Hanging jig

Abstract

To provide a hanging jig capable of lowering a reinforcing bar safely and quickly even when a circular vertical shaft has a small diameter.SOLUTION: Provided is a hanging jig 1 used to hang a hoop 10 formed in an arc shape in plan view into a vertical shaft 3 constructed with a circular cross section by lifting means. The jig includes a lower jig 40 formed in an arc shape corresponding to the planar shape of the hoop 10 and capable of hanging the hoop 10, and an upper jig 20 formed in a polygonal shape that is substantially inscribed in the lower jig 40 formed in an arc shape in plan view, capable of hanging the lower jig 40, and hung by the lifting means.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a lifting jig, and more particularly to a lifting jig that can safely and quickly lower a reinforcing bar into a circular vertical shaft excavated in the ground. [Background technology]

[0002] It has been known to create a tunnel through which groundwater and other materials can flow by, for example, excavating a circular shaft underground and lining the surface of the shaft with concrete. The concrete lining work for such a shaft requires a process above ground in which reinforcing bars called hoops, bundled together in multiple layers, are lowered to the bottom of the shaft.

[0003] This type of work can be done in a variety of ways, including by placing multiple workers on scaffolding that is erected inside the shaft and reaches the ground, and directly passing the hoops from the ground to the bottom, or by using heavy machinery such as a crane to lower the hoops to the bottom.However, the former method results in a significant loss of manpower and time, and the latter method has the disadvantage that if the shaft is circular and has a small diameter, it is difficult to ensure a sufficient gap between the scaffolding erected in the center and the surface of the surrounding shaft, and depending on the position of the hoops as they are lowered, they may get caught on the scaffolding or the surface of the shaft, reducing workability. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Publication No. 2022-23373 Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention has been made to solve the above-mentioned problems, and aims to provide a lifting jig that can safely and quickly lower reinforcing bars even when the circular shaft has a small diameter. [Means for solving the problem]

[0006] In order to solve the above problems, the present invention is configured to provide a hanging jig used when suspending a hoop reinforcement formed in an arc shape in plan view within a vertical shaft constructed with a circular cross section by a lifting means, the hanging jig comprising a lower jig formed in an arc shape corresponding to the planar shape of the hoop reinforcement and capable of suspending the hoop reinforcement, and an upper jig formed in a polygon substantially inscribed in the lower jig formed in an arc shape in plan view, capable of suspending the lower jig, and suspended by the lifting means.

[0007] According to this configuration, the lower jig, which is formed in an arc shape corresponding to the planar shape of the hoop and can hang the hoop, is formed in a polygon that is substantially inscribed in the lower jig and can be hung from an upper jig that is suspended by a lifting means, so that the arc-shaped hoop can be hung down in a stable position.

[0008] The upper jig may be triangular in plan view, and the suspending means hanging from positions corresponding to the vertices of the triangle may be connected to the center and both ends of the arc of the lower jig, which is formed in an arc shape. Also, any of the suspending means may be configured to be adjustable in length. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram showing the entire construction site. [Figure 2] FIG. [Figure 3] FIG. [Figure 4] FIG. 2 is a schematic diagram showing the relationship between an upper jig and a lower jig. DETAILED DESCRIPTION OF THE INVENTION

[0010] The process of lowering a hoop reinforcement 10 using a lifting jig 1 will be described below with reference to Figures 1 and 2. In the figure, a vertical shaft 3 is a hole excavated in the ground, and is a circular vertical shaft set to a depth of 30 m and a diameter of 4 m, for example. On the surface (circumferential surface) of the vertical shaft 3, steel rings 5, also known as urban rings, which are divided along the circumference, are arranged in multiple layers vertically, forming an earth retaining wall. Inside the vertical shaft 3, a work scaffolding 7, which includes stairs, handrails, etc., is erected from the bottom toward the ground, and workers can use the scaffolding 7 to move between the inside and outside of the vertical shaft 3.

[0011] Hoops 10 are arranged on the inner diameter side of the ring 5, which serves as an earth retaining wall. As shown in each figure, the hoops 10 are formed in a lattice pattern with an arc-shaped planar shape along the inner circumferential surface of the shaft 3 (ring 5) by connecting multiple horizontal reinforcements extending in an arc in a plan view with vertical reinforcements extending linearly in a direction perpendicular to the horizontal reinforcements. The circumferential length of the hoops 10 is set to approximately divide the circumferential length of the shaft 3 into two or three parts. By arranging multiple hoops 10 along the circumference of the shaft 3, a ring-shaped hoop 10 is formed on the inner diameter side of the ring 5. The number of divisions of the hoops 10 can be set as appropriate, and multiple layers of hoops 10 may be arranged on the inner diameter side of the shaft 3. As shown in FIG. 1, the hoops 10 are carried into the shaft 3 by a lifting device 9, such as a crane, via the lifting jig 1 of the present invention.

