JP2001198906A - Dowel for jointing and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dowel for joining wherein not only a simple jointing structure can be realized, but also joining strength is excellent and cross section fracture also can be decreased. SOLUTION: A joining dowel 1 for joining woods 11 and 12 by respectively inserting or force fitting both ends into dowel holes 15 and 16 formed on respective joining faces 13 and 14 of a pair of woods 11 and 12 to be joined mutually, is formed of compacted wood 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dowel for joining a pair of articles to be joined, and a method for manufacturing the same.

[0002]

2. Description of the Related Art In general, as a joint structure between woods, a structure in which joints and joints are formed or joints such as nails and bolts are used are well known. A joint / joint joint structure is one in which a projection called a tenon is formed on one of the members to be joined, and the tenon is inserted into a tenon hole formed on the other member to join the two members together. is there. Such a joint structure has been frequently used in a wooden building since ancient times, and a joint is formed only of wood without using a joint fitting.

[0003]

However, the conventional joining structure described above has the following problems. That is, in the joint structure in which the joint / joint processing is performed, the tenon portion is dried over time after the joining, and the moisture content is initially about 20% to 30% but about 12% to 13%. Due to the decrease in the water content, there is a problem that the tenon portion shrinks, the joint portion is loosened, and the joining strength is reduced. When performing joint and joint processing, it is necessary to consider such a decrease in moisture content, but the processing technology is required to be extremely advanced, and it is difficult to perform it easily unless it is a skilled carpenter could not. For this reason, there has been a demand for a simple and high bonding strength bonding structure that does not require advanced processing techniques. Also, it has been pointed out that if many mortises are used in one place, the cross-sectional defect at that part becomes large, thereby reducing the strength of the wood itself having the mortise.

[0004] On the other hand, a joining structure using a joining fitting has the advantage that a simple joining structure can be realized without the need for advanced machining techniques such as the above-described joint and connection machining.
However, for example, when a bolt is used, there has been a problem that, as time elapses, the resistance of a portion tightened by the bolt decreases due to a creep phenomenon (stress relaxation), and the bonding strength decreases. Further, in the case of this joint fitting, there is also a problem of rust when using iron as a material.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a joining dowel which not only can realize a simple joining structure but also has excellent joining strength and can reduce cross-sectional defects. One of its purposes.
Another object of the second invention is to provide a method of manufacturing the joining dowel which can easily produce the joining dowel.

[0006]

In order to solve the above-mentioned problems, according to the first aspect of the present invention, a dowel formed of consolidated wood and formed on each joint surface of a pair of articles to be joined to each other is formed. The gist of the invention is a joining dowel in which both ends are respectively inserted or press-fitted into the holes and the two articles are joined at a joining surface.

Accordingly, by joining a pair of articles using the joining dowel of the present invention, the joining structure is
Since it is only necessary to insert or press-fit both ends of the joining dowels into the dowel holes formed in the joining surfaces of the two articles to be joined, it becomes simple. Further, since the joining dowel is formed of compacted wood, the mechanical strength is higher than that of the joining dowel using ordinary wood or simply compressed wood. Therefore, the bonding strength is also excellent. Further, since the mechanical strength is increased, a high strength can be obtained even if the cross section substantially perpendicular to the longitudinal direction is reduced, and therefore, it is possible to reduce cross-sectional defects at the joint. Therefore, according to the present invention, not only a simple joining structure can be realized, but also a joining dowel can be obtained which has excellent joining strength and can reduce cross-sectional defects.

According to the second aspect of the present invention, in the joining dowel according to the first aspect, when the dowel is inserted or press-fitted into the dowel hole via an adhesive, moisture of the adhesive is removed in the dowel hole. The gist is that it absorbs and expands.

