JP2017214741A - Anchor and construction method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain a strength during construction while preventing an anchor from being loosened even in the case where a ceiling suspension object is vibrated, and to easily construct such an anchor.SOLUTION: An anchor 1 is attached into a lower hole 7 that is provided on a ceiling slab S, and supports a hanger bolt 9 in a hung state. The anchor 1 comprises: a shaft member 10; a fixed part 3 which is provided in an upper portion of the shaft member 10 and fixed into the lower hole 7 while being inserted into the lower hole 7; and a hanger bolt support fitting 50 including a first flat plate part 51 which is provided in a lower portion of the shaft member 10 in parallel with a lower face of the ceiling slab S, a longitudinal plate part 52 which is suspended from an end of the first flat plate part 51 and a second flat plate part 53 extending from a lower end of the longitudinal plate part 52 in parallel with the first flat plate part 51. A fitting hole 55 into which the hanger bolt 9 can be inserted is provided on the second flat plate part 53.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an anchor for attaching a suspension bolt to a ceiling slab and a construction method thereof.

  Conventionally, an anchor is fixed to a pilot hole provided in a ceiling slab, and a suspension bolt is attached to the anchor. For example, the anchor of Patent Document 1 has a configuration in which an expansion sleeve is attached to a shaft portion on which a male screw is formed, and a cone nut is attached to the tip of the shaft portion. Then, with the tip of the anchor inserted in the pilot hole, by rotating the nut portion provided at the lower portion of the shaft portion, the cone nut is lowered along the shaft portion, and the cone nut extends the expansion portion of the expansion sleeve from the inside. By expanding outward, the anchor is fixed to the pilot hole. After the anchor is fixed to the prepared hole, a suspension bolt is attached to the nut portion below the anchor.

JP 2012-177290 A

  As described above, the suspension bolt attached to the anchor has various ceiling suspensions attached to the lower end thereof, and supports the ceiling suspensions at a predetermined height from the ceiling slab. This type of suspended ceiling includes a pipe that conveys a fluid, such as a refrigerant pipe of an air conditioner. That is, the fluid piping may be attached to the lower end portion of the suspension bolt attached to the anchor.

  However, when the fluid pipe is attached to the lower end of the suspension bolt supported by the anchor, vibration is generated in the pipe due to a change in the flow rate inside the pipe. This vibration acts on the anchor tip fixed to the prepared hole of the ceiling slab via the suspension bolt. Therefore, when used for a long period of time, there is a possibility that the tip of the anchor gradually loosens due to the vibration of the fluid piping.

  The present invention has been made in order to solve the above-described conventional problems, and even when a ceiling suspended object such as a fluid pipe vibrates, the strength at the time of construction is not loosened. An object of the present invention is to provide an anchor that can be maintained, and to provide a construction method that allows such an anchor to be easily constructed.

  In order to achieve the above object, firstly, the present invention is provided with an anchor (1, 1) attached to a pilot hole (7) provided in a ceiling slab (S) and supporting a suspension bolt (9) in a suspended state. 1a), a shaft member (10) and a fixing portion provided on the shaft member (10) and fixed to the lower hole (7) in a state of being inserted into the lower hole (7) ( 3), a first flat plate portion (51) provided below the shaft member (10) and parallel to the lower surface of the ceiling slab (S), and suspended from an end of the first flat plate portion (51). A vertical plate portion (52) and a second flat plate portion (53) extending in a direction parallel to the first flat plate portion (51) from a lower end of the vertical plate portion (52), and the second flat plate portion ( 53) and a suspension bolt support fitting (50) provided with attachment holes (55, 69) into which the suspension bolt (9) can be inserted.

  Secondly, in the anchor (1.1a) having the first configuration, the present invention provides the suspension bolt (55, 69) inserted into the mounting hole (55, 69) from the lower surface side of the second flat plate portion (53). 9) is further provided with a retaining nut (59, 88, 89) attached to the tip.

  Thirdly, according to the present invention, in the anchor (1, 1a) having the above-described second configuration, the suspension bolt support metal fitting (50) is provided on the lower surface side of the second flat plate portion (53) with the mounting hole ( 55, 69) and a nut portion (60) having an inner hole communicating with the nut portion (60), the nut portion (60) being attached to the second flat plate portion (53) via a thin-walled fracture portion (63) (62), and the hole formed inside the breaking nut (62) has a larger diameter than the outer diameter of the suspension bolt (9).

  Fourth, according to the present invention, in the anchor (1) having the third configuration, the nut portion (60) is provided by being joined to the lower surface of the second flat plate portion (53). And a screw hole (64) screwed with the suspension bolt (9) is formed inside the fixing nut (61).

  Fifth, according to the present invention, in the anchor (1a) having the third configuration, the nut portion (60) is provided by being joined to the lower surface of the second flat plate portion (53). And the hole formed inside the fixing nut (61) has a larger diameter than the outer diameter of the suspension bolt.

  Sixth, according to the present invention, in the anchor (1a) having the fifth configuration, the retaining nut (88, 89) and the second flat plate portion (53) are arranged at the tip of the suspension bolt (9). It further comprises an elastic member (80) interposed between the two.

