JP2000318976A - On-board gate crane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the inclination of a hull during cargo handling operation of a heavy cargo by providing a counter weight for correcting the inclination of the hull by the load of a cargo suspended from a trolley, and making the counter weight rigid by a water tank. SOLUTION: This gate crane is traveled on rails 8 provided on both outboard, and it comprises a girder 3 provided so as to connect leg parts 2 on both side, and the girder 3 has a rail to horizontally travel a trolley 4. Further, this crane comprises a counter weight 13 for correcting the inclination of the hull by the load of a cargo suspended from the trolley 4, and the counter weight 13 is formed of a water tank, and horizontally traveled on the girder 3 including a cantilever 7. The counter weight 13 is moved in the reverse direction to the trolley 4 moving while suspending a cargo 1 relative to the central line of the vessel to correct the inclination of the hull.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gantry type crane particularly suitable for loading and unloading goods stored in pallets, containers and the like, and more particularly to a small boat having a large inclination angle when a heavy load is loaded. It is suitable for.

[0002]

2. Description of the Related Art A crane for cargo handling is often used in a harbor, but using a crane equipped on a hull enables convenient cargo handling without being restricted by the location of a quay. . Particularly, in a ship that handles pallets, containers, and the like having a fixed shape, a crane having a dedicated function may be provided. By the way, since the unit weight of a load such as a pallet or a container becomes large, when a crane provided on the hull is used, the inclination of the hull at the time of loading and unloading becomes a problem. Even if it is not a problem for a large ship on a foreign route, the impact will be great for a relatively small ship for domestic transportation. For example, even a single steel coil can reach up to 20 tons, but a plurality of such coils are loaded on a pallet, loaded on a ship, and transported between factories in Japan. In such a case, a plurality of heavy objects are originally lifted together, and the use of a shipboard crane becomes difficult due to the inclination of the hull.

[0003]

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to provide an on-board crane in which the inclination of the hull is suppressed as much as possible during the loading of heavy objects.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and a girder having a portion projecting from a side of a portal crane traveling on rails provided on both sides of a hull. And a trolley that traverses the trolley, and a luggage hanging device is coupled to the trolley via a hoisting rope, and the hull of the hull due to the load of the luggage suspended from the trolley by traversing the girder without interfering with the trolley. A gantry type crane characterized in that a counterweight for correcting the inclination is provided, and the counterweight is constituted by a water tank.

Further, in a portal crane running on rails provided on both sides of the hull, a girder having a portion protruding from the side of the ship and a trolley traversing the girder are provided, and the trolley is connected to the trolley via a hoisting rope. A counterweight is provided to couple the baggage lifting device and correct the inclination of the hull due to the load of the load hung from the trolley by traversing the rail provided between both sides of the hull, and the counterweight is provided by a water tank. It is a shipboard type crane characterized by being constituted.

Further, in a portal crane running on rails provided on both sides of the hull, a girder having a portion protruding from the side of the ship and a trolley traversing the girder are provided, and the trolley is connected to a hoisting rope via a hoisting rope. Attached to the end of the arm extending from the axis of rotation provided on the center line of the hull, and attached to the end of an arm extending from the axis of rotation, the hull was tilted due to the load of the load suspended from the trolley by moving between both sides. A counterbore-type crane, wherein the counterweight is provided by a water tank.

[0007] In each of the above-mentioned ship-side gate cranes, portions protruding from both sides of the girder are bendable, and are rotated around a vertical axis between the trolley and the luggage hanging device. It is also characterized in that a turning device for changing the direction of the load is provided.

[0008] In each of the above-mentioned onboard gantry cranes, a position signal transmitter is connected to a driving device for traversing the trolley and moving the counterweight, respectively.
Based on these signals, the distances of the trolley and the counterweight from the centerline position of the hull are determined, and the weight of the suspended load is measured to determine the load of the trolley, and the position of the trolley from the centerline position of the hull and the trolley are determined. Calculate the moment by the trolley by the product of the load of the trolley, and minimize the difference between the value obtained by dividing the moment by the trolley by the known weight of the counterweight and the distance of the counterweight from the centerline position of the hull. This is a method for controlling a shipboard type crane characterized by controlling a counterweight position.

