JP7372851B2 - Cranes and crane rope tensioning methods - Google Patents

Description

The present invention relates to a crane having a lifting device suspended by a rope from a trolley and a rope tensioning method for the crane. Specifically, the present invention relates to a crane having a lifting device suspended by a rope from a trolley, and a rope tensioning method for the crane. This article relates to a crane that can be used and a crane rope tensioning method.

Various cranes have been proposed that have hanging tools suspended from a trolley by ropes (see, for example, Patent Document 1). The crane described in Patent Document 1 has a structure in which the rope is stretched in a W-shape along the long side of the hanging device, and the rope is stretched in a V-shape along the short side of the hanging device. It was equipped with

When a rope is stretched in a V-shape or W-shape, a horizontal force is generated from the inclined portion in accordance with the tension. The swinging of the hanging tool in the long side direction and the short side direction was suppressed by this horizontal force. In the crane described in Patent Document 1, the rope stretched between the trolley and the hoist can provide a steadying effect for the hoist.

For example, in the crane described in Patent Document 1, when considering improving the steadying effect in the short side direction, it was necessary to widen the upper interval of the rope stretched in a V-shape along the short side direction. In this case, it was necessary to make the trolley larger along the short side.

Japanese Patent Application Publication No. 2015-193462

The present invention has been made in view of the above-mentioned problems, and its purpose is to provide a crane and a rope tensioning method for a crane that can improve the swaying effect in the short side direction of the hanging device without increasing the size of the trolley. It is.

A crane for achieving the above purpose includes a lifting device that is formed into a substantially rectangular shape having a pair of long sides and a pair of short sides in a plan view, and has a plurality of lower sheaves installed therein, and In the crane, the crane includes a trolley that is disposed in a trolley and has a plurality of upper sheaves installed thereon, and a rope that is routed around the lower sheave and the upper sheave to suspend the hanging tool from the trolley, the rope comprising: The short side direction rope Rx is stretched along the short side direction which is the direction in which the short side extends, and the long side direction rope R is stretched along the long side direction which is the direction in which the long side is extended. The lower sheave is configured such that its axial direction is parallel to the long side direction, and is located near both ends of the hanging tool in the long side direction, and approximately at the center of the hanging tool in the short side direction. The upper sheave is made up of four lower sheaves Sax, which are installed at positions such that the short-side direction ropes Rx are wound around them, and four lower sheaves Sa, around which the long-side direction ropes R are wound around. , an upper sheave Sbx around which the short side direction rope Rx is wound, and an upper sheave Sb around which the long side direction rope R is wound around, and the short side direction rope Rx is arranged at intervals in the short side direction. It has a configuration in which the upper sheave Sbx and the lower sheave Sax are arranged on the trolley with a gap between them, and the long side direction rope R is routed from the trolley toward the lower sheave Sa. and a second portion extending from the lower sheave Sa toward the upper sheave Sb , and the position of the hanging tool in the vertical direction when viewed in a direction parallel to the short side direction. Regardless, the first part becomes a vertical state where it is stretched within a range of ±5 degrees with respect to the vertical direction, and the second part becomes an inclined state where it is stretched in a state that is inclined with respect to the first part, and the long side direction When viewed in a parallel direction, the second part is in a vertical state stretched within a range of ±5 degrees with respect to the vertical direction, regardless of the position of the hanging tool in the vertical direction, and the first part becomes the second part. The two lower sheaves Sa installed on the hanging tool are spaced apart from each other in the long side direction when viewed in a direction parallel to the short side direction. and two upper sheaves Sb installed on the trolley at intervals in the long side direction, and the two lower sheaves Sa are arranged inside the two upper sheaves Sb in the long side direction. The second portion extending from one of the lower sheaves Sa toward one of the upper sheaves Sb and the second portion extending from the other of the lower sheaves Sa toward the other of the upper sheaves Sb intersect with each other. It is characterized by not

