JPH0348108B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application This invention is capable of twisting thin wires, such as thin copper wires, optical fiber core wires, etc., which have a low tensile strength and are easy to stretch, without reducing the performance of the wires. The present invention relates to a tension adjustment device for unwinding a wire from a bobbin with a tension of 1,000,000 yen, and particularly to a tension adjusting device suitable for installing the device in a rotating body such as a planetary type twisting machine.

B. Prior Art In a twisting machine for optical fibers, since the optical fibers are weak, the tension of the wires fed out from the bobbin must be precisely controlled. As a tension adjustment device for this purpose, for example, the plan view shown in FIG.
An apparatus is used whose front view is shown in FIG. That is, the thin wire 1 wound around the bobbin 2 is connected to the fixed dancer roller 4 and the movable dancer roller 3.
It is fed out in the direction of the arrow in the drawing. The movable dancer roller 3 can freely slide along the guide rail 5 and is always pulled in the opposite direction to the fixed dancer roller by a tension spring 6, thereby applying tension to the line. A rack 7 is fixed to the movable dancer roller 3,
The rack 7 detects the displacement of the moving dancer roller by rotating a pinion 8 attached to the shaft of a displacement detector 12.

On the other hand, the electric signal from the displacement detector is transmitted to the motor 9 for driving the unwinding bobbin 2 via the control device, and the bobbin 2 is driven by the chain 13.
The wire feeding speed is controlled by controlling the rotational speed of the wire, and the tension of the wire is controlled by keeping the position of the moving dancer roller constant.

However, in this device, the tension force of the tension spring 6 that pulls the moving dancer roller 3 that applies tension to the wire increases or decreases in proportion to the amount of extension, so if the position of the moving dancer roller changes, the tension on the wire also changes. Unable to maintain constant tension. Also, since the movement of the moving dancer roller is transmitted to the displacement detector via a rack and pinion (or a chain, etc.), a transmission loss occurs due to friction, which increases the resistance of the moving dancer roller. Then,
It has the disadvantage of causing variations in wire tension.

FIGS. 3 and 4 are front views showing other conventionally used more general tension control devices.
In the apparatus shown in FIG. 3, a movable dancer roller 3 is provided directly below a fixed dancer roller 4, and the displacement of the movable dancer roller is taken as the rotation of a lever 14 to which a weight 15 is attached, and the rotation is detected by a displacement detector 1.
Detect with 2. In the device shown in FIG. 4, the displacement of the movable dancer roller 3 directly below the fixed dancer roller 4 is controlled by a rod 1 that slides along a guide rail 5.
6 to a belt 17 to which a weight 15 is attached, and the displacement detector 12 detects the movement of the belt 17 as rotation of a belt pulley. These devices are often used because they have a simple structure and good accuracy. However, since these devices use a weight to apply tension to the wire, they are not suitable for installation in a rotating body, such as a planetary type wire twisting machine, where the entire device rotates greatly and centrifugal force is exerted.

C. OBJECTS OF THE INVENTION It is an object of the present invention to provide a tension adjusting device which can eliminate the drawbacks of the conventional tension adjusting device described above, can keep the tension of a wire constant, and can be especially installed inside a rotating body.

D. Disclosure of the Invention The present invention provides a tension adjustment device that feeds out a wire from a bobbin through a line of dancer rollers, that is, a fixed dancer roller and a moving dancer roller, and controls the tension of the wire by detecting the displacement of the moving dancer roller. A constant tension spring is attached directly to the shaft of the detector, and the tip of the constant tension spring is connected to the shaft of the moving dancer roller to transmit an electric signal for tension control.

The present invention will be explained below with reference to the drawings.

