Timber connecting structure

Abstract

To provide a timber connecting structure capable of increasing connection strength by bringing end surfaces of a pair of timbers into close contact with each other even in a simple structure.SOLUTION: A timber connection structure has a structure in which end parts of one timber 1 and the other timber 2 abut on each other to connect. Extension parts 1a and 2a are formed at the end parts, abutting protrusion parts are formed at tip ends of the extension parts, and abutting recessed parts to which the abutting protrusion parts are fitted to abut are formed at base ends of the extension parts. Dowel holes 1d for inserting a dowel 3 are formed in the extension parts 1a and 2a in a plate thickness direction. The dowel holes 1d are formed at positions where, in a state that the dowel 3 is inserted into the dowel hole 1d of one timber 1, the dowel hole of the other timber 2 is deviated toward the abutting recessed part side. The abutting protrusion parts are displaced in a direction of the abutting recessed part and are pressed to each other so that centers of the dowel holes 1d coincide with each other when the dowel 3 is inserted into the dowel holes 1d of one timber 1 and the other timber 2.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a wooden piece connecting structure that connects a pair of wooden pieces by abutting their ends together. [Background technology]

[0002] When a longer piece of lumber is required than is commercially available as a standard, or when a piece of lumber of the required length needs to be obtained from multiple pieces of existing lumber, the multiple pieces of lumber have traditionally been joined together.

[0003] Various techniques for joining wooden pieces have been known for some time. For example, Japanese Patent No. 3011692 (Patent Document 1) discloses a method for joining the ends of a pair of wooden pieces by abutting them together, in which both ends of a wooden dowel are inserted into connecting holes in the wooden pieces to be joined, and the wooden pieces are joined via the dowel. Japanese Patent Laid-Open Publication No. 2003-227182 (Patent Document 2) also discloses a method for joining a pair of wooden pieces by forming slits in the ends of the pair of wooden pieces, inserting a steel plate into the slit, and then inserting a joint bolt into through holes formed in the wooden pieces and the steel plate and fastening them together with a joint nut. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 3011692 [Patent Document 2] Japanese Patent Application Laid-Open No. 2003-227182 Summary of the Invention [Problem to be solved by the invention]

[0005] The wooden piece connecting structure shown in the aforementioned Patent Document 1 (Japanese Patent No. 3011692) involves inserting a dowel into a connecting hole formed in the longitudinal direction of each end face of a pair of wooden pieces, and then expanding the dowel with an adhesive absorbed into the dowel, causing it to adhere tightly to the inner surface of the connecting hole and connect with the adhesive. The connecting structure disclosed in Patent Document 1 connects the wooden pieces only with dowels inserted in the longitudinal direction of the wooden pieces, resulting in low tensile strength in the longitudinal direction. Furthermore, when the pair of wooden pieces is bent, the load on the small diameter dowel becomes too great, leading to breakage. Furthermore, it takes a long time for the adhesive absorbed into the dowel to dry and harden, which reduces workability.

[0006] On the other hand, the wooden piece connecting structure shown in Patent Document 2 (JP Patent Publication No. 2003-227182) involves inserting a steel plate into a slit formed at the end of a pair of wooden pieces and connecting them with a bolt and nut. Using a steel plate, bolt, and nut in this way increases costs, and the bolt and nut must be fastened, resulting in poor workability. Furthermore, if there is an error between the positions of the insertion holes formed in the wooden piece's slit and the steel plate, a gap will form between both end faces of the pair of wooden pieces.

[0007] The problem that the present invention aims to solve is to provide a wooden joint structure that can increase the joint strength by bringing the end faces of a pair of wooden pieces into close contact with each other, even though it has a simple structure. [Means for solving the problem]

[0008] Therefore, the connecting structure for wood according to the present invention is a connecting structure that connects the ends of one piece of wood and the other piece of wood by abutting them together, wherein an extension portion is formed on the end, an abutting protrusion is formed at the tip of the extension portion, and an abutting recess is formed at the base end into which the abutting protrusion is fitted and abuts, and the extension portion has a dowel hole formed in the thickness direction of the board for inserting a dowel, and the dowel hole is formed in a position that is offset toward the abutting recess when the dowel is inserted into the dowel hole of the one piece of wood, and when the dowel is inserted into the dowel holes of the one piece of wood and the other piece of wood, the abutting protrusion is displaced toward the abutting recess so that the centers of the dowel holes coincide, and they are pressed against each other.

