JP7099907B2 - Container crane - Google Patents

Description

The present invention relates to a container crane, and more particularly to a container crane capable of reducing the impact energy acting on the container crane by a snag load while reducing the risk of the hoisting wire breaking.

When loading and unloading a container to a container ship with a container crane, if you try to lift the container while the hanger (spreader) or container is caught in the cell guide of the container ship, a shocking load will be applied to the hanger and hoisting wire. It works. The phenomenon described above is called snag road. Conventionally, when a snag load occurs, a large load is applied to the container crane structure (garda, boom, leg structure, etc.) through the sheave around which the hoisting wire is hung, and the container crane can be seriously damaged. there were.

Therefore, a container crane structure protection mechanism that reduces the impact energy acting on the container crane by the snag load has been proposed (see Patent Document 1). As shown in FIG. 7, in the container crane structure protection mechanism 20X (hereinafter referred to as protection mechanism 20X) described in Patent Document 1, the lower end portion of the sheave bracket 23 to which the girder end sheave 10 is pivotally supported and the girder end sheave 10 A plate-shaped hoisting wire bending member 24 is provided between the two.

As shown in FIG. 8, in this protection mechanism 20X, when a snag load occurs, the shear pin 25 connecting the lower portion of the sheave bracket 23 and the tip end portion of the rod 26a of the jack cylinder 26 breaks, and the sheave bracket As the 23 rotates about the support shaft 22 toward the sea side (upward), the impact energy (tension) applied to the winding wire 9 in the axial direction by the snag load is reduced. Further, when the sheave bracket 23 rotates about the support shaft 22, the winding wire bending member 24 lifts and bends the winding wire 9 from below, and the energy in the axial direction of the winding wire 9 is used to cause the winding wire 9 to swing. By converting to energy in the direction and bending direction, the impact energy due to the snag load can be attenuated (reduced).

However, as shown in FIG. 8, in the conventional protection mechanism 20X, since the main purpose is to greatly bend the winding wire 9 by the winding wire bending member 24, the sheave bracket 23 rotates about the support shaft 22. The structure is such that the upper end position 24H of the sea side end portion of the winding wire bending member 24 can rise to a position higher than the lower end position 10L of the girder end sheave 10 (see FIG. 6 of Patent Document 1). Therefore, the winding wire 9 can be greatly bent, but on the other hand, when the winding wire bending member 24 lifts the winding wire 9 from below, the winding wire 9 is vigorously flipped upward, so that the winding wire 9 can be bent. Kink (breaking habits and twisting) may occur. Further, since the winding wire 9 is locally greatly bent at the sea side end of the winding wire bending member 24, a large shear load is applied locally to the winding wire 9. Therefore, in the conventional protection mechanism 20X, the effect of damping the impact energy by bending the winding wire 9 is large, but on the other hand, there is a demerit that the winding wire 9 may be broken.

Japanese Unexamined Patent Publication No. 2010-235244

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a container crane capable of reducing the impact energy acting on the container crane by a snag load and reducing the risk of the hoisting wire breaking. It is in.

In the container crane of the present invention for achieving the above object, a hanger is suspended from a trolley moving along a girder and a boom via a hoisting wire, and the tip of the hoisting wire is the sea of the boom. It is fixed to the side end, and the rear part of the hoisting wire is wound around the drum via a girder end sheave provided at the land side end of the girder, and the girder end sheave is a component of the sheave bracket. A pair of sheave bracket pieces are rotatably supported between the sheave bracket pieces, and the upper portion of the sheave bracket is rotatably connected to a support bracket provided at the land side end of the girder via a support shaft. The lower part of the sheave bracket is connected to the tip of the rod of the jack cylinder connected to the land side end of the girder via a shear pin, and is connected between the lower end of the sheave bracket and the girder end sheave. A hoisting wire bending member is provided between the pair of sheave bracket pieces, and when the shear pin breaks and the sheave bracket rotates about the support shaft, the hoisting wire bending member is provided. In a container crane configured to lift and bend the hoisting wire from below, the rotatable range of the sheave bracket when the shear pin breaks and the sheave bracket rotates about the support shaft is described above. It is characterized in that the upper end position of the sea side end portion of the hoisting wire bending member is set in a range equal to or less than the lower end position of the girder end sheave.

