Crane and method for lowering the boom of the crane

Abstract

To provide a crane capable of appropriately derricking a boom while suppressing the damage of a pendant rope.SOLUTION: A crane 1 comprises a boom 4 and a pendant rope 6 to derrickably suspend and support the boom 4. A longitudinal direction of the pendant rope 6 is held parallel to a boom derricking surface on which the boom 4 performs a derricking operation when the pendant rope 6 suspends and supports the boom 4.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a crane and a method for lowering a boom of the crane. [Background technology]

[0002] 2. Description of the Related Art Cranes that raise and lower a boom using a pendant rope that suspends the boom are known. In this type of crane, the tip of the boom is generally tapered, so when the boom is suspended by a pair of pendant ropes, for example, the pendant ropes will be inclined relative to the boom (see, for example, Patent Document 1).

[0003] If the pendant rope is inclined relative to the boom, there is a risk that the widthwise position of the pendant rope placed on the boom will change when the boom is raised from a collapsed state and then collapsed again.

[0004] A bracket is provided on the boom to support the pendant rope, but if the widthwise position of the pendant rope on the boom changes, the pendant rope will no longer be properly placed on the bracket. As a result, the pendant rope may come into contact with parts of the bracket other than the rope support part or with the boom, which may be damaged. One option would be to make the bracket larger, but it would be difficult to simply make it larger because of the need to ensure space for workers to move around. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Utility Model Application Publication No. 62-29384 Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention has been made in consideration of the above circumstances, and has an object to preferably raise and lower a boom while suppressing damage to the pendant rope, etc. [Means for solving the problem]

[0007] The present invention relates to a crane, Boom and A pendant rope that suspends and supports the boom so that it can be raised and lowered, When the pendant rope is supporting the boom, the longitudinal direction of the pendant rope is held parallel to the boom hoisting surface on which the boom is hoisted. 、 The pendant rope is provided in a pair spaced apart in the width direction of the boom, A spacer member is provided to maintain the space between the pair of pendant ropes in the width direction, Each of the pair of pendant ropes includes a base end rope arranged on the base end side of the boom, and a tip end rope arranged on the tip end side of the boom adjacent to the base end rope and connected to the base end rope, The spacing member maintains a state in which the distance between the pair of base end ropes and the distance between the pair of tip end ropes are different when the pendant ropes support the boom. The composition was as follows.

[0008] The present invention also provides a crane, Boom and A pendant rope that suspends and supports the boom so that it can be raised and lowered, The pendant rope is provided in a pair spaced apart in the width direction of the boom, Each of the pair of pendant ropes includes a base end rope arranged on the base end side of the boom, and a tip end rope arranged on the tip end side of the boom adjacent to the base end rope and connected to the base end rope, The boom is configured to have a spacing maintaining member that maintains a state in which the distance between a pair of the base end ropes and the distance between a pair of the tip end ropes are different when the boom is suspended by the pendant rope.

[0009] The present invention also provides a method for producing a method for manufacturing a semiconductor device comprising the steps of: the above A method for lowering a boom of a crane, comprising the steps of: The pendant rope is connected to the boom in a state where the longitudinal direction of the pendant rope is parallel to a boom hoisting surface on which the boom is hoisted, When the boom is lowered from an upright state by the pendant rope while the pendant rope is held parallel to the boom hoisting surface, the pendant rope is placed on a bracket provided on the boom, The pendant rope is fixed to the bracket. Effect of the Invention

[0010] According to the present invention, the boom can be raised and lowered suitably while suppressing damage to the pendant rope, etc. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a side view that illustrates a crane according to an embodiment. [Diagram 2] FIG. 2(a) is a side view of the crane with the pendant rope placed on the lowered boom, and FIG. 2(b) is a plan view of the boom and pendant rope of FIG. 2(a). [Diagram 3] 1A is a plan view showing the end of a unit boom, and FIG. 1B is a view of the upper part of FIG. [Figure 4] 1A and 1B are plan views of a spreader, in which (a) shows a state in which a link in the widthwise center is closed, and (b) shows a state in which the link is open. [Diagram 5] 4 is a flowchart showing a flow of a method for assembling the crane according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

