JPH108566A - Beam, processing method and tool of beam - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and tools to securely and easily prevent a ceiling from sagging down owing to the deflection of beams. SOLUTION: The guide face 35 for a processing tool 30 is bent to form a valley bent downward in the longitudinal direction. A pair of guide body 32A and beam 20 are parallelly and adjacently put on the flat face 31 on which these are laid. The underface 21 or the beam 20 is cut along the guide face 35 for the tool and bent to form a chevron-shaped slope 21A bent upward in the longitudinal direction. In this way, even when the beam 20 warps, the center of the underface thereof can be prevented from projecting lower downward than the ends and hence, the ceiling can be securely prevented from sagging down owing to the deflection of the beam.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small beam, a method for processing a small beam, and a jig for processing a small beam to be installed between upper beams of a building unit.

[0002]

2. Description of the Related Art In a building constructed by a conventional construction method, a ceiling portion of a living room is constructed by attaching a field edge to a lower end of a hanging tree lowered from a beam in a lattice shape and attaching a ceiling surface material to a lower surface of the field edge. Is formed. In such a ceiling structure, a phenomenon in which the field edge sags under its own weight and the center of the ceiling surface of the living room hangs down tends to occur. To prevent this phenomenon,
By changing the length of the hanging tree between the central part and the peripheral part of the room,
Scalping has been implemented in which the central part of the ceiling surface is formed higher than the peripheral part.

[0003]

On the other hand, in recent years, a unit construction method has been used in which a plurality of building units are manufactured in a factory in advance, and these are combined at a construction site to construct a building. The building unit has a rectangular parallelepiped frame including four pillars, an upper beam connecting the upper ends of these pillars, and a lower beam connecting the lower ends of the pillars, and a plurality of small beams are defined between the upper beams. It is spanned at intervals. The ceiling part of the living room formed in the framework is formed by attaching a ceiling panel to the lower surface of the small beam. In such a ceiling structure, the phenomenon of the ceiling drop described above is hardly observed, but when an excessive load is applied to the ceiling part by a heavy lighting fixture or the like, the beam may be bent and the ceiling drop may occur. Conceivable.

An object of the present invention is to provide a small beam, a small beam processing method and a small beam processing jig capable of reliably and easily preventing the ceiling from being lowered due to the bending of the small beam.

[0005]

The present invention will be described with reference to the drawings. In the present invention, four pillars 11 and an upper beam 12 connecting the upper ends of the pillars 11 and a lower end of the pillars 11 are connected. A building unit 10 having a framework 10A including a lower beam 13
A small beam 20 erected between the upper beams 12, wherein the lower surface 21 is formed in a concave shape in the longitudinal direction.

In the present invention, since the lower surface 21 of the beam 20 is formed in a concave shape in the longitudinal direction, even if the beam 20 bends due to a load, the central portion of the lower surface 21 projects below the end. Can be suppressed. Therefore, even if the small beam 20 bends, the ceiling surface does not hang down, and the ceiling can be reliably prevented from lowering due to the bending of the small beam 20. Thereby, the above object is achieved.

The lower surface 21 may be an arc-shaped curved surface 21B that curves upward in the longitudinal direction. In this way, the ceiling surface can be formed into a curved surface in the same manner as the conventional ceiling of the conventional method, and even if the small beam 20 bends, the ceiling surface can be maintained as a curved surface or a flat surface without unevenness.

The lower surface 21 may be a mountain-shaped inclined surface 21A that is bent upward in the longitudinal direction. If the lower surface 21 of the small beam 20 is constituted by the inclined surface 21A in this manner, it can be easily processed by cutting or the like,
Can be processed more easily than when making a curved surface.

