Material conveyance method and lifting fixture

Abstract

To appropriately lift and convey a construction material formed with a protruded part protruded from a base.SOLUTION: When a foundation material K having a base Ka and a protruded part Kb is lifted to be conveyed, a construction material having the protruding direction of the protruded part Kb is along a vertical direction is disposed between a first arm 22 and a second arm 24 provided in a lifting fixture 10. THe first arm 22 is rotated about a rotary shaft 12 provided in the intersection place of both the arms. The foundation material K is supported by a first support 32 and a second support 34. A movable hook 52 is moved along a guide rail 42 provided in the lifting fixture 10 to adjust the position of the movable hook 52. In a state where a hook of a crane is hooked to the movable hook 52 disposed at the adjusted position, the foundation material K supported by the first support 32 and the second support 34 is lifted and conveyed by the crane.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a material transport method, and more particularly to a material transport method for hoisting and transporting construction materials having a protrusion protruding from a base portion and intersecting the base portion. The present invention also relates to a lifting jig used in the above-mentioned material transport method. [Background technology]

[0002] At a building construction site, a lifting jig may be used when lifting construction materials with a crane or the like and transporting the materials to a place where they will be used (see, for example, Patent Document 1). Patent Document 1 describes a lifting jig used to lift precast concrete blocks for slab footings. This lifting jig is a lifting ring attached to the upper end of an anchor bolt that penetrates the precast concrete block. According to the technology described in Patent Document 1, the above-mentioned lifting jig is attached to both longitudinal ends of the precast concrete block, so that the concrete block is lifted at both longitudinal ends. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 10-219708 Summary of the Invention [Problem to be solved by the invention]

[0004] However, at a construction site, a situation may be imagined where a construction material having a protruding portion protruding from a base portion needs to be lifted. It is required to lift such construction material in a well-balanced and suitable position and transport it appropriately.

[0005] Therefore, the present invention has been made in consideration of the above problems, and its object is to provide a material transport method that can properly lift and transport construction materials having a protruding portion protruding from a base portion, and a material lifting jig used in the method. [Means for solving the problem]

[0006] The above problem is solved by the material transport method of the present invention, which is a material transport method for lifting and transporting a construction material having a base portion and a protruding portion that protrudes in a direction intersecting the base portion, by placing the construction material with the protruding portion protruding in a vertical direction between a first arm and a second arm that are arranged to intersect with each other on a lifting jig, rotating the first arm around a pivot axis provided at the intersection of the first arm and the second arm to support the construction material with a first support portion connected to the lower end of the first arm and a second support portion connected to the lower end of the second arm, moving the movable hanging portion along the extension portion that is provided in a state extending in the extension direction on the lifting jig to adjust the position of the movable hanging portion, and hanging the hook of a crane on the movable hanging portion that is positioned in the adjusted position, and transporting the construction material supported by the first support portion and the second support portion while lifting it with a crane. In the material transport method of the present invention, the construction material is appropriately supported by the support parts (first support part and second support part) connected to the first arm and the second arm that cross each other, and a suitable lifting position can be set by moving the movable hanging part. This makes it possible to appropriately lift and transport the construction material having a protruding part protruding from the base part.

[0007] In addition, in the material transport method of the present invention, it is preferable that each of the first support part and the second support part is constructed of an angle-shaped member, and in the process of supporting the construction material by the first support part and the second support part, each of the first support part and the second support part is abutted against the underside of the base part and engaged with a corner portion of the lower end part of the base part. According to the above configuration, the first support portion and the second support portion can support the construction material in a more stable state, so that the construction material can be more appropriately lifted and transported.

[0008] Furthermore, in the material transport method of the present invention, when the corner portions of the lower end of the base portion are cut out, in the process of supporting the construction material with the first support portion and the second support portion, it is more preferable to abut each of the first support portion and the second support portion against the underside of the base portion and to engage the tip portions of each of the first support portion and the second support portion with the cutout portions formed in the corner portions of the lower end of the base portion. According to the above configuration, the first and second support parts can support the construction material in a more stable state by engaging the tip portions of the first and second support parts with the notches formed in the corners of the lower end of the base part, which allows the construction material to be lifted and transported more appropriately.

