JP2012001985A - Building - Google Patents

Abstract

PROBLEM TO BE SOLVED: To adequately reduce vibration of a girder of a building.SOLUTION: Vibration of a floor damper 20 on a second floor can effectively be restrained by arranging a dynamic damper 32 on an antinode of the vibration thereof. The dynamic damper 32 is preferentially arranged on a peak position of the antinode of the vibration or close to a floor beam 29 when the floor beam 29 coincides with the peak position of the antinode of the vibration.

Description

  The present invention relates to a building, and more particularly to a building capable of reducing vibration transmission from an upper floor to a lower floor.

  2. Description of the Related Art Conventionally, a damping structure (see, for example, Patent Document 1) that suppresses vibration of a panel member by installing a damper on a beam member that supports the panel member such as a floor or a ceiling, that is, a so-called joist or other small beam is known.

Japanese Patent Application Laid-Open No. 2007-126940.

  In the damping structure disclosed in Patent Document 1, since a damper is installed on the floor beam, a certain effect can be obtained in reducing the impact sound generated on the floor beam. Since it is not aimed at reduction, a sufficient effect cannot be obtained for impact sound (vibration) generated in the vicinity of a large beam.

  In view of the above facts, an object of the present invention is to provide a building that can sufficiently reduce vibration of a large beam.

  The building according to claim 1 is a building comprising a large beam connected to a pillar, and a plurality of small beams spanned between one of the large beams facing each other and the other of the large beams, The small beam is connected to a position where the vibration of the large beam becomes antinode, and a damper for suppressing vibration is opposite to the small beam connected to the position where the antinode of vibration of the large beam is connected It is installed on the side.

Next, the operation of the building according to claim 1 will be described.
In the building according to the first aspect, the vibration of the large beam is reduced by the dynamic damper installed on the side opposite to the side to which the small beam of the large beam is connected.
For example, when a large beam on the floor on the second floor vibrates, the vibration of the large beam propagates from the beam to a column, a wall connected to the column, etc., or propagates to a member placed opposite the beam via air. However, by suppressing the vibration of the large beam, it is possible to suppress the vibration of the column, the wall connected to the column, and the member disposed facing the large beam.

The damper is most preferably installed at a portion (peak position) where the vibration amplitude of the large beam is maximized.
In the building according to claim 1, the small beam is connected to the position where the vibration of the large beam becomes an antinode, but the damper is installed on the side opposite to the small beam, so the damper has a portion where the vibration amplitude becomes maximum. It can be installed, and the vibration of the large beam can be effectively reduced.

  The building according to claim 2 is a building comprising a large beam connected to a pillar, and a plurality of small beams spanned between one of the large beams facing each other and the other of the large beams, The small beam is connected to a position where the vibration of the large beam becomes antinode, and a damper for suppressing vibration is provided on the large beam, on the side where the small beam is connected, and becomes an antinode of vibration of the large beam. It is installed close to the beam connected to the position.

Next, the operation of the building according to claim 2 will be described.
In the building according to claim 2, the vibration of the large beam is reduced by the damper installed on the side where the small beam of the large beam is connected.
In the building according to claim 2, the small beam is connected to the position where the vibration of the large beam becomes antinode, and the damper is installed on the side where the small beam is connected, but the damper becomes the antinode of vibration of the large beam. Since it is installed close to the beam connected to the position, it is possible to obtain a vibration reduction effect comparable to that when installed in a portion where the amplitude of vibration is maximized.

  The building according to claim 3 suppresses vibration of a first order mode that suppresses vibration of a first order mode, and a second order mode that has a vibration frequency different from that of the first order mode. A second damper, wherein the first order mode vibration antinode and the second order mode vibration antinode overlap the first order mode vibration antinode. One of the dampers is installed on the opposite side of the small beam connected to the position where the vibration of the large beam is antinode, and the other of the first damper and the second damper is the small beam It is installed on the side to be connected and in the vicinity of the small beam connected to the position where the vibration of the large beam becomes antinode.

Next, the operation of the building according to claim 3 will be described.
In the building according to claim 3, the first damper that suppresses the vibration of the first order mode and the second order mode that suppresses the vibration of the second order mode having a vibration frequency different from that of the first order mode. Since the two dampers are provided, vibrations in two types of modes having different orders, for example, primary vibration and secondary vibration can be reduced.
In addition, since either one of the first damper and the second damper is installed on the side opposite to the small beam, the damper can be installed in a portion where the amplitude of the vibration is maximized, so that the vibration of the large beam is effective. Can be reduced.
The other of the first damper and the second damper is installed on the side to which the small beam is connected, and the damper is adjacent to the small beam connected to the position where the vibration of the large beam becomes antinode. Therefore, it is possible to obtain a vibration reduction effect that is comparable to the case where the vibration is installed in a portion where the vibration amplitude is maximum.

