JPH078715B2 - Hive compensator - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heave compensator for removing looseness of a cord (hereinafter referred to as a wire or a cable) extending from a winch.

(Prior art) For example, when a rope is suspended in the sea from a winch mounted on a ship for various observations, the tension decreases due to rolling, pitching, or waves of the ship. The slack is generated and the tension is suddenly increased, which is repeated.

Such fluctuations in tension not only promote fatigue of the rope, but also risk that the rope may come off the pulley, or impact loads are repeatedly applied to the winch. In addition, if the cord is repeatedly over-tensioned or loosened, the cord may be cut, and if slack occurs during winding of the cord, the cord that was tidy until then would be tidy. Fluctuations in tension adversely affect the rope and winch, such as deterioration of the wound state.

Conventionally, various compensators have been put into practical use in order to eliminate various obstacles associated with fluctuations in tension. That is, FIG. 3 shows an example of a conventional compensator, in which a pair of fixed pulleys C are pivotally supported in front of a winch B that winds a cord A, and are arranged between the fixed pulleys C. The movable pulley D is moved up and down by the cylinder E according to the slack of the rope A, so that the length of the rope A stored between the fixed pulleys C is increased or decreased to absorb the slack.

On the other hand, in order to increase the amount of slack absorbed with respect to the stroke of the compensator (movable pulley D), for example, as shown in FIG. There is also one in which the cord A is multi-layered (multi-layer winding).

However, in the former case, since the absorption rate and the amount of absorption of slack are limited, the usable sea area is limited, and beyond that, the function cannot be exhibited. In the latter case, in which the cord is wound in multiple layers, since the plurality of movable pulleys move (elevate) at the same time, not only the slack side but also the side where no slack is generated simultaneously As a result, the movable pulley is difficult to move smoothly, which is a problem.

(Problem to be Solved by the Invention) An object of the present invention is to provide a heave compensator having a small size and a simple structure, which can quickly and accurately absorb the slack of a cord.

(Means for Solving the Problem) A means for solving the problem in the present invention is to pivotally mount a central portion of an arm 13 between a pair of fixed pulleys 7 arranged in front of a winch, Movable pulleys 14 are axially attached to both ends of the arm 13. Then, the movable pulley 14 and the fixed pulley 7 stretch and hold the cord 11 located between the fixed pulleys 7 in a substantially S-shape, and the arm is normally or reversely rotated depending on the looseness of the cord. A drive device for turning drive is provided.

(Operation) The degree of the S-shape formed by the fixed pulley 7 and the movable pulley 14 by changing the turning speed and the turning angle of the arm 13 according to the slack (tension) of the rope 11 (of the pair of fixed pulleys). The length of the cord located between them is changed so that the cord 11 is not loosened.

An embodiment will be described with reference to FIGS. 1 and 2. In the figure, a winch 3 is installed on the upper surface of a second deck 2 covered with a main deck 1. Example winch 3
Is composed of a stock winch 4, a turning pulley 5 and a traction winch 6, but may be an integral winch.

On the upper surface of the main deck 1, a pair of fixed pulleys 7 are pivotally mounted by a bracket (not shown), and a compensator 8 is installed between the fixed pulleys 7.
In addition, a cord that passes through the winch 3 and each compensator 8
The reference numeral 11 extends into the sea via a turning pulley 9 and a David pulley 10.

The compensator 8 is provided with an arm 13 rotatably rotatably mounted at its central portion to an output shaft of a drive device 12 such as a hydraulic motor or a pneumatic motor equipped with a speed reducer, and at both ends of the arm 13. It is composed of a pair of movable pulleys 14. Then, the cords 11 are bent in the S-shape by rolling contacting the cords 11 with the movable pulleys 14 and the fixed pulleys 7 from the reaction direction. Further, by driving the drive device 12 in the forward and reverse directions in response to a command from a controller (not shown), the arm 13 is pivotally driven in the forward and reverse directions to change the retracting length of the cord 11 by each movable pulley, thereby Line
I am trying to eliminate the slack of 11.