[0013] [Crane outline] Fig. 1 is a side view showing a crane 1 according to this embodiment. For ease of understanding, a pendant rope 6, which will be described later, is shown by a thick line in Fig. 1 and Fig. 2. As shown in Fig. 1, the crane 1 is a so-called mobile crawler crane. Specifically, the crane 1 includes a self-propelled crawler-type lower traveling body 2, an upper rotating body 3 rotatably mounted on the lower traveling body 2, and a boom 4 attached to the front side of the upper rotating body 3 so as to be able to rise and fall. In the following description, the front, rear, left and right directions as seen by a passenger on the upper rotating body 3 are defined as the front, rear, left and right directions of the crane 1.

[0014] A base end of a boom 4 is supported on the front side of the upper rotating body 3. In addition, a base end of a mast 31 is supported on the rear side of the boom support position on the upper rotating body 3. A counterweight 5 for balancing the weight of the boom 4 and the suspended load is attached to the rear of the upper rotating body 3.

[0015] The boom 4 is attached to the upper rotating body 3 so as to be able to rise and fall about its base end. The boom 4 comprises a lower boom 41 on the base end side, an upper boom 42 on the tip end side, and an intermediate boom 43 therebetween. The lower boom 41, the upper boom 42, and the intermediate boom 43 are detachably connected to each other, and the intermediate boom 43 is configured by detachably connecting a plurality of (three in this embodiment) intermediate boom blocks 431. In this specification, among these divided smallest blocks of the boom 4, those excluding the lower boom 41 (i.e., the upper boom 42 and the intermediate boom block 431) are referred to as "unit booms." In other words, the boom 4 is configured by detachably connecting a plurality of unit booms 40 to the lower boom 41 in the extension direction (longitudinal direction) X. In such a boom 4, the length can be adjusted by increasing or decreasing the number of intermediate boom blocks 431. In addition, the upper boom 42 is tapered in the width direction Y (left and right direction) toward the tip side in the extension direction X (at least the width at the tip side is smaller than the width of the intermediate boom 43) (see Figure 2 (b)).

[0016] One end of a pendant rope 6 that suspends and supports the boom 4 so that it can be raised and lowered is connected to the tip (upper end) of the boom 4. The other end of the pendant rope 6 is connected to an upper spreader 311 at the upper end of the mast 31. The specific configuration of the pendant rope 6 will be described later. A lower spreader (not shown) is provided at the rear of the upper rotating body 3, and a hoisting rope 33 is wound multiple times between the upper spreader 311 and the lower spreader. The hoisting rope 33 is wound around a hoisting winch (not shown) on the upper rotating body 3, and when the hoisting rope 33 is wound up or unwound by this hoisting winch, the distance between the upper spreader 311 and the lower spreader changes, causing the mast 31 to tilt and the boom 4 to be raised or lowered.

[0017] In addition, sheaves 441, 442 are provided at the tip of the boom 4, and one end of a hoisting rope 35 is connected to a hook 36 via the sheaves 441, 442. The other end of the hook 36 is wound around a hoisting winch (not shown) on the upper rotating body 3, and the hook 36 is raised and lowered by driving the hoisting winch.

[0018] The crane 1 having the above-mentioned configuration is configured to be able to be assembled and disassembled for the purpose of facilitating transportation, etc. Here, "able to be assembled and disassembled" means that it is at least possible to reversibly attach and detach.

