EP3728713B1 - Method and system for twisting tyre cords with a controlled tension - Google Patents

Description

The present invention relates to the field of the production of wire elements, called “cabled”, by assembly by twisting of several continuous strands, in particular of textile yarns.

The present invention relates more particularly to the application of such an assembly method to the manufacture of reinforcing wire elements which are intended to enter into the constitution of tires, in particular pneumatic tires for vehicles.

It is known to produce wire elements by interlacing several strands with each other, by twisting, by means of a twisting device of the ring loom type.

Generally, the strands are stored on input spools, from which each strand is unwound to an assembly point, at which said strand is interlaced with the other strand(s) to form a wired element, called " cable ".

The strands may have been previously subjected, before being unwound and assembled, to a twisting operation, in order to present a certain pre-twist around their axis.

It is known to provide, along the strand in question, a motorized drive device, such as a capstan, which is placed between the input reel and the assembly point in order to give the strand in question a speed of predetermined advance.

Furthermore, the wire element is itself driven, downstream of the assembly point, by a motorized output reel, on which said wire element is wound as it is manufactured.

Within a ring loom, there is also, between the assembly point and the motorized output spool, a slider which is mounted to slide freely on a ring, coaxial with the axis of rotation of the output spool. output, and through which the wired element passes before joining the coil.

Thus, the rotation of the coil generates traction on the wired element, which in turn induces a stress on the slider which, by reaction, travels in rotation along the ring and thus causes a twisting movement which generates the intertwining of the strands at the assembly point.

In practice, it is necessary to empirically determine an appropriate combination between, on the one hand, a reel rotation speed at which the motorized output reel is rotated, and, on the other hand, for each strand, a suitable advance speed. , as imparted by the capstan upstream of the assembly point, so that the subtle dynamic balance of the cursor movement, which takes place when applying this combination of speeds, makes it possible to obtain a wire element which has the desired qualities, in particular in terms of mechanical properties.

It is therefore sometimes difficult to develop such methods of manufacturing wired elements, and in particular to determine the capstan and output spool speed settings which guarantee obtaining the desired properties of the wired element.

In addition, even when such settings are suitably determined, there remains a risk of drift related to the sensitivity of the process to variations in the conditions of implementation, and in particular to the sensitivity of the process to the fluctuations of the frictions which operate within the different mechanical components of the ring loom, for example at the level of the unwinding elements or else at the level of the slider.

Similarly, the behavior of the slider is sensitive to the degree of filling of the output spool, insofar as the orientation of the wired element which leaves the slider to join the spool varies depending on whether the output spool is very sparsely filled , in which case the wire element, which has a small turn diameter, is oriented quasi-radially with respect to the axis of the coil, and therefore quasi-radially with respect to the axis of the ring which carries the slider , or depending on whether the output coil is on the contrary filled, in which case the wire element, which has a large turn diameter, is oriented almost tangentially to the outer perimeter of said coil.

Of course, the sensitivity of the method to the conditions of implementation of the cursor is potentially detrimental to the reproducibility of the manufacturing method.

The objects assigned to the invention therefore aim to remedy the aforementioned drawbacks and to propose a new method and a new installation for manufacturing a wire element by interlacing strands, the implementation of which is facilitated, and which has improved robustness and good reproducibility.

Another object assigned to the invention aims to propose a new method and a new installation for manufacturing wire elements which has a certain versatility, by making it possible to carry out on request, and in a reproducible manner, a wide variety of manufacturing ranges of wireframe elements, with distinct properties.

The objects assigned to the invention are achieved by means of a method of manufacturing a wire element by interlacing at least a first strand and a second strand distinct from the first strand, according to claim 1.

The inventors have in fact observed that, in a certain number of situations, and in particular depending on the nature of the strands used, the properties of the manufactured wire element could closely depend on the tension of the strands at the time of assembly.

Advantageously, the implementation of a regulation by the tension of one or more strands, rather than by speeds, therefore makes it possible to finely control, and in a reproducible manner, the properties of the fabricated wire element.

In addition, such voltage regulation makes it possible to compensate at least in part for any friction fluctuations in the twisting installation, which makes the method much less sensitive to said friction fluctuations, in particular to the friction fluctuations which occur upstream of the assembly point.

The method according to the invention is therefore particularly robust and reproducible.

In addition, such a method not only makes it possible to carry out better controlled industrial production, but also to facilitate the transition between the development and the industrialization of a new wired element.

Indeed, it is possible, by applying this method, to develop first of all, on an installation offering voltage regulation in accordance with the invention, a wired element with well-defined properties, by fixing a voltage specification of one or more strands, then then to deduce therefrom, empirically, by measuring the speeds which result from the application of voltage regulation, corresponding settings intended for speed regulation, which, reciprocally, will make it possible to obtain the desired voltage(s) with a reasonable degree of precision and reproducibility, and which can advantageously be applied to existing industrial machines for mass production which do not have voltage regulation, but only voltage regulation speed.

According to a particularly preferred possibility, the method makes it possible to simultaneously control one strand in tension and the other strand in speed. The invention makes it possible to select, by means of a selector, for at least one of the strands or even for each strand of the wired element, a voltage control or a speed control, which in particular offers multiple possibilities. combinations when searching for new wireframe elements with particular properties.

It will also be noted that, advantageously, the interlacing which occurs at the assembly point makes it possible in a way to "freeze" the properties which have been conferred on the wire element thanks to the tension and/or speed servo-controls chosen for the different constituent strands of said wired element, and therefore to substantially retain the properties and advantages procured by the specific combination of these chosen controls.

In addition, the method according to the invention is perfectly applicable to the manufacture of a wire element involving different lengths of strands from one strand to another, and in particular to the manufacture of so-called "covered" wire elements. one strand of which forms a central core around which one or more other strands are wound helically.

Other objects, characteristics and advantages of the invention will appear in more detail on reading the description which follows, as well as with the aid of the appended drawings, provided for purely illustrative and non-limiting purposes, among which:

There figure 1 illustrates, in a schematic view, an example of an installation, of the ring loom type, making it possible to implement the manufacturing method according to the invention.

There figure 2 illustrates, in a schematic view, an arrangement of rollers in "trio" which can be used, depending on the configuration of the rollers and the path of the strand through said rollers, either as a motorized drive device to achieve speed regulation, or as a voltage monitoring device, to measure the voltage of the strand.

There picture 3 illustrates, according to a schematic perspective view, an example of a tension monitoring device using a wire guide, of the pulley type, mounted on an elastically deformable support formed by a cantilever beam.

The present invention relates to a method of manufacturing a wire element 1 by interlacing at least a first strand 2 and a second strand 3, said second strand 3 being distinct from the first strand.

The wire element 1 thus obtained is also called a "wired".

By "wireframe", is meant an element which extends longitudinally along a main axis, corresponding to the longitudinal direction, and which has a transverse section, perpendicular to the main axis, the largest dimension D of which is relatively small compared to to dimension L along the main axis. By “relatively low”, it is meant that L/D is greater than or equal to 100, preferably greater than or equal to 1000.

This definition covers wireframe elements 1 of circular cross-section as well as wireframe elements 1 of non-circular cross-section, for example of polygonal or oblong cross-section. In the case of wire reinforcement elements of non-circular cross-section, the ratio of the largest dimension D of the section to the smallest dimension d of the section may for example be greater than or equal to 20, preferably greater than or equal to 30 and more preferably greater than or equal to 50.

