Joining structure of wooden beams

Abstract

This invention provides a wooden beam joint structure that improves workability when forming each beam while preventing problems caused by the use of a circular cross-section joint axis by using a circular cross-section joint axis for joining the upper and lower beam members at their intersection. [Solution] In a wooden beam joining structure that joins an upper wooden beam 6 and a lower wooden beam 7 in a predetermined intersecting state, the structure includes a joining shaft 21 with a circular cross-section extending from the intersection portion 6A of the upper beam 6 and the intersection portion 7A of the lower beam 7, a fixing device 22 for fixing the joining shaft 21 to the respective intersection portions 6A and 7A, and fitting portions 6c and 7c formed on the respective intersection portions 6A and 7A in a manner that allows them to fit together from above and below in a predetermined intersecting state.

Description

Technical Field

[0001] The present invention relates to a joining structure of wooden beam members that joins upper and lower wooden beam members in a predetermined intersecting state.

Background Art

[0002] As the background art of the present invention, for example, in a connection structure of horizontal members in a framed wooden building that connects alternately intersecting wooden horizontal members (upper and lower beam members) at their intersection parts, a technique is known that uses a connection fitting (joint axis) in the form of a corner pipe spanning them and a drift pin for fixing this connection fitting to the intersection parts of each horizontal member for connection (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In Patent Document 1 above, as a comparative example to the above technique, a technique of connecting the intersection parts of each horizontal member with a round pipe-shaped connection fitting instead of a connection fitting in the form of a corner pipe is described. And, as a problem that occurs in this comparative example, due to the rotation of the round pipe-shaped connection fitting at the intersection parts of each horizontal member, the through hole for inserting the drift pin formed in the connection fitting and the through hole for inserting the drift pin formed at the intersection parts of each horizontal member are displaced, making it difficult to drive the drift pin is described. On the other hand, in the technique described in Patent Document 1, by using a connection fitting in the form of a corner pipe, the rotation of the connection fitting at the intersection parts of each horizontal member is prevented, and the displacement between the through hole of the connection fitting and the through holes of each horizontal member is prevented. As a result, it is described that it becomes easy to drive the drift pin.

[0005] However, in the configuration described in Patent Document 1, it is necessary to provide square holes, which are difficult to form, instead of round holes, which are easy to form, as connecting holes for inserting connecting fittings. Therefore, there is room for improvement in terms of improving workability when forming each horizontal member so that they can be connected at their intersections. Furthermore, when the intersections of each horizontal member are connected, the horizontal forces acting on each horizontal member and the rotational torque centered on the connecting fittings are concentrated on the connecting fittings, requiring the use of connecting fittings with a larger cross-section. This leads to increased costs due to the larger size of the connecting fittings, and a decrease in load-bearing capacity due to the increased cross-sectional loss at the intersections of each horizontal member caused by the enlargement of the connecting holes resulting from the larger size.

[0006] In view of these circumstances, the main objective of the present invention is to provide a joint structure for wooden beams that improves workability when forming each beam while preventing problems caused by the use of a joint axis with a circular cross-section, by using a joint axis with a circular cross-section for joining the upper beam and the lower beam at their intersection. [Means for solving the problem]

[0007] The first characteristic configuration of the present invention is a wooden beam joining structure that joins an upper wooden beam and a lower wooden beam in a predetermined intersecting state, A connecting axis with a circular cross-section extending from the intersection of the upper beam member and the intersection of the lower beam member, A fixing device for fixing the aforementioned connecting shaft to each of the aforementioned intersection points, The feature is that it is provided with fitting portions formed on each of the intersection points in a manner that allows them to fit together from above and below in the predetermined intersection state.

[0008] According to this configuration, a connecting shaft with a circular cross-section is used to join the upper beam member and the lower beam member in a predetermined intersecting state, allowing the connecting holes for inserting the connecting shaft, which are provided at the intersection of each beam member, to be easily formed as circular holes. This improves work efficiency when forming each beam member so that they can be connected at their intersections.

