JP6544546B1 - Brace - Google Patents

Abstract

The present invention provides a pin joint type buckling restrained brace capable of adjusting the overall length of the brace and introducing tension after installation, and a tensile brace which is its basic configuration. A brace 7 is obtained by adding a buckling restraint member to a tension brace 5 and diverting it to a buckling restraint brace, and two round steels 21 and 21 are circular steel pipes 8 as buckling restraint members, respectively. , 8 is a configuration enclosed. Both circular steel pipes 8 and 8 are externally fitted so as to straddle the cylindrical female screw members 3b and 4b of the joint members 3 and 4 and the cylindrical female screw member 6 located at the center. Inside the circular steel pipes 8 and 8, a plurality of ring-shaped spacers 9 made of a steel material are inserted through a pair of round steels 21 and 21 (braces core material), and attached at predetermined intervals in the longitudinal direction It is done. These ring-shaped spacers 9 are set to a size substantially in contact with the circular steel pipes 8 and 8 and the brace core members 21 and 21, and are fixed by the fixing fitting 91. [Selected figure] Figure 3

Description

  The present invention relates to a steel brace used to reinforce a steel frame structure, and more particularly, in the form of a basic configuration, it can be used as a tension brace, and further, a buckling restrained brace is added with a buckling restrained member. The present invention relates to a brace that is excellent in compressive force load, easy to adjust the length of the brace, and capable of introducing tension.

  Traditionally, types of braces used to reinforce steel frame structures include tensile braces, compression braces and buckling restrained braces. Tensile braces are used effectively for the advantages of steel materials, and steels with small cross-sections have high resistance, and thus are often used in small to medium-sized steel frame structures. On the other hand, the performance of the compression brace is determined based on the buckling strength of the brace core (steel material), but the joining member joined to the end of the brace core and the gusset plate on the steel frame side The buckling strength is different due to the difference in the joint conditions (pin joint or fixed joint).

  Furthermore, a buckling restrained brace is provided with features of both a tensile brace and a compression brace, and a steel tube called a buckling restrained steel tube is used as a means for preventing the buckling of the tensile brace material (brace core material). By covering the outer periphery of the structure, the structure is configured to prevent a decrease in brace resistance due to buckling of the brace core material.

By the way, in the buckling restrained brace which consists of the above-mentioned composition, the following problems exist in terms of construction nature, productivity, reinforcement performance, etc.
(1) In the steel frame construction work, the work accuracy is not good because the dimensional accuracy among the attachment positions of the braces is largely dispersed.
(2) In the case of fixed connection with high strength bolts, since a large number of bolt insertion holes are required, the dimension between the insertion holes in the joint member and the gusset plate is likely to vary, leading to a decrease in workability.
(3) The productivity is poor because the brace can not be manufactured unless the original dimensions at the brace mounting position are confirmed.
(4) Since the steel material itself is deformed or bent at a stage before being processed into a brace, the bending is not eliminated even after being processed into a brace.
(5) After attachment of the brace, the weight of the brace itself causes deflection, resulting in deflection of the brace and making correction impossible.
(6) It is a structure which is difficult to cope with the manufacturing error of the brace itself, the manufacturing error of the gusset plate, the error generated by welding and the like.
(7) Brace subjected to compressive force is likely to cause compressive bending failure, local buckling failure, neck breakage and the like at the end of the brace, particularly at the lower end side.

  Among the above-mentioned problems, in particular, with regard to (1) to (3), a buckling restrained brace capable of adjusting the entire length of the brace has been proposed as a solution means (Patent Document 1).

Patent No. 5506744 (See FIGS. 1 to 3, paragraph 0032, etc.)

  The buckling-restrained brace of the above-described conventional example has a straight shape by screwing male threads on both ends of a rod-shaped steel material having a smaller cross-sectional area than the brace core to the female threads of a pair of braces The length of the entire brace is adjusted by connecting (coaxially) and rotating the rod-shaped steel material positioned in the middle. However, since the rod-shaped steel member connecting the pair of brace core members hides inside the buckling restrained tube in a state where both ends of the brace are joined to the gusset plate, the turnbuckle function is necessary after installation of the brace. It is difficult to eliminate deflection and introduce tension by using it. For this reason, in the buckling restrained brace of the said prior art, there existed a problem that it was not effective with respect to the said problem (4)-(6).

  The present invention was created to solve the above-mentioned problems of the prior art, and it is possible to easily adjust the entire length of the brace and to introduce a tension even after installation. An object of the present invention is to provide a highly convenient brace that can also be used as a tension brace in a basic configuration without a buckling restraint member.

