Method and system for detecting lateral winding defects

Abstract

The invention relates to a method for detecting lateral winding defects when winding a link (L) onto a spool (1) rotatably driven about its longitudinal axis (X), the link (L) being alternately guided in translation relative to the spool (1) along the longitudinal axis (X) between two reversal positions by a guide pulley (2), the method comprising measuring the position of the guide pulley (2) relative to the spool (1) along the longitudinal axis (X) over time, measuring the position (P2) of an adjusting device that adjusts the advancement speed of the link on the guide pulley over time, determining from the measurements the deviation between a reference position (P3r) and the position (P3) of the adjusting device at each reversal position (Pi1, Pi2), and detecting the formation of cavities or bumps in the winding from the deviation.

Description

Technical Field

[0001] The present invention relates to a method and system for detecting traverse winding defects.

Background Art

[0002] There are numerous applications where links intended to carry fluids or transmit energy and / or signals (e.g., electric current, optical signals, mechanical tension, fluids, etc.) must be wound onto spools for transportation, storage, and / or use.

[0003] Generally, it is necessary for the winding of the link on the spool to be uniform, i.e., the link is wound onto the spool in the form of one or more continuous layers of the bonding coil or with a minimum gap between them. Such a uniform winding ensures the mechanical integrity of the link and enables the link to be rewound with a substantially constant tension of the link.

[0004] To achieve this purpose, a winding system for winding the link comprises a traverse winding system including a guide pulley disposed facing the spool and configured to control the location of each new coil with respect to the coils already deposited on the core of the spool. When the link is being wound, the spool is rotatably driven about the revolution axis of the core, and the guide pulley is alternately driven translationally with respect to the spool in a direction parallel to the axis between two reversal positions disposed near each of the two flanges of the spool (or vice versa).

[0005] However, due to an imperfect adjustment of the reversal positions of the guide pulley, too long a link may accumulate near the flange of the spool, causing bumps on the outer surface of all turns, or conversely, the link may not be wound up to the flange, causing cavities on the outer surface of all coils.

[0006] In practice, the width of the spool corresponding to the distance between the two flanges is not necessarily accurately known. For example, if the spool is made of molded plastic, there may be significant dimensional variations between two similar spools.

[0007] Moreover, when the link is wound around the spool, the flanks may separate due to the pressure of the link, which affects the filling of the spool.

[0008] Such defects can be visually observed by the operator and can be corrected by changing the dimensions of the inversion position.

[0009] However, this detection is not accurate and can only be performed when significant winding defects are observed, which is not satisfactory.

[0010] Patent Document 1 describes a traverse winding system for winding an optical fiber onto a spool, which includes a motor equipped with a rotary encoder and a ball screw coupled to the motor and the spool so as to alternately drive the spool in a translational manner in two traverse winding directions facing the fixed pulley. The motor changes the rotation direction based on data from a proximity sensor disposed on a support for detecting the position of the flange of the spool. This device further includes a sensor for detecting the position of the optical fiber and a control device for controlling the rotation direction of the motor based on the fiber speed signal at the pulley and the traverse winding position signal provided by the encoder. A curve representing the position of the wire at the time of a change in the traverse winding direction detected by the detector is drawn. The presence of a bump indicates an extra thickness of the spooling at the flange of the spool. In response to the detection of such an extra thickness, the control device adjusts the inversion position of the traverse winding direction. As a result, the bump decreases at the next inversion position.

[0011] Patent Document 2 describes a lateral winding system including a sensor for measuring the distance of the axis of a guide pulley with respect to one of the flanges of a spool. The moment of change in the transverse winding direction is determined based on geometric considerations. The transverse winding direction is reversed when the distance between the wire and the flange is less than half the diameter of the wire.

[0012] Patent Document 3 describes a lateral winding system in which the wire advancement and winding speeds on the spool are controlled by respective encoders so that these two speeds are equalized.

Summary of the Invention

Problems to be Solved by the Invention

[0013] One object of the present invention is to design a method for detecting lateral winding defects that can be automatically implemented.

[0014] Advantageously, this detection method must also be compatible with a method for automatically correcting lateral winding defects.