Typically, the wire element 1 may have a cross section whose largest dimension D is between 0.05 mm and 5 mm, or even for example between 0.2 mm and 2 mm, and, more particularly, whose section transverse is geometrically inscribed in a cylinder, centered on the main axis of the wire element, the diameter of which is between 0.05 mm and 5 mm, or even for example between 0.2 mm and 2 mm.

As an indication, said wired element 1 may have a continuous length L equal to or greater than 1 m, 10 m, 100 m, or even 1,000 m, and for example between 500 m and 100,000 m.

Similarly, each of the strands 2, 3 may have a cross-section whose largest dimension D is between 0.05 mm and 5 mm, or even for example between 0.2 mm and 2 mm, and, more particularly , whose cross section is geometrically inscribed in a cylinder, centered on the main axis of the wire element, whose diameter is between 0.05 mm and 5 mm, or even for example between 0.2 mm and 2 mm.

By way of indication, the strand 2, 3 considered may have a continuous length L equal to or greater than 1 m, 10 m, 100 m, or even 1,000 m, and for example between 500 m and 100,000 m.

The first strand 2, and/or the second strand 3, may be monofilament, that is to say made up of a single monolithic filament, or multi-filament, that is to say made up of a set of filaments forming a bundle.

The filament or filaments constituting the first strand 2, respectively the second strand 3, may be of any suitable nature.

Preferably, textile filaments will be used, preferably made of polymer material, for example Polyamide (Nylon ^™ ), Aramid, Rayon (fiber from wood cellulose), PolyEthylene Terephthalate (PET), etc., or in any combination of such polymer materials.

Of course, the method can be applied to the assembly of any number of strands 2, 3.

By way of example, the number of strands 2, 3 used to form the wire element 1 may be between two and twelve strands, and particularly preferably between two and four strands.

In particular, it will thus be possible to produce a wire element 1 with four strands, comprising a central strand forming a core and three peripheral strands wound around said core.

For simple convenience of description, we can, when necessary, refer to, and make a distinction between, a first strand 2 and a second strand 3, it being understood that we can assign and adapt mutatis mutandis to any which strand considered the characteristics described in connection with the first strand 2 or the second strand 3.

In particular, it will be noted that each of the implementation variants of the supply devices 6A, 6B, 6C, 6D, 6E represented on the figure 1 can be applied to the first strand 2, to the second strand 3, to any one of the strands used to make the wire element 1, or even to all of the strands used to make the wire element 1. Each strand depicted on said figure 1 therefore bears, for convenience of description, the double reference “2, 3”.

The present invention naturally relates to an installation 5 for implementing the method.

As will be seen in the following, said installation 5 may correspond to a ring loom which will have been improved by adding to it in particular a voltage servo unit 30, or voltage servo units 30, making it possible to control in closed loop the tension of the strand 2, 3 considered or, respectively, the respective tensions of the strands 2, 3 considered.

In a manner known per se, the method comprises a supply step (a) during which the first strand 2 and, respectively, the second strand 3 are conveyed to an assembly point 4 at the level of which the first strand 2 and the second strand 3 come together.

The installation 5 will comprise for this purpose a supply device 6 responsible for conveying the first strand 2 and, respectively, the second strand 3, up to an assembly point 4 at the level of which the first strand 2 and the second strand 3 come together.

In practice, and as illustrated in the figure 1 , the supply device 6 will preferably be arranged so as to allow the strand 2, 3 concerned to be unrolled and conveyed to the assembly point 4, from an input reel 7 on which said strand 2, 3 is initially stored.

It will be noted that one and/or the other of the strands 2, 3 intended for assembly may have undergone prior individual twisting, before their use by the installation 5, and thus form one or more "overtwists", stored each on its respective input coil 7.

The supply device 6 of the strand 2, 3 considered may advantageously comprise a motorized drive device 8.

Said motorized drive device 8 is located upstream of said assembly point 4, and is arranged to impart to the considered strand 2, 3 a so-called "advance speed" speed V_fwd in response to a drive instruction that the is applied to said motorized drive device 8.

Thus, the motorized drive device 8 makes it possible to drive the strand 2, 3, in a direction called "direction of transport" F , from the input coil 7 towards the assembly point 4.

By convention, it will be considered that the direction of transport F according to which the strand 2, 3 moves from the input coil 7 towards the assembly point 4, then beyond, corresponds to an upstream-downstream direction of movement .

Preferably, the motor drive device 8 will be formed by a capstan, as shown in the figure 1 .

In a manner known per se, such a capstan 8 may comprise two rollers 9, 10, including a motorized roller 9 and a free roller 10, around which several turns of the strand 2, 3 considered are wound, so as to carry out a drive of the strand 2, 3 by friction.

It is possible to provide, on the surface of the motorized roller 9 and/or of the idler roller, an anti-slip coating which improves the adhesion of the strand 2, 3 to the roller 9, 10.

As a variant, one could use, instead of a capstan, any type of suitable motorized drive device 8, for example a call trio 11, such as that illustrated in the picture 2 .

Such a call trio 11 comprises three rollers 12, 13, 14, including a planetary roller 12, preferably free, and two satellite rollers 13, 14, preferably motorized and synchronized, said rollers 12, 13, 14 being arranged so that the strand 2, 3 is driven by friction between said rollers, along a path in the form of Ω (capital omega).

In this configuration intended to drive the strand 2, 3 in displacement, the planetary roller 12 can preferably come into contact with the two satellite rollers 13, 14, and the cylindrical surface of the planetary roller 12 can be coated with a layer of non-slip rubber. , in order to improve the driving of said planetary roller 12 by the satellite rollers 13, 14.

Of course, the feed device 6 may comprise several separate motorized drive devices 8, each assigned to a different strand 2, 3.

Thus, it is possible to provide, in addition to a first motorized drive device 8 assigned to the first strand 2, a second motorized drive device 8, similar to the first motorized drive device but distinct from the latter, and assigned to the second strand 3, where appropriate a third motorized drive device 8 assigned to a third strand, etc.

The method also comprises an interlacing step (b) during which the first strand 2 and the second strand 3 are interlaced with each other, at the assembly point 4, so as to form an element wired 1 from said at least first and second strands 2, 3.

The interlacing can preferably be carried out by twisting so as to wind the second strand 3 around the first strand 2 in a helix, or the second strand 3 and the first strand 2 around each other, to form the element wired 1.

The installation 5 will therefore comprise an interlacing device 15, and more particularly a twisting device 15, responsible for interlacing the first strand 2 and the second strand 3 with each other, at the assembly point. 4, so as to form a wire element 1 from said at least first and second strands 2, 3.

The method will also comprise a step (c) of evacuation, during which the wire element 1 is routed from the assembly point 4 to an exit station located downstream of the assembly point 4, and, more preferably , during which said wire element 1 is wound on an output reel 16.

According to a possibility of arrangement, moreover known per se within an installation of the "ring loom" type, the interlacing device 15 may comprise a guide eyelet 17, for example made of ceramic, intended to guide the wired element 1 downstream of the assembly point 4, here directly downstream of the assembly point, as well as a ring 18 which is coaxial with the output coil 16 and on which a slider 19, which forms a crossing point of the wired element located downstream of the guide eyelet 17 and upstream of the output coil 16, is mounted in free sliding.

