JP2001272551A - Optical fiber pulling device and method for controlling tension imparted to optical fiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a means for solving a problem that a drawing speed of an optical fiber by a drawing device does not coincide with a speed of the optical fiber fed to an accumulating device. SOLUTION: In an optical fiber pulling device which receives the optical fiber 35 from the drawing device 37 and feeds the optical fiber to the fiber accumulating device 40, the pulling device 1 is provided with at least one fixed pulley 32 onto which at least a certain length of the optical fiber 35 is wound and at least one movable pulley 9 onto which a certain length of the optical fiber 35 is wound. A device for measuring tension imparted to the fiber interacts with motor driving devices 24, 26, 5, 7 for moving the movable pulley 9, and whereby a distance between shafts 33, 20 of the pulleys 32, 9 is controlled so that tension imparted to the fiber is automatically kept at a nearly constant.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001] The present invention relates to an optical fiber pulling apparatus and a method for controlling the tension applied to an optical fiber, particularly during winding of the fiber.

Generally, optical fibers are formed from a preform of glass material in a draw tower. The draw tower generally comprises a traction device ("capstan"), for example, a motor-driven pulley that can pull the optical fiber down and supply it to the accumulator. Integrated devices usually consist of motor driven reels around which optical fibers are wound.

In many operating situations, the speed at which the optical fiber is pulled by the traction device (withdrawal speed) does not correspond to the speed at which the optical fiber is fed to the accumulator, which, for example, causes the traction device and the accumulator to be connected. This is caused by fluctuations in the driving motor speed. The difference between these speeds causes a variation in fiber tension with respect to the target tension. In particular, a fiber tension greater than the target tension will damage the fiber, while a tension lower than the target tension will make the integration process inefficient.

[0004] In order to solve this problem, there is a known example in which a tension device that is interposed between a pulling device and an integrated device and that can control the tension of an optical fiber is used. In particular, there are known tensioning devices with at least one fixed pulley and one movable pulley capable of guiding optical fibers. By moving the movable pulley, the tension of the optical fiber can be changed. In the following description, the term “fixed pulley” refers to a pulley whose axial position is fixed by a pulley that freely rotates around an axis, and the term “movable pulley” refers to a pulley that freely rotates around an axis. Denotes a variable pulley.

[0005] US Pat. No. 4,712,866 describes a tensioning device located between a pulling tower traction device and an accumulator with a take-up reel. This tensioning device includes a pair of fixed pulleys and a “dancer arm (d
and a movable pulley disposed on a reciprocating arm, also referred to as "anchor arm)". Since the dancer arm exerts a conventional speed control, the fiber is wound on a take-up reel with a tension determined by the weight described above.

US Pat. No. 5,790,292 relates to an optical fiber transport process and more particularly describes a draw tower in which a pulling device with two pulleys is interposed between the pulling device and the take-up reel. (FIG. 7).

US Pat. No. 4,138,069 relates to an optical glass filament winding device,
A traction device pulls the filament from the molten glass source,
It is supplied to a set of take-up reels via a pulling device. The tensioning device comprises two fixed pulleys and one movable pulley mounted on one end of the dancer arm. The dancer arm extends from a device in which a spring or other means applies a constant force to move the movable pulley away from the fixed pulley.

[0008] The tensioning device can be used in devices other than the drawing tower. U.S. Pat. No. 5,076,104 describes an apparatus for measuring underload on an optical fiber, which includes a tensioning device having a pair of fixed pulleys and one movable pulley. . Also provided is a tensioning device with one fixed grooved wheel and one movable grooved wheel. The movable wheel is arranged below the fixed grooved wheel, is movable vertically, and is connected to a predetermined weight. The optical fiber is wound in its feed path on both a grooved fixed wheel and a grooved movable wheel, thus being kept at a constant tension.

US Pat. No. 4,505,222 describes an extrusion coating device for optical fibers, in which a tensioning device is located slightly upstream of the take-up reel. U.S. Pat. No. 4,127,370 describes an extrusion coating device for optical fibers, in which first, second and third pulleys are connected to a device slightly downstream of a fiber take-up reel. Located at the entrance. The first and second pulleys are spaced apart from each other and are spaced apart from the take-up reel. The third pulley is unsupported and is mounted on the optical fiber between the first and second pulleys, and the weight of the third pulley causes the optical fiber to move between the first pulley and the second pulley. The space is U-shaped and passes through.
A pair of photovoltaic cells are used to detect the vertical position of the third pulley and control the rotation speed of the take-up reel so that the position of the third pulley, that is, the fiber tension is kept substantially constant.

