Lag screw bolt hole construction jig and lag screw bolt hole construction method

Abstract

To provide a lag screw hole construction jig and a lag screw hole construction method that can construct lag screw bolt holes in wood materials that enable the correct screwing of lag screw bolts into pre-drilled holes. [Solution] A lag screw bolt hole construction jig 50 is used when constructing a lag screw bolt hole 68 extending inward from the surface 61 of a wood material 60 into which a lag screw bolt is rotated. The jig has an axially extending shaft-shaped body, and the shaft-shaped body 50 has a tip guide 10 that is inserted into a pre-hole 63 extending inward from the surface 61 of the wood material 60 and has a length that can maintain the insertion position of the shaft-shaped body 50, a threaded portion 20 having a plurality of threads 22 that form a helical guide groove 65 when the lag screw bolt is rotated into the wall surface of the pre-hole 63, and a mounting portion 30 that is attached to a power tool D.

Description

Technical Field

[0001] The present invention relates to a lag screw bolt hole construction jig and a lag screw bolt hole construction method.

Background Art

[0002] When installing lag screw bolts at joints of wooden members such as wooden columns and wooden beams constituting a wooden building, an electric tool such as an electric wrench is used to align the axial direction of the lag screw bolt with the direction perpendicular or parallel to the material axis direction of the wooden member, and the construction has to be carried out with care to ensure the correct driving direction.

[0003] The reason for this is that if the lag screw bolt is not properly driven in the direction parallel or perpendicular to the material axis direction, joining with other wooden members may become difficult or impossible. When there are a large number of lag screw bolt installation locations, a great deal of construction labor is required. In addition, when an electric tool is used, the gripping posture of the worker is not stabilized by the power during operation, and the construction accuracy of the lag screw bolt tends to decrease due to the tilting of the electric tool.

[0004] Here, Patent Document 1 proposes an embedding method in which, when a first wooden structural frame and a second wooden structural frame of a wooden building are connected and fixed via a joint fitting, a lag screw bolt used for fixing the joint fitting to the first wooden structural frame is embedded while being screwed into a bolt hole on the first wooden structural frame side.

[0005] This embedding method involves forming a spiral guide groove on the inner circumferential wall of the bolt hole to guide the threads of the lag screw bolt. When screwing in the lag screw bolt, the threads near the tip of the screw portion are driven into the wood within the guide groove, and the lag screw bolt is embedded by advancing while being guided by the threads of the screw portion within the guide groove. In this method, a tap is used to form the spiral guide groove on the inner circumferential wall of the bolt hole. The tap has a guide head at the tip of the tap body and a cutting section behind the guide head. The tap body is inserted while being guided by the guide head along a pre-machined pilot hole, and the guide groove is formed by rotating the cutting section with a drilling device. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2022-113876 [Overview of the project] [Problems that the invention aims to solve]

[0007] The tap used to form a helical guide groove on the inner circumferential wall surface of a bolt hole, as described in Patent Document 1, has a short guide head at its tip. However, with such a short guide head, it is difficult to maintain a stable position of the cutting part when the drilling device is operated. As a result of the cutting part rotating in an unstable position, it is difficult to correctly form a helical guide groove on the inner circumferential wall surface of the bolt hole. In other words, the guide groove, which is constructed with the aim of correctly screwing a lag screw bolt into the bolt hole, is not correctly formed on the inner circumferential wall surface of the bolt hole, and as a result, it becomes impossible to correctly screw a lag screw bolt into the bolt hole.

[0008] This invention has been made in view of the above problems, and aims to provide a lag screw hole construction jig and a lag screw hole construction method that can construct lag screw bolt holes that enable correct screwing of lag screw bolts by utilizing pre-drilled holes made in wood material. [Means for solving the problem]

[0009] To achieve the above objective, one embodiment of the lag screw bolt hole construction jig according to the present invention is: A lag screw hole construction jig is used when constructing a lag screw hole extending from the surface to the interior of a wood material, into which a lag screw bolt, which has male threads on its outer circumference, is rotated and inserted, It has an axial body that extends in the axial direction, The aforementioned axial body is A tip guide, which is inserted into a pre-hole extending inward from an opening on the surface of the wood material and has a length that allows it to maintain the inserted position of the shaft-shaped body, A threaded portion having multiple threads, adjacent to the tip guide, which forms a helical guide groove when the lag screw bolt is rotated and inserted into the wall of the pre-drilled hole, It is characterized by having a mounting portion adjacent to the screw thread portion and being attached to a power tool.

