Tensioning device and crane equipped with same

Abstract

To provide a tension application device capable of reducing working man-hours and cost, and a crane equipped with the same.SOLUTION: This tension application device comprises: a brake drum 3; a brake gear 4 that applies a brake force to the brake drum 3; and a sheave 6. A rope 40 is wound on the sheave 6 and the brake drum 3 in order from a drum side, and the upper end of the sheave 6 is at a position higher than that of the brake drum 3.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a tensioning device that applies tension to a rope to be wound, and to a crane equipped with the same. [Background technology]

[0002] Patent Document 1 discloses a rope reeling device that reels out a rope while applying tension to it toward a winch drum of a crane. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2018-52629 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when the rope is fed from the tensioning device to the crane, there is a difference in height between the tensioning device and the crane drum, so if the rope is fed directly to the drum, the rope will interfere with the crane's boom, frame, etc. Therefore, it is necessary to lift the rope using a pulley or other device suspended by another crane to prevent the rope from interfering with these, which increases the number of work steps and costs.

[0005] An object of the present invention is to provide a tensioning device that can reduce the number of work steps and costs, and a crane equipped with the same. [Means for solving the problem]

[0006] The present invention is a tensioning device that applies tension to a rope wound around a drum, and is characterized in that it comprises a brake drum, a brake device that applies braking force to the brake drum, and a sheave, and the rope is wound around the sheave and the brake drum in that order from the drum side, and the upper end of the sheave is positioned at a higher position than the upper end of the brake drum. [Effects of the Invention]

[0007] According to the present invention, the upper end of the sheave is positioned higher than the upper end of the brake drum. Therefore, the route of the rope between the sheave and the drum is higher than when the rope is fed directly from the brake drum to the drum. This prevents the rope from interfering with the boom or frame of the crane when feeding the rope onto the crane drum, even if the rope is not lifted by a pulley suspended by another crane. This reduces the labor hours and costs required for winding the rope onto the drum. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 2 is a side view of the tensioning device. [Figure 2] FIG. 2 is a top view of the tensioning device. [Figure 3] FIG. 1 is a side view of a crane. [Figure 4] FIG. 10 is a diagram showing the rope being wound onto the winch drum. [Figure 5] FIG. 1 is a diagram showing a conventional method of winding a rope onto a drum of a winch. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

[0010] (Configuration of tension applying device) The tensioning device in this embodiment applies tension to a rope to be wound. As shown in Fig. 1, which is a side view of tensioning device 1, and Fig. 2, which is a top view of tensioning device 1, tensioning device 1 has a base 2, a brake drum 3, a brake device 4, an air compressor 5, a sheave 6, a load cell 7, a meter 8, and a controller (control device) 9. Note that rope 40 is not shown in Fig. 2.

[0011] The base 2 is placed on the ground, for example. On the base 2, a brake drum 3, a brake device 4, an air compressor 5, a sheave 6, a load cell 7, a meter 8, and a controller 9 are arranged.

[0012] As shown in FIG. 1, the brake drum 3 is disposed at one end (right end) of the base 2. A rope 40, which is reeled out from a rope reeling device 80 (see FIG. 4), is wound around the brake drum 3. The brake device 4 applies a braking force to the brake drum 3. In this embodiment, the brake device 4 is a caliper brake (air brake), but is not limited to this and may be a disc brake or the like.

[0013] The brake device 4 has a disc 51 and a pad 52. The disc 51 is disposed on each side of the brake drum 3. The disc 51 is coaxial with the brake drum 3 and rotates in synchronization with the brake drum 3. The pads 52 are provided in pairs so as to sandwich the disc 51 from the radial direction of the disc 51.

[0014] The air compressor 5 supplies compressed air to the brake device 4. This compressed air drives a pair of pads 52, which then sandwich a disc 51, applying braking force to the brake drum 3. The pressure of the compressed air from the air compressor 5 is adjusted with a valve, thereby adjusting the braking force applied to the brake drum 3.

[0015] As shown in FIG. 1, the sheave 6 has a first sheave 61 and a second sheave 62. The first sheave 61 is disposed above the brake drum 3 by a support member 70 disposed on the base 2. As shown in FIG. 2, the support members 70 are provided on both sides of the first sheave 61 in the axial direction of the first sheave 61 (the up-down direction in the figure). As shown in FIG. 1, the support member 70 has a pair of support legs 71. Each of the pair of support legs 71 supports an end of the shaft of the first sheave 61.

