FR3041499A1 - STRUCTURE OF A MODULE FOR INTEGRATING ELECTRONIC COMPONENTS OF POWER AND ESPECIALLY STRUCTURE OF A SATELLITE - Google Patents

Abstract

This structure comprises: a support (2) made of a composite material having at least one core (8) and a first superficial skin (10), said support (2) comprising at least two parallel fold lines (24) and being folded along said folding lines (24) so that the first surface skin (10) is found inside the folded support, and - two closure panels (26) connected to the support (2) to define with its first superficial skin (10) a confined volume.

Description

The present invention relates to a structure of a module for integrating electronic power components, more particularly the structure of a satellite and its manufacturing method.

The field of the present invention is for example that of the space industry and more particularly the realization of the structure of a satellite, including an artificial satellite. However, the present invention can also find terrestrial applications when it comes for example to achieve a power module on a vehicle in particular.

The existing satellite structures (or platforms, buses) usually consist of an assembly of composite panels fixed on a framework having bars or point-connecting angles. The panels are generally sandwich type panels with a core disposed between two sheets, or sheets, outside. This assembly principle involves the integration of many fittings or inserts in the core of the panels, both for the connections on the frame and for the attachment of the equipment (electronic boxes, solar generators, propulsion ...) on the structure .

The document FR2372083 for example discloses a carrier structure for an artificial satellite of this type.

The principles of development and realization of satellites are still most often adapted to the supply of structures in very small quantities, each satellite being almost a prototype dedicated to a mission. The development of a constellation of satellites involving mass production would be strongly impacted technically and financially by the implementation of these principles.

The present invention aims to reduce the manufacturing costs of the structure and integration of equipment, without penalizing performance. Preferably, the present invention will also provide a significant gain on technical performance (weight reduction, mechanical and thermal homogeneity, rigidity, EMC shielding). For this purpose, the present invention proposes a structure of a module intended to integrate electronic components which, according to the present invention, comprises: a support made of a composite material having at least one core and a first superficial skin, said support having at least two parallel fold lines and being folded along said fold lines so that the first surface skin is found inside the folded support, and - two closure panels connected to the support for delimiting with its first superficial skin a volume.

Such a structure is particularly well suited for the manufacture of satellites. However, it can be used for structures used on the ground (on land, sea or in the air). It is intended here, instead of coming to assemble panels on a trellis or other frame, to use a composite plate and to fold to form the faces of a box and close the box with closure panels. The box can be parallelepipedic, which is the most usual form, but could also have three, or five, or more, connected faces. The composite plate is folded maintaining continuity inside the formed box. The soul of the support is then found outside the box formed. It is then possible to fix on the surface skin which is thus on the inner side in the box all the components. There is then no need to connect panels and the electrical connection between the equipment / components attached to the surface skin can be achieved before folding the structure.

In a preferred embodiment, the composite material of the support comprises a second superficial skin; the core is disposed between the first and second superficial skin, and the second skin is cut at the fold lines. Here we find a classic structure of a composite material with a soul sandwiched between two skins.

To facilitate holding the support in folded position and also the connection between the support and the closure panels, provision is made for example that the support has longitudinal edges perpendicular to the fold lines, and that each superficial skin has a rim protruding from the core of the support along said longitudinal edges. In this embodiment, when the support is made of a "sandwich" type material, the rim of the first surface skin can be folded substantially at right angles to the inside of the folded support, the closure panels can come to rest each on one edge of the support core, and each rim of the second surface skin may be folded over the corresponding closure panel such that the peripheral edge of each closure panel is sandwiched between an edge of the core and a rim of the second superficial skin.

To strengthen the structure, it may further comprise reinforcement elements arranged along the fold lines outside the support.

In order to obtain a light structure, the core is advantageously of the honeycomb type.

For the realization of a parallelepipedic structure, it is expected that the support comprises three fold lines thus defining four panels of rectangular shape.

