JPS62137512A - Water entry angle measuring apparatus for installation of submarine cable - Google Patents

Abstract

PURPOSE:To enable accurate measurement of water entry angle of a cable regardless of rocking or pitching of an installation ship, by keeping a reference of an angle measuring element at a fixed position in cooperation of a mobile member fixed on a shaft with a stationary member of an angle measuring element fastened on a pendulum. CONSTITUTION:A cable to be installed is sent out under a cable guide 12 at the tip of an arm 3. The arm 3 tends to turn downward by own gravity and turns shaft 4 lifting the tip upward or downward, following variations in the feed angle of a cable. With the rotation of a shaft 4, a mobile contact driving shaft 10 of a potentiometer 11 is turned to set the mobile contact at the position corresponding to the angle of rotation of the arm 3. A pendulum 8 is loosely fitted into the shaft 4 and a box body of a potentiometer 11 fastened to the pendulum 8 keeps vertical with a weight 13. Thus, regardless of any rolling and pitching of the installation ship, the reference the angle measuring element of the potentiometer 11 can be maintained at a fixed position, thereby preventing errors due the swing of the ship.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a water entry angle measuring device for measuring the water entry angle of a submarine cable during installation.

[Technical background of the invention and its problems] When laying a submarine cable, the tension acting on the cable is controlled. Therefore, the angle at which the cable enters the sea surface, that is, the angle of entry into the water, is measured and kept constant. Conventionally, as shown in Figure 5, the angle θ between the horizontal plane passing the stern of the laying ship S and the cable C (equal to the angle of entry between the cable C and the sea surface M) was measured using an angle meter. We measure it and try to keep it constant. However, the construction ship S is constantly rocking due to pitching, rolling, etc., and has the drawback that the horizontal plane L (reference 0') described above fluctuates. Therefore, the measured value includes a variation in the horizontal plane, resulting in a large error.

[Object of the Invention] The present invention was made based on the above-mentioned circumstances, and an object of the present invention is to obtain a cable water entry angle measuring device that can accurately measure the water entry angle despite the rocking of a laying ship.

[Summary of the Invention] The cable entry angle measurement device for submarine cable installation of the present invention includes a shaft that is rotatably supported on a mounting mount and rotates following the cable being sent out, and a shaft that is loosely fitted onto the shaft. an angle measuring element comprising: a pendulum; a movable member having a drive shaft concentrically fixed to the shaft; and a fixed member fixed to the pendulum and cooperating with the movable member to measure an angle. It is characterized by

In the water entry angle measuring device of the present invention, the reference (0 position) of the angle measuring element is set using a weight, a magnetic damper, etc.
It is kept vertical at all times to prevent errors caused by rocking of the laying ship.

[Embodiments of the Invention] Fig. 1 is a perspective view showing the external appearance of an embodiment of the present invention, and Fig. 2 is a sectional view showing the internal structure of the main part. The device consists of three parts: an electrical housing 1, a mounting mount 2, and an arm 3. The electrical housing 1 houses angle measuring components as will be explained later with reference to FIG. Further, the shaft of the arm 3, which is not shown in FIG. 1, is housed within the mounting mount 2.

In FIG. 2, the shaft 4 of the arm 3 is rotatably supported on the mounting mount 2 by a pillow block 5, a bearing 6, etc., and a pendulum 8 is attached to the end inside the electrical housing 1 via a bearing 7. are rotatably engaged. A potentiometer mounting plate 9 is fixed to this pendulum 8. Further, a housing of a potentiometer 11 is fixed to the potentiometer mounting plate 9, and a drive shaft 10 of a movable contact is fixed concentrically to the axis of the shaft 4. Although not shown in FIG. 2, a cable guide 12 is attached to the tip of the arm 3 in parallel with the shaft 4, as shown in FIG.

Furthermore, 13 in FIG. 2 indicates a weight attached to the pendulum 8.

In the water entry angle measuring device of the present invention having the above configuration, the water entry angle is measured as follows. The cable to be laid is
It is sent out through under the cable guide 12 at the end of the arm. The arm 3 has a tendency to rotate its tip downward due to its own weight, and as the cable feed angle changes, the tip moves up and down accordingly, causing the shaft 4 to rotate left and right.

As the shaft rotates, the drive shaft 10 of the movable contact of the potentiometer 11 is rotated, and the movable contact is connected to the arm 3.
Set the position corresponding to the rotation angle.

On the other hand, since the weight 13 keeps the pendulum 8 in a vertical position, the housing of the potentiometer 11 fixed to the pendulum 8 maintains the reference (
The 0° position) is held at a constant position, and there is no risk of causing errors in measured values due to rocking.

FIG. 3, in which the same parts as in FIGS. 1 and 2 are denoted by the same reference numerals, shows another embodiment of the present invention, and FIG. 4 shows a perspective view of the main parts thereof. In this embodiment, a magnetic damper 14 shown in FIG. 4 and described later is installed in place of the weight 13 of the previously described embodiment.

In this embodiment, the pendulum 8 is made of non-magnetic metal, and pole plates 15 also made of non-magnetic metal are attached to both sides of its tip. The electrical housing 1 also includes a mounting mount 2.
When the pendulum is in a horizontal position, a permanent magnet 16 is installed opposite the lower end of the pendulum 8, and the upper surface of the permanent magnet 16 has a U-shape, and the tip of the pendulum 8 is placed between the legs. A sandwiching yoke 17 is attached.

In the embodiment with the above configuration, the magnetic damper 14 can hold the pendulum 8 in a vertical position similarly to the weight 13 in the first embodiment described above, and can prevent errors in measurement values from occurring.

Note that the present invention is not limited to the embodiments described above.

For example, as the element for measuring the angle, a potentiometer or other suitable element can be used. Further, the pendulum can be held in a vertical position by suitable means such as a magnetic damper or a weight.

[Effects of the Invention] As is clear from the above, in the water entry angle measuring device of the present invention, the measurement standard is maintained in the correct position even when the laying ship is rocking, and accurate measurement values can be obtained. , it is possible to correctly manage cable tension during submarine cable installation.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing the external appearance of one embodiment of the present invention, Fig. 2 is a cross-sectional view showing its internal structure, Fig. 3 is a cross-sectional view showing the internal structure of another embodiment, and Fig. 4 is its outline. FIG. 5 is an explanatory diagram illustrating the situation in which the cable entry angle is measured. 1...Electric housing 2...Mounting mount 3...Arm 4...
Shaft 8... Pendulum 9...
・Mounting plate 11... Potentiometer 11... Cable guide 13... Weight application agent

Claims (1)

[Claims] A shaft rotatably supported by a mounting mount and rotated following the cable being sent out, a pendulum loosely fitted to the shaft, and a movable member having a drive shaft concentrically fixed to the shaft. A water entry angle measuring device for submarine cable installation, comprising: a fixed member fixed to the pendulum and measuring the angle in cooperation with the movable member.