Composite beam, building, and reinforcing metal fitting

Abstract

A composite beam (10) constitutes a part of a framework of a building. The composite beam (10) is provided with a first beam member (20) and a second beam member (30). The first beam member (20) has a first end surface (21), and a second end surface on the opposite side to the first end surface (21) in the longitudinal direction (X1). The second beam member (30) has a third end surface (34), and a fourth end surface on the opposite side to the third end surface (34) in the longitudinal direction (X2). The second beam member (30) is disposed along the first beam member (20) below the lower surface (20Y) of the first beam member (20), and is coupled to the first beam member (20). In the longitudinal direction (X1) of the first beam member (20), the third end surface (34) is positioned further inward than the first end surface (21), and the fourth end surface is positioned further inward than the second end surface.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a composite beam, a building, and a reinforcement fitting.BACKGROUND ART

[0002] A known technology for increasing the strength of a building strengthens a structural body that includes a wooden beam and a wooden post. For example, Patent Literature 1 discloses a structural body including wooden posts, wooden beams spanning over the wooden posts, and steel reinforcements arranged along the lower surfaces of the wooden beams and having ends joined to the wooden beams. Ends of the steel reinforcements are joined to side surfaces of the wooden posts.CITATION LISTPatent Literature

[0003] [Patent Literature 1] JP2010-031610ASUMMARY OF INVENTIONTechnical Problem

[0004] Installations may be arranged on a ceiling of a building. An example of such an installation is a cornice box. For example, when arranging a cornice box near a wall, the attachment of the cornice box to the lower surface of a beam will result in the cornice box projecting downward from the ceiling surface. Thus, the cornice box will adversely affect the continuity of the ceiling surface in the horizontal direction. In this manner, it is difficult to arrange an installation in the space above the ceiling.Solution to Problem(1) In one general aspect, a composite beam forms a portion of a frame assembly of a building. The composite beam includes a first beam that includes a first end surface and a second end surface located at an opposite side of the first end surface in a longitudinal direction and a second beam including a third end surface and a fourth end surface located at an opposite side of the third end surface in a longitudinal direction. The second beam is arranged along the first beam below a lower surface of the first beam and is coupled to the first beam. In the longitudinal direction of the first beam, the third end surface is located inward from the first end surface, and the fourth end surface is located inward from the second end surface.

[0006] With this structure, when the first end surface of the first beam is connected to the structural member of the building, space extends between the structural element and the third end surface. Further, when the second end surface of the first beam is connected to the structural member of the building, space extends between the structural element and the fourth end surface. The installation may be arranged in the space between the structural element and the third end surface, and in the space between the structural element and the fourth end surface. This allows the installation to be arranged in a ceiling.

[0007] (2) The composite beam according to (1), the first beam is formed from wood, and the second beam is formed from steel. In contrast with when the second beam is formed from wood, this structure improves the rigidity of the composite beam.

[0008] (3) The composite beam according to (1) or (2), further includes first fittings that couple the second beam to the first beam. The first fittings are connected to the lower surface of the first beam and an upper surface of the second beam. With this structure, multiple first fittings connect the lower surface of the first beam and the upper surface of the second beam. This restricts displacement of the first beam and the second beam.

[0009] (4) The composite beam according to (3), where the first fittings each include a first plate arranged between the first beam and the second beam, a first projection projecting from the first plate and inserted in a first insertion hole of the first beam, and a second projection projecting from the first plate and inserted in a second insertion hole formed in the second beam. With this structure, the first projection is inserted into the first insertion hole of the first beam, and the second projection is inserted into the second insertion hole of the second beam. This limits displacement of the first beam and the second beam.

[0010] (5) The composite beam according to (3) or (4), where the first fittings in a vicinity of an end of the composite beam are arranged at a smaller interval than the first fittings arranged in a vicinity of a central part of the composite beam in the longitudinal direction of the first beam. This allows the number of the first fittings in the vicinity of the central part of the composite beam to be reduced. Thus, the efficiency of assembling the composite beam is improved.

[0011] (6) The composite beam according to any one of (1) to (5), further includes a second fitting including a first coupling portion coupled to a lower surface end portion located in the lower surface of the first beam between the first end surface and the third end surface in the longitudinal direction of the first beam, and a second coupling portion coupled to the third end surface of the second beam. With this structure, the second fitting connects the lower surface end portion in the lower surface of the first beam and the third end surface of the second beam. This restricts displacement of the first beam and the second beam.

[0012] (7) The composite beam according to any one of (1) to (6), the lower surface of the first beam and an upper surface of the second beam are spaced apart by a gap. With this structure, air flows through the gap between the lower surface of the first beam and the upper surface of the second beam. This limits the water that collects between the first beam and the second beam. Thus, corrosion is limited in the first beam and the second beam.

[0013] (8) In another general aspect, a building includes a structural member that is a beam, a girder, or a post, a composite beam connected to the structural member, and an installation arranged in a vicinity of an end of the composite beam. The composite beam includes a first beam including a first end surface connected to a side surface of the structural member, and a second beam including a third end surface facing the side surface of the structural member. The second beam is arranged along the first beam below a lower surface of the first beam and is coupled to the first beam. The installation is arranged between the structural member and the third end surface. With this structure, the installation is arranged in the space between the structural member and the third end surface. Accordingly, the portion of the installation projecting downward from the ceiling is limited, and the dimension of the downward-projecting portion of the installation is reduced.

[0014] (9) In a different general aspect, a building includes a structural member that is a beam, a girder, or a post and a composite beam connected to the structural member. The composite beam includes a first beam including a first end surface connected to a side surface of the structural member, and a second beam including a third end surface facing the side surface of the structural member. The second beam is arranged along the first beam below a lower surface of the first beam and is coupled to the first beam. The structural member and the third end surface are spaced apart by an arrangement space allowing for arrangement of an installation. This allows the installation to be arranged in an arrangement space. Thus, the installation is arranged in the ceiling.

[0015] (10) In a different general aspect, a reinforcement fitting is arranged on a composite beam. The composite beam includes a first beam including a first end surface and a second end surface located at an opposite side of the first end surface in a longitudinal direction, and a second beam including a third end surface and a fourth end surface located at an opposite side of the third end surface in a longitudinal direction. The second beam is arranged along the first beam below a lower surface of the first beam. The third end surface is located inward from the first end surface in the longitudinal direction of the first beam. The reinforcement fitting is coupled to a lower surface end portion located in a lower surface of the first beam between the first end surface and the third end surface in the longitudinal direction of the first beam, and is coupled to the third end surface. With this structure, the third end surface of the second beam is connected to the lower surface end portion by the reinforcement fitting. Thus, the third end surface does not need to be connected to the structural member. When the first end surface of the first beam is connected to the structural member of the building, the installation may be arranged in the space between the structural member and the third end surface. This allows the installation to be is arranged in the ceiling.Advantageous Effects of Invention

[0016] In the present disclosure, a composite beam, a building, and a reinforcement fitting allows an installation such as a cornice box or the like to be arranged on the ceiling in a preferable manner.BRIEF DESCRIPTION OF DRAWINGS

[0017] FIG. 1 A schematic diagram of a building in accordance with an embodiment.

[0018] FIG. 2 A side view of a composite beam in accordance with the embodiment.

[0019] FIG. 3 A side view of an end of the composite beam in the embodiment.

[0020] FIG. 4 A cross-sectional view taken along line D4-D4 in FIG. 2.

[0021] FIG. 5 A perspective view of a first fitting.

[0022] FIG. 6 A partial perspective view of the composite beam in accordance with the embodiment.

[0023] FIG. 7 A side view of a composite beam in accordance with a first modification

[0024] FIG. 8 A diagram of a building in accordance with a second modification.

[0025] FIG. 9 A diagram of a building in accordance with a third modification.DESCRIPTION OF EMBODIMENTSEmbodiment

[0026] A building 1, a composite beam 10, and a reinforcement fitting 60 in accordance with an embodiment will now be described with reference to FIGS. 1 to 6.Building

[0027] FIG. 1 is a schematic diagram showing an example of a building 1. Examples of the building 1 include a single-family residential building, a collective residential building, and a public facility. The building 1 of the present embodiment is a single-family residential building. The building 1 includes a first space S1 and a second space S2 connected to the first space S1. An example of the first space S1 is an indoor space of the building 1. Examples of the first space S1 include rooms such as a living room, a dining room, a kitchen, a bedroom, and a children's room. The second space S2 is, for example, an outdoor space of the building 1. An example of the second space S2 is a piloti. The second space S2 may be an indoor space differing from the first space S1. The building 1 includes a first ceiling 2 provided in the first space S1 and a second ceiling 3 provided in the second space S2.

[0028] The building 1 includes structural members 4, composite beams 10, and an installation 5. The structural members 4 are portions of a frame assembly of the building 1. The structural members 4 and the composite beams 10 are portions of a structural body of the building 1. In the present embodiment, the structural members 4 include a girder 4A. The girder 4A is a portion of the frame assembly that forms a wall 6 of the building 1. The wall 6 is located between the first space S1 and the second space S2. In the first space S1, the structural members 4 may include another girder 4B located at an opposite side of the girder 4A. A distance D1 between the girder 4A and the other girder 4B is, for example, between 6.5 m and 7.5 m, inclusive. The distance D1 may be between 5.5 m and 6.5 m, inclusive. The distance D1 may be between 4.5 m and 5.5 m, inclusive. The distance D1 may be between 3.5 m and 4.5 m, inclusive.

[0029] When viewed from above, a girder is defined as a member that extends in a direction parallel to the long sides, and a beam is a member that extends in a direction parallel to the short sides and intersects the girder. The girder is also defined as a horizontal member that receives a rafter, and the beam is defined as a member that does not receive a rafter and intersects the girder. However, there is no limitation to these definitions.

[0030] The installation 5 is attached to the first ceiling 2 exposed to the first space S1. The installation 5 is, for example, a curtain box. The curtain box accommodates a curtain rail. The curtain rail may be a rail allowing for automatic opening and closing of a curtain. The installation 5 may be equipment attached to the ceiling. The installation 5 may be indirect lighting.

[0031] The installation 5 is arranged in the vicinity of an end 11 of the composite beam 10. The installation 5 is arranged in the vicinity of the girder 4A. The building 1 may include another installation 5A arranged in the vicinity of the other girder 4B. The other installation 5A is arranged in the vicinity of an end 11 at the opposite side of the end 11 where the installation 5 is located. The installation 5 may differ from the other installation 5A. The other installation 5A may be omitted.Composite Beam

[0032] As shown in FIG. 1, each composite beam 10 is a portion of the frame assembly of the building 1. The composite beam 10 is arranged on the first ceiling 2. The composite beam 10 extends between the girder 4A and the other girder 4B. The composite beam 10 is connected to the structural members 4. The composite beam 10 is connected to the girder 4A and the other girder 4B. The building 1 may include multiple composite beams 10 arranged next to one another in a direction extending from the front side toward the rear side of the sheet of FIG. 1 as seen from the viewer.

[0033] As shown in FIG. 2, in a longitudinal direction X1, the composite beam 10 includes the ends 11 and a central part 12. The ends 11 of the composite beam 10 include a first end 11A and a second end 11B at the opposite side of the first end 11A. The composite beam 10 has a length L set in correspondence with the distance D1 from the girder 4A to the other girder 4B. The length Lis, for example, between 6.5 m and 7.5 m, inclusive. The length L may be between 5.5 m and 6.5 m, inclusive. The length L may be between 4.5 m and 5.5 m, inclusive. The length L may be between 3.5 m and 4.5 m, inclusive.