[0009] In addition, in the material transport method of the present invention, in the process of adjusting the position of the movable hanging part, the position of the movable hanging part may be adjusted in the extension direction of the guide rail by moving a moving body to which the movable hanging part is fixed along the guide rail as an extension part. According to the above configuration, the position of the movable hanging part can be easily adjusted by moving the moving body along the guide rail, so that a suitable hanging position can be more easily set.

[0010] Furthermore, in the above-mentioned material transport method, when the movable body is an elongated body extending along a direction intersecting the guide rail, and the upper end of the first arm is attached to the movable body in a state in which it can move along the longitudinal direction of the movable body, it is more preferable that in the step of rotating the first arm around the pivot axis, the first arm is rotated while moving the upper end of the first arm along the longitudinal direction of the movable body. According to the above configuration, the first arm can be smoothly rotated, thereby allowing the first support part connected to the first arm to be smoothly moved to a position where the construction material can be appropriately supported by the first support part and the second support part.

[0011] In addition, in the above-mentioned material transport method, when the first support part is connected to the lower end part of the first arm in a state in which it can rotate around a first connecting axis along the rotation axis, in the process of supporting the construction material by the first support part and the second support part, the first support part may be rotated relative to the lower end part of the first arm to adjust the inclination of the first support part relative to the lower end part of the first arm. According to the above configuration, since the inclination of the first support part relative to the lower end of the first arm is adjustable, the inclination can be adjusted to a suitable state when the construction material is supported by the first support part and the second support part, which makes it possible to support the construction material more appropriately.

[0012] In the above-mentioned material transport method, the construction material may be made of precast concrete and used as a slab for a building. According to the above configuration, precast concrete foundation materials can be appropriately lifted and transported at a building construction site.

[0013] In addition, the above-mentioned problems are solved by the lifting jig of the present invention, which is a lifting jig used in the above-mentioned material transport method, comprising a first arm and a second arm arranged crossing each other, a first support part connected to the lower end of the first arm, a second support part connected to the lower end of the second arm, an extension part extending in the extension direction, and a movable hanging part movable along the extension part and on which a crane hook is hung, wherein the first arm is rotatable around a pivot axis arranged at the intersection of the first arm and the second arm, and the first support part and the second support part support construction materials placed between the first arm and the second arm. By using the above-mentioned lifting jig, construction materials having a protruding portion protruding from a base portion can be appropriately lifted and transported.

[0014] Furthermore, in the above-mentioned lifting jig, each of the first arm and the second arm has an arm main body portion and an arm upper portion extending in an inclined direction relative to the arm main body portion and continuous with the upper end of the arm main body portion, and it is preferable that the arm upper portion of the first arm and the arm upper portion of the second arm intersect with each other and are supported on the pivot shaft in a state capable of rotating around the pivot shaft. With the above configuration, the first arm and the second arm each rotate around a rotation axis, making it possible to position each arm in an appropriate position to support construction materials placed between the two arms. Effect of the Invention

[0015] According to the present invention, construction materials having a protrusion protruding from a base portion can be appropriately lifted and transported. [Brief description of the drawings]

[0016] [Figure 1] 1 is a diagram showing an example of construction materials transported by the material transport method of the present invention. [Diagram 2] FIG. 1 is a perspective view of a lifting jig according to one embodiment of the present invention. [Diagram 3] FIG. 1 is a diagram showing a lifting jig according to one embodiment of the present invention, in which a construction material is being lifted using the lifting jig, as viewed from the side of the jig. [Figure 4] FIG. 1 is a diagram showing a lifting jig according to one embodiment of the present invention, in which the jig is viewed from the front and shows a state in which construction materials are being lifted using the lifting jig. [Diagram 5] 4 is an enlarged view of a connecting portion between an arm and a support portion of the lifting jig according to one embodiment of the present invention. FIG. [Figure 6]FIG. 2 is a diagram showing the state of using the lifting jig according to one embodiment of the present invention, showing the stage before lifting construction materials. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] <<About one embodiment of the present invention>> Hereinafter, one embodiment of the present invention (hereinafter, this embodiment) will be described with reference to the accompanying drawings. Note that in the drawings, each component is illustrated somewhat simplified and schematic in order to make the description easier to understand. Also, the size of each component and the spacing between components illustrated in the drawings may differ from the actual ones. In addition, in the following explanation, when describing the position, orientation, posture, etc. of each device, unless otherwise specified, the position, orientation, posture, etc. of the device when it is being used in its normal manner will be described.

