Friction damper

Abstract

A friction damper (10) has: a first pressure contact plate (5w) provided to one member; a second pressure contact plate (7w) provided to another member; a third pressure contact plate (8) that, together with the first pressure contact plate, sandwiches the second pressure contact plate with prescribed pressure contact force from both sides; and pipes (27, 28) provided so as to be inserted through first through-holes (5a) of the first pressure contact plate, second through-holes (7a-7e) of the second pressure contact plate that are long in a prescribed direction, and third through-holes (8a) of the third pressure contact plate, while having bolts (21) inserted therein that are provided so as to be inserted through the first through-holes, the second through-holes, and the third through-holes. The first pressure contact plate is allowed to slide in the prescribed direction with respect to the second pressure contact plate by the second through holes, and force for causing the third pressure contact plate to slide in the prescribed direction with respect to the second pressure contact plate is transmitted from the first pressure contact plate to the third pressure contact plate via the pipes. Gaps are formed between the pipes and the first through-holes in relation to the prescribed direction. The long-hole minor axis of each second through-hole has a wide part formed in a central portion, which is the range of relative movement in the prescribed direction, and narrow parts formed in a range beyond the two prescribed-direction ends of the central portion in the prescribed 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, in the friction damper disclosed in Patent Document 1, friction dampers are provided on the flange and web of a brace (H-shaped steel) of a building frame, and are 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 installed only on the webs, rather than on the flanges. In this case, if the bending moment exceeds the design assumption, the bolts inserted into the webs (slots) of the friction dampers come into contact with the inner surface of the slots in the minor axis direction, resisting buckling. However, there is a risk of damage to the bolts or buckling of the components that make up the brace. This issue is also present in multi-stage friction dampers that can suppress relative movement under the action of different external forces (earthquakes and wind loads), for example.

[0005] The present invention has been made in consideration of the above-mentioned problems, and its purpose is to suppress buckling without affecting the bolt, even in the case of a multi-stage friction damper.

[0006] The main invention for achieving the above object is a friction damper that is disposed between a pair of members that move relatively in a predetermined direction, and that suppresses the relative movement by frictional force between pressure plates that slide in association with the relative movement, the friction damper comprising: a first pressure plate that is integral with one of the pair of members; a second pressure plate that is integral with the other of the pair of members; a third pressure plate that sandwiches the second pressure plate from both sides with a predetermined pressure force between the first pressure plate; bolts that are inserted through a first through hole of the first pressure plate, a second through hole that is long in the predetermined direction of the second pressure plate, and a third through hole of the third pressure plate in order to apply the pressure force; and bolts that are inserted through the first through hole, the second through hole, and the third through hole while inserting the bolt inside. and a pipe provided in the first through hole, wherein the second through hole allows the first press plate to slide relative to the second press plate in the predetermined direction, and when the third press plate slides relative to the second press plate in the predetermined direction in conjunction with the sliding, the force for causing the sliding is transmitted from the first press plate to the third press plate via engagement between the first through hole and the third through hole of the pipe, a gap is formed between the pipe and the first through hole in the predetermined direction, and the second through hole has a wide portion formed in a central part of the range of relative movement in the predetermined direction, and narrow portions formed at both end portions beyond both ends of the central portion in the predetermined direction, the narrow portions having a minor axis smaller than that of the wide portion.

[0007] The main invention for achieving the above object is a friction damper that is disposed between a pair of members that move relatively in a predetermined direction, and that suppresses the relative movement by frictional force between pressure contact plates that slide in conjunction 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; a third pressure contact plate that sandwiches the second pressure contact plate from both sides with a predetermined pressure contact force between the first pressure contact plate and the second pressure contact plate; bolts that are inserted through a first through hole of the first pressure contact plate, a second through hole that is long in the predetermined direction of the second pressure contact plate, and a third through hole of the third pressure contact plate in order to apply the pressure contact force; and a pipe that is inserted through the first through hole, the second through hole, and the third through hole while the bolt is inserted inside, and the second through hole prevents the second pressure contact plate from sliding forward against the first pressure contact plate. When the first pressure plate is allowed to slide in the predetermined direction and the third pressure plate slides in the predetermined direction relative to the second pressure plate in conjunction with the sliding, the force for the sliding is transmitted from the first pressure plate to the third pressure plate through engagement with the first through hole and the third through hole of the pipe, a gap is formed between the pipe and the first through hole in the predetermined direction, the minor axis of the second through hole has a constant width within the range of relative movement in the predetermined direction, the pipe has a central portion pipe provided in the central portion of the range of relative movement in the predetermined direction in the second through hole, and both end portion pipes provided at both end portions beyond the both ends of the central portion in the predetermined direction, and the outer diameter of the both end portion pipes is larger than the outer diameter of the central portion pipe, making it a friction damper.