  According to a fourth aspect of the present invention, in the building according to the second or third aspect of the present invention, the small beam connected to the vibration antinode that appears at a position different from the longitudinal central portion of the large beam. The damper is installed on the side of the large beam to which the small beam is connected and close to the central portion of the small beam in the longitudinal direction of the large beam.

Next, the operation of the building according to claim 4 will be described.
When the position of the small beam is connected to a position different from the longitudinal central portion of the large beam and the connected position of the small beam becomes an antinode of vibration, the vibration is vibration of a second or higher mode (1 The antinode of the vibration of the next mode is the central part of the long beam in the longitudinal direction). Therefore, the damper installed in the vicinity of the small beam connected to the anti-vibration portion that appears at a position different from the longitudinal center of the large beam can reduce the vibration of the second and higher modes.

By the way, since both ends of the large beam are connected to columns, the rigidity is high and hardly deformed. For example, regarding the first-order mode, the amplitude of the large beam is large at the center in the longitudinal direction.
Further, since the damper has a mass, attaching the damper to a portion where the large beam vibrates is effective in suppressing vibration of the low order of the large beam. For this reason, it is better to install the damper installed close to the small beam on the side where the amplitude of the large beam is large, that is, on the center side in the longitudinal direction.

  Invention of Claim 5 has the said small beam connected to the longitudinal direction center part of the said large beam in the building of Claim 2 or Claim 3, and the said small beam of the said large beam is connected And the damper installed on one side or the other side in the longitudinal direction of the small beam.

Next, the operation of the building according to claim 5 will be described.
The central part of the long beam in the longitudinal direction is the position where the amplitude of the primary vibration is the largest. Therefore, if the small beam is connected to the central part of the long beam in the longitudinal direction, the damper must be installed at a position that does not interfere with the small beam. There is.
The small beam is connected to the longitudinal center of the large beam, so when installing the damper on the side where the small beam of the large beam is connected, the damper may be installed on one side of the large beam in the longitudinal direction of the large beam. Since the vibration reduction effect does not change even if installed on the other side in the longitudinal direction of the small beam, the damper is installed on either one side or the other side in the longitudinal direction of the small beam as in claim 5. Just do it.

  According to a sixth aspect of the present invention, in the building according to any one of the first to fifth aspects, the girder on which the damper is installed is a floor girder having two or more floors.

Next, the operation of the building according to claim 6 will be described.
In the building according to claim 6, a damper is installed on a floor beam on the second floor or higher. Therefore, the vibration of the upper floor beam is suppressed by the damper, and the vibration of the upper floor beam is prevented from propagating to the lower floor pillars, walls, ceiling, etc. The sound is suppressed.

  According to a seventh aspect of the present invention, in the building according to any one of the first to sixth aspects, the damper is installed on the girder side beam.

Next, the operation of the building according to claim 7 will be described.
The girder-side girder is longer and easier to vibrate than the gable-side girder, so installing a damper on the girder-side girder has a greater vibration suppression effect than installing a damper on the gable-side girder. It is done.

  According to an eighth aspect of the present invention, in the building according to the seventh aspect, the damper is installed on each of the one large beam and the other large beam on the beam side facing each other.

Next, the operation of the building according to claim 8 will be described.
By installing a damper on each of the one girder facing each other and the other girder, vibration of each girder can be suppressed, and a greater vibration suppression effect than installing a damper on only one of the girder Is obtained.

  The invention according to claim 9 is the building according to any one of claims 1 and 3 to 8, wherein the building units are configured by connecting a plurality of building units and adjacent to each other. The damper is installed in a gap between the large beam and the large beam of the other building unit.

Next, the operation of the building according to claim 9 will be described.
By installing the damper in the gap between the large beam of one building unit and the large beam of the other building unit, the dead space between the large beams can be used effectively, and the damper can be installed without interfering with other members.

  A tenth aspect of the present invention is the building according to any one of the first to ninth aspects, wherein the damper includes a first member used for connection to the girder and the first member. A dynamic damper comprising: an elastic body connected to the second member; a second member connected to a position different from the first member of the elastic body; and a weight connected to the second member. is there.

Next, the operation of the building according to claim 10 will be described.
The damper according to claim 10 is a dynamic damper, and when the large beam vibrates, the weight vibrates in a direction to cancel the vibration of the large beam, and as a result, the vibration of the large beam is reduced. The mass of the weight and the spring constant of the elastic body are set according to the frequency of vibration to be reduced. In addition, the dynamic damper has a small number of constituent members, and a large vibration suppressing effect can be obtained with a simple structure.

