JP7120951B2 - Cranes and crane control methods - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crane having a spreader that is substantially rectangular in plan view, and more particularly to a crane and a crane control method capable of controlling the attitude of the spreader.

Various portal cranes have been proposed that include a trolley that travels along a horizontal beam and a spreader that is suspended from the trolley with a rope (see, for example, Patent Document 1). The spreader has a substantially rectangular shape in plan view, the longitudinal direction of the spreader is parallel to the traveling direction of the crane, and the lateral direction of the spreader is parallel to the transverse direction of the crane.

Generally, in a portal crane, a trolley that lifts a container moves in the transverse direction, so the center of gravity of the crane fluctuates in the transverse direction. With this change in the center of gravity, the crane sometimes tilted. Especially in the case of a crane whose wheels are made of rubber tires, the crane tends to tilt.

As the crane tilted, the container sometimes tilted about the longitudinal direction of the spreader. A jolt could occur when placing a tilted container on the chassis. Further, when a container that is tilted by being lifted by a crane is placed on another container placed on the storage lane, the position of the placed container may be shifted in the transverse direction.

Japanese Patent Application Laid-Open No. 2013-209213

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object thereof is to provide a crane and a crane control method capable of controlling the attitude of a spreader.

A crane for achieving the above object comprises a spreader which is formed in a substantially rectangular shape having a pair of long sides and a pair of short sides in a plan view and on which a plurality of sheaves are installed; a trolley on which a plurality of sheaves are installed; a rope that is looped around the sheaves installed on the spreader and the sheaves installed on the trolley to suspend the spreader from the trolley; a wound drum, a first pair of lower sheaves positioned along one of the long sides of the spreader and a second pair of lower sheaves positioned along the other of the long sides of the spreader a sheave, a first rope respectively wound around the pair of first lower sheaves via an upper sheave installed on the trolley, a first drum around which the first rope is wound, and the upper A second rope wound around the pair of second lower sheaves via sheaves, a second drum around which the second rope is wound, and the first drum and the second drum are independent of each other. and a control mechanism for controlling rotation in a state in which one of the first rope and the second rope is wound up relatively longer than the other, and the longitudinal direction, which is the direction in which the long sides are extended, is hoisted. It is characterized in that the control mechanism has a configuration for performing wrist control for tilting the spreader as a central axis .

A crane control method for achieving the above object comprises a spreader having a substantially rectangular shape having a pair of long sides and a pair of short sides in a plan view and having a plurality of sheaves installed thereon; a trolley on which a plurality of sheaves are installed; a rope that is looped around the sheaves installed on the spreader and the sheaves installed on the trolley to suspend the spreader from the trolley; In this method of controlling a crane comprising a drum on which a rope is wound, a pair of first lower sheaves are arranged along one of the long sides of the spreader and a pair of sheaves are arranged along the other long side of the spreader. A second lower sheave is arranged, the first rope paid out from the first drum is wound around the pair of first lower sheaves, and the second rope paid out from the second drum is wound around the pair of second lower sheaves. The length of the second rope paid out from the second drum is relatively longer than the first rope paid out from the first drum, and the length of the second rope paid out from the first drum is increased in the longitudinal direction, which is the direction in which the long side extends. is the center axis, and the spreader is tilted.

According to the present invention, it is possible to control the difference in length between the first rope and the second rope, so that it is possible to raise or lower one of the long sides of the spreader. This is advantageous for controlling the attitude of the spreader.

It is an explanatory view illustrating a crane of the present invention in a perspective view. FIG. 2 is an explanatory diagram illustrating a state of a rope of the crane of FIG. 1; FIG. 3 is an explanatory diagram illustrating states of a first rope and a second rope in FIG. 2; FIG. 3 is an explanatory diagram illustrating a state of a third rope in FIG. 2; FIG. 5 is an explanatory diagram illustrating a state of list control of a spreader; FIG. 5 is an explanatory diagram illustrating how the container is placed in an inclined state together with the spreader; FIG. 4 is an explanatory diagram illustrating a modification of FIG. 3; FIG. 5 is an explanatory diagram illustrating the state of skew control of a spreader;

DETAILED DESCRIPTION OF THE INVENTION A crane and a crane control method according to the present invention will be described below based on embodiments shown in the drawings. In the drawing, the longitudinal direction of the spreader, which is substantially rectangular in plan view, is indicated by arrow y, the lateral direction perpendicular to the longitudinal direction y is indicated by arrow x, and the vertical direction is indicated by arrow z.