[0008] Other features of the present invention will become apparent from the following description and drawings.

[0009] According to the present invention, even a multi-stage friction damper can suppress buckling without affecting the bolt.

[0010] 1A and 1B are schematic explanatory diagrams of a friction damper 10 according to the present embodiment. FIG. 2A is a plan view of a brace segment 5, FIG. 2B is a cross-sectional view of the brace segment 5, and FIG. 2C is a schematic cross-sectional view showing the relationship between the first through hole 5a and the pipe 27. FIG. 3A is a plan view of a connecting member 7, FIG. 3B is a cross-sectional view of the connecting member 7, and FIG. 3C is a schematic cross-sectional view showing the relationship between the second through holes 7a and 7b and the pipe 27. FIG. 4A is a plan view of one of the multiple pressing members 8, and FIG. 4B is a cross-sectional view of one of the multiple pressing members 8. FIG. 1B is a cross-sectional view of the periphery of a fastening member 20 (cross-sectional view A-A in FIG. 1). FIG. 6A is a schematic cross-sectional view showing the relationship between the second through hole 7d and the pipe 27 in a first modified example, and FIG. 6B is a schematic cross-sectional view showing the relationship between the second through hole 7e and the pipes 27 and 28 in a second modified example.

[0011] At least the following points will become clear from the description and drawings to be described later.

[0012] (Aspect 1) A friction damper is disposed between a pair of members that move relative to one another in a predetermined direction, and suppresses the relative movement by frictional force between pressure plates that slide in accordance with the relative movement, the friction damper comprising: a first pressure plate that is integral with one of the pair of members; a second pressure plate that is integral with the other of the pair of members; a third pressure plate that sandwiches the second pressure plate from both sides with a predetermined pressure force between the first pressure plate; bolts that are inserted through a first through hole of the first pressure plate, a second through hole that is long in the predetermined direction of the second pressure plate, and a third through hole of the third pressure plate in order to apply the pressure force; and a pipe that is inserted through the first through hole, the second through hole, and the third through hole while the bolt is inserted inside. wherein the second through hole allows the first press-fit plate to slide relative to the second press-fit plate in the predetermined direction, and when the third press-fit plate slides relative to the second press-fit plate in the predetermined direction in conjunction with the sliding, a force for causing the sliding is transmitted from the first press-fit plate to the third press-fit plate via engagement between the first through hole and the third through hole of the pipe, a gap is formed between the pipe and the first through hole in the predetermined direction, and the second through hole has a wide portion formed in a central portion of a range of relative movement in the predetermined direction, and narrow portions formed at both end portions beyond both ends of the central portion in the predetermined direction, the narrow portions having a minor axis smaller than that of the wide portion.

[0013] According to the friction damper of aspect 1, even if it is a multi-stage friction damper, 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 inner surface of the long hole in the minor axis direction. Furthermore, by providing the pipe, the bolt does not come into contact with the inner surface of the long hole in the minor axis direction, so the important bolt that bears the axial force can be protected (the bolt can be prevented from being damaged).

[0014] (Aspect 2) In the friction damper according to aspect 1, it is preferable that the narrow width portion is formed in a range where one of the pressure contact force applying units that applies the pressure contact force slides at both end portions.

[0015] According to the friction damper of aspect 2, even if it is a multi-stage friction damper, 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 inner surface of the long hole in the minor axis direction. Furthermore, by providing the pipe, the bolt does not come into contact with the inner surface of the long hole in the minor axis direction, so the important bolt that bears the axial force can be protected (the bolt can be prevented from being damaged).

[0016] (Aspect 3) In the friction damper according to aspect 2, it is desirable that the narrow portion be separated from the central portion at the both end portions.

[0017] According to the friction damper of aspect 3, the sliding position can be restricted, and the pipe can be prevented from being caught at the boundaries between the end portions and the central portion during sliding.

