Mobile turntable and method for changing the direction of construction materials using the same

Abstract

In construction sites with height restrictions, when it is necessary to change the direction of construction materials, this device can be set up as needed to easily change the direction of construction materials to any desired direction. [Solution] The mobile turntable MT has a table 1 and a table rotation support member 2. In particular, the height of the table rotation support member 2 is lowered to a predetermined height. At various construction sites, the turntable MT is moved to the construction position by forklift, the table 1 is lowered and installed at the construction position, construction materials are placed on the table 1 with a forklift, and the construction materials are manually rotated on the turntable MT.

Description

Technical Field

[0001] The present invention relates to a mobile turntable that is installed at various construction sites as needed and is used for changing the direction of construction materials, and a method for changing the direction of construction materials using the same.

Background Art

[0002] In tunnel construction, for example, as disclosed in Patent Document 1, a shield method using a shield tunneling machine is known. The shield tunneling machine has a cylindrical shape for the tunneling machine body, and a cutter head having a disk shape with a plurality of cutter bits is attached to the front part of the tunneling machine body. A large number of shield jacks for advancing the tunneling machine body and an erector for assembling segments on the inner wall surface of an existing tunnel are attached to the rear part of the tunneling machine body. In the shield method, such a shield tunneling machine is used to excavate the ground ahead while rotating the cutter head in the ground, and the shield jacks are extended to obtain a reaction force from the existing segments to advance the tunneling machine body. The erector assembles segments in a ring shape on the inner wall surface of the existing tunnel to construct a tunnel of a predetermined length.

[0003] In such tunnel construction, for example, as shown in FIGS. 5 and 6, a gantry T is assembled in an existing tunnel from a starting shaft to the rear of the tunnel boring machine, rails R are laid on this gantry T, and a segment carriage C is arranged on these rails R so as to be able to travel. The segments are transported by this segment carriage C. In this case, the segment carriage C is a traverser with a turntable, is installed on a pair of rails, and is connected to a cable that is fed out and wound up from a cable reel driven by a driving device to travel. The turntable is of a ball bearing type (a method of laying balls on a rotating part), includes a motor, a speed reducer, an electric circuit, etc., is installed on the traverser C, and is rotationally driven by power. In this way, the segment is placed on the traverser in the launch shaft with its longitudinal direction facing the direction of the traverser's movement, and the traverser transports the segment to a segment transfer position near the rear of the shield tunneling machine. At this segment transfer position, the rotation of the traverser's turntable orients the longitudinal direction of the segment perpendicular to the direction of the traverser's movement. The erector at the rear of the shield tunneling machine has a gripping part that grips the segment and a gripping part drive mechanism that moves the gripping part along the inner circumferential surface of the rear of the shield tunneling machine and pushes it toward the inner circumferential surface of the rear of the shield tunneling machine. At the segment transfer position, the segment is gripped by the erector and assembled into a ring shape inside the rear of the shield tunneling machine. In addition, a turntable with wheels may be used instead of the traverser described above. In this way, the segments are assembled into a cylindrical shape as a whole, and the tunnel is constructed. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2003-239695 [Overview of the project] [Problems that the invention aims to solve]

[0005] Incidentally, in tunnel construction like this, cranes are sometimes used to lift segments from the segment trolley to transfer them between the segment trolley and the erector. In this case, if the construction space is narrow and the rails for the segment trolley are laid up to the segment transfer point, the height of the rails and segment trolley may prevent sufficient lifting clearance for the segment by the crane at the transfer point. Furthermore, the segments handled by recent large shield tunneling machines are large, which can make it even more difficult to secure sufficient lifting clearance for the segment by the crane. The same problem can occur even when using a turntable with wheels. Therefore, in this case, the height of the traverser, rails, and wheels becomes an obstacle.

[0006] Furthermore, the segment transfer point between the segment trolley and the erector may be located along the movement paths of heavy machinery or vehicles, or within the heavy machinery's work yard. In this case, the rail equipment of the segment trolley becomes an obstacle.

[0007] When the rail equipment for the segment trolley becomes an obstacle, the only option is to use heavy machinery such as forklifts to transfer the segments to the erector, instead of using equipment such as turntable-equipped traversers or rails.

[0008] However, even in this case, depending on the assembly position of the segments within the tunnel, it may be necessary to temporarily change the orientation of the segments, for example, by handing them over to an erector with one end facing the erector. In such cases, forklifts have the problem of not being able to handle the change in segment orientation because they can only hand over segments to erectors in a horizontal position.

