WO2010116103A1

WO2010116103A1 - Device for spooling a thread on a spool with a constant spooling ratio

Info

Publication number: WO2010116103A1
Application number: PCT/FR2010/050686
Authority: WO
Inventors: Carlos Matas; Alain Bonnefoy
Original assignee: Ritm
Priority date: 2009-04-09
Filing date: 2010-04-09
Publication date: 2010-10-14
Also published as: FR2944271A1; FR2944271B1

Abstract

The device of the invention is adapted to spool threads (F) at a high count and at a high speed, and comprises: a means for rotating the spool (2); a rotation speed sensor (13) for said spool; a back-and-forth movement system (8) driven by an actuator or a motor (9); a sensor (14) measuring the instantaneous position of the thread guide; and a unit (12) for driving the actuator or the motor (9). The device is connected to programmed calculation means for, considering a target spooling ratio R: measuring the back-and-forth movement period; measuring and calculating the mean period of rotation of the spool; calculating the ratio of actual spooling R1 between the back-and-forth movement period (Pt) and the period of rotation of the spool (Pb); comparing R1 to the target spooling ratio R; if there is a difference between the actual value R1 and the target value R, correcting the running speed.

Description

DEVICE FOR WINDING A WIRE ON A REEL SPOOL

CONSTANT WINDING

The invention relates to the technical field of the winding of a wire or, more generally of a continuous elongated material, which will be referred to in the following as "wire", to form a coil, which consists in winding the wire around a support, which will be referred to in the following as "tube", said tube being rotated either by its axis or by pressure on a pilot member. To perform such an operation, the wire is distributed along a generatrix along the coil in the form of crossed helical turns.

The invention relates more particularly to the case where the distribution of the wire is carried out by means of a wire guide moving along the generatrix of the coil, in a rectilinear or curvilinear trajectory, according to an alternating movement composed of a moving at a substantially constant speed from one end to the other of the reel, followed by an inversion of said speed to effect a displacement in the other direction, and so on. Such a device will be designated in the following by the term "back and forth". The combination of the rotation of the coil with the reciprocating speed of the wire guide leads to a removal of the wire on the surface of the coil in helical turns in one direction and then in the other.

This results in two characteristics of the winding:

The "winding ratio": The number of turns made by the spool during a complete cycle of return of the guide wire in its movement back and forth. This number is usually fractional. "Cruise angle" means the angle at which the turns intersect, resulting from the ratio of the transverse speed of movement of the wire guide to the tangential peripheral speed of the coil, tangential velocity being proportional to the product of the rotational speed of the reel by its diameter.

According to the characteristics described above, there are two types of windings:

The winding with "constant winding ratio" for depositing parallel turns. Depending on the chosen winding ratio, the turns are deposited at regular intervals or against each other, in an orderly manner known as the "precision winding". The crest angle decreases as the diameter of the spool increases.

The winding at "constant crest angle" to obtain a constant coil density. The winding ratio increases as the diameter of the coil increases, creating an apparent disorder in the removal of successive turns, known as the "wild cross".

The winding systems are traditionally equipped with reciprocating systems made by means of cams or any other mechanism transforming a reciprocating translational movement in one direction then in the other. The reciprocating cycle is entirely determined by the profile of the cam and / or the kinematics of the mechanical device, so that the winding ratio is set by the ratio between the rotational speed of the coil and the speed of rotation. the rotation controlling said back and forth. It is known to fix this gear ratio by a mechanical transmission, pinions and / or belts between the drive system of the back and forth and that of the coil. It is also known to drive the back and forth and the drive system of the coil, by two independent motors controlled by speed-controlled driving systems, as is apparent for example from the teaching of patents FR2330632 or US4394986. Such systems make it possible to produce windings with a constant crosstalk angle or a constant winding ratio. To combine the advantages of the two types of windings, such systems also make it possible to produce a winding ratio winding evolving in stages.

