JP3728739B2 - Wood dowel, method for manufacturing the same, and joining method using wood dowel - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention belongs to the technical field of joining members to be joined such as wood, and in particular, uses a wooden dowel in which the surface of a wooden dowel (wood plug) is restored to a convex shape after joining, a method for manufacturing the same, and a wooden dowel The present invention relates to a joining method.
[0002]
[Prior art]
Conventionally, as shown in FIG. 8, the wood dowel 20 has a tapered portion 20 </ b> A at its end, and is widely used as a joining tool for connecting woods (members to be joined). When joining, dowel holes having a diameter smaller than the diameter of the wood dowel 20 are drilled on both wood surfaces, and the ends of the wood dowel 20 are driven into the dowel holes for joining. When the wood dowel 20 is driven, the diameter of the dowel hole is slightly smaller than the diameter of the wood dowel 20, so the wood dowel 20 is driven in a compressed state.
[0003]
[Problems to be solved by the invention]
However, in the wooden dowel of the conventional structure, the portion that contacts the dowel hole has a uniform flat surface, and thus the sticking force between the two may be reduced after driving. In particular, when it is necessary to bond large block-shaped timbers with a strong adhesive force, the adhesive force is insufficient and a reliable joining state may not be ensured. In some cases, there has been a problem that after joining the wood dowels are loosened due to insufficient fixing force, resulting in a failure in the joining state between the woods.
[0004]
In order to prevent this, it is only necessary to strictly manage the fitting condition between the dowel hole and the wood dowel and increase the compression adhesive force of the wood dowel inserted into the dowel hole. However, in this case, there is a problem that it is necessary to design and process the dowel hole and the dowel hole with a very strict diameter, and it is difficult to perform the operation of driving the dowel hole into the dowel hole.
In view of the above-described problems of the prior art, the present invention can increase the bonding strength between members to be joined without strictly processing the dowel hole and the wood dowel and can perform the operation of driving the wood dowel. It is an object of the present invention to provide a wood dowel, a method for manufacturing the same, and a joining method using the wood dowel.
[0005]
[Means for Solving the Problems]
In order to achieve this object, the wood dowel of the present invention has a plurality of reverse-line compaction portions on the surface that are deformed into a convex shape by moisture after being driven into the dowel hole, and the compaction portion adds the convex portions provided on the surface. It is characterized by being formed by pressing. In this wood dowel manufacturing method, after forming protrusions on the surface of the original plate, the surface of the original plate is uniformly formed by pressing, and a wooden dowel of a predetermined width is cut from the formed original plate. It is characterized by. Furthermore, in the method of joining the members to be joined using the wood dowels, the reverse eye compaction portion is deformed into a convex shape by water-containing expansion after joining.
[0006]
In order to manufacture this reverse-line-consolidated wood dowel, a plurality of parallel grooves are formed on the surface of the original plate, for example, a wooden plate on both sides or one side by a cutting machine or the like, and protrusions extending in a predetermined direction are provided on the original plate surface. . Thereafter, compaction is performed by hot pressing with the original plate interposed therebetween. In this case, the hot press temperature varies depending on the material of the original plate, but is preferably 160 ° C. or lower, and more preferably in the range of 140 ° C. to 150 ° C. Further, pressure is maintained until the thickness of the original plate is reduced to a predetermined thickness and the plate surface is uniform. Then, after releasing the clamping pressure of the original plate by the press, the original plate is cut in a direction perpendicular to the direction of the ridges, and a rod-shaped dowel having a predetermined size, for example, a width of 6 to 8 mm is separated and manufactured in a plate-cut method. . The pressing pressure at this time is 25 to 55 kgf / cm ^2. , More preferably 30-50 kgf / cm ² Is good.
[0007]
The members to be joined by wooden dowels are usually made of wood, but if the material has the same hardness or surface roughness as wood, non-woody materials such as synthetic resin, hard rubber, metal, paper, etc. It can also be applied to. The shape of the member to be joined is usually a block shape, but can be applied to a plate shape, a rod shape, a sphere or a stone shape. When joining the members to be joined, dowel holes are made in both of the members to be joined, and wood dowels are driven into the dowel holes for joining. The diameter of the dowel hole is formed slightly smaller than the diameter of the wood dowel, and when driving, the wood dowel is gradually fitted and inserted into the dowel hole in a compressed state. It does not matter whether the cross-sectional shape of the dowel hole and the wood dowel is round or square. The cross-sectional shape of the dowel hole and the wood dowel may be the same or different.
[0008]
At the time of joining, for example, an appropriate amount of moisture is given to the wood dowel immediately before joining, and the reverse eye compaction portion is restored to the original protruding shape. In other words, the reverse eye compaction portion is restored to a convex shape by utilizing the principle of hydrous expansion. In this case, if the member to be joined is a raw material, the moisture necessary for the expansion can use the moisture contained in the raw material itself, but if the member to be joined is a desiccant, the inner surface of the dowel hole before driving Sprinkle water or add water to the wooden dowel as appropriate.