[0009] The present invention aims to solve these conventional problems by providing a mobile turntable that can be set up at a construction site as needed to easily change the direction of construction materials in any direction when it is necessary to change the direction of construction materials at construction sites with height restrictions, and a method for changing the direction of construction materials using the same. [Means for solving the problem]

[0010] To achieve the above objective, the mobile turntable of the present invention is: A table for placing construction materials at a construction site, A table rotation support member is provided concentrically and integrally on the lower surface of the table, for supporting the table so that it can be manually rotated, Equipped with, The table rotation support member is set to a minimum height or close to that height on the underside of the table, such that the forks of a forklift can be inserted around the table rotation support member. This mobile turntable is movable by a forklift and installed at the construction site with the table lowered to a low level. This is the gist of it.

[0011] In this case, the table rotation support member preferably consists of a slewing bearing having an annular outer ring, an inner ring arranged along the inner circumference of the outer ring and forming an annular shape along the inner circumference of the outer ring, and a plurality of rolling elements arranged between the outer ring and the inner ring so that the outer ring and the inner ring can rotate relative to each other. Furthermore, in this case, it is desirable that the table be fixed to the upper part of either the inner or outer ring, and the mounting base be fixed to the lower part of the other.

[0012] Furthermore, in order to achieve the above objective, the method for changing the direction of construction materials using the mobile turntable of the present invention is as follows: A method for changing the direction of construction materials at construction sites with height restrictions, Using the above-mentioned mobile turntable, The forks of the forklift are used to grasp the mobile turntable on its underside, transport it to the construction site, and then lower the table to the construction site before setting it up. Construction materials are placed on the aforementioned table using a forklift, and these materials are rotated to any angle by manually operating the table on the table rotation support member, thereby changing their direction to any desired direction. This is the gist of it. [Effects of the Invention]

[0013] According to the present invention, the mobile turntable and the method for changing the direction of construction materials using the same are used to move the mobile turntable to the construction site using a forklift, set up the table at the construction site with the table lowered, place construction materials on the table using a forklift, and rotate the materials manually. Therefore, when it is necessary to change the direction of construction materials at construction sites with height restrictions, the mobile turntable can be set up at the construction site as needed, and the direction of construction materials can be easily changed to any direction, thus providing a unique and distinct effect of the present invention. [Brief explanation of the drawing]

[0014] [Figure 1] This figure shows the configuration of a mobile turntable according to one embodiment of the present invention ((A) is a front cross-sectional view, (B) is a top view). [Figure 2] This diagram illustrates how to change the direction of construction materials and heavy machinery using the same mobile turntable. [Figure 3] This diagram shows a method for changing the direction of construction materials and heavy machinery using the same mobile turntable, illustrating the state in which the turntable is held by a forklift. [Figure 4] This diagram shows a method for changing the direction of construction materials and heavy machinery using the same mobile turntable, illustrating the state in which a forklift supports and transports the segments. [Figure 5]A diagram showing the situation of conventional tunnel construction, particularly showing the state where a gantry is assembled from a starting shaft to the rear of a tunnel boring machine inside an existing tunnel [Figure 6] A diagram showing a state in conventional tunnel construction where rails are laid on a gantry assembled inside an existing tunnel, and a segment trolley is arranged to be able to run on these rails

Embodiments for Carrying out the Invention

[0015] Next, embodiments for carrying out this invention will be described with reference to the drawings. The mobile turntable of this invention is used for changing the direction of various construction materials at various construction sites. Also, this mobile turntable is used for changing the direction of various construction heavy machines including forklifts at various construction sites. Here, construction sites include civil engineering sites and building sites. Also, here, various construction materials are those used at civil engineering sites and building sites, for example, precast concrete products are one of them. There are also a variety of these precast concrete products, for example, segments used in tunnel construction are one of them. Here, corresponding to the description of the background art described above, a tunnel construction site is exemplified as the construction site, and segments used in tunnel construction are exemplified as the construction materials.

[0016] Fig. 1 shows a mobile turntable according to an embodiment of this invention. As shown in Fig. 1, the mobile turntable MT is composed of a table 1 and a table rotation support member 2.

[0017] The table 1 is for placing construction materials including segments and construction heavy machines including forklifts at a construction site, and is formed in a predetermined size by a metal material having rigidity so that segments, forklifts, etc. can be mounted.

