Building unit

Abstract

To provide a building unit inexpensively improved in sound insulation performance.SOLUTION: In a building unit, floor small beams 40 are bridged between facingly arranged floor large beams 20, 20 made of channel steel, and end parts in the longitudinal direction of the floor small beams 40 are fixed to the floor large beams 20 via fitting metals 50, 250. The fitting metals 50, 250 are formed in a U-shaped cross-section by a small beam joint plate 51 fixed with the floor small beams 40 and an upper flange 52 and a lower flange 53 provided above and under the small beam joint part 51 and fixed to the floor large beam 20. Furthermore, the small beam joint plate 51 of the fitting metals 50, 250 has a bead part 54 formed in a recessed shape.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to building units.

Background Art

[0002] Generally, a building unit that constitutes a unit building is known to have a rectangular parallelepiped frame structure composed of columns arranged at the four corners, a floor girder that connects and spans the lower ends of these columns, and a ceiling girder that connects and spans the upper ends of the columns (see, for example, Patent Document 1).

[0003] Further, in this conventional building unit with a frame structure, channel steel with a U-shaped cross section is used for the floor girder and the ceiling girder. In the floor part, floor joists are spanned between a pair of opposing floor girders. And both ends of the floor joists are welded to the floor girder via mounting brackets.

[0004] Also, the mounting bracket is formed in a U-shaped cross-sectional shape by a joist joint plate to which the end face of the floor joist is welded, and an upper flange and a lower flange that are bent substantially at right angles from the upper and lower edges of this joist joint plate. And the upper flange and the lower flange are joined above and below the floor girder.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In recent years, in order to improve the quality of unit buildings constructed by building units, an improvement in sound insulation has been demanded. However, adding sound insulation materials, reinforcing materials, etc. leads to an increase in cost due to an increase in the number of parts and an increase in the labor of manufacturing.

[0007] The present disclosure has been made paying attention to the above-described conventional problems, and an object thereof is to provide a building unit capable of improving sound insulation performance at low cost.

Means for Solving the Problems

[0008] In the building unit of the present disclosure, floor joists are spanned between grooved steel floor girders arranged opposite to each other, and longitudinal end portions of the floor joists are fixed to the floor girders via mounting brackets. The mounting brackets are formed in a U-shaped cross-sectional shape by a joist joint plate to which the floor joists are fixed, and an upper flange and a lower flange provided above and below the joist joint plate and fixed to the floor girders. Further, the joist joint plate of the mounting bracket includes a bead portion formed in a concave shape. Further, the mounting fitting includes a rising piece that is raised from an edge portion of at least one of the small beam joint plate and the both flanges and is continuously provided across the small beam joint plate and the one flange.

Effects of the Invention

[0009] In the building unit of the present disclosure, by providing a bead portion on the joist joint plate of the mounting bracket, the support rigidity of the floor joists by the mounting bracket is improved, thereby suppressing the amount of deflection of the floor joists when a load is input to the floor joists and suppressing the vibration of the floor joists. Therefore, the generation of noise when a load is input to the floor can be suppressed, and the sound insulation performance can be improved. Further, the mounting fitting includes a rising piece that is raised from an edge portion of at least one of the small beam joint plate and the both flanges and is continuously provided across the small beam joint plate and the one flange. Therefore, the rising piece can further improve the support rigidity of the floor small beam by the mounting fitting, and can further improve the sound insulation property of the building unit.

[0010] In this way, the rigidity of the building unit can be improved without increasing the sound insulation material or the reinforcing material, and the sound insulation performance can be improved at low cost.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

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Figure 8

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Figure 10

Figure 11

Figure 12

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Figure 14

Embodiments for Carrying Out the Invention

[0012] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. (Embodiment 1) As shown in Fig. 1, the building unit of Embodiment 1 is formed into a box-shaped ramen structure including columns 10 arranged at the four corners, a floor girder 20 connecting the lower ends of the columns 10, and a ceiling girder 30 connecting the upper ends of the columns 10.

[0013] The column 10 is formed of a square steel pipe, and the floor girder 20 and the ceiling girder 30 are formed of channel steel materials with a U-shaped cross section. Specifically, as shown in Fig. 2, the floor girder 20 includes a web 21, and an upper flange 22 and a lower flange 23 that are bent at substantially right angles above and below the web 21 and arranged substantially parallel to each other vertically. The ceiling girder 30 is also formed in a similar shape.

[0014] Then, as shown in Fig. 1, floor joists 40 made of square steel plates are spanned between a pair of opposing floor girders 20, 20 on the girder side. Both ends of each floor joist 40 in the longitudinal direction are fixed to the floor girder 20 via mounting brackets 50 formed of steel materials. The floor girder 20 supports a floor material 60 as shown in Fig. 2. As the floor material 60, a laminate of a particle board and a hard wood chip cement material can be used, but it is not limited thereto, and plywood or the like can be used.

