Post-installed anchor

Abstract

To provide a post-construction anchor capable of obtaining sufficient pull-out resistance force easily while forming an anchor hole easily.SOLUTION: A post-construction anchor 10 comprises a rod-shape anchor member 20 inserted into an anchor hole 12A in a fixed bore diameter and having a male screw 22 formed at a tip part, a filling material 30 filled into a gap between the anchor member 20 and the anchor hole 12A, a wedge member 40 having a female screw 42 into which the male screw 22 is threaded and an expansion member 50 enclosing the wedge member 40 and having a plurality of expansion pieces 52 that are pressed by the wedge member 40, pulled up by rotation of the anchor member 20, and expanded to surface-press a hole wall of the anchor hole 12A.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a post-installed anchor. [Background technology]

[0002] Patent Document 1 below describes an anchor structure in which an expansion fitting is driven onto a tapered nut inserted into an anchor hole to expand the diameter of the expansion fitting. The tapered nut is threaded onto a threaded rod, and the expansion fitting engages with the anchor hole, thereby fixing the threaded rod in the anchor hole. In addition, a filler material is filled in the gap between the threaded rod and the anchor hole. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-311224 Summary of the Invention [Problem to be solved by the invention]

[0004] The anchor structure of Patent Document 1 has an anchor hole with an expanded diameter at the bottom, which requires special tools and makes construction less easy than when only an anchor hole with a fixed diameter is formed.

[0005] Furthermore, because the amount of expansion of the expansion fitting changes depending on how deeply it is driven, there is a possibility that only the tip of the expansion fitting will come into linear contact with the anchor hole and apply pressure. Meanwhile, the portion filled with filler exerts pull-out resistance through planar contact between the threaded rod and filler, and between the filler and the anchor hole. For this reason, there is a possibility that the pull-out resistance at the expansion fitting portion will be insufficient, making it difficult to obtain sufficient pull-out resistance for the entire anchor bolt.

[0006] In consideration of the above, an object of the present invention is to provide a post-installed anchor that allows for easy formation of an anchor hole and facilitates obtaining sufficient pull-out resistance. [Means for solving the problem]

[0007] The post-installed anchor of claim 1 is TeA A plurality of expansion pieces that can press the hole wall of the anchor hole with their surfaces a bottom portion formed at a base end of the expansion piece and arranged opposite to the bottom of the anchor hole; an expansion member having the above structure; a wedge member disposed inside the expansion piece and having an internal thread formed thereon; a rod-shaped anchor member inserted into the anchor hole and having an external thread formed at the tip thereof threaded into the internal thread of the wedge member and rotated to pull up the wedge member and expand the expansion piece; and a filler material filled in a gap between the anchor member and the anchor hole. The wedge member is pulled up by the long side of its outer surface, which slopes inward from the bottom to the top, catching on the extension piece and suppressing rotation associated with the rotation of the anchor member, and the long side is chamfered by the short side that does not contact the extension piece, forming an octagonal shape in a planar view, and the chamfer width of the short side is formed so as to gradually increase from the top to the bottom of the wedge member.

[0008] In the post-installed anchor of claim 1, the expansion piece pressed by the wedge member presses against the hole wall of the anchor hole over a surface. Also, the gap between the anchor member and the anchor hole is filled with a filler. This generates an adhesive force between the anchor member and the anchor hole, providing surface pull-out resistance.

[0009] In this way, with the post-installed anchor of this aspect, a planar pull-out resistance force is obtained across the expansion piece and the anchor member. Therefore, it is easier to obtain sufficient pull-out resistance force compared to, for example, when the expansion piece presses against the anchor hole wall only with the tip portion.

