JP2006299576A - Triple pipe damping brace having slot - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a triple pipe damping brace excellent in energy absorption capacity without lowering proof stress by the whole buckling and local buckling of an axial pipe resulting from earthquake. <P>SOLUTION: A plurality of slots 32 axially extended are formed in a triple pipe structure of the axial pipe 12 the cross section of the axial pipe 12 is intentionally reduced, and the triple pipe damping brace 10 is so constituted that stiffening pipes (14 and 16) are respectively coaxially arranged in both inside and outside of the axial pipe 12. It may be also allowable that the triple pipe damping brace 10 includes a length adjusting mechanism. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a seismic control brace, and more specifically, when the axial force pipe absorbs a stress such as compression or tension acting on a building due to an earthquake, the proof stress is reduced due to overall and local buckling. There are no triple-pipe seismic braces.

  Conventionally, as a countermeasure against a yield load of an axial force pipe due to an earthquake, there is a double pipe structure as disclosed in, for example, Japanese Patent Application Laid-Open No. 11-193570. This will be described with reference to FIG. 5. A thick-walled tube 82 made of a general structural or architectural steel material and a thin-walled tube 84 made of a low yield point steel material having a lower yield point are coaxially joined. Clevis joints 86a and 86b are attached to both ends of the axial force tube 80 via caps 88a and 88b. The outer side of the axial force tube 80 is concentrically arranged over the entire length to prevent buckling of the axial force tube. A tube 81 is disposed and welded 83 to one base 88b.

  However, what is shown in this publication is that the outer tube 81 is used to buckle the thin tube 84 of the axial force tube 80 when the stress is applied to the axial force tube 80 due to an earthquake. However, there is a problem that there is no way to prevent buckling that dents inward. In addition, since a gap is formed over the entire length between the thin tube 84 and the outer tube 81, there is a problem that this cannot be avoided when local buckling occurs in the thin tube 84. The same applies to the double tube structure disclosed in JP-A-8-68110.

  In addition, as a seismic structural material having a double-pipe structure, for example, as disclosed in Japanese Patent Application Laid-Open No. 2003-34983, there is one in which an inner tube is provided inside an axial force tube. In this publication, the buckling inward of the axial force tube is suppressed by the inner tube, but this time, there is no attempt to suppress the buckling outward. There is a problem. Moreover, in this case as well, since a gap is formed over the entire length between the axial force tube and the inner tube, local buckling of the axial force tube may not be avoided by the inner tube. There is also a problem.

  On the other hand, the applicant of the present application has previously applied for a seismic brace having a triple-pipe structure. This is a low yield point steel pipe of an axial force pipe in which a steel pipe of a general structural or architectural steel and a steel pipe of a low yield point steel having a lower yield point than that of the structural or architectural steel pipe are coaxially joined. The stiffening tube is disposed on both the inside and the outside of the tube so as to be concentric with a small gap between the tube and the axial force tube.

  According to this, when stress due to repeated axial forces of compression and tension acts on an axial force tube due to an earthquake, if the low yield point steel tube of the axial force tube tries to buckle inward, the inner stiffening tube If buckling is suppressed and an attempt is made to buckle outward, buckling is suppressed by the outer stiffening tube. However, even with such a triple pipe structure, there is a gap over the entire length between the low yield point steel pipe of the axial force pipe and both the inner and outer stiffening pipes, so the local part of the axial force pipe There is a problem that it is impossible to avoid a decrease in yield strength due to a typical buckling.

  Therefore, the present applicant, in the above-mentioned triple-tube structure damping brace, in order to fill the gap that has occurred over the entire length between the low yield point steel pipe of the axial force pipe and both the inner and outer stiffening pipes, An application has also been filed for a triple pipe structure damping brace in which a coil-shaped gap adjusting member formed in a spiral shape with a pitch interval in the axial direction is provided in the gap between the axial force pipe and the stiffening pipe.

  According to this, a decrease in proof stress due to local buckling of the axial force pipe due to the gap formed over the entire length between the low yield point steel pipe of the axial force pipe and the inner and outer stiffening pipes is suppressed. The Rukoto.

  However, in order to fill the gap, it is necessary to manufacture a gap adjusting member separately, and thus there is a problem that the material cost is increased and the manufacturing process is increased.

Japanese Patent Laid-Open No. 11-193570 JP-A-8-68110 JP 2003-34983 A

  The problem to be solved by the present invention is a triple-tube seismic brace in which the axial force tube does not buckle as a whole even if the axial force tube is subjected to stress caused by repeated compression and tension due to an earthquake. An object of the present invention is to provide a triple-tube seismic brace having excellent energy absorption capability in which the axial tube does not buckle locally in the triple-pipe structure.

