Needling system for manufacturing a textile preform

Description

Technical Field

[0001] The present invention relates to the manufacture of textile preforms by needle punching, and more particularly to a needle punching system for the manufacture of a textile preform. Previous technique

[0002] Textile preforms form the reinforcement of organic or ceramic matrix composite materials. They create a framework for the material that absorbs most of the mechanical stresses, which is reinforced and protected by the organic or ceramic matrix of the composite material.

[0003] The production of textile preforms by needle punching involves layering textile plies and joining them together by needle punching. Specifically, needle punching joins the plies by transferring fibers from one plies to another in the Z direction, that is, along the thickness of the preform, thus creating mechanical bonds between the plies in this direction. Current needle punching systems therefore allow the production of axisymmetric preforms or preforms with through-hole geometries.

[0004] Current needle-punching systems are programmed to follow a specific trajectory to needle the preform according to certain criteria, such as fiber density in the Z-axis. These programs are specific to the machine being used and cannot be used on another. Furthermore, they can follow an axisymmetric profile based on an adaptive mode, which corrects the machine's position according to the excess material encountered during needle-punching.

[0005] However, some preforms, such as thermal protection preforms for atmospheric reentry, may have a spherical cap shape (non-opening geometry) or a non-axissymmetric geometry, and current needle-pointing methods are not suitable for this type of geometry.

[0006] Document FR 2 669 941 describes an installation for the production of needle-punched fibrous preforms intended for the manufacture of parts in composite material.

[0007] The CN 105 755 680 document describes a needle-punching robot for the manufacture of a fibrous preform having six degrees of freedom.

[0008] Documents CN 112 318 499 and CN 110 109 421 describe methods for programming the movement of a needle-punching robot for the manufacture of a fibrous preform.

[0009] The article "Robot needle-punching path planning for complex surface preforms" by Chen Xiaoming et al. published in August 2018 in Robotics and Computer Integrated Manufacturing describes a method for programming a needle-punching robot for the fabrication of a fibrous preform.

[0010] It is therefore desirable to have a new, more versatile needle-punching system that can needle preforms with non-axissymmetric and / or non-through geometry, or with axisymmetric or non-axissymmetric, through or non-through geometry, and capable of needle-punching textile strips with fully parameterizable trajectories, without trajectory limitations.

[0011] It is also desirable to have a new programming solution for the pointing means that can be used on several pointing machines and adapt to any type of preform geometry, including non-axissymmetric and non-through geometries. Description of the invention

[0012] The present invention relates to a method for determining a movement and orientation program for a needle-punching head for producing a textile preform by needle-punching a textile strip onto a support tool, comprising at least: the determination of a set of coordinate triplets (x, y, z) of the points of passage of the needle-punching head as a function of the positions of the fibers along the Z axis in the textile preform to be produced, its local geometry and a predetermined minimum distance to be respected between the needle-punching head and the support tooling or the preform allowing to avoid a collision with the latter, and the determination of the angular orientation of the needle-punching head (α, β, γ) for each point of passage as a function of the angular orientation of the textile web and the fibers in Z in the textile preform to be produced, the process further includes determining a local movement speed of the needle-punching head as a function of the fiber content in Z in the associated area of ​​the textile preform to be produced and a rotation of the support tooling.

[0013] Thanks to the invention's process, the needle-punching head's passage points and orientation are determined before the needle-punching process begins, taking into account the complexity of the preform's geometry, the fiber density and Z-orientation, while ensuring that the support tooling and the preform do not collide with the needle-punching head. This program is therefore not tied to a specific machine and can be adapted to any machine and desired preform shape. It thus enables the versatile production of textile preforms by needle-punching according to specific needs and desired thermostructural properties, such as fiber density and Z-orientation.

[0014] Furthermore, because the complexity of the preform's geometry is taken into account, the number of iteration points is adjusted to reduce computation time and the program itself. For example, if an area has a small local radius of curvature, the number of iteration points will be greater in that area than in another area with a larger radius of curvature.

[0015] The determination of the coordinate triplets of the switching head's passage points and the angular orientation of the head can result from one or more calculations, or certain parameters (coordinate or angle) can be predefined in advance.