In order to solve the above problems, the brace according to the main configuration of the present invention comprises a brace core made of round steel whose ends are formed by right-handed and left-handed screws, and one end of each end of the brace core. A pair of joining members which are screwed together by a female screw portion and are respectively pin-joined to a pair of gusset plates attached to a rectangular frame surface of a steel frame by a plate portion on the other end, and the entire length of the brace core A brace provided with a buckling restraint member made of a circular steel pipe, and a plurality of ring-shaped spacers smaller in diameter than the circular steel pipe and having an outer diameter close to the inner diameter are inserted into the brace core material at predetermined intervals in the longitudinal direction And secondary buckling restraint members consisting of a circular steel pipe or a coiled steel bar having an outer diameter smaller than the inner diameter of the circular steel pipe and a length substantially the same as that of each section divided by the ring-shaped spacers are individually Insertion It is, is characterized by employing the technical means that (claim 1).

According to the above configuration, when the buckling restraint member made of a circular steel pipe is not used, it can be used as a tensile brace due to the large resistance of the round steel used for the brace core material. Furthermore, when the brace core material is a pair of round steels connected by a cylindrical female screw member (claim 2), adjustment of the overall length dimension of the brace is achieved by rotating the central cylindrical female screw member. In addition, tensile force can be introduced to the brace core material, and the original strain existing before the processing of the steel material and the bending of the brace itself due to its own weight are eliminated.

In the upper Ki構 formed, the brace core compartment portion in a ring-shaped spacer, circular steel tube outer diameter smaller than the inner diameter of the circular steel tube is disposed on the outermost periphery (buckling restraint member) or circular steel tube, ( the coiled steel bar small coil outer diameter than the inner diameter of the buckling restraint member) through interpolation as a secondary buckling restraint member, including these ring-shaped spacer and secondary buckling restraint member, steel tube (buckling restraint member) in since it is configured that surrounds the entire brace core, because where the buckling restraint member and the secondary buckling restraint member to effectively prevent the buckling of the inner brace core, effective buckling restraint braces it can be used for.

Further, in the bonding member of the main configuration, the plate portion can be a pair of two plates through which pin bolts are inserted in a state in which the gusset plate is received between the opposing surfaces (claim 3 ). According to such a configuration, by inserting the pin bolt in a state where the pin holes of the gusset plate and the pin holes of the pair of plates are aligned, it is possible to simply and reliably pin-bond the braces.

In the brace according to the present invention, the following effects can be obtained by adopting the above configuration.
(1) The brace according to the present invention can be used as a tension brace when the circular core (buckling restraint member) does not surround the brace core, and when the circular core surrounds the brace core Since it can be used as a buckling restrained brace, it is easy to respond to various usage conditions by its selection, and it becomes a brace easy to use.
(2) When the brace core material is a pair of round steels connected by a cylindrical female screw member, the direction in which the pair of round steels approach or separate from each other by the rotation of the cylindrical female screw member positioned in the middle Because of the displacement, it is possible to easily adjust the length dimension of the entire brace over a wide range.
(3) Further, since the cylindrical female screw member for screwing and connecting the pair of round steels is exposed to the outside, the cylindrical female screw member is appropriately selected even in a state where the brace is attached to the gusset plate. The rotation in the direction makes it possible to reliably introduce tension into the brace body.

(A), (b) is the front view and side view concerning the 1st reference example (tensile brace) relevant to the brace of the present invention, respectively. (A), (b) is the front view and side view concerning the 2nd reference example (tensile brace) relevant to the brace of the present invention, respectively. (A), (b) is the front view and partial longitudinal cross-section which concern on the 3rd reference example (buckling-restrained brace) relevant to the brace of the present invention, respectively. (A), (b) is the front view and longitudinal cross-sectional view of the ring-like spacer used by 3rd reference example of FIG. 3, and this invention . It is explanatory drawing which showed the attachment method of the ring-shaped spacer of FIG. It is a front view of the fixing bracket used for fixing of the ring-shaped spacer of FIG. (A), (b) is explanatory drawing which showed the load-bearing model of the buckling restrained brace based on the 3rd reference example of FIG. 3, and its buckling shape. (A) and (b) show the load resistance model of the buckling restrained brace and its buckling shape in the case of using one brace core with the same brace length as FIG. 7 as a comparative example corresponding to FIG. 7 FIG. (A), (b) is the front view and partial longitudinal cross-sectional view concerning the 4th reference example (buckling restraint brace) relevant to the brace of the present invention, respectively. (A), (b) is explanatory drawing which showed the deformation | transformation state which showed the explanatory view which showed typically the behavior which leads to the buckling of a brace core material in the buckling restrained brace by a prior art. (A), (b) is respectively the front view and partial longitudinal cross-sectional view which concern on 1st Embodiment (buckling-restrained brace) of the brace of this invention. (A), (b) is respectively a front view and a partial longitudinal cross-sectional view concerning a 2nd embodiment (buckling restraint brace) of a brace of the present invention. It is the front view which showed the connection method with a gusset plate in construction of the buckling restrained brace of 3rd reference example, 4th reference example, 1st Embodiment, and 2nd embodiment . It is the front view which showed the method of introduce | transducing tension into a buckling restrained brace as a next | following process of FIG.