A rope tensioning method for a crane to achieve the above object includes a lifting device that is formed into a substantially rectangular shape having a pair of long sides and a pair of short sides in a plan view, and is provided with a plurality of lower sheaves; A crane that is provided with a trolley that is placed above the hanging tool and has a plurality of upper sheaves installed thereon, and a rope that is passed around the lower sheave and the upper sheave and suspends the lifting tool from the trolley. In the rope tensioning method, the rope includes a short side direction rope Rx stretched along the short side direction which is the extension direction of the short side, and a short side direction rope Rx stretched along the long side direction which is the extension direction of the long side. The lower sheave is configured with a longitudinal rope R stretched in the longitudinal direction. four lower sheaves Sax installed at substantially central positions of the hanging tool in the side direction and around which the short side direction ropes Rx are wound; and four lower sheaves Sax around which the long side direction ropes R are wound. The upper sheave is composed of an upper sheave Sbx around which the short side direction rope Rx is wound, and an upper sheave Sb around which the long side direction rope R is wound around, and the upper sheave When the rope is passed from the lower sheave to the upper sheave, the short side direction rope Rx connects the upper sheave Sbx, which is arranged on the trolley at intervals in the short side direction, and the lower sheave. The rope R in the long side direction extends from the trolley toward the lower sheave Sa regardless of the position of the hanging tool in the vertical direction when viewed in a direction parallel to the short side direction. The first part extending from the lower sheave Sa to the upper sheave Sb is tensioned so as to be within a range of ±5 degrees with respect to the vertical direction, and the second part extending from the lower sheave Sa toward the upper sheave Sb is tensioned so as to be inclined with respect to the first part. and the second part is stretched in a range of ±5 degrees with respect to the vertical direction, regardless of the position of the hanging tool in the vertical direction when viewed in a direction parallel to the long side direction. At the same time, when the first part is stretched so as to be inclined with respect to the second part, and when viewed in a direction parallel to the short side direction, the two lower parts are attached to the hanging tool with an interval in the long side direction. A sheave Sa is installed, the two upper sheaves Sb are installed on the trolley at intervals in the long side direction, and the two lower sheaves Sa are placed inside the two upper sheaves Sb in the long side direction. and the second portion extends from one of the lower sheaves Sa toward one of the upper sheaves Sb , and the second portion extends from the other of the lower sheaves Sa toward the other of the upper sheaves Sb . They are characterized by not intersecting each other.

According to the present invention, since the rope stretched along the long side of the hanging device has a portion that is inclined also in the short side direction, the anti-vibration effect in the short side direction of the hanging device is improved. It is advantageous to do so.

FIG. 2 is an explanatory diagram illustrating, in perspective, the state of a rope stretched between a trolley and a hanging tool. FIG. 2 is an explanatory diagram showing a state of a rope stretched in the short side direction of FIG. 1; It is an explanatory view showing the state of the rope stretched in the long side direction of Drawing 1. FIG. 4 is an explanatory diagram illustrating the view of arrow AA in FIG. 3; FIG. 4 is an explanatory diagram illustrating the view of arrow BB in FIG. 3; FIG. 5 is an explanatory diagram illustrating the CC arrow view of FIG. 4; FIG. 4 is an explanatory diagram illustrating an enlarged example of the lower sheave in FIG. 3; 4 is an explanatory diagram illustrating a modification of FIG. 3. FIG. FIG. 9 is an explanatory diagram illustrating the view from the DD arrow in FIG. 8; FIG. 9 is an explanatory diagram illustrating the view of arrow EE in FIG. 9;

Hereinafter, a crane and a rope tensioning method for the crane will be described based on the embodiment shown in the drawings. In the figure, the short side direction, which is the extension direction of the short side of the hanging tool, is indicated by arrow x, and the long side direction, which is a direction that crosses this short side direction x at right angles and is also the extension direction of the long side of the hanging tool, is indicated by arrow y. The vertical direction is indicated by an arrow z.

As illustrated in FIG. 1, the crane 1 includes a trolley 2 that moves along a horizontal beam, and a hanging tool 3 suspended from the trolley 2 via a rope R. In FIG. 1, the trolley 2 is shown by a broken line for explanation. The crane 1 is composed of, for example, a gantry crane. The crane 1 is not limited to this, and may be any crane provided with a trolley 2 and a hanging device 3, and may be configured with a quay crane, an unloader, or an overhead crane, for example.

