JP4732975B2 - Brace-type viscoelastic damper mounting structure - Google Patents

Description

  The present invention relates to a structure for attaching a viscoelastic damper in a K brace shape to attenuate a vibration caused by an external force such as an earthquake in a framework frame of a building having a lightweight steel structure.

In a building such as a house, an outer tube, an inner tube that is loosely inserted into the outer tube, and an outer tube and an inner tube are attached in a frame frame formed of columns and horizontal members. A viscoelastic damper consisting of a viscoelastic body is installed in a K-brace shape, and the vibration energy is absorbed by shear deformation of the viscoelastic body due to the reciprocal movement of the outer tube and inner tube during vibration. Damping structures are often used. As an attachment structure between the brace viscoelastic damper and the frame assembly, for example, as shown in Patent Document 1, there is a structure in which a reinforcing plate or a fixing member fixed to the outer periphery of a column is pin-joined via a gusset plate. Are known.
As another mounting structure, as disclosed in Patent Document 2, a structure in which a damper-side steel plate is frictionally joined to a gusset plate fixed to a joint portion of a shaft frame by a high-strength bolt is also known. Yes.

JP 2002-339590 A JP 2001-164790 A

  In the case of the former pin joint, high dimensional accuracy is required for the viscoelastic damper and the shaft frame, leading to an increase in cost. In addition, since the latter structure using high-strength bolts requires a certain joining length in order to secure joining strength, there is a possibility that the length of the damper part (viscoelastic body part) is constrained. However, if the bolts are enlarged to ensure strength, they will not fit within the thickness of the frame. This is the same in the case of a lightweight steel structure. In particular, in a frame structure of a lightweight steel structure, a C-shaped steel may be used as a column with an opening portion in the frame. It is necessary to intervene many intermediate members for reinforcement or the like in the connection with the elastic damper, so that the joint portion is easily complicated, and it is difficult to ensure the length of the damper portion and to make the joint portion compact.

  Therefore, the present invention can secure the maximum length of the damper portion even if the viscoelastic damper is a double pipe, and can be suitably attached to a lightweight steel frame frame with a low-cost and compact configuration. An object of the present invention is to provide a mounting structure for a brace-type viscoelastic damper.

In order to achieve the above object, according to the first aspect of the present invention, a pair of outer tube fittings are inserted and fixed in a state where a predetermined gap is formed between ends of the viscoelastic damper on the outer tube side. On the other hand, a plate-shaped inner tube mounting bracket is fixed to the end portion on the inner tube side, and a pair of sandwiching brackets are provided at predetermined intervals in the frame thickness direction on the upper and lower ends of one column in the frame assembly frame. Are fixed in parallel with the frame surface, while an intermediate bracket is fixed in the middle of the other column in parallel with the frame surface, the viscoelastic damper is clamped, and the intermediate bracket is sandwiched between the outer tube mounting brackets. While joining with a high-strength bolt, the inner pipe mounting bracket is sandwiched directly or indirectly with a clamping bracket, and both are joined with a high-strength bolt, so that it is installed in a K-shape within the shaft frame. Is.
Note that the “upper and lower ends of one column” to which the clamp is fixed in the present invention is the case where the clamp is provided only on the column in the vicinity of the joint between the column and the horizontal member. Including a case where a clamp is provided across the frame.
In addition to the object of the first aspect, the second aspect of the invention provides the outer tube mounting bracket with a pair of U-shaped brackets whose open sides are mutually external. It is configured to be arranged back to back in the direction.
In order to maintain good workability and workability on the side of the frame frame, in addition to the object of claim 1 or 2, the invention described in claim 3 has a cross-section A pair of U-shaped fittings are arranged so that a predetermined gap parallel to the frame surface is formed between them, and the inner pipe fitting is sandwiched by the fittings.
In addition to the object of any one of claims 1 to 3, the invention described in claim 4 provides an intermediate metal fitting in the axial direction of the viscoelastic damper in order to obtain an intermediate metal fitting that can be reduced in weight while maintaining strength. Thus, a pair of joint portions whose width gradually increases from the viscoelastic damper side to the column side is formed into a plate-like body formed symmetrically in the vertical axis.

