Roof structure

Abstract

To provide a roof structure in which joining work can be made easier, joint parts with high strength and rigidity can be realized, and appropriate performance of joining can be confirmed afterwards.SOLUTION: A roof structure according to the present invention includes a horizontal member 1 that has a through hole 12 extending from a lower surface 10 to an upper surface 11, a first fastening body 3 inserted into the through hole 12 from the lower surface 10 of the horizontal member 1, a rafter member 2 placed on the horizontal member 1, and a second fastening body 4 disposed inside or on the rafter member 2. The horizontal member 1 and the rafter member 2 are fastened by threadedly connecting the first and second fastening bodies 3 and 4, the first fastening body 3 has a head 30 that can be rotated through operation from below the horizontal member 1, and the second fastening body 4 is configured or placed so that co-rotation when threadedly connected with the first fastening body 3 is restricted.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a roof structure in which a horizontal member and a rafter member are joined together.

Background Art

[0002] Examples of this type of roof structure that have been conventionally used include the structures shown in Patent Documents 1 and 2 below.

[0003] Patent Document 1 discloses a structure in which a horizontal member (upper frame member) of a roof and a rafter member are joined by a joining metal fitting. The joining metal fitting is formed by bending a flat steel plate having a predetermined plate thickness into a predetermined shape, and has abutting portions that abut against the horizontal member and the rafter member. The horizontal member and the rafter member are joined via the joining metal fitting by driving screws into the abutting portions with the respective abutting portions abutted against the horizontal member and the rafter member.

[0004] Patent Document 2 discloses a structure in which a horizontal member (eaves beam and main roof) of a roof and a rafter member are joined by long screws. The long screws are driven so as to penetrate the field board and the rafter member from above the field board and reach the horizontal member with the field board and the rafter member placed on the horizontal member.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] When using metal connectors as disclosed in Patent Document 1, it is necessary to install the connectors after the rafter members have been precisely positioned, which requires skilled labor. Similarly, when using screws as disclosed in Patent Document 2, it is necessary to install the screws after the rafter members have been precisely positioned, which also requires skilled labor. Furthermore, after other members have been placed on top of the roof sheathing, it is not possible to check the screws used to join the rafter members, making it difficult to later confirm that the joints have been properly made. Moreover, in both the case of metal connectors and screws, there is room for improvement in the load-bearing capacity and rigidity of the joints.

[0007] This invention was made to solve the above-mentioned problems, and one of its objectives is to provide a roof structure that makes joining work easier, realizes a joint with high load-bearing strength and rigidity, and allows for later confirmation that the joining has been done properly. [Means for solving the problem]

[0008] In one embodiment, the roof structure according to the present invention comprises a horizontal member having a through hole extending from the bottom surface to the top surface, a first fastener inserted through the through hole from the bottom surface of the horizontal member, a rafter member resting on the horizontal member, and a second fastener positioned inside or on top of the rafter member, wherein the horizontal member and the rafter member are fastened together by screwing the first and second fasteners, the first fastener having a head that can be rotated by operation from below the horizontal member, and the second fastener being configured or positioned so as to restrict co-rotation with the first fastener when screwed together. [Effects of the Invention]

[0009] According to one embodiment of the roof structure of the present invention, the horizontal member and the rafter member are fastened together by screwing together first and second fasteners. The first fastener has a head that can be rotated by operation from below the horizontal member, and the second fastener is configured or arranged so as to restrict co-rotation when screwed together with the first fastener. This makes the joining work easier, enables the realization of a joint with high load-bearing strength and rigidity, and allows for later confirmation that the joining has been properly performed. [Brief explanation of the drawing]

[0010] [Figure 1] This is a side view showing a roof structure according to Embodiment 1 of the present invention. [Figure 2] This is a cross-sectional view of a rafter member along line II-II in Figure 1. [Figure 3] This is a perspective view showing the first and second fastening components. [Figure 4] Figure 3 is a perspective view showing the first modified example of the washer. [Figure 5] Figure 3 is a perspective view showing a second modified example of the washer. [Figure 6] Figure 3 is a perspective view showing a third modified example of the washer. [Figure 7] Figure 3 is a perspective view showing a fourth modified example of the washer. [Figure 8] Figure 1 is a perspective view showing a roof panel unit including rafter members. [Figure 9] This is a flowchart showing a roof construction method according to an embodiment of the present invention. [Figure 10] This is a side view showing a roof structure according to Embodiment 2 of the present invention. [Figure 11] This is a side view showing a first modified example of the roof structure shown in Figure 10. [Figure 12] This is a side view showing a second modified example of the roof structure shown in Figure 10. [Figure 13] This is a side view showing a roof structure according to Embodiment 3 of the present invention. [Figure 14] Figure 13 is a perspective view showing the washer. [Figure 15]It is a side view showing the roof structure according to Embodiment 4 of the present invention. [Figure 16] It is a side view showing the roof structure according to Embodiment 5 of the present invention. [Figure 17] It is a side view showing the roof structure according to Embodiment 6 of the present invention. [Figure 18] It is a perspective view showing the field board and washer of FIG. 17. [Figure 19] It is a side view showing the roof structure according to Embodiment 7 of the present invention. [Figure 20] It is a perspective view showing the second fastening body of FIG. 19. [Figure 21] It is a plan view showing the in-plane shear test of the roof structure. [Figure 22] It is a graph showing the in-plane shear test results of the roof structure in the examples. [Figure 23] It is a graph showing the in-plane shear test results of the roof structure in the comparative examples.

Embodiments for Carrying Out the Invention

[0011] Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. The present invention is not limited to each embodiment, and components can be deformed and embodied without departing from the gist thereof. Also, various inventions can be formed by appropriately combining a plurality of components disclosed in each embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, components of different embodiments may be appropriately combined.

