EP1939131A2

EP1939131A2 - Crane

Info

Publication number: EP1939131A2
Application number: EP07020201A
Authority: EP
Inventors: Toshihito Shimotsu
Original assignee: Mitsubishi Heavy Industries Ltd
Current assignee: Mitsubishi Heavy Industries Ltd
Priority date: 2006-12-26
Filing date: 2007-10-16
Publication date: 2008-07-02
Also published as: JP4295784B2; EP1939131A3; JP2008156094A; CN101209803A

Abstract

A crane (1) in which the sway of a lifter (spreader) (9) or a lifted load (container) can be stopped (suppressed) in a short period of time, the positioning of the lifter (9) or the lifted load can be carried out easily and quickly, the operability of the crane can be improved, and shortening of the loading and unloading time can be achieved. The crane (1) is provided with a lifter that holds plural loads (22,23), there is provided an actuator (15) that is able to change a relative position between the lifted loads (22,23), and by driving the actuator (15) according to a deviation from the target position, the lifted load (22,23) or load holding part of the lifter (9) can be positioned on a target position.

Description

BACKGROUND OF THE INVENTION

1. FIELD OF THE INVENTION

The present invention relates to a crane, in particular to a container crane that travels along a quay wall and moves back and forth between the land and a vessel in order to unload loaded cargoes such as containers from a vessel alongside of the quay wall to the land, or to load containers on the land onto the vessel.
This application is based on Japanese Patent Application No. 2006-349573 , the content of which is incorporated herein by reference.

2. DESCRIPTION OF RELATED ART

As a container crane, there is known for example one disclosed in Japanese Unexamined Patent Application, First Publication No. 2003-252568 .
In the container crane disclosed in the above document there is provided an anti sway device that stops (suppresses) sway of a lifter (spreader) or a lifted load (load such as a container).
However, such an anti sway device is to stop (suppress) sway of the lifter or lifted load by moving a trolley or a hoisting rope. Therefore, there has been a problem in that there is a time lag in transmitting the movement of the trolley or the hoisting rope to the lifter in correspondence with the cycle of the sway, so that the response speed is reduced, and an amount of time required for stopping the sway becomes longer.

