JP2024086206A - Anchor bolt, and adjustment member for anchor bolt - Google Patents

Abstract

To provide an anchor bolt and a member for an anchor bolt which allow a joint member to be easily inserted without stress and ensures necessary strength for both shear force and axial force.SOLUTION: An anchor bolt comprises: a shaft portion to be embedded in a foundation of a structure; and a protrusion portion protruding from the foundation, and the protrusion portion is inserted into a joint member to fix it. An adjustment portion is provided at the shaft portion side of the protrusion portion and a threaded portion is provided at a tip side. A tapered portion is provided at an end of the adjustment portion at the threaded portion side. A shaft diameter of the adjustment portion is larger than a shaft diameter of the threaded portion. An axial shaft diameter of the adjustment portion protruding from the foundation is greater than a size obtained by subtracting an allowable clearance from a diameter of a bolt insertion hole provided in the joint member, and is less than a diameter of the bolt insertion hole.SELECTED DRAWING: Figure 1

Description

The present invention relates to an anchor bolt and an adjustment member for the anchor bolt, and more specifically, to an anchor bolt and an adjustment member for the anchor bolt used to fasten a joint member to the foundation of a building.

When constructing the foundations of low-rise steel-framed buildings, components are generally secured to anchor bolts embedded in the concrete foundations using nuts or other fasteners.

For this anchor bolt, the bolt axial force (axial force) is calculated using the strength of the effective cross-sectional area of the bolt thread, and the shear force (shear force) is calculated using the shear strength of the bolt axial cross-sectional area and the bearing strength of the hole side. In this case, the diameter of the bolt insertion hole for inserting the anchor bolt installed in the connecting member is stipulated in the Building Standards Act (Building Standards Act Notification No. 1456) as a hole clearance of up to bolt diameter + 5 mm. However, if the friction with the concrete is insufficient, it is necessary to weld a washer plate with a small hole clearance to prevent slippage.

On the other hand, even if the bolt insertion holes in the connecting members are made with a high degree of precision, they may become misaligned on-site, making it difficult to insert the bolt insertion holes into the anchor bolts. In particular, when joining one connecting member to multiple anchor bolts that are far apart, the misalignment of the bolt insertion holes can become significant, and adjusting for this can take a lot of time and effort.

Several proposals have been made to address this problem. For example, Patent Document 1 proposes an eccentric spacer, a spacer for correcting misalignment of bolt insertion holes, in which a large upper cylindrical section and a small lower cylindrical section are integrally formed with the same circular center in a metal member, and a through hole for inserting an anchor bolt is formed in a position eccentric to the circular center. It is said that by using this eccentric spacer, it is possible to absorb misalignment of the anchor bolt installed in the building foundation and stably fix the connecting member in a specified position.

JP 2016-114231 A JP 2021-188670 A

However, when using the eccentric spacer proposed in the above Patent Document 1, it is assumed that the through hole provided in the joining member and the axial position of the anchor bolt are misaligned. For example, if there is no misalignment in the axial position, it is considered that adjustment will be difficult. In addition, because the allowable range of clearance is set large, it is considered that it cannot be used when considering the provisions of the Building Standards Act (Article 68-4 of the Enforcement Order of the Building Standards Act).

The inventors have proposed a fastening bolt in Patent Document 2 as a bolt used to join multiple overlapping members to be joined, but it has been difficult to use this fastening bolt as an anchor bolt that has a long shaft and is embedded in the foundation.

The present invention was made in consideration of the above circumstances, and aims to provide an anchor bolt and a component for an anchor bolt that allows joining members to be easily inserted and fixed without stress, and ensures the necessary strength for both shear force and axial force.

