JP3329011B2 - Ocean floating body motion absorption device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for absorbing the motion of a floating marine body, which is used to absorb the motion of the floating body from the marine floating body in a state of being suspended from the floating body. It is.

[0002]

2. Description of the Related Art When a heavy object is suspended from a floating body such as a ship into the sea, even if the floating body is shaken by waves or the like, the movement is not transmitted to the heavy substance suspended in the sea. 2. Description of the Related Art A method of suspending a heavy object, which absorbs vibration, has conventionally been employed.

In a conventional method of suspending a heavy object from a floating sea, a passive suspension mechanism is used as shown in FIG. That is, the supporting frame 2 erected on the floating body 1
The pulley 4 is attached to the end (lower end) on the head side and the pulley 6 is attached to the tip (upper end) of the piston rod 5, and the load for suspending and supporting the heavy object 9 via the rope 10 wound around the pulleys 4 and 6. A support cylinder 3 is mounted, an accumulator 7 is connected to the head side pressure chamber 3a of the load support cylinder 3, and an air tank 8 is connected to the accumulator 7.
Is connected to adjust the air pressure in the air tank 8 so that the working oil pressure acting on the head side pressure chamber 3a from the accumulator 7 is adjusted. Floating body 1 due to spring effect
What is absorbed is used.

The load supporting cylinder 3 employed in the above-described conventional method of suspending a heavy object has a head-side pressure chamber 3a.
Since the hydraulic oil pressure in the inside is balanced by the air pressure supplied from the air tank 8 to the accumulator 7 and the accumulator 7, the load of the suspended heavy object 9 is supported by adjusting the air pressure of the air tank 8 The cushion effect is provided by the spring effect. 11 is a pulley attached to the floating body 1, 12 is a pipe for supplying compressed air to the air tank 8, and 13 is a vent pipe.

[0005]

However, the suspension mechanism used in the above-mentioned conventional method of suspending a heavy object absorbs the movement of the floating body 1 by the cushion function of the load supporting cylinder 3 when the floating body 1 is shaken. Can be prevented from being transmitted to the suspended weight 9, but when the weight of the suspended weight 9 increases, the spring strength of the load supporting cylinder 3 is increased to maintain the suspended weight 9 in the sea. However, when the spring strength is increased, there is a problem that the function as a cushion is reduced, and the natural period of the spring system in which the suspended heavy object 9 is suspended becomes close to the oscillation period of the floating body 1. On the other hand, there is a problem that the movement of the suspended heavy object 9 is amplified in the vicinity thereof due to the tuning of the spring.

In view of the above, the present invention is also directed to maintaining the underwater position of a suspended heavy object by enhancing the cushion function without increasing the spring strength of the load supporting cylinder even when the underwater position of the suspended heavy object is held in the sea. It is an object of the present invention to provide an apparatus for absorbing the motion of a floating body on the sea, which is capable of improving the workability and the work efficiency of suspending a heavy object underwater.

[0007]

In order to solve the above-mentioned problems, the present invention provides a load supporting cylinder for suspending and supporting a heavy object via a rope by applying a pneumatic pressure to hydraulic oil to provide a cushioning function. In addition to installing on a floating body, an active control force generating device for generating an active control force by filling the pressure chambers on both sides of the piston with hydraulic oil and adjusting the pressure of both pressure chambers is installed on the floating body, A variable displacement pump connected to a load supporting cylinder and adjusting the flow rate of hydraulic oil to both pressure chambers of the active control force generating device; and a detection value of an acceleration sensor on a floating body and a movement of the load supporting cylinder. The vertical displacement and the vertical movement speed of the suspended heavy object are obtained by inputting the detection value of the stroke sensor, and the active force is calculated based on the force proportional to the vertical displacement and the vertical movement speed of the suspended heavy object. The differential pressure between both pressure chambers of the control force generating device a configuration comprising a control panel to control the discharge flow rate of the variable displacement pump.

