TWI883541B - Metal expansion anchor and method of installing the same - Google Patents

Abstract

The present invention provides a metal expansion anchor and a method of installing a metal expansion anchor that does not require special tools for installation and that allows the constructor or manager to visually check the state of installation. The metal expansion anchor 100 comprises an anchor body 10 having a threaded hole 11b, an expansion sleeve 20 into which a second shaft 12 is inserted, a diameter-expanding member 30 screwed to the second shaft 12, and a rotating body 40 having a threaded shaft 42 screwed to the threaded hole 11b. The second shaft portion 12 is formed with male threads. The diameter-expanding member 30 enters the inside of the expansion sleeve 20 and expands the expansion sleeve 20 as the anchor body 10 rotates. The rotating body 40 goes from a first screwed state to a second screwed state as the screwing of the threaded shaft 42 progress. When a rotational torque exceeding a specified value is applied to the rotating body 40 in the second screwed state, the screw fit between the threaded shaft 42 and the threaded hole 11b is released and the rotating body 40 idles.

Description

Metal expansion anchor bolt and construction method of metal expansion anchor bolt

The present invention relates to a metal expansion anchor bolt and a construction method of the metal expansion anchor bolt.

Metal expansion anchors are used when installing various machines, pipelines, pipes, etc. on the concrete frame that constitutes a building or structure. The metal expansion anchor is inserted into the hole formed in the concrete frame and fixed. The metal expansion anchor includes an axial (rod-shaped) anchor and an expansion member provided at one end of the anchor. The expansion member of the metal expansion anchor expands radially outward as it is tightened. Thereby, the expansion member is inserted into the inner circumference of the hole, so that the metal expansion anchor is fixed to the concrete frame. Various machines, pipelines, pipes, etc. can be installed on the metal expansion anchor.

If such metal expansion anchors are not sufficiently fixed to the holes formed in the concrete frame, there is a risk that the anchors themselves may shake due to the weight of the objects being carried, or fall out of the holes.

The quality of metal expansion anchors may vary depending on the skill level of the constructor. Therefore, the constructor or manager must visually check whether the metal expansion anchors are properly fixed during or after construction.

Patent document 1 describes a metal expansion anchor having a structure with an annular fracture groove formed on the outer peripheral surface. If a torque exceeding a specified value is applied to the metal expansion anchor using a tool such as a socket wrench, fracture will occur in the fracture groove. By tightening the anchor until fracture occurs, it can be confirmed that the expansion member has fully expanded in the hole and the metal expansion anchor is securely fixed.

[Prior technical literature] [Patent Literature]

[Patent Document 1] Japanese Patent No. 6047382

In the metal expansion anchor bolts as described above, the socket wrench and other tools must be fitted only on the side of the fracture groove that will be removed due to fracture (the side away from the concrete frame). If the tool spans both the removed side across the fracture groove and the remaining side on the concrete frame, the moment that causes fracture in the fracture groove will not be generated. Therefore, when constructing the metal expansion anchor bolts as described above, the depth of the socket wrench is limited. Furthermore, after construction, the broken pieces that broke in the fracture groove become waste, and there is a problem of time-consuming processing.

In view of the above situation, one purpose of the present invention is to provide a metal expansion anchor bolt and a construction method of the metal expansion anchor bolt that do not require special tools during construction and can be visually confirmed by the construction worker or manager.

The first type of metal expansion anchor of the present invention comprises: an anchor body, which includes a first shaft portion having a screw hole at one end and a second shaft portion extending from the other end of the first shaft portion; an expansion sleeve, which is sleeved on the second shaft portion; an expanded diameter member, which is screwed to the second shaft portion; and a rotatable body, which has a screw shaft screwed to the screw hole; wherein a male thread is formed on the second shaft portion. The expansion member enters the inner side of the expansion sleeve by the rotation of the anchor body to expand the expansion sleeve. The rotating body changes from the first screw connection state to the second screw connection state by the screw connection rotation of the screw shaft relative to the screw hole. When the rotating body is applied with a rotation torque exceeding a specified value in the second screw connection state, the threaded engagement between the screw shaft and the screw hole is released and the rotating body rotates idly.

