Joint structure of wooden truss frame

Abstract

To provide a joint structure that facilitates on-site construction and easily copes with repair of joint members when jointing wooden members gathered at truss nodes of a wooden truss frame.SOLUTION: Material end plates 3 protruding in axial directions of truss members 2 are provided at ends of the truss members 2 at truss nodes where the truss members 2 gather. The material end plates 3 are welded and integrated with fixing plates 3a and are fixed to edges of material ends of the truss members 2 by lag screw bolts 10. Both wing portions 4a of a U-shaped node plate 4 connecting the material end plates 3 of the truss members 2 adjacent to each other have spread according to an angle formed by axes of the truss members 2 and inclination of the material end plates 3 with a bottom portion 4b interposed them. A spread shape of both wing portions 4a is fixed by welding with a rib plate 4c.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a joint structure that joins multiple wooden members that come together at a truss node (a point where the axes of multiple truss members intersect; the same applies below) in a wooden truss structure that uses wood as truss members, such as a single-layer truss structure used for the roofs of buildings, etc. [Background technology]

[0002] Fig. 1 shows an example of the external appearance of a single-layer truss structure (assuming the truss members are made of wood) used for curved roofs such as dome roofs, and Fig. 2 is an enlarged view of the vicinity of the truss node where the truss members come together (the dashed ellipse in Fig. 1). In a single-layer truss structure that forms a curved surface, the nodal members of the truss node section are required to have a structure that can effortlessly join multiple truss members that come together from various directions. Here, the "truss node section" refers to the part where the ends of multiple truss members are joined around the truss node section, and the "nodal member" refers to the member that joins the truss members that come together at the truss node section. The same applies below.

[0003] It is conceptually easy to draw the axis centers of each truss member that converges at a single truss node to a single point without eccentricity; however, in reality, since the members have cross-sections, it is necessary to shorten the members somewhat before the truss node to avoid interference with adjacent members, and the axial directions of the nodal members of adjacent truss nodes (inward and outward directions of the roof) do not necessarily face the same direction (i.e., the axes of both nodal members are in the same plane).

[0004] Therefore, when joining both ends of a truss member to a node member, end plates are attached to both ends of the truss member and the orientation of the cross section (generally in the inward / outward direction of the roof) is determined so that it is effective around the strong axis of the cross section (plane perpendicular to the member axis) of both ends of the truss member.In order to join the face of a gusset plate (hereinafter referred to as a node plate) attached to the node member in an orientation that coincides with its axis (inward / outward direction of the roof) without any gaps, for example with bolts, it is necessary to align the face of the end plate on the truss member side to the inclination angle of the node plate by processing such as twisting the truss member.

[0005] However, while twisting components is relatively easy for steel frame components, it is difficult for wooden components, so it is necessary to devise a shape for the joint metal or joint members attached to both ends of the components.

[0006] Prior art related to joint structures that join multiple wooden members that converge at the truss nodes of a wooden truss frame includes, for example, the invention described in Patent Document 1 and the invention described in Patent Document 2, an unpublished earlier application by the applicant. In the invention described in Patent Document 2, a nodal plate for attaching each of the wooden members is welded to the surface of a nodal member that has a bearing plate installed inside a cylindrical hollow metal fitting as reinforcement, at an angle that matches the surface of a slit 2a (see Figure 2) that is provided at a certain length (depth) from the end face of each of the wooden members that converge from any direction.

[0007] In the invention described in Patent Document 2, the node plates are inserted into slits provided at the ends of each wooden member and secured with through bolts, resulting in extremely compact joints for the wooden truss members. However, there are problems in that the space required for on-site installation of the through bolts is narrow, and because the inclination of the node plates relative to the axis of the cylindrical hollow metal fittings varies, if the error in the direction and inclination angle of even one node plate is too large, the hollow metal fitting that is integrated with the node plate must be replaced in its entirety. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Patent No. 3691926 [Patent Document 2] Patent application No. 2021-065923 Summary of the Invention [Problem to be solved by the invention]

[0009] The present invention aims to provide a joint structure for joining multiple wooden members that converge at truss nodes in a wooden truss frame, which can be easily constructed on-site and which can be dealt with by partially adjusting the node members even if manufacturing defects such as the attachment angle between the node members and the wooden members occur. [Means for solving the problem]

[0010] The means for solving the above problems according to the present invention is a joint structure for a wooden truss frame, in which the truss node portion has the following configuration.