[0010] According to this embodiment, the shaft-shaped body extending in the axial direction has a tip guide that is long enough to be inserted into a pre-drilled hole extending from the surface to the interior of the wood material and to maintain the inserted position of the shaft-shaped body. This allows the axis of the shaft-shaped body and the axis of the pre-drilled hole to be aligned (matched or nearly matched), and a guide groove can be formed on the wall surface of the pre-drilled hole to guide the lag screw bolt in along the axis of the lag screw bolt hole.

[0011] Here, "a pre-drilled hole extending inward from an opening on the surface of the wood material" includes both forms where the pre-drilled hole extends to an intermediate position inside the wood material and forms where the pre-drilled hole penetrates the wood material. Furthermore, "the length that can maintain the insertion position of the shaft-shaped body" means the length at which the shaft-shaped body can maintain a stable position with its axis aligned with the axis of the pre-drilled hole when the tip guide is inserted into the pre-drilled hole and the worker releases their hand from the shaft-shaped body. The length can be set in various ways depending on the diameter of the pre-drilled hole and the shaft-shaped body, the overall length of the shaft-shaped body, etc. However, if, for example, the tip guide is too short compared to the total length of the shaft-shaped body, the shaft-shaped body will tilt and will not be able to maintain a stable insertion position.

[0012] Furthermore, since the lag screw bolt hole construction jig of this embodiment forms a guide groove that enables the lag screw bolt to be screwed in correctly, it is not necessary to provide a guide groove along the entire length of the pre-drilled hole. Even if the guide groove is formed only near the opening of the pre-drilled hole on the surface of the wood material, the lag screw bolt guided by the guide groove formed near the opening will be screwed into the pre-drilled hole with its axis aligned with the axis of the pre-drilled hole to the extent that it is deeper than the guide groove in the pre-drilled hole. Here, "near the pre-drilled hole" means a range of several grooves (2 or 3 grooves) to about 10 grooves in a side view of the spiral guide groove formed from the opening of the pre-drilled hole. Therefore, the lag screw bolt hole formed by the lag screw bolt hole construction jig of this embodiment is a hole in which a spiral guide groove is provided on the wall surface near the opening of the pre-drilled hole, which has the embedding length of the lag screw bolt to be screwed in.

[0013] Furthermore, other embodiments of the lag screw bolt hole construction jig according to the present invention are: In the threaded portion, the height of the multiple threads gradually increases from the tip guide side toward the mounting portion side, and the outer diameter of threads 2 to 4 on the mounting portion side is the same as or substantially the same as the outer diameter of the lag screw bolt.

[0014] According to this embodiment, in the threaded portion, the height of the multiple threads gradually increases from the tip guide side toward the mounting portion side, thereby improving the workability of the guide groove formed by the threaded portion. Furthermore, since a guide groove is formed that enables the lag screw bolt to be screwed in correctly, the outer diameter of threads 2 to 4 on the mounting portion side of the shaft-shaped body is the same as or approximately the same as the outer diameter of the lag screw bolt. Therefore, even if the number of threads in the spiral guide groove formed on the wall surface near the opening of the pre-drilled hole constructed by these threads is small, around 2 to 4, a guide groove that enables the lag screw bolt to be screwed in correctly can be formed.

[0015] Furthermore, other embodiments of the lag screw bolt hole construction jig according to the present invention are: The tip guide is characterized in that its outer diameter is the same as, or slightly smaller than, the inner diameter of the pre-drilled hole.

[0016] According to this embodiment, by having the outer diameter of the tip guide be the same as the inner diameter of the pre-drilled hole, a stable self-supporting position of the tip guide relative to the pre-drilled hole can be guaranteed. On the other hand, by having the outer diameter of the tip guide be slightly smaller than the inner diameter of the pre-drilled hole, both ease of insertion of the tip guide into the pre-drilled hole and a nearly stable self-supporting position of the tip guide relative to the pre-drilled hole can be ensured.

[0017] Furthermore, other embodiments of the lag screw bolt hole construction jig according to the present invention are: A feature is that a discharge recess is provided in the screw thread for discharging chips generated during the construction of the guide groove through the opening.

[0018] According to this embodiment, a discharge recess is provided in the screw threads to discharge chips through an opening when the guide groove is constructed, thereby enabling smooth construction of the guide groove while suppressing chips from getting caught in the screw threads.