[0009] Furthermore, when joining the upper and lower beam members in a predetermined intersection state, fitting parts provided at their intersections can be engaged to prevent horizontal misalignment between the upper and lower beam members that may occur when joining the intersection of the upper and lower beam members along a joining axis, as well as relative rotation between the upper and lower beam members around the joining axis that may occur when using a joining axis with a circular cross-section. This prevents the inconvenience of difficulty in joining beams at their intersections using the joining axis, which can occur, for example, due to the horizontal misalignment of the joining holes in the upper and lower beams as described above. Furthermore, for example, when using drift pins as fasteners to fix the connecting shaft, the relative rotation of the upper and lower beam members as described above can cause misalignment between the through-holes for inserting the drift pins in the connecting shaft and the through-holes for inserting the drift pins in each beam member, thereby preventing the inconvenience of difficulty in fixing the connecting shaft to each beam member with drift pins.

[0010] Furthermore, the aforementioned fitting mechanism prevents horizontal forces acting on each beam member and rotational torques around the joint axis from being applied to the joint axis when the intersecting parts of each beam member are connected. This allows for cost reduction by using smaller diameter joints, and improved load-bearing capacity at the intersections of beam members by reducing the diameter of the joint holes provided at the intersections of each beam member, thereby minimizing cross-sectional loss.

[0011] Therefore, by using a circular cross-section connecting axis to join the upper and lower beam members at their intersection, it is possible to provide a wooden beam joining structure that improves workability when forming each beam member so that it can be connected at their intersection, while preventing the occurrence of problems caused by using a circular cross-section connecting axis.

[0012] A second characteristic feature of the present invention is that, at the intersection of one of the upper and lower beam members, the convex portion remaining in the center of the beam width direction is provided as the fitting portion by cutting out both ends in the beam width direction at the intersection, and at the intersection of the other beam member, a fitting groove portion is provided as the fitting portion by cutting out the center of the beam width direction at the intersection, which is the portion opposite to the convex portion, across both ends in the beam width direction.

[0013] According to this configuration, the fitting portions of the upper and lower beam members are formed by cutting out both ends in the beam width direction at the intersection of the beam members, or by cutting out across both ends in the beam width direction. This makes the cutting work for forming each fitting portion easier compared to, for example, forming it in the center of the beam width direction at the intersection.

[0014] Furthermore, since each fitting portion is formed by partially cutting out the intersection points of each beam material, the cross-sectional loss at each intersection point can be reduced compared to when each intersection point is cut out entirely.

[0015] Therefore, while improving workability when forming fitting sections at each intersection of the upper and lower beam members, it is possible to improve the load-bearing capacity at the intersections of each beam member by reducing the cross-sectional loss at each intersection. [Brief explanation of the drawing]

[0016] [Figure 1] Perspective view of a mixed-structure building using steel frame and wood. [Figure 2] Beam layout drawing showing the arrangement of grid beams with upper and lower beam members for triangularly arranged main beams. [Figure 3] (a) is a vertical cross-sectional view of the main part showing the connection structure between the first main beam and the upper and lower beam members, and (b) is a horizontal cross-sectional view of the main part showing the connection structure between the first main beam and the lower beam member. [Figure 4](a) is a vertical sectional view of a main part showing the joint structure of the second main beam and the upper beam member, (b) is a vertical sectional view of a main part showing the joint structure of the steel column, the second main beam, and the lower beam member, and (c) is a vertical sectional view of a main part showing the joint structure of the steel column and the second main beam, etc. [Figure 5] Plan drawing regarding the setting of the erection direction of the lattice beam [Figure 6] Beam elevation view of a main part showing the erection direction of the lattice beam [Figure 7] Exploded perspective view showing the joint structure at the intersection of the upper beam member and the lower beam member [Figure 8] Vertical sectional view showing the joint structure at the intersection of the upper beam member and the lower beam member [[ID=从13]] [Figure 9] (a) is a plan view showing the intersection part of the lower beam member, and (b) is a bottom view showing the intersection part of the upper beam member

Mode for Carrying Out the Invention

[0017] Hereinafter, as an example of a mode for carrying out the present invention, an embodiment in which the joint structure of the wooden beam members according to the present invention is applied to a mixed-structure building using a steel frame structure and a wooden structure, which is an example of a building, will be described based on the drawings. Note that the joint structure of the wooden beam members according to the present invention is not limited to a mixed-structure building using a steel frame structure and a wooden structure, and may be applied to, for example, a mixed-structure building using a reinforced concrete structure and a wooden structure, or a wooden building using only a wooden structure.