According to the present invention, when the joining dowel is inserted or press-fitted into the dowel hole via the adhesive to join the pair of workpieces, the joining dowel absorbs the moisture of the adhesive in the dowel hole. Then, the wall surface forming the dowel hole is pressed by the joining dowel. For this reason, there is no backlash between the joining dowel and the wall surface of the dowel hole, and the joining strength, that is, the strength against pull-out can be further increased. Further, since the joining dowel expands in the dowel hole, even if the machining accuracy of the dowel hole is somewhat poor, the poor machining accuracy is absorbed by the expansion of the joining dowel. For this reason, even if processing accuracy of a dowel hole is bad, joining strength can be raised certainly.

According to the third aspect of the present invention, in the joining dowel according to the first or second aspect, a plurality of layers of consolidated wood are provided, and a layer structure including a plurality of layers appears in a cross section orthogonal to the longitudinal direction. The gist is that it was formed.

In general, in the process of growing wood, wood fibers do not always grow in a certain specific direction but grow in various ways in response to changes in the surrounding environment and the like. Due to such properties of the wood itself, the direction in which the wood fibers extend is different for each piece of compacted wood, and it is rare that the wood fibers are exactly the same. For this reason,
When a plurality of layers are formed from a plurality of compacted pieces of wood, the directions in which the wood fibers extend are crossed as a whole. As a result, the joining dowel of the present invention in which a plurality of layers of consolidation wood are used to form a plurality of layers is less likely to be split than a case where the entirety is formed of one piece of consolidation wood, thereby further increasing mechanical strength. I have. As a result, if a pair of articles is joined using the joining dowels, cross-sectional defects can be further reduced.

[0012] In the invention described in claim 4, in the joining dowel according to claim 3, the compression direction in the consolidation processing of the consolidation wood of each layer constituting the plurality of layers with the adjacent consolidation wood is substantially the same. The point is that they are orthogonal to each other.

According to the present invention, when the dowel for joining is inserted or press-fitted into the dowel hole to join a pair of objects to be joined, the dowel for joining is used when the adhesive is interposed therebetween. When the object to be joined is wood even without the use of an adhesive, it absorbs water in the wood and expands. At this time, since each compacted wood has its compression direction in the consolidation process substantially orthogonal to the adjacent compacted wood, it is surely expanded in two substantially orthogonal specific directions, and the expansion direction is in one specific direction side. There is no bias. For this reason, the location where the wall surface forming the dowel hole is pressed by the joining dowel is not biased. Therefore, the joining strength, that is, the strength against pulling out can be reliably improved.

Further, since the compression direction of the consolidation treatment is made substantially orthogonal between the adjacent layers, the expansion direction is different from the case where the joining dowel is manufactured without specifying the compression direction. However, it is specified in a direction that is substantially orthogonal.
As a result, the joining dowels can be made uniform as a product.

According to the fifth aspect of the present invention, there is provided a joining dowel for bonding a plurality of compacted wood pieces in a plate shape, and then forming an overall shape such that a layer structure composed of a plurality of layers appears in a cross section orthogonal to the longitudinal direction. The gist is the manufacturing method. ADVANTAGE OF THE INVENTION According to this invention, it is excellent in the joining strength at the time of joining a pair of to-be-joined objects, and also can manufacture easily the dowel for joining with few cross-sectional defects.

According to a sixth aspect of the present invention, in the method for manufacturing a joining dowel according to the fifth aspect, adjacent compacted wood pieces are bonded so that the compression directions in the compaction treatment are substantially orthogonal. ADVANTAGE OF THE INVENTION According to this invention, the more excellent joining strength can be implement | achieved, and moreover, the uniform dowel for joining can be easily manufactured as a product.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment will be described below with reference to FIGS. FIG. 1 shows a dowel 1 for joining. The joining dowel 1 is formed entirely of consolidated wood 2. The compacted wood 2 is wood obtained by subjecting ordinary wood to compaction processing. Consolidation treatment is a process in which wood is impregnated with water, irradiated with high-frequency waves (microwaves) to soften the wood, and then the tissue structure is densified by a hot press without destroying the cell structure of the wood fibers. This is a process of compression-molding so as to obtain and drying in the compressed state. In this consolidation treatment, it is possible to adjust the moisture content after molding and drying. For this reason, the consolidated wood 2
Already, the moisture content of the aged wood (12-13)
%) Or lower.

