Friction damper

Abstract

A friction damper that is disposed between a pair of members which move relative to one another in a prescribed direction and suppresses said relative movement by means of frictional force between pressure contact plates that slide in conjunction with the relative movement, said friction damper comprising a first pressure contact plate integrally provided to one member among the pair of members, a second pressure contact plate integrally provided to the other member among the pair of members, and a fastening member that is inserted into a through hole in the first pressure contact plate and a through hole in the second pressure contact plate to press the first pressure contact and the second pressure contact into contact in the plate thickness direction, wherein: one through hole among the through hole in the first pressure contact plate and the through hole in the second pressure contact plate is an elongated hole that is elongated in the prescribed direction; the other through hole among the through hole in the first pressure contact plate and the through hole in the second pressure contact plate is a bolt hole; the fastening member has a bolt that is inserted through the elongated hole and the bolt hole, a nut that is threaded onto the bolt, and a pipe that accommodates the bolt and is accommodated in the elongated hole and the bolt hole; and when the friction damper is subjected to an axial force in the prescribed direction, the pipe contacts the short-diameter portion of the elongated hole to suppress buckling in an intersecting direction intersecting the prescribed direction and the plate-thickness direction.

Description

Friction damper

[0001] The present invention relates to a friction damper.

[0002] Friction dampers are known that are disposed between a pair of members that move relative to each other in a predetermined direction to suppress the relative movement. For example, the friction damper disclosed in Patent Document 1 is provided on the flange and web of a brace (H-shaped steel) of a building frame, and is capable of responding not only to axial forces along the brace span direction but also to stresses (bending moments) in a direction intersecting the span direction.

[0003] Japanese Patent Application Laid-Open No. 2015-113955

[0004] However, sometimes friction dampers are not installed on the flanges, but only on the webs. In this case, if the bending moment exceeds the design assumption, the bolts inserted into the webs (long holes) of the friction dampers abut against the inner surface of the short diameter of the long holes, providing resistance to prevent buckling. However, there is a risk of damage to the bolts or buckling of the components that make up the brace.

[0005] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to suppress buckling without affecting the bolt.

[0006] The main invention for achieving the above object is a friction damper that is disposed between a pair of members that move relative to each other in a predetermined direction, and that suppresses the relative movement by frictional force between pressure contact plates that slide in association with the relative movement, the friction damper comprising: a first pressure contact plate that is integral with one of the pair of members; a second pressure contact plate that is integral with the other of the pair of members; and fastening members that are inserted through through holes in the first pressure contact plate and the second pressure contact plate, and that press the first pressure contact plate and the second pressure contact plate together in a plate thickness direction perpendicular to the opposing surfaces of the first pressure contact plate and the second pressure contact plate; one of the through hole of the first crimped plate and the through hole of the second crimped plate is a long hole that is long in the predetermined direction, the other of the through hole of the first crimped plate and the through hole of the second crimped plate is a bolt hole, the fastening member has a bolt inserted into the long hole and the bolt hole, a nut threaded onto the bolt, and a pipe through which the bolt is passed and housed in the long hole and the bolt hole, and when an axial force in the predetermined direction acts on the friction damper, the pipe is brought into contact with the short diameter portion of the long hole, thereby suppressing buckling in the predetermined direction and a transverse direction that intersects the plate thickness direction.

[0007] Other features of the present invention will become apparent from the following description and drawings.

[0008] According to the present invention, buckling can be suppressed without affecting the bolt.

[0009] 2A and 2B are schematic explanatory diagrams of a friction damper 10 according to the present embodiment. Fig. 2A is a plan view of a brace fragment 5, and Fig. 2B is a cross-sectional view of the brace fragment 5. Fig. 3A is a plan view of a connecting member 7, and Fig. 3B is a cross-sectional view of the connecting member 7. Fig. 1 is a cross-sectional view taken along line A-A in Fig. 1. Fig. 1 is a cross-sectional view taken along line B-B in Fig. 1.

[0010] At least the following points will become clear from the description and drawings to be described later.