It has been proposed to replace the mechanical back and forth systems by systems consisting of a wire guide directly displaced by an actuator or an electric motor or rotary reciprocating, such as those which emerge from the teachings of patents EP0556212 or EP0453622. To obtain speed and accuracy of speed reversal at the ends comparable to mechanical systems, such systems require motors or actuators having a very high instantaneous force or torque, associated with sophisticated means of control such as those disclosed by the EP0453622 or EP0999992. Such systems require complex and expensive specific developments. Given the technological limitations, they allow high speeds to be achieved with fine wires (very low density) and wound at low voltages, but for wires of larger head, and / or wound at higher voltages. they offer limited performance.

The winding constant winding ratio, and particularly the precision winding with removal of the son contiguous turns carried under high voltages, particularly relates to son of high titles, for example son formed by wiring several elementary son. The principle of performing a constant winding ratio winding and / or a precision winding by means of a reciprocating composed of a wire guide directly displaced by an actuator or a rotary or linear motor driven by a reciprocating movement, results from the teachings of patent EP0556212, which does not disclose the means for solving the problems described above. Conventional servo control provides performance that is incompatible with the requirements of precision winding of high speed high speed threads.

Now it has been found, and it is the object of the present invention, a device for winding a wire on a coil with a constant and / or constant winding ratio by step and / or precision, using a and comes directly controlled by an actuator or a reciprocating motor adapted to winding son of high title and high speed.

The winding device according to the invention consists of: a means for driving the rotating spool associated with a control device, - a speed sensor for rotating said spool, a speed system and forth comprising a wire guide directly moved by an actuator or a motor driven by a reciprocating motion, a sensor measuring a magnitude representative of the instantaneous position of the wire guide, a control unit of the actuator or of the motor, programmed to perform a slaving of the movement of the wire guide in a sequence which describes the cycle of back and forth, said winding system being provided with a calculation capacity and being programmed to take into account a winding ratio R to be achieved: measuring the time taken by the to-and-fro to perform said complete cycle (variation period); back and forth), - measure and calculate by averaging over the complete cycle back and forth, the time taken by the coil to perform a full rotation (rotation period of the coil) calculate the actual winding ratio Rl between the back-and-forth period and the period of rotation of the coil, - compare Rl with the winding ratio R to be achieved, if there is a difference between the real value R1 and the value to be attained R, perform a correction of the speed of execution of at least part of the sequence to reduce this difference during the next complete cycle of back and forth.

According to the invention, the sequence that describes the reciprocating cycle may consist of a series of positional commands, the control of the actuator being programmed to perform a servocontrol of the position of the guide wire, and / or a set of speed commands, the control of the actuator being programmed to perform a servo of the speed of the guide wire.

According to an important aspect of the invention, the total travel carried out by the wire guide during the reciprocating cycle is adjustable, this adjustment being made by applying a multiplying factor to the series of position or speed instructions describing the cycle of back and forth.

According to an improvement of the invention, the sequence which describes the back-and-forth cycle is subdivided into a plurality of distinct phases, each being executed according to modes and / or different servo parameters.

According to this improvement, the sequence which describes the reciprocating cycle is subdivided into phases defined according to the positioning of the wire guide: when the wire guide is positioned between two predetermined positions, a speed control phase of the guide wire according to an instantaneous setpoint equal to the instantaneous speed of rotation of the coil multiplied by a coefficient K, - when the wire guide reaches one of the two predetermined positions, a phase of inversion of the speed of the motor according to a slowdown cycle and re-acceleration in the opposite direction until reaching the instantaneous setpoint of rotation of the coil multiplied by a coefficient K.

According to this improvement, the system is programmed to take into account a winding ratio R to be achieved, compare R1 to the winding ratio R to be attained, and if there is a difference between the real value R1 and the value at to reach R, to make a correction of the coefficient K so that this difference is reduced during the next complete cycle of back and forth.

According to this improvement, the total travel carried out by the wire guide during the back-and-forth cycle is adjustable, this adjustment being made by modifying the predetermined positions defining the tilting of the operating phase in constant speed regulation towards the phase reversing speed.