[0012] Embodiment 1. Figure 1 is a side view showing a roof structure according to Embodiment 1 of the present invention, Figure 2 is a cross-sectional view of the rafter member 2 along line II-II in Figure 1, and Figure 3 is a perspective view showing the first and second fasteners 3 and 4. Furthermore, Figure 4 is a perspective view showing a first modified example of the washer 41 in Figure 3, Figure 5 is a perspective view showing a second modified example of the washer 41 in Figure 3, Figure 6 is a perspective view showing a third modified example of the washer 41 in Figure 3, and Figure 7 is a perspective view showing a fourth modified example of the washer 41 in Figure 3. Note that in Figure 1, a portion of the lip 22 of the rafter member 2 is cut out to reveal the second fastener 4.

[0013] The roof structure shown in Figure 1 can constitute part of a structure such as a wooden house. As shown in Figure 1, the roof structure of this embodiment includes a horizontal member 1, rafter members 2, a first fastener 3, and a second fastener 4.

[0014] The horizontal member 1 and the rafter member 2 are longitudinal members arranged so that their respective axial directions 1a and 2a (longitudinal directions) intersect each other. Preferably, the axial direction 1a of the horizontal member 1 is perpendicular to the axial direction 2a of the rafter member 2. The horizontal member 1 may be a horizontally extending member such as a purlin or eaves beam. The rafter member 2 rests on the horizontal member 1. In other words, the rafter member 2 is positioned on top of the horizontal member 1. Although not shown in Figure 1, other members such as roof sheathing 50, waterproof sheeting 52, and roofing material 51 (tiles, etc.) may be positioned on top of the rafter member 2 (see Figure 8).

[0015] In this embodiment, the rafter member 2 extends at an inclination with respect to the horizontal direction. More specifically, the rafter member 2 extends at an inclination such that one end in the axial direction 2a is located above the other end. The upper end of the rafter member 2 can be located on the ridge side of the roof, and the lower end of the rafter member 2 can be located on the eaves side of the roof. The inclination angle of the rafter member 2 with respect to the horizontal direction may differ for each roof of the structure.

[0016] In this embodiment, the horizontal member 1 is made of wood. However, the horizontal member 1 may be made of metal, such as a rectangular steel pipe. The horizontal member 1 has a lower surface 10 and an upper surface 11 that are spaced apart from each other in the vertical direction. The lower surface 10 may extend in the horizontal direction. The upper surface 11 may extend at an inclination with respect to the extended surface of the lower surface 10. The inclination angle of the upper surface 11 with respect to the lower surface 10 may be equal to the inclination angle of the rafter member 2 with respect to the horizontal direction.

[0017] The rafter member 2 in this embodiment is made of structural steel. More specifically, the rafter member 2 is made of hollow structural steel having an open cross-section. Even more specifically, the rafter member 2 is made of lip channel steel having a web 20, a pair of flanges 21 extending from the upper and lower ends of the web 20, and a pair of lips 22 extending from the tips of each flange 21 in a direction toward each other. In the illustrated embodiment, the outer surface of the lower flange 21 rests on the upper surface 11 of the horizontal member 1, but the orientation of the structural steel is not limited to this, and the structural steel may be used in other orientations, for example, with the outer surface of the web 20 resting on the upper surface 11 of the horizontal member 1. However, the rafter member 2 may also be made of hollow steel pipe (such as a square steel pipe) having a closed cross-section.

[0018] These horizontal members 1 and rafter members 2 are fastened and joined by first and second fasteners 3 and 4. The fastening and joining of the horizontal members 1 and rafter members 2 by the first and second fasteners 3 and 4 will be described in more detail below.

[0019] The horizontal member 1 has a through hole 12 that extends from the lower surface 10 to the upper surface 11. The first fastener 3 is inserted through the through hole 12 from the lower surface 10 of the horizontal member 1. The second fastener 4 is positioned inside or on top of the rafter member 2. In this embodiment, the second fastener 4 is positioned inside the rafter member 2. The horizontal member 1 and the rafter member 2 are fastened and joined by screwing these first and second fasteners 3 and 4 together. The first fastener 3 has a head 30 that can be rotated by operation from below the horizontal member 1, and the second fastener 4 is configured or positioned so as to restrict co-rotation when screwed with the first fastener 3. That is, the first and second fasteners 3 and 4 are configured to be screwed together by rotating the head 30 from below the horizontal member 1 without manually holding the second fastener 4.

[0020] Since the horizontal member 1 and the rafter member 2 are fastened and joined by screwing together the first and second fasteners 3 and 4, misalignment of the horizontal member 1 and the rafter member 2 is permissible as long as the first and second fasteners 3 and 4 can be screwed together, making the joining work easier compared to conventional configurations using metal fasteners or long screws. Furthermore, since the horizontal member 1 and the rafter member 2 are fastened together, a joint with higher load-bearing capacity and rigidity can be achieved compared to conventional configurations using metal fasteners or long screws. In addition, since the first fastener 3 has a head 30 that can be rotated by operation from below the horizontal member 1, even after the roof sheathing, waterproof sheet and / or roofing material are placed on top of the rafter member 2, it is possible to check whether the horizontal member 1 and the rafter member 2 are properly joined by checking the first fastener 3 from below the horizontal member 1.