[0009]
In this wood dowel, the reverse mesh compacted portion is deformed into a convex shape by water-containing expansion, so that the convex surface of the reverse eye compacted portion is in close contact with the inner surface of the dowel hole, and the adhesion force of the wood dowel to the dowel hole is enhanced. Accordingly, a sufficient adhesive force is generated between the wood dowels and the dowel holes, so that the joining strength between the members to be joined is remarkably increased. For example, even when the members to be bonded are particularly required to be bonded with a strong fixing force, the bonding state between the members to be bonded is stably maintained, and it is possible to satisfactorily prevent the occurrence of problems such as rattling over a long period of time. .
[0010]
Thus, in this invention, the compression adhesive force of the wooden dowel inserted in the dowel hole can be improved. In this case, since it is not necessary to strictly process the diameter of the dowel hole and the diameter of the wooden dowel, the dowel hole and the wooden dowel can be easily processed and manufactured. In addition, since it is not necessary to strictly manage the fitting dimensions of the two, the insertion operation of the wood dowel into the dowel hole can be easily performed.
[0011]
In the present invention, for example, when joining timbers with wooden dowels, the wood dowel body is added with a function of preventing the timbers from separating from each other, or a function of maintaining the state where the timbers are once pulled. The adhesion effect between the woods can be enhanced.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described based on examples shown in the drawings.
1 is a perspective view showing a wooden dowel and a block body according to the present invention, FIG. 2A is a front view showing a wooden dowel before shape restoration, and FIG. 1B is a front view showing a wooden dowel after shape restoration, FIG. 3 (a) is a plan view showing an original plate of a wooden dowel according to the present invention, (b) is a side view, FIG. 4 (a) is a plan view illustrating a cutting line of the original plate in FIG. 3, and (b) is a side view. FIG. 5 is a partial cross-sectional plan view for explaining a pull-out test of a block body according to the present invention, FIG. 6 (a) is a front view of a main part for explaining a joint tensile test in a direction orthogonal to wood fibers, and FIG. FIG. 7 (a) is a front view showing a wooden dowel having a W-shaped reverse mesh consolidation portion, FIG. 7 (b) is a front view showing a wooden dowel having a cross-shaped reverse mesh consolidation portion, and FIG. 7 (c) is a sectional circle. It is a front view which shows the wooden dowel which has an arc-shaped reverse eye consolidation part.
[0013]
【Example】
In FIG. 1, reference numeral 1 denotes a wooden dowel having a square section with a total length of 120 mm for joining the block bodies 7A and 7B, which are members to be joined. As the material of the wood dowel 1, cedar having a moisture content of 15% is used. On the opposite side surfaces of the square wooden dowel 1, that is, the upper and lower sides or both front and rear surfaces in FIG. A taper portion 1A is formed at the tip of the wooden dowel 1 so as to extend in a direction perpendicular to the direction P). Here, the cross-sectional shape of the wood dowel 1 is a square having a side length of 7 mm, and the wood pattern of the reverse stitch consolidated portion 2 has a compressed appearance pattern that is not continuous with the wood grain of the wood dowel 1 body. In this embodiment, the same cedar material as the wood dowel 1 is used as the block members 7A and 7B which are the members to be joined, but it goes without saying that plastics having the same properties as wood can also be joined. Yes.
[0014]
As shown in FIG. 2A, dozens of reverse-eye compacted portions 2 provided on the surface of the wood dowel 1 are formed at predetermined intervals in the longitudinal direction of the wood dowel 1. The reverse mesh compacted portion 2 is formed by compacting a convex portion (projection) on the surface of the wooden dowel 1 with a press to form a flat uniform surface having a predetermined thickness. As shown in FIG. 2 (b), the reverse eye consolidated portion 2 has a property of being restored to the original convex shape by absorbing moisture.
[0015]
In order to manufacture the wood dowel 1, as shown in FIG. 3A, for example, a square original plate (plate material) 4 having a side length of 120 mm is used. The tree species of the original plate 4 is cedar and has a plate thickness of 14 mm, a moisture content of 15%, and a density of 0.5. As shown in FIGS. 3A and 3B, the surface of the original plate 4 is cut with a cutting machine or the like as shown in FIGS. Are formed in parallel at predetermined intervals. Thereby, dozens of ridges 6 having a predetermined width extending in the left-right direction LR are formed on both the front and back surfaces of the original plate 4.