[0009]

FIG. 1 is a front view showing an example of an on-board gate crane according to the present invention, and FIG. 2 is a plan view of the on-board gate crane of FIG. There are various types of ship cranes, but a portal crane is used in the present invention because of the ability to handle heavy objects and to make the direction of the lifted cargo constant. This portal crane runs on rails 8 provided on both sides of the hull, and has legs 2 on both sides.
And a girder 3 is provided. The girder is provided with a rail (not shown) so that the trolley 4 can traverse.
A luggage hanging tool 6 such as a spreader or a hook is connected via the. By these means, the luggage 1 such as a pallet can be loaded and unloaded between the quay 9 and the hold 10 by running the gantry body, running the trolley, and operating the hoisting rope.

The above girder needs to protrude from the hull with a clearance longer than that of the legs in order to lift or hang the load from the quay. However, since the girder projecting from the side of the ship may impair the stability of the ship during the voyage, it is preferable that the portions projecting from both sides bendable vertically during the voyage. For example, the protruding portion of the girder, that is, the cantilever 7 may be rotatably connected via the hinge 11 so that the girder can be bent from the horizontal direction in a state continuous with the girder body portion to almost vertically downward. In this case, the rails are made continuous so that the trolley 4 can continuously traverse the girder main body and the cantilever 7 during cargo handling. In this example, the bending operation of the cantilever is performed from above by the wire rope 12, but a method of providing a hydraulic cylinder or a link mechanism and supporting the cantilever from below by the leg 2 of the crane can also be adopted. The support by the wire rope and the support by a hydraulic cylinder or the like can be used together. When the width of the girder or the cantilever in the horizontal direction is small, in addition to the above-described method of rotating the cantilever downward, it is also possible to rotate the cantilever in a horizontal direction by connecting it with a vertical rotation axis.

In this way, the cargo can be loaded and unloaded between the quay and the ship by the onboard gate crane. In the present invention, the counterweight 13 for correcting the inclination of the hull due to the load of the load suspended from the trolley 4 is further provided. Provide. The counterweight is provided so as to traverse on the girder 3 including the cantilever 7, and moves in the opposite direction across the center line of the ship with the trolley 4 that moves while hanging the load 1, thereby correcting the inclination of the hull. The counterweight 13 must be able to move in either side of the side without interfering with the trolley 4 when moving on the girder. Therefore, the rails of the trolley are provided on the lower side and the rails of the counterweight are provided on the upper side of the girder so as to be able to cross up and down as shown in FIG. If the width of the girder is large, trolleys and counterweight rails can be provided on the girder in parallel with the longitudinal direction of the ship. It is preferable that the weight of the counterweight is commensurate with the total weight of the suspended load, the load suspender, the trolley and the swing device described below (hereinafter, referred to as the load of the trolley), but at least the effect of reducing the inclination of the hull. Is enough and the purpose can be achieved.

The counterweight does not traverse on the girder of the portal crane as described above, but traverses on a rail provided in the width direction of the ship between both sides of the hull, for example, at the deck position. Is also good. FIG. 3 is a front view showing an example in which such a counterweight 21 is installed, and is provided at a portion where there is no hold near the bow or stern. In this case, there is an advantage that the load applied to the crane itself is reduced by the amount of the counter weight, as compared with the crane provided on the girder 3. On the other hand, depending on the case, there is a problem that it interferes with loading and unloading of the load and a space for the load is reduced.

As another example of the counterweight,
It may be attached to the tip of an arm extending from a rotation axis provided on the center line of the hull and move between both sides. FIG. 4 is a plan view showing such a counterweight 22, in which the hull shows only a portion near the stern. In FIG. 4, reference numeral 23 denotes a rotating shaft, and 24 denotes an arm. The counterweight 22 can move between both sides by rotating around the rotating shaft within a range of 180 degrees.

Further, in the present invention, the counterweight is constituted by a water tank. If the weight of the counterweight is not changed, not only will the load be wasted while sailing, but also the counterweight which traverses on the girder of the portal crane, will increase the center of gravity of the ship and deteriorate the stability against rolling. . On the other hand, the above-mentioned problem can be avoided if the counterweight is constituted by a water tank and water is filled only during cargo handling and drained and emptied during voyage. Not only fresh water, but also seawater can be used for the water tank by taking necessary anticorrosion measures.