The anchor bolt and anchor bolt component of the present invention have been made to solve the above technical problems and are characterized as follows:

First, the anchor bolt of the present invention is an anchor bolt comprising a shaft portion to be embedded in a foundation of a structure and a protruding portion protruding from the foundation, the protruding portion being inserted into a joining member for fastening,
An adjustment portion is provided on the shaft portion side of the protrusion, and a screw portion is provided on the tip side of the protrusion,
A tapered portion is provided at an end of the adjustment portion on the side of the screw portion,
The shaft diameter of the adjustment part is larger than the shaft diameter of the threaded part, and the shaft diameter of the adjustment part protruding from the foundation is greater than or equal to the diameter of the bolt insertion hole provided in the connecting member minus the allowable clearance, and less than the diameter of the bolt insertion hole.
Secondly, in the anchor bolt of the first invention, the allowable clearance is preferably 5 mm or less.
Thirdly, in the anchor bolt of the first or second invention, it is preferable that the shaft portion is a deformed bar.
Fourthly, the anchor bolt of the present invention is an adjustment member that is connected to an anchor bolt whose shaft portion is embedded in a foundation of a structure and whose threaded portion protrudes from the foundation to fix a joining member,
an adjustment unit body having a female thread portion that screws into the thread portion of the anchor bolt, or a through portion that fits into the thread portion or the shank portion of the anchor bolt, and a tapered portion provided at an end of the adjustment unit body;
The adjustment member is characterized in that the axial length of the adjustment member is equal to the thickness of the joining member, and the diameter is greater than or equal to the dimension obtained by subtracting the allowable clearance from the diameter of the bolt insertion hole provided in the joining member, and less than the diameter of the bolt insertion hole.
Fifth, in the adjusting member for an anchor bolt of the fourth invention, the allowable clearance is preferably 5 mm or less.

The anchor bolt of the present invention allows the joining members to be easily inserted and fixed without stress, and makes it possible to ensure the necessary strength for both shear force and axial force.

1 is a schematic diagram showing one embodiment of an anchor bolt of the present invention. 5A and 5B are schematic diagrams showing another embodiment of the anchor bolt of the present invention. 1A is a schematic diagram showing one embodiment of an adjustment member for an anchor bolt of the present invention, (A) is a side view, (B) is a top view, and (C) is a schematic diagram showing the state connected to an anchor bolt. 5A to 5C are schematic diagrams showing another embodiment of an adjustment member for an anchor bolt of the present invention, in which (A) is a side view, (B) is a top view, and (C) is a schematic diagram showing the state connected to an anchor bolt. 4A to 4C are explanatory views of a joining process of members using the anchor bolt of the present invention.

First, the anchor bolt of the present invention will be described in detail with reference to the drawings. Figure 1 is a schematic diagram showing one embodiment of the anchor bolt of the present invention.

The anchor bolt 1 of the present invention is an anchor bolt that has a shaft portion 10 that is embedded in the foundation 6 of a structure and a protruding portion 11 that protrudes from the foundation 6, and is fixed by inserting the protruding portion 11 into a joining member 3. An adjustment portion 13 is provided on the shaft portion 10 side of the protruding portion 11, and a threaded portion 12 is provided on the tip side, and a tapered portion 14 is provided on the end of the adjustment portion 13 on the threaded portion 12 side.

The shaft 10 is the portion that is embedded in the foundation 6 when the anchor bolt 1 of this embodiment is installed in the foundation 6 of a structure, and its length and thickness are not particularly limited and can be determined appropriately according to the design of the foundation 6. In order to prevent one end of the shaft 10 from coming out of the foundation 6, as shown in Figures 2(A) and (B), a head 15 larger in diameter than the shaft 10 can be provided, or the tip can be L-shaped or other shape. In addition, by making the shaft 10 into a deformed rebar as shown in Figure 2(B), it is also possible to prevent it from coming out.

The protruding portion 11 is a portion that protrudes from the surface of the foundation 6 when the anchor bolt 1 is installed in the foundation 6, and this protruding portion 11 is inserted into a bolt insertion hole 30 provided in the connecting member 3 and fixed with a nut 4 or the like. The protruding portion 11 in the anchor bolt 1 of the present invention is provided with an adjustment portion 13 and a threaded portion 12, and a tapered portion 14 is provided at the end of the adjustment portion 13 on the threaded portion 12 side. In addition, the shaft diameter of the adjustment portion 13 is larger than the shaft diameter of the threaded portion 12.

