printed circuit board (41).

4. Electronic card (40) according to any one of claims 1 to 3, the card comprising at least one additional printed circuit board (41) having a slice (411), the fastening means (44) being further configured to receive the slice of the additional printed circuit board so as to lock the additional printed circuit board relative to the second printed circuit board (42).

5. Electronic card according to claim 4, further comprising a flexible printed circuit board (45) connecting the first printed circuit board (41) to at least one of the second printed circuit board (42) and the additional printed circuit board (41).

6. Electronic card according to any one of claims 4 and 5, wherein the fastening means (44) are distributed on the connection face (420) of the second printed circuit board (41) so that the first printed circuit board (41) and the additional printed circuit board(s) (41) form a circular arrangement.

7. Electronic card (40) according to any one of claims 1 to 6, further comprising a third printed circuit board (43) having an additional connection face (430), and additional fastening means (44) mounted on the additional connection face, the additional fastening means being configured to receive the edge of the first printed circuit board so as to lock the first printed circuit board relative to the third printed circuit board.

8. Electronic card (40) according to claim 7, wherein the second printed circuit board (42) and the third printed circuit board (43) are connected to the first printed circuit board (41) so as to extend opposite each other or so that the third printed circuit board extends in a plane intersecting with a plane comprising the second printed circuit board.

9. Electronic card (40) according to any one of claims 1 to 8, wherein the fastening means (44) are further configured to electrically connect the first printed circuit board (41) and the second printed circuit board (42).

10. Electronic module (21, 22) for aircraft embedded system comprising a housing (210, 220) and an electronic card (40) according to any one of claims 1 to 9, the electronic card being inserted in the housing.

11. Aircraft embedded system (200) comprising: - an electronic module (21, 22) according to claim 10; and - a sensor (30) electrically connected to the module.

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