According to the container crane of the present invention, the rotatable range of the sheave bracket when the shear pin is broken is set to a range in which the upper end position of the sea side end of the winding wire bending member is equal to or less than the lower end position of the girder end sheave. This makes it possible to prevent the hoisting wire from bending significantly locally at the seaside end of the hoisting wire bending member when the hoisting wire bending member lifts the hoisting wire from below. As a result, the impact energy acting on the container crane by the snag load can be reduced by the winding wire bending portion, and the risk of the winding wire breaking can be reduced.

It is explanatory drawing which schematically exemplifies the embodiment of the container crane of this invention from the side view. It is explanatory drawing which schematically exemplifies the winding structure of the winding wire of FIG. 1 from the perspective. It is explanatory drawing which enlarges and exemplifies the vicinity of the container crane structure protection mechanism of FIG. 1 from the side view. FIG. 3 is a sectional view taken along the line AA of FIG. FIG. 3 is an explanatory view schematically illustrating a state in which the shear pin of FIG. 3 is broken and the sheave bracket is located at the uppermost position of the rotatable range in a side view. It is explanatory drawing which shows the vicinity of the girder end sheave of FIG. 5 in a larger scale. It is explanatory drawing which expands and exemplifies the vicinity of the container crane structure protection mechanism of the conventional container crane from the side view. It is explanatory drawing which illustrates the state which the shear pin of FIG. 7 was broken in the side view.

Hereinafter, the container crane of the present invention will be described based on the embodiment shown in the figure. In the figure of the present application, the X direction indicates the transverse direction X of the container crane, the Y direction indicates the traveling direction Y of the container crane orthogonal to the transverse direction X in the horizontal direction, and the Z direction indicates the vertical direction Z (vertical direction) of the container crane. ..

As shown in FIG. 1, the container crane 1 of the embodiment according to the present invention has a leg structure 2, a girder 3 extending in the X direction provided on the upper part of the leg structure 2, and a sea side of the girder 3. It is provided with a boom 4 connected to, a trolley 5 that moves in the X direction along the girder 3 and the boom 4, and a hanging tool (spreader) 6 for a container C arranged below the trolley 5. The container crane 1 further includes a machine room 7 arranged in the upper part of the leg structure 2, drums 8 (8a, 8b) housed in the machine room 7, and hoisting wires 9 (9a ~) wound around the drum 8. It is equipped with 9d). The machine room 7 and the drum 8 may be configured to be arranged on the upper part of the girder 3.

As shown in FIG. 2, four girder end sheaves 10 (10a to 10d) are provided at the land-side end of the girder 3 at intervals in the Y direction. The trolley 5 is provided with a total of eight trolley sheaves 12 (12a to 12h), two at each of the four corners, and the hanger 6 is provided with a total of four hanger sheaves 13 (13a to 13d), one at each of the four corners. Is provided. At the seaside end of the boom 4, four boom end sheaves 14 (14a to 14d) and a fixture 15 (15a, 15b) for fixing the tip of the winding wire 9 are provided.

In this container crane 1, the hanger 6 is suspended from the trolley 5 via the hoisting wire 9, the tip of the hoisting wire 9 is fixed to the seaside end of the boom 4, and the rear part of the hoisting wire 9 is a girder end sheave. It is wound around the drum 8 via the 10.

More specifically, as shown in FIG. 2, the winding wire 9a drawn out from the drum 8a is hung in the order of the girder end sheave 10a, the trolley receive 12a, the hanger sheave 13a, the trolley receive 12b, and the boom end sheave 14a. The tip of the winding wire 4a is fixed to the fixture 15a provided at the sea side end of the boom 4. The other winding wire 9b pulled out from the drum 8a is hung in the order of the girder end sheave 10b, the trolley receive 12c, the hanger sheave 13b, the trolley receive 12d, and the boom end sheave 14b, and the tip of the winding wire 9b. Is fixed to the fixture 15b installed at the sea side end of the boom 4.