The hanging device 3 includes, for example, a spreader for handling containers, a bucket for handling loose cargo such as ore, and the like. The hanging device 3 may be composed of a head block connected to the upper surface of the spreader. In this embodiment, the hanging device 1 is comprised of a spreader for handling a 20ft container. This spreader can also slide in the long side direction to handle a 40ft container. The hanging tool 3 is formed into a substantially rectangular shape having a pair of long sides and a pair of short sides when viewed from above. For example, the crane 1 is configured such that the long side direction y is parallel to the traveling direction of the crane 1, and the short side direction x is parallel to the traverse direction, which is the moving direction of the trolley 2. A plurality of lower sheaves Sa are installed on the upper surface of the hanging tool 3.

The trolley 2 is arranged above the hanging tool 3. The trolley 2 has a configuration in which it traverses in the short side direction x along a horizontal beam (not shown). A plurality of upper sheaves Sb are installed on the trolley 2. A rope R is stretched between the upper sheave Sb of the trolley 2 and the lower sheave Sa of the hanging tool 3. The hanging tool 3 is suspended from the trolley 2 by this rope R.

A drum 4 for feeding out and winding up the rope R is installed on the upper surface of the trolley 2. In this embodiment, the drum 4 is arranged so that its axial direction is parallel to the long side direction y, and at a position that is approximately at the center of the trolley 2 in the short side direction x. Two drums 4 are installed on the trolley 2. A speed reducer 5 is arranged between the two drums 4 to transmit the rotational force received from the motor to the drum 4. The reduction gear 5 allows the two drums 4 to rotate in the same direction and at the same speed.

The configuration of the drum 4 is not limited to the above. The two drums 4 may each have a reduction gear 5, and the rotating direction and rotation speed may be controlled respectively. Further, the drum 4 may be composed of one drum disposed approximately at the center of the trolley 2 in the short side direction x with the long side direction y as the axial direction, or one or more drums with the short side direction x as the axial direction. It may also consist of two drums.

In this embodiment, four tilting mechanisms J are installed on the trolley 2. The tilting mechanism J is installed approximately at the center of the trolley 2 in the long side direction y, and near both ends of the trolley 2 in the short side direction x. The tilting mechanism J is composed of an electric jack that is extendable and retractable along the long side direction y. The tilting mechanism J is not limited to this, and may have a function of varying the tension of the connected rope R. The tilting mechanism J can be configured, for example, by a combination of a sheave and a link mechanism, a telescoping cylinder, or a combination of a telescoping cylinder and a sheave.

As illustrated in FIG. 2, the four lower sheaves Sax (Sax1, Sax2, Sax3, Sax4) are installed on the hanger 3 with their axial directions parallel to the long side direction y. Lower sheaves Sax1 and Sax2 and lower sheaves Sax3 and Sax4 are installed at positions near both ends of the hanging tool 3 in the long side direction y, respectively. The lower sheave Sax is installed at a position approximately in the center of the hanging tool 3 in the short side direction x.

The four upper sheaves Sbx (Sbx1, Sbx2, Sbx3, Sbx4) are installed on the trolley 2 with the axial direction thereof being the short side direction x. Upper sheaves Sbx1 and Sbx2 and upper sheaves Sbx3 and Sbx4 are installed at positions near both ends of the trolley 2 in the long side direction y, respectively. The upper sheave Sbx1 and the upper sheave Sbx2 are respectively installed at positions near both ends of the trolley 2 in the short side direction x. Similarly, the upper sheave Sbx3 and the upper sheave Sbx4 are respectively installed at positions near both ends of the trolley 2 in the short side direction x.

A rope Rx1 let out from one of the drums 4 and stretched along the short side direction x is passed around the lower sheave Sax1 and the upper sheave Sbx1, and its end portion is connected to the tilting mechanism J1. The rope Rx2 let out from the drum 4 is passed around the lower sheave Sax2 and the upper sheave Sbx2, and its end is connected to the tilting mechanism J2.

Similarly to the above, the rope Rx3 let out from the other drum 4 and stretched along the short side direction x is passed around the lower sheave Sax3 and the upper sheave Sbx3, and its end is connected to the tilting mechanism J1. . The rope Rx4 let out from the drum 4 is passed around the lower sheave Sax4 and the upper sheave Sbx4, and its end is connected to the tilting mechanism J2.