BRIEF SUMMARY OF THE INVENTION

The present invention takes above circumstances into consideration and its object is to provide a crane that can stop (suppress) sway of the lifter or lifted load in a short period of time, that can carry out positioning of the lifter or the lifted load easily and quickly, that can improve the operability of the crane, and that can achieve shortening of the loading and unloading time.
In order to solve above problems, the present invention employs the following means.
A crane according to the present invention is a crane in which there are provided: a detection device that detects a positional displacement between a target position and a lifted load or a load holding part of the lifter; an actuator that is able to change a relative distance between lifted loads on the lifter that is able to lift plurallifted loads; and a control device that performs control of the actuator according to the positional displacement. The control device is provided with a control program that performs positioning of one load lifted by the lifter, or a load holding part of the lifter, on a target position, based on a positional displacement amount between the target position and the lifted load or the load holing part of the lifter, by driving the actuator and using the inertia of the portion remaining on the lifter and the remaining lifted load.
That is to say, for the lifter and the lifted load that have been lifted by the crane, since a gravity force and a tensile force of wires are substantially balanced out, there is almost no external force. As shown in FIG. 13A and FIG. 13B, when there is no external force by driving the actuator between two objects the position and the velocity of one of the objects can be controlled. By using the ability of the control, one lifted load or one load holding part of the lifter for lifting plural loads at once is stopped above the target position using the actuator within the lifter.
In the above-mentioned crane, it is more preferable that the control device is provided with a device for detecting a height of the target position or a device for receiving height data, and a detector for detecting a hoisting height, and there is provided an automatic landing control program that performs landing and load holding by lowering the lifted load or the load holding position of the lifter while it is stopped above the target position, until it reaches the target position height.
Moreover, in the above crane, it is more preferable that the automatic landing control program is constructed so that in a case where sway or displacement of the lifter is significant and a stroke margin of the actuator becomes low within a part of the sway cycle while the actuator is driven according to the automatic control program, and the lifted load or the load holding part of the lifter cannot be kept stopped above the target position until landing, the unwinding operation for landing is stopped, and when the lifter returns to within the actuator stroke range based on the sway cycle, the lifted load or the load holding part of the lifter is stopped above the target position according to the automatic control program, and the unwinding operation of the crane for landing is performed to let the lifted load or the load holding part of the lifter land on the target position in a stopped state.
Furthermore, in the above crane, it is more preferable that the automatic landing control program is constructed so that after one lifted load or the load holding part of the lifter has landed, after the lifter has held a load in a case of the load holding part of the lifter, taking a frictional force or holding force as a fulcrum of the lifted load or the load holding part of the lifter, the actuator is driven, limiting its driving force so as not to exceed the frictional force or the holding force, to move the remaining lifted load or the remaining parts of the lifter above the target position.
Furthermore, in the above crane, it is more preferable that the lifter is a tandem spreader provided with a first spreader and a second spreader that can lift up two containers in line in a minor axis direction.
Moreover, in the above crane, it is more preferable that the crane is constructed such that on the first spreader and/or the second spreader there are respectively provided image capturing means for capturing the target position, and that image data captured by the image capturing means is output to the control device and processed, after which the data is output to the actuator.
According to such a crane, by operating the actuator to extend and contract a rod of this actuator, then for example either one of the first spreader and the second spreader can be stopped above the target position (loaded position) using the inertia of the other spreader (taking the other spreader as a fulcrum).
That is to say, as shown in FIG. 13A and FIG. 13B, by gathering the overall lifter displacement with respect to the target point and the velocity in an other portion of the lifter, one spreader can be stopped above the target position.
As a result, positioning of one spreader can be easily and quickly done, the operability of the crane can be improved, and a shortening of the loading and unloading time can be achieved.
Moreover, since positioning of the spreader can be performed easily and quickly even by an inexperienced operator, a difference in loading and unloading time due to a difference in operator experience can be reduced.
Furthermore, the lifter can be safely and reliably landed on the container, and the safety of workers on the land and workers on the vessel can be ensured, and collision of the lifter or a container held by the lifter with other containers can be prevented.
One aspect of the crane according to the present invention is a crane provided with a tandem/twin spreader having a first spreader and a second spreader that are vertically movable and lifted from a trolley that moves back and forth along an extending direction of a horizontal girder, and that are arranged in line along the extending direction of the horizontal girder or a direction orthogonal to the extending direction of the horizontal girder, wherein the first spreader and the second spreader are connected to each other via an actuator provided with a rod that extends and contracts along the extending direction of the horizontal girder, or an actuator provided with a rod that extends and contracts along a direction orthogonal to the extending direction of the horizontal girder.
According to such a crane, by operating the actuator to extend and contract a rod of this actuator, then either one of the first spreader and the second spreader can be stopped above the target position using the inertia of the other spreader (taking the other spreader as a fulcrum).
As a result, positioning of the spreader can be easily and quickly done, the operability of the crane can be improved, and a shortening of the loading and unloading time can be achieved.
Moreover, since positioning of the spreader can be performed easily and quickly even by an inexperienced operator, a difference in loading and unloading time due to a difference in operator experience can be reduced.
One aspect of the crane according to the present invention is a crane provided with a tandem spreader having a first spreader and a second spreader that are lifted from a head block that moves back and forth together with a trolley along an extending direction of a horizontal girder, and that are arranged in line along the extending direction of the horizontal girder or a direction orthogonal to the extending direction of the horizontal girder, wherein the first spreader and the second spreader are respectively connected to the head block via an actuator provided with a rod that extends and contracts along the extending direction of the horizontal girder, or an actuator provided with a rod that extends and contracts along a direction orthogonal to the extending direction of the horizontal girder.
According to such a crane, by operating the actuator to extend and contract a rod of this actuator, then the first spreader and/or the second spreader can be stopped above the target position using the inertia of the head block (taking the head block as a fulcrum).
As a result, positioning of the spreader can be easily and quickly done, the operability of the crane can be improved, and a shortening of the loading and unloading time can be achieved.
Moreover, since positioning of the spreader can be performed easily and quickly even by an inexperienced operator, a difference in loading and unloading time due to a difference in operator experience can be reduced.
In the above crane, it is more preferable that there is provided a second actuator provided with a rod that extends and contracts along a direction orthogonal to the direction in which the rod of the above actuator extends and contracts, and one end section of this second actuator is connected to the first spreader, and the other end section is connected to the second spreader.
According to such crane, even when for example the first spreader and/or the second spreader sways in the direction orthogonal to the direction of extension and contraction of the rod of the actuator, either one of the first spreader and the second spreader can be stopped directly above the target container using the inertia of the other spreader or a head block (taking the other spreader or the head block as a fulcrum), the operability and responsiveness of the crane can be further improved, and the loading and unloading time can be further shortened.
According to the present invention, there is the effect that the sway of the lifter (spreader) or the lifted load (cargo such as a container) can be stopped (suppressed) in a short period of time, the positioning of the lifter or the lifted load can be carried out easily and quickly, the operability of the crane can be improved, and shortening of the loading and unloading time can be achieved.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a front view showing a first embodiment of a container crane according to the present invention.
FIG. 2 is a front view of a tandem spreader shown in FIG. 1.
FIG. 3 is a drawing showing a second embodiment of a container crane according to the present invention, being a front view of a tandem spreader.
FIG. 4 is a plan view of the tandem spreader shown in FIG. 3.
FIG. 5 is a flow chart for explaining an operating (control) method of the container crane in the case of approaching to receive a container loaded on a vessel alongside of a quay wall.
FIG. 6 is a flow chart for explaining an operating (control) method of the container crane in the case of approaching to receive a container loaded on a vessel alongside of a quay wall.
FIG. 7 is a drawing showing a third embodiment of a container crane according to the present invention, being a front view of a tandem spreader.
FIG. 8 is a plan view of the tandem spreader shown in FIG. 7.
FIG. 9 is a drawing showing the third embodiment of a container crane according to the present invention, being a front view of a tandem spreader.
FIG. 10 is a drawing showing a fourth embodiment of a container crane according to the present invention, being a front view of a tandem spreader.
FIG. 11 is a drawing of another embodiment of a container crane according to the present invention, being a front view of a tandem spreader.
FIG. 12 is a flow chart for explaining the another embodiment of the container crane according to the present invention.
FIG. 13A and FIG. 13B are respectively drawings for explaining a principle of a method of positioning, in the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Hereunder, embodiments according to the present invention are described, with reference to the drawings.

