FR2914275A1 - Tube support for e.g. aircraft, has support portion supporting tube, where support is folded around axis parallel to rectilinear direction to form non coplanar flaps, where flaps are integrated to fixation portion at folding edge of sheet - Google Patents

Abstract

The support (21) has a support portion (23) supporting a tube, where the support is formed from a sheet extending between two portions along a rectilinear direction (24). The support is folded around an axis (25) parallel to the direction so as to form two non coplanar flaps (25a, 25b), where the flaps are integrated to a fixation portion (22) at a folding edge of the sheet. The portion (22) has two tabs, where each flap is integrated to the tab at the edge. The flaps form a V sectional spanwise beam (P25) integrated to the portion (22) that fixes a casing to a clamping plate (5).

Description

The invention relates to a pipe support on an aircraft.

  Turbojets have, on the surface of their casings or nacelles, various pipes. Among these pipes, we can name the fluid transport lines (oil, water or fuel in particular) and electrical harnesses, that is to say, insulating tubular housings housing electrical conductors.

  These pipes are attached to the casings of the turbojet engine via pipe supports. These supports are fixed directly on the housings, or on the flanges thereof, and directly support the pipes, or pipe fasteners. The fastening elements may comprise clamps or fixing lyres. Referring to Figure 1, the supports 1 are generally in the form of a folded sheet having, at one end, a fixing portion on the housing with recesses 2 for passing fastening means on the housing, to a another end, a support portion of elements 3 for fixing the pipes; it is in this case metal clamps 3 or elastomeric material.

  The supports must be sufficiently numerous and rigid so that the first modes of vibration of the pipes do not resonate with the rotation frequencies of the high-pressure or low-pressure bodies of the turbojet, which may be subject to unbalance. However, a sheet is not very stiff in bending in the direction of its low inertia, that is to say, perpendicularly to the plane of the sheet portion connecting the fixing portion to the housing to the support portion of the pipes. . It is, therefore, often necessary to stiffen the supports. In Figure 1, the support 1 has been reinforced by a rib 4 stamped on the sheet forming the support 1. Other stiffening means are frequently used: welded ribs, reinforcements sheet such as brackets, which prohibit the bending, larger sheet thicknesses, more supports, etc. In all cases, manufacturing costs are higher, specific tools are needed, the mass is greater and risks of poor quality exist. In particular, in the case of welding, the risks of non-quality are great and require the search for cracks on the substrates by bleeding, which is also expensive. Moreover, the part of the support fixed to the housing can not generally be reinforced and the support is therefore subject to bending at this level, unless there is a specific stiffening means there.

  The object of the invention is to provide a sheet metal support which has a greater stiffness in flexion while being, as far as possible, of low mass and cost, to solve the problems presented above.

  For this purpose, the invention relates to a pipe support on an aircraft, formed from a sheet with at least one attachment portion to a structure of the aircraft and a support portion of the pipes, the sheet extending between the two portions, in at least one rectilinear direction, characterized in that the support is folded around at least one axis parallel to said direction, so as to form at least two non-coplanar flaps integral with the portion of fixation.

  Thus folded, the support has a high flexural rigidity. The presence of two flaps, not coplanar, integral with the fixing portion, considerably stiffens the structure. The non-coplanar flaps form a non-planar beam, that is to say of non-straight section, this beam being directly secured by the two flaps of the fixing portion; thus, the stiffening is obtained, not only on the beam, but also at the base of the beam, integral with the fixing portion, which greatly increases the rigidity of the support relative to the supports of the prior art. The invention is distinguished in particular supports having a bracket attached or even integral and folded from a flat plate integral with the fixing portion; indeed, in this case, the flat sheet and the square are not both secured to the fixing portion, only the sheet being.

  A beam with at least two non-coplanar flaps has good inertia in both directions, not just in a direction such as a flat plate. Therefore, it is not necessary that its thickness is very important and it is possible to obtain good stiffness for a mass not too substantial. Due to its rigidity, the beam has vibration modes that do not resonate with the operating frequencies of the turbojet engine. Such a folded sheet is easy to obtain, for example by folding or stamping, without any welding is necessary.

