JP7070219B2 - crane - Google Patents

Description

The present invention relates to a crane provided with a spreader formed in a substantially rectangular shape in a plan view. Specifically, the present invention relates to a problem in which the spreader moves in the longitudinal direction when loading a container whose center of gravity is biased in the longitudinal direction of the substantially rectangular spreader. It is about a crane that can suppress.

Various portal cranes including a trolley traversing along a horizontal beam and a spreader suspended by a rope from the trolley have been proposed (see, for example, Patent Document 1). The spreader is formed in a substantially rectangular shape in a 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.

Patent Document 1 describes between a pair of lower sheaves arranged at both ends in the longitudinal direction of a spreader, a pair of upper sheaves installed at both ends of a trolley, and the upper sheaves in a plane parallel to the traveling direction of the crane. We propose a crane with a sheave and a sheave placed in.

In the crane described in Patent Document 1, a rope is hung around a substantially W-shape having a pair of lower sheaves as a lower end and a pair of upper sheaves and a sheave arranged between them as an upper end.

Among the containers that handle cargo with a crane, there is a container whose center of gravity is biased in the longitudinal direction (hereinafter, may be referred to as an eccentric container). When the eccentric container was lifted by a spreader, the container moved in the direction in which the center of gravity was biased when the container left the ground. The conventional crane has a problem that the spreader that grips the eccentric container moves in the traveling direction.

Japanese Patent Application Laid-Open No. 2013-209213

The present invention has been made in view of the above problems, and an object thereof is to provide a crane capable of suppressing a problem that the spreader moves in the longitudinal direction when loading a container whose center of gravity is deviated in the longitudinal direction of a substantially rectangular spreader. It is to be.

The crane for achieving the above purpose is a spreader formed in a substantially rectangular shape having a pair of long sides and a pair of short sides in a plan view, and a plurality of sheaves are installed, and the crane is arranged above the spreader. A trolley on which a plurality of sheaves are installed, a rope hung around the sheave installed on the spreader and the sheave installed on the trolley, and a rope for suspending the spreader from the trolley, and a drum are provided. In a crane, a pair of upper sheaves installed on the trolley at intervals along the longitudinal direction, which is an extension direction of the long side, and a lower sheave installed at a substantially central portion of the spreader in the longitudinal direction. The rope comprises a second lower sheave installed at substantially the center of the spreader in the lateral direction, which is an extension of the short side, and a counter weight that supports at least a part of the weight of the spreader. As an inclined portion extending from the lower sheave to one of the upper sheaves and an inclined portion extending from the lower sheave to the other upper sheave, the lower sheave is used as the lower end and the pair of upper sheaves is used as the upper end. A first rope having a structure of being hung around a substantially V-shape and being hung around a sheave installed on the counter weight, and a rope different from the first rope, which is unwound from the drum. A second rope having a structure to be hung around the second lower sheave is provided .

According to the present invention, since the load of the container is generated on the rope hung in a substantially V shape through the lower sheave, the tension generated on the rope is hardly affected by the position of the center of gravity of the container. Since the tensions of the inclined portion of the rope extending from the lower sheave to one upper sheave and the inclined portion of the rope extending from the lower sheave to the other upper sheave are almost equal, the difference in the component forces generated in the longitudinal direction from each inclined portion. Can be suppressed. Therefore, it is possible to suppress the spreader from moving in the longitudinal direction.

It is explanatory drawing which illustrates the crane of this invention in a perspective view. It is explanatory drawing which illustrates the state of the rope hung along the longitudinal direction of a spreader. It is explanatory drawing which illustrates the state of the conventional rope hung along the longitudinal direction of a spreader. It is explanatory drawing which illustrates the deformation example of the state of the rope of FIG. It is explanatory drawing which illustrates the state of the rope of the crane of this invention. It is explanatory drawing which illustrates the state of the 1st rope of FIG. It is explanatory drawing which illustrates the state of the 2nd rope of FIG.

Hereinafter, the crane of the present invention will be described based on the embodiment shown in the figure. In the figure, the longitudinal direction of the spreader formed in a substantially rectangular shape in a plan view is indicated by an arrow y, the lateral direction crossing the longitudinal direction y at a right angle is indicated by an arrow x, and the vertical direction is indicated by an arrow z.

As illustrated in FIG. 1, the crane 1 of the present invention is composed of, for example, a portal crane. The crane 1 of the present invention is not limited to the gantry crane, and may be composed of a quay crane. The crane 1 of this embodiment has 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. It is equipped with a device 4. The traveling device 4 includes tires or wheels.