Means for Solving the Problems

[0015] To achieve this object, the present invention provides a method for detecting a lateral winding defect when winding a link around a spool that is rotatably driven about a longitudinal axis, the link being alternately and translationally guided relative to the spool by a guide pulley along the longitudinal axis between two reversal positions, the method comprising: - measuring the position of the guide pulley relative to the spool along the longitudinal axis over time; - measuring the position of an adjustment device that adjusts the advancement speed of the link on the guide pulley over time, the measurement being performed in a measurement window that includes each reversal position; - determining, from the measurements, the deviation between the reference position and the position of the adjustment device at each reversal position; - detecting the formation of voids or bumps in the winding from the deviation.

[0016] According to one embodiment, the adjustment device for adjusting the forward speed of the link is a replica including a pulley disposed at the end of an arm that can pivot about a horizontal axis against the return load of a spring, and the measured position is the angular position of the replica arm with respect to the vertical axis.

[0017] In the present text, "horizontal" means a direction perpendicular to the direction of gravity, and "vertical" means the direction of gravity.

[0018] Particularly preferably, measuring the position of the control device is performed within a measurement window (measurement window) including each inversion position.

[0019] Preferably, the minimum position and the maximum position of the adjustment device are determined in each measurement window, and the deviation between the reference position of the adjustment device and each respective minimum position or maximum position is calculated.

[0020] Particularly preferably, the method includes comparing the absolute value of the deviation and - formation of a cavity in winding when the absolute value of the deviation between the maximum position and the reference position is greater than the absolute value of the deviation between the minimum position and the reference position, - formation of a bump in winding when the absolute value of the deviation between the maximum position and the reference position is less than the absolute value of the deviation between the minimum position and the reference position and determining.

[0021] From the deviation calculated in this way, the lateral winding error is - the deviation between the maximum position and the reference position when the deviation is greater in absolute value than the deviation between the minimum position and the reference position, - the deviation between the minimum position and the reference position when the deviation is greater in absolute value than the deviation between the minimum position and the reference position to which an offset that is a function of the rotational speed of the spool is added, - the deviation between the maximum position and the reference position in other cases is determined to be equal.

[0022] Another object of the present invention relates to a system for detecting lateral winding defects when winding a link onto a spool that is rotatably driven about its longitudinal axis, the link being alternately and translationally guided relative to the spool along the longitudinal axis between two reversal positions by a guide pulley. The system comprises - a first sensor configured to measure the position of the guide pulley relative to the spool along the longitudinal axis over time, - a second sensor configured to measure the position of an adjustment device that adjusts the forward speed of the link on the guide pulley over time, - a control unit, The control unit (a) determines a deviation between a reference position and the position of the adjustment device at each reversal position from the measurement data of the first and second sensors, (c) detects the formation of cavities or bumps in the window from the deviation, is configured as such.

[0023] In an embodiment of the fifth day, the adjustment device that adjusts the forward speed of the link is a replica including a pulley disposed at the end of an arm that can pivot about a horizontal axis against the return load of a spring, and the measured position is the angular position of the replica arm relative to the vertical axis.

[0024] Another object of the present invention relates to a winding system for winding a link onto a spool that is rotatably driven about its longitudinal axis, - a spooler configured to rotatably drive the spool about its longitudinal axis, - a guide pulley that alternately and translationally guides the link relative to the spool along the longitudinal axis between two reversal positions to perform a uniform helical winding of the link guided by the pulley on the spool, - an adjustment device disposed upstream of the guide pulley on the path of the link to adjust the forward speed of the link, - a detection system for detecting lateral winding defects as described above.

[0025] In some embodiments, the spooler is configured to drive the spool only rotationally, and the system includes an actuator configured to drive the guide pulley translationally along the longitudinal axis.

[0026] In other embodiments, the guide pulley is fixed and the spooler includes an actuator configured to drive the spool rotationally and translationally relative to the guide pulley.

[0027] Finally, the present invention relates to a link winder including a winding system as described above.

[0028] Further features and advantages of the present invention will become apparent from the following detailed description when taken in conjunction with the accompanying drawings.

Brief Description of the Drawings

[0029]

Figure 1

Figure 2

Embodiments for Carrying Out the Invention

[0030] FIG. 1 is a schematic view of a winding system for winding (wrapping) a link L around a spool. Such a system is typically part of a winder, which is a machine whose function is, for example, to store the link on the spool after its manufacture or after a link test.

