JPH0571424U - Flexible wood joining bolt - Google Patents

Abstract

(57) [Summary] (Modified) [Objective] The present invention is designed to prevent the timber from shear failure by deforming the bolts used in the joints of timber subjected to one-sided or multi-faced shearing, following the plastic deformation of the timber. (EN) Provided is a flexible wood-bonding bolt that prevents the bolt from slipping into the wood side. [Structure] The whole or a part of the shaft portion of the bolt 1 is formed to be flexible, and as a specific example, a steel rod 5 having a large number of shaft portions is covered with a hard member 6 such as hard rubber and integrally molded. It consists of things.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a joining bolt for joining timbers, and in particular, it is flexible and is suitable for contributing to plastic deformation of a timber frame structure and improving rigidity and toughness of the frame structure. Bolts for joining timber.

[0002]

[Prior Art]

 In the case of bolts used for general structures, their tensile strength and shear strength are required. However, in the case of a bent bolt for joining which is used for a timber joint and receives a shearing force, the property is different from that of the bolt and it is necessary to appropriately plastically deform the bolt. That is, as shown in FIG. 7, for example, a joining bolt 19 used at a joint portion of a wood made up of a main member 17 and two side members 18 sandwiching the main member 17 penetrates the main member 17 and the side members 18. The nut 20 is tightened and arranged. As shown in the drawing, flat washers 21 and 22 are provided between the bolt 19 and the nut 20 and the wood side in order to prevent the wood side from sinking. When the tensile force P is applied to the main material 17 and the side material 18, a shearing force is generated in the bolt 19, and as a result, a slip occurs at the joint between the main material 17 and the side material 18, as shown in FIG. To transform. That is, the shaft portion of the bolt 19 is embedded in the main material 17 or the like and is deformed. The timber frame structure assembled with the main member 17 and the side members 18 absorbs the deformation of the frame structure due to the plastic deformation of the joint, and maintains the overall rigidity and toughness. Therefore, the bolt 19 needs to be plastically deformed appropriately. However, when the ratio of the diameter of the bolt 19 is small, the plastic deformation of the frame is not absorbed, and the side member 18 becomes brittle near the boundary of the bolt 19 and the washer as shown in FIG. May be destroyed.

[0003]

[Purpose of the present invention: Problems to be solved]

 As described above, the bolt used for the joint portion of the timber frame structure needs to undergo appropriate plastic deformation. In addition, it is necessary that the shearing force be smoothly transferred at the contact surface between the bolt and nut and the timber. As a guideline for causing an appropriate plastic deformation of the bolt, it is necessary to maintain the relationship that the diameter d of the bolt is m / d 2> 8 when the thickness of wood is m. However, if the relationship of m / d> 8 is maintained, the size of the bolt becomes extremely small with respect to the plate thickness of the wood, and accordingly the contact area between the bolt head and nut of the bolt and the wood becomes small, There is a problem that the bolts for joining are liable to slip into the wood side. In addition, in order to maintain the relationship of m / d> 8, it is necessary to select a bolt of a size suitable for each change in the thickness of the wood, which makes bolt management complicated and reduces work efficiency. There are problems such as occurrence.

The present invention solves the above-mentioned problems of the prior art, and moderately plastically follows the deformation of the wood, and it is not necessary to change the size of the bolt every time the thickness of the wood changes. An object of the present invention is to provide a flexible wood joining bolt that can improve the work efficiency of assembling and improve the rigidity and toughness of the timber frame structure.

[0005]

[Structure of the present invention; means for solving problems]

 In order to achieve the above-mentioned object, the present invention is a bolt used for a joint portion of wood, in which the whole or a part of the shaft portion is formed flexibly and a nut is attached to the shaft portion. A bolt for joining a flexible wood is formed by forming a screw portion to be screwed, and more specifically, the shaft portion of the bolt is formed of a flexible core material, or a bolt head and a screw are formed. A flexible wood joining bolt is formed by forming a flexible shaft portion between the formed screw shaft portions.

[0006]

[Action]

 Since the whole or a part of the shaft portion of the bolt is formed to be flexible, the bolt can be deformed according to the deformation of the wood. Further, unlike the prior art, it is not necessary to use a bolt having a particularly small diameter, so that the contact area between the bolt head and the nut and the wood is wide, and the bolt or the like is prevented from being caught.