[0011] (Aspect 1) A friction damper is disposed between a pair of members that move relative to each other in a predetermined direction, and suppresses the relative movement by frictional force between pressure contact plates that slide in association with the relative movement, the friction damper comprising: a first pressure contact plate that is integral with one of the pair of members; a second pressure contact plate that is integral with the other of the pair of members; and fastening members that are inserted through through holes in the first pressure contact plate and the second pressure contact plate, and that press the first pressure contact plate and the second pressure contact plate together in a plate thickness direction perpendicular to the opposing surfaces of the first pressure contact plate and the second pressure contact plate. a friction damper characterized in that one of the through holes in the contact plate is a long hole that is long in the predetermined direction, and the other of the through holes in the first pressure-welded plate and the second pressure-welded plate is a bolt hole, the fastening member has a bolt inserted into the long hole and the bolt hole, a nut threaded onto the bolt, and a pipe through which the bolt is passed and housed in the long hole and the bolt hole, and when an axial force in the predetermined direction acts on the friction damper, the pipe is brought into contact with the short diameter portion of the long hole, thereby suppressing buckling in the predetermined direction and a transverse direction that intersects with the plate thickness direction.

[0012] According to the friction damper of aspect 1, when an axial force acts in a predetermined direction, buckling in the transverse direction can be suppressed by bringing the pipe into contact with the minor axis of the slot. Furthermore, by providing the pipe, the bolt does not come into contact with the minor axis of the slot, so the important bolt that bears the axial force can be protected (the bolt can be prevented from being damaged).

[0013] (Aspect 2) In the friction damper according to Aspect 1, it is desirable that the first pressure plate is a web of an H-shaped steel, the second pressure plate is a web of a C-shaped steel, and the pair of flanges of the C-shaped steel are arranged so as not to come into contact with the inside of the pair of flanges of the H-shaped steel.

[0014] According to the friction damper of aspect 2, buckling in the transverse direction can be suppressed by providing a friction damper only on the web without providing a friction damper on the flange.

[0015] (Aspect 3) In the friction damper according to aspect 2, it is desirable that the gap between the minor axis of the long hole and the outer diameter of the pipe is smaller than the gap between the opposing flanges of the H-beam and the C-beam.

[0016] According to the friction damper of aspect 3, the pipe comes into contact with the inner surface of the short diameter of the slot (the web of the H-beam) before the flange of the H-beam and the flange of the C-beam come into contact, thereby preventing the flange of the H-beam and the flange of the C-beam from coming into contact (reducing damage to the flanges).

[0017] (Aspect 4) In the friction damper according to aspect 2 or 3, it is desirable that the other member is an H-shaped steel, the web of the C-shaped steel and the web of the other member are joined, the pair of flanges of the C-shaped steel are positioned inside the pair of flanges of the other member, and the opposing flanges are not joined to each other.

[0018] According to the friction damper of aspect 4, the C-section steel and the other member (H-section steel) can be efficiently joined.

[0019] (Aspect 5) In the friction damper according to any one of Aspects 1 to 4, it is desirable that the length of the pipe is equal to or less than the total thickness of all of the sliding pressure plates.

[0020] According to the friction damper of aspect 5, the pipes can be arranged only in the necessary portions, and the length of the pipes can be shortened, which makes it easier to assemble the friction damper.

[0021] (Aspect 6) In the friction damper according to any one of Aspects 1 to 5, it is desirable that the pipe is made of metal.

[0022] According to the friction damper of aspect 6, the bolt can be protected and prevented from being affected by damage or the like.

[0023] (Aspect 7) A friction damper according to any one of Aspects 1 to 6, further comprising a second fastening member that includes the bolt and the nut but does not include the pipe, and the fastening members are provided in pairs so as to sandwich the second fastening member in the predetermined direction.

[0024] According to the friction damper of aspect 7, the number of pipes required can be reduced. Also, assembly is easier than when pipes are provided for all parts.