[0011] 1) For truss nodes where multiple truss members come together, the length of the wood of the truss members is determined to be shorter than the distance between two adjacent truss nodes, with a certain distance from the truss node that is sufficient to avoid interference between adjacent truss members, and the ends of the wood of the truss members that come together at the truss node are provided with end plates that protrude in the axial direction of the truss members. 2) Both wings of the U-shaped node plate connecting the end plates of adjacent truss members have a V-shaped spread that matches the angle between the axes of the adjacent truss members and the inclination of the faces of the end plates, and three sides of a trapezoidally attached rib plate near the center of both wings and the bottom face of the U-shaped node plate are joined and fixed so that the V-shaped spread shape is maintained. 3) The surfaces of both wings of the node plate are joined to the surfaces of the end plates of the adjacent truss members with no gap between them by fasteners such as bolts. By this, the bottom of the U-shaped node plate is arranged to form a ring-shaped truss node. There are.

[0012] Since the present invention is configured as described above, when the opening angle and the inclination angle of the faces of the two wings of the node plate are matched to the axial direction of the truss members that converge at the truss node and the inclination of the faces of the member end plate, by arbitrarily determining the direction of the bottom face (the inward and outward direction of the roof), a U-shaped spreading shape is uniquely determined with the correlation line where the planes of the two wings and the bottom intersect as the bending line, so that the shape of the node plate can be easily determined with a high degree of freedom.

[0013] When all the truss members gathered at the truss node have been joined, the truss node is closed into a ring shape by the two wing portions of the joined node plate and the end plates of the truss members.The rib plates that fix the spread shape of the two wing portions of the node plate play the role of reinforcing and stiffening the truss node, improving the structural stability of the wooden truss structure.

[0014] In addition, since the bottom of the U-shaped node plate has a constant width and space is secured between the two wing portions, installation work of bolts etc. joining the end plate to the two wing portions is easy.

[0015] Furthermore, if the shape or dimensional accuracy of the U-shaped node plate exceeds the allowable limit and the node plate cannot be joined to the end plates of the truss members to be attached to both wings without any gaps, it is sufficient to replace only the node plate that exceeds the allowable limit.

[0016] As mentioned above, the shape of the node plate can be easily determined with a high degree of freedom, so that the re-production by replacement is easy, and the end plate can be left as it is.

[0017] The present invention also relates to a joint structure for a wooden truss frame, characterized in that a flange portion is provided on one or both edges of the end plate of the truss member.

[0018] By providing a flange portion on one or both edges of the end plate, the bending rigidity of the end plate in the out-of-plane direction is improved, so that when the truss member is subjected to a compressive force, local bending of the end plate alone that does not overlap with the two wing portions of the node plate, which can occur if the end plate is a thin plate, is less likely to occur, and node rotation, which is known as an unstable phenomenon at truss nodes, can be prevented.

[0019] The present invention also provides another method for preventing the instability phenomenon, which is to end This is a joint structure of a wooden truss frame, characterized by the fact that connecting restraint materials are attached to connect the sections together.

[0020] The stress state of the truss members concentrated at the truss nodes is not necessarily uniform, and it is thought that the rotation of the node is triggered by the bending deformation of one of the end plates of the truss members that has the least surplus strength under axial force. end By connecting the sections with the connecting restraint material, bending deformation of the end plates is suppressed and nodal rotation is avoided. Effect of the Invention

[0021] Since the present invention is a joint structure for a wooden truss frame as described above, it has the following effects.

[0022] 1) In wooden truss structures, wooden members that converge at truss nodes from any direction can be easily joined on-site using steel plates and bolts. 2) The U-shaped node plates of the truss nodes are individually manufactured to match the axial direction of the wooden members that come together at the truss node and the inclination of the end plates. Therefore, if there is a problem with the joint during assembly, only the node plate at that point can be easily remanufactured and replaced, leaving the end plates of the truss members intact. 3) Ribs are attached to the U-shaped node plates of the truss nodes, which increases the strength and rigidity of the assembled truss nodes and improves the structural stability of the wooden truss structure. 4) When a flange is provided on the end plate of a truss member, or when adjacent truss members end When the sections are connected with connecting restraint materials, it is effective in preventing node rotation, which is an unstable phenomenon at the truss node. [Brief description of the drawings]