[0034] The composite beam 10 is formed by combining two beam members. The beam members extend in the longitudinal direction X1. The material of one of the two beam members differs from the material of the other one of the two beam members. The composite beam 10 includes a first beam 20 and a second beam 30.First Beam

[0035] The first beam 20 is formed from wood. Wood may be, for example, solid lumber or laminated lumber. The first beam 20 may be formed from, for example, homogeneous-grade lumber. When the first beam 20 is formed from homogeneous-grade lumber, the stacking direction of the sawn boards in the first beam 20 corresponds to the vertical direction.

[0036] The first beam 20 includes a first end surface 21 and a second end surface 22 located at the opposite side of the first end surface 21 in the longitudinal direction X1. The first end surface 21 is connected to a side surface 4Z of the structural member 4. In the present embodiment, the side surface 4Z of the structural member 4 is a side surface of the girder 4A. The second end surface 22 is connected to a side surface of the other girder 4B. The first beam 20 has a first length L1 that is defined as the length from the first end surface 21 to the second end surface 22 in the longitudinal direction X1 of the first beam 20. The first length L1 of the first beam 20 is the same as the length L of the composite beam 10.

[0037] As shown in FIG. 3, the first beam 20 is connected to the structural member 4 by a first support fitting 7 and a second support fitting 8. The first support fitting 7 includes a main body 7A and two slot insertions 7B that are integrally formed with the main body 7A. The main body 7A includes a plate that contacts the side surface 4Z of the structural member 4 and a first end surface 21 of the first beam 20. Each slot insertion 7B includes a plate extending orthogonal to the main body 7A. The slot insertion 7B is inserted into a slot 21A formed in the first end surface 21. As shown in FIG. 6, the first end surface 21 of the first beam 20 includes two slots 21A. First shaft members 7C extend through the structural member 4 and the main body 7A to fix the main body 7A to the structural member 4. The first shaft members 7C may include one or more sets of a bolt and a nut.

[0038] The first support fitting 7 is fixed to the first beam 20 by other first shaft members 7D extending through the first beam 20 and the two slot insertions 7B. The other first shaft members 7D may each include a drift pin.

[0039] The second support fitting 8 includes a main body 8A and a support 8B that is formed integrally with the main body 8A. The main body 8A is L-shaped and contacts the side surface 4Z of the structural member 4 and a lower surface 20Y of the first beam 20. The support 8B is connected to a part of the main body 8A connected to the lower surface 20Y of the first beam 20 and to a part of the main body 8A connected to the side surface 4Z of the structural member 4. The main body 8A is fixed to the structural member 4 by a second shaft member 8C extending through the structural member 4 and the part of the main body 8A contacting the side surface 4Z of the structural member 4. The second shaft member 8C may include a set of a bolt and a nut.

[0040] The part of the main body 8A contacting the lower surface 20Y of the first beam 20 is fixed to the lower surface 20Y of the first beam 20 by screws or the like. In the longitudinal direction X1, a dimension of the part of the main body 8A contacting the lower surface 20Y of the first beam 20 is less than or equal to 120 mm. In the longitudinal direction X1, a dimension of the part of the main body 8A contacting the lower surface 20Y of the first beam 20 is less than or equal to 100 mm.

[0041] As shown in FIG. 4, the first beam 20 has a first height H1 in the vertical direction that is greater than or equal to 100 mm. The first height H1 of the first beam 20 in the vertical direction may be greater than or equal to 120 mm. The height H1 of the first beam 20 in the vertical direction is less than or equal to 330 mm. The first beam 20 in the vertical direction may be less than or equal to 210 mm. The first beam 20 includes a first width W1 that is greater than or equal to 100 mm. The dimension of the first width W1 of the first beam 20 may be less than or equal to the dimension of the first height H1 of the first beam 20.Second Beam

[0042] Referring FIG. 4, the second beam 30 is formed from steel. An example of steel is an H-section steel or an I-section steel. The second beam 30 includes a first flange 31, a second flange 32, and a web 33. The first flange 31 forms an upper surface 30X of the second beam 30. The second flange 32 forms a lower surface 30Y of the second beam 30. The web 33 connects the first flange 31 and the second flange 32.

[0043] As shown in FIG. 2, the second beam 30 includes a third end surface 34 and a fourth end surface 35 located at the opposite side of the third end surface 34 in a longitudinal direction X2. The third end surface 34 faces the side surface 4Z of the structural member 4. The third end surface 34 faces the side surface of the other girder 4B. The longitudinal direction X2 coincides with the longitudinal direction X1. A second length L2 of the second beam 30 is defined as the length between the third end surface 34 and the fourth end surface 35 in the longitudinal direction X2. A ratio of the second length L2 to the first length L1 is greater than or equal to 0.7.

[0044] The second beam 30 extends along the first beam 20 below the lower surface 20Y of the first beam 20 and is coupled to the first beam 20. In the longitudinal direction X1 of the first beam 20, the third end surface 34 is located inward from the first end surface 21 and the fourth end surface 35 is located inward from the second end surface 22. The phrase “located inward” indicates that an end surface is located closer to a center line of the first beam 20 in the longitudinal direction X1 than the compared end surface. In the longitudinal direction X1, the third end surface 34 is located at least 250 mm inward from the first end surface 21. In the longitudinal direction X1, the third end surface 34 may be located at least 350 mm inward from the first end surface 21. In the longitudinal direction X1, the fourth end surface 35 is located at least 250 mm inward from the second end surface 22. In the longitudinal direction X1, the fourth end surface 35 may be located at least 350 mm inward from the second end surface 22.

[0045] As shown in FIGS. 3 and 4, an end plate 36 that is perpendicular to the longitudinal direction X2 is coupled to each end of the second beam 30 through welding or the like. The end plate 36 coupled to one end of the second beam 30 defines the third end surface 34. The end plate 36 coupled to the other end of the second beam 30 defines the fourth end surface 35.

[0046] As shown in FIG. 4, the second beam 30 has a second height H2 that is greater than or equal to 100 mm. The second height H2 of the second beam 30 may be less than or equal to the first height H1 of the first beam 20. The second height H2 of the second beam 30 is less than or equal to 250 mm. The second height H2 of the second beam 30 may be less than or equal to 200 mm. The second beam 30 includes a second width W2 that is greater than or equal to 100 mm. The second width W2 of the second beam 30 may be less than the first width W1 of the first beam 20.

[0047] As shown in FIG. 2, the second beam 30 may include pipe holes 37 extending through the web 33. For example, a vent pipe, a drain pipe, or the like may be arranged in each pipe holes 37. The pipe holes 37 allow a vent pipe, a drain pipe, or the like to be arranged in the ceiling void.Arrangement Space

[0048] As shown in FIGS. 1 and 2, an arrangement space SA extends between the structural member 4 and the third end surface 34 allow for arrangement of the installation 5. The installation 5 is arranged between the structural member 4 and the third end surface 34. A further arrangement space SA may extend between the structural member 4 and the fourth end surface 35.

[0049] The arrangement space SA arranged in the first ceiling 2 opens downwardly. The first ceiling surface 2A of the first ceiling 2 is located below the lower surface 30Y of the second beam 30 of the composite beam 10. The arrangement of the installation 5 in the arrangement space SA allows the installation 5 to be arranged above the first ceiling surface 2A of the first ceiling 2. The arrangement of the installation 5 in the arrangement space SA allows the first ceiling surface 2A of the first ceiling 2 to have the same height as the second ceiling surface 3A of the second ceiling 3. This allows the first ceiling surface 2A and the second ceiling surface 3A to appear as sharing the same flat surface.

[0050] As shown in FIG. 3, a step 13 is formed in the composite beam 10. The step 13 is a cutout portion between the upper surface 20X of the first beam 20 and the lower surface 30Y of the second beam 30 removed from the composite beam 10. The step 13 of the present embodiment is a portion defined by a lower surface end portion 23 and the third end surface 34. The lower surface end portion 23 is where the lower surface 20Y extends between the first end surface 21 and the third end surface 34 in the longitudinal direction X1 of the first beam 20. FIG. 3 shows the example of the side surface of the composite beam 10 at the side of the first end 11A. The side of the second end 11B also includes a step 13. The arrangement space SA is defined in the step 13.First Fitting

[0051] As shown in FIG. 2, the composite beam 10 further includes first fittings 40. In the present embodiment, the composite beam 10 includes nine first fittings 40. The first fittings 40 couple the second beam 30 to the first beam 20. The first fittings 40 are connected to the lower surface 20Y of the first beam 20 and the upper surface 30X of the second beam 30.

[0052] The first fittings 40 are, for example, aligned in the longitudinal direction X1. When the first fittings 40 are arranged at the ends 11 and the central part 12, the first fittings 40 are arranged more sparsely in the vicinity of the central part 12 than in the vicinity of the ends 11. The phrase of “the first fittings 40 are arranged more sparsely” indicates that the number of the first fittings 40 arranged within a predetermined distance in the longitudinal direction X1 is less in the central part 12 than in the ends 11.

[0053] In the longitudinal direction X1 of the first beam 20, an interval G1 of the first fittings 40 arranged in the vicinity of the ends 11 of the composite beam 10 is less than an interval G2 of the first fittings 40 arranged in the vicinity of the central part 12 of the composite beam 10. The intervals G1 and G2 between the first fittings 40 are, for example, the distance between the axes of the adjacent first fittings 40 in the longitudinal direction X1. In an example shown in FIG. 2, the first fittings 40A are the first fittings40 arranged in the vicinity of the first end 11A of the end 11 of the composite beam 10. The second fittings 40B are the first fittings 40 arranged in the vicinity of the central part 12 of the composite beam 10. First fittings 40C are the first fittings 40 arranged in the vicinity of a second end 11B of the end 11 of the composite beam 10. The intervals G1 and G2 are set in accordance with the length L of the composite beam 10, the number of the first fittings 40, or the like. The interval G1 of the adjacent first fittings 40 arranged in the vicinity of the ends 11 of the composite beam 10 is, for example, 500 mm. The interval G2 of the adjacent first fittings 40 arranged in the vicinity of the central part 12 of the composite beam 10 is, for example, 1000 mm.

[0054] As shown in FIGS. 4 and 5, each first fitting 40 includes a first plate 41, a first projection 42, and second projections 43. The first plate 41 is arranged between the first beam 20 and the second beam 30. The first projection 42 projects from the first plate 41 and is into a first insertion hole 24 formed in the first beam 20. Each second projection 43 projects from the first plate 41 and is inserted into a corresponding second insertion hole 38 formed in the second beam 30. The second insertion hole 38 is formed in the first flange 31 of the second beam 30.

[0055] As viewed in the longitudinal direction X1, a third width W3 of the first plate 41 is less than the first width W1 of the first beam 20. As viewed in the longitudinal direction X1, the third width W3 of the first plate 41 is greater than the second width W2 of the second beam 30. Since the third width W3 of the first plate 41 is less than the first width W1 of the first beam 20 and greater the than the second width W2 of the second beam 30, the water from the surfaces of the first beam 20 that collect on the first plate 41 will be limited. Thus, the water from the surfaces of the first beam 20 will flow downward from to the first plate 41 without contacting the lower surface 20Y of the first beam 20. This limits the water that permeates the first beam 20, which is formed from wood, in the composite beam 10.