[0021] Although Figure 1 shows only one through-hole 12, the horizontal member 1 may have multiple through-holes 12 spaced apart from each other in the axial direction 1a. The through-holes 12 may be positioned at the lower part of the rafter member 2. As shown in Figure 1, the through-holes 12 may be positioned at the center of the horizontal member 1 in the direction perpendicular to the axis 1b (width direction). The through-holes 12 may be positioned so as to include the center of the horizontal member 1 in the direction perpendicular to the axis 1b inside. The cross-sectional shape of the through-hole 12 may be circular, but it may also be other shapes such as a rectangle. The diameter or width of the through-hole 12 is sized so that the first fastener 3 (especially the nut 31 described later) can move back and forth. Also, the diameter or width of the through-hole 12 is sized so that the first fastener 3 (especially the nut 31 described later) can rotate inside the through-hole 12. The through-hole 12 may be an elongated hole in which the dimension in the axial direction 1a of the horizontal member 1 is larger than the dimension in the direction 1b perpendicular to the axis of the horizontal member 1.

[0022] The interior of the rafter member 2 can be the space enclosed by the wall portion of the rafter member 2 when viewed in a cross-section perpendicular to the axial direction 2a of the rafter member 2. When an open-section steel section is used as the rafter member 2, as in this embodiment, the space enclosed by the straight line connecting the ends of the open portion of the rafter member 2 and the wall portion of the rafter member 2 can be understood as the interior of the rafter member 2. For example, in the case of a lip channel steel section, the space enclosed by the straight line connecting the wall portion such as the web 20 and the tip of the lip 22 can be understood as the interior of the rafter member 2.

[0023] The head 30 of the first fastener 3 may protrude from the lower surface 10 of the horizontal member 1, as shown in the illustrated configuration. However, the head 30 of the first fastener 3 may be housed in a recess provided on the lower surface 10.

[0024] The method of configuring or arranging the second fastener 4 so as to restrict co-rotation when screwed with the first fastener 3 is arbitrary. The second fastener 4 may be configured or arranged so as to receive a reaction force from other members such as the rafter member 2 when screwed with the first fastener 3. For example, the second fastener 4 may restrict co-rotation by contact or fitting with other members such as the rafter member 2, or by being fixed to other members. In this embodiment, as will be explained in detail later, the rotation of the second fastener 4 is restricted by the corner portion 40b of the square-head bolt 40 being inserted (fitted) into the opening 41a of the washer 41, and by the washer 41 being positioned (fitted) between the web 20 and the lip 22 of the rafter member 2. However, other methods may be used, such as providing a hole or groove in the flange 21 into which at least a part of the washer 41 fits, or fixing the washer 41 to the rafter member 2 by welding or other methods.

[0025] The second fastening body 4 may have a square-head bolt 40 and a washer 41.

[0026] As is particularly evident in Figure 3, the square-head bolt 40 is a bolt in which a corner portion 40b is provided at the base of the shaft portion 40a. The outer circumference of the shaft portion 40a is threaded. The base of the shaft portion 40a is the connection part between the head portion 40c and the shaft portion 40a, and is sometimes called the neck portion. The corner portion 40b is the part with a polygonal cross-section. The width of the corner portion 40b is greater than the diameter of the shaft portion 40a. Also, the width of the corner portion 40b is smaller than the diameter of the head portion 40c. The width of the corner portion 40b may be the dimension between a pair of opposite sides, or the diameter of the smallest circle that can contain the cross-section of the corner portion 40b.

[0027] The washer 41 is a member provided with an opening 41a through which the shaft portion 40a and corner portion 40b of the square-head bolt 40 can be inserted. The corner portion 40b of the square-head bolt 40 is inserted through the opening 41a of the washer 41. The washer 41 may be configured or positioned to take reaction force from the rafter member 2 or from the roof sheathing fixed to the upper part of the rafter member 2 when the square-head bolt 40 is screwed into the first fastener 3. In this way, the corner portion 40b of the square-head bolt 40 is inserted into the opening 41a of the washer 41, and the washer 41 takes reaction force from the rafter member 2 or roof sheathing, thereby restricting the co-rotation of the second fastener 4 when screwed into the first fastener 3. When the second fastener 4 or the washer 41 is located inside the rafter member 2, as in this embodiment, the washer 41 may be configured or positioned to take reaction force from the rafter member 2. When the second fastener 4 or washer 41 is positioned on the upper part of the rafter member 2, as will be described later in another embodiment, the washer 41 may be configured or positioned to take reaction force from the roof sheathing.

[0028] The washer 41 has a lower surface 41c that extends at an angle corresponding to the inclination of the rafter member 2 relative to the horizontal member 1, such that the upper surface 41b extends horizontally when the washer 41 is placed inside or on top of the rafter member 2. The lower surface 41c may be an actual wall surface, as shown in the second modified example in Figure 5, or it may be a virtual surface (a surface that contacts those ends) defined by the ends of the washer 41 that come into contact with other members when the washer 41 is placed on other members. Having such a lower surface 41c allows the square-head bolt 40 to be positioned vertically more reliably, even when the rafter member 2 is positioned at an inclination relative to the horizontal, and the horizontal member 1 and the rafter member 2 can be fastened more reliably.

[0029] The washer 41 may be a member formed by bending a plate. The washer 41 may also have a base 41d and at least one leg 41e extending from at least one end of the base 41d. The leg 41e may extend from the ends of the base 41d spaced apart in the axial direction 2a of the rafter member 2. The washer 41 is configured such that the base 41d extends horizontally when the washer 41 is placed inside the rafter member 2, due to the difference in the protruding lengths of the at least one leg 41e from the base 41d. This allows the upper surface 41b of the washer 41 to extend horizontally more reliably.

[0030] In the washer 41 shown in Figure 3, the leg portion 41e extends from one end of the base portion 41d, while the leg portion 41e does not extend from the other end of the base portion 41d. That is, there is a significant protrusion length of the leg portion 41e at one end of the base portion 41d, while the protrusion length of the leg portion 41e is zero at the other end of the base portion 41d. The lower surface 41c is defined by the surface where the other end of the base portion 41d and the tip of the leg portion 41e are in contact. When the washer 41 is placed inside or on top of the rafter member 2, one end of the base portion 41d may be located on the eaves side of the roof, and the other end of the base portion 41d may be located on the ridge side of the roof.