[0018] As shown in FIGS. 1 to 2, the mixed-structure building B exemplified in the present embodiment is constructed by connecting a first building part B1 mainly made of a steel frame structure (the part shown by dots in FIGS. 1 to 2) and a second building part B2 mainly made of a wooden structure. Although the illustration is omitted, the first building part B1 is constructed in a ramen structure having braces. As shown in FIG. 1, the second building part B2 is provided with a large roof R covering a large space and a framework part F supporting the large roof R with a large span.

[0019] As shown in Figures 1 and 3, the roof underlayment of the main roof R is formed of multiple roof panels 1 that are aligned and connected in the direction of the extension of the eaves. Each roof panel 1 is made of wooden structural plywood formed into a predetermined triangular shape according to the shape of the main roof R. As shown in Figure 1, the multiple roof panels 1 are basically formed so that two sides extending from the ridge to the eaves of the main roof R are the longer sides, and one side spanning those two sides is the shorter side. The multiple roof panels 1 are connected in such a way that the joint lines L formed at their adjacent sides are either mountain fold lines L1 or valley fold lines L2, and are positioned alternately.

[0020] In other words, the main roof R is formed in a folded plate shape where the aforementioned joint lines L alternately form mountain fold lines L1 or valley fold lines L2. As a result, the main roof R is constructed to have high rigidity against horizontal forces acting in the direction from its ridge to its eaves and vertical deflection.

[0021] Incidentally, regarding the large roof radius (R), finite element analysis has verified that when it is formed in the aforementioned folded plate shape, the rigidity against horizontal forces and vertical deflection is higher compared to when it is not formed in the folded plate shape.

[0022] As shown in Figures 2-4, the frame F is equipped with a plurality of first main beams 2 (see Figures 2-3) arranged along the joint line L of the main roof R, a plurality of second main beams 3 (see Figures 2 and 4) arranged along the eaves of the main roof R, and a grid beam 5 that spans between these main beams 2 and 3 and supports the roof panels 1 via a plurality of rafters 4 (see Figures 3-4). Each roof panel 1 of the main roof R is screwed to the first main beams 2 and rafters 4 (see Figures 3-4). The grid beam 5 is configured as a two-tiered beam structure in which an upper beam member 6 and a lower beam member 7, which are erected in two tiers on the first main beams 2 and second main beams 3, are joined in a predetermined intersecting state at their intersection points 6A and 7A (see Figures 3-4), thereby achieving a mutual support effect between the upper beam member 6 and the lower beam member 7. The upper beam member 6 and the lower beam member 7 may be secondary beams having the same beam depth as shown in Figures 3 and 4, or they may be secondary beams having different beam depths for reasons such as structural strength. Each of the main beams 2 and 3 and the upper and lower beam members 6 and 7 are made of wood. For example, structural laminated timber made by joining wooden boards can be used for each of the main beams 2 and 3 and the upper and lower beam members 6 and 7. Wooden square timbers are used for the rafters 4.

[0023] In other words, in the second building section B2 illustrated in this embodiment, the large roof R is formed in a folded plate shape that has high rigidity against the aforementioned horizontal force and vertical deflection, and the grid beam 5 of the frame section F is configured as a two-stage beam structure that provides the aforementioned mutual support effect. Thus, a frame structure is realized that can support the large roof R over a large span while using wooden members with small cross-sections.

[0024] As shown in Figures 1 and 4, the frame section F is equipped with multiple wooden columns (not shown) that support the first main beam 2, and multiple steel columns 9 that support the second main beam 3. The wooden columns are rectangular columns with a square cross-section, and like the main beams 2 and 3, they can be made of materials such as the structural laminated timber mentioned above. For the steel columns 9, circular steel pipes, square steel pipes, or H-shaped steel can be used, for example. Furthermore, wooden columns may be used instead of steel columns 9 to support the second main beam 3.