[0015] The mounting bracket 50 is formed of a steel material with a thickness of about 4 mm into a substantially U-shaped cross-sectional shape by a joist joint plate 51, an upper flange 52, and a lower flange 53 as shown in Figs. 3 and 4. The upper flange 52 and the lower flange 53 are formed by bending the upper and lower end portions of the joist joint plate 51 by bending, and the bent portions are curved with a radius of about 4 mm.

[0016] Furthermore, the mounting bracket 50 includes bead portions 54 and rising pieces 55, 55. The horizontal width dimension L1 of the mounting bracket 50 is formed to be about 90 mm, and the height dimension L2 is formed to be about 150 mm. The width dimension L3 of the upper flange is formed to be about 40 mm, and the width dimension L4 of the lower flange 53 is formed to be about 70 mm.

[0017] Then, as shown in FIG. 2, the floor joist connecting plate 51 is joined by welding with the longitudinal end portions of the floor joists 40 abutted thereagainst. Further, the upper flange 52 is joined by welding in a state where it is superposed on the upper surface of the upper flange 22 of the floor girder 20. The lower flange 53 is joined by welding in a state where it is superposed on the upper surface of the lower flange 23 of the floor girder 20.

[0018] The bead portion 54 is formed by drawing so as to be recessed inward (in a direction approaching the web 21 of the floor girder 20) by a depth of about 8 mm or more as shown in FIG. 4(c). Further, the bead portion 54 has a horizontal width L11 that is smaller than the inner dimension of the floor joist 40 in the horizontal direction and is about 62 mm, and a dimension L12 in the height direction (see FIG. 4(a)) is formed in a substantially rectangular shape when viewed from the front with a dimension of about 100 mm.

[0019] The rising piece 55 is continuously formed across the floor joist connecting plate 51 and the lower flange 53 as shown in FIG. 4(b). That is, the rising piece 55 is formed by bending the end portions of the floor joist connecting plate 51 and the lower flange 53 so as to form a substantially right angle with respect to the end portions of the floor joist connecting plate 51 and the lower flange 53. Note that this bent portion is curved with a radius of about 4 mm.

[0020] Further, in the rising piece 55, the dimension L21 in the direction along the lower flange 53 is about 35 mm, and the dimension L22 in the direction along the floor joist connecting plate 51 is formed to be about 115 mm. Further, the height L23 of the portion arranged along the floor joist connecting plate 51 is formed to be about 20 mm, and the height L24 of the portion along the lower flange 53 is also formed to be about 20 mm.

[0021] (Embodiment 2) Next, the building unit of Embodiment 2 will be described. In this Embodiment 2, only the differences from Embodiment 1 will be described.

[0022] Embodiment 2 is different from Embodiment 1 in the structure of the mounting fitting 250, and other configurations are the same as those in Embodiment 1.

[0023] As shown in FIG. 5, the mounting fitting 250 used in Embodiment 2 is obtained by omitting the rising piece 55 of the mounting fitting 50 used in Embodiment 1. Other configurations are the same as those in Embodiment 1, and the same reference numerals as those in Embodiment 1 are given to the configurations common to Embodiment 1, and the description thereof is omitted.

[0024] (Operations of Embodiments 1 and 2) Next, the operations of the building units of Embodiments 1 and 2 will be described. <Explanation of the concentrated load resistance performance> FIG. 6 is an explanatory view of the floor joist 40 as viewed from above. For this concentrated load resistance performance, a predetermined load F1 was applied to the center CE in the longitudinal direction of each of the floor joists 40 of the comparative example, Embodiment 1, and Embodiment 2, and the displacement amount in the vertical direction of the floor joist 40 at that time was detected to obtain the rigidity.

[0025] Note that, as described in the prior art, in the comparative example, both ends in the longitudinal direction of the floor joist 40 are fixed to the floor girder 20 by a mounting fitting having a U-shaped cross section, and the structure of the mounting fitting 250 in Embodiment 2 does not include the bead portion 54. Also, for the U-shaped cross-section portion composed of the joist joint plate 51, the upper flange 52, and the lower flange 53, the same materials and dimensions were used in all of the comparative example, Embodiment 1, and Embodiment 2.

[0026] FIGS. 7 and 8 show the characteristics of the comparative example, Embodiment 1, and Embodiment 2 obtained by applying the load F1 to the center CE of the floor joist 40. FIG. 7 shows the displacement amount characteristics with respect to the load F1, and FIG. 8 shows the rigidity.