The invention also relates to a twisting and / or direct cabling twisting machine equipped with double twist spindles and / or direct wiring associated with a winding spooling device. constant and / or constant by step, and / or a precision winding system according to the invention as described above.

The invention also relates to a twin-twisting machine with integrated reception in the spindle, known as a winding spindle, equipped with a winding device integrated in the spindle, with a constant and / or constant winding ratio. compensate, and / or a precision winding system according to the invention as described above.

The invention will be better understood with reference to the appended figures and drawings given by way of example and in which:

Figures 1, 2: give a general perspective diagram of a winding device according to two embodiments of the system of back and forth.

Figure 3: Gives a general diagram of the device according to the invention and its control system. Figure 4 shows an example of operating diagrams of the device according to the invention. Figure 5, 6, 1: Show examples of coil shapes obtained with a winding device according to the invention. Figure 8: Shows a diagram of a wire transformation unit using a device according to the invention.

The invention therefore applies to winding devices or winding which consists of winding the wire (F) on a support or tube (3) to form a coil (2). As illustrated in Figures 1 and 2, the coil (2) is rotated by friction, being held by a support (4) resting on a cylinder (5) which is rotated by a motor (6). ). Without departing from the invention, the coil (2) can also be driven by a motor acting directly on its tube (3).

According to the embodiment of the invention illustrated in FIG. 3, the winding device comprises a means for driving the spool, consisting of the cylinder (5) and its motor (6) associated with a control unit (10) by example a frequency converter. The speed of the cylinder (5) can be constant or variable, depending on the process of transformation of the wire (F) upstream of the winding.

The winding device is equipped with a sensor (13) for rotation speed of the coil (2). Importantly, this sensor must measure very accurately the actual speed of the coil (2) or its tube (3). For example, such a sensor may consist of an encoder driven integrally by the tube (3) of the coil. According to a preferred embodiment, such a sensor may consist of an optical or magnetic detector (13) detecting the passage of elements arranged on a member rotating integrally with the tube (3) of the coil (2) or on the tube (3) itself.

The wire (F) is wound around the coil (2) by being distributed over the width thereof by means of a wire guide (7) driven by a reciprocating motion communicated by a system ( 8).

FIG. 1 represents an embodiment of a reciprocating system (8) formed of a belt integral with the guide wire (7) circulating between pulleys (here two in number), and driven by an engine (9). FIG. 2 represents another embodiment of a reciprocating system (8) formed of an arm directly mounted on the shaft of an engine (9), and carrying the wire guide (7) to its end.

In both cases, given as non-limiting examples, the guide wire (7) is directly driven by the motor (9) which is driven reciprocating. The motor or actuator (9) can be a linear or rotary, stepping or permanent magnet motor.

The reciprocating system (8) comprises a sensor measuring a magnitude representative of the instantaneous position of the wire guide (7). Advantageously, the position sensor or the encoder (14) of the actuator or the motor (9) is used.

The actuator or motor (9) is associated with a control unit (12) similar to those used for producing a conventional servomotor, in association with a sensor (14). One of the advantages of the invention is to realize the system with relatively standard components and widespread on the market and therefore inexpensive.

In order to understand the invention, reference is made to FIG. 4. The curve (18) represents the rotation of the coil (2) expressed in number of revolutions, as a function of time. In the example shown, the speed of rotation is constant. The curves (16) and (17) represent the cycle of back and forth. The curve (16) represents the distance (d) of the wire guide (7) with respect to one of the ends of the tube (3) of the coil and the curve (17) represents the instantaneous speed (Vg) of said wire guide ( 7) as a function of time. The control unit (12) of the actuator or motor is programmed to move the wire guide (7) in a sequence that describes the reciprocating cycle. Said sequence may consist of a series of position instructions of the wire guide (7), the control unit of the actuator (10) being programmed to perform a servocontrol of the position of said guide wire, and / or a set of speed commands, the control of the actuator (10) being programmed to perform a servo of the speed of the guide wire.

The sequence that describes the reciprocating cycle can be subdivided into a plurality of distinct phases, each of which is executed in different modes and / or servo parameters.