[0016] 1, the upper end of the first sheave 61 is located at a position higher than the upper end of the brake drum 3. In addition, the shaft of the first sheave 61 is located at a position higher than the upper end of the brake drum 3.

[0017] As shown in Fig. 1, the second sheave 62 is disposed below the first sheave. The second sheave 62 is also disposed at the other end (left end) of the base 2. In this embodiment, the upper end of the second sheave 62 is lower than the lower end of the first sheave 61. As shown in Fig. 2, the second sheave 62 is disposed between a pair of support members 70. Specifically, the second sheave 62 is disposed between the support legs 71 of the pair of support members 70.

[0018] By supporting the first sheave 61 with the pair of support members 70, a space is created below the first sheave 61 and between the pair of support members 70. By disposing the second sheave 62 in this space, it is possible to make effective use of this space.

[0019] The sheave 6 is disposed closer to the drum side (left side in the drawing) of the winch 27 of the crane 20 (see FIG. 3) than the brake drum 3. As shown in FIG. 1, the rope 40 is wound around the first sheave 61, the second sheave 62, and the brake drum 3 in this order from the drum side of the winch 27 of the crane 20.

[0020] Here, the brake drum 3 is disposed at one end of the base 2, and the second sheave 62 is disposed at the other end of the base 2. By maximizing the distance between the brake drum 3 and the second sheave 62 within a limited range on the base 2, the fleet angle can be appropriately set. This makes it possible to suppress fluctuations in the fleet angle, thereby preventing the life of the rope 40 from being shortened. Here, the fleet angle refers to the angle formed between a line connecting the center of the brake drum 3 and the center of the second sheave 62 and a line connecting the end of the brake drum 3 and the center of the second sheave 62 in the top view shown in FIG. 2.

[0021] The load cell 7 is attached to the sheave 6 and detects the tension of the rope 40. Specifically, the load cell 7 is attached to the shaft of the second sheave 62 and detects the tension of the rope 40 from the distortion of the shaft. The meter 8 displays the detection value of the load cell 7.

[0022] The controller 9 is provided, for example, in a wiring box that houses the meter 8. The controller 9 adjusts the braking force of the braking device 4 so that the tension detected by the load cell 7 matches a target value. Specifically, the controller 9 adjusts the braking force of the braking device 4 by controlling the opening of a valve that adjusts the pressure of compressed air from the air compressor 5.

[0023] (Crane configuration) 3, which is a side view of crane 20, crane 20 is configured to hoist and lower a load (not shown), and has a configuration in which an upper rotating body (crane body) 22 is rotatably provided on top of a crawler-type lower traveling body 21. Note that crane 20 is not limited to a crawler-type crane, and may also be a wheel-type crane.

[0024] The upper rotating body 22 has a rotating frame 23, a boom 24, a gantry 25, a lower spreader 26, a winch 27, and a counterweight 28.

[0025] The swivel frame 23 is attached to the lower running body 21 via a swivel bearing (not shown). The boom (hoisting member) 24 is connected to the front of the swivel frame 23 so that it can be raised and lowered relative to the swivel frame 23. The boom 24 is a lattice boom and is made up of a lower boom 24a, one or more intermediate booms 24b, and an upper boom 24c. One end of a boom guy line 29 is connected to the tip of the boom 24.

[0026] A point sheave 32 is provided at the tip of the boom 24. A hook device 34 is suspended from this point sheave 32 via a hoisting rope 33.

[0027] The gantry 25 is attached to the rear of the revolving frame 23. The lower spreader 26 is attached to the upper end of the gantry 25. A boom hoisting rope 31 is hung between the lower spreader 26 and an upper spreader 30 connected to the other end of the boom guy line 29.

[0028] A plurality of winches 27 are arranged in the central portion of the revolving frame 23. The winches 27 wind and unwind the rope 40, and are used for hoisting and lowering a suspended load, raising and lowering the boom 24, and the like.

[0029] The winch 27 includes a hook winch and a boom hoist winch. The hook winch winds in or pays out a hoisting rope 33 to raise or lower the hook device 34. The boom hoist winch winds in or pays out a boom hoist rope 31 to raise or lower the boom 24 around the boom foot pin 24s, which serves as its fulcrum. The hoisting rope 33 and the boom hoist rope 31 are included in the ropes 40.

[0030] The counterweight 28 is mounted on the rear of the revolving frame 23.

