Working machinery

Abstract

To provide a work machine capable of preventing a rope from interfering with a counterweight when the position of a support member is changed.SOLUTION: A crane comprises: an upper slewing body 2; a boom 3; a gantry 4 supported by the upper slewing body 2 with a sheave 41T so that the posture can be changed between an upright posture and an inverted posture, and supporting the boom 3; a counterweight 5 attached to the upper slewing body 2 behind the gantry 4; a boom hoisting winch 10 arranged behind the boom 3 and in front of the counterweight 4; a boom hoisting rope 9 pulled out from the boom hoisting winch 10 and hung on the sheave 41T; and at least one support device 70 capable of supporting the boom hoisting rope 9 between the sheave 41T and the boom hoisting winch 10 so as to prevent contact between the boom hoisting rope 9 and the counterweight 5 when the gantry 4 changes its position.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present invention relates to a working machine provided with a support member that can be raised and lowered.

Background Art

[0002] As a working machine such as a crane, there is known one having a machine body, a lifting member supported by the machine body so as to be able to be lifted and lowered, and a support member that supports the lifting member so as to be able to be lifted and lowered behind the lifting member. Patent Document 1 discloses a technique in which a boom as the lifting member is supported from behind by a gantry as the support member. In this technique, the crane further has a boom hoist winch mounted on the machine body, and a boom hoist rope drawn out from the boom hoist winch is connected to the tip of the boom via a sheave provided at the tip of the gantry and a boom guy line. When the boom hoist winch winds up and pays out the boom hoist rope, the boom rises and falls with respect to the machine body.

[0003] In the technique described in Patent Document 1, the gantry can change its posture between a standing posture and a lying posture. In the standing posture, a part of the gantry extends rearward and upward, so that the boom can be supported from behind. In the lying posture, the gantry lies down rearward from the standing posture and takes a posture along the machine body. In this lying posture, the gantry can be transported and stored together with the machine body.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the technology described in Patent Document 1, there is a problem in that, during the gantry's lowering operation, the boom luffing rope interferes with the counterweight attached to the rear of the machine, causing damage to the rope. Furthermore, if the shape of the counterweight is partially removed to avoid such damage, the weight of the counterweight necessary to maintain the crane's balance decreases, resulting in a problem in that the crane's maximum lifting capacity is reduced.

[0006] This invention has been made in view of the above problems, and aims to provide a work machine that can prevent the rope from interfering with the counterweight when the posture of the support member is changed. [Means for solving the problem]

[0007] The present invention provides a work machine. The work machine comprises a machine body, a luffing member supported on the machine body so as to be luffable, a support member having a sheave and rotatably supported on the machine body behind the luffing member so as to be able to change its posture between an upright posture relative to the machine body and a reclined posture lying on the machine body, and functioning as a support column for the luffing member in the upright posture, a counterweight supported on the machine body behind the support member, a winch positioned in front of the counterweight, a rope pulled out from the winch and draped over the sheave of the support member, and at least one support device capable of supporting the rope between the sheave and the winch so as to prevent contact between the rope and the counterweight when the support member changes its posture from the upright posture to the reclined posture.

[0008] With this configuration, when changing the orientation of the support member from an upright position to a reclined position, the support device can support the rope between the sheave and the winch, thus preventing the rope from interfering with and damaging the counterweight. Furthermore, the need to change the placement or shape of the counterweight to avoid such interference is reduced.

[0009] In the above configuration, the at least one support device may be attached to the counterweight.

[0010] With this configuration, since the support device is attached to the counterweight, interference between the counterweight and the rope can be reliably prevented by the support device supporting the rope at a position closer to the counterweight.

[0011] In the above configuration, the counterweight is made up of multiple weight bodies stacked on top of each other, and further has an upper surface portion and a front surface portion, and the at least one support device may be attached to the front surface portion of the counterweight so as to leave the upper surface portion open.

[0012] With this configuration, the support device is attached to the front of the counterweight, and the top of the counterweight is open, thus preventing the support device from interfering with the stacking and unstacking of multiple weights.

[0013] In the above configuration, the counterweight may have an upper surface portion and a front surface portion, and the support device may be attached to the upper end of the front surface portion of the counterweight and support the rope so as to guide the rope extending upward from the winch toward the rear.