On the other hand, the present invention provides a building having a frame 10A including four pillars 11, an upper beam 12 connecting the upper ends of these pillars 11, and a lower beam 13 connecting the lower ends of the pillars 11. Small beam 20 erected between the upper beams 12 of the unit 10
Processing method, wherein the flat beam 2
0 and guide bodies 32A and 32B provided with arc-shaped guide surfaces 45 curved downward in the longitudinal direction are arranged in parallel and close to each other, and the lower surface 21 of the small beam 20 is attached to the guide surface 45. Cutting or cutting along.

In the present invention, the guide members 32A, 32
Since the lower surface 21 of the small beam 20 is cut or cut along the guide surface 45 of B, the lower surface 21 can be easily processed into a curved surface shape corresponding to the guide surface 45. Further, since the shape of the guide surface 45 is an arc shape that curves downward in the longitudinal direction, the lower surface 21 of the small beam 20 is processed into an arc-shaped curved surface 21B that curves upward in the longitudinal direction, The ceiling can be reliably prevented from lowering due to the deflection of the small beams 20, and the ceiling surface can be maintained as a curved surface or a flat surface without unevenness even if the small beams 20 bend. These objects are achieved by these.

The present invention also provides a building having a frame 10A including four pillars 11, an upper beam 12 connecting the upper ends of the pillars 11, and a lower beam 13 connecting the lower ends of the pillars 11. Small beam 20 erected between the upper beams 12 of the unit 10
Processing method, wherein the flat beam 2
0, a valley-shaped guide surface 3 bent downward in the longitudinal direction
The guide members 32A and 32B provided with the guide members 5 are arranged in parallel and close to each other, and the lower surface 21 of the small beam 20 is cut or cut along the guide surface 35.

In the present invention, the guide members 32A, 32
Since the lower surface 21 of the small beam 20 is cut or cut along the guide surface 35 of B, the lower surface 21 can be easily processed into a shape corresponding to the guide surface 35. In addition, since the shape of the guide surface 35 is a valley shape bent downward in the longitudinal direction, the guide surface 35 can be formed more easily than forming an arc-shaped guide surface. Further, since the lower surface 21 of the small beam 20 is processed into a mountain-shaped inclined surface 21A that is bent upward in the longitudinal direction by the shape of the guide surface 35, the ceiling can be reliably prevented from lowering due to the bending of the small beam 20. These objects are achieved by these.

The present invention provides a building having a framework 10A including four pillars 11, an upper beam 12 connecting the upper ends of the pillars 11, and a lower beam 13 connecting the lower ends of the pillars 11. Small beam 2 erected between the upper beams 12 of the unit 10
0, the beam 20 is placed on an arc-shaped fixing surface 61 curved upward in the longitudinal direction with its lower surface 21 facing upward, and the beam 20 is placed along the fixing surface 61. The lower surface 2 of the beam 20
1 is characterized by being cut or cut flat.

In this manner, the curved lower protruding portion of the lower surface 21 of the small beam 20 is cut or cut flat, and the lower surface 21 of the small beam 20 is fixed to the fixing surface 61.
Can easily be processed into a curved surface shape corresponding to the curvature of the object. In addition, since the shape of the fixing surface 61 is an arc shape that curves upward in the longitudinal direction, the lower surface 21 of the small beam 20 is an arc-shaped curved surface 21 that curves upward in the longitudinal direction.
As a result, the ceiling can be reliably prevented from lowering due to the deflection of the small beam 20, and the ceiling surface can be maintained as a curved surface or a flat surface without unevenness even if the small beam 20 bends. These objects are achieved by these.

The present invention also relates to a building provided with a frame 10A including four pillars 11, an upper beam 12 connecting the upper ends of these pillars 11, and a lower beam 13 connecting the lower ends of the pillars 11. Small beam 20 erected between the upper beams 12 of the unit 10
In the processing method, the beam 20 is placed on a mountain-shaped fixing surface 51 that is bent upward in the longitudinal direction with its lower surface 21 facing upward, and the beam 20 is placed along the fixing surface 51. It is characterized in that it is fixed in a bent state and the lower surface 21 of the beam 20 is cut or cut flat.