[0019] Furthermore, in another embodiment of the lag screw bolt hole construction jig according to the present invention, The aforementioned mounting portion includes: characterized in that a head portion to which the power tool is mounted, and a pull-out hole through which a pull-out rod applied when pulling the shaft-shaped main body out from the pilot hole is inserted are provided.

[0020] According to this aspect, the pull-out rod is inserted through the pull-out hole provided in the shaft-shaped main body, and a worker grips the pull-out rod to pull the shaft-shaped main body out from the pilot hole. Thereby, after the power tool is rotated in the forward direction to form the guide groove, when the power tool is rotated in the reverse direction to retract the threaded portion from the guide groove and pull out the shaft-shaped main body, even if the threaded portion bites into the guide groove and the shaft-shaped main body cannot be pulled out smoothly, the shaft-shaped main body can be reliably pulled out. In addition, since the guide groove is formed not over the entire length of the pilot hole but on the wall surface in the vicinity of the opening of the pilot hole, even if the shaft-shaped main body cannot be pulled out even by rotating the power tool in the reverse direction, the worker can pull out the shaft-shaped main body relatively easily when gripping and pulling the pull-out rod.

[0021] Further, one aspect of the lag screw bolt hole forming method according to the present invention is: A lag screw bolt hole forming method for forming a lag screw bolt hole extending inward from the surface of a wood material, into which a lag screw bolt having a male thread on the outer periphery is rotatably inserted, the method comprising: Step A of forming a pilot hole extending inward from an opening on the surface of the wood material; and Step B of using a lag screw bolt hole forming jig having a shaft-shaped main body extending in the axial direction, wherein the shaft-shaped main body has a tip guide having a length capable of maintaining the inserted posture of the shaft-shaped main body, a threaded portion adjacent to the tip guide and provided with a plurality of threads, and a mounting portion adjacent to the threaded portion and mounted to a power tool, the method comprising mounting the mounting portion to the power tool, inserting the tip guide into the pilot hole, operating the power tool to rotate the shaft-shaped main body, and forming a spiral guide groove on the wall surface in the vicinity of the opening in the pilot hole by the rotating threaded portion.

[0022] According to this aspect, the distal end guide provided on the shaft-shaped main body constituting the lag screw bolt hole construction jig is inserted into the pre-drilled hole to maintain the inserted posture of the shaft-shaped main body, and the power tool mounted on the mounting part provided on the shaft-shaped main body is operated to form a spiral guide groove on the wall surface in the vicinity of the opening of the pre-drilled hole by the threaded portion provided on the shaft-shaped main body. Since the guide groove is formed in a state where the axis of the shaft-shaped main body and the axis of the pre-drilled hole are aligned, the guide groove for guiding the lag screw bolt to be screwed along the axis of the lag screw bolt hole can be formed on the wall surface of the pre-drilled hole.

[0023] Further, in another aspect of the lag screw bolt hole construction method according to the present invention, The wood material is the restraining member in a buckling-restrained brace, which has a steel plate-shaped core member, and a wooden restraining body formed of a pair of wooden restraining members that are wider than the core member and disposed to face two wide surfaces of the core member.

[0024] According to this aspect, the wood material in which the lag screw bolt hole is constructed is the restraining member of the buckling-restrained brace provided with the wooden restraining body which is disposed to face the two wide surfaces of the steel plate-shaped core member and formed of a pair of wooden restraining members wider than the core member, whereby it is possible to contribute to the formation of a buckling-restrained brace having a wooden restraining body in which the pair of restraining members are firmly joined to each other by the lag screw bolts provided on both sides or the lag screw bolt provided on either one of them.

[0025] Here, the lag screw bolts that are screwed into the lag screw bolt holes can have a male thread on the outer circumference and a through hole inside (for example, the first form), or a male thread on the outer circumference and a female thread inside (for example, the second form). For example, if the first and second forms of lag screw bolts are screwed into the respective lag screw bolt holes of a pair of restraining members, a fastener (such as a wood screw or coach screw bolt) having a head at one end and a male thread at the other end can be inserted through the through hole of the first form of lag screw bolt, the male thread of the second form of lag screw bolt can be screwed into the female thread, and the head can be engaged with the end of the through hole, thereby firmly joining the pair of restraining members with the two types of lag screw bolts and the fastener. [Effects of the Invention]

