JPH0693654A - Double steel pipe truss structure service structural material and joint method thereof - Google Patents

Abstract

PURPOSE:To adopt a double pipe whose cross section outside dimensions are small to a location to which a large load of a truss steel structure exerts and to increase and stabilize plastic deformation of an outer pipe. CONSTITUTION:On both sides of a connection bolt 26, there are installed a connection male screw 26a which is threaded into a screw hole of a contact material and a connection male screw 26b which is threaded into a screw hole 25a of an end material mounted to an outer pipe of a double pipe and which is reversely spiraled at the same pitch with the connection screw 26a. A steel pipe structural member 23 and a bending resistant steel pipe 24 to be inserted thereinto are fixed at the central part in the longitudinal direction and the tip of the bending resistant steel pipe 24 is inserted between an outer peripheral surface 25c of a guide 25B of the end member 25 and an inner peripheral surface 23a of the steel pipe structural member 23. There is formed a guide a space 28 whose dimensions are longer than 1/2 of a bucking allowable length L33 which allows the end of the bending steel pipe 24 to be deformable relatively when the steel pipe structural member 23 is subjected to buckling between an end face 24a of the bending resistant steel pipe 24 and a rear side 25b of a cover 25A.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structural member for a double steel pipe type truss structure and a joining method thereof, and more specifically, a plurality of members applied to a truss steel structure such as a large span structure or a tower structure. The long steel pipe structural member of the above, a structural material capable of easily and firmly joining the end member to the node member, the joining method thereof, and when assembling a truss using a large number of structural materials. The present invention relates to a truss construction method suitable for.

[0002]

2. Description of the Related Art When a large span structure or tower-like structure is constructed by using a large number of structural members such as long steel pipes, the end of each structural member is joined to a node member to form a truss. Often structured. Then, in order to radially join some structural members to one node member forming a polyhedron, a joining bolt that is displaceable in the axial direction of the structural member is used. Japanese Patent Laid-Open No. 63-51539, Japanese Utility Model Laid-Open No. 2-
There is a joining device proposed in Japanese Patent No. 18003 and Japanese Utility Model Laid-Open No. 2-125102. Each of these has a joining bolt and a sleeve body as main components, and engages with the outer surface of a boss portion having a cross section larger than the diameter of the threaded portion formed on the joining bolt to transmit a rotational force, and the joining bolt. With the rotation of the sleeve body that allows axial displacement of the joint member, the joint bolt mounted on the end of the structural member can be fed into the screw hole formed in the node member.

All of the above-mentioned joining devices that have been proposed so far have a structure applied when a thin pipe such as a steel pipe is adopted as a structural member. On the other hand, in a truss structure, it is well known that the axial load acting on each structural member is large and small, and in particular, a very large force acts on the columnar portion of the tower-shaped structure. Therefore, if only thin-walled steel pipes are adopted as structural members,
A large-diameter joining bolt is required for a structural member that exerts a large axial load, and accordingly, a large-diameter steel pipe must be used. In that case, the thickness of the structural members in the truss structure will be significantly uneven and the appearance will be impaired, and when joining several structural members radially to one node member, a large joining device will be necessary to attach other joining devices. The situation occurs such as blocking. By the way, if a structural member such as a rod or a thick-walled pipe having a solid cross section is adopted as the structural member having a proof stress equivalent to that of a large-diameter steel pipe, the cross-sectional size can be reduced. However, there are almost no examples of adopting a joining device including a joining bolt that is displaceable in the axial direction of a structural member in order to join a structural member using a solid material or a thick-walled pipe to a node member. . This is because a compact joining device capable of balancing the extremely large cross-sectional proof strength of a structural member such as a solid material has not been developed. Therefore, normally, the bolts are welded to the ends of the solid material in advance, and the bolts are transported to a high place where a truss is constructed. However, in a large truss structure that requires the input of a large amount of structural members, in order to join the bolt-welded structural members to the node members located at the ends of the other structural members that are assembled one after another, The member itself must be rotated, and there is a drawback that incorporating a solid material, a thick-walled tube, or the like is a very complicated and large-scale work.

On the other hand, the applicant of the present invention has filed in Japanese Patent Laid-Open No. 14934/1992.
In Japanese Patent No. 5 publication, a double tube type structural member for truss was proposed. This is because it is possible to suppress the bending of a long steel pipe structural member and greatly increase the buckling deformation, and to allow a large axial shortening only for the desired steel pipe structural member among the steel pipe structural members constituting the truss steel structure. It is possible to do. According to this structural member, even if a steel pipe structural member receives a large axial load during a large-scale earthquake, the large truss structure can be prevented from being suddenly collapsed due to the large plastic deformation and the total strength of the double pipe. Can be demonstrated. As shown in FIG. 19, the structural member 50 includes a steel pipe structural member 51 such as a thin-walled pipe and a bending resistance steel pipe 52 fitted and inserted therein.
And an end member 54 having a screw hole mechanism 53 for closing the end opening of the steel pipe structural member 51, a joining device 56 including a joining bolt 55 attached to the screw hole mechanism 53, and the like. The structural member 50 can be joined to the nodal member 57 via the interposition member. The bending resistance steel pipe 52 is provided with an outer diameter that minimizes the clearance between the bending resistance steel pipe 52 and the inner peripheral surface of the steel pipe structural member 51, and is allowed by design when the steel pipe structural member 51 is plastically deformed in the axial direction. It is shortened at both ends by half the predetermined allowable buckling length β.

According to such a structure, when the structural member 50 receives a large axial compressive force P, the steel pipe structural member 51 yields without being influenced by the bending resistance steel pipe 52, and the buckling allowable length β is reached. It can be shortened and a large axial deformation of the structural material 50 is realized. Even if a bending force acts during the deformation, the bending resistant steel pipe 52 supplements the bending rigidity of the steel pipe structural member 51. If the steel pipe structural member 51 is shortened by the buckling allowable length β, the end surface 52a of the bending resistance steel pipe 52 will be the end member 5
The axial compressive force P that is in contact with the back surface 54a of No. 4 and acts on the structural member 50 is opposed by the sum of the respective proof stresses of the steel pipe structural member 51 and the bending resistance steel pipe 52, and the subsequent progress of plastic deformation is moderate. can do. If the buckling allowable length β is secured in the steel pipe structural member 51 described above, the desired axial plastic deformation of the structural material 50 can be achieved, but
Steel pipe structural member 5 with half the allowable buckling length β secured
At both ends of No. 1, portions where the bending resistant steel pipe 52 does not exist remain. That is, the portion between the end surface 52a of the bending resistance steel pipe 52 and the back surface 54a of the end member 54 is the steel pipe structural member 5
However, there is a problem that the plastic deformation after yielding of the steel pipe structural member 51 in that portion is not always axisymmetric and is likely to be unstable because the steel pipe structural member 51 is not reinforced by the bending resistance steel pipe 52. In that case, as indicated by the solid line A in FIG. 20, the proof stress immediately after plastic deformation sharply decreases, and thereafter, the compressive force is opposed by the total proof stress of the steel pipe structural member 51 and the bending resistance steel pipe 52. Can't do it.