Applicants have known that in known pulling devices, it is necessary to use at least one of gravity and a predetermined elastic motion to control the position of the movable pulley, and to apply a predetermined uncontrollable force to the movable pulley. I noticed that Therefore, it is inevitably impossible to modulate the force applied to the movable pulley in order to modify the response of the tensioning device.
Thus, the tension control provided by known devices is of the non-modulated type and will be inappropriate under certain operating conditions.

[0011] The applicant has realized that the above-mentioned problem can be at least partially solved by using an optical fiber pulling device, which comprises a movable pulley to which the optical fiber is fed and an optical fiber. And a device for moving the movable pulley, which can control the position of the movable pulley according to a signal generated by the tension measuring device.

The tensioning device according to the invention can receive the optical fiber from a fiber guide or return element or another type of device, for example a traction device or a supply device, and after automatically controlling the tension, guides the optical fiber further. It can be fed back to a return element or, for example, an integrated device for optical fibers (especially a reel winding device).

More specifically, a tensioning device according to the present invention includes a fixed pulley mounted on a support structure, and a movable pulley mounted on a slider slidable along a linear guide mounted on the support structure. is there.

The optical fiber fed into the pulling device is wound around a fixed pulley over a predetermined length, is sent from here to a movable pulley, and is further wound a certain length. The distance between the fixed pulley and the movable pulley is variable to modify the length of the fiber section extending between the two pulleys, and thus the tension applied to the fiber. In order to change the distance between the fixed pulley and the movable pulley, as described above, a tension measuring device, for example, a load meter interlocking with the fixed pulley, and a fiber that controls the distance between the pulley shafts according to a signal supplied by the tension measuring device. A slider moving device that automatically keeps the tension substantially constant is used. The transmission can be composed of an electric motor and a system for transmitting movement from the motor to the slider.For example, in a system in which a screw and a nut are coupled, the screw extends in parallel to the linear guide and can be driven to rotate by the power of the motor. And the nut is connected to a slider or a belt transmission, for example a toothed belt transmission.

Since the fiber tension is automatically controlled without using forces such as gravity or other predetermined forces, the optical fiber tensioning device is used to modulate the tension applied to the optical fiber in a desired manner. be able to.

Thus, the movement of the movable pulley is achieved completely independently of gravity and a predetermined elastic force, and is achieved by applying a controllable force. Thus, there is provided a tensioning device that automatically adapts itself to any changes in operating conditions.

As a first feature, the present invention relates to an optical fiber pulling device used for an optical fiber feeding path, comprising at least one movable pulley around which an optical fiber is wound over at least a predetermined length. A tension measuring device that measures the applied tension and generates a tension instruction signal, wherein the tension measuring device is configured to measure a tension applied to the movable pulley so that a tension applied to the optical fiber is corrected. Receiving the instruction signal, moving the movable pulley according to the tension instruction signal,
The motor drive transmission for the movable pulley, which automatically keeps the tension applied to the optical fiber substantially constant.

Preferably, the pulling device also includes a fixed pulley around which the optical fiber is wound at least over a predetermined length, wherein a distance between the fixed pulley and the movable pulley is variable, and The tension applied to the fiber can be modified, and the motor drive transmission can control the distance to automatically keep the tension applied to the optical fiber substantially constant.

The motor drive transmission includes a guide for moving and guiding a slider supporting the movable pulley, and an actuator device for moving the slider along the guide.

The actuator device may further comprise a screw rotatably movable under the force of the electric motor for connecting the motor to the slider, and a nut coupled to the slider.
Alternatively, it is provided with an electric motor and a belt transmission system (for example, using a toothed belt).

The tensioning device includes an electronic control unit that receives a reference signal and a measurement signal at an input and generates an operation signal for controlling the motor drive transmission in a closed loop in response to the input.

The electronic control unit forms a system for controlling the tension applied to the optical fiber in a closed loop, and includes a tension reference signal proportional to a target tension value of the optical fiber and a tension reference signal indicating the tension of the optical fiber. A subtractor to which a measurement signal composed of a signal is supplied; and a drive signal used to receive the tension error signal supplied from the output of the subtractor to the input and to operate the motor drive transmission to control the distance. And preferably a proportional / integral / differential type controller.