  It should be noted here that, by folded sheet metal, is meant the shape of the sheet, not the method of obtaining this form; it is therefore a sheet having at least two flaps, secured to one another along an edge parallel to said direction between the two portions of the support, this shape possibly being obtained from any what way. In particular, a folded sheet can be obtained by folding or stamping.

  According to one embodiment, the flaps are integral with the fastening portion at at least one folding edge of the sheet.

  According to one embodiment in this case, the fixing portion comprising at least two tabs, each flap is integral with a tab at a folding edge.

  According to one embodiment in this case, the tabs extend in at least one plane, which is coplanar with none of the shutter planes.

  According to one embodiment, the support comprises, between the integral flaps of the fastening portion, at least one additional flap obtained by folding about axes parallel to said direction.

  According to one embodiment, the support extending between the attachment and support portions in a plurality of rectilinear directions, the support is folded around at least one axis parallel to a first direction to form the integral parts of the portion. and the support is folded around at least one axis parallel to at least a second direction to form non-coplanar flaps.

  According to a particular embodiment, the support comprising two V-section beams formed by the flaps, the V direction of the first beam is inverted with respect to the V direction of the second beam.

  According to one embodiment, the support is formed from a single sheet.

  According to one embodiment, the support portion of the pipes comprises at least one pipe support lug, obtained by folding the sheet.

  According to one embodiment, the flaps comprise at least one recess for lightening the support.

  According to one embodiment, the support comprises, along the free end of at least one flap, a fin forming an angle with the flap, to stiffen the support.

  According to one embodiment, the shutters form a beam, of V-shaped section, with tabs secured to the flaps, folded in the space between the flaps and fixed to one another.

  According to one embodiment, the support portion is directly formed on a flap.

  The invention also relates to a turbojet, comprising pipes and at least one pipe support as shown above. The invention will be better understood with the aid of the following description of the preferred embodiments of the invention, with reference to the attached plates, in which: FIG. 1 represents a perspective view of a support of the art prior; FIG. 2 represents a perspective view of a first embodiment of the support of the invention; - Figures 3a and 3b show two perspective views of a second embodiment of the support of the invention; FIG. 4 represents a perspective view of a third embodiment of the support of the invention; FIG. 5 represents a perspective view of a fourth embodiment of the support of the invention; FIG. 6 represents a perspective view of a fifth embodiment of the support of the invention; - Figure 7 shows a front view of two possible structures of the fixing portion of the support of the invention to a housing flange, in a first type of configuration of the support; - Figures 8 and 9 show a front view of two possible structures of the fixing portion of the support of the invention to a housing flange, in a second type of support configuration; FIG. 10 represents a sectional view of a first particular embodiment of the support of the invention; - Figure 11 shows a sectional view of a second particular embodiment of the support of the invention and - Figure 12 shows a sixth embodiment of the support of the invention.

  In the following description, with the exception of numbers 1 to 7, the reference numbers comprise a first digit corresponding to the figure, the following figures designating the various elements of the parts described. Similar, equivalent or corresponding elements will be designated by the same digits after the figure number; in this case, the description of all the elements of each embodiment will not be systematically developed.

  With reference to FIG. 2, a support 21 is formed from a single sheet. It comprises a portion 22 for attachment to a flange 5 of a casing 6 of a turbojet engine of an aircraft and a portion 23 of support for pipe fasteners, such as fluid or air transport ducts. , or harness fixation, as explained in the introduction to the description above. The support 21 extends between these two end portions 22, 23 in at least one rectilinear direction, here in a single direction 24.

  The support 21 is folded around said direction 24, that is to say it is folded about an axis 25 parallel to the direction 24, forming an edge 25. The support is folded once, thus forming two wings or flaps 25a, 25b. The support 21 is thus between the two attachment portions 22 and support 23, in the form of a P25 beam of non-straight section, here V-section.

  The folding of the P25 beam in two parts 25a, 25b can be obtained by folding or stamping. The difference between these two methods is that the folding is an operation which is done continuously and lasts a certain time, while the stamping is an operation by which the deformation is obtained abruptly, by shock, generally between two matrices.