[0026] As can be understood from the above explanation, the lag screw bolt hole construction jig and lag screw bolt hole construction method of the present invention make it possible to construct lag screw bolt holes that enable the correct screwing of lag screw bolts by utilizing pre-drilled holes made in advance in the wood material. [Brief explanation of the drawing]

[0027] [Figure 1A] This is a side view of an example of a lag screw bolt hole construction jig according to an embodiment. [Figure 1B] This is a view from the direction of arrow B in Figure 1A. [Figure 1C] This is a view from the CC arrow in Figure 1A. [Figure 2] This is a side view of another example of the lag screw bolt hole construction jig according to the embodiment. [Figure 3A] This is a process diagram of an example of a lag screw bolt hole construction method according to the embodiment. [Figure 3B] Following Figure 3A, this is a process diagram of an example of a lag screw bolt hole construction method according to the embodiment. [Figure 3C] Following Figure 3B is a process diagram illustrating an example of a lag screw bolt hole construction method according to the embodiment. [Figure 3D] Following Figure 3C is a process diagram illustrating an example of a lag screw bolt hole construction method according to the embodiment. [Figure 3E] Following Figure 3D, the next figure is a process diagram of an example of a lag screw bolt hole construction method according to the embodiment, showing an example of a constructed lag screw bolt hole. [Figure 4A] This is a perspective view of an example of a buckling-restrained brace having a wooden restraint body consisting of a pair of restraint members equipped with lag screw bolts. [Figure 4B] Figure 4A is a view along the BB arrow, and is a longitudinal cross-sectional view taken at the embedded position of the lag screw bolt. [Modes for carrying out the invention]

[0028] The lag screw bolt hole construction jig and lag screw bolt hole construction method according to the embodiment will be described below with reference to the attached drawings. In this specification and drawings, substantially identical components are denoted by the same reference numerals to avoid redundant explanations.

[0029] [Lag screw bolt hole construction jig and lag screw bolt hole construction method according to an embodiment] An example of a lag screw bolt hole construction jig and lag screw bolt hole construction method according to the embodiment will be described with reference to Figures 1 to 4. Here, Figure 1A is a side view of an example of a lag screw bolt hole construction jig according to the embodiment, Figure 1B is a view in the direction of arrow B in Figure 1A, and Figure 1C is a view in the direction of arrow CC in Figure 1A. Figure 2 is a side view of another example of a lag screw bolt hole construction jig according to the embodiment. Furthermore, Figures 3A to 3E are, in order, process diagrams of an example of a lag screw bolt hole construction method according to the embodiment, and Figure 3E is a diagram further showing an example of a constructed lag screw bolt hole.

[0030] The lag screw bolt hole construction jig 50 shown in Figures 1A to 1C has a steel shaft-shaped body with a circular cross-section perpendicular to the axial direction. The shaft-shaped body 50 comprises, in order along its axial direction, a tip guide 10, a threaded portion 20 adjacent to the tip guide 10, and a mounting portion 30 adjacent to the threaded portion 20. The shaft-shaped body 50 may be a solid, substantially cylindrical shape, or it may be a substantially cylindrical shape with a hollow extending in the axial direction.

[0031] The total length t1 of the shaft-shaped body 50 can be set to approximately 300 mm, for example, within a range of approximately 200 mm to 400 mm, and the diameter s1 of the general part of the shaft-shaped body 50 (threaded portion 20 and mounting portion 30) can be set within a range of approximately 20 mm to 30 mm, but the diameter s1 of the general part of the shaft-shaped body 50 is set based on the diameter of the lag screw bolt hole installed in the wood material.

[0032] In the illustrated example, the diameter s2 of the tip guide 10 is set to be slightly larger than the diameter s1 of the general part, and the length t2 of the tip guide 10 is set to a length that allows the insertion position of the shaft-shaped body 50 to be stably maintained without the need for a worker to grip it, when the tip guide 10 is inserted into the pre-hole 63 extending from the surface 61 to the interior of the wood material 60, as shown in Figure 3B. Here, the tip guide 10, the threaded portion 20, and the mounting portion 30 may all have the same diameter.

[0033] The diameter s2 of the tip guide 10 is set to be the same as the inner diameter s4 of the pre-hole 63 into which it is inserted (see Figure 3A), or slightly smaller than the inner diameter s4 of the pre-hole 63.

