JPS6246224A - Submerged tension measuring apparatus - Google Patents

Abstract

PURPOSE:To make it possible to search a cable with high accuracy, by connecting a housing, in which a tension sensor and an electric circuit are mounted, formed into a pressure resistant structure between a grapnel and a grappling rope. CONSTITUTION:The titled apparatus is constituted of a tension sensor main body 1, a connector 2, a circuit housing 3, a hook 4, a protective housing 5, a relief valve 6, a joint cylinder 8, a ginbal housing 9, bellows 10, signal wires 11a, 11b, an anchor 12 and boots 13 etc. When this apparatus is mounted to the leading end of a grappling rope 14 and towed by a searching ship, the cable laid on the bottom of the sea is caught by the grapnel engaged with the hook 4 and the tension applied to the hook 4 increases. Therefore, strain is generated in a central shaft and the electrical characteristic of a strain gauge changes to be converted to an electric signal in the circuit housing 3 while the electric signal is transmitted to the observation apparatus on a ship through the signal wires 11a, 11b by the signal wires in the grappling rope 14. By this method, only the tension received by the hook 4 is acculately detected and the state of the caught grapnel can be accurately judged.

Description

[Detailed Description of the Invention] [Field of Application in Business] This invention uses a rope suspended from a ship to connect probe lines and auxiliary lines to cables and the like installed at the bottom of the water or on the seabed. The present invention relates to an underwater tension measuring device used in the measurement.

[Conventional technology]

Conventionally, when searching for the location of cables installed on the seabed or the bottom of the water, grapnels were used from exploration vessels.
The probe lobe with a grapnel) was towed in the city, and the tension of the probe lobe being towed was measured using a load cell (tension measuring device) on board the ship, and the FJL cut was made to determine whether the grapnel or cable was grasped. Figure 5 schematically shows the line search method described in p).
R is a probe lobe to which a clubnel G is connected to the cable C as an auxiliary wire.
On the side, row 1: connected to cell M.

When the exploration vessel S is tipped at the point where the cable C of [J target 4) is installed, the grapnel G of the exploration probe R being towed gets caught on the cape It/C sunk on the seabed. Then, since the tension applied to the probe lobe R increases, the ship -
It can be detected by the load cell M of L.

Then, at this point, the cable C is pulled out or cut, and repair work 12 is performed while it is being held.

[Problem that the invention seeks to solve]

1. While steering, a tensile force based on the underwater weight of the search rope H is constantly applied to the load cell in the ship 1. For example, in the case of deep seabed, this underwater weight becomes extremely large, so cable whaling There is a problem in that it becomes difficult to detect an increase in tensile force at a time based on the resolution of the load cell.

In particular, when the varying tensions generated in the probe lobe due to waves, ocean currents, changes in ship speed, etc. are combined, it becomes extremely difficult to accurately detect cable information using a load cell on board.

This invention was made in view of these problems,
This invention relates to an underwater tension measuring device that can more accurately detect tension fluctuations during cable whaling.

[Means for solving problems]

The casing has a pressure-resistant structure, which includes a tension sensor with a bellows-type pressure balance mechanism between the grapnel and the probe lobe, and a TL air circuit for amplifying the signal detected by the tension sensor and converting it into an appropriate signal. and combine.

[Effect]

Tension fluctuations when the grapnel catches the target cable are detected by a tension sensor on the ocean floor or on the bottom of the water, and can be detected on the ship via a signal line in the probe lobe. Therefore, the influence of external tension fluctuations on the search lobe is eliminated, and tension fluctuations during whaling can be accurately detected.

〔Example〕

FIG. 1 shows a side view of the underwater tension device of the present invention, where l is the tension sensor body, 2 is a watertight connector, and 3 is a side view of the underwater tension device of the present invention.
numeral 4 is a circuit case for amplifying the signal obtained from the tension sensor, converting it into a predetermined signal format and outputting it if necessary; 4 is a hook for locking the grapnel, etc. mentioned above; 5 is the tension sensor main body l; and the circuit A pressure-resistant protective case that protects the case 3, 6 is a relief tt for water pressure balance, which will be described later, and 7
a, 7b are watertight bushings, 8 is a joint cylinder, 9
is the gimbal housing, and 10 is the bellows. lla
is a signal line outputted from the circuit case 3 via the water damage bushing 7a, and this signal line 11a is connected within the joint cylinder 8 to a signal line 11b inserted into the probe rope. . Reference numeral 12 indicates a tapered anchor that holds the tensile strength line of the search rope 14, and reference numeral 13 indicates a boot. Incidentally, as the grapnel to be secured to the hook 4, one having a cutting holding function can be used.

