JPH08105116A - Joint method of truss structure - Google Patents

Abstract

PURPOSE: To prevent the weight increase of a truss structure while transmitting a large shaft force and a bending moment between a frame member and a spherical joint, in order to secure the safety of a structure forming a lattice dome. CONSTITUTION: A set bolt 5 is screwed in a bolt shaft 3 at right angles direction against it through a cap 2 connected to the end of a frame member 1. And the bolt 3 is screwed in the female screw 41 of the spherical joint 4, while being conducted to the spherical joint 4 side by the front end of set bolt 5. Thereafter, in the frame members 1 assembled in the spherical joint 4, the outer periphery of the cap 2 of the frame member 1 loaded with a large shaft force or bending moment is welded with the butt-joint part of the spherical joint 4 to connect the frame member 1 to the spherical joint 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joint method for a truss frame in which a part of frame material connected to a ball joint is rigidly joined to the ball joint.

[0002]

2. Description of the Related Art Among the lattice dome as shown in FIGS. 2 to 5, particularly, in the truss frame structure in which only some nodes located on the outer peripheral portion of the truss frame structure are supported by the lower structure, Since the frame material erected in the section of the nodes supported by the lower structure functions as a beam, the frame material must be rigidly joined to the ball joint in order to bear the bending moment by its own weight.

Further, in the lattice dome shown in FIGS. 6 to 8, in order to secure the safety of the structure, the frame member inside the structure other than the outer peripheral portion and the ball joint may have to be rigidly joined. .

The frame member is usually joined to the ball joint by screwing a bolt inserted in a cap joined to the end of the frame member into the ball joint. Therefore, if the diameter of the bolt is increased, the bending moment is not transmitted. Although it is possible, when tightening the bolt by inserting a wrench from the inside of the ball joint as in Japanese Utility Model No. 5-23681, increasing the diameter of the bolt increases the torque introduced into it. The wrench cannot tighten the bolts sufficiently. Further, as the bolts are expanded, the ball joints are also expanded, which causes an increase in the weight of the truss frame.

Further, in the method of joining the frame member and the ball joint by using the tubular connecting member as in Japanese Utility Model Publication No. 61-37691, the number of members is increased and the workability is deteriorated.

The present invention has been made in view of the above background, and transmits bending moment without depending on bolts.
The joint method that does not increase the weight of the truss frame is proposed.

[0007]

According to the present invention, the bolt inserted into the cap is pulled from the ball joint side with a wrench and screwed into the female thread portion of the ball joint, and the end face of the cap is brought into close contact with the surface of the ball joint. In this state, the cap joint is welded to the ball joint, and the bending moment is directly transmitted from the cap to the ball joint, thereby making it unnecessary to increase the diameter of the bolt and preventing an increase in the weight of the truss frame.

On the cap joined to the end of the frame material, a set screw having a screw tip that meshes with the thread groove of the bolt is screwed vertically to the shaft of the bolt, and the screw tip is hollow in the cap. Butt by pulling the bolt toward the ball joint side by rotating the wrench inserted into the ball joint by holding the bolt in the state where the bolt tip is guided to the ball joint side with the screw tip. Screw it onto the female thread.

After screwing the bolt into the female thread portion of the ball joint,
Among the frame materials joined to the ball joint, the cap of the frame material that bears a large axial force and bending moment and the abutting portion of the ball joint are welded to rigidly join the frame material to the ball joint.

This corresponds to the fact that the diameter of the bolt in the case of bolt connection is greatly increased by welding the cap to the ball joint, and the shaft from the frame material to the ball joint can be obtained without increasing the diameter of the bolt. Forces and bending moments are transmitted. Bolts with or without proof stress,
In some cases, the purpose is simply to assemble the frame material three-dimensionally with high accuracy.

Further, since the cap is directly welded to the ball joint, it is not necessary to install a connecting member and the workability is improved.