[0010] Furthermore, since the pile diameter of the anchor hole is constant, the anchor hole can be formed more easily compared to a structure in which the pile diameter is expanded. The post-installed anchor of claim 2 is the post-installed anchor of claim 1, ,before The wedge member is hooked onto the expansion piece and pulled up by rotating the anchor member with the tip of the anchor member facing the bottom portion. A post-installed anchor according to claim 3 is the post-installed anchor according to claim 1 or 2, wherein the wedge member is The top It is formed in a square shape in plan view. ,before The expansion member is the wedge member The long side of The four extension pieces are in contact with each other. A post-installed anchor of claim 4 is the post-installed anchor according to any one of claims 1 to 3, wherein the wedge member and the expansion member are made of steel.

[0011] Claim 5 The post-installed anchor is Any one of items 1 to 4 In the post-installed anchor described above, when the length of the expansion member along the axial direction of the anchor hole at the part that contacts the anchor hole is L1 and the length of the filler material along the axial direction is L2, the following formula (1) is satisfied.

[0012] 4×L1≦L2 (1)

[0013] Claim 5 In the post-installed anchor, the length L2 of the filler along the axial direction of the anchor hole is set to be at least four times the length L1 of the expansion member along the axial direction of the part that contacts the anchor hole. Therefore, the amount of filler filled is greater than when it is less than four times the length. This increases the pull-out resistance of the post-installed anchor.

[0014] Claim 6 Post-installed anchors are Claim 5 In the post-installed anchor described in 1, the length L1 and the length L2 further satisfy the following formula (2).

[0015] 6×L1≧L2 (2)

[0016] Claim 6 In the case of post-installed anchors, the length L2 of the filler along the axial direction of the anchor hole is set to be six times or less the length L1 of the axial direction of the part of the expansion member that contacts the anchor hole. Therefore, the filling depth of the filler is shallower than when it is six times or more. This helps prevent insufficient filling of the filler. [Effects of the Invention]

[0017] According to the post-installed anchor of the present invention, it is easy to form an anchor hole and to obtain sufficient pull-out resistance. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1A is a cross-sectional view showing a post-installed anchor according to an embodiment of the present invention, FIG. 1B is a cross-sectional view taken along line BB in FIG. 1A, and FIG. 1C is a cross-sectional view showing a modified example of the shape of the wedge member. [Figure 2] (A) is a cross-sectional view showing the state in which a wedge member is placed inside the expansion member, (B) is a cross-sectional view showing the state in which an anchor member with a wedge member and expansion member temporarily fixed to its tip is being inserted into an anchor hole, (C) is a cross-sectional view showing the state in which the anchor member inserted into the anchor hole is rotated to move the wedge member, and (D) is a cross-sectional view along line DD in (C). [Figure 3] (A) is a cross-sectional view showing the state where the wedge member and the expansion piece of the expansion member are in surface contact, (B) is a cross-sectional view showing the state where the nut screwed into the anchor member is rotated to move the anchor member toward the open end of the anchor hole, and (C) is a cross-sectional view showing the state where filler material is filled into the gap between the anchor member and the anchor hole. [Figure 4] FIG. 2 is a perspective view showing an anchor member, a wedge member, and an expansion member in the post-installed anchor according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, a post-installed anchor according to an embodiment of the present invention will be described with reference to the drawings. Components indicated by the same reference numerals in the various drawings are the same components. However, unless otherwise specified in the specification, each component is not limited to one, and multiple components may be present.

[0020] Furthermore, the description of the same components and symbols in each drawing may be omitted. Note that the present invention is not limited to the following embodiments, and may be implemented by making appropriate modifications, such as omitting components or replacing them with different components, within the scope of the object of the present invention.

[0021] In each figure, the directions indicated by arrows X and Y are directions along the horizontal plane and are perpendicular to each other. The direction indicated by arrow Z is a direction along the vertical direction (up and down). In each figure, the directions indicated by arrows X, Y, and Z are assumed to be consistent with each other.

[0022] <Post-installed anchor> As shown in Fig. 1(A), a post-installed anchor 10 according to an embodiment of the present invention is formed with an anchor member 20, a filler material 30, a wedge member 40, and an expansion member 50. The post-installed anchor 10 is an anchor bolt that is inserted into an anchor hole 12A formed in, for example, a skeleton 12 of a building, and fixed to the skeleton 12. The anchor hole 12A has a constant hole diameter.