[First Embodiment]

Hereunder, a first embodiment of a crane (hereunder referred to as "a container crane") according to the present invention is described, with reference to FIG. 1 and FIG. 2. FIG. 1 is a front view of the container crane according to the present embodiment, and FIG. 2 is a front view of a tandem spreader shown in FIG. 1.
The container crane 1 is a crane that travels along a quay wall and moves back and forth between the land and a hatch of a vessel, in order to unload loaded cargoes such as containers (hereunder, referred to as "container") from a vessel (not shown in the drawing) alongside of the quay wall onto the land, or to load containers on the land onto the vessel.
As shown in FIG. 1, the container crane 1 is provided in a standing state on rails R arranged on a base surface G of the quay wall, and main construction components of the container crane 1 include a plurality of traveling wheels 2, leg sections 3, and a horizontal girder 4.
The plurality of the traveling wheels 2 are provided on the bottom end of the leg sections 3. Moreover, on the leg sections 3 there are arranged bracing members 5 that support the other leg sections 3 and the horizontal girder 4, in a plurality of appropriate positions.
The horizontal girder 4 is arranged in a direction parallel with the base surface G of the quay wall. On this horizontal girder 4 there is provided a traveling frame 6, and a trolley 7 travels on this traveling frame 6 in the width (lengthwise) direction thereof. Furthermore, on the horizontal girder 4 there is provided a machine room 8 provided with a driving device for causing this trolley 7 to travel.
From the trolley 7, a tandem spreader 9 for carrying out handling of a lifted container (not shown in the drawing), is lifted via hoisting ropes 10.
Moreover, on one end section (end section on the land side) 4a of the horizontal girder 4 there is provided a lifter tilting device 11 that drives the inclination of the tandem spreader 9 (or container) via the hoisting ropes 10.
As shown in FIG. 2, main construction components of the tandem spreader 9 include a land side spreader (first spreader) 12, a sea side spreader (second spreader) 13, a head block 14, and an actuator 15.
The land side spreader 12 and the sea side spreader 13 are respectively lifted from the head block 14 via lifting ropes 16, and on the bottom sections in the four corners of the land side spreader 12 and the sea side spreader 13 there are respectively provided container catching mechanisms 17.
On the top section of the head block 14 there are provided hoisting sheaves 18, and the hoisting ropes 10 are wound around the respective hoisting sheaves 18.
On the top surface of the land side spreader 12 there is provided an arm 12a, and on the top surface of the sea side spreader 13 there is provided an arm 13a, and one end section of the actuator 15 is connected to the arm 12a via a pin 12b, and the other end section of the actuator 15 is connected to the arm 13a via a pin 13b. Furthermore, the distance between the land side spreader 12 and the sea side spreader 13 is adjusted by operating the actuator 15 to extend and contract a rod 15a of the actuator 15.
The container crane 1 according to the present embodiment is constructed such that tilt adjustment in the longitudinal (lengthwise) direction (trim adjustment), and tilt adjustment in the width (lateral) direction (list adjustment), of the head block 14 can be carried out by the lifter tilting device 11.
Next, an operating (control) method of the container crane 1 in the case of approaching to receive a container loaded on a vessel alongside of the quay wall is described.
First, the driving device that makes the trolley 7 travel is driven to move the trolley 7 along the longitudinal direction of the horizontal girder 4 so that either the land side spreader 12 or the sea side spreader 13 (for example, the land side spreader 12) is brought into (comes into) a position for example 100 cm higher than the top surface of a container by being displaced within the range of stroke of the actuator to directly above the target container (target position (target point)) avoiding interfering with the container, and a hoisting drum (not shown in the drawing) is driven to unwind the hoisting ropes 10 and lower the entire tandem spreader 9.
Subsequently, the actuator 15 is operated to extend and contract the rod 15a of this actuator 15, and thereby, either the land side spreader 12 or the sea side spreader 13 (for example, the land side spreader 12) is stopped directly above the target container, using the inertia of the other spreader (for example, the sea side spreader 13) (taking the other spreader (for example, the sea side spreader 13) as a fulcrum). Then, the hoisting drum (not shown in the drawing) is driven again in this state, and the hoisting ropes 10 are further unwound to further lower the entire tandem spreader 9, and then one of the spreaders (for example, the land side spreader 12) and the target container are connected to each other via the container catching mechanism 17.
Here, unwinding is paused at a height of 100 cm in this operation for the purpose of this description. However, the unwinding operation can be continued.
When one spreader (for example, the land side spreader 12) has held (caught: landed on) the target container, the actuator 15 is operated so that this time, the other spreader (for example, the sea side spreader 13) stops directly above the target container (that is to say, the other spreader is brought into the possible landing range) by using the holding force of the one spreader (for example, the land side spreader 12) that is holding the container on which the spreader is to be landed, and a frictional force of the container (by taking one spreader (for example, the land side spreader 12) as a fulcrum), and the rod 15a of the actuator 15 is extended and contracted so as to connect the other spreader (for example, the sea side spreader 13) to the target container via the container catching mechanism 17.
At this time, it is preferable that the operation proceeds using the lifter tilting device 11 to carry out list adjustment so that the other spreader (for example, the sea side spreader 13) is positioned higher than the one spreader (for example, the land side spreader 12) (that is to say, so that the container catching mechanism 17 of the other spreader (for example, the sea side spreader 13) does not interfere with the top surface of the container).
Next, an operating (control) method of the container crane 1 in the case of approaching to load (approaching to deposit) a container on a vessel alongside of the quay wall is described.
First, the driving device that makes the trolley 7 travel is driven to move the trolley 7 along the longitudinal direction of the horizontal girder 4 so that either the land side spreader 12 or the sea side spreader 13 (for example, the land side spreader 12) is brought into (comes into) a position for example 100 cm higher than the top surface of a container, directly above the target container (target position (target point)), and a hoisting drum (not shown in the drawing) is driven to unwind the hoisting ropes 10 and lower the entire tandem spreader 9.
Subsequently, the actuator 15 is operated to extend and contract the rod 15a of this actuator 15, and thereby, either the land side spreader 12 or the sea side spreader 13 (for example, the land side spreader 12) is stopped directly above the target position (loaded position), using the inertia of the other spreader (for example, the sea side spreader 13) (taking the other spreader (for example, the sea side spreader 13) as a fulcrum). Then, the hoisting drum (not shown in the drawing) is driven again in this state, and the hoisting ropes 10 are further unwound to further lower the entire tandem spreader 9, and then the container held (grasped) by one of the spreaders (for example, the land side spreader 12) is landed on the target position (loaded position).
Here, unwinding is paused at a height of 100 cm in this operation for the purpose of this description. However, the unwinding operation can be continued.
When the container held (grasped) by one spreader (for example, the land side spreader 12) has landed on the target position (loaded position), the actuator 15 is operated so that this time, the other spreader (for example, the sea side spreader 13) stops directly above the target position (loaded position) (that is to say, the other spreader is brought into the possible landing range) by using the holding force of the one spreader (for example, the land side spreader 12) that is holding the container on which the spreader is to be landed, and a frictional force of the container (by taking one spreader (for example, the land side spreader 12) as a fulcrum), and the rod 15a of this actuator 15 is extended and contracted so as that the container held (grasped) by the other spreader (for example, the sea side spreader 13) is landed on the target position (loaded position).
At this time, it is preferable that the operation proceeds using the lifter tilting device 11 to carry out list adjustment so that the other spreader (for example, the sea side spreader 13) is positioned higher than the one spreader (for example, the land side spreader 12) (that is to say, so that the container catching mechanism 17 of the other spreader (for example, the sea side spreader 13) does not interfere with the top surface of the container).
Moreover, since an operating (control) method of the container crane in the case of approaching to load a container onto a trailer on the land side and in the case of approaching to receive a container loaded onto a trailer are substantially same as described above, description thereof are omitted here.
According to the container crane 1 of the present invention, by operating the actuator 15 to extend and contract the rod 15a of the actuator 15, either the land side spreader 12 or the sea side spreader 13 (for example, the land side spreader 12) can be stopped above the target position (loaded position), using the inertia of the other spreader (for example, the sea side spreader 13) (taking the other spreader (for example, the sea side spreader 13) as a fulcrum).
As a result, positioning of the spreaders 12 and 13 can be easily and quickly done, the operability of the container crane 1 can be improved, and shortening of the loading and unloading time can be achieved.
Moreover, since positioning of the spreaders 12 and 13 can be performed easily and quickly even by an inexperienced operator, a difference in loading and unloading time due to a difference in operator experience can be reduced.