The present invention also relates to: a power module comprising a structure on which are fixed components and / or electronic assemblies, or a satellite, characterized in that they comprise a structure as described above.

Finally, the present invention also provides a method of manufacturing a power module.

According to the invention, this method comprises the following steps: providing a support comprising a core and at least one surface skin, producing parallel fold lines by local cutting of the core and optionally a superficial skin, - placement of electronic components and / or assemblies on the support, - wiring of the components and / or electronic assemblies, - testing of the assembly carried out, - folding of the support along the fold lines so that an edge of the support parallel to the fold lines comes join an opposite edge, - connection of the two joined edges, - establishment of closure panels on the support so as to form a closed volume inside which are the components and / or electronic assemblies .

Details and advantages of the present invention will become more apparent from the description which follows, given with reference to the appended schematic drawing in which:

FIG. 1 is a perspective view of a support,

FIG. 2 is an enlarged view of detail A of FIG. 1,

FIG. 3 is a sectional view along section line B1-B1 of FIG. 1,

FIG. 4 is a view similar to FIG. 1 showing the same support at a later process step,

FIG. 5 is an enlarged view of the detail A2 of FIG. 4,

FIG. 6 is a front view of the support at the step illustrated in FIG. 4,

FIG. 7 is an enlarged view of the detail B2 of FIG. 6,

FIG. 8 is a view similar to FIG. 4 showing the same support at a later process step,

FIG. 9 is an enlarged view of detail A3 of FIG. 8,

FIG. 10 is a sectional view along section line B3-B3 of FIG. 8,

FIG. 11 is an enlarged view of the detail C3 of FIG. 10,

FIG. 12 is a perspective view showing the same support as the preceding figures with further electronic assemblies integrated at a subsequent process step,

FIG. 13 is an enlarged view of the detail C4 of FIG. 12,

FIG. 14 is a perspective view of the support of the preceding figures folded and connected to two closure panels,

FIG. 15 is an enlarged view of the detail C5 of FIG. 14,

FIG. 16 shows in perspective a reinforcement that can be used in the present invention,

FIG. 17 shows in perspective the assembly of FIG. 14 with four reinforcements such as that of FIG. 16,

FIG. 18 is a view similar to FIG. 16 for an alternative embodiment of a reinforcement, and

FIG. 19 shows in perspective the assembly of FIG. 14 with four reinforcements such as that of FIG. 18.

The description aims to describe by way of illustrative example a method for producing a satellite platform. However, it will be apparent to those skilled in the art that other modules can also be made according to the principle to be described.

For the implementation of a preferred embodiment of the present invention, it is proposed to first provide a sandwich panel 2 as shown in Figures 1 to 3.

It is an elongated rectangular composite panel defining two longitudinal edges 4 (the long edges) and two transverse edges 6 (shorter length). This panel is made from a composite element comprising a core 8 sandwiched between two superficial skins, a skin called thereafter inner skin 10 and another skin subsequently called outer skin 12. The core 8 has preferably a structure called honeycomb structure, the cells of this structure being perpendicular to the skin surface. The latter are for example each formed by a light alloy sheet, for example an aluminum-based alloy.

It is noted in Figures 1 to 3 that the dimensions of the core 8 are slightly lower than those of the surface skin. Indeed, as shown in Figure 1, the superficial skins protrude from the core 8 and form flanges along the longitudinal edges 4. There is thus a support 2 with protruding skins on the longitudinal edges.

Finally, we note the presence in the panel forming the support 2 of two holes 14 which are optional. These are interface holes for mounting elements that must pass through the structure of the realized module. In the case of an application to a satellite platform, the holes 14 may for example serve as interface holes for receiving motors solar generators.

Figures 4 to 7 illustrate a next step in the manufacture of the satellite structure. Folding lines are formed on the support 2. The shape of the module to be here parallelepipedic, three fold lines are made thus dividing the support 2 into four panels of equal size in pairs. The fold lines are made here parallel to the transverse edges 6.

