JP2889332B2 - Space truss joint structure - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a joint structure for centrally connecting upper and lower chords and diagonal members in a three-dimensional truss for building a bridge or a roof of a building structure.

[Conventional technology]

A building structure such as a large dome is constructed by a three-dimensional truss structure using, for example, a steel pipe or the like as a chord material and an oblique material. The space truss structure is the most efficient construction method in recent years, and is widely adopted from the point of sufficient strength.

Steel pipes are used as chords and diagonals because tensile and compressive stresses act more than bending and shearing on the structure of the space truss, so it is necessary to use buckling-resistant members. is there. And, to use such a steel pipe, the joint that intensively joins each chord material and diagonal material,
It must rely on a pin joint structure using bolts or the like.

However, in actual truss construction work, it often takes considerable time to join the joint body and the chord material due to construction errors. For example, in a general structure in which a sleeve is interposed between a string member and a joint body and a connecting bolt is placed therein, the posture of the bolt is constrained by the sleeve. Struggle to fit female screw holes. In other words, in order for the bolt to be aligned with the female screw hole, the string material itself needs to be in a posture on its axis, and if the string material is long, the work becomes rather complicated. Therefore, the joining work of the string members requires considerable labor and skill, which is one of the factors that hinder improvement in workability.

[Problems to be solved by the invention]

In response to such a problem, the present applicant has filed Japanese Utility Model Application No.
No. 7 proposed a joint structure that allows easy connection between the joint body and the string. In this method, a bolt to be screwed into a joint main body is extrapolated by a sleeve that can move in the axial direction and is integrally rotated, and a feed nut for feeding the bolt is provided. The diameter of the pitch circle of the screw of the feed nut is increased so that the bolt can move freely while swinging the neck, so that the joint between the bolt and the hole on the joint side can be easily performed.

However, although the bolt joining operation is easy, the female thread of the feed nut is biased by the male thread of the bolt, so that the thread is easily cut or crushed. For this reason, if the bolt is screwed in an unreasonable position, the bolt cannot be fed, and replacement of parts is required. Further, since the bolt has a degree of freedom, the alignment between the joint and the string member tends to be loosened, and such a problem of damage to the thread cannot be ignored.

Therefore, an object of the present invention is to make it possible to perform connection work of a joint portion more easily and to perform construction without damaging a bolt on a chord side.

[Means for solving the problem]

The present invention is a joint structure in which a main body of a joint and a truss member are joined by bolts, and a bolt having an axis directed toward the main body is rotatably provided at an end of the truss member, and A feed ring and a sleeve are respectively provided around the bolt between the sleeves, and the sleeve is connected to the bolt so as to be movable in the axial direction and non-rotatably around the axis. It is characterized in that it has an opening with play so that it can swing freely and has an elastic engagement mechanism that is elastically fitted into the valley of the male screw of the bolt.

[Action]

Since the bolt inserted into the sleeve is movable in the axial direction and cannot be rotated in the radial direction, when the sleeve is rotated around the axis from the outside, the bolt also rotates integrally with the sleeve. Further, since the opening of the feed ring into which the bolt is inserted is larger than the outer diameter of the bolt, the bolt faces the body side of the joint with a free direction within a certain range, for example, by setting its axis to a twisted posture. Then, by the elastic engagement mechanism fitted into the valley of the male screw of the bolt, feed is added to the rotation given by the sleeve, and the bolt advances while rotating in the body direction of the joint. At this time, the elastic engagement mechanism moves the engagement point with the male screw according to the posture of the bolt, so that the bolt can take a free posture even in the feed ring.

〔Example〕

FIG. 1 is a partial sectional view of a joint structure showing one embodiment of the present invention.