[0012] [About the hanging jig] As also shown in Figure 2, the hanging jig 1 comprises an upper jig 20 supported via a crane hook 9A, and a lower jig 40 supported via the upper jig 20 and capable of hanging a hoop reinforcement 10 below.

[0013] 2, the upper jig 20 is a steel frame formed in the shape of a substantially right-angled isosceles triangle in plan view, and includes oblique members 22A and 22B that intersect with each other at substantially right angles, a base member 24 that extends to connect the oblique members 22A and 22B, and a reinforcing member 26 that extends from the center of the base member 24 toward the intersection of the oblique members 22A and 22B. Each of these members is formed by an L-shaped angle and has enough strength to hang the hoop 10.

[0014] One end of each of the diagonal members 22A and 22B is fixed by a bolt through a bolt hole in a fixing plate 28 welded to the reinforcing member 26, forming the apex (vertex) of a triangle at an angle of approximately 90°. The other end of each of the diagonal members 22A and 22B is fixed to the ends of the base member 24 via bolts, forming the base of the triangle at an angle of approximately 45°. One end of the reinforcing member 26 on the side of the base member 24 is fixed to the base member 24 with a bolt, and the other end extends toward the vertex of the triangle and terminates protruding beyond the fixing plate 28. A hanging piece 30 is fixed to the other end of the reinforcing member 26 by bolt or welding.

[0015] The hanging piece 30 is a plate-like body formed with locking holes at the top and bottom, and a shackle 30A engages with the locking hole formed at the top and is connected to a hanging ring of an upper hanging means 33 (including a lever block R) described below that hangs down from the hook 9A. A shackle 30B engages with the locking hole formed at the bottom, and a lower hanging means 43 (nylon sling) for suspending the upper jig 20 described below is connected via the shackle 30B. The hanging piece 30 is fixed not only to the other end of the reinforcing member 26 corresponding to the apex of the triangle, but also to both ends of the base member 24 corresponding to the base corners of the triangle, and the upper hanging means 33 and the lower hanging means 43 are connected via each hanging piece 30.

[0016] As shown in Figures 1 and 2, the upper jig 20 configured as described above can be suspended by a hook 9A via an upper suspension means 33. Here, the upper suspension means 33 extending from the hook 9A to the suspension piece 30 at the other end of the reinforcing member 26 forming the apex of the triangle is composed of a wire rope and a Lever Block (registered trademark) (chain) as a length adjustment means. Meanwhile, the upper suspension means 33 extending from the hook 9A to the suspension piece 30 at the other end of the base member 24 forming the base corner of the triangle is composed of a non-elastic wire rope. The upper ends of the upper suspension means 33 are suspended by the hook 9A while being secured (tied together) by a master link M.

[0017] In this way, by making some of the upper hanging means 33 located at positions corresponding to the vertices of the triangle adjustable in length, the horizontal angle of the upper jig 20 (direction of the arrow in Figure 2) can be freely adjusted with the position corresponding to the base angle as the fulcrum, making it possible to adjust the posture when hanging the hoop reinforcement 10 into the vertical shaft 3.

[0018] Next, we will explain the lower jig 40 that can be suspended by the upper jig 20. As shown in Fig. 2, the lower jig 40 is an arc-shaped steel material that roughly matches the circumferential length and curvature of the hoop reinforcement 10 to be suspended, and includes a main body 42 that is made of an L-shaped angle, similar to the upper jig 20. More specifically, the main body 42 is formed in a shape that becomes an arc inscribed with the upper jig 20, which is formed as a roughly right-angled triangle, when viewed from above.

[0019] Lifting pieces 60, each having a similar configuration to the above-described lifting pieces 30, are fixed to the center and both ends of the arc of the main body 42 by bolts, welding, or the like. A nylon sling is connected to a shackle 60A located at the top of the lifting piece 60 as a lower lifting means 43 hanging down from above. Specifically, as shown in FIG. 2 , the nylon sling hanging down from the lifting piece 30 corresponding to the position corresponding to the apex of the upper jig 20 is connected to the lifting piece 60 fixed at the position corresponding to the center of the arc of the main body 42, and each nylon sling hanging down from the lifting piece 30 corresponding to the position corresponding to the bottom corner of the upper jig 20 is connected to the lifting piece 60 fixed at the position corresponding to the arc end of the main body 42. In other words, the lower jig 40 is suspended in a three-point supported state by the upper lifting jig 20.

[0020] In this way, the lower jig 40 formed on an arc is suspended vertically by a nylon sling hanging down from the upper jig 20 formed in a polygonal shape with a top, thereby suppressing circumferential twisting and vibration in the lower jig 40, and the hoop reinforcement 10 suspended by the lower jig 40 can be lowered into the vertical shaft 3 in a stable state.

