JP3327892B2 - Cable engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cable engine for paying out a communication cable or the like laid on the sea floor and having a function of detecting a tension of the cable.

[0002]

2. Description of the Related Art A cable engine is a cable feeding device provided at an end of a hull for laying cables. When laying submarine cables using a dedicated ship,
The cable is pulled out of the hold using a cable engine and sent to the sheave at the bow, and the cable is sent out to the sea according to the speed of the boat. However, in such an operation, if the cable payout speed and the ship speed do not match, excessive tension is applied to the cable, and the cable may be damaged. Therefore, a cable laying ship is provided with a mechanism for measuring the tension together with the cable engine so as to control the cable feeding speed to prevent the cable from being damaged.

FIG. 6 is a configuration diagram showing a cable engine and a conventional cable tension measuring device. The cable 21 to be laid is sent out from the hold of the hull S to the sea via the drum 1, the dynamometer 61, and the sheave 22.
The drum 1 is a device that winds a cable 21 from a hold several times and feeds the cable 21 to a sheave 22.
Is composed of a pulley that lowers the cable 21 from the boat end into the sea. The measurement surface of the dynamometer 61 is disposed so as to be higher than a straight line connecting both uppermost portions of the drum 1 and the sheave 22. As a result, the cable 21 passes through the dynamometer 61 while maintaining a certain angle without loosening between the drum 1 and the sheave 22.

FIG. 7 is a sectional view of the dynamometer shown in FIG. The dynamometer 61 includes a base portion 71 fixed to the hull S, a cable receiving portion 72 serving as a guide for the cable 21, and two load cells 73 interposed between the two. As previously mentioned,
Since the dynamometer 61 is disposed so that the uppermost part thereof is higher than a straight line connecting the uppermost part of the drum 1 and the uppermost part of the sheave 22, the cable 21 is bent at a predetermined angle in the cable receiving part 72. Will do. At this time, the cable receiving portion 72 receives the downward load F from the cable 21 and the load cell 73 can detect the downward load F. Here, since the bending angle of the cable 21 in the dynamometer 61 is constant, if the downward load F due to the bending is known, the tension in the passing direction of the cable 21 can be obtained.

[0005]

In the above-described conventional cable engine, the tension of the cable 21 is indirectly measured from the downward load F, and the rotation of the drum 1 is controlled so that excessive tension is not applied to the cable 21. However, among the tensions applied to the cable 21, a downward component force that is extremely small compared to the tension is detected, and the resultant force (tension) is calculated back. Therefore, errors are likely to accumulate, especially when the resultant force of the cable 21 tension is small. However, there is a problem that the error increases. In addition, since the dynamometer 61 has the cable receiving portion 72 that can move up and down in a cantilever manner on the upper portion thereof, the sliding resistance at the fulcrum of the cantilever cannot be ignored, and the downward component force detected by this can cause an error. And there is a problem that it is also affected by installation errors.

[0006] The present invention has been made in view of the above, and it is another object of the present invention to provide a cable engine capable of accurately measuring cable tension.

[0007]

According to a first aspect of the present invention, there is provided a cable engine for feeding a cable such as a communication cable installed on a cable laying ship.
The mounting portion of the to the drum, the load in the direction of feeding the cable to the fixed support only in a detectable load cell against sheave provided from the drum to the ship edge, Dora the output of the load cell
This is to control the rotation of the system.

[0008] By fixing and supporting the drum only by the load cell, the tension in the feeding direction of the cable with respect to the sheave can be directly detected by the load cell. Further, there is no structure that causes friction loss between the drum and the hull. For this reason, it is possible to accurately measure the cable tension. In addition, the output of the load cell
Excessive tension is applied to the cable by controlling the rotation of the ram.
Can be eliminated.

According to a second aspect of the present invention, the cable engine further includes an inclination angle sensor for detecting an inclination angle of the hull, and a component in the sending direction by the weight of the drum based on the angle detected by the inclination angle sensor. And correcting means for correcting the detected load based on the calculated value.

[0010] Since the ship shakes due to waves, wind and other conditions, a component due to the weight of the drum is added to the load detected by the load cell. The component due to the weight of the drum can be obtained by calculation if the angle at which the hull is inclined with respect to the horizontal direction is known. Therefore, the tension applied to the cable can be accurately obtained by adding or subtracting the weight component of the drum calculated from the angle detected by the sensor to the load detected by the load cell.