[Second Embodiment]

Hereunder, a second embodiment of a container crane according to the present invention is described, with reference to FIG. 3 to FIG. 6.
FIG. 3 is a front view of a tandem spreader according to the present embodiment, FIG. 4 is a plan view of the tandem spreader according to the present embodiment, and FIG. 5 and FIG. 6 are respectively flow charts for explaining an operating (control) method of the container crane in the case of approaching to receive a container loaded on a vessel alongside of a quay wall.
A container crane 20 according to the present embodiment differs from the container crane in the first embodiment in that there is provided a tandem spreader 21 instead of the tandem spreader 9. Since other components are same as those in the first embodiment described above, description of these components is omitted here.
Members the same as those in the first embodiment described above are denoted by the same reference symbols.
As shown in FIG. 3 and FIG. 4, the main construction components of the tandem spreader 21 include a land side spreader (first spreader) 22, a sea side spreader (second spreader) 23, and an actuator 24.
On the top sections of the land side spreader 22 and the sea side spreader 23 there are respectively provided hoisting sheaves 18, and hoisting ropes 10 are wound around the respective hoisting sheaves 18. Moreover, on the bottom sections in the four corners of the land side spreader 22 and the sea side spreader 23 there are respectively provided container catching mechanisms 17. Furthermore, on one side surface (side surface on the land side in the present embodiment) of the land side spreader 22 there is attached a camera (image capturing means) 25 for image capturing the target position (loaded position) and the like, and on one side surface (side surface on the sea side in the present embodiment) of the sea side spreader 23 there is attached a camera (image capturing means) 26 for image capturing the target position (loaded position) and the like. Image data captured by these cameras 25 and 26 is output to a controller (control device) (not shown in the drawing) and processed, after which the data is respectively output to the actuator 24.
On the top surface of the land side spreader 22 there is provided an arm 22a, and on the top surface of the sea side spreader 23 there is provided an arm 23a, and one end section of the actuator 24 is connected to the arm 22a via a pin 22b, and the other end section of the actuator 24 is connected to the arm 23a via a pin 23b. Furthermore, the distance between the land side spreader 22 and the sea side spreader 23 is adjusted by operating the actuator 24 to extend and contract a rod 25a of the actuator 24.
FIG. 3 shows a state where the list adjustment is carried out using the lifter tilting device 11, and the land side spreader 22 is controlled so that it is brought into a position higher than the sea side spreader 23 (that is to say, so that the container catching mechanism 17 of the land spreader 22 does not interfere with the top surface of the container, also when the sea side spreader 23 is landed).
Next, an operating (control) method of the container crane 20 in the case of approaching to receive a container loaded on a vessel alongside of the quay wall is described, with reference to FIG. 5 and FIG. 6.
First, the driving device that makes the trolley 7 travel is driven to move the trolley 7 along the longitudinal direction of the horizontal girder 4 so that either the land side spreader 22 or the sea side spreader 23 (for example, the sea side spreader 23) is brought into (comes into) a position for example 100 cm higher than the top surface of a container, directly above the target container (target position (target point)), and a hoisting drum (not shown in the drawing) is driven to unwind the hoisting ropes 10 and lower the entire tandem spreader 9.
Subsequently, as shown in FIG. 5, based on the displacement amount between the sea side spreader 23 and the target container (target position (target point)) obtained from the image data captured by the camera 26, the actuator 24 is operated (actuated) in the direction in which this displacement amount decreases, that is to say, so that the sea side spreader 23 stops directly above the target container (that is to say, the sea side spreader 23 is brought into the possible landing range) using the inertia of the land side spreader 22 (taking the land side spreader 22 as a fulcrum). Then, list adjustment is carried out in this state using the lifter tilting device 11, and the land side spreader 22 is controlled so that it is brought into a position higher than the sea side spreader 23 (that is to say, so that the container catching mechanism 17 of the land spreader 22 does not interfere with the top surface of the container), and the sea side spreader 23 and the target container are connected to each other via the container catching mechanism 17.
When one spreader (for example, the sea side spreader 23) has held (caught: landed on) the target container, as shown in FIG. 6, this time, based on the displacement amount between the land side spreader 22 and the target container (target position (target point)) obtained from the image data captured by the camera 25, the actuator 24 is operated (actuated) in the direction in which this displacement amount decreases, that is to say, so that the land side spreader 22 stops directly above the target container (that is to say, the land side spreader 23 is brought into the possible landing range) using the holding force of the sea side spreader 23 and the frictional force of the container (taking the sea side spreader 22 as a fulcrum). Then in this state, list adjustment is carried out using the lifter tilting device 11, and the land side spreader 22 is controlled to be brought to a height substantially equal to that of the sea side spreader 23, so that the land side spreader 22 and the target container are connected to each other via the container catching mechanism 17.
Since an operating (control) method of the container crane 20 in the case of approaching to load (approaching to deposit) a container onto a vessel alongside of the quay wall is substantially same as an operating (control) method of the container crane 20 in the case of approaching to receive a container loaded on a vessel alongside of the quay wall, description thereof is omitted here.
Moreover, since an operating (control) method of the container crane in a case of approaching to load a container onto a trailer on the land side, and in a case of approaching to receive a container loaded onto a trailer are substantially the same as described above, description thereof is omitted here.
According to the container crane 20 of the present embodiment, positioning of the spreaders 22 and 23 is done automatically. Therefore, the operability of the container crane can be further improved, and loading and unloading time can be further shortened.
Other operation and effects are same as those in the first embodiment described above, and hence description thereof is omitted here.

[Third Embodiment]