In this way, the bent lower portion of the lower surface 21 of the small beam 20 is cut or cut flat, and the lower surface 21 of the small beam 20 is fixed to the fixed surface 51.
Can be easily processed into a shape corresponding to the bending of In addition, since the shape of the fixing surface 51 is a mountain shape bent upward in the longitudinal direction, the fixing surface 51 can be formed more easily than an arc-shaped fixing surface. Further, depending on the shape of the fixing surface 51, the small beam 20
Is formed into a mountain-shaped inclined surface 21A that is bent upward in the longitudinal direction, so that the ceiling can be reliably prevented from lowering due to the bending of the small beam 20. These objects are achieved by these.

Further, the present invention provides a building having a frame 10A including four pillars 11, an upper beam 12 connecting between upper ends of these pillars 11, and a lower beam 13 connecting between lower ends of the pillars 11. Small beam 2 erected between the upper beams 12 of the unit 10
0, wherein both ends of the beam 20 are fixed, and the center of the upper surface of the beam 20 is pressed in the lower direction to bend the beam 20, and the beam 20 is kept as it is. The lower surface of the small beam 20 is cut or cut flat.

In this manner, a portion of the lower surface 21 of the small beam 20 that is curved and protruded by pressing is cut or cut flat, and the lower surface 21 is formed into a curved surface according to the curved state of the small beam 20. It can be easily processed into a shape. The lower surface 21 of this small beam 20 is an arc-shaped curved surface 2 that curves upward.
1B, the ceiling can be reliably prevented from lowering due to the bending of the small beam 20, and the ceiling surface can be maintained as a curved surface or a flat surface without unevenness even if the small beam 20 bends. In addition, since the upper surface of the small beam 20 is curved by pressing it in the direction of the lower surface 21, the degree of bending of the small beam 20 can be easily adjusted only by adjusting the pressing force. 21 can be processed into a desired curved shape. These objects are achieved by these.

On the other hand, the present invention provides a building having a frame 10A including four pillars 11, an upper beam 12 connecting the upper ends of the pillars 11, and a lower beam 13 connecting the lower ends of the pillars 11. Small beam 20 erected between the upper beams 12 of the unit 10
A flat mounting surface 31 on which the small beam 20 is mounted, and an arc-shaped tool guide surface 45 provided on the mounting surface 31 and curved downward in the longitudinal direction. It is characterized by having.

In the present invention, since the tool guide surface 45 is formed in an arc shape that curves downward in the longitudinal direction, if the lower surface 21 of the beam 20 is cut along the tool guide surface 45, Can be easily processed into a curved surface shape corresponding to the tool guide surface 45. Further, since the lower surface 21 of the small beam 20 is processed into an arc-shaped curved surface 21B that curves upward in the longitudinal direction by the shape of the tool guide surface 45, the ceiling can be reliably prevented from lowering due to the deflection of the small beam 20. In addition, even if the small beams 20 are bent, the ceiling surface can be maintained as a curved surface or a flat surface without unevenness. These objects are achieved by these.

The present invention also provides a building having a frame 10A including four pillars 11, an upper beam 12 connecting the upper ends of the pillars 11, and a lower beam 13 connecting the lower ends of the pillars 11. Small beam 20 erected between the upper beams 12 of the unit 10
A flat mounting surface 31 on which the small beam 20 is mounted, and a valley-shaped tool guiding surface 35 provided on the mounting surface 31 and bent downward in the longitudinal direction. It is characterized by having.

In the present invention, since the tool guide surface 35 is formed in a trough shape bent downward in the longitudinal direction,
If the lower surface 21 of the beam 20 is cut along the tool guide surface 35, the lower surface 21 can be easily machined into a shape corresponding to the tool guide surface 35. Further, since the tool guide surface 35 has a valley shape bent downward, it can be formed more easily than an arc-shaped tool guide surface. Furthermore, this tool guide surface 3
With the shape of 5, the lower surface 21 of the small beam 20 is formed into a mountain-shaped inclined surface 21A that is bent upward in the longitudinal direction, so that the ceiling can be reliably prevented from lowering due to the bending of the small beam 20. With these, the above object is achieved.