[0023] [Figure 1] FIG. 1 is an image diagram showing an example of a single-layer truss structure using wood for the truss members. [Diagram 2] FIG. 2 is an enlarged view of the vicinity of a truss node where truss members are assembled (the dashed ellipse in FIG. 1). [Diagram 3] FIG. 2 is a perspective view of a truss node portion in the first embodiment of the present invention. [Figure 4] FIG. 4 shows an exploded view of a portion of the truss node in FIG. 3, where (a) is a diagram showing the state before the U-shaped node plate and the end plate are joined, and (b) is an exploded view of the node plate. [Diagram 5] FIG. 13 is a perspective view showing an alternative design for an end plate of a truss member, fixed to a wooden member with a drift pin. [Figure 6] This is a second embodiment of the present invention, in which a flange portion is provided on the lower edge of the end plate of the truss member, where (a) is an oblique view corresponding to the end plate shown in Figure 4(a), and (b) is an oblique view corresponding to the end plate shown in Figure 5. [Figure 7] FIG. 11 is a perspective view showing a third embodiment of the present invention, illustrating an example of a state in which shaft ends of adjacent truss members are connected to each other by a connecting restraint material. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] A first embodiment of the present invention will be described with reference to Figures 3 to 5. Figure 3 is a perspective view of a truss node 1 assuming a single-layer truss frame made of wooden members, and Figure 4(a) is a partial view of the truss node 1 in Figure 3 before it is assembled.

[0025] At the truss node where multiple truss members 2, 2, ... come together, the length of the wood of the truss members 2, 2, ... is determined by subtracting a certain dimension from the truss node, and at the ends of the truss members 2, 2, ... that are joined to the truss node portion 1, end plates 3, 3, ... are provided that protrude in the axial direction of the truss members 2, 2, ....

[0026] Referring to FIG. 4(a), the end plates 3, 3 are welded to the fixing plates 3a, 3a to form an integrated unit, and are fixed to the ends of the truss members 2, 2 by lag screw bolts 10, 10, . . .

[0027] As shown in FIG. 4(a), the two wings 4a, 4a of the U-shaped node plate 4 connecting the end plates 3, 3 of the adjacent truss members 2, 2 sandwich the bottom part 4b, and the angle formed by the axes of the truss members 2, 2 and the angle of the end plates 3, 3 are in the range of 0.05 to 0.05 mm. Face According to the inclination V-shaped The two wings 4a, 4a have a wide width. V-shaped The spreading shape To be retained , both wing portions 4a, 4a and bottom portion 4b Face Near the center To , Trapezoidal Rib plate 4c The three sides of It is fixed by welding.

[0028] As shown in FIG. 4(b), the joint plate 4 is made up of four parts: two wing parts 4a, a bottom part 4b, and a rib plate 4c. The shape and dimensions of the joint plate 4 after assembly by welding depend on the angle between the axes of the adjacent truss members 2 and the angle between the end plates 3 and 3. Face Each of the wings 4a, 4a and the bottom 4b may be made by bending a single plate.

[0029] When assembling the truss members 2, 2 and the node plate 4, the faces of the end plates 3, 3 are overlapped with the faces of the two wing portions 4a, 4a and joined with bolts (not shown). However, if it is not possible to tighten them without any gaps, the node plate 4 can be remade to fit the end plates 3, 3.

[0030] When all the truss members 2, 2, ... gathered at the truss node 1 are joined, the truss node 1 is closed in a ring shape by joining both wing parts 4a, 4a, ... of the node plates 4, 4, ... to the end plates 3, 3, ... of the truss members 2, 2, .... V-shaped The rib plates 4c, 4c, ... that fix the spreading shape play a role in reinforcing and stiffening the truss node 1 against the stress acting on it, and contribute to improving the structural stability of the single-layer truss structure made of wooden members.

[0031] In addition, the bottom 4b of the U-shaped node plate 4 has a certain width and space is secured between the two wing portions 4a, 4a, making it easy to insert and tighten bolts (not shown) through the bolt holes 11, 11, ... provided in each of the end plates 3, 3 and the two wing portions 4a, 4a.

