JP2000275139A - Method and apparatus for screening of optical fiber strand - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and an apparatus, for the screening of an optical fiber strand, in which the external damage of the optical fiber strand is not generated due to the sudden take-up of the optical fiber strand on a take-up machine (due to a so-called whiplash phenomenon) when the optical fiber strand is fractured, and in which the optical fiber strand being taken up on the take-up machine does not intrude. SOLUTION: In this screening method for an optical fiber strand, the optical fiber strand 2 which is let off from a letting-off machine 1 is passed through a dancer roll 3 for the letting-off machine, a set tension is applied to the optical fiber strand between a letting-off capstan 4 and a take-up capstan 6, and the optical fiber strand is taken up on a take-up machine 8 via a dancer roll 7 for the take-up machine. A screening tension sensor 10 is installed between the letting-off capstan 4 and the take-up capstan 6. The tension which is applied to the optical fiber strand 2 is monitored by the screening tension sensor 10. The take-up machine 8 is stopped at a point of time when the tension reaches a set value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for screening an optical fiber for guaranteeing the strength of the optical fiber manufactured in the drawing step over the entire length.

[0002]

2. Description of the Related Art An optical fiber is obtained by heating and melting a preform rod composed of a core part and a clad part having a light transmitting function, spinning the rod to a predetermined outer diameter, and applying a protective coating layer. Can be This manufacturing process is called a drawing process. For the manufactured optical fiber, a screening step of applying a constant tension to the optical fiber and then winding it up is imposed in order to guarantee the strength over the entire length. This step is performed immediately after the drawing step. If a low-strength portion exists in the optical fiber, the optical fiber breaks due to the applied tension, and the low-strength portion is deleted by the break.

FIG. 2 is a schematic front view showing a conventional optical fiber screening apparatus. 11 is a feeder, 12 is an optical fiber, 13 is a dancer roll for a feeder, 14 is a feeder capstan, 15 is a load dancer roll, 16 is a take-up capstan, 17 is a dancer roll for a winding machine, and 18 is a winding roll. A picker 19 is a limit switch.

[0004] The optical fiber produced by the drawing process is wound around a bobbin. The bobbin is mounted on the feeder 11, and the optical fiber is fed. The sent optical fiber 12 passes through the feeder dancer roll 13 and is fixed between the feed capstan 14 and the take-up capstan 16 by the load of the load dancer roll 15 or the rotational force of the take-up capstan 16. Is applied, and then wound up by a winder 18 via a dancer roll 17 for the winder. In this manner, the screening of the optical fiber 12 is performed over the entire length.

In the above-described apparatus, limit switches 19 are provided at the respective portions of the dancer roll 13 for the feeder, the dancer roll 17 for the winding machine, and the load dancer roll 15, and the running optical fiber 12 is broken. When opened, these limit switches 19 are operated to stop the drive units such as the winder 18.

[0006]

The conventional method and apparatus for screening an optical fiber have the following problems.

When the optical fiber 12 is broken between the delivery capstan 14 and the take-off capstan 16, the load dancer roll 15 starts to return to the open state. At the same time, the speed of the take-up capstan 16 changes, and the optical fiber 12 between the take-up device 18 and the take-up capstan 16 instantaneously loosens.

At the next moment, the rotation speed of the winder is increased by the control of the dancer roll 17 for the winder, whereby the optical fiber strand 12 between the take-up capstan 16 and the winder 18 is moved. Is wound by the winder 18 with a strong force. Then, the optical fiber 12 causes a phenomenon of whipping the winding machine 18, so to speak, and the wound optical fiber has been damaged by the whipping phenomenon. Alternatively, even if no damage is caused, the optical fiber strand deeply penetrates into the optical fiber strand wound by the winder 18, so that the wound optical fiber strand cannot be used.

Accordingly, an object of the present invention is to solve the above-mentioned drawbacks of the prior art, and when the optical fiber strand breaks, the optical fiber strand is suddenly wound by a winder (the so-called whipping phenomenon). (2) An object of the present invention is to provide a method and an apparatus for screening an optical fiber, which do not cause damage to the optical fiber or damage to the optical fiber wound by the winding machine.

[0010]

According to the present invention, in order to achieve the above object, an optical fiber fed from a feeder is fixed between a feed capstan and a take-up capstan via a dancer roll for the feeder. In the method of screening an optical fiber to be wound by a winder through a winder dancer roll after applying the tension of the winder, a screening tension sensor is provided between the sending-out capstan and the take-off capstan. The tension applied to the optical fiber was monitored by the screening tension sensor, and when the tension reached a set value, the winding machine was stopped.

[0011] The set value of the tension for stopping the winding machine is a minimum of 85% of the specified value applied to the optical fiber.
%, And after the tension monitored by the screening tension sensor has reached the set value, the winder 1
Stopped completely within seconds.

In order to achieve the above object, the present invention provides a feeder for feeding an optical fiber, a feed capstan for applying a constant tension to the optical fiber, a take-off capstan, and the optical fiber. In a screening device for an optical fiber, comprising a winder for winding up, a screening tension sensor for monitoring a tension applied to the optical fiber between the delivery capstan and the take-off capstan, A winder control device for stopping the winder in response to a signal from the screening tension sensor.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic front view showing an embodiment of an optical fiber screening apparatus according to the present invention. 1 is a feeder, 2 is an optical fiber, 3 is a dancer roll for a feeder, 4 is a feed capstan, 5 is a load dancer roll, 6 is a take-up capstan, 7 is a dancer roll for a take-up machine, and 8 is a roll. Taking machine,
9 is a winding machine control device, and 10 is a screening tension sensor.