[0023] The anchor hole 12A is formed by drilling with a drill or the like. If the tip of the drill is sharp, the tip of the anchor hole 12A will be formed in a cone shape, as shown by the two-dot chain line E in Fig. 1(A). In this embodiment, this type of situation is also included in the term "constant" hole diameter of the anchor hole 12A.

[0024] (anchor member) The anchor member 20 is a rod-shaped reinforcing bar having a male thread 22 formed at least at the tip portion that is inserted into the anchor hole 12A. The reinforcing bar used as the anchor member 20 may be a fully threaded bolt, a deformed reinforcing bar having a male thread formed at the tip portion, or a round steel bar having a male thread formed at the tip portion.

[0025] Various methods can be used to form male threads at the tip of deformed reinforcing bars or round steel bars, such as cutting the tip or welding a rod-shaped member having a male thread to the tip.

[0026] (wedge member) The wedge member 40 is a cylindrical member made of metal (for example, steel) and formed with an internal thread 42 into which the external thread 22 of the anchor member 20 is screwed. When placed inside the anchor hole 12A, the wedge member 40 is formed into a cone shape whose diameter decreases from the bottom of the anchor hole 12A toward the open end.

[0027] 1(B), the outer peripheral surface of wedge member 40 is formed into a polygonal shape in plan view (as viewed from the direction along the Z direction, which is the axial direction of anchor hole 12A). In this embodiment, the outer peripheral surface of wedge member 40 has a substantially octagonal shape with the corners of the quadrangular shape chamfered in plan view.

[0028] More specifically, as shown in Fig. 4, the outer peripheral surface of wedge member 40 is formed into an octagonal shape by chamfering long sides 44A, which are inclined toward the female thread side (inward) from the bottom to the top, by short sides 44B. The width of this chamfer gradually increases from the top to the bottom of the wedge member. Furthermore, since the chamfer width is almost zero at the top of wedge member 40, wedge member 40 has a substantially square shape.

[0029] The "bottom" of the wedge member 40 is the portion that faces the bottom of the anchor hole 12A when the wedge member 40 is placed inside the anchor hole 12A, as shown in Figure 1(A), and the "top" of the wedge member 40 is the portion that is placed on the opening end side of the anchor hole 12A when the wedge member 40 is placed inside the anchor hole 12A.

[0030] The long side 44A on the outer peripheral surface of the wedge member 40 is arranged in contact with the expansion piece 52 in plan view as shown in Fig. 1(B), and is also arranged in contact with the expansion piece 52 in side view as shown in Fig. 1(A). In other words, the long side 44A on the outer peripheral surface of the wedge member 40 is arranged in surface contact with the expansion piece 52.

[0031] (expansion member) As shown in Figure 1(B), the expansion member 50 is a metal (e.g., steel) member that is arranged to surround the wedge member 40 in a planar view and whose outer surface is arranged in contact with the inner surface (hole wall) of the anchor hole 12A.

[0032] As shown in Figure 1(A), when the expansion member 50 is placed inside the anchor hole 12A, it has a bottom 54 positioned opposite the bottom of the anchor hole 12A, and a plurality of expansion pieces 52 extending from the bottom 54 toward the open end of the anchor hole 12A.

[0033] Bottom 54 of expansion member 50 has a smaller diameter than anchor hole 12A. Expansion piece 52 is formed with expanded diameter section 52C that gradually expands in diameter from bottom 54 toward the open end of anchor hole 12A. The portion of expansion piece 52 above expanded diameter section 52C (toward the open end of anchor hole 12A) has the same diameter along the axial direction of anchor hole 12A and is disposed in contact with anchor hole 12A.

[0034] The expansion piece 52 is formed so that its thickness gradually increases from the bottom of the anchor hole 12A (from the portion above the enlarged diameter portion 52C) toward the open end. The outer peripheral surface 52A of the expansion piece 52 is formed in an arc shape in a plan view, as shown in FIG. 1(B).