Hereunder, a third embodiment of a container crane according to the present invention is described, with reference to FIG. 7 to FIG. 9.
FIG. 7 and FIG. 9 are front views of a tandem spreader according to the present embodiment, and FIG. 8 is a plan view of the tandem spreader according to the present embodiment.
A container crane 30 according to the present embodiment differs from the container crane in the second embodiment in that there is provided a tandem spreader 31 instead of the tandem spreader 21. Since other components are same as those in the second embodiment described above, description of these components is omitted here.
Members the same as those in the second embodiment described above are denoted by the same reference symbols.
As shown in FIG. 7 to FIG. 9, the main construction components of the tandem spreader 31 include a land side spreader (first spreader) 12, a sea side spreader (second spreader) 13, a head block 14, and an actuators 32 and 33.
The land side spreader 12 and the sea side spreader 13 are respectively lifted from the head block 14 via lifting ropes 16, and on the bottom sections in the four corners of the land side spreader 12 and the sea side spreader 13 there are respectively provided container catching mechanisms 17. Furthermore, on one side surface (side surface on the land side in the present embodiment) of the land side spreader 12 there is attached a camera (not shown) for image capturing the target position (loaded position) and the like, and on one side surface (side surface on the sea side in the present embodiment) of the sea side spreader 13 there is attached a camera (not shown) for image capturing the target position (loaded position) and the like. Image data captured by these cameras is output to a controller (not shown in the drawing) and processed, after which the data is respectively output to the actuators 32 and 33.
On the top section of the head block 14 there are provided hoisting sheaves 18, and the hoisting ropes 10 are wound around the respective hoisting sheaves 18.
On the top surface of the land side spreader 12 there is provided an arm 12a, and on the top surface of the sea side spreader 13 there is provided an arm 13a. Moreover, on the bottom surface of the head block there are provided arms 14a and 14b. One end section of the actuator 32 that operates (actuates) the land side spreader 12 is connected to the arm 12a via a pin 34, and the other end section of the actuator 32 is connected to the arm 14a via a pin 35. On the other hand, one end section of the actuator 33 that operates (actuates) the sea side spreader 13 is connected to the arm 13a via a pin 36, and the other end section of the actuator 33 is connected to the arm 14b via a pin 37. Adjustment of the height of the land side spreader 12, adjustment of the height of the sea side spreader 13, and adjustment of the gap between the land side spreader 12 and the sea side spreader 13 are carried out by operating the actuator 32 and/or the actuator 33 and extending and contracting the rods 32a and 33a of these actuators 32 and 33.
FIG. 9 shows a state where the land side spreader 12 is controlled so that it is positioned higher than the sea side spreader 13 (that is to say, the container catching mechanism 17 of the land side spreader 12 does not interfere with the top surface of the container) with the rod 32a of the actuator 32 extended and the rod 33a of the actuator 33 contracted.
Next, an operating (control) method of the container crane 30 in the case of approaching to receive a container loaded on a vessel alongside of the quay wall is described.
First, the driving device that makes the trolley 7 travel is driven to move the trolley 7 along the longitudinal direction of the horizontal girder 4 so that either the land side spreader 12 or the sea side spreader 13 (for example, the sea side spreader 13) is brought into (comes into) a position for example 100 cm higher than the top surface of a container, directly above the target container (target position (target point)), and a hoisting drum (not shown in the drawing) is driven to unwind the hoisting ropes 10 and lower the entire tandem spreader 31.
Subsequently, based on the displacement amount between the sea side spreader 13 and the target container (target position (target point)) obtained from the image data captured by the camera attached to the sea side spreader 13, the actuator 33 is operated (actuated) in the direction in which this displacement amount decreases, that is to say, so that the sea side spreader 13 stops directly above the target container (that is to say, the sea side spreader 13 is brought into the possible landing range) using the inertia of the head block 14 (taking the head block 14 as a fulcrum). Then, in this state, the rod 32a of the actuator 32 is extended for example to the maximum limit (fully), and the land side spreader 12 is controlled so that it is brought into a position higher than the sea side spreader 13 (that is to say, so that the container catching mechanism 17 of the land spreader 22 does not interfere with the top surface of the container), and the sea side spreader 13 and the target container are connected to each other via the container catching mechanism 17.
Here, unwinding is paused at a height of 100 cm in this operation for the purpose of this description. However, the unwinding operation can be continued.
When one spreader (for example, the sea side spreader 13) has held (caught: landed on) the target container, this time, based on the displacement amount between the land side spreader 12 and the target container (target position (target point)) obtained from the image data captured by the camera attached to the land side spreader 12, the actuator 32 is operated (actuated) in the direction in which this displacement amount decreases, that is to say, so that the land side spreader 12 stops directly above the target container (that is to say, the land side spreader 12 is brought into the possible landing range) using the holding force of the sea side spreader 13 and the frictional force of the container (taking the sea side spreader 13 as a fulcrum). Then, in this state, the rod 32a of the actuator 32 is contracted for example to the maximum limit (fully), and the land side spreader 12 is controlled so that it is becomes substantially the same height as the sea side spreader 13, and the land side spreader 12 and the target container are connected to each other via the container catching mechanism 17.
Since an operating (control) method of the container crane 30 in the case of approaching to load (approaching to deposit) a container onto a vessel alongside of the quay wall is substantially same as an operating (control) method of the container crane 30 in the case of approaching to receive a container loaded on a vessel alongside of the quay wall, description thereof is omitted here.
According to the container crane 30 of the present embodiment, one spreader (for example, the land side spreader 12) is operated so that it is brought into a position higher than the other spreader (for example, the sea side spreader 13) (that is to say, so that the container catching mechanism 17 of the land spreader 12 does not interfere with the top surface of the container), and hence it is not necessary to use the lifter tilting device 11.
As a result, the operability and responsiveness of the container crane 1 can be further improved, and the loading and unloading time can be further shortened.
Other operation and effects are same as those in the second embodiment described above, and hence description thereof is omitted here.

[Fourth Embodiment]