This consolidated wood 2 has several features. That is, first of all, because it is compression molded, the mechanical strength is higher than that of ordinary wood.
In addition, since the compression molding is performed by the above-described consolidation treatment, the wood fibers are not broken as in the case of the wood simply compressed and formed by the pressure treatment, and the mechanical strength is further enhanced. . Also, unlike wood in which wood fibers are broken simply because the wood is simply compression molded by pressure treatment, it expands in the direction opposite to the compression direction in the compaction treatment by absorbing moisture. It also has features.

In addition, the direction in which the wood fibers extend is usually different for each piece of the compacted wood 2 due to the properties of the wood from which it is formed, and it is rare that the wood fibers are the same. This is because in the growth process of wood, wood fibers do not grow evenly in one specific direction but grow in various ways due to changes in the surrounding environment and the like.

The joining dowel 1 is formed of such compacted wood 2 into a substantially columnar shape (having a substantially circular cross section and an equal cross section along the longitudinal direction). Further, the joining dowel 1 is formed by integrally laminating consolidated wood 2 in a direction orthogonal to the longitudinal direction, and has a layer structure composed of a plurality of layers (three layers in the present embodiment). . That is,
The plurality of layers are formed over the entire length of the joining dowel 1 in the longitudinal direction, and appear on the outer peripheral surface 3 and the side surface (end face) 4 orthogonal to the longitudinal direction of the joining dowel 1. Then, on the side surface (end surface) 4, each layer is substantially equally divided by the dividing line 5 in the laminating direction of the consolidated wood 2.

In the case of manufacturing the dowel 1 for joining, the compacted wood 2 subjected to the compaction treatment is formed into a flat plate of the same shape, and a plurality of the compacted woods 2 are formed on a wide flat surface 6 (this embodiment). Then three). In the present embodiment, each compacted wood 2 has the same thickness (length in the stacking direction). Note that a plurality of compacted wood pieces 2 formed into the same flat plate shape by the compacting process may be bonded. Then, a layered wood 7 having a square cross section as shown by a solid line in FIG. 2 is formed. Thereafter, the periphery of the layered timber 7 is removed so that the side surface 8 on which the plurality of layers appear becomes a substantially circular end face, and a substantially columnar joining shape is formed as an overall shape as indicated by a two-dot chain line. A dowel 1 is formed. As a result, the joining dowel 1 is formed such that a layer structure composed of a plurality of layers appears in a cross section orthogonal to the longitudinal direction.

Here, attention will be paid to the direction in which the wood fibers of each compacted wood 2 in the layered wood 7 extend. In order to illustrate the direction in which the wood fibers extend, FIG.
Is shown for each consolidation wood 2, and FIG. 4 shows a state in which the layered wood 7 is viewed from the direction of the arrow A parallel to the lamination direction of the consolidation wood 2. In FIG. 4, the wood fibers appearing on the surface are shown by solid lines, and the wood fibers of the consolidated wood 2 which is one back are shown by dotted lines.

As shown in FIG. 3 and FIG.
Is in a state where the respective wood fibers are intersected with the wood fibers of the other consolidated wood 2. That is, the layered wood 7 is in a state where the directions in which the wood fibers extend as a whole intersect. There is a problem that a single piece of compacted wood 2 is split at the wood fiber boundary. However, such a problem can be solved by having a layered structure including a plurality of layers like the layered wood 7. That is, it is difficult to split and the mechanical strength is increased. The dowel 1 for joining is manufactured based on such a layered wood 7. Therefore,
The joining dowel 1 having a layer structure composed of a plurality of layers has a higher mechanical strength than a case where the joining dowel 1 is made of one consolidated wood as a whole.

The state of the wood fiber shown in FIGS. 3 and 4 is merely an example for convenience of explanation, and the state in which the wood fiber extends in a direction other than the directions shown in FIGS. Exist.

