Mounting jig and mounting method for lag screw bolt

Abstract

To provide a mounting jig for a lag screw bolt capable of screwing a lag screw bolt to the depth of a pilot hole drilled into wood.SOLUTION: A tightening bolt body 1 is formed so as to be connected to a female screw part L3 of a lag screw bolt L. A holding cylinder 2 is formed into which the tightening bolt body 1 is inserted and to which a head part 1B of the tightening bolt body 1 is locked. The tightening bolt body 1 is inserted into the holding cylinder 2 fitted into a pilot hole Q1. The tip of the tightening bolt body 1 is connected to the female screw part L3 of the lag screw bolt L. The tightening bolt body 1 is configured to be screwed in until the holder cylinder 2 is embedded in the pilot hole Q1.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a mounting jig used when embedding a lag screw bolt deep into wood, and a mounting method using this mounting jig. [Background technology]

[0002] Patent Document 1 describes an attachment jig that makes it easier to embed a lag screw bolt in a pilot hole in wood. This jig is equipped with a tightening bolt body 1 that connects to the female thread portion L3 at the end of the lag screw bolt L when the lag screw bolt L without a hexagonal head is screwed into a pilot hole Q1 of wood Q to embed the bolt, and a retaining cylinder 2 that is used when removing the tightening bolt body 1 from the end of the lag screw bolt L.

[0003] To use this mounting jig, the backing plate 3 is placed on the end of the lag screw bolt L, and the lag screw bolt L is embedded until this backing plate 3 abuts against the open end of the pilot hole Q1. When removing the tightening bolt body 1 from the embedded lag screw bolt L, the tightening bolt body 1 is removed while the retaining cylinder 2 is fixed with a wrench or the like.

[0004] The lag screw bolt L without a hexagonal head is used, for example, in the method of connecting cross-laminated timber Q (CLT) described in Patent Document 2. This lag screw bolt L is formed so that the valley diameter dimension of the thread 2 matches the inner diameter dimension of the pilot hole Q1, and has the effect of being able to connect the cross-laminated timber Q (CLT) of a wood-steel hybrid structure to the steel material P without using any adhesive. Moreover, unlike when using a general lag screw bolt with a hexagonal head, it does not require time-consuming work such as drilling the seat of the wood or filling it with epoxy resin, making it an effective part for shortening the construction period of a wood-steel hybrid structure. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 6923984 [Patent Document 2] Patent No. 6986764 Summary of the Invention [Problem to be solved by the invention]

[0006] The mounting jig shown in Patent Document 1 is attached to remove the tightening bolt body 1 from the tightened lag screw bolt L. Therefore, with this mounting jig, the lag screw bolt L can only be embedded to the surface position of the wood Q to a certain extent, which is disadvantageous in that the range of application of the lag screw bolt L is limited.

[0007] On the other hand, lug screw bolts without a hex head do not require the drilling of the seat in the wood or the filling of epoxy resin, as is the case with ordinary lug screw bolts, and so can also be used in new connection methods.

[0008] For example, in wood-steel hybrid structures, a headless lag screw bolt can be embedded deep into a pilot hole drilled into the wood, and then a long connecting bolt, steel rod, or other connecting member can be attached to the lag screw bolt.

[0009] However, this type of connection method has the following problems. First, there is no means for embedding the lag screw bolt deep into the drilled pilot hole. Second, there is a risk that the connecting member connected to the embedded lag screw bolt will buckle inside the pilot hole, or that the connecting member will damage the periphery of the pilot hole opening.

[0010] The first problem is that since a lag screw bolt without a hexagonal head needs to have a special mounting jig attached to the end, it is limited to burying it to the surface of the wood, and it is not possible to bury the lag screw bolt deep into a deep pilot hole. Even if a long tightening bolt is used to bury it deep into the pilot hole, there is a risk that the long lag screw bolt will bend and deform inside the pilot hole, causing the work to be interrupted.

[0011] The second problem is that the connecting member that connects to the lag screw bolt in the pilot hole in the wood is thinner than the diameter of the pilot hole, so when compressive force is applied to the connecting member due to an earthquake, etc., the connecting member may buckle in the pilot hole. Also, when the connecting member shakes, the area around the opening of the pilot hole may be damaged.