[0031] The crane 20 configured as described above is disassembled and assembled at the work site. Furthermore, with the crane 20 in a disassembled state, the rope 40 wound around the drum of the winch 27 is replaced.

[0032] (rope supply) FIG. 4, a side view of the crane 20, shows how the rope 40 is being wound onto the drum of the winch 27. As shown in FIG. 4, when replacing the rope 40, the boom 24 is lowered relative to the upper rotating body 22. Then, the boom 24 is disassembled, leaving only the lower boom 24a connected to the rotating frame 23. The lower spreader 26 is placed on the lower boom 24a. In this state, new rope 40 is reeled out from the rope reeling device 80 and supplied to the winch 27. A tensioning device 1 is disposed between the rope reeling device 80 and the crane 20, and applies tension to the rope 40 being reeled onto the drum of the winch 27.

[0033] 4, the intermediate boom 24b may be connected to the lower boom 24a. Furthermore, when replacing the rope 40, the boom 24 may remain in its original state without being disassembled.

[0034] FIG. 5, a side view of the crane 20, shows how the rope 40 is wound onto the drum of the winch 27 using a conventional tensioning device 90. The conventional tensioning device 90 does not include the sheave 6 of this embodiment. Because there is a difference in height between the brake drum of the tensioning device 90 and the drum of the winch 27 of the crane 20, if the rope 40 is to be directly fed onto the drum of the winch 27, the rope 40 will interfere with the lower boom 24a, lower spreader 26, revolving frame 23, and other components. Furthermore, the rope 40 will interfere with a cover that is provided on the revolving frame 23 and surrounds the revolving motor, reducer, and other components that rotate the revolving frame 23. This cover is located between the boom foot pin 24s and the winch 27.

[0035] Therefore, in the past, the rope 40 was lifted by a pulley 95 suspended by another crane (not shown) to prevent the rope 40 from interfering with these elements, which resulted in an increase in the number of work steps and costs.

[0036] In contrast, as shown in FIG. 4, the tensioning device 1 of this embodiment includes a sheave 6. As shown in FIG. 1, the upper end of the first sheave 61 is located at a position higher than the upper end of the brake drum 3. Therefore, as shown in FIG. 4, the path of the rope 40 between the first sheave 61 and the drum of the winch 27 is higher than the path of the rope 40 when it is unwound from the brake drum 3 and directly supplied to the drum (see FIG. 5). Therefore, even if the rope 40 is not lifted by a pulley 95 suspended by a separate crane, it is possible to prevent the rope 40 from interfering with the lower boom 24a, the lower spreader 26, covers surrounding the swing motor, the reducer, etc. This reduces the number of steps required to wind the rope 40 onto the drum of the winch 27 and the costs associated with the work.

[0037] 1, the tension of the rope 40 is detected by a load cell 7 attached to the second sheave 62. For example, by detecting the tension of the rope 40, it is possible to determine the deviation of the tension from a target value. Therefore, the tension of the rope 40 can be adjusted by adjusting the braking force of the brake device 4 so that the detected tension value becomes the target value.

[0038] Furthermore, since the second sheave 62 is disposed between the first sheave 61 and the brake drum 3 on the path of the rope 40, the contact angle (winding angle) between the second sheave 62 and the rope 40 is constant. Therefore, by providing the load cell 7 to the second sheave 62, which has a constant winding angle, rather than the first sheave 61, whose winding angle changes depending on the drum height of the winch 27 and the installation height of the tensioning device 1, the tension of the rope 40 can be accurately detected.

[0039] Furthermore, the controller 9 adjusts the braking force of the brake device 4 so that the tension detected by the load cell 7 matches the target value. This eliminates the need to manually adjust the braking force so that the tension detection value matches the target value. This reduces the number of workers required and the amount of work required.

[0040] (effect) As described above, with the tensioning device 1 according to this embodiment, the upper end of the first sheave 61 is positioned higher than the upper end of the brake drum 3. Therefore, compared to when the rope 40 unwound from the brake drum 3 is directly supplied to the drum of the winch 27, the route of the rope 40 between the first sheave 61 and the drum is higher. This prevents the rope 40 from interfering with the boom 24 or frame (swivel frame 23, covers surrounding the swivel motor, reducer, etc.) of the crane 20 when supplying the rope 40 to the drum of the crane 20, even if the rope 40 is not lifted by a pulley 95 suspended by another crane. This reduces the man-hours and costs involved in the task of winding the rope 40 onto the drum.