The winding device is provided for winding winding "R". Without departing from the scope of the invention, depending on the type of winding desired, the winding ratio to reach "R" can be constant, variable in steps or continuously variable, for example depending on the diameter reached by the coil. In the example shown in Figure 4, the winding ratio to reach is 1.99.

The winding device measures the time (Pt) set by the back and forth to perform a complete cycle (period of back and forth). This time can be measured by means of the sensor or position encoder (14), or by a magnetic or optical auxiliary sensor detecting the passage of the wire guide (7) at any point on its path.

The winding device establishes, by measurement and calculation, the average (Pb) over the complete cycle of back and forth, the time taken by the coil to perform a complete rotation (rotation period of the coil). According to selected winding ratio, several rotations of the coil are performed during a back and forth. In the example shown in FIG. 4, the coil performs two complete rotations of duration (PbI) and (Pb2). These periods can be measured, for example, by means of the coil rotation sensor (13).

The ratio between the back-and-forth period (Pt) and the rotation period of the coil (Pb) corresponds to the actual winding ratio "Rl".

If this ratio is an integer fraction (of the N / D type, N and D being integers), all the "D" cycles of back-and-forth removal of wire on the coil surface reproduce identically, and so the turns of thread are superimposed exactly. In the case of precision winding, it is sought to deposit the turns parallel to each other, clamped against each other or separated by a constant interval, according to the desired density. The winding ratio "R" to reach is therefore generally equal to a corrected whole fraction of a small value, creating the shift from one turn to the other. Expressed in time, this shift (e) is extremely small. In the example shown in FIG. 4, for a winding ratio of 1.99, this offset (e) is equal to one-hundredth of the back-and-forth time (Pt).

In order to obtain a very high precision on the winding ratio obtained, if there is a difference between the real value R1 and the value to be attained R, the device is programmed to perform a correction of the execution speed of at least a part of the sequence so that this difference is reduced during the next complete cycle of back and forth. Such a correction is, for example, made by readjusting the frequency at which the successive values of the instructions of the sequence describing the back and forth are scanned. According to an important aspect of the invention, the total travel (C) performed by the wire guide (7) during the reciprocating cycle is adjustable, this adjustment being achieved by applying a multiplying factor to the set of instructions. position or speed describing the cycle back and forth.

According to an improvement of the invention, the sequence which describes the reciprocating cycle is subdivided into a plurality of distinct phases, each being executed according to different modes and / or servo parameters, which phases are defined according to the instantaneous position of the wire guide (7).

When the wire guide (7) is positioned between two predetermined positions (d1, d2), the control unit (12) is programmed to perform a speed control of the wire guide according to a set proportional to the instantaneous speed of rotation of the coil multiplied by a coefficient "K" of proportionality between the two speeds. In Figure 4 this situation corresponds to the marked areas (I). The instantaneous speed of rotation of the spool being in this example constant (straight 17), the speed of the thread guide (7) is constant in this zone (I), which corresponds to the straight portions of the curves (16 and 17).

It will be observed that the ratio between the peripheral speed of the coil (2) and the forward speed of the wire guide (7) determines the actual cross-bend angle obtained.

When the wire guide (7) reaches one of the two predetermined positions (d1 or d2), the system executes a speed reversal sequence of the motor or actuator (9) in a slowdown and re-acceleration cycle. reverse until reaching the instantaneous speed of rotation of the coil multiplied by the coefficient "K". In FIG. 4, this situation corresponds to the zones marked (II), the deceleration and re-acceleration corresponding to the curvilinear portions of the curves (16 and 17).

The device calculates the actual winding ratio "R1" and compares it to the winding ratio to reach "R". If there is a difference between the actual value "R1" and the value to be achieved "R", the device performs a correction of the coefficient "K" to correct this difference. For example, if the actual ratio "R1" is less than the ratio to be attained, that is to say that the back-and-forth period (Pt) is too small relative to the rotation period of the coil (Pb), the coefficient "K" is slightly decreased, to reduce the speed of passage of the guide wire, and thus extend this period. Importantly, this correction must be very small, and preferably less than 1% of one cycle on the other.

