Weaving installation

Abstract

The invention relates to a weaving installation (10) comprising: - a plurality of creels each supporting several warp thread bobbins, - a weaving loom present downstream of the plurality of creels in a weaving direction (Dt), the weaving loom comprising a harness (30) in which the warp threads are organized into a plurality of layers and columns that are parallel to one another, - a condensation board (10) present between the plurality of creels and the harness (30), said condensation board (10) comprising a plurality of eyelets, each eyelet being passed through by a warp thread of a bobbin of a creel of the plurality of creels. The condensation board (10) for the warp yarns has the shape of a circular arc, the circular arc being inscribed in a circle (C), the center (O) of which is located between said condensation board (10) for the warp yarns and the harness (30).

Description

Description Title of the invention: Weaving installation Technical Field

[0001] The present invention relates to a three-dimensional weaving installation for fibrous structures, in particular enabling the weaving of large structures. Previous technique

[0002] A three-dimensional weaving installation for fibrous structures typically includes a Jacquard-type loom whose harness has control or heddle wires and warp wires arranged in a plurality of parallel layers and columns, such as that described in document FR 3 074 195 Al, a rack where the warp wire bobbins are arranged in a set of creels, and a warp wire condensation board.

[0003] The warp condenser board is positioned between a rack containing the heddles and the harness. This board gathers all the warp threads from the heddles into a compact unit upstream of the loom. Typically, the warp condenser board is a flat board with holes, called eyelets, through which the warp threads pass.

[0004] Since the width of the fibrous structure to be woven is linked to the number of warp threads, it determines the gaps in the warp's crenellations, that is, its width. The greater the gaps in the warp's crenellations, the greater the friction of some warp threads against the walls of the eyelets they pass through. For an installation with a rack placed at a determined distance from the warp thread condensation board, there is then a maximum width of fibrous structure to be woven beyond which the friction of the warp threads as they pass over the condensation board causes deterioration or even breakage of the latter.

[0005] It would therefore be desirable to have a solution allowing the weaving of large fibrous structures while ensuring guidance of the warp threads from the creels to the harness without damage or breakage of the latter. Description of the invention

[0006] To this end, the present invention proposes a weaving installation comprising: - a plurality of canters, each supporting several reels of warp thread, - a loom located downstream of the plurality of warp threads following a weaving direction, the loom comprising a harness in which the warp threads are arranged in a plurality of layers and columns parallel to each other, - a condensation board present between the plurality of canters and the harness, said condensation board comprising a plurality of eyelets, each eyelet being crossed by a warp thread from a bobbin of a canter of the plurality of canters, characterized in that the condensation board of the warp threads has an arc-shaped form, the arc-shaped form being inscribed in a circle whose center is located between said condensation board of the warp threads and the harness.

[0007] The circular geometry of the warp condenser board minimizes friction between the warp threads and the walls of the eyelets at the board's ends. This warp condenser board significantly reduces the width of the warp thread bundle from the creels. Consequently, the number of warp threads used for weaving can be increased, particularly in width, without risk of damage. Thus, the invention provides a weaving installation that enables the weaving of wide fibrous structures while ensuring that the warp threads from the creels are guided to the harness without damage or breakage.

[0008] According to a particular feature of the weaving installation, the condensation board comprises a plurality of adjacent flat sections, each flat section of the plurality of flat sections receiving yarns of chain originating from at least one canter of the plurality of canters following an angle of incidence defined with respect to the normal to the surface of the plane section, the angle of incidence being less than 5°.

[0009] This allows for low friction between the warp threads and the edges of the eyelets. Indeed, the frictional force exerted by a warp thread on the eyelet wall is minimal when the warp thread arrives in a direction normal to the plane of the eyelet.

[0010] According to another particular feature of the weaving installation, the distance separating the condensation board from the harness and the distance separating said condensation board from the plurality of creels are between 2,000 mm and 45,000 mm.

[0011] This allows for a satisfactory weaving tension on the warp threads without applying excessive tensile stress that could damage them.

[0012] According to another particular feature of the weaving installation, the circle in which the warp thread condensation board is inscribed has a diameter between 1520 mm and 2520 mm.

[0013] This ensures that the angle of incidence of the warp threads on the condenser board is less than the angle beyond which the warp threads would be damaged by friction as they pass through the eyelets of the condenser board. Furthermore, this ensures that the warp threads exit the condenser board with an acceptable deviation from the weaving direction.

[0014] According to another particular feature of the weaving installation, the eyelets of the warp yarn condensation board have a coating of a material having a low coefficient of friction, chosen from: ceramic, polyacetal copolymer (POM-C).

[0015] This further minimizes wear on the warp threads as they pass through the eyelets of the condensation board.

[0016] According to another particular feature of the weaving installation, the angle formed by two adjacent flat sections located on the edges of the warp yarn condensation board is less than or equal to 180°.