As illustrated in FIG. 3, the four lower sheaves Sa (Sa1, Sa2, Sa3, Sa4) are installed on the hanger 3 with their axial directions inclined from the short side direction x toward the long side direction y. That is, the axial direction of the lower sheave Sa is, for example, a direction inclined at a predetermined angle from the short side direction x with the vertical direction z as the central axis. The axial direction of the lower sheave Sa is a direction that is not parallel to either the short side direction x or the long side direction y. Lower sheaves Sa1 and Sa3 and lower sheaves Sa2 and Sa4 are installed at positions near both ends of the hanging tool 3 in the short side direction x, respectively. The lower sheave Sa1 and the lower sheave Sa3 are located inside both ends of the hanging tool 3 in the long side direction y, and are installed at intervals in the long side direction y. Similarly, the lower sheave Sa2 and the lower sheave Sa4 are installed with an interval in the long side direction y.

The four upper sheaves Sb (Sb1, Sb2, Sb3, Sb4) are installed on the trolley 2 with their axial directions aligned in the short side direction x. The four upper sheaves Sb are installed at intervals in the long side direction y and the short side direction x. For example, upper sheaves Sb are installed near both ends of the trolley 2 in the long side direction y and near both ends of the trolley 2 in the short side direction x when viewed from above.

A rope R1 let out from one of the drums 4 and stretched along the long side direction y is passed around the lower sheave Sa1 and the upper sheave Sb1, and its end portion is connected to the tilting mechanism J3. The rope R3 let out from the other drum 4 is passed around the lower sheave Sa3 and the upper sheave Sb3, and its end is connected to the tilting mechanism J3.

Similarly to the above, the rope R2 let out from one of the drums 4 is passed around the lower sheave Sa2 and the upper sheave Sb2, and its end is connected to the tilting mechanism J4. The rope R4 let out from the other drum 4 is passed around the lower sheave Sa4 and the upper sheave Sb4, and its end is connected to the tilting mechanism J4.

As illustrated in FIG. 4, the rope R1 let out from one drum 4 has a first portion 6 extending from the drum 4 installed on the trolley 2 to the lower sheave Sa1, and a second portion 7 extending from the lower sheave Sa1 to the upper sheave Sb1. It has

As illustrated in FIG. 4, when viewed in the short side direction x, the first portion 6 is approximately parallel to the vertical direction z. Hereinafter, the state of the rope R stretched substantially vertically like this first portion 6 may be referred to as a vertical state. The second portion 7 is in a state of being inclined with respect to the first portion 6. Hereinafter, the state of the rope R that is stretched in any direction with respect to the vertical direction z like the second portion 7 may be referred to as a tilted state. In this specification, the vertical state includes a state where the rope R is slightly inclined, for example, by ±5 degrees with respect to the vertical direction z. The tilted state includes not only a state in which the rope R is tilted by, for example, ±45 degrees with respect to the vertical direction z, but also a state in which the rope R is tilted more than the vertical state of the rope R. For example, when the inclination of the rope R in the vertical state is ±0 degrees, the inclination of the rope R in the inclined state can be, for example, within the range of ±3 degrees.

As illustrated in FIG. 4, in the rope R1 and the rope R3, a horizontal force corresponding to the tension is generated from the respective second portions 7 that are in an inclined state. Since this force is generated in directions that cancel each other out along the long side direction y, swinging of the hanging tool 3 in the long side direction y can be suppressed.

As illustrated in FIG. 5, when viewed in the long side direction y, the second portion 7 is substantially parallel to the vertical direction z, and is in a vertical state. The first portion 6 is in an inclined state with respect to the second portion 7. A horizontal force corresponding to the tension is generated from the first portion 6 which is in an inclined state. Since this force is generated in directions that cancel each other out along the short side direction x, swinging of the hanger 3 in the short side direction x can be suppressed.

In addition to the ropes Rx1-Rx4 stretched along the short side direction x (see Figure 2), the ropes R1-R4 stretched along the long side direction y (see Figure 5) are also connected to the short side direction x. You can get a steadying effect. This is advantageous in improving the steadying effect in the short side direction x.

The plane defined by the first part 6 and the second part 7 constitutes a triangular truss structure. This triangle is formed by the respective ropes R1-R4, which are congruent with each other. Since the four congruent triangles generate forces that cancel each other out in the horizontal direction, this is advantageous in improving the steadying effect of the hanging tool 3.