The crane 1 includes a trolley 5 configured to be traversable along the horizontal beam 2 and a spreader 6 arranged below the trolley 5 to handle the cargo of the container C. The trolley 5 and the spreader 6 have a plurality of sheaves. A rope R is hung around the plurality of sheaves. The spreader 6 is suspended from the trolley 5 by the rope R. The spreader 6 is formed in a substantially rectangular shape having a pair of long sides and a pair of short sides in a plan view. The spreader 6 is in a state where the longitudinal direction y, which is the extension direction of the long side of the spreader 6, is parallel to the traveling direction of the crane 1, and the lateral direction x, which is the extension direction of the short side, is parallel to the transverse direction of the crane 1. Have been placed. In this embodiment, the drum 7 around which the rope R is wound is installed in the trolley 5.

The crane 1 travels along the traveling direction (longitudinal direction y) by the traveling device 4, and moves to a position where the container C to be loaded and unloaded is placed. The trolley 5 traverses along the traversing direction (short direction x) and moves to a position directly above the container C. The trolley 5 travels on the horizontal beam 2 by a drive mechanism such as a motor. By feeding out the rope R from the drum 7, the spreader 6 descends, and the spreader 6 comes into contact with the upper surface of the target container C and then grips the container C. By winding the rope R with the drum 7, the container C is lifted by the crane 1.

As illustrated in FIG. 2, the trolley 5 includes a pair of upper sheaves S1 installed at intervals along the longitudinal direction y. The spreader 6 includes a lower sheave S2 installed at a substantially central portion in the longitudinal direction y. In FIG. 2, a part of the structure of the crane 1 such as the horizontal beam 2 is omitted for the sake of explanation. In the present specification, the substantially central portion is a concept including, for example, a central point in the longitudinal direction y of the spreader 6, and a position slightly deviated from this point in the longitudinal direction y.

In this embodiment, the rope R unwound from the drum 7 is hung from one upper sheave S1 to the other upper sheave S1 via the lower sheave S2. One continuous rope R is hung in a substantially V shape with the lower sheave S2 as the lower end and the pair of upper sheaves S1 as the upper end.

A load of the container C is generated on the rope R hung in a substantially V shape along the longitudinal direction y of the spreader 6 via the lower sheave S2. The inclined portion Ra of the rope R extending from the lower sheave S2 to one upper sheave S1 and the inclined portion Rb of the rope R extending from the lower sheave S2 to the other upper sheave S2 are in a direction of being pulled toward the lower sheave S2. Force is generated. The forces generated in the inclined portions Ra and Rb are almost the same because they are generated via the lower sheave S2. The tension generated in the inclined portions Ra and Rb generates component forces Fa and Fb along the longitudinal direction y, respectively.

The component forces Fa and Fb are generated inward to bring the inclined portions Ra and Rb close to each other and cancel each other out. Since the spreader 6 is pressed from both sides in the longitudinal direction toward the center by the component forces Fa and Fb, it is advantageous to suppress the spreader 6 from moving along the longitudinal direction y.

As illustrated in FIG. 3, in the conventional crane, two lower sheaves S2 are installed along the longitudinal direction y of the spreader 6, and three upper sheaves S1 are installed along the longitudinal direction y of the trolley 5. rice field. The rope R unwound from the drum 7 was alternately hung around the upper sheave S1 and the lower sheave S2, and hung in a substantially W shape with the two lower sheaves S2 as the lower ends.

The inclined portion Ra of the rope R extending from one lower sheave S2 to the upper sheave S1 arranged at the substantially central portion in the longitudinal direction y, and the upper sheave S1 arranged from the other lower sheave S2 to the central portion in the longitudinal direction y. Tension is generated in the inclined portion Rb of the extending rope R via the respective lower sheaves S2.

The rope R hung in a substantially W shape is connected to the spreader 6 at two points in the longitudinal direction y. Therefore, tension is generated in the inclined portions Ra and Rb according to the downward force generated in each of the lower sheaves S2. When the center of gravity G of the container C is biased to the left in FIG. 3, for example, from the central portion in the longitudinal direction y, a larger force is applied to the lower sheave S2 arranged to the left than the lower sheave S2 arranged to the right. Occurs.

The tension of the inclined portion Ra is larger than that of the inclined portion Rb, and the component force Fa is larger than the component force Fb. Therefore, there was a problem that the container C moved to the left side in FIG.