[0041] Furthermore, the tension of the rope 40 is detected by the load cell 7 attached to the second sheave 62. For example, by detecting the tension of the rope 40, it is possible to determine the deviation of the tension from a target value. Therefore, the tension of the rope 40 can be adjusted by adjusting the braking force of the brake device 4 so that the detected tension value becomes the target value.

[0042] The load cell 7 is attached to the second sheave 62. The second sheave 62 is disposed on the path of the rope 40 between the first sheave 61 and the brake drum 3, so the contact angle (winding angle) between the second sheave 62 and the rope 40 is constant. Therefore, by providing the load cell 7 to the second sheave 62, which has a constant winding angle, rather than the first sheave 61, whose winding angle changes depending on the drum height of the winch 27 and the installation height of the tensioning device 1, the tension of the rope 40 can be accurately detected.

[0043] Additionally, the second sheave 62 is disposed between a pair of support members 70 that support the first sheave 61 from below. By supporting the first sheave 61 with the pair of support members 70, a space is created below the first sheave 61 and between the pair of support members 70. By disposing the second sheave 62 in this space, it is possible to make effective use of this space.

[0044] In addition, the brake drum 3 is disposed at one end of the base 2, and the second sheave 62 is disposed at the other end of the base 2. The fleet angle can be appropriately set by maximizing the distance between the brake drum 3 and the second sheave 62 within a limited range on the base 2. This makes it possible to suppress fluctuations in the fleet angle, thereby preventing the life of the rope 40 from being shortened.

[0045] Furthermore, the controller 9 adjusts the braking force of the brake device 4 so that the tension detected by the load cell 7 matches the target value. This eliminates the need to manually adjust the braking force so that the tension detection value matches the target value. This reduces the number of workers required and the amount of work required.

[0046] Although the embodiments of the present invention have been described above, they are merely illustrative examples and do not limit the present invention, and the specific configurations and other aspects can be appropriately modified in design. Furthermore, the actions and effects described in the embodiments of the invention are merely a list of the most preferred actions and effects resulting from the present invention, and the actions and effects of the present invention are not limited to those described in the embodiments of the present invention. [Explanation of symbols]

[0047] 1 Tensioning device 2 pedestal 3 Brake drum 4 Brake device 5. Air Compressor 6 Sheaves 7 load cells 8 meters 9 Controller 20 Crane 21 Undercarriage 22 Upper rotating body (crane body) 23 Swivel frame 24 Boom (elevating member) 24a Lower Boom 25 Gantry 26 Lower spreader 27 Winch 28 Counterweight 29 Boom Guyline 30 Upper Spreader 31 Boom hoisting rope 32 point sheave 33 Hoisting rope 34 Hook device 40 Rope 51 discs 52 pads 61 First Sheave 62 Second Sheave 70 Support member 71 Support leg 80 Rope payout device 90 Tensioning device 95 Gold wheel

Claims

1. A tensioning device that applies tension to a rope wound around a drum, Brake drum and a brake device that applies a braking force to the brake drum; Sheaves and and The rope is wound around the sheave and the brake drum in this order from the drum side, A tension applying device characterized in that an upper end of the sheave is located at a position higher than an upper end of the brake drum.

2. 2. The tension applying device according to claim 1, further comprising a load cell attached to the sheave for detecting tension in the rope.

3. The sieve a first sheave having an upper end located at a position higher than an upper end of the brake drum; a second sheave disposed below the first sheave; and The rope is wound around the first sheave, the second sheave, and the brake drum in this order from the drum side, 3. The tensioning device according to claim 2, wherein the load cell is attached to the second sheave.

4. a pair of support members that support the first sheave from below, 4. The tension applying device according to claim 3, wherein the second sheave is disposed between the pair of support members.

5. a base on which the brake drum, the brake device, the first sheave, and the second sheave are disposed, The brake drum is disposed at one end of the base, and 5. The tension applying device according to claim 3, wherein the second sheave is disposed at the other end of the base.

6. The tension applying device according to any one of claims 2 to 5, further comprising a control device that adjusts the braking force of the brake device so that the detected value of the tension detected by the load cell becomes a target value.

7. A tension applying device according to any one of claims 1 to 6; The crane body, The drum provided on the crane body; a hoisting member provided on the crane body so as to be able to be raised and lowered; and A crane characterized in that the hoisting member is lowered relative to the crane body when the rope is wound onto the drum.

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