According to the first aspect of the present invention, since even a double tube viscoelastic damper can be attached to the frame frame with a minimum configuration, the joint portion is compactly accommodated within the frame thickness, and the damper portion The maximum length can be secured and the necessary damping performance can be maintained. In particular, since the mounting bracket is fixed to the outer tube and the inner tube of the viscoelastic damper in advance, the work on site is simplified and the workability is also improved. Therefore, cost reduction can be expected together with downsizing.
According to the second aspect of the invention, in addition to the effect of the first aspect, the cross-sectional area of the metal fitting can be secured large even within a narrow frame thickness, and the reliability of the joint portion is increased.
According to invention of Claim 3, in addition to the effect of Claim 1 or 2, even when C-type steel is used for a pillar, the clamp can be arrange | positioned avoiding the opening part. Therefore, a space (work area for bolting or the like) for attaching the column to the girder can be secured, and workability and workability are not impaired.
According to the fourth aspect of the present invention, in addition to the effect of any one of the first to third aspects, an intermediate fitting that can be reduced in weight while maintaining the strength of the viscoelastic damper in the axial direction can be obtained.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is an explanatory view showing an example of a viscoelastic damper used in the mounting structure of the present invention, FIG. 2 is an enlarged cross sectional view thereof, and a viscoelastic damper 1 includes an outer tube 2 having a rectangular cross section and an outer tube thereof. The inner tube 3 is partially inserted into the outer tube 2 coaxially from one end side, and the overlap between the tubes 2 and 3 is interposed in the entire surface between the tubes 2 and 3. And a viscoelastic body 4 (here, styrene-based, shown in a net shape in FIGS. 1 and 2) to which the opposing surfaces of both the tubes 2 and 3 are bonded.

  The outer tube 2 is formed by joining flanges 6 and 6 extending over the entire length in the longitudinal direction with bolts facing each other with the open sides of a pair of metal fittings 5 and 5 bent in a U shape facing each other. Then, a pair of outer tube fittings 7 and 7 having a U-shaped cross section are inserted into the mounting end portion of the shaft frame, which will be described later, with the open sides facing each other, and the outer tube 2 It is welded to the inner surface and protrudes from the mounting end. In this state, a gap through which a gusset plate 24 described later can be inserted is formed between the back-to-back outer pipe fittings 7 and 7. Reference numerals 8 and 8 denote bolt holes provided on the center line of each outer pipe fitting 7.

On the other hand, the inner pipe fitting 10 is also connected to the end of the inner pipe 3 attached to the shaft frame. The inner pipe fitting 10 is a flat plate having bolt holes 11 and 11 formed on the center line, and is inserted from the end of the inner pipe 3 into notches 9 and 9 formed at the center of both short side surfaces. It is welded in a state and protrudes from the mounting end.
If the mounting brackets 7 and 10 are respectively fixed to the outer tube 2 and the inner tube 3 and the entire surface is subjected to rust prevention treatment, it can be mounted as it is on the site without being post-processed as a brace unit.

  FIG. 3 is a front view showing the shaft frame 20 to which the viscoelastic dampers 1 and 1 are attached, and is used in a light steel frame housing. The frame 20 is composed of a pair of left and right columns 21 and 21 that are C-shaped steels with the opening sides facing each other, and a C-shaped steel that is also disposed with the opening sides facing each other. It has a pair of horizontal members 22, 22 installed between them, and a so-called K brace structure in which the viscoelastic dampers 1, 1 are installed so as to be symmetrical with respect to the vertical axis above and below the frame surface. Yes. Here, the inner tube mounting bracket 10 on the inner tube 3 side of each viscoelastic damper 1 is connected to the upper and lower ends of the left column 21 via a gusset plate 23 serving as a clamping bracket, and a pair on the outer tube 2 side. The outer pipe fittings 7 and 7 are connected to an intermediate portion of the right column 21 via a gusset plate 24 serving as an intermediate fitting. Reference numeral 25 denotes an intermediate rail that is installed horizontally between the gusset plate 24 and the intermediate portion of the left column 21 to connect the two.

As shown in FIG. 4, a pair of gusset plates 23 provided on the left column 21 are welded in parallel to the frame surface at a predetermined interval in the thickness direction of the frame on the inner surface side of the columns 21. A pair of joint fittings 26, 26 having a U-shaped cross section are arranged in the brace direction with the open sides facing outward, and are welded to the opposing surfaces of the gusset plate 23. Yes. In this state, a gap through which the inner tube fitting 10 of the inner tube 3 can be inserted is formed between the joint members 26 and 26. Each joint fitting 26 is provided with bolt holes 27, 27 in parallel at positions corresponding to the bolt holes 11, 11 of the inner pipe fitting 10.
Therefore, the inner pipe 3 is joined to the gusset plate 23 by inserting the inner pipe mounting fitting 10 between the joining fittings 26 and 26 and tightening both fittings with the high strength bolts 28 and 28.