Hereinafter, an embodiment of a brace according to the present invention will be described with reference to the drawings. In each embodiment and reference example , the same parts are indicated by the same reference numerals, and duplicate explanations may be omitted.

Figure 1 (a), (b) are a front view and a side view according to the first exemplary embodiment of the brace that relate to the present invention. The illustrated brace 1 is composed of a brace core 2 and a pair of joining members 3 and 4 disposed on both ends thereof, and is used as a tension brace. The brace core 2 is made of round steel, and a right screw 2a and a left screw 2b are formed at both ends. In the joining members 3 and 4, cylindrical female screw members 3b (right-handed screw) and 4b (left-handed screw) are welded to one surface of the wedge plates 3a and 4a located in the middle, and these cylindrical female-threaded members 3b and 4b It is screwed to the brace core material 2 through. Further, a pair of plate members 3c and 4c are welded to the other surface of the sheathing plates 3a and 4a. Gusset plates (not shown) having insertion holes are juxtaposed at an interval allowing insertion between the opposing surfaces, and two plate members 3c and 4c are provided with insertion holes 3d for pin bolts in the respective plate members 3c and 4c. , 4d are formed in alignment with each other. As these joint members 3 and 4, a bifurcated joint metal generally called a clevis type is used.

FIG. 2 shows a second reference example related to the brace of the present invention, which is an example applied to a tension brace as in the first reference example . The illustrated brace 5 is different from the first reference example in that the brace core 2 is not a single round steel but a pair of round steels 21 and 21 connected by a cylindrical female screw member 6. In this case, both ends of the pair of round steels 21 and 21 are respectively formed by the right screw 21a and the left screw 21b, and the inside of the cylindrical female screw member 6 corresponds to the right screw with the center as the boundary. It is divided into left hand screw. The direction of each male screw part in the two round steel bars 21 and 21 in the coupled state is alternately arranged with right screw, left screw, right screw and left screw from the lower end to the upper end in the drawing. There is.

Figure 3 (a), (b) are a front view and partially sectional view of a third reference example of braces that are related to the present invention. The illustrated brace 7 is obtained by adding a buckling restraint member to the tension brace 5 according to the second reference example and diverting it to a buckling restraint brace. That is, the two round steel bars 21 and 21 are the structures enclosed by the circular steel pipes 8 and 8 as a buckling restraint member, respectively. Both circular steel pipes 8 and 8 are externally fitted so as to straddle the cylindrical female screw members 3b and 4b of the joint members 3 and 4 and the cylindrical female screw member 6 located at the center. Further, inside the circular steel pipes 8, 8, a plurality of ring-shaped spacers 9 made of a steel material are inserted through the pair of round steels 21, 21 (braces core material), and a predetermined interval is provided in the longitudinal direction. Is attached. The ring-shaped spacers 9 are set to a size substantially in contact with the circular steel pipes 8 and 8 and the brace core members 21 and 21 and fixed by a fixing fitting 91 (see FIG. 6). In addition, as for the arrangement | positioning space | interval of the ring-shaped spacer 9, about 6 to 8 times of the axial diameter d1 of the brace core material 21 are suitable. In this reference example , six ring-shaped spacers 9 are used throughout the brace, but by increasing the number of ring-shaped spacers 9, the length of brace core 21 is increased and the entire length of brace 7 is increased. Specifications are also possible, and compressive bending limit loads can be further increased.