[0034] The length t2 that can stably maintain this inserted position can be set in various ways depending on the diameter (diameters s1, s2) of the shaft-shaped body 50 and the overall length t1 of the shaft-shaped body 50, but as shown in the illustrated example, if the overall length t1 is about 300 mm and the diameters s1, s2 are about 25 mm, the length t2 can be set to about 100 mm.

[0035] In the threaded portion 20, a continuous spiral thread is provided on the circular cross-sectional wall surface of the shaft-shaped body 50. More specifically, the threaded portion 20 has two to three complete threads 22 with the highest thread height on the mounting side, as shown in the illustrated example in a side view, and three to four guide threads 24 with a gradually decreasing thread height from the complete threads 22 toward the tip guide side (in Figure 1A, it tapers downward at an angle θ). In other words, the thread height of the multiple guide threads 24 changes continuously along the spiral. Here, the angle θ in the side view at which the spiral guide threads 24 gradually change can be set within a range of, for example, 2 to 10 degrees.

[0036] In the range t3 where the complete thread 22 is provided, the outer diameter s3 of the complete thread 22 is set to be the same as or approximately the same as the outer diameter of the lag screw bolt screwed into the wood material 60. For example, in the illustrated example, when the diameter s1 of the general part (threaded part 20) is 25 to 27 mm, the outer diameter s3 can be set to approximately 35 mm.

[0037] The range t4 in which the guide threads 24 are provided is set to a range in which the outer diameter of the guide threads 24 gradually decreases along the spiral from the outer diameter s3 of the complete thread 22 and rubs against the outer diameter s1 of the threaded portion 20.

[0038] In the axial body 50 shown in the illustration, the guide grooves provided by the lag screw bolt holes installed in the wood material are set to approximately two to three in a side view. Therefore, the number of complete threads 22 is provided in proportion to the number of guide grooves, and the number of complete threads 22 changes according to the number of guide grooves set.

[0039] Following the tip guide 10, guide threads 24 of the threaded portion 20 are provided such that their outer diameter gradually increases toward the mounting portion, and two to four complete threads 22 are provided in a side view. This allows for smooth construction of the guide groove 65 when inserting the tip guide 10 into the pre-drilled hole 63 in the wood material 60 to stably maintain the insertion position of the shaft-shaped body 50, and then rotating the shaft-shaped body 50 while pushing it into the pre-drilled hole 63 to construct a spiral guide groove 65 on the wall surface of the pre-drilled hole 63. More specifically, guide grooves are constructed in a spiral pattern from small-diameter guide threads 24 to the wall surface of the pilot hole 63, gradually increasing in diameter. Complete threads 22 (approximately 2 to 4 complete threads 22 in a side view) allow guide grooves 65 (approximately 2 to 4 guide grooves 65 in a side view) with an inner diameter identical or approximately identical to the outer diameter of the male threads of the lag screw bolt to be constructed near the opening 63A of the pilot hole 63 (see Figure 3E).

[0040] As shown in Figures 1A and 1C, the spirally continuous complete screw threads 22 and the guide screw threads 24 are each provided with corresponding positions (as shown in Figure 1C, in the illustrated example, four corresponding positions at 90-degree intervals in a plan view) where chips generated when constructing the guide groove 65 in the pre-drilled hole 63 are discharged to the outside through the opening 64.

[0041] Since discharge recesses 26 are provided at corresponding positions on the complete screw threads 22 and the guide screw threads 24, the multiple corresponding discharge recesses 26 are aligned axially as shown in Figure 1A. Therefore, as shown in Figure 3C, when constructing the guide groove 65, the chips generated when the wall surface of the pilot hole 63 is cut by the screw threads 20 can be smoothly flowed in the X4 direction through the axially aligned discharge recesses 26 and discharged to the outside of the wood material 60 through the opening 64 of the pilot hole 63. Here, the number of discharge recesses 26 provided on the complete screw threads 22 and the guide screw threads 24 can be set in various ways other than the illustrated example, and the multiple corresponding discharge recesses 26 may not be aligned axially as shown in the illustrated example.

[0042] The mounting portion 30 has a head 32 made of a hexagonal nut at its end, and the recess D2 at the tip of the rotating shaft D1 of the power tool D (see Figure 3C) is mounted to the head 32 in a manner that prevents relative rotation.

[0043] Furthermore, the mounting portion 30 is provided with a pull-out hole 34 that extends in a direction perpendicular to the axial direction of the shaft-shaped body 50, and a pull-out rod B (see Figure 3D) used when a worker grips and pulls out the shaft-shaped body 50 is inserted through the pull-out hole 34.

