Small Mast Lift-Up Crane

Abstract

To provide a small-sized, lightweight mast lift-up crane that breaks the conventional concept of a crane, and improves the convenience of transportation, ease of assembly work, and safety of operation. [Solution] A small mast lift-up crane is configured such that a crane body 4 is attached to the top 31 of the tower mast, the tip of a boom 45 pivoted to the mast top pivot point 44 of the crane body 4 is tilted backward from the central axis of the tower 2, and the tip of an auxiliary boom 46 pivoted to the tip of the boom 45 is folded forward in an L-shape relative to the boom 45, and the crane lifts up or lowers the top 5 of the tower suspended from the auxiliary boom 46. The crane has a lightweight design with a lifting load of less than 500 kg that allows it to assemble and dismantle small-scale towers, and the height of the crane itself when assembled or dismantled is set to 9m or more and 10m or less, the tower mast 3 is made of a single round pipe structure, and the next tower mast 3 is assembled under the lowermost tower mast 3 and lifted up.

Description

[Technical Field]

[0001] This invention relates to a crane-based device for erecting steel towers. More specifically, this relates to improvements to a crane that can assemble and dismantle small steel towers using the mast lift-up method, in which the tower mast is extended to the bottom. [Background technology]

[0002] Recently, there has been an increase in the rebuilding of local steel towers, many of which are small. The base pole method has traditionally been used for the construction of these small steel towers, but it has been plagued by problems, such as the difficulty of securing construction land in mountainous areas and installing guy wires. Furthermore, the base pole method poses problems for the transfer of technology, so there was a need for the development of a small, lightweight crane to replace it. For this reason, the applicant for the utility model registration first provided a crane capable of assembling and dismantling small steel towers, as shown in Patent Document 1.

[0003] The crane shown in Patent Document 1 was developed with the aim of reducing its size and weight, but this was not specifically quantified, and a more clear reduction in size and weight was desired. Furthermore, as shown in Figure 1 of Patent Document 1, the tower mast was made by combining steel materials into a lattice structure, so there was also a need to simplify the tower mast. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 2640928 Summary of the Invention [Problem to be solved by the invention]

[0005] The problem that this invention aims to solve is to further advance the invention previously shown in Patent Document 1, to provide a small mast lift-up crane that breaks the conventional concept of a crane, is made smaller and lighter, and is easier to transport, easier to assemble, and safer to operate. [Means for solving the problem]

[0006] In order to solve the above problems, the first invention is a small mast lift-up crane that can assemble and dismantle small steel towers, which is configured as follows: the crane body is attached to the top of the tower mast installed inside the steel tower to be assembled or dismantled, and an auxiliary boom is attached to the tip of the boom of the crane body, which is attached to the top axis of the mast part of the crane body; the tip of the boom is tilted rearward from the central axis of the steel tower, with the top axis as an axis; the tip of the auxiliary boom attached to the tip of the boom is folded forward in an L-shape relative to the boom; and the wire rope hook hanging from the tip of the auxiliary boom is used to lift up or lower the top of the square pyramid-shaped steel tower to be assembled or dismantled on the steel tower.

[0007] First, the crane has a lightweight design with a lifting load of less than 500 kg, allowing it to assemble and dismantle small steel towers, and the height of the crane itself when assembled and dismantled has been set at 10 m or less and 9 m or more. Second, the tower mast is made of a single round pipe structure. Third, the tower masts are assembled by installing the next tower mast under the lower tower mast and lifting it up.

[0008] The second invention is a small mast lift-up crane that can assemble and disassemble small steel towers, which adds the following means to the first invention. A gap of approximately 50cm square in plan was created inside the tower to allow for the raising and lowering of the tower mast, and when the boom was in the upright position, its planar dimensions were set to be equal to or less than the gap, allowing the crane body to be lowered and dismantled.