[0035] Furthermore, with the outer peripheral surface 52A of the expansion piece 52 in contact with the hole wall of the anchor hole 12A, the inner peripheral surface 52B of the expansion piece 52 is arranged in contact with the long side 44A of the outer peripheral surface of the wedge member 40. In this contact state, as shown in FIG. 1(A), the angle of the inner peripheral surface 52B of the expansion piece 52 relative to the axial direction of the anchor hole 12A is equal to the angle of the long side 44A of the outer peripheral surface of the wedge member 40 relative to the axial direction of the anchor hole 12A.

[0036] As shown in FIG. 1(B), the expansion member 50 is formed with four expansion pieces 52, and the inner peripheral surface 52B of each expansion piece 52 is in surface contact with the four long sides 44A on the outer peripheral surface of the wedge member 40.

[0037] (filling material) The filler 30 is a grout material filled in the gap between the anchor member 20 and the anchor hole 12A. The filler 30 is filled over the entire length from the upper end surface of the expansion member 50 (the end surface on the opening end side of the anchor hole 12A) to the opening end of the anchor hole 12A.

[0038] It is not necessary for the filler material 30 to be densely filled from the upper end surface of the expansion member 50 to the open end of the anchor hole 12A. In other words, "filled over the entire length" with the filler material 30 includes, for example, a state in which air bubbles are mixed in inside the anchor hole 12A.

[0039] Here, if the length of the portion of the expansion piece 52 of the expansion member 50 that contacts the anchor hole 12A along the axial direction of the anchor hole 12A is L1, and the length of the filler material 30 along the axial direction of the anchor hole 12A is L2, then the following formula (1) is satisfied.

[0040] 4×L1≦L2 (1)

[0041] That is, in the post-installed anchor 10, the length L2 of the filler 30 along the axial direction of the anchor hole 12A is four or more times the length L1 of the portion of the expansion piece 52 of the expansion member 50 that contacts the anchor hole 12A along the axial direction of the anchor hole 12A. Therefore, the amount of filler 30 filled is greater compared to when this is less than four times. This increases the pull-out resistance of the post-installed anchor 10.

[0042] Furthermore, the length L1 and the length L2 satisfy the following formula (2).

[0043] 6×L1≧L2 (2)

[0044] That is, the length L2 of the filler 30 along the axial direction of the anchor hole 12A is set to be six times or less the length L1 of the portion of the expansion piece 52 of the expansion member 50 that contacts the anchor hole 12A along the axial direction of the anchor hole 12A. Therefore, the filling depth of the filler 30 is shallower than when it is six times or more. This makes it possible to prevent improper filling of the filler 30.

[0045] <Installation method of post-installed anchors> To form the post-installed anchor 10, first, the wedge member 40 is placed inside the expansion member 50, as shown in Figure 2(A). As a result, the wedge member 40 is placed surrounded by the expansion piece 52.

[0046] It is preferable that the expansion piece 52 of the expansion member 50 is formed so as to be elastically deformable as shown by the arrow M. This makes it easier to arrange the wedge member 40 inside the expansion member 50.

[0047] Next, the male thread 22 formed on the tip of the anchor member 20 is screwed into the wedge member 40. At this time, the expansion member 50 is held with fingers or the like while the male thread 22 is screwed into the wedge member 40. As will be described later, rotation of the wedge member 40 can be suppressed inside the expansion member 50, so that co-rotation of the wedge member 40 due to rotation of the anchor member 20 is suppressed.

[0048] This allows the male screw 22 to be screwed into the wedge member 40, and the wedge member 40 and the expansion member 50 are temporarily fixed to the tip of the anchor member 20, as shown in FIG. 2(B).