The present invention relates to a building having a frame 10A including four pillars 11, an upper beam 12 connecting the upper ends of the pillars 11, and a lower beam 13 connecting the lower ends of the pillars 11. Small beam 2 erected between the upper beams 12 of the unit 10
0, a jig 60, an arc-shaped fixing surface 61 that curves upward in the longitudinal direction, and fixing means 55 that fixes the small beam 20 in a curved state along the fixing surface 61.
And characterized in that:

In the present invention, since the fixing surface 61 is formed in an arc shape that curves upward in the longitudinal direction, the small beams 20 are fixed along the fixing surface 61 by the fixing means 55.
If the lower surface 21 of the small beam 20 is cut flat, the portion of the lower surface 21 of the small beam 20 that is curved and protrudes upward will be cut flat. It can be easily processed into a curved surface shape according to the curvature. Also, depending on the shape of the fixing surface 61, the lower surface 2
1 is processed into an arc-shaped curved surface 21B that curves upward in the longitudinal direction, so that the ceiling can be reliably prevented from lowering due to the deflection of the small beam 20, and the ceiling surface can be flattened even when the small beam 20 bends. Condition can be maintained.
These objects are achieved by these.

The present invention relates to a building having a frame 10A including four pillars 11, an upper beam 12 connecting the upper ends of the pillars 11, and a lower beam 13 connecting the lower ends of the pillars 11. Small beam 2 erected between the upper beams 12 of the unit 10
The jig 50 has a mountain-shaped fixing surface 51 bent upward in the longitudinal direction, and fixing means 55 for fixing the small beam 20 in a bent state along the fixing surface 51. It is characterized by the following.

In the present invention, since the fixing surface 51 is formed in the shape of a chevron which is bent upward in the longitudinal direction, the small beam 20 is arranged along the fixing surface 51 so that the fixing means 5 is fixed.
5 and if the lower surface 21 is cut flat,
The lower surface 21 of the small beam 20 is flattened to bend and project upward, and the lower surface 21 of the beam 20 is fixed to the fixing surface 5.
1 can be easily processed into a shape corresponding to the bending.
Further, since the fixing surface 51 has a mountain shape that is bent upward in the longitudinal direction, it can be formed more easily than an arc-shaped fixing surface. Furthermore, the lower surface 21 of the small beam 20 is bent upward in the longitudinal direction by the fixing surface 51, and the mountain-shaped inclined surface 21 is bent.
Since it is processed into A, it is possible to reliably prevent the ceiling from being lowered due to the deflection of the small beam 20. These objects are achieved by these.

[0027]

Embodiments of the present invention will be described below with reference to the drawings. [First Embodiment] FIG. 1 shows a building unit 10 including a small beam 20 of the present embodiment. Building unit 1
Numeral 0 includes a rectangular parallelepiped frame 10A including four columns 11, an upper beam 12 connecting the upper ends of the columns 11, and a lower beam 13 connecting the lower ends of the columns 11. A plurality of joists 14 are provided between the lower beams 13 of the frame 10A, and a plurality of small beams 20 are provided between the upper beams 12 at predetermined intervals. A ceiling surface material (not shown) is provided on the lower surface 21 of these small beams 20 to form a ceiling surface. As shown in FIG. 2, the lower surface 21 of the small beam 20 is a mountain-shaped inclined surface 21A which is formed in a concave shape in the longitudinal direction and is bent upward.

The small beam 20 of this embodiment as shown in FIG.
Is processed using a processing jig 30 as shown in FIG. The processing jig 30 includes a flat mounting surface 31 on which the small beam 20 is mounted, and a pair of guide bodies 32A and 32B installed in parallel on the mounting surface 31 at a predetermined interval. . Each of the guide bodies 32A and 32B is disposed at a predetermined interval between a pair of prismatic guide members 33 arranged linearly and a gap between the guide members 33 and the mounting surface 31 to reduce the inclination of the guide members 33. And a plurality of adjusting members 34 for adjusting.

