JP6931905B2 - Roof truss unit and roof construction method using it - Google Patents

Description

The present invention relates to a roof truss unit and a roof construction method for a wooden building.

As is well known, in the wooden frame wall construction method and the wooden frame construction method of wooden construction, in order to facilitate the construction work, the roof unit members according to the roof shape are manufactured in advance at the factory, and the roof unit members are lifted by the crane at the site. The construction method of installing on pillars and eaves girders has been adopted.

However, in order to manufacture a lightweight roof unit member that can be easily transported, there is a problem that it is difficult to maintain sufficient strength, for example, the rafter portion must be made of a plate material instead of a square lumber.

Therefore, the applicant has proposed a method of manufacturing a roof truss unit in which a truss structure is previously formed by using a plate material at a factory in advance (see Patent Document 1), thereby facilitating on-site roof construction work. And it has become possible to shorten the construction period.

However, since the roof truss unit of Patent Document 1 is complicated to be connected via a reinforcing plate at the site, it is necessary to manufacture the roof truss unit having a mountain shape at least until it is transported. There was a problem that a big truck was needed for this.

On the other hand, in the past, in order to facilitate transportation, a rafter truss member having a notched shape at one end was manufactured at the factory, and the left and right rafter truss members were fixed at the site using screws or the like to form a mountain shape. A method of making a roof truss unit of the above has been proposed (see Patent Document 2).

However, with respect to this technique, the thickness of the plate material is halved due to the lack of tops, and the strength is not sufficient because the upper chord material and the lower chord material are fixed to each other in only one place. There was a problem.

Japanese Unexamined Patent Publication No. 2016-138400 Japanese Patent No. 4614151

The present invention has been made in view of the above-mentioned problems in the prior art, and an object of the present invention is not only to facilitate construction work and shorten the construction period at a construction site, but also to withstand. It is an object of the present invention to provide a roof truss unit capable of constructing a roof having excellent loadability and easily transporting members, and a roof construction method using the roof truss unit.

The means adopted by the present inventor to solve the above technical problems will be described as follows with reference to the accompanying drawings.

That is, in the present invention, the roof truss unit U used for constructing the roof structure of a building is formed into a mountain shape by the straight portions S of the left and right rafter units 1.1 having a parallel string truss structure via the top T. While the rafter unit 1 is composed of an integrated gassho shape, the rafter unit 1 includes a truss chord member 11 composed of an upper chord member 11a and a lower chord member 11b arranged vertically and vertically along a straight portion S; the truss chord member 11 Bundles 12a arranged at predetermined intervals between the upper chords 11a and the lower chords 11b, and the seams of one of the adjacent bundles 12a and the upper chords 11a, and the other bundles 12a and the lower chords 11b. A truss abdomen 12 made of diagonal members 12b arranged so as to connect the seams of the above; Further, at the top T, the left and right rafter units 1 and 1 are arranged so as to overlap each other, and the upper chord member 11a of one rafter unit 1 is fixed to the upper chord member 11a and the lower chord member 11b of the other rafter unit 1, respectively. The lower chord member 11b of one rafter unit 1 is characterized in that it is fixed to the upper limit member 11a and the lower chord member 11b of the other rafter unit 1, respectively.

Further, it is also possible to adopt a technical means of arranging the joint portion 14 between the bundle member 12a of one of the rafter units 1 and the lower chord member 11b so as to overlap the lower chord member 11b of the other rafter unit 1. can.

Further, the diagonal member 12b of the truss belly member 12 is a bundle on the diagonal line in the frame surrounded by the upper chord member 11a, the lower chord member 11b, and the bundle member 12a adjacent to the lower chord member 11b, and is on the center line C side of the roof truss unit U. It is also possible to adopt a technical means of fixing the joint between the lumber 12a and the lower chord 11b and the joint between the diagonal bundle 12a and the upper chord 11a.

On the other hand, it is also possible to adopt a technical means of fixing the diagonal member 12b of the truss belly member 12 on each diagonal line in the frame surrounded by the upper chord member 11a, the lower chord member 11b and the adjacent bundle member 12a. ..