[0009] Furthermore, it is desirable that the extension portions of the one piece of wood and the other piece of wood are formed in the same shape, that the inner surfaces of the extension portions are formed flat, and that the thickness of the extension portions is formed to be half the thickness of the wood.

[0010] Furthermore, the contact protrusion and the contact recess of the extension are formed in an angular or semicircular shape and fitted together to prevent displacement in the thickness direction when they are brought into contact with each other. [Effects of the Invention]

[0011] According to the present invention, extensions are formed on the ends of one piece of wood and the other piece of wood, abutment protrusions are formed at the tips of the extensions, and abutment recesses are formed at the base ends into which the abutment protrusions are fitted and abutted. Dowel holes are formed in the extensions, respectively, for inserting dowels. The dowel holes are positioned so that, when a dowel is inserted into the dowel hole of one piece of wood, the dowel hole of the other piece of wood is offset toward the abutment recess. When the dowel is inserted into the dowel hole of the one piece of wood and the dowel hole of the other piece of wood, the abutment protrusions are displaced toward the abutment recesses so that the centers of the dowel holes align. This causes the abutment protrusions and the abutment recesses to press against each other and form a tight fit. This results in a strong connection between the ends of the one piece of wood and the other piece of wood. Furthermore, because the abutment protrusions and the abutment recesses are pressed against each other and form a tight fit, the connection strength is increased and gaps are less likely to form when the pieces are connected. Furthermore, the two pieces of wood can be connected by the simple process of inserting a dowel while the extensions of the two pieces of wood are abutting each other, thereby improving workability.

[0012] In particular, when fixing the ends together with adhesive, the dowels are inserted to press the two pieces together in the longitudinal direction, and the dowels are also used to connect the pieces in the thickness direction, allowing for temporary fixing while the adhesive hardens. This eliminates the need for temporary fixing using clamps, which is normally required during adhesive work, making the adhesive work easier. Furthermore, the extensions formed on the ends of one piece of wood and the other piece of wood are simply constructed, so they can be easily and quickly manufactured using well-known, simple methods, reducing costs.

[0013] Furthermore, by forming the extension portions of one piece of wood and the other piece of wood in the same shape, the extension portions of each piece of wood can be manufactured using the same process. Furthermore, by forming the inner surfaces of the extension portions flat, the inner surfaces of the extension portions are joined over a wide area when connected, allowing for a strong connection. In particular, the wide flat portion of the inner surfaces allows for a strong bond due to the wide bonding area. Furthermore, by forming the thickness of the extension portion to be half the thickness of the wood, the thickness of both pieces of wood becomes the same when the extension portions of one piece of wood and the other piece of wood are joined together, making it possible to form a long piece of wood with a very small joint.

[0014] Furthermore, by forming the abutment protrusion and abutment recess of the extension portion into an angular or semicircular shape, the abutment protrusion and abutment recess are fitted closely together, so that even if an attempt is made to bend a pair of connected pieces of wood in the thickness direction, the abutment protrusion and abutment recess will not displace, preventing bending of the wood in the thickness direction. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a perspective view showing a wooden joint structure according to the present invention; [Figure 2] FIG. 10 is a cross-sectional view showing extensions formed at the ends of a pair of wooden pieces. [Figure 3] 10 is a cross-sectional view showing dowel holes formed in the extensions of a pair of wooden pieces, into which dowels are inserted. FIG. [Figure 4] FIG. 10 is a plan view showing the positional relationship of dowel holes into which dowels are inserted. [Figure 5] 10(A), (B), and (C) are explanatory views showing the process of connecting wooden pieces. [Figure 6] Dowel hole for inserting the dowel [Figure 7] 10A and 10B are cross-sectional views showing modified examples of abutment protrusions and abutment recesses formed on the ends of a pair of wooden pieces. [Figure 8] FIG. 10 is a cross-sectional view showing a state in which wooden boards of different thicknesses are connected together. [Figure 9] FIG. 10 is a perspective view showing a state in which a plurality of pieces of wood are connected together. [Figure 10]10(A) and 10(B) are perspective views showing an example in which a plurality of connected wooden pieces are connected in the width direction. [Figure 11] 10A, 10B, and 10C are explanatory diagrams showing an example of connecting connected wooden pieces in the width direction. DETAILED DESCRIPTION OF THE INVENTION