  In order to solve the above-mentioned problems, the triple-tube seismic brace according to the present invention includes concentric stiffening tubes that prevent buckling of the axial force tube on the inner side and the outer side of the axial force tube, respectively. A triple-tube seismic brace arranged in the shape of an axial force tube by forming a plurality of elongated holes or concave recessed grooves extending in the axial direction in the triple-tube structure portion of the axial force tube. The gist is that the shape is intentionally reduced.

  In this case, as described in claim 2, the concave recessed groove is formed on one or both of the facing surface of the axial force tube facing the inner stiffening tube and the facing surface of the outer stiffening tube. It is desirable.

  The axial force tube preferably has a length adjusting mechanism as described in claim 3.

  According to the triple pipe damping brace according to claim 1, the damping brace has a triple pipe structure including an axial force pipe and stiffening pipes disposed inside and outside the axial force pipe. Even if compressive or tensile stress due to earthquake acts on the tube, it restrains the local buckling of the axial force tube from both the inside and outside of the axial force tube, thus preventing the deterioration of the proof stress of the axial force tube against the compression and tension, The energy at the time of an earthquake can be absorbed efficiently. This solves the decrease in yield strength caused by buckling on the unconstrained side due to only one-side restraint, which has been a problem in the conventional double tube structure.

  And, as a shape that intentionally reduces the cross section of the triple-pipe structure part of the axial force pipe, by providing a change in cross-sectional area, it is possible to eliminate the use of a low yield point steel pipe for the triple-pipe structure part of the axial force pipe Since stress such as compression and tension can be concentrated, it is no longer necessary to use an axial force pipe made by welding a structural steel pipe and a low-yield point steel pipe as in the past. An axial force tube can be configured.

  As a result, there is no fear of breakage at the weld seam, which may become a weak point against repeated axial forces of compression and tension in the conventional axial force tube.

  Moreover, since an axial force pipe can be comprised only with a structural steel pipe as mentioned above, the selection range of the steel pipe used for an axial force pipe spreads, and the member structure rich in variation is attained.

  Further, since the axial force pipe is composed only of a structural steel pipe and has no welded seam, the inner stiffening pipe and the outer stiffening pipe can be arranged without leaving a gap with the axial force pipe. The gap is adjusted to the minimum gap without using a gap adjustment member or the like. This prevents local buckling of the axial force tube, which may have been caused by a gap between the axial force tube and the stiffening tube, and completely covers the entire area where the cross section of the axial force tube is reduced. You will be able to surrender.

  And when the shape which makes the cross section of the said axial force pipe small intentionally consists of a concave hollow groove, and when comprised as described in Claim 2, it is a steel pipe shape compared with the case where a hole is made in an axial force pipe Can be easily maintained, and the amount of scraped scraps can be suppressed.

  On the other hand, when the length adjusting mechanism is attached to the triple pipe damping brace according to claim 1, as described in claim 3, the damping brace can be expanded and contracted. The problem of length adjustment caused by enforcement error when attaching seismic braces is solved, and the work process becomes easy. Furthermore, since the entire vibration control brace can be expanded and contracted by rotating only the joint member of the length adjustment mechanism, there is no need to select a joint member for joining the vibration control brace and the building structure. And various joint members such as bolt joints.

  Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS.

  FIG. 1 shows a cross-sectional structure of a triple pipe damping brace according to the present invention. The seismic control brace 10 mainly includes an axial force tube 12 and inner and outer stiffening tubes (14, 16).

  Both ends of the axial force pipe 12 are welded (22a, 22b) to the bases (18a, 18b), and bolt joint members (20a, 20b) are respectively provided at both ends of the bases (18a, 18b). Installed. An outer stiffening tube 16 having a diameter slightly larger than that of the axial force tube 12 is concentrically disposed with a minimum gap between the axial force tube 12 and one end thereof is a base 18b. Further, an inner stiffening tube 14 having a slightly smaller diameter than that of the axial force tube 12 is concentrically arranged with a minimum clearance between the axial force tube 12 and the axial force tube 12. One end of which is also welded 26 to the base 18b.

  Next, the triple tube structure of the axial force tube 12 is shown in an enlarged manner in FIG. As shown in the figure, there are a plurality of long holes 32 in the axial direction in the triple tube structure portion that overlaps the outer stiffening tube 16 and the inner stiffening tube 14 of the axial force tube 12. There is a steel pipe bone 34 in between. In this case, since both ends in the axial direction of the bone portion 34 are wider than the bone portion 34, this region has a dogbone shape.