Further, it is also possible to adopt a technical means in which the tip end portion of the upper chord member 11a of the rafter unit 1 on the eaves side is made longer than the lower chord member 11b in the direction along the straight line portion S of the rafter unit 1.

On the other hand, after manufacturing a plurality of rafter units 1 having a size that can be carried, a roof truss manufactured so that the straight portions S of these rafter units 1 form a mountain-shaped integrated gassho shape via the top T. Units U, U ... are erected on pillars P, P ... or eaves girders E, E ..., respectively, and connecting plates 2 are placed on opposite surfaces of adjacent rafter units 1, 1 ... -It is also possible to adopt a technical means of fixing 2 ... and connecting the roof truss units U, U ... to each other to construct a roof.

In the present invention, by unitizing the rafter members having a complicated truss structure, it is possible not only to facilitate the construction work and shorten the construction period at the construction site, but also to construct a roof having excellent load bearing capacity. Can be done.

In addition, by arranging the joint between one of the bundled lumbers of one rafter unit and the lower chord material so as to overlap the lower chord material of the other rafter unit, the load concentration at the anchoring position is concentrated by the truss belly material. Can be dispersed.

Furthermore, the diagonal material of the truss belly material is fixed to the lower chord material at one end on the center line side of the roof truss unit and to the upper chord material at the other end, so that the load applied to the roof truss unit is efficiently dispersed and the load is applied. Can be reduced.

On the other hand, by fixing the diagonal members of the truss belly material on each diagonal line in the frame surrounded by the upper chord material, the lower chord material and the adjacent bundle material, the load applied to the roof truss unit can be more efficiently dispersed. The load can be further reduced.

Further, by making the tip of the upper chord member of the rafter unit on the eaves side longer than the lower chord member in the direction along the straight portion of the rafter unit, the eaves tip can be formed after the roof is constructed.

On the other hand, by manufacturing a rafter unit of a size that can be transported in advance and then assembling it as a roof truss unit at the site, it is possible to easily transport the members, facilitate the construction work and shorten the construction period at the construction site. ..

As described above, according to the present invention, not only can the construction work be facilitated and the construction period be shortened at the construction site, but also a roof having excellent load bearing capacity can be constructed, and the members can be easily transported. Since the roof truss unit and the roof construction method using the roof truss unit can be provided, the practical value of the present invention is extremely high.

It is an overall perspective view which shows the roof truss unit in Example 1 of this invention. It is a top view which shows the roof truss unit in Example 1 of this invention. It is an exploded perspective view which shows the roof truss unit in Example 1 of this invention. It is a front view which shows the building structure using the roof truss unit in Example 1 of this invention. It is an enlarged view of the top of the roof truss unit in Example 1 of this invention. It is an overall perspective view which shows the roof part of the building structure using the roof truss unit in Example 1 of this invention. It is a partial side view which looked at the installation state of the roof and the pillar in Example 1 of this invention from the eaves side. It is a front view which shows the building structure using the roof truss unit in Example 2 of this invention.

"Example 1"
Example 1 of the present invention will be described below with reference to FIGS. 1 to 7. Incidentally, in the figure, what is indicated by reference numeral 1 is a rafter unit, and what is indicated by reference numeral 2 is a connecting plate. Further, what is indicated by the reference numeral E is an eaves girder, and what is indicated by the reference numeral P is a pillar. Further, what is indicated by the reference numeral U is a roof truss unit composed of left and right rafter units.

[Roof truss unit configuration]
First, in the first embodiment, in the wooden frame wall construction method of a wooden building, the roof truss unit U is composed of two rafter units 1.1 assembled in a mountain shape according to the roof shape, and the left and right rafter units. The straight portions S and S of 1.1 form a mountain-shaped integrated gassho shape via the top T (see FIG. 1). The angle formed by the left and right straight portions S / S of the rafter unit 1 can be freely changed in design according to the roof slope.

At the top T, the left and right rafter units 1 and 1 are arranged so as to overlap each other, and the upper chord member 11a of one rafter unit 1 is fixed to the upper chord member 11a and the lower chord member 11b of the other rafter unit 1, respectively, and one rafter unit is used. The lower chord member 11b of 1 is fixed to the upper chord member 11a and the lower chord member 11b of the other rafter unit 1, respectively (see FIGS. 1 and 2).