Thus, when the output coil 16 is driven in rotation on its axis, preferably vertical, by means of a motorized spindle 20, and thus exerts a traction on the wired element 1, while the supply of strands 2, 3 is ensured by the supply device 6, the slider 19 adopts a relative rotational movement around the output coil 16, which causes a twisting force of the wire element 1, and therefore the twisting of the strands 2, 3 at the assembly point 4, while guiding the progressive winding of said wire element 1 on the output spool 16.

Ring 18 is also moved back and forth in translation along the axis of output coil 16 so as to distribute the turns of wire element 1 over the entire length of the coil output 16.

Furthermore, the supply device 6 can preferably comprise a distributor 21 arranged to distribute the strands 2, 3 in space, and this in order to order the geometric configuration according to which said strands 2, 3 converge towards the point of assembly 4, which assembly point 4 is located downstream, here directly downstream, and more preferably just below, of said distributor 21.

The distributor 21 can be in the form of a support plate 22 which defines a plurality of passage points 23 each intended to guide one of the strands 2, 3 coming from the input coils 7 and/or the devices of motor drive 8.

The passage points 23 can be formed for example by holes, each preferably lined with a ceramic distribution eyelet, or even by guide pulleys.

The passage points 23 define predetermined gaps between the different strands 2, 3, so that, starting from the base represented by the support plate 22, the strands converge by following the edges of at least one polygon (in plan ), or even at least one polyhedron (in three dimensions), whose vertex corresponds to assembly point 4.

According to one possibility of implementation, the first strand 2 passes through a central crossing point 23, around which are arranged the other crossing points 23 intended for the other strands 3 constituting the wired element 1.

According to a more particular possibility of implementation, the central passage point 23 can be arranged with respect to the other passage points 23 so that the first strand 2 follows a trajectory, between the central passage point 23 and the point of assembly 4, which substantially corresponds to a height of the polygon, respectively to a height of the polyhedron, formed by the other strands 3.

Advantageously, the implementation of a central passage point 23 makes it possible in particular to use the first strand 2 as a central core, around which the other strand(s) 3 will wrap.

According to the invention, the method comprises a step (a1) of strand voltage control.

The tension of the strand 2, 3 corresponds to the longitudinal tensile force which is exerted within the strand 2, 3 at the point considered, and therefore to the tensile stress which results from the application of this force.

By convention of use, the tension can be expressed in centi-Newton (cN). It will be noted that a centi-Newton corresponds in practice substantially to the weight of a mass of one gram, so that, by misuse of language, it is sometimes possible to express the tension of the strand in "grams".

Strand voltage control operates in a closed loop.

• on définit une consigne de tension, dite « consigne de tension d'assemblage » T_set, qui est représentative d'un état de tension longitudinale que l'on souhaite obtenir dans le premier brin 2 lorsque ledit premier brin parvient au point d'assemblage 4,
• on mesure, en un premier point de mesure de tension PT1 qui est situé le long dudit premier brin 2 et en amont du point d'assemblage 4 par rapport au sens d'acheminement F dudit premier brin, la tension dite « tension d'assemblage effective » T_actual qui s'exerce au sein dudit premier brin 2,
• on utilise une boucle de rétroaction en tension pour déterminer une erreur, dite « erreur de tension » ER_T, qui correspond à la différence entre la consigne de tension d'assemblage et la tension d'assemblage effective du premier brin : ER_T = T_set - T_actual,
• et l'on pilote, à partir de ladite erreur de tension ER_T, un organe régulateur de tension 34, qui agit sur le premier brin 2 en amont du point d'assemblage 4, de sorte à faire converger automatiquement, au sein dudit premier brin 2, la tension d'assemblage effective T_actual vers la consigne de tension d'assemblage T_set.

To this end, during step (a1) of strand voltage control:

• a tension setpoint, called the "assembly tension setpoint" T_set, is defined, which is representative of a state of longitudinal tension that it is desired to obtain in the first strand 2 when said first strand reaches the assembly point 4 ,
• is measured, at a first voltage measurement point PT1 which is located along said first strand 2 and upstream of the assembly point 4 with respect to the direction of transport F of said first strand, the voltage called "assembly voltage effective” T_actual which is exerted within said first strand 2,
• a voltage feedback loop is used to determine an error, called "tension error" ER_T, which corresponds to the difference between the assembly voltage setpoint and the actual assembly voltage of the first strand: ER_T = T_set - T_actual ,
• and a voltage regulator member 34 is controlled from said voltage error ER_T, which acts on the first strand 2 upstream of the assembly point 4, so as to cause the actual assembly voltage T_actual to converge automatically, within said first strand 2, towards the assembly voltage setpoint T_set.

• un organe 31 de fixation de consigne de tension qui permet de fixer une consigne, dite « consigne de tension d'assemblage » T_set, qui est représentative d'un état de tension longitudinale que l'on souhaite obtenir dans le premier brin 2 lorsque ledit premier brin parvient au point d'assemblage 4,
• un organe 32 de surveillance de tension qui permet de mesurer, en un premier point de mesure de tension PT1 qui est situé le long dudit premier brin 2 et en amont du point d'assemblage 4 par rapport au sens d'acheminement F dudit premier brin, la tension dite « tension d'assemblage effective » T_actual qui s'exerce au sein dudit premier brin 2,
• un organe 33 de rétroaction en tension qui permet d'évaluer une erreur, dite « erreur de tension » ER_T, qui correspond à la différence entre la consigne de tension d'assemblage T_set et la tension d'assemblage effective T_actual du premier brin 2,
• et un organe 34 régulateur de tension, placé sous la dépendance de l'organe de rétroaction en tension 33, et qui peut agir sur le premier brin 2 en amont du point d'assemblage 4 de sorte à faire converger automatiquement, au sein dudit premier brin, la tension d'assemblage effective T_actual vers la consigne de tension d'assemblage T_set.

The installation 5 therefore comprises a voltage servo unit 30, arranged to servo in closed loop the voltage of the strand considered according to an operating mode called "voltage servo mode", said voltage servo unit 30 comprising for this purpose:

• a tension setpoint setting member 31 which makes it possible to set a setpoint, called the "assembly tension setpoint" T_set, which is representative of a state of longitudinal tension which it is desired to obtain in the first strand 2 when said first strand arrives at assemblage point 4,
• a voltage monitoring device 32 which makes it possible to measure, at a first voltage measurement point PT1 which is located along said first strand 2 and upstream of assembly point 4 with respect to the direction of transport F of said first strand , the tension called “effective assembly tension” T_actual which is exerted within said first strand 2,
• a voltage feedback unit 33 which makes it possible to evaluate an error, called "voltage error" ER_T, which corresponds to the difference between the assembly voltage setpoint T_set and the actual assembly voltage T_actual of the first strand 2,
• and a voltage regulator member 34, placed under the control of the voltage feedback member 33, and which can act on the first strand 2 upstream of the assembly point 4 so as to make it converge automatically, within said first strand, the actual assembly voltage T_actual to the assembly voltage setpoint T_set.

The unit 30 for enslaving the voltage strand, and more particularly one and/or the other of the organs 31, 32, 33, 34 for setting the voltage setpoint, voltage monitoring, feedback, and voltage regulation, may include, or be formed by, any appropriate computer or electronic controller.

Advantageously, the voltage slaving can thus take place automatically, substantially in real time.