To define the fold lines, the outer skin 12 is cut out and a transverse web of material is removed. The core 8 is also cut and the edges of the cutout of the core 8 are chamfered. Thus, at each of the fold lines, a V-shaped groove 16 is obtained.

A transverse edge 6, that located on the left in FIGS. 4 and 6, is also cut out. A transverse web of material of the outer skin 12 is removed. A transverse web of honeycomb structure is also removed thus leaving a transverse flange 18 exposed all along the corresponding transverse edge 6. Here again the core 8 is chamfered along the cut that has been made at the end of the support 2. The other transverse edge 6 is simply chamfered. The outer skin 12 is thus slightly cut as well as the core 8.

The modifications made here to the support 2 do not concern the inner skin 10 which remains flat and in one piece. The subsequent step is a folding and cutting step illustrated in FIGS. 8 to 11. Compared to the previous figures, the support has been turned over so that the inner skin 10 in FIGS. 8 to 11 is illustrated on the top. (while in the previous figures the outer skin was in the upper position).

The longitudinal edges of the inner skin 10 which protrude from the core 8 are folded inwards so as to come substantially in the plane of the edge of the core 8.

Here we define an outer / inner direction which is given by the names given to the surface skins of the composite panel forming the support 2 and which will take its direction when the satellite will be formed, the inner skin 10 then being inside the satellite and the outer skin 12 remaining visible.

As illustrated by FIGS. 9 to 11, the folded edges of the inner skin 10 form tabs 20. Cutouts are also made in the tabs 20 to subsequently facilitate the folding of the inner skin 10.

The tools used to make the bends and cuts are precision tools so as to ensure a good flatness of the tabs 20 and the parallelism of the folds made.

As is apparent from the above, the inner skin 10, apart from the tongues 20, that is to say only in areas not covered by the core 8, has not been modified during the previous steps of manufacturing. There is thus an inner skin 10 flat at the entire area of the support 2 resting on the core 8. This flat area is only bordered by the tongues 20 which extend longitudinally perpendicular to said flat area. An original idea is the realization of this flat area to receive the various components of the electronic system intended to take place in the satellite. All equipment and harnesses (illustrated very schematically in Figure 12) can then be presented on their locations on the flat area of the inner skin and be interconnected. The equipments are electronic components or electronic assemblies integrating several electronic components. The electronic system of the satellite is thus realized and its validation can then be done using a means simulating the missing parts. At the end of this phase, the final integration of the equipment and harness can start.

The equipment is assembled on the support 2. The fixing can be made here as is conventionally carried out the attachment of equipment on panels used to make the walls of a satellite. Inserts are then placed in the support by piercing the inner skin 10 and coming to be housed in the core 8. These inserts then form anchor points in the support 2 which allow the attachment of the components (or sets) by screwing. In an alternative embodiment, a bonding attachment to the inner skin 10 of the support 2 can also be envisaged.

Preferably, the attachment of components and / or electronic assemblies is performed without disconnecting harnesses to eliminate any risk of failure. Accessibility to all components is optimal in this deployed structure configuration.

If elements are provided on the external faces of the satellite, these elements (for example thermal control elements or others) can be placed beforehand on the outer skin 12. A tool for gripping and turning will allow the manipulation of the whole by specific interfaces.

Figures 12 and 13 illustrate later steps of realization of the satellite.

The longitudinal edges of the outer skin 12 which protrude from the core 8 are folded to form L-shaped flanges 22. One leg of the L extends in the plane of the remainder of the outer skin 12 while the free branch of the L-shaped flange 22 extends substantially perpendicularly to the first branch inwards. The L-flanges 22 thus each have a branch extending substantially parallel to the tongues 20. Each L-shaped flange 22 thus forms with the corresponding tongue 20 a rabbet for receiving a closure panel as explained later in the description.