The rope R may be replaced due to deterioration over time. Since the ropes R1 to R4 have the same length when the hanging tool 3 is horizontal, the tension can be easily adjusted after rope replacement. This is advantageous in improving the workability of rope replacement work.

When the tilting mechanism J can independently control the tension of the rope R connected to both ends, shift control, trim control, and skew control of the hanging tool 3 can be performed.

As illustrated in FIG. 3, for example, when the tilting mechanism J is composed of an electric jack that can independently control the amount of expansion and contraction at both ends, the tilting mechanisms J3 and J4 are extended in the same direction in the long side direction y. Then, the hanging tool 3 shifts in the direction of the extension. In FIG. 4, when the right side of the tilting mechanisms J3 and J4 is extended, the hanging tool 3 moves in parallel to the right, and when the left side of the tilting mechanisms J3 and J4 is extended, the hanging tool 3 moves to the left. Move in parallel. This shift control is not limited to the above, but if a tension difference is created between the rope R1 and the rope R3, and between the rope R2 and the rope R4, the hanging tool 3 is shifted in a direction where the tension is relatively small. .

In FIG. 1, when all four tilting mechanisms J are extended in the same direction, the tension of the rope R on the extended side is reduced and the hanging tool 3 is lowered. Of both ends of the hanger 3 in the long side direction y, the end on the side where the tilting mechanism J is extended is lowered. Trim control that controls the inclination of the hanger 3 with the short side direction x as the central axis becomes possible.

In the case of a configuration in which the rotation direction and rotation speed of the two drums 4 are independently controlled, trim control can be performed by adjusting the tension of the rope R using the drums 4. If the configuration is such that only trim control can be performed, the tilting mechanism J may not be provided.

In FIG. 2, when the tilting mechanisms J1 and J2 are extended in mutually opposite directions, the hanger 3 moves to the extended side in the short side direction x. Since the pair of short sides move in opposite directions, it is possible to perform skew control to control the rotation of the hanger 3 about the vertical direction z as the central axis.

It is desirable that the crane 1 be configured to perform all of shift control, trim control, and skew control. However, depending on the type of crane 1 and the content of cargo handling work, the crane 1 may be configured to be able to perform at least one of shift control, trim control, and skew control. Further, if there is no need to perform any of the controls, the crane 1 may be provided without the tilting mechanism J.

As illustrated in FIG. 6, the four lower sheaves Sa1-Sa4 around which the ropes R1-R4 stretched along the long side direction y are wound are arranged at positions closer to the inside in the long side direction y. The distance L1 between the axes of the pair of lower sheaves Sa1 and lower sheaves Sa3 in the long side direction y is set in a range of 20 to 80% of the length L0 of the long side of the hanging tool 3. It is desirable that the interval L1 be set within a range of 20 to 50% of the length L0 of the long side. Note that the length L0 of the long side of the hanging device 1 is based on the size of a spreader for handling a 20 ft container. In the case of a spreader extended to handle a 40ft container, the length of the long side is approximately twice the length of L0, so the interval L1 is 10 to 40% of the length of the long side of the hanging device 1, preferably 10%. It is set in the range of ~25%.

It is desirable that the four lower sheaves Sa1 to Sa4 be installed at positions corresponding to the respective vertices of a substantially rectangular shape formed inside the hanger 3 in plan view. In FIG. 6, the aforementioned substantially rectangular shape is shown by a broken line for explanation. The area of the rectangle indicated by the broken line is set to be smaller than the area of the hanging tool 3 in plan view. The long sides of the rectangle shown by broken lines are parallel to the long sides of the hanging tool 3, and the short sides of the rectangle shown by broken lines are parallel to the short sides of the hanging tool 3. The lower sheave Sa is arranged such that the axis of the lower sheave Sa coincides with each vertex of the rectangle indicated by the broken line.

According to this configuration, the lower sheave Sa is arranged inside the four corners of the hanging tool 3, so that the resistance to rotation of the hanging tool 3 about the vertical direction z can be reduced. Since the rope R is less likely to resist the skew control of the hanging tool 3, it becomes easier to obtain the effect of skew control.

