FR2596697A1 - Process and device for continuously laying down reinforcing members for strengthening flexible elongate bodies - Google Patents

Abstract

Process and device for the manufacture of reinforcing members for strengthening flexible elongate bodies. The process for laying down reinforcing-member reinforcement bars for reinforced bodies is characterised in that the said bars 10 are grouped together 21 on a support 1 or 22 in order to constitute the single unit 23. The said bars are removed from this support 22 before being laid down on the core 20 in order to form the reinforcing member. The support includes at least as many grooves as bars grouped together. These grooves are suitable for limiting the movements of the bars. The process enables a large number of bars to be laid down simultaneously whilst limiting the number of reels on the armouring machine. Bars made from reinforced plastic can be moulded in a suitable support. The invention applies especially to flexible pipes used in the oil industry.

Description

The present invention relates to a method and a device making it possible to easily place inverting reinforcement bars in bodies comprising reinforcements of reinforcement.

More particularly, the present invention relates to the manufacture of reinforcing plies of bodies of revolution such as a flexible pipe whose plies are composed of a large number of reinforcing bars.

Indeed, it has been shown in French patent FR-A 2,210,266 the interest for the flexibility of the reinforced flexible conduits and for the reinforcement plies resistant to the traction forces, to use curved reinforcement bars whose moment of inertia of the cross section with respect to an axis passing through its center of gravity and perpendicular to the radius of curvature to be greater than all the other moments of inertia of the section with respect to another axis passing through the center of gravity.

Such a requirement therefore requires, for example when using profiles of rectangular section, that the height of the curved bar (dimension of the straight section along a radius) is greater than its width (dimension of the straight section according to a perpendicular to the radius). However, as the thickness of the reinforcement plies or the height of the reinforcement bars is imposed, this implies: a reduction in the thickness of the bars constituting the ply, or even an increase in their number.

Thus, an increase in the number of bars or wires results in an increase in the number of coils supplying these bars, of equipment and of settings.

Indeed, if we try to place several threads side by side on the same reel, experience shows that we get skeins, in a short time, when we unwind.

It is moreover necessary that the bars are formed very exactly in bending before laying to accept to be put in place without lying down.

The method and the device according to the present invention make it possible in particular to preserve the advantages of the wires that are taller than they are wide, while avoiding the disadvantages of their laying.

The present invention makes it possible, in particular, to arm the tube from a conventional armeuse, without costly modification or the need for high precision adjustment.

The present invention uses an elongated profiled support which keeps the reinforcement bars parallel to one another and in the same orientation, so as to constitute a unitary assembly which is very easy to handle, allowing the rewinding of the bars on the reels of the armeuse, their unwinding. , and their laying on the body lengthens flexible with great ease and security. By orientation is meant that all the centers of curvature of the curved bars located in any cross section of the support Are located on the same side of the support (either above or below).

The reinforcement bars can be assembled by the profiled support for example: either at the time of their preforming or just after if they are metal bars for example of steel, or at the time of the manufacture of the bars, for example when these are made of plastic reinforced with filaments with high resistance to tensile forces.

The unitary assembly thus composed is first rewound before being placed on the armeuse.

In fact, when curved bars of reinforced plastic are produced, it is possible to simultaneously produce a certain number of them in a single-piece mold and to use this mold as a support for the bars for stranding reinforcing plies.

This avoids, in this case, an additional operation of laying a support before stranding and increases the benefits linked to the use of a mold having been used for the simultaneous manufacture of several bars.

The benefits of such a mold, composed of several grooves extending longitudinally which are filled with filaments impregnated with plastic, are due to the increase in the productivity of the manufacturing machine.

This is in particular due to the fact that producing several bars simultaneously increases the production of bars with a covering surface (product of the flow in cumulative length by the width of the bars), since the manufacture of the bars is generally carried out on a drum whose speed circumferential is limited by the fiber impregnation technique itself imposed by economic considerations, and this results among other things by better occupancy of the machines and better manufacturing costs.

The curved bars produced in such a mold can be made, for example, of stabilizable plastic material reinforced with filaments with high resistance to tensile forces such as glass fibers, carbon or organic material. By stabilizable material is meant the bodies which can take a stable form by a physical or chemical process such as fusion with cooling or crosslinking. Thermoplastic, thermosetting, elastomeric materials are, for example, stabilizable materials.