[0018] In addition, in this specification, the meanings of "same," "identical," and "equal" may include a generally acceptable range of error in the technical field to which the present invention belongs. In this specification, "orthogonal," "vertical," and "parallel" include the range of error permitted in the technical field to which the present invention pertains. For example, in this specification, "orthogonal," "vertical," and "parallel" mean being within a range of less than ±10° from strictly orthogonal, vertical, or parallel. The error from strictly orthogonal (vertical) or strictly parallel is preferably 5° or less, and more preferably 3° or less.

[0019] The present invention relates to a technique for lifting and transporting construction materials at a building construction site using a lifting machine such as a crane. Here, the buildings may include houses such as detached houses and apartment buildings, as well as buildings other than houses, specifically, offices, stores, buildings, warehouses, office buildings, commercial facilities, public facilities, and the like.

[0020] In this embodiment, as an example of a construction material, a material used as a continuous foundation for a building (hereinafter, referred to as a foundation material K) is hoisted and transported. In describing this embodiment, first, a configuration of the foundation material K will be described.

[0021] (About foundation materials) As shown in Fig. 1, the foundation material K has an inverted T-shape and has a base part Ka and a protruding part Kb protruding in a direction perpendicular to the base part. The base part Ka is a part that constitutes the footing part of the slab footing, extends linearly, and its cross section when the extension direction is the normal direction is substantially rectangular. The base part Ka may constitute the footing part by itself, or when combined with expansion pieces (fragments) that are placed on both sides of the base part Ka for the purpose of expanding the footing part, it may constitute the footing part together with the pieces.

[0022] The base portion Ka has a width in a direction (hereinafter, width direction) perpendicular to both the extending direction and the up-down direction of the base portion Ka. In Fig. 1, the left-right direction of the figure corresponds to the width direction of the base portion Ka, and the direction penetrating the plane of the figure corresponds to the extending direction of the base portion Ka. Furthermore, as shown in FIG. 1, the base portion Ka has step-shaped cutout portions Kc formed by cutting out corners located at both ends in the width direction of the lower portion of the base portion Ka.

[0023] The protruding portion Kb is a portion protruding from the widthwise center of the base portion Ka, and constitutes the rising portion of the slab footing. The protruding portion Kb is integrated with the base portion Ka, and more specifically, is integrally formed with the base portion Ka using precast concrete. In other words, the foundation material K is a material made of precast concrete.

[0024] The foundation material K is manufactured in a factory or the like, shipped, and then transported to a construction site for a building. The foundation material K is then hoisted by a crane at the construction site and transported to the installation position of the slab footing. At this time, the foundation material K is hoisted and transported with the protruding part Kb located directly above the base part Ka and with the protruding direction of the protruding part Kb aligned vertically (see FIG. 3). Then, when the foundation material K reaches the installation position of the slab footing, the foundation material K is lowered onto the ground. Here, the ground has depressions in multiple places for burying the footing, so the foundation material K is installed on uneven ground.

[0025] As described above, the foundation material K installed on the ground forms a continuous foundation for the building, and bears the ground pressure of the building when it is completed. By using the above foundation material K, the work of constructing a continuous footing at a construction site can be reduced, specifically, assembling formwork, installing reinforcing bars, pouring ready mixed concrete, curing the concrete after pouring, etc. can be omitted. This allows the construction work of a building to proceed more efficiently, shortening the construction period and reducing construction costs.

[0026] (About lifting jigs) At a building construction site, when a foundation material K is hoisted by a crane, a dedicated lifting jig 10 is used. An example of the configuration of the lifting jig 10 will be described below with reference to Figs. 2 to 5. In the following description, the three mutually orthogonal directions are referred to as the X, Y, and Z directions, and the Z direction corresponds to the height direction of the lifting jig 10. When the foundation material K is being lifted using the lifting jig 10, the Z direction is along the vertical direction, and more specifically, is approximately parallel to the vertical direction. The X direction corresponds to the axial direction of the pivot shaft 12, which will be described later.

[0027] The lifting jig 10 has an arm unit 20, a support unit 30, a frame unit 40, and an adjustment unit 50, as shown in FIGS. The arm unit 20 is a part that cooperates with the support unit 30 to support the foundation material K, and has a pair of a first arm 22 and a second arm 24. The first arm 22 and the second arm 24 are arranged to cross each other in an X-shape as shown in Figures 2 and 3, and extend downward in the Z direction. In addition, a rotation shaft 12 is provided along the X direction at the intersection of both arms, and each of the first arm 22 and the second arm 24 is rotatable about the rotation shaft 12. In other words, the first arm 22 and the second arm 24 are connected by a hinge connection.