[0017] This ensures low friction of the warp threads on the edges of the 1000 eyelets.

[0018] According to another particular feature of the weaving installation, the angle formed by two adjacent flat sections located in the central part of the warp yarn condensation board is equal to 180°. Brief description of the drawings

[0019] [Fig. 1] Figure 1 is a schematic view of the weaving installation according to one embodiment of the invention,

[0020] [Fig. 2] Figure 2 is a schematic perspective view of the warp thread condensation board 10 of Figure 1,

[0021] [Fig. 3] Figure 3 is a schematic perspective view showing the structure of the warp wire condensation board 10 of Figure 2. Figure 3 is an enlargement of Box II of Figure 2. Description of the implementation methods

[0022] The invention is now described by means of figures, which are provided for descriptive purposes to illustrate certain embodiments of the invention and which should not be interpreted as limiting the latter.

[0023] Figure 1 schematically illustrates a weaving installation according to one embodiment of the invention. The weaving installation comprises a rack 20, a loom harness 30, and a warp thread condensation board 10. The harness 30 is located downstream of the rack 20 along the weaving direction Dt. The rack 20 includes creels 21, 22, 23, 24, each supporting several bobbins of warp threads. In Figure 1, only the warp threads emerging from the ends of each creel are shown: the warp threads warp threads 31 and 32 from mill 21, warp threads 33 and 34 from mill 22, warp threads 35 and 36 from mill 23, and warp threads 37 and 38 from mill 24. The warp threads are for example made of glass or carbon.

[0024] In this description, the warp thread deflection α corresponds to the angle between the normal direction N30 relative to the plane of the harness 30, this direction coinciding with the weaving direction Dt, and the direction at the entrance of the harness 30 of a warp thread located at the end of the weaving bundle 31 or 38, the angle α being typically between 0° and 7°. The width of the warp thread condensation board 10 is limited by the value of the angle α. An excessively large angle α causes the harness to gradually separate due to the warp columns as one approaches its edges, resulting in significant friction of the warp threads at the reed (the component located at the front of the harness for beating the inserted weft threads).

[0025] According to the invention, the warp wire condensation board 10 has an arc-shaped circular form, the arc of the circular being inscribed in a circle C whose center O is located between said warp wire condensation board 10 and the harness 30.

[0026] A warp thread condensation board 1 is shown in Figure 1 to illustrate the effect of the curvature of the warp thread condensation board 10 on the angle of incidence of the warp threads w. The warp thread condensation board 1 is not included in the weaving installation according to the present invention. Said board 1 corresponds to the warp thread condensation board 10 laid flat, its width being equal to the length of the arc of a circle in which the warp thread condensation board 10 is inscribed.

[0027] The angle of incidence of the warp threads Pi on the developed condensation board 1 corresponds to the angle between the direction exiting the rack 20 of a warp thread located at the end of the weaving bundle 31 or 38 and the normal direction Ni with respect to the plane of the developed condensation board 1, this direction coinciding with the weaving direction Dt. The angle of incidence of the warp threads 10 on the condensation board 10 corresponds to the angle between the direction at the exit of the rack 20 of a warp thread located at the end of the weaving bundle 31 or 38 and the normal direction Nio with respect to the plane of the eyelet through which said warp thread passes. It can be seen that, thanks to the arc-shaped form of the condensation board 10, the angle of incidence of the warp threads Pio on the condensation board 10 is much less than the angle of incidence of the warp threads Pi on the developed condensation board 1. This significantly reduces the frictional force exerted by the warp threads on the wall of the eyelets.

[0028] Furthermore, compared to a flat condensation board like the condensation board developed 1, which is typically used in the prior art, the warp yarn condensation board 10 significantly reduces the width of the warp yarn bundle from the creels 21, 22, 23, 24. The number of warp yarns used for weaving can then be increased, particularly in width, without risk of damage to said yarns. The weaving installation according to the present invention therefore allows the weaving of wider fibrous structures than in the prior art, while ensuring that the warp yarns are guided to the harness 30 without damage or breakage.

[0029] The distance L1 separating the warp board from the warp threads 10 and the harness 30, and the distance L2 separating said warp board from the warp threads 10 and the creels 21, 22, 23, 24, are determined to ensure satisfactory weaving tension on the warp threads without applying excessive tensile stress that could damage them. Furthermore, the distance L1 separating the warp board from the warp threads 10 and the harness 30 is greater than a minimum distance to ensure the permissible angle α.

[0030] For example, the distance L1 separating the condensation board from the warp threads 10 of the harness 30 and the distance L2 separating said condensation board from the warp threads 10 from the creels 21, 22, 23, 24, are determined so as to define a cumulative length L1+L2 between 2,000 mm and 45,000 mm.

[0031] The diameter of circle C is preferably between 1520 mm and 2520 mm.