[0018] In this case, the table 1 is formed in the shape of a disc with a diameter of 1100 mm. Furthermore, multiple bolt insertion holes 10 are drilled in the table 1 at equal intervals in a circular arrangement, along the position of the mounting portion of the table rotation support member 2 (in this case, the inner ring 22, described later). These bolt insertion holes 10 have a recess on the upper side, into which the head of the bolt can be embedded.

[0019] The table rotation support member 2 is provided concentrically and integrally on the underside of the table 1 and is for supporting the table 1 so that it can be rotated manually. The table rotation support member 2 has a minimum height, or close to it, that allows the forks of a typical forklift to be inserted around it on the underside of the table 1.

[0020] In this case, the table rotation support member 2 consists of a slewing bearing (hereinafter sometimes referred to as slewing bearing 2), and has an annular outer ring 21, an inner ring 22 arranged in an annular shape along the inner circumference of the outer ring 21 and forming an annular shape along the inner circumference of the outer ring 21, and a plurality of rolling elements 23 arranged between the outer ring 21 and the inner ring 22 so that the outer ring 21 and the inner ring 22 can rotate relative to each other. The outer ring 21 is formed from a rigid metal material in an annular shape with a diameter smaller than that of the table 1, in this case with a diameter of 800 mm. The inner ring 22 is formed from a rigid metal material in an annular shape so that it can be fitted inside the inner circumference of the outer ring 21. This inner ring 22 is positioned slightly above the outer ring 21 within the outer ring 21, and the upper part (top surface) of the inner ring 22 protrudes slightly above the upper part (top surface) of the outer ring 21. The rolling element 23 consists of steel balls, and multiple steel balls are arranged in a ring shape between the outer ring 21 and the inner ring 22 via spacers (not shown).

[0021] In this case, the table 1 is fixed to the upper part of either the inner ring 22 or the outer ring 21, and the mounting base 3 is fixed to the lower part of the other. Here, the table 1 is fixed to the upper part of the inner ring 22, and the mounting base 3 is fixed to the lower part of the outer ring 21. The upper part of the inner ring 22 is the mounting portion for the table 1. Multiple screw holes 220 are cut from the top to the bottom of the upper surface of the inner ring 22, forming a circular arrangement at equal intervals. Naturally, these multiple screw holes 220 of the inner ring 22 and the bolt insertion holes 10 of the table 1 are formed in correspondence with each other. In this way, the table 1 is placed on top of the inner ring 22, and multiple bolts B are passed through each bolt insertion hole 10 from above the table 1 and tightened into each screw hole 220 of the inner ring 22, thereby fixing the table 1 to the mounting portion on the upper part of the inner ring 22. The lower part of the outer ring 21 is the mounting portion for the mounting base 3. Multiple screw holes 210 are cut from the bottom to the top of the outer ring 21, forming them in a circular arrangement at equal intervals. On the other hand, the mounting base 3 as a whole is an annular shape similar to the outer ring 21, with a square cross-section, a width the same as or slightly larger than the outer ring 21, and a height lower than the outer ring 21. Multiple bolt insertion holes 30 are formed in the mounting base 3 in a circular arrangement at equal intervals, penetrating the top and bottom surfaces. These bolt insertion holes 30 have recesses on the bottom, into which the bolt heads can be embedded. Naturally, the multiple screw holes 210 of the outer ring 21 and the multiple bolt insertion holes 30 of the mounting base 3 are formed in a mutually corresponding manner. In this way, the mounting base 3 is superimposed on the lower part of the outer ring 21, and multiple bolts B are passed through each bolt insertion hole 30 from below the mounting base 3 and tightened into each screw hole 210 of the outer ring 21, thereby fixing the mounting base 3 to the mounting part at the lower part of the outer ring 21.

[0022] Furthermore, in this case, the height of the swivel bearing 2 is slightly greater than the height of the vertical cross-section of the fork (in this case, 90 mm) so that the forklift forks can be inserted around the swivel bearing 2 on the underside of the table 1, as previously described. Here, the height of the swivel bearing 2 is set to approximately 100 mm, including the height of the outer ring 21 and the height of the mounting base 3.

[0023] Thus, the mobile turntable MT is designed to be movable by a forklift, and the table 1 can be lowered and installed at the construction site in various construction locations.