[0021] A sling wire serving as a hoop hoisting means 53 connected to the hoop 10 is connected to the shackle 60B located at the bottom of the lifting piece 60. Detachable V-hooks H are provided at the upper and lower ends of the sling wire, and the V-hook H at the upper end is hooked onto the shackle 60B, and the V-hooks H at the lower end are hooked onto the center and both ends of the arc of the hoop 10 formed on an arc using, for example, horizontal reinforcement, thereby suspending the hoop 10 below the lower jig 40. Furthermore, by providing V-hooks H at both ends of the sling wire in this manner, the hoop 10 can be easily detached from the lifting jig 1 (lower jig 40) when lifting the hoop 10 or when the lifting is completed.

[0022] Next, we will explain the process of suspending the hoop 10 using the suspending jig 1 configured as described above. As shown in Figure 3(a), when suspending the hoop 10 to the deepest part of the shaft 3, the length (number) of the lower suspending means 43 (nylon sling) connecting the upper jig 20 and the lower jig 40 is adjusted so that the hoop 10 and the lower jig 40, which are formed in an arc shape relative to the depth of the circular shaft 3, are lowered until they are simultaneously positioned within the shaft 3. As a result, the lower jig 40 and the hoop 10, which are formed in an arc shape relative to the depth of the shaft 3, are stably accommodated in the gap with an annular cross section formed between the inner surface of the shaft 3 (ring 5) and the scaffolding 7, and the hoop 10 can be stably suspended to the deepest part of the shaft 3. Furthermore, if the hoop reinforcement 10 is tilted when descending into the vertical shaft 3, this can be corrected by operating a lever block provided on part of the upper hanging means 33 to correct the tilt of the lower jig 40 and the hoop reinforcement 10.

[0023] As shown in Figure 3(b), the descent continues, and after the hoop 10 reaches the deepest part, the V-hook H is operated to detach the hoop 10 from the lower jig 40. After detaching from the hanging jig 1, the hoop 10 is positioned at a predetermined position inside the ring 5. Thereafter, by performing the work of hanging and positioning multiple hoops 10 along the inner circumference of the ring 5, the annular hoop located on the inner diameter side of the ring 5 is erected. This process is then repeated from the deepest part to the top of the shaft 3, or by pouring concrete at regular intervals, a reinforced concrete lining integrated with the ring 5 can be constructed along the depth direction of the shaft 3.

[0024] Although the present invention has been described above through the embodiments, the technical scope of the present invention is not limited to the above embodiments. It is obvious to those skilled in the art that various modifications and improvements can be made to the above embodiments, and it is clear from the claims that such modifications and improvements are also included within the technical scope of the present invention.

[0025] For example, FIG. 4(a) shows a schematic diagram of the planar shape relationship between the upper jig 20 and the lower jig 40 according to the embodiment. However, the planar shape of the upper jig 20 is not limited to a triangle. It may be a quadrilateral or a polygonal shape, such as an isosceles trapezoid or a rhombus, as shown in FIG. 4(b), depending on the circumferential length and curvature of the arc-shaped lower jig 40 and the hoop reinforcement 10. Even in these shapes, by forming a polygon that is substantially inscribed in the arc of the lower jig 40 (hoop reinforcement 10), it is possible to suspend the lower jig 40 (hoop reinforcement 10) while maintaining a stable posture without twisting or swinging. Note that "substantially inscribed" does not mean "geometrically or mathematically inscribed," but rather, it is sufficient that the structural relationship in the embodiment is substantially inscribed, allowing for differences such as manufacturing errors. [Explanation of symbols]

[0026] 1 Lifting jig, 3 Shaft, 5 Ring, 10 Hoop, 20 Upper jig, 30 (60) Hanging piece, 33 Upper hanging means, 40 Upper jig

Claims

1. A hanging jig used when hanging down a hoop reinforcement formed in an arc shape in plan view in a vertical shaft constructed with a circular cross section by a lifting means, A lower jig formed in an arc shape corresponding to the planar shape of the hoop and capable of suspending the hoop; an upper jig that can suspend the lower jig, that is formed in a polygonal shape that is substantially inscribed in the lower jig that is formed in an arc shape in a plan view, and that is suspended by the lifting means; A lifting jig comprising:

2. The lifting jig described in claim 1, characterized in that the upper jig is triangular in plan view, and the lifting means hanging from positions corresponding to the vertices of the triangle are connected to the center and both ends of the arc of the lower jig, which is formed in an arc shape.

3. 3. The hanging jig according to claim 2, wherein any one of the hanging means is adjustable in length.

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