[0019] [Pendant rope configuration] FIG. 2(a) is a side view of the crane 1 with a pendant rope 6 placed on the lowered boom 4, and FIG. 2(b) is a plan view of the boom 4 and pendant rope 6 of FIG. 2(a). 2(a) and (b), the pendant rope 6 includes a plurality of pendant ropes (hereinafter referred to as "partial ropes 60") that form a part of the pendant rope 6, and a plurality of connecting members 65 that connect two adjacent partial ropes 60 in the extension direction X to each other in the extension direction X. In addition, the pendant ropes 6 of this embodiment are provided in a pair spaced apart from each other in the width direction Y of the boom 4, and the partial ropes 60 also form a pair on the left and right. In the following, unless otherwise specified, the term "pendant rope" refers to a "pair" of them, and the term "each pendant rope" refers to each of the left and right. A pair of partial ropes 60 may also be referred to as a "partial rope 60 pair." The same applies to the upper rope 62, middle rope 63, and lower rope 64 described below. The multiple pairs of partial ropes 60 are provided in the same quantity corresponding to the multiple unit booms 40, and include a pair of upper ropes 62 corresponding to the upper boom 42 and a pair of intermediate ropes 63 corresponding to the intermediate boom 43 (intermediate boom block 431). Therefore, the pendant rope 6 is configured by connecting the multiple pairs of partial ropes 60 (pairs of intermediate ropes 63 and upper ropes 62) to a pair of lower ropes 64 corresponding to the portion from the upper spreader 311 to the base end of the intermediate boom 43 with a connecting member 65.

[0020] In addition, when the pendant rope 6 is suspending and supporting the boom 4, its longitudinal direction is held parallel to the plane S along which the boom 4 is raised and lowered (i.e., the plane perpendicular to the central axis of rotation of the boom 4; hereinafter referred to as the "boom hoisting plane"). Therefore, among the pendant ropes 6, the pair of intermediate ropes 63 corresponding to the intermediate boom 43 (intermediate boom block 431) are linearly connected and, in this connected state, are arranged parallel to the boom hoisting surface S. Similarly, the pair of lower ropes 64 from the upper spreader 311 to the base end of the intermediate boom 43 and the pair of intermediate ropes 63 on the base end side are also linearly connected and arranged parallel to the boom hoisting surface S. On the other hand, of the pendant ropes 6, the pair of intermediate ropes 63 and the pair of upper ropes 62 at the most distal end side are connected in a stepped manner in the width direction Y of the boom 4. Specifically, the pair of intermediate ropes 63 and the pair of upper ropes 62 are connected in a stepped manner with the pair of upper ropes 62 positioned more inward in the width direction Y than the pair of intermediate ropes 63 so that the pair of upper ropes 62 is held parallel to the boom hoisting surface S in the upper boom 42 formed in a tapered shape in the width direction Y. It is sufficient that the parallel state of the pendant rope 6 is maintained at least when the boom 4 is being suspending and supporting the boom 4.

[0021] The connecting member 65 for connecting the pendant rope 6 includes a plurality of pin connecting fittings 66 and a spreader 67 . Of these, the pin connecting fitting 66, as shown in Fig. 3(a), linearly connects the intermediate ropes 63 to each other or the intermediate rope 63 and the lower rope 64. The pin connecting fitting 66 includes a fitting body 661 attached to the end of the partial ropes 60 to be connected, and a connecting pin 662 that is inserted into a hole in the fitting body 661 to pin-connect the fitting bodies 661 to each other. This pin connecting fitting 66 connects the partial ropes 60 individually one by one.

[0022] 4(a), the spreader 67 connects in a stepped manner the pair of intermediate ropes 63 closest to the tip end and the pair of upper ropes 62 that are shorter in distance in the width direction Y than the pair of intermediate ropes 63. The spreader 67 maintains the distance in the width direction Y between the pair of pendant ropes 6. Specifically, the spreader 67 includes a first connecting fitting 671, a second connecting fitting 672, a first link plate 673, a second link plate 674, and a third link plate 676. The spreader 67 has a pair of these components on each side, and is formed in a generally symmetrical shape. The first connecting fitting 671 is connected to each end of the pair of intermediate ropes 63. A fitting body 661 similar to the pin connecting fitting 66 is attached to the end of each intermediate rope 63, and the first connecting fitting 671 is pin-connected to this fitting body 661 by a connecting pin 662. The second connecting fitting 672 is connected to each end of the pair of upper ropes 62. A fitting body 661 similar to the pin connecting fitting 66 is attached to the end of each upper rope 62, and the second connecting fitting 672 is pin-connected to this fitting body 661 with a connecting pin 662. The first link plate 673 connects a pair of first connecting fittings 671, which are connected to the pair of intermediate ropes 63, in the width direction Y to maintain a gap between them. This first link plate 673 is individually attached to each of the pair of first connecting fittings 671. Then, the two first link plates 673 are disassemblably connected to each other at their tips in the center of the width direction Y by a connecting pin 675, with each first link plate 673 extending along the width direction Y. The second link plate 674 connects a pair of second connecting fittings 672 connected to the pair of upper ropes 62 in the width direction Y to maintain a gap between them. The second link plate 674 is attached to each of the pair of second connecting fittings 672 individually. The two second link plates 674 are connected to each other by a connecting pin 675 at the tip end in the center of the width direction Y in a state where they extend along the width direction Y. In addition, each second link plate 674 has a different length in the width direction Y from the first link plate 673 and is shorter than the first link plate 673. Therefore, the pair of upper ropes 62 connected by the second link plate 674 is located inside the pair of intermediate ropes 63 connected by the first link plate 673 in the width direction Y. The third link plate 676 connects the pair of first connecting fittings 671 connected by the first link plate 673 and the pair of second connecting fittings 672 connected by the second link plate 674 individually on the left and right in the extension direction X. In other words, the third link plate 676 connects the pair of intermediate ropes 63 and the pair of upper ropes 62.