  Next, a method of attaching the ring-shaped spacer 9 will be described with reference to FIGS. FIGS. 4A and 4B are a front view and a longitudinal sectional view of the ring-shaped spacer 9. The ring-shaped spacer 9 has a round nut shape as a whole, but the thread valley of the internal thread 9a is formed shallower than usual. The reason is that the clearance between the brace core (round steels 21 and 21) and the buckling restrained steel pipe (round steels 8 and 8) affects the buckling restraint strength of the brace, so the condition of use of the ring spacer 9 is This is because a situation close to close contact is desired. When round steel is used for the brace core 21, as shown in FIG. 5, the outer diameter d1 of the brace shaft and the outer diameter d2 of the male screw 21a generally have a relationship of d1 ≦ d2. Therefore, when the ring-shaped spacer 9 is attached by passing the male screw portion 21 a, a gap is generated between the inner peripheral surface of the ring-shaped spacer 9 and the outer peripheral surface of the brace core 21. From such a circumstance, in order to enhance the adhesion between the ring spacer 9 and the brace core 21, it is effective to make the thread valley of the internal thread 9a of the ring spacer 9 shallow. Then, at a predetermined position, the ring-like spacer 9 is positioned and prevented from moving by being sandwiched from both sides by a pair of fixing brackets 91 having a substantially C shape and spring property shown in FIG.

FIGS. 7 (a) and 7 (b) show the load resistance model of the buckling restrained brace according to the third reference example of FIG. 3 and its buckling shape, and FIGS. 8 (a) and 8 (b) show brace core materials as comparative examples. It is an explanatory view showing a load-bearing model of a buckling restrained brace (prior art) in the case of one, and its buckling shape. In the comparison of the buckling loads in this buckling shape model, it is assumed that the buckling load Pcr1 in the buckling restrained brace according to the present invention is four times the buckling load Pcr2 in the prior art.

Figure 9 (a), (b) are a front view and a partial longitudinal sectional view of a fourth reference example of braces that are related to the present invention. The illustrated brace 10 has a configuration in which a coiled steel bar 11 is used as a spacer instead of the ring-shaped spacer 9 used in the third reference example , and the entire length of the pair of brace core members 21 and 21 is used. It is inserted one by one by the crossing length. In this case, the axial diameter of the coiled steel bar 11 is the axial diameter of the circular steel bar close to the distance between the circular steel pipe 8 (buckling restraint member) and the brace core 21. Further, the helical pitch of the coiled steel bar 11 is preferably 5 d or less. In this reference example , the fixing bracket 91 is unnecessary, and at the same time a compressive force acts on the brace core 21, a reaction force due to a spring force is generated in the coiled steel bar 11, so compression of the brace core 21 is performed. It can be expected that the rigidity and the compressive strength of the brace core 21 can be enhanced by the effect of reducing the bending deformation.

  10 (a) and 10 (b) are an explanatory view schematically showing the behavior immediately before the buckling load of the brace core 2 in a general buckling restrained brace and an explanatory view showing an actual deformation state. It is. As shown in (a), although the brace core 2 exhibits a relatively gentle buckling bending deformation, in fact, as shown in (b), the brace core 2 undergoes plastic deformation with twisting and buckling It is known to be a bending deformation.

The first embodiment and the second embodiment to be described next are those in which such a situation is considered. 11 (a) and 11 (b) are a front view and a partial longitudinal sectional view according to a first embodiment of the brace according to the present invention. The illustrated brace 12 is an improvement of the brace 7 of the third reference example . That is, for each section in the longitudinal direction of the brace core 21 divided by the plurality of ring-shaped spacers 9, the circular steel pipe 8 (buckling restraint member) disposed on the outside with the same length as the section concerned By separately inserting and attaching circular steel pipes 13 of a small diameter (secondary buckling restrained steel pipes), it is possible to effectively avoid the reduction in the strength of the brace core 21 and the reduction in the rigidity caused by the buckling bending deformation. . Thus, although the inner circular steel pipe 13 disposed between the ring-shaped spacers 9 also serves to position the ring-shaped spacers 9, excessive deformation due to buckling of the brace core 21 generated between the ring-shaped spacers 9 is obtained. from Rukoto is bound as a secondary buckling restraint member, in combination with the buckling restraint function by steel tube 8 (buckling restraint member) disposed outside, stability and improvement in buckling strength and rigidity of brace 12 Can be further enhanced.

12 (a) and 12 (b) are a front view and a partial longitudinal sectional view according to a second embodiment of the brace according to the present invention. The illustrated brace 14 is one in which a coiled steel bar 15 is used as a secondary buckling restraint member in place of the small diameter circular steel pipe 13 used in the brace 12 of the first embodiment. The coiled steel bar 15 also exerts a spring force and exhibits a function equal to or greater than that of the small diameter circular steel pipe 13.