As illustrated in FIG. 6, the axial direction of the lower sheave Sa is set in a substantially horizontal direction that is not parallel to either the long side direction y or the short side direction x. In FIG. 6, the axial direction of the lower sheave Sa is shown by a chain line for explanation. The angle θ between the axial direction of the lower sheave Sa and the short side direction x can be set, for example, in the range of 10 degrees to 60 degrees or -10 degrees to -60 degrees. This angle θ is not limited to this, and can be changed as appropriate depending on the position where the rope R1 is let out from the drum 4 and the position where the upper sheave Sb1 is placed in plan view.

In the embodiment illustrated in FIG. 6, each lower sheave Sa is installed on the hanger 3 such that the axial direction of the lower sheave Sa shown by the dashed line intersects on the outside of the rectangle shown by the broken line. That is, the axial directions of adjacent lower sheaves Sa intersect on the outside of the quadrangle formed by the four lower sheaves Sa.

As illustrated in FIG. 7, the lower sheave Sa may be installed on a support stand 8 that tilts along the axial direction of the lower sheave Sa. In this embodiment, the support stand 8 supports the lower sheave Sa so as to be tiltable only in one direction (to the right in FIG. 7). In FIG. 7, the tilting direction of the lower sheave Sa is indicated by an arrow for explanation. Similarly, in FIG. 6, the tilting direction of the lower sheave Sa is indicated by an arrow. The support stand 8 can tilt the lower sheave Sa in the range of, for example, 0 degrees to 10 degrees with respect to the vertical direction z. As illustrated in FIG. 6, the lower sheaves Sa arranged at intervals in the short side direction x tilt in a direction toward each other. The lower sheave Sa is passively tilted by the tension of the rope R that is wrapped around it.

As illustrated in FIG. 4, the position where the rope R1 is let out from the drum 4 moves in the axial direction of the drum 4 depending on the amount of the rope R1 let out. Therefore, the first portion 6 of the rope R1 is inclined along the long side direction y. Since the lower sheave Sa1 is tilted accordingly, it becomes easier to avoid a problem in which the angle of the rope R1 with respect to the lower sheave Sa exceeds the range of the fleet angle. Since the rope R can be stretched directly from the drum 4 to the lower sheave Sa, the number of sheaves can be reduced. This is advantageous in reducing the manufacturing cost of the crane 1.

The smaller the diameter of the drum 4, the easier the position at which the rope R is let out from the drum 4 moves in the axial direction of the drum 4. Since the lower sheave Sa can be tilted in accordance with the movement of the rope R, it is also possible to make the diameter of the drum 4 relatively small. Since the reduction ratio of the drum 4 can be made small, it is advantageous for reducing the size of the reduction gear 5.

In the present invention, the support stand 8 is not an essential component. If the diameter of the drum 4 is made relatively large, the amount of movement of the rope R in the axial direction of the drum 4 will be reduced, so a lower sheave Sa that does not tilt can be used. Furthermore, by installing a sheave on the trolley 2 and passing the rope R around the lower sheave Sa via this sheave, the lower sheave Sa is not affected by the movement of the rope R in the axial direction of the drum 4. It can be done. In this case as well, the lower sheave Sa that does not tilt can be used.

The lower sheave Sa illustrated in FIG. 7 has a configuration that tilts only to the right in FIG. 7 and does not tilt to the left. Since the lower sheave Sa is configured to tilt only in one direction, it becomes easier to suppress problems such as the lower sheave Sa tilting in the other direction and amplifying vibrations when vibration occurs in the hanging tool 3. The present invention does not exclude a configuration in which the lower sheave Sa is tilted to both sides in the axial direction.

As illustrated in FIGS. 8 and 9, after the rope R1 is passed from the lower sheave Sa1 to the upper sheave Sb1, another upper sheave Sb1' whose axial direction is in the vertical direction z is passed around the rope R1 to the tilting mechanism J3. It may also be configured to be stretched.

As illustrated in FIG. 10, it is preferable that the four lower sheaves Sa1 to Sa4 be installed at positions corresponding to respective vertices of a substantially rectangular shape formed inside the hanger 3 in plan view. In FIG. 10, the above-mentioned substantially rectangle is shown by a broken line for explanation. Further, the direction in which the lower sheave Sa is tilted is indicated by an arrow.