  Conventionally, a low yield point steel pipe has been used for the energy absorption part of a seismic control brace so that it yields faster than a building when an earthquake occurs. It is difficult to use a low yield point steel pipe across the entire brace. Therefore, in general, the axial force pipe in the vibration control brace is combined by joining a low yield point steel pipe and a structural steel pipe having a higher yield point than the low yield point steel pipe.

  The axial force pipe 12 according to the present embodiment is also improved in this respect, and the axial force pipe 12 does not use a low yield point steel pipe but uses only a general structural steel pipe. And in order to provide the energy absorption site | part for absorbing the vibration energy by an earthquake, the long hole 32 is pierced in the part (triple pipe structure part) covered with the stiffening pipe | tube of this axial force pipe, and the above intentional Is provided with a shape to reduce the cross section.

  By making this long hole 32 in the axial force tube 12, the steel material supporting the portion (triple tube structure portion) covered with the stiffening tube of the axial force tube is only the bone portion 34, so compared with the other portions. It is easier to surrender and can absorb the vibration energy from the earthquake faster than the building.

  The number of the long holes 32 is not particularly limited. For example, as shown in the figure, the number of the long holes 32 is formed in parallel at four locations at equal intervals in the circumferential direction, or the number is formed at equal intervals in six circumferential directions. Is a good example. However, if the number of the long holes 32 is increased too much, the cross section of the bone part 34 becomes small, and there is a possibility of local buckling in the plane. Therefore, the number, length, and width of the long holes 32 can be determined as appropriate.

  The triple pipe seismic brace 10 has a proof strength necessary as a brace material, and the triple pipe structure portion of the axial force pipe 12 is more plastically deformed than other regions of the axial force pipe due to an earthquake, and is easily yielded. If so, the number, shape, size and the like of the long holes in the triple tube structure portion of the axial force tube 12 are not particularly limited.

  This long hole portion can be formed by a method such as normal cutting. Further, the shape of the long hole may be a groove whose wall thickness is reduced by cutting the surface of the tube instead of a complete hole. In this case, a concave groove is formed, but this groove may be either the inside or the outside of the axial force tube, or both.

  And according to the damping brace 10 which concerns on this embodiment, since it has the triple pipe structure which consists of the axial force pipe | tube 12 and the stiffening pipe | tube (14, 16) arrange | positioned in the inner side and the outer side, axial force Even if a compressive or tensile stress due to an earthquake acts on the tube 12, the local buckling of the axial force tube 12 can be restrained from both the inside and the outside of the axial force tube 12. Therefore, it is possible to prevent the proof stress of 12 and efficiently absorb the energy at the time of earthquake. Therefore, there is no reduction in yield strength caused by buckling on the unconstrained side due to only one-side restraint, which is a problem in the conventional double tube structure.

  Moreover, the damping brace 10 according to the present embodiment includes an axial force pipe 12 and inner and outer stiffening pipes (14, 16) arranged with a minimum gap as shown in the drawing. No adjustment member is required. As a result, local buckling of the axial force tube 12 due to repeated axial forces of compression and tension is prevented. And in this seismic control brace 10, since it is not necessary to adjust a clearance gap using the clearance adjustment member etc. which were produced separately, the construction cost and a manufacturing process are unnecessary.

  Then, as in this embodiment, in the triple-pipe structure portion where the axial force tube 12 and the inner and outer stiffening tubes (14, 16) overlap each other, the shape of the peripheral surface of the axial force tube 12 is intentionally reduced. Can be intentionally yielded without using a low yield point steel pipe in the triple pipe structure of the axial force pipe 12, and can absorb stress such as compression and tension. Thus, it is not necessary to use an axial force pipe made by welding a structural steel pipe and a low-yield point steel pipe, and the axial force pipe 12 can be configured with only the structural steel pipe.

  As a result, there is no fear of breakage at the weld seam, which may become a weak point against repeated axial forces of compression and tension in the conventional axial force tube.

  Moreover, since the axial force pipe 12 can be comprised only with a structural steel pipe as mentioned above, the selection range of the steel pipe used for the axial force pipe 12 spreads, and the member structure rich in variation is attained.

  As the axial force pipe 12, for example, general structural steel pipes “STK400” and “STK490”, building structural steel pipes “STKN400B” and “STKN490B” can be suitably used.

  On the other hand, for the stiffening pipes (14, 16), a general steel pipe for structural steel similar to the axial force pipe 12 can be selected.