As illustrated in FIG. 1, the crane 1 of the present invention is configured by, for example, a portal crane. The crane 1 of the present invention is not limited to a gate-type crane, and may be configured by other cranes such as a wharf crane. The crane 1 of this embodiment includes a horizontal beam 2 extending in the horizontal direction, legs 3 extending downward from both ends of the horizontal beam 2, and traveling installed at the lower ends of the legs 3. a device 4; The traveling device 4 is equipped with rubber tires or iron wheels.

The crane 1 includes a trolley 5 configured to be able to travel along a horizontal beam 2 and a spreader 6 arranged below the trolley 5 for handling containers C. As shown in FIG. The trolley 5 and spreader 6 are equipped with a plurality of sheaves. A rope R is wound around these sheaves. The rope R suspends the spreader 6 from the trolley 5 . The spreader 6 is formed in a substantially rectangular shape having a pair of long sides and a pair of short sides in plan view. The spreader 6 is placed in a state in which the longitudinal direction y, which is the extending direction of the long sides of the spreader 6, is parallel to the traveling direction of the crane 1, and the lateral direction x, which is the extending direction of the short sides, is parallel to the transverse direction of the crane 1. are placed. In this embodiment, a drum D around which a rope R is wound is installed on a trolley 5 .

The crane 1 travels along the travel direction (longitudinal direction y) by the travel device 4 to a position where the container C to be handled is placed. The trolley 5 moves along the transverse direction (transverse direction x) to a position directly above the container C. As shown in FIG. The trolley 5 runs on the horizontal beam 2 by a driving mechanism such as a motor. The spreader 6 is lowered by letting out the rope R from the drum D, and the spreader 6 grips the target container C after coming into contact with the upper surface of the container C. - 特許庁By winding the rope R on the drum D, the container C is lifted by the crane 1. - 特許庁

A configuration in which the drum D is installed on the leg portion 3 as illustrated in FIG. 2 may be employed. In FIG. 2, the horizontal beam 2 and the legs 3 constituting the crane 1 are indicated by broken lines for explanation. Also, the trolley 5 is omitted.

As illustrated in FIG. 3, the crane 1 has a pair of first lower sheaves S1 arranged along one long side of the spreader 6 and a pair of second lower sheaves S2 arranged along the other long side. and In FIG. 3, the horizontal beam 2, the legs 3 and the trolley 5 are omitted for explanation.

The pair of first lower sheaves S1 are spaced apart in the longitudinal direction y. The pair of second lower sheaves S2 are spaced apart in the longitudinal direction y. The first lower sheave S1 and the second lower sheave S2 are spaced apart in the lateral direction x. Therefore, the first lower sheave S1 and the second lower sheave S2 are arranged at the four corners of the spreader 6 which is substantially rectangular in plan view.

The crane 1 includes two drums D, a first drum D1 wound with a first rope R1 and a second drum D2 wound with a second rope R2. The first rope R1 and the second rope R2 (hereinafter sometimes collectively referred to as rope R) are composed of different ropes. In FIG. 3, the second rope R2 is indicated by a dashed line for explanation. The first drum D1 and the second drum D2 (hereinafter sometimes collectively referred to as the drum D) are on the same side (for example, the left side in FIG. 2) of the legs 3 constituting the crane 1 in the lateral direction x. Located in Section 3.

As illustrated in FIG. 3, a first rope R1 unwound from a first drum D1 is passed through an upper sheave Su installed on a trolley 5 and looped around one of the first lower sheaves S1. The first rope R1 wound around the first lower sheave S1 is wound around the other first lower sheave S1 after passing through the plurality of upper sheaves Su and the sheaves S installed on the horizontal beams 2. be. A first rope R1 wound around the first lower sheave S1 is connected to the first drum D1 via an upper sheave Su. That is, both ends of the first rope R1 are connected to the first drum D1.

Similarly, the second rope R2 that is let out from the second drum D2 is connected to the second drum D2 after being looped around the second lower sheave S2 on one side and the second lower sheave S2 on the other side. The second rope R2 is looped around a plurality of upper sheaves Su and sheaves S installed on the horizontal beam 2 on the way. Both ends of the second rope R2 are connected to the second drum D2.

The route around which the first rope R1 and the second rope R2 are routed is not limited to the above. A sheave S can be appropriately installed and a rope R can be hung around.