As described above, the counterweight moves in the opposite direction across the center line of the ship with the trolley 4 that hangs the load 1, and corrects the inclination of the hull so as to balance the ship. The method of controlling the movement of the counterweight at this time is not particularly limited in the present invention, but according to the method described below with reference to the block diagram of FIG. 5, according to the weight and position of the suspended luggage. This is preferable because the position of the counterweight can be adjusted.

That is, first, it is necessary to grasp the trolley traverse position and the counterweight moving position. For this purpose, a position signal transmitter is connected to each of the driving devices for moving the trolley and the counterweight. FIG.
In FIG. 7, those shown by the trolley traverse position measurement 31 and the counterweight position measurement 36 correspond to these position signal transmitters. A trolley or a counterweight travels on a rail by driving wheels or by providing a separate rack rail and engaging it with a pinion and rotating.For example, a gear tooth included in a power transmission mechanism from a motor is used. What is necessary is just to make a proximity switch oppose a part, and to generate a pulse signal with rotation. Combining this with the signal of the rotation direction of the motor, the wheels etc.
When the reverse rotation is repeated, the addition / subtraction of the pulse integrated value is repeated, and the traveling position can be grasped. In particular, for example, if a limit switch is provided at the centerline position of the hull and a signal is output when passing through it, the distance from the hull centerline at that time is determined by the accumulated pulse value after the limit switch generates a signal. Is required.

In the position measuring method for the trolley and the like, a rotary encoder may be connected to any one of the rotating shafts of the driving device instead of providing the proximity switch on the gear. Since the rotary encoder outputs the rotational position as a numerical value of an address, when a wheel or the like repeats normal rotation and reverse rotation, addition and subtraction of the numerical value are repeated, so that the traveling position can be grasped. That is, in this case, it is not necessary to use the signal of the rotation direction of the motor.

In the case where a counterweight attached to the end of an arm extending from the rotating shaft as shown in FIG. 4 and which moves between both sides is used, the same method as the above-described method for measuring the position of the counterweight is used. What is necessary is just to detect the rotation position of a rotating shaft by a method. However, since the distance of the counterweight from the hull centerline is a value proportional to the sine of the rotation angle from the centerline position, such calculation is necessary.

On the other hand, it is necessary to measure the weight of the suspended load and obtain the load of the trolley together with the weight of the trolley body known in advance. In FIG. 5, trolley load measurement 3
This is the case indicated by 2; for example, a load cell is attached to a member between the trolley and the luggage suspending device, which loads the luggage, and the weight of the suspended load is measured. Since the weight of the trolley that is not measured by the load cell is known in advance, the load of the trolley is determined together with the weight of the suspended load.

Next, the product of the trolley position from the center line position of the hull and the load of the trolley is input to the multiplication circuit 33 to calculate the moment by the trolley. On the other hand, the value of the moment and the counter weight 34 are input to the dividing circuit 35, and the position where the counter weight should be located is obtained. This and the distance of the counterweight from the center line of the hull obtained above are input to the differential amplifier 37, and a counterweight movement command is output therefrom. As a result, the counterweight position is always controlled so as to minimize the inclination of the hull due to the moment of the trolley. In FIG. 5, a broken line 38 indicates mechanical feedback instead of the configuration of the circuit itself. In FIG. 5, the counterweight 34 is described as being known, but may be obtained by measurement in the same manner as the method of measuring the weight of the suspended load described above. FIG. 5 shows a configuration using an analog arithmetic circuit, but it is obvious that control using a digital arithmetic device is also possible.

Further, in the ship-side gate crane of the present invention, it is preferable to provide a swivel device between the trolley 4 and the load hanging device 6 for rotating the direction of the load around a vertical axis. That is, the ship on which the shipboard type crane of the present invention is installed mainly loads pallets and containers as described above. In general, these cargos have a rectangular shape with a long side on a horizontal projection plane. In a relatively small vessel to which the present invention is applied, the cargo is loaded so that the width direction of the vessel is long in terms of balance. Therefore, if you try to load and unload without changing the direction of your luggage,
The direction of luggage on the quay shall be in the short side direction in front of and behind the ship. In this case, unless the length of the girder protrudes longer than in the case of the longitudinal direction of the ship, the load cannot be hung unless the length of the girder is protruded, and the inclination of the hull during loading and unloading becomes even greater. As a countermeasure for this problem, the cargo can be rotated around a vertical axis in a suspended state, and the direction of the cargo on the quay can be such that the long side direction is the front and rear direction of the ship. In this case, the rotation angle may be at least 90 degrees.