[0009] The third invention is a small mast lift-up crane that can assemble and disassemble small steel towers, which adds the following means to the first or second invention. A lift-up chain with a hook is provided on the lift-up lifter of the lift-up device that installs and lifts up the tower mast, a mast lifting hook receiving bracket is provided at the tip of the installed tower mast, the installed tower mast is pulled under the lowest tower mast by the lift-up device, and the tower mast is installed by a spigot-type insertion. [Effects of the Invention]

[0010] The first invention has the following effects. First, the crane's lifting load is less than 500 kg, making it lightweight and capable of assembling and dismantling small steel towers. This allows for more freedom in crane design and makes it easier for users to operate. Secondly, by limiting the height of the crane itself to 9m or more and 10m or less during assembly and disassembly, the assembly and disassembly of the crane can be done with a mini crawler crane, making it easy and safe. Furthermore, it is easy to transport, and the crane can be used to assemble and disassemble small steel towers in narrow spaces.

[0011] Thirdly, by making the tower mast a single-piece round pipe structure, the circular cross section has high rigidity against axial loads, ensuring the strength of the tower mast. In addition, the single-piece structure makes it possible to make the tower mast lightweight, economical, and relatively easy to manufacture. Fourth, the tower masts are assembled by installing the next tower mast under the lowermost tower mast and lifting it up, which means that the tower mast assembly work can be done on the ground, making it safe and easy.

[0012] The effect of the second idea is that by using a round pipe for the tower mast, the gap inside the tower for raising and lowering the tower mast can be reduced to about 50cm square in plan view, and when the boom is in the upright position, the plan view dimension is less than the same dimension as the gap, making it possible to lower the crane body and dismantle it, which made the crane smaller and significantly easier to dismantle.

[0013] The effect of the third invention is that a hanging chain with a hook is attached to the lift-up lifter of the lift-up device that installs and lifts up the tower mast, a mast hanging hook receiving bracket is attached to the tip of the installed tower mast, the installed tower mast is pulled under the lowest tower mast by the lift-up device, and the tower mast is installed by a spigot-type insertion, which simplifies the connection work of the tower mast and makes the tower mast assembly work easier.In addition, the spigot-type insertion prevents misalignment, makes it easier to align the axes of the assembled parts, and prevents them from falling over when force is applied. [Brief explanation of the drawings]

[0014] [Figure 1] Side view showing the height state of the small mast lift-up crane when assembled and disassembled [Figure 2] A partially cutaway overall view of a small mast lift-up crane used for assembling a small steel tower [Figure 3] FIG. 10 is an explanatory diagram showing the assembled state of the tower mast. [Figure 4] An enlarged view showing the connection between the lift-up lifter and the tower mast. [Figure 5] Enlarged cross-sectional view showing the connection of the spigot-type tower mast DETAILED DESCRIPTION OF THE INVENTION

[0015] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a description will be given of a mode for carrying out the present invention together with examples with reference to the drawings. Figure 1 is a side view of a small mast lift-up crane (hereinafter referred to as a lift-up crane) showing the state at the height when assembled and disassembled, and Figure 2 is a partially cutaway overall view when assembling a small steel tower with the lift-up crane. The lift-up crane 1 of this embodiment has a crane body 4 attached to the top tower mast 31, which is the top of the tower mast 3 installed inside the steel tower 2 to be assembled or disassembled.

[0016] As shown in FIG. 1, the crane body 4 has a slewing / hydraulic unit mast 41, which is the mast portion of the crane body 4, installed on the top tower mast 31, which will be described later, a hoisting winch mast 42 installed on top of that, and a boom mounting top mast 43 installed on top of that, and a boom 45 pivoted to a top pivoting portion 44 of the boom mounting top mast 43, which is the upper end of the mast portion of the crane body 4, and an auxiliary boom 46 pivoted to the tip of the boom 45, and a wire rope 48 with a hook 47 attached to the tip of the auxiliary boom 46.