According to a third aspect of the present invention, the cable engine further includes an acceleration sensor provided near the drum of the hull, and a correction of an acceleration component based on the hull acceleration based on the acceleration detected by the acceleration sensor. And a correction means for performing the following.

A ship, unlike a vehicle on the ground, sails while changing acceleration according to tide, waves, and various other conditions. Therefore, if the acceleration of the hull changes, the drum attached to the hull also receives an external force, which hinders the detection of the cable tension. Therefore, an acceleration sensor is provided near the drum, and the tension applied to the cable is corrected by adding or subtracting the external force calculated from the load detected by the load cell. Thus, the cable tension can be accurately measured.

According to a fourth aspect of the present invention, the cable engine further includes a correction load cell provided near the drum, a correction weight fixed on the correction load cell, and a mass of the correction weight. And a correcting means for correcting the detected tension using the ratio of the load cell to the mass of the drum and the output value of the load cell for correction.

As described above, the hull angle and the hull acceleration affect the cable tension detection function of the load cell.
In the present invention, attention is paid to the fact that the hull angle and the hull acceleration are given to the weight attached to the vicinity of the drum similarly to the drum, and the ratio of the mass of the weight to the mass of the drum, and the load cell fixed below the weight The correction value is calculated from the output. Then, the correction value is used for correcting the load detected by the load cell attached to the drum installation portion, and contributes to more accurate tension detection.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. The present invention is not limited by the embodiment. FIG. 1 is a perspective view showing a drum main body according to an embodiment of the present invention. The drum main body 1 has a cylindrical load cell 3 fixed between an installation part 2 and a hull 4. As a result, the drum main body 1 is fixedly supported by only the load cell 3. Although two sets of the drum main body 1 are shown in FIG. 1, this shows a general configuration, and two sets are not particularly required. Further, four load cells 3 are fixed to the installation part 2 of the drum main body 1 per one set of the drum main body 1. However, if the cable engine can maintain and secure the function described later, the number of the load cells 3 is not a problem. Absent.

FIG. 2 is a schematic diagram showing a cable tension measuring device for a cable engine according to the present invention. A large amount of cables 21 are held on the submarine cable laying ship S (not shown).
Is stored in Then, the cable 21 is wound up by the drum main body 1 when necessary from the hold, and then submerged in the sea via a sheave 22 which is a pulley attached to the ship's end (the bow in the figure). become. Since the drum main body 1 for winding the cable 21 needs a large radius of curvature in relation to the bending rigidity of the cable 21, it is fixed to the hull at a position lower than the deck. Further, in order to make the tension direction and the load cell detection direction coincide, the uppermost part of the drum main body 1 and the uppermost part of the sheave 22 are installed so as to be at the same height.

As described above, the load cell 3 is fixed to the installation portion 2 of the drum main body 1 and is supported by the load cell 3. The load cell 3 is also fixed to the hull 4 so as not to move. Here, the load cell 3 used has a cylindrical shape and can detect a radial load. Therefore, according to the above configuration, the tension T of the cable 21 can be directly detected by the load cell 3 as a load in the direction in which the drum main body 1 sends the cable 21 to the sheave 22. That is, the cable tension T is the combined force of the loads F1 and F2 detected by the load cell 3.

Further, since the drum main body 1 does not move or move due to the tension T of the cable 21, there is no friction loss at the sliding portion, and only the tension T of the cable can be directly detected. . If the tension T of the cable 21 detected in this way is used, it is possible to perform control such as increasing the rotation speed of the drum when it is determined that the tension is excessive, and decreasing the rotation speed of the drum when determining that the tension is too small. Also becomes possible. Reference numeral 5 denotes a control device that calculates the tension using the detection signal obtained from the load cell 3 and controls the rotation speed of the drum based on the calculation result.