[0056] The first projection 42 projects upward from the first plate 41. The first projection 42 has a third height H3 that is greater than or equal to 60 mm and less than or equal to the first height H1 of the first beam 20.

[0057] As shown in FIGS. 3 and 4, the first beam 20 and each first projection 42 includes first through holes 25 that extend through the first beam 20 and the first projection 42 in a horizontal direction. Each first through hole 25 extends through side surfaces 20Z of the first beam 20. In the present embodiment, two first through holes 25 are arranged next to each other in the vertical direction. Drift pins 44 are arranged in the through holes 25. The drift pins 44 couple the first beam 20 and each first fitting. The first fitting 40 may be, for example, coupled to the first beam 20 by using a fastener or the like that extends through the first plate 41.

[0058] As shown in FIGS. 4 and 5, each second projection 43 projects downward from the first plate 41. The second projections 43 may include multiple projections. In the present embodiment, the second projections 43 include four projections. Second insertion holes 38 for insertion of the second projection 43 are formed in the first flange 31. The second projections 43 are arranged in the second insertion holes 38 in a manner extending through the first flange 31.

[0059] Each second projection 43 is, for example, a bolt. A nut 45 is fastened to a portion of the second projection 43 projecting out of the first flange 31. The nut 45 couples the second beam 30 and the first fitting 40. The second projection 43 may be a pole.

[0060] As shown in FIG. 3, in the present embodiment, a gap extends between the lower surface 20Y of the first beam 20 and the upper surface 30X of the second beam 30. Each first fitting 40 couples the first beam 20 and the second beam 30 so that the lower surface 20Y of the first beam 20 does not contact the upper surface 30X of the second beam 30. In the present embodiment, the distance from the lower surface 20Y of the first beam 20 to the upper surface 30X of the second beam 30 coincides with the thickness of the first plate 41 in the vertical direction.Second Fitting

[0061] As shown in FIG. 2, the composite beam 10 further includes second fittings 50. The second fittings 50 connect the second beam 30 to the first beam 20. The second fitting 50 is arranged in the arrangement space SA. In the present embodiment, the composite beam 10 includes a second fitting 50 arranged at the first end 11A and another second fitting 50 arranged at the second end 11B. The description hereafter will focus on the second fitting 50 arranged at the first end 11A. The second fitting 50 arranged at the second end 11B has the same structure as the second fitting 50 arranged at the first end 11A.

[0062] As shown in FIG. 6, the second fitting 50 includes a first coupling portion 51 and a second coupling portion 52. The first coupling portion 51 is coupled to a lower surface end portion 23 of the first beam 20. The second coupling portion 52 is coupled to the third end surface 34 of the second beam 30.

[0063] The first coupling portion 51 includes a first plate member 53 contacting the lower surface end portion 23. The first plate member 53 is coupled to the first beam 20 by first coupling members 53A. Each first coupling members 53A is, for example, a lag bolt. The second coupling portion 52 includes a second plate member 54 contacting the third end surface 34. The second plate member 54 is coupled to the first beam 20 by second coupling members 54A. Each second coupling member 54A, for example, includes a bolt and a nut.

[0064] The first coupling portion 51 and the second coupling portion 52 are formed integrally. The first coupling portion 51 and the second coupling portion 52 are formed integrally through welding, stamping, or the like. The second fitting 50 is L-shaped by connecting an end of the second plate member 54 to an end of the first plate member 53.

[0065] The second fitting 50 includes a support portion 55. The support portion 55 is connected to the first coupling portion 51 and the second coupling portion 52. The support portion 55 includes a third plate member 56 that is arranged perpendicular to the first plate member 53 and the second plate member 54.

[0066] The support portion 55 is formed integrally with the first coupling portion 51 and the second coupling portion 52. The third plate member 56 is connected to a surface of the first plate member 53 that is opposite the surface contacting the lower surface end portion 23 through welding or the like. The third plate member 56 is connected a surface of the second plate member 54 that is opposite the surface contacting the third end surface 34 through welding or the like.

[0067] The second fitting 50 is also referred to as a reinforcement fitting 60. The second fitting 50 is arranged on the composite beam 10 of the present embodiment. Further, the second fitting 50 may be arranged on a composite beam having a different structure.

[0068] A first operation of the present embodiment will now be described.

[0069] An installation may be arranged in a ceiling of a building. An example of an installation is a cornice box. For example, when arranging the cornice box on a wall, the attachment of the cornice box to the lower surface of the beam will expose the cornice box from the ceiling surface. The cornice box will adversely affect the continuity of the ceiling surface in the horizontal direction. With the composite beam 10 of the present embodiment, the third end surface 34 of the second beam 30 is located inward from the first end surface 21 of the first beam 20 in the longitudinal direction X1. Thus, when coupling the first beam 20 to the structural member 4 so that that the first end surface 21 of the first beam 20 contacts the structural member 4, a space is formed between the second beam 30 and the structural member 4. This allows the installation 5 to be arranged in the space between the second beam 30 and the structural member 4.

[0070] A second operation of the present embodiment will now be described.

[0071] When arranging the cornice box in the ceiling, in order to arrange the cornice box at a position higher than the ceiling surface, the end of a wooden beam may be cut out to form a step. However, when removing part of the wooden beam to form a step, a load may form a crack in a corner of the step. As the length of the wooden beam increases, the load will increase. This will easily form a crack originating in the corner of the step in the wooden beam. This limits the length of a wooden beam including a step formed by a cutout portion. Such a limitation in length will impose restrictions on the size of a building that uses a wooden beam including a step formed by a cutout portion. With the composite beam 10 of the present embodiment, the step 13 is formed by the lower surface end portion 23 of the first beam 20 and the third end surface 34 of the second beam 30. This structure avoids the formation of a crack in the composite beam 10 in the corner of the step. This eliminates restrictions on the length L of the composite beam 10. In the building 1 that uses the composite beam 10, the composite beam 10 may be long. Thus, the first space S1 may be enlarged.

[0072] A third operation of the present embodiment will now be described.

[0073] The first fittings 40 are arranged so that the interval G2 of the first fittings 40 arranged in the vicinity of the central part 12 of the composite beam 10 is greater than the interval G1 of the first fittings 40 arranged in the vicinity of the end 11 of the first fittings 40. Compared to when the first fittings 40 are arranged at the same interval G1, the number of the first fittings 40 arranged in the vicinity of the central part 12 may be decreased. Thus, the number of the first fittings 40 may be decreased. Bending tests have been conducted to confirm that as compared with when the first fittings 40 in the vicinity of the end 11 of the composite beam 10 are arranged at the interval G1 so that the first fittings 40 are all arranged at the interval G1, a decrease in the number of the first fittings 40 in the vicinity of the central part 12 has subtle effect on the rigidity of the composite beam 10. A decrease in the number of the first fittings 40 will reduce the manufacturing cost of the composite beam 10. Further, a decrease in the number of the first fittings 40 will reduce the number of steps for assembling the composite beam 10.

[0074] A fourth operation of the present embodiment will now be described.

[0075] Although each first fitting 40 is connected to the first beam 20 by the first projection 42 inserted into the corresponding first insertion hole 24 of the first beam 20, the tolerance of the first insertion hole 24 may result in slight horizontal movement of the first projection 42 in the first insertion hole 24. If the first projection 42 moves slightly inside the first insertion hole 24 in the horizontal direction, the first fitting 40 will move in the horizontal direction relative to the first beam 20. Thus, the second beam 30 may be displaced relative to the first beam 20. With the present embodiment, the first coupling portion 51 of the second fitting 50 is coupled to the lower surface end portion 23 of the first beam 20 by the first coupling members 53A. This restricts movement of the second fitting 50 relative to the first beam 20. The second coupling portion 52 of the second fitting 50 coupled to the first beam 20 of the second beam 30 in the horizontal direction restricts movement of the second beam 30 in the horizontal direction relative to the first beam 20.

[0076] Advantages of the present embodiment will now be described.

[0077] (1) The composite beam 10 includes the first beam 20 and the second beam 30. The second beam 30 is arranged along the first beam 20 below the lower surface 20Y of the first beam 20 and is coupled to the first beam 20. In the longitudinal direction X1 of the first beam 20, the third end surface 34 is located inward from the first end surface 21, and the fourth end surface 35 is located inward from the second end surface 22.

[0078] With this structure, when the first end surface 21 of the first beam 20 is connected to the structural member 4 of the building 1, space extends between the structural member 4 and the third end surface 34. Further, when the second end surface 22 of the first beam 20 is connected to the structural member 4 of the building 1, space extends between the structural member 4 and the fourth end surface 35. The installation 5 may be arranged in the space between the structural member 4 and the third end surface 34, and in the space between the structural member 4 and the fourth end surface 35. This allows the installation 5 to be arranged in the first ceiling 2.

[0079] (2) The first beam 20 is formed from wood, and the second beam 30 is formed from steel. In contrast with when the second beam 30 is formed from wood, this structure improves the rigidity of the composite beam 10.

[0080] (3) The composite beam 10 further includes the first fittings 40. The first fittings 40 are connected to the lower surface 20Y of the first beam 20 and the upper surface 30X of the second beam 30. With this structure, multiple first fittings 40 connect the lower surface 20Y of the first beam 20 and the upper surface 30X of the second beam 30. This restricts displacement of the first beam 20 and the second beam 30.

[0081] (4) The first fittings 40 each include the first plate 41, the first projection 42 inserted in the first insertion hole 24 of the first beam 20, and the second projection 43 inserted in the second insertion hole 38 of the second beam 30. With this structure, the first projection 42 is inserted into the first insertion hole 24 of the first beam 20, and the second projection 43 is inserted into the second insertion hole 38 of the second beam 30. This limits displacement of the first beam 20 and the second beam 30.

[0082] (5) The first fittings 40 in a vicinity of the end of the composite beam 10 are arranged at a smaller interval than the first fittings 40 arranged in a vicinity of the central part 12 of the composite beam 10 in the longitudinal direction X1 of the first beam 20. This allows the number of the first fittings 40 in the vicinity of the central part 12 of the composite beam 10 to be reduced. Thus, the efficiency of assembling the composite beam 10 is improved.

[0083] (6) The composite beam further includes the second fitting 50. The second fitting 50 includes the first coupling portion 51 coupled to the lower surface end portion 23 and the second coupling portion 52 coupled to the third end surface 34 of the second beam 30. With this structure, the second fitting 50 connects the lower surface end portion 23 in the lower surface 20Y of the first beam 20 and the third end surface 34 of the second beam 30. This restricts displacement of the first beam 20 and the second beam 30.

[0084] (7) The lower surface 20Y of the first beam 20 and the upper surface 30X of the second beam 30 are spaced apart by a gap. With this structure, air flows through the gap between the lower surface 20Y of the first beam 20 and the upper surface 30X of the second beam 30. This limits the water that collects between the first beam 20 and the second beam 30. Thus, corrosion is limited in the first beam 20 and the second beam 30.

[0085] (8) The building 1 includes the structural member 4, the composite beam 10, and the installation 5. The composite beam 10 includes the first beam 20 and the second beam 30. The second beam 30 is arranged along the first beam 20 below the lower surface 20Y of the first beam 20 and is coupled to the first beam 20. With this structure, the installation 5 is arranged in the space between the structural member 4 and the third end surface 34. Accordingly, the portion of the installation 5 projecting downward from the ceiling is limited, and the dimension of the downward-projecting portion of the installation 5 is reduced.