[0016] The wooden piece connecting structure according to the present invention is a connecting structure that connects the ends of one wooden piece and another wooden piece by abutting them together, wherein an extension portion is formed on the end portion, an abutting protrusion is formed at the tip of the extension portion, and an abutting recess is formed at the base end into which the abutting protrusion is fitted and abuts, and a dowel hole for inserting a dowel is formed in the extension portion in the thickness direction of the board, and when the dowel is inserted into the dowel hole of the one wooden piece, the dowel hole of the other wooden piece is formed in a position that is biased toward the abutting recess, and when the dowel is inserted into the dowel holes of the one wooden piece and the other wooden piece, the abutting protrusion is displaced toward the abutting recess so that the centers of the dowel holes coincide, and they are pressed against each other.

[0017] An embodiment of a wooden piece connecting structure according to the present invention will be described in detail below with reference to the drawings. FIG. 1 shows a state in which the ends of one wooden piece and another wooden piece are abutted and connected. As shown in FIG. 2, one wooden piece 1 and another wooden piece 2 each have an extension 1a, 2a formed at their end. Abutment protrusions 1b, 2b are formed at the tip of each of these extensions 1a, 2a, and abutment recesses 1c, 2c are formed at the base end. Furthermore, dowel holes 1d, 2d are formed approximately at the center of each of the extensions 1a, 2a, penetrating the board thickness direction. Furthermore, the inner surfaces 1e, 2e of each extension 1a, 2a are formed flat.

[0018] The first piece of wood 1 and the second piece of wood 2 are common pieces of wood used in houses, furniture, etc. Preferably, the first piece of wood 1 and the second piece of wood 2 are rectangular columnar scraps that are left over when manufacturing houses or furniture. By forming extensions 1a, 2a at the ends of short scraps, long pieces of wood of the desired length can be obtained. The first piece of wood 1 and the second piece of wood 2 are connected by abutting their respective ends, as shown in FIG. 1 . The extensions 1a, 2a and 1d, 2d formed at the ends of the first piece of wood 1 and the second piece of wood 2 have the same shape.

[0019] It is desirable that the thickness of the extensions 1a, 2a formed at each end be half the thickness of the one piece of wood 1 and the other piece of wood 2. When the ends of the one piece of wood 1 and the other piece of wood 2 are abutted together and the inner surfaces 2c of the extensions 1a, 2a are joined together, even if the extensions 1a, 2a have half the thickness, they will have the same thickness as the one piece of wood 1 and the other piece of wood 2, forming a single long piece of wood.

[0020] Furthermore, the abutment protrusions 2a formed at the tips of the extensions 1a, 2a and the abutment recesses 2b formed at the base ends are formed to have the same shape, and when the ends of one piece of wood 1 and the other piece of wood 2 are abutted and connected, the abutment protrusions 2a fit tightly into the abutment recesses 2b with no gaps, resulting in a strong connection. As shown in the figure, the abutment protrusions 2a have a triangular cross section with an acute angle and protrude so that the inner surface of the extensions 1a, 2a is longer. On the other hand, the abutment recesses 2b are recessed into the corners of a triangle with an acute interior angle, as shown in the figure, to fit the abutment protrusions 2a.

[0021] As shown in the circle in Fig. 2, the contact protrusion 2a has a notch 2f formed at its tip. Similarly, the contact protrusion 1a also has a notch 1f formed at its tip. When the contact protrusion 2a abuts against the contact recess 2b, which has a triangular shape with an acute interior angle, a gap is formed at the innermost part of the contact recess 2b by the notch 2f of the contact protrusion 2a. This gap can be used as a reservoir 13 for storing adhesive when bonding the contact protrusion 2b and the contact recess 1b with wood adhesive. The cutouts 1f and 2f are unnecessary if no adhesive is used.