[0028] The first arm 22 and the second arm 24 are arranged symmetrically when viewed from the X direction, but have the same shape and size. Specifically, as shown in Figures 2 and 3, each of the first arm 22 and the second arm 24 is bent at a midpoint and has an arm upper portion 26 located above the bent point and an arm main body portion 28 located below the bent point. As shown in Figures 2 and 3, the arm main body portion 28 extends linearly, and a support unit 30 (more specifically, the first support portion 32 or the second support portion 34) is connected to its lower end portion.

[0029] 2 and 3, the arm upper part 26 extends linearly in a direction inclined relative to the arm main body part 28, and is continuous with the upper end part of the arm main body part 28. The arm upper part 26 of the first arm 22 and the arm upper part 26 of the second arm 24 intersect with each other and are supported by the rotating shaft 12 in a state in which they can rotate about the rotating shaft 12. The upper end part of each arm upper part 26 is assembled to a moving rail 44 provided on the frame unit 40, and more specifically, is attached to the moving rail 44 in a state in which they can move along the Y direction, which is the extension direction of the moving rail 44. In addition, as a structure for assembling the upper end of the arm portion 26 to the movable rail 44 in a state in which it can move along the extension direction of the movable rail 44, a known structure may be adopted, for example a structure for assembling the upper end of an X-arm to a frame or the like in a state in which it can move along the frame or the like.

[0030] In the arm unit 20 configured as described above, each of the first arm 22 and the second arm 24 rotates around the pivot axis 12, causing the position of each arm, more specifically, the position of the lower end of the arm main body portion 28 of each arm, to change in the Y direction and the Z direction.

[0031] The material of the first arm 22 and the second arm 24 is not particularly limited, but should be one having sufficient strength to hold the foundation material K, and is preferably, for example, metal. 2 and 4, the lifting jig 10 according to this embodiment is provided with a plurality of arm units 20 (two arm units 20 in the configuration shown in Figs. 2 and 4) spaced apart in the X direction. However, the number of arm units 20 provided on the lifting jig 10 is not particularly limited, and may be only one, or may be three or more.

[0032] The support unit 30 supports the foundation material K when lifting and transporting the foundation material K, and has a first support part 32 and a second support part 34 spaced apart in the Y direction as shown in Figures 2 and 3. The first support part 32 is connected to the lower end of the arm body part 28 of the first arm 22, and the second support part 34 is connected to the lower end of the arm body part 28 of the second arm 24.

[0033] The first support portion 32 and the second support portion 34 form a pair and are arranged symmetrically when viewed from the X direction, but have the same shape and size. Specifically, each of the first support portion 32 and the second support portion 34 is formed of an L-shaped angle member. The material of the first support portion 32 and the second support portion 34 is not particularly limited, but should be one having sufficient strength to hold the foundation material K, and is preferably, for example, a metal.

[0034] 4, the first support portion 32 and the second support portion 34 extend long in the X direction and are connected to each of the arm units 20 arranged at intervals in the X direction. That is, the first support portion 32 is connected to the lower end portion of each of the first arms 22 arranged in the X direction (strictly speaking, the lower end portion of the arm main body portion 28). Similarly, the second support portion 34 is connected to the lower end portion of each of the second arms 24 arranged in the X direction (strictly speaking, the lower end portion of the arm main body portion 28). However, without being limited to the above configuration, the first support portion 32 and the second support portion 34 may be provided in a state in which they are divided into a plurality of angles in the X direction. In this case, it is preferable that the angle constituting each support portion is connected to a corresponding one of the plurality of arm units 20 (specifically, the nearest arm unit 20).

[0035] The positions of the first support portion 32 and the second support portion 34, in other words, the distance between the first support portion 32 and the second support portion 34, change in conjunction with the rotation of the first arm 22 and the second arm 24. As shown in FIG. 3, the first support portion 32 and the second support portion 34 support the foundation material K by sandwiching the base portion Ka of the foundation material K between them. More specifically, the first support portion 32 having an L-shaped angle abuts and engages with one corner portion (strictly speaking, the corner portion on one end side in the Y direction) of the lower end portion of the base portion Ka, and the second support portion 34 having an L-shaped angle abuts and engages with the other corner portion (strictly speaking, the corner portion on the other end side in the Y direction). As a result, the foundation material K is supported by the two support portions 32, 34, and more specifically, is held between the two support portions 32, 34.