[0012]

The present invention relates to a lattice dome shown in FIGS. 2 to 5 in which a frame member 1 which is gathered at nodes located on the outer periphery and bears a large axial force or bending moment is rigidly joined to a ball joint 4. is there. The joint part shown in FIG. 1 is shown in FIGS.
Of the nodes on the outer peripheral portion of the truss frame shown in (4), this corresponds to a node that bears a bending moment and is not supported by the lower structure 6.

A set screw 5 having a screw tip that engages with a screw groove of the bolt 3 is vertically engaged with the shaft of the bolt 3, and the screw tip projects into the hollow portion of the cap 2. For the bolt 3, the screw tip of the set screw 5 is butted against the screw groove of the bolt 3 inserted into the hollow portion of the cap 2, and the wrench 7 is rotated by guiding the bolt 3 to the ball joint 4 side by the screw tip and turning the wrench 7. 4 is screwed into the female screw portion 41.

After the bolt 3 is screwed into the female thread portion 41 of the ball joint 4 to bring the end surface of the cap 2 into close contact with the surface of the ball joint 4, a large axial force or Cap 2 of frame material 1 that bears bending moment
The outer periphery and the periphery of the butted portion of the ball joint 4 are welded to join the frame member 1 to the ball joint 4.

A groove 21 is formed on the outer periphery of the end surface of the cap 2 in order to secure a welding space between the adjacent frame members 1, 1, and the set screw 5 is arranged closer to the frame member 1 than the groove 21. It

When structurally safe by only transmitting the stress by the bolt 3, the cap 2 of the frame material 1 is not welded, but is completed only by joining by the bolt 3.

FIGS. 6 to 8 show that the present invention can be applied to a lattice shell dome such as an HP shell or a thrust type, but in these cases, the safety of the structure is not limited to the outer peripheral portion of the structure. The frame member 1 and the ball joint 3 inside the structure may be rigidly joined to secure the structure.

[0018]

The present invention is as described above. The bolt inserted in the cap is pulled from the ball joint side and screwed into the female thread portion of the ball joint, and the end face of the cap is brought into close contact with the surface of the ball joint. In this condition, if the axial force and bending moment are not sufficiently transmitted, it is a method of joining the frame material to the ball joint by welding around the cap to the ball joint, so it is necessary to increase the diameter of the bolt from the frame material to the ball joint. Axial force and bending moment can be transmitted to the joint. As a result, it is possible to reduce the size of the ball joint as compared with the joint using only bolts, and the weight of the truss frame is not increased.

Further, since the cap is directly welded to the ball joint, it is not necessary to install a connecting material and the workability can be improved.

[Brief description of drawings]

FIG. 1 is a detailed view showing a joint portion of the present invention.

FIG. 2 is a plan view showing a truss frame.

FIG. 3 is an elevational view of FIG.

FIG. 4 is a plan view showing another truss frame.

FIG. 5 is an elevational view of FIG.

FIG. 6 is a schematic diagram showing an HP shell type truss frame.

FIG. 7 is a schematic view showing another HP shell type truss frame.

FIG. 8 is a schematic diagram showing a thrust truss frame.

[Explanation of symbols]

1 ... Frame material, 2 ... Cap, 21 ... Groove, 3 ...
… Bolts, 4 …… Ball joints, 41 …… Female threads, 5 …… Set screws, 6 …… Substructure, 7 …… Wrench.

Claims (1)

[Claims] 1. A lattice dome formed by arranging a frame member between ball joints and screwing a bolt inserted into the frame member into a female thread portion screwed on the ball joint with a wrench. In the cap joined to the end of the frame material, a set screw having a screw tip that meshes with the thread groove of the bolt is screwed vertically to the shaft of the bolt, and the screw tip of this set screw is placed in the hollow portion of the cap. Butt into the thread groove of the bolt inserted from the frame material side, guide the bolt to the ball joint side with the screw tip, screw the bolt into the female thread part of the ball joint, and then , A joint method for a truss frame that welds the cap end of the frame material that bears a large axial force and bending moment, and the abutting part of the ball joint.