Joint structure of wooden frame members
The joint structure for wooden shaft members uses an endless groove and a steel cylindrical member with distributed stress to address cross-sectional defects and stress concentration, improving structural integrity and reducing material costs.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- DAIWA HOUSE INDUSTRY CO LTD
- Filing Date
- 2024-12-25
- Publication Date
- 2026-07-07
Smart Images
Figure 2026113149000001_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a joint structure of a wooden shaft member.
Background Art
[0002] In a wooden building constructed by a wooden frame construction method, wooden shaft members forming columns, beams, foundations, etc. are joined to each other via joining metal fittings, and by tightening the members together, improvements such as seismic resistance are achieved.
[0003] Although a drift pin may be applied as the above-described joining metal fitting, there are mainly two types of joint structures using a drift pin in a wooden shaft member (the joint structure at the location where another wooden shaft member is joined in a wooden shaft member).
[0004] One form is a so-called tenon pipe type joint form in which a small-diameter pipe with a pin hole is inserted into a pilot hole having an inner diameter approximately equal to the outer diameter of the pipe, the pilot hole is machined from, for example, the end face of the wooden shaft member into the interior, the pipe is inserted into the pilot hole, and a drift pin is driven from the side face of the wooden shaft member through the pin hole of the pipe for joining.
[0005] On the other hand, the other form is a joint form in which a slit is machined from, for example, the end face of the wooden shaft member into the interior, a steel plate with a pin hole is inserted into the slit, and a drift pin is driven from the side face of the wooden shaft member in a direction perpendicular to the steel plate through the pin hole for joining.
[0006] Here, referring to FIGS. 1A and 1B, an example of the above-described tenon pipe type joint structure will be outlined. FIG. 1A is a view for explaining the joint structure of a wooden shaft member to which a conventional tenon pipe is applied, and is an enlarged view of the end face side in a longitudinal sectional view cut along the longitudinal direction of the wooden shaft member, and FIG. 1B is a view taken in the direction of arrow B - B in FIG. 1A.
[0007] For example, a pre-hole 14 is machined from the end grain 12 of a wooden shaft member 10, which has a plan view (cross-sectional view of a cross section perpendicular to the longitudinal direction) of a square (an example of a rectangle) with side length B, into which a tenon pipe 20 with an outer diameter of φ1 and a hollow 22 is inserted, and the tenon pipe 20 is inserted into the pre-hole 14.
[0008] The tenon pipe 20 has multiple sets of pin holes 24, 25 (two sets in the illustrated example) at multiple positions in the longitudinal direction (four positions in the illustrated example) and at corresponding positions across the hollow 22, through which drift pins are inserted in mutually orthogonal directions. The joint structure 50 is formed when the corresponding drift pins 27, 28 are driven in from the side surface 11 of the wooden shaft member 10 so as to pass through the pin holes 24, 25 of each set. For example, the wooden shaft member 10 and the other member are joined when the end face 12 or side surface 11 comes into contact with another member (another wooden shaft member) and the end face of the tenon pipe 20 is welded or otherwise attached to a joint fitting (another wooden shaft member) on the other member.
[0009] In the conventional mortise-and-tenon pipe type joint structure 50 shown in the illustration, a pre-drilled hole 14 with the dimensions of the mortise pipe 20 is machined from the end grain surface 12 of the wooden shaft member 10 into the interior, resulting in a problem of large cross-sectional loss in the area surrounding the joint structure 50 with other members on the wooden shaft member 10.
[0010] Therefore, in order to minimize the cross-sectional loss of the wooden shaft member 10 and to increase the strength of the joint structure by increasing the cross-sectional area of the steel material compared to the tenon pipe 20 with a hollow 22, one possible approach is to use a solid round steel bar instead of the tenon pipe 20 with a hollow 22 as shown in the illustrated example.
[0011] Here, with reference to Figures 2A and 2B, we will outline an example of a joint structure to which round steel is applied. Figure 2A is a diagram illustrating a joint structure of a wooden stile member to which conventional round steel is applied, and is an enlarged view of the end grain side of a longitudinal section cut along the longitudinal direction of the wooden stile member, while Figure 2B is a view from arrow BB in Figure 2A.
[0012] A pilot hole 15 is machined from the end grain 12 of the wooden shaft member 10 into which a solid round steel 30 with an outer diameter of φ2 (smaller than the outer diameter φ1 of the tenon pipe 20) is inserted, and the round steel 30 is inserted into the pilot hole 15.