[0007]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings. (1) Embodiment 1 FIG. 1 shows a flexible wood joining bolt 1 (hereinafter referred to as bolt 1) of a first embodiment of the present invention. 2 is an enlarged sectional view taken along the line AA of FIG. The bolt 1 is formed of a bolt head 3 and a core member 2 into which the bolt head 3 on one end side is fitted and a screw portion 4 is threaded on the other end side. In the present embodiment, the core material 2 is formed by integrally molding a hard rod 5 made of a small-diameter steel rod (PC steel rod) or carbon fiber, and a hard member 6 such as hard rubber or ceramic encapsulating the hard rod 5. Formed from. That is, a large number of hard rods 5 are put in soft rubber or powdery ceramics in a flexible state, and they are inserted into a mold having a bolt diameter d and vulcanized or sintered to form the core material 2. It is formed by fitting a bolt head 3 on one end side and screwing a screw portion 4 on the other end side. With the above-mentioned structure, the bolt 1 is formed of a material that has appropriate flexibility when removed in the shearing direction and has sufficient tensile strength in the tensile direction. Further, the bolt 1 of this embodiment does not need to satisfy m / d> 8 when the diameter d of the core material 2 and the plate thickness of wood are m, and a relatively thick one is adopted. Therefore, the contact area between the bolt head 3 and the wood can be increased. (2) Second Embodiment FIG. 3 shows a second embodiment of the present invention. The bolt 1a is composed of a bolt head portion 3a and a core material 2a having a bolt head portion 3a fitted on one end side thereof and a screw portion 4a screwed on the other end side thereof. The core material 2a is formed by winding a hard wire 7 such as a PC steel wire or a carbon fiber wire having a small diameter into a stranded wire and enclosing it with a hard member 8 such as hard rubber or ceramic. The hard wire 7 wound linearly with the diameter d is put into a hard rubber or powdery ceramic in a flexible state, vulcanized or sintered, and then a bolt head 3a is fitted on one end side, and the like. It is formed by threading a screw portion 4a on the end side. As in the first embodiment, the bolt 1a having the above-described structure can be used for a joint portion of wood even if it does not satisfy m / d> 8, and it is appropriately deformed to prevent plastic deformation of wood. Can be absorbed. (3) Third Embodiment A third embodiment of the present invention shown in FIG. 5 is shown. The bolt 1b includes a hexagonal bolt head 3b, a screw shaft portion 9 on which a screw 4b is threaded, and a flexible shaft portion 10 interposed between the bolt head 3b and the screw shaft portion 9. The flexible shaft portion 10 is formed by alternately laminating and bonding a steel plate 11 having a diameter substantially equal to the diameter d of the screw shaft portion 9 and a hard flexible plate 12 made of hard rubber or slightly soft plastic. The steel plates 11 (or the hard flexible plates 12) at both ends of the flexible shaft portion 10 are laminated and adhered to the bolt head 3b and the screw shaft portion 9. With the above structure, the bolt 1b can deform the flexible shaft portion 10 and follow the plastic deformation of the joint portion of the wood.

Next, the operation of the above embodiment will be described. The operation of the embodiment of FIGS. 1 to 3 is almost the same, and the operation when the bolt 1b of the third embodiment is used as a representative as shown in FIG. 6 will be described. In FIG. 6, the bolt 1b is used at the joint portion of the pair of timbers 13 and 13 subjected to the one-sided shear. The bolt 1b is arranged so as to penetrate through the timbers 13, 13, and a nut 16 is screwed onto the screw 4b. Washers 14 and 15 are provided between the bolt head 1b and the nut 16 and the timbers 13 and 13. As shown in the drawing, when tensile forces in opposite directions (arrow P) are applied, first, partial shear failure progresses in the woods 13, 13 and a relative displacement occurs between the woods 13, 13. Thereby, a shearing force (one-sided shearing) acts on the bolt 1b. As described above, since the bolt 1b has the flexible shaft portion 10 formed by alternately laminating and bonding the steel plate 11 and the hard flexible plate 12, as shown in FIG. 6, the steel plate 11 and the hard flexible plate 12 are bonded. The plates 12 are displaced in a stepwise manner and are greatly deformed. That is, since it can be plastically deformed to a greater extent than a solid bolt having a diameter d, it is possible to follow the relative displacement of the joint portion of the wood pieces 13, 13. On the other hand, the bolt head 3b of the bolt 1b and the nut 16 contact the woods 13 and 13 via the washers 14 and 15, respectively, and abut on each other with a relatively large contact area. It is prevented from slipping into the 13 and 13 side, and an unreasonable force does not act on the contact surface between the bolt 1b and the wood 13. As described above, the joint portion of the timbers 13 and 13 can be easily displaced relative to each other even when a tensile force is applied, and the shear failure of the timbers 13 and 13 can be prevented. Further, even if a tensile force in the axial direction acts on the bolt 1b, the flexible shaft portion having the diameter d resists, so that a sufficient tensile force can be obtained as compared with the conventional small diameter bolt satisfying m / d> 8. It can maintain strength.