[0014] With this configuration, since the support device is positioned at the upper end of the front part of the counterweight, the rope can be easily guided toward the rear of the counterweight.

[0015] In the above configuration, the at least one support device may have at least one roller that is rotatable around a rotational axis extending in the left-right direction and includes an outer circumferential surface that supports the rope.

[0016] With this configuration, the support device receives the rope on the outer surface of the roller, thus preventing damage to the rope due to contact between the support device and the rope. In particular, because the roller is rotatable, even if the rope comes into contact with the roller while moving in its longitudinal direction, the contact resistance between the roller and the rope can be reduced.

[0017] In the above configuration, the at least one roller may have a plurality of rollers, and the plurality of rollers may include a first roller and a second roller positioned behind and higher than the first roller.

[0018] With this configuration, the rope can be supported by the outer surfaces of multiple rollers, allowing for a larger bending radius of the rope and reducing the load on the rope compared to when the rope is supported by the outer surface of a single roller.

[0019] In the above configuration, the at least one support device may include a plurality of support devices attached to the front surface of each of the plurality of weight bodies.

[0020] With this configuration, since a support device is attached to the front of each of the multiple weight bodies, the support devices can support the rope regardless of the loading order of the multiple weight bodies.

[0021] In the above configuration, at least one support device may be detachably attached to the front portion of each of the plurality of weight bodies.

[0022] According to this configuration, after stacking multiple weight units, a support device can be attached to, for example, the uppermost weight unit, thereby stably supporting the rope when the orientation of the support member changes.

[0023] In the above configuration, the airframe may have a rope holding portion that holds the tip of the rope pulled out from the winch, and the support device may have a first support portion that can support the rope pulled out from the winch between the winch and the sheave, and a second support portion that can support the rope between the sheave and the rope holding portion.

[0024] According to this configuration, by supporting the portion of the rope that is paid out from the winch with the first support portion and the tip side portion of the rope with the second support portion, the rope can be supported in a balanced manner.

[0025] In the above configuration, the first support portion may include a plurality of rollers that have an outer peripheral surface for supporting the rope and are rotatable around a rotation center axis extending in the left-right direction, and the second support portion may include a groove portion that has a curved shape in a cross section orthogonal to the left-right direction and can support the rope along the curved shape.

[0026] According to this configuration, by receiving the portion of the rope that is likely to change its contact position with the support device due to the rotation of the winch or the change in the posture of the support member with a plurality of rollers, damage to the rope can be reliably suppressed. On the other hand, by receiving the tip side portion of the rope that is fixed to the rope holding portion and is relatively difficult to move with the groove portion having a curved shape, the cost of the support device can be reduced without providing a plurality of rollers in the second support portion.

Effect of the Invention

[0027] According to the present invention, there is provided a working machine capable of preventing the rope from interfering with the counterweight when the posture of the support member is changed.

Brief Description of the Drawings

[0028] [Figure 1] It is a side view of a crane according to an embodiment of the present invention. [Figure 2] In the crane according to an embodiment of the present invention, it is a side view of a state where the gantry is in a standing posture with respect to the airframe. [Figure 3] This is a cross-sectional view taken at position III-III in the line of the arrow in Figure 2. [Figure 4] This is a side view of a support device in a crane according to one embodiment of the present invention. [Figure 5] This is a plan view of a support device in a crane according to one embodiment of the present invention. [Figure 6] This is a front view of a support device in a crane according to one embodiment of the present invention. [Figure 7] This is a side view showing how the gantry of a crane according to one embodiment of the present invention tilts relative to the machine body. [Figure 8] This is an enlarged view showing how a rope is supported by a support device in a crane according to one embodiment of the present invention. [Modes for carrying out the invention]

[0029] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Figure 1 is a side view of the crane 100 (working machine) according to this embodiment. In addition, the following figures, including Figure 1, show directions such as "up," "down," "right," "left," "front," and "rear." These directions are shown for convenience in explaining the structure of the crane 100 according to this embodiment and do not limit the manner in which the working machine according to the present invention is used.