[0025] (Aspect 8) A friction damper is disposed between a pair of members that move relative to each other in a predetermined direction, and suppresses the relative movement by frictional force between pressure-welded plates that slide in conjunction with the relative movement, the friction damper comprising: a first pressure-welded plate that is integral with one of the pair of members; a second pressure-welded plate that is integral with the other of the pair of members; and fastening members that are inserted through holes in the first and second pressure-welded plates and press the first and second pressure-welded plates together in a plate thickness direction perpendicular to the opposing surfaces of the first and second pressure-welded plates, wherein the first pressure-welded plate is a web of an H-beam and the second pressure-welded plate is a web of a C-beam, and the pair of flanges of the C-beam are positioned so as not to come into contact with the insides of the pair of flanges of the H-beam, and when an axial force in the predetermined direction is applied to the friction damper, the pair of flanges of the C-beam suppress buckling in the plate thickness direction.

[0026] According to the friction damper of Aspect 8, the C-section steel has a pair of flanges, which makes it difficult for the steel to deform in the thickness direction. This makes it possible to suppress buckling in the thickness direction when an axial force is applied in a predetermined direction.

[0027] Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. The same or equivalent components, members, etc. shown in the drawings will be designated by the same reference numerals, and redundant descriptions will be omitted where appropriate.

[0028] ===Present Embodiment=== <<Regarding the Friction Damper>> The friction damper of this embodiment is a brace-type friction damper that is incorporated into a brace connecting both ends of a diagonal line (column-beam joint) in a column-beam frame surrounded by columns and beams, for example.

[0029] Generally, such brace-type friction dampers suppress vibrations by using the frictional force between the pressure-welded plates that slide in conjunction with the relative movement of the brace in the span direction.

[0030] However, when an axial force along the brace span direction acts on such a friction damper, stress may act not only in the axial force but also in the orthogonal direction (in-plane and out-of-plane directions of the opposing surfaces of the pressure-welded plates).If a friction damper is installed only on the web of the brace (H-beam), the above-mentioned stress may cause the bolts inserted into the web to come into contact with the web and be damaged, or the components that make up the brace may buckle.

[0031] Therefore, in this embodiment, buckling can be suppressed without affecting the bolt.

[0032] <<Configuration of Friction Damper 10 >> Hereinafter, the friction damper 10 of this embodiment will be described with reference to the drawings.

[0033] Fig. 1 is a schematic explanatory diagram of a friction damper 10 of this embodiment. As shown in Fig. 1, the friction damper 10 of this embodiment is a brace-type friction damper incorporated into a brace of a column-beam frame 1 (building frame) surrounded by a column 1a erected in the vertical direction and a beam 1b extending in the horizontal direction.

[0034] Hereinafter, the brace spanning direction in Fig. 1 is referred to as the X direction, and the direction perpendicular (intersecting) to the X direction in the structural plane of the beam-column frame 1 is referred to as the Y direction. The direction perpendicular to the X and Y directions (the direction perpendicular to the paper surface in Fig. 1) is referred to as the Z direction. The X direction corresponds to the "predetermined direction," the Y direction corresponds to the "intersecting direction," and the Z direction corresponds to the "plate thickness direction."

[0035] As shown in Fig. 1, a pair of gusset plates 2 are provided at both diagonal ends (column-beam joints) of the column-beam frame 1. The gusset plates 2 are fixed (joined) to the column 1a and the beam 1b by, for example, welding. A pin joint structure 3 is rotatably joined (pin-jointed) to each of the pair of gusset plates 2. A brace 4 is provided between the pair of pin joint structures 3 at the diagonal positions of the column-beam frame 1.

[0036] The brace 4 is mainly composed of H-shaped steel, which is divided at an appropriate position at a predetermined distance from each other to form a pair of brace segments 5, 6. The pair of brace segments 5, 6 corresponds to a "pair of members." The brace segments 5, 6 are each fixed (joined) to the pin joint structure 3, which allows them to move relative to each other in the X direction (predetermined direction).

[0037] The brace pieces 5, 6 are connected by a connecting member 7. The connecting member 7 in this embodiment is made of C-section steel, as will be described later.