[0018] (Aspect 4) 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-contact plates that slide in association with the relative movement, the friction damper comprising: a first press-contact plate integral with one of the pair of members; a second press-contact plate integral with the other of the pair of members; a third press-contact plate that sandwiches the second press-contact plate from both sides with a predetermined pressure between the first press-contact plate; bolts that are inserted through a first through-hole of the first press-contact plate, a second through-hole that is long in the predetermined direction of the second press-contact plate, and a third through-hole of the third press-contact plate in order to apply the pressure; and a pipe that is inserted through the first through-hole, the second through-hole, and the third through-hole while the bolt is inserted inside, and the second through-hole prevents the first press-contact plate from moving forward relative to the second press-contact plate. a friction damper in which sliding in the specified direction is allowed, and when the third pressure contact plate slides in the specified direction relative to the second pressure contact plate in conjunction with the sliding, the force for the sliding is transmitted from the first pressure contact plate to the third pressure contact plate through engagement with the first through hole and the third through hole of the pipe, a gap is formed between the pipe and the first through hole in the specified direction, the minor axis of the second through hole has a constant width within the range of relative movement in the specified direction, the pipe has a central portion pipe provided in a central portion of the range of relative movement in the specified direction in the second through hole, and both end portion pipes provided at both end portions beyond the both ends of the central portion in the specified direction, and the outer diameter of the both end portion pipes is larger than the outer diameter of the central portion pipe.

[0019] According to the friction damper of aspect 4, even if it is a multi-stage friction damper, 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 inner surface of the slot in the minor axis direction. Furthermore, by providing the pipe, the bolt does not come into contact with the inner surface of the slot in the minor axis direction, so the important bolt that bears the axial force can be protected (the bolt can be prevented from being damaged).

[0020] (Aspect 5) In the friction damper according to aspect 4, 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 face each other so as not to come into contact with the inside of the pair of flanges of the H-shaped steel.

[0021] According to the friction damper of aspect 5, the pipe comes into contact with the inner surface of the slot in the minor axis direction (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).

[0022] (Aspect 6) In the friction damper according to any one of Aspects 1 to 5, it is desirable that the length of the pipe is set to the maximum value equal to the total thickness of all of the sliding pressure plates.

[0023] According to the friction damper of aspect 6, 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.

[0024] 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.

[0025] ===Present Embodiment=== <<About 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 (building frame) surrounded by columns and beams.

[0026] Such a brace-type friction damper suppresses vibrations by utilizing the frictional force between the pressure-welded plates that occurs as the brace moves relative to one another in the span direction (in this embodiment, the relative movement of a pair of brace segments 5, 6, which will be described later).

[0027] 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 perpendicular direction (the in-plane direction of the opposing surfaces of the pressure-welded plates).If a friction damper is provided only on the web of the brace (H-beam), the above 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.

[0028] Therefore, in this embodiment, buckling can be suppressed without affecting the bolt.

[0029] <<Configuration of Friction Damper 10 >> Hereinafter, the friction damper 10 of this embodiment will be described with reference to the drawings.

[0030] 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.

[0031] 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." The plate thickness direction is also the direction perpendicular to the opposing surfaces of the web 5w of the brace segment 5 (described later) and the web 7w of the connecting member 7 (described later).

[0032] 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.

[0033] 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).

[0034] 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.

[0035] Furthermore, a splice member 8 is spliced ​​to the connecting member 7. The splice member 8 in this embodiment is made of flat steel, as will be described later.

[0036] 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 splice member 8, and a fastening member 20. A plurality of fastening members 20 (five in this example) are arranged side by side in the X direction, and a plurality of splice members 8 (five in this example) are also arranged side by side in the X direction to correspond to the fastening members 20.

[0037] Furthermore, in this embodiment, an appropriate amount of friction force can be generated to damp vibrations not only against large external forces such as earthquakes but also against small external forces such as wind loads, so that a single friction damper 10 of this embodiment can effectively damp vibrations of the beam-column frame 1 against both earthquakes and wind loads. Therefore, compared to the case where separate friction dampers are provided for earthquakes and wind loads, costs can be reduced and the structure can be made more compact.

[0038] Furthermore, in this embodiment, as will be described later, the friction damper 10 has four or more sliding surfaces (four surfaces in this example). For example, compared to a case where the friction damper has three or fewer sliding surfaces (for example, two surfaces), increasing the number of sliding surfaces by increasing the number of pressure contact plates increases the number of sliding contact plates and increases the frictional force, thereby more reliably damping vibrations. Also, by increasing the number of pressure contact plates and the number of sliding surfaces, it is possible to gradually change the frictional force between the sliding surfaces.

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

[0040] 2A is a plan view of brace segment 5, FIG. 2B is a cross-sectional view of brace segment 5, and FIG. 2C is a schematic cross-sectional view showing the relationship between first through hole 5a and pipe 27. FIG. 3A is a plan view of connecting member 7, FIG. 3B is a cross-sectional view of connecting member 7, and FIG. 3C is a schematic cross-sectional view showing the relationship between second through holes 7a, 7b and pipe 27. FIG. 4A is a plan view of one of the multiple pressing members 8, and FIG. 4B is a cross-sectional view of one of the multiple pressing members 8. FIG. 5 is a cross-sectional view of the periphery of fastening member 20 (cross-sectional view taken along A-A 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] As shown in FIG. 2A , the web 5w of the brace segment 5 has a plurality of first through holes 5a (five in this embodiment) that penetrate in the Z direction and are spaced apart in the X direction. While this embodiment can be applied to a multi-stage friction damper, for simplicity, the diameters of the first through holes 5a are set to be the same. When the diameters of the first through holes 5a are the same in this way, it becomes a two-stage brake damper. The first through holes 5a are provided to correspond to the fastening members 20, which will be described later.