[0030] The crane 100 comprises a lower traveling body 1 that can travel on the ground, an upper slewing body 2 (main unit) positioned above the lower traveling body 1, and a boom 3 as a luffing member. A cab is provided at the front end of the upper slewing body 2. The cab corresponds to the crane's operator's seat. The upper slewing body 2 is mounted on the lower traveling body 1 so as to be able to rotate around a slewing center CL (Figure 1) that extends in the vertical direction. The upper slewing body 2 is equipped with a slewing frame 21 as a base.

[0031] The boom 3 is supported in a luffable manner by the slewing frame 21 of the upper slewing body 2.

[0032] The crane further comprises a pair of left and right gantry 4 (support members), a counterweight 5, a pair of left and right boom guy lines 6, a lower spreader 8A and an upper spreader 8B, a boom luffing rope 9 (rope), a boom luffing winch 10 (winch), a boom point sheave 11, an idler sheave 12, a hook 13, a hoisting rope 14, and a hoisting drum 15.

[0033] The pair of left and right gantry units 4 are mounted on the rear of the slewing frame 21 of the upper slewing unit 2. Specifically, the pair of left and right gantry units 4 are rotatably supported on the upper slewing unit 2 at the rear of the boom 3 so that they can change their posture between an upright position relative to the upper slewing unit 2 and a reclined position where they are reclined on the upper slewing unit 2 (see Figure 7), and they function as supports for the boom 3 in the upright position. Note that in Figure 1, the right gantry unit 4 on the near side of the page is shown.

[0034] The counterweight 5 is mounted on the slewing frame 21 at the rear of the gantry 4 and has the function of maintaining the crane's balance when the crane is lifting a load.

[0035] The lower spreader 8A and the upper spreader 8B each contain multiple sheaves. The lower spreader 8A is supported at the tip of the gantry 4. The upper spreader 8B is connected to the tip of the boom 3 by a boom guy line 6.

[0036] The boom luffing rope 9 is pulled out from the boom luffing winch 10, hooked onto the sheave 41T (Figure 2) at the tip of the gantry 4, and then looped around multiple times between the lower spreader 8A and the upper spreader 8B. The boom luffing winch 10 is located at the rear of the slewing frame 21, more specifically, behind the boom 3 and in front of the counterweight 5. The tip of the pulled-out boom luffing rope 9 is fixed near the boom luffing winch 10, as will be described in detail later. The boom luffing winch 10 changes the distance between the lower spreader 8A and the upper spreader 8B by winding and unwinding the boom luffing rope 9, thereby luffing the boom 3 while rotating it relative to the gantry 4.

[0037] The hoisting drum 15 is mounted in the center of the slewing frame 21. The boom point sheave 11 and idler sheave 12 are rotatably supported at the tip of the boom 3. A hook 13 for lifting loads is attached to the end of the hoisting rope 14 that is pulled out from the hoisting drum 15. One end of the hoisting rope 14 is wrapped between the boom point sheave 11 at the tip of the boom 3 and the sheave of a sheave block (not shown) on the hook 13, and then fixed to the tip of the boom 3. The other end of the hoisting rope 14 is wound around the hoisting drum 15 via the boom point sheave 11 and idler sheave 12. Therefore, when the hoisting drum 15 winds up or unwinds the hoisting rope 14, the distance between the boom point sheave 11 and the sheave of the hook 13 changes, causing the hook 13, which hangs down from the tip of the boom 3, to be raised or lowered.

[0038] Figure 2 is a side view of the crane 100 according to this embodiment, in which the gantry 4 is in an upright position relative to the upper slewing body 2.

[0039] As shown in Figure 2, the swivel frame 21 has a pair of left and right vertical walls 21H. Each vertical wall 21H has a predetermined height in the vertical direction and extends long in the front-to-back direction. In Figure 2, the right vertical wall 21H on the front side of the paper is visible. The aforementioned counterweight 5 is composed of multiple weight bodies 50 stacked on top of each other. In Figure 2, the counterweight 5 has three layers of weight bodies 50.

[0040] Each of the pair of left and right gantry 4 has a compression member 41 and a tension member 42. Each of the compression member 41 and tension member 42 is supported by the upper rotating body 2 and is arranged to form a roughly triangular shape when viewed along the left-right direction.