[0031] The link may be an electrical cable, an optical fiber or a bundle of optical fibers, a mechanical cable, a hydraulic or pneumatic conduit, or any other suitable means for transporting a fluid or transmitting energy and / or signals.

[0032] The spool 1 includes a cylindrical core 10 that receives the link in the form of a uniformly wound coil, and two flanges 11, 12 that hold the link on the core.

[0033] The spool 1 is integral with a spooler (not shown) that includes a motor configured to rotatably drive the spool along a longitudinal axis X that is the revolution axis of the cylindrical core 10.

[0034] The spool 1 may be at the outlet of a link manufacturing machine that includes an extrusion line, a link tester, or any other machine through which the link is advanced before being wound onto the spool. The winder may be an integral part of the machine or may be juxtaposed to the machine.

[0035] The machine is not shown in FIG. 1 except for the outlet capstan 4, the function of which is to apply a mechanical tension to the link.

[0036] A number of pulleys are arranged between the capstan 4 and the spool 1, one of which is referenced by item 32 and the others by item 21, although not all of them are necessarily shown in FIG. 1.

[0037] The winding of the link on the spool may be in the form of helical laps with a combined coil obtained by combining the following two movements. - Rotation of the spool about the axis X - Axial movement of the link (i.e., along the axis X), performed by a lateral winding system whose function is to perform a uniform helical winding of the link on the spool by moving the inlet point of the wire axially in proportion to the rotation of the spool.

[0038] Generally, the axis X is located in a horizontal plane that is generally parallel to the floor plane of the mounting on which the link winding is implemented.

[0039] The traverse winding system includes a regulation device for adjusting the forward speed of the link and a guide pulley for guiding the link.

[0040] The regulation device for adjusting the speed of the link is represented in the form of a replica 3 and includes an arm 31 pivotally rotatable about an axis perpendicular to axis X against the return load of a spring (not shown) and a pulley 30 disposed at the end of the arm on the side opposite the pivot axis. In FIG. 1, axis 31 is collinear with the vertical axis Z, but axis 31 can be inclined to either side with respect to this axis.

[0041] The angular position of the arm 31 is adjusted to adjust the difference in the forward speed of the link.

[0042] The guide pulley 2 is disposed between the replica 3 and the spool 1 on the path of the link.

[0043] The function of the pulley 2 is to guide the link facing the core of the spool and guide its winding.

[0044] A pulley 32 disposed upstream of the replica in the path of the link increases the bar feed on the replica 30 and keeps the inlet angle on the replica constant.

[0045] The pulley 21 performs a compensation function configured such that the length between the replica and the traverse winding system is the same regardless of the position of the guide sheave. The pulley 21 moves along axis X by half of the traverse winding pitch at each traverse winding pitch.

[0046] In the illustrated embodiment, the spool is translationally fixed and the guide pulleys are alternately translationally movable along the axis X of the spool. Thus, the guide pulley 2 is integral with the belt 20. A motor (not shown) alternately translationally moves the belt along the axis X.

[0047] In an alternative embodiment (not shown), the guide pulleys may be translationally fixed and the spool may be translationally movable along the axis X (in addition to its rotational movement).

[0048] The movement of the guide pulley 2 relative to the spool occurs alternately in both directions between two reversal positions which are the extreme positions of the movement of the guide pulley relative to the spool.

[0049] The reversal positions are determined as a function of the position of the flanges in order to ensure that the first and last coils of each helical wrap are positioned as close as possible to each flange so as not to create a cavity on the outer surface of the wrap.

[0050] In practice, the reversal positions can be determined when loading a new spool by measuring the position of one flange relative to the other flange which is considered to be the origin of the measurement.

[0051] The lateral winding system includes several sensors which are normally present in lateral winding systems on the market and thus do not need to be specifically added for the implementation of the present invention.

[0052] The first sensor measures the position of the guide pulley 2 relative to the spool 1 along the axis X over time. For example, this sensor can be an encoder of the motor that actuates the belt integral with the guide pulley.

[0053] A second sensor is used to measure the angular position of the replica 3 relative to the axis Z over time.

[0054] The system further includes a control unit including at least one processor configured to implement an algorithm for calculating lateral winding defects.