[0025] Incidentally, when planning a frame structure equipped with lattice beams 5, for example, prioritizing the aesthetic appearance when viewed from above, one could set the installation direction of the upper beam member 6 in the lattice beam 5 to the same direction as the installation direction of one of the pair of first main beams 2 that support the two long sides of the roof panel 1, and set the installation direction of the lower beam member 7 to the same direction as the installation direction of the other of the pair of first main beams 2. However, if aesthetics are prioritized in this way, the length of both the upper beam member 6 and the lower beam member 7 will be increased, resulting in a structurally disadvantageous frame plan.

[0026] Therefore, as a means of improving the structurally unfavorable structural plan, it is conceivable to set the installation direction of the lower beam member 7, which greatly affects the aesthetic appearance, in the same direction as the installation direction of the first main beam 2, prioritizing the aesthetic appearance, while changing the installation direction of the upper beam member 6, which has little impact on the aesthetic appearance, to a structurally advantageous direction.

[0027] Furthermore, the following two technical considerations were taken into account when changing the installation direction of the upper beam member 6 to a structurally advantageous direction. Firstly, when calculating the stresses that occur in a rectangular slab or other structure, the idea is that most of the weight on the structure is supported by the shorter sides, and the bending moment that occurs on the longer sides is determined by the length of the shorter sides. Therefore, the rectangular structure is replaced with two orthogonal beams to obtain an approximate value. Secondly, the same principle applies when calculating the stresses generated in a triangular structure. Based on this idea, the shorter side of the triangular structure is the point, as shown in Figure 5, where the inscribed circle C touches the two sides S1 and S2 on the vertex side with the smallest vertex angle θa, forming a straight line La connecting the points of tangency P1 and P2.

[0028] Based on the above technical considerations, as shown in Figure 5, a straight line La is set as the short side of each triangular roof panel 1, connecting the points of tangency P1 and P2 where the inscribed circle C touches the two sides S1 and S2 on the vertex side having the smallest vertex angle θa. Also, a straight line Lb is set as the second shortest short side of each roof panel 1, connecting the points of tangency P1 and P3 where the inscribed circle C touches the two sides S1 and S3 on the vertex side having the second smallest vertex angle θb. The set short side (straight line La) is then set as the first principal axis of each roof panel 1, and the second shortest short side (straight line Lb) is set as the second principal axis of each roof panel 1.

[0029] Subsequently, computational design was used to search for and extract the installation direction of the upper beam member 6 that would satisfy predetermined conditions regarding both deflection and stress between the first main axis La and the second main axis Lb of each roof panel member 1. From the extracted installation directions of the upper beam member 6, an optimal installation direction D (in Figure 5, the direction along the second main axis Lb is shown as an example) that is aesthetically pleasing and matches the design was selected, and the installation direction of the upper beam member 6 was changed to the selected optimal installation direction D.

[0030] As a result, as shown in Figures 2 and 6, of the upper and lower beam members 6 and 7 used in the lattice beam 5 supporting the large roof R, the lower beam members 7, which greatly affect the aesthetics, can be erected in the same direction as the first main beam 2, prioritizing aesthetics, while the upper beam members 6, which have less impact on aesthetics, can be erected in the optimal erection direction D, which prioritizes structural advantages while also considering aesthetics. As a result, a lattice beam 5 with excellent aesthetics can be constructed while improving structural disadvantages.

[0031] As shown in Figure 3, the first main beam 2 is provided with a steel plate bracket 11 to which the end of the upper beam member 6 or the end of the lower beam member 7 is joined. The bracket 11 is formed in a T-shape in plan view by welding a connecting plate 11B for joining beam members to a rectangular base plate 11A that fits into a rectangular first recess 2a formed on the side surface of the first main beam 2, with the connecting plate 11B extending laterally outward from the first main beam 2. The base plate 11A is joined to the side surface of the first main beam 2 in the first recess 2a of the first main beam 2 using a plurality of through bolts 12, which are an example of fasteners. A second recess 2b is formed on the side surface of the first main beam 2 on the bolt insertion side, into which a wooden insert 13 is fitted to conceal the through bolts 12, etc. The connecting plate 11B is inserted into the slit-shaped first recesses 6a and 7a formed at the end of the upper beam member 6 or the lower beam member 7, and then the end of the upper beam member 6 or the lower beam member 7 is fixed using a plurality of drift pins 14, which are an example of fasteners. Although not shown in the figures, the ends of the upper beam member 6 and the lower beam member 7 are provided with wooden inserts that fit into the insertion holes of the drift pins 14.