The winding wire 9c drawn out from the drum 8b is hung in the order of the girder end sheave 10c, the trolley receive 12e, the hanger sheave 13c, the trolley sheave 12f, and the boom end sheave 14c, and the tip of the winding wire 9c is the fixing tool 15b. It is fixed to. The other winding wire 9d pulled out from the drum 8b is hung in the order of the girder end sheave 10d, the trolley receive 12g, the hanger sheave 13d, the trolley receive 12h, and the boom end sheave 14d, and the tip of the winding wire 9d. Is fixed to the fixture 15a.

In this container crane 1, the drum 8 (8a, 8b) is rotationally driven by a motor to move the spreader 6 up and down in the Z direction. In FIG. 2, the winding wires 9a and 9d are shown by thick solid lines and the winding wires 9b and 9c are shown by thin solid lines so that the winding wires 9a to 9d can be easily distinguished. The thickness of is the same.

As shown in FIG. 3, a container crane structure protection mechanism 20 (hereinafter referred to as a protection mechanism 20) for reducing the impact energy acting on the container crane 1 by the snag load is provided at the land side end of the girder 3. There is. The protection mechanism 20 rotates the support bracket 21 fixed to the land side end of the girder 3, the sheave bracket 23 that pivotally supports the girder end sheaves 10 (10a to 10d), and the upper portion of the sheave bracket 23 to the support bracket 21. A support shaft 22 that is rotatably connected, a jack cylinder 26 whose rear end is connected to a predetermined position of the girder 3, and a shear pin that rotatably connects the lower portion of the sheave bracket 23 to the tip of the rod 26a of the jack cylinder 26. 25 and a winding wire bending member 24 fixed to the sheave bracket 23 are provided.

The protection mechanism 20 further includes an L-shaped lever 27 fixed to the tip of the rod 26a, a proximity switch 28 fixed to the lower end of the sheave bracket 23, and a control device 29 to which the proximity switch 28 is connected. It has a stopper 30 fixed to the support bracket 21. The protection mechanism 20 is provided in each of the four girder end sheaves 10a to 10d.

As shown in FIG. 4, the sheave bracket 23 has a pair of sheave bracket pieces 23a and 23b arranged at intervals in the Y direction, and a connecting portion 23c for joining the pair of sheave bracket pieces 23a and 23b. It is composed of. The girder end sheave 10 is rotatably supported between a pair of sheave bracket pieces 23a and 23b, and freely rotates about a rotation shaft 11.

As shown in FIG. 3, the girder end sheave 10 is drawn from the axis center of the rotation axis 11 of the girder end sheave 10 to the first virtual straight line V1 connecting the axis center of the support shaft 22 and the axis center of the shear pin 25. It is preferable to arrange the vertical line PL at a position where the length D is equal to or larger than the radius of the girder end shear 10 and equal to or smaller than the diameter of the girder end shear 10. The dimensions of the girder end sheave 10 and the length D of the vertical line PL can be appropriately determined according to the size of the container crane 1, etc., but in the case of a container crane whose cargo handling target is a 20-foot container C or a 40-foot container C. The girder end sheave 10 having a diameter of, for example, 1000 mm or more and 1500 mm or less may be adopted, and the girder end sheave 10 may be arranged at a position where the length D of the above-mentioned vertical line PL is, for example, 400 mm or more and 600 mm or less.

The winding wire bending member 24 (hereinafter referred to as a bending member 24) is formed by processing, for example, a metal plate or the like. Most of the bent member 24 is composed of a flat plate portion 24a having a flat surface, and the sea side end portion of the bent member 24 is composed of a curved portion 24b formed in an arc shape. The bending member 24 is arranged between the lower end of the sheave bracket 23 and the girder end sheave 10 and between the pair of sheave bracket pieces 23a and 23b.

As shown in FIG. 3, in a state where the lower portion of the sheave bracket 23 and the tip end portion of the rod 26a are connected by the shear pin 25, the bending member 24 (flat plate portion 24a) inclines downward from the land side toward the sea side. It is fixed to the shear bracket 23 in the orientation. A part of the flat plate portion 24a of the bending member 24 is arranged at a position close to the outer edge portion of the girder end sheave 10, and the curved portion 24b projects toward the sea side from the sheave bracket 10.