As indicated in the introduction, taking into consideration the voltage of the strand 2, 3, and the voltage servoing in accordance with the invention which results therefrom, make it possible to control in a precise and reproducible manner the conditions of formation of the wired element. 1, and this continuously, which makes it possible to obtain properties that are homogeneous and conform to the specifications over almost all, or even all of the length of the wire element 1 obtained.

Of course, as indicated above, it is perfectly possible to provide for one and/or the other of the strands 3 other than the first strand 2, and in particular specifically for the second strand 3, a voltage servo unit 30 which applies to the strand 3 concerned, and which acts on said strand concerned distinctly from the voltage servo unit 30 which manages the first strand 2.

Thus, it is possible to provide, for one and/or the other strands 2, 3, and preferably for several of the strands to be assembled, or even for all the strands to be assembled, a structure similar to that described above, which comprises, for each strand concerned, a voltage servo unit 30 for the strand concerned, said voltage servo unit comprising a member 31 for fixing an assembly voltage setpoint T_set for the strand concerned, a device 32 for monitoring the effective voltage T_actual of the strand concerned at a first voltage measurement point PT1 located along said strand concerned, a feedback device 33, and a voltage regulator device 34 which acts on said strand concerned to converge automatically the actual tension of the strand concerned towards the voltage setpoint applicable to said strand.

To this end, it is possible to duplicate, on several of the feed devices 6, and preferably on each of the feed devices 6 provided within the installation 5, a voltage servo unit 30, to offer the possibility to enslave, or not, the strand concerned in tension, and this individually and independently of the other strands.

Of course, it will be possible to set, if necessary, different assembly voltage setpoints T_set for different strands 2, 3, and ensure a separate servo-control of each of said strands 2, 3, independent of the other strands.

Preferably, the effective assembly tension T_actual of the strand in question is measured by means of a tension monitoring device 32 comprising a thread guide 35, such as a pulley or a roller in free rotation, which bears against the strand 2, 3 considered, here at the chosen tension measurement point PT1, and which is carried by an elastically deformable support 36 whose elastic deformation is measured by means of a suitable sensor 37, for example by means of a strain gauge.

According to a possibility of implementation illustrated on the picture 3 , the tension monitoring member 32 may comprise a wire guide 35 formed by a pulley carried by a support 36 formed by a beam, preferably horizontal, mounted cantilevered.

Thus, the force exerted by the strand 2, 3 coming to bear against the pulley 35 results in a bending of the beam 36 which can be measured by an appropriate sensor, such as a strain gauge 37.

According to another possibility of implementation corresponding to the picture 2 , the tension monitoring device 32 may take the form of a trio 11, within which the planetary roller 12, in free rotation, will form the yarn guide 35 and will be mounted on a support 36 comprising a movable bearing which carries said planetary roller 12 and which cooperates with an elastic suspension member, of the spring type, so that the sensor 37 will measure the compression deformation of said spring, or, equivalently, will measure the displacement of the planetary roller 12 and of its bearing suspended against said spring, to deduce therefrom the effective assembly tension T_actual of the strand considered.

According to a possible configuration, the planetary roller 12 will then be distant from the satellite rollers 13, 14 of the trio 11, themselves also in free rotation, and the strand will follow a path in Ω passing below each satellite roller 13, 14 and over planetary roller 12, so that the strand tension results in a force which tends to bring planetary roller 12 closer to the fictitious straight line passing through the respective centers of the two satellite rollers.

According to another possible configuration, which may in particular correspond to the arrangement schematized on the branches 6A, 6B, 6C, 6D, 6E of the supply device 6 of the figure 1 , strand 2, 3 passes above planetary rollers 13, 14 of the trio, and below planetary roller 12, which is close enough to planetary rollers 13, 14 to interfere with strand 2, 3 and force said strand 2, 3, supported by the satellite rollers 13, 14, to bypass said planetary roller 12, so that the tension of the strand 2, 3 is translated by a force which tends to move the planetary roller 12 away from the fictitious straight line passing through the respective centers of the two satellite rollers 13, 14.

Of course, without departing from the scope of the invention, any other suitable means could be used, and in particular any suitable set of rollers or pulleys, to evaluate the effective assembly tension T_actual.

Furthermore, during step (a) of supply, the first strand 2 is preferably, as mentioned above, driven in displacement towards the assembly point 4 by means of a drive device motor 8, such as a capstan, which is located upstream of said assembly point 4 and which is arranged to impart to the first strand 2 a so-called "advance speed" speed V_fwd in response to a drive instruction that the is applied to said motorized drive device 8.

Preferably, the first voltage measurement point PT1 is then chosen, where the actual assembly voltage T_actual is measured, so that said first voltage measurement point PT1 is located in a section of the first strand, called "approach section", which extends from the motorized drive device 8, upstream, and the assembly point 4, downstream.

Thus, advantageously, the measurement of the effective assembly tension T_actual is done at a measurement point PT1 which is between the position (considered along the path taken by the strand concerned) of the motorized drive device 8 and the position (considered along the path taken by the strand concerned) of assembly point 4, and which is therefore particularly close to assembly point 4.

More particularly, the voltage measurement point PT1 thus chosen can therefore be located between the assembly point 4 and the last motor element, here the motorized drive device 8, which precedes the assembly point 4, in the direction upstream-downstream routing of strand 2, 3.

The effective assembly voltage T_actual is therefore preferably measured downstream of the last motorized device (here the motorized drive device 8) which is capable of acting actively on the strand 2, 3 considered and significantly modifying the voltage. before said strand 2, 3 reaches assembly point 4.

In this regard, it will be noted that the possible presence of one or even several passive return rollers 40, in free rotation, placed along the strand 2, 3 between the motorized drive device 8 and the assembly point 4 n has little influence on the tension that reigns within said strand 2, 3.

Consequently, the measurement of the effective assembly tension T_actual, which is carried out as close as possible to the assembly point 4, in an approach section little disturbed by external forces, is particularly reliable, and well representative of the tension which is actually exerted in the strand 2, 3 concerned at the moment when said strand reaches assembly point 4.

As indicated above, a similar voltage measurement arrangement and operation can be found on one and/or any other of the strands 2, 3 forming the subject of the assembly.

In absolute terms, one could consider using a voltage regulator member 34 forming a controlled brake, which is capable of acting on the relevant strand 2, 3 by more or less slowing down the progression of said strand 2, 3.

The more the strand will be slowed down by the voltage regulator member 34 upstream of the assembly point 4, the higher the tension of said strand will be. Conversely, the looser the brake, the less stretch 2 will be.

The voltage regulator member 34 may then for example comprise a friction roller, coming into contact with the strand 2, 3, and opposing the advance of the strand a braking torque which is adjusted, for example by means of a pad friction or a magnetic brake, depending on the value of the voltage error ER_T.

According to a preferred characteristic which may constitute an invention in its own right, during step (a1) of strand tension servo-control, the motorized drive device 8 will preferably be used, in particular the motorized drive device 8 associated with the first strand 2, as a voltage regulator member 34, by adjusting, as a function of the voltage error ER_T, the training instruction that is applied to said (first) motorized training device 8.