In the embodiment illustrated in FIG. 10, unlike the embodiment illustrated in FIG. 6, each lower sheave Sa is installed on the hanging tool 3 in such a state that the axial direction of the lower sheave Sa indicated by the dashed line intersects inside the rectangle indicated by the broken line. has been done. That is, the axial directions of adjacent lower sheaves Sa intersect inside the quadrangle formed by the four lower sheaves Sa.

As illustrated in FIG. 9, all or part of the pair of second portions 7 are arranged between the pair of first portions 6 in the long side direction y. The ropes R1 to R4 stretched along the long side direction y are stretched close to the center of the hanging tool 3 in plan view. Since the rope R is less likely to resist the skew control by the tilting mechanism J, it becomes easier to obtain the effect of skew control.

For example, when the driver's cab is installed near the trolley 2 of a gate-type crane, the embodiment illustrated in FIG. It becomes easier. Therefore, in the case of the crane 1 in which the operator's seat is installed near the trolley 2, the embodiment illustrated in FIG. 4 is more preferable than the embodiment illustrated in FIG. 9. Furthermore, the embodiment illustrated in FIG. 4 can reduce the number of sheaves S, which is advantageous in reducing the manufacturing cost of the crane 1.

The first portion 6 is not limited to the configuration extending from the drum 4 to the lower sheave Sa. The first portion 6 may be formed by a portion that is let out from the drum 4, is wrapped around the upper sheave Sb, and extends from the upper sheave Sb to the lower sheave Sa. In other words, the first portion 6 may be any portion of the rope R extending from the trolley 2 toward the lower sheave Sa. The upper end of the first portion 6 may extend to either the drum 4 or the upper sheave Sb.

1 Crane 2 Trolley 3 Hanging tool 4 Drum 5 Reducer 6 First part 7 Second part 8 Support base x Short side direction y Long side direction z Vertical direction R Rope Rx1-4 Short side direction rope R1-4 Long side direction rope Sa Lower sheave Sa1-4 Lower sheave (long side direction)
Sax, Sax1-4 Lower sheave (short side direction)
Sb Upper sheave Sb1-4, Sb1'-Sb4' Upper sheave (long side direction)
Sbx, Sbx1-4 Upper sheave (short side direction)
J, J1-4 Tilt mechanism

Claims (6)