[0041] Specifically, the compression member 41 is rotatably supported at approximately the center of the vertical wall 21H in the front-rear direction, with its base pivot point 41P as the pivot. In the upright position of the gantry 4 shown in Figure 2, the compression member 41 extends from the base pivot point 41P so as to be obliquely inclined rearward and upward. A sheave 41T is rotatably mounted on the tip (rotating end) of the compression member 41. The sheave 41T has an outer surface that supports the boom luffing rope 9. The boom luffing rope 9, via the sheave 41T, is then routed sequentially to the lower spreader 8A and the upper spreader 8B, as described above.

[0042] The tension member 42 is supported by the vertical wall 21H behind the compression member 41 and immediately in front of the counterweight 5. The tension member 42 includes a first member 42A and a second member 42B. The first member 42A constitutes the upper part of the tension member 42, and the second member 42B constitutes the lower part of the tension member 42. The tip of the first member 42A is rotatably supported at an upper support point 42Q provided at the tip of the compression member 41. On the other hand, the base end of the second member 42B is rotatably supported at a lower support point 42P provided at the rear end of the vertical wall 21H. Furthermore, the lower end of the first member 42A and the upper end of the second member 42B are rotatably connected relative to each other at a central support point 42S. In other words, the tension member 42 has a structure that can bend and extend with the central support point 42S as the pivot point. Furthermore, the tip of the tension member 42 (upper fulcrum 42Q) is connected to the tip of the compression member 41, below the sheave 41T and on the rear side of the compression member 41. Also, the central axis of each rotational movement in the gantry 4 in Figure 2 extends in the left-right direction.

[0043] Furthermore, the gantry 4 has a cylinder 43. The cylinder 43 is a hydraulic cylinder and extends and retracts by receiving a supply of hydraulic fluid discharged from a hydraulic pump (not shown). As shown in Figure 2, the tip of the rod portion of the cylinder 43 is rotatably connected to the rear side surface of the compression member 41, and the base end of the cylinder body of the cylinder 43 is rotatably supported by a support mechanism that supports the hoisting drum 15. The gantry 4 can change its posture between an upright position and a reclined position as the cylinder 43 extends and retracts.

[0044] As shown in Figure 2, in this embodiment, the boom luffing winch 10 is fixed to the front of the counterweight 5 within the slewing frame 21. The boom luffing rope 9, pulled out from the boom luffing winch 10, is routed to the lower spreader 8A via a sheave 41T located at the tip of the gantry 4 in the upright position. In this position, if the gantry 4 attempts to change its position from upright to lowered, there is a concern that the boom luffing rope 9 may interfere with the counterweight 5 and be damaged. To solve this problem, in this embodiment, the crane 100 is equipped with a support device 70. As shown in Figure 2, the support device 70 is attached to the counterweight 5.

[0045] Figure 3 is a cross-sectional view taken at position III-III in the line of arrow III in Figure 2. Figures 4, 5, and 6 are a side view, a top view, and a front view of the support device 70 in the crane 100 according to this embodiment. The support device 70 is a device capable of supporting the boom luffing rope 9 between the sheave 41T and the boom luffing winch 10 so as to prevent contact between the boom luffing rope 9 and the counterweight 5 when the gantry 4 changes its posture from an upright position to a lowered position.

[0046] Each weight body 50 constituting the counterweight 5 has a roughly rectangular parallelepiped shape, having a top surface 501, a front surface 502, and a pair of left and right side surfaces 503. At the upper end of the front surface 502 of each weight body 50, in the center in the left-right direction, there is a mounting portion 50S to which a support device 70 can be attached. Multiple bolt holes are pre-formed in the mounting portion 50S. As shown in Figure 3, when viewed from the front, each mounting portion 50S is located between the pair of left and right gantry 4. The winch drum of the boom luffing winch 10, located near the base end of the tension member 42 of the pair of left and right gantry 4 (Figure 2), is rotatably supported by a winch support portion 10H that constitutes part of the slewing frame 21.