According to one embodiment of this improvement, the inversion sequence (II) of the speed of the wire guide (7) at the ends of the coil (2) is defined by a speed table, the control device (12) being programmed to perform speed control during this phase.

In order to improve the control of the location of the reversal point of the reciprocating movement of the wire guide, according to a preferred embodiment of the invention, the inversion sequence (II) of the speed of the guide wire (7) at the ends of the coil (2) is defined by a position table, the control unit (12) being programmed to perform position control during this phase. This embodiment makes it possible to optimize the precision and the reproducibility of the position of the inversion point and to optimize the movement of the wire guide (7), for example to reproduce similar characteristics to those obtained by means of a mechanical cam.

According to this improvement, the total stroke (C) of the reciprocating system is adjustable according to the diameter of the coil (2). In a particularly preferred manner, this adjustment of the total reciprocating stroke (C) is effected by modifying the predetermined positions (d1, d2) defining the tilting of the operation in constant speed regulation (I) towards the sequence of inversion of the speed (II).

The advantage of this improvement is clear from this explanation:

The device performs the correction of the speed of execution of the cycle on the part, mark (I) in FIG. 4, where the device operates a regulation at a substantially constant speed under a load related to the tension of the thread which does not have any variation brutal, allowing stable regulation with a very small error.

The reversal sequence, during which the operating conditions are critical (strong deceleration and re-acceleration of the wire guide (7) under a load related to the strongly variable wire tension) is not affected by these corrections. .

As a result, the control parameters can be optimized independently in the traversing sequences (I) with respect to the inversion (II) sequences.

In particular, the inversion sequence (II) can be optimized to obtain a very high dynamic, in accordance with the winding requirements, which can tolerate errors (delays or positional deviations) provided that these errors are reproducible from one cycle to another, offset by the correction made on the other parts of the cycle. It is thus possible to use less sophisticated equipment and / or less oversized, and thus either to reduce the costs of the equipment, or to push the limits of speed or allowable voltages.

Whatever the improvements described above, the winding device according to the invention allows variations of the total stroke (C) of the comings and goings of a cycle on the aure.

A first particularly advantageous application of this characteristic is to make a variation of the stroke as a function of the diameter reached by the coil, separately or in combination: - to compensate for the bulge of the flanks of the coil (2) due to the pressure exerted by the upper layers on the lower layers.

and / or producing a coil having conical or bi-conical sides.

According to this first application, in a preferred manner, the variation of a cycle back-and-forth to the other of the total travel of the back and forth (C) is less than 1%.

Figures 5 and 6 show two examples of evolution law of the total stroke (C) depending on the diameter and the coil shape thus obtained. Figure 5 shows how to make a spool with straight sides, with and without compensation of bulges due to the pressure exerted by the upper layers on the lower layers. Figure 6 shows how to make a bi-conical coil, with and without compensation of bulges because of the pressure exerted by the upper layers on the lower layers.

A second advantageous application of this characteristic consists in forming layers of turns of reduced width compared to the nominal stroke, for example:

at the beginning of winding to facilitate the formation of the first layers of wire on the empty tube at the beginning of winding,

- or periodically during winding to reduce the density of coils on these flanks.

FIG. 7 illustrates an example of a method of depositing the son according to this second application. In the case of precision-wound winding with contiguous turn wire removal, the system is advantageously programmed to form a complete reduced-stroke layer before returning to the nominal stroke. The number of back-and-forth cycles necessary to form a complete layer is determined by the ratio between the value (e) creating the shift between the worst and the period (Pb) of rotation of the coil.

In order to realize a winding device according to the invention, the measurement of the periods of back-and-forth (Pt) and rotation of the coil (Pb) can be performed in the control unit (10) of the system. driving the coil and / or in the control unit (12) of the reciprocating system, and calculating the actual winding ratio "R1" and correcting the execution speed of the sequence or part sequence, or the coefficient "K" can be achieved for example in the control unit (12) of the system of back and forth.