[0017] 2, the lift-up crane 1 according to the embodiment is capable of assembling and dismantling small-scale steel towers by tilting the tip of the boom 45 rearward from the central axis of the steel tower 2 around the top pivot 44, folding the tip of the auxiliary boom 46 pivoted to the tip of the boom 45 forward in a V-shape relative to the boom 45, and lifting up or lowering the quadrangular pyramidal steel tower top 5 to be assembled or dismantled on the steel tower 2 with a hook 47 of a wire rope 48 suspended from the tip of the auxiliary boom 46. Note that reference numeral 6 in the figure denotes power line support members installed horizontally at the top, center, and bottom of the steel tower 2.

[0018] The lift-up crane 1 is designed to be lightweight, with a lifting load of less than 500 kg, making it possible to assemble and disassemble small steel towers. The reason for setting the lifting load at less than 500 kg is that the crane is easy to handle. In this embodiment, the lifting load is set to 498 kg.

[0019] The crane body 4 described above is lifted up by extending from its lower end the tower mast, which is erected on the base 7 installed at the center of the steel tower 2. The lifting is performed by a lifting device 8. The lifting device 8 is installed to the side of the base 7 near the bottom of the lift-up crane 1.

[0020] The lift-up device 8 is configured such that a lift-up winch 81 is installed on the side of the base 7, a lift-up frame 82 is installed on the side of the lift-up winch 81 closer to the base 7, and a lift-up lifter 83 is placed in the center above the base 7. The lift-up winch 81 is operated using guide rollers 85 provided on the lift-up frame 82 and the lift-up lifter 83, and the tower mast 3 described below is pulled up and assembled using a lift-up wire 84.

[0021] Assembly and disassembly of the lift-up crane 1 according to the present invention involves the assembly and disassembly of the crane body 4. The height of the lift-up crane 1 during assembly and disassembly is set to 9m or more but not to 10m. In this embodiment, it is set to 9.11m. Therefore, the work up to this point can be performed on the ground using a mini crawler crane.

[0022] 1, the lift-up crane 1 at the height it is at when assembled or disassembled already has one tower mast 32 suspended from the lift-up frame 82 of the lift-up device 8, and the top tower mast 31 attached to the upper end of the tower mast 32, with the two joined and suspended as a single unit. The crane body 4 is attached to the top tower mast 31, which is the top of the tower mast 3.

[0023] The top tower mass 31 and tower mast 32, as well as the other tower masts 3 that are incorporated, are made of a single round pipe structure. The circular cross section has high rigidity against axial loads, ensuring the strength of the tower mast, and the single-material structure makes the tower mast lightweight, economical, and relatively easy to manufacture. Furthermore, the tower masts 3 are assembled by incorporating the next tower mast 3 under the bottom tower mast 3 and lifting it up, which makes the assembly work of the tower masts 3 easy.

[0024] As shown in Figures 3 and 4, the tower mast 3 is assembled by attaching a hook-equipped suspension chain 86 to the lift-up lifter 83 of the lift-up device 8, which assembles and lifts up the tower mast 3, attaching a mast suspension hook receiving bracket 34 to the tip of the assembled tower mast 33, and connecting the hook receiving bracket 34 to the hook of the hook-equipped suspension chain 86. The assembled tower mast 33 is then pulled under the lowest tower mast 35 by the lift-up device 8, and assembled by a spigot-type insertion, and the assembled tower mast 33 is then joined to the lowest tower mast 35.

[0025] As shown in Figure 5, the spigot-type insertion is a structure in which one side of the tower mast 3 is made into a concave portion 36 and the other side into a convex portion 37, allowing the tower masts 3 to be fitted together and fixed. This is a method for stronger fixing, making it possible to achieve a strong and stable joint. It prevents misalignment between parts and allows for highly accurate assembly. In addition, it makes the assembly work easy and quick.

[0026] In addition, in the lift-up crane 1 shown in Figure 1 at the height when assembled and disassembled, the tower mast 32 that is joined to the top tower mast is already suspended upward, so the first tower mast 33 to be installed there, although not shown, is suspended diagonally from the tower mast 32 that is joined to the top tower mast, and is installed below the tower mast 32 that is joined to the top tower mast in the same manner as described above.

