JPH0769276A - Fluctuation absorbing device at cargo handling on sea - Google Patents

Abstract

PURPOSE:To absorb relative displacement in the vertical direction between a load suspended by means of a crane and a material transport ship at cargo handling on the sea so as to facilitate operation of the crane. CONSTITUTION:A fluctuation absorbing cylinder 12 is provided on a crane 2 of a marine floating body 1, and hence the delivering quantity of a rope 6 wound up by means of a winch 9 can be adjusted. The working oil side of the fluctuation absorbing cylinder 12 is communicated to an accumulator 16, the accumulator 16 is connected to an air tank 17, and cushioning function due to air spring effect is added to the fluctuation absorbing cylinder 12 by a passive air spring mechanism 18. An active control force generating device 19 is connected to the fluctuation absorbing cylinder 12 so as to give it active control force by the discharge quantity from a variable delivery pump. The relative speed between a load 11 suspended with the crane 2 and a material transport ship 10 is controlled so as to conform to the indication by the crane operator, for load elevatable speed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a marine cargo handling crane on a marine floating body for transferring cargo between the marine floating body and the material carrier, and the cargo and the material carrier ship due to shaking of the marine floating body or the material carrier during marine cargo handling work. The present invention relates to a vibration absorbing device that is used by being attached to a crane so as to absorb a relative fluctuation between them.

[0002]

2. Description of the Related Art In a marine cargo handling operation in which cargo is transferred between the marine floating body and a material carrier using a crane for marine cargo handling on the marine floating body, as shown in FIG. The rope 6 having the hook 5 suspended via the pulley 4 at the tip of the jib 3 of the crane 2 is hung on the pulley 8 on the revolving frame 7, and then wound on the winch 9 to wind the rope 6 by the winch operation of the crane operator. , The feeding operation and the turning operation of the crane 2 are performed, and the material carrier 10
The upper luggage 11 is lifted by the crane 2 and moved onto the floating body 1 on the sea, or the luggage 11 on the floating body 1 is hung down and moved onto the material carrier 10.

[0003]

However, in the above-mentioned conventional marine cargo handling work, when the sea is calm and the sea floating body 1 and the material carrier 10 are little shaken, the crane 2 moves the material carrier 10 to the sea floating body 1 or the sea surface. Although the cargo handling work from the floating body 1 to the material carrier 10 can be easily performed, in the sea cargo handling work in the waves, the marine floating body 1 equipped with the crane 2 and the material carrier 10 cause different sway, and thus the crane When landing a luggage 11 hung by 2 on the material carrier 10, or from the material carrier 10 to the luggage 1
When the crane 1 is hoisted by the crane 2, an accident such as a load 11 suspended by the crane 2 hitting the material carrier 10 is likely to occur, which makes it difficult to operate the crane.

As a result, the material carrier 10 may wait in the vicinity of the sea during the waves until the waves are subsided and the sea cargo handling work can be performed, which may hinder the progress of the sea work.

In view of the above, the present invention provides a crane and materials so that the cargo suspended by the crane does not hit the material carrier even if the floating body equipped with the crane for cargo handling and the material carrier are separately shaken. Adjusting the rope payout amount according to the relative displacement of the carrier, and making it possible to lift and lower the cargo just like loading and unloading on land, improving the difficulty of crane operation, waiting for work in waves, etc. It tries to prevent it.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a marine cargo-handling crane on a floating body with a cushioning function due to the effect of an air spring by exerting air pressure on hydraulic oil. In addition, a swinging absorption cylinder that is wrapped around a rope so that the amount of the rope that is wound up by a winch and suspended from the tip of the crane can be adjusted, and the pressure chambers on both sides of the piston are filled with hydraulic oil. By installing an active control force generating device for generating an active control force in the vibration absorbing cylinder, the active control force generating device is connected to the vibration absorbing cylinder, and both of the active control force generating device are connected. Equipped with a variable capacity pump that adjusts the flow rate of hydraulic oil to the pressure chamber. Furthermore, the value detected by a distance measurement sensor that detects the distance between the tip of the crane and the material carrier The active control force is generated in order to generate the active control force so that the equivalent speed obtained from the relative distance between the suspended load and the material carrier based on the detection value of the stroke sensor that detects the movement of the Linda matches the instruction of the crane lifting speed by the crane operator. The controller is provided with a controller for controlling the discharge flow rate of the variable displacement pump based on the pressure values of both pressure chambers of the apparatus.

[0007]

[Operation] When the floating body on which the crane is mounted and the material carrier move differently due to waves, etc., the distance between the tip of the crane and the material carrier is detected by the distance measuring sensor, and the amount of rope unrolling at that time is detected. If a difference is found between the variable speed of the relative distance between the suspended load and the material carrier, which is obtained from these values by the stroke sensor, and the instruction speed for lifting and lowering the load by the crane operator, a force proportional to the difference is generated. Is applied as an active control force to the vibration absorbing cylinder to control the amount of rope unreeling. As a result, the relative position change between the suspended load and the material carrier is controlled so as to match the crane operator's load lifting instruction, so that the load can be prevented from hitting the carrier.