[0012] As such, there were various issues that needed to be resolved with this new construction method in which lag screw bolts are buried deep within the timber and connected.

[0013] Therefore, the present invention has been created to solve the above-mentioned problems, and aims to provide an installation jig and installation method for a lug screw bolt that can reliably embed a lug screw bolt deep into a pilot hole drilled into wood, prevent buckling of the connecting member connected to the lug screw bolt, and prevent damage around the opening of the pilot hole. [Means for solving the problem]

[0014] In order to achieve the above object, the first aspect of the present invention is an attachment jig for screwing a lag screw bolt L having a female threaded portion L3 at its end into a pilot hole Q1 formed in a piece of wood Q and deeper than the length of the lag screw bolt L, A tightening bolt body 1 that connects a connecting end 1A to the female thread portion L3 of the lag screw bolt L; a retaining cylinder 2 having one end abutting against the end of the lag screw bolt L and the other end engaging with the head 1B of the tightening bolt body 1; A fixing head 2A is formed on the other end of the retaining cylinder 2 so as to come into contact with the surface of the pilot hole Q1. The tip of the fastening bolt body 1 inserted into the retaining cylinder 2 is connected to the female thread portion L3 of the lag screw bolt L, and the end of the retaining cylinder 2 is abutted against the end of the lag screw bolt L, This is an attachment jig configured so that the lag screw bolt L is screwed in with the tightening bolt body 1 until the fixing head 2A of the retaining cylinder 2 abuts against the surface side of the pilot hole Q1.

[0015] The fixing head 2A of the second means is configured to be fixed with a fixing tool when the tightening bolt body 1 is removed from the lag screw bolt L embedded in the pilot hole Q1 having a diameter between the root diameter and the crest diameter of the thread L2 of the lag screw bolt L.

[0016] The third means is a method for attaching a lag screw bolt L having a female thread portion L3 recessed at the end thereof, A processing step of drilling a pilot hole Q1 deeper than the length of the lag screw bolt L into the wood Q, and an embedding step of embedding the lag screw bolt L deep into the pilot hole Q1 via a retaining cylinder 2 between the head 1B of a tightening bolt body 1 connected to the female thread portion L3 and the lag screw bolt L. a removal process of removing the fastening bolt body 1 from the embedded lag screw bolt L and extracting the retaining cylinder body 2 from the pilot hole Q1; a reinforcing step of inserting a cylindrical reinforcing member 3 into the pilot hole Q1 from which the holding cylinder 2 has been removed; and a connecting step of connecting a connecting member 4 to the female thread portion L3 of the lag screw bolt L through the reinforcing member 3.

[0017] In the embedding step of the fourth means, the lag screw bolt L is a hollow lag screw bolt L.

[0018] In the reinforcing step of the fifth means, the reinforcing member 3 is the lag screw bolt L having the female thread portion L3 at an end thereof, which is formed into a cylindrical shape.

[0019] In the reinforcing step of the sixth means, the reinforcing member 3 is configured such that a fitting recess L4 having a polygonal shape in plan view is recessed in place of the female thread portion L3. Effect of the Invention

[0020] The mounting jig of the present invention eliminates the risk of work being interrupted due to bending deformation of the tightening bolt caused by the load during burying, even if a long tightening bolt is used to bury the lag screw bolt deep into the pilot hole. Therefore, the lag screw bolt can be reliably buried deep into the pilot hole. Moreover, the long tightening bolt can be easily removed from the lag screw bolt buried deep into the pilot hole.