[0031] As shown in the first modified example in Figure 4, the legs 41e (first and second legs 41e1, 41e2) may extend from both ends of the base 41d. The protruding length of the first leg 41e1 from the base 41d is longer than the protruding length of the second leg 41e2 from the base 41d. Also, as shown in the second modified example in Figure 5, the washer 41 may be a block-shaped member. Such a block-shaped washer 41 can be cut from a thick plate.

[0032] As shown in the third modified example in Figure 6, the legs 41e (first and second legs 41e1, 41e2) may extend from both sides of the base 41d. In this embodiment as well, the protruding length of the leg 41e at one end of the base 41d can be made longer than the protruding length of the leg 41e at the other end of the base 41d.

[0033] Furthermore, as shown in Figure 7, the washer 41 may be a square washer, as in the fourth modified example. A square washer is made by deforming a rectangular plate and has a plate-shaped base 41g, a deformed portion 41h that protrudes or extends from the base 41g, and a plurality of locking claws 41j formed on the outer edge of the base 41g. The deformed portion 41h has an upper surface 41b that extends inclined with respect to the lower surface 41c of the base 41g. The inclination angle of the upper surface 41b with respect to the lower surface 41c is set so that the upper surface 41b extends horizontally when the washer 41 in Figure 7 is placed inside or on top of the rafter member 2. The deformed portion 41h is hollow and has an opening 41a on its upper surface 41b. The shaft portion 40a and the corner portion 40b of the square-head bolt 40 can be inserted through this opening 41a. When the side of the deformed portion 41h that protrudes from the base portion 41g is considered the front side of the base portion 41g, the locking claws 41j are formed by bending a plate material on the back side of the base portion 41g. In the illustrated embodiment, locking claws 41j are provided at the four corners of the base portion 41g. That is, four locking claws 41j are provided. However, the number of locking claws 41j is arbitrary, and the locking claws 41j at any of the corners may be omitted, or locking claws 41j may be provided on the sides between the four corners. Note that when the washer 41 is placed inside the rafter member 2 as in this embodiment, all locking claws 41j may be omitted. The locking claws 41j are particularly useful when the washer 41 is placed on the upper part of the rafter member 2, more specifically in the embodiment where the washer 41 is placed on the upper part of the roof sheathing 50, as will be explained later with reference to the figures. The locking claws 41j can bite into the roof sheathing 50 to stop the rotation of the washer 41.

[0034] The washer 41 is positioned inside the rafter member 2, more specifically between the web 20 and the lower lip 22 of the rafter member 2, and rests on the lower flange 21. The washer 41 is prevented from rotating together with the first fastener 3 when screwed in by contact with the web 20 and the lip 22 or by being fitted between the web 20 and the lip 22. The lower surface 41c may correspond to the inner surface of the flange 21.

[0035] It is preferable that the inner wall-to-inner wall dimension D1 of the rafter member 2 in the direction perpendicular to the axis 2b is equal to the outer wall-to-inner wall dimension D2 of the washer 41 in the direction perpendicular to the axis 2b of the rafter member 2. By making the inner wall-to-inner wall dimension D1 of the rafter member 2 equal to the outer wall-to-inner wall dimension D2 of the washer 41, the rotation of the washer 41 can be more reliably restricted. The inner wall-to-inner wall dimension D1 of the rafter member 2 may be the dimension between the inner surfaces of the web 20 and the lip 22 in the direction perpendicular to the axis 2b. The outer wall-to-inner wall dimension D2 of the washer 41 may be the width of the base 41d or leg 41e in the direction perpendicular to the axis 2b. Note that the statement that the inner wall-to-inner wall dimension D1 of the rafter member 2 is equal to the outer wall-to-inner wall dimension D2 of the washer 41 includes not only cases where these inner wall-to-inner wall dimensions D1 and outer wall-to-inner wall dimensions D2 are strictly equal, but also cases where these inner wall-to-inner wall dimensions D1 and outer wall-to-inner wall dimensions D2 are substantially equal. For example, when the ratio of the outer wall dimension D2 to the inner wall dimension D1 (D2 / D1) is 80% or more and 100% or less, it can be understood that these inner wall dimension D1 and outer wall dimension D2 are equal.

[0036] The lower flange 21 of the rafter member 2 is provided with an opening 21a through which the shaft portion 40a of the square-head bolt 40, which is combined with a washer 41, can be inserted. Preferably, the washer 41 and the square-head bolt 40 are sized to allow temporary fastening when they are positioned inside the rafter member 2. That is, it is preferable that the washer 41 and the square-head bolt 40 do not fall off when the rafter member 2 is moved with the washer 41 and the square-head bolt 40 positioned on the flange 21, even without manually holding them. This temporary fastening can be achieved by inserting the shaft portion 40a of the square-head bolt 40 into the opening 21a. More specifically, the washer 41 and the square-head bolt 40 can be temporarily fastened if the shaft portion 40a of a predetermined length or longer (for example, 20 mm or more) passes through the opening 21a. The corner portion 40b of the square-head bolt 40 may or may not enter the opening 21a of the flange 21. As will be shown later in another embodiment, the rotation of the square-head bolt 40 may be restricted by fitting the corner portion 40b into the opening 21a of the flange 21 or the through hole 12 of the horizontal member 1 (see Figure 15).