  Seventh, the present invention is a construction method for constructing an anchor (1, 1a) that is attached to a prepared hole (7) provided in a ceiling slab (S) and supports a suspended bolt (9) in a suspended state. The anchor (1, 1a) is provided on the shaft member (10) and an upper portion of the shaft member (10), and is inserted into the lower hole (7), and the lower hole (7) A fixed portion (3) fixed to the shaft member, a first flat plate portion (51) provided at a lower portion of the shaft member (10) and parallel to the lower surface of the ceiling slab (S), and the first flat plate portion (51 ) Extending from the lower end of the vertical plate portion (52) in a direction parallel to the first flat plate portion (51) and inserting the suspension bolt (9) A second flat plate portion (53) provided with possible mounting holes (55, 69), and an inner hole provided on the lower surface side of the second flat plate portion (53) and communicating with the mounting holes (55, 69) A nut portion (60) having the nut portion (60) through the thin fracture portion (64). A suspension bolt having a break nut (62) attached to the flat plate portion (53), and a hole formed inside the break nut (62) having a larger diameter than the outer diameter of the suspension bolt (9) A mounting bracket (50), and the construction method includes inserting the tip of the suspension bolt (9) into the mounting hole (55, 69) through the inner hole of the nut portion (60), A first step of assembling the anchor (1, 1a) and the suspension bolt (9) in an inseparable state by attaching the suspension bolt (9) to the suspension bolt support bracket (50), and the anchor (1 , 1a) can be accommodated inside the suspension bolt (9) inseparably separated from the suspension bolt (9), and the tubular body (70), which is longer than the suspension bolt (9). ) And an engagement portion (71) that engages with the breaking nut (62), and a tool attachment portion (75) that is provided at the lower end of the cylindrical body (70) and for attaching a tool. When, With respect to the anchoring tool (2), the lower end of the suspension bolt (9) is inserted into the cylindrical body (70) from the engagement portion (71), and the breaking nut (62) is engaged with the engagement tool (2). A second step of engaging the portion (71), a third step of inserting the fixing portion (3) of the anchor (1, 1a) into the pilot hole (7), and the anchor application tool (1 , 1a) by rotating the anchoring tool (2) by mounting a rotating tool on the tool mounting part (75), the shaft of the anchor (1, 1a) together with the suspension bolt support bracket (50) A fourth step of rotating the member (10) to fix the fixing portion (3) to the prepared hole (7), and by continuing the rotation of the anchoring tool (2), the breaking nut (62) A fifth step of breaking the fracture portion (63) by applying a torque of a predetermined value or more to the anchoring tool (2) from the suspension bolt (9) after the fracture portion (63) is fractured. The sixth work to pull out And it is configured to have a.

  According to the present invention, when a ceiling suspension such as a fluid pipe is attached to a suspension bolt supported by the anchor, even if the ceiling suspension is vibrated, the anchor to the ceiling slab is The fixing strength does not loosen, and the strength at the time of construction can be maintained. Furthermore, according to the present invention, the construction work of the anchor is simplified, so that the construction work can be performed efficiently.

It is a disassembled perspective view which shows one structural example of the anchor in 1st Embodiment. It is sectional drawing which shows the structure of the suspension bolt support metal fitting in 1st Embodiment. It is a perspective view which shows the state in which the suspension bolt was assembled | attached with respect to the anchor. It is a perspective view which shows the aspect which mounts an anchor and a suspension bolt to an anchor application tool. It is sectional drawing which shows the structure of an anchor application tool. It is a perspective view which shows the state with which the anchor and the suspension bolt were mounted | worn with respect to the anchor application tool. It is sectional drawing in the state of FIG. It is a partial cross section figure of the state which inserted the fixing | fixed part of the anchor into the prepared hole of the ceiling slab. It is a partial sectional view in the state where the widening member entered the inside of a plurality of expansion walls. It is a partial cross section figure of the state where the fracture part of the nut part fractured. It is a partial cross section figure which shows the extraction process of an anchor application tool. It is a partial cross section figure which shows the state after anchor construction. It is a partial cross section figure which shows the angle adjustment process of a suspension bolt support metal fitting. It is a figure which shows the modification of the suspension bolt support metal fitting in 1st Embodiment. It is a figure which shows the modification by which the suspending bolt support metal fitting and the nut part were comprised as a different body. It is a disassembled perspective view which shows one structural example of the anchor in 2nd Embodiment. It is sectional drawing which shows the structure of the suspension bolt support metal fitting in 2nd Embodiment. It is a perspective view which shows the state in which the suspension bolt was assembled | attached with respect to the anchor. It is a perspective view which shows the state in which the suspension bolt was assembled | attached with respect to the anchor. It is a perspective view which shows the state with which the anchor and the suspension bolt were mounted | worn with respect to the anchor application tool. It is a partial cross section figure which shows the construction method of an anchor. It is a figure which shows the aspect from which the attitude | position of a suspension bolt changes. It is a figure which shows the modification of the suspension bolt support metal fitting in 2nd Embodiment.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In addition, in each drawing referred to below, the same code | symbol is attached | subjected to the mutually common member, and the overlapping description about them is abbreviate | omitted.

(First embodiment)
First, a first embodiment of the present invention will be described. FIG. 1 is an exploded perspective view showing a configuration example of the anchor 1 according to the first embodiment of the present invention. The anchor 1 includes a shaft member 10, a washer 20, an expansion member 30, a widening member 40, and a suspension bolt support bracket 50, and an upper portion thereof is fixed to a pilot hole 7 provided in the ceiling slab S. While being configured as the fixed portion 3, the lower portion is configured as a support portion 4 that supports the suspension bolt 9 in a state where it is suspended from the ceiling slab S.

  The shaft member 10 is a member in which, for example, the first shaft portion 11 and the second shaft portion 12 are formed coaxially. The first shaft portion 11 has a smaller diameter than the second shaft portion 12 and has a length that allows the washer 20, the expansion member 30, and the widening member 40 to be mounted. A male screw 14 is formed at least on the distal end side of the first shaft portion 11. The second shaft portion 12 has substantially the same diameter as the suspension bolt 9, and a male screw 15 is formed on the entire outer peripheral surface of the second shaft portion 12 in the axial direction. Further, the shaft member 10 has a flange portion 13 that protrudes outward between the first shaft portion 11 and the second shaft portion 12.

  The washer 20, the expansion member 30, and the widening member 40 are sequentially attached to the first shaft portion 11 of the shaft member 10 as described above, so that the portion above the flange portion 13 is fixed to the fixed portion 3. Configured as A suspension bolt support fitting 50 is attached to the second shaft portion 12 of the shaft member 10, and the suspension bolt 9 can be attached to the lower portion of the suspension bolt support fitting 50. Therefore, a portion below the flange portion 13 of the shaft member 10 is configured as the support portion 4.

  The washer 20 is a disk-shaped member having a hole 21 through which the first shaft portion 11 can be inserted at the center. The inner diameter of the hole 21 is larger than the first shaft portion 11 and smaller than the diameter of the flange portion 13. Therefore, when the washer 20 is attached to the first shaft portion 11, the lower surface thereof is joined to the flange portion 13. In other words, the flange portion 13 is a receiving member that receives the washer 20.