[0024] Figures 2, 3, and 4 show an example of a method for changing the direction of construction materials using a mobile turntable MT (hereinafter simply referred to as "the method"). This method involves changing the orientation of segments at the segment handover point, which is a construction location with height restrictions at the tunnel construction site. Furthermore, in this tunnel construction, due to height restrictions at the segment transfer point near the rear of the shield tunneling machine, it is not possible to secure sufficient lifting height for the segments using cranes or other means. Therefore, the segments are transferred to the segment transfer point using forklifts. In addition, since forklifts can only handle segments horizontally, and for the purpose of constructing the segments, it is necessary to temporarily orient the segments longitudinally towards the tunnel axis at the segment transfer point. Therefore, a mobile turntable is used to change the direction of the segments.

[0025] This method utilizes the aforementioned mobile turntable MT (hereinafter sometimes simply referred to as "turntable MT"). Since this turntable MT is approximately 1100mm in diameter and 130mm in height, it can be placed in any available space at the construction site. In Figure 2(1), prior to transporting and transferring segments to the segment transfer position using a forklift, the turntable MT is transported and installed at the segment transfer position using a forklift. The forklift used has a weight capacity of 12-15 tons and four forks (each fork is approximately 90 mm thick). In this case, as shown in Figure 3, the two inner forks f1 of the forklift are inserted around the swivel bearing 2 on the underside of the table 1, the two inner forks f1 grip the turntable MT on the underside of the table 1, transport it to the segment transfer position, and lower it to the segment transfer position. In this way, as shown in Figure 2(1), the turntable MT is installed at the segment transfer position with the table 1 lowered. This accommodates the height restriction at the segment transfer position.

[0026] Next, as shown in Figure 2(2), segment S is transferred and placed at the segment transfer position via table 1. In this case, as shown in Figure 4, segment S is carried by gripping it from the outside with the four forks f of the forklift, lowered to the segment transfer position, and placed on table 1.

[0027] Then, as shown in Figure 2(3), the segment S is manually pushed in the rotational direction, and the rotation of the table 1 on the slewing bearing 2 rotates it by an arbitrary angle, in this case 90°, thereby changing the orientation of the longitudinal direction of the segment S to the axial direction of the tunnel.

[0028] Subsequently, the segment is transported to the segment transfer position by forklift, placed on the turntable MT, and then pushed in the rotational direction to rotate it together with table 1. This process is repeated.

[0029] Up to this point, we have illustrated the case of changing the direction of segments at a tunnel construction site, but as mentioned above, this mobile turntable MT can also be used to change the direction of construction heavy machinery, including forklifts. In this case, as described above, the turntable MT is moved to the desired construction location at the tunnel construction site using a forklift or the like, the table 1 is lowered and set up at this construction location, the construction heavy machinery is placed on the table 1 using a forklift, and the construction heavy machinery is manually rotated on the turntable MT.

[0030] As described above, this mobile turntable MT comprises a table 1 for placing construction materials, including segments, and construction heavy machinery, including forklifts, at various construction sites, and a table rotation support member 2 that is concentrically and integrally provided on the underside of the table 1 to manually support the rotation of the table 1. In particular, the table rotation support member 2 is set to a minimum height or close to that height on the underside of the table 1, allowing the forks of a forklift to be inserted around the table rotation support member 2. In this way, the turntable MT is movable by forklift and can be installed at the construction site with the table 1 at a low height.

[0031] Furthermore, this method of changing the direction of construction materials and heavy machinery using the turntable MT is used at construction sites with height restrictions, including tunnel construction sites, to change the direction of construction materials including segments and construction heavy machinery including forklifts. In this method, first, the turntable MT is grasped by the forks of the forklift on the underside of the table 1 and transported to the construction site, where the table 1 is lowered and installed. Next, the construction materials and heavy machinery are placed on the table 1 using the forklift. Then, these materials and heavy machinery are rotated by a desired angle by manual operation, using the rotation of the table 1 on the table rotation support member 2, thereby changing their direction to a desired direction.

[0032] In this way, at various construction sites, the turntable MT is moved to the construction position by forklift, the table 1 is lowered and installed at the construction position, construction materials including segments and construction heavy machinery including forklifts are placed on the table 1 by forklift, and the construction materials and heavy machinery are rotated manually on the turntable MT. Therefore, at tunnel construction sites, as described above, when it is necessary to change the direction of segments at segment transfer positions with height restrictions, the turntable MT can be installed at the segment transfer position as needed, and the turntable MT can be installed at the segment transfer position without occupying the installation surface or becoming a height obstruction. Then, by placing a segment on the turntable MT with a forklift and rotating it manually by any angle, in this case 90°, the direction of one end of the segment can be easily changed toward the axial direction of the tunnel.