[0008]

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. Similar to the marine cargo handling crane shown in FIG. 3, a swivel frame 7 is installed on a floating body 1 on the sea, and the swivel frame 7 is mounted on the swivel frame 7. The jib 3 is movably mounted and supported, and a winch 9 is installed. A rope 6 wound around the winch 9 is attached to a pulley 8 on a revolving frame 7 and a pulley 4 at the tip of the jib 3.
The rope 6 by the winch 9, and the hook 5 is hung by the unwinding and unwinding.
A marine cargo handling crane 2 adapted to move up and down 1 is mounted, and the swing absorber of the present invention is provided on the swing frame 7 of the crane 2.

That is, the swing absorbing cylinder 12 having the pulley 14 attached to the tip of the piston rod 13 and the pulley 15 attached to the end on the head side is installed on the swing frame 7 of the marine cargo handling crane 2, and the winch 9 is attached to the winch 9. The rope 6 wound around the pulleys 14 and 15 is wound around the pulleys 14 and 15, and then the rope 6 is hooked on the pulley 8 on the revolving frame 7.
The accumulator 16 is connected to the accumulator 1
6, an air tank 17 is connected to the vibration absorbing cylinder 1
2 to the hydraulic oil in the head side pressure chamber A, the accumulator 16
And passive air spring mechanism 18 consisting of air tank 17
Is configured to exert a cushion function by the effect of an air spring by applying the air pressure, and the pressure chambers B and C on both sides of the piston in a double rod type hydraulic cylinder having rods 21 on both sides of the piston 20 are filled with pressure oil. Then, an active control force generator 19 for generating an active control force by adjusting the pressures of both pressure chambers B and C is installed on the revolving frame 7, and the pressure chamber B of the active control force generator 19 is installed.
The tip of the side piston rod 21 is connected to the piston rod 13 of the vibration absorbing cylinder 12, and the vibration absorbing cylinder 12 has a passive air spring force and active control for supporting the static load of the suspended load 11. Let the forces combine.

The pressure chambers B and C on both sides of the active control force generator 19 are connected in a closed circuit via a variable displacement pump 22 capable of discharging in both directions.
The discharge flow rate is controlled by changing the tilt angle of 2 so that a predetermined active control force is generated by the active control force generator 19, and the discharge flow rate of the variable displacement pump 22 is commanded by the controller 23. Control.

The controller 23 detects a value a detected by an optical distance measuring sensor 24 for detecting the relative distance between the tip of the jib 3 of the crane 2 and the material carrier 10, and shakes when the load 11 is suspended. By inputting the detection value b from the stroke sensor S of the absorption cylinder 12, the luggage 11 and the material carrier 1
The function to obtain the relative speed by obtaining the relative distance from 0 and the crane operator instructing the ascending / descending speed with the operation lever to wind up / down the winch 9 and move out the load 11 Instructed speed value V _{0 when}
Is inputted, the function of instructing the generation of the active control force so that the relative speed matches the lifting speed instruction of the crane operator, and both pressure chambers B of the active control force generator 19.
Detection value Pa of the internal pressure sensors P ₁ and P ₂ for detecting the internal pressure of C
, Pb are input and the discharge flow rate of the variable displacement pump 22 is controlled based on the detection values Pa, Pb from the internal pressure sensors P ₁ , P ₂ .

Active control force is generated in order to absorb the vertical displacement between the cargo 11 suspended by the crane 2 and the material transport ship 10 by shaking the floating body 1 and the material transport ship 10 to perform smooth work. A block diagram of active control in which an active control force is generated by the device is as shown in FIG.

In FIG. 2, the same elements as those in FIG. 1 are designated by the same reference numerals, and 25 in the controller 23 is a differentiator, 26.
Is a gain, and 27 is a pump discharge amount control unit. Also 28
Is a winch operation, 29 is disturbance due to vertical movement of the floating body 1 (vertical movement of the crane), 30 is vertical movement of the material carrier (disturbance), and c is the crane 2 and the luggage 11 when the luggage 11 is hung by the crane 2. Relative movement, d is a suspension load (disturbance) acting on the rocking absorption cylinder 12 due to the vertical movement of the crane associated with the vertical movement of the floating body 1, V _R is the cargo and the material carrier measured by the distance measuring sensor 24 and the stroke sensor S. The relative speed obtained by differentiating the relative distance of V in the differentiator 25, V ₀ is the ascending / descending speed instruction, e is the active control force generation instruction, f is the discharge amount instruction, FA is the active control force, and FP is the suspended load. Is a passive air spring force for indicating the static load of.