In the above-described manufacturing process of the dowel 1 for joining, when a plurality of compacted woods 2 are to be bonded, the adjacent compacted woods 2 are bonded so that the compression directions in the compaction process are substantially orthogonal. Thereby, the joining dowel 1 having a property different from that obtained by simply bonding a plurality of sheets is formed. This is "consolidated wood"
Utilizes the property that when expanded by absorbing moisture, it expands in the direction opposite to the compression direction in the consolidation process.

That is, the consolidated wood 2 of each layer constituting the plurality of layers
However, the dowels (hereinafter, referred to as joining dowels) formed so that the compression directions in the compaction treatment of the adjacent compacted wood 2 are substantially orthogonal.
This is referred to as a second joining dowel 9. It should be noted that the term “joining dowel 1” simply includes the second joining dowel 9. )
Has the property that, upon absorbing moisture, each compacted wood 2 expands in a direction substantially orthogonal to each other. For this reason, the second joining dowels 9 are substantially orthogonal to each other when they absorb moisture.
It expands in one specific direction, and the expansion direction is not biased.

Next, a description will be given of a joining structure for joining a pair of wood pieces (objects to be joined) having a square cross section by using such a joining dowel 1. FIG. 5 shows the first wood 1
1 shows a state in which the first and second timbers 12 are joined together at mutually facing parallel joining surfaces (joining portions) 13 and 14. The first wood 11 has a first dowel hole 15 formed on its joint surface 13, and the second wood 12 has a second dowel hole 16 formed on its joint surface 14. These dowel holes 1
Reference numerals 5 and 16 are formed to have substantially the same cross-sectional shape as the joining dowel 1 along a direction substantially perpendicular to the joining surfaces 13 and 14, respectively. When the first wood 11 and the second wood 12 are joined, the depths of the dowel holes 15 and 16 are set so that the joining surfaces 13 and 14 of both the woods 11 and 12 are joined almost entirely. The dowel holes 15 and 16 are formed so that the combined length of the dowel holes 15 and 16 is slightly longer than at least the longitudinal length of the joining dowel 1. In the present embodiment, the first dowel hole 15 and the second dowel hole 16 are formed so that their depths are substantially the same.

The first lumber 11 and the second lumber 12 are inserted or press-fitted into the first dowel hole 15 or the second dowel hole 16 at both ends of the dowel 1 for joining.
The joining surfaces 13 and 14 are joined together. An adhesive containing moisture is used for joining the dowel 1 for joining to the dowel holes 15 and 16, and the dowel 1 for joining is bonded and fixed in the dowel holes 15 and 16.

Then, the dowel 1 for bonding gradually expands by absorbing the moisture of the adhesive and the moisture in the woods 11 and 12. Thereby, the dowel 1 for joining presses the wall surface which forms the dowel holes 15 and 16 of the 1st wood 11 and the 2nd wood 12, and the 1st wood 11
Wood 11 and the second wood 12 have their joint surfaces 13, 14
Will be held in a joined state. In this state, since the joining dowel 1 expands and presses the wall surface forming the dowel holes 15 and 16, play occurs between the joining dowel 1 and the wall surfaces of the dowel holes 15 and 16. Therefore, the first wood 11 and the second wood 12 are securely joined.

In particular, when the second joining dowel 9 is used as the joining dowel 1, the second joining dowel 9 expands in two specific directions which are substantially perpendicular to each other, so that the dowel holes 15 and 16 are formed. The location where the wall surface is pressed is not biased. Therefore, the first wood 11 and the second wood 12 are more reliably joined.

According to the joining dowel 1 described above, the following operation and effect can be obtained. (1) Using the dowel 1 for joining, a pair of woods 11 and 12
By joining the two, the joint structure, both wood 11,
Dowel holes 15, 16 formed in the joint surfaces 13, 14
Only by inserting or press-fitting both ends of the joining dowel 1 respectively. Further, since the joining dowel 1 is formed of the consolidated wood 2, the mechanical strength is increased and the joining strength is excellent. Further, since the mechanical strength is increased, a high strength can be obtained even if the cross section substantially perpendicular to the longitudinal direction is reduced, so that the cross-sectional defect at the joint can be reduced.