Thus, a closed-loop control of the fiber tension is provided, whereby the tension is constantly monitored and direct intervention of the gearing is provided whenever the measured tension deviates from the reference tension. The fiber tension is thus kept constant at the reference tension, and particularly fine control is performed.

Preferably, the tension measuring device includes a load cell connected to the fixed pulley for generating and outputting a tension instruction signal. Preferably, the motor drive transmission device includes a guide that guides a slider that supports the movable pulley, and an actuator device that moves the slider along the guide, and the electronic control unit is configured to move along the guide. A system for controlling the position of the slider in a closed loop is provided.

Preferably, the tensioning device is operatively connected to an optical fiber integrated device for receiving an optical fiber, and wherein the system for controlling the position of the slider along the guide in a closed loop comprises the system along the guide. Another subtractor, to which a reference signal correlated to the reference position of the slider and a measurement signal proportional to the actual position of the slider along the guide, and an output from the other subtractor to the input. And preferably another proportional-integral-differential type controller for receiving another tension error signal and outputting another drive signal used for operating the integrated device.

The accumulator has at least one motor-driven reel on which an optical fiber from a pulling device is wound, and the motor-driven reel is rotated by an electric motor. The other drive signal is a signal that can be used to control the electric motor.

[0027] Preferably, the electronic control unit receives a signal correlated with a moving speed of the slider along the guide at an input, and generates and outputs the measurement signal proportional to an actual position of the slider along the guide. It has an integrator.

In this way, it is ensured that the movable pulley is always kept close to the reference position, and that it is always possible to move the movable pulley from this reference position in a manner that is effective in compensating for variations in tension. Thus, the slider is no longer allowed to be positioned at a terminal position where the movable pulley can no longer move in one direction.

As a further feature, the present invention relates to a method of controlling the tension applied to an optical fiber along a feed path of the optical fiber, the method being variable to modify the applied tension of the fiber. Forming a part of the feed path having a length, measuring a tension applied to the optical fiber, automatically controlling the length by a motor according to the measured tension, and applying the length to the optical fiber. Maintaining the tension substantially constant.

Preferably, the method comprises the steps of: at least one reference signal proportional to a target tension of the fiber, and a measuring signal generated in the tension measuring step and proportional to a tension actually applied to the optical fiber. In a closed loop control of the tension applied to the

Preferably, the step of controlling the tension in a closed loop includes a step of comparing the measurement signal with the reference tension signal to generate a tension error signal, and a step of processing the error signal to correct the length by a motor. And generating and outputting a drive signal used to keep the tension in the fiber substantially constant.

[0032] The method preferably comprises the step of following the at least one reference signal proportional to the target position of the movable member and the measurement signal generated in the tension measuring step and being proportional to the current position of the movable member. A step of controlling the position in a closed loop, wherein a change in the position of the movable member causes a change in the length.

The method preferably comprises the step of integrating an optical fiber at the end of the feed path, wherein the step of controlling the position of the movable member in a closed loop comprises comparing the position measurement signal with the position reference signal. Generating a position error signal;
Processing the position error signal to generate and output a drive signal used to modify the speed at which the optical fiber is integrated.

As a further feature, the present invention relates to an optical fiber processing system, for example, a drawing tower, an extrusion process, or an apparatus for measuring the breaking strength of an optical fiber, in which an optical fiber is supplied from an optical fiber source, such as an optical fiber puller. There is an optical fiber tensioning device for receiving and delivering the optical fiber to a device for accumulating the optical fiber, for example a motor driven reel, wherein the tensioning device comprises at least an optical fiber wound around at least a predetermined length. A tension measuring device including one movable pulley, wherein the position of the movable pulley is variable to correct the tension applied to the optical fiber, and further measures the applied tension to generate a tension instruction signal; and Upon receiving the signal, the movable pulley is moved according to the tension instruction signal, and the tension applied to the optical fiber is automatically kept substantially constant. Wherein in which and a motor drive transmission system for a movable pulley which can.

Preferably, the system comprises an electronic control unit which can constitute a closed-loop control system for the tension applied to the optical fiber, the system comprising a tension reference signal proportional to the target tension value of the optical fiber. And a subtractor to which a measurement signal consisting of the signal indicating the tension is supplied, and a tension error signal supplied to the input from the output of the subtracter, and the motor drive transmission device is operated to determine the distance. And a controller for generating and outputting a drive signal used for control.