[0013] The round steel 30 has multiple pin holes 34 and 35 (two of each in the illustrated example) at multiple positions in the longitudinal direction (four in the illustrated example) that extend in mutually perpendicular directions. The joint structure 50A is formed when the corresponding drift pins 27 and 28 are driven in from the side surface 11 of the wooden shaft member 10 so as to pass through each of the pin holes 34 and 35.
[0014] As is clear from comparing Figure 1 and Figure 2, by machining a pilot hole 15 into which a round steel 30 with an outer diameter φ1 smaller than the outer diameter φ2 of the tenon pipe 20 is inserted, the cross-sectional loss of the wooden shaft member 10 is reduced. Furthermore, by using a solid round steel 30 that does not have a hollow core, the amount of steel material increases compared to the joint structure 50, thereby increasing the strength of the joint structure 50A.
[0015] On the other hand, when a small-diameter round steel 30 is used, as shown in Figure 2A, when a tensile force N is applied to the round steel 30 which is joined to other members (not shown), the drift pin 27(28) deforms in a mode where it is bent downward in the direction of the tensile force N. This can cause a large stress q1, which is a concentrated stress, to act from the drift pin 27(28) on the central region of the wooden shaft member 10 corresponding to the small-diameter round steel 30 with an outer diameter of φ2. This large stress q1 can lead to new problems such as splitting or break-out of the wooden shaft member 10. In addition to the splitting of the wooden shaft member 10, this stress concentration also leads to a requirement for a high-strength drift pin that can withstand this large concentrated stress.
[0016] Therefore, a joint structure for a wooden slat member is desired that can suppress cross-sectional defects in the wooden slat member and suppress the concentration of stress acting on the wooden slat member from the drift pin.
[0017] Here, Patent Document 1 proposes a joining structure for wooden shaft members. This joining structure is a wooden shaft member joining a first wooden shaft member and a second wooden shaft member, in which a fourth bolt hole is provided at the location where the first connecting piece is provided in the first wooden shaft member, and a fifth bolt hole is provided at the location where the second connecting piece is provided, and metal reinforcing shaft members are embedded in the fourth bolt hole and the fifth bolt hole, respectively. [Prior art documents] [Patent Documents]
[0018] [Patent Document 1] Japanese Patent Publication No. 2021-161631 [Overview of the project] [Problems that the invention aims to solve]
[0019] According to the joint structure for wooden slat members described in Patent Document 1, it is possible to increase the design load in the joint structure. However, Patent Document 1 does not disclose any means to solve the above-mentioned problems, namely, the problems of suppressing cross-sectional defects in the wooden slat member and suppressing the concentration of stress acting on the wooden slat member from the drift pin.
[0020] The present invention has been made in view of the above-mentioned problems, and aims to provide a joint structure for a wooden shaft member that can suppress cross-sectional defects in the wooden shaft member and suppress the concentration of stress acting on the wooden shaft member from the drift pin. [Means for solving the problem]
[0021] To achieve the above objective, one embodiment of the joint structure for a wooden slat member according to the present invention is: A joint structure for wooden slat members, in which a wooden slat member is joined to another member, An endless groove, in the shape of a frame in plan view, is provided extending from the end grain surface to the interior of the aforementioned wooden shaft member. A steel cylindrical member with a hollow and having a shape complementary to the endless groove has a plurality of sets of pin holes at corresponding positions straddling the hollow at a plurality of stages in its longitudinal direction, and is fitted into the endless groove. A plurality of drift pins embedded between a pair of opposing side surfaces of the wooden shaft member penetrate the corresponding pin holes.
[0022] According to this aspect, a steel cylindrical member having a complementary shape and a hollow is fitted into an endless groove in a frame shape in a plan view provided from the end face of the wooden shaft member to the inside. A plurality of drift pins embedded between a pair of opposing side surfaces of the wooden shaft member penetrate the corresponding pin holes provided in the cylindrical member, so that the wooden shaft member at a position corresponding to the hollow of the cylindrical member is left. Therefore, cross-sectional loss of the wooden shaft member can be suppressed.
[0023] Also, since the drift pins are spanned across the corresponding opposing side surfaces of the cylindrical member having a relatively large outer diameter instead of a solid round steel or the like, when a tensile force acts on the cylindrical member connected to another member, the drift pins are separated. Tensile force component forces act from two points at positions, and the stress acting on the wooden shaft member from the drift pins is not a concentrated stress but a stress evenly dispersed as much as possible. Therefore, splitting or the like caused by the action of concentrated stress from the drift pins on the wooden shaft member can be prevented.
[0024] Also, since stress does not concentrate on the drift pins, high-strength drift pins that can resist concentrated stress are not required, leading to a reduction in material costs.