Advantageously, the use of a motorized device makes it possible, depending on the voltage error ER_T measured, either to slow down the strand 2, 3, upstream of the point assembly 4, by applying to the strand, via the motorized device 8, a sufficiently reduced advance speed V_fwd, which will have the effect of retaining the strand 2, 3 and therefore increasing the tension of said strand 2 , 3, or on the contrary to accelerate the strand 2, 3, upstream of the assembly point 4, that is to say to increase the speed of advance V_fwd of said strand, which will have the effect of reducing the tension of said strand 2, 3, by "giving slack" to said strand.

In this way, it is advantageously possible to correct and adapt the effective assembly tension T_actual by actively promoting either a relaxation of the strand 2, 3, or an accentuation of the tension of said strand 2, 3.

Furthermore, the use of the motorized drive device 8 as a voltage regulator member 34 makes it possible to produce a compact and inexpensive installation 5, since the same motorized drive device 8 is used both for supplying of the strand 2, 3 concerned and the enslavement of the voltage of said strand 2, 3.

Of course, here again, provision may be made mutatis mutandis for voltage regulation, and in particular individual voltage regulation, by a motorized drive device 8 associated with the strand in question, on any strand 2, 3 intended for assembly, and where appropriate on several of the strands, or even on all of the strands intended for assembly.

Advantageously, it will thus be possible to operate simultaneously and simply on several strands 2, 3 as many voltage regulations, independent of each other.

According to another preferred characteristic which may constitute an invention in its own right, if, during step (a) of supply, the strand in question, for example the first strand 2, is moved towards the assembly point 4 by means of a motorized drive device 8, such as a capstan, which is located upstream of the assembly point 4, in particular as described above, then the method can also comprise a step (a0 ) unwinding, during which the strand in question is unwound, here for example the first strand 2, from an input reel 7, by means of an unwinding device 50 which is separate from the drive device motorized 8 (of the strand considered) and which is located upstream of said motorized drive device 8.

Such a possibility is particularly illustrated, in a non-limiting way, on the variants 6A and 6C of supply devices 6 of the figure 2 .

The unwinding device 50 comprises a motorized spool holder 51 intended to receive and drive in rotation, at a speed called “input spool speed” ω7 chosen, the input spool 7 concerned.

Advantageously, as shown in particular in branch 6C of the figure 1 , it is then possible to measure, at a second voltage measurement point PT2 which is located along the strand considered, here for example along the first strand 2, between the motorized reel holder 51 and the motorized drive device 8, the so-called effective “unwinding voltage” tension T_unwind_actual which is exerted in the first strand 2, and consequently adjusting the input winding speed ω7 so as to cause said effective unwinding tension T_unwind_actual to converge towards an unwinding voltage setpoint T_unwind_set predetermined.

Indeed, by controlling on the one hand, upstream, the input reel speed ω7 and therefore the unwinding speed at which the strand 2, 3 is released, and on the other hand, downstream, the speed of advance V_fwd conferred by the motorized drive device 8, one can advantageously choose the unwinding tension of the strand, which prevails between the unwinding device 50, upstream, and the motorized drive device, downstream.

Advantageously, the strand 2, 3 concerned, which comes at the input of the motorized drive device 8, is thus provided with a well-controlled effective unwinding tension T_unwind_actual, which sets a first pre-tension level, from which it will be possible then, thanks to the action of the motorized drive device 8, modify the state of tension of the strand 2, 3 in the approach section, downstream of the motorized drive device 8 and upstream of the assembly point 4, in order to give said strand 2, 3 the desired effective assembly voltage T_actual.

The inventors have as such found that the creation and maintenance, thanks to a double motorization (successively that of the unwinding device 50 then that of the motorized drive device 8), of a tension pre-stress, in the form an effective unwinding tension T_unwind actual of regular and well-controlled value, advantageously made it possible to adjust more precisely and more easily the effective assembly tension T_actual of the strand concerned.

Indeed, from the first tension level, equal to the effective unwinding tension T_unwind_actual, and which can easily be stabilized as much as necessary, it is possible, by an additive action exerted by the motorized drive device 8 ( consisting in increasing the tension by braking the strand) or on the contrary by a subtractive action exerted by the motorized drive device 8 (consisting in reducing the tension by accelerating the strand), to achieve with precision an effective assembly tension T_actual resultant, which forms a second voltage level, and which can be freely chosen within a very wide range of effective assembly voltage.

In absolute terms, thanks to such a process with two voltage levels, which uses two voltage measurement points PT1, PT2 located upstream of the assembly point 4, on the same strand 2, 3, and distant from one on the other hand, one can freely choose the assembly voltage setpoint T_set, and reliably obtain a corresponding effective assembly voltage T_actual, in a range whose lower limit may be lower (in absolute value) than the first level voltage, that is to say lower than the effective unwinding voltage T_unwind_actual, and whose upper limit may be higher than said first voltage level.

For example, we can choose for the first tension level an unwinding tension T_unwind set (and therefore obtain an effective unwinding tension T_unwind_actual) between 50 cN (fifty centi-Newton) and 600 cN, and for example equal at 100 cN, at 200 cN, or at 400 cN, and obtain, at the level of the second tension level, an assembly tension T_actual, precise and stable, which will be perfectly in accordance with a setpoint T_set which one will have freely chosen in a very wide possible range, between 15 cN (fifteen centi-Newtons, which corresponds to a mass of approximately 15 grams) and 100 N (one hundred Newton, which corresponds to a mass of approximately ten kilograms), or even between 5 cN (five centi-Newtons, which corresponds to a mass of about 5 grams) and 200 N (two hundred Newtons, which corresponds to a mass of about twenty kilograms).

It will be noted that, according to a preferred implementation option, the method advantageously makes it possible to set an assembly voltage setpoint T_set which is chosen lower than the unwinding tension setpoint T_unwind_set, and to obtain a stable assembly tension servo-control.

In addition, the inventors have found that the existence of a first tension level, defined by the unwinding tension, makes it possible to lower, in the second tension level, the assembly tension (both the tension setpoint d assembly than the corresponding effective assembly tension) T_set, T_actual at a very low level, for example of the order of a few centi-Newtons (which is equivalent to the weight of a mass of a few grams) or a few tens of centi-Newton (which is equivalent to the weight of a mass of a few tens of grams), without risk of creating jolts of tension in the strand, and without risk of causing the effective assembly tension T_actual to pass by a value null, which would risk causing the strand 2, 3 to come out of the guides (pulleys, rollers, etc.) which define the path of the said strand through the installation 5.

In particular, such a method makes it possible in particular to obtain effective regulation of the assembly tension for any freely chosen assembly tension setpoint value T_set in an assembly tension range comprised between T_actual=5 cN (five hundred -Newton) and T_actual = 100 cN (one hundred centi-Newton).

The voltage measurement at the second voltage measurement point PT2 can be performed by any voltage monitoring device 32 as described above and placed at said second measurement point PT2, for example a trio 11 according to the figure 2 or a pulley 35 cantilevered according to the picture 3 .