Hereunder, a fourth embodiment of a container crane according to the present invention is described, with reference to FIG. 10. FIG. 10 is a front view of a tandem spreader according to the present embodiment.
A container crane 40 according to the present embodiment differs from the container crane in the first embodiment in that there is provided a tandem spreader 41 instead of the tandem spreader 9. Since other components are same as those in the first embodiment described above, description of these components is omitted here.
Members the same as those in the first embodiment described above are denoted by the same reference symbols.
As shown in FIG. 10, the main construction components of the tandem spreader 41 include a land side spreader (first spreader) 42, a sea side spreader (second spreader) 43, a head block 44, and actuators 45 and 46.
The land side spreader 42 and the sea side spreader 43 are respectively lifted from the head block 44 via a guide rail and guide rollers (both not shown in the drawing), and are constructed so as to be able to move back and forth (slide) along the longitudinal direction of the horizontal girder 4. Moreover, on the bottom sections in the four corners of the land side spreader 42 and the sea side spreader 43 there are respectively provided container catching mechanisms 17.
On the top section of the head block 44 there are provided hoisting sheaves 18, and the hoisting ropes 10 are wound around the respective hoisting sheaves 18.
On the top surface of the land side spreader 42 there is provided an arm 42a, and on the top surface of the sea side spreader 43 there is provided an arm 43a. One end section of the actuator 45 that operates (actuates) the land side spreader 42 is connected to the arm 42a via a pin 47, and the other end section of the actuator 45 is connected to the side face (the face parallel with the longitudinal direction of the horizontal girder 4) of the head block 44 via a pin 48. On the other hand, one end section of the actuator 46 that operates (actuates) the sea side spreader 43 is connected to the arm 43a via a pin 49, and the other end section of the actuator 46 is connected to the side face (the face parallel with the longitudinal direction of the horizontal girder 4) of the head block 44 via a pin 50. Adjustment of the gap between the land side spreader 42 and the sea side spreader 43 is carried out by operating the actuator 45 and/or the actuator 46 and extending and contracting the rods 45a and 46a of these actuators 45 and 46.
Next, an operating (control) method of the container crane 40 in the case of approaching to receive a container loaded on a vessel alongside of the quay wall is described.
First, the driving device that makes the trolley 7 travel is driven to move the trolley 7 along the longitudinal direction of the horizontal girder 4 so that either the land side spreader 42 or the sea side spreader 43 (for example, the land side spreader 42) is brought into (comes into) a position for example 100 cm higher than the top surface of a container, directly above the target container (target position (target point)), and a hoisting drum (not shown in the drawing) is driven to unwind the hoisting ropes 10 and lower the entire tandem spreader 41.
Subsequently, using the inertia of the head block 44 (taking the head block 44 as a fulcrum), the actuator 45 is operated to extend and contract the rod 45a of this actuator 45, and thereby, either the land side spreader 42 or the sea side spreader 43 (for example, the land side spreader 42) is stopped directly above the target container. Then, the hoisting drum (not shown in the drawing) is driven again in this state, and the hoisting ropes 10 are further unwound to further lower the entire tandem spreader 41, and one of the spreaders (for example, the land side spreader 42) and the target container are connected to each other via the container catching mechanism 17.
Here, unwinding is paused at a height of 100 cm in this operation for the purpose of this description. However, the unwinding operation can be continued.
When one spreader (for example, the land side spreader 42) has held (caught: landed on) the target container, the actuator 46 is operated so that this time, the other spreader (for example, the sea side spreader 43) stops directly above the target container (that is to say, the other spreader is brought into the possible landing range) by using the holding force of the one spreader (for example, the land side spreader 42) that has landed on the container, and the frictional force of the container (by taking the land side spreader as a fulcrum), and the rod 46a of this actuator 46 is extended and contracted to connect the other spreader (for example, the sea side spreader 43) to the target container via the container catching mechanism 17.
At this time, it is preferable that the operation proceeds using the lifter tilting device 11 to carry out list adjustment so that the other spreader (for example, the sea side spreader 43) is positioned higher than the one spreader (for example, the land side spreader 12) (that is to say, so that the container catching mechanism 17 of the other spreader (for example, the sea side spreader 13) does not interfere with the top surface of the container).
Since an operating (control) method of the container crane 40 in the case of approaching to load (approaching to deposit) a container on a vessel alongside of the quay wall is substantially same as an operating (control) method of the container crane 40 in the case of approaching to receive a container loaded on a vessel alongside of the quay wall, description thereof is omitted here.