The rafter units 1 and 1 are connected to each other by driving a plurality of, preferably five, nails, screws, or other fastening members (not shown) at each fastening position N. The fastening position N is a portion where the upper chord member 11a and the lower chord member 11b of one rafter unit 1 and the upper chord member 11a and the lower chord member 11b of the other rafter unit 1 overlap each other at the top T (FIG. 5). reference).

Further, the lengths of the upper chord members 11a / 11a and the lower chord members 11b / 11b of the left and right rafter units 1 and 1 are such that the end face on the top T side is from the other rafter unit 1 when the roof truss unit U is viewed from the front. They are arranged so that they do not pop out.

At this time, in order to prevent the wood board from cracking during fixing, the end face on the top T side is manufactured in advance so as to protrude slightly from the upper chord member 11a of the other rafter unit 1, and the rafters cover the protruding portion. A part of the shape of the face material 13 (described later) of the unit 1 is formed into a convex shape.

[Structure of rafter unit]
Next, the configuration of the rafter unit 1 will be described. First, the overall shape of the rafter unit 1 is a thin plate made of wood board, and the left and right straight portions S and S are arranged in parallel vertically along the straight portion S with the upper chord member 11a. The truss chord member 11 including the lower chord member 11b and the truss belly member 12 including the upper chord member 11a and the bundle member 12a and the diagonal member 12b arranged inside the lower chord member 11b form a parallel chord truss structure. (See FIGS. 1 and 3).

Further, among the truss belly members 12, the bundle members 12a, 12a ... Are arranged at predetermined intervals between the upper chord member 11a and the lower chord member 11b of the truss chord member 11 (see FIGS. 1 and 3). The bundle member 12a may or may not be orthogonal to the upper chord member 11a and the lower chord member 11b.

At this time, in any one of the rafter units 1's bundle 12a, the joint portion 14 between the bundle 12a and the lower chord plate 11b is arranged so as to overlap the lower chord 11b of the other rafter unit 1. (See FIGS. 4 and 5). In addition, "to overlap" means that at least a part of the seam portion 14 overlaps with the lower chord member 11b of the other rafter unit 1 when the roof truss unit U is viewed from the front.

By arranging in this way, the load applied to the fastening position N can be released through the truss abdominal member 12, and the strength of the entire roof truss unit U is increased.

Further, among the truss belly members 12, the diagonal members 12b, 12b ... Are on the diagonal line in the frame surrounded by the upper chord member 11a and the bundle members 12a, 12a ... Adjacent to the lower chord member 11b, and are roof truss units. It is fixed to the joint portion between the lower chord member 11b and the bundle member 12a on the center line C side of the U, and the joint portion between the upper chord member 11a and the bundle member 12a on the diagonal side thereof (see FIG. 4). The "center line C" refers to a line that passes through the intersections of the upper chord members 11a and 11a of the roof truss unit U and intersects the ground G perpendicularly.

Further, in this embodiment, the truss chord member 11 and the truss belly member 12 constituting the rafter unit 1 are made of wood board having a thickness of 91 mm (about 3 inches) or less. It is more preferable to use a lumber having a thickness of 30 to 76 mm (about 1 to 2 inches) in order to form a thinner shape while ensuring strength.

Further, the rigidity of the rafter unit 1 is improved by attaching face members 13 and 13 to both sides of the frame of the parallel chord truss structure composed of the truss chord member 11 and the truss belly member 12. (See FIGS. 2 and 3). Here, the face material 13 may be attached to only one side of the frame body. In this embodiment, a structural plywood that is inexpensive and has excellent durability is used for the face material 13.

Further, in this embodiment, the face materials 13 and 13 are attached to the truss chord material 11 and the truss belly material 12 from the outside to the inside of the face material 13 with a fixing member (not shown) such as a nail or a screw. I'm driving in.

[Roof construction method using roof truss unit]
Next, a roof construction method using the roof truss unit U will be described. First, in this embodiment, a plurality of rafter units 1 having a size that can be transported (a size that can be placed on a loading platform such as a truck) are manufactured in a precut factory or the like, and these are transferred to a construction site. Of course, the rafter unit 1 can also be assembled on-site as needed.