[0047] Referring to Figures 4 to 6, the support device 70 has a base plate 71, a first support portion 72, and a second support portion 73. The support device 70 having these structures is detachably attached to the mounting portion 50S (front portion 502) of the weight body 50 by a plurality of bolts V.

[0048] The base plate 71 is a plate-shaped portion positioned opposite the front portion 502 of the weight body 50, and supports the first support portion 72 and the second support portion 73. Referring to Figure 4, the base plate 71 has a plate body 711 and a protruding portion 712. The plate body 711 extends in the vertical direction, and a hole (not shown) is formed in the plate body 711 through which the bolt V is inserted. The protruding portion 712 protrudes rearward from the upper end of the plate body 711. When attaching the base plate 71 to the mounting portion 50S, the base plate 71 can be hooked onto the mounting portion 50S such that the protruding portion 712 abuts against the upper part of the mounting portion 50S. This makes it possible to improve the positioning accuracy of the support device 70, and the support device 70 can reliably receive the reaction force from above by the boom luffing rope 9.

[0049] The first support section 72 has the function of supporting the portion of the boom luffing rope 9 that is unfurled from the boom luffing winch 10 (the first rope section 91 in Figure 3). The first support section 72 is fixed to the right side of the base plate 71. The first support section 72 has a pair of left and right side plates 721 and three (or more) support rollers 722. The pair of left and right side plates 721 are arranged to extend forward from the base plate 71. As shown in Figure 5, the right side plate 721 and the left side plate 721 have different shapes in plan view. The shape of each side plate 721 is not limited to those shown in Figure 5, etc. The three support rollers 722 are arranged between the pair of left and right side plates 721 and are rotatably supported by each side plate 721. The axis of rotation of each support roller 722 extends in the left-right direction. As shown in Figure 4, the positions of the axis of rotation and the outer circumferential surfaces of the three support rollers 722 are arranged to be different from each other in the front-rear and up-down directions. In other words, the axis of rotation of the three support rollers 722 (the same applies to the outer surface) is such that the support roller 722 at the rear (second roller) is positioned higher than the support roller 722 at the front (first roller). That is, these support rollers 722 are positioned so that they are angled upwards towards the rear.

[0050] The second support section 73 has the function of supporting the tip portion (second rope section 92 in Figure 3) of the boom luffing rope 9 after it has been stretched over the sheave 41T, the lower spreader 8A, and the upper spreader 8B. The tip portion of the boom luffing rope 9 is fixed to the winch support section 10H in Figure 3. The second support section 73 is fixed to the left side portion of the base plate 71. The second support section 73 has a pair of left and right side plates 731, a support plate 732, and a connecting section 734. The pair of left and right side plates 731 are arranged to extend forward from the base plate 71. The support plate 732 is arranged to connect the pair of left and right side plates 731 in the left-right direction, and when viewed along the left-right direction, it is composed of a curved surface having a downward-sloping arc shape (curved shape) towards the front. The arc shape is convex upward. As a result, the left and right pair of side plates 731 and the support plate 732 form a groove 73K (Figure 6) capable of receiving the second rope section 92. Furthermore, the connecting portion 734 is a connecting pin that connects the left and right pair of side plates 731 to each other below the support plate 732. As shown in Figure 5, the support plate 732 of the first support section 72 is positioned closer to the front section 502 than the three support rollers 722 of the first support section 72.

[0051] Figure 7 is a side view showing the gantry 4 tilting relative to the upper slewing body 2 in the crane 100 according to this embodiment. The dashed line in Figure 7 shows the state of the gantry 4 as shown in Figure 2, and the solid line shows the state in which the gantry 4 has tilted over the upper slewing body 2. In this embodiment, the state shown by the solid line in Figure 7 corresponds to the tilted position of the gantry 4, in other words, the stowed position, and in this state, the gantry 4 and counterweight 5 are transported and stored together with the upper slewing body 2.

[0052] As shown in Figure 7, during the lowering operation of the gantry 4, the second member 42B of the tension member 42 rotates forward, and the first member 42A rotates backward around the central pivot point 42S. The compression member 41, which rotates backward, is positioned to overlap the first member 42A. The boom luffing rope 9 extends linearly between the boom luffing winch 10 and the sheave 41T. If the support device 70 according to this embodiment is not present, the boom luffing rope 9 will extend as shown by the dashed line L in Figure 7 when the gantry 4 is in the lowered position. In this case, the boom luffing rope 9 may interfere with the counterweight 5 and be damaged.