According to the container crane 40 of the present embodiment, the actuator is operated to extend and contract the rod of this actuator, and thereby either the land side spreader 42 or the sea side spreader 43 (for example, the land side spreader 42) is stopped above the target position (loaded position), using the inertia of the head block 44 (taking the head block 44 as a fulcrum).
As a result, positioning of the spreaders 42 and 43 can be easily and quickly done, the operability of the container crane 40 can be improved, and shortening of the loading and unloading time can be achieved.
Moreover, since positioning of the spreaders 42 and 43 can be performed easily and quickly even by an inexperienced operator, a difference in loading and unloading time due to a difference in operator experience can be reduced.
The present invention is not limited to the above described embodiments, and it is more preferable that the tandem spreader 21 described in the above second embodiment is provided with a traveling direction moving device 60 that moves either one of the land side spreader 22 and the sea side spreader 23 (for example, the land side spreader 22) back and forth along the direction parallel with the extending direction of the rail R (the traveling direction of the container crane 20) using the inertia of the other spreader (for example, the sea side spreader 23) (taking the other spreader (for example, the sea side spreader 23) as a fulcrum).
As shown in FIG. 11, the main construction components of the traveling direction moving device 60 include a frame 61 and an actuator (second actuator) 62.
The frame 61 is a member with one end section thereof being fixed on the top surface of the land side spreader 22 and it extends from the top surface of the land side spreader 22 toward above the sea side spreader 23, and it has an arm 61a on the other end section thereof.
One end section of the actuator 62 is connected to the arm 61a via a pin 63, and the other end section of the actuator 62 is connected to an arm 65 provided on the top surface of the sea side spreader 23 via a pin 64.
As a result, even when the tandem spreader 21 sways in the direction parallel with the extending direction of the rail R, one of either the land side spreader 22 and the sea side spreader 23 (for example, the land side spreader 22) can be stopped directly above the target container using the inertia of the other spreader (for example, the sea side spreader 23) (taking the other spreader (for example, the sea side spreader 23) as a fulcrum). Hence the operability and responsiveness of the container crane 20 can be further improved, and the loading and unloading time can be further shortened.
Furthermore, in the above described embodiment, it is more preferable that there is built-in to the above mentioned controller an automatic landing control program (for example, a control program shown in FIG. 12) in which, in the case where a stroke margin of the actuator becomes low during the operation of the actuator and either the land side spreader or the sea side spreader cannot be stopped directly above the target container in some portion of a sway cycle, while there is a possibility of no stroke margin of the actuator and occurrence of displacement within the time of spreader landing, landing of either the land side spreader or the sea side spreader on the container is postponed, and then while the stroke margin of the actuator becomes higher in some portion of the sway cycle and it becomes possible to stop either the land side spreader or the sea side spreader directly above the target container, the hoisting ropes are unwound to allow landing.
As a result, the spreader can be safely and reliably landed on the container, and the safety of workers on the land and workers on the vessel who are performing the loading and unloading operation can be ensured, and collision of the spreader or the container held by the spreader with other containers can be prevented.
Moreover, it is more preferable that there is provided an attention attracting function that calls the attention of the operator or the workers on the land and the workers on the vessel, with a voice or an alarm sound in the case where the stroke margin of the actuator becomes low and either the land side spreader or the sea side spreader cannot be stopped directly above the target container in some portion of the sway cycle (or in the case where either the land side spreader or the sea side spreader is significantly displaced from directly above the target container in some portion of the sway cycle) while the actuator is operated.
As a result, the spreader can be more safely landed on the container, and the safety of the workers on the land and the workers the vessel who are performing the loading and unloading operation can be better ensured.
Furthermore, in the above described embodiments, two of each of the actuators 15, 24, 32, 33, 45, 46 are provided along the direction parallel with the longitudinal direction of the horizontal girder 4. However, the present invention is not limited to this, and either one of the actuators may be a link mechanism.
In any of the examples, rotation sway of the container and the spreader can be addressed by independently driving the two actuators arranged in parallel (24 in FIG. 4, 32 and 33 in FIG. 8, and 24 in FIG. 11).
Furthermore, in the above described embodiments, the container crane provided with the tandem spreader having the land side spreader and the sea side spreader arranged in a line along the extending direction of the horizontal girder 4 was described. However, the present invention is not limited to such a container crane, and can be applied to a crane provided with a lifter that hoists a plurality of lifted loads.