  Such a P25 beam with a non-straight section is very rigid in bending because it is very difficult to bend it perpendicularly to the bending edge. It is rigid in both directions perpendicular to its large dimension (the direction 24), while a flat sheet is rigid only in one direction. Furthermore, the two flaps 25a, 25b are directly integral with the fastening portion 22, here comprising two tabs. These tabs extend in a plane, which is the plane of the flange 5; this plane is coplanar with none of the plans of the flaps 25a, 25b; it follows a "triangularization" of the support 21 between its flaps 25a, 25b and its fastening portion 22, which provides a high rigidity to the support 21, in particular at the base of the beam P25, that is to say in the portion that connects the fastening portion 22 to the P25 beam. This stiffening is all the more beneficial as it is in this area that the bending moments are the most important.

  By "triangularization" is meant the formation of at least three non-coplanar surfaces, which provides better rigidity.

  Conventionally, the portion 22 for fastening to the flange 5 of the casing 6 comprises bores 22a for the passage of fastening screws, here for the passage of the screws intended to be inserted into the holes of the flange 5, while the portion 23 support of the pipe fasteners comprises recesses, here a single recess 23a, for fixing said fasteners. These fixing elements comprise, for example, collies or fixing lyres. The pipes could be directly fixed on the support portion 23, without the intermediary of fixing elements.

  In the embodiment of FIG. 1, the support portion 23 comprises an ear 23, on which is formed the recess 23a, obtained by folding the sheet, in this case around two folding axes 23a 'and 23a. ", forming two edges 23a ', 23a", for greater stiffening of this support portion 23.

  Note that, according to an alternative embodiment not shown, the support portion 23 is formed directly on the P25 beam, without a particular distinct structure such as an ear 23 is provided. In this case, for example, bores for fixing the collars or lyres are directly formed on one of the flaps or on the two flaps 25a, 25b of the beam P25.

  Such a straight support 21 may be arranged to extend in any direction relative to its attachment plane - here the plane of the flange 5 - to the structure of the turbojet engine (parallel to this plane, perpendicularly or at an angle by simple adaptation of the attachment portion 22 and its connection area to the beam P25).

  In the embodiment of FIGS. 3a and 3b, the support 31 extends, between its end portions 32, 33, in two rectilinear directions 34, 34 ', substantially perpendicular to each other, this is that is, it has two straight beams P35, P35 'each extending generally parallel to a direction 34, 34'. In other words, the support 31 is bent.

  The support 31, extending between its attachment portions 32 and support 33 in two rectilinear directions 34, 34 ', is folded about an axis 35 parallel to the first direction 34 to form two flaps 35a, 35b integral with the fixing portion 32 and is folded about an axis 35 'parallel to the second direction 34' to form non-coplanar flaps 35'a, 35'b, forming the second beam P35 '.

  Parallel to each direction 34, 34 ', the support 31 is folded around an edge 35, 35', but at angles with opposite directions. Thus, the support 31 is folded around the first edge 35 to form two flaps 35a, 35b extending towards the outside of the support 31 (the outside means here from the outside with respect to the angle right elbow between the two beams P35, P35 ', this right angle is considered to be on the inside). Furthermore, the support 31 is folded around the second edge 35 'to form two flaps 35'a, 35'b extending towards the interior of the support 31. In other words, the direction of the V of the section of the support 31 is reversed on either side of the elbow formed by the support 31.

  Such folding around two directions 34, 34 'is here obtained thanks to two additional folding edges 36, 36', for forming the bend between the two beams P35, P35 '. A support is obtained with two beams P35, P35 ', integral with each other and each section V, the first beam P35 being secured, by each of its flaps 35a, 35b, the fixing portion 32; the latter comprises two tabs 32a, 32b, planar and here coplanar, each traversed by a fastening screw to the structure of the turbojet engine. As previously, the planes of the flaps 35a, 35b integral with the fastening portion 32 and the plane of this fastening portion 32 are not coplanar, this "triangularization" providing a high rigidity to the assembly and in particular at the level of the base of the beam P35 integral with the fixing portion 32.

  It will be noted that the chosen folding structure makes it possible to obtain the bent support 31 from a single flat sheet, by folding or stamping, without welding.