The adjustment portion 13 is a portion located on the inner wall surface of the bolt insertion hole 30 of the connecting member 3 when the connecting member 3 is joined as shown in FIG. 5(C). The axial length of the adjustment portion 13 in the anchor bolt 1 of the present invention is a dimension equivalent to the thickness of the connecting member 3, and the diameter of the adjustment portion 13 is set to be equal to or greater than the dimension obtained by subtracting the allowable clearance from the diameter of the bolt insertion hole 30 provided in the connecting member 3, and less than the diameter of the bolt insertion hole 30. Here, the dimension equivalent to the thickness of the connecting member 3 only needs to be a support dimension required for design, and if the tapered portion 14 or the adjustment portion 13 protrudes from the connecting member 3, a spacer 5 is inserted to make an adjustment.

In addition, the thickness of the support part of the adjustment part 13 and the bolt insertion hole 30 of the connecting member 3 (required thickness for support) is required to withstand the shear force applied to the connecting member 3, so the thickness of the connecting member 3 only needs to be equal to or greater than the required thickness for support, and may be made thicker depending on other conditions such as bending force.

However, since the axial length of the adjustment section 13 (thickness of the support section) only needs to be the necessary thickness for support, it may be smaller than the thickness of the joining member 3, but making it larger would be a waste. In other words, if it is smaller than the thickness of the joining member 3, the spacer 5 can be omitted if the tapered section 14 is equal to or smaller than the thickness of the joining member 3.

The allowable clearance in the present invention refers to the difference between the diameter of the bolt insertion hole 30 and the diameter of the adjustment portion 13 when the anchor bolt 1 is inserted into the bolt insertion hole 30 of the connecting member 3. The allowable clearance in this embodiment is 5 mm or less, preferably 3 mm or less, and more preferably 1 mm or less, when complying with the provisions of the Building Standards Act (Building Standards Act Notification No. 1456). The lower limit of the allowable clearance is preferably 0.5 to 0.2 mm.

The threaded portion 12 is provided to fix the joining member 3 by screwing the nut 4, and to temporarily hold the joining member 3 at the position of the threaded portion 12 and ensure play in the bolt insertion hole 30 before the joining member 3 is fully tightened. This makes it possible, for example, to insert the threaded portion 12 into all of the multiple bolt insertion holes 30 provided in the joining member 3. In addition, there are no particular restrictions on the thread diameter of the threaded portion 12 as long as it is smaller than the diameter of the adjustment portion 13, and the thread pitch, etc. can also be determined to match the nut 4 that fixes the joining member 3.

Furthermore, the tapered portion 14 provided at the boundary between the adjustment portion 13 and the threaded portion 12 is provided to facilitate the transition from the threaded portion 12 to the adjustment portion 13 within the bolt insertion hole 30 during the final tightening process after the threaded portion 12 of the anchor bolt 1 is inserted up to the thickness of the connecting member 3. For example, if the tapered portion 14 is not provided, a step will be created and a smooth transition from the threaded portion 12 to the adjustment portion 13 will not be possible.

From the above viewpoint, it is desirable to set the tapered portion 14 to have as gentle a slope as possible in the longitudinal direction of the shaft; however, since the axial length of the tapered portion 14 is included in the length of the adjustment portion 13, it is necessary to set it taking into consideration the height of the spacer 5, washer 41, etc. to be inserted. Also, taking into consideration the friction and resistance between the inner wall of the bolt insertion hole 30 and the tapered portion 14, it is desirable for the angle of the tapered portion 14 to be about 30° with respect to the shaft.