[0023] The spreader 67 configured in this manner allows the pair of intermediate ropes 63 and the pair of upper ropes 62 to be connected in a stepped manner with the pair of upper ropes 62 positioned inside the pair of intermediate ropes 63 in the width direction Y. In other words, the pair of intermediate ropes 63 is held by the bracket 46 (base end rope arrangement portion) on the intermediate boom 43, and the pair of upper ropes 62 is held by the bracket 46 (tip end rope arrangement portion) on the upper boom 42 at a distance in the width direction Y that is smaller than the pair of intermediate ropes 63. The spreader 67 is configured to be able to connect the pair of intermediate ropes 63 arranged on the bracket 46 of the intermediate boom 43 and the pair of upper ropes 62 arranged on the bracket 46 of the upper boom 42 without changing the magnitude relationship of the distance in the width direction Y between them. That is, when the pendant ropes 6 suspend and support the boom 4, the spreader 67 can maintain a state in which the distance in the width direction Y of the pair of upper ropes 62 is different from the distance in the width direction Y of the pair of intermediate ropes 63. As a result, the pair of intermediate ropes 63 and the pair of upper ropes 62, which have different distances in the width direction Y, can be suitably connected in a state in which they are each held parallel to the boom hoisting surface S. In addition, the two first link plates 673 that connect the intermediate ropes 63 to each other in the width direction Y and the two second link plates 674 that connect the upper ropes 62 to each other in the width direction Y are each pin-connected so that the center portion in the width direction Y can be opened. In other words, the first link plate 673 and the second link plate 674 are configured so that the connection in the width direction Y (maintenance of the interval) can be released. Therefore, as shown in FIG. 4(b), by opening each of the two first link plates 673 and the two second link plates 674, the hoisting rope 35 that raises and lowers the hook 36 can be passed between the spreaders 67. As a result, even if the hoisting rope 35 is mistakenly wired from the upper side of the spreader 67, the hoisting rope 35 can be easily corrected to the correct position by passing it between the spreaders 67. Note that the method of releasing the connection in the width direction Y (maintenance of the interval) is not limited to opening at the center portion. For example, although the center portion in the width direction Y is made openable, the present invention is not limited to this. For example, the connection between the first link plate 673 and the first connecting fitting 671 may be released, thereby releasing the connection in the width direction Y (maintenance of the gap).

[0024] Furthermore, when the boom 4 is lowered and disassembled, the pendant rope 6 is disassembled into a plurality of pairs of partial ropes 60. Each of the plurality of pairs of partial ropes 60 is placed on and fixed to the corresponding unit boom 40 in a left-right pair, and is unitized with the unit boom 40. At this time, each pair of partial ropes 60 is formed to a length corresponding to the length of the extension direction X of the corresponding unit boom 40, and is fixed to the unit boom 40 in a state along the extension direction X. In this embodiment, the pendant rope 6 is fixed while being held parallel to the boom 4 in the same manner as when the boom 4 is suspending and supporting the boom 4.