For example, Japanese Unexamined Patent Publication No. 56-25549 discloses a structure in which a double tube is used and an inner tube is displaceable with respect to an outer tube. The inner pipe of this structural member exerts bending resistance during plastic deformation of the outer pipe, and one end face of the inner pipe abuts the back face of the end member that closes the end opening of the outer pipe. The compressive load can be resisted by the proof stress of the pipe. However, the other end of the inner pipe is fixed to the end member that closes the other end of the outer pipe, and plastic deformation after yielding of the outer pipe that is not affected by the inner pipe is possible only on the one side. Has become. That is, as a result of the above-mentioned allowable buckling length being given to only one side of the structural member, the portion of one end of the outer pipe that is not reinforced by the inner pipe becomes longer, and a large amount of plastic deformation is given to the outer pipe. Then, there is a problem that the unstable deformation as described above is further promoted. In order to avoid this, the structural member is made into a triple pipe, one end of the first inner pipe is fixed to one end member, and the other end of the second inner pipe fitted into the first inner pipe is connected to the other end. A complicated structure such as fixing to a member is inevitable. This increases the weight of the structural member and limits its use.
If the two inner pipes are made thinner to reduce the weight, the rigidity and compression strength of each inner pipe will be reduced, and the reinforcement of the outer pipe against bending in the part where the inner pipe is not doubled will be significantly reduced. There are drawbacks. By the way, when trying to exert the proof stress of the double steel pipe type structural member to the single steel pipe type structural member,
The diameter of the single steel pipe type structural member becomes significantly large. Therefore, when the double steel pipe type structural member is realized, the outer diameter thereof can be reduced. On the other hand, a joining device suitable for joining the structural member of the double pipe to the nodal member has not yet been proposed. Even if an attempt is made to adopt a double steel pipe type structural member in a truss structure where a large load acts, if it is not possible to join it to the node member joining the single steel pipe type structural member, the load sharing It becomes impossible to arrange several structural members radially on one node member.

The present invention has been made in view of the above problems, and an object thereof is a double steel pipe type in which the outer diameter dimension is smaller than that of a single pipe, the plastic deformation amount is large, and the proof stress can be increased. The structural materials of 1) can be used in truss structures together with other single steel pipe type structural members, etc., and the unevenness of the thickness of many structural members that make up the truss structure can be reduced to improve the appearance. Proposal of a compact joining device for double steel pipe type structural material, which is inevitable when using double steel pipe type structural material A structural material for a double steel pipe truss structure that realizes stabilization of plastic deformation after yielding, that it is possible to increase the bending resistance while avoiding duplication in the structural material, and Joining method, as well, to provide a truss construction method in large-span structure or tower-like structure or the like.

[0008]

According to the present invention, a joining bolt for connecting an end portion of a steel pipe structural member to a nodal point member is attached to an outer surface of a boss portion having a cross section larger than a diameter of a screw portion formed on the joining bolt. By rotating the sleeve body that enables the joint bolt to transmit the rotational force and axially displaces the joining bolt, it can be fed into the screw hole formed in the node member, and the steel pipe structural member A bending resistance steel pipe that is shorter than the steel pipe structural member is inserted into the steel pipe structural member so that the axial compressive force acting on is not immediately transmitted.
The outer diameter of the bending-resistant steel pipe is selected so that its outer surface faces the inner peripheral surface of the steel pipe structural member with a gap as small as possible, and the axial compressive force acts on the steel pipe structural member to deform the steel pipe structural member. Applied to double steel pipe type structural members for truss steel structures, in which the bending resistance steel pipe can prevent the steel pipe structural members from bending in the direction perpendicular to the axis of the steel pipe structure. To be done. The feature is that, with reference to FIG. 1, the end member 25, which is attached to the end portion of the steel pipe structural member 23 and has a screw hole 25a extending in the direction of the axis 25m, abuts on the end surface of the steel pipe structural member 23. Cover 2 for covering the opening 23b of the steel pipe structural member 23
5A and a guide portion 25B having an outer diameter smaller than that of the cover portion 25A and continuing to the back surface 25b of the cover portion 25A and protruding into the steel pipe structural member 23. Joining bolt 26
The node member 21 (see FIG. 2) is provided on one side of the boss portion 26A.
A male screw 26a for joining that meshes with the screw hole 21a of the end member 25 is formed on the other side.
A connecting male screw 26b is formed in a. The connecting male screw 26a is formed in a reverse spiral having the same pitch as the meshing male screw 26a. The joining male screw 26b has a threaded portion having a screw-in length L ₁ necessary for meshing with the screw hole 21a of the node member 21, while the connecting male screw 26b has a screw thread provided on the end member 25. Screw-in length L required for engagement with hole 25a
₂ threads are secured. Length L of sleeve 27
_S is the total length L of the joining bolt 26 and the joining male screw 26a
Is set longer than the size obtained by subtracting the total length L _{11 of the above} and the total length L ₂₂ of the connecting male screw 26b. The bending resistance steel pipe 24 inserted into the steel pipe structural member 23 is fixed at the central portion in the direction of the axis 24m thereof at the central portion in the direction of the axis 23m of the steel pipe structural member 23 (see welding point 32 in FIG. 2). . Between the outer peripheral surface 25c of the guide portion 25B and the inner peripheral surface 23a of the steel pipe structural member 23, the bending resistance steel pipe 2
Bend resistance steel pipe 24
Between the end surface 24a of the and the back surface 25b of the cover portion 25A,
When the steel pipe structural member 23 is buckled, the end portion of the bending resistant steel pipe 24 can be relatively displaced toward the back surface 25b of the cover portion 25A. A displacement gap longer than 1/2 of the allowable buckling length L _33. The guide space 28 in which 29 is secured is formed.
Also, as shown in FIG. 5, 1/2 of the allowable buckling length L ₃₃
And a designed allowable tensile displacement amount δ _{t at} which one end surface 24a of the bending resistant steel pipe 24 is relatively separated from the cover portion side when the steel pipe structural member 23 receives an axial tensile force, The length L ₆₆ subtracted from the total length L _{t of the} space 28 is set to 1 to 4 times the inner diameter D ₂₄ of the bending resistance steel pipe 24. Returning to FIG. 1, the sleeve body 27 engaged with the outer surface of the boss portion 26A is prevented from falling off at a portion of the boss portion 26A near the male screw 26a for joining, and the steel pipe structural member 23 is joined to the nodal member 21. For this purpose, it is advisable to attach a fall-off prevention member 30 that can be broken or easily removed when the joining bolt 26 is rotated.

In the joining method, as shown in FIG.
First, the connection male thread 26b, of approximately equal length L ₃ minutes only the end member 25 to the length obtained by subtracting the threaded length L ₁ of the joining external thread 26a from its entire length L ₂₂ screw holes 25a
Engage in advance. Next, the joint bolt 26 is slidably displaced by the rotation of the sleeve body 27 while being rotated, and the joining male screw 26a is fed into the screw hole 21a of the node member 21 and the connecting male screw 26b is fitted into the screw hole 25a of the end member 25. Send in (see FIG. 7). Sleeve body 27
One end 27a (see FIG. 8) is the joint surface 2 of the node member 21.
When the other end 27b comes into contact with the outer end surface 25p of the end member 25, the additional tightening is performed. In the invention of the truss construction method, the joining device 2
The double steel pipe type structural material 22 with the
To join. After the distance between the cores of the node members 21 and 21 is determined, the rotational force is generated by engaging with the outer surface of the boss portion 37A having a cross-sectional outer shape larger than the diameter of the screw portion 37a formed in the joining bolt 37 (see, for example, FIG. 12). The sleeve body 34 that transmits the force and enables the joint bolt 37 to be displaced in the axial direction.
And the joint bolt 37 can be retracted to the structural member 35 side and retracted into the sleeve body 34 (see FIG. 13).
After that, by the joining device 36 that can advance the joining bolt 37 from the sleeve body 34,
That is, the single steel pipe type structural member 35 is sequentially joined between the two.