The method according to the invention consists in starting from one or more unitary assembly (s), placed on one or as many coils as necessary of the armourer, consisting of reinforcement bars connected by the support, to unwind these assemblies , to place them as one puts a strip or a wide profile on the core of the pipe to be filled, and to remove the support while the bars no longer risk entangling between them.

For the metal reinforcement bars, although this requires an additional operation (the assembly of the bars on a profiled support comprising several grooves), it is, in certain cases, very advantageous for a certain number of bars to form a unitary assembly at the time of their pose. Thus, when there are many bars to be twisted simultaneously, this makes it possible in particular to reduce the number of coils on the armeuse.

More particularly in the manufacture and use of bars of reinforced plastic, but without the use of this type of support being limiting, the support can be profiled and elongated and include substantially parallel grooves extending along the axis longitudinal so as to allow the molding of the bars at least in the section of the grooves. At least one throat can only be partially filled.

 The invention provides a method of continuously laying reinforcements for flexible elongated bodies, the reinforcements being made up of several curved reinforcing bars. The method according to the invention is characterized in that the laying machine is supplied with at least one unitary assembly composed of several bars grouped on a support and in that the support is removed during the laying bars for the formation of armor.

The bars can be tensioned before and during their installation.

We can perform the separation of the support bars in an area where the bars, out of the support or present in the support, are stretched.

The bars can be removed from the support before they constitute the reinforcement.

Before feeding the laying machine with the unitary assembly, the bars making up the assembly may be grouped on a support.

We can group the bars making up the unitary assembly, once they have been bent.

The invention also provides a device for continuously placing reinforcements for reinforcing flexible elongated bodies using at least one unitary assembly composed of several bars. reinforcement grouped by a support. This device is characterized in that it comprises means making it possible to separate the reinforcement bars from the support.

Of course this operation is carried out at a time when the risks of entanglement of the bars between them are eliminated. This occurs in particular once the bars are placed on the elongated body, or when the bars are tensioned before they are placed on the elongated body or when they are close enough to the elongated body so that they can no longer become entangled between them .

The device may include means for storing the support once it has been used for installation.

The device may include means for storing and supplying the unitary assembly for the installation of its bars.

The device may include means for tensioning the bars during their installation.

The tensioning means may act at the level of the storage and supply means of the unitary assembly.

The device may include a bar arrangement grid for the constitution of the frame.

The invention further provides support for grouping bars and holding them in a certain direction. This support is characterized in that it is composed of several disjoint elements.

The invention is illustrated by the appended figures where - Figure 1 is a cross-sectional view of a support now
bars which is used for their installation in the making of
reinforcing reinforcement plies, - Figure 2 shows schematically a method of manufacturing bars in
stabilizable plastic inside a mold support, - Figure 3 shows schematically, seen along the axis of the flexible elongated body
(profile), a method of laying, according to the invention, bars for the
manufacture of reinforcing plies, and - Figure 4 shows schematically, seen from the front, a laying process according to
the invention, illustrated by FIG. 3.

In FIG. 1, the reference 1 designates a support holding the bars 10 which make up a reinforcing ply of an elongated reinforced body.

The support has at least as many grooves extending longitudinally as it contains bars. The bars are placed inside the grooves. The sections of the grooves are adapted to those of the bars so as to limit the movements of the bars.

The bars are oriented as they will be placed on said body. If these bars are bent the centers of their osculating radius are all on the same side of the support.

Until the moment when we want to separate them, the bars can be kept in their support either by temporary joining, for example by means of a bonding or obstacle (s) or wedging, the effect disappears beyond a certain stress threshold, that is to say naturally for those which are curved and which are in a support where one or more other bars are secured. The support for the bars is disconnected, which may or may not be integral with it, for example mechanically with traction and / or torsion.

Indeed, it appears that when the curved bars of reinforced stabilizable plastic are produced inside a mold support (fig. 2), it may suffice that one bar, such as the central bar of the support, or several bars, such as the end bars of the support are joined to the support so that the other bars are held there naturally. The support, deforming like the integral bar or bars, follows the movement of the other bars and keeps them (nen) t in their respective grooves despite the forces exerted during stranding, in fact the different bars being supposed to have similar mechanical behavior .