[0053] On the other hand, in this embodiment, when the gantry 4 is lowered, the support device 70 attached to the counterweight 5 receives and supports the boom luffing rope 9 between the sheave 41T and the boom luffing winch 10. As a result, the boom luffing rope 9 is arranged to bend in two parts: the region extending from the boom luffing winch 10 toward the support device 70 and the region extending from the support device 70 toward the sheave 41T (Figure 7). That is, the support device 70 supports the boom luffing rope 9 so as to guide the boom luffing rope 9 extending upward from the boom luffing winch 10 toward the rear, bypassing the counterweight 5. As a result, the boom luffing rope 9, which is arranged to surround the counterweight 5, is prevented from directly interfering with the counterweight 5, which is made of steel or the like, and damage to the boom luffing rope 9 is prevented.

[0054] In this embodiment, which includes the support device 70 described above, the need to change the arrangement or shape of the counterweight 5 to avoid interference between the boom luffing rope 9 and the counterweight 5 is reduced. For example, interference between the two can be avoided by removing the area of ​​the counterweight 5 above the imaginary line L in Figure 7, but in this case, the total weight of the counterweight 5 is reduced, so the maximum lifting load that can be balanced with the counterweight 5 becomes smaller. In other words, the lifting capacity of the crane 100 will decrease. Alternatively, as a way to maintain the lifting capacity, it is conceivable to increase the height of the left and right ends of the counterweight 5 or widen its width to compensate for the weight of the missing part of the counterweight 5, but in this case, the rearward visibility as seen from the cab of the crane 100 will deteriorate. Alternatively, it is conceivable to secure the above weight by widening the rear end of the counterweight 5, but in this case, the slewing radius of the rear end of the upper slewing body 2 will become larger.

[0055] Thus, in this embodiment, while avoiding problems caused by changing the shape and arrangement of the counterweight 5, it becomes possible to transport and store the upper slewing body 2, gantry 4, and counterweight 5 as a single unit with the boom luffing rope 9 attached and the gantry 4 in a lowered position. Furthermore, as shown in Figure 2, it becomes possible to prevent interference when the gantry is lowered while making maximum use of the space immediately behind the tension member 42 of the gantry 4 in the upright position for the counterweight 5. Therefore, it becomes possible to secure the weight of the counterweight 5 and maintain a high lifting capacity of the crane 100.

[0056] Furthermore, in this embodiment, since the support device 70 is attached to the counterweight 5, the support device 70 supports the boom luffing rope 9 at a position closer to the counterweight 5, thereby reliably preventing interference between the counterweight 5 and the boom luffing rope 9.

[0057] Furthermore, in this embodiment, the support device 70 is mounted on the front portion 502 of the counterweight 5 so as to protrude forward, and the upper portion 501 of the counterweight 5 is open. Therefore, compared to the case where the support device 70 is mounted on the upper portion 501, the support device 70 is less likely to obstruct the stacking and unstacking operations of multiple weight bodies 50. In addition, since the structure of multiple weight bodies 50 can be standardized, it is possible to reduce the cost of the counterweight 5.

[0058] Furthermore, since the support device 70 is positioned at the upper end of the front portion 502 of the counterweight 5, the boom luffing rope 9 can be easily guided toward the rear of the counterweight 5.

[0059] Furthermore, in this embodiment, since the support device 70 receives the boom luffing rope 9 on the outer circumferential surface of the support roller 722, damage to the boom luffing rope 9 due to contact between the support device 70 and the boom luffing rope 9 can be reliably prevented. In particular, since the support roller 722 is rotatable, even if the boom luffing rope 9 comes into contact with the support roller 722 while moving in its longitudinal direction, the contact resistance between the support roller 722 and the boom luffing rope 9 can be reduced.