Although the bolts including the core material and the flexible shaft portion of various shapes have been described by the above-described first to third embodiments, the shapes of the core material and the flexible shaft portion are the same as those in the above embodiments. It is not limited to. Further, the hard rod and the hard wire are made of PC steel rod, PC steel wire, etc., but not limited thereto. Further, the hard member is not limited to hard rubber or ceramic.

[0010]

[Effect of the device]

 The bolt of the present invention has the following effects. (1) The bolt is plastically deformed due to the deformation of the one-sided and multi-sided wood joints, and the shearing force of the wood is not applied, so that the shear failure of the wood is prevented. (2) Since thick bolts that do not satisfy m / d> 8 can be adopted, the contact area between the bolt head and the nut and the wood can be widened, and it is possible to prevent the bolt from getting into the wood side. .. (3) The flexibility of setting the shaft flexibility is wide, and a bolt having a desired function can be manufactured. (4) Even if the shaft portion is formed to be flexible, it can have a higher tensile strength than the conventional bolt connection. (5) Bolts are set without depending on the thickness of the timber, which reduces the labor for bolt management and improves work efficiency. (6) Since the proof stress as a bending bolt is improved as compared with a conventional bolt having the same m / d value, the number of bolts used can be reduced.

[Brief description of drawings]

FIG. 1 is an axial sectional view of a bolt according to a first embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view taken along the line AA of FIG.

FIG. 3 is an axial sectional view of a bolt according to a second embodiment of the present invention.

FIG. 4 is an enlarged sectional view taken along line BB of FIG.

FIG. 5 is an axial sectional view of a bolt according to a third embodiment of the present invention.

6 is an axial sectional view showing a mounted state of the bolt shown in FIG. 5 and a deformed state thereof.

FIG. 7 is a cross-sectional view showing an engaged state of wood and a bolt or the like in conventional two-sided shearing.

FIG. 8 is a cross-sectional view showing a deformed state of wood and a bolt.

FIG. 9 is a cross-sectional view showing a state in which wood is sheared and broken due to insufficient plastic deformation of bolts.

[Explanation of symbols]

 1 Flexible wood joining bolt (bolt) 1a Flexible wood joining bolt (bolt) 1b Flexible wood joining bolt (bolt) 2 Core material 2a Core material 3 Bolt head 3a Bolt head 3b Bolt head Part 4 Screw part 4a Screw part 4b Screw 5 Hard rod 6 Hard member 7 Hard wire rod 8 Hard member 9 Screw shaft part 10 Flexible shaft part 11 Steel plate 12 Hard flexible plate 13 Wood 14 Washer 15 Washer 16 Nut

Claims (4)

[Scope of utility model registration request] 1. A joining bolt used for joining timbers, wherein the whole or a part of the shaft portion is formed to be flexible, and a screw portion which is screwed into a nut is attached to the shaft portion. A bolt for joining flexible wood, which is formed. 2. The shaft portion is formed of a flexible core member integrally formed by a small-diameter hard rod and a hard member encapsulating the rod.
The bolt for joining flexible wood according to claim 1, wherein a bolt head is fitted on one end side of the bolt and the threaded portion is formed on the other end side. 3. The shaft portion is formed of a flexible core material obtained by integrally molding a shaft made of a hard wire into a linear shape by a hard member, and a bolt head is fitted to one end side thereof. The bolt for joining flexible wood according to claim 1, wherein the threaded portion is formed on the other end side. 4. The flexible shaft portion according to claim 1, wherein a steel plate and a hard flexible plate are alternately laminated and bonded between the screw shaft portion forming the screw and the bolt head portion. Flexible wood joining bolt.