JP2584798B2 - Auto tensioner device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION (Field of Industrial Application) The present invention relates to a means for preventing rocking of a submersible operation, such as a deep-sea investigation boat, a seafloor, and a capsule, which is suspended from a mother ship by a cable in the sea.

(Prior art) When an underwater device such as a deep-sea investigation boat, a sea-bottom explorer, or a capsule is hung from the mother ship to the sea with a cable for ocean surveys and sea-bottom exploration, the movement of the mother ship due to sea level fluctuations may occur. Cable tension must be kept within a certain range to prevent transmission to underwater equipment via the cable.

As a mechanism for this, for example, a passive type auto tensioner device in which sheaves are attached to both ends of a ram cylinder connected to an accumulator and a cable connecting a mother ship and an underwater device is wrapped around the sheave over a plurality of lines is known. Have been. In this case, the ram cylinder contracts while accumulating pressure in the accumulator when the cable tension increases, and expands due to the pressure accumulated in the accumulator when the tension decreases. This allows the cable to be sent or taken in in response to a change in tension.

(Problems to be Solved by the Invention) However, in the case of this device, the ram cylinder does not expand or contract unless the cable tension fluctuates more than a certain value due to frictional resistance of the sheave and internal friction of the ram cylinder and the accumulator. It is easy to transmit to the underwater equipment without absorbing small sway. In other words, there is a dead zone for the change in tension near the neutral position of the ram cylinder, which causes a problem that the attenuation rate of the tension fluctuation is low.

On the other hand, recently, the use of optical fiber for such a cable for retrieval has often led to the dual use of the signal transmission cable between the mother ship and the undersea equipment, in which case the malfunction of the signal circuit due to the deformation or damage of the cable is prevented. In order to achieve this, it is particularly necessary to keep the cable tension constant.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and detects a fluctuation of a hull to be absorbed and positively controls expansion and contraction of a ram cylinder, thereby preventing a fluctuation in cable tension and a function of stabilizing an undersea device. The purpose is to improve the quality.

(Means for Solving the Problems) According to the present invention, a midway of a cable for suspending an undersea device from a mother ship is wound around a sheave of a ram cylinder provided on the mother ship, and the pressure is accumulated by an accumulator hydraulically connected. In an auto-tensioner device that elastically supports a ram cylinder in the extension direction, a servo cylinder that expands and contracts the ram cylinder, a sway amount detector that detects sway of the mother ship to be absorbed, and absorbs sway generated from the detected value. And a hydraulic control circuit for driving and controlling the servo cylinder.

(Operation) When the fluctuation amount detector such as an accelerometer detects the fluctuation of the mother ship to be absorbed, the hydraulic control circuit drives the ram cylinder in a direction to absorb the vibration generated through the servo cylinder.
For this reason, even when the tension change of the cable due to the swing is smaller than the friction resistance of the ram cylinder, the ram cylinder actively expands and contracts to absorb the swing.

In addition, even when the ram cylinder expands and contracts to some extent due mainly to a change in cable tension,
When the servo cylinder induces expansion and contraction, the response of the ram cylinder to the motion of the hull is accelerated, and the motion is absorbed at a high damping rate.

(Embodiment) FIGS. 1 and 2 show an embodiment of the present invention.

In FIG. 1, reference numeral 1 denotes a mother ship, and reference numeral 2 denotes a launcher as an underwater device, which is suspended underwater by a cable 4 from a sheave 3A attached to a tip end of an A-type frame 3 protruding rearward of the stern of the mother ship 1. The sheave 3A is provided with a movement amount detector 20 such as an accelerometer for detecting the movement of the mother ship 1 to be absorbed and a load cell 21 for detecting the tension of the cable 4.

The mother ship 1 has a cable winch 5 and a traction winch 6 for winding and sending out the cable 4 on a deck 9.
And A cable length meter 24 shown in FIG. 2 is attached to the traction winch 6 to detect the length of the cable 4 sent out.