[0037] The first fastening body 3 may have a nut body 31 that can be screwed onto the square-head bolt 40, and a bolt 32 that is screwed onto the nut body 31. The nut body 31 has a certain length and is sometimes called a long nut. The nut body 31 may have a square outer shape as shown by the solid line in Figure 3, but it may also have a circular outer shape as shown by the dashed line in Figure 3. The nut body 31 has a shaft hole 31a with threads on its inner circumference. The head 30 described above is provided at one end of the bolt 32. The bolt 32 has a shaft portion 32a that can be screwed into the shaft hole 31a of the nut body 31. The first fastening body 3 may further have a washer 33 that is attached to the bolt 32 so as to be interposed between the lower surface 10 of the horizontal member 1 and the head 30.

[0038] With the shaft portion 32a of the bolt 32 screwed into the shaft hole 31a of the nut body 31, the nut body 31 can be inserted through the through hole 12 (see Figure 1) of the horizontal member 1, and one end of the shaft portion 40a of the square-head bolt 40 can be pressed against one end of the shaft hole 31a of the nut body 31. After this pressing, the head 30 can be rotated to screw the shaft portion 40a of the square-head bolt 40 into the shaft hole 31a of the nut body 31. The square-head bolt 40 can be screwed into the nut body 31 inside the through hole 12.

[0039] Here, it is preferable that the amount of insertion of the bolt 32 into the nut body 31 is greater than the amount of insertion of the square-head bolt 40 into the nut body 31. This allows the amount of friction or resistance between the nut body 31 and the bolt 32 to be greater than the amount of friction or resistance between the nut body 31 and the square-head bolt 40, and by rotating the head 30, the square-head bolt 40 can be screwed into the nut body 31 more reliably.

[0040] Next, Figure 8 is a perspective view showing a roof panel unit 5 including the rafter member 2 of Figure 1. The rafter member 2 may be a single component, but as shown in Figure 8, the rafter member 2 may constitute part of a unitized roof panel unit 5 together with the roof sheathing 50 and roofing material 51. The roof panel unit 5 may also include other components such as a waterproof sheet 52. For illustrative purposes, Figure 8 shows a partially cutaway view of the components. The rafter member 2 can be lifted together with the entire roof panel unit 5 by a crane or the like and positioned above the horizontal member 1. Before the rafter member 2 is positioned above the horizontal member 1, the second fastener 4 (square-head bolt 40 and washer 41) can be placed inside the rafter member 2.

[0041] Next, Figure 9 is a flowchart showing a roof construction method according to an embodiment of the present invention. This roof construction method corresponds to a manufacturing method for producing the roof structure shown in Figure 1. As shown in Figure 9, when constructing a structure such as a wooden house, a horizontal member 1 is installed on top of the structure (step S1). Through holes 12 may be provided in the horizontal member 1 at the construction site, or through holes 12 may be provided in the horizontal member 1 in advance at another location such as a factory.

[0042] Next, the second fastening component 4 (square-head bolt 40 and washer 41) is positioned (step S2). When constructing the roof structure shown in Figure 1, the second fastening component 4 is positioned inside the rafter member 2. More specifically, the square-head bolt 40 is combined with the washer 41, and the square-head bolt 40 and washer 41 are positioned between the web 20 and the lower lip 22 of the rafter member 2. At this time, the shaft portion 40a of the square-head bolt 40 can be passed through the opening 21a of the lower flange 21 of the rafter member 2, and the square-head bolt 40 and washer 41 can be temporarily fastened. This opening 21a may be provided at the construction site, or it may be provided in advance at another location, such as a factory. Steps S1 and S2 may be performed in reverse or simultaneously.

[0043] Next, the rafter member 2 is placed on the horizontal member 1 (step S3). The rafter member 2 is lifted by a crane or the like. When the rafter member 2 constitutes part of the roof panel unit 5, the rafter member 2 is lifted as part of the roof panel unit 5. After step S3, the second fastening members 4 (square-head bolts 40 and washers 41) may be arranged.

[0044] Next, the first and second fasteners 3 and 4 are screwed together to fasten and join the horizontal member 1 and the rafter member 2 (step S4). That is, after the rafter member 2 is placed on the horizontal member 1, the bolt 32 and washer 33 are assembled onto the nut body 31, and the nut body 31 is inserted into the through hole 12 of the horizontal member 1 from below. After that, the head 30 of the bolt 32 is rotated to screw the square-head bolt 40 onto the nut body 31, thereby fastening and joining the horizontal member 1 and the rafter member 2.

[0045] Furthermore, in the roof structure of this embodiment, the screws of the first and second fasteners 3 and 4 can be released during roof repair or demolition without damaging or deforming the horizontal members 1, rafter members 2, and roof panel units 5. Therefore, the horizontal members 1, rafter members 2, and roof panel units 5 can be reused as they are after roof repair or demolition.

[0046] Embodiment 2. Figure 10 is a side view showing a roof structure according to Embodiment 2 of the present invention. As shown in Figure 10, two rafter members 2 (first and second rafter members 201, 202) may be arranged adjacent to each other. In the illustrated configuration, the second rafter member 202 is positioned on the ridge side (upper side in the direction of the roof slope) of the first rafter member 201. In such a position, two through holes 12 (first and second through holes 121, 122) may be provided in the horizontal member 1, aligned in the direction perpendicular to the axis 1b (width direction) of the horizontal member 1. The first through hole 121 is provided so as to be located at the lower part of the first rafter member 201, and the second through hole 122 is provided so as to be located at the lower part of the second rafter member 202.

[0047] The first fastener 3 is inserted through the first and second through holes 121 and 122, respectively. The second fastener 4 is positioned inside the first and second rafter members 201 and 202, respectively. The first and second fasteners 3 and 4 are screwed together, thereby fastening and joining the first and second rafter members 201 and 202 to the horizontal member 1. In the embodiment shown in Figure 10, the washer 41 (first washer 411) attached to the square-head bolt 40 (first square-head bolt 401) inserted through the first through hole 121 is separate from the washer 41 (second washer 412) attached to the square-head bolt 40 (second square-head bolt 402) inserted through the second through hole 122.