[0043] The first through hole 5a is formed with a diameter (diameter) larger than the diameter of a pipe 27 (described later) that accommodates a bolt 21 (described later). Here, as shown in FIG. 2C , a gap is formed between the outer periphery of the pipe 27 and the inner surface of the first through hole 5a, thereby allowing relative movement between the first through hole 5a and the pipe 27 at least in a predetermined direction (X direction). Also, as shown in FIG. 5 , the size e1 of the gap between the first through hole 5a of the web 5w of the brace piece 5 and the pipe 27 (described later) is set to be larger than the amount of relative movement in the X direction (brace spanning direction; predetermined direction) expected under the action of a wind load (an example of a small external force).

[0044] As shown in FIG. 1 , one end of the brace piece 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 the web 6 w of the brace segment 6 has bolt holes (not shown) for joining the connecting member 7, which correspond to bolt holes 7 c (described later) in the web 7 w of the connecting member 7.

[0046] As shown in FIG. 1 , one end of the brace fragment 6 (the end on the beam-column joint side) is fixed (joined) to the pin joint structure 3 , similar to the brace fragment 5 .

[0047] As shown in Figure 5, friction plates 5m are immovably fixed to both sides in the Z direction of the web 5w of the brace segment 5. Furthermore, as will be described later, sliding plates 7s (e.g., stainless steel plates) 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 friction plates 5m. The relationship between the friction plates 5m and the sliding plates 7s may be reversed. That is, sliding plates may be provided on the webs 5w of the brace segment 5, and friction plates may be provided on the webs 7w of the connecting members 7.

[0048] <Regarding the Connecting Member 7> As shown in FIG. 3B, the connecting member 7 is a steel material (C-beam) having a substantially U-shaped cross section, and has a pair of flanges 7f and a web 7w (corresponding to a second pressure-welded plate).

[0049] 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 FIG. 1 . The same applies to the relationship between the brace segment 6 and the connecting member 7.

[0050] The connecting member 7 is joined to the brace segment 6 by bolts 40 or the like shown in FIG. 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. Furthermore, the connecting member 7 is provided so as to be displaceable relative to the brace segment 5 and the splice member 8.

[0051] As shown in FIG. 3A , the web 7w (corresponding to the second pressure-contact plate) of the connecting member 7 of this embodiment is formed with a plurality of second through holes 7a, 7b (five second through holes 7a, 7b in total, sometimes collectively referred to as "a plurality of second through holes") that penetrate in the Z direction and are elongated in the X direction. The plurality of second through holes are provided corresponding to the fastening members 20 described below. A pair (two) of second through holes 7a are provided on the outside of the plurality of second through holes 7b (three in this embodiment) aligned in the X direction, sandwiching them. As shown in FIG. 5 , the size e2 of the gap between the second through hole 7a in the web 7w of the connecting member 7 and the pipe 27 (described later) is set larger than the size e1 of the gap between the first through hole 5a in the web 5w of the brace segment 5 and the pipe 27 (described later) (e2 > e1), in consideration of earthquakes.

[0052] The minor axis (length in the Y direction) of each of the plurality of second through holes is larger than the diameter of the bolt 21 (described later) and is also larger than the outer diameter of the pipe 27 (described later). In this embodiment, the diameter of the bolt 21 refers to the diameter of the shaft portion of the bolt 21 excluding the head portion. Furthermore, as shown in FIG. 3C , the minor axis w2 (length in the Y direction) of the second through hole 7a is smaller than the minor axis w2' (length in the Y direction) of the second through hole 7b (w2<w2').

[0053] Therefore, the plurality of second through holes have wide portions 32 and narrow portions 31 when viewed as a whole. The wide portions 32 are formed in the central portion of the range of relative movement of the brace pieces 5, 6 in the X direction (predetermined direction). The narrow portions 31 are formed at both end portions beyond the central portion in the X direction (predetermined direction) from both ends in the X direction (predetermined direction), and are portions with a smaller minor axis than the wide portions 32. Note that the narrow portions 31 are formed in the range where one fastening member 20 that applies the pressure contact force slides at both end portions.