According to the structure of the first form of the present invention, the construction worker or manager can visually confirm whether the rotating body has reached the second screw connection state after the construction, thereby being able to confirm the construction state of the metal expansion anchor bolt.

According to the structure of the first type of the present invention, since no special tools are required during construction, construction becomes easy.

The second type of metal expansion anchor of the present invention, in the first type of metal expansion anchor, the rotating body includes a head disposed at one end of the screw shaft, and when the rotating body is in the second screw connection state, the head is closer to the anchor body than in the first screw connection state.

According to the structure of the second embodiment of the present invention, it is possible to easily confirm by visual inspection that the rotating body is in the second screw connection state.

The metal expansion anchor bolt of type 3 of the present invention, in the metal expansion anchor bolt of type 1 or type 2, has a depth of the screw hole greater than the length of the screw shaft.

According to the structure of the third form of the present invention, the head of the rotating body contacts or approaches the anchor body in the second screw connection state. Therefore, it is possible to easily confirm that the rotating body is in the second screw connection state by visual inspection.

The metal expansion anchor bolt of type 4 of the present invention, in the metal expansion anchor bolt described in any one of types 1 to 3, when the rotating body is applied with a rotational torque exceeding the specified value, the thread of at least one of the screw shaft and the screw hole is broken and the thread engagement is released.

According to the structure of the fourth embodiment of the present invention, the thread engagement can be released by the force of rotating the rotating body. Therefore, the rotating body can be made to idle with easy operation.

The fifth embodiment of the present invention provides a method for constructing a metal expansion anchor bolt. The metal expansion anchor bolt comprises an anchor bolt body, an expansion sleeve, an expansion member and a rotating body. The anchor bolt body comprises a first shaft portion having a screw hole at one end and a second shaft portion extending from the other end of the first shaft portion. The expansion sleeve is sleeved on the second shaft portion. The expansion member is screwed to the second shaft portion. The rotating body has a screw shaft screwed to the screw hole. The method for constructing the metal expansion anchor bolt comprises the following steps: forming a hole in an object. ; inserting the metal expansion anchor bolt in the first screw connection state of the rotating body into the hole, and rotating the rotating body from the first screw connection state to the second screw connection state, and at the same time rotating the anchor bolt body by the rotation of the rotating body, thereby expanding the expansion sleeve by the expansion member, so that the expansion sleeve is engaged with the inner surface of the hole; and applying a rotational torque exceeding a specified value to the rotating body in the second screw connection state, so that the threaded engagement between the screw shaft and the screw hole is released and the rotating body is idle.

According to the structure of the fifth form of the present invention, after the construction, the construction worker or manager can visually confirm whether the rotating body has reached the second screw connection state, thereby being able to confirm the construction state of the metal expansion anchor bolt.

According to the structure of the fifth form of the present invention, since no special tools are required during construction, construction becomes easy.

According to the type of the present invention, no special tools are required during construction. According to the type of the present invention, the construction worker or manager can visually confirm the construction status.

100:Metal expansion anchor bolt

10: Anchor body

11: First axis

11A: Part 1

11a: First end

11b: Screw hole

11b1: First area

11b2: Second area

11c: Second end

12: Second axis

13: Stairs

20: Expansion sleeve

20a: Front end

21: Narrow seam

22: Expansion area

30: Tapered nut

30a: Screw hole

31: Cone

31a: Front end

31b: base end

32: Equal diameter part

40: Bolts

41: Head

41a: Hexagonal hole

42: Screw shaft

60: Architecture

61:Prepared hole

110: Anchor body

111b: Screw hole

140: Bolts

142: Screw shaft

143: Base end

C: Center axis

D1: Depth of screw hole

L1: Length of screw shaft

P1: Boring step

P2: Engagement step

P21: Bolt threading steps

P22: Nut screwing steps

P3: Unmating steps

P4: Idle step

[Figure 1A] is a top view showing a bolt of a metal expansion anchor bolt according to an embodiment.

[Figure 1B] is a side view showing the appearance of the metal expansion anchor bolt according to the embodiment.

[Figure 2] is an exploded view of a metal expansion anchor bolt according to an embodiment.