[0032] As shown in Figure 4, the second main beam 3 is provided with a steel plate bracket 15 to which the end of the upper beam member 6 or the end of the lower beam member 7 is joined. The bracket 15 is formed in a T-shape in plan view by welding a connecting plate 15B for joining beam members to a rectangular base plate 15A that fits into a rectangular first recess 3a formed on the side surface of the second main beam 3, with the connecting plate 15B extending laterally outward from the second main beam 3. The base plate 15A is joined to the side surface of the second main beam 3 in the first recess 3a of the second main beam 3 using a plurality of through bolts 16, which are an example of fasteners. A second recess 3b is formed on the side surface of the second main beam 3 on the bolt insertion side, into which a wooden insert 17 is fitted to conceal the through bolts 16, etc. The connecting plate 15B is inserted into the slit-shaped second recesses 6b and 7b formed at the end of the upper beam member 6 or the end of the lower beam member 7, and then the end of the upper beam member 6 or the end of the lower beam member 7 is fixed using a plurality of drift pins 18, which are an example of fasteners. Although not shown in the figures, the ends of the upper beam member 6 and the lower beam member 7 are provided with wooden inserts that fit into the insertion holes of the drift pins 18.

[0033] Furthermore, the second main beam 3 has a column joint 3A to which a steel plate bracket 19, provided on the upper part of the steel column 9, is joined. The bracket 19 is constructed by welding a wide joining plate 19B to a base plate 19A, which is welded to the upper end of the steel column 9, with the wide joining plate 19B extending upward. The joining plate 19B is inserted into a slit-shaped third recess 3c formed in the joint 3A of the second main beam 3, and then both ends in the width direction are fixed to the second main beam 3 using drift pins 20, which are an example of fasteners. The second main beam 3 is provided with a wooden insert (not shown) that fits into the insertion holes of the drift pins 20. In the center of the joining plate 19B in the width direction, there are multiple through holes 19a that are larger in diameter than the outer diameter of the through bolts 16, allowing the insertion of through bolts 16. This makes it easy to connect the second main beam 3 and the bracket 15 using through bolts 16 without being hindered by the connecting plate 19B inserted into the third recess 3c of the second main beam 3.

[0034] Although not shown in the diagram, the main beams of the first building section B1 are made of steel such as H-shaped steel, and steel plate brackets are welded to these main beams to which the ends of the upper beam member 6 or the lower beam member 7 are joined. These brackets extend laterally outward from the main beam, similar to the joining plates 11B and 15B of the brackets 11 and 15 provided on the first main beam 2 and the second main beam 3. The brackets are then inserted into slit-shaped recesses formed in the ends of the upper beam member 6 or the lower beam member 7, and then the ends of the upper beam member 6 or the lower beam member 7 are fixed using a plurality of drift pins, which are an example of fasteners. The ends of the upper beam member 6 and the lower beam member 7 are provided with wooden inserts that fit into the holes through which the drift pins are inserted.

[0035] In this embodiment, the wooden beam joint structure according to the present invention is applied to the joint between the upper wooden beam 6 and the lower wooden beam 7 used in the lattice beam 5. As shown in Figures 7 to 9, the wooden beam joint structure illustrated in this embodiment includes a joint axis 21 (see Figures 7 to 8) with a circular cross-section extending from the intersection 6A of the upper wooden beam 6 to the intersection 7A of the lower wooden beam 7, a drift pin 22 which is an example of a fastener for fixing the joint axis 21 to the intersection 6A and 7A respectively, and fitting portions 6c and 7c formed on the intersection 6A and 7A respectively in a manner that allows them to fit together from above and below in a predetermined intersection state.

[0036] In other words, in the wooden beam joint structure illustrated in this embodiment, a joint shaft 21 with a circular cross-section is used to join the upper beam 6 and the lower beam 7 in a predetermined intersecting state. This makes it possible to make the joint holes 6d, 7d (see Figure 9) for inserting the joint shaft, provided at the intersection portion 6A of the upper beam 6 and the intersection portion 7A of the lower beam 7, into easily formed circular holes.