[0022] A wooden dowel 3, which will be described later, is inserted in a press-fit state into the dowel holes 1d, 2d formed in the extension portions 1a, 2a of the first wooden piece 1 and the second wooden piece 2. When the dowel 3 is cylindrical, the dowel holes 1d, 2d are circular. As shown in FIGS. 3 and 4, the dowel holes 1d, 2d are formed so that, with the dowel 3 inserted into the extension portion 1a of the first wooden piece 1, the dowel hole 2d of the second wooden piece 2 is slightly offset toward the abutment recess 2b. That is, the center CU of the dowel hole 1d of the first wooden piece 1 is offset slightly to the right in the figure with respect to the center CU of the dowel hole 1d of the first wooden piece 1. The offset distance G is set appropriately depending on the size of the first wooden piece 1 and the second wooden piece 2 and the size of the dowel 3, but is preferably approximately 0.2 to 1 mm.

[0023] FIG. 5 shows the process from processing one piece of wood 1 to the other piece of wood 2 until they are connected. First, an extension 1a is machined at the end of one piece of wood 1. The abutment protrusion 1a and abutment recess 1b formed in the extension 1a are machined using, for example, a groove cutting cutter 4 for joinery processing, as shown in FIG. 5(A). This processing can also be performed using or in combination with a tenon cutting machine or saw commonly used for wood processing. Using such a woodworking machine also makes it easier to process the extension 1a. Furthermore, the aforementioned dowel hole 1d is formed at a predetermined position approximately in the center of the extension 1a using a woodworking machine such as a drill press or router.

[0024] In the above-described embodiment, the dowel hole 1d is formed at approximately the center of the extension portion 1a. By forming the dowel hole 1d at approximately the center in this manner, the extension portions 1a and 2a of the one piece of wood 1 and the other piece of wood 2 can be machined and the dowel holes 1d and 2d can be machined to the same shape, thereby improving processing efficiency.

[0025] The pieces of wood 1 and 2 thus produced are arranged with the extension 1a of one piece of wood 1 facing upward and the extension 2a of the other piece of wood 2 facing downward, as shown in Figure 5(B), and are brought closer together in the direction of the arrows, so that the abutting protrusions 1b and 2b and the abutting recesses 1c and 2c of the one piece of wood 1 and the other piece of wood 2 abut against each other, as shown in Figure 5(C).

[0026] When the dowel 3 is then pressed into the dowel hole 1d of one piece of wood 1 from above, the dowel 3 stops at the upper end because the dowel hole 2d of the other piece of wood 2 is offset. When the dowel 3 is further inserted into the dowel hole 2d of the other piece of wood 2, the dowel 3 displaces the other piece of wood 2 to the left in the figure so that the centers of the two dowel holes 1d and 2d are aligned, as shown by the arrow in Figure 5(C), and the abutment protrusion 2b of the other piece of wood 2 abuts against the abutment recess 1b of one piece of wood 1 and then presses against it. At the same time, the abutment protrusion 1b of one piece of wood 1 abuts against the abutment recess 2c of the other piece of wood 2 and then presses against it. As a result, the abutment protrusions 1b, 2b and the abutment recesses 1c, 2c that are fitted together are held in a tight, pressed state.

[0027] The wooden dowel 3 to be inserted into the two dowel holes 1d, 2d has an outer dimension φ1 that is approximately 10 to 30% larger than the inner diameter φ2 of the dowel holes 1d, 2d. This ensures that when the dowel 3 is press-fitted into the dowel holes 1d, 2d, the outer surface of the dowel 3 contracts while the inner surfaces of the dowel holes 1d, 2d compress, eliminating the risk of the dowel 3 coming loose after insertion. The outer dimension φ1 of the dowel 3 and the inner diameter φ2 of the dowel holes 1d, 2d may be the same. In this case, since the dowel hole 1d in one piece of wood 1 and the dowel hole 2d in the other piece of wood 2 are offset, the inserted dowel 3 is pressed from the outer periphery and firmly held in place when the dowel 3 is displaced to align the centers of the two dowel holes 1d, 2d. This eliminates the risk of the dowel 3 coming loose from the dowel holes 1d, 2d.