[0027] In FIG. 7, the solid line indicates the displacement characteristic of the comparative example, the dashed-dotted line indicates the displacement characteristic of Embodiment 1, and the two-dot chain line indicates the displacement characteristic of Embodiment 2. As shown in FIG. 7, compared with the displacement amount of the comparative example, the displacement amount of Embodiment 2 was suppressed, and the displacement amount of Embodiment 1 was further suppressed. Further, as shown in FIG. 8, with respect to the rigidity of 0.96 of the comparative example, Embodiment 2 was 1.01 which is 1.06 times, and Embodiment 1 was 1.19 which is 1.25 times. Embodiments 1 and 2 were able to improve the concentrated load rigidity as compared with the comparative example.

[0028] <Explanation of horizontal plane rigidity> FIG. 9 is an explanatory diagram of a horizontal plane rigidity test of the floor joist 40. In this horizontal plane rigidity test, one end of the floor joist 40 is fixed to the floor girder 20 via the mounting bracket 50, while the other end is a free end, and a load P is applied in the horizontal direction orthogonal to the floor joist 40 at the longitudinal center CE, and the horizontal displacement amount δ of the floor joist 40 is detected.

[0029] In FIG. 10, the solid line indicates the displacement characteristic of the comparative example, the dashed-dotted line indicates the displacement characteristic of Embodiment 1, and the two-dot chain line indicates the displacement characteristic of Embodiment 2. As shown in FIG. 10, compared with the displacement amount of the comparative example, the displacement amount of Embodiment 2 was suppressed, and the displacement amount of Embodiment 1 was further suppressed. Further, as shown in FIG. 11, with respect to the rigidity of 0.031 of the comparative example, Embodiment 2 was 0.035 which is 1.12 times, and Embodiment 1 was 0.055 which is 1.76 times. Embodiments 1 and 2 were able to improve the horizontal plane rigidity as compared with the comparative example.

[0030] As described above, in the building units of Embodiments 1 and 2, the support rigidity of the floor joist 40 by the mounting brackets 50 and 250 is improved, and the vibration of the floor joist 40 at the time of load input can be suppressed. Thereby, the sound insulation of the building unit can be improved at low cost without increasing the number of parts.

[0031] (Effects of Embodiments 1 and 2) The effects of the building units of Embodiments 1 and 2 are listed below. (1) In the building units of Embodiments 1 and 2, floor joists 40 are spanned between opposed channel steel floor girders 20, 20, and the longitudinal ends of the floor joists 40 are fixed to the floor girders 20 via mounting brackets 50, 250. The mounting brackets 50, 250 are formed in a U-shaped cross-sectional shape by a joist joint plate 51 to which the floor joists 40 are fixed, and an upper flange 52 and a lower flange 53 that are provided above and below the joist joint plate 51 and fixed to the floor girder 20. Further, the joist joint plates 51 of the mounting brackets 50, 250 are provided with bead portions 54 formed in a concave shape. In the mounting bracket 50 having the dimensions shown in Embodiments 1 and 2, it is desirable that the depth of the bead portion 54 be 8 mm or more.

[0032] Therefore, the support rigidity of the floor joists 40 by the mounting brackets 50, 250 is improved, and the vibration of the floor joists 40 during load input can be suppressed. Thereby, the sound insulation property of the building unit can be improved at low cost without increasing the number of parts.

[0033] (2) In the building unit of Embodiment 1, the mounting bracket 50 further includes rising pieces 55, 55. The rising pieces 55 are raised from the edge portions of the joist joint plate 51 and the lower flange 53, and are continuously provided straddling the joist joint plate 51 and the lower flange 53.

[0034] Therefore, the support rigidity of the floor joists 40 by the mounting bracket 50 can be further improved, and the sound insulation property of the building unit can be further improved.

[0035] (3) In the building unit of Embodiment 1, the rising piece 55 of the mounting bracket 50 is formed by bending the edge portions of the joist joint plate 51 and the lower flange 53.

[0036] Therefore, compared with forming the rising piece 55 in the mounting bracket 50 by a separate member from the joist joint plate 51 and the lower flange 53, the number of parts can be suppressed and the manufacturing cost can be suppressed.

[0037] (Other Embodiments) Next, as another embodiment of the present disclosure, a modification example of the mounting bracket will be described. In the following description, components common to the embodiments are denoted by the same reference numerals, and the description thereof will be omitted, and only the differences will be described.

[0038] (Embodiment 3) Based on FIG. 12, the mounting bracket 350 applied to the building unit of Embodiment 3 will be described. The shape of the rising piece 355 of this mounting bracket 350 is different from the shape of the rising piece 55 of Embodiment 1.