Reference numeral 15 is an air jet provided between the fixed pulley 7 and the turning pulley 9 to blow off water adhering to the cord 11.

The present invention has the above-described structure, and when the tension of the cord 11 is maintained at a predetermined value, the pair of cords 11 positioned between the pair of movable pulleys 14 is arranged as shown in FIG. 2A. Fixed pulley 7
Arm at a position almost orthogonal to the straight line connecting the rotation centers of
13 is held by turning.

Further, when the tension of the rope 11 becomes higher than a predetermined value due to rolling, pitching, waves or the like of the ship, the drive device 12 drives the arm 13 to rotate in the clockwise direction by a signal from a controller (not shown). Then, the pull-in length of the cord 11 by the pair of movable pulleys 14 gradually decreases, so that the increase in tension due to waves or the like is suppressed. FIG. 2B shows a state in which the retracted length of the cord 11 is the minimum (zero).

On the other hand, when the tension of the rope 11 becomes lower than a predetermined value due to rolling, pitching, or waves of the ship, the drive device 12 causes the arm 12 to move based on a signal from a controller (not shown).
Drive 13 counterclockwise. Then the arm
Since the pull-in length of the cord 11 by the movable pulley 14 pivotally attached to the shaft 13 is increased, the cord 11 is reduced due to the decrease in tension.
The slack of is avoided. FIG. 2C shows a state in which the pull-in length is maximum.

In this way, by rotating the arm 13 having the movable pulleys 14 rollingly contacting the ropes 11 between the fixed pulleys 7 to rotate, the pull-in length of the ropes 11 between the fixed pulleys 7 is changed. Arm to be able to remove 11 slack
Movable pulley 14 no matter what position 13 is held in
The tension on both sides of is the same. Therefore, since the cord 11 is necessarily pulled in from the slack side, the arm 13 can be swung smoothly.

In the embodiment, the tension of the rope is used as a function of the slack to control the drive device.However, the slack of the rope is determined based on, for example, the load of the winch, the winding speed of the rope, the inclination of the ship, etc. The state can also be detected.

Further, the present invention can be used not only as the signal cable winch shown in the embodiment but also as a heave compensator for a winding device in all fields such as mooring to a quay of a ship, oil rig, subsea boring, deep sea mooring. It is possible. It is also possible to double the amount of slack absorption by arranging a plurality of compensators in series.

(Effect of the invention) The present invention absorbs slack in a cord by rotating an arm having movable pulleys attached to both ends, and quickly removes the slack caused by an external factor in the cord. Is something that can be done.

Further, the present invention can be applied to a winch installed in a limited space such as a ship because the device is simple and small.

[Brief description of drawings]

FIG. 1 is a front view of the entire apparatus showing an embodiment of the present invention, FIGS. 2A, B, C are front views showing the operating state of the main parts, and FIG. 3 is a front view showing an example of the prior art, FIG. 4 is a perspective view showing another example of the prior art. 1 ... Main deck, 2 ... Second deck, 3 ... Winch, 4 ... Stock winch, 5 ... Turning pulley, 6 ... Traction winch, 7 ... Fixed pulley, 8 ... Compensator, 9 ... Turning pulley 10 …… Davit pulley, 11 …… Rope, 12 …… Drive device 13 …… Arm, 14 …… Movable pulley, 15 …… Air jet

Claims (1)

[Claims] 1. A pair of fixed pulleys (7) arranged in front of a winch for winding a rope, and an arm (13) pivotably attached to a central portion between the fixed pulleys (7). The arm (1
3) A movable pulley (14) axially attached to both ends of the movable pulley (14), and a drive device (12) for driving the arm (13) to rotate in the forward and reverse directions. The rope (11) wound around the winch is stretched and held between the fixed pulley (7) and the arm (13) according to the slack of the rope by (7). A heave compensator characterized by swivel-driving in the forward and reverse directions according to the tension of the strip to remove the looseness of the cord extending from the winch.