[0055] The control unit receives measurement data from different sensors.

[0056] From this data, the processor determines the deviation between the angular position of the replica and the reference angular position at each inversion position.

[0057] From the deviation thus determined, the processor detects the formation of hollows or bumps in the winding.

[0058] Figure 2 illustrates the principle of measuring the angular position of the replica.

[0059] The horizontal axis is the time axis.

[0060] The vertical axis represents the position of the guide pulley and the angular position of the replica (in arbitrary units).

[0061] The triangular graph P2 represents the change in the position of the guide pulley as a function of time. This position varies periodically between two consecutive inversion positions Pi1 and Pi2 corresponding to the tip of the triangle.

[0062] The curve P3 represents the change in the angular position of replica 3 with respect to the axis Z over time.

[0063] The curve P3r represents the change in the reference angular position of replica 3 with respect to the axis Z over time. In Figure 2, it is observed that this reference angular position takes two different constant values during the forward and backward movement of the guide pulley between two inversion positions Pi1, Pi2.

[0064] Particularly advantageously, the angular position of replica 3 is not measured occasionally at each inversion position, but is measured within a measurement time window (window) F encompassing each inversion.

[0065] The reference angular position P3r can be determined as the arithmetic mean of the instantaneous angular positions of the replicas measured when opening a window during several measurements (e.g., 50 measurements) preceding the current measurement for the same inversion position Pi1 or Pi2. This smooths the measurements and avoids consideration of small disturbances without changing the useful signal related to the actual movement of the replicas.

[0066] During the opening and closing of the measurement window, the instantaneous angular position of replica 3 is recorded. The minimum position p3min and the maximum position p3max within window F are determined and stored.

[0067] From these measured values, a deviation Δmin equal to the deviation between the minimum angular position p3min of the replica within the corresponding window and the reference position P3r is determined for each inversion position, and a deviation Δmax equal to the deviation between the maximum angular position p3max of the replica within that window and the reference position P3r is determined.

[0068] Particularly advantageously, the deviation Δmin integrates the offset applied to the minimum position p3min in order to take into account the fact that the replica has a natural (decreasing) movement during inversion. This offset is a function of the winding speed of the link. The control unit may include a memory in which different predetermined values of the offset to be applied as a function of the winding speed are stored.

[0069] By comparing the absolute values of the two deviations Δmin and Δmax within the same window, it is possible to detect the tendency to form cavities or bumps during winding.

[0070] In practice, the cavity is characterized by a smaller link winding radius, and thus, for a given rotational speed of the spool, the length of the link wound up is smaller, which results in the movement of the shoe in the direction of the increase of the deviation Δmax. Therefore, the absolute value of Δmax, which is greater than the absolute value of Δmin, represents the formation of a cavity in the winding.

[0071] Conversely, the bump is characterized by a larger link winding radius, and thus, for a given rotational speed of the spool, the length of the link wound up is larger, which results in the movement of the shoe in the direction of the increase of the deviation Δmin. Therefore, the absolute value of Δmax, which is smaller than the absolute value of Δmin, represents the formation of a bump in the winding.

[0072] Next, the lateral winding error can be defined as the maximum absolute values of the deviations Δmax and Δmin. When these two deviations have close values, it is preferable to detect the cavity. This is because the detection of the cavity is more significant than the detection of the bump biased by an offset that is not accurately determined. Thus, in practice, if the absolute value of Δmax is greater than the absolute value of Δmin, the value Δmax is assigned to the lateral winding error. If the absolute value of Δmin is greater than the absolute value of Δmax to which an offset that is a function of the winding speed is added, the value Δmin is assigned to the lateral winding error. If the absolute values of Δmax and Δmin are close, the value Δmax is assigned to the lateral winding error.

[0073] Since the amplitude of the oscillation of the replica increases with the rotational speed of the spool, it is possible to apply an error harmonisation term proportional to the speed of the spool so that, regardless of the speed of the spool, the same deviation has the same order of magnitude of error.

[0074] A method for detecting lateral winding defects, which is particularly often used for winding fine and / or fragile links whose angular position is measured relative to the vertical, has been described for an adjustment replica. Those skilled in the art will use any other adjustment device equipped with a position sensor and use the measurement of this position in a measurement window including each inversion position according to the same principle as above.