[0032] By way of non-limiting example, a weaving installation according to the invention comprising a warp yarn condensation board 10 inscribed in a circle C of diameter of 2020 mm with a cumulative length L1+L2 of the distance L1 separating the warp yarn condensation board from the harness and the distance L2 separating said warp yarn condensation board from the creels 21, 22, 23, 24, between 2,000 mm and 45,000 mm allows 6500 yarns to be woven over a width of 890 mm.

[0033] According to a particular feature, the warp thread condensation board 10 comprises adjacent flat sections 11, 12, 13, 14, and 15. In the example described here, the flat sections 11 and 15, located at the ends of the warp thread condensation board 10, each receive warp threads from the creels positioned at the ends of the rack 20. Flat section 11 receives warp threads from creel 21, including warp thread 31, and flat section 15 receives warp threads from creel 24, including warp thread 38.The flat sections 12, 13, 14, which are not located at the ends of the warp thread condensation board 10, each receive warp threads from two adjacent creels: the flat section 12 receives warp threads from creels 21 and 22, including warp threads 32 and 33; the flat section 13 receives warp threads from creels 22 and 23, including warp threads 34 and 35; and the flat section 14 receives warp threads from creels 23 and 24, including warp threads 36 and 37. Other configurations for supplying warp threads to the flat sections from the creels can, of course, be considered.

[0034] The flat sections 11, 12, 13, 14, 15 of the warp thread condensation board 10 receive warp threads at an angle of incidence Pio of less than 5°. This ensures low friction of the warp threads on the edges of the eyelets 1000.

[0035] The angle A formed by two adjacent plane sections is preferably less than or equal to 180°. This ensures low friction of the warp threads on the edges of the eyelets 1000. The angle A formed by two adjacent plane sections located on the edges of the warp thread condensation board 10, such as plane sections 11 and 12 or 14 and 15 in Figure 1, is preferably less than 180°. The angle A formed by two adjacent plane sections located in the central part of the warp wire condensation board 10, such as plane sections 12 and 13 or 13 and 14 in Figure 1, can be equal to 180°.

[0036] Figure 2 schematically illustrates the warp yarn condensation board 10 of the weaving installation shown in Figure 1. The warp yarn condensation board 10 is held in position by a support element 50. The warp yarn condensation board 10 comprises the adjacent flat sections 11, 12, 13, 14, 15 held together by connecting rods 300.

[0037] Figure 3 is an enlargement of Inset II of Figure 2. Figure 3 schematically illustrates the structure of the planar section 13 of the warp yarn condensation board 10 shown in Figure 2. The planar section 13 comprises subsections 131, 132, and 133, each having rows of eyelets 1000 through which the warp yarns pass. Subsections 131, 132, and 133 are fastened to each other by means of connecting elements 200. The planar section 13 is held against the planar sections 12 and 14 by fixing rods 300 and sublayer interface connecting elements 400. The structure of the other sections 11, 12, 14, and 15 is identical to that of the planar section 13 just described.

Claims

Demands

1. Weaving installation (10) comprising: - a plurality of canters, each supporting several reels of warp thread, - a loom located downstream of the plurality of warp threads along a weaving direction (Dt), the loom comprising a harness (30) in which the warp threads are arranged in a plurality of layers and columns parallel to each other, - a condensation board (10) having between the plurality of creels and the harness (30) said condensation board (10) comprising a plurality of eyelets (1000), each eyelet being crossed by a warp thread from a bobbin of a creel of the plurality of creels, characterized in that the condensation board of the warp threads (10) has a circular arc shape, the circular arc being inscribed in a circle (C) whose center (O) is located between said condensation board of the warp threads (10) and the harness (30) and in that the condensation board (10) comprises a plurality of plane sections adjacent to each other, each plane section of the plurality of plane sections receiving warp threads from at least one creel of the plurality of creels at an angle of incidence (Pio) defined with respect to the normal (Nio) of the surface of the plane section, the angle of incidence being less than 5°.

2. Installation according to claim 1, wherein the distance separating the condensation board from the harness (L1) and the distance separating said condensation board from the plurality of canters (L2) are between 2,000 mm and 45,000 mm.

3. Installation according to claim 2, wherein the circle (C) in which the warp wire condensation board (10) is inscribed has a diameter between 1520 mm and 2520 mm.

4. Installation according to any one of claims 1 to 3, wherein the eyelets (1000) of the warp thread condensation board (10) have a coating of a material having a low coefficient of friction, selected from one of the following materials: ceramic, polyacetal copolymer (POM-C).

5. An installation according to any one of claims 1 to 4, wherein the angle (A) formed by two adjacent plane sections located on the edges of the warp thread condensation board is less than or equal to 180°.

6. An installation according to any one of claims 1 to 5, wherein the angle (A) formed by two adjacent plane sections located in the central part of the warp thread condensation board is equal to 180°.

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