The grooves of the support may include asperities of shapes preventing the bars from coming out, such as a constriction of the groove at its upper level or opening. The support being elastic, a bending of longitudinal axis produces the opening of the grooves and allows the placed bars to come out at the chosen time.

In the case of curved bars of reinforced plastic produced inside a support mold, this can be made of polyamide 11 (generally designated by the brand
Rilsan) which has the advantage of being suitable for molding and laying of profiled bars, of being demolded from several profiles at the same time and of being able to be possibly reused.

The bars, immobilized in the support but not integral with the latter, may be covered with a non-stick product, such as a release agent of the type common in the plastics industry, in order to facilitate the release of the bars at the desired time.

FIG. 2 schematically illustrates a process for manufacturing curved bars 10 made of reinforced stabilizable plastic material inside a support mold 1.

The comb 1, coming from the coil 2 passes between the tensioning rollers 9 and guide 8 before being wound on the mandrel 3. In the preferred embodiment, the largest face of the mold rests on the mandrel, but we can easily imagine that it is the tops of the partitions which lean against the mandrel.

The shaft 3a of the drum 3 is connected to means for driving this drum in rotation, which for example comprise a chain 4 meshing on a toothed pinion 5 wedged on the shaft 3a.

The shaft 3a rests on the bearing 6 by means of bearings, this bearing being integral with a chassis 7.

 The support mold 1 has several longitudinal grooves, which as the winding on the drum 3 is filled with high resistance filaments, or rovings, previously impregnated with a stabilizable plastic material capable or not of adhering to internal walls of the grooves according to their position in the mold and as required, and capable of adhering to said filaments. This mixture of filaments and stabilizable plastic will form after stabilization of the reinforcement bars.

After the lining of the mold, it passes into an oven 14 where it is subjected to a heat treatment capable of stabilizing the reinforced plastic that it contains.

The oven 14 is supplied with energy by any suitable means, such as for example the cable 14a, if electric heating means are used.

After at least partial stabilization of the plastic, the unitary assembly composed of the support mold 1 and the bars 10 is released from the mandrel to be either directly used for stranding or stored on a reel adaptable to the armeuse such as the supply reel 26 (Fig. 3).

The joining of the bars 10 to the support mold 1 may be carried out for example by gluing or by mechanical anchoring. We can use SCOTCH-WELD 2216 B / A epoxy glue which is a registered trademark by the company Minnesota Mining and Manufacturing, in the proportions recommended by the manufacturer. We can measure the adhesion means, so that from a selected stress threshold, the bars no longer adhere to the support mold.

A counterform, as described in French patent FR-A-2,312,356, can be used to achieve a good distribution of the filaments 11 in the grooves of the mold.

Figure 3 which is a view along the axis of the elongated body during stranding, shows schematically a method of laying, according to the invention, bars for the manufacture of reinforcing plies with recovery of the support before the bars reach the core 20 of the elongated body.

The frame of the elongated body is placed in the case of the figure using four groups of bars 21 from four unitary assemblies 23. It is easy to envisage a greater or a smaller number of groups of bars or unitary sets. This number depends on the number of bars per group and the number of bars making up the reinforcement.

The unitary assembly 23, composed of the group of bars 21 and the support 22 which keeps them oriented, is stored on the supply reel 26.

The unitary assembly 23 passes over an orientation roller 24 which makes it possible on the one hand to maintain a substantially constant laying angle of the bars and on the other hand to release the bars from their support 22.

The coil 26 is braked in rotation by a suitable means such as a strap or belt brake so as to maintain tension on the unitary assembly and the bars. The purpose of this tension is in particular to prevent the bars from forming tangles and possibly to offer resistance to the forces when the support is removed. These braking means may be controlled by the tension exerted on the bars and / or on the unit assembly.

It will be possible without drawback otherwise to tension the unit assembly and / or the bars, for example, using two retarder rollers.

While the group of bars 21 is supported by the roller 24, the support 22 bypasses a sector of the roller 24 in order to release the bars with minimum effort and to avoid any deformation thereof.

The bars are released through the openings in the grooves in the support. These openings being directed towards the space delimited by the bars and not containing the centers of the osculating circles of the curved bars.

The support 22 once separated from the group of bars 21 is wound on the reel 25.

The support 22 can without drawbacks be recovered, possibly after cleaning, for the manufacture of a new unitary assembly.