After that, the left and right rafter units 1 and 1 are arranged so as to overlap at the top T, and the straight parts S and S are assembled so as to form a mountain-shaped integrated gassho shape via the top T, and the roof truss unit. Complete U.

At this time, the upper chord member 11a of one rafter unit 1 is fixed to the upper chord member 11a and the lower chord member 11b of the other rafter unit 1, respectively, and the lower chord member 11b of one rafter unit 1 is the upper chord member 11a of the other rafter unit 1. And fixed to the lower chord material 11b, respectively. The rafter units 1 and 1 are connected to each other by driving a plurality of, preferably five, nails, screws, or other fastening members (not shown) at each fastening position N.

After that, the roof truss unit U is lifted by a crane or the like and placed on the pillars P and P of the wall panels W and W of the building structure under construction. Is fixed with a fastening member (not shown) such as a nail or a screw and installed (see FIGS. 6 and 7). Then, by repeating this, the roof truss units U, U ... are arranged in the girder direction, and the connecting plates 2 and 2 are fixed to the facing surfaces of the adjacent roof truss units U, U, and the roof truss units U, U are connected to each other. Are concatenated (see FIG. 6).

At this time, in order to improve the strength of the roof and facilitate the construction, when the roof is viewed from the upper surface, the fixing positions of the connecting plates 2.2 ... It is preferable to arrange the staggered arrangement by alternately shifting the positions to half of the pitch (see FIG. 6). The connecting plates may be arranged in series instead of in a staggered arrangement.

Further, in this embodiment, the connecting plate 2 is attached to the roof truss units U and U with a fastening member (not shown) such as a nail or a screw, but the bundle member 12a of the truss belly member 12 The connecting plate 2 is mounted on the roof truss unit U according to the positions of the bundled members 12a and 12a ... arranged at predetermined intervals so that the load applied to the fixed portion of the connecting plate 2 can be absorbed by the 12a ... Preferred (see FIG. 6).

Further, in this embodiment, the strength of the top T is increased by arranging the two connecting plates 2 close to the top T of the roof truss unit U. Further, in this embodiment, a wood board material having a thickness of 91 mm or less is used for the connecting plate 2, but it is more preferable to use a wood board material having a thickness of 30 to 76 mm in consideration of the strength and weight balance of the roof. preferable.

Furthermore, in this embodiment, the connecting plates 2 and 2 ... Are arranged on the upper chord member 11a side and the lower chord member 11b side of the roof truss unit U, respectively, to improve the strength of the roof (see FIG. 6). It may be arranged only on either the upper chord member 11a side or the lower chord member 11b side. Further, by increasing the vertical width of the connecting plate 2, the connecting plate 2 can be fixed to the bundle member 12a with a fastening member (not shown).

Then, after the roof truss unit U is installed on the pillars P and P, a field board (not shown) is attached to the upper side of the roof truss unit U to construct the roof surface. Since the wooden board material forming the roof truss unit U is thin, the roof truss unit U can be arranged at a high density, the field board can be easily attached, and the strength can be improved.

By configuring the roof truss unit U as described above, it is possible not only to facilitate the construction work and shorten the construction period at the construction site of the wooden frame wall construction method of the wooden building, but also to make the roof excellent in load bearing capacity. Can be built.

"Example 2"
Next, Example 2 of the present invention will be described below with reference to FIG. In the second embodiment, the diagonal member 12b of the truss belly member 12 is fixed on each diagonal line in the frame surrounded by the upper chord member 11a, the lower chord member 11b, and the adjacent bundle member 12a (see FIG. 8). ..

Further, in this embodiment, the tip of the upper chord members 11a / 11a of the rafter units 1.1 is longer than the lower chord members 11b / 11b in the direction along the straight portions S / S of the rafter units 1.1. (See Fig. 8).

Further, in this embodiment, the roof truss unit U is lifted by a crane or the like and placed on the upper eaves girders E1 and E1 and the lower eaves girders E2 and E2 of the building structure under construction. The metal fittings (not shown) attached to both ends of the 11a and the lower chord members 11b and 11b on the eave side are fixed to the upper eaves girders E1 and E1 and the lower eaves girders E2 and E2 for installation (see Fig. 8).

By configuring the roof truss unit U as described above, the strength of the roof truss unit U can be further improved, and the eaves can be formed when the field board is attached. Not only can the construction work be facilitated and the construction period be shortened at the construction site, but it is also possible to construct a roof with excellent load resistance.

Although the present invention is generally configured as described above, the present invention is by no means limited to the illustrated embodiment, and various modifications can be made within the description of "Claims", for example. The face member 13 constituting the rafter unit 1 can be attached only to a part of the frame of the truss chord member 11.

Further, for fixing one rafter unit 1 and the other rafter unit 1 at the top T, a reinforcing plate for increasing the width is added near the top T of the upper chord member 11a or the lower chord member 11b, and the reinforcing plate is attached to the reinforcing plate. It can also be fixed.

Furthermore, the intervals between the upper chord member 11a and the bundle members 12a, 12a ... Arranged inside the lower chord member 11b are not even, and can be made dense in the part where a large load is applied and sparse in the other parts. Any of the above belongs to the technical scope of the present invention.

In recent years, in the field of construction, there has been a demand for the development of new roofs and construction methods that can reduce construction costs and improve construction efficiency while ensuring sufficient strength required for building structures. ing. Under such circumstances, the roof truss unit and the roof construction method of the present invention can not only facilitate the construction work and shorten the construction period, but also have excellent load bearing capacity, and the members can be transported very much. Since it is a useful technology that makes it easy, its industrial utility value is very high.

1 rafter unit
11 Truss chord material
11a First chord material
11b lower chord material
12 truss belly material
12a Lumber
12b diagonal lumber
13 Face material
14 Joint between lower chord and bundle 2 Connecting plate U Roof truss unit N Fastening position S Straight part T Top G Ground C Center line W Wall panel E Eaves girder
E1 first eaves girder
E2 Lower eaves girder P pillar

Claims (6)

A roof truss unit used to build the roof structure of a building.
While the straight parts of the left and right rafter units, which consist of parallel chord truss structures, are composed of a gassho shape that is integrated into a chevron shape via the top.
The rafter unit is composed of a truss chord member composed of an upper chord member and a lower chord member arranged vertically in parallel along a straight line portion; and a bundle member arranged at a predetermined interval between the upper chord member and the lower chord member of the truss chord member. , And a truss belly member composed of diagonal members arranged so as to connect one bundle of adjacent bundles and the joint of the upper chord and the other of the bundle and the joint of the lower chord; with the truss chord. It is composed of a face material attached to a frame made of the truss belly material, and is composed of a face material.
Further, at the top, the left and right rafter units are arranged so as to overlap each other, the upper chord material of one rafter unit is fixed to the upper chord material and the lower chord material of the other rafter unit, respectively, and the lower chord material of one rafter unit is the other. A roof truss unit characterized in that it is fixed to the upper and lower chords of the rafter unit. The roof truss unit according to claim 1, wherein the joint portion between the bundle member of any one of the rafter units and the lower chord member is arranged so as to overlap the lower chord member of the other rafter unit. The diagonal members of the truss belly material are on the diagonal line in the frame surrounded by the upper chord material, the lower chord material, and the adjacent bundle material, and the joint portion between the bundle material and the lower chord material on the center line side of the roof truss unit. The roof truss unit according to claim 1 or 2, wherein the roof truss unit is fixed to a joint portion between the diagonal bundle member and the upper chord member. The roof truss unit according to claim 1 or 2, wherein the diagonal members of the truss belly member are fixed on each diagonal line in a frame surrounded by the upper chord member, the lower chord member, and the adjacent bundle member. .. The roof truss unit according to any one of claims 1 to 4, wherein the tip of the upper chord member of the rafter unit on the eaves side is longer than the lower chord member in the direction along the straight line portion of the rafter unit. The invention according to claim 1 to 5, wherein after manufacturing a plurality of rafter units having a size that can be carried, the straight portions of these rafter units are manufactured so as to form a gassho shape integrated into a mountain shape via the top. A method for constructing a roof in which roof truss units are erected on columns or eaves girders, connecting plates are fixed to facing surfaces of adjacent rafter units of the roof truss units, and roof truss units are connected to each other.

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