The body 1 of the joint is provided with a female screw hole 1a whose axis is directed in a predetermined direction, and a high tension bolt 2 screwed into the female screw hole 1a, and a sleeve 3 and a feed ring of the bolt 2 around the bolt. 4 are arranged. Further, a bush 6 through which the bolt 2 is inserted is attached to an end of a truss member 5 such as a steel pipe or the like, which is an upper and lower chord member and a diagonal member.

The bolt 2 has a male screw 2a to be screwed into the female screw hole 1a formed on the distal end side, and a pin 2c is fixed to a peripheral surface between the male screw 2a and the head 2b. The pin 2c is made of a steel bar or the like having a circular cross section, and has a fixed posture that protrudes from the center of the bolt 2 in the radial direction.

The sleeve 3 has a hexagonal shape as shown in the front view of FIG. 2, and has a retaining hole 3a through which the bolt 2 is inserted in the axial direction. The inner diameter of the holding hole 3a is such that the body of the bolt 2 can slide in the axial direction. Also, the holding hole 3a
A groove 3b into which the pin 2c of the bolt 2 is fitted is cut into the inner peripheral wall along the entire length in the axial direction. When the bolt 2 is passed through the sleeve 3, the main body of the bolt 2 is slidably incorporated into the holding hole 3a as shown in FIG. 3 (a sectional view taken along the line II of FIG. 1). As a result, the pin 2c fits into the groove 3b and moves only in the axial direction. Therefore, when a tool is hung on the hexagonal outer periphery of the sleeve 3 and rotated, the bolt 2 rotates integrally since the pin 2c is engaged with the groove 3b.

The bush 6 is assembled such that an opening 6a is opened in the axial direction so that the main body of the bolt 2 can slide, and the head 2b is positioned inside the truss member 5. Therefore, in the actual assembling, it is necessary to pass the bolt 2 through the opening 6a and then attach the pin 2c to a predetermined position.

The feed ring 4 is a circular annular body as shown in the cutaway front view of FIG. 4, and has an opening 4a through which the bolt 2 is inserted in the axial direction, and one female screw hole for attachment in the radial direction.
4b. The inner diameter of the opening 4a is set to be large enough to freely receive the bolt 2 even when the axis is twisted to some extent. When the bolt 2 is rotated by the sleeve 3, an elastic engagement mechanism A for feeding the bolt 2 and screwing it into the female screw hole 1a is fixed to the female screw hole 4b for attachment.

The elastic engagement mechanism A utilizes an elastic plunger mechanism. As shown in an enlarged vertical sectional view of FIG. 5, a sleeve 7 having a thread cut on the outer periphery is screwed into the female screw hole 4b for mounting and a fixing nut 8 is provided. Is fixed by screwing. One end of the sleeve 7 is closed by a bushing 7a, and a feed pin 7b is incorporated so as to be able to protrude and retract from an opening at the other end. The feed pin 7b is urged outward by a coil spring 7c contained in the sleeve 7. Also, feed pin
7b has a shape such that the tip is sharp enough to fit into the valley 2a-1 of the male screw 2a of the bolt 2, and the ridge 2a-2 of the male screw 2a.
The tip is spherical so as not to damage it.

After the sleeve 3 and the feed ring 4 are integrated by passing the bolt 2 through the opening 6 a of the bush 6, the male screw 2 a
Attached separately from the side. Then, the pin 2c of the bolt 2 is fitted in the groove 3b of the sleeve 3 as shown in the lower left diagonal member in FIG. When the bolt 2 is inserted, the feed pin 7b of the feed ring 4 contracts the coil spring 7c and moves outward, so that the feed pin 7b can be easily set.

Boss 2, sleeve 3 and feed ring 4
After the installation, the connection work to the main body 1 is started. This operation is started by setting the posture of the truss member 5 so that the tip of the bolt 2 matches the female screw 1a to be connected, as shown in the lower left diagonal member in FIG. When the sleeve 3 is turned by hand, the bolt 2 is also rotated by the engagement between the pin 2c and the groove 3b. On the other hand, since the feed pin 7b of the feed ring 4 fits into the valley 2a-1 of the male screw 2a, the valley 2a-1 moves so as to be guided by the feed pin 7b, and the bolt 2 is provided with the sleeve 3. Feed is provided in addition to rotation. Therefore, as the sleeve 3 rotates, the bolt 2 advances while rotating into the female screw hole 1a, and the bolt 2 can be screwed and connected to the female screw hole 1a as in the horizontal member in FIG.