[0049] Next, the tip of the anchor member 20, to which the wedge member 40 and the expansion member 50 are temporarily fixed, is inserted into the anchor hole 12A. Then, as shown in FIG. 2(C), the anchor member 20 is rotated by hand or the like while pressing the tip of the anchor member 20 against the bottom 54 of the expansion member 50.

[0050] The diameter of the anchor hole 12A is preferably formed to approximately match the diameter of the circle forming the arc formed on the outer peripheral surface 52A of the expansion piece 52. This allows the outer peripheral surface 52A of the expansion piece 52 to come into surface contact with the hole wall of the anchor hole 12A.

[0051] As a result, the anchor member 20 is screwed into the wedge member 40, and the wedge member 40 moves toward the open end of the anchor hole 12A along the axial direction of the anchor member 20. At this time, although there is a gap between the wedge member 40 and the expansion piece 52, as shown in FIG. 2(D), the corner between the long side 44A and the short side 44B on the outer peripheral surface of the wedge member 40 catches on the inner peripheral surface 52B of the expansion piece 52, suppressing rotation of the wedge member 40. In other words, the wedge member 40 is unlikely to rotate together with the rotation of the anchor member 20.

[0052] As the anchor member 20 continues to rotate, the wedge member 40 is pulled up toward the opening end of the anchor hole 12A, and as shown in Figure 3(A) (and Figure 1(B)), the long side 44A on the outer surface of the wedge member 40 comes into contact with the inner surface 52B of the expansion piece 52.

[0053] If an attempt is made to rotate the anchor member 20 by hand in this state, the long side 44A of the wedge member 40 presses against the inner circumferential surface 52B of the expansion piece 52, and the outer circumferential surface 52A of the expansion piece 52 presses against the wall of the anchor hole 12A. For this reason, the reaction force acting from the wall of the anchor hole 12A makes it difficult to rotate by hand.

[0054] 3(B), a nut 24 is screwed onto the anchor member 20 outside the anchor hole 12A. The nut 24 is rotated with a tool while abutting against the body 12 at the open end of the anchor hole 12A, causing the tip of the anchor member 20 to move away from the bottom 54 of the expansion member 50. As the anchor member 20 moves, the wedge member 40 moves further toward the open end of the anchor hole 12A. The wedge member 40 then expands the expansion piece 52 outward.

[0055] The distance by which the tip of the anchor member 20 is separated from the bottom 54 of the expansion member 50, i.e., the distance that the wedge member 40 moves after the long side 44A of the wedge member 40 abuts against the inner circumferential surface 52B of the expansion piece 52, may be so small that it cannot be seen. Similarly, the expansion width of the expansion piece 52 may also be so small that it cannot be seen.

[0056] Even in such a case, by increasing the torque applied to the nut 24, the pressing force with which the outer surface 52A of the expansion piece 52 presses against the hole wall of the anchor hole 12A increases, thereby increasing the pull-out resistance of the anchor member 20 against the anchor hole 12A.

[0057] Furthermore, by controlling the torque applied to the nut 24, the pull-out resistance of the anchor member 20 against the anchor hole 12A can be adjusted to a desired magnitude.

[0058] Next, as shown in Figure 3(C), the nut 24 is removed and the gap between the anchor member 20 and the anchor hole 12A is filled with filler 30. To fill the filler 30, it is preferable to use a tube that can be inserted into the gap between the anchor member 20 and the anchor hole 12A. This makes it easy to fill the gap with filler 30. Through the above steps, the post-installed anchor 10 shown in Figure 1 is formed.

[0059] After the filler has hardened, the nut 24 may be screwed back into the anchor member 20. In this case, it is preferable that the nut 24 be in contact with the body 12. This prevents the anchor member 20 from moving toward the groove bottom even if a force acts on the anchor member 20 to push it toward the bottom of the anchor hole 12A, and allows the pull-out resistance to be maintained.

[0060] <Action and effect> In the post-installed anchor 10 according to the embodiment of the present invention, the expansion piece 52 pressed by the wedge member 40 presses against the hole wall of the anchor hole 12A over a surface. The gap between the anchor member 20 and the anchor hole 12A is filled with a filler 30. This generates an adhesive force between the anchor member 20 and the anchor hole 12A, providing surface pull-out resistance.