  A support 31 such as that of Figures 3a and 3b can be used because the path to follow between the fixing portion 32 of the support 31 and its support portion 33 is not straight, for example to bypass an obstacle.

  It goes without saying that several elbows can be provided and that the angles of these elbows are not necessarily then right angles.

  In the embodiment described in FIGS. 3a, 3b, a hole 37 (obtained for example by laser drilling) is provided in the region where the folding edges 35, 35 ', 36, 36' meet, in order to reduce the constraints on the sheet,

  In the embodiment of FIG. 4, the support 41 comprises a V-section straight beam P45, comprising two flaps 45a, 45b united by a folding edge 45. The support portion 43 is in the form of a flat sheet portion in which is formed a recess 43a, for fixing the fasteners of the pipes. This support portion 43 extends parallel to the direction 44 around which the beam P45 is folded along its V-section, in the axis of the beam P45. The embodiment of FIG. 4 shows a particular folding of the sheet allowing the passage, without discontinuity, by folding and without welding, from a flat sheet, of a V-section beam P45 to such a flat ear 43 of support. Thus, from a flat expanded sheet metal, the support 41 of FIG. 4 is obtained simply by folding or stamping. Moreover, the folding edges ensuring the transition from the P45 beam to the flat support portion 43 provides good rigidity to this area.

  In the embodiment of Figure 5, the support 51 is in the form of a beam P55 C section. It is folded around two fold axes 55, 55 ', forming two edges 55, 55' , parallel to the direction 54 in which generally extends the beam P55, leaving three flaps 55a, 55b, 55c.

  Thus, the beam P55 comprises two flaps 55a, 55c secured to the fixing portion 52 and an additional flap 55b extending between the two flaps 55a, 55c, obtained by folding around axes 55, 55 'parallel to the direction 54.

  The attachment portion 52 here comprises two lugs 52 ', 52 ", each having a recess 52a, 52b, respectively, for the passage of a fixing screw to the flange 5 of the housing 6. From each lug 52', 52 ", the support 51 comprises two folds 56 which form, so to speak, hinges in opposition and allow the transition to the beam P55. The presence of these hinges in opposition makes the support 51 very rigid. In this case, the brackets 52 ', 52 "are not only directly integral with the two outer flaps 55a, 55c, but also directly integral with the central flap 55b, thanks to these folding lines 56 adapted.

  The support 51 of Figure 5 finds a particularly interesting application for the formation of a support, parallel to the housing 6 and of great length. In particular, it can allow the formation of a support extending between two flanges remote from the casing 6. On the flange opposite the flange 5 of FIG. 5, a support similar to the support 51 is mounted, the two supports extending towards each other and being fixed to each other (for example by riveting or bolting). These supports are also bored holes for fixing necklaces or lyres, for example. Note that, in this case, the support portion, with bores for fixing the collars and lyres, can be formed directly on the folded flaps of the beam P55, without being provided a particular structure such as ears .

  In the embodiment of Figure 6, wherein the carrier 61 is in the form of a single beam P65 V-section, the flaps 65a, 65b of the beam P65 are recessed, so as to lighten the structure. It is thus possible to find the best compromise between mass and rigidity. The presence of recesses 68 allows in particular the use of a thicker sheet. The thicker sheet is thus more rigid at the level of the support portion 63 (on which schematically shown fixing clamps 63a, 63b) and the additional mass generated by the greater thickness is compensated by the loss of mass due to the presence of the recesses 68.

  In Figure 7 are shown two supports 71A, 71B, in front view. These supports 71A, 71B comprise a P75A beam, P75B, respectively, with a V-shaped section, and a portion 72A, 72B for fastening to a flange 5 of a casing 6 which, in the configuration of FIG. 7, comprises two lugs ( 72A ', 72A "), (72B', 72B") perpendicular to the folding edge 75A, 75B of the beam P75A, P75B. The support 71A of the left part of FIG. 7 is fixed at its tabs 72A ', 72A "on two successive flange holes, while the support 7113 of the right part of FIG. 7 is fixed at its flaps. 72B ', 72B "on two non-successive flange holes, spaced from one flange hole therebetween. The choice between the two configurations is based on the desired dimension for the attachment portion 72A, 72B. An advantage of the invention is noted here: in the prior art, in the case of a wide fixing portion which extended over three flange holes, it was necessary to drill three holes on the fixing portion; thanks to the invention and in particular to the beam 75B V-section, the beam "straddles" the central flange hole and it is not necessary to provide a passage bore in the attachment portion 72B for the inserted screw in this flange hole, which allows a saving in manufacturing and maintenance.