As shown in FIG. 3, when viewed from the Y direction, the angle θ formed by the first virtual straight line V1 connecting the axis center of the support shaft 22 and the axis center of the shear pin 25 and the bent portion 24 (flat plate portion 24a) is For example, it may be set to 20 degrees or more and 45 degrees or less. Further, the sea side end portion (curved portion 24b) of the bending member 24 passes through the first virtual straight line V1, the axis center of the support shaft 22, and the axis center of the rotation axis 11 of the girder end sheave 10. The bending member 24 may be arranged so as to be located between the V2 and the V2.

As shown in FIG. 4, before the shear pin 25 breaks, that is, before the snag load occurs, the tip of the rod 26a of the jack cylinder 26 is arranged between the pair of sheave bracket pieces 23a and 23b. The lower part of the sheave bracket 23 and the rod 26a are formed by a shear pin 25 for inserting the lateral hole 23d provided in the lower part of the pair of sheave bracket pieces 23a and 23b and the lateral hole provided in the tip end portion of the rod 26a. It is in a state of being connected to the tip. In a state where the lower portion of the sheave bracket 23 and the tip end portion of the rod 26a are connected by the shear pin 25, the rod 26a of the jack cylinder 26 corresponding to each of the girder end sheaves 10a to 10d is expanded and contracted to move the hanger. The steady rest of 6 and the posture of the hanger 6 can be changed.

The proximity switch 28 is attached to the lower end of the sheave bracket 23, and the L-shaped lever 27 is attached to the tip of the rod 26a of the jack cylinder 26. Before the shear pin 25 breaks, the lever 27 is arranged within the detectable range of the proximity switch 28. The control device 29 is installed at a predetermined position of the container crane 1, and the proximity switch 28 and the control device 29 are connected wirelessly or by wire.

When a snag load occurs and a large impact energy (tension) is applied to the winding wire 9, the sheave bracket 23 supporting the girder end sheave 10 is pulled toward the sea, and the lower part of the sheave bracket 23 and the tip of the rod 26a are pulled. A large load is applied to the shear pin 25 connecting the portion. Then, when a load of a predetermined value or more is applied to the shear pin 25, the shear pin 25 breaks.

As shown in FIG. 5, when the shear pin 25 breaks, the connection between the sheave bracket 23 and the tip of the rod 26a by the shear pin 25 is released, so that the lower portion of the sheave bracket 23 becomes a free end and the sheave bracket 23 becomes a free end. Rotates toward the sea side (upward) about the support shaft 22. Along with this, the proximity switch 28 separates from the lever 27, and the lever 27 comes out of the detectable range of the proximity switch 28. When the lever 27 is removed from the detectable range of the proximity switch 28, the motor driving the drum 8 is stopped by the control device 29, the brake provided on the drum 8 is activated, and the rotation of the drum 8 is urgently stopped. It has become.

In this way, when a snag load occurs in the protection mechanism 20 and the shear pin 25 breaks, the control device 29 urgently stops the winding of the winding wire 9 by the drum 8, and the sheave bracket 23 rotates to girder. By moving the end shear 10 to the sea side, the impact energy (tension) applied in the axial direction of the winding wire 9 is reduced.

Further, as shown in FIG. 6, when the sheave bracket 23 rotates, the winding wire 9 (9a to 9d) has the girder end sheave 10 (10a to 10d) and the trolley receive 12 (12a, 12c, 12e, 12g). The winding wire 9 is gently bent by the portion between them being lifted from below by the bending member 24. As a result, the impact energy applied in the axial direction of the winding wire 9 by the snag load is converted into energy in the swing direction and the bending direction of the winding wire 9, and as a result, the impact energy due to the snag load is attenuated.