[0010]

First, the bending resistance steel pipe 24 shorter than the steel pipe structural member 23 is inserted into the steel pipe structural member 23, and the central portion of the bending resistance steel pipe 24 and the central portion of the steel pipe structural member 23 are fixed (see FIG. 2). ), The bending resistance steel pipe 24 is the steel pipe structural member 2
Keep it stationary in 3. Then, the end member 25 is attached to the steel pipe structural member 23 so that the guide portion 25B covers the opening 23b of the steel pipe structural member 23.
As a result, a guide space 28 is formed between the outer peripheral surface 25c of the guide portion 25B and the inner peripheral surface 23a of the steel pipe structural member 23, and the tip end portion of the bending resistance steel pipe 24 is the guide space 28.
Is inserted and placed. At this time, the displacement gap 2 which is slightly longer than 1/2 of the allowable buckling length L ₃₃ , which is predetermined in design, between the end surface 24a of the bending resistance steel pipe 24 and the cover portion 25A.
9 is secured. Next, the connecting male screw 26b of the joining bolt 26 is inserted into the screw hole 25a provided in the end member 25, and the connecting male screw 26b has a length obtained by subtracting the screw-in length L ₁ of the joining male screw 26a from the total length L ₂₂ thereof. The length L ₃ substantially equal to the length is engaged with the screw hole 25a.
The sleeve body 27 is fitted to the boss portion 26A of the joining bolt 26 (see FIG. 6), and the double steel pipe type structural material 22 is attached to the node member 21.
And the male screw 26a for joining the joining bolt 26 is exposed to the screw hole 21a of the node member 21. The connecting male screw 26b is a reverse screw having the same pitch as the joining male screw 26a, and when the sleeve body 27 is rotated (see FIG. 7), the joining male screw 26a is fed into the node member 21 and at the same time, the connecting male screw 26b is also The same amount is fed into the screw hole 25a of the end member 25. Since the connecting male screw 26b is inserted into the screw hole 25a by a length L ₃ in advance, the sleeve body 27 is rotated and the connecting male screw 26a is screwed into the screw hole 2a.
When the screwing length L ₁ required for engagement with 1a is inserted, the connecting male screw 26b also achieves the screwing length L ₂ required for engagement with the screw hole 25a (see FIG. 8). The length L _s of the sleeve body 27 is from the total length L of the connecting bolt 26 to the total length L ₁₁ of the connecting male screw 26a and the connecting male screw 26b.
Is longer than the total length L _{22 of} the joining male screw 26a, the joining male screw 26a has a screwing length L ₁ of the joining male screw 26a.
When a also reaches the screwed length L ₂ , the sleeve body 2
Both ends 27a and 27b of 7 are the node member 21 and the end member 2
Abut 5. If the sleeve body 27 is further tightened in this state, a joined state with sufficient joining strength is realized even if a large axial force acts.

When a compressive load is applied to the double steel pipe type structural member 22 which is joined to the truss structure by joining as described above, the compressive force transmitted from the node member 2 is connected from the joining male screw 26a. It is transmitted to the steel pipe structural member 23 via the external male screw 26b. Even if bending is going to occur at that time,
The steel pipe structural member 23 is reinforced by the bending-resistant steel pipe 24 and does not easily bend. If the axial compressive force is large, the steel pipe structural member 23 will yield and start plastic deformation.
However, the tip portion of the bending resistant steel pipe 24 is inserted into the guide space 28 (see FIG. 1), and the end face 24 thereof is
Since the guide portion 25B of the end member 24 is also located between a and the back surface 25b of the cover portion 25A, the buckling deformation of the steel pipe structural member 23 is an axially symmetrical shape in which the steel pipe structural member 23 bulges outward near the end member 25. It is stable and stable (see Fig. 4). Due to the buckling of the steel pipe structural member 23, the end portion 24a of the bending resistant steel pipe 24 is relatively displaced in the guide space 28 with respect to the steel pipe structural member 23, and the steel pipe structural member 23 has an allowable buckling length L _33.
When the length is shortened, the end surface 24a of the bending resistance steel pipe 24 contacts the back surface 25a of the end member 25. At this point, the buckling of the steel pipe structural member 23 stops, and the buckling resistance of the steel pipe structural member 23 and the bending resistant steel pipe 24 opposes the axial compression force. Since the opposing force is larger than that of the steel pipe structural member 23 alone, the double steel pipe type structural member 22 is gently deformed by the subsequent compressive force.

When a tensile load is applied to the double steel pipe type structural material 22, the tensile force does not reach the bending resistance steel pipe 24, and when a tensile force of a design allowable level is applied, An elongation of the allowable tensile displacement amount δ _t (see FIG. 5) occurs on one side of the steel pipe structural member 23. As a result, bending the end surface 24a of the resistance steel pipe 24 is excessively separated by the displacement amount [delta] _t to the opposite cover portion. However, at that time, the sum of half the allowable tensile displacement [delta] _t of buckling allowable length L _33, the length L ₆₆ minus the total length L _t of the guide space 28, the bending resistance steel tube 24 If 1 to 4 times the inner diameter D ₂₄ is secured, even if a compressive load acts immediately after a tensile load acts on the double steel pipe type structural material 22 to cause compressive yield, the end portion of the steel pipe structural member 23 The buckling deformation that occurs in is kept axisymmetric, and becomes stable with the same behavior as when the compressive load is first applied. By the way, if the fall prevention member 30 (see FIG. 1) is attached to the boss portion 26A near the joining male screw 26a, the double steel pipe type structural member 22 is transported to the position of the node member 21 during truss construction. It is possible to prevent the sleeve body 27 engaged with the outer surface 26m of the boss portion 26A from falling off. The fall prevention member 30
When the joining bolt 26 is rotated to join the structural member 22 to the node member 21, the joining bolt 26 is broken due to relative movement with the sleeve body 27, or can be easily removed by hand, which hinders joining work. It won't come.

In the truss construction method, the joining device 20 is used.
When the double-steel pipe type structural material 22 having the above is sequentially joined to the nodal members 21 (see FIG. 11), the inter-center distance between the nodal members 21 and 21 is determined. After that, the joining bolt 37 (see FIG. 12) can be retracted to the structural member 35 side and retracted into the sleeve body 34, and thereafter, the joining bolt 37 can be advanced from the sleeve body 34 by the joining device 36. The structural member 35 is sequentially joined between the node members 21 and 21. The cross-sectional external dimensions of the double steel pipe type structural material 22 are
It is significantly smaller than the case where a single pipe for exerting equivalent yield strength is adopted, and unevenness in thickness with the structural member 35 applied to a portion in the truss structure where a large load does not act is suppressed. In addition, the double steel pipe type structural material 22 can be joined to the nodal member 21 by the compact joining device 20, and even when joining to one nodal member 21 together with many other single steel pipe type structural members 35, the joining device It becomes easier to avoid mutual interference.

[0014]

According to the present invention, the joining male screw for joining the nodal member is formed on one side of the boss portion of the joining bolt, and the connecting male screw for connecting to the end member of the end portion of the steel pipe structural member is formed on the other side. Therefore, a double steel pipe type structural material that replaces the thick steel pipe can be adopted for a truss steel structure such as a large span structure or a tower structure. As a result, the work of welding the bolts, which is required when using a solid material or the like, becomes unnecessary, and the manufacturing of the structural member is simplified. Also, the joining device can be made compact. In the truss assembling work, it is not necessary to rotate a long and heavy structural member, which facilitates the joining work. In addition, by using the sleeve body, it is possible to simultaneously feed the male threads for joining and the male threads for connection of the reverse thread configuration to the node member and the end member, so the tightening by the sleeve body will be even more precise and a large tightening will be possible. It is possible to form a highly rigid joint portion to which torque is applied. If it becomes possible to use double steel pipe type structural material, the diameter will be reduced by the member with large cross-sectional strength, and the thickness will be the same as that of a single pipe that is joined to other places where large load does not act. The truss can be configured with and its appearance will be significantly improved. Even if the double steel pipe type structural material receives a compressive load, it is reinforced by the bending resistance steel pipe and the bending rigidity is increased, so that a bending behavior is less likely to occur. The buckling deformation that occurs after the steel pipe structural member yields due to the compressive force is stable because the steel pipe structural member is constrained by the bending resistance steel pipe and the guide portion of the end member, and becomes an axially symmetric shape that bulges outward. When the end surface of the bending-resistant steel pipe comes into contact with the back surface of the cover part of the end member, the buckling of the steel pipe structural member stops, and the axial compressive force can be countered by the proof strength of the steel pipe structural member and the proof stress of the bending-resistant steel pipe. The deformation of the structural material becomes gentle with respect to the subsequent compressive force. Therefore, a sudden collapse of the truss structure is avoided, people inside the building become aware of the danger at the time of the first major deformation and allow time to escape to the outdoors during the subsequent gentle deformation. It Even if the posture of the structural material is not horizontal while transporting the double steel pipe type structural material to the predetermined position of the truss structure under construction, by attaching the fall prevention member to the part of the boss near the external thread for joining. The sleeve body engaged with the outer surface of the boss does not have to be dropped. When the sleeve body is rotated to relatively displace the joining bolts in order to join the double steel pipe type structural material to the nodal point member, the fall prevention member is easily broken, and it can be easily removed manually. Therefore, the smoothing of the joining work is promoted.