[0025] Also, since it is a cylindrical member instead of a solid steel member, an increase in the amount of steel can be suppressed.
[0026] Here, the "frame shape in a plan view" includes a circular shape in a plan view, an elliptical shape in a plan view, a rectangular shape in a plan view, a polygon other than a rectangle, and the like.
[0027] In this embodiment, the wooden axial member is a wooden column or wooden beam (including a wooden foundation), and the end grain surface of the wooden axial member, for example, is joined to another member, such as another wooden axial member or a steel member such as a structural steel member. The "joint structure of the wooden axial member" refers to the structure of the region in the wooden axial member that is joined to another member.
[0028] Furthermore, another embodiment of the joint structure for the wooden slat member according to the present invention is: The ratio of the outer diameter (φ) of the cylindrical member to the maximum width (B) of the end edge of the end face of the wooden shaft member (φ / B) is characterized in that it is in the range of 0.4 to 0.6.
[0029] According to this embodiment, by having the ratio φ / B of the outer diameter φ of the cylindrical member to the maximum width B of the end edge at the end face of the wood shaft member be in the range of 0.4 to 0.6, the effect of suppressing stress concentration acting from the drift pin to the wood shaft member can be enhanced.
[0030] Ratio: In the range where φ / B is less than 0.4, stress tends to concentrate at the drift pin inside the hollow interior of the cylindrical member, as shown in Figure 2A when using round steel, and as a result, stress tends to concentrate from the drift pin to the wooden shaft member. Therefore, 0.4 is set as the lower limit. On the other hand, in the range where φ / B exceeds 0.6, the distance between the two corresponding pin holes in the cylindrical member becomes longer, and in this range, the bending of the drift pin increases. This causes stress to concentrate at the drift pin inside the hollow interior, and as a result, stress tends to concentrate from the drift pin to the wooden shaft member. Therefore, 0.6 is set as the upper limit. In other words, if φ / B is too small or too large, stress tends to concentrate at the drift pin inside the hollow interior of the cylindrical member, and concentrated stress acts from the drift pin to the wooden shaft member.
[0031] Furthermore, another embodiment of the joint structure for the wooden slat member according to the present invention is: The endless groove is circular, and the cylindrical member is cylindrical in shape.
[0032] According to this embodiment, since the endless groove is a circular groove and the cylindrical member has a cylindrical shape, it is preferable that when a tensile force is applied to the cylindrical member, the stress can be applied as uniformly as possible from the cylindrical member to the wood shaft member.
[0033] Furthermore, another embodiment of the joint structure for the wooden slat member according to the present invention is: The end of the cylindrical member is closed by a closing plate, and the closing plate is joined to the other member.
[0034] According to this embodiment, the end of the cylindrical member is closed by a closing plate and exposed to, for example, the end grain surface of the wooden shaft member, and the closing plate is joined to other members by welding, bolting, or the like, thereby forming a joint structure between the wooden shaft member and other members.
[0035] Furthermore, in another embodiment of the joint structure of the wooden axial member according to the present invention, The multiple sets of pin holes are provided in the cylindrical member such that the extension directions of the corresponding drift pins are mutually orthogonal to each other.
[0036] According to this embodiment, the multiple sets of pin holes are provided in the cylindrical member such that the extension directions of the drift pins corresponding to the multiple sets of pin holes are mutually orthogonal to each other. This is preferable because, when a tensile force is applied to the cylindrical member, the stress can be applied as uniformly as possible from the cylindrical member to the wooden shaft member.
[0037] Furthermore, another embodiment of the joint structure for the wooden slat member according to the present invention is: A portion of the cylindrical member is a protruding part that extends from the end grain surface. The aforementioned protruding portion is provided with a pair of pin holes at corresponding positions that straddle the hollow space, A drift pin embedded between a pair of opposing sides of the aforementioned other member is characterized in that it penetrates the pin hole.