[0025] As shown in FIGS. 3( a ) and 3 ( b ), each pair of disassembled partial ropes 60 is fixed at each end in the extension direction X to the unit boom 40 by a bracket 46 in a left-right pair. The brackets 46 are an example of rope fixing means according to the present invention, and are disposed on both sides of the unit boom 40 in the width direction Y in correspondence with the positions of the pairs of partial ropes 60 in the width direction Y, and are fixed to the sub-pipe material 40a of the unit boom 40. Each partial rope 60 is fixed by a U-shaped fixing member 461 in a state where it is placed on the upper surface of the bracket 46 so as not to fall off. Two guide plates 462 that define the position of the partial rope 60 to be fixed in the width direction Y are provided on the upper surface of the bracket 46. The partial rope 60 is placed on the upper surface of the bracket 46 between the two guide plates 462 and fixed thereto.

[0026] [How to assemble and disassemble a crane] FIG. 5 is a flowchart showing the flow of a method for assembling the crane 1. As shown in this figure, when assembling the crane 1, first, the machine body, i.e., the lower traveling body 2 and the upper rotating body 3 are assembled (step S1). In addition, the mast 31 is erected on the upper rotating body 3, and the hoisting rope 33 is wound between the upper spreader 311 at the tip of the mast and the lower spreader.

[0027] Next, the boom 4 is assembled (step S2). Here, first, the lower boom 41 is connected to the upper revolving body 3. Then, the multiple unit booms 40 (the multiple intermediate boom blocks 431 and the upper boom 42) are connected to the lower boom 41 in order from the base end side. At this time, since the corresponding pair of partial ropes 60 is fixed to each unit boom 40 in advance, the arrangement of the pair of partial ropes 60 (that is, the pendant ropes 6) is also almost completed along with the arrangement of the unit booms 40.

[0028] Next, the multiple pairs of partial ropes 60 and the pairs of lower ropes 64 are connected to complete the pendant rope 6 (step S3). Here, first, the pairs of intermediate ropes 63 and the pair of lower ropes 64 and the pair of intermediate ropes 63 are connected with pin connectors 66, and the pair of intermediate ropes 63 and the pair of upper ropes 62 are connected with a spreader 67. Then, the fixing members 461 of each bracket 46 are removed, and the fixing of each partial rope 60 is released. At this time, pairs of partial ropes 60 are arranged in advance on each unit boom 40 in parallel to the extending direction X. Therefore, by simply connecting a plurality of pairs of partial ropes 60, a pendant rope 6 that is held in parallel to the boom hoisting surface S is obtained. The completed pendant rope 6 is then connected to the boom 4 and the upper spreader 311.

[0029] Next, the hook 36 is connected to the tip of the hoisting rope 35 hung around the sheaves 441, 442 at the tip of the boom 4 (step S4). Then, the hoisting winch takes up the hoisting rope 33 to raise the boom 4 from the collapsed state (step S5). At this time, the pendant rope 6 hoists the boom 4 while suspending and supporting the boom 4, with its longitudinal direction held parallel to the boom hoisting plane S. In this manner, the assembly of the crane 1 is completed.

[0030] On the other hand, when disassembling the crane 1, the crane 1 is basically disassembled by the steps reverse to those of the assembly steps described above. Among these, in the process of disassembling the pendant rope 6, the boom 4 is lowered from an upright position to place the pendant rope 6 on the boom 4, and then the connecting member 65 is removed and the pendant rope 6 is disassembled into multiple pairs of unit ropes 60 and a lower rope 64.

[0031] At this time, when the pendant rope 6 is supporting the boom 4, its longitudinal direction is held parallel to the boom hoisting surface S. Therefore, even if the boom 4 is raised from a lowered state and then lowered again, or the intermediate boom block 431 is increased or decreased to change the length of the boom 4, the position of the pendant rope 6 in the width direction Y on the boom 4 does not change, unlike when the pendant rope is inclined relative to the boom hoisting surface. Therefore, even in these cases, the pendant rope 6 fits on the bracket 46 of the boom 4 when the boom 4 is lowered. The pendant rope 6 arranged on the bracket 46 is fixed to the bracket 46. This makes it possible to prevent the pendant rope 6 from coming into contact with parts of the bracket 46 other than the rope support part (fixing member 461, guide plate 462, etc.) or the boom 4, which would cause damage to these parts.