[0054] Furthermore, in the friction damper 10 of this embodiment, the second through holes 7 a and the second through holes 7 b are separated from each other. Therefore, the narrow portions 31 at both ends are also separated from the wide portion 32 in the center.

[0055] As shown in FIG. 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.

[0056] As shown in Figure 5, sliding plates 7s (e.g., stainless steel plates) are immovably fixed to both sides of the web 7w of the connecting member 7 in the Z direction. Furthermore, as will be described later, friction plates 8m are immovably fixed to the surfaces of the pressing members 8 arranged on both sides of the web 7w, facing the sliding plates 7s. The relationship between the sliding plates 7s and the friction plates 8m may be reversed. That is, a friction plate may be provided on the web 7w of the connecting member 7, and a sliding plate may be provided on the pressing member 8.

[0057] <Regarding the splice member 8> The splice member 8 (corresponding to the third pressure plate) is a steel material (flat steel) having a substantially plate-like cross section, as shown in Fig. 4B. Note that Figs. 4A and 4B show one of the multiple splice members 8 (five in this embodiment as shown in Fig. 1) that the friction damper 10 has and that are arranged in the X direction.

[0058] The splicing members 8 are provided to correspond to each of the multiple (five in this embodiment as shown in FIG. 1 ) fastening members 20 (described below) lined up in the X direction. The length (width) of the splicing members 8 in the Y direction is shorter than the length (the distance between the pair of flanges 7 f) of the web 7 w of the connecting member 7 in the Y direction. This allows the splicing members 8 to be arranged so as to overlap the web 7 w of the connecting member 7, as shown in FIG. 1 . As described above, the length (width) of the connecting member 7 in the Y direction is shorter than the length (the distance between the pair of flanges 5 f) of the web 5 w of the brace piece 5, and therefore the same applies to the relationship between the splicing members 8 and the brace piece 5.

[0059] The splicing member 8 is provided so as to be displaceable relative to the connecting member 7 .

[0060] 4A, the splicing member 8 is provided with a third through hole 8a, which is a bolt hole that penetrates in the Z direction. The third through hole 8a is provided to correspond to a fastening member 20, which will be described later. The third through hole 8a is formed with a diameter that is slightly larger than the diameter of a bolt 21 (described later).

[0061] As shown in FIG. 5, the splicing members 8 are provided on both sides of the web 7w of the connecting member 7 (a pair) so as to sandwich the web 7w.

[0062] A friction plate 8m is immovably fixed to the surface of each of the pair of splicing members 8 facing the web 7w of the connecting member 7. As described above, a sliding plate 7s is immovably fixed to the surface of the web 7w of the connecting member 7 facing the friction plate 8m.

[0063] <Regarding the Fastening Member> As shown in FIG. 5 , the fastening member 20 includes 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 .

[0064] The bolts 21 are, for example, high-strength bolts, and are inserted through the third through-holes 8a of the pair of splice members 8, the second through-holes 7a of the webs 7w of the pair of connecting members 7, and the first through-holes 5a of the webs 5w of the brace segments 5. The bolts 21 are also inserted through the washers 23, the splice plates 26, and the guide bushes 25.

[0065] A nut 22 is threaded onto the tip side of the bolt 21. By means of this bolt 21 and nut 22, the web 5w of the brace segment 5 is sandwiched between the webs 7w of the pair of connecting members 7, and the webs 7w of the pair of connecting members 7 are further fastened while being sandwiched between the pair of splicing members 8, thereby applying a clamping pressure (corresponding to a predetermined pressure) in the plate thickness direction (Z direction). The fastening member 20 corresponds to a pressure force applying unit.

[0066] This pressing force causes the friction plate 5m of the web 5w of the brace segment 5 to come into contact with the sliding plate 7s on the side of the web 7w of the connecting member 7 that faces the web 5w. Also, the sliding plate 7s on the side of the web 7w of the connecting member 7 that faces the splice member 8 comes into contact with the friction plate 8m of the splice member 8. Therefore, when the connecting member 7 slides against the brace segment 5 and the splice member 8, a friction force corresponding to the pressing force is generated. This friction force acts as a damping force for vibration of the beam-column frame 1. The magnitude of the pressing force is stabilized by the elastic force of the disc spring 24 interposed between the nut 22 and the splice plate 26.

[0067] 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.