[0039] That is, the rising piece 355 is formed such that the dimension L31 of the length in the direction along the joist joint plate 51 is longer than that of the rising piece 55 shown in Embodiment 1, and has a height of dimension L32 over its entire length. Note that the rising piece 355 is formed by bending, similarly to Embodiment 1.

[0040] Therefore, even in Embodiment 3, in the floor joist 40, rigidity equivalent to or higher than that of Embodiment 1 can be obtained, and it is possible to improve the sound insulation performance at low cost.

[0041] (Embodiment 4) Based on FIG. 13, the mounting bracket 450 applied to the building unit of Embodiment 4 will be described. The shape of the rising piece 455 of this mounting bracket 450 is different from the shape of the rising piece 55 of Embodiment 1.

[0042] That is, in the rising piece 455, the portion 455a provided along the lower flange 53 has a height L41 (for example, 8 mm) that provides desired rigidity. Also, in the rising piece 455, a cutout portion 455c is provided between the portion 455b provided along the joist joint plate 51 and the portion 455a. And at the location where the cutout portion 455c is formed in the portion 455b, it has a height L42 of a dimension (for example, 8 mm) that provides necessary rigidity.

[0043] Therefore, even in the fourth embodiment, the floor joist 40 can achieve the same rigidity as that in the first embodiment, and it is possible to improve the sound insulation performance at low cost. Further, by providing the cut portion 455c between the portion 455a and the portion 455b in the rising piece 455, the bending process of the portion 455a and the portion 455b becomes easier compared to the case where the cut portion 455c is not provided.

[0044] (Embodiment 5) The mounting bracket 550 applied to the building unit of the fifth embodiment will be described with reference to FIG. 14. The shape of the bead portion 554 of this mounting bracket 550 is different from that of the bead portion 54 of the first embodiment.

[0045] That is, the bead portion 554 is continuously formed across the joist joint plate 51 and the lower flange 53. Therefore, the rigidity of the mounting bracket 550 can be further enhanced.

[0046] Therefore, even in the fifth embodiment, the floor joist 40 can achieve the same or higher rigidity as that in the first embodiment, and it is possible to improve the sound insulation performance at low cost.

[0047] As described above, the embodiments of the building unit of the present disclosure have been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and design changes that do not deviate from the gist of the present invention are included in the present invention.

[0048] In the embodiment, the rising piece is formed by bending the joist joint plate and the lower flange, but it is not limited thereto. For example, a separate piece from the joist joint plate and the lower flange may be integrally provided by welding or the like, or a piece integrated with one of the joist joint plate and the lower flange may be bent and integrally provided with the other by welding or the like.

[0049] In addition, in the embodiment, the rising piece is provided across the joist joint plate and the lower flange, but it may be provided across the joist joint plate and the upper flange. In this case, the upper flange is joined by being overlapped on the lower surface of the upper flange of the floor girder. Alternatively, the rising piece may be provided across the joist joint plate, the lower flange, and the upper flange. In this case, the upper flange is joined by being overlapped on the lower surface of the upper flange of the floor girder, and the lower flange is joined by being overlapped on the upper surface of the lower flange of the floor girder.

[0050] Also, if the bead portion is formed on the joist joint plate, it may be formed across the upper flange, or may be formed across both the upper flange and the lower flange. Further, in the embodiment, the bead portion is formed in a rectangular shape, but the shape is not limited thereto, and further improvement in rigidity can be achieved by increasing the number of corners.

Explanation of Reference Numerals

[0051] 10 Column 20 Floor Girder 30 Ceiling Girder 40 Floor Joist 50 Mounting Bracket 51 Joist Joint Plate 52 Upper Flange 53 Lower Flange 54 Bead Portion 55 Rising Piece 250 Mounting Bracket 350 Mounting Bracket 355 Rising Piece 450 Mounting Bracket 455 Rising Piece 550 Mounting Bracket 554 Bead Portion

Claims

1. Floor joists are spanned between channel steel floor girders arranged opposite to each other, The longitudinal ends of the floor joists are fixed to the floor girders via mounting brackets, The mounting bracket is a building unit formed in a U-shaped cross-section by a joist joint plate to which the floor joist is fixed, and an upper flange and a lower flange provided above and below the joist joint plate and fixed to the floor girder, The joist joint plate of the mounting bracket is provided with a bead portion formed in a concave shape, The mounting bracket is a building unit provided with a rising piece that rises from an edge portion of at least one of the joist joint plate and both flanges and is continuously provided across the joist joint plate and the one flange.

2. In the building unit according to Claim 1, The rising piece is formed by bending an edge portion of the joist joint plate and an edge portion of the flange on which the rising piece is provided among both flanges.

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