[0032] Here, the parallelism of the pendant rope 6 to the boom hoisting surface S may be within a range in which the position in the width direction Y of the pendant rope 6 placed on the boom 4 does not deviate from the bracket 46 (between the two guide plates 462). Therefore, the allowable range of this parallelism is determined taking into account the distance D between the brackets 46 that are furthest apart in the extension direction X and the distance L between the two guide plates 462 of the bracket 46 (see FIG. 3(b)). This allowable range also allows for connection play in each connecting member 65. Specifically, the pendant rope 6 is parallel up to an inclination of an angle θ where tanθ=L / D. Such an angle θ is preferably 4 degrees or less, more preferably 2 degrees or less, and even more preferably 1 degree or less. As a specific example of these angles θ, consider a case where the angle θ changes according to the number of intermediate boom blocks 431. For example, when there is one intermediate boom block 431, if the distance D between the brackets 46 furthest apart in the extension direction X is 3000 mm and the distance L between the two guide plates 462 is about 160 mm, when the intermediate boom 43 is composed of only one intermediate boom block 431, tanθ=160 / 3000. Therefore, θ≒3°. When the intermediate boom 43 is composed of two intermediate boom blocks 431, tanθ=160 / 6000, and θ≒1.5°. When the intermediate boom 43 is composed of three intermediate boom blocks 431, tanθ=160 / 9000, and θ≒1°.

[0033] [Technical effect of the present embodiment] As described above, according to this embodiment, the pendant rope 6 that suspends and supports the boom 4 so that it can be hoisted is held with its longitudinal direction parallel to the boom hoisting plane S when suspending and supporting the boom 4. Therefore, even if the boom 4 is raised from a lowered state and then lowered again, or even if the intermediate boom block 431 is increased or decreased to change the length of the boom 4, the position of the pendant rope 6 in the width direction Y on the boom 4 does not change. This makes it possible to prevent the pendant rope 6 from contacting parts of the bracket 46 other than the rope support part or the boom 4. Therefore, the boom 4 can be raised and lowered suitably while preventing damage to the pendant rope 6 and the like.

[0034] In addition, according to this embodiment, when the pendant rope 6 is suspending and supporting the boom 4, the spreader 67 maintains a state in which the distance between the pair of intermediate ropes 63 and the distance between the pair of upper ropes 62 are different. This allows the boom 4 to be raised and lowered while maintaining the position of the pendant rope 6 in the width direction Y. Therefore, the boom 4 can be raised and lowered in an optimal manner while preventing damage to the pendant rope 6 and the like.

[0035] In addition, according to this embodiment, the spreader 67 has two first link plates 673 and two second link plates 674 that connect the pairs of partial ropes 60 in the width direction Y, and these two first link plates 673 and two second link plates 674 are configured to be able to release the connection in the width direction Y. Therefore, by disconnecting the two first link plates 673 and the two second link plates 674, the hoisting rope 35 for raising and lowering the hook 36 can be passed between the spreaders 67. As a result, even if the hoisting rope 35 is mistakenly wired from above the spreader 67, the hoisting rope 35 can be easily corrected to the correct position by passing it between the spreaders 67.

[0036] [others] Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment. For example, in the above embodiment, the pendant ropes 6 are paired with one on each side. However, the pendant ropes according to the present invention may be paired with two (or three or more) on each side, or may not be paired on the left and right. Furthermore, the upper boom 42 may have approximately the same distance in the width direction Y as the intermediate boom 43. In this case, the pair of pendant ropes 6 have approximately the same distance in the width direction Y over their entire lengths. Also,

[0037] Furthermore, the crane to which the present invention can be applied is not particularly limited as long as it is one in which the boom is raised and lowered by a pendant rope. In addition, the details shown in the above embodiment can be modified as appropriate without departing from the spirit of the invention. [Explanation of symbols]