FIG. 5 and FIG. 6 are a plan view and a front view showing an embodiment of the present invention. The thin wire 1 wound around the bobbin 2 passes through a fixed dancer roller 4 and a movable dancer roller 3 and is fed out in the direction of the arrow in the drawing. The movable dancer roller 3 can freely slide along the guide rail 5. On the other hand, a constant tension spring 20 is attached to the shaft of the displacement detector 12.
is wrapped around it. The tip of this constant tension spring 20 is connected to the shaft of the movable dancer roller 3, and is always pulled in the direction opposite to the fixed dancer roller 4 of the movable dancer roller 3 to apply tension to the wire. As shown in FIG. 7, the constant tension spring 20 is a plate spring preformed in the shape of a clockwork, and the center of the coil portion of the mainspring is centered around the shaft 21.
, one tip is stretched out in a straight line, and the return force of that tip is used as a spring. As shown in the drawing, when the tip of this constant tension spring is stretched by △L, the leaf spring of the coil part becomes △
It is unraveled in a straight line by θ. If the energy accumulated per unit length of the leaf spring in the coil part when making it straight is E, then if the tip of the constant tension spring is extended by △L, the coil part will be extended straight by r (radius of curvature) x △θ. Therefore, △E∞r△θ∞△L, and △E
=F×ΔL (where F=proportionality constant, force), and therefore F (force)=constant. The coiled portion is fixed to the shaft 21 of the displacement detector 12, and the tip of the straight portion 22 is fixed to the shaft of the movable dancer roller 3. In this way, the moving side dancer roller 3
is always pulled with a constant tension in the opposite direction of the fixed dancer roller 4, that is, the tension of the unreeled wire is constant regardless of the position of the movable dancer roller 3. Further, the displacement of the movable dancer roller 3 is directly transmitted by the coil portion of the constant tension spring 20 as rotation of the shaft of the displacement detector. That is, the displacement is transmitted to the displacement detector by the constant tension spring 20 itself, and there is no resistance factor such as frictional resistance between them, which does not affect the tension.

E. Effects of the Invention As explained in detail above, the tension adjustment device of the present invention uses a constant tension spring to pull the movable dancer roller for adjusting the tension of the wire in the opposite direction to the fixed dancer roller, and The axis of the displacement detector is directly rotated by a constant tension spring, and the dancer roller displacement signal from the displacement detector is sent out to control the motor that drives the rotation of the bobbin to adjust the tension of the wire. Therefore, the tension of the wire can always be kept constant regardless of the position of the moving dancer roller, and since the displacement detector is directly moved by the constant tension spring, there is no transmission loss, and furthermore, no weight or the like is used. Even if this adjusting device is provided inside a rotating body like a petite netary type wire twisting machine, the performance is not impaired by centrifugal force and is an effective device having many features.

[Brief explanation of drawings]

FIG. 1 and FIG. 2 are a plan view and a front view, respectively, of a conventional tension adjusting device for drawing out a thin wire from a bobbin. 3 and 4 are front views of a tension adjustment device using a weight. 5 and 6 are a plan view and a front view showing a tension adjusting device according to an embodiment of the present invention, and FIG. 7 is a front view showing the structure of a constant tension spring. 1...Thin wire, optical fiber core wire, 2...Feeding bobbin, 3...Moving side dancer roller, 4...
... fixed side dancer roller, 5 ... guide rail, 6 ... tension spring, 7 ... rack, 8 ... pinion, 9 ... drive motor, 10, 11 ... chain wheel, 12 ... displacement detector, 13...
Chain, 14... Lever, 15... Weight, 16
...rod, 17...belt, 20...constant tension spring,
21... Shaft, 22... Straight line part of constant tension spring.

Claims (1)

[Claims] 1. A payout line that is wound around a payout bobbin attached to a member that is inside a rotating body and rotates along a circumferential orbit in space, and is fed out through a fixed dancer roller and a moving dancer roller. In the tension adjustment device, a dancer roller on the movable side is movable along a guide rail provided almost parallel to the rotation axis, and a plate of a constant tension spring whose one end is preformed in a spiral shape and the other end is a flat plate. The tip of the shaped part is fixed to the support frame of the moving dancer roller so that the moving dancer roller is pulled in the opposite direction to the stationary dancer roller to apply tension to the wire, and the spiral coil part of the spring is The center is directly fixed to the axis of the displacement detector, and the displacement of the moving side dancer roller is detected as rotation of the axis of the displacement detector, and the detection signal is fed back to the input of the bobbin drive motor to determine the rotational speed of the unwinding bobbin. A wire tension adjustment device using a constant tension spring.