[0016] The determination of the coordinate triplets of the needle head's passage points can also be carried out based on the width of the textile strip and its possible overlap.

[0017] The determination of the angular orientation of the switching head can be carried out with respect to the normal to the local geometry.

[0018] According to a particular feature of the invention, the support tooling is in rotation around an axis of rotation and the method comprises a mathematical projection of the determined passage points onto a reference plane fixed or movable relative to the support tooling and comprising the axis of rotation of the support tooling.

[0019] This allows the conversion of coordinate triplets (x, y, z) into polar coordinates (r, θ, z) and thus makes it easier to implement the coordinates of the needle-tapping head's passage points in the needle-tapping machine.

[0020] According to the invention, the method includes determining a local displacement speed of the needle-punching head as a function of the Z-fiber ratio in the associated area of ​​the preform to be produced and a rotation of the support tooling.

[0021] This allows the needle density to be adapted according to the geometry of the preform, and thus increase, decrease or keep this density constant according to the local geometric characteristics of the preform.

[0022] According to another particular feature of the invention, the process further comprises the creation of a mesh of the geometry of the textile preform to be produced, the determination of the set of coordinate triplets (x, y, z) being carried out on this mesh.

[0023] The mesh allows for a more precise mathematical use of the geometry of the preform in order to then apply all the operations of determining the passage points and the angular orientation of the head, but also to discretize the number of passage points according to the geometric complexity of the preform to be produced.

[0024] According to another particular feature of the invention, the support tooling has a non-axissymmetric and / or non-through shape.

[0025] This makes it possible to create a textile preform with complex geometry.

[0026] Another object of the invention is a method for manufacturing a textile preform by needle punching comprising determining a program for the movement and orientation of a needle punching head according to the invention and manufacturing the textile preform by needle punching on a support tool, the shape of which corresponds to that of the textile preform to be produced, using a needle punching head programmed according to the determined program. Brief description of the drawings

[0027] Other features and advantages of the present invention will become apparent from the description given below, with reference to the attached drawings which illustrate examples of embodiment without any limiting character. [ Fig. 1 ] There figure 1 represents, schematically and partially, a switching system according to an embodiment of the invention. Fig. 2 ] There figure 2 represents, in part, a needle-pointing head during the deposition and needle-pointing process according to an embodiment of the invention. Fig. 3 ] There figure 3 represents, schematically and partially, the switching head of the figure 2 , in particular the orientation of the needles relative to the deposited strip. Fig. 4 ] There figure 4 represents a flowchart of the process for determining a movement and orientation program for a switch head according to an embodiment of the invention. Fig. 5A ] There figure 5A represents, schematically and partially, step 409 of the process described in figure 4 . [ Fig. 5B ] There figure 5B represents, schematically and partially, step 410 of the process described in figure 4 . [ Fig. 5C ] There figure 5C represents, schematically and partially, step 420 of the process described in figure 4 . [ Fig. 5D ] There figure 5D represents, schematically and partially, step 421 of the process described in figure 4 . [ Fig. 6 ] There figure 6 represents a flowchart of the manufacturing process of a textile preform by needle punching according to an embodiment of the invention. Description of the implementation methods

[0028] There figure 1 represents, schematically and partially, a needle-punching system 100 according to an embodiment of the invention allowing the production of a textile preform.

[0029] The system 100 includes a needle-punching head 110 on which is mounted a textile strip feeding device 130, a robotic arm 120 mobile in several degrees of freedom and carrying the needle-punching head 110 and a control unit 140.

[0030] The robotic arm 120 is configured to move the switching head 110 along predetermined trajectories and orientations.

[0031] The feeding device 130 is configured to deposit the textile strip onto a support and proceed to cut the deposited strip.

[0032] The control unit 140 is configured to control the robotic arm 120, the actuation of the needle-punching head 110 and the deposition of the textile strip according to a predefined program for the production of the textile preform.

[0033] There figure 2 represents, in part, a needle-punching head 210 carrying a feeding device 230 for a textile strip 233 according to an embodiment of the invention during the manufacture of a textile preform, in particular during the deposition and needle-punching of a textile strip 234 onto a support tool 250. figure 3 represents a schematic view of the figure 2 , in particular the orientation of the needles of the needle-tapping head relative to the deposited strip, the references used for these two figures representing the same objects.

[0034] The feeding device 230 for a textile strip 233 includes a cassette support 232 and a cassette 231 containing the textile strip 233 and placed on the cassette support 232. The cassette 231 has a width corresponding substantially to the width of the textile strip 233 wound on the cassette 231.

[0035] Textile tape 233 is for example a tape or sheet of yarns whose properties are useful as fibrous reinforcement in the preform composing a composite material, for example a yarn or set of yarns, a fabric, a multidirectional non-woven textile (or "Non Crimp Fabric, NCF"), a braid, or a non-woven veil.

[0036] The needle-punching head 210 comprises a plurality of needles 211 mounted on a needle board, which are used to needle the textile strip 234 that has just been deposited onto the support tool 250. This textile strip 234 is thus needle-punched along with the previously deposited strips 235 to create the textile preform. To obtain the desired geometry, the depositing and needle-punching take place on the support tool 250, which has a shape corresponding to that of the preform to be produced. Thus, to create a non-axissymmetric preform, the support tool 250 has a non-axissymmetric shape. The support tool 250 can also be mobile, for example, rotating around an axis, to facilitate the movements of the robotic arm and the needle-punching head 210.

[0037] The needle-tapping head 210 also includes a deburrer 212 comprising a plate having a plurality of perforations. The plate has an inner and an outer face, the outer face being on the side of the support tooling 250. The needle board is positioned opposite the inner face of the deburrer, and the needles 211 are aligned with the perforations on the deburrer plate 212. During the needle-punching of the web 234, the needles 211 alternately move from a retracted position, in which they do not protrude from the outer surface of the deburrer plate 212, to an extended position, in which they protrude from the outer face of the plate in order to penetrate the textile web 234. The textile web feeding device 230 is attached to the needle-punching head 210 transversely to the perforated plate of the deburrer 212, which is intended to be traversed by the needles 211.

[0038] The feeding device 230 for a textile belt 233 may include a guiding system 270 for the textile belt and / or a braking system that allows adjustment of the belt tension 234 during its placement. The guiding system 270 may be fixed to the surface of the deburrer 212 or to the needle-punching head 210, ideally as close as possible to the surface of the deburrer 210, which carries the feeding device 230.

[0039] Furthermore, the textile web guiding system can be equipped with adjustable guide rollers 271, which can be positioned along a three-dimensional coordinate system, particularly a spherical one. These rollers 271 can, for example, be adjusted in translation along the width direction of the web 234 and in rotation along two axes, allowing adjustment of the web 234's angle relative to the support tooling 250. These guide rollers 271 guide the web 234 from the cassette 231 to the support tooling 250's deposition surface. The width of these rollers 271 can be adapted to the width of the web 234.

[0040] Regardless of the embodiment, the textile belt feeding device can be configured to store a textile belt with a width between 5 mm and 500 mm, preferably between 5 mm and 200 mm.

[0041] Regardless of the specific design, the needle-punching head can be configured for different needle board widths (the support holding the multiple needles) and / or different needle-removing device widths, for example, to be able to needle-punch textile strips with widths ranging from 5 mm to 500 mm, preferably textile strips with widths between 5 mm and 200 mm. The needle board and the needle-removing device can also be detached from the needle-punching head to adapt them to the geometry of the preform to be produced and / or the widths of the needle-punched textile strips.

[0042] Regardless of the embodiment, the needle-pointing head, in particular the needles, forms an angle α (represented on the figure 3 The angle of the needle-punching head is variable with respect to a perpendicular axis 270 to the tangent plane 260 of the support tooling 250 during all or part of the deposition and needle-punching of the textile web. For example, this angle is between -85° and 85°, preferably between -30° and 30°. More generally, the needle-punching head is adjustable in all directions around this perpendicular axis 270. This allows the textile webs to be needle-punched in different orientations, for example, diagonally or at an angle to transfer fibers in a specific orientation to impart certain thermomechanical and / or abrasion-resistant properties to the final part.

[0043] Regardless of the specific embodiment, the needle-punching head can be programmed to move and orient itself, using the robotic arm, around the support tooling to deposit and needle the textile web. The needle-punching head movement and orientation program thus includes the points of passage and the angular orientation of the needle-punching head around the support tooling.

[0044] The points of passage can be determined based on the Z-shaped fiber positions within the textile preform to be produced, its local radius of curvature, and a minimum distance to be maintained between the needle-punching head and the support tooling or the preform to avoid damaging the preform. The angular orientation of the needle-punching head can be determined for each point of passage based on the angular orientation of the Z-shaped fibers within the preform to be produced.

[0045] Furthermore, to facilitate the programming of the switching head, and in the case of a support tool rotating on its own axis, the passage points can be expressed in terms of the distance between the switching head and the support tool. To do this, the passage points can be projected onto a fixed reference plane relative to the support tool, and the head can then be programmed according to the distance between the switching head and the support tool.

[0046] Regardless of the specific implementation, it is also possible to control the pressure of the descaling device. In particular, the descaling device can apply pressure to the belt to hold it in place as the needles exit.

[0047] Regardless of the embodiment, it is also possible to control the needle-tapping head by a servo system based on the pressure of the scourer and / or based on the position of the scourer if it is floating and / or based on the position of the needles

[0048] It is also possible to control the robot's position by a servo system based on the pressure of the unblocker and / or based on the position of the unblocker if it is floating and / or based on the position of the needles.

[0049] It is also possible to control the position of the support by a servo system based on the pressure of the deburrer and / or based on the position of the deburrer if it is floating and / or based on the position of the needles.

[0050] There figure 4 represents a flowchart of the method 400 for determining a movement and orientation program for a switch head according to an embodiment of the invention, and the figures 5A , 5B , 5C And 5D represent the different stages of this same process. The process is thus described with reference to figures 4, 5A , 5B , 5C And 5D .

[0051] The process 400 is a method for determining a movement and orientation program for a needle-punching head 530 for producing a textile preform 500 by needle-punching a textile strip onto a support tool 505. This process 400 includes determining 410 a set of coordinate triplets (x, y, z), (x1, y1, z1), (x2, y2, z2), (x3, y3, z3) of the passage points 520, 521, 522, 523 of the needle-punching head 530. For clarity, only a few points are visible in the figures; however, the number of passage points is not limited to these four. Furthermore, the position of these visible points on the figure 5B This does not mean that point 520 (or point 522) is determined before point 521 (or point 523). Generally, the order in which the various head passage points are determined follows the unwinding and needle-punching of the textile strip on the support tooling.

[0052] The passage points 521, 522, 523 are determined based on the fiber positions along the X, Y, and Z axes, particularly along the Z axis in the textile preform 500 to be produced, the local geometry of the preform 500, for example, its local radius of curvature, and the minimum distance dmin. This minimum distance dmin is a distance that prevents a collision between the needle-punching head 530 and the preform 500 being produced or the support tooling 505. The minimum distance dmin is predetermined by the user. This step 410 is shown on the figure 5B .

[0053] The number of passing points 520, 521, 522, 523 can depend on the complexity of the preform to be made 500. For example, if the preform is of complex shape (e.g., a non-axissymmetric shape), the number of passing points will generally be greater than for a preform of simple shape (e.g., an axisymmetric shape).

[0054] Then, process 400 includes determining 420 the angular orientation of the needle-punching head 530 for each pass point 520, 521, 522, 523 determined in step 410 as a function of the angular orientation of the Z-fibers in the textile preform to be produced 500. This step 420 is shown on the figure 5C . In this step 420, we determine, for example, the angle α formed between the needle-tapping head 530 and the Z axis for the passage point 520 and / or the angle β formed between the needle-tapping head 530 and the X axis for the passage point 520. More particularly, in the example of determining the angle α, the angle α is formed between the Z axis and the orientation of the head, which corresponds to the 560 orientation of the fibers in Z for this passage point 520.

[0055] The process 400 may also include a step 409 of creating a mesh 510 of the geometry of the textile preform to be produced 500. The determination 410 of all the coordinate triplets (x, y, z) of the passing points is thus carried out on this mesh 510. This step 409 is represented on the figure 5A This simplifies the geometry of the preform 500 and makes it easier to determine the passage points 520.