[0038] The friction damper 10 of this embodiment is incorporated into the brace 4 and includes brace pieces 5 and 6, a connecting member 7, a first fastening member 20a, and a second fastening member 20b. A plurality of second fastening members 20b (six in this example) are arranged side by side in the X direction, and a pair (two) of first fastening members 20a are provided so as to sandwich the plurality of second fastening members 20b in the X direction.

[0039] The configuration of each of these components will be described below.

[0040] Fig. 2A is a plan view of the brace fragment 5, and Fig. 2B is a cross-sectional view of the brace fragment 5. Fig. 3A is a plan view of the connecting member 7, and Fig. 3B is a cross-sectional view of the connecting member 7. Fig. 4 is a cross-sectional view taken along line A-A in Fig. 1, and Fig. 5 is a cross-sectional view taken along line B-B in Fig. 1.

[0041] <Regarding the Brace Fragments 5, 6> The brace fragment 5 (corresponding to one of the members) is a steel material (H-shaped steel) with an H-shaped cross section, in which a pair of flanges 5 f are connected at approximately the center by a web 5 w, as shown in Fig. 2B . In this embodiment, the brace fragment 5 is arranged so that the web 5 w of the brace fragment 5 is along the structural surface of the beam-column frame 1.

[0042] Furthermore, as shown in FIG. 2A, the web 5w (corresponding to the first pressure-welded plate) of the brace piece 5 of this embodiment has a long hole 5a (through hole) that penetrates in the Z direction and is long in the X direction.

[0043] The long diameter of the elongated hole 5a (here, the length in the X direction) is longer than the length along which the bolts 21 provided on each of a plurality of fastening members (specifically, two first fastening members 20a and six second fastening members 20b) described below are aligned in the X direction. The short diameter of the elongated hole 5a (the length in the Y direction) is larger than the diameter of the bolt 21 and is also larger than the outer diameter of the pipe 27. In this embodiment, the diameter of the bolt 21 refers to the diameter of the shaft of the bolt 21, excluding the head.

[0044] In addition, one end of the brace fragment 5 (the end on the column-beam joint side) is fixed (joined) to the pin joint structure 3.

[0045] The brace segment 6 (corresponding to the other member) is also a steel material (H-shaped steel) having the same cross-sectional shape as the brace segment 5, and has a pair of flanges 6 f and a web 6 w. The brace segment 6 in this embodiment is shorter in length in the X direction than the brace segment 5, and no elongated holes are provided in the brace segment 6. Note that bolt holes (not shown) for joining the connecting member 7 are provided in the web 6 w of the brace segment 6, corresponding to bolt holes 7 c (described later) in the web 7 w of the connecting member 7.

[0046] Similarly to the brace fragment 5 , one end of the brace fragment 6 (the end on the column-beam joint side) is fixed (joined) to the pin joint structure 3 .

[0047] <Regarding the Connecting Member 7> As shown in FIG. 3B, the connecting member 7 is a steel material (C-beam) having a generally U-shaped cross section, and has a pair of flanges 7f and a web 7w (corresponding to a second pressure-welded plate).

[0048] The connecting member 7 is bridged between the brace segments 5 and 6 that make up the brace 4. The length (width) of the connecting member 7 in the Y direction is shorter than the length (the distance between the pair of flanges 5f) of the web 5w of the brace segment 5 in the Y direction. This allows the web 7w of the connecting member 7 to be arranged so as to overlap the web 5w of the brace segment 5, as shown in Figures 1, 4, and 5. The same applies to the relationship between the brace segment 6 and the connecting member 7.

[0049] The connecting member 7 is joined to the brace segment 6 by bolts 30 or the like shown in Figure 1. Specifically, the web 7w of the connecting member 7 is joined to the web 6w of the brace segment 6, and the flange 7f of the connecting member 7 is not joined to the flange 6f of the brace segment 6. This reduces the effort and cost and enables efficient joining. However, the flange 7f of the connecting member 7 and the flange 6f of the brace segment 6 may also be joined.