[0036] In this embodiment, when the foundation material K is supported by the first support part 32 and the second support part 34, the inclination of each support part can be adjusted (see FIG. 5). To explain in more detail, the upper end of the long side part of the first support part 32 having an L-shaped angle shape is connected to the lower end part of the first arm 22 (strictly speaking, the lower end part of the arm main body part 28) in a state in which it can rotate around the first connecting shaft 14 along the rotation shaft 12. Then, the inclination of the first support part 32 is adjusted by rotating the first support part 32 relatively to the lower end part of the first arm 22 around the first connecting shaft 14. Here, the inclination of the first support part 32 refers to the degree of inclination of the long side part of the first support part 32 having an L-shaped angle shape with respect to the lower end part of the arm main body part 28 of the first arm 22 (in other words, the mounting angle). After adjusting the inclination of the first support part 32, a nut (not shown) is fitted onto the first connecting shaft 14 and the first support part 32 is fixed with the nut, thereby setting the inclination of the first support part 32 to the adjusted inclination.

[0037] Similarly, the upper end of the long side of the second support part 34 having an L-shaped angle is connected to the lower end of the second arm 24 (strictly speaking, the lower end of the arm main body part 28) in a state where it can rotate about the second connecting shaft 16 along the rotation shaft 12. The second support part 34 rotates relatively to the lower end of the second arm 24 about the second connecting shaft 16, thereby adjusting the inclination of the second support part 34. Here, the inclination of the second support part 34 refers to the degree of inclination of the long side of the second support part 34 having an L-shaped angle with respect to the lower end of the arm main body part 28 of the second arm 24. After adjusting the inclination of the second support part 34, a nut (not shown) is fitted onto the second connecting shaft 16 and the second support part 34 is fixed with the nut, thereby setting the inclination of the second support part 34 to the inclination after adjustment.

[0038] The frame unit 40 forms the upper end of the lifting jig 10, is located directly above the arm unit 20, and is the part from which the arm unit 20 is suspended. When viewed from above, the frame unit 40 has a ladder shape as shown in Fig. 2, and has a pair of guide rails 42 spaced apart in the Y direction, and a movable rail 44 and a fixed rail 46 that are arranged between the pair of guide rails 42 in the Y direction.

[0039] The pair of guide rails 42 correspond to extension portions, and are provided in a state of extending in the X direction in the lifting jig 10. That is, in this embodiment, the X direction corresponds to the extension direction of the guide rails 42. Each guide rail 42 is made of steel, specifically, a channel steel, and is arranged so that a flange portion faces inward in the X direction (the side where the pair of guide rails 42 is located).

[0040] The moving rails 44 correspond to a moving body, and are long bodies extending in a direction perpendicular to the guide rails 42 (i.e., the Y direction), and are assembled to each of the pair of guide rails 42 in a state in which they can move in the X direction along the guide rails 42. To be more specific, the moving rails 44 are made of steel, specifically H-shaped steel, and each of both end portions of the moving rails 44 is sandwiched between the flange portions of the guide rails 42. In addition, the end portions of the moving rails 44 are engaged with the guide rails 42 in a state in which they can slide in the X direction along the guide rails 42. In addition, as for the structure in which the end of the moving rail 44 engages with the guide rail 42 in a state in which it can slide along the guide rail 42, a known structure, specifically a slide rail structure or the like, may be adopted.

[0041] Also, as described above, the arm unit 20 is suspended from the moving rail 44. Specifically, as shown in Figs. 2 and 3, the upper end of each of the arm upper parts 26 of the first arm 22 and the second arm 24 is assembled in a state in which it can move in the Y direction (the longitudinal direction of the moving rail 44) along the moving rail 44. Then, when the moving rail 44 moves along the guide rail 42, the arm unit 20 (i.e., the first arm 22 and the second arm 24) assembled to the moving rail 44 moves in the X direction. As a result, the connection point between the first arm 22 and the first support part 32 and the connection point between the second arm 24 and the second support part 34 change in the X direction. In other words, the movement of the moving rail 44 changes the relative position of the first arm 22 with respect to the first support part 32 and the relative position of the second arm 24 with respect to the second support part 34.