[0056] When the support tooling 505 rotates about a rotation axis 580, the process 400 can further include a step 421 of projecting the passage points 520 determined in step 410 onto a reference plane 540, fixed or movable relative to the support tooling 505, and including the rotation axis 580 of the support tooling 505. The reference plane 540 can, for example, be the (YZ) plane, the (XY) plane, or the (λ) plane. This allows the polar coordinates (r, θ, z) of the passage points 520 to be determined. This step 421 is shown in the figure 5D .

[0057] The process 400 includes determining a local movement speed of the needle-punching head 530 as a function of the fiber content in Z in the associated area of ​​the preform to be produced 500 as a function of a possible movement of the support tooling 505. For example, if the support tooling 505 is rotating during needle-punching, according to the radius of curvature of the geometry of the preform to be produced 500, it may be advantageous to vary the movement speed of the needle-punching head 530 between the passage points 520 along this radius of curvature to best adapt the fiber content of Z.

[0058] There figure 6 represents a flowchart of process 600 for manufacturing a textile preform by needle punching according to an embodiment of the invention.

[0059] The process 600 first comprises determining 610 a movement and orientation program for a needle-punching head according to the invention, for example, according to the process described previously, and then manufacturing 620 by needle-punching the textile preform onto a support tool. The support tool has the same shape as the internal surface of the preform to be produced. The needle-punching is carried out using a needle-punching head programmed according to the program determined in step 601.

[0060] A needle-pointing system used in manufacturing is, for example, a system comprising: a needle-punching head programmed according to the determined program; a robotic arm mobile with several degrees of freedom, carrying the needle-punching head and configured to move the needle-punching head along trajectories and orientations predetermined in the movement and orientation program; a textile strip feeding device mounted on the needle-punching head and configured to deposit the textile strip onto a support tooling and proceed with its cutting, and a control unit configured to command the robotic arm, the actuation of the needle-punching head and the depositing of the textile strip according to the movement and orientation program of the head.

[0061] The support tooling used to determine the movement and orientation program of the needle-punching head and for manufacturing the textile preform can have a non-axissymmetric and / or non-through shape. This allows for the creation of a non-axissymmetric and / or non-through preform, which could, for example, form a thermal protection preform for atmospheric reentry.

[0062] The support tooling can also rotate in both directions around a pivot point during the pointing process to facilitate the movement of the robotic arm. In this case, the control unit can control the rotation of the support tooling. For example, it can control the axis of rotation and / or the rotation speed of the support tooling.

[0063] The expression "between ... and ..." should be understood as including the boundaries.

Claims

1. The method (400) for determining a program of displacement and orientation of a needling head (530) for making a textile preform (500) by needling a textile strip on a support tooling (505), comprising at least: - determining (410) a set of triplets of coordinates (x, y, z), (x1, y1, z1), (x2, y2, z2), (x3, y3, z3) of the points of passage (520, 521, 522, 523) of the needling head (530) as a function of the positions of the fibers along the Z axis in the textile preform to be made (500), of its local geometry and of a predetermined minimum distance (dmin) to be met between the needling head and the support tooling (505) or the preform making it possible to avoid a collision with the latter, and - determining (420) the angular orientation (α, β, γ) of the needling head for each point of passage as a function of the angular orientation of the textile strip and of the Z fibers in the textile preform to be made, the method further comprising determining a local speed of displacement of the needling head as a function of the content of Z fibers in the associated area of the textile preform to be made and of a rotation of the support tooling.

2. The method according to claim 1, wherein the support tooling is rotating about an axis of rotation (580) and the method comprises a mathematical projection (421) of the points of passage determined in a reference plane (540, λ) fixed or movable relative to the support tooling and comprising the axis of rotation.

3. The method according to any one of claims 1 or 2, further comprising making (409) a mesh (510) of the geometry of the textile preform to be made, the determination of all the triplets of coordinates (x, y, z) being performed on this mesh.

4. The method according to any one of claims 1 to 3, wherein the support tooling has a non-axisymmetric and / or non-through shape.

5. A method for manufacturing (600) a textile preform by needling comprising determining (610) a program of displacement and orientation of a needling head according to any of claims 1 to 4 and manufacturing by needling (620) the textile preform on support tooling, whose shape corresponds to that of the textile preform to be made, using a needling head programmed according to the determined program.

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