The upper surface of the guide member 33 is a tool guide surface 35, and the pair of guide members 33 is inclined so that the tool guide surface 35 of each of the guide bodies 32A and 32B is bent downward in the longitudinal direction. It has been installed. The adjusting member 34 is detachably attached to the guide member 33 so that the adjusting member 34 can be replaced with one of various heights. The difference between the heights changes the distance between the guide member 33 and the mounting surface 31 to change the guide member 33. The inclination of can be adjusted. The adjustment member 34 is detachably fixed to the mounting surface 31 by locking means (not shown).

Using such a processing jig 30, the beam 20 is processed in a process as shown in FIG. First, the lower surface 21
A normal beam 20 having a flat surface is prepared, and the beam 20 is arranged on the mounting surface 31 between the guides 32A and 32B. Then, the guide members 32A and 32B are brought into contact with both side surfaces of the small beam 20, and the adjustment member 34 is fixed to the mounting surface 31 by a locking means (not shown) in the state as it is. Next, electric canna 3
6 is used to cut the lower surface 21 of the beam 20 along the tool guide surface 35. Thereby, the lower surface 21 of the small beam 20 is processed into a mountain-shaped inclined surface 21A that is bent upward in the longitudinal direction.

According to this embodiment, the following effects can be obtained. That is, since the lower surface 21 of the small beam 20 is formed in a concave shape in the longitudinal direction, even if the small beam 20 bends due to the load of the lighting equipment installed on the ceiling surface, the center of the lower surface 21 is lower than the end. It can be restrained from protruding. Therefore, even if the small beam 20 bends, the ceiling surface does not hang down, and the ceiling can be reliably prevented from lowering due to the bending of the small beam 20. Further, since the lower surface 21 of the small beam 20 is formed by the mountain-shaped inclined surface 21A, it can be processed more easily than a curved surface.

Since the lower surface 21 of the beam 20 is cut along the tool guide surface 35 of the guide bodies 32A and 32B,
The lower surface 21 can be easily processed into a shape corresponding to the tool guide surface 35. In addition, since the tool guide surface 35 has a valley shape that is bent downward in the longitudinal direction, it can be configured simply by adjusting the inclination of the pair of guide members 33 with the adjusting member 34, and is easier than the arc-shaped tool guide surface. Can be formed.

In the first embodiment, the lower surface 21 of the small beam 20 is a mountain-shaped inclined surface 21A which is bent upward. However, as shown in FIG. 5, the lower surface 21 is curved upward in the longitudinal direction. It may be an arcuate curved surface 21B. When processing the lower surface 21 of the small beam 20 into a curved surface 21B in this manner, a processing jig 40 as shown in FIG. 6 may be used. In this processing jig 40, the tool guide surfaces 45 of the guide bodies 32A and 32B are formed in an arc shape that curves downward in the longitudinal direction. If the lower surface 21 of the beam 20 is cut using the processing jig 40 in the same manner as in the first embodiment, the lower surface 21 can be processed into an arc-shaped curved surface 21B that curves upward.

By using the small beam 20, the same operation and effect as those of the first embodiment can be obtained.
Of the lower surface 21 is an arc-shaped curved surface 21B that is curved upward in the longitudinal direction, so that the ceiling surface can be formed in a curved shape like the conventional ceiling of the conventional method.
Even if it warps, the ceiling surface can be maintained as a curved surface or a flat surface without irregularities. Also, since the shape of the tool guide surface 45 is an arc shape that curves downward in the longitudinal direction, the lower surface 21 of the small beam 20 is simply cut along the tool guide surface 45 so that the lower surface 21 becomes It can be easily processed into the corresponding curved surface 21B shape.