The satellite manufacturing process then comprises a step of folding the support 2 along folding lines 24 (already visible in FIG. 8) which are parallel to the transverse edges 6. This folding step can be performed while the support and the components it carries is in vertical configuration (all the panels defined by the support sections located between two fold lines are then arranged vertically) or horizontal (a panel is arranged horizontally). Folding is performed according to a sequence (order of execution of the folds) depending on the tools used and also depending on the positioning of the components on the support.

The folding must guarantee the parallelism of the transverse folds made in the inner skin 10 as well as the precision (or at least the repeatability) of the distances between the folds.

The folding could be achieved by a tool whose hinges would bend the inner skin 10 of the support, without the need to use a punch.

The positioning of the harnesses of the system will be designed to limit the constraints during the folding phase. It is proposed here to run parallel to the fold lines rigid strands.

During the folding operation, or before it, a closure panel 26 (Figure 14) is disposed in the rabbet formed by the L-shaped flanges 22 and tabs 20. A closure panel 26 is thus taken place at each longitudinal edge 4.

When the folding is completed, that is to say when a fold of 90 ° is made around each fold line 24, the structure illustrated in FIG. 14 is obtained, the closure panels 26 being held prisoner in the corresponding rebates.

The final connection, to close the box, is provided by gluing the transverse flange 18 initially provided for this purpose on the face of the opposite panel.

The closure panels 26 can be fixed in various ways. Inserts may have been provided prior to the folding of the support 2 in the longitudinal edges of the core 8 to receive screws or the like. Adhesive bonding can also be considered.

The steps given here are for illustrative purposes only. Variations can be envisaged. It is for example possible to fold the support before making the flanges L. The closure panels can then take place on the longitudinal edges of the core 8 and on the tongues 20. An attachment by gluing for example on the tabs 20 can be provided here. If this solution is retained, the tabs 20 are preferably slightly inclined relative to the plane perpendicular to the remainder of the inner skin 10 so as to be deformed elastically during the establishment of the closure panels. Thus, a prestress favorable to a good bonding is achieved when fixing the closure panels.

Figures 16 to 19 illustrate optional manufacturing steps. Figures 16 and 18 each show an angle bracket 28 (Figure 16) or 29 (Figure 18) intended to strengthen the angles of the structure thus formed at the fold lines 24 and the transverse flange 18 connecting.

The angles are preferably glued on the edges of the structure. A mixed attachment, implementing both a bonding and screws, can be advantageously envisaged. The angles thus fixed promote the transfer of flux on the outer skin of the support and increase the rigidity of the structure.

If necessary, these angles also allow the implantation of interface fittings 30, 31 with a payload guaranteeing optimal transfer of effort to the structure and in particular the low satellite interface.

As illustrated in Figures 16 and 18, the brackets 28, 29 of reinforcement may have a variable section according to the needs of rigidity and / or mechanical strength. The shape illustrated in Figures 18 and 19 allows a transfer of forces on both the outer skin and also on the inner skin of the support.

As is apparent from the foregoing, there is provided here a structure composed of: - a sandwich panel of extended length, the support 2, which, after specific machining and after integration of components, is folded so as to form four adjacent faces a satellite, and - two additional sandwich panels that close the box thus formed.

The principles of integration are intrinsically linked to the process of realization of this structure: The integration of equipment and electrical connection harnesses are made on the extended panel in unfolded configuration. The validation of the system can also be performed in this configuration after connecting the equipment and electrical harnesses.

The extended panel equipped is then folded on a tool ensuring geometric accuracy and closing panels are finally close the structure to form a box.

The structure thus produced may possibly be reinforced by angles. It presents, with or without reinforcements, the following advantages.

Thanks to continuous and homogeneous connections on each edge of the structure, a great rigidity and a good mechanical homogeneity are brought to the structure (in lieu of point connections creating local constraints which one observes generally on the structures of the art prior).