[0068] The pipe 27 is a cylindrical metal member. In the friction damper 10 of this embodiment, the pipe 27 is provided around the bolt 21 between the washer 23 and the splice plate 26, and is accommodated in the first through hole 5 a of the web 5 w of the brace segment 5, the plurality of second through holes in the webs 7 w of the pair of connecting members 7, and the third through holes 8 a of the pair of splice members 8. As described above, a plurality of splice members 8 (five in this embodiment as shown in FIG. 1 ) are lined up in the X direction, and the pipe 27 is accommodated in the third through holes 8 a of all of the splice members 8.

[0069] 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 friction plate 5m), pair of webs 7w (including sliding plate 7s), and pair of splice members 8 (including friction plate 8m)) in the fastening member 20. This allows the pipe 27 to be placed only in the portion necessary to suppress buckling (the length of the pipe 27 can be shortened), making assembly easier.

[0070] The inner diameter of the pipe 27 is larger than the diameter of the bolt 21 .

[0071] 3C , in the friction damper 10 of this embodiment, the outer diameter r2 of the pipe 27 inserted through the second through hole 7a is the same as the outer diameter r2 of the pipe 27 inserted through the second through hole 7b. However, as described above, the minor axis w2 (length in the Y direction) of the second through hole 7a is smaller than the minor axis w2' (length in the Y direction) of the second through hole 7b (w2<w2'). Therefore, the gap d2 between the outer surface of the pipe 27 and the inner surface of the second through hole 7a in the minor axis direction (Y direction) is smaller than the gap d2' between the outer surface of the pipe 27 and the inner surface of the second through hole 7b in the minor axis direction (Y direction) (d2<d2').

[0072] <<Operation of Friction Damper 10 >> Next, the operation of the friction damper 10 of this embodiment will be described.

[0073] When an axial force (tensile force or compressive force) in the X direction acts on the column-beam structure 1 due to external forces such as an earthquake or wind, the brace fragments 5 and 6 connected by this friction damper 10 move relative to each other in the X direction.

[0074] First, under the action of wind load, the external force is small, so the relative movement between the brace segments 5, 6 is also small. Furthermore, as mentioned above, the size e1 of the gap between the pipe 27 and the first through hole 5a of the web 5w of the brace segment 5 is set larger than the relative movement in the X direction (the brace span direction; the predetermined direction) expected under the action of wind load. Therefore, even when the column-beam frame 1 vibrates, the pipe 27 only moves relatively within the gap and does not come into contact with the inner surface of the first through hole 5a in the X direction. Therefore, no force in the X direction acts from the web 5w of the brace segment 5 to the pipe 27, and no force to slide the splice member 8 is transmitted from the web 5w of the brace segment 5 to the splice member 8. As a result, only the web 5w of the brace segment 5 slides against the web 7w of the connecting member 7, and the splice member 8 does not slide. Therefore, for vibrations with a small amount of relative movement, such as those caused by wind loads, that is, vibrations caused by small external forces, the friction damper 10 generates a small frictional force, which enables the friction damper 10 to effectively damp vibrations caused by small external forces such as wind loads with a small frictional force of a corresponding magnitude.

[0075] Furthermore, during an earthquake, the external force is greater than the external force under wind load, so the amount of relative movement between the brace segments 5, 6 becomes greater than the size e1 of the gap between the pipe 27 and the first through hole 5a of the web 5w of the brace segment 5. As a result of this relative movement, the pipe 27 comes into contact with and engages with the inner surface of the first through hole 5a in the X direction. Furthermore, with this engagement, the pipe 27 also comes into contact with and engages with the inner surface of the third through hole 8a of the splicing member 8 in the X direction. Through this engagement between the pipe 27 and the inner surfaces of the first through hole 5a and the third through hole 8a in the X direction, a force is transmitted from the web 5w of the brace segment 5 to the splicing member 8, and this transmitted force acts to slide the splicing member 8. As a result, the splicing member 8 also slides relative to the web 7w of the connecting member 7 in conjunction with the web 5w of the brace segment 5. As a result, the friction damper 10 generates a large frictional force in response to vibrations with a large amount of relative movement, i.e., vibrations caused by a large external force during an earthquake. Therefore, the friction damper 10 can effectively damp vibrations caused by a large external force during an earthquake with a large frictional force corresponding to the vibrations.

[0076] As mentioned above, when an axial force (compressive force) acts on the brace 4 and the 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 of 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. In this embodiment, as will be described later, the pipe 27 that comes into contact with the inner surface in the minor diameter direction of the second through hole 7a of the web 7w of the connecting member 7 suppresses in-plane buckling of the sliding surface between the sliding pressure-welded plates.