[Second Embodiment] In the description of this embodiment, the same parts as those in FIGS. 1 to 6 are denoted by the same reference numerals, and detailed description thereof will be omitted. Only different parts will be described below in detail. The beam 20 of the present embodiment is the same as the beam 20 of the first embodiment shown in FIG. 2, and the processing method and the processing jig 50 are different. As shown in FIG. 7, the processing jig 50 of the present embodiment includes a mountain-shaped fixing surface 51 that is bent upward in the longitudinal direction, and a small beam 20 along the fixing surface 51.
And a vise 55 as a fixing means for fixing in a bent state. The fixing surface 51 is constituted by upper surfaces of a pair of support members 52 which are arranged in a mountain-like manner. A plurality of adjusting members 5 are provided on the lower surface of the support member 52 at predetermined intervals.
3 is detachably attached, and the inclination of the support member 52 can be adjusted by the difference in the height dimension of the adjustment member 53 as in the first embodiment.

The beam 20 of this embodiment is processed by using the processing jig 50 in the steps shown in FIG. First, a normal small beam 20 having a flat lower surface 21 is prepared.
The small beam 20 is placed on the fixed surface 51 of the processing jig 50 with its lower surface 21 facing upward. Subsequently, the small beam 20 is fixed to the fixing surface 51.
, And both ends are fixed with the vice 55 together with the ends of the support members 52 as they are. Next, the lower surface 2 of the small beam 20 is
1 is cut flat. At this time, the electric canna 36 may be made to follow the flat guide surface of the existing guide body. As a result, a portion of the lower surface 21 of the small beam 20 that is bent and protrudes upward is cut flat by the electric canner 36, and the lower surface 21 is bent upward in the longitudinal direction. Processed into

According to this embodiment, the same operation and effect as those of the first embodiment can be obtained.
The following effects are obtained. That is, the fixing surface 51 is formed in a chevron shape that is bent upward in the longitudinal direction, and the small beam 20 is fixed along the vice 55 along the fixing surface 51 and the lower surface 21 is cut flat. Lower surface 2 of beam 20
The portion that is bent and protrudes upwards of 1 is cut flat, and the lower surface 21 of the small beam 20 can be easily processed into a shape corresponding to the bending of the fixed surface 51. In addition, since the fixing surface 51 has a mountain shape that is bent upward in the longitudinal direction, the fixing member 51 can be configured by simply arranging the pair of support members 52 in a straight line and adjusting the inclination thereof with the adjusting member 53. It can be formed more easily than a surface.

It should be noted that the present invention is not limited to the above embodiments, but includes other configurations capable of achieving the object of the present invention, and also includes the following modifications. That is, in the second embodiment, the fixing surface 51 of the processing jig 50 is constituted by a pair of inclined surfaces bent in a chevron shape. However, as shown in FIG. May be used as the fixing surface 61. When the lower surface 21 of the small beam 20 is cut using the processing jig 60 in the same manner as in the second embodiment, the lower surface 21 is processed into an upwardly curved arc-shaped curved surface 21B as shown in FIG. it can.

In this manner, substantially the same effects as those of the above embodiments can be obtained. In addition, the shape of the fixing surface 61 is formed in an arc shape that curves upward in the longitudinal direction, and the small beam 20 is fixed along the fixing surface 61 by the fixing means 55,
The lower surface 21 of the small beam 20 was cut flat.
1, the curved and protruding portion is cut flat, and the lower surface 21 of the small beam 20 is formed into an arc-shaped curved surface curved upward in the longitudinal direction according to the curvature of the fixing surface 61. It can be easily processed.