• un organe 61 de fixation de consigne de vitesse qui permet de fixer une consigne, dite « consigne de vitesse d'avance » V_fwd_set, qui correspond à une valeur de vitesse d'avance que l'on souhaite conférer au brin 2, 3 considéré, ici par exemple le premier brin 2, en amont du point d'assemblage 4,
• un organe 62 de surveillance de vitesse qui permet de mesurer, en un point de mesure de vitesse d'avance PV1 qui est situé le long dudit brin 2, 3 considéré, ici par exemple le lond dudit premier brin 2, et en amont du point d'assemblage 4, une valeur de vitesse dite « vitesse d'avance effective » V_fwd_actual qui est représentative de la vitesse d'avance effective du brin considéré, ici par exemple du premier brin, au point de mesure PV1 considéré,
• un organe 63 de rétroaction en vitesse qui permet d'évaluer une erreur, dite « erreur de vitesse » ER_V, qui correspond à la différence entre la consigne de vitesse d'avance et la vitesse d'avance effective du brin 2, 3 considéré, ici du premier brin : ER_V = V_fwd_set - V_fwd_actual,
• et un organe 64 régulateur de vitesse, placé sous la dépendance de l'organe 63 de rétroaction en vitesse, et qui peut agir sur le brin 2, 3 considéré, ici par exemple sur le premier brin 2, en amont du point d'assemblage 4, de sorte à faire converger automatiquement la vitesse d'avance effective V_fwd_actual du brin 2, 3 considéré, ici par exemple du premier brin 2, vers la consigne de vitesse d'avance V_fwd_set.

According to an essential characteristic of the invention, the installation 5 also comprises a feed rate servo-control unit 60 arranged to servo in a closed loop the feed rate V_fwd of one of the strands 2, 3, preferably of the first strand 2, according to an operating mode called "speed servo mode", said speed servo unit 60 comprising for this purpose:

• a member 61 for setting the speed setpoint which makes it possible to set a setpoint, called the "advance speed setpoint" V_fwd_set, which corresponds to a value of the advance speed that it is desired to confer on the strand 2, 3 considered, here for example the first strand 2, upstream of the assembly point 4,
• a speed monitoring device 62 which makes it possible to measure, at a point of measurement of the forward speed PV1 which is located along said strand 2, 3 considered, here for example along said first strand 2, and upstream of the point of assembly 4, a speed value called "effective forward speed" V_fwd_actual which is representative of the effective forward speed of the strand considered, here for example of the first strand, at the measurement point PV1 considered,
• a speed feedback unit 63 which makes it possible to evaluate an error, called "speed error" ER_V, which corresponds to the difference between the forward speed setpoint and the effective forward speed of the strand 2, 3 considered, here of the first strand: ER_V = V_fwd_set - V_fwd_actual,
• and a speed regulator member 64, placed under the control of the speed feedback member 63, and which can act on the strand 2, 3 considered, here for example on the first strand 2, upstream of the assembly point 4, so as to automatically converge the effective forward speed V_fwd_actual of the strand 2, 3 considered, here for example of the first strand 2, towards the forward speed setpoint V_fwd_set.

The installation 5, according to the invention, comprises a selector 70 which makes it possible to activate selectively, for the first strand 2, the voltage servo mode or the speed servo mode.

In other words, the invention proposes to offer the user a possibility of selection, at least for the first strand 2, and if necessary for one and/or the other of the other strands 3, between a mode for enslaving said strand in tension, and a mode for enslaving said strand in forward speed.

The method according to the invention thus provides for a corresponding selection step.

The selector 70 allows the user to choose, for the strand in question, and preferably strand by strand, whether he wishes to perform voltage regulation or speed regulation.

Installation 5 therefore offers great versatility of use.

The selector 70 may be formed either by any suitable mechanical, electromechanical, electronic or computer unit.

Preferably, the installation comprises one or more selectors 70 which make it possible to select, for each of the first and second strands 2, 3, and independently for each of the first and second strands 2, 3, a voltage servo mode or, alternatively, a speed servo mode.

In this case, and, more generally, in the case where several, or even all, of the branches of the supply device 6, that is to say if several, or even all, of the strands 2, 3, are each equipped with a voltage servo unit 30, a speed servo unit 60, and a selector 70 for switching between these two units 30, 60, then it is possible to make multiple assembly combinations , in which one strand is voltage-regulated, or even several strands are voltage-regulated, while another strand, or even several other strands, are speed-regulated.

Of course, although one can preferably equip at least one and the same strand 2, or even each of the set of strands 2, 3, both with a voltage servo unit 30, with a speed control 60, and a selector 70 making it possible to alternately implement one or the other of these units 30, 60 on the strand 2 considered, provision may just as well be made to equip separately at least one first strand 2 of a voltage servo unit 30, and at least one other strand 3 of a speed servo unit 60.

Thus, ultimately, the invention may relate as such to a method of manufacturing a wired element 1 during which at least one first strand 2 is slaved in tension as described above, so as to confer on said strand 2, when said strand 2 reaches assembly point 4, a state of longitudinal tension corresponding to a tension setpoint T_set, while at least one second strand 3 is simultaneously controlled in advance speed, so as to give the second strand 3, when said strand 3 reaches the assembly point 4, a forward speed which corresponds to a determined forward speed setpoint V_fwd_set.

Of course, the invention can therefore in particular relate to a corresponding installation 5, which comprises at least one voltage servo unit 30 making it possible to servo the first strand 2 in voltage and a speed servo unit 60 making it possible to enslave the second strand 3 in advance speed.

Thanks to the invention, it is therefore possible to produce easily, and in a reproducible manner, many types of wire elements 1.

• soit en tension en appliquant mutatis mutandis au second brin une étape (a1) d'asservissement en tension (telle que cette étape a été décrite plus haut en référence préférentielle au premier brin 2),
• soit en vitesse conformément à une étape (a2) d'asservissement en vitesse, selon laquelle on fixe une consigne de vitesse d'avance V_fwd_set, qui correspond à une valeur de vitesse d'avance que l'on souhaite conférer au second brin 3 en amont du point d'assemblage 4, et l'on utilise un organe régulateur de vitesse 64, qui agit sur le second brin 3 en amont du point d'assemblage 4, de sorte à faire converger automatiquement, la vitesse d'avance effective V_fwd_actual du second brin 3 vers la consigne de vitesse d'avance V_fwd_set. Cette étape (a2) d'asservissement en vitesse pourra bien entendu être réalisée à l'aide de l'unité 60 d'asservissement en vitesse décrite ci-dessus.

By way of example, it is possible in particular, during the method according to the invention, to separately enslave each of the first and second strands 2, 3, the first strand 2 being enslaved in voltage in accordance with step (a1) of enslavement in strand tension, and the second strand 3, at your choice:

• either in voltage by applying mutatis mutandis to the second strand a step (a1) of voltage slaving (such as this step was described above with preferential reference to the first strand 2),
• either in speed in accordance with a step (a2) of speed control, according to which a forward speed setpoint V_fwd_set is fixed, which corresponds to a forward speed value that it is desired to confer on the second strand 3 in upstream of the assembly point 4, and a speed regulating member 64 is used, which acts on the second strand 3 upstream of the assembly point 4, so as to cause the effective advance speed V_fwd_actual to converge automatically of the second strand 3 to the feedrate reference V_fwd_set. This speed control step (a2) can of course be carried out using the speed control unit 60 described above.

As indicated above, we can of course provide, if the two servo modes, speed and voltage, are available for the same strand, here the second strand 3, a selection step by which we decide, by means of a selector 70, to opt either for a servo-control of the second strand 3 in voltage, by applying to the second strand 3 a voltage servo-control step (a1), or for a servo-control of the second strand 3 in speed, in accordance with a speed control step (a2).

It will be noted that the speed control mode is based on a feed rate measurement, and does not involve measurement of the tension of the strand, which makes the two control modes independent of each other. , or even mutually exclusive (in that it may be impossible to regulate at the same point of a strand both the forward speed of the strand and the tension of said strand).