According to the invention of the joining method, the double steel pipe type structural material can be joined to the nodal member quickly and reliably,
In addition, the sleeve body can be tightened to achieve a strong joint. In the truss construction method, double steel pipe type structural materials are sequentially joined to the nodal members by the joining device, and after the intercenter distance of the nodal members is determined, the joint bolts are retracted into the sleeve body and advanced out of the sleeve body. If a single pipe, which is applied to a place where a large load does not act, is joined between the nodal members using a joining device that can be used, it is possible to increase the thickness of structural members in a truss steel structure such as a large span structure or tower structure. It's relatively easy to align and looks good. Not only that,
The joining device has also been made compact, and mutual interference of the joining devices when joining multiple double steel pipe type structural materials and single steel pipe type structural members to one node member is avoided, and the desired number of structural members is provided. You will be able to arrange.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A structural material for a double steel pipe type truss structure and a joining method using the same according to the present invention will be described below in detail with reference to the drawings. FIG. 2 is an overall view of joining one double steel pipe type structural member 22 between two node members 21 and 21 using the joining devices 20 and 20. Each of the joining devices 20 is provided with a joining bolt 26, which will be described in detail later, and is provided with a boss portion having a hexagonal cross-sectional outer shape larger than the diameter of the threaded portion itself at both ends. ing. Then, the joint bolt 26 is engaged with the outer surface thereof to transmit the rotational force, and the joint bolt 26 is engaged with the screw hole 21a formed in the nodal member 21 by the rotation of the sleeve body 27 which enables the joint bolt 26 to be displaced in the axial direction. In addition, the double steel pipe type structural material 22 can be firmly joined to the node member 21. The above-mentioned structural material 22 is a double steel pipe structure as described below, and the nodal member 21 that joins it has, for example, joint surfaces 21p and 21p formed at four peripheral positions and front and rear surfaces,
It is a polyhedron capable of radially joining some structural members 22.

FIG. 1 is a longitudinal sectional view on one side of a structural member 22 including a joining device 20, wherein a steel pipe structural member 23 as an outer pipe and a bending resistance steel pipe 24 as an inner pipe constitute a double pipe. . The bending resistance steel pipe 24 is the steel pipe structural member 23.
It is made shorter than the steel pipe structural member 23 so that the axial compressive force P acting on is not immediately transmitted. Its outer diameter is the outer surface 2
4c is selected so as to face the inner peripheral surface 23a of the steel pipe structural member 23 with a gap α as small as possible. Specifically, for example, a steel pipe structural member 23 having an outer diameter of 60.5 mm and a thickness of 3.2 mm and a bending resistance steel pipe 24 having an outer diameter of 53.6 mm are adopted, and the clearance α around the periphery is 0.25 mm.
Is secured. Such a small clearance α is provided so that the bending resistance steel pipe 24 can be inserted into the steel pipe structural member 23, and when the steel pipe structural member 23 starts to be deformed by the axial compressive force. This is because, as shown in FIG. 3 exaggeratedly, the steel pipe structural member 23 is made to function so as to suppress the bending of the steel pipe structural member 23 in the direction perpendicular to the axis 23m. If a drawn steel pipe is used as the bending resistance steel pipe 24, the processing for obtaining the required inner and outer diameter dimensions becomes easy. Returning to FIG. 1, an end member 25 having a screw hole 25a of a left spiral extending in the direction of the axis 25m is fixed to the end of the steel pipe structural member 23 by welding or the like. This includes a cover portion 25A that abuts on the end surface of the steel pipe structural member 23 and covers the opening 23b, and the cover portion 25A.
A guide portion 25B that has a smaller outer diameter and is continuous with the back surface 25b of the cover portion 25A and that projects into the steel pipe structural member 23.
It has and.

The joining device 20 attached to the end member 25 comprises a joining bolt 26 and a sleeve body 27. A boss portion 26A is formed on the joining bolt 26 at a substantially central portion in the axial direction, and a right-hand screw that engages with a screw hole 21a of the node member 21 (see FIG. 2) on one side, that is, the left side of the boss portion 26A. Male screw 26a for joining is formed. The right side engages with the screw hole 25a formed in the central portion of the end member 25 and is the male screw 26a for joining.
And a left-handed connecting male screw 26b having the same pitch. The male thread 26a for joining has a threaded portion having a screw-in length L ₁ necessary for meshing with the screw hole 21a of the node member 21, while the male thread 26b for connection has a threaded portion with the screw hole 25a. By the way, a threaded portion having a required screw-in length L ₂ is secured. The male screw 26a for joining has a total length L ₁₁ slightly longer than the screw-in length L ₁ , and the male screw 26b for connection has a total length L ₂₂ longer than the screw-in length L ₂ . The screwing length L ₁ of the male screw 26a for joining described above is shorter than the screwing length L _{2 of the} male screw 26b for connection. This is because the material strength of the node member 21 is generally larger than the combined strength of the steel pipe structural member 23 and the bending resistance steel pipe 24, so the screwing length L _{2 of the} male screw 26b for connection is set.
Based on the fact that it is preferable to keep it longer. However, in the present invention, as will be described later, the structural material 22
Since it is necessary to engage the joining bolt 26 with the end member 25 in advance to some extent before joining the connecting member 21 to the node member 21, the screwing length L ₂ of the connecting male screw 26b is the screwing length L of the joining male screw 26a. Inevitably longer than ₁ .

As described above, since the length required for the male screw 26a for joining with the node member 21 to mesh is L ₁ and the total length of the male screw 26b for connecting is L ₂₂ , the joining bolt 26 is initially when attached to the end member 25, the length L ₃ which is summed chewing the connecting male screw 26b threaded hole 25a is, L ₂₂ -L ₁ or greater than the selected bit shorter (see FIG. 6). This length L _3, the addition of the length L ₁ to suit biting into the screw hole 25a for connection external thread 26b by the rotation of the sleeve body 27, threaded end member 25 hole 2
The screw-in length L _{2 of the} male screw 26b for connection required for the engagement with the 5a is achieved (see FIG. 8). As a result, even if the maximum design axial force is transmitted from the node member 21 having a large material strength to the structural material 22 after the truss structure is assembled, it is possible to secure the joining strength capable of sufficiently withstanding it. In FIG. 1 in the same state as FIG. 6, the distance L ₄ from the tip of the male screw 26a for joining to the one end 27a of the sleeve body 27 is set to be twice the required screw-in length L ₁ of the male screw 26a for joining. Therefore, connecting male screw 2
6b is engaged with the screw hole 25a. As a result, when the desired amount of the male screw 26a for joining is fed into the screw hole 21a of the node member 21, one end 27a of the sleeve body 27 abuts the joining surface 21p of the node member 21, as shown in FIG.
The other end 27b also comes into contact with the outer end surface 25p of the end member 25.