[0086] (9) The building 1 includes the structural member 4 and the composite beam 10. The composite beam 10 includes the first beam 20 and the second beam 30. The second beam 30 is arranged along the first beam 20 below the lower surface 20Y of the first beam 20 and is coupled to the first beam 20. The structural member 4 and the third end surface 34 are spaced apart by the arrangement space SA allowing for arrangement of the installation 5. This allows the installation 5 to be arranged in the arrangement space SA. Thus, the installation 5 is arranged in the first ceiling 2.

[0087] (10) The reinforcement fitting 60 is coupled to the lower surface end portion 23 located in the lower surface 20Y of the first beam 20 and the third end surface 34. With this structure, the third end surface 34 of the second beam 30 is connected to the lower surface end portion 23 by the reinforcement fitting 60. Thus, the third end surface 34 does not need to be connected to the structural member 4. When the first end surface 21 of the first beam 20 is connected to the structural member 4 of the building 1, the installation 5 may be arranged in the space between the structural member 4 and the third end surface 34. This allows the installation 5 to be arranged in the first ceiling 2.Modifications

[0088] The above embodiments exemplify structures of the building, the composite beam, and the reinforcement fittings, and are not intended to impose any limitation. The building, the composite beam, and the reinforcement fittings may differ from the structures exemplified in the above embodiments. Parts of the structures described in the embodiments may be replaced, changed, or omitted. Otherwise, a new feature may be added to the structures of the embodiments. Modifications of the embodiments will now be described.

[0089] As shown in FIG. 7, the pipe holes 37 may be arranged in the first beam 20. The composite beam 10 of the modification may include protectors 70 that protect the first beam 20. Each protector 70 covers the inside of a corresponding pipe hole 37 and the surrounding of the pipe hole 37 so that a pipe arranged inside the pipe hole 37 does not directly contact the first beam 20.

[0090] As shown in FIGS. 1, 8, and 9, the structural member 4 may be the girder 4A, the beam 71, or the post 72. FIG. 8 shows an example in which the structural member 4 is the beam 71. FIG. 9 shows an example in which the structural member 4 is the post 72.

[0091] As long as the building 1 includes the structural member 4 and the composite beam 10, the installation 5 does not need to be included. In this modification, the installation 5 may be retrofitted in the arrangement space SA after the building 1 is constructed when necessary.

[0092] The second beam 30 may be formed from the same material as the first beam 20. In this modification, the second beam 30 may be formed from wood.

[0093] In the longitudinal direction X1, the third end surface 34 may be located inward from the first end surface 21, and the fourth end surface 35 may be located at the same position as the second end surface 22 or may be located outward from the second end surface 22. Further, in the longitudinal direction X1, the third end surface 34 may be located at the same position as the first end surface 21 or may be located outward from the first end surface 21, and the fourth end surface 35 may be located inward from the second end surface 22. In this modification, the step 13 is arranged at either one of the first end 11A and the second end 11B of the composite beam 10.

[0094] The first fittings 40 may all be spaced apart at the same interval. In the longitudinal direction X1 of the first beam 20, the interval G1 of the first fittings 40 arranged in the vicinity of the end 11 of the composite beam 10 may be the same as the interval G2 of the first fittings 40 arranged in the vicinity of the central part 12 of the composite beam 10.

[0095] The number of the first fittings 40 may be changed. The number of the first fittings 40 arranged in the central part 12 may differ from the number of the first fittings 40 arranged in the first end 11A or the second end 11B of the composite beam 10. For example, there may be two first fittings 40, in which one of the first fittings 40 is arranged at the first end 11A. and the other first fitting 40 is arranged at the second end 11B. A first fitting 40 does not need to be arranged at the central part 12. As another example, there may be three first fittings 40, in which one first fitting 40 is arranged at the first end 11A, another first fitting 40 is arranged at the central part 12, and a further first fitting 40 is arranged at the second end 11B. In a further example, there may be five first fittings 40, in which two first fittings are arranged at the first end 11A, one first fitting 40 is arranged at the central part 12, and two first fittings 40 are arranged at the second end 11B. The number of the first fittings may be ten or greater.

[0096] The number of the first fittings 40 may be set in accordance with the length L of the composite beam 10. In an example, when the length L of the composite beam 10 is between 6.5 m and 7.5 m, inclusive, the number of the first fittings 40 may be nine. In another example, when the length L of the composite beam 10 is between 5.5 m and 6.5 m, inclusive, the number of the first fittings 40 may be eight.

[0097] The lower surface 20Y of the first beam 20 may be in contact with the upper surface 30X of the second beam 30. In this modification, there is no space between the lower surface 20Y of the first beam 20 and the upper surface 30X of the second beam 30. In this modification, a groove for fitting the first plate 41 of the first fitting 40 may be arranged on the lower surface 20Y of the first beam 20 or on the upper surface 30X of the second beam 30 so that the lower surface 20Y of the first beam 20 and the upper surface 30X of the second beam 30 contact each other.

[0098] One of the first fitting 40 and the second fitting 50 may be omitted. In this modification, the second beam 30 may be coupled to the first beam 20 by the other one of the first fitting 40 or the second fitting 50.

[0099] In this specification, the following technologies are disclosed.Clause 1

[0100] A composite beam forming a portion of a frame assembly of a building, the composite beam comprising:

[0101] a first beam including a first end surface and a second end surface located at an opposite side of the first end surface in a longitudinal direction; and

[0102] a second beam including a third end surface and a fourth end surface located at an opposite side of the third end surface in a longitudinal direction, wherein

[0103] the second beam is arranged along the first beam below a lower surface of the first beam and is coupled to the first beam, and

[0104] in the longitudinal direction of the first beam, the third end surface is located inward from the first end surface, and the fourth end surface is located inward from the second end surface.

[0105] Clause 2

[0106] The composite beam according to clause 1, where

[0107] the first beam is formed from wood, and

[0108] the second beam is formed from steel.

[0109] Clause 3

[0110] The composite beam according to clause 1 or 2, further comprising first fittings that couple the second beam to the first beam;

[0111] where the first fittings are connected to the lower surface of the first beam and an upper surface of the second beam.Clause 4

[0112] The composite beam according to clause 3, where the first fittings each include:

[0113] a first plate arranged between the first beam and the second beam,

[0114] a first projection projecting from the first plate and inserted in a first insertion hole of the first beam, and

[0115] a second projection projecting from the first plate and inserted in a second insertion hole of the second beam.Clause 5

[0116] The composite beam according to clause 3 or 4, where the first fittings in a vicinity of an end of the composite beam are arranged at a smaller interval than the first fittings arranged in a vicinity of a central part of the composite beam in the longitudinal direction of the first beam.Clause 6

[0117] The composite beam according to any one of clauses 1 to 5, further comprising a second fitting including:

[0118] a first coupling portion coupled to a lower surface end portion located in the lower surface of the first beam between the first end surface and the third end surface in the longitudinal direction of the first beam, and

[0119] a second coupling portion coupled to the third end surface of the second beam.Clause 7

[0120] The composite beam according to any one of clauses 1 to 6, where the lower surface of the first beam and an upper surface of the second beam are spaced apart by a gap.Clause 8

[0121] A building, comprising:

[0122] a structural member that is a beam, a girder, or a post;

[0123] a composite beam connected to the structural member; and

[0124] an installation arranged in a vicinity of an end of the composite beam; where

[0125] the composite beam includes

[0126] a first beam including a first end surface connected to a side surface of the structural member, and

[0127] a second beam including a third end surface facing the side surface of the structural member,

[0128] the second beam is arranged along the first beam below a lower surface of the first beam and is coupled to the first beam, and

[0129] the installation is arranged between the structural member and the third end surface.Clause 9

[0130] A building, comprising:

[0131] a structural member that is a beam, a girder, or a post;

[0132] a composite beam connected to the structural member; where

[0133] the composite beam includes

[0134] a first beam including a first end surface connected to a side surface of the structural member, and

[0135] a second beam including a third end surface facing the side surface of the structural member,

[0136] the second beam is arranged along the first beam below a lower surface of the first beam and is coupled to the first beam, and

[0137] the structural member and the third end surface are spaced apart by an arrangement space allowing for arrangement of an installation.Clause 10

[0138] A reinforcement fitting arranged on a composite beam, where

[0139] the composite beam includes

[0140] a first beam including a first end surface and a second end surface located at an opposite side of the first end surface in a longitudinal direction, and

[0141] a second beam including a third end surface and a fourth end surface located at an opposite side of the third end surface in a longitudinal direction,

[0142] the second beam is arranged along the first beam below a lower surface of the first beam,

[0143] the third end surface is located inward from the first end surface in the longitudinal direction of the first beam, and

[0144] the reinforcement fitting is coupled to a lower surface end portion located in a lower surface of the first beam between the first end surface and the third end surface in the longitudinal direction of the first beam, and is coupled to the third end surface.REFERENCE SIGNS LIST1) building; 4) structural member; 4A) girder; 5) installation; 10) composite beam; 11) end; 12) central part; 20) first beam; 21) first end surface; 22) second end surface; 23) lower surface end portion; 24) first insertion hole; 30) second beam; 34) third end surface; 35) fourth end surface; 38) second insertion hole; 40, 40A, 40B, 40C) first fitting; 41) first plate; 42) first projection; 43) second projection; 50) second fitting; 51) first coupling portion; 52) second coupling portion; 60) reinforcement fitting; 71) beam; 72) post.

Examples

embodiment

[0026]A building 1, a composite beam 10, and a reinforcement fitting 60 in accordance with an embodiment will now be described with reference to FIGS. 1 to 6.

Building

[0027]FIG. 1 is a schematic diagram showing an example of a building 1. Examples of the building 1 include a single-family residential building, a collective residential building, and a public facility. The building 1 of the present embodiment is a single-family residential building. The building 1 includes a first space S1 and a second space S2 connected to the first space S1. An example of the first space S1 is an indoor space of the building 1. Examples of the first space S1 include rooms such as a living room, a dining room, a kitchen, a bedroom, and a children's room. The second space S2 is, for example, an outdoor space of the building 1. An example of the second space S2 is a piloti. The second space S2 may be an indoor space differing from the first space S1. The building 1 includes a first ceiling 2 provided in...

TECHNICAL FIELD

[0001] The present disclosure relates to a composite beam, a building, and a reinforcement fitting.BACKGROUND ART

[0002] A known technology for increasing the strength of a building strengthens a structural body that includes a wooden beam and a wooden post. For example, Patent Literature 1 discloses a structural body including wooden posts, wooden beams spanning over the wooden posts, and steel reinforcements arranged along the lower surfaces of the wooden beams and having ends joined to the wooden beams. Ends of the steel reinforcements are joined to side surfaces of the wooden posts.CITATION LISTPatent Literature

[0003] [Patent Literature 1] JP2010-031610ASUMMARY OF INVENTIONTechnical Problem

[0004] Installations may be arranged on a ceiling of a building. An example of such an installation is a cornice box. For example, when arranging a cornice box near a wall, the attachment of the cornice box to the lower surface of a beam will result in the cornice box projecting downward from the ceiling surface. Thus, the cornice box will adversely affect the continuity of the ceiling surface in the horizontal direction. In this manner, it is difficult to arrange an installation in the space above the ceiling.Solution to Problem(1) In one general aspect, a composite beam forms a portion of a frame assembly of a building. The composite beam includes a first beam that includes a first end surface and a second end surface located at an opposite side of the first end surface in a longitudinal direction and a second beam including a third end surface and a fourth end surface located at an opposite side of the third end surface in a longitudinal direction. The second beam is arranged along the first beam below a lower surface of the first beam and is coupled to the first beam. In the longitudinal direction of the first beam, the third end surface is located inward from the first end surface, and the fourth end surface is located inward from the second end surface.