In order not to overload the drawings, the detail of the speed control unit 60 and of its constituent members 61, 62, 63, 64 has been represented only on the branch 6A of the supply device 6 of the figure 1 .

Of course, such an arrangement of speed servo unit 60 is however perfectly applicable, alone or in combination with a voltage servo unit 30 and a selector 70, to one or the other of, or even to all the other branches 6B, 6C, 6D, 6E of the supply device 6, that is to say to one and/or the other of the strands, to the majority of the strands, or even to all strands 2, 3.

Preferably, if one of the strands 3, for example the second strand 3, is provided with a speed servo unit 60 but without a voltage servo unit 30, then at least one other strand, for example, the first strand 2 will be provided with at least one voltage servo unit 30, or even both a voltage servo unit 30 and a speed servo unit 60 which will then be associated to a selector 70 making it possible to selectively opt for the use of one or the other of these servo units 30, 60 available at the level of the first strand 2.

The unit 60 for enslaving the speed strand, and more particularly one and/or the other of the organs 61, 62, 63, 64 for setting the speed setpoint, speed monitoring, feedback, and speed regulation, may include, or be formed by, any appropriate computer or electronic controller.

Advantageously, the speed control can thus be carried out automatically, substantially in real time.

It will also be noted that the speed control, and in particular the measurement of the effective forward speed V_fwd_actual of the strand 2, 3 considered, preferably intervenes near the assembly point 4, and for example in the section of approach, between the last motorized element which precedes assembly point 4 and said assembly point 4, so that the forward speed considered, and slaved, is representative of the forward speed at which the strand 2, 3 arrives at assemblage point 4.

Preferably, the speed measurement point PV1 could be located at the level of the motorized drive device 8.

As such, it is possible, for example, to use, as speed monitoring device 62, a rotation speed sensor integrated into the motor which drives said motorized drive device 8, for example a rotation speed sensor integrated into the motor which drives the motorized roller of the capstan 8 or of the trio 11 which forms said motorized driving device 8.

According to a preferred feature which may constitute an invention in its own right, if the feed device 6 comprises a motorized drive device 8, such as a capstan, in particular as described above, which is located upstream of said point of assembly 4 and which causes the first strand 2 to move towards the assembly point 4, then, preferably, said motorized drive device 8 can alternatively form, according to the servo mode defined by the selector 70, the voltage regulator 34 used by voltage servo unit 30 or speed regulator 64 used by speed servo unit 60.

Advantageously, the invention therefore proposes to use the same motorized drive device 8 selectively either as voltage regulator 34, or as speed regulator 64 of the strand 2, 3 considered.

Such use of a means common to the two servo modes advantageously makes it possible to simplify the structure of the installation 5, and to reduce the cost and the size of said installation 5.

For purely illustrative purposes, there will be found below a brief description of the variants of branches 6A, 6B, 6C, 6D, 6E of the supply device 6, illustrated on the figure 1 .

The branch 6A makes it possible to select, thanks to the selector 70, between a voltage servo mode (unit 30) and a speed servo mode (unit 60). It is the assembly voltage servo mode which is active here. It is completed by an unwinding device 50 with motorized reel holder 51.

Branch 6B illustrates “basic” unwinding, with an input coil 7 in free rotation. Voltage control is available, but inactive.

Branch 6C proposes a motorized unwinding device 50 which makes it possible to control the unwinding tension of the strand T_unwind_actual, and which supplies a device motor drive 8, here of the capstan type, which performs a voltage servo. A regulation with two voltage levels is therefore obtained.

Branch 6D is a variant of branch 6B, in which the unwinding of the input reel 7, with a vertical axis, has been replaced by unwinding called "on the run" from an input reel 7 with a vertical axis. horizontal.

Branch 6E is a variant of branch 6A, in which the unwinding of the input reel 7, with a vertical axis, has been replaced by unwinding called "on the run" from an input reel 7 with a vertical axis. horizontal, and within which it has been chosen to carry out assembly voltage servoing, and accordingly configured the selector 70 to activate the voltage servo unit 30 and deactivate the speed servo unit 60 .

Claims (13)

1. Method for manufacturing a filamentary element (1) by interlacing at least a first strand (2) and a second strand (3) separate from the first strand, said method comprising the following steps:

   - a feeding step (a), during which the first strand (2) and, respectively, the second strand (3) are conveyed to an assembly point (4) at which the first strand and the second strand meet,

   - an interlacing step (b), during which the first strand (2) and the second strand (3) are interlaced with one another at the assembly point (4) so as to form a filamentary element (1) from said at least first and second strands (2, 3),

   said method being characterized in that it comprises a selection step, during which a selector (70) is used to selectively activate a control mode for the first strand (2) from among

   a closed-loop strand tension control mode, in which:

   - a tension setpoint, referred to as "assembly tension setpoint" (T_set), which is representative of a state of longitudinal tension that is desired to be obtained in the first strand (2) when said first strand arrives at the assembly point (4), is defined,

   - the tension referred to as "actual assembly tension" (T_actual) that is exerted within said first strand is measured at a first tension measuring point (PT1) which is located along said first strand and upstream of the assembly point (4) in relation to the conveying direction (F) of said first strand (2),

   - a tension feedback loop is used to determine an error, referred to as "tension error" (ER_T), which corresponds to the difference between the assembly tension setpoint and the actual assembly tension of the first strand,

   - and, on the basis of said tension error (ER_T), a tension regulator member (34) which acts on the first strand (2) upstream of the assembly point (4) is controlled so as to automatically converge, within said first strand, the actual assembly tension (T_actual) towards the assembly tension setpoint (T_set);

   a speed control mode, in which:

   - a setpoint, referred to as "forward speed setpoint" (V_fwd_set), which corresponds to a value for a forward speed that is desired to be conferred on the first strand (2) upstream of the assembly point (4), is defined,

   - at a forward speed measuring point (PV1) which is located along said first strand (2) and upstream of the assembly point (4), a speed value referred to as "actual forward speed" (V_fwd_actual), which is representative of the actual forward speed of the first strand at the measuring point (PV1) in question, is measured,

   - a speed feedback member (63) is used to evaluate an error, referred to as "speed error" (ER _V), which corresponds to the difference between the forward speed setpoint and the actual forward speed of the first strand,