A rotating force acting portion 33 (see FIG. 1) for rotating the boss portion 26A of the joining bolt 26 is formed on the outer surface of the sleeve body 27 which constitutes the joining device 20, and has a hexagonal cross section. It is provided with a hexagonal insertion hole 27n that engages with the outer surface 26m of the portion 26A to transmit a rotational force and allows the joining bolt 26 to be displaced while sliding in the axial direction. The length L _s of the sleeve body 27 is from the total length L of the connecting bolt 26 to the total length L _{11 of the} connecting male screw 26a.
It is selected to be slightly longer than the size obtained by subtracting the total length L ₂₂ of the connecting male screw 26b. The sleeve body 27 is provided with the joining bolt 2 before joining the structural member 22 to the node member 21.
It fits in 6. Then, when the sleeve body 27 is rotated, as shown in FIG. 8 through FIG. 7, while the joining bolt 26 is displaced in the axial direction, the joining male screw 26a is attached to the nodal member 2.
1, the male screw 26b for connection can be fed into the screw hole 25a of the end member 25 at the same time. In addition,
A male screw 26b for connection is provided in the screw hole 25a of the end member 25.
Is inserted in advance by a length L ₃ to be described later, and the joining bolt 26 is attached (see FIG. 6). In this way, the structural member 22 to which the joining bolt 26 is attached is moved to the position of the node member 21. However, in consideration of the fact that the structural material 22 may not be kept horizontal during transportation by a crane or the like, the sleeve body 2 externally inserted in the joining bolt 26 is considered.
In order to prevent the 7 from falling off easily, a falling prevention member 30 as shown in FIG. 1 is attached. The drop-preventing member 30 rotates the joining bolt 26 to join the structural member 22 to the node member 21, and the sleeve body 27 moves the node member 2 to the node member 2.
It is attached to a portion of the boss portion 26A near the male screw 26a for joining so that it can be broken or fallen off when it approaches 1 and can be easily removed by hand. This is, for example, a short plastic pin 30a and may be set up in a small hole provided in the boss portion 26A. Alternatively, a hole may be formed in the boss portion 26A at a position separated by 180 degrees, and a C-shaped hook (not shown) may be engaged with the hole.

The double steel pipe type structural material 22 includes the above-mentioned steel pipe structural member 23, the bending resistance steel pipe 24, the end member 25 fixed to the end of the steel pipe structural member 23, and the end member 25 thereof.
The joining bolts 26 used in the joining device 20 include:
A high-strength bolt suitable for joining the double steel pipe type structural material 22 to the node member 21 is adopted. The steel pipe structural member 23 and the bending resistance steel pipe 24 forming the double pipe are the bending resistance steel pipe 24.
Are fixed at the central portion in the direction of the axis 24m and the central portion in the direction of the axis 23m of the steel pipe structural member 23. This is accomplished by plug welding 32 or the like as shown in FIG. In that case, a hole is formed in the steel pipe structural member 23, and the bending resistant steel pipe 24 can be integrated with the steel pipe structural member 23 by welding and overlaying the hole.
Of course, although not shown in the drawing, a screw is formed in the above hole, and a bolt is inserted into the screw hole to strongly press, for example, three places on the circumference of the bending resistance steel pipe 24, or to bend the bending resistance steel pipe 2.
It is also possible to adopt a form of screwing into the screw hole provided in 4. This is, regardless of the mounting posture of the structural member 22, in the initial state the guide space 28 described below.
(See FIG. 1) has the same length on the left and right, and even if the steel pipe structural member 23 receives an axial compressive force or an axial tensile force to change the axial length, relative displacement does not occur at the central portion. This is to make the relative changes on the left and right the same. Although described later, the guide portion 25B of the end member 25 is set longer than the cover portion 25A, and a guide space is provided between the outer peripheral surface 25c of the guide portion 25B and the inner peripheral surface 23a of the steel pipe structural member 23. Two
8 is formed in a ring shape. In this guide space 28,
Although the tip end portion of the bending resistance steel pipe 24 is inserted, the gap γ between the inner surface 24b and the outer peripheral surface 25c of the guide portion 25B is made as small as possible. Then, between the end surface 24a of the bending resistance steel pipe 24 and the back surface 25b of the cover portion 25A, at least when the steel pipe structural member 23 buckles, the end portion of the bending resistance steel pipe 24 faces toward the back surface 25b of the cover portion 25A. A displacement gap 29 that is half of the allowable buckling length L ₃₃ that can be dynamically displaced or slightly longer than that is secured. Incidentally, the allowable buckling length L ₃₃ is selected to be about 10 mm when the structural member 22 has a length of 2 m, and about 15 mm when the structural member 22 has a length of 3 m.

The above bending-resistant steel pipe 24 enhances the bending rigidity of the steel pipe structural member 23 when the structural material 22 receives a compressive load, and at the same time, axisymmetrically stabilizes the plastic deformation of the steel pipe structural member 23 after yielding. It has the function of guiding you to take shape. That is, when the axial compressive force P acts on the steel pipe structural member 23 and the buckling load acts, the bending resistance steel pipe 24 exerts the bending preventing action in the state shown in FIG. 3, as described above.
Not only that, but in buckling deformation after the steel pipe structural member 23 yields, the steel pipe structural member 2 near the end member 25
As shown in FIG. 4, the periphery of 3 is uniformly guided so as to easily bulge outward. In order to make the function of the bending-resistant steel pipe 24 more effective, the guide space 28 is a space for the tip portion of the bending-resistant steel pipe 24 to move relative to the steel pipe structural member 23. Of the bending resistance steel pipe 24 and the relative displacement of the bending resistant steel pipe 24. The guide space 28 has a length that is at least 1/2 of the above-described allowable buckling length L ₃₃ and 1 to 4 times the inner diameter D ₂₄ of the bending resistance steel pipe 24. Incidentally, considering that the structural material 22 not only receives a compressive load but also a tensile load, the guide space 28
As shown in FIG. 5, when the steel pipe structural member 23 is subjected to an axial tensile force, one end surface 24a of the bending resistance steel pipe 24 is relatively separated to the opposite cover portion side as shown in FIG. It is better to add the above allowable tensile displacement amount δ _t . In this case, half the allowable tensile displacement δ length L ₆₆ minus the total length L _t of the sum of the _t guide space 28 of the buckling allowable length L ₃₃ also, the inner diameter D ₂₄ of the bending resistance steel tube 24 It is 1 to 4 times. In any of the above figures, the length L ₆₆ is represented by a size that is about one time the inner diameter D ₂₄ .

As described above, the reason why the axisymmetric deformation of the steel pipe structural member 23 is apt to occur is that when a large compressive load is applied, as shown by the broken line B in FIG. This is because a large plastic deformation is realized and the truss structure is allowed to largely deform when a large load is applied by an earthquake or the like. However, when a large load is applied thereafter, the end surface 24 of the bending resistance steel pipe 24
a comes into contact with the end member 25, the load is counteracted by the sum of the proof stress of the steel pipe structural member 23 and the proof stress of the bending resistant steel pipe 24, and the deformation is performed as in the substantially flat portion Ba at the right end of the broken line B. It can be sustained and prevent the truss structure from collapsing rapidly. Incidentally, although the joining bolt 26 is meshed with the screw hole 25a penetrating the cover portion 25A and the guide portion 25B of the end member 25, although not shown, the cover portion 25A of the end member 25 has a central portion thereof. A hole larger than the connecting male screw 26b is made in the portion, and a separate guide portion 25B having a screw hole with which the connecting male screw 26b engages is provided on the back surface 25b of the cover portion 25A.
It may be integrated by welding to, for example. In that case, something like a hexagon nut can be adopted as the guide portion 25B.