In this container crane 1, the rotatable range of the sheave bracket 23 when the sheave bracket 23 rotates about the support shaft 22 is the upper end position 24H of the sea side end portion (curved portion 24b) of the bending member 24. The range is set so that the lower end position of the girder end sheave 10 is 10 L or less. That is, even when the shear pin 25 is broken and the sheave bracket 23 is rotated, the upper end position 24H of the sea side end portion of the bending member 24 is not located above the lower end position 10L of the girder end sheave 10. , The bent member 24 (flat plate portion 24a) is inclined downward from the land side toward the sea side, or is in a state parallel to the horizon HL.

In this embodiment, the sheave bracket 23 rotates on the support bracket 21 so that the sheave bracket 23 does not rotate toward the sea side (above) the position where the bending member 24 (flat plate portion 24a) is parallel to the horizon HL. A stopper 30 is provided to regulate the possible range.

As described above, in the container crane 1 of the present invention, the rotatable range of the sheave bracket 23 when the shear pin 25 is broken is such that the upper end position 24H of the sea side end portion of the bending member 24 is the lower end position of the girder end sheave 10. By setting the range to 10 L or less, when the bending member 24 lifts the hoisting wire 9 from below, the hoisting wire 9 is locally greatly bent at the seaside end of the hoisting wire bending member 24. Can be avoided. As a result, the impact energy acting on the container crane 1 due to the snag load can be reduced by the bent portion 24, and the risk of the winding wire 9 breaking can be reduced.

If the hoisting wire 9 is broken by the snag load, it takes a lot of time to restart the container crane 1 because the hoisting wire 9 needs to be replaced. However, in the container crane 1 of the present invention, the hoisting wire 9 is hoisted. Since the wire 9 is unlikely to break, the container crane 1 can be quickly restarted even when a snag load occurs.

As in this embodiment, the sea side end portion of the bending member 24 connects the axis center of the support shaft 22 and the axis center of the shear pin 25 (the center of the lateral hole 23d) with the first virtual straight line V1 and the support shaft 22. The winding wire 9 is locally located at the seaside end of the bending member 24 when the configuration is such that it is located between the center of the shaft and the second virtual straight line V2 passing through the center of the rotation shaft 11 of the girder end sheave 10. The winding wire 9 can be sufficiently bent as a whole while avoiding a large bending. Therefore, it is advantageous to reduce the risk of the winding wire 9 breaking while ensuring a high impact energy reduction effect by the bending member 24.

In other words, when the sea side end portion of the bending member 24 is located on the land side (lower side) of the first virtual straight line V1, it becomes difficult for the bending member 24 to bend the winding wire 9. Further, when the sea side end portion of the bending member 24 is located on the sea side (above) of the second virtual straight line V2 as in the conventional protection mechanism 20X shown in FIG. 8, the sea side of the bending member 24 is located. Since the winding wire 9 is locally greatly bent at the side end portion, the possibility that the winding wire 9 is broken is high.

As in this embodiment, the axis center of the rotating shaft 11 of the girder end sheave 10 is located on the sea side of the axis center of the support shaft 22, and the first from the axis center of the rotating shaft 11 of the girder end sheave 10. When the length D of the perpendicular line PL drawn on the virtual straight line V1 is not less than the radius of the girder end sheave 10 and not more than the diameter of the girder end sheave 10, the following effects can be obtained.

As shown in FIG. 3, when the girder end sheave 10 is offset to the sea side with respect to the first virtual straight line V1 and the rotation axis 11 of the girder end sheave 10 is arranged at a position where the length D of the perpendicular line PL becomes longer. , As shown in FIGS. 5 and 6, the height position of the rotation shaft 11 when the sheave bracket 23 is rotated toward the sea side (upward) arranges the rotation shaft 11 near the first virtual straight line V1. It will be higher than the case. That is, the longer the length D of the perpendicular line PL, the wider the vertical movement range of the girder end sheave 10 when the sheave bracket 23 rotates. The wider the vertical movement range of the girder end sheave 10, the larger the winding wire 9 can be bent as a whole by the bending member 24, so that the effect of damping the impact energy by bending the winding wire 9 becomes higher. The length D of the vertical wire PL can be appropriately determined, but if the length D of the vertical wire PL is set to be equal to or larger than the radius of the girder end sheave 10, the effect of damping the impact energy by bending the winding wire 9 becomes high.