Further, a ram cylinder 8 for absorbing the fluctuation of the mother ship 1 in response to a change in the tension of the cable 4 is interposed between the traction winch 6 and the sheave 3A. The ram cylinder 8 is a single-acting hydraulic cylinder, and sheaves between a base end of the cylinder portion 8A and a tip end of a piston rod 8B protruding from the cylinder portion 8A.
14 and 15 are supported, respectively, and the cable 4 is wrapped around these sheaves 14 and 15 over a plurality of strips. The accumulator 16 is connected to the cylinder portion 8A, and the piston rod 8B is elastically supported in the expansion direction by the pressure of the compressed air stored in the gas chamber 16A of the accumulator 16. The gas chamber 16A is further equipped with an air source 19 such as a compressor.
And the supporting force of the piston rod 8B can be arbitrarily adjusted by the supply of compressed air from the air source 19. Note that a stroke sensor 23 is interposed in the ram cylinder 8 to detect the stroke position of the piston rod 8B.

A servo cylinder 17 is interposed between the cylinder portion 8A of the ram cylinder 8 and the piston rod 8B. The servo cylinder 17 is a double-acting cylinder in which the cylinder part 17A is locked to the cylinder part 8A and the rod part 17B is locked to the upper end of the piston rod 8B, and selectively supplies pressure oil to the oil chambers 12 and 13 formed inside. By doing so, the piston rod 8B is forcibly driven to the extension side or the contraction side, and for this purpose, the servo valve 18 is interposed before the oil chambers 12 and 13. The servo valve 18 is connected to the controller 22 by an electric circuit, and selectively connects the pressure oil supply device (pump) 7 and the tank 10 to the oil chambers 12 and 13 according to the supply current from the controller 22, and controls the flow rate. I do.

The above-mentioned fluctuation amount detector 20, load cell 21, stroke sensor 23 and cable length meter 24 are all connected to the controller 22 by a signal circuit, and the detected values are input as signal currents. When the controller 22 detects the sway of the hull to be absorbed by comparing the input signals from the sway detector 20 and the load cell 21 with a value set in advance, the controller 22 connects the servo valve 18 so as to absorb the sway. By controlling the direction and the flow rate, the servo cylinder 17 is expanded and contracted. In addition, the weight of the cable 4 is calculated from the length of the cable 4 sent out from the cable length meter 24, and the pressure of the accumulator 16 is adjusted based on the input signal from the stroke sensor 23. The neutral position (average position) is always kept constant. For this purpose, a pressure control valve (not shown) controlled by the controller 22 is interposed between the accumulator 16 and the ETER source 19.

 Next, the operation will be described.

When suspending the launcher 2 from the mother ship 1 to the sea surface,
By operating the controller 22, the accumulated pressure of the accumulator 16 is lowered to bring the ram cylinder 8 into the most contracted state, and only the cable winch 5 and the traction winch 6 are extended to suspend the launcher 2. During this time, the auto-tensioner device does not operate, but while the launcher 2 is in the air, the movement of the mother ship 1 hardly affects the tension of the cable 4.

Once the launcher 2 has landed, the controller 22 is operated and compressed air is immediately supplied from the air source 19 to the accumulator 16 so that the ram cylinder 8 is extended to the neutral position of maximum compression and maximum expansion against the tension of the cable 4. . As a result, the auto tensioner device becomes operable.

When the mother ship 1 shakes in this state, the tension of the cable 4 for suspending the launcher 2 fluctuates greatly. On the other hand, the auto-tensioner device compensates for the change in tension by performing a so-called passive operation in which the ram cylinder 8 expands and contracts in response to the change in tension, absorbs the fluctuation of the mother ship 1 and stably holds the launcher 2. .

By the way, when the launcher 2 is submerged in the sea, buoyancy acts on the underwater portion of the launcher 2 and the cable 4, so that the tension itself of the cable 4 decreases and the change in the tension of the cable 2 due to the oscillation of the mother ship 1 also decreases. On the other hand, due to frictional resistance, the ram cylinder 8 does not expand or contract unless the tension of the cable 4 changes more than a certain value. Therefore, after the launcher 2 is suspended in the sea, the ram cylinder 8 does not expand and contract unless the mother ship 1 is shaken to some extent only by the passive operation, and the shake may be directly transmitted to the launcher 2. On the other hand, this auto-tensioner device absorbs such fluctuations by active operation via the controller 22 and the servo cylinder 17.

That is, when the fluctuation amount detector 20 detects the fluctuation amount of the mother ship 1 to be absorbed and the load cell 21 detects the tension of the cable 4 and outputs a signal to the controller 22, the controller 22 generates the signal based on these signals. The servo cylinder 17 is driven via the servo valve 18 to expand and contract the ram cylinder 8 in the direction of absorbing the movement, that is, in the direction of compensating for the change in the tension of the cable 4. As a result, the stationary ram cylinder 8 forcibly starts to expand and contract, and
The cable 4 wound between 14 and 15 is sent out of the boat or taken in the boat according to the sway. In this way, even when the tension change of the cable 4 is less than the frictional resistance, the ram cylinder 8 smoothly expands and contracts due to the active operation, so that the dead zone near the neutral position due to the frictional resistance is eliminated, and small fluctuations are sufficiently absorbed.

