JPH06127892A - Pre-tension device for rope - Google Patents

Abstract

PURPOSE:To set the tension of a rope desirably and freely, and perform the work safely and quickly without damaging the rope. CONSTITUTION:A pre-tension device for rope consists of a pair of drums 1A, 1B, which have plural lines of rope grooves and which are located on a base freely to turn and so that cores thereof are in parallel with each other, and a brake 2 for generating the torque in, at least, any one of the drums, and a roller 7 for pressing a rope 20 to the rope groove of one end side of the drums 1A, 1B. Furthermore, the rope 20 is inserted from a clearance between the rope grooves of one end side of the drums 1A, 1B and the roller 7, and the rope 20 is wound around of the rope grooves of a pair of drums 1A, 1B in order, and thereafter, the rope 20 is drawn to generate a desirable tension in the drawing side of the rope 20.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for pulling out a rope while maintaining tension when winding the rope while applying initial tension to a winch or the like.

[0002]

2. Description of the Related Art In order to prevent a rope of a winch wound in a plurality of layers from being caught between the ropes or damaged by the tension of the rope,
It is necessary to apply initial tension to the rope and wind it up beforehand. Conventionally, a method as shown in FIG. 4 has been adopted as a method of giving an initial tension to a rope. First, a drum-shaped drum 10 provided with a braking motor for generating torque.
0 around the rope 20 several times, pull out the rope 20
The end of B is fixed to the winch 30. Next, the feeding-side rope 20A is pressed with a piece of wood 101, etc., and is slid while applying a brake to generate a frictional force between the drum-shaped drum 100 and the rope 20 to keep the tension of the withdrawing-side rope 20B constant. While winding up on winch 30.

As another method, a rope wound around a wooden frame and received in advance is wound around a winch for temporary winding, and the end of the rope is hooked on a pulley provided above the tower and fixed to the winch. A weight is attached between the temporary winding winch and the pulley, and the rope is wound so that the weight is lifted, and tension is applied to the rope by the weight of the weight to wind the rope.

[0004]

According to the conventional method shown in FIG. 4, a rope wound around a drum-shaped drum has a small diameter portion near the center of the drum and a large diameter portion on the outside. Since there is a difference in peripheral speed between the rope and the outer circumference of the drum, slip occurs on the rope located outside the drum. Furthermore, since the rope on the feeding side is wound to the outside of the drum to the outside, the rope is damaged because the slope of the drum-shaped drum is used to cause the rope to slide toward the center of the drum.

Further, it is difficult to hold the rope with a constant force while sliding the rope between the pieces of wood and the like, and it is also difficult to secure a predetermined rope tension.

[0006]

Means for Solving the Problems A pair of drums having a plurality of rows of rope grooves and rotatably installed on a base so that their axes are parallel to each other, and a torque is applied to at least one of the drums. It is composed of a brake machine attached to generate it and a rope attached to press the rope into the rope groove on one end side of the drum.

Further, in order to turn the rope on the feeding side, a pulley having a transmission means for rotating in synchronization with the peripheral speed of the drum is additionally provided on an extension line of the rope groove on one end side of the drum. The roller presses the rope in the rope groove of the pulley.

[0008]

The relationship between the rope tension on the pull-out side and the rope pressing force on the feed-in side in the device of the present invention related to the above means will be described with reference to FIG.

First, when the roller 7 presses the rope on the drum, if the pressing force is W and the friction coefficient between the drum and the rope is μ, the frictional force R acting on the rope is given by the formula 1.

[0010]

[Equation 1]

Next, when the rope is wound around the drum to which the braking torque is applied, the friction coefficient between the drum and the rope is μ, the contact angle between the drum and the rope is θ, the number of windings around the drum is n, and the natural number is If the logarithm is e, the rope 20 on the drawer side
The tension F of B is given by equation 2.

[0012]

[Equation 2]

Substituting equation 1 into equation 2 yields equation 3.

[0014]

[Equation 3]

For example, μ = 0.15, θ = π, n = 1
When 0 and W = 50 kg, the number 4 is obtained.

[0016]

[Equation 4]

Therefore, the rope 20A on the feeding side is set to 50
By pushing with the force of k8, the rope 2 on the drawer side
At 0B, a tension of 835 kg is generated.

Therefore, by setting the braking torque of the brake within this tension range, the rope can be continuously wound around the winch or the like while maintaining the desired tension.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The apparatus of FIG. 1 has a pair of drum grooves 1A, 1B installed on a base 10 so as to be rotatable and have their axes parallel to each other, and a plurality of rope grooves, and the drum 1B. On the extension line of the rope groove on one end side of the drum 1B, and the braking inverter motor 2 attached to generate a torque on the
It has a pulley 6 having a belt 5 for rotating in synchronization with the peripheral speed of the drum, and a roller 7 for pressing the rope 20 in the rope groove of the pulley 6.