[0050] Furthermore, the connecting member 7 is provided so as to be capable of moving relative to the brace piece 5 .

[0051] 3A , a plurality of bolt holes 7a, 7b (through holes) penetrating in the Z direction are provided in the web 7w of the connecting member 7 with a gap in the X direction. The bolt hole 7a is provided corresponding to a first fastening member 20a (described later), and the bolt hole 7b is provided corresponding to a second fastening member 20b (described later). Specifically, a pair (two) of bolt holes 7a are provided on the outside of a plurality (six in this embodiment) of bolt holes 7b aligned in the X direction, sandwiching them.

[0052] The bolt hole 7b is formed to have a diameter (diameter) slightly larger than the diameter of the bolt 21. The bolt hole 7a is formed to have an even larger diameter than the bolt hole 7b (and the bolt 21) in order to accommodate a pipe 27 (described later) between the bolt hole 7a and the bolt 21.

[0053] 3A, a bolt hole 7c penetrating in the Z direction is formed in the web 7w of the connecting member 7. The bolt hole 7c is a hole for inserting a bolt 30 (see FIG. 1) that joins the connecting member 7 and the brace segment 6. The connecting member 7 (web 7w) and the brace segment 6 (web 6w) can be joined by inserting the bolt 30 through the bolt hole 7c of the connecting member 7 and a bolt hole (not shown) in the web 6w of the brace segment 6 and tightening it with a nut (not shown). Note that the method for joining the connecting member 7 and the brace segment 6 is not limited to this, and they may also be joined by welding, for example.

[0054] As shown in FIGS. 4 and 5, the connecting members 7 are provided on both sides of the web 5w of the brace piece 5 (one pair) so as to sandwich the web 5w.

[0055] Sliding plates 5s (e.g., stainless steel plates) are immovably fixed to both the front and back surfaces of the web 5w of the brace segment 5. Furthermore, friction plates 7m are immovably fixed to the surfaces of the webs 7w of the connecting members 7 arranged on both sides of the web 5w, facing the sliding plates 5s. The relationship between the sliding plates 5s and the friction plates 7m may be reversed. That is, a friction plate may be provided on the web 5w of the brace segment 5, and a sliding plate may be provided on the web 7w of the connecting member 7.

[0056] <Regarding the Fastening Member> (First Fastening Member 20a) As shown in FIG. 4 , the first fastening member 20a (corresponding to the fastening member) has a bolt 21, a nut 22, a washer 23, a disc spring 24, a guide bush 25, a splice plate 26, and a pipe 27.

[0057] The bolts 21 are, for example, high-strength bolts, and are inserted through the bolt holes 7a in the webs 7w of the pair of connecting members 7 and the elongated holes 5a in the webs 5w of the brace segments 5. The bolts 21 are also inserted through washers 23, splice plates 26, and guide bushes 25.

[0058] A nut 22 is threaded onto the tip of the bolt 21. The web 5w of the brace segment 5 is fastened by the bolt 21 and the nut 22 while being sandwiched between the webs 7w of the pair of connecting members 7, thereby applying a pressure force for sandwiching in the plate thickness direction (Z direction).

[0059] This pressure contact force causes the friction plate 7m of the web 7w of the connecting member 7 to abut against the sliding plate 5s of the web 5w of the brace segment 5, generating a friction force corresponding to the pressure contact force during sliding. This friction force acts as a damping force for the vibration of the beam-column frame 1. The magnitude of the pressure contact force is stabilized by the resilience of the disc spring 24 interposed between the nut 22 and the splice plate 26.

[0060] In this embodiment, the disc spring 24 (and guide bush 25) and the like are provided on one side of the web 5w of the brace piece 5, but this is not limiting, and a disc spring, guide bush, and the like may also be provided on the other side of the web 5w (the side where the washer 23 is arranged). In this case, the pressing force can be applied more effectively.