FIG. 13 is a front view showing a method of installing the brace 7 according to the third reference example of FIG. 3. First, the upper gusset plate 93 welded to the diagonal position of the rectangular frame surface 90 of the steel frame composed of the steel frame column 91 and the steel frame beam 92 is located on one end side of the brace 7 of the third reference example. The pin bolt 94 is inserted in a state where the insertion hole of the joint member 4 and the insertion hole of the gusset plate 93 are aligned, and the upper part of the brace 7 is temporarily fixed by screwing a nut from the opposite side. In a state in which the brace 7 is suspended by the pin bolt 94, the cylindrical female screw member 6 exposed in the central portion is rotated to adjust the length of the brace 7. Then, insert the pin bolt 94 at a position where the position of the insertion hole 96 of the insertion hole and the lower gusset plates 95 of the joint member 3 on the other end of the brace 7 (lower side) matches, the opposite side or Rana Tsu bets Tightening completes installation of the brace 7.

Next, as shown in FIG. 14, when the cylindrical female screw member 6 is rotated in a predetermined direction, the distance between the cylindrical female screw members 3 b and 4 b located at both ends is narrowed, and the brace core 21 is desired. Since the tensile axial force is introduced, the bending of the brace core 21 and the like can be eliminated. In the mounting structure using the lube race 7 mounted in this manner, since the joint members 3, 4 of the upper and lower gusset plate 93 and 95 and the brace 7 is pin bonded form a clevis-type brace 7 compressive stress Can be limited to deformation in a structural surface surrounded by columns and beams, and breakage of an outer wall and the like can be prevented. In addition, when tensile force works, unlike the fixing method with high strength bolts, the inter-pin space of the brace core 21 becomes linear, so the joining members 3 and 4 are less susceptible to stress concentration such as bending deformation by tensile force. Become. In addition, regarding such a construction method, it is applicable also to braces 12 and 14 which concern on the said embodiment of this invention which equipped the cylindrical internal thread member 6 in the intermediate part.

  As mentioned above, although the structure of this invention and its effect were demonstrated based on embodiment, this invention is not limited to the said embodiment. For example, it is possible to use something other than clevis as the joining member, and one of the ends of the brace is not at the intersection of the steel column and the steel beam but across the steel column and the base plate joined to its lower end Of course, various modifications within the scope of the invention, such as bonding to a provided gusset plate, are possible.

  The brace of the present invention can be used as a tensile brace in the basic configuration, and can be a buckling restrained brace by adding an appropriate buckling restrained member, and can further adjust the overall length of the brace and introduce tension. Therefore, further development of the use as reinforcement braces for steel frame structures etc. is expected.

1, 5, 7, 10, 12, 14: Brace, 2, 21: Brace core material (round steel), 3, 4: Joint member, 2a, 21a: Right screw, 2b, 21b: Left screw, 3a, 4a Reference numeral 3b, 4b: cylindrical internal thread member, 3c, 4c: plate member, 3d, 4d: insertion hole, 6: cylindrical internal thread member, 8: circular steel pipe (buckling restraint member), 9: ring Spacer, 9a: female screw, 11: coiled steel bar, 13: circular steel pipe (secondary buckling restraint member), 15: coiled steel bar (secondary buckling restraint member), 90: rectangular frame surface, 91 : Fixing bracket, 93, 95: Gusset plate, 94: Pin bolt

Claims (3)

A brace core made of round steel whose ends are formed into right-handed and left-handed screws, and female threads on one end are screwed to each end of this brace core, and a steel frame is formed on the plate on the other end A brace comprising a pair of joining members respectively pin-joined to a pair of gusset plates attached to the rectangular frame surface and a buckling restraint member consisting of a circular steel pipe surrounding the entire length of the brace core , In the core material, a plurality of ring-shaped spacers smaller in diameter than the circular steel pipe and having an outer diameter close to the inner diameter are inserted at predetermined intervals in the longitudinal direction, and each section divided by the ring-shaped spacers A brace characterized in that a secondary buckling restraint member consisting of a circular steel pipe or a coiled steel bar having an outer diameter smaller than the inner diameter of the section and substantially the same length as the section is individually inserted .   The brace according to claim 1, wherein the brace core comprises a pair of round steels connected by a cylindrical female screw member. The brace according to claim 1 or 2 , wherein the plate portion of the joining member is a pair of two plates through which pin bolts are inserted with the gusset plate being received between the facing surfaces.

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