  FIG. 3 shows an example in which the triple pipe seismic brace according to the present invention is provided with a length adjusting mechanism. The triple pipe seismic brace 50 shown in FIG. 3 comprises an axial force pipe part A and a length adjusting part B, and the axial force pipe part A comprises a triple pipe seismic brace 10 having the structure shown in FIGS. One end of the triple pipe seismic brace 10 is joined to the length adjusting portion B.

  The length adjusting part B is formed by projecting male screw shafts (54a, 54b) having left and right reverse screw structures at both ends of the joint member 52. Then, on one end of the axial force tube portion A and the base 22a, female threads (56a, 56b) having left and right reverse screw structures are respectively threaded on the inner peripheral surface thereof, and male threaded shafts (54a, 54b) of the joint member 52 are formed. And a screw 22, and the base 22 a to which the axial force pipe part A and the bolt joint member 20 a on both sides are attached by the rotation of the joint member 52 is configured so that the entire triple pipe seismic brace 50 can be expanded and contracted by a mechanism that moves away from each other. Has been. Therefore, it is possible to solve the problem of construction errors when attaching to the framework of the building structure, and the work process for expanding and contracting the entire brace becomes easy.

  FIG. 4 shows an example in which the triple pipe seismic brace according to the present invention is applied to a building structure. As shown in the figure, gussets (66a, 66b) are respectively provided at one corner of a frame (building structure) 60 composed of columns 62 and beams 64 and at one corner of the diagonal position. Both end portions of the two are attached to the gussets (66a, 66b) by bolt joints (68a, 68b) through bolt holes formed in the bolt joint members (20a, 20b).

  And in the state where it was incorporated in the framework of such a building structure, when the axial force tube 12 was repeatedly subjected to compression and tension due to an earthquake, the axial force tube 12 tried to buckle outward. In this case, the buckling is restrained by the outer reinforcing steel pipe 16, and when the axial force pipe 12 tries to buckle inward, the buckling is restrained by the inner stiffening pipe 14.

  Therefore, when the axial force tube 12 is about to buckle in either the outward or inward direction, the buckling is suppressed, and the energy absorption efficiency is excellent, and the pillars and beams of the building structure are broken. The safety of the skeleton is maintained.

  As mentioned above, although embodiment of this invention was described in detail, this invention is not limited to the said embodiment at all, A various change is possible in the range which does not deviate from the summary of this invention.

  For example, in the above-described embodiment, the triple-pipe structure portion of the axial force tube 12 is mainly shown for a long hole, but even if a concave groove is formed instead of a complete hole. It is important that the area is easily yielded, so that the original function can be exhibited.

  Moreover, since the seismic brace 50 provided with the length adjustment mechanism can expand and contract the entire seismic brace 50 only by the rotation of the joint member 52, the seismic brace 50 and the building structure 60 are joined. Needless to say, the joining member for this purpose can correspond not only to the bolt joining members (20a, 20b) but also to various things such as clevis joints.

  The triple-pipe seismic brace according to the present invention can be used for various building structures such as steel-framed reinforced concrete architecture, reinforced concrete architecture, steel-framed architecture, and civil engineering structures if necessary.

It is the figure which showed the cross-section of the triple pipe vibration control brace which concerns on one Embodiment of this invention. It is the figure which showed the triple pipe structure part of the axial force pipe in the triple pipe damping brace shown in FIG. It is the figure which showed the cross-section of what provided the length adjustment member in the triple pipe damping brace shown in FIG. It is the figure which showed an example of the building structure to which the triple pipe seismic brace shown in FIG. 1 is applied. It is the figure which showed an example of the vibration damping brace of the double pipe structure known conventionally.

Explanation of symbols

10 Triple pipe seismic brace 12 Axial force pipe 14 (inside) stiffening pipe 16 (outside) stiffening pipe 32 long hole 34 bone 52 length adjustment member

Claims (3)

  In a triple-tube structure damping brace in which stiffening tubes for preventing buckling of the axial force tube are concentrically disposed on the inner side and the outer side of the axial force tube, respectively, the triple tube structure portion of the axial force tube A triple-tube seismic bracing characterized in that a plurality of elongated holes or concave recess grooves extending in the axial direction are formed on the shaft to intentionally reduce the cross section of the axial force tube.   The said recessed hollow is formed in any one or both of the opposing surface of the inner side stiffening pipe of the said axial force pipe | tube, and the opposing surface of an outer side stiffening pipe | tube. Triple-tube seismic control brace. The vibration control brace having a triple pipe structure according to claim 1, wherein the axial force pipe has a length adjusting mechanism.

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