[0077] <Regarding the Y direction> When the web 5w and splice member 8 of the brace segment 5 and the web 7w of the connecting member 7 are displaced relative to each other in the Y direction, the pipe 27 comes into contact with the inner surface of the first through hole 5a of the brace segment 5 and the inner surface of the third through hole 8a of the splice member 8. As the displacement progresses further, the brace segment 5 and splice member 8 and the pair of connecting members 7 move relatively in the Y direction. At this time, frictional forces are generated between the friction plate 5m and the sliding plate 7s facing the web 5w, and between the sliding plate 7s facing the splice member 8 and the friction plate 8m.

[0078] In the friction damper 10 of this embodiment, the gap d2 between the inner surface of the second through hole 7a in the minor axis direction and the outer diameter of the pipe 27 is smaller than the gap between the flange 5f of the brace segment 5 and the flange 7f of the connecting member 7. Therefore, when the brace segment 5 and the splice member 8 move (slide) in the Y direction relative to the connecting member 7, the web 7w (inner surface in the minor axis direction of the second through hole 7a) of the connecting member 7 comes into contact with the pipe 27 before the flanges 5f and 7f come into contact with each other. In other words, the pair of flanges 7f of the connecting member 7 face each other so as not to come into contact with the insides of the pair of flanges 5f of the brace segment 5. This prevents the flanges 5f and 7f from coming into contact with each other (preventing damage caused by the flanges coming into contact with each other).

[0079] As described above, the minor axis w2 (length in the Y direction) of the second through hole 7a is smaller than the minor axis w2' (length in the Y direction) of the second through hole 7b (w2<w2'). Therefore, when the brace fragment 5 and the splice member 8 move (slide) in the Y direction relative to the connecting member 7, the pipe 27 comes into contact only with the second through hole 7a. After coming into contact with the web 7w of the connecting member 7, the pipe 27 moves (rotates) along the inner surface of the second through hole 7a. 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.

[0080] On the other hand, the minor axis w2' (length in the Y direction) of the second through hole 7b is larger than the minor axis w2 (length in the Y direction) of the second through hole 7a (w2'>w2). Therefore, even if the inner surface of the second through hole 7a of the web 7w comes into contact with the pipe 27, the inner surface of the second through hole 7b does not come into contact with the pipe 27.

[0081] The minor diameters of all the second through holes may be the same (the pipe 27 may be allowed to contact the inner surfaces of all the second through holes). However, as in the present embodiment, by allowing the pipe 27 to contact only the outer pair of second through holes 7 a, buckling can be efficiently suppressed.

[0082] As described above, the second through holes 7a and 7b are separated from each other. That is, the narrow portions 31 at both ends are separated from the wide portion 32 at the center, so that the sliding position can be regulated and the pipe 27 can be prevented from being caught at the boundaries between the both ends and the center during sliding.

[0083] <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.

[0084] 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, and a pair of splice members 8 are provided on both sides of the web 7w of the pair of connecting members 7, thereby further suppressing buckling in the Z direction.

[0085] <<Modifications of Friction Damper>> FIG. 6A is a schematic cross-sectional view showing the relationship between the second through hole 7d and the pipe 27 in a first modification.

[0086] In the above-described embodiment, the second through holes 7a and 7b are separated as shown in FIG. 3C . That is, the narrow portions 31 at both ends are separated from the wide portion 32 in the center. However, in the first modification, as shown in FIG. 6A , the second through hole 7d is integrally formed, and the minor axis w2 (length in the Y direction) of the narrow portion 31 is smaller than the minor axis w2' (length in the Y direction) of the wide portion 32 (w2<w2'). Note that, in the first modification, all the pipes 27 inserted through the second through holes 7d have the same outer diameter r2. Therefore, in the first modification, the gap d2 between the outer periphery of the pipe 27 and the inner surface of the narrow portion 31 of the second through hole 7d in the minor axis direction (Y direction) is smaller than the gap d2' between the outer periphery of the pipe 27 and the inner surface of the wide portion 32 of the second through hole 7d in the minor axis direction (Y direction) (d2<d2').

[0087] FIG. 6B is a schematic cross-sectional view showing the relationship between the second through-hole 7e and the pipes 27 and 28 in the second modified example.

[0088] In the first modified example described above, all of the pipes 27 inserted through the second through holes 7d have the same outer diameter r2. However, as in the second modified example, the minor diameter w2 of the second through holes 7e may be the same (w2) in the X direction, and the pipes 27 having the outer diameter r2 and the pipes 28 having the outer diameter r2' smaller than the outer diameter r2 may be provided (r2 > r2'). As a result, even in the second modified example, the gap d2 between the outer periphery of the pipe 27 and the inner surface of the second through hole 7e in the minor diameter direction (Y direction) is smaller than the gap d2' between the outer periphery of the pipe 28 and the minor diameter direction (Y direction) of the second through hole 7e (d2 < d2').