[0006] With this structure, when the first end surface of the first beam is connected to the structural member of the building, space extends between the structural element and the third end surface. Further, when the second end surface of the first beam is connected to the structural member of the building, space extends between the structural element and the fourth end surface. The installation may be arranged in the space between the structural element and the third end surface, and in the space between the structural element and the fourth end surface. This allows the installation to be arranged in a ceiling.

[0007] (2) The composite beam according to (1), the first beam is formed from wood, and the second beam is formed from steel. In contrast with when the second beam is formed from wood, this structure improves the rigidity of the composite beam.

[0008] (3) The composite beam according to (1) or (2), further includes first fittings that couple the second beam to the first beam. The first fittings are connected to the lower surface of the first beam and an upper surface of the second beam. With this structure, multiple first fittings connect the lower surface of the first beam and the upper surface of the second beam. This restricts displacement of the first beam and the second beam.

[0009] (4) The composite beam according to (3), where the first fittings each include a first plate arranged between the first beam and the second beam, a first projection projecting from the first plate and inserted in a first insertion hole of the first beam, and a second projection projecting from the first plate and inserted in a second insertion hole formed in the second beam. With this structure, the first projection is inserted into the first insertion hole of the first beam, and the second projection is inserted into the second insertion hole of the second beam. This limits displacement of the first beam and the second beam.

[0010] (5) The composite beam according to (3) or (4), where the first fittings in a vicinity of an end of the composite beam are arranged at a smaller interval than the first fittings arranged in a vicinity of a central part of the composite beam in the longitudinal direction of the first beam. This allows the number of the first fittings in the vicinity of the central part of the composite beam to be reduced. Thus, the efficiency of assembling the composite beam is improved.

[0011] (6) The composite beam according to any one of (1) to (5), further includes a second fitting including a first coupling portion coupled to a lower surface end portion located in the lower surface of the first beam between the first end surface and the third end surface in the longitudinal direction of the first beam, and a second coupling portion coupled to the third end surface of the second beam. With this structure, the second fitting connects the lower surface end portion in the lower surface of the first beam and the third end surface of the second beam. This restricts displacement of the first beam and the second beam.

[0012] (7) The composite beam according to any one of (1) to (6), the lower surface of the first beam and an upper surface of the second beam are spaced apart by a gap. With this structure, air flows through the gap between the lower surface of the first beam and the upper surface of the second beam. This limits the water that collects between the first beam and the second beam. Thus, corrosion is limited in the first beam and the second beam.

[0013] (8) In another general aspect, a building includes a structural member that is a beam, a girder, or a post, a composite beam connected to the structural member, and an installation arranged in a vicinity of an end of the composite beam. The composite beam includes a first beam including a first end surface connected to a side surface of the structural member, and a second beam including a third end surface facing the side surface of the structural member. The second beam is arranged along the first beam below a lower surface of the first beam and is coupled to the first beam. The installation is arranged between the structural member and the third end surface. With this structure, the installation is arranged in the space between the structural member and the third end surface. Accordingly, the portion of the installation projecting downward from the ceiling is limited, and the dimension of the downward-projecting portion of the installation is reduced.

[0014] (9) In a different general aspect, a building includes a structural member that is a beam, a girder, or a post and a composite beam connected to the structural member. The composite beam includes a first beam including a first end surface connected to a side surface of the structural member, and a second beam including a third end surface facing the side surface of the structural member. The second beam is arranged along the first beam below a lower surface of the first beam and is coupled to the first beam. The structural member and the third end surface are spaced apart by an arrangement space allowing for arrangement of an installation. This allows the installation to be arranged in an arrangement space. Thus, the installation is arranged in the ceiling.

[0015] (10) In a different general aspect, a reinforcement fitting is arranged on a composite beam. The composite beam includes a first beam including a first end surface and a second end surface located at an opposite side of the first end surface in a longitudinal direction, and a second beam including a third end surface and a fourth end surface located at an opposite side of the third end surface in a longitudinal direction. The second beam is arranged along the first beam below a lower surface of the first beam. The third end surface is located inward from the first end surface in the longitudinal direction of the first beam. The reinforcement fitting is coupled to a lower surface end portion located in a lower surface of the first beam between the first end surface and the third end surface in the longitudinal direction of the first beam, and is coupled to the third end surface. With this structure, the third end surface of the second beam is connected to the lower surface end portion by the reinforcement fitting. Thus, the third end surface does not need to be connected to the structural member. When the first end surface of the first beam is connected to the structural member of the building, the installation may be arranged in the space between the structural member and the third end surface. This allows the installation to be is arranged in the ceiling.Advantageous Effects of Invention

[0016] In the present disclosure, a composite beam, a building, and a reinforcement fitting allows an installation such as a cornice box or the like to be arranged on the ceiling in a preferable manner.BRIEF DESCRIPTION OF DRAWINGS

[0017] FIG. 1 A schematic diagram of a building in accordance with an embodiment.

[0018] FIG. 2 A side view of a composite beam in accordance with the embodiment.

[0019] FIG. 3 A side view of an end of the composite beam in the embodiment.

[0020] FIG. 4 A cross-sectional view taken along line D4-D4 in FIG. 2.

[0021] FIG. 5 A perspective view of a first fitting.

[0022] FIG. 6 A partial perspective view of the composite beam in accordance with the embodiment.

[0023] FIG. 7 A side view of a composite beam in accordance with a first modification

[0024] FIG. 8 A diagram of a building in accordance with a second modification.

[0025] FIG. 9 A diagram of a building in accordance with a third modification.DESCRIPTION OF EMBODIMENTSEmbodiment

[0026] A building 1, a composite beam 10, and a reinforcement fitting 60 in accordance with an embodiment will now be described with reference to FIGS. 1 to 6.Building

[0027] FIG. 1 is a schematic diagram showing an example of a building 1. Examples of the building 1 include a single-family residential building, a collective residential building, and a public facility. The building 1 of the present embodiment is a single-family residential building. The building 1 includes a first space S1 and a second space S2 connected to the first space S1. An example of the first space S1 is an indoor space of the building 1. Examples of the first space S1 include rooms such as a living room, a dining room, a kitchen, a bedroom, and a children's room. The second space S2 is, for example, an outdoor space of the building 1. An example of the second space S2 is a piloti. The second space S2 may be an indoor space differing from the first space S1. The building 1 includes a first ceiling 2 provided in the first space S1 and a second ceiling 3 provided in the second space S2.

[0028] The building 1 includes structural members 4, composite beams 10, and an installation 5. The structural members 4 are portions of a frame assembly of the building 1. The structural members 4 and the composite beams 10 are portions of a structural body of the building 1. In the present embodiment, the structural members 4 include a girder 4A. The girder 4A is a portion of the frame assembly that forms a wall 6 of the building 1. The wall 6 is located between the first space S1 and the second space S2. In the first space S1, the structural members 4 may include another girder 4B located at an opposite side of the girder 4A. A distance D1 between the girder 4A and the other girder 4B is, for example, between 6.5 m and 7.5 m, inclusive. The distance D1 may be between 5.5 m and 6.5 m, inclusive. The distance D1 may be between 4.5 m and 5.5 m, inclusive. The distance D1 may be between 3.5 m and 4.5 m, inclusive.

[0029] When viewed from above, a girder is defined as a member that extends in a direction parallel to the long sides, and a beam is a member that extends in a direction parallel to the short sides and intersects the girder. The girder is also defined as a horizontal member that receives a rafter, and the beam is defined as a member that does not receive a rafter and intersects the girder. However, there is no limitation to these definitions.

[0030] The installation 5 is attached to the first ceiling 2 exposed to the first space S1. The installation 5 is, for example, a curtain box. The curtain box accommodates a curtain rail. The curtain rail may be a rail allowing for automatic opening and closing of a curtain. The installation 5 may be equipment attached to the ceiling. The installation 5 may be indirect lighting.

[0031] The installation 5 is arranged in the vicinity of an end 11 of the composite beam 10. The installation 5 is arranged in the vicinity of the girder 4A. The building 1 may include another installation 5A arranged in the vicinity of the other girder 4B. The other installation 5A is arranged in the vicinity of an end 11 at the opposite side of the end 11 where the installation 5 is located. The installation 5 may differ from the other installation 5A. The other installation 5A may be omitted.Composite Beam

[0032] As shown in FIG. 1, each composite beam 10 is a portion of the frame assembly of the building 1. The composite beam 10 is arranged on the first ceiling 2. The composite beam 10 extends between the girder 4A and the other girder 4B. The composite beam 10 is connected to the structural members 4. The composite beam 10 is connected to the girder 4A and the other girder 4B. The building 1 may include multiple composite beams 10 arranged next to one another in a direction extending from the front side toward the rear side of the sheet of FIG. 1 as seen from the viewer.

[0033] As shown in FIG. 2, in a longitudinal direction X1, the composite beam 10 includes the ends 11 and a central part 12. The ends 11 of the composite beam 10 include a first end 11A and a second end 11B at the opposite side of the first end 11A. The composite beam 10 has a length L set in correspondence with the distance D1 from the girder 4A to the other girder 4B. The length Lis, for example, between 6.5 m and 7.5 m, inclusive. The length L may be between 5.5 m and 6.5 m, inclusive. The length L may be between 4.5 m and 5.5 m, inclusive. The length L may be between 3.5 m and 4.5 m, inclusive.

[0034] The composite beam 10 is formed by combining two beam members. The beam members extend in the longitudinal direction X1. The material of one of the two beam members differs from the material of the other one of the two beam members. The composite beam 10 includes a first beam 20 and a second beam 30.First Beam

[0035] The first beam 20 is formed from wood. Wood may be, for example, solid lumber or laminated lumber. The first beam 20 may be formed from, for example, homogeneous-grade lumber. When the first beam 20 is formed from homogeneous-grade lumber, the stacking direction of the sawn boards in the first beam 20 corresponds to the vertical direction.

[0036] The first beam 20 includes a first end surface 21 and a second end surface 22 located at the opposite side of the first end surface 21 in the longitudinal direction X1. The first end surface 21 is connected to a side surface 4Z of the structural member 4. In the present embodiment, the side surface 4Z of the structural member 4 is a side surface of the girder 4A. The second end surface 22 is connected to a side surface of the other girder 4B. The first beam 20 has a first length L1 that is defined as the length from the first end surface 21 to the second end surface 22 in the longitudinal direction X1 of the first beam 20. The first length L1 of the first beam 20 is the same as the length L of the composite beam 10.

[0037] As shown in FIG. 3, the first beam 20 is connected to the structural member 4 by a first support fitting 7 and a second support fitting 8. The first support fitting 7 includes a main body 7A and two slot insertions 7B that are integrally formed with the main body 7A. The main body 7A includes a plate that contacts the side surface 4Z of the structural member 4 and a first end surface 21 of the first beam 20. Each slot insertion 7B includes a plate extending orthogonal to the main body 7A. The slot insertion 7B is inserted into a slot 21A formed in the first end surface 21. As shown in FIG. 6, the first end surface 21 of the first beam 20 includes two slots 21A. First shaft members 7C extend through the structural member 4 and the main body 7A to fix the main body 7A to the structural member 4. The first shaft members 7C may include one or more sets of a bolt and a nut.