[0008]

When the floating body is shaken, the floating body is absorbed by the air spring effect of the load supporting cylinder. On the other hand, the pressure difference between the pressure chambers on both sides of the active control force generator, which fluctuates following the movement of the load supporting cylinder, is input to the control panel, and discharge from the variable displacement pump to the active control force generator is performed according to a command from the control panel. By controlling the flow rate and generating a predetermined active control force, the underwater position of the suspended heavy object is properly maintained, and amplification of the movement of the suspended heavy object due to the synchronization between the air spring and the floating body sway is increased. Can be suppressed.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an outline of an embodiment of the present invention. As in the case of the passive type load supporting mechanism shown in FIG. 3, a pulley 6 is attached to the tip of a piston rod 5 and is attached to an end on the head side. A pulley 4 is attached, and a load support cylinder 3 for hanging a heavy object 9 on a rope 10 wrapped around both pulleys 4 and 6 is installed on a support frame 2 on a floating body 1 on the sea with the head side facing downward. At the same time, an accumulator 7 is connected to the head-side pressure chamber 3a of the load supporting cylinder 3, and an air tank 8 is connected to the accumulator 7, and the pressure of the air tank 8 causes the head-side pressure chamber 3a of the load supporting cylinder 3 to be connected. The relative displacement between the floating body 1 and the suspended heavy object 9 is adjusted by adjusting the working oil pressure of the load supporting cylinder 3.
And a device for generating an active control force on the load support cylinder 3 of the passive type suspension mechanism is provided in the configuration provided with the passive type suspension mechanism that is absorbed by the cushion function.

That is, the rods 1 on both sides of the piston 15
An active control force generator 14 in which pressure chambers A and B on both sides of the piston are filled with pressurized oil in the double rod type hydraulic cylinder having the piston 6 is attached to the support frame 2, and the piston rod 16 on the pressure chamber A side is mounted. Is integrally connected to the piston rod 5 of the load support cylinder 3, and the load control cylinder 3 is actively controlled by the pressure difference between the two pressure chambers A and B while following the movement of the piston rod 5 of the load support cylinder 3. Try to generate force. Active control force generator 1
The pressure chambers A and B on both sides separated by a piston 15 of a double rod type hydraulic cylinder as the fourth unit 4 are connected in a closed circuit via a variable displacement pump 17 capable of discharging in both directions, and the variable displacement pump 17 is connected. The discharge flow rate is controlled by changing the tilt angle of the active control force generator 1.
In step 4, a predetermined active control force is generated, and a control panel 18 for instructing to adjust the discharge flow rate of the variable displacement pump 17 is provided. The control panel 18 includes pressure sensors P ₁ and P ₂ for detecting the pressures in the pressure chambers A and B on both sides of the hydraulic cylinder as the active control force generator 14,
The signals from the stroke sensor S for detecting the displacement of the load supporting cylinder 3, that is, the displacement of the piston rod 5, and the signal from the floating body vertical motion acceleration sensor 19 installed on the floating body 1 are input to the pressure sensors P ₁ , P _2, the flow rate of the variable displacement pump 17 is controlled so as to generate the active control force commanded by the acceleration sensor 19 and the stroke sensor S based on the differential pressure signal between the pressure chambers A and B on both sides of the active control force generator 14. Let it do.

FIG. 2 shows an active control block diagram in which an active control force is generated by the active control force generator 14 when absorbing the relative displacement of the suspended body 1 in the vertical direction with the suspended heavy object 9 when the floating body 1 shakes. It is shown.

In FIG. 2, the same components as those in FIG. 1 are denoted by the same reference numerals, and 20 and 21 in the control panel 18 are integrators, 22 is differentiators, 23 and 24 are gains, and 25 is flow rate control. Vessel 26 is a disturbance (wave forcing) applied to the floating body 1,
a is an active control force generation command, b is a differential pressure signal, and c is a flow rate command.

[0014] Lower heavy 9 hanging the floating body 1 of the sea is displaced vertically, the relative displacement amount of the vertical displacement Z _R of lowering heavy 9 hanging with vertical displacement Z _S of the floating body 1 (Z _R -Z _S) A proportional force F _K is generated in the load-carrying cylinder 3. At this time, the relative displacement between the floating body 1 and the suspended heavy object 9 is detected by the stroke sensor S as the displacement of the piston rod 5 of the load supporting cylinder 3 and input to the control panel 18, and the detected value of the acceleration sensor 19 Is input to the control panel 18.

In the control panel 18, the relative displacement (Z _R −Z _S ) detected by the stroke sensor S is calculated by the differentiator 22.
And the relative vertical movement speed (Z _R1 −Z _S1 ) is obtained. On the other hand, the detected value from the acceleration sensor 19 is integrated by the integrator 20 to obtain the vertical movement speed Z _S1. Dynamic speed Z _S1 and the relative vertical motion speed (Z _R1 −Z _S1 )
The vertical moving speed of the suspended heavy object 9 (absolute vertical moving speed)
With obtaining the Z _R1, vertical movement speeds Z _S1 of the floating body 1 is integrated by the integrator 21 is required vertical displacement Z _S of the floating body 1, the relative displacement from the floating vertical displacement Z _S and the stroke sensor S ( Z vertical displacement of _R -Z _S) and scolded hanging heavy 9 (absolute vertical displacement) Z _R is obtained.