On the other hand, as illustrated in FIG. 2, the rope R hung in a substantially V shape is connected to the spreader 6 at only one point in the longitudinal direction y. Therefore, tension is generated in the rope R due to the downward force generated at one point of the lower sheave S2. Even when the center of gravity G of the container C is biased to the left of FIG. 2, for example, from the central portion in the longitudinal direction y, the load of the container C is transmitted to the rope R via the lower sheave S2. That is, regardless of the position of the center of gravity G of the container C, the load of the container C is transmitted to the rope R via only one point of the lower sheave S2. Since the tensions generated in the inclined portions Ra and Rb are always substantially equal, the component forces Fa and Fb along the longitudinal direction y are also always substantially equal. The container C is in a state in which it is difficult to receive a force biased to either one in the longitudinal direction y. Therefore, it is advantageous to avoid the problem that the container C moves in the longitudinal direction y due to the bias of the center of gravity G.

In the traveling direction of the crane 1 parallel to the longitudinal direction y, the relative position of the container C hardly changes between when it is in contact with the ground and when it is lifted. It is advantageous to avoid a problem that the container C moves when the container C is lifted and comes into contact with an adjacent container or the like.

Since the container C is difficult to move in the longitudinal direction y regardless of the position of the center of gravity G, the container C gripped by the spreader 6 is always present at a predetermined position directly under the trolley 5. When the crane 1 is automated and automatically loaded and unloaded, the position of the container C is accurately determined, which is extremely advantageous. It is possible to avoid a problem that the suspended container C moves in the longitudinal direction y and the container C is placed at a position shifted from the planned location. Even with the crane 1 that handles cargo by automatic operation, it is possible to accurately stack and place a plurality of containers C.

It is not an essential requirement that the rope R hung in a substantially V shape between the pair of upper sheaves S1 and the lower sheaves S2 is connected. As illustrated in FIG. 4, even if the two ropes R are hung around each other, the above-mentioned effect can be obtained if the rope R is hung around in a substantially V shape.

In the embodiment of FIG. 4, two lower sheaves S2 are installed in a substantially central portion of the spreader 6 in the longitudinal direction y. The two lower sheaves S2 may be arranged so as to be displaced in the lateral direction x or may be arranged so as to be displaced in the longitudinal direction y. Any lower sheave S2 may be arranged substantially in the center of the spreader 6 in the longitudinal direction y.

One rope R extending from the upper sheave S1 on the left side of FIG. 4 is hung around the lower sheave S2. For the sake of explanation, this rope R is shown by a broken line. The other rope R extending from the upper sheave S1 on the right side of FIG. 4 is hung around the other lower sheave S2. Each rope R has inclined portions Ra and Rb, respectively. The inclined portions Ra and Rb receive a downward force from the lower sheave S2 that is hung around each other to generate tension. Since the two lower sheaves S2 are arranged close to each other, the tensions generated in the inclined portions Ra and Rb are almost equal. The component forces Fa and Fb along the longitudinal direction y are also in a substantially equal state. It is advantageous to suppress the movement of the spreader 6 in the longitudinal direction y.

In the embodiment of FIG. 4, for example, the upper sheave S1 on the left side is arranged in a state where the axial direction is the lateral direction x, and the upper sheave S1 on the right side is tilted from the longitudinal direction y to the vertical direction z. It is arranged in a state of being. The axial direction of the sheave S when arranging the sheave S is not limited to the above. When arranging the sheave S, the axial direction of the sheave S can be appropriately determined according to the extending direction of the rope R and the like.

As illustrated in FIG. 5, the crane 1 can be provided with a counterweight 8 that supports a part of the weight of the spreader 6. In this embodiment, a counterweight 8 is installed on one leg 3 of the gantry crane 1. In FIG. 5, the horizontal beam 2 and the leg portion 3 of the crane 1 are shown by broken lines for explanation. Also, the trolley 5 is omitted.

As illustrated in FIGS. 5 and 6, in this embodiment, the rope R1 is hung from the sheave S installed on the counterweight 8 to the sheave S installed on the leg 3. This rope R1 is stretched along the horizontal beam 2 in the lateral direction x, and is stretched from one upper sheave S1 of the trolley 5 via the lower sheave S2 installed at the substantially central portion of the spreader 6 in the longitudinal direction y. It is hung around the other upper sheave S1. At this time, the rope R1 is hung in a substantially V shape along the longitudinal direction y of the spreader 6. In FIG. 6, the horizontal beam 2, the leg portion 3, and the trolley 5 are omitted for the sake of explanation.