[0060] Figure 8 is an enlarged view showing how the boom luffing rope 9 is supported by the support device 7 in the crane 100. In this embodiment, as shown in Figure 8, the boom luffing rope 9 can be supported by the outer circumferential surfaces of multiple support rollers 722. Compared to the case where the boom luffing rope 9 is supported by the outer circumferential surface of a single support roller 722, the boom luffing rope 9 can be supported with a larger virtual arc shape. As a result, it becomes possible to set a larger bending radius R of the boom luffing rope 9, and the load on the boom luffing rope 9 can be reduced.

[0061] Furthermore, the support device 70 is detachably attached to the front portion 502 of each of the multiple weight bodies 50. Therefore, after stacking the multiple weight bodies 50, for example, by having an operator attach the support device 70 to the uppermost weight body 50, the boom luffing rope 9 can be stably supported when the posture of the gantry 4 is changed.

[0062] Furthermore, in this embodiment, the upper slewing body 2 has a winch support part 10H (rope holding part) that holds the tip portion (second rope portion 92) of the boom luffing rope 9 pulled out from the boom luffing winch 10. The support device 70 has a first support part 72 that can support the first rope portion 91 of the boom luffing rope 9 pulled out from the boom luffing winch 10 between the boom luffing winch 10 and the sheave 41T, and a second support part 73 that can support the second rope portion 92 of the boom luffing rope 9 between the sheave 41T and the winch support part 10H. With this configuration, the boom luffing rope 9 can be supported in a balanced manner by supporting the portion of the boom luffing rope 9 that is unfurled from the boom luffing winch 10 with the first support part 72 and supporting the tip portion of the boom luffing rope 9 with the second support part 73.

[0063] In particular, by supporting the first rope section 91 of the boom luffing rope 9, which is prone to changes in contact position with the support device 70 due to the rotation of the boom luffing winch 10 and the change in posture of the gantry 4, with multiple support rollers 722, damage to the boom luffing rope 9 can be reliably prevented. On the other hand, by supporting the tip portion of the boom luffing rope 9, which is fixed to the winch support section 10H and is relatively difficult to move, with an arc-shaped groove section 73K (side plate 731, support plate 732), the cost of the support device 70 can be reduced compared to the case where the entire first support section 72 and second support section 73 are composed of multiple rollers. Furthermore, by using each support roller 722 only on the first rope section 91, the length of the support roller 722 can be shortened, thereby increasing the rigidity and strength of the support roller 722. Therefore, each support roller 722 can stably support the boom luffing rope 9.

[0064] The above describes a crane equipped with a support device 70 according to one embodiment of the present invention. However, the present invention is not limited to these embodiments. The following modified embodiments are possible in the present invention.

[0065] (1) In the above embodiment, the gantry 4 was used as the support member according to the present invention, but the present invention is not limited thereto. The support member may be other members such as a mast. Also, the gantry 4 is not limited to a structure having a compression member 41 and a tension member 42, but may be composed of a single member. Furthermore, the rope and winch according to the present invention are not limited to the boom luffing rope 9 and boom luffing winch 10, but may be other ropes and winches. Moreover, the winch, represented by the boom luffing winch 10, is not limited to one mounted on the upper slewing body 2, but may also be positioned at the base end of a support member such as the gantry 4. In this case, the winch moves together with the support member, but damage to the rope is similarly prevented by positioning the support device 70 to prevent interference between the rope and the counterweight 5.

[0066] (2) In the above embodiment, the support device 70 was described as being attached to the counterweight 5, but a column member (not shown) may be attached to the slewing frame 21 of the upper slewing body 2, and the support device 70 may be fixed to the upper end of the column member. Also, the luffing member according to the present invention is not limited to the boom 3, but may be any other luffing member.

[0067] (3) Furthermore, the counterweight 5 is not limited to being composed of multiple weight bodies 50, but may be a single component. Moreover, the support device 70 is not limited to being placed on the front portion 502 of the counterweight 5 (weight body 50), but may be attached to the top portion 501.

[0068] (4) Furthermore, the structure of the part of the support device 70 that receives the boom luffing rope 9 is not limited to the support roller 722 and support plate 732, but may have other shapes and structures. A single support roller 722 with a relatively large diameter may be used instead of multiple support rollers 722. Also, the structures of the first support part 72 and the second support part 73 may be the same, or a single support part that combines the functions of these support parts may be provided.