When the vertical movement speed Z _R1 and vertical displacement Z _{R of the} suspended heavy object 9 are obtained in the control panel 18, a component (corresponding to a spring) proportional to the vertical displacement Z _R of the suspended heavy object is obtained. An active control force generation command a is input to the flow controller 25 as a sum of components proportional to the vertical movement speed Z _R1 of the suspended heavy object,
Further, the flow controller 25 includes an active control force generator 14.
Both the pressure chamber A from the pressure sensor P ₁ and P _2, the differential pressure signal b of B are inputted. Accordingly, based on the active control force generation command a indicated as the sum of components proportional to the vertical displacement Z _R of the suspended heavy object and the vertical movement speed Z _R1 of the suspended heavy object, the pressure sensor P ₁ , flow rate command c is given by the flow rate controller 25 by differential pressure signal b from P ₂ to the variable displacement pump 17, so that the active control force generator 14 is to generate a predetermined active control force F _a, the variable capacitance The discharge flow rate from the pump 17 to the active control force generating device 14 is controlled, so that an active control force can be added while following the movement of the load support cylinder 3, and the sway of the floating body 1 causes a suspended heavy object. 9 so that workability can be improved.

[0017]

As described above, according to the apparatus for absorbing the motion of a marine floating body of the present invention, a device for generating an active control force is attached to a conventional passive load supporting cylinder to follow the movement of the load supporting cylinder. And actively generating a force that combines a force proportional to the amount of vertical displacement of the suspended heavy object and a force proportional to the vertical movement speed of the suspended heavy object to maintain the suspended underwater position of the suspended heavy object. Thus, the following excellent effects can be obtained. (i) By generating an active control force proportional to the vertical displacement of the suspended heavy object, part of the function of maintaining the position of the suspended heavy object in the sea, which was performed by the load supporting cylinder, can be taken over. Even if the spring strength of the load supporting cylinder is reduced, it is possible to maintain the position of the suspended heavy object in the sea. (ii) Since the spring strength of the load supporting cylinder can be reduced by the above (i), the cushion function can be greatly improved, while the spring force as the active control force is proportional to the displacement of the suspended heavy object itself. However, since it is not affected by the vertical movement of the floating body, it is not related to the vertical movement of the floating body. Therefore, a combination of the spring force of the small load supporting cylinder and the active control spring force that assists the same can realize both a high cushioning function and a function of holding a suspended heavy object in the sea,
The workability and efficiency of hanging heavy objects underwater can be improved. (iii) By generating an active control force proportional to the vertical movement speed of the suspended heavy object, the same effect as when the damping force against the movement of the suspended heavy object is increased is produced. Movement in the vicinity of the natural period can be reduced.

[Brief description of the drawings]

FIG. 1 is a partially cutaway schematic view showing an embodiment of a motion absorbing device for a sea floating body of the present invention.

FIG. 2 is a block diagram of the active control shown in FIG.

FIG. 3 is a schematic view of a conventional marine floating body vibration absorbing device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Floating body 3 Load support cylinder 3a Head side pressure chamber 4 Pulley 5 Piston rod 6 Pulley 7 Accumulator 8 Air tank 9 Hanging heavy object 14 Active control force generator 15 Piston 17 Variable displacement pump 18 Control panel 19 Acceleration sensor A, B Pressure chamber P _1, P ₂ the pressure sensor S stroke sensor

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-50-78090 (JP, A) JP-A-51-69863 (JP, A) JP-B-46-139 (JP, B1) (58) Field (Int. Cl. ⁷ , DB name) B63B 35/00 F16F 15/02

Claims (1)

(57) [Claims] An air pressure is applied to hydraulic oil to provide a cushioning function by an air spring effect, and a load supporting cylinder for suspending and supporting a heavy object via a rope is installed on a floating body. An active control force generator that generates an active control force by filling the pressure chambers with hydraulic oil and adjusting the pressures of both pressure chambers is installed on a floating body, connected to the load support cylinder, and A variable displacement pump that adjusts the flow rate of hydraulic oil to both pressure chambers of the control force generator, and a detection value of an acceleration sensor on a floating body and a detection value of a stroke sensor that detects the movement of the load support cylinder are suspended. The vertical displacement and the vertical movement speed of the heavy object are obtained, and based on the force proportional to the vertical displacement and the vertical movement speed of the suspended heavy object, the differential pressure between the two pressure chambers of the active control force generator is calculated. And a control panel for controlling the discharge flow rate of the variable displacement pump.