[Figure 3] is a partial cross-sectional view showing a portion of a metal expansion anchor bolt according to an embodiment.

[Figure 4] is a partial cross-sectional view showing a portion of a metal expansion anchor bolt according to an embodiment.

[Figure 5] is a partial cross-sectional view showing a portion of a metal expansion anchor bolt according to an embodiment.

[Figure 6] is a flow chart showing the construction method of the metal expansion anchor bolt according to the embodiment.

[Figure 7] is a diagram showing a specific example of the rotational torque of the bolt during the construction of the metal expansion anchor according to the embodiment.

[Figure 8] is a partial cross-sectional view showing a portion of the anchor bolt body according to a modified example.

[Figure 9] is a side view showing a rotating body according to a modified example.

The metal expansion anchor bolt and the construction method of the metal expansion anchor bolt according to the embodiment are explained with reference to the drawings.

[Metal expansion anchor bolt]

FIG. 1A is a top view showing a bolt 40 of a metal expansion anchor bolt 100 according to an embodiment. FIG. 1B is a side view showing the appearance of a metal expansion anchor bolt 100 according to an embodiment. FIG. 2 is an exploded view of the metal expansion anchor bolt 100. FIG. 3 to FIG. 5 are partial cross-sectional views showing a portion of the metal expansion anchor bolt 100.

As shown in FIG. 1A, FIG. 1B and FIG. 2, the metal expansion anchor 100 includes an anchor body 10, an expansion sleeve 20, a tapered nut 30 (expanding member) and a bolt 40 (rotating body).

In FIG. 2 , C is the central axis of the metal expansion anchor bolt 100. The left-right direction in FIG. 2 is the X direction. The X direction extends along the central axis C. The right direction in FIG. 2 is the +X direction. The direction opposite to the +X direction is the -X direction. The "circumferential direction" is the direction around the central axis C.

[Anchor body]

As shown in FIG. 2 , the anchor body 10 includes a first shaft portion 11 and a second shaft portion 12. The outer peripheral surface of the first portion 11A of the first shaft portion 11 is formed with a male thread. The first portion 11A is a length portion including the first end 11a (one end) (one end on the -X side) of the first shaft portion 11. The end surface of the first end 11a of the first shaft portion 11 is formed with a screw hole 11b. The screw hole 11b is formed along the central axis C of the first shaft portion 11.

As shown in FIG3 , the inner circumference of the screw hole 11b has a first area 11b1 and a second area 11b2.

The first area 11b1 is an area of the inner circumference of the screw hole 11b including the opening end of the screw hole 11b. The second area 11b2 is an area deeper than the first area 11b1 (area on the +X side) on the inner circumference of the screw hole 11b. The first area 11b1 is formed with a female thread. The second area 11b2 is not formed with a female thread. The depth of the first area 11b1 is, for example, about half of the depth D1 of the screw hole 11b. The depth D1 of the screw hole 11b is, for example, the total length of the first area 11b1 and the second area 11b2.

As shown in FIG4 , when the screw shaft 42 is threadedly connected to the entire length of the first area 11b1, the bolt 40 is in the first threaded state.

The first screwing state is achieved by simply screwing the bolt 40 along the entire length of the first area 11b1. Therefore, the operation of putting the bolt 40 into the first screwing state becomes easy. Since the second area 11b2 does not have a female thread, the positional deviation of the bolt 40 in the depth direction of the screw hole 11b can be suppressed.

The depth D1 of the screw hole 11b is preferably greater than the length L1 of the screw shaft 42 of the bolt 40. In other words, the depth D1 of the screw hole 11b is preferably equal to or greater than the length L1 of the screw shaft 42. By making the depth D1 of the screw hole 11b greater than the length L1 of the screw shaft 42, in the second threaded state (see FIG. 5 ), the head 41 is in contact with or close to the anchor body 10.

As shown in FIG. 2 , the second shaft portion 12 extends from the second end 11c (the other end) (the end on the +X side) of the first shaft portion 11 in the +X direction. The second end 11c is the end opposite to the first end 11a of the first shaft portion 11. The outer peripheral surface of the second shaft portion 12 is formed with a male thread. The outer diameter of the second shaft portion 12 is, for example, smaller than the outer diameter of the first shaft portion 11. The second end 11c of the first shaft portion 11 is formed with a step portion 13 due to the difference in outer diameters between the first shaft portion 11 and the second shaft portion 12.