[0061] The pipe 27 is a cylindrical metal member. The pipe 27 is provided around the bolt 21 between the washer 23 and the splice plate 26, and is housed in the elongated hole 5 a in the web 5 w of the brace segment 5 and the bolt hole 7 a in the web 7 w of the connecting member 7.

[0062] In other words, the length of the pipe 27 in this embodiment is equal to or less than the total thickness of all the pressure plates (web 5w (including sliding plate 5s) and pair of webs 7w (including friction plate 7m)) in the first fastening member 20a. This allows the pipe 27 to be placed only in the area necessary to suppress buckling (the length of the pipe 27 can be shortened), making assembly easier.

[0063] The inner diameter of the pipe 27 is larger than the diameter of the bolt 21. The gap d1 between the outer diameter of the pipe 27 and the minor axis of the long hole 5a (the inner surface in the Y direction) is smaller than the gap d2 between the flange 5f of the brace piece 5 and the flange 7f of the connecting member 7.

[0064] (Second fastening member 20b) As shown in FIG. 5 , the second fastening member 20b includes a bolt 21, a nut 22, a washer 23, a disc spring 24, a guide bush 25, and a splice plate 26. That is, the second fastening member 20b has a configuration in which the pipe 27 of the first fastening member 20a is removed. The bolt 21 of the second fastening member 20b is inserted through the bolt hole 7b in the web 7w of the pair of connecting members 7 and the elongated hole 5a in the web 5w of the brace piece 5. Furthermore, since the second fastening member 20b does not have the pipe 27, the gap d1' between the bolt 21 and the minor axis (inner surface in the Y direction) of the elongated hole 5a shown in FIG. 5 is larger than the gap d1 between the outer diameter of the pipe 27 and the minor axis (inner surface in the Y direction) of the elongated hole 5a in FIG. 4 .

[0065] <<Operation of Friction Damper 10 >> Next, the operation of the friction damper 10 of this embodiment will be described.

[0066] When an axial force (tensile or compressive force) in the X direction acts on the beam-column frame 1 due to an external force such as an earthquake, the brace segments 5 and 6 connected by this friction damper 10 move relative to each other in the X direction. In this case, the connecting member 7 fixed to (integrally provided with) the brace segments 6 moves relative to the brace segments 5, and the bolts 21 of each fastening member (first fastening member 20a, second fastening member 20b) move together with the connecting member 7 in the longitudinal direction of the elongated hole 5a (X direction). In other words, the web 5w of the brace segment 5 and the web 7w of the connecting member 7 slide along the longitudinal direction while being pressed against each other by the fastening members (first fastening member 20a and second fastening member 20b). At this time, frictional force is generated between the sliding plate 5s and the friction plate 7m, thereby suppressing vibration.

[0067] As mentioned above, when an axial force (compression force) acts on the brace 4 and friction damper 10 in the X direction (brace span direction), not only the axial force but also a bending moment (shear force) may act in a direction intersecting the X direction (Y direction or Z direction). The friction damper 10 in this embodiment is provided only on the web 5w of the brace segment 5 (H-shaped steel), but it can also suppress buckling in the Y direction and Z direction.

[0068] <Regarding the Y direction> When the web 5w of the brace segment 5 and the web 7w of the connecting member 7 are displaced relative to each other in the Y direction, for example, in Figure 4, the pipe 27 comes into contact with the inner circumferential surface of the bolt hole 7a of the connecting member 7. As the displacement progresses further, the brace segment 5 and the pair of connecting members 7 move relative to each other in the Y direction. At this time, a frictional force is also generated between the sliding plate 5s and the friction plate 7m.

[0069] In the friction damper 10 of this embodiment, the gap d1 between the inner surface (inner surface of the short diameter portion) of the elongated hole 5a and the outer diameter of the pipe 27 shown in FIG. 4 (first fastening member 20a) is smaller than the gap d2 between the flange 5f of the brace segment 5 and the flange 7f of the connecting member 7. Therefore, when the connecting member 7 moves (slides) in the Y direction relative to the brace segment 5, the web 5w (inner surface of the short diameter portion of the elongated hole 5a) of the brace segment 5 comes into contact with the pipe 27 before the flanges 5f and 7f come into contact with each other. This prevents the flanges 5f and 7f from coming into contact with each other (preventing damage caused by contact between the flanges).