(2) The dowel 1 for joining is inserted or press-fitted into the dowel holes 15 and 16 via an adhesive, and a pair of woods 11 and
When the dowels 12 are joined, the dowels 1 for joining expand in the dowel holes 15 and 16 by absorbing the adhesive or moisture in the wood. As a result, the walls forming the dowel holes 15 and 16 are pressed by the joining dowel 1. Therefore, the joining dowel 1 and the dowel hole 1
There is no play between the wall surfaces 5 and 16, and the joining strength, that is, the strength against pulling out can be further increased.

(3) Since the dowel 1 for joining absorbs the adhesive or the moisture in the wood and expands in the dowel holes 15 and 16,
Even if the machining accuracy of the dowel holes 15 and 16 is somewhat poor, the poor machining accuracy is absorbed by the expansion of the joining dowel 1. For this reason, even if the processing accuracy of the dowel holes 15 and 16 is poor, the joining strength can be reliably increased. Further, since precision is not required for machining the dowel holes 15 and 16, it is possible to contribute to a reduction in manufacturing cost of a workpiece using the joining dowel 1.

(4) Since the joining dowel 1 has a plurality of layers made of a plurality of pieces of compacted wood, it is less likely to be split than a single piece composed of one piece of compacted wood as a whole. Strength is further enhanced. Therefore, if the pair of woods 11 and 12 are joined using such a joining dowel 1, cross-sectional defects can be further reduced.

(5) When the second joining dowel 9 expands, it is formed by bonding a plurality of compacted woods 2 so that the compression directions in the compacting process are substantially perpendicular to each other. The expansion is reliably performed in two specific directions, and the expansion direction is not biased toward one specific direction. Therefore, dowel hole 1
The places where the wall surfaces forming 5 and 16 are pressed by the second joining dowels 9 are not biased. Therefore, the joining strength, that is, the strength against pulling out can be reliably improved.

(6) Since the compression direction of the consolidation process of the second bonding dowel 9 is set to be substantially orthogonal between the adjacent layers, the bonding dowel is manufactured without specifying the compression direction. Unlike this, the expansion direction is specified in a direction that is substantially orthogonal without being dispersed. As a result, the second joining dowel 9 can be made uniform as a product.

(7) The dowel 1 for joining is made by bonding a plurality of flat compacted wood pieces on a wide plane 6 so that a layer structure composed of a plurality of layers appears on a side face (end face) 4 orthogonal to the longitudinal direction. Manufactured by forming the overall shape.
Further, the second joining dowel 9 is manufactured by adhering adjacent compacted woods so that the compression directions in the compacting process are substantially orthogonal. Therefore, the joining dowel 1 and the second joining dowel 9 can be easily manufactured.

This embodiment can be modified, for example, as follows. The cross-sectional shape of the joining dowel 1 may be a predetermined cross-sectional shape such as an elliptical cross-sectional shape or a square cross-sectional shape. That is, the entire shape of the joining dowel 1 may be a substantially long columnar shape, a substantially prismatic shape, or the like.

The pair of articles to be joined using the joining dowels 1 may be bar-shaped wood having a circular cross section, flat wood, or the like. Further, the pair of articles to be joined may not be pieces having the same shape. For example, a bar-shaped piece of wood having a square cross section and a piece of wood having a flat shape may be joined.

If the pair of objects to be joined using the joining dowel 1 uses an adhesive, the joining dowel 1 expands by absorbing the water content of the adhesive, and therefore does not need to be made of wood. For example, it may be made of metal, plastic, concrete or the like.

If a pair of objects to be joined using the joining dowel 1 is wood, an adhesive may not be used at the time of joining. This is because the joining dowel 1 can expand by absorbing moisture in wood. However, it is preferable to use an adhesive even for wood.