According to one embodiment of the invention, the control units (10) and (12) are themselves controlled by a calculation unit (15), the measuring the periods (Pt) and (Pb), the actual winding ratio (Rl). The calculation of the corrections of the speed of execution of all or part of the sequence or of the coefficient "K", as well as of total stroke variations (C), is entrusted to said calculation unit (15) which can be a card electronic or a PLC or a calculator that may have other functions.

The invention also relates to a thread transformation machine by twisting process and / or cabling equipped with a winding device according to the invention.

In particular, the invention relates to a machine for converting son by double torsion and / or direct wiring, equipped with double twist spindles and / or direct wiring, associated with a winding device with a constant and / or constant winding ratio. to overcome, and / or to a precision winding device according to the invention as previously exposed. A schematic representation that is in no way limiting to the working unit of such a machine is shown in FIG. 8. In a known manner, a wire-processing machine may consist of a workstation or several juxtaposed workstations.

The invention also relates to a double twist twisting machine with integrated reception, equipped with double twist spindles, known as winder spindles equipped with a winding device integrated in the spindle, constant winding ratio and / or or constant by step, and / or a precision winding device according to the invention as described above. In both cases, the twist imparted to the yarn results from the ratio between the speed of rotation of the spindle (20) and the speed of advancement of the yarn (F) therein. Now the speed of call of the wire (F) by the winding system is equal to the peripheral speed of the coil (2) divided by the sine of the half-angle of crossing. In order to obtain a perfectly controlled twisting of the yarn, the drive speed of the bobbin (2) is thus controlled in relation to the speed of the spindle (20) and the crest angle. The reciprocating control system (12) is programmed to automatically adjust its cycle (traversing speed and reciprocating period) with respect to the driving speed of the spool (2).

It follows from this feature a particularly advantageous combination of the spindle (20) of torsion or direct wiring rotated by an individual motor (21) associated with a control device (22), with the winding device according to the invention , allowing an independent optimization of the winding, particularly for making high speed precision windings with high titre wires and high winding voltage, at a cost substantially lower than conventional means.

A particularly advantageous embodiment of a machine according to the invention consists of the following elements:

A pin (20) for twisting or direct wiring, rotated by a motor (21) associated with a driver (22). In a preferred manner, the control device (22) performs a servocontrol of the speed of the spindle (20) in a closed loop by means of a speed sensor (23). A drive system (18) of the wire (F) by a motor (16) associated with a control unit (17). Optionally, the control unit (17) performs a servocontrol of the speed of the drive system (18) closed loop through the speed sensor (19).

A drive means of the wire receiving coil (2) (F) consisting of the cylinder (5) on which said coil (2) is held applied by means of a support (4), which cylinder (5) is driven by a motor (6) associated with the control unit (10). In a preferred manner, the control unit (10) performs a servocontrol of the rotation of the coil (2) in a closed loop thanks to the speed sensor of (13). A reciprocating system (8) driving the wire guide (7) controlled by a motor (9), associated with the control unit (10), to perform an alternating cycle according to the present invention,

The set of elements being controlled by a computing unit (15).

Without departing from the invention, a twisting machine and / or wiring according to the invention consists of a winding pin, that is to say a spindle equipped with a winding system according to the present invention disposed therein.

Claims

1. A device for winding a wire (F) on a coil (2) with a constant winding ratio, suitable for high-speed and high-speed wire winding (F), and comprising: a drive means for driving the wire coil (2) in rotation associated with a control unit (10); a rotational speed sensor of said coil (13); a reciprocating system (8) comprising a wire guide (7) directly controlled by an actuator or a motor (9) driven with reciprocating motion; a sensor (14) measuring a magnitude representative of the instantaneous position of the wire guide; a control unit (12) of the actuator or the motor (9); characterized in that it is subject to calculation means programmed to, given a winding ratio R to reach: measuring the time (Pt) set by the back and forth (8) to perform a complete cycle (period of back and forth); measuring and averaging over the complete cycle back and forth, the time (Pb, average Pl, Pb2 ...) put by the coil to perform a complete rotation (rotation period of the coil); calculating the actual winding ratio R1 between the back-and-forth period (Pt) and the rotation period of the spool (Pb); compare R1 to the winding ratio R to be reached; if there is a difference between the actual value R1 and the value to be attained R, effecting a correction of the execution speed of at least a part of the sequence so that this difference is reduced during the next complete cycle of back and forth.