The inner skin being continuous on the four adjacent faces carrying the various components and equipment, a homogeneity of thermal flows between each side of the box is provided by the conduction through this single inner skin. The continuous envelope formed by the inner skin and which comes directly from the principle of realization of the structure also contributes to the electromagnetic compatibility of the created structure. The invention also makes it possible to reduce the mass of the entire satellite by eliminating (with respect to a known structure of the prior art having panels assembled together) the various parts dedicated to inter-panel links, in particular connecting fittings, fastening inserts and the associated glue (expansive glue filling cells of the honeycomb structure), fasteners, ...

A gain in mass is also obtained by reducing the mass dedicated connectors provided on electrical harnesses of the prior art and which are provided to be able to disassemble the panels.

It will also be apparent to those skilled in the art that the manufacturing method proposed above also leads to a significant reduction in the cost of manufacturing a satellite. Indeed, the proposed manufacturing method allows: - a removal of many machined parts (high chip removal) such as inserts, connecting hardware, fittings internal to the panels, ... - a suppression of the phases of laying d inserts (manual manufacturing phase) if a glued assembly is preferred, - a removal of certain geometric precision constraints on the equipment interfaces and the inter-panel link (precision is necessary on the tooling reused for each specimen).

Of course, the present invention is not limited to the preferred embodiment of a structure and a manufacturing method described above by way of non-limiting example and to the variants mentioned, but also relates to any variant embodiment. the scope of those skilled in the art within the scope of the claims below.

Claims (10)

1. Structure of a module for integrating electronic components, characterized in that it comprises: a support (2) made of a composite material having at least one core (8) and a first surface skin (10), said carrier (2) having at least two fold lines (24) parallel and being folded along said fold lines (24) such that the first surface skin (10) is inside the folded support, and - two closure panels (26) connected to the support (2) for defining with its first surface skin (10) a volume. 2. Structure according to claim 1, characterized in that the composite material of the support (2) comprises a second skin surface (12), in that the core (8) is disposed between the first surface skin (120) and the second superficial skin (12), and in that the second superficial skin (12) is cut at the fold lines (24). 3. Structure according to one of claims 1 or 2, characterized in that the support (2) has longitudinal edges (4) perpendicular to the fold lines (24), and in that each skin surface (10, 12) has a flange protruding from the core (8) of the support (2) along said longitudinal edges (4). 4. Structure according to claims 2 and 3, characterized in that the rim of the first skin surface (10) is folded substantially at right angles to the inside of the folded support, in that the closure panels (26) come to rest each on an edge of the web of the support, and in that each rim of the second skin surface (12) is folded over the corresponding closure panel (26) so that the peripheral edge of each closure panel (26) ) is sandwiched between an edge of the core (8) and a flange (22) of the second surface skin (12). 5. Structure according to one of claims 1 to 4, characterized in that it further comprises reinforcing elements (28; 29) arranged along the fold lines (24) outside the support (2). . 6. Structure according to one of claims 1 to 5, characterized in that the core (8) is of honeycomb type. 7. Structure according to one of claims 1 to 6, characterized in that the support (2) comprises three fold lines (24) thus defining four panels of rectangular shape. Power module comprising a structure on which components and / or electronic assemblies are fixed, characterized in that the structure is a structure according to one of claims 1 to 7. 9. Satellite, characterized in that it comprises a structure according to one of claims 1 to 7. 10. A method of producing a power module, characterized in that it comprises the following steps: - providing a support (2) comprising a core (8) and at least one surface skin (10), - embodiment parallel folding lines (24) by local cutting of the core (8) and optionally of a surface skin (12), - placement of components and / or electronic assemblies on the support (2), - wiring of the electronic components and / or assemblies, - testing of the assembly carried out, - folding of the support (2) along the fold lines (24) so that an edge (6) of the support (2) parallel to the fold lines ( 24) comes to join an opposite edge (6), - connection of the two joined edges, - establishment of closing panels (26) on the support (2) so as to form a closed volume inside which are the electronic components and / or assemblies.