  Figures 8 and 9 show two supports 81, 91 in flange fastening situations comparable to those of Figure 7, left and right supports, respectively. In the configuration of FIGS. 8 and 9, the supports 81, 91 are supports whose portion 82, 92 for attachment to the casing comprises two tabs (82 ', 82 "), (92', 92") parallel to the ridge 85, 95 of the P85 beam, P9.5. The carrier 81 of FIG. 8 is attached to two successive flange holes, while the carrier 91 of FIG. 9 is attached to two flange holes separated by a flange hole. Again, thanks to the V-shaped section of the beam P95, the screw 7 inserted in this central flange hole does not interfere with the mounting of the support 91, without it being necessary to provide a passage of this screw 7 on the support 91.

  In the embodiment of FIG. 10, the support 101 comprises, along the free end of each flap 105a, 105b of the beam P105, a fin 105a ', 105b' forming an angle with the flap 105a, 105b, obtained by folding the sheet. On each flap 105a, 105b, the beam P105 may comprise a plurality of fins or a continuous fin, extending over all or part of the length of the flap 105a, 105b. These fins 105a ', 105b' provide additional rigidity to the support 101 and are simply obtained, by stamping or folding, without additional fastening means. Note that, for an angled support of the type of that of Figures 3a and 3b, if one provides fins such as those of Figure 10, it is necessary to interrupt the fins on both sides of the elbow of the support.

  In the embodiments described above, the section of the beams is open: it is an open V or C. In the embodiment of Figure 11, the V-shaped section of the beam P115 is closed by tabs 115a ', 115b', folded in the space between the flaps 115a, 115b forming the V section and fixed one to the other. The tabs 115a ', 115b' may, for example, be riveted or bolted to each other. These tabs 115a ', 115b' are formed by folding the sheet. The beam P115 may comprise a plurality of pairs of tabs, distributed along the beam P115, or a single pair of tabs 115a ', 115b' extending over all or part of the length of the beam P115, thus forming a sort of third shutter on all or part of the beam P115. These tabs 115a ', 115b' further stiffen the beam P115.

  In the embodiment of FIG. 12, a support 121 is shown, comprising two beams P125A, P125B, the beams P125A, P125B being joined by a sheet metal plate forming a support portion 123 common to the two beams P125A, P125B, for necklaces and lyres 123a, 123b, 123c, 123d. In the embodiment of Figure 12, the assembly is formed in one piece, from a single sheet metal plate. Thus, a support structure 121 called "gantry" is formed.

  It should be noted that, in all the embodiments described, the folding of the support to form a beam with at least two non-coplanar flaps is made in such a way that the flaps are directly integral with the fastening portion of the support to the structure of the turbojet engine. . The fastening of the flaps to the fixing portion is at at least one folding edge of the sheet. Thus, the connection zone between the fixing portion and the beam is stiffened, which is beneficial because it is the area that is subjected to the strongest bending moments when the pipes hung on the support are stressed in vibration.

  The "triangularization" of the support, obtained by the formation of two non-coplanar flaps with the plane of the fixing portion, provides a high rigidity to the support. It may be noted that the attachment portion could extend in a plurality of planes, for example two non-coplanar planes corresponding to two legs; preferably, none of these plans is then coplanar with the flaps of the beam.

  Moreover, in all the described embodiments, obtaining the geometry of the support is done by a folding or stamping operation, preferably by a single operation; the plastic deformations of the sheet therefore remain limited; subsequent heat treatment may not be necessary.

  Note that additional stiffening of the media described can of course be obtained by the use of a sheet of greater thickness.

  The invention has been presented in relation to beams with a V or C folded section. It goes without saying that other bends may be envisaged, for example a W-fold.

  It goes without saying that, subject to structural incompatibilities, the various forms of achievement that have been described may be combined with each other or with others.