FIG. 3 is a schematic view showing a state in which the drum body is tilted due to the motion of the hull. In the figure, reference numeral 31 indicates an angle sensor, and reference numeral 32 indicates an acceleration sensor. First, a method of detecting the tension T of the cable 21 when the hull S is tilted without considering the acceleration will be described. Since the load cell 3 detects the cylindrical radial load, when the hull is tilted, the load cell radial component of the own weight of the drum body 1 is detected by being mixed with the tension of the cable 21.

That is, assuming that the mass of the drum body 1 is W, the gravitational acceleration is g, and the inclination of the hull S with respect to the horizontal plane is θ, the total output of the load cell 3 can be expressed by a relational expression of F1 + F2 = T + Wg sin θ. Therefore, the angle sensor 31 that can detect the inclination angle θ of the hull S with respect to the horizontal plane
Is attached to the hull S or the drum main body 1, and the correction value is calculated by calculating Wgsin θ using the angle θ obtained from the angle sensor 31. Then, the tension T of the cable is obtained by adding or subtracting the correction value to or from the value detected by the load cell 3. The calculation of the correction value and the correction of the detection value are performed by the control device 5.

Next, a method of detecting the tension T of the cable 21 when acceleration occurs in the hull S without considering the inclination of the hull S will be described. Vessels, unlike land vehicles, may need to navigate while swaying due to waves, wind, and other weather conditions. At that time, an acceleration a due to the motion is generated in the hull S. If the acceleration a occurs in the hull, all the accessories of the hull are in a state equivalent to receiving an external force. Therefore, in that case, the hull S
The drum body 1 attached to is also subjected to external force,
As a result, the component detected by the acceleration is mixed in the load detected by the load cell 3. Therefore, the total output of the load cell 3 can be expressed by a relational expression of F1 + F2 = T + Wa. Therefore, an acceleration sensor 32 is attached to the hull S or the drum main body 1, and the acceleration value a detected by the acceleration sensor 32 is multiplied by the mass W of the drum main body to calculate a correction value Wa. And
The tension T of the cable 21 is obtained by adding or subtracting the correction value Wa to the detected value of the load cell 3. It is preferable that the attachment position of the acceleration sensor 32 be as close to the drum body 1 as possible to make the correction value more accurate. The calculation of these correction values and the correction of the detection values are
The control is performed by the control device 5.

When the hull S is tilted and acceleration occurs,
The above two methods may be used in combination, and the load detected by the load cell 3 may be corrected using the respective correction values. Therefore, by using these configurations and methods, it is possible to eliminate the influence of the fluctuation of the hull S on the function of detecting the tension of the cable 21 by the load cell 3. For this reason, the tension applied to the cable 21 can be detected more accurately, and the speed of the hull and the number of rotations of the drum according to the tension can be controlled.

FIG. 4 is another schematic diagram showing a state in which the drum body is tilted due to the motion of the hull. In this configuration, the correction weight 41 is fixed to the drum main body 1 via the correction load cell 42. When the hull S is tilted and acceleration occurs, the correction weight 41 is also a part of the hull S, so that the correction weight 41 is inclined with respect to the horizontal plane similarly to the hull S, and an external force is applied by the acceleration. .
FIG. 5 is a schematic diagram showing the correction weight 41 and the correction load cell 42 in such a state. The correction load cell 42 capable of detecting a cylindrical radial load detects a component due to the acceleration and the weight of the correction weight 41.

That is, assuming that the load detected by the correction load cell 42 is Fb and the mass of the correction weight is m, Fb = mgsinθ + ma = m (gsinθ + a), so that the influence of the inclination angle applied to the correction loadcell and the acceleration in the tension detection direction are obtained. For a, the relational expression of gsin θ + a = Fb / m holds. At this time, the mass W of the drum is assumed to include the mass m of the weight for correction, and the load F detected by the load cell 3 fixedly supporting the drum body 1 is detected.
1 + F2 is a value obtained by adding the force generated on the drum due to the above-described inclination angle and acceleration to the tension T, Becomes In this formula, the influence of the inclination angle and the acceleration gsin θ + a in the tension detection direction are replaced with Fb / m. Is satisfied. Therefore, the tension T of the cable to be obtained is changed from the resultant force F1 + F2 of the load cell 3 to the detected load Fb of the correction load cell 42 and the drum body 1
Is multiplied by the ratio (W / m) of the mass of the correction weight 41 to the mass of the correction weight 41.