The bracket 9 of the roller 7 is provided with a spring 8 so that the rope 20 is pressed from the bracket 11 on the base side to the pulley 6 by the roller 7. Theoretically, the peripheral speed of the rope groove of the drums 1A and 1B and the peripheral speed of the rope groove of the pulley 6 may be the same, but in consideration of the slip of the rope 20, the pulley 6 is practically used. It is preferable that the peripheral speed on the side is slightly smaller than the peripheral speed of the drums 1A and 1B.

In order to generate a desired torque in the braking inverter motor 2, the inverter control board 12 can arbitrarily change the current value. A predetermined current value is set by the inverter control board 12 to generate a desired torque, but the rotation speed command of the braking inverter motor 2 is set to zero. By operating the winch 30, only the length of the rope 20 pulled, and
The inverter motor 2 is adapted to rotate following the pulled speed.

Although an inverter motor is used as a braking device in this embodiment, a DC motor, a hydraulic motor or the like may be used instead of the inverter motor.

Using the apparatus of the present invention, in order to wind the winch 30 while applying rope tension, the rope 20 wound around the wooden frame drum 40 is taken out and the pulley 6
Is inserted from the gap between the rope groove and the roller 7, wound around the rope grooves of the pair of drums 1A and 1B in order, and then pulled out and fixed to the drum of the winch 30.

Next, the rope 20A on the feeding side is pulled backward to make the winch 30 and the pair of drums 1A, 1
After eliminating the slack between B and the pulley 6, the winch 30 is operated. Then, when the pull-out side rope 20B is wound, tension is generated in the rope 20B.

In the present embodiment, the rope 20A on the feeding side is provided.
Although the pulley 6 is attached to turn the rope in the direction of, the roller for pressing the rope directly into the rope groove on one end side of the drum 1A as shown in FIG. 2 when turning is not necessary. 7 may be attached.

[0026]

The rope holding force on the feeding side can be kept constant by feeding the rope in synchronism with the rotation of the drum while pushing the rope by the pressing force of the roller, and the rope wound around the drum can be kept. The rope is not damaged because it does not slip. The rope tension can be easily set by simply changing the current value of the inverter motor.

Further, even if the rope speed on the payout side changes, the rope tension can be kept constant, and even if the winch is stopped and the rope payout speed becomes zero, the rope tension can be maintained. it can.

[Brief description of drawings]

FIG. 1 shows an embodiment of a rope pre-tensioning device according to the second aspect of the present invention and a situation in which the device is used to wind a rope around a winch while applying initial tension.

FIG. 2 shows an embodiment of a rope pre-tensioning device according to the first aspect of the present invention and a situation in which the device is used to wind a rope around a winch while applying initial tension.

FIG. 3 is a diagram for explaining the relationship between the rope tension on the pulling side and the rope pressing force on the winding side according to the present invention.

FIG. 4 is a diagram showing an example of a conventional technique, showing a situation in which a rope is wound around a drum-shaped drum and the rope is wound around a winch while applying initial tension.

[Explanation of symbols]

 1A, 1B ... Drum 2 ... Braking device; Inverter motor 3, 4 ... Belt wheel 5 ... Belt 6 ... Pulley 7 ... Roller 8 ・ ・ ・ Spring 12 ・ ・ ・ ・ ・ Inverter control panel 20 ・ ・ ・ ・ ・ Rope 20A ・ ・ ・ Feeding side rope 20B ・ ・ ・ ・ ・ Pulling side rope 30 ・ ・ ・ Winch 40 ...... Crate drum

Claims (2)

[Claims] 1. A plurality of rows of rope grooves are provided so that the rope grooves can rotate freely.
In addition, a pair of drums installed on the base with their axes parallel to each other, a brake attached to generate torque on at least one of the drums, and a rope pushed in the rope groove on one end side of the drum. A roller attached for attaching, a rope is inserted from a gap between the roller groove and the roller groove on one end side of the drum, wound around the rope groove of the pair of drums, and then pulled out, A rope pretensioning device, characterized in that a desired tension is generated on the pull-out side of the rope. 2. A pulley having transmission means for rotating the drum in synchronization with the peripheral speed of the drum is further provided on an extension line of the rope groove on one end side of the drum, and the roller is provided in the rope groove of the pulley. The rope pretensioning device according to claim 1, wherein the rope pretensioning device is configured to press the rope.