Preferably, the motor drive transmission comprises:
A system for guiding a slider that supports the movable pulley, the actuator being configured to move the slider along the guide, wherein the electronic control unit controls the position of the slider in a closed loop along the guide. It is provided with.

Preferably, the tensioning device is operatively connected to an optical fiber integrated device, and the system for closed-loop control of the position of the slider along the guide is provided at a reference position of the slider along the guide. Another subtractor provided with a correlated reference signal and a measurement signal proportional to the actual position of the slider along the guide;
Another controller for receiving a tension error signal supplied from an output of the another subtractor to an input, and outputting another drive signal used to operate the integrated device;
It preferably has a proportional / integral / differential controller.

Hereinafter, although not limited thereto,
The present invention will be described with reference to the accompanying drawings, which illustrate preferred embodiments of the invention. In FIG. 1, reference numeral 1 indicates the entire optical fiber pulling apparatus.

The tensioning device 1 includes a support panel (for example, made of metal) 3 mounted on a frame (not shown), and the frame fixedly positions the support panel 3 in, for example, a horizontal or vertical position. ing.

The tensioning device 1 also comprises, in this case, two cylindrical rods 12a, 12b specially mounted on the support panel 3.
And a slider 7 that can reciprocate along the linear guide 5 and supports a first pulley 9, which is hereinafter referred to as a movable pulley. The moving direction of the slider 7 is indicated by D in FIG.

The cylindrical rods 12a and 12b are arranged in parallel with each other, and each end is supported by a pair of support members 15a and 15b fixed to the support panel 3. The slider 7 may be rectangular in plan view and may include sliding elements 7a, 7b which engage rods 12a, 12b, respectively. For example, the sliding engagement between the slider 7 and the rods 12a and 12b can be formed by a collar of the sliding bearing 18 or a ball bearing.

The movable pulley 9 is preferably mounted on a pin 20 extending vertically from the slider 7 so that the rotation axis of the movable pulley 9 is perpendicular to the moving direction D of the slider 7. The slider 7 is driven by the power of an electric motor 24, preferably a motor having an output shaft connected to a screw 26 arranged between the rods 12a, 12b and extending parallel to both rods. The motor 24 can protrude on a bracket 28 fixed to the panel 3, the ends of the screws 26 preferably being supported by corresponding support members 30 a, 30 b also fixed to the panel 3. I have. The screw 26 is advantageously connected to a revolving ball nut (not shown) fixed to the side of the slider 7 opposite to the movable pulley 9.

In addition, the transmission operation from the motor 24 to the movable pulley 9 can be provided by, for example, belt transmission provided with a toothed belt (not shown). The tensioning device 1 also comprises a second pulley, hereinafter referred to as a fixed pulley, which extends, for example, perpendicularly to the panel 3 on the part of the panel 3 opposite to that occupied by the motor 24, for example. Mounted on pin 33.

The fixed pulley 32 preferably has the same diameter as the movable pulley 9, and the axes of rotation of the pulleys 9 and 32 are preferably parallel to each other. The rotation of the transmission motor 24 causes a linear movement of the slider 7 along the guide 5,
Thus, the distance Dp between the movable pulley 9 and the rotation axis of the fixed pulley 32 is corrected.

In particular, the distance Dp is determined by the slider 7
4 (Dp) at the first end position (not shown) locked by the brackets 15a and 15b farthest from
Min) and the maximum value (DpMax) when the slider 7 is at a second end position (not shown) in which the slider 7 is locked to the brackets 15a and 15b closer to the motor 24. .

The tensioning device 1 can also be provided with a transparent protective housing (wagon, not shown) which can be connected to the support panel 3 and accommodate the entire mounting of the panel 3. The tensioning device 1 can be adapted to a feed path of the optical fiber 35, for example, an optical fiber drawing tower (not shown), and can receive an optical fiber from an optical fiber source 37 (schematically shown). A non-limiting example contemplated here is where the fiber optic source 37 is a traction device ("capstan") for a fiber optic draw tower (not shown). Alternatively, the fiber optic source 37 may be a member or device for returning or guiding the fiber or a supply reel of fiber.