[0069] (5) In the above embodiment, a number of support devices 70 less than the number of weight bodies 50 is prepared, and the support devices 70 are detachably attached to the mounting portion 50S of each weight body 50, but the present invention is not limited thereto. Multiple support devices 70 may be prepared in advance, and each support device 70 may be attached to the front portion 502 of each of the multiple weight bodies 50. In this case, the counterweight 5 can be mounted on the upper slewing body 2 in any order and combination of the multiple weight bodies 50, and the support devices 70 can support the boom luffing rope 9 regardless of which weight body 50 is positioned at the upper end of the counterweight 5. Furthermore, it becomes possible to stack and unload the weight bodies 50 with the support devices 70 attached to each weight body 50. [Explanation of Symbols]

[0070] 1. Lower running body 10 Boom luffing winch (winch) 100 Cranes 10H Winch support section (rope holding section) 2. Upper rotating body (aircraft) 21 Swivel Frame 21H vertical wall 3. Boom (relieving member) 4. Gantry (support member) 41 Compression Members 41P Proximal fulcrum part 41T Sheave 42 Tension Members 42A First Member 42B Second Member 42P Lower fulcrum part 42Q Upper fulcrum part 42S Central fulcrum part 43 cylinders 5 Counterweight 50 Weight Body 501 Top part 502 Front part 503 Side part 50S mounting part 6 Boom Guyline 70 Support device 71 Base plate 72 1st support part 721 Side panel 722 Support roller (roller) 73 Second support part 731 Side panel 732 Support plate 734 Connection part 73K Groove 8A Lower spreader 8B Upper spreader 9. Boom luffing rope (rope) 91 First Rope Section 92 Second Rope Section CL rotation center L virtual line V-bolt

Claims

1. The aircraft and, A luffing member supported on the aforementioned aircraft so as to be able to be raised and lowered, A support member having a sheave, which is rotatably supported by the aircraft at the rear of the luffing member so as to be able to change its posture between an upright position relative to the aircraft and a reclined position on the aircraft, and which functions as a support column for the luffing member in the upright position, A counterweight supported by the aircraft body at the rear of the support member, A winch positioned in front of the counterweight, A rope pulled out from the winch and attached to the sheave of the support member, A support device capable of supporting the rope between the sheave and the winch so as to prevent contact between the rope and the counterweight when the support member changes its posture from the upright position to the downed position, A work machine equipped with the following features.

2. The work machine according to claim 1, wherein the at least one support device is attached to the counterweight.

3. The aforementioned counterweight is constructed by stacking multiple weight bodies, and further has an upper portion and a front portion. The work machine according to claim 2, wherein the at least one support device is mounted on the front portion such as to leave the upper portion of the counterweight open.

4. The counterweight has an upper portion and a front portion, The support device is attached to the upper end of the front portion of the counterweight. The work machine according to claim 2, comprising supporting the rope so as to guide the rope extending upward from the winch toward the rear.

5. The working machine according to any one of claims 1 to 4, wherein the at least one support device has at least one roller that is rotatable about a rotational axis extending in the left-right direction and includes an outer circumferential surface for supporting the rope.

6. The aforementioned at least one roller has a plurality of rollers, The work machine according to claim 5, wherein the plurality of rollers include a first roller and a second roller positioned behind and higher than the first roller.

7. The work machine according to claim 3, wherein the at least one support device includes a plurality of support devices attached to the front portion of each of the plurality of weight bodies.

8. The work machine according to claim 3, wherein the at least one support device is detachably attached to the front portion of each of the plurality of weight bodies.

9. The aforementioned machine has a rope holding part that holds the end of the rope pulled out from the winch, The aforementioned support device is A first support portion capable of supporting the rope pulled out from the winch between the winch and the sheave, A second support portion capable of supporting the rope is provided between the sheave and the rope holding portion. The work machine according to claim 1, having the following features.

10. The first support portion has an outer circumferential surface for supporting the rope and includes a plurality of rollers that are rotatable around a rotational axis extending in the left-right direction. The working machine according to claim 9, wherein the second support portion has a curved shape in a cross section perpendicular to the left-right direction and includes a groove capable of supporting the rope along the curved shape.

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