[0042] In this embodiment, the lifting jig 10 is provided with a plurality of arm units 20, and the same number of moving rails 44 as the arm units 20 are provided, and in the configuration shown in Fig. 2, two moving rails 44 are provided. The two moving rails 44 are disposed at positions spaced apart from each other in the X direction. In addition, both of the two moving rails 44 are movable in the X direction along the guide rails 42.

[0043] The fixed rails 46 are disposed between a pair of guide rails 42 in the Y direction to connect the guide rails 42 to each other, and cannot move in the X direction like the movable rails 44, and are fixed to each guide rail 42. In this embodiment, as shown in Fig. 2, one fixed rail 46 is fixed to each of one end, a center portion, and the other end portion of the guide rails 42 in the X direction, and the movable rail 44 is disposed between the fixed rails 46.

[0044] The adjustment unit 50 is for adjusting the lifting position when the foundation material K is lifted using the lifting jig 10, and includes a movable hanging part 52 on which the hook F of a crane is hung, as shown in Figs. 2 to 4. The movable hanging part 52 is made of a known lifting tool, for example, a ring-shaped part, and in this embodiment, as shown in Fig. 2, is fixed to the center of the Y direction of the upper end surface of the moving rail 44. The movable hanging part 52 moves integrally with the moving rail 44 when the moving rail 44 moves in the X direction along the guide rail 42. This adjusts the position of the movable hanging part 52 in the X direction (i.e., the extension direction of the guide rail 42), and as a result, the lifting position when the foundation material K is lifted using the lifting jig 10 is adjusted.

[0045] In this embodiment, as described above, a plurality of movable rails 44 are provided, and one movable hanger 52 is provided for each movable rail 44. However, the number of movable hangers 52 provided on the lifting jig 10 and the number of movable hangers 52 fixed to one movable rail 44 are not particularly limited, and can be set to any number.

[0046] (Material conveying method according to the present embodiment) In the following, as an example of the material transport method of the present invention, a method of lifting and transporting foundation material K using the above-mentioned lifting jig 10 at a building construction site will be described.

[0047] In this embodiment, when one foundation material K is lifted, one lifting jig 10 is used. In the material transport method of this embodiment, the steps of placing the foundation material K, rotating the first arm 22 and the second arm 24, supporting the foundation material K by the support unit 30, adjusting the position of the movable hanging part 52, and lifting and transporting the foundation material K are performed in this order.

[0048] More specifically, when lifting the foundation material K, first, the foundation material K is positioned with the protruding direction of the protrusion portion Kb aligned vertically, and the foundation material K in this state is then placed between the first arm 22 and the second arm 24 as shown in Figure 6.

[0049] 6, both the first arm 22 and the second arm 24 are rotated around the rotation shaft 12. Specifically, each of the first arm 22 and the second arm 24 is rotated so that the upper ends of the first arm 22 and the second arm 24 move inward in the Y direction along the moving rail 44 to which the upper ends of the first arm 22 and the second arm 24 are attached.

[0050] As a result of each arm operating as described above, the first support part 32 connected to the first arm 22 and the second support part 34 connected to the second arm 24 approach each other. Then, the respective tips of the first support part 32 and the second support part 34 forming an L-shaped angle, more specifically, the tips (free ends) of the short sides, wrap around the underside of the base part Ka of the foundation material K.

[0051] Thereafter, as shown in Fig. 5, the first support part 32 is rotated around the first connecting shaft 14 to adjust the inclination of the first support part 32 with respect to the first arm 22. As a result, the first support part 32 having an L-shaped angle shape is caught on the lower corner part of the base part Ka of the foundation material K, and abuts against the lower surface of the base part Ka and engages with the lower end part of the base part Ka, as shown in Fig. 3. In particular, in this embodiment, the corner part of the lower end part of the base part Ka is cut out, and by appropriately adjusting the inclination of the first support part 32, the first support part 32 abuts against the lower surface of the base part Ka, and the tip part of the first support part 32 engages with the cutout part Kc formed in the corner part of the lower end part of the base part Ka.