[0038] 1. Crane 4. Boom 40 unit boom 41 Lower boom 42 Upper Boom 43 Intermediate boom 431 Mid-boom block 6 Pendant Rope 60 Pieces Rope 62 Upper Rope 63 Intermediate Rope 64 Lower Rope 46 Bracket 462 Guide plate 65 Connecting member 66 Pin coupling fitting 67 Spreader (spacing member) 673 First link plate (base end connection part) 674 Second link plate (tip side connection part) 676 3rd link plate (longitudinal connection) 311 Upper Spreader S Boom elevation surface X Boom extension direction Y Boom width direction

Claims

1. Boom and A pendant rope that suspends and supports the boom so that it can be raised and lowered, When the pendant rope is supporting the boom, the longitudinal direction of the pendant rope is held parallel to a boom hoisting surface on which the boom is hoisted, The pendant rope is provided in a pair spaced apart in the width direction of the boom, A spacer member is provided to maintain the space between the pair of pendant ropes in the width direction, Each of the pair of pendant ropes includes a base end rope arranged on the base end side of the boom, and a tip end rope arranged on the tip end side of the boom adjacent to the base end rope and connected to the base end rope, The spacing member maintains a state in which the distance between the pair of base end ropes and the distance between the pair of tip end ropes are different when the pendant ropes suspend and support the boom. crane.

2. Boom and A pendant rope that suspends and supports the boom so that it can be raised and lowered, The pendant rope is provided in a pair spaced apart in the width direction of the boom, Each of the pair of pendant ropes includes a base end rope arranged on the base end side of the boom, and a tip end rope arranged on the tip end side of the boom adjacent to the base end rope and connected to the base end rope, A spacing member is provided for maintaining a state in which the distance between the pair of base end ropes and the distance between the pair of tip end ropes are different when the boom is suspended by the pendant rope. crane.

3. The spacing member has a base end side connecting portion that connects the pair of base end side ropes together and a tip end side connecting portion that connects the pair of tip end side ropes together, and the base end side connecting portion and the tip end side connecting portion have different lengths in the width direction of the boom. A crane as claimed in claim 1 or 2.

4. The spacing member has a longitudinal connecting portion that connects the base end rope and the tip end rope. A crane as claimed in any one of claims 1 to 3.

5. The boom has a base end side rope arrangement portion that arranges the pair of base end side ropes at a first width direction distance, and a tip end side rope arrangement portion that arranges the pair of tip end side ropes at a second width direction distance that is smaller than the first width direction distance, The spacing member is configured to be able to connect the pair of base end ropes arranged in the base end rope arrangement section and the pair of tip end ropes arranged in the tip end rope arrangement section without changing the magnitude relationship between the first width direction distance and the second width direction distance. A crane as claimed in any one of claims 1 to 4.

6. The spacing member is configured to be able to release the retention of the widthwise spacing. A crane as claimed in any one of claims 1 to 5.

7. The boom is configured by connecting a plurality of unit booms, The pair of pendant ropes are composed of a plurality of pairs of partial ropes including a pair of base end ropes arranged on the base end side of the boom, and a pair of tip end ropes arranged adjacent to the base end ropes on the tip side of the boom and connected to the base end ropes, The plurality of pairs of partial ropes are provided for each pair, the number of which corresponds to the number of unit booms, Each pair of the plurality of pairs of partial ropes is placed on a corresponding unit boom when the boom is lowered. A crane as claimed in any one of claims 1 to 6.

8. The pair of tip-side ropes and the pair of base-side ropes correspond to an upper boom tapered in the width direction of the boom and an intermediate boom connected to the upper boom. A crane as claimed in any one of claims 1 to 7.

9. A method for lowering a boom of a crane as described in claim 1 or claim 2, comprising: The pendant rope is connected to the boom in a state where the longitudinal direction of the pendant rope is parallel to a boom hoisting surface on which the boom is hoisted, When the boom is lowered from an upright state by the pendant rope while the pendant rope is held parallel to the boom hoisting surface, the pendant rope is disposed on a bracket provided on the boom, The pendant rope is fixed to the bracket. How to lower a crane boom.

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