[0032] The end plate 3 of the truss member 2 may not be fixed by the lag screw bolts 10, 10, ... as shown in Fig. 4(a), but may be inserted into the slit 2a of the truss member 2 and fixed by drift pins 12, 12, ... as shown in Fig. 5. Of course, the method of fixing the end plate 3 to the truss member 2 is not limited to these.

[0033] As a method of attaching the end plate 3 according to the present invention, a flange portion 3b may be integrally provided on the lower edge of the end plate 3 as shown in Fig. 6. Fig. 6(a) shows the case where the flange portion 3b is attached to the lower edges of the end plate 3 and the anchor plate 3a by welding, and Fig. 6(b) shows the case where the flange portion 3b is attached to the lower edge of the end plate 3 that extends into the slit 2a by welding and fixed to the underside of the truss member 2 with set screws 13, 13, ...

[0034] The flange portion 3b is provided on the end plate 3 because, in a single-layer truss structure, if the bending rigidity of the end joint of the truss member joined to the truss node portion 1 is low, an instability phenomenon that causes node rotation is known. As described above, by attaching the flange portion 3b to the end plate 3 of the truss member 2, the bending rigidity of the end plate 3 in the out-of-plane direction is increased, which is effective in preventing this instability.

[0035] In addition, the flange portion 3b shown in Figure 6 is attached to only one side of the end plate 3. If the flange portion 3b were on both sides of the end plate 3, the holt tightening tool would not be able to be inserted when the end plates 3, 3 are joined to the two wing portions 4a, 4a of the node plate 4 with bolts, so it is necessary to leave one side open.

[0036] Of course, the flange portions 3b may be attached to both the upper and lower edges of the end plate 3 (not shown), in which case the bending rigidity in the out-of-plane direction is further increased, and the effect of preventing instability is further increased.

[0037] As another method for preventing the instability phenomenon, for example, as shown in Figure 7, a method of connecting the axial ends of adjacent truss members 2, 2 with connecting restraint members 14, 14 can be considered. In Figure 7, the axial ends of the truss members 2, 2 are connected at two points, the top and bottom, but a certain degree of effect can be expected with just one point at one end or the middle.

[0038] The stress state of the truss members 2, 2, ... that gather at the truss node 1 is not necessarily uniform, and it is thought that bending deformation in any of the end plates 3 of the truss members 2, 2, ... that gather at the truss node 1, which has the least amount of spare strength, will trigger node rotation. However, by connecting the axial ends of adjacent truss members 2, 2, ... with connecting restraint members 14, 14, ..., the progression of bending deformation of the end plates 3 is suppressed and node rotation is avoided. [Industrial Applicability]

[0039] According to the present invention, in a truss structure using wooden members, on-site construction is easy when joining multiple wooden members that converge at a truss node from any direction, and adjustments to the node members are also easily accommodated, thereby contributing to the spread of single-layer truss structures and the like that use wooden members. [Explanation of symbols]

[0040] 1: Truss node 2: Truss member 2a: Slit 3: End plate 3a: Fixed version 3b: Flange part 4: Nodal plate 4a: Both wings 4b: Bottom 4c: Rib plate 10: Lug screw bolt 11: Bolt hole 12: Drift pin 13: Set screw 14: Connecting restraint material

Claims

1. In the joint structure of a wooden truss structure using wood as a truss member, 1) For truss nodes where multiple truss members come together, the length of the wood of the truss members is determined to be a certain distance from the truss node that is sufficient to avoid interference between adjacent truss members, and is shorter than the distance between two adjacent truss nodes, and an end plate protruding in the axial direction of the truss member is provided at the end of the wood of the truss members that come together at the truss node. 2) Both wings of the U-shaped node plate connecting the end plates of adjacent truss members have a V-shaped spread that matches the angle between the axes of the adjacent truss members and the inclination of the faces of the end plates, and three sides of a trapezoidally attached rib plate near the center of both wings and the bottom face of the U-shaped node plate are joined and fixed so that this V-shaped spread shape is maintained. 3) The surfaces of both wings of the node plate are joined to the surfaces of the end plates of the adjacent truss members without any gaps using fastening material, so that the bottom of the U-shaped node plate forms a ring-shaped truss node. A joint structure for a wooden truss frame, characterized by comprising the above configuration.

2. 2. A joint structure for a wooden truss frame according to claim 1, wherein a flange portion is provided on the upper edge or on the upper edge and lower edge of the end plate.

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