  The expansion member 30 is configured by a cylindrical tubular member 31 having an inner diameter slightly larger than that of the first shaft portion 11, and is attached to the outside of the shaft member 10 so as to surround the first shaft portion 11. When the expansion member 30 is attached to the first shaft portion 11, the lower end portion of the cylindrical member 31 is in a state of being joined to the upper surface of the washer 20. In addition, a plurality of extension walls 33 separated from each other by the longitudinal grooves 32 are provided on the upper portion of the cylindrical member 31 so as to be extended and deformed outward of the first shaft portion 11. In the present embodiment, an example is shown in which three longitudinal grooves 32 are provided at equal intervals along the circumferential direction of the cylindrical member 31, and three extension walls 33 are arranged in the circumferential direction on the upper portion of the cylindrical member 31. doing. However, the number of the extension walls 33 is not necessarily limited to three. Further, a cutout portion 34 that is cut out so as to be connected to the longitudinal groove 32 is provided at the upper end portion of the cylindrical member 31. The notch 34 is formed so that, for example, the upper end of the cylindrical member 31 is notched in a triangular shape, and one apex of the triangle is connected to the longitudinal groove 32. By providing such a notch 34, the tip of the expansion wall 33 can be easily expanded outward.

  The widening member 40 is a member configured such that the outer dimensions gradually decrease from the upper end portion 43 toward the lower end portion 42. The widening member 40 of the present embodiment is constituted by a cone nut 41 and is formed so that the outer diameter of the lower end portion 42 is smaller than the outer diameter of the upper end portion 43. The widening member 40 has a through screw hole 44 that is screwed into the male screw 14 formed in the first shaft portion 11 inside the cone nut 41. The widening member 40 is mounted such that the lower end portion 42 of the widening member 40 is fitted into the distal ends of the plurality of expansion walls 33 of the expansion member 30 when the male screw 14 is inserted into the through screw hole 44. The A plurality of grooves 42 a are provided in the lower end portion 42 of the widening member 40 in the vertical direction. Since the plurality of grooves 42a engage with the inside of the expansion wall 33 to generate a frictional force in the circumferential direction, the plurality of grooves 42a have an effect of preventing the widening member 40 from rotating inside the expansion wall 33. Further, the plurality of grooves 42 a also show an effect of smoothly guiding the widening member 40 toward the inside of the expansion wall 33 in the axial direction of the shaft member 10.

  The suspension bolt support fitting 50 includes a first flat plate portion 51 attached to the second shaft portion 12 of the shaft member 10, a vertical plate portion 52 that hangs from the end portion of the first flat plate portion 51, and a lower end of the vertical plate portion 52. It has the 2nd flat plate part 53 extended in the direction parallel to the 1st flat plate part 51, and is comprised as a substantially U-shaped metal fitting. Further, the suspension bolt support fitting 50 includes a nut portion 60 on the lower surface side of the second flat plate portion 53. 1 illustrates an example in which the nut portion 60 is integrally assembled to the lower surface side of the second flat plate portion 53 by welding or the like.

  FIG. 2 is a cross-sectional view showing the structure of the suspension bolt support fitting 50. The 1st flat plate part 51 has the screw hole 54 screwed together with the male screw 15 of the 2nd axial part 12 in the center. The shaft member 10 is firmly tightened so that the male screw 15 of the second shaft portion 12 is screwed into the screw hole 54 of the first flat plate portion 51 and the flange portion 13 is joined to the upper surface of the first flat plate portion 51. Then, a nut 58 is fastened to the distal end portion of the second shaft portion 12 protruding from the lower surface of the first flat plate portion 51. Thereby, since the double nut effect by the screw hole 54 and the nut 58 is obtained, the shaft member 10 is firmly fixed to the first flat plate portion 51. As a result, the first flat plate portion 51 is fixed so as to be perpendicular to the shaft member 10.

  The second flat plate portion 53 is disposed so as to face the first flat plate portion 51 at a position below the first flat plate portion 51. An attachment hole 55 into which the suspension bolt 9 can be inserted is provided at the center of the second flat plate portion 53. The inner diameter of the mounting hole 55 is slightly larger than the outer diameter of the suspension bolt 9. Therefore, the attachment hole 55 does not engage with the male screw 9 a formed on the outer peripheral surface of the suspension bolt 9. However, the mounting hole 55 communicates with the inner hole of the nut portion 60 provided on the lower surface of the second flat plate portion 53 as shown in FIG. In the inner hole of the nut portion 60, a female screw that is screwed with the male screw 9a of the suspension bolt 9 is formed.

  The nut portion 60 includes a fixed nut 61 that is bonded and fixed to the second flat plate portion 53 and a breaking nut 62 that is provided below the fixing nut 61, and between the fixing nut 61 and the breaking nut 62. It has a thin-walled fracture portion 63. The fixing nut 61 and the breaking nut 62 are formed as hexagonal nuts, for example. The breaking portion 63 is configured as a thin wall portion 63 a that connects the fixing nut 61 and the breaking nut 62 by forming a groove along the circumferential direction at a substantially central position of the fixing nut 61 and the breaking nut 62. . Inside the fixing nut 61, a screw hole 64 that is screwed with the male screw 9a of the suspension bolt 9 is formed. On the other hand, the inner diameter 65 of the breaking nut 62 and the breaking portion 63 is formed so that the inner diameter is slightly larger than the outer diameter of the suspension bolt 9 and does not engage with the male screw 9 a of the suspension bolt 9. Therefore, when the suspension bolt 9 is attached to the nut portion 60, only the screw hole 64 provided inside the fixed nut 61 is engaged with the male thread 9a of the suspension bolt 9, and the break nut 62 and break The inner wall of the inner hole 65 provided in the portion 63 does not contact the surface of the suspension bolt 9.

  The suspension bolt 9 is inserted into the inner hole 65 of the nut portion 60 and the attachment hole 55 of the second flat plate portion 53. As shown in FIG. 1, the suspension bolt 9 is attached to the second flat plate portion 53 by attaching a nut 59 to the tip of the suspension bolt 9. The nut 59 is a retaining nut that prevents the suspension bolt 9 from coming off from the second flat plate portion 53.