[0070] After contacting the web 5w, the pipe 27 moves (rotates) along the inner surface of the elongated hole 5a. Because the pipe 27 is made of metal, it is possible to suppress buckling of the brace 4 and the friction damper 10 without affecting the important bolt 21 that bears the axial force to exert frictional force.

[0071] Furthermore, because the second fastening member 20b is not provided with the pipe 27, as described above, the gap d1' shown in Fig. 5 is larger than the gap d1 shown in Fig. 4. Therefore, even if the web 5w (inner surface of the elongated hole 5a) and the pipe 27 come into contact with each other in the first fastening member 20a, the web 5w (inner surface of the elongated hole) and the bolt 21 do not come into contact with each other in the second fastening member 20b (this prevents damage to the bolt 21).

[0072] All of the multiple fastening members may be first fastening members 20a (including pipes 27). However, as in the present embodiment, by using only the outer pair of fastening members as first fastening members 20a and the rest as second fastening members 20b (not including pipes 27), buckling can be efficiently suppressed.

[0073] <Regarding the Z Direction> In the friction damper 10 of this embodiment, a C-shaped steel connecting member 7 is used as a member for connecting the brace segments (brace segment 5 and brace segment 6) of the brace 4. Because the connecting member 7 (C-shaped steel) has a pair of flanges 7 f, it has a larger cross-sectional area (larger moment of inertia) and is less likely to deform in the Z direction than when a plate-shaped steel plate is used (when only the web 7 w is used). In other words, when an axial force along the X direction (brace spanning direction) acts on the friction damper 10, the pair of flanges 7 f of the connecting member 7 suppresses buckling of the brace 4 and the friction damper 10 in the Z direction. Therefore, in this case as well, buckling can be suppressed without affecting the bolts 21.

[0074] In particular, in this embodiment, a pair of connecting members 7 are provided on both sides of the web 5w of the brace fragment 5 so as to sandwich the web 5w, thereby further suppressing buckling in the Z direction.

[0075] ===Other Embodiments===The above embodiments are intended to facilitate understanding of the present invention and are not intended to limit the present invention. The present invention may be modified or improved without departing from the spirit thereof, and it goes without saying that the present invention includes equivalents thereof. In particular, the embodiments described below are also included in the present invention.

[0076] In the above-described embodiment, the friction damper 10 is incorporated into the brace 4 of the beam-column frame 1, but this is not limiting and the friction damper may be incorporated into a part of the building other than the brace (for example, a stud or a partition wall). The friction damper may also be incorporated into a structure other than a building. The friction damper may be installed between a pair of members that move relative to each other due to an external force such as an earthquake.

[0077] In the above embodiment, the friction damper 10 has two sliding surfaces, but the number of sliding surfaces is not limited to this and may be any other number (for example, four surfaces). Increasing the number of sliding surfaces by increasing the number of pressure plates increases the number of sliding contacts between the pressure plates, thereby increasing the frictional force, thereby more reliably damping vibrations. It is also possible to change the frictional force in stages.

[0078] In the above-described embodiment, the brace segments 5, 6 and the gusset plates 2 are joined by pin joints using the pin joint structures 3, but this is not limiting and rigid joints may also be used. For example, the brace segments 5, 6 may be joined to the corresponding gusset plates 2 by welding or bolts without using the pin joint structures 3.

[0079] In addition, in the above-described embodiment, the surfaces of the webs 5w, 6w of the brace fragments 5, 6 are aligned along the structural plane of the beam-column structure 1, but this is not limited to this, and the surfaces of the webs 5w, 6w may be perpendicular to the structural plane of the beam-column structure.

