JPH0811912B2 - Membrane roof truss structure - Google Patents

Description

TECHNICAL FIELD The present invention relates to a truss construction structure for a membrane roof supporting a membrane roof material such as a flexible plastic sheet.

[Problems to be Solved by Conventional Techniques and Inventions]

Conventionally, a truss-assembling structure for a membrane roof supporting a membrane roof material such as a flexible plastic sheet generally has a lower chord member b of juxtaposed trusses a and a horizontal joint member c as shown in FIGS. 2 and 3. A middle fulcrum is provided on the lower chord member b to secure its horizontal rigidity, and points A and A are distributed from the intersection point O between the lower chord member b and the horizontal joint member c to the horizontal joint member c at equal distances.
And a point B on the truss upper chord member d just above the intersection O between the lower chord member b and the horizontal joint member c are connected by buckling prevention diagonal members e, e to provide an intermediate fulcrum also on the upper chord member d. , Its horizontal rigidity is secured.

This is because, due to the nature of the membrane roof material f, the slack generated between the trusses a and a of the membrane roof material f supported by the truss upper chord member d is suppressed by the restraining cable g arranged between the trusses a and a. The membrane roof is a combination of peaks and valleys, and the upper chord member d cannot be provided with a horizontal member for ensuring its horizontal rigidity. Therefore, if an X-shaped horizontal member is provided on the lower chord member b instead of providing a horizontal member on the upper chord member d, the X-shaped horizontal member becomes an obstacle to looking up from below. In order to avoid this, the buckling prevention diagonal member e is formed by connecting the upper chord member d and the horizontal tie member c in the downward direction so as not to contact the valley of the membrane roof. Is connected to the upper chord member d at a right angle, there is a problem that the horizontal rigidity of the upper chord member d cannot be sufficiently secured.

As another method, there is also a method of rigidly joining the lower chord member b and the horizontal tie member c to secure the horizontal rigidity of the truss a by its ramen effect, but this method only complicates the joining joint, Its effect is small.

In view of the above-mentioned conventional problems, the present invention has been made to solve this problem, without touching the membrane roof that is a combination of mountains and valleys, and there is no annoying horizontal member, Moreover, it is an object of the present invention to provide a truss assembling structure for a membrane roof that can remarkably enhance the rigidity of the truss.

[Means for solving the problem]

In order to achieve the above-mentioned object, the present invention is to connect the lower chord members of the trusses arranged in parallel with each other by the horizontal tie member, and to distribute the lower chord member and the horizontal tie member at an equal distance from the intersection point of the lower chord member and the horizontal tie member, and Truss directly above the intersection of the lower chord and the horizontal tie material Two trusses that are equidistantly distributed on the upper chord from the point on the upper chord, and are connected to each other by buckling-preventing diagonal members. I am trying.

[Action]

The lower chords are connected by a horizontal tie, and the upper chords are two points that are equidistantly distributed on the horizontal tie from the intersection of the lower chord and the horizontal tie, and immediately above the intersection of the lower chord and the horizontal tie. Since it is connected by a buckling prevention diagonal member that connects the points on the truss upper chord member to the two points that are distributed equidistantly on the upper chord member, the distance between the fulcrums of the upper chord member becomes short and Since the buckling prevention diagonal members intersect at an internal angle of 90 degrees or less, the connection with the upper chord member is close to the rigid frame structure, and without the contact with the membrane roof of the reinforcing material and the disturbing horizontal member, the truss structure structure is used. The rigidity can be remarkably enhanced.

〔Example〕

The present invention will be described in detail below with reference to an embodiment shown in the drawings.

In FIG. 1, 1 is a truss in which an upper chord member 1a and a lower chord member 1b are connected by a diagonal member 1c, which are juxtaposed at a predetermined interval, and the lower chord members 1b of each truss 1 are juxtaposed at a predetermined interval. It is connected by 2. In order to secure the horizontal rigidity of the upper chord member 1a of each truss 1, 3 is a buckling prevention diagonal member which is provided at each crossing point with the truss 1, the lateral connecting member 2, and the lower chord member 1b and the lateral connecting member 2. From the intersection point O on the upper chord member 1a directly above the intersection point O between the lower chord member 1b and the horizontal joint member 2 to the upper chord member 1a. The two points B ′ and B ′, which are distributed equidistantly, are connected by diagonal members. The connection angle between the upper chord member 1b and the buckling prevention diagonal member 3 is
About 45 degrees is mechanically preferable.

The truss construction structure of the membrane roof of the present invention is constructed as described above, and the truss construction structure is covered with a membrane roof such as a flexible plastic sheet as shown in FIG.
A restraining cable is stretched between the trusses 1 and the slack of the membrane roof that occurs between the trusses 1 is suppressed.

〔The invention's effect〕

As described above, in the truss construction structure of the membrane roof of the present invention, the lower chord members are connected by the horizontal tie members, and the upper chord members are distributed equidistantly on the horizontal tie members from the intersections of the lower chord members and the horizontal tie members. Since two points are connected by a buckling prevention diagonal member that connects two points, that is, the point on the truss upper chord member just above the intersection point of the lower chord member and the horizontal tie member, to the two points on the upper chord member equidistantly, As the distance between the fulcrums of the upper chord becomes shorter and the buckling anti-buckle intersects with the upper chord at an internal angle of 90 degrees or less, the connection with the upper chord becomes close to the rigid frame structure and the membrane of the reinforcement material. The effect is that the rigidity of the truss structure can be remarkably strengthened without contact with the body roof and unobtrusive horizontal members.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention, FIG. 2 is a vertical sectional view showing an example of a conventional truss assembly structure of a membrane roof, and FIG. 3 is a perspective view of the same conventional example. 1 ... Truss, 1a ... Upper chord, 1b ... Lower chord, 2 ... Horizontal tie, 3 ... Buckling prevention diagonal, O ... Intersection of lower chord and horizontal tie, O '... Point on upper chord just above point O, A
…… B ', which is the point that is equidistantly distributed from the O point on the horizontal connecting material
...... The point where the upper chord material is distributed equidistantly from the O'point.

Claims (1)

[Claims] 1. The lower chord members of the trusses which are arranged in parallel are connected by a horizontal tie member, and two points which are distributed equidistantly from the intersection point of the lower chord member and the horizontal tie member, and the lower chord member and the horizontal tie member. The truss structure of the membrane roof, characterized in that the two trusses on the upper chord that are equidistant from the point on the upper chord of the truss just above the intersection with the timber are connected by buckling prevention diagonals.