[0027] The height at which the entire weight can be supported by this lift-up device 8 is the free-standing height, which is approximately 15 m in this embodiment. If the height is to exceed this, support from the steel tower 2 is required, and assembly of the steel tower 2 also begins. In this embodiment, four tower masts 3, excluding the top tower mast 31, are assembled up to the free-standing height. To prevent the crane body 4 from falling over even when it becomes taller, the horizontal support fittings provided on the tower masts 3 are fixed to the steel tower 2 with wires during assembly of the steel tower. The free-standing height is the maximum height at which the horizontal support fittings can stand on their own without requiring any additional measures to support the steel tower 2.

[0028] After the steel tower 2 is completed, it is necessary to lower the crane body 4 from the steel tower 2 and dismantle it. In the lift-up crane 1 of the present invention, the tower mast 3 is made of a round pipe, so a small gap with a planar dimension of about 50 cm square can be created inside the steel tower 2 for raising and lowering the tower mast 3.By making the planar dimension of the boom 45 of the crane body 4 when in the upright position equal to or smaller than the same dimension of the gap, the crane body 4 can be lowered from the steel tower 2 and dismantled. [Explanation of symbols]

[0029] 1. Lift-up crane 2. Steel tower 3. Tower mast 31 Top tower mast 32. Tower mast joined to the top tower mast 33 Built-in tower mast 34 Mast hanging hook bracket 35. Bottom tower mast 36...Concave part 37 Convex part 4. Crane body 41 Swing Hydraulic Unit Mast 42······Hoisting winch mast 43 Boom mounting top mast 44...Top shaft attachment part 45 Boom 46 Auxiliary boom 47 Wire rope hook 48. Wire rope 5. Pyramid-shaped tower top 6. Transmission line support member 7. Base 8. Lift-up device 81······Lift-up winch 82······Lift-up frame 83······Lift-up lifter 84······Lift-up wire 85 Guide roller 86······ Hanging chain with hook

Claims

1. A small mast lift-up crane capable of assembling and dismantling small steel towers is configured such that a crane body is attached to the top of a tower mast installed inside the steel tower to be assembled or dismantled, an auxiliary boom is attached to the tip of the boom of the crane body which is attached to the top pivot point of the mast portion of the crane body, the tip of the boom is tilted rearward from the central axis of the steel tower around the top pivot point, the tip of the auxiliary boom attached to the tip of the boom is folded forward in a U-shape relative to the boom, and the top of the square pyramid-shaped steel tower to be assembled or dismantled on the steel tower is lifted up or lowered using a wire rope hook hanging from the tip of the auxiliary boom, This small mast lift-up crane is capable of assembling and dismantling small steel towers, characterized in that the crane has a lightweight design with a lifting load of less than 500 kg that allows it to assemble and dismantle small steel towers, the height of the crane when assembling and dismantling the crane itself is 9 m or more and 10 m or less, and further, the tower mast is made of a single round pipe structure, and the next tower mast is assembled under the lower end tower mast and lifted up.

2. 2. A small mast lift-up crane capable of assembling and dismantling small steel towers according to claim 1, characterized in that a gap of approximately 50 cm square in plan is created inside the steel tower for raising and lowering the tower mast, and the planar dimensions of the boom when in an upright position are set to be equal to or less than the same dimensions of the gap, allowing the crane body to be lowered and dismantled.

3. 3. A small mast lift-up crane capable of assembling and dismantling small steel towers according to claim 1 or 2, characterized in that a lift-up lifter of a lift-up device that assembles and lifts up a tower mast is provided with a hanging chain with a hook, a mast hanging hook receiving bracket is provided at the tip of the assembled tower mast, the assembled tower mast is pulled under the lowest tower mast by the lift-up device, and the tower mast is assembled by a spigot-type insertion.

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