[0038] According to this embodiment, the protruding portion that extends from the end grain surface, which is part of the cylindrical member, is provided with a pair of pin holes at corresponding positions that straddle the hollow, and the drift pins embedded between a pair of opposing sides of the other member pass through the pin holes of the protruding portion, thereby enabling a high-strength joint between the wooden shaft member and the other member. [Effects of the Invention]
[0039] As can be understood from the above explanation, the joint structure of the wooden shaft member of the present invention can suppress cross-sectional defects in the wooden shaft member and suppress the concentration of stress acting on the wooden shaft member from the drift pin. [Brief explanation of the drawing]
[0040] [Figure 1A] This diagram illustrates the joint structure of a wooden stile member to which conventional mortise pipes are applied, and is an enlarged view of the end grain side of a longitudinal cross-sectional view obtained by cutting the wooden stile member in the direction along its longitudinal direction. [Figure 1B] This is a view from arrow BB in Figure 1A. [Figure 2A] This diagram illustrates the joint structure of a wooden slat member to which conventional round steel is used, and is an enlarged view of the end grain side of a longitudinal cross-sectional view obtained by cutting the wooden slat member in the direction along its longitudinal direction. [Figure 2B] This is a view from arrow BB in Figure 2A. [Figure 3A] This figure illustrates the joint structure of a wooden slat member according to an embodiment, and is an enlarged view of the end grain side of a vertical cross-sectional view obtained by cutting the wooden slat member in a direction along the longitudinal direction. [Figure 3B] This is a view from arrow BB in Figure 3A. [Modes for carrying out the invention]
[0041] The joint structure of the wooden stile member according to the embodiment will be described below with reference to the attached drawings. In this specification and drawings, substantially identical components may be denoted by the same reference numerals to avoid redundant explanations.
[0042] [Joint structure of wooden frame member according to the embodiment] Referring to Figure 3, the joint structure of the wooden slat member according to the embodiment will be described. Here, Figure 3A is a diagram illustrating the joint structure of the wooden slat member according to the embodiment, and is an enlarged view of the end grain side of a longitudinal cross-sectional view obtained by cutting along the longitudinal direction of the wooden slat member, and Figure 3B is a view taken along arrow BB in Figure 3A.
[0043] In the illustrated joint structure 60, a circular groove 16 (an example of an endless groove) with a circular shape in plan view (an example of a frame shape in plan view) is machined as a pre-groove from the end grain surface 12 of the wooden shaft member 10 to the interior, and a cylindrical body 41 of a cylindrical steel cylindrical member 40, which has a shape complementary to the circular groove 16, is fitted into this circular groove 16.
[0044] In other words, a portion 10A of the wooden shaft member 10 remains inside the circular groove 16, and, as explained with reference to Figure 1A, for example, the internal wooden shaft member is not completely removed, unlike in conventional mortise pipes.
[0045] A closing plate 46 is provided at the end of the cylindrical body 41, and its inner surface 46a is in contact with the end grain surface 12.
[0046] The outer surface 46b of the closing plate 46 is welded or bolted to other members not shown, such as steel members formed from shaped steel materials like H-beams, or separate wooden stile members.
[0047] The cylindrical body 41 is provided with multiple sets of pin holes 43 and 44 (two sets each in the illustrated example) at positions in multiple stages along its longitudinal direction (four stages in the illustrated example) and at corresponding positions that straddle the wooden shaft member in the hollow 42 of the cylindrical body 41, through which drift pins 27 and 28 are inserted in mutually orthogonal directions. The joint structure 60 is formed when the corresponding drift pins 27 and 28 are driven in from the side surface 11 of the wooden shaft member 10 so as to pass through each set of pin holes 43 and 44.
[0048] The wooden axial member 10 in the illustrated example has a cross-sectional shape perpendicular to its longitudinal direction that is a square (rectangle) with a side width of B, and is applicable to wooden columns and wooden beams, for example.
[0049] Here, the ratio of the outer diameter of the cylindrical body (φ3) to the maximum width of the end edge length at the end face of the wooden shaft member (in the illustrated example, the width of each end edge) (φ3 / B) is set to a range of 0.4 to 0.6.
[0050] In the illustrated example of the joint structure 60 of the wooden shaft member, a steel cylindrical member 40 having a complementary shape and a hollow 42 is fitted into an endless groove 16 in the shape of a frame in plan view, which is provided from the end grain surface 12 into the interior of the wooden shaft member 10. Multiple drift pins 27, 28 embedded between a pair of opposing side surfaces 11 of the wooden shaft member 10 pass through corresponding pin holes 43, 44 provided in the cylindrical member 40. As a result, a portion 10A of the wooden shaft member located at the position corresponding to the hollow 42 of the cylindrical member 40 is left in place, thereby suppressing cross-sectional loss of the wooden shaft member.
[0051] Furthermore, unlike solid round steel bars as explained with reference to Figure 2A, the drift pins 27 and 28 are stretched across opposing sides 11 of a cylindrical member 40 with a relatively large outer diameter. Therefore, when a tensile force N acts on the cylindrical member 40, which is connected to other members (not shown), the drift pins 27 and 28 receive component forces of the tensile force from two points at separate locations. As a result, the stress acting on the wooden shaft member 10 from the drift pins 27 and 28 is not a concentrated stress but rather a distributed stress q2 as evenly as possible, preventing cracking and other damage caused by concentrated stress acting on the wooden shaft member 10 from the drift pins 27 and 28. This leads to maximizing the bearing capacity of the wooden shaft member 10.