All the tensioned and oriented bars necessary for constituting the reinforcement ply, after having been extracted in groups 21 from each of the supports 22, are conveyed to the core 20 where they are placed in groups so as to produce the reinforcement, thanks to the relative rotation of the bars around the core.

In the figure, the core is fixed and the four bars supply assemblies 21, 22, 23, 24, 25, 26 are placed in a support cage 27 which is supported by the rollers 28 rotating around the core 20. We would have very could have designed a stationary cage 27 and a rotating core. The movement of the cage relative to the core being a right or left screwing depending on the direction of the winding step.

The bars can possibly be tightened together either when they constitute the groups 21, or once on the mandrel, as for example with the die 30 shown in FIG. 4.

FIG. 4 shows diagrammatically, seen from the front, the same laying method according to the invention as that illustrated in profile view in FIG. 3.

To allow the stranding of the core 20 by the bars arranged in four groups, the core is animated by an axial translation allowing the laying of the bars over its entire length.

The separating grid 29, placed just before the bars reach the core 20, ensures the correct positioning of the bars between them and thus their good arrangement in the reinforcing frame.

The openings in the support grooves can also be directed towards the centers of curvature of the bars. Therefore, the roller 22 which in Figure 3 is inside the bars (the inside being the space delimited by the bars and containing the centers of curvature of the curved bars) must be outside the bars (the outside being the space delimited by the bars and not containing the centers of curvature of the curved bars) and in the same way the support 22 will bypass a sector of the roller 24 to allow the release of the bars which are contained in the support.

FIG. 4 illustrates the production of a reinforcing reinforcement, the pitch of the bars of which is on the right, but it is possible in the same way to carry out a pitch on the left for example by modifying the orientation, relative to the axis of the core, of the power assemblies and by changing the direction of either translation or rotation of the core.

In the preferred stranding method and illustrated in FIGS. 3 and 4, the bars are released from the support before the bars reach the core. It will not depart from the scope of the present invention by removing the support from the bars once the unitary assembly is placed on the core.

 If the bars are separated before they reach the reinforcement, these can be either inside or outside the bars.

It will not depart from the scope of the present invention to bend groups of bars placed in a support, as could be done with metal reinforcing bars assembled on a support.

The support used for grouping the bars can hold the bars either over their entire length or on certain sections of their length. In the latter case, the support is therefore composed of several disjointed elements which maintain the orientation and grouping of all the bars.

Claims (13)

1. A method of continuously laying reinforcements for flexible elongated bodies, said reinforcements being constituted by several curved reinforcing bars, characterized in that the laying machine is supplied with at least one unitary assembly (23) composed of several grouped bars (21) on a support (22) and in that one proceeds to the removal of said support during the laying of said several bars for the formation of said frame. 2. Method according to claim 1, characterized in that the bars are stretched before and during their installation. 3. Method according to one of claims 1 and 2, characterized in that one carries out the separation of the bars (21) of said support (22) in an area where the bars, exits from said support or present in said support, are stretched . 4. Method according to one of claims 1 and 3, characterized in that the bars (21) of said support (22) are removed before these constitute the reinforcing reinforcement. 5. Method according to claim 1, characterized in that before supplying the laying machine with the unitary assembly (23), said bars comprising said assembly are grouped on a support (22). 6. Method according to claim 5, characterized in that said bars composing said unitary assembly, once they have been bent. 7. Device for continuously placing reinforcements for reinforcing flexible elongated bodies using at least one unit assembly (23) composed of several reinforcing bars (21) grouped together by a support (22), characterized in that said device comprises means (24) for separating said reinforcement bars from the support. 8. Device according to claim 7, characterized in that said device comprises means (25) for storing said support (22) once it has been used for laying.  9. Device according to claim 7, characterized in that said device comprises storage means (26) and supply of said unitary assembly for the installation of its bars. 10. Device according to claim 7, characterized in that said device comprises means for tensioning the bars during their installation. 11. Device according to claim 10, characterized in that said tensioning means act at the storage means (26) and supply of said unitary assembly. 12. Device according to claim 7, characterized in that said device comprises an arrangement grid (29) of the bars (21) for the constitution of the frame. 13. Support for grouping bars and keeping them in a certain direction, characterized in that the support is composed of several disjoint elements.