The optical fiber 35 extends from the pulling device 37 toward the fixed pulley 32 to form a straight portion 35a, and is wound around the fixed pulley 32 (for example, over 180 °). Extending between the fixed pulley 32 and the movable pulley 9 to form a second linear portion 35b, which is wound (over 180 °) around the movable pulley 9;
Finally, it extends between the movable pulley 9 and the device 40, thus forming a third linear portion 35c. A non-limiting example contemplated here is that the device 40 (schematically shown) comprises a motor-driven reel 4 on which an optical fiber 35 can be wound.
2 is an integrated device. Motor driven reel 42
Can be rotated around the rotating shaft 43 in accordance with the movement of the electric motor 45. Otherwise, device 4
0 may be a member or device for returning or guiding the optical fiber.

Although not essential, preferably, the straight portion 35
a, 35b, and 35c are preferably parallel to each other. It is advantageous to provide between the device 37 and the tensioning device 1 and between the tensioning device 1 and the device 40 a return pulley, not shown in FIG. 1 for simplicity.

The electronic control circuit 50 can control the electric motor 24 and the electric motor 45 via corresponding drive circuits (“drivers”) 24p and 45p. The tensioning device 1 advantageously comprises a tension measuring device 56, for example a load cell, which is preferably connected to the pin 33 of the fixed pulley 32. The tension measuring device 56 can generate a signal Tmis proportional to the tension applied to the optical fiber 35 and is connected to the electronic control unit 50 that supplies the signal Tmis to the electronic control unit 50.

With particular reference to FIG.
Is illustrated in detail. The electronic unit 50 includes a subtractor 60 to which a signal To proportional to the target tension of the fiber and a signal Tmis proportional to the tension actually applied to the optical fiber 35 are supplied. The subtractor 60 calculates the error signal ε = ΔT =
To-Tmis (tension error) is generated, and this error signal is supplied to a controller, particularly a PID (proportional / integral / differential) type controller, which outputs an output signal ω (a voltage-operated drive circuit 24p). It generates and outputs a compatible voltage signal.

The PID controller is a controller which receives an input signal Si and generates an output signal So normally specified below. So (t) = Kp ｛Si (t) + (1 / Ti) ∫Si (t) dt + T
d · dSi (t) / dt｝ where the integral section of the integral term is from 0 to t.

The PID controller is therefore specified by three constants Kp, Ki = Kp / Ti, Kd = Kp.Td. The signal ω is converted into a power signal by a (known) drive circuit 24p to operate the motor 24. The rotational speed of the motor 24 is therefore correlated to the signal ω. Signal ω
Is also supplied to the conversion unit 64 to generate and output an output signal V correlated to the linear movement speed of the slider 7 along the guide 5.

In practice, the maximum speed of the motor 24 (the number of revolutions per second rps) is V _max , ω _max is the (voltage) value of the signal ω related to the maximum speed V _max , and the pitch of the screw is p. , The general value of the signal ω at time t (output from the controller 62)
Assuming (t), the conversion unit 64 generates and outputs a signal V, and the value V (t) at time t is given by V (t) = (V _max / ω _max ) · ω (t) · p .

In practice, the conversion unit 64 is provided with a conversion function relating to the rotation angle of the screw 26 with respect to the linear velocity of the slider 7. The signal V is supplied to a further conversion unit 66, which integrates the signal V,
A signal Pmis (voltage) related to the instantaneous position of the slider 7 along the guide 5 is generated and output.

The position signal Pmis is supplied to a subtractor 70, to which a signal Po proportional to the target position of the slider 7 along the guide 5 is also supplied. Preferably, the target position of the slider is located at an intermediate position between the first and second end positions.

The subtractor 70 calculates the error signal ε = ΔP = Po−
Pmis is generated and output.
2 (especially PID (proportional / integral / derivative) controller)
The controller generates an output signal ωb that is converted into a power signal by a (known) drive circuit 45p after the conversion, and drives the motor 45. The signal ωb is output to the reel 42
Correlates with the rotation speed of

In operation, the fiber tension Tmis increases and deviates from the target value To when the accumulating device imparts a higher speed to the incoming optical fiber 35 than the speed provided by the output of the traction device 37.

As a result, the tension error ΔT (in this case, a negative value) increases in absolute value, and the controller 62
Drives the motor 24 via the drive circuit 24p, thereby moving the slider 7 to the first end position, so that the distance Dp and the length of the fiber portion 35b located between the two pulleys 9 and 32 are reduced. Decrease. The decrease in the length of the portion 35b thus opposes the increase in fiber tension to keep the fiber tension substantially constant.