When the winch 9 mounted on the floating body 1 is operated and the cargo 11 is hung by the crane 2 to perform the cargo handling work, the relative movement e between the cargo 11 hung by the crane 2 and the crane 2 is absorbed by the shaking. The stroke change of the cylinder 12 is detected by the stroke sensor S, and the sea floating body 1 and the material carrier 10 sway separately due to waves or the like, and the crane up / down movement (disturbance) 29 and the carrier up / down movement (disturbance) 30 are relative. The relative distance between the crane 2 and the carrier 10 at the time of sudden occurrence is detected by the optical distance measuring sensor 24.
4 and the relative distance between the suspended load by the crane detected by the stroke sensor S and the carrier 10 is differentiated by the differentiator 25 of the controller 23 to obtain the relative speed V _R. This relative speed V _R is different from the ascending / descending speed instruction V ₀ when the crane operator operates the winch 9 to move the winch 9 up and down by instructing the ascending / descending speed suitable for loading and unloading with the lever for operating the ascending / descending cargo. At this time (V _R −V ₀ ), in order to apply a force proportional to the difference to the oscillation absorbing cylinder 12 as an active control force, an active control force generation instruction e is issued to the pump discharge amount control unit 27.
To the pressure chamber B of the active control force generator 19,
The internal pressures Pa and Pb of the internal pressure sensors P ₁ and P ₂ of C are input to and controlled by the pump discharge amount control unit 27, and the discharge amount instruction f is given to the variable displacement pump 22, and the variable displacement pump 22 is controlled.
The active control force FA is applied to the vibration absorbing cylinder 12 by controlling the discharge amount from. As a result, the stroke of the vibration absorbing cylinder 12 is adjusted to adjust the amount of rope unwinding, and when the cargo 11 hung by the crane 2 leaves the carrier 10 or is unloaded on the carrier 10, the carrier 10 may be hit. Can be prevented.

An air spring mechanism 18 applies a passive air spring force FP for supporting the static suspension load of the suspended load to the vibration absorbing cylinder 12 to which the active control force FA is applied. The force generated by the vibration absorbing cylinder 12 is a combination of the air spring force FP and the active control force FA.

[0017]

As described above, according to the rocking absorbing apparatus at the time of the sea cargo handling work of the present invention, the cargo suspended by the crane on the sea floating body and the material carrier are separated from each other. When the relative displacement is caused by shaking, it is detected as the relative speed of the load and the material carrier, and the active control force is applied to the shaking absorbing cylinder so that this relative speed matches the lifting speed instruction instructed by the crane operator. When viewed from the top of the carrier even in waves, the movement of the suspended load is similar to that of loading and unloading on land, and it is possible to prevent the bag from hitting the carrier, especially when the bag is lifted from the carrier or when the bag is seated on the carrier. It is possible to achieve the excellent effect that the difficulty of crane operation is reduced, the cargo handling work can be efficiently performed, and the cargo handling work can be prevented from waiting until the wave stops. .

[Brief description of drawings]

FIG. 1 is a schematic view showing an embodiment of a vibration absorbing device during marine cargo handling work according to the present invention.

2 is a block diagram of the active control shown in FIG. 1. FIG.

FIG. 3 is a schematic diagram of a conventional vibration absorbing device during cargo handling work at sea.

[Explanation of symbols]

1 Sea Float 2 Crane 3 Jib 6 Rope 7 Swing Frame 9 Winch 10 Material Carrier 11 Luggage 12 Swing Absorption Cylinder 14, 15 Pulley 16 Accumulator 17 Air Tank 18 Air Spring Mechanism 19 Active Control Force Generator 22 Variable Capacity Pump 23 Controller 24 Distance measuring sensor A Head side pressure chamber B, C Pressure chamber S Stroke sensor P ₁ , P ₂ Internal pressure sensor Pa, Pb Internal pressure VR _R Relative speed V ₀ Lifting speed instruction

Claims (1)

[Claims] 1. A vibration absorber for a marine cargo-handling crane on a floating floating body, wherein a hydraulic oil exerts a cushioning function by the effect of an air spring by exerting an air pressure and a rope wound around a winch is wound around the crane. The cylinder and the pressure chambers on both sides of the piston are filled with hydraulic oil to adjust the pressures of both pressure chambers, and an active control force generator for generating an active control force is installed in the vibration absorbing cylinder. Equipped with a variable displacement pump that connects the force generator to the vibration absorbing cylinder and adjusts the flow rate of hydraulic oil to both pressure chambers of the active control force generator, and also measures the distance between the tip of the crane and the material carrier. The relative speed obtained from the relative distance between the suspended load and the material carrier based on the detected value of the distance measuring sensor and the detected value of the amount of rope unrolled from the stroke sensor of the vibration absorption cylinder A controller for controlling the discharge amount of the variable displacement pump based on the internal pressures of both pressure chambers of the active control force generator in order to generate an active control force in accordance with the load lifting / lowering speed instruction of the operator. A vibration absorbing device for cargo handling work at sea characterized by being provided.