[0048] Next, Figure 11 is a side view showing a first modified example of the roof structure of Figure 10. As shown in Figure 11, the first washer 411 may be integrated with the second washer 412. In the embodiment shown in Figure 11, the first washer 411 and the second washer 412 of Figure 10 are connected by a connecting wall 413. The connecting wall 413 connects the ridge-side end of the first washer 411 to the eaves-side end of the second washer 412. The connecting wall 413 may extend along the mounting surface (flange 21) of the first and second washers 411 and 412. The connecting wall 413 may be formed from the same plate material as the first and second washers 411 and 412, or it may be integrated with the first and second washers 411 and 412 by any fixing method such as welding.

[0049] Next, Figure 12 is a side view showing a second modified example of the roof structure of Figure 10. As shown in Figure 12, the first and second fasteners 3 and 4 may be positioned closer to the ends of the first and second rafter members 201 and 202. In such cases, the first and second washers 411 and 412 may be positioned adjacent to each other. The connecting wall 413 (the portion along the mounting surface of the first and second washers 411 and 412) in Figure 11 may be omitted, and the first and second washers 411 and 412 may be integrated with each other. The other configurations are the same as in Embodiment 1.

[0050] Embodiment 3. Figure 13 is a side view showing a roof structure according to Embodiment 3 of the present invention, and Figure 14 is a perspective view showing the washer 41 in Figure 13. As shown in Figure 13, the rafter member 2 may extend horizontally. In this case, as shown in Figure 14, the lower surface 41c of the washer 41 may extend parallel to the upper surface 41b. Also, the protruding lengths of the leg portions 41e (41e1, 41e2) from the base portion 41d may be the same. Otherwise, it is the same as Embodiments 1 and 2.

[0051] Embodiment 4. Figure 15 is a side view showing a roof structure according to Embodiment 4 of the present invention. In particular, when the rafter member 2 extends horizontally, the washer 41 may be omitted. In this case, the corner portion 40b of the square-head bolt 40 can enter the opening 21a of the flange 21 or the through hole 12 of the horizontal member 1. By making the opening 21a of the flange 21 polygonal, or by making the cross section of the through hole 12 of the horizontal member 1 polygonal at least partially (for example, only the upper cross section), the rotation of the square-head bolt 40 can be restricted. The other configurations are the same as in Embodiments 1 to 3.

[0052] Embodiment 5. Figure 16 is a side view showing a roof structure according to Embodiment 5 of the present invention. As shown in Figure 16, the roof structure may include a roof deck 50 fixed to the upper part of the rafter member 2. The second fastener 4 may also be positioned on the upper part of the rafter member 2, or it may be fitted into a hole 53 provided in the roof deck 50.

[0053] In the illustrated embodiment, the washer 41 is positioned on the upper part of the rafter member 2 and fitted into the hole 53 of the roof sheathing 50. The square-head bolt 40 enters the interior of the rafter member 2 through the opening 41a of the washer 41. Inside the rafter member 2, the square-head bolt 40 is screwed into the nut body 31. The hole 53 is sized to accommodate the whole or most of the washer 41. The fitting of the second fastener 4 into the hole 53 restricts the rotation of the rafter member 2 when screwed with the first fastener 3. That is, the second fastener 4 may take a reaction force from the roof sheathing 50 when screwed with the first fastener 3. The hole 53 may penetrate the roof sheathing 50, but it does not have to penetrate the roof sheathing 50 (the depth of the hole 53 may be shallower than the thickness of the roof sheathing 50). The other configurations are the same as in embodiments 1 to 4.

[0054] Embodiment 6. Figure 17 is a side view showing a roof structure according to Embodiment 6 of the present invention, and Figure 18 is a perspective view showing the roof sheathing 50 and washer 41 of Figure 17. The hole 53 provided in the roof sheathing 50 may be sized so that at least the end of the washer 41 is fitted in, rather than accommodating the entire or most of the washer 41. The tips of the legs 41e (first and second legs 41e1, 41e2) of the washer 41 are provided with a plurality of discretely arranged sharp or tapering protrusions 41f, which may bite into the roof sheathing 50. The protrusions 41f biting into the roof sheathing 50 allows the hole 53 for restricting the rotation of the rafter member 2 to be made shallower. In addition, depending on the embodiment, the hole 53 may be omitted. The other configurations are the same as in Embodiments 1 to 5.

[0055] Furthermore, when the washer 41 is placed inside the rafter member 2 as in embodiments 1 to 3, the hole 53 into which the end of the washer 41 is fitted may be provided in the wall of the rafter member 2, for example, the flange 21.

[0056] Embodiment 7. Figure 19 is a side view showing a roof structure according to Embodiment 7 of the present invention, and Figure 20 is a perspective view showing the second fastener 4 of Figure 19. As shown, the second fastener 4 may have a washer 41 with a nut portion 42 integrally provided thereon. The shaft portion 32a of the bolt 32 of the first fastener 3 can be screwed onto the nut portion 42. When using a second fastener 4 having such a washer 41, the square-head bolt 40 and nut portion 31 described in Embodiments 1 to 6 may be omitted. The other configurations are the same as in Embodiments 1 to 6.