On the other hand, if the movement of the mother ship 1 is large, the change in the tension of the cable 4 is large, and the expansion and contraction of the ram cylinder 8 is mainly performed by a passive operation based on the direct action of the change in the tension. But,
In this case as well, the controller 22 continues to drive the servo cylinder 17, and the ram cylinder 8 expands and contracts with a good response to the movement of the mother ship 1 because the servo cylinder 17 leads the expansion and contraction of the ram cylinder 8, and shakes with a high damping rate. Absorb. Thus, the underwater launcher 2 always maintains a stable state regardless of the magnitude of the oscillation of the mother ship 1.

By the way, the cable weight increases as the cable 4 is unreeled into the sea. On the other hand, the controller 22 sends the cable 4 based on a signal input from a cable length meter 24 attached to the traction winch 6. A pressure control valve having the air pressure of the accumulator 16 interposed with the air source 19 so that the average position of the ram cylinder 8 does not change based on the stroke position input from the stroke sensor 23. Adjust through the control of. For this reason, even if the launcher 2 is at any depth below the sea surface, or when the launcher 2 is ascending or descending, there is no possibility that the fluctuation absorbing ability of the ram cylinder 8 will change.

Note that the servo cylinder 17
The expansion and contraction force of the servo cylinder 17 need only exceed the frictional resistance of the ram cylinder 8, and a small capacity servo cylinder 17 is sufficient. On the other hand, if the servo cylinder 17 has a large capacity, the ram cylinder 8 can be fully activated.
In this case, the three operation modes of only the active operation, only the passive operation, and the combination thereof can be arbitrarily selected according to the weather conditions in the sea area.

In addition, since the motion of the hull often has a regularity, a specific waveform pattern is set in the controller 22 in advance, or the motion amount detector 20 such as an accelerometer is used.
The waveform pattern read from the output signal of
It is also possible to control the servo valve 18 based on this waveform pattern so that it is automatically set to 22.

(Effects of the Invention) As described above, the auto-tensioner device of the present invention interposes the servo cylinder on the ram cylinder which expands and contracts by compensating the cable tension, and detects the hull to be absorbed detected by a fluctuation amount detector such as an accelerometer. The servo cylinder is driven to expand and contract based on the fluctuation of the cable, so the small movement that could not be absorbed due to frictional resistance only by the passive operation in which the ram cylinder expands and contracts directly due to the change in the tension of the cable causes the servo cylinder to move. Absorbed by active actuation.

In addition, the response of the ram cylinder is improved by leading the expansion and contraction of the ram cylinder by the servo cylinder even in the case of a large fluctuation, so that the damping rate in fluctuation absorption can be increased.

For this reason, according to the present invention, the ability of the auto tensioner device to stabilize the posture of the underwater device suspended from the mother ship and prevent sudden tension fluctuation of the cable suspending the same is significantly increased, and the use of an optical fiber or the like increases the signal. The requirement when the transmission cable is also used as the recovery cable can be sufficiently satisfied.

[Brief description of the drawings]

FIG. 1 is an arrangement view of an auto-tensioner device on a ship showing an embodiment of the present invention, and FIG. 2 is a control circuit diagram of the same. 1 ... mother ship, 2 ... launcher, 4 ... cable, 8 ...
Ram cylinder, 14,15 ... sheave, 16 ... accumulator, 17 ... servo cylinder, 18 ... servo valve, 20
…… a fluctuation amount detector, 22 …… a controller.

Claims (1)

(57) [Claims] 1. A middle part of a cable for suspending an underwater apparatus from a mother ship is wound around a sheave of a ram cylinder provided on the mother ship, and the ram cylinder is elastically supported in the extension direction by accumulating a hydraulically connected accumulator. In an auto tensioner device, a servo cylinder that expands and contracts a ram cylinder, a fluctuation amount detector that detects the fluctuation of the mother ship to be absorbed, and a hydraulic pressure that drives and controls the servo cylinder to absorb the fluctuation generated from the detected value An auto-tensioner device comprising a control circuit.