[0061] In this way, with the post-installed anchor 10 of this embodiment, planar pull-out resistance is obtained across the expansion piece 52 and the portion of the anchor member 20 where the expansion piece 52 is not located. For this reason, sufficient pull-out resistance is more easily obtained compared to, for example, when the expansion piece 52 presses against the hole wall of the anchor hole 12A only with its tip portion.

[0062] Furthermore, since the anchor hole 12A has a constant pile diameter, the anchor hole can be formed more easily than in a structure in which the pile diameter is expanded.

[0063] <Other embodiments> In this embodiment, when the length of the expansion piece 52 of the expansion member 50 along the axial direction of the anchor hole 12A at the portion that contacts the anchor hole 12A is L1 and the length of the filler material 30 along the axial direction of the anchor hole 12A is L2, the above-mentioned formulas (1) and (2) are satisfied, but the embodiment of the present invention is not limited to this.

[0064] For example, the lengths L1 and L2 may satisfy either formula (1) or (2), or neither. Even with this configuration, it is possible to obtain a post-installed anchor that is easy to form an anchor hole and easily obtains sufficient pull-out resistance.

[0065] In addition, in this embodiment, the wedge member 40 has an octagonal shape in plan view as shown in Fig. 1(B), but the embodiment of the present invention is not limited to this. For example, the wedge member 40 may have a square shape without chamfers in plan view. Even if the wedge member 40 has a square shape, it can press the four extension pieces 52.

[0066] Furthermore, the wedge member of the present invention may be pentagonal or other polygonal in plan view, as in wedge member 60 shown in Fig. 1(C). In this case, the number of extension pieces 52 in extension member 50 may be changed appropriately to match the shape of the wedge member. [Explanation of symbols]

[0067] 12A anchor hole 20 Anchor member 22 Male thread 30 Filling material 40 Wedge member 42 Female thread 50 Extension member 52 Expansion Piece 60 Wedge member

Claims

1. an expansion member having a plurality of expansion pieces that can expand to press the hole wall of the anchor hole with their surfaces, and a bottom portion formed at a base end of the expansion pieces and arranged opposite the hole bottom of the anchor hole; a wedge member disposed inside the extension piece and having an internal thread; a rod-shaped anchor member that is inserted into the anchor hole, and has a male screw formed at a tip end that is screwed into the female screw of the wedge member and rotated to pull up the wedge member and expand the expansion piece; a filler material filled in a gap between the anchor member and the anchor hole; Equipped with The wedge member is The long side of the outer peripheral surface, which is inclined inward from the bottom to the top, is caught by the expansion piece, and rotation associated with the rotation of the anchor member is suppressed, thereby being pulled up, The long sides are chamfered by short sides that do not contact the extension pieces, forming an octagonal shape in a plan view, and the chamfer width of the short sides is gradually increased from the top to the bottom of the wedge member. Post-construction anchors.

2. The wedge member is hooked onto the expansion piece and pulled up by rotating the anchor member with the tip of the anchor member facing the bottom.

2. The post-installed anchor according to claim 1.

3. The wedge member has a top formed in a quadrangular shape in a plan view, The extension member has four extension pieces that contact the long sides of the wedge member.

3. A post-installed anchor according to claim 1 or 2.

4. 4. The post-installed anchor according to claim 1, wherein the wedge member and the expansion member are made of steel.

5. In the expansion member, a length along the axial direction of the anchor hole at a portion in contact with the anchor hole is defined as L1, The post-installed anchor according to any one of claims 1 to 4, wherein the following formula (1) is satisfied, where L2 is a length of the filler material along the axial direction: 4 × L1 ≦ L2 (1)

6. The post-installed anchor according to claim 5 , wherein the length L1 and the length L2 further satisfy the following formula (2): 6 × L1 ≧ L2 (2)

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