[0052] Similarly, the second support part 34 is rotated around the second connecting shaft 16 to adjust the inclination of the second support part 34 with respect to the second arm 24. As a result, the second support part 34 having an L-shaped angle shape is caught on the lower corner part of the base part Ka and abuts against the lower surface of the base part Ka and engages with the base part Ka, as shown in Fig. 3. Particularly, in this embodiment, by appropriately adjusting the inclination of the second support part 34, the second support part 34 abuts against the lower surface of the base part Ka, and the tip part of the second support part 34 engages with the notch part Kc formed in the corner part of the lower end part of the base part Ka.

[0053] By the above-mentioned procedure, the foundation material K is supported by the first support part 32 and the second support part 34. To explain in more detail, the first support part 32 and the second support part 34 can appropriately support the foundation material K by sandwiching it between the first support part 32 and the second support part 34 while favorably maintaining the posture of the foundation material K in a state in which the protruding direction of the protruding part Kb is aligned with the vertical direction.

[0054] Next, the crane is operated after the hooks F of the crane are hung on each of the multiple movable hanging parts 52 provided on the adjustment unit 50, and the lifting jig 10 and the foundation material K are lifted up to the so-called ground clearance height. At this time, the first support part 32 and the second support part 34 support the foundation material K at a position lower than the center of gravity of the foundation material K. On the other hand, the first arm 22 to which the first support part 32 is connected and the second arm 24 to which the second support part 34 is connected cross each other at a position higher than the center of gravity of the foundation material K, and both arms are supported by the rotating shaft 12 provided at the crossing point. With this configuration, when the foundation material K is lifted using the lifting jig 10, the foundation material K can be lifted more stably and in a well-balanced manner.

[0055] After the lifting jig 10 and foundation material K are lifted up to the ground clearance height, the movable rail 44 to which the movable hanging part 52 is fixed is moved in the X direction along the guide rail 42 to adjust the position of the movable hanging part 52 in the X direction. This adjusts the suspension position and determines it to a suitable position with respect to the center of gravity of the foundation material K. In this manner, in this embodiment, the suspension position can be more easily set to a suitable position by adjusting the position of the movable hanging part 52 by moving the movable rail 44 along the guide rail 42. Furthermore, with the above configuration, fine adjustments of the suspension position can also be easily performed.

[0056] Next, the crane is operated with the hook F of the crane hooked on the movable hanging part 52 arranged in the adjusted position. Then, the foundation material K supported by the first support part 32 and the second support part 34 is lifted by the crane and transported to a predetermined position at the construction site (more specifically, to the installation location of the foundation material K). At this time, since the lifting position was set to a suitable position in the immediately preceding process, the lifting jig 10 and the foundation material K can be lifted in a well-balanced manner, and as a result, the foundation material K can be appropriately transported to the predetermined position.

[0057] Then, when the foundation material K is transported to a predetermined position, the lifting jig 10 and the foundation material K are lowered at that position, and the lifting jig 10 is removed from the foundation material K. In other words, the support state of the foundation material K by the first support part 32 and the second support part 34 is released. As a result, the foundation material K is placed on the ground, and more specifically, the lower surface of the base part Ka is grounded. At this time, the foundation material K is appropriately placed on the ground even if the ground is uneven. This is because the foundation material K can be lifted in a well-balanced manner by the lifting jig 10 during transportation, and transported while maintaining an appropriate posture.

[0058] <<Other embodiments>> Although the lifting jig and the material transport method of the present invention have been described above with reference to specific embodiments, the above-mentioned embodiments are merely examples for facilitating understanding of the present invention and do not limit the present invention. In other words, the present invention may be modified or improved without departing from the spirit of the present invention. In addition, the present invention naturally includes its equivalents.

[0059] In the above embodiment, when the foundation material K is supported by the first support part 32 and the second support part 34 of the lifting jig 10, both the first arm 22 and the second arm 24 are rotated about the rotation axis 12, but this is not limited to the above. For example, the foundation material K may be supported by the first support part 32 and the second support part 34 by rotating only the first arm 22 without moving the second arm 24 (i.e., rotating relative to the second arm 24).

[0060] In the above embodiment, when the foundation material K is supported by the first support part 32 and the second support part 34 of the lifting jig 10, both the inclination of the first support part 32 relative to the first arm 22 and the inclination of the second support part 34 relative to the second arm 24 are adjusted. However, this is not limited to this, and it is also possible to adjust only the inclination of the first support part 32 relative to the first arm 22, without adjusting the inclination of the second support part 34 relative to the second arm 24.