According to the above construction, the double steel pipe type structural member 22 can be firmly joined to the node member 21 by using the high strength bolt 26 as follows. First, a bending resistance steel pipe 24 shorter than the steel pipe structural member 23 is inserted into the steel pipe structural member 23, and the bending resistance steel pipe 24 is arranged so that the central portion thereof coincides with the axial central portion of the steel pipe structural member 23. Then, the bending resistance steel pipe 24 is attached to the steel pipe structural member 2 by welding or screwing both central portions.
It is fixed so that it does not move in 3 (see Fig. 2). next,
A cover portion 25A having a screw hole 25a extending in the direction of the axis 25m and a guide portion 25B having an outer diameter smaller than that of the cover portion 25A and being continuous with the back surface 25b of the cover portion 25A and protruding into the steel pipe structural member 23 are provided. The end member 25 provided is attached by welding or the like so that the cover portion 25A abuts the end portion of the steel pipe structural member 23 and covers the opening 23b. As a result, a guide space 28 is formed between the outer peripheral surface 25c of the guide portion 25B and the inner peripheral surface 23a of the steel pipe structural member 23. Bending resistance steel pipe 24
The distal end portion of is the shape that is inserted into the guide space 28. Further, between the end surface 24a of the bending resistance steel pipe 24 and the back surface 25b of the cover portion 25A, a displacement gap 29 longer than 1/2 of the buckling allowable length L ₃₃ predetermined in design is secured.

A male screw 26a for joining that meshes with the screw hole 21a of the node member 21 on the ground at the truss construction site.
The connecting bolt 26 in which the
It engages with the screw hole 25a provided in the end member 25 via b. At this time, the boss portion 26A of the joining bolt 26 is manually rotated counterclockwise toward the end member 25, and the connecting male screw 26b is length L ₃ of the screw hole 25a of the end member 25.
(See FIG. 1). Then, the sleeve body 27 is engaged with the outer surface 26m of the boss portion 26A, and the other end 27b
Touches the outer end surface 25p of the end member 25. Then, a drop-preventing pin 30a is set up at a position close to the one end 27a of the sleeve body 27. Operation of inserting only the threaded hole 25a length L ₃ of the connection the external thread 26b of the work of temporarily stopping the fastening bolt 26 to the end member 25, furthermore, fastening bolt 26 to the sleeve member 2
If the work of attaching the pin 30a after fitting 7 is performed at the time of shipping the structural material 22, the labor at the work site can be saved. Even if the sleeve body 27 tries to rotate counterclockwise during the transportation of the structural material 22, the advancing of the joining bolt 26 is prevented by the pin 30a, and the predetermined engagement length L ₃ with the screw hole 25a of the male screw 26b for connection is maintained. . On the other hand, if the sleeve body 27 rotates to the right, the connecting male screw 26
engagement length and b of the screw hole 25a is less than L _3, as long as the amount of rotation is not much, without orientation of the structural member 22 is not held horizontally, the sleeve member 27 by a pin 30a The dropout is prevented. In addition, when the sleeve body 27 rotates a little to the right during transportation, the sleeve body 27 may rotate the outer end surface 25p of the end member 25 or the pin 30.
Since it is separated from either one of a, male screw for connection 2
It can be seen at a glance that the engagement length with the screw hole 25a of 6b is less than L ₃ . In that case, if the sleeve body 27 is manually rotated to the left just before being joined to the node member 21, the predetermined engagement length L ₃ can be easily reproduced.

The double pipe with the joining devices 20 attached to both ends is moved to the position of the node member 21 during construction of the truss by a crane or the like, and is joined to the screw hole 21a of the node member 21 as shown in FIG. The tip of the joining male screw 26a of the bolt 26 is exposed. The connecting male screw 26b is the joining male screw 26a.
It is a reverse screw with the same pitch as the above, and a wrench or the like is hooked on the rotational force acting portion 33 of the sleeve body 27 to rotate it clockwise as shown in FIG. 7. The joining bolt 26 rotates through the insertion hole 27n, and the joining male screw 26a becomes the screw hole 21a of the node member 21.
Sent in. At the same time, the male screw for joining 26a
The left-handed connecting male screw 26b having the same pitch as is also fed into the screw hole 25a of the end member 25 by the same amount. During this time, the pin 30a is attached to the one end 2 of the sleeve body 27.
7a, and the joint bolt 26 is broken by the sleeve body 2
7 slides in the insertion hole 27n in the axial direction. Since the connecting male screw 26b has been inserted into the screw hole 25a by the length L ₃ in advance, the sleeve body 27 is rotated and the joining male screw 2b is rotated.
When 6a is inserted by a screw-in length L ₁ required for engagement with the screw hole 21a (see FIG. 8), the connecting male screw 26b
Achieves the engagement of the length L ₃ + L _{1 in} the screw hole 25a, that is, the screw-in length L ₂ required for engagement. The length L _s of the sleeve body 27 is selected to be slightly longer than the total length L of the joining bolt 26 minus the total length L ₁₁ of the joining male screw 26a and the total length L ₂₂ of the connecting male screw 26b. As a result, at the time when the joining bolt 26 is fed by the screwing length L ₁ described above, the one end 27a of the sleeve body 27 abuts on the flat joining surface 21p of the node member 21, and at the same time, the other end 27b thereof ends. Outer surface 25
abut p. In the state of FIG. 8, the sleeve body 2
7 can be tightened by applying a large torque, and the structural member 22 is connected to the node member 2 through the joint having high rigidity.
1 is firmly joined.

In this way, the structural member 22 is connected to the nodal member 2
If joined to 1, the structural material 22 can be sequentially assembled in the direction of the arrow in FIG. 9, for example. By the way, as will be described later, the columns joined in this way are described below.
A truss of a desired shape can be constructed by joining a large number of structural members 35 such as steel pipes to the respective node members 21 by using another type of joining device 36 as shown in FIG. As can be seen from the movements of FIGS. 6 to 8, when the joining bolt 26 is fixed and viewed, the double pipe moves leftward,
The node member 21 behaves so as to move to the right, and the distance between them becomes the length L _s of the sleeve body 27. In practice, the position of the node member 21 is often fixed, and the sleeve body 27
The structural material 22 moves with the rotation of. However, the structural member 22 is in a state of being suspended by a crane or the like, and its movement is not hindered at all. By the way, not only the length of the sleeve body 27, but also the dimension from the outer end surface 25p of the end member 25 to the outer end surface 25p of the other end member 25 should be extremely accurately the desired length with the current processing technology. You can Therefore, when the structural member 22 is joined to the node member 21, the distance between the left and right node members 21 and 2 of the structural member 22 is as planned. Although the double steel pipe type structural material 22 has a very large cross-sectional proof stress, a joining device that allows correspondingly large load transmission can be formed compactly. At the same time, if a single steel pipe is adopted in a portion where a large force acts, its outer diameter will increase, but the use of a double steel pipe type structural material with a small cross-sectional outer shape despite exhibiting the same or higher yield strength. Is possible. In the past, when trying to adopt solid materials etc., it was necessary to weld high strength bolts, but it is only necessary to process the end members with screw holes, the structure material is easy to manufacture and transport It will be easy. Not only that, it is not necessary to rotate the long structural member itself in joining with the node member, the joining work is simplified, and it becomes extremely easy to apply a desired torque to the joining portion.

Incidentally, the length of the boss portion 26A need not be close to the length of the sleeve body 27 as shown in FIG. As long as the sleeve body 27 can be engaged with the outer surface 26m of the boss portion 26A when the joining bolt 26 is initially assembled in the double pipe, it may be a short one as shown by the chain double-dashed line. In the joining device, the shape of the boss portion 26A formed on the joining bolt 26 used for the joining device is not limited to the hexagonal cross section described above, and a polygon capable of transmitting torque can be adopted. In that case, it goes without saying that the insertion hole 27n formed in the sleeve body 27 may also have a shape that matches the shape. The diameters of the joining male screw 26a and the connecting male screw 26b of the joining bolt 26 need not be the same as long as they are reverse screws having the same pitch. Therefore, a desired screw diameter may be given to the connecting male screw 26b in consideration of the size of the node member 21 and the sectional dimensions of the steel pipe structural member 23 and the like.