On the other hand, as the length D of the perpendicular line PL becomes longer, the movement range of the girder end sheave 10 in the X direction when the sheave bracket 23 rotates becomes narrower, and the impact energy due to the movement of the guard end sheave 10 toward the sea side becomes narrower. The effect of reducing (tension) is low. If the length D of the perpendicular line PL is made longer than the diameter of the girder end sheave 10, the above-mentioned impact energy (tension) reduction effect is reduced. Therefore, in order to effectively enjoy both the impact energy attenuation effect by bending the winding wire 9 and the impact energy (tension) reduction effect by moving the guard end sheave 10 to the sea side, it is necessary to use the vertical wire PL. It is preferable that the length D is not less than the radius of the girder end sheave 10 and not more than the diameter of the girder end sheave 10.

The present invention is not limited to the embodiments exemplified above, and the number of drums 8 of the container crane 1, the number of hoisting wires 9, the number and arrangement of each sheave (trolley sheave 12, hanging tool sheave 13, etc.) and the like. The installation angle, the hoisting wire winding structure (the hoisting direction, the hoisting order, etc.) and the like can be configured differently from the embodiments exemplified above.

1 Container crane 2 Leg structure 3 Girder 4 Boom 5 Trolley 6 Hanger 7 Machine room 8, 8a, 8b Drum 9, 9a-9d Winding wire 10, 10a-10d Girder end sheave 10L (Garder end sheave) lower end position 11 Rotating shaft 12, 12a-12h Trolley sheave 13, 13a-13d Suspension sheave 14, 14a-14d Boom end sheave 15a, 15b Fixture 20 Container crane structure protection mechanism 20X Conventional container crane structure protection mechanism 21 Support bracket 22 Support Shaft 23 Sheave bracket 23a, 23b Sheave bracket piece 23c Connecting part 23d Horizontal hole 24 Winding wire bending member 24a Flat plate part
24b Curved part 24H Upper end position of seaside end (of winding wire bending member) 25 Sheep pin 26 Jack cylinder 26a Rod 27 Lever 28 Proximity switch 29 Control device 30 Stopper C Container V1 First virtual straight line V2 Second virtual straight line PL (down from the axis center of the rotation axis of the girder end sheave to the first virtual straight line) Perpendicular line HL horizontal line

Claims (3)

A hanger is suspended from a trolley moving along the girder and boom via a hoisting wire, the tip of the hoisting wire is fixed to the seaside end of the boom, and the rear part of the hoisting wire is the land of the girder. The girder end sheave is wound around a drum via a girder end sheave provided at a side end, and the girder end sheave is rotatably supported between a pair of sheave bracket pieces which are constituent members of the sheave bracket. A jack in which the upper part of the sheave bracket is rotatably connected to a support bracket provided at the land side end of the girder via a support shaft, and the lower part of the sheave bracket is connected to the land side end of the girder. A hoisting wire bending member is provided between the lower end of the sheave bracket and the girder end sheave and between the pair of sheave bracket pieces, which are connected to the tip of the rod of the cylinder via a shear pin. In a container crane having a structure in which the hoisting wire bending member lifts the hoisting wire from below and bends it when the shear pin breaks and the sheave bracket rotates about the support shaft.
When the shear pin breaks and the sheave bracket rotates about the support shaft, the rotatable range of the sheave bracket is such that the upper end position of the sea side end of the hoisting wire bending member is the girder end. A container crane characterized in that it is set within the range below the lower end position of the shear. The axis center of the rotation axis of the girder end sheave is located on the sea side of the axis center of the support shaft, and from the axis center of the rotation axis of the girder end sheave to the axis center of the support shaft and the shear pin. The container crane according to claim 1, wherein the length of the vertical line drawn on the first virtual straight line connecting the axes is equal to or greater than the radius of the girder end sheave and equal to or less than the diameter of the girder end sheave. The sea-side end of the hoisting wire bending member is a first virtual straight line connecting the axis center of the support shaft and the axis center of the shear pin, and the axis of the axis of the support shaft and the axis of the rotation axis of the girder end sheave. The container crane according to claim 1 or 2, which is located between a second virtual straight line passing through a center.

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