2. A winding device according to claim 1 characterized in that the sequence which describes the reciprocating cycle consists of a series of position instructions, the control of the actuator (9) being programmed to perform a servo positioning of the wire guide.

3. A winding device according to claim 1 characterized in that the sequence which describes the reciprocating cycle consists of a series of speed setpoints, the control of the actuator (9) being programmed to perform a servo speed of the wire guide.

4. Winding device according to any one of claims 1 to 3 characterized in that the total stroke (C) performed by the guide wire (7) during the cycle back and forth is adjustable, this adjustment being achieved by applying a multiplying factor to the series of position or speed commands describing the cycle back and forth.

5. A winding device according to any one of claims 1 to 4 characterized in that the sequence which describes the reciprocating cycle is subdivided into a plurality of distinct phases, each being executed according to modes and / or different servo settings.

6. A winding device according to claim 5 characterized in that the sequence which describes the reciprocating cycle is subdivided into phases defined according to the positioning of the wire guide: when the wire guide is positioned between two predetermined positions, a slaving speed phase of the wire guide according to an instantaneous instruction equal to the instantaneous speed of rotation of the coil multiplied by a coefficient K, when the wire guide reaches one of the two predetermined positions, a phase of inversion of the speed of the motor according to a cycle of deceleration and re-acceleration in the opposite direction until reaching the instantaneous set point of rotation of the coil multiplied by a coefficient K.

7. A winding device according to claim 6 characterized in that, given a winding ratio R to reach, it is programmed to: calculate the actual winding ratio Rl between the period of back and forth

(Pt) and the rotation period of the coil (Pb), - compare Rl with the winding ratio R to be achieved, if there is a difference between the real value R1 and the value to be achieved R, perform a correction of the coefficient K so that this gap is reduced during the next complete cycle of back and forth.

8. A winding device according to any one of claims 5 to 7 characterized in that the total stroke performed by the wire guide during the reciprocating cycle is adjustable, this adjustment being achieved by changing the predetermined positions defining switching from operation to constant speed control to the speed reversal sequence.

9. A winding device according to any one of claims 5 to 8 characterized in that the inversion sequence is defined by a table of positions, the control unit (12) being programmed to perform a position control during the phase (II) of reversal of speed.

10. Winding device according to any one of claims 5 to 9 characterized in that the total stroke (C) of the reciprocating system is adjustable according to the diameter reached by the coil (2), the variation from one cycle to another of the total travel of the back and forth being less than 1%.

11. A winding device according to any one of claims 5 to 10 characterized in that the adjustment of the total stroke (C) of winding is performed by changing the predetermined positions (dl, d2) defining the tilting operation in regulation constant speed (I) to the speed inversion sequence (II).

12. A winding device according to any one of claims 1 to 11 characterized in that the drive device of the coil consists of a motor directly driving the tube (3) of the coil (2).

13. A winding device according to any one of claims 1 to 11 characterized in that the drive means is constituted by a cylinder (5) connected to a motor (6) on which the coil (2) is maintained supported by a support (4) and is driven by friction.

Machine for converting yarn by double torsion and / or wiring and / or direct wiring, characterized in that it is equipped with double-twist spindles and / or direct wiring associated with a winding device with a constant winding ratio. , and / or constant by step, and / or a precision winding system according to any one of claims 1 to 13.

15. Machine for converting the wire by double twist and / or wiring and / or direct wiring, characterized in that it is equipped with pins known as the spindle winder, equipped with a winding device constant winding ratio , and / or constant by step, and / or a precision winding system according to any one of claims 1 to 13.