Conversely, when the accumulator 40 dispenses the incoming optical fiber 35 with a lower speed than the output of the traction device 37, the fiber tension Tmis decreases and deviates from the target value To. . As a result, the tension error ΔT
(In this case, a positive value) increases and the controller 6
2 rotationally drives the motor 24 via the drive circuit 24p,
This causes the slider 7 to move toward the second end position, thereby increasing the distance Dp and the length of the portion 35b. Increasing the length of portion 35b opposes decreasing the fiber tension to keep the fiber tension substantially constant.

Thus, motor-driven closed loop control of the tension is performed, which returns the fiber tension to the target value To. Further, the unit 66 determines the instantaneous position Pmis of the slider 7 along the guide 5 by integrating the signal V (correlated to the linear velocity of the slider 7). This instantaneous position is compared with the target position Po, and the position error ΔP processed by the conversion unit 72 generates a variation in the rotation speed of the motor 45. In particular, when the slider 7 is in the first position
Approaching the end position of FIG. 1 (in FIG. 1 with the slider 7 moved to the left), the control system reduces the rotational speed of the motor 45, thereby reducing the tension in the fiber 35 and causing the tension control loop to The slider 7 is moved toward the second end position (i.e., to the right in FIG. 1) to compensate for the tension fluctuation (by the motor 24 and the screw 26), and thus the position fluctuation is compensated.

Further, when the slider 7 is at the second position
Approaching the end position (with slider 7 moved to the right in FIG. 1), the control system increases the rotational speed of motor 45 so that the tension in fiber 35 increases, and the tension control loop The slider 7 is moved toward the first end position (i.e., to the left in FIG. 1) to compensate for the tension variation (by the motor 24 and the screw 26), and thus the position variation is compensated.

Thus, the closed loop position control is performed, and the slider is returned to the target position Po. If requested
The position controller may be eliminated. In that case, the control device does not include the components represented by reference numerals 64, 66, 70, 72, and 45p.

In the above description, the movement of the movable pulley 9 depends only on the movement of the electric motor 24 and is completely independent of the gravity or other force (for example, elastic force) applied to the movable pulley 9. In this regard, the present invention clearly illustrates the advantages of the present invention. This is because a force of a value that can be automatically controlled in accordance with an operation signal given to the motor 24
5 is given. The tensioning device 1 automatically adapts itself to any changes in operating requirements (such as fluctuations in the pulling speed or changes in the position of the slider 7), and returns the tension value applied to the fiber to the target value. .

Further, the movable pulley 9 is always kept close to the reference position (in particular, the center position of the guide 5), and can be moved therefrom (to the right or to the left) in an always effective manner.
It is ensured that the tension change can be effectively prevented. That is, the slider 7 is prevented from being positioned near the first and second end positions where the movement of the slider in one of the two directions is no longer possible.

The tensioning device 1 is a device of a different type, for example, a drawing tower, an extrusion process, a test device for testing an optical fiber for breaking strain (“selection device”).
ngapparatus).

The drawing tower is a preformed product (pre) of a glass material.
a furnace for melting the form, a traction member (ie, a "capstan", such as one of a single pulley type or a two pulley type) for pulling down the optical fiber produced from the molten preform, and a furnace. The coating device includes a coating device disposed between the pulling member and the optical fiber to cover the optical fiber with a protective film, and a fiber take-up reel that receives the fiber from the pulling member. As described above, the tensioning device 1 is conveniently arranged between the traction member and the take-up reel.

The extruding step is a processing step in which a plurality of optical fibers are fed together with a wire-shaped supporting element. In accordance with this step, a polymer material is extruded onto the supporting element, whereby the optical fiber is incorporated into the supporting element. In a fixed state at the position around the optical cable, thus forming the optical core of the optical cable. The extrusion process typically extrudes a take-up reel for a support element, a plurality of fiber supply reels, an extruder capable of receiving both the fiber and the support element at an inlet, and an optical core formed within the extruder. It has a cooling container received from the machine and a final take-up reel. During the extrusion process, the tensioning device 1 is arranged, for example, downstream of each fiber supply reel.

The selection device is typically used to check that the fiber can withstand a given tension and is thus independent of significant structural defects. The selection device generally forms a supply reel for the optical fiber, a take-up reel for the optical fiber, and an optical fiber path between the supply reel and the take-up reel. It has a plurality of guide and / or return elements that can apply a predetermined tension. In the selection device, the device 1 can be arranged at any location on the feed path.

At the conclusion, it is evident that modifications and variations can be made to the described device without departing from the scope of the invention. In particular, the system for moving the slider 7 (the screw 26 and the nut connected to the slider 7) can be different from the one described above, for example a movable tooth between two end pulleys connected to the slider 7. An attached belt (not shown) may be used.

Finally, the position Pmis of the slider 7 along the guide 5 is determined not by the indirect method as shown in FIG.
A row of position sensors (not shown), such as photocell rows and optical strips (that is, a one-dimensional array light detection component such as a one-dimensional array CCD (not shown)) arranged along
Can also be measured by a direct method.

[Brief description of the drawings]

FIG. 1 is a plan view of an optical fiber pulling device according to the present invention.

FIG. 2 is a block diagram of an electronic unit for the control device of FIG. 1 according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Tension device 3 Support panel 3a, 3b, 15a, 15b Support member 5 Guide (motor drive transmission device) 7 Slider (motor drive transmission device) 7a, 7b Sliding element 9 Movable pulley 12a, 12b Cylindrical rod 18 Sliding bearing 20, 33 axis 24 electric motor (actuator device, motor drive transmission device) 24p, 45p drive circuit 25, 35 optical fiber 26 screw (actuator device, motor drive transmission device) 28 bracket 32 fixed pulley 37 optical fiber source 40 optical fiber integration Device 42 Motor driven reel 45 Electric motor 50 Electronic control device (motor drive transmission device) 56 Tension measuring device 56 Load meter 60, 70 Subtractor 62, 72 Controller 66 Integrator

 ────────────────────────────────────────────────── ─── Continuation of the front page (71) Applicant 591011856 p. A (72) Inventor Roberto Pata, Italy 24121 Bergamo, Via dei Partigianni 10 (72) Inventor Franco Veronelli Milan, Italy, 20020 Lainate, Vicolo Stopani 5

Claims (20)