[0038] The first support fitting 7 is fixed to the first beam 20 by other first shaft members 7D extending through the first beam 20 and the two slot insertions 7B. The other first shaft members 7D may each include a drift pin.

[0039] The second support fitting 8 includes a main body 8A and a support 8B that is formed integrally with the main body 8A. The main body 8A is L-shaped and contacts the side surface 4Z of the structural member 4 and a lower surface 20Y of the first beam 20. The support 8B is connected to a part of the main body 8A connected to the lower surface 20Y of the first beam 20 and to a part of the main body 8A connected to the side surface 4Z of the structural member 4. The main body 8A is fixed to the structural member 4 by a second shaft member 8C extending through the structural member 4 and the part of the main body 8A contacting the side surface 4Z of the structural member 4. The second shaft member 8C may include a set of a bolt and a nut.

[0040] The part of the main body 8A contacting the lower surface 20Y of the first beam 20 is fixed to the lower surface 20Y of the first beam 20 by screws or the like. In the longitudinal direction X1, a dimension of the part of the main body 8A contacting the lower surface 20Y of the first beam 20 is less than or equal to 120 mm. In the longitudinal direction X1, a dimension of the part of the main body 8A contacting the lower surface 20Y of the first beam 20 is less than or equal to 100 mm.

[0041] As shown in FIG. 4, the first beam 20 has a first height H1 in the vertical direction that is greater than or equal to 100 mm. The first height H1 of the first beam 20 in the vertical direction may be greater than or equal to 120 mm. The height H1 of the first beam 20 in the vertical direction is less than or equal to 330 mm. The first beam 20 in the vertical direction may be less than or equal to 210 mm. The first beam 20 includes a first width W1 that is greater than or equal to 100 mm. The dimension of the first width W1 of the first beam 20 may be less than or equal to the dimension of the first height H1 of the first beam 20.Second Beam

[0042] Referring FIG. 4, the second beam 30 is formed from steel. An example of steel is an H-section steel or an I-section steel. The second beam 30 includes a first flange 31, a second flange 32, and a web 33. The first flange 31 forms an upper surface 30X of the second beam 30. The second flange 32 forms a lower surface 30Y of the second beam 30. The web 33 connects the first flange 31 and the second flange 32.

[0043] As shown in FIG. 2, the second beam 30 includes a third end surface 34 and a fourth end surface 35 located at the opposite side of the third end surface 34 in a longitudinal direction X2. The third end surface 34 faces the side surface 4Z of the structural member 4. The third end surface 34 faces the side surface of the other girder 4B. The longitudinal direction X2 coincides with the longitudinal direction X1. A second length L2 of the second beam 30 is defined as the length between the third end surface 34 and the fourth end surface 35 in the longitudinal direction X2. A ratio of the second length L2 to the first length L1 is greater than or equal to 0.7.

[0044] The second beam 30 extends along the first beam 20 below the lower surface 20Y of the first beam 20 and is coupled to the first beam 20. In the longitudinal direction X1 of the first beam 20, the third end surface 34 is located inward from the first end surface 21 and the fourth end surface 35 is located inward from the second end surface 22. The phrase “located inward” indicates that an end surface is located closer to a center line of the first beam 20 in the longitudinal direction X1 than the compared end surface. In the longitudinal direction X1, the third end surface 34 is located at least 250 mm inward from the first end surface 21. In the longitudinal direction X1, the third end surface 34 may be located at least 350 mm inward from the first end surface 21. In the longitudinal direction X1, the fourth end surface 35 is located at least 250 mm inward from the second end surface 22. In the longitudinal direction X1, the fourth end surface 35 may be located at least 350 mm inward from the second end surface 22.

[0045] As shown in FIGS. 3 and 4, an end plate 36 that is perpendicular to the longitudinal direction X2 is coupled to each end of the second beam 30 through welding or the like. The end plate 36 coupled to one end of the second beam 30 defines the third end surface 34. The end plate 36 coupled to the other end of the second beam 30 defines the fourth end surface 35.

[0046] As shown in FIG. 4, the second beam 30 has a second height H2 that is greater than or equal to 100 mm. The second height H2 of the second beam 30 may be less than or equal to the first height H1 of the first beam 20. The second height H2 of the second beam 30 is less than or equal to 250 mm. The second height H2 of the second beam 30 may be less than or equal to 200 mm. The second beam 30 includes a second width W2 that is greater than or equal to 100 mm. The second width W2 of the second beam 30 may be less than the first width W1 of the first beam 20.

[0047] As shown in FIG. 2, the second beam 30 may include pipe holes 37 extending through the web 33. For example, a vent pipe, a drain pipe, or the like may be arranged in each pipe holes 37. The pipe holes 37 allow a vent pipe, a drain pipe, or the like to be arranged in the ceiling void.Arrangement Space

[0048] As shown in FIGS. 1 and 2, an arrangement space SA extends between the structural member 4 and the third end surface 34 allow for arrangement of the installation 5. The installation 5 is arranged between the structural member 4 and the third end surface 34. A further arrangement space SA may extend between the structural member 4 and the fourth end surface 35.

[0049] The arrangement space SA arranged in the first ceiling 2 opens downwardly. The first ceiling surface 2A of the first ceiling 2 is located below the lower surface 30Y of the second beam 30 of the composite beam 10. The arrangement of the installation 5 in the arrangement space SA allows the installation 5 to be arranged above the first ceiling surface 2A of the first ceiling 2. The arrangement of the installation 5 in the arrangement space SA allows the first ceiling surface 2A of the first ceiling 2 to have the same height as the second ceiling surface 3A of the second ceiling 3. This allows the first ceiling surface 2A and the second ceiling surface 3A to appear as sharing the same flat surface.

[0050] As shown in FIG. 3, a step 13 is formed in the composite beam 10. The step 13 is a cutout portion between the upper surface 20X of the first beam 20 and the lower surface 30Y of the second beam 30 removed from the composite beam 10. The step 13 of the present embodiment is a portion defined by a lower surface end portion 23 and the third end surface 34. The lower surface end portion 23 is where the lower surface 20Y extends between the first end surface 21 and the third end surface 34 in the longitudinal direction X1 of the first beam 20. FIG. 3 shows the example of the side surface of the composite beam 10 at the side of the first end 11A. The side of the second end 11B also includes a step 13. The arrangement space SA is defined in the step 13.First Fitting

[0051] As shown in FIG. 2, the composite beam 10 further includes first fittings 40. In the present embodiment, the composite beam 10 includes nine first fittings 40. The first fittings 40 couple the second beam 30 to the first beam 20. The first fittings 40 are connected to the lower surface 20Y of the first beam 20 and the upper surface 30X of the second beam 30.

[0052] The first fittings 40 are, for example, aligned in the longitudinal direction X1. When the first fittings 40 are arranged at the ends 11 and the central part 12, the first fittings 40 are arranged more sparsely in the vicinity of the central part 12 than in the vicinity of the ends 11. The phrase of “the first fittings 40 are arranged more sparsely” indicates that the number of the first fittings 40 arranged within a predetermined distance in the longitudinal direction X1 is less in the central part 12 than in the ends 11.

[0053] In the longitudinal direction X1 of the first beam 20, an interval G1 of the first fittings 40 arranged in the vicinity of the ends 11 of the composite beam 10 is less than an interval G2 of the first fittings 40 arranged in the vicinity of the central part 12 of the composite beam 10. The intervals G1 and G2 between the first fittings 40 are, for example, the distance between the axes of the adjacent first fittings 40 in the longitudinal direction X1. In an example shown in FIG. 2, the first fittings 40A are the first fittings40 arranged in the vicinity of the first end 11A of the end 11 of the composite beam 10. The second fittings 40B are the first fittings 40 arranged in the vicinity of the central part 12 of the composite beam 10. First fittings 40C are the first fittings 40 arranged in the vicinity of a second end 11B of the end 11 of the composite beam 10. The intervals G1 and G2 are set in accordance with the length L of the composite beam 10, the number of the first fittings 40, or the like. The interval G1 of the adjacent first fittings 40 arranged in the vicinity of the ends 11 of the composite beam 10 is, for example, 500 mm. The interval G2 of the adjacent first fittings 40 arranged in the vicinity of the central part 12 of the composite beam 10 is, for example, 1000 mm.

[0054] As shown in FIGS. 4 and 5, each first fitting 40 includes a first plate 41, a first projection 42, and second projections 43. The first plate 41 is arranged between the first beam 20 and the second beam 30. The first projection 42 projects from the first plate 41 and is into a first insertion hole 24 formed in the first beam 20. Each second projection 43 projects from the first plate 41 and is inserted into a corresponding second insertion hole 38 formed in the second beam 30. The second insertion hole 38 is formed in the first flange 31 of the second beam 30.

[0055] As viewed in the longitudinal direction X1, a third width W3 of the first plate 41 is less than the first width W1 of the first beam 20. As viewed in the longitudinal direction X1, the third width W3 of the first plate 41 is greater than the second width W2 of the second beam 30. Since the third width W3 of the first plate 41 is less than the first width W1 of the first beam 20 and greater the than the second width W2 of the second beam 30, the water from the surfaces of the first beam 20 that collect on the first plate 41 will be limited. Thus, the water from the surfaces of the first beam 20 will flow downward from to the first plate 41 without contacting the lower surface 20Y of the first beam 20. This limits the water that permeates the first beam 20, which is formed from wood, in the composite beam 10.

[0056] The first projection 42 projects upward from the first plate 41. The first projection 42 has a third height H3 that is greater than or equal to 60 mm and less than or equal to the first height H1 of the first beam 20.

[0057] As shown in FIGS. 3 and 4, the first beam 20 and each first projection 42 includes first through holes 25 that extend through the first beam 20 and the first projection 42 in a horizontal direction. Each first through hole 25 extends through side surfaces 20Z of the first beam 20. In the present embodiment, two first through holes 25 are arranged next to each other in the vertical direction. Drift pins 44 are arranged in the through holes 25. The drift pins 44 couple the first beam 20 and each first fitting. The first fitting 40 may be, for example, coupled to the first beam 20 by using a fastener or the like that extends through the first plate 41.

[0058] As shown in FIGS. 4 and 5, each second projection 43 projects downward from the first plate 41. The second projections 43 may include multiple projections. In the present embodiment, the second projections 43 include four projections. Second insertion holes 38 for insertion of the second projection 43 are formed in the first flange 31. The second projections 43 are arranged in the second insertion holes 38 in a manner extending through the first flange 31.

[0059] Each second projection 43 is, for example, a bolt. A nut 45 is fastened to a portion of the second projection 43 projecting out of the first flange 31. The nut 45 couples the second beam 30 and the first fitting 40. The second projection 43 may be a pole.

[0060] As shown in FIG. 3, in the present embodiment, a gap extends between the lower surface 20Y of the first beam 20 and the upper surface 30X of the second beam 30. Each first fitting 40 couples the first beam 20 and the second beam 30 so that the lower surface 20Y of the first beam 20 does not contact the upper surface 30X of the second beam 30. In the present embodiment, the distance from the lower surface 20Y of the first beam 20 to the upper surface 30X of the second beam 30 coincides with the thickness of the first plate 41 in the vertical direction.Second Fitting

[0061] As shown in FIG. 2, the composite beam 10 further includes second fittings 50. The second fittings 50 connect the second beam 30 to the first beam 20. The second fitting 50 is arranged in the arrangement space SA. In the present embodiment, the composite beam 10 includes a second fitting 50 arranged at the first end 11A and another second fitting 50 arranged at the second end 11B. The description hereafter will focus on the second fitting 50 arranged at the first end 11A. The second fitting 50 arranged at the second end 11B has the same structure as the second fitting 50 arranged at the first end 11A.