[0044] The lag screw bolt hole construction jig 50A shown in Figure 2 differs from the lag screw bolt hole construction jig 50 in that neither the complete thread 22 nor the guide thread 24 that constitute the threaded portion 20A have an ejection recess 26.

[0045] In the illustrated example, the lag screw bolt hole construction jigs 50 and 50A do not construct a guide groove 65 that runs spirally along the entire length of the pilot hole 63, but rather construct the guide groove 65 near the opening of the pilot hole 63. Therefore, it is considered unlikely that a large amount of chips will be generated, and that chips will get stuck between the pilot hole 63 and the lag screw bolt hole construction jigs 50 and 50A, making it impossible to move the lag screw bolt hole construction jigs 50 and 50A. Based on this idea, the machining of the discharge recess 26 has been omitted.

[0046] Next, an example of a lag screw bolt hole construction method according to the embodiment will be described with reference to Figures 3A to 3E. While this description will focus on a construction method using the lag screw bolt hole construction jig 50 shown in Figure 1A, etc., the construction method using the lag screw bolt hole construction jig 50A shown in Figure 2 is substantially the same.

[0047] As shown in Figure 3A, a pilot hole 63 extending inward from an opening 64 on the surface 61 of the wood material 60 is made using a cutting tool (not shown) (e.g., an electric drill). Here, the diameter s4 of the pilot hole 63 is set to be the same as or approximately the same as the diameter of the shaft portion of the lag screw bolt that will be screwed in, excluding the male thread. Also, the length t5 of the pilot hole 63 is set to be the same as or approximately the same as the length of the lag screw bolt that will be screwed in. In addition to the illustrated example, the pilot hole may also be a through hole that penetrates from the surface 61 to the back surface 62 of the wood material 60 (Above, step A).

[0048] Next, as shown in Figure 3B, the tip guide 10 of the lag screw bolt hole construction jig 50 is inserted into the pre-drilled hole 63 in the X1 direction through the opening 64. As already explained, the length t2 of the tip guide 10 is set to a length that can maintain the insertion position of the shaft-shaped body 50. Therefore, when the tip guide 10 is inserted into the pre-drilled hole 63, tilting of the shaft-shaped body 50 can be suppressed, and the axis L1 of the pre-drilled hole 63 and the axis L2 of the shaft-shaped body 50 can be aligned or nearly aligned, thus aligning the axis L1 and L2.

[0049] Next, as shown in Figure 3C, the recess D2 at the tip of the rotating shaft D1 of the power tool D is attached to the hexagonal head 32 of the mounting part 30 in a manner that prevents relative rotation. The power tool D is then operated (forward rotation), and the shaft-shaped body 50 is pushed in while rotating it in the X2 direction around its axis L2. As a result, the shaft-shaped body 50 gradually enters the interior of the pre-hole 63 in the X3 direction. During this process, the guide threads 24 of the threaded portion 20 sequentially cut the wall surface of the pre-hole 63, and a spiral guide groove 65 is constructed near the opening 63A of the pre-hole 63 by two to four complete threads 22 as seen from the side. This guide groove 65 has an inner diameter that is the same as or approximately the same as the outer diameter of the male thread of the lag screw bolt that is screwed in.

[0050] Furthermore, the chips generated when the wall surface of the pilot hole 63 is cut by the screw thread portion 20 are flowed in the X4 direction through the discharge recesses 26 provided by the complete screw thread 22 and the guide screw thread 24, respectively, and discharged to the outside of the wood material 60 through the opening 64 of the pilot hole 63.

[0051] Next, as shown in Figure 3D, the rotation of the power tool D (not shown, see Figure 3C) is reversed, and the threaded portion 20 is pulled back in the X5 direction toward the opening 64 along the constructed guide groove 65.

[0052] If the shaft-shaped body 50 can be completely pulled out of the opening 64 by the reverse rotation of the power tool D alone, no additional pulling measures are necessary. However, if a part of the guide groove 65 and a part of the screw thread 20 engage and the shaft-shaped body 50 cannot be completely pulled out, as shown in Figure 3D, the power tool D is removed from the mounting part 30, the pulling rod B is inserted into the pulling hole 34, and the pulling rod B is grasped by a worker and pulled upward in the X5 direction to completely pull out the shaft-shaped body 50.

[0053] By withdrawing the shaft-shaped body 50 from the pilot hole 63, a lag screw bolt hole 68 is constructed in which a spiral guide groove 65 is formed near the opening 63A of the pilot hole 63, as shown in Figure 3E (this completes step B).