As illustrated in FIGS. 2 and 3, the crane 1 includes a control mechanism 7 that controls the first drum D1 and the second drum D2 independently of each other. The control mechanism 7 can be installed, for example, at a position near the drum D on the leg 3 . The control mechanism 7 can be composed of, for example, a PLC (Programmable Logic Controller) or a computer. The control mechanism 7 is connected to the drum D via a signal line (not shown).

As exemplified in FIG. 2, a structure in which a small turning mechanism 8 is installed on the leg portion 3 on the right side of FIG. 2 may be employed. The small turning mechanism 8 is installed in each of the intermediate portions of the first rope R1 and the second rope R2. The small turning mechanism 8 is composed of, for example, a double-headed cylinder, and ropes R such as the first rope R1 are connected to both ends thereof. The rope R can be displaced in the longitudinal direction y by operating the small turning mechanism 8 . This operation of the small turning mechanism 8 enables skew control for turning the spreader 6 with the vertical direction z as the central axis. The small turning mechanism 8 is not an essential requirement of the present invention.

As illustrated in FIG. 4, the crane 1 includes a pair of third lower sheaves S3 arranged substantially in the center of the long sides of the spreader 6, respectively. The third lower sheave S3 is arranged substantially at the center of the long side of the spreader 6 in the longitudinal direction y. The pair of third lower sheaves S3 are spaced apart in the lateral direction x.

In this embodiment the crane 1 is provided with a counterweight 9 which supports part of the weight of the spreader 6 . This counterweight 9 is installed on one leg 3 of the gate-shaped crane 1 .

In this embodiment, the third rope R3 is looped from the sheave S installed on the counterweight 9 to the sheave S installed on the leg portion 3 . This third rope R3 is stretched in the lateral direction x along the horizontal beam 2, and the third lower sheave S3 is installed substantially in the center of the spreader 6 in the longitudinal direction y from one upper sheave Su of the trolley 5. to the other upper sheave Su. At this time, the third rope R3 is wound along the longitudinal direction y of the spreader 6 in a substantially V shape. In FIG. 4, the horizontal beam 2, the legs 3 and the trolley 5 are omitted for explanation.

The third rope R3 extends from the other upper sheave Su of the trolley 5 via the sheave S installed on the leg 3 and the sheave S installed on the counterweight 9 to the sheave S installed on the other leg 3. be hung up on. This third rope R3 is wound around the other upper sheave Su from the sheave S installed on the other leg 3 via one upper sheave Su of the trolley 5 and the third lower sheave S3 of the spreader 6. be. At this time, the third rope R3 is wound along the longitudinal direction y of the spreader 6 in a substantially V shape. That is, the third rope R3 is wound around the pair of long sides of the spreader 6 in a substantially V shape.

The configuration of the third rope R3 that is wound along the longitudinal direction y of the spreader 6 is not limited to the above. A sheave S can be appropriately installed on the spreader 6 and the third rope R3 can be hung therearound. Also, the counterweight 9 is not an essential requirement of the present invention.

As illustrated in FIG. 5, when the first drum D1 is rotated by the control mechanism 7 to wind up the first rope R1 and the rotation of the second drum D2 is stopped, one of the pair of long sides of the spreader 6 is one rises. In FIG. 5, the long side on which the first lower sheave S1 is installed rises due to the hoisting of the first rope R1. In FIG. 5, the second rope R2 is indicated by a dashed line for explanation.

Control by the control mechanism 7 is not limited to the above. The control mechanism 7 is configured to wind one of the first rope R1 around the first lower sheave S1 and the second rope R2 around the second lower sheave S2 relatively longer than the other. should have For example, the control mechanism 7 may rotate the second drum D2 so that the second rope R2 is paid out longer than the first rope R1.

Control by the control mechanism 7 enables wrist control for raising any one of the pair of long sides of the spreader 6 relative to the other. It is possible to control the tilting of the spreader 6 with the longitudinal direction y as the central axis.

The spreader 6 rises when the first rope R1 and the second rope R2 are hoisted by the same length at the same time, and the spreader 6 is lowered when the same length is let out at the same time.

The wrist control allows the crane 1 to land the container C parallel to the chassis even when the crane 1 is tilted with the longitudinal direction y as the central axis. Since the bottom surface of the container C lands on the chassis as a surface, it is advantageous in suppressing the impact on the chassis that occurs when the container C lands on the floor. When the container C is tilted, it lands on the chassis from the corners of the bottom surface of the container C, so the impact on the chassis is relatively large.