The rope R1 is hung from the other upper sheave S1 of the trolley 5 to the sheave S installed on the other leg 3 via the sheave S installed on the leg 3 and the sheave S installed on the counterweight 8. It is turned. The rope R1 is hung from the sheave S installed on the other leg 3 to the other upper sheave S1 via one upper sheave S1 of the trolley 5 and the lower sheave S2 of the spreader 6. At this time, the rope R1 is hung in a substantially V shape along the longitudinal direction y of the spreader 6. That is, the rope R1 is hung around the pair of long sides of the spreader 6 in a substantially V shape.

As illustrated in FIG. 5, the drum 7 can be installed on the leg 3 of the crane 1. In this embodiment, the drum 7 is installed on the leg portion 3 on the side different from the leg portion 3 on which the counterweight 8 is installed. Since the drum 7 having a relatively large weight can be installed at a relatively low position of the crane 1, the center of gravity of the crane 1 is lowered and the stability of the crane 1 can be improved. Since the stability of the crane 1 is improved, the strength of the legs 3 and the horizontal beam 2 can be reduced to reduce the weight.

The configuration in which the drum 7 is installed on the leg portion 3 is not an essential requirement of the present invention. Similar to the embodiment shown in FIG. 1, in the embodiment illustrated in FIG. 5, the drum 7 may be installed on the trolley 5.

The rope R2 unwound from the drum 7 can be composed of a rope R different from the rope R1 hung on the counterweight 8. Hereinafter, the rope hung on the counterweight 8 may be referred to as a first rope R1, and the rope drawn from the drum 7 may be referred to as a second rope R2.

The configuration in which the first rope R1 and the second rope R2, which are independent of each other, are adopted is not an essential requirement of the present invention. The first rope R1 and the second rope R2 may be configured by a single rope R connecting the ropes R1 and the second rope R2.

As illustrated in FIG. 7, the second rope R2 unwound from the drum 7 is hung in a substantially V shape along the lateral direction x of the spreader 6. That is, in addition to the longitudinal direction y, the rope R hung along the lateral direction x is also formed in a substantially V shape. It is advantageous to prevent the spreader 6 from moving in the lateral direction x.

In this embodiment, the rope R hung in a substantially V shape along the lateral direction x is formed by two ropes R in a substantially V shape as in the embodiment illustrated in FIG. In the embodiment illustrated in FIG. 7, the second upper sheave S3 installed in the trolley 5 is arranged in a state where the longitudinal direction y is the axial direction. That is, the axial direction of the sheave S in the embodiment illustrated in FIG. 7 is different from the axial direction of the sheave S in the embodiment illustrated in FIG.

Specifically, one of the second ropes R2 shown by the broken line is extended from the drum 7 in the lateral direction x along the horizontal beam 2 via the sheave S installed on the leg portion 3. Ru. The second rope R2 has a second upper sheave S3 installed at a substantially central portion of the trolley 5 in the lateral direction x and a second lower sheave S4 and a trolley installed at a substantially central portion of the spreader 6 in the lateral direction x. It is stretched along the horizontal beam 2 via the other second upper sheave S3 of 5. At this time, the second rope R2 forms a part of a substantially V-shape. The second rope R2 then passes through a sheave S installed on the leg 3 on the side where the counterweight 8 is arranged, and forms a substantially V-shaped part on the other short side of the spreader 6 to form a drum. Up to 7.

Similarly, the other second rope R2 shown by the solid line is unwound from the drum 7 to form a substantially V-shaped part along the lateral direction x of the spreader 6, and the counterweight 8 is arranged. It is hung around the sheave S of the side leg 3. The second rope R2 then forms a substantially V-shaped part on the other short side of the spreader 6 to reach the drum 7.

The second rope R2 hung in a substantially V shape in the lateral direction x of the spreader 6 may have the same configuration as that of the embodiment illustrated in FIG. The configuration in which the second rope R2 is hung in a substantially V shape along the lateral direction x of the spreader 6 is not an essential requirement of the present invention.

It is desirable to install the small turning device 9 in the vicinity of the sheave S of the leg portion 3 on the side where the counterweight 8 is arranged. The small turning device 9 is arranged between the pair of sheaves S. By operating the small turning device 9, the relative positions of the pair of sheaves S can be displaced in the lateral direction x. This operation of the small turning device 9 makes it possible to tilt the spreader 6 with the vertical direction z as the central axis.