As described above, in the above configuration, the drum body 1
The correction load cell 42 is provided on the
The correction weight 41 is fixed above, and the detected tension of the load cell 3 is corrected using the ratio of the mass of the weight to the mass of the drum and the output value Fb of the load cell 42 for correction. It is possible to detect the cable tension. Further, since an inclination angle sensor and an acceleration sensor are not required, the present invention has an excellent effect that a simple and inexpensive structure can detect a cable tension. The correction and the rotation speed control of the drum main body 1 are performed by the control device 5.

[0026]

As described above, according to the cable engine of the present invention (claim 1), the cable tension in the direction in which the drum sends out the cable to the sheave provided at the ship end is directly monitored by the load cell. . Further, the drum is fixedly supported only by the load cell. Therefore, the cable tension can be accurately measured. Ma
Also, it is necessary to control the rotation of the drum by the output of the load cell.
With this, excessive tension is not applied to the cable.
Wear.

Further, according to the cable engine of the present invention (claim 2), the inclination angle of the hull is detected, the component of the sending direction due to the weight of the drum is calculated from the inclination angle, and based on the calculated value. Since the detected load is corrected, the cable tension can be accurately measured without the influence of the sway of the hull.

According to the cable engine of the present invention, the acceleration of the hull is detected by the acceleration sensor provided in the vicinity of the drum of the hull, and the acceleration component based on the hull acceleration is determined from the detected acceleration. Is corrected, the cable tension can be measured more accurately.

According to the cable engine of the present invention, the correction load cell is provided near the drum, and the correction weight is fixed on the load cell.
Since the detected tension is corrected using the ratio between the weight of the weight and the mass of the drum and the output value of the load cell of the correction weight, it is possible to more accurately detect the cable tension. Further, since the inclination angle sensor and the acceleration sensor are not required, the cable tension can be detected with a simple and inexpensive structure.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a drum main body according to an embodiment of the present invention.

FIG. 2 is a schematic view showing a cable tension measuring device for a cable engine according to the present invention.

FIG. 3 is a schematic view showing a state in which a drum main body is tilted due to a motion of a hull.

FIG. 4 is another schematic diagram showing a state in which the drum main body is tilted due to the motion of the hull.

FIG. 5 is an enlarged view of a correction weight and a correction load cell.

FIG. 6 is a schematic diagram showing a conventional cable engine.

FIG. 7 is a sectional view of the dynamometer shown in FIG. 6;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Drum main body 2 Installation part 3 Load cell 4 Hull 5 Control device 21 Cable 22 Sheave 31 Angle sensor 32 Acceleration sensor 41 Correction weight 42 Correction load cell 61 Dynamometer 71 Base part 72 Cable receiving part 73 Load cell S Hull T Cable tension W Mass of drum body m Weight of correction weight a Acceleration θ Angle of hull with respect to horizontal plane

──────────────────────────────────────────────────の Continuation of the front page (51) Int.Cl. ⁷ identification code FI H02G 9/00 H02G 9/00 D (58) Field surveyed (Int.Cl. ⁷ , DB name) H02G 1/06 B63B 35 / 04 G01L 5/06 H02G 9/00

Claims (4)

(57) [Claims] 1. A communication cable installed on a cable-laying ship
The installation of the drum for feeding the cable such Le, the load in the direction of feeding the cable to the fixed support only in a detectable load cell against sheave provided on the boat end from the drum, the rotation control of the drum by the output of the load cell Row
Cormorants cable engine, characterized in that. 2. A tilt angle sensor for detecting a tilt angle of the hull, and a component in the sending direction due to the weight of the drum is calculated from the angle detected by the tilt angle sensor, and the detected load is calculated based on the calculated value. The cable engine according to claim 1, further comprising: a correction unit configured to perform correction. 3. An acceleration sensor provided near a drum of a hull, and a correction means for correcting an acceleration component caused by the hull acceleration from the acceleration detected by the acceleration sensor. Item 2. The cable engine according to item 1. 4. A correction load cell provided near the drum, a correction weight fixed on the correction load cell, a ratio of a mass of the correction weight to a mass of the drum, and The cable engine according to claim 1, further comprising a correction unit configured to correct the detected tension using the output value.