[0021] In addition, the mounting method of the present invention can prevent buckling of the connecting member connected to the lag screw bolt and damage to the area around the opening of the pilot hole. As a result, it becomes possible to use the lag screw bolt in a new construction method. [Brief description of the drawings]

[0022] [Figure 1] FIG. 1 is an exploded perspective view showing an embodiment of a mounting jig according to the present invention. [Diagram 2] FIG. 4 is a partially cutaway front view showing the mounting state using the mounting jig of the present invention. [Diagram 3] 1(a) to 1(c) are diagrams showing the mounting process of the mounting jig of the present invention. [Figure 4] 6(a) to 6(c) are diagrams showing a process of attaching a reinforcing member. [Diagram 5] 13(a) and 13(b) are diagrams showing the state in which the reinforcing member is attached. [Figure 6] 1 shows another embodiment of the reinforcing member, where (a) is a bottom view of the mounting jig, (b) is a side view of the mounting jig, (c) is a plan view of the reinforcing member, and (d) is a side cross-sectional view of the reinforcing member. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] The present invention relates to a mounting method and a mounting jig for embedding a lag screw bolt L into wood Q such as cross-laminated timber (CLT).

[0024] Cross-laminated timber (CLT) is a type of wood that is made by arranging lamina and then laminating and gluing them so that the grain direction is perpendicular to the board. This type of wood is also used for architectural structures, civil engineering materials, furniture, etc.

[0025] On the other hand, the lag screw bolt L is a bolt that connects earthquake-resistant hardware, previously known as hold-down hardware or pull-in hardware, and is an important connecting member that ensures earthquake resistance by attaching earthquake-resistant hardware to the foundation or base and columns, or between columns or between columns and beams on upper and lower floors, in order to counter the pull-out force acting on the load-bearing walls when a wooden building is subjected to horizontal force.

[0026] Furthermore, lag screw bolts are important connecting components that have advantages when constructing rigid frame or truss structures at the joints of walls, floors, columns, beams, roofs, etc. in wooden buildings using structural laminated timber, and in mixed steel and wooden structures.

[0027] In new construction methods using cross-laminated timber (CLT), such as wood-steel hybrid structures, lag screw bolts L without a hexagonal head and with a recessed female thread at the end are now being used.

[0028] The mounting jig of the present invention is composed of a tightening bolt body 1 and a retaining cylinder body 2 (see Fig. 1). It is used when screwing a lag screw bolt L deep into a pilot hole Q1 formed in a piece of wood Q (see Fig. 2). At this time, the pilot hole Q1 is formed to be at least deeper than the length of the lag screw bolt L, and the lag screw bolt L is buried deep into this depth.

[0029] The tightening bolt body 1 has a connecting end 1A that connects to the female thread portion L3 of the lag screw bolt L, and has a head 1B that engages with the opening of the retaining cylinder 2 (see FIG. 2). Then, with the lag screw bolt L screwed into the tip of the tightening bolt body 1 that has passed through the retaining cylinder 2, the lag screw bolt L is screwed deep into the pilot hole Q1.

[0030] The retaining cylinder 2 is shaped like a cylinder to be inserted into the pilot hole Q1, with one end abutting against the end of the lag screw bolt L and the other end engaging with the head 1B of the tightening bolt body 1. Furthermore, a fixing head 2A is provided around the other end (see FIG. 1). In the illustrated example, the fixing head 2A has a nut welded to the outer periphery of the retaining cylinder 2 (see FIG. 2).

[0031] This fixing head 2A is a member that comes into contact with the opening of the pilot hole Q1 when the lag screw bolt L is embedded to a predetermined depth in the pilot hole Q1 (see FIG. 2). Therefore, the length of the retaining cylinder 2 is determined by the depth to which the lag screw bolt L is embedded.

[0032] Furthermore, this fixed head 2A is fixed with a rotating tool such as a wrench when the tightening bolt body 1 is removed from the lag screw bolt L embedded in the pilot hole Q1. That is, when the lag screw bolt L is embedded, the connecting end 1A of the tightening bolt body 1 strongly meshes with the female thread portion L3 of the lag screw bolt L, so that when the tightening bolt body 1 is rotated in the reverse direction, the tightening bolt body 1 will return together with the retaining cylinder 2 with the lag screw bolt L fixed to it. Therefore, the fixed head 2A of the retaining cylinder 2 is fixed with a rotating tool to prevent the lag screw bolt L from returning, while the tightening bolt body 1 is removed from the lag screw bolt L.

