JPH03115631A - Structure for jointing space truss - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a joint structure that centrally connects upper and lower chord members and diagonal members in a three-dimensional truss for constructing bridges, roofs of architectural structures, etc.

[Conventional technology]

Architectural structures such as large domes are constructed with a three-dimensional truss structure using, for example, steel pipes as chord members and diagonal members. The three-dimensional truss structure is the most efficient construction method in recent years, and is widely used because of its sufficient strength.

Steel pipes are used as chord members and diagonal members because tensile stress and compressive stress act on the structure of a space truss to a greater extent than bending and shearing, so the members must be resistant to buckling. be. Since such steel pipes are used, the joints that intensively join each chord member and diagonal member have to have a pin joint structure using bolts or the like.

As a joint used in such a three-dimensional truss,
For example, there is one described in Japanese Patent Publication No. 61-42059. This is a sleeve provided around a bolt that is interposed between the joint body and the string member and connects them. Then, both ends of this sleeve are brought into contact with the string material side and the joint body, and the compressive force applied to the string material is absorbed by acting directly on the joint body,
We are trying to improve the strength of the string material.

[Problem to be solved by the invention]

However, in actual truss construction work, it often takes a considerable amount of time to join the joint body and the string members due to construction errors. For example, in the bolt described in the above publication, the posture of the bolt is restricted by the sleeve, so it is difficult to align the axis with the female threaded hole in the joint body.In other words, the bolt is aligned with the female threaded hole. To let
The string itself needs to be positioned on its axis, and if the string is long, the work becomes quite complicated.

Therefore, the work of joining the string members requires a considerable amount of labor and skill, which is actually one of the reasons for hindering the improvement of workability.

In response to such problems, the applicant has filed Utility Application No. 15453.
We proposed a joint structure using No. 7 that allows easy connection between the joint body and the string material. In this system, a bolt screwed into a joint main body is movable in the axial direction of the joint body and is inserted by a sleeve that rotates integrally with the bolt, and the bolt is screwed into the truss member to such an extent that its axis can swing. By swinging the bolt, it can be easily aligned with the female screw hole of the joint.

In addition to these improvements, devices have already been developed that make it easier to join joints. However, the conventional method combines multiple special members to increase the degree of freedom of joining, and even with the method proposed by the applicant, the joining bolt needs to be a special product with an integrated key. was there. Therefore, although the work of joining the joint portions becomes easier, the cost increases because special products are used.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a joint structure that allows the joint portion to be connected easily and at the same time reduces costs.

[Means to solve the problem]

The present invention provides a joint structure in which a main body of a joint and a truss member are joined by a bolt, and the bolt has a female thread at the joint end of the truss member that is inserted in a loosely-fitting manner with the head of the bolt remaining inside the truss member. A sleeve is provided around the bolt between the bushing and the main body, and a cylindrical ring formed with a male thread that is screwed into the female thread of the bushing is connected by a pin projecting in the radial direction. A keyway is fixed to the circumferential surface of the bolt, and a keyway into which the pin fits is formed in the inner circumferential wall of the sleeve in the axial direction, and a keyway in the radial direction is formed between the male thread of the ring and the female thread of the bushing. It is characterized by being playful.

〔Example〕

FIG. 1 is a partial sectional view of a joint structure showing an embodiment of the present invention, and FIG. 2 is a longitudinal sectional view taken along the line 1--1 in FIG.

The main body 1 of the joint is provided with a female screw hole 1a whose axis is oriented in a predetermined direction, and a high tension bolt 2 is screwed into the female screw hole 1a, and a sleeve 3 is arranged around the bolt. Further, a pusher L into which a bolt 2 is screwed is attached to an end of a truss member 4 such as a steel pipe that serves as an upper and lower chord member and diagonal member.
5 is attached.

Figure 3 shows bolt 2. Sleeve 3. and FIG. 5 is an exploded view of the bushing 5.

The bolt 2 has a ring 6 integrated on the circumferential surface between the male screw 2a screwed into the female screw hole 1a and the head 2b.

As shown in FIG. 4, the ring 6 has a cylindrical shape with a male thread 6a formed on the outer peripheral surface on the side into which the bolt 2 is inserted. Then, the ring 6 is integrated with the bolt 2 by drilling a pin insertion hole 6b into which the pin 7 is driven and driving the pin 7 into the pin hole 2c provided in the bolt 2. By using the ring 6 in this manner, a commercially available bolt 2 can be used, and can be used simply by machining the pin hole 2c.

The bush 5 has an opening 5a in the axial direction that has an inner diameter such that the main body of the bolt 2 is loosely fitted therein and has play.
One end side has a female screw 5 into which the male screw 6a of the ring 6 is screwed.
b is formed. Then, as shown in FIG. 1, the bolt head 2b is located inside the truss member 4, and the ring 6 is assembled so as to be located outside the bushing 5. Therefore, in actual assembly, the bolt 2 is passed through the opening 6a, the ring 6 is fitted from the male screw 2a side, and the ring 6 is fixed to the bolt 2 with the pin 7. The opening 5a has an inner diameter slightly larger than the main body of the bolt 2, and the female thread 5b has a male thread 6 of the ring 6.
It is slightly larger than the diameter of the pitch circle a, so that the bolt 2 has some play in the radial direction when screwed in, so that it can wobble a little. If the male screw 6a is loosely fitted into the female screw 5b, the bolt 2 can be twisted with respect to the axis of the bush 5.

As a result, before the bolt 2 is screwed into the female thread 1a of the main body 1, as shown on the diagonal side in FIG. It can be swayed to some extent.