[0028] To further securely connect the first wooden piece 1 and the second wooden piece 2, they are adhesively fixed together. In this case, as shown in FIG. 5(B), adhesive G is applied to the inner surface 1e of the flatly formed extension 1a. Then, as described above, the abutment projections 1b, 2b and abutment recesses 1c, 2c of the first wooden piece 1 and the second wooden piece 2 are abutted against each other, and the dowel 3 is press-fitted into the dowel holes 1d, 2d from above. At this time, the centers of the dowel holes 1d, 2d are displaced to coincide, as described above, and the abutment projections 2a, 2b and abutment recesses 1a, 1b are pressed against each other, preventing longitudinal displacement. Press-fitting the dowel 3 also prevents displacement in the thickness direction. This provides a temporary fastening effect while the adhesive G solidifies, after which the dowel 3 and adhesive G form an even stronger connection. When performing this type of bonding work, clamps are generally used to prevent misalignment, but because the dowel 3 also serves as a temporary fastener, the work of attaching and removing the clamps can be omitted, improving work efficiency. Also, in the longitudinal direction, the centers of both dowel holes 1d, 2d are displaced so as to align, and the abutment protrusions 2a, 2b and the abutment recesses 1a, 1b are pressed together, eliminating the need to use a tool such as a press to apply pressure.

[0029] The dowel 3 is not limited to being made of wood, but may be a metal rod, a screw such as a bolt, or a rod made of synthetic resin. The shape may be cylindrical or prismatic. If the material is hard, the dowel itself will not shrink much when pressed in, so it is desirable to set the inner diameter of the dowel hole 1d of the one piece of wood 1 and the other piece of wood 2 to an appropriate size that will expand.

[0030] Furthermore, since the contact protrusion 2b of the other wooden piece 2 is fitted into the contact recess 1c of one wooden piece 1 and pressed against it, even if an attempt is made to bend the connected wooden piece 1 or the other wooden piece 2 as shown by the arrow in Figure 5(C), the tip of the contact protrusion 2b fits into the contact recess 1b, preventing vertical displacement, thereby achieving the same bending strength as a single piece of wood. Furthermore, the flat inner surfaces 1e, 2e of the extensions 1a, 2a are joined in close contact with each other, further increasing bending strength. To further increase strength, the dowel 3 may be bonded with wood adhesive between the dowel holes 1d, 2d, or between the contact protrusion 2b and the contact recess 1b where they are joined, and further between the inner surfaces 1e, 5e of the extensions 1a, 2a. When adhesive is used, a small amount of excess adhesive is stored in reservoir 13, which reduces the amount of adhesive that flows out to the sides in the width direction, and also increases the adhesive strength due to the adhesive stored in reservoir 13. Two or more dowel holes 1d, 2d may be formed in one piece of wood 1 and the other piece of wood 2, and this number is set appropriately depending on the width of the wood or the required connection strength.

[0031] FIG. 6 shows an example in which the dowel hole 1d formed in the extension 1a of one piece of wood 1 is formed as a blind hole so as not to penetrate the wood. The dowel hole 2d formed in the extension 2a of the other piece of wood 2 penetrates the wood from top to bottom. When the dowel 3 is pressed into the dowel hole 2d of the other piece of wood 2, the tip of the dowel 3 reaches the bottom of the dowel hole 1d. During this process, the dowel 3 displaces the wood pieces 1 and 2 so that the centers of the dowel holes 1d and 2d align, pressing the protruding portions 1b and 2b of the two pieces of wood 1 against the recessed portions 1b and 2b, as in the previous example. In this way, by forming the dowel hole 1d of the one piece of wood 1 as a blind hole so as not to penetrate the wood, the dowel 3 is not exposed on the surface of the one piece of wood 1. This allows the surface of the one piece of wood 1 to be beautifully finished.