   - a speed regulator member (64), which is dependent on the speed feedback member (63), is used to act on the first strand upstream of the assembly point (4) so as to automatically converge the actual forward speed (V_fwd_actual) of the first strand towards the forward speed setpoint (V_fwd_set).
2. Method according to Claim 1, characterized in that, during the supplying step (a), the first strand (2) is moved towards the assembly point (4) by means of a motorized drive device (8), such as a spool, which is located upstream of said assembly point (4) and is designed to confer on the first strand (2) a speed referred to as "forward speed" (V_fwd) in response to a drive setpoint applied to said motorized drive device (8), and in that said motorized drive device (8), depending on the selected control mode, is selectively used as tension regulator member (34) used by the tension control mode (30) or as speed regulator member (64) used by the speed control mode (60).
3. Method according to Claim 1 or 2, characterized in that, during the selection step, use is made of the selector (70), which is electronic or computerized.
4. Method according to one of Claims 1 to 3, characterized in that, during the supplying step (a), the first strand (2) is moved towards the assembly point (4) by means of a motorized drive device (8), such as a spool, which is located upstream of the assembly point (4), in that the tension control mode is applied to the first strand, in that the first tension measuring point (PT1), at which the actual assembly tension (T_actual) is measured, is located in a portion of the first strand, referred to as "approach portion", which extends from the motorized drive device (8), upstream, to the assembly point (4), downstream, and in that said method comprises an unwinding step (a0), during which the first strand (2) is unwound from an input reel (7) by means of an unwinding device (50) which is separate from the motorized drive device (8), is located upstream of said motorized drive device (8) and comprises a motorized reel holder (51) intended to receive the input reel (7) and drive it in rotation at a selected speed referred to as "input reel speed" (w7), and in that the tension referred to as actual "unwinding tension" (T_unwind_actual), which is exerted in the first strand (2), is measured at a second tension measuring point (PT2) which is located along the first strand (2), between the motorized reel holder (51) and the motorized drive device (8), and the input reel speed (w7) is adjusted so as to converge said actual unwinding tension (T_unwind_actual) towards a predetermined unwinding tension setpoint (T_unwind_set) so as to define, in the strand in question which is at the inlet of the motorized drive device (8), a first tension level equal to the actual unwinding tension (T_unwind_actual), on the basis of which, by way of an action of braking the strand or an action of accelerating the strand which is performed by the motorized drive device (8), the desired actual assembly tension (T_actual), which, downstream of the motorized drive device (8), forms a second tension level of which the value will preferably be less than the first tension level, for example between 5 cN and 100 cN, is conferred on said strand.
5. Method according to one of the preceding claims, characterized in that control is performed separately for each of the first and second strands (2, 3), the first strand (2) in accordance with the strand tension control mode, and the second strand (3) in accordance with a speed control mode, in which a forward speed setpoint (V_fwd_set), which corresponds to a value for a forward speed that is desired to be conferred on the second strand (3) upstream of the assembly point (4), is defined and use is made of a speed regulator member (64), which acts on the second strand (3) upstream of the assembly point (4), so as to automatically converge the actual forward speed (V_fwd_actual) of the second strand (3) towards the forward speed setpoint (V_fwd_set).
6. Method according to one of the preceding claims, characterized in that it includes a selection step, which is used to make a decision on whether to opt for tension control of the second strand (3), by applying, mutatis mutandis, a tension control mode to the second strand, or to opt for speed feedback control of the second strand (3), in accordance with a speed control mode, in which a forward speed setpoint (V_fwd_set), which corresponds to a value for a forward speed that is desired to be conferred on the second strand (3) upstream of the assembly point (4), is defined, and use is made of a speed regulator member (64), which acts on the second strand (3) upstream of the assembly point (4), so as to automatically converge the actual forward speed (V_fwd_actual) of the second strand (3) towards the forward speed setpoint (V_fwd_set).
7. Method according to one of the preceding claims, characterized in that, when the tension control mode is selected, the actual assembly tension (T_actual) of the strand in question is measured by means of a tension monitoring member (32) comprising a thread guide (35), such as a pulley or a roller that rotates freely, comes to bear against the strand (2, 3) in question and is borne by an elastically deformable support (36), the elastic deformation of which is measured by means of a suitable sensor (37), for example by means of a strain gauge.
8. Method according to one of the preceding claims, characterized in that, during the interlacing step (b), the interlacing is performed by twisting so as to helically wind the second strand (3) around the first strand (2) or the second strand (3) and the first strand (2) one around the other, to form the filamentary element (1) .
9. Installation (5) for manufacturing a filamentary element (1) by interlacing at least a first strand (2) and a second strand (3) separate from the first strand, said installation comprising:

   - a feeding device (6) charged with conveying the first strand (2) and, respectively, the second strand (3) to an assembly point (4) at which the first strand and the second strand meet,

   - an interlacing device (8) charged with interlacing the first strand (2) and the second strand (3) with one another at the assembly point (4) so as to form a filamentary element (1) from said at least first and second strands (2, 3),

   said installation being characterized in that it comprises a tension control unit (30), designed for closed-loop control of the tension of the strand in an operating mode referred to as "tension control mode", said tension control unit (30) to that end comprising:

   - a tension setpoint defining member (31), which makes it possible to define a setpoint, referred to as "assembly tension setpoint" (T_set), which is representative of a state of longitudinal tension that is desired to be obtained in the first strand (2) when said first strand arrives at the assembly point (4),

   - a tension monitoring member (32), which makes it possible to measure the tension referred to as "actual assembly tension" (T_actual), which is exerted within said first strand (2), at a first tension measuring point (PT1) which is located along said first strand and upstream of the assembly point (4) in relation to the conveying direction (F) of said first strand,

   - a tension feedback member (33), which makes it possible to evaluate an error, referred to as "tension error" (ER_T), which corresponds to the difference between the assembly tension setpoint (T_set) and the actual assembly tension (T_actual) of the first strand,

   - and a tension regulator member (34), which is dependent on the tension feedback member (33) and can act on the first strand (2) upstream of the assembly point (4) so as to automatically converge, within said first strand, the actual assembly tension (T_actual) towards the assembly tension setpoint (T_set);

   said installation being characterized in that it also comprises a forward speed control unit (60) designed for closed-loop control of the forward speed (V_fwd) of the first strand (2) in an operating mode referred to as "speed control mode", said speed control unit to that end comprising:

   - a speed setpoint defining member (61), which makes it possible to define a setpoint, referred to as "forward speed setpoint" (V_fwd_set), which corresponds to a value for a forward speed that is desired to be conferred on the first strand (2) upstream of the assembly point (4),

   - a speed monitoring member (62), which makes it possible to measure, at a forward speed measuring point (PV1) which is located along said first strand (2) and upstream of the assembly point (4), a speed value referred to as "actual forward speed" (V_fwd_actual), which is representative of the actual forward speed of the first strand at the measuring point (PV1) in question,

   - a speed feedback member (63), which makes it possible to evaluate an error, referred to as "speed error" (ER _V), which corresponds to the difference between the forward speed setpoint and the actual forward speed of the first strand,

   - and a speed regulator member (64), which is dependent on the speed feedback member (63) and can act on the first strand upstream of the assembly point (4) so as to automatically converge the actual forward speed (V_fwd_actual) of the first strand towards the forward speed setpoint (V_fwd_set),

   and in that said installation has a selector (70) which makes it possible to selectively activate, for the first strand, the tension control mode or the speed control mode.
10. Installation according to Claim 9, characterized in that it comprises multiple selectors (70) which make it possible to select, for each of the first and second strands (2, 3), and independently for each of the first and second strands, a tension control mode or, alternatively, a speed control mode.
11. Installation according to Claim 9 or 10, characterized in that the supplying device (6) has a motorized drive device (8), such as a spool, which is located upstream of said assembly point (4) and moves the first strand (2) towards the assembly point (4), and in that said motorized drive device (8), depending on the control mode defined by the selector (70), alternatively forms the tension regulator member (34) used by the tension control unit (30) or the speed regulator member (64) used by the speed control unit (60).
12. Installation (5) according to one of Claims 9 to 11, characterized in that it comprises at least one tension control unit (30) for tension control of the first strand (2) and a speed control unit (60) for forward speed control of the second strand (3).
13. Installation according to one of Claims 9 to 12, characterized in that the selector (70) is formed by an electromechanical, electronic or computerized unit.

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