[0033] The mounting method of the present invention involves deeply embedding a lag screw bolt L in wood Q such as cross-laminated timber (CLT) and connecting various connecting members 4 to the lag screw bolt L. The basic steps of the present invention include a processing step, an embedding step, a removal step, and a connecting step.

[0034] The processing step is a step of drilling a pilot hole Q1 deeper than the length of the lag screw bolt L into the wooden piece Q using a drill or the like (see FIG. 3(A)). The diameter of this pilot hole Q1 is the same as the root diameter of the thread L2 of the lag screw bolt L. The pilot hole Q1 may also be formed so as to penetrate the stacked wooden pieces Q (see FIG. 5).

[0035] The embedding step is a step of embedding the lag screw bolt L inside the pilot hole Q1 (see FIG. 3(b)). At this time, an installation jig consisting of a tightening bolt body 1 and a retaining cylinder body 2 is used to embed the lag screw bolt L deep into the pilot hole Q1. The lag screw bolt L shown in the figure is a lag screw bolt L having a female threaded portion at the end. It is also possible to use a lag screw bolt L formed into a cylindrical shape with a female threaded portion at the end (see FIG. 5(b)). In this case, the weight of the lag screw bolt L can be reduced, making it suitable for use when using a large diameter lag screw bolt L.

[0036] In the pilot hole Q1 that penetrates the stacked wooden pieces Q, a lag screw bolt L can be embedded to connect each piece of wooden piece Q (see FIG. 5(A)). It is also possible to embed the lag screw bolt L in accordance with the piece of wooden piece Q at the back of the stacked wooden pieces Q (see FIG. 5(B)). In this way, the depth and position at which the lag screw bolt L is embedded inside the pilot hole Q1 can be set as desired.

[0037] The removal process involves removing the tightening bolt body 1 from the buried lag screw bolt L and extracting the retaining cylinder 2 from the pilot hole Q1 (see FIG. 3(c)). To remove the tightening bolt body 1 from the lag screw bolt L, the tightening bolt body 1 is rotated in the reverse direction and removed while the fixed head 2A of the retaining cylinder 2 is held in place with a rotating tool such as a wrench. This is followed by the task of extracting the retaining cylinder 2 from the pilot hole Q1.

[0038] Next, the reinforcing step is a step of inserting a reinforcing member 3 into the pilot hole Q1 from which the holding cylinder 2 has been removed (see FIG. 4). This reinforcing member 3 has a cylindrical shape that fits into the pilot hole Q1, and the shape and length of the reinforcing member 3 can be changed as desired as long as it is a cylindrical shape that fits into at least the opening side of the pilot hole Q1.

[0039] The reinforcing member 3 shown in the figure is a tubular member formed from a lag screw bolt having a female thread at its end (see FIG. 4). When the end of this reinforcing member 3 abuts against the embedded lag screw bolt L, the pull-out strength of the lag screw bolt L can be maximized (see FIG. 4(C)). It is also possible to fit this reinforcing member 3 into the opening side of the pilot hole Q1 and use it at a length that does not abut against the lag screw bolt L (not shown).

[0040] To insert this reinforcing member 3 into the pilot hole Q1, a conventional mounting jig 10 is used (see FIG. 4). That is, a tightening bolt body 11, a retaining cylinder 12, and a backing plate 13 are used (see FIG. 4(A)). The tightening bolt body 11 is then connected to the female threaded portion 3A at the end of the reinforcing member 3, and the reinforcing member 3 is screwed in until the backing plate 13 abuts against the opening side of the pilot hole Q1 (see FIG. 4(B)). To remove the tightening bolt body 11 from the reinforcing member 3, the retaining cylinder 12 is fixed with a fixture and then removed.

[0041] Furthermore, the reinforcing member 3 may have a planar polygonal fitting recess 3B recessed into its end instead of the female threaded portion 3A (see FIG. 6(d)). When inserting this reinforcing member 3 into the pilot hole Q1, a mounting jig 20 is used that has a fitting protrusion 21 at its end that fits into the fitting recess 3B of the reinforcing member 3 (see FIG. 6(b)). In FIG. 6(a) is a bottom view of the mounting jig 20, and FIG. 6(c) is a plan view of the reinforcing member 3.