On the other hand, as shown in FIG. 5, the outer tube 2 is connected by inserting a gusset plate 24 between the outer tube fittings 7 and 7. The gusset plate 24 is a plate-like body in which a pair of joint portions 24a and 24a whose width gradually increases in the axial direction of the viscoelastic damper 1 from the viscoelastic damper 1 side to the column 21 side are formed symmetrically in the vertical axis. Since the bolt holes 29 and 29 are formed at positions corresponding to the bolt holes 8 of the outer tube mounting bracket 7 at the joint portion 24a, the outer tube mounting brackets 7 and 7 and the gusset plate 24 are connected to the high strength bolt. The outer tube 2 is joined to the gusset plate 24 by tightening with 30 and 30.
In the axial frame 20 in which the pair of viscoelastic dampers 1 and 1 are thus constructed, when a horizontal external force is repeatedly applied in the plane direction of the frame due to an earthquake or the like, the upper and lower viscoelastic dampers 1 and 1 are axially moved. The compressive force and the tensile force act alternately on the outer tube 2 and the outer tube 2 and the inner tube 3 operate in the opposite axial directions. By this operation, the viscoelastic body 4 is sheared to cause a damping action.

  Thus, according to the attachment structure of the viscoelastic damper 1 of the above-described form, a predetermined gap is formed between the pair of outer tube fittings 7 and 7 at the end of the viscoelastic damper 1 on the outer tube 2 side. On the other hand, the plate-shaped inner tube mounting bracket 10 is fixed to the end on the inner tube 3 side, and the thickness direction of the frame is on the upper and lower ends of one column 21 in the frame frame 20. The pair of gusset plates 23 and 23 are fixed in parallel to the frame surface at a predetermined interval, while the gusset plate 24 is fixed to the middle portion of the other column 21 in parallel to the frame surface. 1 and 1, the gusset plate 24 is sandwiched between the outer pipe mounting brackets 7 and 7 and both are joined with the high-strength bolts 30, while the inner pipe mounting bracket 10 is joined with the gusset plates 23 and 23 via the joining brackets 26 and 26. And indirectly sandwiched Since both are joined with the high-strength bolt 28, the double-tube viscoelastic damper 1 can be attached to the frame frame 20 with a minimum configuration, so the joint is compact within the frame thickness. Therefore, it is possible to secure the maximum length of the damper portion and maintain the required damping performance. In particular, since the mounting brackets 7 and 10 are fixed in advance to the outer tube 2 and the inner tube 3 of the viscoelastic damper 1, work on site is simplified and workability is improved. Therefore, cost reduction can be expected together with downsizing.

In particular, here, a pair of fittings 26, 26 having a U-shaped cross section are arranged on the opposing surfaces of the gusset plates 23, 23 so that a predetermined gap parallel to the frame surface is formed therebetween. Since the inner pipe mounting bracket 10 is sandwiched between the joining brackets 26, 26, the gusset plates 23, 23 can be disposed avoiding the opening of the C-shaped steel used for the column 21. Therefore, a space (working area for bolting or the like) for attaching the column 21 to a large beam such as H steel can be secured, and workability and workability are not impaired.
Further, since the outer tube mounting bracket 7 and the joining bracket 26 are arranged in a pair of brackets having a U-shaped cross section back to back with the open sides facing each other, the sectional area of the bracket can be reduced within a narrow frame thickness. A large amount can be secured, and the reliability of the joint is increased.
In addition, the pair of joints 24a and 24a whose width gradually increases in the axial direction of the viscoelastic damper 1 from the viscoelastic damper 1 side to the column 21 side in the gusset plate 24 serving as an intermediate metal fitting are symmetrical in the vertical axis. By using the formed plate-like body, the width on the side to be joined to the column 21 is secured widely, while the side to which the middle rail 25 is joined is cut out so as to be triangular. Accordingly, it is possible to reduce the weight while maintaining the strength of the viscoelastic damper 1 in the axial direction.

In the above embodiment, the mounting structure of the present invention is applied to a frame frame using C-shaped steel as a column. However, the present invention can be similarly applied to a frame frame using other type steel. It is. For example, a shaft frame 40 shown in FIG. 6 is constructed by viscoelastic dampers 1 and 1 laid in a K-brace shape between a pair of columns 41 and 41 using square pipes, and is used for a partition wall.
In this frame frame 40, it is not necessary to consider the workability of mounting to the girder like the frame frame 20 in FIG. 3, so that the gusset plates 23, 23 are illustrated in the thickness direction of the frame as shown in FIG. The inner pipe mounting bracket 10 of the inner pipe 3 is inserted between the gusset plates 23 and 23 and directly joined by high-strength bolts 28 and 28. The mounting on the outer tube 2 side is the same as that in the form of FIG.
According to this modified example, the joining brackets 26 and 26 for joining the gusset plate 23 and the inner tube mounting bracket 10 to the inner tube 3 side become unnecessary, so that the number of parts can be reduced and the cost can be reduced as compared with the configuration of FIG. This is advantageous.