According to the anchor bolt 1 of the present invention, by providing the protrusion 11 of the above configuration, for example, when a plurality of anchor bolts 1 of this embodiment are arranged on a foundation 6 and these plurality of anchor bolts 1 are fixed by being inserted into insertion holes provided in one connecting member 3, even if the insertion is stressed due to misalignment of the anchor bolt 1 or misalignment of the bolt insertion holes 30 provided in the connecting member 3, it is possible to force connecting members 3 with different sizes and numbers of bolt insertion holes 30 to fit the anchor bolt 1 for the anchor bolt installed with high precision.

In addition, in the present invention, a post-installed anchor bolt adjustment member 2 can be attached to a normal anchor bolt 7 having a threaded portion 71 on the protruding portion to have the same configuration as the anchor bolt 1 of the present invention. The anchor bolt adjustment member 2 of the present invention has an adjustment unit main body 20 having a female threaded portion 22 that screws into the threaded portion 71 of a normal anchor bolt 7 as shown in Figures 3 (A) and (B), a through portion 23 that fits into the threaded portion 71 or the shaft portion 72 as shown in Figures 4 (A) and (B), and a tapered portion 21 provided at the end of the adjustment unit main body 20, and the axial length of the anchor bolt adjustment member 2 is equal to the thickness of the joining member 3, and the diameter is equal to or greater than the diameter of the bolt insertion hole 30 provided in the joining member 3 minus the allowable clearance, and is less than the diameter of the bolt insertion hole 30.

The anchor bolt adjustment member 2 may be screwed onto the threaded portion 71 of a normal anchor bolt 7 as in FIG. 3(C) or fitted onto the shaft portion 72 as in FIG. 4(C) and may be integrated with the anchor bolt by welding or the like, or may be screwed onto the threaded portion 71 or fitted onto the shaft portion 72 of the anchor bolt 7 after the anchor bolt 7 is installed. By attaching the anchor bolt adjustment member 2 having the above-mentioned configuration to a normal anchor bolt 7, it is possible to obtain the same effect as the anchor bolt 1 having the adjustment portion 13 of the present invention.

The method for joining anchor bolts of the present invention will be described in detail below with reference to the drawings. Figures 5(A) to 5(C) are explanatory diagrams of the joining process of joining members using the anchor bolts of the present invention. This embodiment of the joining process is composed of an insertion and holding process and a tightening process. This embodiment shows a case in which two anchor bolts 1 are embedded into a foundation 6 with a gap between them, and one joining member 3 is joined to the two anchor bolts 1.

(Insertion and holding process)
In the insertion and holding step, first, as shown in FIG. 5A, two anchor bolts 1 are embedded in a foundation 6, and then the two anchor bolts 1 are inserted through the threaded portions 12 of the two anchor bolts 1 into the two bolt insertion holes 30 provided through the connecting member 3 up to the position of the taper portion 14. In this state, a spacer 5 and a washer 41 are disposed on the threaded portion 12, and the nut 4 is screwed and held. In the insertion and holding step, the threaded portion 12 has a smaller thread diameter than the allowable clearance of the bolt insertion hole, so that the clearance is enlarged, and the connecting member 3 can be slid between the two anchor bolts 1, and the threaded portion 12 of the anchor bolt 1 can be easily inserted into each bolt insertion hole 30. In this embodiment, the interval between the two bolt insertion holes 30 provided through the connecting member 3 is larger than the interval between the two anchor bolts 1, so that the hole interval of the connecting member 3 is adjusted (corrected) by expanding and contracting according to the installation position of the anchor bolt 1. If the spacing between the bolt insertion holes 30 of the joining member 3 is small, a large correction force is required, and therefore high-precision hole spacing processing is required.

Here, the length of the adjustment section 13 is basically equal to the thickness of the joining member 3 to be joined, but for example, if the thickness of the joining member 3 is thinner than the length of the adjustment section 13, that is, if the adjustment section 13 or tapered section 14 protrudes from the top surface of the joining member 3 after joining, it is necessary to adjust by inserting a spacer 5 with a thickness equal to or greater than the amount of protrusion, or by inserting a washer 41 such as a flat washer or spring washer of an appropriate thickness. In this embodiment, the height is adjusted by inserting the spacer 5 and the washer 41.