Further, as shown in FIG. 10, both ends of the small beam 20 are fixed by locking members 71 and the like, and the center of the upper surface of the fixed small beam 20 is pressed toward the lower surface 21 by the cylinder device 72 and the like. Alternatively, the small beam 20 may be curved, and the lower surface of the small beam 20 may be cut flat by an electric saw 73 or the like in this state. As a result, the lower surface 21 of the small beam 20 is processed into an arcuate curved surface curved upward in the longitudinal direction. Also, the upper and lower surfaces 2 are placed on the horizontal mounting surface.
The beam 20 is mounted so that 1 is perpendicular to the mounting surface, and both ends thereof are fixed to the mounting surface, and the upper surface is pressed horizontally (toward the lower surface 21) by a cylinder device 72 or the like. The lower surface 21 may be cut flat in this state.

In this manner, substantially the same effects as those of the above embodiments can be obtained. In addition, since the upper surface of the small beam 20 is curved by pressing it toward the lower surface 21 with the cylinder device 72, the degree of curvature of the small beam 20 can be easily adjusted only by adjusting the air pressure or the hydraulic pressure of the cylinder device 72. The lower surface 21 can be processed into a desired curved shape by changing the degree of curvature.

[0042]

【Example】

[Example 1] In the first embodiment, a rectangular section (vertical
The lower surface 21 was machined into a mountain-shaped inclined surface 21A that is bent upward in the longitudinal direction using a small beam 20 made of a square material (90 mm x 30 mm in width). The inclination angle of each guide member 33 of the processing jig 30 was adjusted so that the distance between the mounting surface 31 and the guide member 33 was 3 mm at the maximum and 0 mm at the minimum. Then, 11 obtained small beams 20 were bridged between the upper beams 12 on the long side of the building unit 10 at a constant pitch interval. The frame 10A has a prescribed dimension (910 mm) as one module, a long side dimension of 6 modules, and a short side dimension of 2.5 modules. The height of the center of the lower surface 21 of each installed small beam 20 was measured with reference to the height of the end of the lower surface 21, and the deflection of the small beam 20 was examined. The result is shown in FIG.
Shown in Note that the horizontal axis of the graph represents each beam 20 in order from the end.
The vertical axis indicates the height of the center of the lower surface 21 of the small beam 20 with reference to the height of the end.

[Embodiment 2] The long side dimension of the skeleton 10A is set to 4
The deflection of the lower surface 21 of the small beam 20 was examined in the same manner as in Example 1 except that nine small beams 20 were installed as a module.
The result is shown in FIG.

As shown in the graph of FIG. 10, all of the small beams 20 of the first and second embodiments have a center height of −2 mm or more and 0 mm or less based on the edge of the lower surface 21. It can be seen that the deflection of the small beam 21 can be prevented and the ceiling can be prevented from lowering due to the deflection of the small beam 20.

[0045]

As described above, according to the present invention,
Since the lower surface of the small beam is formed in a concave shape in the longitudinal direction, even if the small beam is bent by the load of the lighting fixture or the like, it is possible to prevent the central portion of the lower surface from projecting below the end portion. Therefore, even if the small beams are bent, the ceiling surface does not hang down, and it is possible to reliably prevent the ceiling from being lowered due to the bending of the small beams.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a perspective view showing the processing jig of the embodiment.

FIG. 4 is a process diagram showing a processing step of the small beam of the embodiment.

FIG. 5 is a sectional view showing a modified form of the small beam of the embodiment.

FIG. 6 is a perspective view showing a modification of the processing jig of the embodiment.

FIG. 7 is a perspective view showing a processing jig according to a second embodiment of the present invention.

FIG. 8 is a process chart showing a processing step of the small beam of the embodiment.

FIG. 9 is a perspective view showing a modification of the processing jig of the embodiment.

FIG. 10 is a side view showing a modification of the present invention.