[0054] According to the illustrated lag screw bolt hole construction method, the shaft-shaped body 50, which has a circular cross-section, is inserted into a pre-drilled hole extending from the surface 61 of the wood material 60 and has a tip guide 10 that is long enough to maintain the inserted position of the shaft-shaped body 50. This allows the axis L2 of the shaft-shaped body 50 and the axis L1 of the pre-drilled hole 63 to be aligned, and a guide groove 65 can be formed on the wall surface of the pre-drilled hole 63 to guide the lag screw bolt as it is screwed in along the axis L1 of the lag screw bolt hole 68. As a result, when a lag screw bolt, for example, which has a helical male thread on its outer circumference along its entire length, is screwed into the lag screw bolt hole 68, the male thread at the tip is guided along the guide groove 65, and for the wall surface of the pre-drilled hole 63 deeper than where the guide groove 65 does not exist, the male thread of the lag screw bolt proceeds in the depth direction of the pre-drilled hole 63 while constructing the female thread, and is screwed in.

[0055] In other words, because a guide groove 65 is constructed near the opening 63A of the lag screw bolt hole 68, enabling the correct threading of the lag screw bolt, the lag screw bolt is screwed in with its axis L2 aligned with the axis L1 of the lag screw bolt hole 68.

[0056] Furthermore, since the spirally continuous guide threads 24 that constitute the threaded portion 20 of the lag screw bolt hole construction jig 50 are set so that the height of the threads gradually increases from the tip guide side towards the mounting portion side, the workability of the guide groove 65 by the threaded portion 20 can be improved.

[0057] Next, with reference to Figures 4A and 4B, an example of the application of wood materials in which lag screw bolt holes are constructed using the lag screw bolt hole construction method with the illustrated lag screw bolt hole construction jigs 50 and 50A will be described. Here, Figure 4A is a perspective view of an example of a buckling-restrained brace having a wooden restraint body consisting of a pair of restraint members equipped with lag screw bolts, and Figure 4B is a longitudinal cross-sectional view taken along the BB arrow in Figure 4A, cut at the embedded position of the lag screw bolt.

[0058] The buckling-restrained brace 100 shown in Figure 4A has a steel, plate-shaped core material 90 and a wooden restraint body 70 which is formed by a pair of wooden restraint members 60A and 60B that are wider than the core material 90 and are arranged opposite the two wide surfaces of the core material 90.

[0059] As shown in Figure 4B, a pair of restraining members 60A and 60B have lag screw bolts 80A and 80B screwed into corresponding lag screw bolt holes 69A and 69B located at their respective positions. As shown in Figure 4A, near both ends of the wooden restraining body 70 in the short direction, lag screw bolt holes 69A and 69B are provided along the longitudinal direction at predetermined pitches, and lag screw bolts 80A and 80B are screwed into each of the lag screw bolt holes 69A and 69B.

[0060] Although not shown in the diagram, both restraining members 60A and 60B have lag screw bolt holes 68 constructed in the manner already described with reference to Figures 3A to 3E. By screwing lag screw bolts 80A and 80B, which have male threads 81 and 83 on their outer circumference, into the lag screw bolt holes 68, lag screw bolt holes 69A and 69B are formed as the lag screw bolts 80A and 80B are screwed in.

[0061] In this example, the buckling-restrained brace 100 is provided with spacers 75 on the left and right sides of the core material 90, and through holes 76 are provided in each spacer 75 at positions corresponding to the lag screw bolt holes 69A and 69B.

[0062] In Figure 4B, the lag screw bolt hole 69A of one of the restraining members 60B is a through hole that extends from the front surface 61 to the back surface 62 of the restraining member 60B, and the lag screw bolt 80A that is screwed into it has a through hole 82 inside.

[0063] On the other hand, the lag screw bolt hole 69B of the other restraining member 60A extends from the surface 61 to an intermediate position inside, and the lag screw bolt 80B that is screwed into it has an internal female thread 84.

[0064] A bolt 85, which has a head 86, a shaft 87, and a male thread 88 at the tip of the shaft 87, is inserted through the through hole 82 of the lag screw bolt 80A, and then through the through hole 76 of the spacer 75, the male thread 88 is screwed into the female thread 84 of the lag screw bolt 80B, and the head 86 is engaged with the upper end 80a of the lag screw bolt 80A. By screwing the bolt 85 into all sets of lag screw bolts 80A and 80B, a buckling-restrained brace 100 is formed in which the core material 90 is surrounded by a wooden restraint body 70 in which a pair of restraint members 60 are firmly integrated.