The boat gate type crane shown in FIG. 1 shows an example in which such a turning device is provided. That is, a swivel column 15 rotating around a vertical axis depends from the trolley 4, and the swivel table 14 is connected to the tip of the swivel column 15. The turning column 15 can be turned by a rotating mechanism (not shown) mounted on the trolley. A wire rope hoisting device 16 is provided on the swivel table 14, and a luggage hanging device 6 such as a spreader or a hook is connected to a tip of the wire rope 5 which is suspended therefrom. The turning device is not limited to the one shown in FIG. 1 and various types of mechanisms can be used.

[0023]

According to the gantry crane of the present invention, the counterweight is moved in accordance with the movement of the load hung by the crane. Therefore, even when a heavy load such as a pallet or a container is loaded, the counterweight can be moved. The inclination of the hull can be reduced. In addition, since the counterweight is composed of a water tank, it is emptied except during cargo handling to avoid unnecessary loads due to the counterweight, and the center of gravity of the counterweight that traverses on the girder of the portal crane has a center of gravity. It is possible to prevent the stability against rolling from being deteriorated due to the increase.

[Brief description of the drawings]

FIG. 1 is a front view showing an example of a shipboard type crane according to the present invention.

FIG. 2 is a plan view of the onboard gate type crane of FIG.

FIG. 3 is a front view showing another example of the shipboard type crane according to the present invention.

FIG. 4 is a plan view showing another example of the shipboard type crane according to the present invention.

FIG. 5 is a block diagram illustrating a method of controlling a counterweight position.

[Explanation of symbols]

 Reference Signs List 1 luggage 2 legs 3 girder 4 trolley 5 hoisting rope 6 luggage hanging tool 7 cantilever 8 rail 9 quay 10 hold 11 hinge 12 wire rope 13 counterweight 14 turning table 15 turning column 16 hoisting device 21, 22 counterweight 23 rotating shaft 24 arm

Claims (6)

[Claims] 1. A portal crane running on rails provided on both sides of a hull, comprising: a girder having a portion protruding from the side of the ship; and a trolley traversing the girder.
The trolley is connected with a luggage hanging device via a hoisting rope, and provided with a counterweight for correcting the inclination of the hull due to the load of the luggage suspended from the trolley by traversing the girder without interfering with the trolley. A boat gate type crane, wherein the counterweight is constituted by a water tank. 2. A portal crane running on rails provided on both sides of a hull, comprising: a girder having a portion projecting from a side and a trolley traversing the girder;
The trolley is connected with a load suspender via a hoisting rope, and a counterweight for correcting the inclination of the hull due to the load of the load suspended from the trolley by traversing on a rail provided between both sides of the hull. A boat gate type crane, wherein the counter weight is constituted by a water tank. 3. A portal crane running on rails provided on both sides of a hull, comprising: a girder having a portion protruding from the side of the hull; and a trolley traversing the girder.
The trolley is connected with a luggage hanging device via a hoisting rope, and is attached to the end of an arm extending from a rotation axis provided on the center line of the hull, and moves between both sides to move luggage from the trolley. A counterweight for correcting the inclination of the hull due to the load of the ship, wherein the counterweight is constituted by a water tank. 4. The shipboard crane according to claim 1, wherein the portions of the girder projecting from both sides are bendable. 5. A shipboard according to claim 1, further comprising a swivel device that rotates around a vertical axis to change the direction of the load, between the trolley and the load hanging device. Portal crane. 6. A gantry crane according to claim 1, wherein a position signal transmitter is connected to a drive device for traversing the trolley and moving the counterweight, respectively, and the hull is controlled by these signals. The distance between the trolley and the counterweight from the centerline position of the hull is determined, the weight of the suspended load is measured to determine the load on the trolley, and the product of the trolley position from the centerline position of the hull and the load on the trolley is obtained. Calculates the moment by the trolley, and controls the position of the counter weight so as to minimize the difference between the value obtained by dividing the moment by the trolley by the previously known weight of the counter weight and the distance of the counter weight from the center line position of the hull. A method for controlling a shipboard type crane, comprising: