JP7519963B2 - Retractable lifting equipment - Google Patents

Description

The present invention relates to a retractable lifting device used during shaft construction.

Shafts constructed underground are used for multiple purposes, such as the launch and arrival base for shield machines in shield tunnel construction, intermediate storage for radioactive waste, and foundations for bridges. Construction of these shafts involves tasks such as excavating and blasting the inside of the shaft, and constructing the side walls and bottom slabs, so a work platform that can freely ascend and descend within the shaft from ground level to the depth at which work is being performed is required.
Generally, in the construction of a shaft, the work platform is replaced following the excavation of the ground, and if blasting is involved, the work platform needs to have a function to prevent scattering during blasting work. The conventional method for replacing the work platform is to use a lifting device such as a crane installed on the ground to lower the work platform, and during work on the work platform, to engage it with a retaining wall or shoring installed on the shaft wall.
Patent Document 1 discloses a working platform for vertical shaft construction and its mounting device, which is provided with an equipment loading/unloading door and a worker loading/unloading door that can be opened and closed freely, either inscribed in the inner wall of the shaft or with a small gap between them, and which is formed with an equipment loading/unloading window for suspending and lowering pipes and machines, and an access point for workers to ascend and descend.

Utility Model Registration No. 3107458

In the construction of a vertical shaft, the height between the above-mentioned working floor and the excavation surface may be about 10 m in order to ensure a sufficient operating range for heavy machinery required for excavation and soil removal work. A simple ladder as described in Patent Document 1 is generally used as a means for ascending and descending to the working floor and the excavation surface. Despite this considerable height, a simple ladder has structural instability and safety issues. On the other hand, a wall-mounted ladder may be used, although it is not suitable for the construction of a vertical shaft, where the excavation surface changes according to the excavation cycle. However, in the case of a wall-mounted ladder, it is necessary to replace it each time the excavation surface changes, which is inefficient, and there is also a possibility that it will be damaged every time blasting is performed due to a direct hit from blasting flying stones.
The present invention aims to solve the above-mentioned problems, and has as its object to provide a retractable lifting equipment that has a simple configuration, can safely and reliably move up and down between the work platform and the excavation surface, and is not damaged even by blasting stones.

The retractable lifting equipment of the present invention for solving the above-mentioned problems is a retractable lifting equipment for ascending and descending to the excavation surface of a vertical shaft, characterized in that it comprises a guide body erected on a work floor that can be accommodated in the vertical shaft, and a ladder body suspended from the guide body so as to slide along the guide body and move up and down within an opening provided in the work floor.
According to this configuration, the ladder body is suspended from the guide body that absorbs the reaction force from the work platform, and can move up and down through an opening in the work platform along the guide body, allowing the worker to move between the work platform and the excavation surface. When excavating with heavy machinery, the ladder body can be stored on the work platform, allowing work to be done without interfering with the turning range. Furthermore, the ladder body will not be directly hit and damaged by flying stones caused by blasting.

It is also preferable that a bottom plate capable of closing the underside of the opening is fixed to the underside of the ladder body.
If a bottom plate is fixed to the underside of the ladder body, the opening of the work floor can be blocked, so it is possible to reliably prevent flying stones caused by blasting from entering through the opening. In addition, by having workers board the bottom plate or load materials onto it, it also serves as a simple elevator.

Furthermore, it is preferable that a roller that enables the sliding movement is attached to the guide body.
By interposing rollers in the sliding part of the guide body, smooth up and down movement of the ladder body is possible, and by providing the ladder body with a rail material that can slide along the rollers, the ladder body is more restrained against left and right swinging and rotation, thereby reducing excessive swinging and vibration during movement.

The ladder body may be suspended from the guide body by an electric chain block.
If an electric chain block is used to move the ladder body up and down, the ladder body can be controlled to any height by remote control, not only from the work platform or excavation surface, but also from inside the ladder body. Also, the electric chain block is easy to install and remove.

The retractable lifting equipment of the present invention is suspended from a guide body that absorbs reaction forces from the work floor, and allows movement between the work floor and the excavation surface using a ladder body that can move up and down through an opening in the work floor along the guide body. This makes it possible to provide a structure that can safely and reliably move up and down between the work floor and the excavation surface with a simple configuration, and that is not damaged by flying blasting stones.

FIG. 1 is a cross-sectional layout diagram of a retractable lifting facility during construction of a vertical shaft according to an embodiment of the present invention. FIG. 2 is a plan view of the retractable lifting equipment during construction of a vertical shaft according to an embodiment of the present invention (as viewed along the arrows A-A in FIG. 1). 3A and 3B are cross-sectional views of the working floor during construction of a vertical shaft according to an embodiment of the present invention (viewed along the arrows B-B in FIG. 2), in which (a) shows the loading/unloading entrance open, and (b) shows the loading/unloading entrance closed. FIG. 3 is a detailed plan view of the retractable lifting equipment during construction of a vertical shaft according to an embodiment of the present invention (part C in FIG. 2 ). 1A and 1B are detailed cross-sectional views of a retractable lifting equipment according to an embodiment of the present invention during shaft construction, in which (a) shows the equipment being stored on the work platform, and (b) shows the equipment being lowered to the excavation surface.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings as appropriate.
<Overall composition>
Fig. 1 shows a cross-sectional layout diagram of the retractable lifting equipment during construction of a vertical shaft according to an embodiment of the present invention. Fig. 2 shows a plan layout diagram of the retractable lifting equipment during construction of a vertical shaft according to an embodiment of the present invention, taken along the line A-A in Fig. 1.

As shown in FIG. 1, in a relatively soft layer from the ground surface, a retaining wall 11 is constructed on the ground G so as to surround a rectangular shape (not shown) in plan view. The internal excavation of the area surrounded by the retaining wall 11 and the erection of the support structure 12 are repeated multiple times as one cycle, and the ground is excavated to a specified depth. For hard ground deeper than that, a deep foundation method is adopted, and internal excavation is performed with a circular shape (not shown) in plan view contained within the retaining wall 11 as the excavation range, and divided ring supports are erected on the exposed natural ground wall surface by excavation, assembled and closed in a ring shape, and installed, and the wall surface 13 is constructed by wrapping it with sprayed concrete, while repeating this cycle multiple times to construct the wall surface 13 to the planned depth. Excavation is basically performed using heavy machinery such as a backhoe or breaker, but blasting is also used as necessary. During one cycle of excavation and construction, heavy machinery and workers work together or independently near the excavation surface 14, so the movement of workers, heavy machinery, and equipment in and out of the shaft 1, and lifting work such as removing residual soil, are frequently performed. For this reason, in this embodiment, the work floor 2 is provided about 7 m above the excavation surface 14, taking into consideration the operating range of the heavy machinery and the impact of flying stones caused by blasting. The height of the work floor 2 is changed over following the excavation of the ground, and the work floor is lowered using lifting equipment such as a crane installed on the ground, and while work is being done on the work floor 2, the support force is secured from the ring support installed on the wall surface 13.

As can be seen from the figure, the retractable lifting equipment 3 of the present invention is a lifting equipment for workers to ascend and descend between the work floor 2 and the excavation surface 14, and is composed of a guide body 31 erected on the work floor 2 that can be stored in the shaft 1, and a ladder body 32 suspended from the guide body 31 so as to slide along the guide body 31 and move up and down within an opening O2 provided in the work floor 2.

As shown in Figure 2, the work floor 2 comprises a stage 21 processed to a shape and dimensions that can be accommodated in the wall surface 13, a loading/unloading entrance O1 that is rectangular in a plan view and is provided on the stage 21, a set of side plates 22, 22 that are approximately inverted V-shaped in a side view and are erected along one edge of the loading/unloading entrance O1, and a set of cover plates 24, 24 that are freely rotatable around the other opposing edge of the loading/unloading entrance O1, and the cover plates 24, 24 are configured to cover the edges of the side plates 22, 22 when the loading/unloading entrance O1 is closed.
The retractable lifting equipment 3 is positioned close to the wall surface 13 so that the lifting body 32 (in the same figure, the ladder section 324 described later) extended above the excavation surface 14 does not interfere with work by heavy machinery, etc.

<Work floor>
FIG. 3 is a cross-sectional view of the work floor during construction of a vertical shaft according to an embodiment of the present invention, taken along the line B-B in FIG. 2, where (a) shows the loading/unloading entrance open, and (b) shows the loading/unloading entrance closed.

3, the stage 21 is formed as a single unit by combining beams made of multiple H-shaped steel beams and flooring made of steel plates such as checkered steel plates, and joining them with bolts, welding, or other methods. The stage 21 is machined to a shape and dimensions that do not interfere with the inner periphery of the wall 13 or the various temporary materials laid on the inner periphery. A loading/unloading entrance O1 that is rectangular in plan view is formed near the center of the stage 21, and its shape and dimensions are determined taking into consideration all expected work, such as the removal of waste soil from excavation and construction work carried out below the work floor 2, the supply of concrete, the introduction and removal of temporary equipment and materials, removal for the evacuation of heavy machinery during blasting work, and re-import. In addition, when work is carried out simultaneously above and below the work floor 2, the loading/unloading entrance O1 is designed to be able to be closed with side panels 22, 22 and cover panels 24, 24, which will be described later, to ensure the safety of workers below against objects flying and falling from the loading/unloading entrance O1, and to prevent accidents caused by flying gravel and other debris due to blasting work below.

The side plate 22 is a plate material that is erected along one of the opposing edges of the loading/unloading entrance O1 and has a roughly inverted V shape in side view, and is formed by combining multiple steel sections and steel plates. One of the support materials 23, 23, 23 is fixed to the rear side of the side plate 22 facing the loading/unloading entrance O1, and the other side is fixed to the stage 21. The support material 23 is a diagonal material made of H-shaped steel.

The cover plate 24 is a plate material that is installed to be freely rotatable about the other opposing edge of the loading/unloading entrance O1, and is formed by combining a plurality of steel shapes and steel plates, similar to the side plate 22. The rotation of the cover plate 24 is realized by connecting it to a plurality of hinges 26, 26, 26... so as to straddle the edge of the cover plate 24 and the stage 21. The shape and dimensions of the cover plate 24 are determined so that when the loading/unloading entrance O1 is closed, it covers the edge of the side plate 22 and no gap is generated between the butted edges of the cover plates 24, 24.
As shown in FIG. 13B, when the loading/unloading entrance O1 is in a closed state, it can be locked by locking members 25, 25 so that it will not be easily opened by an explosion caused by blasting performed below the work floor 2.
One end of the first wire 27 is rotatably fixed to the rear side of the opening of the cover plate 24, and the other end is hooked around a pulley provided on a stopper 28 erected on the stage 21 and then wound around a winch fixed on the stage 21. The cover plate 24 is opened and closed by feeding and winding the winch.
When the loading/unloading entrance O1 is open, the center of gravity of the cover plate 24 is supported by the stopper 28 so as to act toward the loading/unloading entrance O1. This ensures that tension is always applied to the first wire 27, making manual labor unnecessary and allowing the cover plate 24 to be opened and closed only by controlling the winch.

<Retractable lifting equipment>
Fig. 4 shows a detailed plan view of the retractable lifting equipment during construction of a vertical shaft, which is an embodiment of the present invention, as shown in part C of Fig. 2. Fig. 5 shows a detailed cross-sectional view of the retractable lifting equipment during construction of a vertical shaft, which is an embodiment of the present invention, in which (a) shows the equipment being stored on the work platform, and (b) shows the equipment being lowered to the excavation surface.

As shown in Figures 4 and 5, the guide body 31 is made by combining multiple steel beams, and a lower frame body 313, which is shaped like a picture frame in a plan view, is fixed to surround the opening O2 provided in the work floor 2 (stage 21). Support columns 311, 311, 311, 311 are erected at the four corners of the lower frame body 313, and an upper frame body 312 similar to the lower frame body 313 is joined to the upper part of the support columns 311, 311 to form a box body made of a framework. In addition, an entrance/exit is provided between the support columns 311, 311 to allow workers to get on and off the lifting body 32 (not shown), and first diagonal members 314, 314 are arranged in a structurally necessary range between the support columns 311, 311. In addition, the upper frame body 312 and the lower frame body 313 are provided with rotatable cylindrical rollers 315, 315... at four positions each facing each other, for a total of eight positions.

Like the guide body 31, the lifting body 32 is formed by combining multiple steel sections, and is mainly composed of rail members 321, 321, 321, 321 that serve as supports at the four corners and can be inserted into the guide body 31, and a joint member 321 that connects the rail members 321, 321 horizontally, joined together to form a box body made of a framework. In addition, an entrance/exit (not shown) is provided between the rail members 321, 321 to allow workers to get on and off, and second diagonal members 3234, 3234 are arranged in the range required for the structure between the rail members 321, 321.