[0057] Although preferred embodiments of the present invention have been described in detail above with reference to the attached drawings, the present invention is not limited to these examples. It is clear to any person with ordinary skill in the art to which the present invention belongs that various modifications or alterations can be conceived within the scope of the technical idea described in the claims, and these are also understood to naturally fall within the technical scope of the present invention. [Examples]

[0058] The inventors conducted an in-plane shear test of a roof structure according to an embodiment of the present invention. The basic elements of the test were based on the in-plane shear test of a sheathed roof structure in the Allowable Stress Design for Wooden Frame Houses (2017 Edition). Specifically, as shown in Figure 21, a pair of beam members 7 were joined to a pair of horizontal members 1 to form a rectangular frame overall. Five rafter members 2 were placed on the frame in a direction perpendicular to the horizontal members 1, and the rafter members 2 were joined to the horizontal members 1 or beam members 7. A roof sheathing board 50 (roof sheathing) was fixed to the upper part of these rafter members 2 to prepare a test specimen 60. The test specimen 60 was placed horizontally, one horizontal member 1 was fixed to a base 61, and an actuator 62 was connected to the other horizontal member 1. Furthermore, in the in-plane shear test of the shear surface of a panel-covered roof structure in the Allowable Stress Design for Wooden Frame Houses (2017 Edition), the fixed girders correspond to one of the horizontal members 1, and the load-bearing girders in the same test correspond to the other horizontal member 1.

[0059] As for the test specimen 60, as described in Embodiments 1 to 6, two types were used: one in which the horizontal member 1 and the rafter member 2 were fastened and joined using a nut body 31 and bolt 32 as the first fastening body 3, and a square-head bolt 40 and washer 41 as the second fastening body 4 (Example), and another in which the horizontal member 1 and the rafter member 2 were joined with nails (Comparative Example). The dimensions of the test specimen 60 were 1.82 m in width and 2.73 m in length. For the horizontal member 1 and beam member 7, Douglas fir lumber with a cross-sectional dimension of 150 × 105 mm was used. For the rafter member 2, lip channel steel with a cross-sectional dimension of C-90 × 45 × 20 mm (plate thickness 0.8 mm) was used in the Example, and cedar lumber with a cross-sectional dimension of 45 × 75 mm was used in the Comparative Example. For the roof sheathing 50, board material equivalent to 12 mm thick structural plywood grade 2 was used.

[0060] As shown in the figure, multiple displacement gauges H1, H2, V3, and V4 were connected to the horizontal member 1 and the rafter member 2, and vibration 63 was applied to the test specimen 60 by the actuator 62. From the outputs of each displacement gauge H1, H2, V3, and V4, the apparent shear deformation angle γ (rad), the shear deformation angle θ (rad) of the leg, and the true shear deformation angle γ0 (rad) were calculated, as shown in the following equations 1 to 3. γ = (δ1 - δ2) / H ···(1) θ = (δ³ - δ⁴) / V ... (2) γ0 = γ - θ ···(3) However, δ1 is the output of displacement meter H1 (horizontal displacement of the load girder (mm)), δ2 is the output of displacement meter H2 (horizontal displacement of the fixed girder (mm)), H is the distance between displacement meter H1 and H2 (mm), δ3 is the output of displacement meter V3 (vertical displacement of the beam base (mm)), δ4 is the output of displacement meter V4 (vertical displacement of the beam base (mm)), and V is the distance between displacement meter V3 and V4 (mm).

[0061] The test involved alternating positive and negative loads, with apparent shear deformation angles of 1 / 450, 1 / 300, 1 / 200, 1 / 150, 1 / 100, 1 / 75, and 1 / 50 rad, each applied three times in alternating positive and negative directions, followed by a final load of 1 / 15 rad.

[0062] Figure 22 is a graph showing the in-plane shear test results of the roof structure in the embodiment, and Figure 23 is a graph showing the in-plane shear test results of the roof structure in the comparative example. In the graphs of Figures 22 and 23, the vertical axis represents the load (kN) of vibration 63 applied during the test, and the horizontal axis represents the true shear deformation angle γ0 (rad). The short-term standard shear strength was determined from these graphs, and the short-term allowable shear strength was determined from this short-term standard shear strength. The short-term allowable shear strength was 5.03 kN in the embodiment, while it was 1.77 kN in the comparative example. Furthermore, when the roof strength ratio was calculated, it was 1.4 in the embodiment, while it was 0.50 in the comparative example. From these results, it was confirmed that the embodiment has more than twice the strength of the comparative example. In other words, it was confirmed that when the horizontal member 1 and the rafter member 2 are fastened and joined using the first and second fasteners 3 and 4 described above, a joint with higher strength and rigidity can be achieved than when nails are used.

[0063] The invention described herein may also be described as follows: [1] A horizontal member having a through-hole extending from the bottom to the top, The first fastening body is inserted through the through hole from the lower surface of the horizontal member, The rafter member placed on the aforementioned horizontal member, A second fastening body disposed inside or on top of the rafter member Equipped with, The horizontal member and the rafter member are fastened together by screwing the first and second fasteners together. The first fastening member has a head that can be rotated by operation from below the horizontal member, The second fastening member is configured or positioned such that it is prevented from rotating together with the first fastening member when screwed together. Roof structure. [2] The second fastening body has a square-headed bolt with a square portion at the base of the shaft. The roof structure described in paragraph 1. [3] The second fastening body further includes a washer having an opening through which the shaft portion and the corner portion of the square-head bolt can be inserted. The corner portion of the square-headed bolt is inserted into the opening. The washer is configured or positioned to receive a reaction force from the rafter member or from the roof sheathing fixed to the upper part of the rafter member when the square-head bolt is screwed into the first fastening body. The roof structure described in paragraph 2. [4] The washer has a lower surface that extends at an angle corresponding to the inclination of the rafter member with respect to the horizontal member, such that when the washer is placed inside or on top of the rafter member, its upper surface extends horizontally. The roof structure described in paragraph 3. [5] The washer is a member formed by bending a plate, and has a base and at least one leg extending from at least one end of the base. Due to the difference in the protruding lengths of the at least one leg portion from the base portion, the base portion is configured to extend horizontally when the washer is positioned inside or on top of the rafter member. The roof structure described in paragraph 4. [6] The rafter members are made of structural steel or steel pipes. The second fastening member is located inside the rafter member, A roof structure as described in any one of items 1 through 5. [7] The inner wall-to-inner wall dimension of the rafter member in the direction perpendicular to the axis of the rafter member is equal to the outer wall-to-inner wall dimension of the washer in the direction perpendicular to the axis of the rafter member. Roof structures as described in paragraph 6, relating to paragraphs 3, 4, or 5. [8] The first fastening body has a nut body that can be screwed onto the square-head bolt, and a bolt that is screwed onto the nut body. The amount of the bolt that penetrates the nut body is greater than the amount of the square-headed bolt that penetrates the nut body. A roof structure as described in any one of items 2 through 7. [9] The roof sheathing is further fixed to the upper part of the rafter member, The second fastening member is positioned on the upper part of the rafter member and is fitted into a hole provided in the roof sheathing. A roof structure as described in any one of items 1 through 8.