A hanging device that is formed into a substantially rectangular shape having a pair of long sides and a pair of short sides when viewed from above and has a plurality of lower sheaves installed thereon, and a plurality of upper sheaves placed above the hanging device. A crane comprising a trolley, and a rope that is routed around the lower sheave and the upper sheave to suspend the hanging tool from the trolley,
The rope includes a short side direction rope Rx stretched along the short side direction which is the extension direction of the short side, and a long side direction rope Rx stretched along the long side direction which is the extended direction of the long side. It consists of a rope R,
The lower sheave is installed in a state in which the axial direction is parallel to the long side direction, and is located near both ends of the hanging tool in the long side direction, and at a position that is approximately at the center of the hanging tool in the short side direction. and four lower sheaves Sax around which the short side direction ropes Rx are wound, and four lower sheaves Sa around which the long side direction ropes R are wound.
The upper sheave is composed of an upper sheave Sbx around which the short-side direction rope Rx is passed around, and an upper sheave Sb around which the long-side direction rope R is passed around,
The short side direction rope Rx is configured to be wound around the upper sheave Sbx and the lower sheave Sax, which are arranged on the trolley at intervals in the short side direction,
The longitudinal rope R has a first portion extending from the trolley toward the lower sheave Sa , and a second portion extending from the lower sheave Sa toward the upper sheave Sb ,
When viewed in a direction parallel to the short side direction, the first portion is in a vertical state stretched within a range of ±5 degrees with respect to the vertical direction regardless of the position of the hanging tool in the vertical direction, and the second portion is in a vertical state. is in an inclined state where it is stretched in a state where it is inclined with respect to the first part,
When viewed in a direction parallel to the long side direction, the second portion is in a vertical state stretched within a range of ±5 degrees with respect to the vertical direction regardless of the position of the hanging tool in the vertical direction, and the first portion is in a tilted state where it is stretched in a state where it is tilted with respect to the second part,
When viewed in a direction parallel to the short side direction, the two lower sheaves Sa are installed on the hanging fixture at intervals in the long side direction, and the two lower sheaves Sa are installed on the trolley at intervals in the long side direction. the two upper sheaves Sb , and the two lower sheaves Sa are arranged inside the two upper sheaves Sb in the long side direction, and the lower sheave Sa is connected to the upper sheave Sb . A crane characterized in that the second portion extending toward the other upper sheave Sb and the second portion extending from the other lower sheave Sa toward the other upper sheave Sb do not intersect with each other. The lower sheave Sa has a configuration that is installed at a position corresponding to each vertex of a substantially rectangular shape formed inside the hanging tool in a plan view,
The crane according to claim 1 , wherein the lower sheave Sax is arranged outside a substantially rectangular shape formed by the four lower sheaves Sa. When viewed in a direction parallel to the short side direction, the distance between the axes of the two lower sheaves Sa installed on the hanging tool with an interval in the long side direction is equal to the length of the long side of the hanging tool. The crane according to claim 2, wherein the crane is set within a range of 20 to 80% of its height. It has a drum that is installed on the trolley and that pays out and winds up the rope,
The drum has a configuration in which the axial direction of the drum is parallel to the long side direction and is installed at a substantially central position in the short side direction,
The crane according to any one of claims 1 to 3, wherein a portion of the rope linearly connecting the drum and the lower sheave Sa is the first portion . The lower sheave Sa is provided with a support base that supports the lower sheave Sa in a state where the axial direction of the lower sheave Sa is between the short side direction and the long side direction in a plan view, The crane according to any one of claims 1 to 4, wherein the support base has a structure for supporting the crane in a state where it can be tilted only in one direction . A hanging device that is formed into a substantially rectangular shape having a pair of long sides and a pair of short sides when viewed from above and has a plurality of lower sheaves installed thereon, and a plurality of upper sheaves placed above the hanging device. A rope tensioning method for a crane comprising: a trolley that is attached to a crane; and a rope that is routed around the lower sheave and the upper sheave and suspends the hanging tool from the trolley,
The rope includes a short side direction rope Rx stretched along the short side direction which is the extension direction of the short side, and a long side direction rope Rx stretched along the long side direction which is the extended direction of the long side. It consists of a rope R,
The lower sheave is installed in a state in which the axial direction is parallel to the long side direction, and is located near both ends of the hanging tool in the long side direction, and at a position that is approximately at the center of the hanging tool in the short side direction. and four lower sheaves Sax around which the short side direction ropes Rx are wound, and four lower sheaves Sa around which the long side direction ropes R are wound.
The upper sheave is composed of an upper sheave Sbx around which the short-side direction rope Rx is passed around, and an upper sheave Sb around which the long-side direction rope R is passed around,
When the rope is routed from the trolley to the upper sheave via the lower sheave,
The short side direction rope Rx is wound around the upper sheave Sbx and the lower sheave Sax which are arranged on the trolley at intervals in the short side direction,
When the long-side rope R is viewed in a direction parallel to the short-side direction, the first portion extending from the trolley toward the lower sheave Sa is relative to the vertical direction regardless of the position of the hanging tool in the vertical direction. and the second portion extending from the lower sheave Sa toward the upper sheave Sb is stretched in a state where the second portion is inclined with respect to the first portion,
When viewed in a direction parallel to the long side direction, the second portion is stretched in a range of ±5 degrees with respect to the vertical direction regardless of the position of the hanging tool in the vertical direction, and the first portion is stretched. is stretched in a state that is inclined with respect to the second part,
When viewed in a direction parallel to the short side direction, the two lower sheaves Sa are installed on the hanging fixture at intervals in the long side direction, and the two lower sheaves Sa are installed on the trolley at intervals in the long side direction. The upper sheave Sb is installed, and the two lower sheaves Sa are arranged inside the two upper sheaves Sb in the long side direction, and from one of the lower sheaves Sa toward one of the upper sheaves Sb. A rope tensioning method characterized in that the second extending portion and the second portion extending from the other lower sheave Sa toward the other upper sheave Sb do not intersect with each other.

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