  FIG. 3 is a perspective view showing a state in which the suspension bolt 9 is assembled to the anchor 1. As shown in FIG. 3, the anchor 1 of the present embodiment can be applied to the ceiling slab S in a state in which the suspension bolt 9 is assembled in advance. When the anchor 1 is constructed, an anchoring tool 2 described later is attached to the fracture nut 62 of the nut portion 60. Then, the rotational torque by the anchoring tool 2 acts on the breaking nut 62. This rotational torque propagates to the fixing nut 61 and the second flat plate portion 53 through the thin fracture portion 63 and rotates the suspension bolt support fitting 50. Since the shaft member 10 is firmly fixed to the first flat plate portion 51 of the suspension bolt support fitting 50, when the suspension bolt support fitting 50 rotates, the shaft member 10 rotates together therewith. And if the fixing | fixed part 3 of the anchor 1 is firmly fixed with respect to the prepared hole 7 of the ceiling slab S, the resistance with respect to the rotation direction of the shaft member 10 will increase. Therefore, the torque acting on the breaking nut 62 generates a shearing stress on the wall portion 63a of the breaking portion 63. And when the torque which acts on the fracture | rupture nut 62 exceeds a predetermined value, since the shear stress which acts on the wall part 63a exceeds a limit value, the fracture | rupture part 63 will fracture | rupture. That is, the nut portion 60 provided on the suspension bolt support fitting 50 is configured such that the fracture nut 62 can be separated from the fixed nut 61 by breaking the fracture portion 63. The torque at which the breaking portion 63 breaks can be adjusted by changing the thickness t of the wall portion 63a shown in FIG. Therefore, the thickness t of the wall portion 63a may be adjusted in advance so that the fastening strength required at the construction site is obtained.

  As shown in FIG. 2, the nut portion 60 is colored 66 using a predetermined color paint such as red or yellow on the lower surface of the break nut 62. Therefore, when the nut portion 60 of the anchor 1 constructed on the ceiling slab S is viewed from below, if the lower surface is a predetermined color, it can be visually confirmed that the fracture portion 63 is not broken, and the lower surface is a predetermined color. Otherwise, it can be visually confirmed that the broken portion 63 is broken. Therefore, there is an advantage that the construction state of the anchor 1 can be visually confirmed by coloring 66 on the lower surface of the breaking nut 62.

  Next, the construction method of the anchor 1 as described above will be described. When constructing the anchor 1, the worker first puts the anchor 1 and the suspension bolt 9 into a state as shown in FIG. 3. That is, the operator attaches the washer 20, the expansion member 30, and the widening member 40 to the first shaft portion 11 of the shaft member 10, and attaches the suspension bolt support fitting 50 to the second shaft portion 12. Thereby, the fixed part 3 and the support part 4 are formed with respect to the shaft member 10 of the anchor 1. The anchor 1 has a washer 20, an expansion member 30, and a widening member 40 attached in advance to the first shaft portion 11, and a suspension bolt support fitting 50 attached in advance to the second shaft portion 12. It does not matter.

  Subsequently, the operator inserts the tip of the suspension bolt 9 into the nut portion 60 as shown in FIG. At this time, the operator rotates the suspension bolt 9 by screwing the male screw 9a of the suspension bolt 9 into the screw hole 64 formed inside the fixing nut 61, whereby the tip of the suspension bolt 9 is moved to the second flat plate. It is assumed that a predetermined length protrudes from the upper surface of the portion 53. Then, the operator fixes the suspension bolt 9 to the second flat plate portion 53 by attaching a nut 59 to the tip of the suspension bolt 9 protruding from the upper surface of the second flat plate portion 53. That is, the anchor 1 and the suspension bolt 9 are assembled together before construction on the ceiling slab S.

  Next, as shown in FIG. 4, the worker attaches the anchor 1 and the suspension bolt 9 assembled together to the anchor application tool 2. FIG. 5 is a cross-sectional view showing the structure of the anchoring tool 2. The anchor application tool 2 includes a long cylindrical body 70 having an accommodation space 74 that can accommodate the suspension bolt 9 inside, and an anchor 1 that is provided at the upper end of the cylindrical body 70 and is attached with the suspension bolt 9. An engaging portion 71 that engages with the lower portion of the cylindrical body 70 and a tool mounting portion 75 that is provided at the lower end of the cylindrical body 70 and for mounting an electric tool or the like.

  The cylindrical body 70 is longer than the suspension bolt 9 attached to the suspension bolt support bracket 50 of the anchor 1. For example, the anchor 1 is attached to the pilot hole 7 provided in the ceiling slab S while the operator is on the floor surface. It is long enough for construction. The accommodation space 74 has an inner diameter larger than the outer diameter of the suspension bolt 9, and the suspension bolt 9 can be inserted smoothly. The accommodation space 74 is also formed longer than the length of the suspension bolt 9.

  The engaging portion 71 is configured to engage with the breaking nut 62 of the nut portion 60, and a hexagonal concave portion 72 that engages with the outer peripheral surface of the breaking nut 62 is formed inside thereof. The center of the bottom of the recess 72 communicates with a storage space 74 formed inside the cylindrical body 70. The bottom periphery of the recess 72 is configured as a flat bottom surface 73 that engages with the lower surface of the breaking nut 62, and the lower surface of the breaking nut 62 is supported by the bottom surface 73.

  Moreover, the tool mounting part 75 is comprised by the cover member 77 with which the screw part 76 provided in the lower end of the cylindrical body 70 is screwed and mounted | worn with the lower end of the cylindrical body 70, for example. That is, the tool mounting portion 75 is provided so as to protrude downward from the lower surface of the lid member 77, and has the same shape as a hexagon nut, for example, as shown in FIG. Therefore, a tool such as an electric tool can be mounted on the tool mounting portion 75.

  FIG. 6 is a perspective view showing a state where the anchor 1 and the suspension bolt 9 that are integrally assembled are attached to the anchor application tool 2. FIG. 7 is a cross-sectional view in that state. As shown in FIGS. 6 and 7, when the unit of the anchor 1 and the suspension bolt 9 is attached to the anchor application tool 2, the fracture nut 62 of the nut portion 60 is engaged with the engagement portion 71 of the anchor application tool 2. It becomes a state. At this time, the fracture portion 63 of the nut portion 60 is positioned in the vicinity of the upper end of the anchoring tool 2, and the fixing nut 61 of the nut portion 60 is not engaged with the engagement portion 71. That is, the worker engages the engaging portion 71 of the anchoring tool 2 with the breaking nut 62 below the breaking portion 63 of the nut portion 60. At this time, the lower end 9c of the suspension bolt 9 is in the accommodation space 74 of the anchoring tool 2 as shown in FIG.