[Expansion sleeve]

The expansion sleeve 20 is formed into a cylindrical shape. The inner diameter of the expansion sleeve 20 is the same as or larger than the outer diameter of the second shaft portion 12. The expansion sleeve 20 is sleeved on the second shaft portion 12. The second shaft portion 12 is inserted into the expansion sleeve 20. The inner diameter of the expansion sleeve 20 is smaller than the outer diameter of the step portion 13. Therefore, the movement of the expansion sleeve 20 in the -X direction is restricted by the step portion 13.

The expansion sleeve 20 has a plurality of slits 21 (cracks) formed in the length portion including the front end 20a. The slits 21 extend along the length direction of the expansion sleeve 20. The expansion sleeve 20 has a length portion including the front end 20a, which is divided into a tab-shaped expansion portion 22 by the slits 21. When the expansion portion 22 is pushed outward by the tapered portion 31 of the tapered nut 30, it can be bent and deformed radially outward (in the expansion direction).

It is preferred that a plurality of slits 21 are formed at positions that are rotationally symmetrical in the axial direction. In this embodiment, slits 21 are formed every 90° in the axial direction. The length portion of the expansion sleeve 20 including the front end 20a is divided into four expansion portions 22 by four slits 21. The number of slits is preferably two or more (for example, three or more).

[Tapered nut]

The conical nut 30 has a conical portion 31 and a constant diameter portion 32. The constant diameter portion 32 is formed in a cylindrical shape. The conical portion 31 extends from one end of the constant diameter portion 32 in a direction of -X with a gradually decreasing diameter. The conical portion 31 is formed in a cone shape. The outer peripheral surface of the conical portion 31 is a conical surface with a gradually decreasing diameter in the direction of -X. The outer diameter (minimum outer diameter) of the front end 31a of the conical portion 31 is less than the inner diameter of the expansion sleeve 20. The outer diameter (maximum outer diameter) of the base end 31b of the conical portion 31 is larger than the inner diameter of the expansion sleeve 20.

The tapered nut 30 is formed with a screw hole 30a. The screw hole 30a is formed to penetrate the tapered nut 30 along the center axis C. The second shaft portion 12 is inserted into the screw hole 30a. A female thread that is threaded with the male thread of the second shaft portion 12 is formed on the inner circumference of the screw hole 30a. The tapered nut is an example of an "expansion member". The tapered nut is also called an expansion nut.

〔Bolt〕

The bolt 40 has a head 41 and a screw shaft 42. The head 41 is disposed at one end of the screw shaft 42. The head 41 is formed, for example, in a cylindrical shape. The outer diameter of the head 41 is larger than the outer diameter of the screw shaft 42. The bolt 40 is an example of a "rotating body".

The head 41 is formed with a rotational operating part (drive part). The rotational operating part has a structure that transmits the rotational force of a rotational tool (such as an electric tool or a hand tool) to the bolt 40 when the bolt 40 is rotated. As the rotational operating part, a wrench hole formed on the outer surface (-X side surface) of the head 41 can be listed. As the wrench hole, a hexagonal hole, a square hole, a cross hole, a slotted groove, etc. can be listed. In this embodiment, the rotational operating part is a hexagonal hole 41a formed in the head 41 (refer to FIG. 1A).

The shape of the head is not particularly limited. The head may also be in the shape of a prism (hexagonal prism, quadrangular prism, etc.). The maximum outer dimension of the head (the dimension in the direction perpendicular to the center axis) is, for example, larger than the outer diameter of the screw shaft. When the head is in the shape of a prism, the head can function as a rotating operating unit.

As shown in FIG3 , the entire length of the outer peripheral surface of the screw shaft 42 is formed with a male thread. The screw shaft 42 protrudes from one surface (the surface on the +X side) of the head 41 in the +X direction. The screw shaft 42 is threadedly connected to the screw hole 11b of the first shaft portion 11.