[0032] Figure 7 shows another embodiment of the abutment projections and abutment recesses formed on the extensions of one wood piece and the other wood piece. The extensions 1a, 2a of the one wood piece 1 and the other wood piece 2 shown in Figure 7 are the same as those in the previously described embodiment, and therefore will not be described here. The difference from the previously described embodiment is that the abutment projections 5b, 6b and abutment recesses 5c, 6c formed on the extensions 1a, 2a are semicircular and fit together. As in the previously described embodiment, when the abutment projections 5b, 6b are fitted into the abutment recesses 5c, 6c and pressed, the tip portions of the abutment recesses 5c, 6c prevent the abutment projections 5b, 6b from separating in the thickness direction. This prevents the abutment projections 5b, 6b from displacing in the vertical direction, and, like the previously described triangular shape, provides the same bending strength as a single piece of wood.

[0033] FIG. 8 shows an example in which the thicknesses of the first and second wooden pieces are different. The thickness of the first wooden piece 1 shown in FIG. 8 is the same as in the previous example, t1, while the thickness of the second wooden piece 21, t2, is thicker than that of the first wooden piece 1. Similar to the previously described second wooden piece 2, the second wooden piece 21 has an extension 21a at its end, a contact protrusion 21b at its tip, and a contact recess 21c at its base. Furthermore, a dowel hole 21d is formed in the approximate center of the extension 2a, penetrating it in the thickness direction. The difference from the previously described second wooden piece 2 is that the extension 21a is thicker and the dowel hole 21d is longer due to the increased thickness. Therefore, the dowel 3 inserted into the dowel hole 21d is longer.

[0034] While the above-described embodiment shows an example of connecting two pieces of wood, one piece of wood 1 and the other piece of wood 2, it is possible to form even longer pieces of wood by connecting multiple pieces of wood using a similar connecting structure. That is, as shown in FIG. 9 , an extension 2f is formed on the opposite end of the other piece of wood 2 connected to the end of the first piece of wood 1, and this extension 2f is formed with a contact protrusion, a contact recess, and a dowel hole, as in the above-described example. Furthermore, a third piece of wood 4 is connected to the extension 2f formed on the opposite side of the other piece of wood 2. This third piece of wood 4 is formed with an extension 4a formed with a contact protrusion, a contact recess, and a dowel hole, similar to the configurations of the first piece of wood 1 and the other piece of wood 2. The contact protrusion and the contact recess are abutted against the extension 2f on the opposite side of the other piece of wood 2, and a dowel is inserted into the dowel hole 3, resulting in a strong connection. In this way, by forming an extension on the opposite end of the third wooden piece 4, it is possible to connect a fourth wooden piece (not shown), and further to connect multiple wooden pieces in a row. In the case of scrap wood, many scrap pieces are relatively short and of different dimensions, so by forming an extension and abutting protrusions and abutting recesses on the end of the scrap wood, regardless of its length, it is possible to form wooden pieces of the desired length, thereby making effective use of scrap wood that would otherwise be discarded.

[0035] FIG. 10 shows an application example of the wooden piece connecting structure according to the present invention. For example, as shown in FIG. 9, multiple pieces of wood, each formed by connecting multiple scrap pieces to a single piece of wood, can be connected together widthwise to form a large-area flat board 10 that can be used as a tabletop or other top. Each connecting piece 11 is similar to the connecting piece described above, but each connecting piece 11 is formed to the same dimensions according to the desired length of the flat board 10. Furthermore, both ends of multiple connecting pieces 11 arranged side by side widthwise are fixed by connecting plates 12, commonly referred to as ears. The widthwise end faces of the connecting plates 12 are formed with extensions 12a, similar to the ends of the first wooden piece 1 and the second wooden piece 2 described above. These extensions 12a are formed with the abutment protrusions and abutment recesses formed on the first wooden piece 1 and the second wooden piece 2 described above. Furthermore, dowel holes 12b are formed at positions corresponding to the connecting pieces 11.