  When the anchoring tool 2 is mounted on the anchor 1 and the suspension bolt 9 unit as described above, the worker provides the fixing portion 3 of the anchor 1 on the ceiling slab S while supporting the lower part of the anchoring tool 2. Insert into the prepared hole 7. FIG. 8 is a partial cross-sectional view showing a state where the fixing portion 3 of the anchor 1 is inserted into the prepared hole 7 of the ceiling slab S. The ceiling slab S is provided with a pilot hole 7 deeper than the fixing portion 3 of the anchor 1 in advance. The inner diameter of the lower hole 7 is the same as or slightly larger than the outer diameter of the fixing portion 3 of the anchor 1. The fixing portion 3 of the anchor 1 is inserted into the prepared hole 7. At this time, the operator inserts the fixing portion 3 deeply into the lower hole 7 until the washer 20 comes into contact with the lower surface 6 of the ceiling slab S at the peripheral edge of the lower hole 7 as shown in FIG. This work can be performed while the worker is on the floor. When the fixing portion 3 of the anchor 1 is inserted deeply into the lower hole 7, at least a part of the widening member 40 and the expansion member 30 are in contact with the inner wall of the lower hole 7. Further, the first flat plate portion 51 is in a state parallel to the lower surface 6 of the ceiling slab S.

  Thereafter, the operator attaches a tool such as an electric tool to the tool attachment portion 75 at the lower end of the anchor application tool 2 and rotates the anchor application tool 2 in the R direction (clockwise direction). This operation is also an operation that can be performed while the worker is on the floor. As a result, torque in the R direction is generated with respect to the nut portion 60, and the torque is transmitted to the suspension bolt support fitting 50, and the suspension bolt support fitting 50 rotates in the R direction. The shaft member 10 is fixed to the first flat plate portion 51 of the suspension bolt support fitting 50. Therefore, the shaft member 10 rotates in the R direction together with the suspension bolt support fitting 50. The widening member 40 moves downward along the axial direction of the shaft member 10 along with the rotation of the male screw 14 of the first shaft portion 11, and proceeds toward the inside of the plurality of expansion walls 33 of the expansion member 30. . Along with this, the plurality of expansion walls 33 of the expansion member 30 expand outward and press the inner wall of the lower hole 7 from the inside.

  FIG. 9 is a diagram illustrating a state in which the widening member 40 has entered the inside of the plurality of expansion walls 33. As shown in FIG. 9, when the widening member 40 enters a predetermined depth inside the plurality of expansion walls 33, each of the plurality of expansion walls 33 is in a state of being firmly engaged with the inner wall of the lower hole 7. Therefore, the anchor 1 is fixed to the prepared hole 7. When the operator continues to rotate the anchoring tool 2, the torque acting on the breaking nut 62 of the nut portion 60 gradually increases as the fixing strength of the anchor 1 increases, and the breaking portion 63 The acting shear stress gradually increases. When the torque acting on the break nut 62 exceeds a predetermined value, the break portion 63 of the nut portion 60 breaks. That is, when the anchor 1 is fixed to the lower hole 7 with a strength higher than a predetermined strength, the fracture portion 63 is fractured.

  FIG. 10 is a diagram illustrating a state in which the fracture portion 63 of the nut portion 60 is fractured. When the fracture portion 63 of the nut portion 60 is fractured, as shown in an enlarged view A in FIG. 10, the fixing nut 61 and the fracture nut 62 in the nut portion 60 are divided. Thereby, even if the anchoring tool 2 is rotated, the suspension bolt support fitting 50 does not rotate. That is, when the fracture portion 63 breaks, the anchoring tool 2 becomes idle, so that the operator can easily grasp that the fracture portion 63 is broken while performing work on the floor surface.

  Thereafter, the operator pulls the anchoring tool 2 downward as indicated by an arrow F2 in FIG. At this time, since the breaking nut 62 is not screwed with the suspension bolt 9, the breaking nut 62 is detached from the anchor 1 as the anchoring tool 2 is pulled out. On the other hand, since the suspension bolt 9 is firmly fixed to the second flat plate portion 53 of the suspension bolt support fitting 50 in the anchor 1, the suspension bolt 9 is suspended from the ceiling slab S even when the anchoring tool 2 is turned. It remains in the state. When the anchoring tool 2 is removed from the periphery of the suspension bolt 9, the anchor 1 is firmly fixed to the lower hole 7 of the ceiling slab S and the suspension bolt 9 is firmly secured by the anchor 1, as shown in FIG. The construction is completed in a state supported by

  As shown in FIG. 12, the anchor 1 fixed to the prepared hole 7 of the ceiling slab S supports the suspension bolt 9 via the suspension bolt support fitting 50. Therefore, even if the suspension bolt 9 vibrates in the X direction shown in FIG. 12, the vibration is absorbed or attenuated at the two bent portions P <b> 1 and P <b> 2 of the suspension bolt support fitting 50. It is not transmitted to. Therefore, even if the pipe for fluid is attached to the lower end of the suspension bolt 9 and the suspension bolt 9 vibrates due to a change in the flow rate inside the pipe, the fixing portion of the anchor 1 fixed to the lower hole 7 of the ceiling slab S. 3 will not loosen. Therefore, even when the anchor 1 of this embodiment is used over a long period of time, the fixing strength immediately after construction can be maintained well. Further, when the anchor 1 of the present embodiment is constructed, by using the above-described anchoring tool 2, the operator can perform all the work on the ceiling slab S while being on the floor surface, so that a stepladder, a scaffold, etc. are provided. There is also an advantage that it is not necessary and can be applied easily and efficiently.

  By the way, depending on the construction site, after the anchor 1 is fixed to the ceiling slab S as shown in FIG. 12, the angle adjustment of the suspension bolt support fitting 50 is required so that the suspension bolt support fitting 50 faces a certain direction. There is. In such a case, the operator pulls out the anchoring tool 2 from the suspension bolt 9 and collects the fracture nut 62, and then attaches the anchoring tool 2 to the suspension bolt 9 again as shown in FIG. The two engaging portions 71 are engaged with the fixing nut 61. Thereafter, the operator attaches a tool such as an electric tool to the tool attachment portion 75 at the lower end of the anchor application tool 2, and rotates the anchor application tool 2 again in the R direction (clockwise direction). That is, the operator further rotates the anchor 1 by applying a torque of a predetermined value or more to the fixing nut 61. Since the rotation direction at this time is the same as the direction in which the anchor 1 is fixed to the lower hole 7, the fixing strength of the anchor 1 is not loosened, but rather the fixing strength is increased. Then, the operator can adjust the suspension bolt support fitting 50 to a predetermined direction as shown in FIG. 13 by rotating the anchoring tool 2 within a range of less than 360 degrees.