The wrist control allows the crane 1 to land the container C parallel to the ground that forms the storage lane. Further, the crane 1 can land the container C on the floor in parallel with the upper surface of another container C stored in the storage lane. It is advantageous to accurately determine the position of the container C when it lands.

If the landing surface 10 and the bottom surface of the container C are not parallel to each other as illustrated in FIG. In FIG. 6, when the container C is in a state parallel to the landing surface 10, the position where the container C lands is indicated by a dashed line as a target position 11. As shown in FIG.

If the container C and the landing surface 10 are parallel to each other by the wrist control, the container C can be easily landed on the target position 11 accurately. This is particularly advantageous when the crane 1 is operated remotely or automatically. Further, in recent years, the number of stacking stages of containers C has been increased in order to improve storage efficiency of containers C in storage lanes. Since the containers C can be stacked straight, it becomes easy to cope with an increase in the number of stacked stages.

The crane 1 may be configured to have four drums D as illustrated in FIG. In this embodiment, one end of the first rope R1 is connected to the first drum D1 and the other end is connected to the third drum D3. One end of the second rope R2 is connected to the second drum D2 and the other end is connected to the fourth drum D4. In FIG. 7, the second rope R2 is indicated by a dashed line for explanation.

In this embodiment, the first rope R1 unwound from the first drum D1 is wound around one first lower sheave S1 and the other first lower sheave S1, and then connected to the third drum D3. Similarly, the second rope R2 unwound from the second drum D2 is wound around the second lower sheave S2 on one side and the second lower sheave S2 on the other side, and then connected to the fourth drum D4.

When the first rope R1 is let out from the first drum D1 under the control of the control mechanism 7, the first lower sheave S1 around which the first rope R1 is wound is lowered. Similarly, when the first rope R1 is wound by the third drum D3, the other first lower sheave S1 around which the first rope R1 is wound rises.

When the second rope R2 is wound on the second drum D2, the second lower sheave S2 on which the second rope R2 is wound is lifted. Similarly, when the second rope R2 is let out from the fourth drum D4, the other second lower sheave S2 around which the second rope R2 is wound is lowered.

As illustrated in FIG. 8, the first lower sheave S1 on one side and the second lower sheave S2 on the other side of the spreader 6, which is substantially rectangular in plan view, are lowered and positioned diagonally. The other first lower sheave S1 and the one second lower sheave S2 rise. Therefore, the spreader 6 turns counterclockwise around the vertical direction z as a central axis.

Control by the control mechanism 7 is not limited to the above. It is sufficient that the control mechanism 7 has a configuration that relatively raises one of the two sets of sheaves S positioned diagonally on the spreader 6 having a substantially rectangular shape relative to the other set. For example, the control mechanism 7 may perform control such that only one set of sheaves S is lifted and the other set of sheaves S is not moved in the vertical direction z.

By controlling the control mechanism 7, skew control for rotating the spreader 6 with the vertical direction z as the central axis is possible. It is advantageous to control the attitude of spreader 6 .

Similar to the embodiment illustrated in FIG. 2, the crane 1 of this embodiment is also capable of wrist control. Wrist control can be achieved by controlling the four drums D with the control mechanism 7 to raise either the pair of first lower sheaves S1 or the pair of second lower sheaves S2.

Further, for example, a configuration for performing control to wind up one of the rope R unreeled from the first drum D1 and the second drum D2 and the rope R unreeled from the third drum D3 and the fourth drum D4 relatively longer than the other. may be provided in the control mechanism 7. This control enables trim control for relatively raising any one of the pair of short sides of the spreader 6, which is formed in a substantially rectangular shape in plan view.

The attitude of the spreader 6 can be controlled in more detail by skew control. For example, when the crane 1 is automatically operated to perform cargo handling work, it may be difficult to accurately determine the stop position of the crane 1 due to deformation of rubber tires. Even in such a case, by controlling the attitude of the spreader 6, the container C can be easily landed at an accurate position on the chassis. In other words, even if an error occurs in the positioning of the crane 1, which is a relatively large structure, by controlling the attitude of the spreader 6, the container C can be landed at an accurate position. This is advantageous for realizing automatic operation of the crane 1 .

In addition, the direction of the container C is adjusted in the storage lane, and the container C can be easily stacked straight.