FIG. 2 is a side view showing the inside of the tension sensor l.
Reference numeral 15 has screw holes 15a on both ends for engaging the hooks 4, a joint cylinder 8, a gimbal housing 9, and an anchor 1.
The center + is provided with a screw hole 15b for locking the circuit housing flange 4a that transmits tension to the probe rope 14 through the center +
Reference numerals 14+ and 16 are strain gauges attached to the surface of the central shaft 15, and may be electrical elements that change the impedance value when strain occurs on the central shaft 15, for example. Reference numeral 17 indicates silicone oil filled in the tension sensor 1, and reference numeral 18 indicates a bellows for balancing the external pressure and the internal pressure of the tension sensor and uniformizing the pressure applied to the strain gauge 16.

Since the underwater tension measuring device of the present invention has the structure as described above, it can be accessed at the tip of the probe rope 14, sunk to the bottom of the water, or towed by a probe vessel, as described above. As shown, the cable laid on the bottom of the '116 is caught by the grapnel which is fixed to the rig 4. Then, the tension applied to the hook 4 increases, causing strain in the central shaft 15, thereby changing the electrical characteristics of the strain gauge 16. This change characteristic is converted into an electric signal by an amplifier and a modulator T which are hidden inside the circuit case 3, and is transmitted to the signal line in the search lobe 14 via the signal lines 11a and llb for observation of the ship. 411 device.

Therefore, it is possible to accurately detect only the tension applied to the hook 4, and the condition of the caught grapnel can be accurately determined as seen in the data described below.

Figure 3 is a graph showing tension fluctuation data obtained from a whaling experiment using a conventional load cell installed on ship-L under the same conditions and from a supplementary wire experiment using the underwater tension measuring device of the present invention. Measurement data according to the invention, B is from a conventional load cell.

The horizontal axis shows the time from sinking the search rope to supplementary line, T1 is the time when the grapnel landed on the sea floor,
T2 indicates the time when the cable was supplemented during subsequent towing, and T3 indicates the time when the cable was cut after supplementation.

As can be easily understood from this figure, the data obtained using the underwater tension measuring device of the present invention shows extremely low tension until the time of supplementary line, and the tension increases rapidly at the moment of supplementary line. Furthermore, amplitude fluctuations (noise) are extremely small and S/N is high compared to those using conventional load cells. Therefore, the resolving power is improved and the landing time, supplementary line time, and cutting time can be detected very clearly.

FIG. 4 is a detailed side view of the relief valve 6 provided in the protective case 5, in which 19 is a relief valve cylinder;
0 is an automatic valve, and this automatic valve is configured to slide on the sill 19 via an O-ring 20a. Reference numeral 21 denotes a vertically long cut groove carved in the syringe 19, 22 a cap provided with an opening 22a that fits into one end of the cylinder 19, and 23 the other end of the syringe 19. The cap is provided with an opening 23a that is fitted into the cap.

This relief valve 6 has an automatic valve 20 that moves when the water pressure increases when the underwater tension meter body is submerged in the sea, and balances the internal pressure of the silicone oil filled inside the underwater tension meter body with the water pressure. , At the same time as increasing the pressure resistance of the protective casing, if abnormal water pressure is applied, at the position indicated by the line! , 1JLW21 conducts between the outside and the inside, thereby preventing an accident that would crush the protective case 5.

In addition, even if seawater flows in, the tension sensor body is equipped with a bellows, so this double lance structure protects the inside of the expensive tension sensor from contamination and corrosion, resulting in an expensive Accuracy can be maintained.

〔Effect of the invention〕

As explained above, by installing the underwater tension jilt fixing device of the present invention between the search rope and the grapnel, it is possible to search for cables with higher accuracy compared to the search work using conventional load cells. The advantage is that tension can be accurately measured on the waterbed or under the seabed, and cable reinforcement work can be carried out without any external influences, especially on deep seabeds or in adverse environmental conditions. There is.

[Brief explanation of the drawing]

FIG. 1 is a side view of an underwater tension measuring device showing an embodiment of the present invention, FIG. 2 is a side view showing an example of a tension sensor, and FIG. 3 is a side view of an underwater tension measuring device of the present invention and a conventional load cell. Fig. 4 is a detailed side view of the relief valve, and Fig. 5 is a diagram illustrating auxiliary line work on the seabed or under water. In the figure, 1 is the tension sensor body, 3 is the circuit case, 4 is the hook that locks the grapnel, 5 is the protection case, 6 is the relief valve, 8 is the joint sill, 9 is the gimbal housing,
11a and llb are signal lines, 12 is an anchor, and 14 is a probe rope. Figure 2 Figure 3

Claims (1)

[Claims] For probe lines and auxiliary lines of cables laid or buried at the bottom of the water, a protective case containing a tension sensor equipped with a bellows-type pressure balance mechanism and a circuit to amplify the signal of the tension sensor is installed between the grapnel and probe rope. An underwater tension measuring device characterized by being coupled between.