The optical fiber produced by the drawing step is wound around a bobbin. The bobbin is mounted on the feeder 1, and the optical fiber is fed. The fed optical fiber 2 passes through the feeder dancer roll 3 and is fixed between the feed capstan 4 and the take-up capstan 6 by the load of the load dancer roll 5 or the rotational force of the take-up capstan 6. And then wound up by a winder 8 via a winder dancer roll 7. In this manner, the screening of the optical fiber 2 is performed over the entire length.

The screening tension sensor 10 has a structure in which a load cell capable of measuring a tensile load or a compressive load up to about several kg is incorporated in a turn pulley immediately after the delivery capstan 4. The tension of the optical fiber 2 can be monitored.

When the optical fiber 2 is broken by the applied tension, the tension falls below the specified value almost simultaneously with the break. Here, it is important that the screening tension sensor 10 sense the change in the tension and the winder control device 9 outputs a stop signal to the winder 8 promptly.

The stop signal is transmitted from the screening tension sensor 1
The point at which the monitored tension of 0 decreases to a value of 85% of the prescribed applied tension is defined as the breakage of the optical fiber, and is generated at the latest by this breakage. In response to the stop signal, the winder 8 is configured to completely stop within one second after the stop signal is issued or when the screening tension sensor 10 detects a change in tension.

Here, after a break, that is, when the stop signal is issued after the monitored tension has decreased to 85% or less of the specified applied tension, the winder 8 stopped within one second. Even if the stop signal is output to the winding machine 8 and the winding is stopped, the same control as during traveling is performed on the optical fiber before winding, and the problem is not solved. In other words, the so-called whipping phenomenon cannot be suppressed, and the time for controlling the winder 8 is too slow.

If the stopping time of the winding machine 8 is 1 second or longer, the optical fiber strand is wound on the winding machine 8 even if no damage occurs on the wound optical fiber strand. A phenomenon that penetrates deeply into the bare optical fiber,
The problem cannot be solved because the wound optical fiber cannot be used.

Therefore, the time when the tension decreases to 85% of the specified applied tension is defined as the breakage of the optical fiber, and the winder 8 is stopped within one second from this point, so that the dancer roll 7 for the winder is stopped. Before the rotation speed of the winder 8 is increased by the control of (1), the winder 8 is completely stopped, and the problem of the prior art is solved. That is, when the optical fiber is broken, the optical fiber is rapidly wound by the winder 8 (by a so-called whiplash phenomenon), or the optical fiber is wound by the winder 8. The phenomenon of biting into the existing optical fiber does not occur.

[0021]

According to the method and the apparatus for screening an optical fiber of the present invention, the tension applied to the traveling optical fiber is monitored, and the tension is applied to the optical fiber. When a minimum value of 85% is reached, a stop signal is sent to the winder, and it can be completely stopped within 1 second. Therefore, when the optical fiber is broken, It is possible to prevent an optical fiber strand from being damaged due to sudden winding by the winder (a so-called whiplash phenomenon) and biting into the optical fiber wound by the winder.

[Brief description of the drawings]

FIG. 1 is a schematic front view showing an embodiment of an optical fiber screening apparatus of the present invention.

FIG. 2 is a schematic front view showing a conventional optical fiber screening apparatus.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 feeder 2 optical fiber 3 feeder dancer roll 4 feeder capstan 5 load dancer roll 6 take-up capstan 7 winder dancer roll 8 winder 9 winder control device 10 screening tension sensor 11 feeder Reference Signs List 12 optical fiber 13 dancer roll for feeder 14 feeder capstan 15 load dancer roll 16 take-up capstan 17 dancer roll for winder 18 winder 19 limit switch

Claims (3)

[Claims] 1. An optical fiber fed from a feeder is fed through a dancer roll for a feeder, a constant tension is applied between a feed capstan and a take-up capstan, and then passed through a dancer roll for a winder. In the method for screening an optical fiber to be wound by a winder, a screening tension sensor is provided between the delivery capstan and the take-off capstan, and the screening tension sensor applies the screening tension sensor to the optical fiber. A method for screening an optical fiber, wherein the tension is monitored and the winding machine is stopped when the tension reaches a set value. 2. A set value of a tension for stopping the winding machine is a minimum value of 85% of a specified value applied to the optical fiber, and a tension monitored by the screening tension sensor is equal to the set value. 2. The method for screening an optical fiber according to claim 1, wherein the winder is completely stopped within one second after that. 3. A feeder for feeding an optical fiber,
An optical fiber screening apparatus comprising: a feed capstan for applying a constant tension to the optical fiber; a take-up capstan; and a winding machine for winding the optical fiber. A screening tension sensor for monitoring the tension applied to the optical fiber between the take-up capstan and the take-up capstan; and a winder control device for stopping the winder by a signal from the screening tension sensor. An optical fiber screening device, characterized in that: