JPH0527731B2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a ball joint for a space truss.

[Prior art]

Conventionally, ball joints have been widely used for space trusses constructed from closed cross-section members such as circular or square cross-sections because they have no directionality. The connection can be made by screwing a connecting bolt into the connecting member, or by screwing the male threaded portions at both ends of the connecting bolt into both the sphere and the connecting member.

[Problems to be Solved by the Invention] However, according to the former method, in a ball joint having such a configuration, the connecting bolt must be attached from the inside of the sphere, and therefore the sphere must be formed to be larger and thicker. Not only is it extremely troublesome to manufacture, but it also has the disadvantage of being significantly heavy, making it difficult to handle, and resulting in an unavoidable decline in workability.

On the other hand, according to the latter method, the connecting bolt, the sphere, and the connecting member are all connected by a screw type, so there is a drawback that it is almost impossible to adjust the angular error of the connecting member due to construction errors. It was necessary to pay close attention to.

This invention was proposed in order to solve the above-mentioned conventional problems, and aims to provide a three-dimensional truss ball joint that can improve workability and be economical.

[Means for solving problems]

In this invention, a plurality of screw holes are provided in the sphere toward its center, end metal fittings are provided at the ends of the connecting member, and a through hole is provided in the center of the connecting member to penetrate in the longitudinal direction of the connecting member. A connecting bolt having a bolt head one size larger than the through hole and a continuous groove on the surface of the threaded portion in the axial direction is inserted into the through hole from the inside of the connecting member, and the threaded portion of the connecting bolt is rotated. inserting the material, screwing a nut onto the threaded part on the outside of the rotating material, screwing a set screw into the rotating material toward the groove of the connecting bolt, and rotating the rotating material while holding the nut. Screw the connecting bolt into the screw hole of the sphere, and with the bolt head of the connecting bolt in contact with the end hardware, rotate the nut toward the end hardware to compress the bolt head, end hardware, and rotating material. The purpose of achieving the above objective is to prevent the bolt from rattling by making the bolts adhere tightly.

〔Example〕

The present invention will be described below with reference to an illustrative embodiment. A joint of a three-dimensional truss is composed of a sphere 1, a connecting member 2, an end metal fitting 3, a connecting bolt 4, a rotating member 5, a nut 6, etc. has been done.

The sphere 1 is formed hollow by forging or the like, and a plurality of screw holes 7 are formed at predetermined positions toward the center of the sphere 1 according to the mounting direction of the connecting member 2, and the tips thereof reach the hollow part. There is.

Further, a large hole 8 is formed in one side of the sphere 1 and is continuous with the hollow part, and the tips of each screw hole 7 can be confirmed through this large hole 8.

The connecting member 2 is formed of a steel pipe with a hollow closed cross section, which is circular or square in cross section, and end metal fittings 3, 3 are attached to both ends thereof.

The end hardware 3 is formed into a substantially truncated conical shape by forging or the like, and has a recess 9 of a predetermined diameter and a predetermined depth formed on the back side, and a through hole one size smaller than the bolt head 4a of the connecting bolt 4 on the front side. 10 are formed. The through hole 10 is connected to the recess 9.

The end hardware 3 formed in this way is connected to the connecting member 2.
It is attached by welding to both ends of the

The connecting bolt 4 is inserted into the through hole 10 of the end metal fitting 3 from the inside side of the connecting member 2, that is, from the recess 9 side, and the male threaded portion 4b completely passes through the through hole 10 and is completely removed from the through hole 10. It stands out. Further, the bolt head 4a of the connecting bolt 4 touches the peripheral edge of the through hole 10, so that it does not come out to the front side. A groove portion 4c is formed continuously in the longitudinal direction on the surface of the male threaded portion 4b of the connecting bolt 4. Further, the rotating member 5 is inserted into the male threaded portion 4b of the connecting bolt 4, and the rotating member 5 is inserted on the tip side of the male threaded portion 4b, that is, the rotating member 5
A nut 6 is screwed into the external male threaded portion 4b, and the tip of the male threaded portion 4b is screwed into the screw hole 7 of the sphere 1, thereby connecting the sphere 1 and the connecting member 2.

A radial screw hole 5a is formed in the rotating member 5, and a set screw 11 is screwed into the screw hole 5a.

The tip of the set screw 11 fits into the groove 4 of the connecting bolt 4.
c, thereby preventing rotation of the rotating member 5 and making it possible to fix it at a predetermined position in the longitudinal direction of the male threaded portion 4b.

In this configuration, the assembly of the three-dimensional truss will be described. First, the connecting member 2, which has the end hardware 3, the connecting bolt 4, the rotating member 5, and the nut 6 attached to both ends, is installed between the spheres 1 and 1.

Next, attach the male threaded portion 4b of the connecting bolt 4 to the sphere 1.
while holding down the nut 6, rotate the rotating member 5. As a result, since the rotation of the rotating member 5 is prevented by the set screw 11, the connecting bolt 4 rotates together with the rotating member 5, and the male threaded portion 4b of the connecting bolt 4 is screwed into the screw hole 7 of the sphere 1.
The sphere 1 and the member 2 are connected. Note that the screw engagement between the male threaded portion 4b of the connecting bolt 4 and the screw hole 7 of the spherical body 1 shall be confirmed through the large hole 8 of the spherical body 1.

〔Effect of the invention〕

Since the present invention has the above configuration, it has the following effects.

The connecting bolt is not attached to the sphere from inside,
Since they are screwed together from the connecting member side, there is no need to attach bolts inside the sphere, making it possible to significantly reduce the size of the sphere, and thereby reduce the weight of the sphere and save material, thereby reducing production costs.

Furthermore, workability can be improved by reducing the weight of the sphere.

In addition, since the connecting bolt is passed through the through hole of the end hardware at the end of the connecting member, if the through hole is made slightly larger, a universal connection can be made between the connecting member and the sphere. , the angular error of the member can be easily absorbed.

In addition, by rotating the nut toward the end hardware while the bolt head of the connecting bolt is in contact with the end hardware, the bolt head, end hardware, and rotating material can be compressed into tight contact, preventing the bolt from rattling. can do.

[Brief explanation of drawings]

1 to 4 show an embodiment of the present invention, and FIG. 1 is a perspective view of a three-dimensional truss structure;
FIG. 2 is a partially cutaway side view showing the state of the joint between the sphere and the member, and FIGS. 3 and 4 are partially broken side views showing the state of the joint between the sphere and the member. 1... Sphere, 2... Connecting member, 3... End hardware, 4... Connecting bolt, 5... Rotating member, 6... Nut, 7... Screw hole, 8... Large hole, 9... recess,
10...Through hole, 11...Set screw.

Claims (1)

[Claims] 1 A plurality of screw holes are provided in the sphere toward its center, and end metal fittings are provided at the ends of the connecting member, and a through hole is provided in the center of the sphere that penetrates in the longitudinal direction of the connecting member. A connecting bolt having a bolt head one size larger than the through hole and a continuous groove on the surface of the threaded portion in the axial direction is inserted from the inside of the connecting member, and a rotating material is inserted into the threaded portion of the connecting bolt. inserting the nut into the threaded part on the outside of the rotating member, and threading a set screw into the rotating member toward the groove of the connecting bolt;
A ball joint for a three-dimensional truss, characterized in that the connection bolt is screwed into a screw hole of the sphere.