(Tightening process)
After the bolt insertion holes 30 of the joining member 3 have been inserted into the threaded portions 12 of the two anchor bolts 1, the nuts 4 screwed onto the threaded portions 12 of the anchor bolts 1 are alternately tightened to fit the joining member 3 into the adjustment portion 13, as shown in Fig. 5(B). At this time, the transition from the threaded portion 12 of the bolt insertion hole 30 of the joining member 3 to the adjustment portion 13 is smoothed by the tapered portion 14 provided at the end of the adjustment portion 13. This completes the joining of the joining member 3 to the anchor bolt 1 of this embodiment, as shown in Fig. 5(C). Note that an anchor bolt using the anchor bolt adjustment member 2 of the present invention can also be configured substantially the same as the anchor bolt 1 of the present invention, and therefore can be joined by a process similar to the joining process described above.

The anchor bolt 1 and the adjustment member 2 for the anchor bolt of the present invention have been described above based on the embodiments, but the present invention is not limited to the above embodiments, and various modifications are possible within the scope of the gist of the present invention.

For example, in the above embodiment, one joining member 3 is joined to the anchor bolt 1, but two or more joining members 3 may be stacked and joined.

In addition, in the above embodiment, the shaft diameter of the adjustment part 13 is set to be larger than the shaft diameter of the shaft part 10, but the shaft diameter of the shaft part 10 may be equal to or larger than the shaft diameter of the adjustment part.

The anchor bolt 1 of the present invention having the above configuration and the anchor bolt to which the anchor bolt adjustment member 2 of the present invention is attached can ensure the necessary strength for both shear force and axial force, and can be easily inserted without stress and tightened for fixed construction.

REFERENCE SIGNS LIST 1 Anchor bolt 10 Shaft portion 11 Protruding portion 12 Threaded portion 13 Adjustment portion 14 Tapered portion 15 Head portion 2 Adjustment member for anchor bolt 20 Adjustment portion main body 21 Tapered portion 22 Female threaded portion 23 Through portion 3 Joint member 30 Bolt insertion hole 4 Nut 41 Washer 5 Spacer 6 Foundation 7 Anchor bolt (normal)
71 Threaded portion 72 Shaft portion

Claims (5)

An anchor bolt having a shaft portion to be embedded in a foundation of a structure and a protruding portion protruding from the foundation, the protruding portion being inserted into a joining member to be fixed,
An adjustment portion is provided on the shaft portion side of the protrusion, and a screw portion is provided on the tip side of the protrusion,
A tapered portion is provided at an end of the adjustment portion on the side of the screw portion,
an axial diameter of the adjustment portion is larger than an axial diameter of the threaded portion, and an axial diameter of the adjustment portion protruding from the foundation is equal to or larger than a diameter of a bolt insertion hole provided in the connecting member minus an allowable clearance, and is smaller than the diameter of the bolt insertion hole. The anchor bolt according to claim 1, characterized in that the allowable clearance is 5 mm or less. The anchor bolt according to claim 1, characterized in that the shaft portion is a deformed steel bar. An adjustment member having a shaft portion embedded in a foundation of a structure and a threaded portion protruding from the foundation for connection to an anchor bolt that fixes a joining member,
an adjustment unit body having a female thread portion that screws into the thread portion of the anchor bolt, or a through portion that fits into the thread portion or the shank portion of the anchor bolt, and a tapered portion provided at an end of the adjustment unit body;
An adjustment member for an anchor bolt, wherein a diameter of the adjustment member is equal to or greater than a dimension obtained by subtracting an allowable clearance from the diameter of a bolt insertion hole provided in the connecting member, and is smaller than the diameter of the bolt insertion hole. 5. The adjusting member for an anchor bolt according to claim 4, wherein the allowable clearance is 5 mm or less.