When a compressive load is applied to the double steel pipe type structural member 22 assembled into the truss structure by joining as described above, the compressive force transmitted from the node member 2 is connected from the joining male screw 26a. It is transmitted to the steel pipe structural member 23 via the external male screw 26b. At that time, even if a bending force is applied, the steel pipe structural member 23 is reinforced by the bending resistance steel pipe 24 and is not easily bent. If the compressive force is large, the steel pipe structural member 23 will yield and start plastic deformation. However, the tip portion of the bending-resistant steel pipe 24 is inserted in the guide space 28, and the end face 24a and the cover portion 25 are inserted.
The guide portion 2 of the end member 24 is also provided between the back surface 25b of A and the back surface 25b.
Since 5B is located, the buckling deformation of the steel pipe structural member 23 becomes a stable axially symmetrical shape that bulges outward near the end member 25, as shown in FIG. Due to the buckling of the steel pipe structural member 23, the end portion of the bending resistant steel pipe 24 moves relatively in the displacement gap 29 with respect to the steel pipe structural member 23,
When the steel pipe structural member 23 is shortened by the allowable buckling length L ₃₃ , the end face 24a of the bending resistance steel pipe 24 becomes the back face 2 of the end member 25.
5a (see FIG. 4). At this point, the axially symmetric buckling deformation of the steel pipe structural member 23 stops, and the steel pipe structural member 2
3, and the buckling resistance of the bending resistance steel pipe 24 opposes the axial compression force. Since the counter force is larger than that of the steel pipe structural member 23 alone, the double steel pipe type structural member 22 is extremely gently deformed with respect to the subsequent compressive force (see the broken line Ba in FIG. 20). Thus, a sudden collapse of the truss structure is avoided, people inside the building are aware of the danger at the time of the first major deformation and can escape to the outdoors during subsequent gentle deformation. When a tensile load is applied to the double steel pipe type structural material 22, the tensile force is applied to the bending resistance steel pipe 2.
No more than four. When a tensile force of a design-permitted amount is applied, elongation of the allowable tensile displacement amount δ _t occurs on one side of the steel pipe structural member 23, and as a result, one end surface 24a of the bending resistance steel pipe 24 is opposite to the cover portion side. Separate the allowable tensile displacement δ _t . However, at that time, as shown in FIG. 5, the sum of the allowable tensile displacement [delta] _t and buckling allowable length L _33, a length obtained by subtracting from the total length L _t of the guide space 28 L
_{If 66} is secured for 1 to 4 times the inner diameter D ₂₄ of the bending resistance steel pipe 24, even if a compressive load acts immediately after a tensile load acts on the double steel pipe type structural member 22, the yield will be yielded. The buckling deformation occurring at the end of the steel pipe structural member 23 is maintained in an axially symmetrical shape, and the behavior becomes the same as that when the compressive load is applied from the beginning.

FIG. 11 shows an example in which the double steel pipe type structural members 22 and 22 are used for the columns of the tower-like structure by the above-mentioned joining device 20. The thick member in the figure is a double pipe, and the member shown in the middle or thin is a single pipe structural member 3
It is 5. The structural member 35 such as the thin-walled pipe is adopted in a truss structure where a large force does not act,
Generally, the pipe is thinner than the structural member 22.
Moreover, after the structural material 22 is arranged, the nodal members 21 and 21 located at both ends are defined by the length of the structural material 22.
The distance between cores is often fixed. So, I touched on the structural member 35 a little in the prior art.
The structure described in JP-A-63-51539, that is, as shown in FIG. 12, the screw portion 37 formed on the joining bolt 37.
While engaging the outer surface of the boss portion 37A having a cross section larger than the diameter of a to transmit the rotational force, the joint bolt 37
Is provided with a sleeve body 34 capable of axial displacement, and the joint bolt 37 is pushed toward the structural member 35 side.
A joining device that can be completely retracted inside is used, or the structure described in Japanese Utility Model Laid-Open No. 2-180303, that is, the bonding device 39 shown in FIG.
It is advisable to employ a joining device as disclosed in Japanese Patent No. 125102.

In the former case, the spring 38 is interposed between the back portion of the joining bolt 37 located in the sleeve body 34, that is, between the boss portion 37A and the end surface 35p on the side of the structural member 35. Then, the joining device 36 is configured such that the joining bolt 37 is pushed toward the structural member 35 side by utilizing the elasticity of the spring 38 and can be completely retracted into the sleeve body 34. Therefore, when the tip of the joining bolt 37 is brought into contact with the joining surface 21p of the node member 21 as shown in FIG. 13, the spring 38 contracts and the joining bolt 37 retracts, and the joining bolt 37 is screwed into the screw hole 21a of the node member 21.
Then, the screw portion 37a is restored by the elastic force of the spring 38. When the sleeve body 34 is rotated thereafter, the joining bolt 37 advances and the structural member 35 can be firmly joined to the node member 21 (see FIG. 12). In the joining device 39 of FIG. 14 described above, the joining bolt 40 is formed with the displacement screw 42 that enables forward and reverse feeding by rotation of the sleeve body 41. By the way, in this joining device 39, the thin steel pipe 4
An end member 43A is fixed to an end portion of the screw 3, and the displacement screw 42 is attached to the support cylinder 43B fixed by meshing with the end member 43A.
Are screwed together. Therefore, before carrying the structural member 43 to the nodal member, the displacement screw 42 is advanced into the support cylinder 43B to retract the joining bolt 40 by reverse rotation of the sleeve body 41 via the boss portion 40A, as shown in the figure. If the threaded portion 40a of the joining bolt 40 is exposed to the threaded hole of the node member and the sleeve body 41 is normally rotated,
The joining bolt 40 is advanced to achieve a strong joining. In any of the above, since the structural member can be arranged after the inter-center distance between the two node members is determined, as shown in FIG. 10 and FIG.
The entire truss structure can be assembled by mixing the structural member 35 such as a single pipe and the double steel pipe type structural material 22. A hollow single pipe that has the same yield strength as a solid material has an extremely large diameter, but if a double pipe is adopted instead,
Since the structure material 22 can be made thinner than the single pipe,
Variations in thickness with other structural members 35 and the like are reduced, and the appearance of the truss structure is improved. The joining device 20 is made compact as described above, and there is little mutual interference when it is attached to the node member 21 together with the other joining device 36, and the structural member 22 or the structural member 35 having a desired proof strength is arranged. You can

FIG. 15 shows the support points 44, 4 of the truss structure.
FIG. 16 is an example in which 4 is present only on two opposite sides, and FIG. 16 is a plan view when the support points 45, 45 are only at four corners. Incidentally, FIGS. 17 and 18 show the front view and the side view of FIG. 15, respectively. The double-lined portion in the figure is the double-tube structural member 22, and the single-lined portion is the single-tube structural member 35. In any of these cases, the stress acting on the structural member 22 indicated by the double line is extremely large as compared with the structural member 35 at other points. It will be understood that the structural material 22 having a large yield strength, which employs the joining apparatus 20 of the present invention, may be used in such a place. As can be seen from the above description, the double steel pipe type structural material 22 and the joining device 20 adopted therein are preferably applied to, for example, columns of a tower-shaped structure on which a very large force acts, Even when used in combination with a structural member using a hollow material or a thin-walled pipe, the unevenness of the thickness of the structural member adopted for the truss steel structure is reduced, and the appearance thereof is good.

[Brief description of drawings]

FIG. 1 is an enlarged vertical cross-sectional view of an end portion of a structural material for a double steel pipe type truss structure according to the present invention including a joining device.

FIG. 2 is an overall view of a state in which one structural member is joined to left and right node members.

FIG. 3 is an exaggerated schematic view of a double steel pipe type structural material in a state of being bent and deformed.

FIG. 4 is a partial cross-sectional view of a structural material when a steel pipe structural member is plastically deformed in an axially symmetric shape.