[0033] In particular, with this turntable MT, the rotation of table 1 is operated manually and does not use power, so there is no need to arrange motors, reducers, electrical circuits, etc. around the table rotation support member 2. Compared to conventional turntables that generally have motors, reducers, electrical circuits, etc. and are driven by power, the entire machine can be made significantly smaller and lighter. Furthermore, by making the height of the table rotation support member 2 on the underside of table 1 the minimum height or close to it, such as the height at which a forklift's forks can fit around the table rotation support member 2, the overall height of the machine (machine height) is made as low as possible, resulting in a low profile for table 1, and making this turntable MT easy to carry (move) with a forklift. By making the machine height as low as possible and lowering the profile of table 1 in this way, it is possible to secure the lifting height of segments by crane, etc., in construction locations with height restrictions. Furthermore, by making the Turntable MT easily transportable by forklift, it can be used, for example, temporarily placed on the vehicle traffic route at a construction site or in the work yard of heavy machinery, and can be easily removed (moved) immediately after use.

[0034] Furthermore, this turntable MT is constructed such that the table rotation support member 2 is made of a swivel bearing, the table 1 is fixed to the upper part of either the inner ring 22 or the outer ring 21, and the mounting base 3 is fixed to the lower part of the other. This allows the entire turntable MT to have a simple structure, ensuring reliable rotation performance even with heavy objects such as segments, and also allowing the turntable MT to be manufactured at a low cost. In this embodiment, the table 1 is fixed to the upper part of the inner ring 22 and the mounting base 3 is fixed to the lower part of the outer ring 21. However, conversely, the table 1 may be fixed to the upper part of the outer ring 21 and the mounting base 3 may be fixed to the lower part of the inner ring 22. The same effects and advantages as in the above embodiment can be achieved even in this configuration.

[0035] In this embodiment, we have provided an example of changing the direction of a segment in the axial direction of the tunnel at a segment handover location with height restrictions at a tunnel construction site. However, as mentioned above, this mobile turntable and the method for changing the direction of construction materials and heavy machinery using it can be used at various construction sites such as civil engineering sites and building construction sites. In particular, it can be applied in the same manner as in the above embodiment to any situation where it is necessary to change the direction of various concrete secondary products other than segments, various construction materials other than concrete secondary products, and various construction heavy machinery including forklifts used at various construction sites, especially at construction locations with height restrictions, and it goes without saying that the same effects and advantages as in the above embodiment can be achieved. [Explanation of Symbols]

[0036] MT Mobile Turntable 1 table 10 bolt insertion holes 2. Table rotation support member (swivel bearing) 21 Outer ring 210 screw holes 22 Inner Ring 220 screw holes 23 Rolling element 3. Installation base 30 bolt insertion holes B bolt f fork f1 Two inner forks S segment

Claims

1. A table for placing construction materials at a construction site, A table rotation support member is provided concentrically and integrally on the lower surface of the table, for supporting the table so that it can be manually rotated, Equipped with, The table rotation support member is set to a minimum height or close to that height on the underside of the table, such that the forks of a forklift can be inserted around the table rotation support member. This mobile turntable is movable by a forklift and installed at the construction site with the table lowered to a low level. A mobile turntable characterized by the following features.

2. A movable turntable according to claim 1, wherein the table rotation support member comprises a slewing bearing having an annular outer ring, an inner ring arranged along the inner circumference of the outer ring and forming an annular shape along the inner circumference of the outer ring, and a plurality of rolling elements arranged between the outer ring and the inner ring so as to allow the outer ring and the inner ring to rotate relative to each other.

3. The mobile turntable according to claim 2, wherein a table is fixed to the upper part of one of the inner or outer rings, and a mounting base is fixed to the lower part of the other.

4. A method for changing the direction of construction materials at construction sites with height restrictions, Using the mobile turntable of claim 1, The forks of the forklift are used to grasp the mobile turntable on its underside, transport it to the construction site, and then lower the table to the construction site before setting it up. Construction materials are placed on the aforementioned table using a forklift, and these materials are rotated to any angle by manually operating the table on the table rotation support member, thereby changing their direction to any desired direction. A method for changing the direction of construction materials using a mobile turntable, characterized by the following:

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