In the crane 1 illustrated in FIG. 5, the spreader 6 can be moved up and down by winding or unwinding the second rope R2 with the drum 7. When the container C is lifted by the spreader 6, the second rope R2 is wound by the drum 7. At this time, a part of the weight of the spreader 6 and the container C is offset by the counterweight 8. Since the energy required for winding the second rope R2 on the drum 7 can be suppressed, it is advantageous to suppress the energy consumption of the crane 1. Further, since the capacity of the motor of the drum 7 can be reduced, it is advantageous to suppress the manufacturing cost of the crane 1.

Since the first rope R1 is hung in a substantially V shape along the longitudinal direction y of the spreader 6, the container C is on the ground even when the center of gravity G of the container C is biased in the longitudinal direction y. It is possible to avoid a problem that the container C moves in the longitudinal direction y when it is separated from the above.

Further, since the second rope R2 is hung in a substantially V shape along the lateral direction x of the spreader 6, even if the center of gravity G of the container C is biased in the lateral direction x, the container It is possible to avoid the problem that C moves in the lateral direction x.

That is, the crane 1 of the embodiment illustrated in FIG. 5 can stabilize the position of the container C regardless of the position of the center of gravity G of the container C. Since the position of the container C suspended by the spreader 6 is stable almost directly under the trolley 5, it is advantageous to improve the accuracy of the automatic operation of the crane 1.

Since the first rope R1 does not generate a tension exceeding the weight of the counterweight 8, it is advantageous for suppressing the deterioration of the first rope R1. Since tension proportional to the weight of the container C is repeatedly generated in the second rope R2 during cargo handling work, it is in a state of being more easily deteriorated than the first rope R1.

The rope R of the crane 1 is composed of an independent first rope R1 and a second rope R2. Therefore, when replacing the rope R of the crane 1, it is possible to replace only the second rope R2, which is relatively easily deteriorated. It is easier to replace only the second rope R2 than to replace the entire rope R of the crane 1.

The crane 1 may be configured not to have a counterweight 8. In this case, the rope R unwound from the drum 7 is hung in the longitudinal direction y in addition to the lateral direction x of the spreader 6.

1 Crane 2 Horizontal beam 3 Leg 4 Traveling device 5 Trolley 6 Spreader 7 Drum 8 Counterweight 9 Small turning device x Short direction y Longitudinal direction z Vertical direction R Rope R1 First rope R2 Second rope Ra Inclined part Rb Inclined Part C Container G Center of gravity S Sheave S1 Upper sheave S2 Lower sheave S3 Second upper sheave S4 Second lower sheave Fa, Fb component

Claims (4)

A spreader that is formed in a substantially rectangular shape with a pair of long sides and a pair of short sides in a plan view and has multiple sheaves installed, and a trolley that is arranged above the spreader and has multiple sheaves installed. In a crane provided with a rope and a drum that are hung around the sheave installed on the spreader and the sheave installed on the trolley to suspend the spreader from the trolley.
A pair of upper sheaves installed in the trolley in a state of being spaced along the longitudinal direction which is an extension direction of the long side, a lower sheave installed in a substantially central portion of the spreader in the longitudinal direction, and the short side. It is provided with a second lower sheave installed at substantially the center of the spreader in the lateral direction, which is an extension direction of the side, and a counter weight that supports at least a part of the weight of the spreader .
The rope includes an inclined portion extending from the lower sheave to one of the upper sheaves and an inclined portion extending from the lower sheave to the other upper sheave, and a pair of the upper sheaves with the lower sheave as a lower end. A first rope having a structure of being hung around a substantially V-shape as an upper end and being hung around a sheave installed on the counterweight, and a rope different from this first rope from the drum. A crane comprising a second rope having a configuration of being unwound and hung around the second lower sheave . The crane according to claim 1, wherein the first rope is hung from one of the upper sheaves to the other upper sheave via the lower sheave. It is equipped with a pair of second upper sheaves installed in the trolley at intervals along the lateral direction .
The second rope comprises an inclined portion extending from the second lower sheave to one of the second upper sheaves and an inclined portion extending from the second lower sheave to the other second upper sheave. (Ii) The crane according to claim 1 or 2, wherein the second rope is hung around a substantially V-shape having the pair of the second upper sheaves as the upper end and the lower sheave as the lower end. It is composed of a gantry crane having a horizontal beam on which the trolley traverses and a pair of legs extending downward from both ends of the horizontal beam.
The crane according to any one of claims 1 to 3, wherein the drum is installed on one of the legs and the counterweight is installed on the other leg.

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