FIG. 11 is a graph showing the deflection of the lower surface of a small beam.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Building unit 10A Frame 11 Column 12 Upper beam 13 Lower beam 20 Small beam 21 Lower surface 30, 40, 50, 60 Processing jig 31 Mounting surface 32A, 32B Guide body 35, 45 Tool guide surface 51, 61 which is a guide surface Fixing surface 55 Fixing means

Claims (12)

[Claims] 1. A small unit erected between upper beams of a building unit having a framework including four columns, an upper beam connecting between upper ends of these columns, and a lower beam connecting between lower ends of the columns. A beam having a lower surface formed in a concave shape in a longitudinal direction thereof. 2. The beam according to claim 1, wherein the lower surface is an arc-shaped curved surface that curves upward in the longitudinal direction. 3. The beam according to claim 1, wherein the lower surface is a mountain-shaped inclined surface that is bent upward in the longitudinal direction. 4. A small unit erected between upper beams of a building unit having a framework including four columns, an upper beam connecting upper ends of these columns, and a lower beam connecting lower ends of the columns. A beam processing method, comprising: arranging, on a flat mounting surface, the small beam and a guide body having an arc-shaped guide surface curved downward in the longitudinal direction in parallel and close to each other; A method for processing a small beam, wherein the lower surface of the small beam is cut or cut along the guide surface. 5. A small unit erected between said upper beams of a building unit having a framework including four columns, an upper beam connecting between upper ends of these columns, and a lower beam connecting between lower ends of said columns. A beam processing method, comprising: arranging, on a flat mounting surface, the small beam and a guide body having a valley-shaped guide surface that is bent downward in the longitudinal direction, in parallel with and close to each other; A method for processing a small beam, wherein the lower surface of the small beam is cut or cut along the guide surface. 6. A small unit erected between upper beams of a building unit having a framework including four columns, an upper beam connecting between upper ends of these columns, and a lower beam connecting between lower ends of the columns. A beam processing method, wherein the small beam is placed on an arc-shaped fixing surface that curves upward in a longitudinal direction with its lower surface facing upward, and the small beam is curved along the fixing surface. And cutting or cutting the lower surface of the beam in a flat manner. 7. A small unit erected between upper beams of a building unit having a framework including four columns, an upper beam connecting between upper ends of these columns, and a lower beam connecting between lower ends of the columns. A beam processing method, comprising: placing the small beam on a mountain-shaped fixing surface that is bent upward in the longitudinal direction with its lower surface facing upward, and bending the small beam along the fixed surface. And cutting or cutting the lower surface of the beam in a flat manner. 8. A small unit installed between the upper beams of a building unit having a framework including four columns, an upper beam connecting between upper ends of these columns, and a lower beam connecting between lower ends of the columns. A method of processing a beam, comprising fixing both ends of the beam, pressing a central portion of an upper surface of the fixed beam in a lower surface direction to bend the beam, and holding the beam as it is. A method for processing a small beam, wherein the lower surface is cut or cut flat. 9. A small unit erected between said upper beams of a building unit having a framework including four columns, an upper beam connecting between upper ends of these columns, and a lower beam connecting between lower ends of said columns. A beam processing jig, comprising: a flat mounting surface on which the small beam is mounted; and an arc-shaped tool guide surface provided on the mounting surface and curved downward in the longitudinal direction. A special jig for processing small beams. 10. A small unit erected between upper beams of a building unit having a framework including four columns, an upper beam connecting upper ends of these columns, and a lower beam connecting lower ends of the columns. A beam processing jig, comprising: a flat mounting surface on which the small beam is mounted; and a valley-shaped tool guide surface provided on the mounting surface and bent downward in the longitudinal direction. A special jig for processing small beams. 11. A small unit erected between upper beams of a building unit having a framework including four columns, an upper beam connecting upper ends of these columns, and a lower beam connecting lower ends of the columns. A beam processing jig, comprising: an arc-shaped fixing surface that curves upward in a longitudinal direction; and fixing means that fixes the small beam in a curved state along the fixing surface. Jig for processing small beams. 12. A small unit erected between said upper beams of a building unit having a framework including four columns, an upper beam connecting between upper ends of these columns, and a lower beam connecting between lower ends of said columns. A beam processing jig, comprising: a mountain-shaped fixing surface bent upward in a longitudinal direction; and fixing means for fixing the small beam in a bent state along the fixing surface. Jig for processing small beams.