[0075] Regardless of the adjustment device used, the present invention has the advantage of detecting lateral winding defects using a sensor integrated into this adjustment device without the need for any additional measurement means. Therefore, the implementation of lateral winding defect detection does not require any structural modification of the lateral winding system and can thus be carried out at a lower cost.

Prior Art Documents

Patent Documents

[0076]

Patent Document 1

Patent Document 2

Patent Document 3

Claims

1. A method for detecting a lateral winding defect when winding a link around a spool that is rotatably driven about a longitudinal axis, wherein the link is alternately and translationally guided relative to the spool by a guide pulley along the longitudinal axis between two reversal positions, and the method comprises - measuring the position of the guide pulley relative to the spool along the longitudinal axis over time, - measuring the position of an adjustment device for adjusting the forward speed of the link on the guide pulley over time, the measurement being carried out in a measurement time window encompassing each reversal position, - determining from the measurement the deviation between a reference position and the position of the adjustment device at each reversal position, - detecting the formation of voids or bumps in the winding from the deviation, characterized in that the minimum and maximum positions of the adjustment device are determined in each measurement time window, and the deviation between the reference position of the adjustment device and each respective minimum or maximum position is calculated. Method.

2. The adjustment device for adjusting the forward speed of the link is a replica comprising a pulley arranged at the end of an arm that can pivot about a horizontal axis against the return load of a spring, and the measured position is the angular position of the arm of the replica relative to a vertical axis. The method according to claim 1.

3. Comparing the absolute values of the deviations, - the formation of voids in the winding when the absolute value of the deviation between the maximum position and the reference position is greater than the absolute value of the deviation between the minimum position and the reference position, - the formation of bumps in the winding when the absolute value of the deviation between the maximum position and the reference position is less than the absolute value of the deviation between the minimum position and the reference position determining, The method according to claim 1 or 2.

4. The lateral winding error is - the deviation between the maximum position and the reference position when the deviation is greater in absolute value than the deviation between the minimum position and the reference position, - the deviation between the minimum position and the reference position when the deviation is greater in absolute value than the deviation between the minimum position and the reference position plus an offset that is a function of the rotational speed of the spool, - the deviation between the maximum position and the reference position in other cases determined to be equal to The method according to any one of claims 1 to 3.

5. A system for detecting a lateral winding defect when winding a link around a spool that is rotatably driven about a longitudinal axis, wherein the link is alternately and translationally guided relative to the spool along the longitudinal axis between two inversion positions by a guide pulley, and the system comprises - a first sensor configured to measure the position of the guide pulley relative to the spool along the longitudinal axis over time; - a second sensor configured to measure the position of an adjustment device that adjusts the forward speed of the link on the guide pulley over time in a measurement time window that includes each inversion position; - a control unit, and the control unit (a) determines a minimum position and a maximum position of the adjustment device in each measurement time window from the measurement data of the second sensor; (b) determines a deviation between a reference position and the position of the adjustment device at each inversion position from the measurement data of the first and second sensors; (c) detects the formation of a cavity or a bump in the measurement time window from the deviation, is configured as system.

6. The adjustment device for adjusting the forward speed of the link is a replica including a pulley disposed at an end of an arm that can pivot about a horizontal axis against the return load of a spring, and the measured position is the angular position of the arm of the replica with respect to a vertical axis. The system according to claim 5.

7. A winding system for winding a link around a spool that is rotatably driven about a longitudinal axis, - a spooler configured to rotatably drive the spool about the longitudinal axis; - a guide pulley that alternately and translationally guides the link relative to the spool along the longitudinal axis between two inversion positions for performing a uniform helical winding of the link guided by the pulley on the spool; - an adjustment device disposed upstream of the guide pulley on the path of the link for adjusting the forward speed of the link; - a system for detecting a lateral winding defect according to claim 5 or 6, winding system.

8. The spooler is configured to drive only the spool rotatably, and the winding system includes an actuator configured to drive the guide pulley translationally along the longitudinal axis, the winding system according to claim 7.

9. The guide pulley is fixed, and the spooler includes an actuator configured to drive the spool rotatably and translationally with respect to the guide pulley, the winding system according to claim 7.

10. A link winder including the winding system according to any one of claims 7 to 9.

Images