C-shaped steel is used for the rail material 321, and it is arranged so that its recess faces outward. The roller 315 is housed in the recess so that it can slide freely.

Furthermore, a ladder section 324 is fixed to the lifting body 32 along the inner surface of the joint member 322 so that a worker can ascend and descend. Furthermore, a bottom plate 33 capable of blocking the underside of the opening O2 when the lifting body 32 is raised is fixed to the lower end of the rail members 321, 321, 321, 321. A beam member 34 for improving the rigidity of the bottom plate 33 is integrally joined to the underside of the bottom plate 33, and is provided with a locking section 35 with a hole at one end.

The second wire 362 is hung on a hook 361 suspended from an electric chain block 33 attached to the top of the guide body 31 and is engaged with the engaging portion 35, and the lifting body 32 is raised and lowered by the power of the electric chain block 36.

As described above, according to the retractable lifting equipment 3 of this embodiment, it is possible to move between the work floor 2 and the excavation surface 14 using the lifting body 32 that is suspended from the guide body 31 that receives the reaction force from the work floor 2 and moves up and down through the opening O2 provided in the work floor 2 along the guide body 31. In addition, when excavating with heavy machinery, the lifting body 32 can be stored on the work floor 2, so that work can be performed without interfering with the turning range. Furthermore, there is no risk of direct damage from flying stones caused by blasting. If the bottom plate 33 is fixed to the underside of the lifting body 32, the opening O2 of the work floor 2 can be blocked, so that it is possible to reliably prevent flying stones caused by blasting from entering through the opening O2. In addition, by having workers board the bottom plate 33 or loading materials onto it, it also serves as a simple elevator. By providing rollers 315 in the sliding portion of the guide body 31, smooth vertical movement of the lifting body 32 is possible. In addition, by providing the lifting body 32 with rail members 321 that can slide along the rollers 315, the lifting body 32 is more restricted in its left-right swing and rotation, reducing excessive swinging and vibration during movement. If an electric chain block 36 is used to move the lifting body 32 up and down, the movement of the lifting body 32 can be controlled by the associated remote control operation so that the lifting body 32 is at any height, not only from the work platform 2 or the excavation surface 14, but also from inside the lifting body 32. The electric chain block 36 is also easy to install and remove.

The above describes an embodiment of the present invention, but the present invention is not limited to the above embodiment and can be modified as appropriate without departing from the spirit of the present invention. For example, in this embodiment, the lifting body 32 alone can move between the work floor 2 and the excavation surface 14, but the lifting body 32 can be slid to a height halfway between the work floor 2 and the excavation surface 14, and a conventional ladder can be used in combination to move between the lifting body 32 and the excavation surface 14. Furthermore, if the weight of the lifting body 32 is heavy and affects the lifting operation of the work floor 2, the electric chain block 36 can be hung on a support structure on the wall. It is also possible to reduce the weight load on the work floor 2.

G Ground O1 Carry-out entrance O2 Opening 1 Vertical shaft 11 Retaining wall 12 Shoring 13 Wall surface 14 Excavation surface 2 Working floor 21 Stage 22 Side plate 23 Support material 24 Cover plate 25 Locking member 26 Hinge 27 First wire 28 Stopper 3 Retractable lifting equipment 31 Guide body 311 Support 312 Upper frame body 313 Lower frame body 314 First diagonal member 315 Roller 32 Lifting body 321 Rail material 322 Joint material 323 Second diagonal member 324 Ladder section 33 Bottom plate 34 Beam material 35 Locking section 36 Electric chain block 361 Hook 332 Second wire

Claims (4)

A retractable lifting device for ascending and descending to the excavation face of a shaft,
A guide body erected on a work platform that can be accommodated in the shaft;
Sliding along the guide body,
a lifting body suspended from the guide body so as to be movable up and down within an opening provided in the work floor. The retractable lifting equipment according to claim 1, characterized in that a bottom plate capable of closing the bottom of the opening is fixed to the underside of the lifting body. The retractable lifting equipment according to claim 1 or 2, characterized in that the guide body is fitted with rollers that enable the sliding movement. The retractable lifting equipment according to any one of claims 1 to 3, characterized in that the lifting body is suspended from the guide body by an electric chain block.

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