The joining dowels may be made of a single piece of consolidated wood, instead of a plurality of pieces of consolidated wood. Also in this joining dowel, since the mechanical strength is increased as compared with ordinary wood or compressed wood, cross-sectional defects can be reduced.

A plurality of compacted wood pieces which are formed in a predetermined shape according to the entire shape of the joining dowel 1 in advance are prepared and bonded to produce a joining dowel having an overall shape such as a substantially columnar shape. You may.

In the manufacturing process of the joining dowel 1, a plurality of flat compacted wood pieces having different thicknesses may be bonded to each other. The number of the flat compacted wood pieces 2 to be bonded may be two or four or more.

In forming the layered timber 7 having a square cross section as shown in FIG. 2, instead of simply bonding a plurality of flat-plated timbers 2 together, a plurality of the timbers are compacted by a fitting relationship. A plurality of layers may be formed in combination.

When the dowel 1 for joining is inserted or press-fitted into the dowel holes 15 and 16, the direction of the dividing line 5 is not limited to the state shown in FIG. 5, but is rotated by a predetermined angle about the central axis from the state shown in FIG. It may be in a state.

Next, technical ideas other than the claims that can be grasped from the above embodiments will be described together with their effects. -The joining dowel according to claim 1 or 2, wherein a layer structure composed of a plurality of layers is formed by a plurality of consolidated woods, and the layer structure is formed such that a dividing line that partitions each layer is formed along the longitudinal direction on the outer peripheral surface. . According to this configuration, the same operation and effect as the invention described in claim 3 can be obtained.

[0048]

As described above in detail, according to the joining dowel of the present invention, not only can a simple joining structure be realized,
Excellent bonding strength and reduced cross-sectional defects.
Further, according to the method for manufacturing a dowel for joining of the second invention, the dowel for joining can be easily produced.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a joining dowel of the present embodiment.

FIG. 2 is a perspective view showing a state in which plate-shaped compacted timber is attached.

FIG. 3 is an exploded perspective view of a layered timber.

FIG. 4 is a plan view of the layered timber from the direction of arrow A.

FIG. 5 is a perspective view showing a state in which a pair of wood pieces are joined using the joining dowels.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Dowel for joining, 2 ... Consolidated wood, 11 ... 1st wood (object to be joined), 12 ... 2nd wood (object to be joined), 13, 14
... joining surface (joining portion), 15 ... first dowel hole, 16 ... second
Dowel hole.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) F16B 13/00 F16B 13/00 F-term (Reference) 2B250 AA40 BA01 CA07 DA04 EA02 EA13 FA03 FA21 FA31 FA37 GA05 HA01 3J023 EA01 FA02 GA03 3J024 AA47 BB03 CA14 3J025 AA03 CA03 3J039 AA08 BB03 FA12 LA02

Claims (6)

[Claims] 1. Both ends are respectively inserted or press-fitted into dowel holes formed at respective joints of a pair of articles to be joined formed of consolidated wood and joined to each other to join the two articles at the joints. Dowel for joining. 2. The joining dowel according to claim 1, wherein when inserted or press-fitted into the dowel hole via an adhesive, the dowel for bonding absorbs moisture of the adhesive in the dowel hole and expands. 3. The dowel for joining according to claim 1, wherein the dowel is made of a plurality of pieces of consolidated wood, and formed so that a layer structure composed of a plurality of layers appears in a cross section orthogonal to the longitudinal direction. 4. The dowel for joining according to claim 3, wherein the compressed wood in each of the layers constituting the plurality of layers has a compression direction substantially orthogonal to that of an adjacent compacted wood. 5. A method for manufacturing a dowel for joining, comprising bonding a plurality of plate-shaped compacted wood pieces and then forming an overall shape such that a layer structure composed of a plurality of layers appears in a cross section orthogonal to the longitudinal direction. 6. The method for manufacturing a dowel for joining according to claim 5, wherein adjacent compacted wood pieces are bonded so that compression directions in the compaction treatment are substantially orthogonal.