[0052] Here, as described above, by setting φ3 / B in the range of 0.4 to 0.6, the effect of suppressing stress concentration acting from the drift pins 27 and 28 to the wooden shaft member 10 can be enhanced.
[0053] Ratio: When the ratio φ3 / B is less than 0.4, stress tends to concentrate on the drift pins 27 and 28 inside the hollow 42 of the cylindrical member 40, so 0.4 is set as the lower limit.
[0054] On the other hand, in the range where φ3 / B exceeds 0.6, the distance between the two corresponding pin holes 43 and 44 of the cylindrical member 40 increases, and because the bending of the drift pins 27 and 28 increases in this range, stress tends to concentrate on the drift pins 27 and 28 inside the hollow 42. Therefore, 0.6 is set as the upper limit.
[0055] Thus, since stress does not concentrate on the drift pins 27 and 28, high-strength drift pins capable of withstanding concentrated stresses become unnecessary, leading to a reduction in material costs.
[0056] Furthermore, because the cylindrical member 40 (specifically its cylindrical body 41) is fitted into the endless groove 16, if, for example, a crack occurs in a part 10A of the wooden shaft member located at a position corresponding to the hollow 42 of the cylindrical member 40, the cylindrical body 41 can prevent this crack from spreading radially outward from the wooden shaft member 10.
[0057] Furthermore, as shown in Figure 2A, since a cylindrical member 40 is used instead of a solid steel member, an increase in the amount of steel material can be suppressed.
[0058] Furthermore, since the processing of the wooden shaft member 10 only requires processing an endless groove 16 from the end grain surface 12, relatively simple woodworking is sufficient, allowing the wooden shaft member 10 to be processed with good manufacturability and the joint structure 60 to be formed.
[0059] Furthermore, other embodiments may be used in which other components are combined with the configurations listed in the above embodiments, and the present invention is not limited in any way to the configurations shown herein. In this regard, modifications can be made without departing from the spirit of the present invention, and can be appropriately determined according to the application form.
[0060] For example, although not shown in the diagram, a protruding portion extending from the end grain surface, which is part of the cylindrical member, may be provided with a pair of pin holes at corresponding positions spanning the hollow, and a drift pin embedded between a pair of opposing sides of the other member may be joined to the other member so as to pass through the pin holes of the protruding portion. This joining structure allows for a stronger bond between the wooden shaft member and the other member. [Explanation of Symbols]
[0061] 10: Wooden frame member 10A: Part of a wooden framing member 11: Side view 12: End grain 16: Circular groove (endless groove, leading groove) 27,28: Drift pins 40: Cylindrical member 41: Cylindrical body 42:Hollow 43, 44: Pinholes 46: Occlusion plate 60: Joint structure (Joint structure of wooden frame members)
Claims
1. A joint structure for wooden slat members, in which a wooden slat member is joined to another member, An endless groove, in the shape of a frame in plan view, is provided extending from the end grain surface to the interior of the aforementioned wooden shaft member. A hollow steel cylindrical member having a shape complementary to the endless groove is fitted into the endless groove, with multiple sets of pin holes at corresponding positions across the hollow at multiple stages along its longitudinal direction. A joint structure for a wooden shaft member, characterized in that a plurality of drift pins embedded between a pair of opposing sides of the wooden shaft member pass through the corresponding pin holes.
2. The joint structure for a wooden shaft member according to claim 1, characterized in that the ratio of the outer diameter of the cylindrical member (φ) to the maximum width of the end edge at the end face of the wooden shaft member (φ / B) is in the range of 0.4 to 0.
6.
3. The joint structure for a wooden shaft member according to claim 2, characterized in that the endless groove is a circular groove and the cylindrical member has a cylindrical shape.
4. The joint structure for a wooden shaft member according to claim 1, characterized in that the end of the cylindrical member is closed by a closing plate, and the closing plate is joined to the other member.
5. The joint structure for a wooden shaft member according to claim 2, characterized in that multiple sets of pin holes are provided in the cylindrical member such that the extension directions of the drift pins corresponding to each set are mutually orthogonal to each other.
6. A portion of the cylindrical member is a protruding part that extends from the end grain surface. The aforementioned protruding portion is provided with a pair of pin holes at corresponding positions that straddle the aforementioned hollow, The joint structure for a wooden shaft member according to claim 1, characterized in that a drift pin embedded between a pair of opposing sides of the other member penetrates the pin hole.