  The rotation angle of the anchoring tool 2 for adjusting the angle of the suspension bolt support fitting 50 is preferably performed within a range of less than 360 degrees as described above. This is because, when the rotation angle of the anchoring tool 2 exceeds 360 degrees, the descending amount of the widening member 40 with respect to the shaft member 10 increases, and the expansion wall 33 of the expansion member 30 is damaged inside the lower hole 7. Because there is a possibility. On the other hand, if the rotation angle is less than 360 degrees, the descending amount of the widening member 40 with respect to the shaft member 10 does not increase so much, and the anchor 1 is fixed more firmly because the fixing strength of the anchor 1 is increased as described above. 1 can be fixed, and the suspension bolt support fitting 50 can be adjusted to an arbitrary angle.

  When the construction is completed as described above, the fracture nut 62 is removed from the nut portion 60. Therefore, for example, when a worker or a site manager confirms the construction state, a colored 66 of a predetermined color is present below the anchor 1. If it is confirmed whether or not to do, the construction state can be easily grasped. That is, if the predetermined color 66 remains in the lower part of the anchor 1, it is possible to grasp that the anchor 1 is not fixed with sufficient strength because the fracture portion 63 of the nut portion 60 is not broken. it can. On the other hand, if the predetermined color 66 does not remain in the lower part of the anchor 1, it can be understood that the anchor 1 is fixed with sufficient strength. Therefore, the anchor 1 of this embodiment has an advantage that not only the work at the time of construction is simplified, but also the work of confirming the construction state after construction can be easily performed.

  As described above, in the construction method described above, the anchor 1 is inserted by inserting the tip of the suspension bolt 9 into the attachment hole 55 through the inner hole 65 of the nut portion 60 and attaching the suspension bolt 9 to the suspension bolt support fitting 50. The first step of assembling the suspension bolt 9 and the suspension bolt 9 in an inseparable state, and the suspension bolt 9 assembled in an inseparable state with the anchor 1 can be accommodated inside, and the tubular body 70 is longer than the suspension bolt 9. An engaging portion 71 provided at the upper end of the cylindrical body 70 and engaged with the breaking nut 62; a tool mounting portion 75 provided at the lower end of the cylindrical body 70 for mounting a tool; A second step of inserting the lower end of the suspension bolt 9 into the cylindrical body 70 from the engaging portion 71 and engaging the breaking nut 62 with the engaging portion 71 with respect to the tool 2, and the lower hole 7 of the ceiling slab S On the other hand, the fixing part 3 of the anchor 1 Rotating and fixing the shaft member 10 of the anchor 1 together with the suspension bolt support fitting 50 by attaching the rotary tool to the tool attachment portion 75 of the anchor application tool 2 and rotating the anchor application tool 2. A fourth step of fixing the portion 3 to the prepared hole 7 of the ceiling slab S and a step of breaking the fracture portion 63 by applying a torque greater than a predetermined value to the fracture nut 62 by continuing the rotation of the anchoring tool 2. 5 steps and a sixth step of pulling out the anchoring tool 2 from the suspension bolt 9 after the breaking portion 63 is broken.

  All the operations from the first step to the sixth step are operations that can be performed while the worker is on the floor. That is, the construction method described above has an advantage that the work efficiency is remarkably improved as compared with the conventional method because the construction method is configured by a process that does not require the worker to perform work at a high place in the vicinity of the ceiling slab S. In particular, if the operations from the first step to the second step are performed on the floor as preparation operations, the subsequent operations from the third step to the sixth step are performed on the anchor tool 2 while the worker is on the floor. Therefore, the work efficiency is remarkably improved. Moreover, since the construction method mentioned above does not require an operator's skill level etc., there is also an advantage that a homogeneous construction state can be obtained no matter who works.

  In addition, in the above, the case where the suspension bolt support metal fitting 50 was comprised as a substantially U-shaped metal fitting was illustrated. However, the shape of the suspension bolt support fitting 50 is not necessarily limited to a substantially U-shape. For example, the suspension bolt support fitting 50 may have a form as shown in FIG. 14 includes a first flat plate portion 51 that is attached to the second shaft portion 12 of the shaft member 10, and a pair of vertical plate portions 52 that are suspended from both ends of the first flat plate portion 51. The lower plate portions of the pair of vertical plate portions 52 are connected to each other and have a second flat plate portion 53 provided in parallel with the first flat plate portion 51, and is configured as a substantially rectangular frame. Even with such a suspension bolt support bracket 50, when the suspension bolt 9 vibrates, the vibration can be absorbed or attenuated at the four bent portions, so that the fixing portion 3 of the anchor 1 is prevented from loosening. can do.

  Moreover, in the above, the case where the nut part 60 was integrally formed in the lower surface side of the suspension bolt support metal fitting 50 was illustrated. However, the suspension bolt support fitting 50 and the nut portion 60 may be configured as separate members separated from each other. FIG. 15 is a diagram illustrating a modification in which the suspension bolt support fitting 50 and the nut portion 60 are configured as separate members. As shown in FIG. 15, when the nut portion 60 is configured as a separate member from the suspension bolt support fitting 50, the suspension bolt 9 is connected to the upper surface and the lower surface with the second flat plate portion 53 interposed therebetween. It is fixed to the suspension bolt support fitting 50 by the fixing nut 61 of the nut portion 60. Even in this case, the anchor 1 can be constructed by the same construction method as described above. In addition, as shown in FIG. 15, since the suspension bolt support fitting 50 and the nut portion 60 are configured separately, it is not necessary to assemble the suspension bolt support fitting 50 and the nut portion 60 in advance by welding or the like. Costs can be kept cheap.

(Second Embodiment)
Next, a second embodiment of the present invention will be described. FIG. 16 is an exploded perspective view showing a configuration example of the anchor 1a according to the second embodiment of the present invention. As in the first embodiment, the anchor 1a includes the shaft member 10, the washer 20, the expansion member 30, the widening member 40, the suspension bolt support fitting 50, the elastic member 80, the washer 85, the nut 88, 89, the upper part of which is configured as a fixing part 3 fixed to a lower hole 7 provided in the ceiling slab S, and the lower part of which supports the suspension bolt 9 in a state where it is suspended from the ceiling slab S. Configured as part 4.

  The fixing part 3 of the anchor 1a is the same as in the first embodiment. That is, the shaft member 10, the washer 20, the expansion member 30, and the widening member 40 are the same as in the first embodiment, and the washer 20 and the expansion member are disposed on the first shaft portion 11 above the flange portion 13 of the shaft member 10. By mounting 30 and the widening member 40, the fixing portion 3 of the anchor 1a is configured.

  The anchor 1a of the present embodiment is different from the anchor 1 of the first embodiment in that a specific configuration of the suspension bolt support fitting 50 and an elastic member 80, a washer 85, and nuts 88 and 89 are provided. Hereinafter, these will be described.

  FIG. 17 is a cross-sectional view showing the structure of the suspension bolt support fitting 50 in the second embodiment. The suspension bolt support fitting 50 of this embodiment includes a first flat plate portion 51, a vertical plate portion 52, a second flat plate portion 53, and a nut portion 60, as in the first embodiment. However, in the present embodiment, the attachment hole 69 provided in the second flat plate portion 53 communicates with the inner hole of the nut portion 60 while maintaining the same axis and the same diameter, and the suspension bolt 9 is connected to the inner hole of the nut portion 60. A female screw that is screwed with the male screw 9a is not formed. The inner diameter of the attachment hole 69 is slightly larger than the outer diameter of the suspension bolt 9, and the suspension bolt 9 is inserted into the attachment hole 69. The elastic member 80, the washer 85, and the nuts 88 and 89 are attached to the tip of the suspension bolt 9 that protrudes from the upper surface of the second flat plate portion 53.

  The elastic member 80 is a disk-shaped member having flexibility and elasticity, and is made of, for example, rubber or resin. A hole 81 having a size substantially equal to the outer diameter of the suspension bolt 9 is formed at the center of the elastic member 80, and is in close contact with the outer peripheral surface of the suspension bolt 9. The washer 85 is a disk-shaped member having a hole 86 through which the suspension bolt 9 can be inserted at the center thereof, and is disposed on the elastic member 80. The nuts 88 and 89 are retaining nuts attached to the tips of the suspension bolts 9 through which the elastic member 80 and the washer 85 are inserted, and are firmly attached to the suspension bolts 9 by a double nut effect. Thereby, the suspension bolt 9 is assembled in an inseparable state with respect to the second flat plate portion 53 of the suspension bolt support fitting 50.

  18 and 19 are perspective views showing a state in which the suspension bolt 9 is assembled to the anchor 1a. In the anchor 1a of the present embodiment, the suspension bolt 9 is not fixed to the second flat plate portion 53 and the nut portion 60. However, as shown in FIG. 18, since the elastic member 80, the washer 85, and the nuts 88 and 89 are attached to the tip of the suspension bolt 9, the suspension bolt 9 does not fall off from the second flat plate portion 53. As shown in FIG. 19, when the suspension bolt 9 is pushed upward from below, the elastic member 80 is lifted from the second flat plate portion 53. That is, the suspension bolt 9 is attached to the attachment hole 69 formed in the second flat plate portion 53 of the suspension bolt support fitting 50 in a slidable or swingable state.

  Next, the construction method of the anchor 1a as described above will be described. When constructing the anchor 1a, the worker first puts the anchor 1a and the suspension bolt 9 into a state as shown in FIG. Next, as shown in FIG. 20, the operator attaches the anchor 1 and the suspension bolt 9 unit assembled in an inseparable state to the anchor application tool 2. The specific configuration of the anchoring tool 2 is the same as that described in the first embodiment. At this time, the operator attaches the anchor 1a to the anchor application tool 2 so that the fracture nut 62 of the nut portion 60 is engaged with the engagement portion 71 of the anchor application tool 2 as in the first embodiment. To do.

  When the anchoring tool 2 is mounted on the anchor 1 and the suspension bolt 9 unit as described above, the worker provides the fixing portion 3 of the anchor 1 on the ceiling slab S while supporting the lower part of the anchoring tool 2. Insert into the prepared hole 7. Then, a tool such as an electric tool is mounted on the tool mounting portion 75 at the lower end of the anchoring tool 2, and the anchoring tool 2 is rotated, thereby fixing the fixing portion 3 of the anchor 1a to the lower hole 7 of the ceiling slab S. . Then, as shown in FIG. 21, when the fracture | rupture part 63 fractures | ruptures, the anchor 1a will be fixed with the strong intensity | strength more than predetermined intensity with respect to the lower hole 7. FIG. Then, when the operator pulls out the anchor application tool 2 from the periphery of the suspension bolt 9, the construction of the anchor 1a is completed.

  The anchor 1a thus constructed supports the suspension bolt 9 in a state where the posture of the suspension bolt 9 can be changed. FIG. 22 is a diagram illustrating a manner in which the posture of the suspension bolt 9 changes. As shown in FIG. 22, when the suspension bolt 9 vibrates in the X direction, the anchor 1a allows the vibration. That is, the anchor 1 a allows the suspension bolt 9 to swing according to the inner diameter of the mounting hole 69 formed in the second flat plate portion 53. Therefore, even when the suspension bolt 9 vibrates in the X direction, the vibration is not transmitted to the shaft member 10 of the anchor 1a, and the anchoring portion 3 of the anchor 1a fixed to the lower hole 7 of the ceiling slab S is provided. It is possible to prevent loosening due to vibration. Further, even if the vibration of the suspension bolt 9 is a large vibration exceeding the allowable swing range by the mounting hole 69, the vibration is absorbed or attenuated at the two bent portions P1 and P2 of the suspension bolt support fitting 50. Therefore, it is not transmitted to the shaft member 10 of the anchor 1. Therefore, it is possible to satisfactorily prevent the anchor 1a from being loosened.

  Also in this embodiment, when it is necessary to adjust the angle of the suspension bolt support fitting 50, the operator pulls out the anchoring tool 2 from the periphery of the suspension bolt 9 and collects the fracture nut 62. The angle is easily adjusted by attaching the anchoring tool 2 to the suspension bolt 9 again and rotating the anchoring tool 2 again in a state where the engaging portion 71 of the anchoring tool 2 is engaged with the fixing nut 61. be able to. Also in this embodiment, when the construction is completed as described above, the fracture nut 62 is removed from the nut portion 60. For example, when an operator or a site manager confirms the construction state, the bottom of the anchor 1 is used. If it is confirmed whether the coloring 66 of a predetermined color exists, the construction state can be easily grasped.

  As mentioned above, the construction method of the anchor 1a in this embodiment also has the 6th process from the 1st process demonstrated in 1st Embodiment. Therefore, there is an advantage that the working efficiency can be remarkably improved as compared with the conventional case.

  In addition, also in this embodiment, although the case where the suspension bolt support metal fitting 50 was comprised as a substantially U-shaped metal fitting was illustrated, it is not restricted to this. For example, the suspension bolt support bracket 50 may have a form as shown in FIG. 23 includes a first flat plate portion 51 that is attached to the second shaft portion 12 of the shaft member 10 and a pair of vertical plate portions 52 that hang down from both ends of the first flat plate portion 51. The lower plate portions of the pair of vertical plate portions 52 are connected to each other and have a second flat plate portion 53 provided in parallel with the first flat plate portion 51, and is configured as a substantially rectangular frame. Even with such a suspension bolt support bracket 50, when the suspension bolt 9 vibrates, the vibration can be allowed, absorbed, or attenuated, so that the fixing portion 3 of the anchor 1a is loosened. Can be prevented.

(Modification)
As mentioned above, although several embodiment regarding this invention was described, this invention is not limited to what was demonstrated in the said embodiment, A various modification is applicable. Hereinafter, some modified examples will be described.

  For example, in the said embodiment, the shaft member 10 illustrated what the 1st axial part 11, the 2nd axial part 12, and the flange part 13 were formed integrally. However, the present invention is not limited thereto, and the first shaft portion 11, the second shaft portion 12, and the flange portion 13 are configured as separate bodies in advance, and the shaft member 10 described above is configured by assembling them. It does not matter.

  Moreover, in the said embodiment, although the case where the shaft member 10 and the suspension bolt support metal fitting 50 were separate members was illustrated, it is not restricted to this. That is, the suspension bolt support fitting 50 may be integrally provided in advance on the lower portion of the shaft member 10 by welding or the like.

  Moreover, in the said embodiment, although the case where the 1st axial part 11 and the 2nd axial part 12 of the shaft member 10 were different diameters was illustrated, it is not restricted to this, The 1st axial part 11 and the 2nd axial The part 12 may have the same diameter.

DESCRIPTION OF SYMBOLS 1,1a Anchor 2 Anchor application tool 3 Fixing part 7 Pilot hole 9 Hanging bolt 10 Shaft member 20 Washer 30 Expansion member 40 Widening member 50 Long nut 60 Breaking nut 61 First nut part 62 Second nut part 63 Breaking part 70 Cylindrical shape Body 71 Engagement part 72 Tool mounting part

Claims (7)

An anchor that is attached to a pilot hole provided in a ceiling slab and supports a suspended bolt in a suspended state,
A shaft member;
A fixing portion provided at an upper portion of the shaft member and fixed to the lower hole in a state of being inserted into the lower hole;
A first flat plate portion provided at a lower portion of the shaft member and parallel to a lower surface of the ceiling slab; a vertical plate portion depending from an end portion of the first flat plate portion; and a first flat plate from a lower end of the vertical plate portion. A second flat plate portion extending in a direction parallel to the portion, and a suspension bolt support bracket provided with an attachment hole into which the suspension bolt can be inserted into the second flat plate portion,
An anchor comprising:   The anchor according to claim 1, further comprising a retaining nut attached to a tip of the suspension bolt inserted into the mounting hole from the lower surface side of the second flat plate portion. The suspension bolt support fitting includes a nut portion having an inner hole communicating with the mounting hole on the lower surface side of the second flat plate portion,
The nut portion has a break nut attached to the second flat plate portion via a thin break portion, and a hole formed inside the break nut has a larger diameter than an outer diameter of the suspension bolt. The anchor according to claim 2.   The nut portion includes a fixing nut provided to be joined to a lower surface of the second flat plate portion, and a screw hole that engages with the suspension bolt is formed inside the fixing nut. Item 4. The anchor according to item 3.   The nut portion has a fixing nut provided to be joined to the lower surface of the second flat plate portion, and a hole formed inside the fixing nut is larger in diameter than an outer diameter of the suspension bolt. The anchor according to claim 3.   The anchor according to claim 5, further comprising an elastic member inserted between the retaining nut and the second flat plate portion at a tip portion of the suspension bolt. A construction method for constructing an anchor attached to a prepared hole provided in a ceiling slab and supporting a suspended bolt in a suspended state,
The anchor is
A shaft member;
A fixing portion provided at an upper portion of the shaft member and fixed to the lower hole in a state of being inserted into the lower hole;
A first flat plate portion provided at a lower portion of the shaft member and parallel to a lower surface of the ceiling slab; a vertical plate portion depending from an end portion of the first flat plate portion; and a first flat plate from a lower end of the vertical plate portion. A second flat plate portion extending in a direction parallel to the portion and provided with an attachment hole into which the suspension bolt can be inserted, and an inner hole provided on the lower surface side of the second flat plate portion and communicating with the attachment hole. A nut portion, and the nut portion has a break nut attached to the second flat plate portion through a thin break portion, and a hole formed inside the break nut is suspended. A suspension bolt support bracket that is larger than the outer diameter of the bolt,
With
The construction method is
The anchor and the suspension bolt are assembled in an inseparable state by inserting the end of the suspension bolt into the mounting hole through the inner hole of the nut portion and attaching the suspension bolt to the suspension bolt support bracket. A first step;
The suspension bolt inseparably assembled with the anchor can be accommodated inside, a tubular body longer than the suspension bolt, provided at the upper end of the tubular body, and engaged with the breaking nut An anchoring tool provided on the lower end of the cylindrical body, and a tool mounting portion for mounting a tool, and an anchoring tool having a lower end of the suspension bolt from the engagement portion to the cylindrical body. A second step of inserting inside and engaging the breaking nut with the engaging portion;
A third step of inserting the anchor portion of the anchor into the pilot hole;
A rotating tool is mounted on the tool mounting portion of the anchor applying tool and the anchor applying tool is rotated, whereby the shaft member of the anchor is rotated together with the suspension bolt support bracket, and the fixing portion is moved to the prepared hole. A fourth step of fixing;
A fifth step of breaking the fractured portion by causing a torque greater than a predetermined value to act on the fracture nut by continuing the rotation of the anchoring tool;
A sixth step of pulling out the anchoring tool from the suspension bolt after the breakage portion is broken;
Construction method having

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