[0016]
Subsequently, it compacts with the hot press apparatus on both sides of the front and back of the original plate 4. The hot press temperature is set to 160 ° C. or less, here about 140 ° C. to 150 ° C. In this case, the press working pressure is set to 30 to 50 kgf / cm ² . When the original plate 4 having a thickness of 14 mm is thinned to a thickness T = 7 mm and held until the plate surface is formed into a uniform flat surface, as shown in FIGS. 4 (a) and 4 (b). In addition, the reverse mesh compacted portions 2 are formed on both the front and back surfaces of the original plate 4.
[0017]
Next, after releasing the clamping pressure of the original plate 4 by the press device, along the dozen cut lines provided on the original plate 4, it is alternately cut and separated every predetermined width of 7 mm and 3 mm. In this embodiment, the original plate 4 is cut with a predetermined width along a cutting line C (a broken line in the vertical direction in FIG. 4A) extending in a direction orthogonal to the longitudinal direction LR of the ridge 6. As a result, a bar-shaped wood joint having a predetermined size, for example, two types of wood dowels 1 having a length of 120 mm, a width of 7 mm, and 3 mm, is produced. The wood dowel 1 manufactured in this way has dozens of reverse-line consolidated portions 2 on opposite surfaces, and the cross-sectional shape is a square with a side length of 7 mm, and is compressed to a density of 0.7. Become. Thereafter, as shown in FIG. 2, the tapered portion 1 </ b> A is formed at the tip of the wooden dowel 1, but this need not be formed if necessary.
[0018]
Next, a method of joining the block bodies (members to be joined) 7A and 7B, which are cedar materials, with the wood dowel 1 will be described. At the time of joining, dowel holes 8A and 8B are drilled in advance in the center of both block bodies 7A and 7B. The cross-sectional shape of the dowel holes 8A and 8B may be round or square, but the diameter of the dowel holes 8A and 8B is formed slightly smaller than the diameter of the wood dowel 1. Then, the block bodies 7A and 7B are overlapped so that the center positions of both the dowel holes 8A and 8B are aligned, and the tip tapered portion 1A of the wood dowel 1 is sequentially placed in the dowel hole 8A of the block body 7A and the dowel hole 8B of the block body 7B. Insert and drive in.
[0019]
At the time of driving, the diameter of the main body portion of the wooden dowel 1 is slightly larger than the diameter of the dowel holes 8A and 8B, so that the wooden dowel 1 is gradually driven into the dowel holes 8A and 8B while being deformed by reaction force. Go. In other words, the wood dowel 1 is inserted while maintaining the compressed state while receiving the reaction force from the inner surfaces of the dowel holes 8A and 8B while expanding the inner diameter surface of the dowel holes 8A and 8B as the wood dowel 1 enters. Go.
[0020]
Thereafter, moisture is applied to the reverse eye compacted portion 2 of the wooden dowel 1 to restore the reverse eye compacted portion 2 to its original convex shape. In other words, the shape restoration of the reverse eye consolidated portion 2 is performed by utilizing the property that the wood expands with water. In this case, if the member 1 is a raw material, the water necessary for the water-containing expansion uses the water contained in the material. Moreover, if the members 7A and 7B to be joined are desiccants, the dowel holes 8A and 8B are sprayed on the inner surface side before being driven. The strength of adhesion between the wood dowel 1 and the dowel holes 8A and 8B varies depending on the type, size, number, etc. of the convex shape when the reverse mesh compacted portion 2 is restored, but these are appropriately changed in production design. By doing so, a desired degree of joining can be determined.
[0021]
In the wood dowel 1 of the present invention, the reverse mesh compacted portion 2 on the surface is restored to a convex shape by hydrous expansion. For this reason, after the wood dowel 1 is driven into the dowel holes 8A and 8B of the block bodies 7A and 7B, the convex tip end surface of the reverse mesh compacted portion 2 is strongly pressed against the inner surfaces of the dowel holes 8A and 8B. , 8B is remarkably enhanced. Therefore, the joint degree between the block bodies 7A and 7B through the wood dowel 1 is also significantly improved.
[0022]
Thus, the adhesive strength of the wood dowel 1 with respect to the dowel holes 8A and 8B is enhanced by the shape restoration of the reverse mesh consolidation portion 2 due to the water-containing expansion. Therefore, it is not necessary to strictly process the fitting dimensions between the dowel holes 8A and 8B and the wooden dowel 1, and accordingly, the allowable range of the dimensional error between the dowel holes 8A and 8B and the wooden dowel 1 can be increased. Further, since the fitting dimensions between the dowel holes 8A, 8B and the wood dowel 1 can be set to a fitting state with a margin, the reaction force when driving is small, and the driving work is facilitated.