[0037] As a result, it is possible to improve work efficiency when forming the upper beam member 6 and the lower beam member 7 so that they can be connected at their intersection points 6A and 7A.

[0038] Then, when joining the upper beam member 6 and the lower beam member 7 in a predetermined intersecting state, first, the upper or lower side of the joining shaft 21 is inserted through the joining holes 6d, 7d of either the upper beam member 6 or the lower beam member 7, and then fixed to the intersecting portion 6A of the upper beam member 6 or the intersecting portion 7A of the lower beam member 7 with a drift pin 22.

[0039] Subsequently, the intersection point 6A of the upper beam member 6 and the intersection point 7A of the lower beam member 7 are overlapped vertically so that a drift pin 22 fixed to one of them is inserted through the joint holes 6d, 7d of the other. At this time, the fitting parts 6c, 7c provided at each intersection point 6A, 7A are fitted together, thereby maintaining the upper beam member 6 and the lower beam member 7 in a predetermined intersection state. This prevents horizontal displacement between the upper beam member 6 and the lower beam member 7 that may occur when the drift pin 22 fixed to one of the intersection points 6A of the upper beam member 6 and the lower beam member 7 is fixed to either the intersection point 6A of the upper beam member 6 or the intersection point 7A of the lower beam member 7, as well as relative rotation between the upper beam member 6 and the lower beam member 7 around the joint axis 21 that may occur when using a joint axis 21 with a circular cross-section.

[0040] As a result, for example, due to the misalignment of the upper beam member 6 and the lower beam member 7 as described above, the joint holes 6d of the upper beam member 6 and 7d of the lower beam member 7 are misaligned horizontally, which can prevent the inconvenience of difficulty in joining the upper beam member 6 and the lower beam member 7 at the intersection points 6A and 7A using the joint axis 21.

[0041] Furthermore, as a result of the relative rotation of the upper beam member 6 and the lower beam member 7 as described above, the through holes 6e and 7e for inserting drift pins, provided at the intersection 6A of the upper beam member 6 or the intersection 7A of the lower beam member 7, become misaligned, which can prevent the inconvenience of difficulty in fixing the upper beam member 6 or the lower beam member 7 with the drift pins 22.

[0042] Furthermore, the fitting of the aforementioned fitting portions 6c and 7c prevents horizontal forces acting on each beam member 6 and 7, as well as rotational torque around the joining axis 21, from being applied to the joining axis 21 when the intersection portion 6A of each upper beam member 6 and the intersection portion 7A of the lower beam member 7 are connected. This makes it possible to reduce costs by using a smaller diameter joining axis 21, and to improve the load-bearing capacity at the intersection portions 6A and 7A of each beam member 6 and 7 by making the joining holes 6d and 7d provided at the intersection portions 6A and 7A of each beam member 6 and 7 smaller in diameter to reduce cross-sectional loss.

[0043] Incidentally, the predetermined intersection state of the upper beam member 6 and the lower beam member 7 in this embodiment is the state in which the upper beam member 6, which is erected in the optimal erection direction described above, and the lower beam member 7, which is erected in the same direction as the erection direction of the first main beam 2, intersect at their intersection points 6A and 7A. The joining hole 6d for inserting the joining shaft, provided at the intersection point 6A of the upper beam member 6, is a circular recess drilled upward from the bottom surface of the upper beam member 6. Similarly, the joining hole 7d for inserting the joining shaft, provided at the intersection point 7A of the lower beam member 7, is a circular recess drilled downward from the top surface of the lower beam member 7. For the joining shaft 21 with a circular cross-section, a round steel bar or a circular steel pipe can be used. Furthermore, the connecting holes 6d and 7d for inserting the connecting shaft may be through holes that penetrate the upper beam member 6 or the lower beam member 7 in the vertical direction. Also, the fasteners for fixing the connecting shaft 21 to the intersection points 6A and 7A may be bolts and nuts other than the drift pins 22. Similarly, the fasteners for the base plates 11A and 15A may be drift pins other than the through bolts 12 and 16, and the fasteners for the connecting plates 11B, 15B, and 19B may be bolts and nuts other than the drift pins 14, 18, and 20.