[0062] As shown in FIG. 6, the second fitting 50 includes a first coupling portion 51 and a second coupling portion 52. The first coupling portion 51 is coupled to a lower surface end portion 23 of the first beam 20. The second coupling portion 52 is coupled to the third end surface 34 of the second beam 30.

[0063] The first coupling portion 51 includes a first plate member 53 contacting the lower surface end portion 23. The first plate member 53 is coupled to the first beam 20 by first coupling members 53A. Each first coupling members 53A is, for example, a lag bolt. The second coupling portion 52 includes a second plate member 54 contacting the third end surface 34. The second plate member 54 is coupled to the first beam 20 by second coupling members 54A. Each second coupling member 54A, for example, includes a bolt and a nut.

[0064] The first coupling portion 51 and the second coupling portion 52 are formed integrally. The first coupling portion 51 and the second coupling portion 52 are formed integrally through welding, stamping, or the like. The second fitting 50 is L-shaped by connecting an end of the second plate member 54 to an end of the first plate member 53.

[0065] The second fitting 50 includes a support portion 55. The support portion 55 is connected to the first coupling portion 51 and the second coupling portion 52. The support portion 55 includes a third plate member 56 that is arranged perpendicular to the first plate member 53 and the second plate member 54.

[0066] The support portion 55 is formed integrally with the first coupling portion 51 and the second coupling portion 52. The third plate member 56 is connected to a surface of the first plate member 53 that is opposite the surface contacting the lower surface end portion 23 through welding or the like. The third plate member 56 is connected a surface of the second plate member 54 that is opposite the surface contacting the third end surface 34 through welding or the like.

[0067] The second fitting 50 is also referred to as a reinforcement fitting 60. The second fitting 50 is arranged on the composite beam 10 of the present embodiment. Further, the second fitting 50 may be arranged on a composite beam having a different structure.

[0068] A first operation of the present embodiment will now be described.

[0069] An installation may be arranged in a ceiling of a building. An example of an installation is a cornice box. For example, when arranging the cornice box on a wall, the attachment of the cornice box to the lower surface of the beam will expose the cornice box from the ceiling surface. The cornice box will adversely affect the continuity of the ceiling surface in the horizontal direction. With the composite beam 10 of the present embodiment, the third end surface 34 of the second beam 30 is located inward from the first end surface 21 of the first beam 20 in the longitudinal direction X1. Thus, when coupling the first beam 20 to the structural member 4 so that that the first end surface 21 of the first beam 20 contacts the structural member 4, a space is formed between the second beam 30 and the structural member 4. This allows the installation 5 to be arranged in the space between the second beam 30 and the structural member 4.

[0070] A second operation of the present embodiment will now be described.

[0071] When arranging the cornice box in the ceiling, in order to arrange the cornice box at a position higher than the ceiling surface, the end of a wooden beam may be cut out to form a step. However, when removing part of the wooden beam to form a step, a load may form a crack in a corner of the step. As the length of the wooden beam increases, the load will increase. This will easily form a crack originating in the corner of the step in the wooden beam. This limits the length of a wooden beam including a step formed by a cutout portion. Such a limitation in length will impose restrictions on the size of a building that uses a wooden beam including a step formed by a cutout portion. With the composite beam 10 of the present embodiment, the step 13 is formed by the lower surface end portion 23 of the first beam 20 and the third end surface 34 of the second beam 30. This structure avoids the formation of a crack in the composite beam 10 in the corner of the step. This eliminates restrictions on the length L of the composite beam 10. In the building 1 that uses the composite beam 10, the composite beam 10 may be long. Thus, the first space S1 may be enlarged.

[0072] A third operation of the present embodiment will now be described.

[0073] The first fittings 40 are arranged so that the interval G2 of the first fittings 40 arranged in the vicinity of the central part 12 of the composite beam 10 is greater than the interval G1 of the first fittings 40 arranged in the vicinity of the end 11 of the first fittings 40. Compared to when the first fittings 40 are arranged at the same interval G1, the number of the first fittings 40 arranged in the vicinity of the central part 12 may be decreased. Thus, the number of the first fittings 40 may be decreased. Bending tests have been conducted to confirm that as compared with when the first fittings 40 in the vicinity of the end 11 of the composite beam 10 are arranged at the interval G1 so that the first fittings 40 are all arranged at the interval G1, a decrease in the number of the first fittings 40 in the vicinity of the central part 12 has subtle effect on the rigidity of the composite beam 10. A decrease in the number of the first fittings 40 will reduce the manufacturing cost of the composite beam 10. Further, a decrease in the number of the first fittings 40 will reduce the number of steps for assembling the composite beam 10.

[0074] A fourth operation of the present embodiment will now be described.

[0075] Although each first fitting 40 is connected to the first beam 20 by the first projection 42 inserted into the corresponding first insertion hole 24 of the first beam 20, the tolerance of the first insertion hole 24 may result in slight horizontal movement of the first projection 42 in the first insertion hole 24. If the first projection 42 moves slightly inside the first insertion hole 24 in the horizontal direction, the first fitting 40 will move in the horizontal direction relative to the first beam 20. Thus, the second beam 30 may be displaced relative to the first beam 20. With the present embodiment, the first coupling portion 51 of the second fitting 50 is coupled to the lower surface end portion 23 of the first beam 20 by the first coupling members 53A. This restricts movement of the second fitting 50 relative to the first beam 20. The second coupling portion 52 of the second fitting 50 coupled to the first beam 20 of the second beam 30 in the horizontal direction restricts movement of the second beam 30 in the horizontal direction relative to the first beam 20.

[0076] Advantages of the present embodiment will now be described.

[0077] (1) The composite beam 10 includes the first beam 20 and the second beam 30. The second beam 30 is arranged along the first beam 20 below the lower surface 20Y of the first beam 20 and is coupled to the first beam 20. In the longitudinal direction X1 of the first beam 20, the third end surface 34 is located inward from the first end surface 21, and the fourth end surface 35 is located inward from the second end surface 22.

[0078] With this structure, when the first end surface 21 of the first beam 20 is connected to the structural member 4 of the building 1, space extends between the structural member 4 and the third end surface 34. Further, when the second end surface 22 of the first beam 20 is connected to the structural member 4 of the building 1, space extends between the structural member 4 and the fourth end surface 35. The installation 5 may be arranged in the space between the structural member 4 and the third end surface 34, and in the space between the structural member 4 and the fourth end surface 35. This allows the installation 5 to be arranged in the first ceiling 2.

[0079] (2) The first beam 20 is formed from wood, and the second beam 30 is formed from steel. In contrast with when the second beam 30 is formed from wood, this structure improves the rigidity of the composite beam 10.

[0080] (3) The composite beam 10 further includes the first fittings 40. The first fittings 40 are connected to the lower surface 20Y of the first beam 20 and the upper surface 30X of the second beam 30. With this structure, multiple first fittings 40 connect the lower surface 20Y of the first beam 20 and the upper surface 30X of the second beam 30. This restricts displacement of the first beam 20 and the second beam 30.

[0081] (4) The first fittings 40 each include the first plate 41, the first projection 42 inserted in the first insertion hole 24 of the first beam 20, and the second projection 43 inserted in the second insertion hole 38 of the second beam 30. With this structure, the first projection 42 is inserted into the first insertion hole 24 of the first beam 20, and the second projection 43 is inserted into the second insertion hole 38 of the second beam 30. This limits displacement of the first beam 20 and the second beam 30.

[0082] (5) The first fittings 40 in a vicinity of the end of the composite beam 10 are arranged at a smaller interval than the first fittings 40 arranged in a vicinity of the central part 12 of the composite beam 10 in the longitudinal direction X1 of the first beam 20. This allows the number of the first fittings 40 in the vicinity of the central part 12 of the composite beam 10 to be reduced. Thus, the efficiency of assembling the composite beam 10 is improved.

[0083] (6) The composite beam further includes the second fitting 50. The second fitting 50 includes the first coupling portion 51 coupled to the lower surface end portion 23 and the second coupling portion 52 coupled to the third end surface 34 of the second beam 30. With this structure, the second fitting 50 connects the lower surface end portion 23 in the lower surface 20Y of the first beam 20 and the third end surface 34 of the second beam 30. This restricts displacement of the first beam 20 and the second beam 30.

[0084] (7) The lower surface 20Y of the first beam 20 and the upper surface 30X of the second beam 30 are spaced apart by a gap. With this structure, air flows through the gap between the lower surface 20Y of the first beam 20 and the upper surface 30X of the second beam 30. This limits the water that collects between the first beam 20 and the second beam 30. Thus, corrosion is limited in the first beam 20 and the second beam 30.

[0085] (8) The building 1 includes the structural member 4, the composite beam 10, and the installation 5. The composite beam 10 includes the first beam 20 and the second beam 30. The second beam 30 is arranged along the first beam 20 below the lower surface 20Y of the first beam 20 and is coupled to the first beam 20. With this structure, the installation 5 is arranged in the space between the structural member 4 and the third end surface 34. Accordingly, the portion of the installation 5 projecting downward from the ceiling is limited, and the dimension of the downward-projecting portion of the installation 5 is reduced.

[0086] (9) The building 1 includes the structural member 4 and the composite beam 10. The composite beam 10 includes the first beam 20 and the second beam 30. The second beam 30 is arranged along the first beam 20 below the lower surface 20Y of the first beam 20 and is coupled to the first beam 20. The structural member 4 and the third end surface 34 are spaced apart by the arrangement space SA allowing for arrangement of the installation 5. This allows the installation 5 to be arranged in the arrangement space SA. Thus, the installation 5 is arranged in the first ceiling 2.

[0087] (10) The reinforcement fitting 60 is coupled to the lower surface end portion 23 located in the lower surface 20Y of the first beam 20 and the third end surface 34. With this structure, the third end surface 34 of the second beam 30 is connected to the lower surface end portion 23 by the reinforcement fitting 60. Thus, the third end surface 34 does not need to be connected to the structural member 4. When the first end surface 21 of the first beam 20 is connected to the structural member 4 of the building 1, the installation 5 may be arranged in the space between the structural member 4 and the third end surface 34. This allows the installation 5 to be arranged in the first ceiling 2.Modifications

[0088] The above embodiments exemplify structures of the building, the composite beam, and the reinforcement fittings, and are not intended to impose any limitation. The building, the composite beam, and the reinforcement fittings may differ from the structures exemplified in the above embodiments. Parts of the structures described in the embodiments may be replaced, changed, or omitted. Otherwise, a new feature may be added to the structures of the embodiments. Modifications of the embodiments will now be described.

[0089] As shown in FIG. 7, the pipe holes 37 may be arranged in the first beam 20. The composite beam 10 of the modification may include protectors 70 that protect the first beam 20. Each protector 70 covers the inside of a corresponding pipe hole 37 and the surrounding of the pipe hole 37 so that a pipe arranged inside the pipe hole 37 does not directly contact the first beam 20.

[0090] As shown in FIGS. 1, 8, and 9, the structural member 4 may be the girder 4A, the beam 71, or the post 72. FIG. 8 shows an example in which the structural member 4 is the beam 71. FIG. 9 shows an example in which the structural member 4 is the post 72.