[0023]
Actually, a pull-out test was conducted to confirm the degree of bonding. In the pull-out test, as shown in FIG. 5, the block bodies 7A and 7B joined by the wood dowel 1 are held by the block body clamp 10, and the base end of the wood dowel 1 is held by the wood dowel clamp 11 in this state. And then pulling it out. When the pulling force when the wooden dowel 1 was pulled out was measured, it was 45 kgf / cm. As a result, it was found that the bonding strength was increased by 15% as compared with the tensile force of 30 kgf / cm by the wooden dowel of the conventional structure.
[0024]
Furthermore, a joint tensile test in the direction orthogonal to the wood fibers was performed. FIG. 6 shows this, and the two cedar plates 7C facing each other are arranged so as to be sandwiched between two cedar plates 7D so as to be orthogonal to the fiber direction. Prepared three wooden dowels 1 each. When the clamps 13 and 14 were fixed to the end portions of the two cedar plates 7C and the tensile test was performed, the tensile force was 170 kgf, and it was found that the tensile strength was sufficient.
[0025]
In addition, this invention is not limited to the said Example, A various application is possible in the range which does not deviate from the meaning of this invention. For example, in the embodiment, the convex shape of the reverse eye compaction part to be restored is formed into a U-shaped pattern by forming a concave groove with a U-shaped cross section on the original plate, but by changing the cross-sectional shape of the concave groove, The convex shape of the reverse eye consolidation portion can be changed to various patterns. For example, as shown in FIGS. 7A to 7C, convex shapes such as a W shape 16, a L shape 17, and an arc shape 18 can be obtained. Particularly, in the case of the L-shaped 17 in FIG. 7B, the one end side and the other end side of the wooden dowel 1 are formed so that the directions of the L-shaped protruding patterns are opposite to each other from the center. By using this, the members to be joined can be joined with extremely high strength. Moreover, you may provide the taper part 1A not only at one end but the other end of the wooden dowel 1 as needed.
[0026]
【The invention's effect】
According to the wood dowel and the joining method thereof according to the present invention, since the reverse eye compaction portion is restored to a convex shape by water-containing expansion after the wood dowel is driven, the adhesion force of the wood dowel to the dowel hole can be increased. The joining strength between the joining members can be greatly increased. In particular, according to the wood dowel manufacturing method of the present invention, a number of wood dowels can be efficiently produced at one time by producing a wood dowel by cutting into a predetermined width after pressing an original plate having protrusions. it can.
[0027]
Moreover, according to this invention, the material of a to-be-joined member can be applied not only to wood but also to non-wood. In addition, it is not necessary to strictly manage the fitting size between the dowel hole and the wooden dowel, and accordingly, the allowable range of dimensional error can be increased accordingly. Therefore, there is an excellent effect that the machining of the dowel hole and the wood dowel becomes easy and the operation of driving the wood dowel into the dowel can be easily performed.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a wood dowel and a block body (members to be joined) according to the present invention.
2A is a front view showing a wooden dowel before shape restoration, and FIG. 2B is a front view showing a wooden dowel after shape restoration.
3A is a plan view showing an original plate of a wooden dowel according to the present invention, and FIG. 3B is a side view.
4A is a plan view for explaining a cutting line of the original plate in FIG. 3, and FIG. 4B is a side view.
FIG. 5 is a partial cross-sectional plan view for explaining a pull-out test of a block body according to the present invention.
6A is a front view of a main part for explaining a joint tensile test in a direction orthogonal to a wood fiber, and FIG. 6B is a plan view.
FIG. 7A is a front view showing a wooden dowel having a W-shaped reverse eye consolidation portion, FIG. 7B is a front view showing a wooden dowel having a cross-shaped reverse eye consolidation portion, and FIG. It is a front view which shows the wooden dowel which has an arc-shaped reverse eye consolidation part.
FIG. 8 is a front view showing a conventional wooden dowel.
[Explanation of symbols]
1 Wood dowels
1A Taper part 2 Reverse eye consolidation part 4 Original plate (plate material)
5 groove 6 ridge (protrusion)
7A Block body (members to be joined)
7B Block body (members to be joined)
8A Dowel hole 8B Dowel hole 10 Block body clamp 11 Dowel clamp 13 Clamp 14 Clamp 16 W-shaped reverse eye compaction portion 17 Re-shaped reverse eye consolidation portion 18 Arc-shaped reverse eye consolidation portion C Cutting line

Claims (3)

The surface has a plurality of reverse-eye compacted portions that deform into a convex shape by moisture after being driven into the dowel hole, and the compacted portions are formed by pressing the convex portions provided on the surface. Tree dowels. A method for producing a wooden dowel, comprising: forming a protrusion on a surface of an original plate, and then uniformly forming the surface of the original plate by pressing, and cutting and manufacturing a wooden dowel of a predetermined width from the formed original plate. A method for joining members to be joined made of wood or similar materials using the wood dowels according to claim 1, wherein the reverse-consolidated portion is deformed into a convex shape by hydrous expansion after joining. Joining method using wood dowels characterized by

Images