FIG. 5 is a cross-sectional view showing an end structure of the double steel pipe type structural material when it is first subjected to an axial tensile force and then an axial compressive force.

FIG. 6 is an installation state diagram immediately before the joining bolt is engaged with the node member.

FIG. 7 is an operation diagram in the middle of rotating the sleeve body and engaging the joining bolt with the node member and the end member.

FIG. 8 is a joining state diagram after the double tube is completely joined to the node member by the joining device.

FIG. 9 is a joining state diagram when joining the structural materials of the double steel pipe so as to extend in one direction.

FIG. 10 is an enlarged view in the vicinity of a node member when a double steel pipe structural member and a single steel pipe type structural member are radially joined to one node member.

FIG. 11 is a partial view of a truss structure in which a double steel pipe type structural material is applied to columns of a tower-shaped structure.

FIG. 12 is a structural cross-sectional view of a joining device in which a joining bolt can be moved back and forth by expansion and contraction of a spring.

FIG. 13 is an operation explanatory view in which the joining bolt is retracted into the sleeve body.

FIG. 14 is a cross-sectional view of a configuration of a joining device in which the joining bolt can be moved back and forth by a displacement screw formed on the joining bolt.

FIG. 15 is a plan view illustrating a truss structure in which supporting points are provided on both sides, which is a mounting location of a double steel pipe type structural material.

FIG. 16 is a plan view illustrating a truss structure in which the support points are four corners, and where the double steel pipe structural material is attached.

17 is a view taken along the line XVII-XVII in FIG.

18 is a view taken along the line XVIII-XVIII in FIG.

FIG. 19 is an explanatory view showing a state in which a double pipe of a prior art is joined to a node member.

FIG. 20 is a graph illustrating elasto-plastic deformation of a double pipe in the prior art and a double steel pipe type structural material according to the present invention.

[Explanation of symbols]

21 ... Nodal member, 21a ... Screw hole, 21p ... Joining surface, 2
2 ... Double steel pipe type structural material, 23 ... Steel pipe structural member, 23a
... inner peripheral surface, 23b ... opening, 23m ... axis, 24 ... bending resistance steel pipe, 24a ... end surface, 24c ... outer surface, 24m ... axis,
25 ... end member, 25A ... cover part, 25B ... guide part, 25a ... screw hole, 25b ... back surface, 25c ... outer peripheral surface,
25m ... Axis line, 25p ... Outer end face, 26 ... Joining bolt, 2
6A ... Boss portion, 26a ... Male thread for joining, 26b ... Male thread for connection, 26m ... Outer surface, 27 ... Sleeve body, 27a ... One end, 27b ... Other end, 28 ... Guide space, 29 ... Displacement gap, 30 ... preventing member, 35 ... single tube structure members, D ₂₄ ... bending the inner diameter of the resistance steel, L ... overall length of fastening bolt, L ₁ ... joining male thread needs to engagement with the screw hole of the joint member screwing length, L ₂ … The screwing length required for the male screw for connection to engage with the screw hole provided in the end member, L ₁₁ … The total length of the male screw for joining, L ₂₂ … The total length of the male screw for connection, L ₃ (≈L ₂₂ − L ₁ ) ... the length at which the male screw for connection is initially engaged with the screw hole, L ₃₃ ... allowable buckling length, L ₆₆
... Length, L _s ... Length of sleeve body, L _t ... Total length of guide space, P ... axial compression force, α ... gap, δ _t ... allowable tensile displacement amount.

Claims (5)

[Claims] 1. A rotating bolt is transmitted by engaging a joining bolt for connecting an end portion of each steel pipe structural member to a node member with an outer surface of a boss portion having a cross section larger than a diameter of a screw portion formed on the joining bolt. With the rotation of the sleeve body that enables axial displacement of the joining bolt, it can be fed into the screw hole formed in the node member, and the axial compressive force acting on the steel pipe structural member is A bending resistance steel pipe shorter than the steel pipe structural member so as not to be transmitted immediately is inserted into the steel pipe structural member, and the outside diameter of the bending resistance steel pipe is as large as possible with the inner peripheral surface of the steel pipe structural member. When the steel pipe structural member begins to deform due to an axial compressive force acting on the steel pipe structural member, the steel pipe structural member bends in a direction perpendicular to its axis. In front of A double steel pipe type structural member for a truss steel structure which can be restrained by a bending resistance steel pipe, wherein an end having a threaded hole extending in the axial direction attached to the end of the steel pipe structural member is formed. The member has a cover portion that abuts on an end surface of the steel pipe structural member and covers the opening of the steel pipe structural member, and a guide that has an outer diameter smaller than that of the cover portion and that is connected to the back surface of the cover portion and that projects into the steel pipe structural member. And a male screw for joining to a screw hole of the node member is formed on one side of the boss portion of the joining bolt, and a male screw for engaging the screw hole of the end member on the other side. A male thread for connection is formed with a reverse spiral having the same pitch as the male thread, and the male thread for joining is secured with a threaded portion having a screwing length necessary for meshing with the screw hole of the node member.
The connecting male screw has a threaded portion having a screwing length necessary for meshing with a screw hole provided in the end member, and the length of the sleeve body is from the entire length of the joining bolt to the joining male screw. Of the bending resistance steel pipe inserted into the steel pipe structure member, the central portion in the axial direction of the bending resistance steel pipe is set to be longer than the dimension obtained by subtracting the total length of the steel pipe structural member and the total length of the connecting male screw. The tip end portion of the bending resistance steel pipe is inserted between the outer peripheral surface of the guide portion and the inner peripheral surface of the steel pipe structural member, and the end surface of the bending resistance steel pipe and the back surface of the cover portion are fixed. For a displacement longer than 1/2 of the allowable buckling length by which the end portion of the bending resistant steel pipe can be relatively displaced toward the back surface of the cover portion when the steel pipe structural member is buckled. Secure a gap Double Tube-shaped truss structure for structural member, wherein the guide space is formed. 2. A design in which one end surface of the bending resistant steel pipe is relatively separated from the opposite cover portion side when the buckling allowable length is 1/2 and the steel pipe structural member receives an axial tensile force. The length obtained by subtracting the sum of the above allowable amount of tensile displacement from the total length of the guide space is 1 to 4 times the inner diameter of the bending resistant steel pipe. Structural material for double steel tube type truss structure. 3. A portion of the boss portion near the male screw for joining is used to prevent the sleeve body engaged with the outer surface of the boss portion from falling off and to join the steel pipe structural member to the nodal member. The structural material for a double steel pipe type truss structure according to claim 1, further comprising a fall-off preventing member that is broken or easily removed when the joining bolt is rotated. 4. The structural material for a double steel pipe type truss structure according to claim 1, wherein the connecting male screw has a screwing length (L ₁ ) of the connecting male screw from its entire length (L ₂₂ ). The threaded hole formed in the end member is pre-engaged with a length (L ₃ ) substantially equal to the subtracted length, and the sleeve bolt is slidably displaced by the rotation of the sleeve body, whereby the male thread for joining is screwed. While feeding into the screw hole of the node member, the connecting male screw is fed into the screw hole of the end member, one end of the sleeve body abuts on the joint surface of the node member, and the other end of the end member A joining method for a structural material for a double steel pipe type truss structure, characterized in that it is retightened when it comes into contact with the outer end surface. 5. The screw member formed on the joint bolt after the structural members for the double steel pipe type truss structure according to claim 1 are sequentially joined to the nodal members and the intercenter distance of the nodal members is determined. A sleeve body that engages an outer surface of a boss portion having a cross section larger than the diameter of the boss portion to transmit a rotational force and enables axial displacement of the joining bolt, and the joining bolt retracts toward the structural member side A large span structure characterized in that a single steel pipe type structural member is sequentially joined between the node members by a joining device capable of retreating to the Truss construction method for tower structures.