[0089] ===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.

[0090] 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.

[0091] 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.

[0092] 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.

[0093] DESCRIPTION OF SYMBOLS 1 Beam-column frame 1a Column 1b Beam 2 Gusset plate 3 Pin joint structure 4 Brace 5 Brace fragment (one member; H-shaped steel) 5a First through hole 5f Flange 5w Web (first pressure-welded plate) 5m Friction plate 6 Brace fragment (other member; H-shaped steel) 6f Flange 6w Web 7 Connecting member (C-shaped steel) 7a, 7b, 7d, 7e Second through hole 7c Bolt hole 7f Flange 7w Web (second pressure-welded plate) 7s Sliding plate 8 Splice member (flat steel, third pressure-welded plate) 8a Third through hole 8m Friction plate 10 Friction damper 20 Fastening member 21 Bolt 22 Nut 23 Washer 24 Disc spring 25 Guide bush 26 Splice plate 27, 28 Pipe 31 Narrow section 32 Wide section 40 Bolt

Claims

1. A friction damper is disposed between a pair of members that move relative to one another in a predetermined direction, and suppresses the relative movement by frictional force between pressure plates that slide in accordance with the relative movement, comprising: a first pressure plate that is integral with one of the pair of members; a second pressure plate that is integral with the other of the pair of members; a third pressure plate that sandwiches the second pressure plate from both sides with a predetermined pressure force between the first pressure plate and the second pressure plate; a bolt that is inserted through a first through hole of the first pressure plate, a second through hole that is long in the predetermined direction of the second pressure plate, and a third through hole of the third pressure plate in order to apply the pressure force; and a pipe that is inserted through the first through hole, the second through hole, and the third through hole while the bolt is inserted inside. a friction damper in which the second through hole allows the first pressure contact plate to slide relative to the second pressure contact plate in the predetermined direction, and when the third pressure contact plate slides relative to the second pressure contact plate in the predetermined direction in conjunction with the sliding, the force causing the sliding is transmitted from the first pressure contact plate to the third pressure contact plate via engagement between the first through hole and the third through hole of the pipe, a gap is formed between the pipe and the first through hole in the predetermined direction, and the second through hole has: a wide portion formed in a central part of the range of relative movement in the predetermined direction, and narrow portions formed at both end portions beyond both ends of the central portion in the predetermined direction, the narrow portions having a minor axis smaller than that of the wide portion.

2. The friction damper according to claim 1, wherein the narrow width portion is formed in a range where one of the pressure contact force applying units that applies the pressure contact force slides at both end portions.

3. The friction damper according to claim 2, wherein the narrow portion is separated from the central portion at the both end portions.

4. A friction damper that is disposed between a pair of members that move relatively in a predetermined direction and that suppresses the relative movement by frictional force between pressure plates that slide in conjunction with the relative movement, comprising: a first pressure plate that is integral with one of the pair of members; a second pressure plate that is integral with the other of the pair of members; a third pressure plate that sandwiches the second pressure plate from both sides with a predetermined pressure force between the first pressure plate and the second pressure plate; a bolt that is inserted through a first through hole of the first pressure plate, a second through hole that is long in the predetermined direction of the second pressure plate, and a third through hole of the third pressure plate in order to apply the pressure force; and a pipe that is inserted through the first through hole, the second through hole, and the third through hole while the bolt is inserted inside. a friction damper, wherein the second through hole allows the first press-fit plate to slide relative to the second press-fit plate in the predetermined direction, and when the third press-fit plate slides relative to the second press-fit plate in the predetermined direction in conjunction with the sliding, the force causing the sliding is transmitted from the first press-fit plate to the third press-fit plate via engagement between the first through hole and the third through hole of the pipe, a gap is formed between the pipe and the first through hole in the predetermined direction, the minor axis of the second through hole has a constant width within the range of relative movement in the predetermined direction, the pipe has a central portion pipe provided in the central portion of the range of relative movement in the predetermined direction in the second through hole, and both end portion pipes provided at both end portions beyond the both ends of the central portion in the predetermined direction, and the outer diameter of the both end portion pipes is larger than the outer diameter of the central portion pipe.

5. A friction damper as claimed in any one of claims 1 to 4, wherein the first pressure plate is a web of an H-shaped steel and the second pressure plate is a web of a C-shaped steel, and the pair of flanges of the C-shaped steel face each other so as not to come into contact with the inside of the pair of flanges of the H-shaped steel.

6. A friction damper according to any one of claims 1 to 5, wherein the length of the pipe is set to the maximum value equal to the total thickness of all of the sliding pressure plates.

Images