[Claims] An optical fiber pulling device for use in a feed path of an optical fiber (35), comprising at least one movable pulley (9) around which the optical fiber (35) is wound at least over a predetermined length. The tensioning device, wherein the position of the movable pulley (9) is variable so that the tension applied to the optical fiber (35) can be corrected. The tension that measures the applied tension and generates and outputs a tension instruction signal (Tmis). A measuring device (56) and a motor drive transmission (24,
26, 5, 7, 50), and the tension instruction signal (T
mist), and a device that moves the movable pulley according to the tension instruction signal (Tmis) and automatically keeps the tension applied to the optical fiber (35) substantially constant. . 2. The apparatus according to claim 1, further comprising a fixed pulley (32) around which the optical fiber (35) is wound over at least a predetermined length, wherein a shaft (33) of the fixed pulley (32). ) And the distance (Dp) between the movable pulley shaft (20) is variable to correct the tension applied to the optical fiber, and the motor drive transmission (24, 26, 5, 7) An apparatus for controlling the distance (Dp) to automatically keep the tension applied to the optical fiber substantially constant. 3. The device according to claim 1, wherein the motor drive transmission (24, 26, 5, 7) guides the slider (7) for supporting the movable pulley (9) to move. 5) and an actuator device (26, 24) for moving the slider (7) along the guide (5). 4. The device according to claim 3, wherein the actuator device is coupled to a screw (26) rotatable under the force of an electric motor (24) and the slider (7). An apparatus, comprising: a nut; 5. The device according to claim 3, wherein the actuator device comprises an electric motor (24) and a belt-driven transmission system. 6. The device according to claim 2, wherein the reference signal (To, Po) and the measurement signal (Tmis, Pm)
is) as an input, and in response to the input signal, an electronic control unit (50) for generating an operation signal (24p, 45p) for performing closed-loop control of the motor drive transmission (24, 26, 5, 7). ). 7. The device according to claim 6, wherein the electronic control unit (50) comprises the optical fiber (35).
Forming a closed-loop control system for the tension applied to the optical fiber, and a tension reference signal (T
o) and a measurement signal (Tmi) comprising the tension instruction signal.
s) is supplied, and a tension error signal (ε = ΔT = To−Tmis) supplied from the output of the subtracter (60) to the input is received, and the motor drive transmission device (24) is supplied. , 26, 5, 7) to output a drive signal (ω) used to control the distance (Dp). 8. The apparatus according to claim 7, wherein the controller (62) is of a proportional-integral-differential operation type.
(rivative) controller. 9. Apparatus according to claim 7, wherein the tension measuring device (56) comprises the fixed pulley (32).
A load cell (56) connected to the load cell for outputting the tension indication signal (Tmis). 10. The device according to claim 6, wherein the motor drive transmission (24, 26, 5, 7) guides a movement of a slider (7) supporting the movable pulley (9). (5), and an actuator device (26, 24) for moving the slider (7) along the guide (5), wherein the electronic control unit (50) includes the slider along the guide (5). (7) An apparatus for configuring a system for performing closed-loop control of the position. 11. The apparatus according to claim 10, wherein the apparatus is operatively connected to an optical fiber accumulator (40) capable of receiving and accumulating optical fibers from a pulling device, along the guide (5). The closed-loop control of the position of the slider (7) by means of a position reference signal (P _O ) correlated to a reference position of the slider (7) along the guide (5);
And a measurement signal (Pmis) proportional to the actual position of said slider (7) along
0) and a position error signal (ε = ΔP = Po−Pmis) supplied to the input from the output of the other subtracter (70), and is used to operate the integrated device (40) (45).
p) another controller (72) for outputting another drive signal (ωb) to be applied. 12. The apparatus according to claim 11, wherein said another controller (72) comprises:
An apparatus comprising a differential operation type controller. 13. The device according to claim 11, wherein the accumulator (40) comprises at least one motor-driven reel (42) around which the optical fiber (25) from the pulling device (1) is wound. The motor-driven reel (42) is provided with an electric motor (4).
In response to the movement of 5), it rotates around the rotation axis (43), and the other drive signal (ωb) is
(45p) used for the control of the apparatus. 14. The device according to claim 11, wherein the electronic control unit (50) receives an input signal (V) that is correlated to a speed of movement of the slider (7) along the guide (5). The measurement signal (Pmi) proportional to the actual position of the slider (7) along the guide (5)
device comprising an integrator (66) for outputting s). 15. A method for controlling the tension applied to an optical fiber along a feed path of an optical fiber (35), wherein the length (Dp) is varied to correct the tension applied to the fiber. The step of forming a part (35b) of the feed path having a step of measuring (56) a tension applied to an optical fiber; and the length (Dp) according to the measured tension. Automatically controlling by a motor to keep the tension applied to the optical fiber substantially constant. 16. The method according to claim 15, wherein at least one reference signal (To) proportional to the target tension of the fiber and a measurement signal generated in the tension measuring step and proportional to the actual tension experienced by the optical fiber. (Tmis) in accordance with (Tmis), the method comprising the step of: controlling the tension applied to the optical fiber in a closed loop. 17. The method of claim 16, wherein the step of controlling the tension in a closed loop comprises comparing the tension reference signal (To) with the measurement signal (Tmis).
Generating a tension error signal (ε = ΔT = To−Tmis); processing (62) the error signal; and correcting the length (Dp) with a motor to keep the fiber tension substantially constant. Generating and outputting a drive signal used in the method. 18. The method according to claim 15, wherein at least one reference signal (Po) proportional to a target position of the movable member (7) and a measurement signal (Pmis) proportional to a current position of the movable member. And controlling the position of the movable member in a closed loop according to the method, wherein a change in the position of the movable member (7) causes a change in the length (Dp). 19. The method according to claim 18, wherein an optical fiber is integrated at the end of the feed path, and the step of closed-loop control of the position of the movable member (7) comprises the step of controlling the position reference signal (Po). To the position measurement signal (Pmi
s) and compares (70) with the position error signal (ε = ΔP = Po).
-Pmis) and processing (72) the position error signal to generate and output a drive signal (ωb) used (45p) to modify the speed at which the optical fiber is integrated. A method, comprising: 20. An optical fiber processing system, comprising: an optical fiber source (37); an optical fiber tensioning device (1) for receiving an optical fiber (35) from the optical fiber source (37); and a tensioning device (1). An optical fiber accumulator (40) for receiving an optical fiber from the optical fiber; the tensioning device (1) comprises at least one movable pulley (9) around which the optical fiber (35) is wound by at least a predetermined length; The position of the movable pulley (9) is variable so that the tension applied to the optical fiber can be corrected. The tensioning device (1) measures the applied tension and outputs a tension instruction signal (Tmis). A measuring device (56) to be generated; and a motor drive that receives the tension instruction signal, moves the movable pulley (9) according to the tension instruction signal, and automatically keeps the fiber tension substantially constant. A dynamic transmission (7, 24, 26).