[0065] Furthermore, other embodiments may be used in which other components are combined with the configurations listed in the above embodiments, and the present invention is not limited in any way to the configurations shown herein. In this regard, modifications can be made without departing from the spirit of the present invention, and can be appropriately determined according to the application form. [Explanation of Symbols]

[0066] 10: Tip Guide 20,20A: Screw thread section 22: Perfect screw thread (screw thread) 24: Guide screw thread (screw thread) 26: Discharge recess 30: Mounting part 32:Hexagon head 34: Pull-out hole 50, 50A: Lag screw bolt hole construction jig (shaft-shaped body) 60,60A,60B: Wooden material (restraint material) 61: Surface 62: Back side 63: Pre-drilled hole 63A: Near the opening 64:Aperture 65: Guide groove 68: Lag screw bolt hole 69A, 69B: Lag screw bolt holes 70: Wooden restraints 75: Spacer 76: Through hole 80A, 80B: Lag screw bolts 80a:Top end 81, 83: Male screw 82: Through hole 84: Female thread 85: Bolt (fastener) 86: Head 87: Shaft 88: Male screw 90: Core material 100: Buckling-restrained brace L1: Center of the pilot hole (center of the lag screw bolt hole, center of the hole) L2: Axis of the shaft-shaped body (axis) D:Power tools B: Pulling rod

Claims

1. A lag screw hole construction jig is used when constructing a lag screw hole extending from the surface to the interior of a wood material, into which a lag screw bolt, which has male threads on its outer circumference, is rotated and inserted, It has an axial body that extends in the axial direction, The aforementioned axial body is A tip guide, which is inserted into a pre-hole extending inward from an opening on the surface of the wood material and has a length that allows it to maintain the inserted position of the shaft-shaped body, A threaded portion having multiple threads, adjacent to the tip guide, which forms a helical guide groove when the lag screw bolt is rotated and inserted into the wall of the pre-drilled hole, A lag screw bolt hole construction jig characterized by having a mounting portion adjacent to the screw thread portion and being attached to a power tool.

2. The lag screw bolt hole construction jig according to claim 1, characterized in that, in the threaded portion, the height of the plurality of threads gradually increases from the tip guide side toward the mounting portion side, and the outer diameter of threads 2 to 4 on the mounting portion side is the same as or substantially the same as the outer diameter of the lag screw bolt.

3. The lag screw bolt hole construction jig according to claim 1, characterized in that the outer diameter of the tip guide is the same as the inner diameter of the pre-drilled hole, or slightly smaller than the inner diameter of the pre-drilled hole.

4. The lag screw bolt hole construction jig according to claim 1, characterized in that a discharge recess for discharging chips generated when constructing the guide groove is provided in the screw threads through the opening.

5. The aforementioned mounting portion includes: The lag screw bolt hole construction jig according to claim 1, characterized in that it is provided with a head to which the aforementioned power tool is attached, and a pull-out hole through which a pull-out rod used when pulling out the shaft-shaped body from the pre-drilled hole is inserted.

6. A method for constructing lag screw bolt holes extending from the surface to the interior of a wood material, into which a lag screw bolt having a male thread on its outer circumference is rotated and inserted, Step A involves drilling a pre-drilled hole extending inward from an opening on the surface of the aforementioned wood material. A method for constructing a lag screw bolt hole, characterized by using a lag screw bolt hole construction jig having an axially extending shaft-shaped body, wherein the shaft-shaped body has a tip guide having a length that can maintain the insertion position of the shaft-shaped body, a threaded portion adjacent to the tip guide and having a plurality of threads, and a mounting portion adjacent to the threaded portion that is attached to a power tool, wherein the mounting portion is attached to the power tool, the tip guide is inserted into the pre-drilled hole, the power tool is operated to rotate the shaft-shaped body, and the rotating threaded portion constructs a spiral guide groove on the wall surface near the opening in the pre-drilled hole.

7. The method for constructing lag screw bolt holes according to claim 6, characterized in that the wood material is a restraining member in a buckling restraint brace having a steel plate-shaped core and a wooden restraint body formed by a pair of wooden restraining members wider than the core, which are arranged to face the two wide surfaces of the core.

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