Since the crane 1 of this embodiment can perform skew control, the small turning mechanism 8 illustrated in FIG. 2 is not required. A line or the like for supplying electric power or hydraulic pressure to the small turning mechanism 8 is also unnecessary. Maintenance of the small turning mechanism 8, which requires work at a high place, becomes unnecessary.

1 Crane 2 Horizontal beam 3 Leg 4 Travel device 5 Trolley 6 Spreader 7 Control mechanism 8 Small turning mechanism 9 Counterweight 10 Landing surface 11 Target position x Short direction y Long direction z Vertical direction R Rope S Sheave S1 First Lower sheave S2 Second lower sheave S3 Third lower sheave Su Upper sheave R Rope R1 First rope R2 Second rope R3 Third rope D Drum D1 First drum D2 Second drum D3 Third drum D4 Fourth drum C Container

Claims (4)

A spreader which is formed in a substantially rectangular shape having a pair of long sides and a pair of short sides in a plan view and on which a plurality of sheaves are installed, and a trolley which is arranged above the spreader and on which a plurality of sheaves are installed. , a crane comprising: a rope that is looped around the sheave installed on the spreader and the sheave installed on the trolley to suspend the spreader from the trolley; and a drum around which the rope is wound,
a pair of first lower sheaves arranged along one of the long sides of the spreader and a pair of second lower sheaves arranged along the other long side of the spreader;
a first rope wound around the pair of first lower sheaves via an upper sheave installed on the trolley, and a first drum around which the first rope is wound;
a second rope wound around the pair of second lower sheaves via the upper sheave, and a second drum around which the second rope is wound;
A control mechanism for controlling the rotation of the first drum and the second drum independently of each other ,
One of the first rope and the second rope is wound up relatively longer than the other, and wrist control is performed to tilt the spreader about the longitudinal direction, which is the extension direction of the long side, as a central axis. A crane, wherein the control mechanism comprises: A spreader which is formed in a substantially rectangular shape having a pair of long sides and a pair of short sides in a plan view and on which a plurality of sheaves are installed, and a trolley which is arranged above the spreader and on which a plurality of sheaves are installed. , a crane comprising: a rope that is looped around the sheave installed on the spreader and the sheave installed on the trolley to suspend the spreader from the trolley; and a drum around which the rope is wound,
a pair of first lower sheaves arranged along one of the long sides of the spreader and a pair of second lower sheaves arranged along the other long side of the spreader;
a first rope wound around the pair of first lower sheaves via an upper sheave installed on the trolley, and a first drum around which the first rope is wound;
a second rope wound around the pair of second lower sheaves via the upper sheave, and a second drum around which the second rope is wound;
A control mechanism for controlling the rotation of the first drum and the second drum independently of each other,
a third drum to which the other end of the first rope unwound from the first drum is connected;
a fourth drum to which the other end of the second rope fed out from the second drum is connected,
The crane, wherein the control mechanism controls the rotation of the first drum, the second drum, the third drum, and the fourth drum independently of each other. A spreader which is formed in a substantially rectangular shape having a pair of long sides and a pair of short sides in a plan view and on which a plurality of sheaves are installed, and a trolley which is arranged above the spreader and on which a plurality of sheaves are installed. , the control of a crane comprising: a rope that is looped around the sheave installed on the spreader and the sheave installed on the trolley to suspend the spreader from the trolley; and a drum on which the rope is wound. In the method
arranging a pair of first lower sheaves along one of said long sides of said spreader and arranging a pair of second lower sheaves along said other of said long sides,
A first rope paid out from a first drum is hung around the pair of first lower sheaves, and a second rope paid out from a second drum is hung around the pair of second lower sheaves,
The length of the second rope paid out from the second drum is relatively longer than the first rope paid out from the first drum, and the longitudinal direction, which is the extension direction of the long side, is the center. A method of controlling a crane, characterized in that the spreader is tilted as an axis. connecting the other end of the first rope unwound from the first drum to a third drum, connecting the other end of the second rope unwound from the second drum to a fourth drum,
Of the four sheaves consisting of a pair of the first lower sheaves and a pair of the second lower sheaves, one pair of the first lower sheaves and one set of the first lower sheaves positioned diagonally across the spreader, which is substantially rectangular in plan view, and The second lower sheave is raised relative to the other pair of the first and second lower sheaves located diagonally, and the spreader is swiveled around the vertical direction as a central axis. 3. The crane control method according to 3.

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