[0042] Furthermore, when forming a cylindrical reinforcing member 3 and inserting it into the pilot hole Q1, it is also possible to fit the reinforcing member 3 inserted into the pilot hole Q1 by hitting it with a hammer or the like (not shown). In this way, the shape and length of the reinforcing member 3 can be changed as desired.

[0043] Finally, the connecting step is a step of connecting the connecting member 4 to the female threaded portion L3 of the lag screw bolt L through the reinforcing member 3 (see FIG. 5). The connecting member 4 shown in the figure is a long connecting bolt. The steel plate R is connected to the wood Q by this connecting member 4. Alternatively, the connecting member 4 may be a steel rod with male threads on both ends (not shown) and another member may be connected to the lag screw bolt L via the steel rod connecting member 4. In this case, the reinforcing member 3 prevents damage to the wood Q even if the side of the steel rod comes into contact with the opening side of the pilot hole Q1.

[0044] In addition, in the present invention, the structure, dimensions, materials, uses, etc. of the mounting jig, reinforcing member 3, connecting member 4, and lag screw bolt L are not limited to the examples shown in the drawings, and can be changed as desired without changing the gist of the present invention. [Explanation of symbols]

[0045] Q Wood Q1 Pilot hole R steel plate L lag screw bolt L1 Bolt body L2 Thread L3 Female thread L4 Mating recess 1 Fastening bolt body 1A connection end 1B Head 2 Holding cylinder 2A fixed head 3 Reinforcement members 3A Female thread 3B Mating recess 4 Connecting members 10 Mounting jig 11 Fastening bolt body 12 Holding cylinder 13 Toban 20 Mounting jig 21 Fitting protrusion

Claims

1. A mounting jig for screwing a lag screw bolt having a female threaded portion at its end into a pilot hole formed in wood that is deeper than the length of the lag screw bolt, A tightening bolt body that connects a connecting end portion to the female thread portion of the lag screw bolt; a retaining cylinder that is inserted into the pilot hole, one end of which abuts against the end of the lag screw bolt L, and the other end of which is engaged with the head of the tightening bolt body; A fixing head is formed on the other end of the holding cylinder so as to come into contact with the surface of the pilot hole, The tip of the fastening bolt body inserted into the retaining cylinder is connected to the female thread portion of the lag screw bolt, and an end of the retaining cylinder is abutted against an end of the lag screw bolt; A mounting jig for a lag screw bolt, characterized in that the lag screw bolt is screwed in with a tightening bolt body until the fixed head of the retaining cylinder abuts against the surface side of the pilot hole.

2. 2. An installation jig for a lag screw bolt as described in claim 1, wherein the fixing head is configured to be fixed with a fixing tool when the tightening bolt body is removed from the lag screw bolt embedded in the pilot hole having a diameter between the root diameter and the crest diameter of the thread of the lag screw bolt.

3. A method for installing a lag screw bolt having a female thread recessed at an end thereof, comprising the steps of: A processing step of drilling a pilot hole deeper than the length of the lag screw bolt into the wood; an embedding step of embedding the lag screw bolt deep into a pilot hole via a retaining cylinder between a head of a tightening bolt body connected to the female threaded portion and an end of the lag screw bolt; a removal process of removing the tightening bolt body from the embedded lag screw bolt and extracting the retaining cylinder body from the pilot hole; a reinforcing step of inserting a cylindrical reinforcing member into the pilot hole from which the holding cylinder was removed; a connecting step of connecting a connecting member to the female threaded portion of the lag screw bolt through the reinforcing member.

4. 4. The method for installing a lag screw bolt according to claim 3, wherein in the embedding step, the lag screw bolt is a hollow lag screw bolt.

5. 5. The method for attaching a lag screw bolt according to claim 4, wherein in the reinforcing step, the reinforcing member is a reinforcing member formed by forming the lag screw bolt having the female thread portion at an end into a cylindrical shape.

6. 5. The method for attaching a lag screw bolt according to claim 4, wherein in the reinforcing step, the reinforcing member is configured to have a fitting recess having a planar polygonal shape recessed therein instead of the female thread portion.

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