On the other hand, the viscoelastic damper is not limited to a tube having a rectangular cross section, and a tube having another cross section such as a circular cross section may be used. Further, the outer tube may be formed by rivet joining or welding between a pair of metal fittings, or may be formed by a single tube like the inner tube. Further, the viscoelastic body is not limited to the entire surface between the tube bodies, but may be bonded to a part thereof.
In addition, the fixing to the outer tube mounting bracket, the inner tube mounting bracket and the viscoelastic damper side is not limited to welding, and other fixing means such as a high-strength bolt, a normal bolt, and a rivet can be used.

Further, the outer tube-side outer tube fitting and the inner tube-side fitting are not limited to a U-shaped cross section, and can be appropriately adopted such as a trapezoidal shape, a flat plate shape, and a square pipe.
Similarly, the holding metal fittings and intermediate metal fittings are not limited to flat plates, and if strength is required, they may be changed as appropriate, such as a U-shaped cross section with both ends folded back or using flat rectangular pipes. Absent.
In addition, fixing to the outer tube mounting bracket and inner tube mounting bracket and the shaft frame side is not limited to high-strength bolts, but can be appropriately designed to increase the number of bolts or tighten them in multiple rows to replace normal bolts. Can change. In addition, it is clear from the modified example of FIG. 6 that the joint metal fitting can be omitted.

It is explanatory drawing (a top shows a plane and the bottom shows a side surface, respectively) of a viscoelastic damper. It is an expansion cross-sectional view of a viscoelastic damper. It is a front view of a shaft frame. It is explanatory drawing which shows the attachment structure of the viscoelastic damper in the upper and lower ends of a pillar. It is explanatory drawing which shows the attachment structure of the viscoelastic damper in the intermediate part of a pillar, (A) shows the cross section of a damper longitudinal direction, (B) shows the cross section of a transversal direction, respectively. It is a front view which shows the example of a change of a shaft frame. It is explanatory drawing which shows the attachment structure of the viscoelastic damper in the upper and lower ends of the pillar in FIG.

Explanation of symbols

  1 ・ ・ Viscoelastic damper 2 ・ ・ Outer tube 3 ・ ・ Inner tube 4 ・ ・ Viscoelastic body 7 ・ ・ Outer tube mounting bracket 10 ・ ・ Inner tube mounting bracket 20, 40 ・ ・ Frame assembly 21, 41... Pillar, 22.. Horizontal member, 23, 24 .. Gusset plate, 26 .. Joint fitting, 28, 30.

Claims (4)

An outer tube, an inner tube partially inserted coaxially with the outer tube, and a viscoelastic body between the overlapping portions of both the tubes and the opposite surfaces of the two tubes are bonded to each other, A viscoelastic damper that shears and deforms the viscoelastic body by an operation in the opposite axial direction to the inner tube to cause a damping action is installed in a K-shape in a frame assembly formed by a column and a horizontal member. Brace-type viscoelastic damper mounting structure for
A pair of outer tube fittings are inserted and fixed to the outer tube side end of the viscoelastic damper in a state where a predetermined gap is formed therebetween, while the inner tube side end is formed into a plate-like shape. Fix the inner pipe mounting bracket,
On the upper and lower ends of one column in the frame frame, a pair of clamping brackets are fixed in parallel with the frame surface at a predetermined interval in the thickness direction of the frame, while the frame surface is positioned at the middle portion of the other column. Fix the intermediate bracket in parallel with
The viscoelastic damper is sandwiched between the intermediate fitting with the outer pipe fitting and joined with a high-strength bolt, while the inner pipe fitting is directly or indirectly pinched with the clamping fitting to increase the height of both. A brace-type viscoelastic damper mounting structure, wherein the brace-type viscoelastic damper is installed in a K-shape in the shaft frame by joining with a force bolt.   2. The brace-type viscoelastic damper mounting structure according to claim 1, wherein the outer tube mounting bracket is a pair of brackets having a U-shaped cross section arranged back to back with the open sides facing each other.   A pair of joining brackets having a U-shaped cross section are arranged on the opposing surfaces of the sandwiching fixture so that a predetermined gap parallel to the frame surface is formed therebetween, and the inner fitting fitting is attached by the joining fixture. The mounting structure of the brace type viscoelastic damper according to claim 1 or 2, wherein the structure is sandwiched. The intermediate metal fitting is a plate-like body in which a pair of joint portions whose width gradually increases in the axial direction of the viscoelastic damper from the viscoelastic damper side to the column side are formed symmetrically in the vertical axis. A brace-type viscoelastic damper mounting structure according to any one of the above.

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