[0080] DESCRIPTION OF SYMBOLS 1 Column-beam frame 1a Column 1b Beam 2 Gusset plate 3 Pin joint structure 4 Brace 5 Brace fragment (H-shaped steel) 5a Slotted hole 5f Flange 5w Web (first pressure-welded plate) 5s Sliding plate 6 Brace fragment (H-shaped steel) 6f Flange 6w Web 7 Connecting member (C-shaped steel) 7a, 7b, 7c Bolt hole 7f Flange 7w Web (second pressure-welded plate) 7m Friction plate 10 Friction damper 20a First fastening member (fastening member) 20b Second fastening member 21 Bolt 22 Nut 23 Washer 24 Disc spring 25 Guide bush 26 Splice plate 27 Pipe 30 Bolt

Claims

1. A friction damper is disposed between a pair of members that move relatively in a predetermined direction, and suppresses the relative movement by frictional force between press-fit plates that slide in conjunction with the relative movement, comprising: a first press-fit plate that is integral with one of the pair of members; a second press-fit plate that is integral with the other of the pair of members; and a fastening member that is inserted through a through hole in the first press-fit plate and a through hole in the second press-fit plate, and presses the first press-fit plate and the second press-fit plate together in a plate thickness direction perpendicular to the opposing surfaces of the first press-fit plate and the second press-fit plate, wherein one of the through hole in the first press-fit plate and the through hole in the second press-fit plate is an elongated hole that is long in the predetermined direction, and the other of the through hole in the first press-fit plate and the through hole in the second press-fit plate is a bolt hole, and the fastening member comprises: a bolt inserted through the elongated hole and the bolt hole; a nut threaded onto the bolt; and a pipe through which the bolt is passed and which is housed in the elongated hole and the bolt hole. a friction damper characterized in that, when an axial force in the predetermined direction acts on the friction damper, the pipe is brought into contact with the minor axis portion of the long hole, thereby suppressing buckling in the predetermined direction and a transverse direction that intersects with the plate thickness direction.

2. A friction damper as claimed in claim 1, characterized in that the first pressure-welded plate is a web of an H-shaped steel, the second pressure-welded plate is a web of a C-shaped steel, and the pair of flanges of the C-shaped steel are arranged so as not to come into contact with the inside of the pair of flanges of the H-shaped steel.

3. A friction damper as claimed in claim 2, characterized in that the gap between the minor diameter of the long hole and the outer diameter of the pipe is smaller than the gap between the opposing flanges of the H-beam and the C-beam.

4. A friction damper as claimed in claim 2, wherein the other member is an H-shaped steel, the web of the C-shaped steel and the web of the other member are joined, and the pair of flanges of the C-shaped steel are positioned inside the pair of flanges of the other member, and the opposing flanges are not joined to each other.

5. A friction damper according to any one of claims 1 to 4, characterized in that the length of the pipe is equal to or less than the total thickness of all of the sliding pressure plates.

6. A friction damper according to any one of claims 1 to 4, characterized in that the pipe is made of metal.

7. A friction damper as set forth in any one of claims 1 to 4, characterized in that it has a second fastening member that includes the bolt and the nut but does not include the pipe, and the fastening members are provided in pairs so as to sandwich the second fastening member in the predetermined direction.

8. A friction damper that is arranged between a pair of members that move relatively in a predetermined direction, and that suppresses the relative movement by frictional force between pressure-welded plates that slide in conjunction with the relative movement, comprising: a first pressure-welded plate that is integral with one of the pair of members; a second pressure-welded plate that is integral with the other of the pair of members; and fastening members that are inserted into the through holes of the first pressure-welded plate and the second pressure-welded plate, and that press the first pressure-welded plate and the second pressure-welded plate together in a plate thickness direction perpendicular to the opposing surfaces of the first pressure-welded plate and the second pressure-welded plate; wherein the first pressure-welded plate is a web of an H-beam and the second pressure-welded plate is a web of a C-beam, and the pair of flanges of the C-beam are arranged so as not to come into contact with the insides of the pair of flanges of the H-beam, and when an axial force in the predetermined direction is applied to the friction damper, the pair of flanges of the C-beam suppress buckling in the plate thickness direction.

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