[10] The aforementioned rafter members, together with the roof sheathing and roofing materials, constitute part of a unitized roof panel unit. A roof structure as described in any one of items 1 through 9. [Explanation of symbols]

[0064] 1: Horizontal structural members 10: Bottom surface 11:Top surface 12: Through hole 2: Rafter members 3: First fastening body 30:Head 31: Nut body 32: Bolt 4: Second fastening body 40: Square-headed bolt 40a:Shaft part 40b: Corner 40c:Head 41: Washer 41a:Aperture 41b:Top surface 41c: Bottom surface 41d: base 41e: Legs 5: Roof panel unit 50: Field board 51: Roofing materials 53: Hole

Claims

1. A horizontal member having a through-hole extending from the bottom to the top, The first fastening body is inserted through the through hole from the lower surface of the horizontal member, The rafter member placed on the aforementioned horizontal member, A second fastening body disposed inside or on the upper part of the rafter member Equipped with, The horizontal member and the rafter member are fastened together by screwing the first and second fastening members together. The first fastening member has a head that can be rotated by operation from below the horizontal member, The second fastening member is configured or positioned such that it is prevented from rotating together with the first fastening member when screwed together. The second fastening body has a square-rooted bolt with a corner at the base of the shaft, The second fastening body further includes a washer having an opening through which the shaft portion and the corner portion of the square-head bolt can be inserted. The corner portion of the square-headed bolt is inserted into the opening. The washer is configured or positioned to receive a reaction force from the rafter member or from the roof sheathing fixed to the upper part of the rafter member when the square-head bolt and the first fastening body are screwed together. The washer has a lower surface that extends at an angle corresponding to the inclination of the rafter member with respect to the horizontal member, such that when the washer is placed inside or on top of the rafter member, its upper surface extends horizontally. The washer is a member formed by bending a plate, and has a base and at least one leg extending from at least one end of the base. Due to the difference in the protruding lengths of the at least one leg portion from the base portion, the base portion is configured to extend horizontally when the washer is positioned inside or on top of the rafter member. Roof structure.

2. The rafter members are made of structural steel or steel pipes. The second fastening member is located inside the rafter member. The roof structure according to claim 1.

3. A horizontal member having a through hole extending from the bottom surface to the top surface, The first fastening body is inserted through the through hole from the lower surface of the horizontal member, The rafter member placed on the aforementioned horizontal member, A second fastening body disposed inside or on the upper part of the rafter member Equipped with, The horizontal member and the rafter member are fastened together by screwing the first and second fastening members together. The first fastening member has a head that can be rotated by operation from below the horizontal member, The second fastening member is configured or positioned such that it is prevented from rotating together with the first fastening member when screwed together. The second fastening body has a square-rooted bolt with a corner at the base of the shaft, The second fastening body further includes a washer having an opening through which the shaft portion and the corner portion of the square-head bolt can be inserted. The corner portion of the square-headed bolt is inserted into the opening. The washer is configured or positioned to receive a reaction force from the rafter member or from the roof sheathing fixed to the upper part of the rafter member when the square-head bolt and the first fastening body are screwed together. The rafter members are made of structural steel or steel pipes. The second fastening member is located inside the rafter member, The inner wall-to-inner wall dimension of the rafter member in the direction perpendicular to the axis of the rafter member is equal to the outer wall-to-inner wall dimension of the washer in the direction perpendicular to the axis of the rafter member. Roof structure.

4. The washer has a lower surface that extends at an angle corresponding to the inclination of the rafter member with respect to the horizontal member, such that when the washer is placed inside or on top of the rafter member, the upper surface extends horizontally. The roof structure according to claim 3.

5. The washer is a member formed by bending a plate, and has a base and at least one leg extending from at least one end of the base, Due to the difference in the protruding lengths of the at least one leg portion from the base portion, the base portion is configured to extend horizontally when the washer is positioned inside or on top of the rafter member. The roof structure according to claim 4.

6. The first fastening body has a nut body that can be screwed onto the square-head bolt, and a bolt that is screwed onto the nut body. The amount of the bolt that penetrates the nut body is greater than the amount of the square-headed bolt that penetrates the nut body. The roof structure according to claim 1.

7. The roof sheathing is further fixed to the upper part of the rafter member, The second fastening member is positioned on the upper part of the rafter member and is fitted into a hole provided in the roof sheathing. The roof structure according to claim 1.

8. The aforementioned rafter members, together with the roof sheathing and roofing materials, constitute part of a unitized roof panel unit. The roof structure according to claim 1.

9. The through hole is an elongated hole in which the dimension in the axial direction of the horizontal member is larger than the dimension in the direction perpendicular to the axis of the horizontal member. The roof structure according to any one of claims 1 to 8.

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