[0044] As shown in Figures 7-9, at the intersection 7A of the lower beam member 7, the convex portion remaining in the center of the beam width direction is provided as a fitting portion 7c by cutting out both ends of the intersection 7A in the beam width direction. Similarly, at the intersection 6A of the upper beam member 6, a fitting groove portion is provided as a fitting portion 6c by cutting out the center of the beam width direction of the intersection 6A, which is the portion opposite to the convex portion of the fitting portion 7c of the lower beam member 7, across both ends of the beam width direction.

[0045] In other words, in the wooden beam joint structure illustrated in this embodiment, the fitting portion 6c of the upper beam member 6 and the fitting portion 7c of the lower beam member 7 are formed by cutting out both ends in the beam width direction at the intersection portions 6A and 7A of the beam members 6 and 7, or by cutting out a portion that extends across both ends in the beam width direction. Therefore, compared to, for example, forming the fitting portions 6c and 7c in the center of the beam width direction at the intersection portions 6A and 7A, the cutting work required to form each fitting portion 6c and 7c becomes easier.

[0046] Furthermore, since each fitting portion 6c, 7c is formed by partially cutting out the intersection portions 6A, 7A of the beam members 6, 7, the cross-sectional loss at each intersection portion 6A, 7A can be reduced compared to when each intersection portion 6A, 7A is cut out entirely.

[0047] As a result, it is possible to improve workability when forming fitting portions 6c, 7c at the intersections 6A, 7A of the upper beam member 6 and the lower beam member 7, while also improving the load-bearing capacity at the intersections 6A, 7A of the beam members 6 and 7 by reducing the cross-sectional loss at each intersection 6A, 7A.

[0048] [Another embodiment] Other embodiments of the present invention will be described. Furthermore, the configurations of each embodiment described below are not limited to being applied individually, but can also be applied in combination with the configurations of other embodiments.

[0049] (1) In the above embodiment, the joint structure of the wooden beam members was exemplified as a state in which the upper beam member 6 and the lower beam member 7 intersect when the upper beam member 6, which is erected in the optimal erection direction described above, intersects with the lower beam member 7, which is erected in the same direction as the erection direction of the first main beam 2. However, it is not limited to this, and for example, the upper beam member 6, which is erected in the same direction as the erection direction of one of the pair of first main beams 2, intersects with the lower beam member 7, which is erected in the same direction as the erection direction of the other first main beam 2, or the upper beam member 6, which is erected in the same direction as the erection direction of the first main beam 2, intersects with the lower beam member 7, which is erected in the optimal erection direction described above.

[0050] (2) In the above embodiment, as a joint structure for wooden beam members, the fitting portion 6c formed at the intersection portion 6A of the upper beam member 6 becomes the aforementioned fitting groove portion, and the fitting portion 7c formed at the intersection portion 7A of the lower beam member 7 becomes the aforementioned convex portion. However, the embodiment is not limited to this, and for example, the fitting portion 6c formed at the intersection portion 6A of the upper beam member 6 becomes the aforementioned convex portion, and the fitting portion 7c formed at the intersection portion 7A of the lower beam member 7 becomes the aforementioned fitting groove portion. [Explanation of Symbols]

[0051] 6. Upper beam material 6A Crossing point 6c Fitting part (fitting groove) 7 Lower beam material 7A Intersection site 7c Fitting part (convex part) 21 Joint axis 22. Drift pin (fixing device)

Claims

1. A wooden beam joining structure in which an upper wooden beam and a lower wooden beam are joined in a predetermined intersecting state, A connecting axis with a circular cross-section extending from the intersection of the upper beam member and the intersection of the lower beam member, A fixing device for fixing the aforementioned connecting shaft to each of the aforementioned intersection points, A joint structure for wooden beams, comprising: fitting portions formed at each of the intersection points in a manner that allows them to fit together from above and below in the predetermined intersection state; and

2. The wooden beam joining structure according to claim 1, wherein at the intersection of one of the upper beam member and the lower beam member, the convex portion remaining in the center in the beam width direction is provided as the fitting portion by cutting out both ends in the beam width direction at the intersection, and at the intersection of the other beam member, a fitting groove portion is provided as the fitting portion by cutting out the center in the beam width direction at the intersection, which is the portion opposite to the convex portion, across both ends in the beam width direction.

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