[0091] As long as the building 1 includes the structural member 4 and the composite beam 10, the installation 5 does not need to be included. In this modification, the installation 5 may be retrofitted in the arrangement space SA after the building 1 is constructed when necessary.

[0092] The second beam 30 may be formed from the same material as the first beam 20. In this modification, the second beam 30 may be formed from wood.

[0093] In the longitudinal direction X1, the third end surface 34 may be located inward from the first end surface 21, and the fourth end surface 35 may be located at the same position as the second end surface 22 or may be located outward from the second end surface 22. Further, in the longitudinal direction X1, the third end surface 34 may be located at the same position as the first end surface 21 or may be located outward from the first end surface 21, and the fourth end surface 35 may be located inward from the second end surface 22. In this modification, the step 13 is arranged at either one of the first end 11A and the second end 11B of the composite beam 10.

[0094] The first fittings 40 may all be spaced apart at the same interval. In the longitudinal direction X1 of the first beam 20, the interval G1 of the first fittings 40 arranged in the vicinity of the end 11 of the composite beam 10 may be the same as the interval G2 of the first fittings 40 arranged in the vicinity of the central part 12 of the composite beam 10.

[0095] The number of the first fittings 40 may be changed. The number of the first fittings 40 arranged in the central part 12 may differ from the number of the first fittings 40 arranged in the first end 11A or the second end 11B of the composite beam 10. For example, there may be two first fittings 40, in which one of the first fittings 40 is arranged at the first end 11A. and the other first fitting 40 is arranged at the second end 11B. A first fitting 40 does not need to be arranged at the central part 12. As another example, there may be three first fittings 40, in which one first fitting 40 is arranged at the first end 11A, another first fitting 40 is arranged at the central part 12, and a further first fitting 40 is arranged at the second end 11B. In a further example, there may be five first fittings 40, in which two first fittings are arranged at the first end 11A, one first fitting 40 is arranged at the central part 12, and two first fittings 40 are arranged at the second end 11B. The number of the first fittings may be ten or greater.

[0096] The number of the first fittings 40 may be set in accordance with the length L of the composite beam 10. In an example, when the length L of the composite beam 10 is between 6.5 m and 7.5 m, inclusive, the number of the first fittings 40 may be nine. In another example, when the length L of the composite beam 10 is between 5.5 m and 6.5 m, inclusive, the number of the first fittings 40 may be eight.

[0097] The lower surface 20Y of the first beam 20 may be in contact with the upper surface 30X of the second beam 30. In this modification, there is no space between the lower surface 20Y of the first beam 20 and the upper surface 30X of the second beam 30. In this modification, a groove for fitting the first plate 41 of the first fitting 40 may be arranged on the lower surface 20Y of the first beam 20 or on the upper surface 30X of the second beam 30 so that the lower surface 20Y of the first beam 20 and the upper surface 30X of the second beam 30 contact each other.

[0098] One of the first fitting 40 and the second fitting 50 may be omitted. In this modification, the second beam 30 may be coupled to the first beam 20 by the other one of the first fitting 40 or the second fitting 50.

[0099] In this specification, the following technologies are disclosed.Clause 1

[0100] A composite beam forming a portion of a frame assembly of a building, the composite beam comprising:

[0101] a first beam including a first end surface and a second end surface located at an opposite side of the first end surface in a longitudinal direction; and

[0102] a second beam including a third end surface and a fourth end surface located at an opposite side of the third end surface in a longitudinal direction, wherein

[0103] the second beam is arranged along the first beam below a lower surface of the first beam and is coupled to the first beam, and

[0104] in the longitudinal direction of the first beam, the third end surface is located inward from the first end surface, and the fourth end surface is located inward from the second end surface.

[0105] Clause 2

[0106] The composite beam according to clause 1, where

[0107] the first beam is formed from wood, and

[0108] the second beam is formed from steel.

[0109] Clause 3

[0110] The composite beam according to clause 1 or 2, further comprising first fittings that couple the second beam to the first beam;

[0111] where the first fittings are connected to the lower surface of the first beam and an upper surface of the second beam.Clause 4

[0112] The composite beam according to clause 3, where the first fittings each include:

[0113] a first plate arranged between the first beam and the second beam,

[0114] a first projection projecting from the first plate and inserted in a first insertion hole of the first beam, and

[0115] a second projection projecting from the first plate and inserted in a second insertion hole of the second beam.Clause 5

[0116] The composite beam according to clause 3 or 4, where the first fittings in a vicinity of an end of the composite beam are arranged at a smaller interval than the first fittings arranged in a vicinity of a central part of the composite beam in the longitudinal direction of the first beam.Clause 6

[0117] The composite beam according to any one of clauses 1 to 5, further comprising a second fitting including:

[0118] a first coupling portion coupled to a lower surface end portion located in the lower surface of the first beam between the first end surface and the third end surface in the longitudinal direction of the first beam, and

[0119] a second coupling portion coupled to the third end surface of the second beam.Clause 7

[0120] The composite beam according to any one of clauses 1 to 6, where the lower surface of the first beam and an upper surface of the second beam are spaced apart by a gap.Clause 8

[0121] A building, comprising:

[0122] a structural member that is a beam, a girder, or a post;

[0123] a composite beam connected to the structural member; and

[0124] an installation arranged in a vicinity of an end of the composite beam; where

[0125] the composite beam includes

[0126] a first beam including a first end surface connected to a side surface of the structural member, and

[0127] a second beam including a third end surface facing the side surface of the structural member,

[0128] the second beam is arranged along the first beam below a lower surface of the first beam and is coupled to the first beam, and

[0129] the installation is arranged between the structural member and the third end surface.Clause 9

[0130] A building, comprising:

[0131] a structural member that is a beam, a girder, or a post;

[0132] a composite beam connected to the structural member; where

[0133] the composite beam includes

[0134] a first beam including a first end surface connected to a side surface of the structural member, and

[0135] a second beam including a third end surface facing the side surface of the structural member,

[0136] the second beam is arranged along the first beam below a lower surface of the first beam and is coupled to the first beam, and

[0137] the structural member and the third end surface are spaced apart by an arrangement space allowing for arrangement of an installation.Clause 10

[0138] A reinforcement fitting arranged on a composite beam, where

[0139] the composite beam includes

[0140] a first beam including a first end surface and a second end surface located at an opposite side of the first end surface in a longitudinal direction, and

[0141] a second beam including a third end surface and a fourth end surface located at an opposite side of the third end surface in a longitudinal direction,

[0142] the second beam is arranged along the first beam below a lower surface of the first beam,

[0143] the third end surface is located inward from the first end surface in the longitudinal direction of the first beam, and

[0144] the reinforcement fitting is coupled to a lower surface end portion located in a lower surface of the first beam between the first end surface and the third end surface in the longitudinal direction of the first beam, and is coupled to the third end surface.REFERENCE SIGNS LIST1) building; 4) structural member; 4A) girder; 5) installation; 10) composite beam; 11) end; 12) central part; 20) first beam; 21) first end surface; 22) second end surface; 23) lower surface end portion; 24) first insertion hole; 30) second beam; 34) third end surface; 35) fourth end surface; 38) second insertion hole; 40, 40A, 40B, 40C) first fitting; 41) first plate; 42) first projection; 43) second projection; 50) second fitting; 51) first coupling portion; 52) second coupling portion; 60) reinforcement fitting; 71) beam; 72) post.

Examples

embodiment

[0026]A building 1, a composite beam 10, and a reinforcement fitting 60 in accordance with an embodiment will now be described with reference to FIGS. 1 to 6.

Building

[0027]FIG. 1 is a schematic diagram showing an example of a building 1. Examples of the building 1 include a single-family residential building, a collective residential building, and a public facility. The building 1 of the present embodiment is a single-family residential building. The building 1 includes a first space S1 and a second space S2 connected to the first space S1. An example of the first space S1 is an indoor space of the building 1. Examples of the first space S1 include rooms such as a living room, a dining room, a kitchen, a bedroom, and a children's room. The second space S2 is, for example, an outdoor space of the building 1. An example of the second space S2 is a piloti. The second space S2 may be an indoor space differing from the first space S1. The building 1 includes a first ceiling 2 provided in...

Claims

1. A composite beam forming a portion of a frame assembly of a building, the composite beam comprising:a first beam including a first end surface and a second end surface located at an opposite side of the first end surface in a longitudinal direction;a second beam including a third end surface and a fourth end surface located at an opposite side of the third end surface in a longitudinal direction; andfirst fittings that couple the second beam to the first beam, wherein the second beam is arranged along the first beam below a lower surface of the first beam and is coupled to the first beam,in the longitudinal direction of the first beam, the third end surface is located inward from the first end surface, and the fourth end surface is located inward from the second end surface,the first beam is formed from wood,the second beam is formed from steel,the first fittings are connected to the lower surface of the first beam and an upper surface of the second beam,the first fittings each include:a first plate arranged between the first beam and the second beam;a first projection projecting from the first plate and inserted in a first insertion hole of the first beam; anda second projection projecting from the first plate and inserted in a second insertion hole of the second beam,in a state in which the first projection of the first fitting is inserted into the first insertion hole of the first beam, a first through hole is formed through the first beam and the first projection, anda drift pin is arranged in the first through hole.

2. (canceled)3. (canceled)4. (canceled)5. The composite beam according to claim 1, wherein the first fittings in a vicinity of an end of the composite beam are arranged at a smaller interval than the first fittings arranged in a vicinity of a central part of the composite beam in the longitudinal direction of the first beam.

6. The composite beam according to claim 1, further comprising a second fitting including:a first coupling portion coupled to an end lower surface portion of the first beam located in the lower surface of the first beam between the first end surface and the third end surface in the longitudinal direction of the first beam, anda second coupling portion coupled to the third end surface of the second beam.

7. The composite beam according to claim 1, wherein the lower surface of the first beam and an upper surface of the second beam are spaced apart by a gap.

8. (canceled)9. (canceled)10. A reinforcement fitting configured to be arranged on a composite beam, whereinthe composite beam includesa first beam including a first end surface and a second end surface located at an opposite side of the first end surface in a longitudinal direction, anda second beam including a third end surface and a fourth end surface located at an opposite side of the third end surface in a longitudinal direction,the second beam is arranged along the first beam below a lower surface of the first beam,the third end surface is located inward from the first end surface in the longitudinal direction of the first beam, andthe reinforcement fitting is coupled to an end lower surface portion of the first beam located in a lower surface of the first beam between the first end surface and the third end surface in the longitudinal direction of the first beam, and is coupled to the third end surface.

11. A composite beam forming a portion of a frame assembly of a building, the composite beam comprising:a first beam including a first end surface and a second end surface located at an opposite side of the first end surface in a longitudinal direction;a second beam including a third end surface and a fourth end surface located at an opposite side of the third end surface in a longitudinal direction; andfirst fittings that couple the second beam to the first beam, whereinthe second beam is arranged along the first beam below a lower surface of the first beam and is coupled to the first beam, andin the longitudinal direction of the first beam, the third end surface is located inward from the first end surface, and the fourth end surface is located inward from the second end surface,the first fittings are connected to the lower surface of the first beam and an upper surface of the second beam, andthe first fittings in a vicinity of an end of the composite beam are arranged at a smaller interval than the first fittings arranged in a vicinity of a central part of the composite beam in the longitudinal direction of the first beam.

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