[0036] The dowel hole 12b formed in the connecting plate 12 is positioned slightly offset toward the abutment recess, similar to the dowel hole 1d formed in one of the wooden pieces 1 described above. The extension 11a of each connecting piece 11 and the extension 12a of the connecting plate 12 are abutted by fitting the abutment projection and abutment recess, as in the previous example. Furthermore, when a dowel is inserted into the dowel hole 12b of the connecting plate 12 and the dowel hole of the connecting piece 11, the centers of the two dowel holes attempt to align, displacing the connecting piece 11 and the connecting plate 12. As a result, the abutting abutment projection and abutment recess are pressed together, firmly connecting the connecting piece 11 and the connecting plate 12. To further increase the connection strength, the connecting piece 11 and the connecting plate 12 may be fixed with an adhesive.

[0037] In this way, by connecting multiple connecting pieces of wood 11 in the width direction, a flat plate 10 with a patchwork pattern can be produced. When used as a tabletop, the dowels 3 inserted into the dowel holes 1d and 2d are exposed on the surface. If the exposed dowels 3 are undesirable for design reasons, as in the example shown in Figure 6, the dowel holes on the surface side of the flat plate 10 are formed as blind holes so that they do not penetrate, and on the back side, the dowel holes are formed so that they penetrate to the top and bottom surfaces, and the dowels 3 are inserted and connected from the back side by press-fitting. As a result, as shown in Figure 10(B), the dowels 3 are formed in a hidden state on the surface side of the flat plate 10. On the other hand, the dowels 3 are exposed on the back side of the flat plate 10 shown in Figure 10(A).

[0038] When connecting the sides of connecting pieces 10 to form a flat plate, the well-known jointing method shown in Figure 11 can be used. Figure 11(A) shows tongue and groove jointing, in which a convex protrusion 11c is formed on one side of connecting piece 11, a groove 11b is formed on the other side, and a tongue 11c is fitted into this groove 11b to join the pieces. Figure 11(B) shows tongue and groove jointing, in which a groove 11b is formed on one side of connecting piece 11 and a rectangular tongue 13 is fitted into the groove 11b to join the pieces. Furthermore, Figure 11(C) shows a type of general half-slit joint, in which the end-to-end connection structure of the above-mentioned embodiment is applied to a side-to-side connection structure.

[0039] Although the present invention has been specifically described based on the embodiments, the present invention is not limited to the above embodiments and can be modified in various ways without departing from the spirit of the present invention. In the above embodiments, the one piece of wood and the other piece of wood are described as square pillars, but they may also be round bars or flat plates having a predetermined thickness. [Explanation of symbols]

[0040] 1. One piece of wood 1a Extension part 1b Contact protrusion 1c Contact recess 1d dowel hole 1e Inner surface 2. The other wood 2a Extension 2b Contact protrusion 2c Contact recess 2d dowel hole 2e Inner surface 3 dowels

Claims

1. A wooden joint structure in which the ends of one wooden piece and the other wooden piece are joined together by abutting them together, An extension portion is formed at the end portion, a contact protrusion is formed at the tip of the extension portion, and a contact recess is formed at the base end into which the contact protrusion is fitted and brought into contact, The extension portion has a dowel hole formed in the thickness direction thereof for inserting a dowel therein, The dowel hole is formed at a position where the dowel hole of the other wooden piece is biased toward the abutment recess side when the dowel is inserted into the dowel hole of the one wooden piece, A wooden connecting structure characterized in that when the dowel is inserted into the dowel holes of the one wooden piece and the other wooden piece, the abutting protrusion is displaced toward the abutting recess so that the centers of the dowel holes coincide and are pressed against each other.

2. The wooden joint structure according to claim 1, wherein the extension portions of the one wooden piece and the other wooden piece are formed in the same shape, the inner surfaces of the extension portions are formed flat, and the board thickness is formed to be half the thickness of the wooden pieces.

3. 2. The wood connecting structure according to claim 1, wherein the abutment protrusion and the abutment recess of the extension are formed in an angular or semicircular shape and fitted together to prevent displacement in the thickness direction of the board when the two are abutted.

Images