Here, since the inside diameter of the opening 4a of the feed ring 4 is such that the posture of the bolt 2 can be freely changed, the bolt 2 moves while acting with play. For such movement,
Since the feed pin 7b is urged by the coil spring 7c, the feed pin 7b moves in and out of the sleeve 7 according to a change in the posture of the bolt 2. For this reason, the directional direction of the tip of the bolt 2 inserted into the feed ring 4 can not only coincide with the axis of the feed ring 4 but also swing within a certain range, and feeding can be given reliably. Therefore, even if the axis of the truss member 5 does not exactly coincide with the female screw hole 1a of the main body 1, the female screw hole 1a receives the change in the posture of the bolt 2 and the joining is easily started.

Next, when the sleeve 3 is further rotated, the bolt 2 advances toward the main body 1, and finally the male screw 2a is screwed into the female screw hole 1a as shown in the horizontal member of FIG. 2b comes into contact with the end face of the bush 6. When the sleeve 3 is further tightened using a tool such as a wrench, the truss member 5 is firmly connected to the main body 1.

In the connection state of the truss constructed in the manner described above, both end surfaces of the sleeve 3 and the feed ring 4 abut on the peripheral surface of the main body 1 and the bush 6, respectively. 2, the main body 1 is directly loaded by the sleeve 3 and the feed nut 4. Therefore, the compression force is effectively absorbed, and the strength of the entire system is improved.

〔The invention's effect〕

According to the present invention, the feed ring for feeding the bolt has play so that the bolt can swing freely, and the elastic engagement mechanism moves the engagement point with the external thread according to the posture of the bolt. The bolts are fed while maintaining the degree of freedom. By swinging the bolt, the bolt can be easily aligned with the female screw hole of the joint at the time of joining with the joint body. Therefore, the degree of freedom of the posture of the truss member with respect to the joint is increased, so that labor can be reduced and workability can be improved. Further, since the male screw of the bolt is elastically hit by the elastic engagement mechanism, the connection with the joint main body can be reliably performed without the wear of the male screw of the bolt.

[Brief description of the drawings]

FIG. 1 is a partial sectional view of a joint portion of a space truss showing one embodiment of the present invention, FIG. 2 is a front view of a sleeve, and FIG.
FIG. 4 is a sectional view taken along line II of FIG. 1, FIG. 4 is a cutaway front view of the feed ring, and FIG. 5 is an enlarged longitudinal sectional view of a main part of the elastic engagement mechanism. 1: Body, 1a: Female screw hole 2: Bolt, 2a: Male screw 2b: Head, 2c: Pin 3: Sleeve, 3a: Holding hole 4: Feed ring, 4b: Female screw hole for mounting 5: Truss member, 6 : Bush 7: Sleeve, 7a: Bushing 7b: Feed pin, 7c: Coil spring 8: Fixed nut, A: Elastic engagement mechanism

Claims (1)

(57) [Claims] 1. A joint structure for joining a main body of a joint and a truss member by bolts, wherein a bolt having an axis directed toward the main body is rotatably provided at an end of the truss member, and the main body and the truss member are connected to each other. A feed ring and a sleeve are respectively provided around the bolt, the sleeve is connected to the bolt so as to be axially movable and non-rotatably around the axis, and the feed ring is larger than the outer diameter of the bolt. A joint structure for a space truss, characterized in that the joint structure has an opening with play so that the head can be swung freely and an elastic engagement mechanism that is elastically fitted into a valley of a male screw of the bolt.