Claims

A crane in which there are provided: a detection device that detects a positional displacement between a target position and a lifted load or a load holding part of a lifter; an actuator that is able to change a relative distance between lifted loads on a lifter that is able to lift plural loads; and a control device that performs control of said actuator according to said positional displacement, wherein
said control device is provided with a control program that performs positioning of one load lifted by said lifter, or a load holding part of the lifter, on a target position, based on a positional displacement amount between the target position and the lifted load or the load holding part of the lifter, by driving said actuator and using the inertia of the remaining portion of the lifter and the remaining lifted load.
A crane according to claim 1, wherein said control device is provided with a device for detecting a height of the target position or a device for receiving height data, and a detector for detecting a hoisting height, and there is provided an automatic landing control program that performs landing and load holding by lowering the lifted load or the load holding part of the lifter while it is stopped above the target position, until it reaches the target position height.
A crane according to claim 2, wherein said automatic landing control program is constructed so that in a case where sway or displacement of the lifter is significant and a stroke margin of said actuator becomes low within a part of the sway cycle while said actuator is driven according to said automatic control program, and the lifted load or the load holding part of the lifter cannot be kept stopped above the target position until landing, the lowering operation for landing is stopped, and when the lifter returns to within the actuator stroke range based on the sway cycle, the lifted load or the load holding part of the lifter is stopped above the target position according to the automatic control program, and the lowering operation of the crane for landing is performed to let the lifted load or the load holding part of the lifter land on the target position in a stopped state.
A crane according to either one of claim 2 and claim 3, wherein said automatic landing control program is constructed so that after one lifted load or the load holding part of the lifter has landed, after the load has been held in a case of the load holding part of the lifter, taking a frictional force or holding force of the lifted load or the load holding part of the lifter as a fulcrum, said actuator is driven, limiting its driving force so as not to exceed said frictional force or holding force, to position the remaining lifted load or the remaining load holding part of the lifter above the target position.
A crane according to any one of claim 1 through claim 4, wherein said lifter is a tandem spreader provided with a first spreader and a second spreader that can lift two containers in line in a minor axis direction.
A crane according to claim 5, constructed such that on said first spreader and/or said second spreader there are respectively provided image capturing means for capturing the target position, and image data captured by the image capturing means is output to the control device and processed after which the data is output to said actuator.
A crane provided with a tandem spreader having a first spreader and a second spreader that are vertically movable and lifted from a trolley that moves back and forth along an extending direction of a horizontal girder, and that are arranged in line along the extending direction of said horizontal girder or a direction orthogonal to the extending direction of said horizontal girder, wherein
said first spreader and said second spreader are connected to each other via an actuator provided with a rod that extends and contracts along the extending direction of said horizontal girder, or an actuator provided with a rod that extends and contracts along a direction orthogonal to the extending direction of said horizontal girder.
A crane provided with a tandem spreader having a first spreader and a second spreader that are lifted from a head block that moves back and forth together with a trolley along an extending direction of a horizontal girder, and that are arranged in line along the extending direction of said horizontal girder or a direction orthogonal to the extending direction of said horizontal girder, wherein
said first spreader and said second spreader are respectively connected to the head block via an actuator provided with a rod that extends and contracts along the extending direction of said horizontal girder, or an actuator provided with a rod that extends and contracts along a direction orthogonal to the extending direction of said horizontal girder.
A crane according to any one of claim 5 through claim 8, wherein there is provided a second actuator provided with a rod that extends and contracts along a direction orthogonal to the direction in which the rod of said actuator extends and contracts, and one end section of said second actuator is connected to said first spreader, and the other end section is connected to said second spreader.