FIG. 4 shows the metal expansion anchor 100 with the bolt 40 in the first threaded state. In the first threaded state, the bolt 40 is threaded into the screw hole 11b with the head 41 spaced from the first end 11a of the anchor body 10 on the -X side. At the beginning of construction, the bolt 40 is in the first threaded state. The screw shaft 42 is threaded into the entire length of the first area 11b1. Therefore, about half of the length of the screw shaft 42 is threaded into the screw hole 11b.

FIG. 5 shows a metal expansion anchor 100 with a bolt 40 in a second threaded state. Compared to the first threaded state, the second threaded state is a state in which the screw shaft 42 is threadedly rotated. Compared to the first threaded state, the head 41 is closer to the anchor body 10. In the example shown in FIG. 5 , the head 41 contacts or approaches the anchor body 10. The entire length of the screw shaft 42 is inserted into the screw hole 11b.

The anchor body 10, the expansion sleeve 20, the tapered nut 30 and the bolt 40 are formed of metal.

[Construction method of metal expansion anchor bolt]

Next, the construction method of the metal expansion anchor bolt according to the embodiment is explained.

<Hole cutting step P1>

As shown in FIG. 6 (A), the frame 60 is a construction object (object). The frame 60 is made of, for example, concrete. For example, a pre-hole 61 (hole) is formed in the frame 60 by a drill bit of a rotary tool (not shown). The pre-hole 61 is formed, for example, perpendicular to the surface of the frame 60. The inner diameter of the pre-hole 61 is larger than the outer diameter of the metal expansion anchor 100. The inner diameter of the pre-hole 61 is determined so that the expansion portion 22 of the expansion sleeve 20 can be engaged with the inner circumferential surface of the pre-hole 61 when expanded. The depth of the pre-hole 61 is determined so that the length of the metal expansion anchor 100 including the upper end (first end 11a) of the anchor body 10 protrudes from the surface of the frame 60 (refer to FIG. 6 (B)).

The drilling step P1 is an example of a step of forming a hole in an object.

<Engagement step P2>

The engagement step P2 includes a bolt threading step P21 and a tapered nut threading step P22. These steps are described in detail.

[Bolt threading step P21]

As shown in FIG6 (B), the metal expansion anchor 100 with the bolt 40 in the first threaded state (see FIG4) is inserted into the prepared hole 61. The lower end of the metal expansion anchor 100 (the lower end of the second shaft 12) reaches the bottom surface of the prepared hole 61. The length portion of the metal expansion anchor 100 including the upper end (first end 11a) of the anchor body 10 protrudes upward from the surface of the frame 60. The tapered nut 30 is threaded to the second shaft 12, for example, in a state where the portion including the front end of the tapered portion 31 is inserted into the expansion sleeve 20.

The head 41 of the bolt 40 is rotated around the axis (tightening direction) using a rotating tool (e.g., an electric tool). The screw shaft 42 is threadedly rotated toward the screw hole 11b by the rotation of the bolt 40. The rotating tool is, for example, an impact driver (electric tool) and a hexagonal screwdriver head. The portion of the hexagonal screwdriver head including the base end is combined with the rotating portion of the impact driver. The engaging portion at the front end of the hexagonal screwdriver head engages with the hexagonal hole 41a (see FIG. 1A).

By screwing the bolt 40 toward the screw hole 11b, the bolt 40 changes from the first screwing state (see FIG. 4 ) to the second screwing state (see FIG. 5 ). When the bolt 40 progresses from the first screwing state to the second screwing state, a portion of the screw shaft 42 rotates from the first area 11b1 to the second area 11b2. In the second area 11b2, for example, a thread is formed by the screw shaft 42.

In the second threaded state, since the head 41 is located close to the anchor body 10, it is easy to visually confirm that the bolt 40 is in the second threaded state. When the head 41 reaches the first end 11a of the anchor body 10, the threading of the screw shaft 42 toward the screw hole 11b is completed.