[0061] In the above embodiment, the construction material to be hoisted and transported is a material for a slab foundation, specifically, a foundation material K made of precast concrete. However, construction materials to which the material transport method of the present invention can be applied are not limited to the above foundation material K, and may be construction materials other than the foundation material K as long as they have a base portion and a protruding portion that protrudes in a direction intersecting the base portion. [Explanation of symbols]

[0062] 10 Lifting fixture 12 Rotating shaft 14 1st connection shaft 16 2nd connection shaft 20 Arm Unit 22 First Arm 24 Second Arm 26 Upper arm 28 Arm body 30 Support Unit 32 1st support part 34 Second support part 40 Frame Unit 42 Guide rail (extension) 44 Moving rail (moving body) 46 Fixed Rail 50 Adjustment Unit 52 Movable hanging part F Hook K Foundation materials (construction materials) Ka Base Kb protrusion Kc Cutout

Claims

1. A material transport method for lifting and transporting a construction material having a base portion and a protruding portion protruding in a direction intersecting the base portion, comprising: The construction material with the protruding portion protruding in the vertical direction is placed between a first arm and a second arm that are provided so as to cross each other in a lifting jig; The first arm is rotated about a rotation axis provided at an intersection of the first arm and the second arm, and the construction material is supported by a first support part connected to a lower end of the first arm and a second support part connected to a lower end of the second arm. The movable hanging part is moved along the extension part provided in the lifting jig in a state of extending in the extension direction to adjust the position of the movable hanging part; A material transport method in which, with a crane hook attached to the movable hanging part that has been arranged in the adjusted position, the construction material supported by the first support part and the second support part is lifted and transported by the crane.

2. Each of the first support portion and the second support portion is formed of an angle-shaped member, 2. The material transport method according to claim 1, wherein in the process of supporting the construction material by the first support portion and the second support portion, each of the first support portion and the second support portion is abutted against the underside of the base portion and engaged with a corner portion of the lower end portion of the base portion.

3. 3. The material transport method of claim 2, wherein in the process of supporting the construction material with the first support part and the second support part when the corner portion of the lower end part of the base part is cut out, each of the first support part and the second support part is abutted against the lower surface of the base part, and the tip portions of each of the first support part and the second support part are engaged with cutout portions formed in the corner portion of the lower end part of the base part.

4. The material transport method according to claim 1, wherein in the step of adjusting the position of the movable hanging part, a movable body to which the movable hanging part is fixed is moved along a guide rail as the extension part, thereby adjusting the position of the movable hanging part in the extension direction of the guide rail.

5. The movable body is an elongated body extending in a direction intersecting the guide rail, and When the upper end portion of the first arm is attached to the movable body in a state in which the upper end portion of the first arm is movable along the longitudinal direction of the movable body, 5. The material transport method according to claim 4, wherein in the step of rotating the first arm around the rotation axis, the first arm is rotated while moving an upper end of the first arm along the longitudinal direction of the movable body.

6. When the first support portion is connected to the lower end portion of the first arm in a state in which the first support portion is rotatable about a first connecting shaft that is aligned with the rotation shaft, 3. The material transport method according to claim 2, wherein in the process of supporting the construction material by the first support part and the second support part, the first support part is rotated relative to a lower end part of the first arm to adjust an inclination of the first support part relative to the lower end part of the first arm.

7. 2. The material transport method according to claim 1, wherein the construction material is made of precast concrete and is used as a foundation for a building.

8. A lifting jig used in the material transport method according to any one of claims 1 to 7, a first arm and a second arm provided so as to cross each other; a first support portion connected to a lower end portion of the first arm; a second support portion connected to a lower end portion of the second arm; An extension portion extending in an extension direction; A movable hanging portion that is movable along the extension portion and on which a hook of a crane is hung, the first arm is rotatable about a rotation axis provided at an intersection of the first arm and the second arm, A lifting jig, wherein the first support portion and the second support portion support the construction material disposed between the first arm and the second arm.

9. Each of the first arm and the second arm has an arm main body portion and an arm upper portion extending in a direction inclined with respect to the arm main body portion and continuous with an upper end portion of the arm main body portion, The lifting jig of claim 8, wherein the arm upper portion of the first arm and the arm upper portion of the second arm intersect with each other and are supported by the pivot shaft in a state capable of rotating around the pivot shaft.

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