  The invention has been presented in connection with a turbojet engine for an aircraft, but it applies to a turbojet engine for any aircraft. The invention still applies to the pipe support on an aircraft, apart from the turbojet engine. In other words, the invention applies to pipe support in the aeronautical field.

Claims (14)

claims   1- Pipe support on an aircraft, formed from a sheet with at least one portion (22, 32, 52, 72A, 72B, 82, 92) for attachment to a structure of the aircraft and a portion (23 , 33, 43, 63, 123), the sheet extending between the two portions in at least one rectilinear direction (24, (34, 34 '), 44, 54), characterized in that the carrier is folded about at least one axis (25, 35, 45, (55, 55 '), 75A, 75B, 85, 95) parallel to said direction (24, (34, 34'), 44, 54), so as to form at least two flaps ((25a, 25b), (35a, 35b), (45a, 45b), (55a, 55b, 55c), (65a, 65b), (105a, 105b), (115a, 115b)) non-coplanar, integral with the fixing portion (22, 32, 52, 72A, 72B, 82, 92).   2- pipe support according to claim 1, wherein the flaps ((25a, 25b), (35a, 35b), (45a, 45b), (55a, 55b, 55c), (65a, 65b), (105a, 105b), (115a, 115b)) are secured to the fastening portion (22, 32, 52, 72A, 72B, 82, 92) at at least one folding edge of the sheet.   3- pipe support according to claim 2 wherein, the fixing portion (22, 32, 52, 72A, 72B, 82, 92) comprising at least two tabs, each flap (25a, 25b), (35a, 35b ), (45a, 45b), (55a, 55b, 55c), (65a, 65b), (105a, 105b), (115a, 115b)) is integral with a tab at a folding edge.   4- pipe support according to claim 3, wherein the tabs extend in at least one plane, which is coplanar with none of the planes of the flaps (25a, 25b), (35a, 35b), (45a, 45b), (55a, 55b, 55c), (65a, 65b), (105a, 105b), (115a, 115b)). 4- pipe support according to one of claims 1 to 3 comprising, between the flaps (55a, 55c) integral with the fastening portion (52), at least one additional flap (55b) obtained by folding around axes (55 , 55 ') parallel to said direction.   5- pipe support according to one of claims 1 to 4 wherein, the support extending between the attachment portions (32) and support (33) in a plurality of rectilinear directions (34, 34 '), the support is folded around at least one axis (35) parallel to a first direction (34) to form the flaps (35a, 35b) integral with the fixing portion (32) and the support is folded around at least one axis (35 ') parallel to at least a second direction (34') to form non-coplanar flaps (35'a, 35'b).   6- pipe support according to claim 5, wherein the support comprising two beams (P35, P35 ') V-section formed by the flaps ((35a, 35b), (35'a, 35'b)), the V direction of the first beam (P35) is inverted with respect to the V direction of the second beam (P35 ').   7- pipe support according to one of claims 1 to 6, formed from a single sheet.   8- Pipe support according to one of claims 1 to 7, wherein the support portion (23) of the pipes comprises at least one lug (23) for supporting the pipes, obtained by folding the sheet.   9- Pipe support according to one of claims 1 to 8, wherein the flaps (65a, 65b) comprise at least one recess (68) for lightening the support.   10- pipe support according to one of claims 1 to 9, wherein the carrier (101) comprises, along the free end of at least one flap (105a, 105b), a fin (105a ', 105b). ') forming an angle with the flap (105a, 105b), to stiffen the support (101).   11- pipe support according to one of claims 1 to 10, wherein the flaps (115a, 115b) form a beam (P115), of V-shaped section, with tabs (115a ', 115b'), integral with the shutters (115a, 115b), folded in the space between the flaps (115a, 115b) and fixed to one another.   12- pipe support according to one of claims 1 to. 11, wherein the support portion (23, 33, 43, 63, 123) is directly formed on a flap ((25a, 25b), (35a, 35b), (45a, 45b), (55a, 55b, 55c ), (65a, 65b), (105a, 105b), (115a, 115b)).   13- Pipe support according to one of claims 1 to 12, obtained by folding or stamping.   14- turbojet, comprising pipes and at least one pipe support according to one of claims 1 to 13.