The sleeve 3 has a hexagonal shape as shown in the sectional view of FIG. 5, and has a holding hole 3a through which the bolt 2 is inserted in the axial direction. The inner diameter of this holding hole 3a is approximately the same as the outer diameter of the ring 6 integrated with the bolt 2, and the ring 6 and the bolt 2 integrated therewith can slide in the axial direction within the sleeve 3.

A keyway 3b into which the pin 7 protruding from the ring 6 is fitted is cut into the inner circumferential wall of the holding hole 3a over the entire length in the axial direction.

These bolts 2. Of the members of the bush 5 and sleeve 3, the bolt 2 and pusher 55 are first fixed to the end of the truss member 4. That is, after passing the bolt 2 through the opening 5a of the bush 5, the ring 6 is fitted into a predetermined position from the opposite side and fixed with the pin 7. Then, the male screw 6a of the ring 6 is screwed all at once into the female screw 5b of the pusher 5 as shown by the diagonal in FIG. Thereafter, the bush 5 with the bolt 2 integrated therein is fixed to the end of the truss member 4 by welding, and the bolt 2 b is attached to the bush 5.
Insert it until it is far away from the edge of the

On the other hand, the sleeve 3 is fitted over the bolt 2 protruding from the bush 5 so that the pin 7 is fitted into the keyway 3b. At this time, the sleeve 3 is freely rotatable, and when the sleeve 3 is rotated, the rotation is transmitted to the bolt 2 by the keyway 3b and the pin 7, and the male of the ring 6 screwed into the female thread 5b of the pusher 5 is rotated. Rotate the screw 6a to feed the bolt 2 against the pusher 55.

Bolt 2 to truss member 4. After attaching the sleeve 3 and the pusher 5, the connection work to the main body 1 is started.

This work begins by setting the attitude of the truss member 5 so that the tip of the bolt 2 matches the female thread 1a to be connected, as in the case of the diagonal member in FIG. When the sleeve 3 is turned by hand, the bolt 2 is also rotated and fed, and the bolt 2 advances into the female threaded hole 1a while rotating, and the bolt 2 is rotated like the horizontal member in Fig. 1. Female screw hole 1
It can be threadedly connected to a.

Here, the pitch circle diameter of the female thread 5b of the bush 5 is larger than that of the male thread 6a of the ring 6, and when screwed together, the bolt 2 behaves with play and can freely change its posture. explained. That is, the orientation direction of the tip of the bolt 2 can be swiveled within a range that does not only coincide with the axis of the bushing 5 at the initial stage when the male thread 2a is fitted into the female thread 1a. Therefore, the truss member 5
Even if the axis of the bolt 2 does not exactly match the female screw hole 1a of the main body 1, the change in the posture of the bolt 2 causes the female screw hole 1a to accept it and start joining easily.

Next, when the sleeve 3 is further rotated, the bolt 2 advances in the direction of the main body 1, and the male thread 6a of the ring 6 separates from the female thread 5b of the bushing 5, and finally the male thread 6a, like the horizontal member in FIG. The screw 2a is screwed into the female screw hole la, and the bolt 2b of the bolt 2 comes into contact with the end surface of the bushing 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 connected state of the truss constructed in the above manner,
Since both end surfaces of the sleeve 3 abut against the circumferential surface of the main body 1 and the pusher 6, the compressive stress applied to the truss member 5 is reduced by the bolt 2. A load is applied directly to the main body 1 by the sleeve 3 and the push-piece 5. Therefore, compressive force is effectively absorbed, and the strength of the entire system is improved.

〔Effect of the invention〕

As explained above, in the present invention, the feed nut that feeds the bolt is held with play so that the bolt can swing freely. This oscillation of the bolt allows the bolt to be easily aligned with the female threaded hole of the joint when joining the joint main body. Therefore, the degree of freedom in the posture of the truss member with respect to the joint is increased, making it possible to reduce labor and improve workability. In addition, the rotation of the sleeve is transmitted using a pin that fits a ring onto the bolt and fixes it.
It is sufficient to simply drill a pin hole for fixing the pin in a commercially available bolt, and there is no need to make a special product such as integrating a key as in the past.

[Brief explanation of drawings]

Fig. 1 is a partial sectional view of a joint portion of a space truss showing an embodiment of the present invention, Fig. 2 is a longitudinal sectional view taken along line 1-1 in Fig. 1, and Fig. 3 shows a bolt bush and sleeve. FIG. 4 is an exploded view, FIG. 4 is a view showing how the ring is fixed to the bolt, and FIG. 5 is a longitudinal sectional view of the bushing viewed in the axial direction. l: Body 1a; Female screw hole 2: Bolt 2a: Male screw 2b: Head 2c: Pin hole 3 Ni sleeve 3a: Retaining hole 3b: Keyway 4 Nidras member 5: Push 5 5a: Opening 5b; Female screw 6; Ring 6a : Male screw 6b: Pin insertion hole 7: Pin

Claims (1)

[Claims] 1. A joint structure in which the main body of the joint and a truss member are joined by bolts, and the joint end of the truss member has a female thread that allows the bolt to loosely insert into the truss member with its head remaining inside the truss member. A bush is provided, a sleeve is provided around the bolt between the bush and the main body, and a cylindrical ring having a male thread that engages with the female thread of the bush is attached to the bolt by a pin protruding in the radial direction. a key groove into which the pin fits is formed in the axial direction on the inner circumferential wall of the sleeve, and play is provided in the radial direction between the male thread of the ring and the female thread of the bush. A three-dimensional truss joint structure characterized by having