[Tapered nut screwing step P22]

The rotational force applied to the bolt 40 is transmitted to the anchor body 10. Therefore, the anchor body 10 rotates around the axis (tightening direction). Since the tapered nut 30 contacts the inner circumference of the prepared hole 61, it is difficult to rotate due to friction. Therefore, the number of rotations of the tapered nut 30 is reduced compared to the anchor body 10. Therefore, the anchor body 10 and the tapered nut 30 rotate around the axis relative to each other. Thereby, the tapered nut 30 is threaded and rotated relative to the anchor body 10, causing the tapered nut 30 to rise.

As the tapered nut 30 rises, the expansion sleeve 20 is pushed upward. The expansion sleeve 20 abuts against the step portion 13 and its rise is restricted. When the tapered nut 30 rises while the rise of the expansion sleeve 20 is restricted by the step portion 13, the tapered nut 30 penetrates into the inner side of the expansion sleeve 20. The expansion portion 22 of the expansion sleeve 20 is pushed outward by the tapered portion 31 of the tapered nut 30 and is radially bent outward (in the expansion direction) Deformed. As the expansion portion 22 expands, the portion of the expansion portion 22 including the front end engages with the inner circumference (inner surface) of the prepared hole 61.

Due to the engagement of the expanded portion 22 with the inner circumference of the prepared hole 61, the torque required for the anchor body 10 to rotate increases. When the engagement force of the expanded portion 22 with the inner circumference of the prepared hole 61 becomes large enough, the rotation of the anchor body 10 stops.

The bolt threading step P21 and the tapered nut threading step P22 can be performed one by one or both at the same time.

The engagement step P2 is an example of a step of expanding the expansion sleeve so that the expansion sleeve engages with the inner surface of the hole.

<Unmating step P3>

As shown in (C) of FIG. 6 , in the second threaded state, when a rotational torque exceeding a specified value is applied to the bolt 40, for example, the thread of at least one of the screw shaft 42 and the screw hole 11b is broken, thereby releasing the thread engagement between the screw shaft 42 and the screw hole 11b. Specifically, for example, the portion of the screw hole 11b including the top of the thread is deformed due to the axial force applied by the screw shaft 42, so that the thread becomes lower. As a result, the engagement force between the threads of the screw shaft 42 and the screw hole 11b is reduced.

The release of the threaded engagement between the screw shaft 42 and the screw hole 11b is considered to be caused by the deformation of the part of the screw shaft 42 including the top of the thread, which causes the thread to become lower. The release of the threaded engagement between the screw shaft 42 and the screw hole 11b can also be caused by the deformation of the threads of both the screw shaft 42 and the screw hole 11b.

<Idle step P4>

As shown in FIG. 6 (D), by releasing the threaded engagement between the screw shaft 42 and the screw hole 11b, the bolt 40 idles relative to the anchor body 10. The engagement release step P3 and the idle rotation step P4 are an example of a step of releasing the threaded engagement between the screw shaft and the screw hole and causing the rotating body to idle.

[Specific example of the construction method of metal expansion anchor bolts]

FIG. 7 is a diagram showing a specific example of the rotational torque of the bolt 40 in the engagement step P2, the engagement release step P3, and the idling step P4 during the construction of the metal expansion anchor 100. In FIG. 7, the horizontal axis represents the number of rotations. The vertical axis represents the rotational torque.

As shown in Figure 7, at the beginning of the test (the time point when the rotational torque is zero), the bolt 40 is in the first threaded state (refer to Figure 4).

In the bolt threading step P21 of the engagement step P2, as the screw shaft 42 is threadedly rotated relative to the screw hole 11b, the rotational torque of the bolt 40 gradually increases. When the bolt threading step P21 is completed, the bolt 40 becomes the second threaded state (refer to Figure 5).

In the tapered nut screwing step P22, the rotational torque increases because the expansion portion 22 is engaged with the inner circumference of the prepared hole 61. In this example, the tapered nut screwing step P22 starts at the same time as the bolt screwing step P21. The tapered nut screwing step P22 also continues after the bolt screwing step P21 is completed.

In the engagement release step P3, the rotational torque is rapidly reduced due to the release of the threaded engagement between the screw shaft 42 and the screw hole 11b.

In the idling step P4, the bolt 40 idles.

The construction worker who operates the rotating tool can confirm the completion of the construction of the metal expansion anchor 100 by the idle rotation of the bolt 40. By releasing the thread engagement, the reaction force acting on the rotating tool is reduced, and the construction worker can identify the idle rotation of the bolt 40 according to the movement of the rotating tool. The construction worker can confirm the completion of the construction by the idle rotation of the bolt 40.

After the construction, the construction worker or manager (manager of the construction) can confirm the construction status of the metal expansion anchor 100 (whether the construction is completed normally) by visually confirming whether the bolt 40 is in the second threaded state. For example, for the metal expansion anchor 100 whose bolt 40 is in the second threaded state, the construction worker or manager can determine that the construction is completed normally. For the metal expansion anchor 100 whose bolt 40 has not yet become the second threaded state, the construction worker or manager can determine that the construction is not yet completed. In this way, the construction worker or manager can easily grasp the construction status of the metal expansion anchor 100 after the construction.

The completed metal expansion anchor bolt 100 can be used to fix the installation objects of the frame 60, etc.

[Effects of the metal expansion anchor bolt and its construction method in the embodiment]

In the metal expansion anchor 100 of this embodiment, when a rotational torque exceeding a specified value is applied to the bolt 40 in the second threaded state, the threaded engagement between the screw shaft 42 and the screw hole 11b is released and the bolt 40 idles. By the idle rotation of the bolt 40, the construction worker can confirm the completion of the construction. Therefore, the construction of the metal expansion anchor 100 becomes easy.

In the metal expansion anchor 100, the construction worker or manager can confirm the construction status by visually confirming whether the bolt 40 is in the second threaded state. Therefore, it is easy to confirm the completion of the construction after the construction. Therefore, the construction management of the construction worker or manager becomes easy.

The metal expansion anchor 100 is different from other metal expansion anchors that require special tools to rotate the nut. No special tools are required during construction, making construction easier.

The metal expansion anchor 100 can be installed by simply applying a rotational force to the bolt 40 with a rotation tool, so it is easier to install than a metal expansion anchor that must be tightened with a torque wrench.

Unlike anchor bolts that may partially break during construction, the metal expansion anchor bolt 100 does not require subsequent steps such as recovery of broken pieces and rust-proofing of the broken surface. Therefore, construction becomes easy.

In the second threaded state, the head 41 of the bolt 40 is close to the anchor body 10. Therefore, it is possible to easily confirm that the bolt 40 is in the second threaded state by visual inspection.

In the metal expansion anchor 100, when the depth of the screw hole 11b is greater than the length of the screw shaft 42 of the bolt 40, the head 41 of the bolt 40 contacts or approaches the anchor body 10 in the second threaded state. Therefore, it is possible to easily confirm that the bolt 40 is in the second threaded state by visual inspection.

The threaded engagement between the screw shaft 42 of the bolt 40 and the screw hole 11b can be released due to, for example, thread breakage of at least one of the screw shaft 42 and the screw hole 11b. Therefore, the threaded engagement can be released by the force of rotating the bolt 40. Therefore, the bolt 40 can be made to idle with easy operation.

The construction method of the metal expansion anchor 100 of this embodiment can release the threaded engagement between the screw shaft 42 and the screw hole 11b by applying a rotational torque exceeding a specified value to the bolt 40 in the second threaded state, thereby causing the bolt 40 to idle. By idling the bolt 40, the construction worker can confirm the completion of the construction. Therefore, the construction of the metal expansion anchor 100 becomes easy.

[Anchor body] (variation example)

FIG8 is a partial cross-sectional view showing a portion of the anchor body 110 according to a modified example.

As shown in FIG8 , the entire length of the inner circumference of the screw hole 111b of the anchor body 110 is formed with a female thread.

The bolt 40 can also be temporarily fixed to the anchor body 10 by adhesive or the like in the first threaded state. In this way, the positional deviation of the bolt 40 during movement can be suppressed, and the first threaded state can be maintained.

[Rotating body] (variation example)

FIG9 is a partial cross-sectional view showing a bolt 140 according to a modified example.

As shown in FIG. 9 , the portion of the bolt 140 including the base end of the screw shaft 142 (base end portion 143) is not formed with a male thread.

Each structure and combination in the embodiment is an example. The structure can be added, omitted, replaced or otherwise modified without departing from the purpose of the present invention. The present invention is not limited to the embodiment.

For example, in the metal expansion anchor 100 shown in FIG. 1A and FIG. 1B , a bolt 40 having a head 41 and a screw shaft 42 is used as a rotating body, but the rotating body is not limited to this example. For example, the rotating body may not have a head as long as it has a screw shaft that can be screwed into the screw hole of the anchor body.

In the metal expansion anchor 100, a step portion 13 formed by the outer diameter difference between the first shaft portion 11 and the second shaft portion 12 is adopted in the anchor body 10 as a structure for limiting the rise of the expansion sleeve 20, but the structure for limiting the rise of the expansion sleeve is not particularly limited. For example, the rise of the expansion sleeve can be limited by replacing the step portion with an annular protrusion formed on the outer peripheral surface of the anchor body.

In the metal expansion anchor bolt 100, a washer (flat washer, spring washer, etc.) can also be provided between the head 41 and the first end 11a.

There is no particular limitation on the construction target of metal expansion anchors. For example, the construction target is the floor surface of a structure made of concrete, etc., or it can be a wall surface. The construction target can also be the ceiling surface of the structure.

100:Metal expansion anchor bolt

10: Anchor body

11: First axis

11A: Part 1

11a: First end

11b: Screw hole

11c: Second end

12: Second axis

13: Stairs

20: Expansion sleeve

20a: Front end

21: Narrow seam

22: Expansion area

30: Tapered nut

30a: Screw hole

31: Cone

31a: Front end

31b: base end

32: Equal diameter part

40: Bolts

41: Head

42: Screw shaft

C: Center axis

Claims (5)

A metal expansion anchor bolt comprises: an anchor bolt body, which comprises a first shaft portion having a screw hole at one end and a second shaft portion extending from the other end of the first shaft portion; an expansion sleeve, which is sleeved on the second shaft portion; an expansion member, which is screwed to the second shaft portion; and a rotatable body, which has a screw shaft screwed to the screw hole; wherein a male thread is formed on the second shaft portion, and the expansion member is screwed to the second shaft portion. The component enters the inner side of the expansion sleeve by the rotation of the anchor body to expand the expansion sleeve. The rotating body changes from the first screw connection state to the second screw connection state by the screw connection rotation of the screw shaft relative to the screw hole. When the rotating body is applied with a rotation torque exceeding a specified value in the second screw connection state, the threaded engagement between the screw shaft and the screw hole is released and the rotating body rotates idly. The metal expansion anchor as described in claim 1, wherein the rotating body includes a head disposed at one end of the screw shaft, and when the rotating body is in the second threaded state, the head is closer to the anchor body than when it is in the first threaded state. A metal expansion anchor as described in claim 1, wherein the depth of the screw hole is greater than the length of the screw shaft. A metal expansion anchor as described in any one of claims 1 to 3, wherein when a rotational torque exceeding the specified value is applied to the rotating body, the thread of at least one of the screw shaft and the screw hole is broken, causing the thread engagement to be released. A construction method of a metal expansion anchor bolt, the metal expansion anchor bolt comprises an anchor bolt body, an expansion sleeve, an expansion member and a rotating body, the anchor bolt body comprises a first shaft portion having a screw hole at one end and a second shaft portion extending from the other end of the first shaft portion, the expansion sleeve is sleeved on the second shaft portion, the expansion member is screwed to the second shaft portion, and the rotating body has a screw shaft screwed to the screw hole, wherein the construction method of the metal expansion anchor bolt comprises the following steps: forming a hole in an object; The metal expansion anchor bolt with the rotating body in the first screw connection state is inserted into the hole, and the rotating body is rotated from the first screw connection state to the second screw connection state, and the anchor bolt body is rotated by the rotation of the rotating body, thereby expanding the expansion sleeve by the expansion member, so that the expansion sleeve is engaged with the inner surface of the hole; and by applying a rotation torque exceeding a specified value to the rotating body in the second screw connection state, the threaded engagement between the screw shaft and the screw hole is released, so that the rotating body is idle.