It is a perspective view of a unit building constituted by connecting a plurality of building units. It is a longitudinal cross-sectional view of the boundary part of the 1st floor and the 2nd floor. (A), (B) is a top view which shows the floor unit of the 2nd floor. (A) is a vertical cross-sectional view perpendicular to the small beam of the floor unit on the second floor, and (B) is a vertical cross-sectional view perpendicular to the large beam on the floor unit of the second floor (4B-4B in FIG. 4A). FIG. It is a perspective view which shows the connection part of a floor big beam and a floor small beam. (A)-(C) are sectional drawings of the floor girder to which the dynamic damper was attached. It is a top view which shows schematic structure of the floor unit which concerns on other embodiment, and the mode of vibration. It is a top view which shows schematic structure of the floor unit which concerns on other embodiment, and the mode of vibration. It is a top view which shows schematic structure of the floor unit which concerns on other embodiment, and the mode of vibration. It is a top view which shows schematic structure of the floor unit which concerns on other embodiment, and the mode of vibration. It is a top view which shows schematic structure of the floor unit which concerns on other embodiment, and the mode of vibration. It is a top view which shows schematic structure of the floor unit which concerns on other embodiment, and the mode of vibration. It is a side view of the damper concerning other embodiments. It is the enlarged view to which a part of side surface of the damper concerning other embodiments was expanded. It is a front view of the damper concerning other embodiments.

[First Embodiment]
Hereinafter, a first embodiment of a building of the present invention will be described with reference to the drawings.
In FIG. 1, a two-story unit building 10 including a plurality of building units 12 is shown.
2 shows a boundary portion between the first floor and the second floor, and FIG. 3 shows a schematic configuration of the floor frame 26 on the second floor in a plan view. 4 is a cross-sectional view of the floor frame 26, and FIG. 5 is a perspective view showing a connecting portion between the large floor beam 20 and the small floor beam 29.

  For convenience of explanation, names are given to the members of the building unit 12. The building unit 12 includes four pillars 14, two sets of long and short ceiling beams 16 and 18 arranged in parallel to each other, and two sets of long and short sets arranged parallel to the ceiling beams 16 and 18 in the vertical direction. The floor girder 20 and 22 are provided, and the end portion of the beam is welded to a ceiling and a floor joint to form a ramen structure. However, the unit configuration is not limited to the above, and another box-shaped frame structure may be used.

  In the present embodiment, channel steel (grooved steel) having a U-shaped cross section is used for the ceiling beams 16 and 18 and the floor beams 20 and 22.

  The building unit 12 includes a ceiling frame 24 and a floor frame 26 assembled in a rectangular frame shape, and is configured such that four pillars 14 are erected between them. The ceiling frame 24 includes ceiling joint portions (columns) 28 at four corners, and the end portions of the ceiling beams 16 and 18 having different lengths are welded to the ceiling joint portion 28.

  Similarly, the floor frame 26 includes floor joints (columns) 30 at four corners, and the ends of the longitudinal beams 20 and 22 having different lengths are welded to the floor joint 30.

As shown in FIGS. 2 and 3, the floor frame 26 is provided with a plurality of floor beams 29 arranged at a fixed interval spanning one floor beam 20 on the girder side and the other floor beam 20. .
As shown in FIGS. 4 and 5, the floor beam 29 is welded to a sheet metal bracket 21 welded to the inside of the floor beam 20.
As shown in FIG. 4, a joist 23 is attached to the upper surface of the floor girder 20, and the floor material 27 arranged on the floor joist 29 and the joist 23 is a screw 25 and the floor joist 29 and the joist 23. It is fixed.

As shown in FIG. 2, a ceiling material 31 is attached to the lower surface side of the ceiling frame 24, and a plurality of ceiling beams 16 are connected at a predetermined interval so as to connect one ceiling beam 16 on the beam side and the other ceiling beam 16. A ceiling beam 33 is attached.
Then, the upper and lower ends of the column 14 are rigidly joined by welding between the ceiling joint portion 28 and the floor joint portion 30 that are arranged to face each other in the vertical direction, and are temporarily fixed by bolts. Composed.

The building unit 12 of the present embodiment has a size called a “3P unit”, and has a pitch dimension L of 3 m in the longitudinal direction on one side of the large floor beam 22 and the other side of the large floor beam 22. “3” of “3P unit” means that the pitch dimension is 3 m.
Further, in the floor frame 26 of the present embodiment, the pitch dimension of the floor girder 22 and the floor girder 29 and the pitch dimension of the floor girder 29 and the floor girder 29 are each 50 cm, and the floor girder 29 is equally spaced. Is arranged.

(Dynamic damper)
Next, the main part of the vibration reduction structure of this embodiment will be described in detail.
As shown in FIG. 3 and FIGS. 6A and 6B, in the building unit 12 of the present embodiment, a plurality of dynamics are provided on the inner side surface of the web between the upper and lower flanges of the floor beam 20 on the second-story girder side. A damper 32 is attached via an L-shaped bracket 34. The bracket 34 is attached to the web of the floor girder 20 with bolts 35 or the like.

The dynamic damper 32 includes a first plate 36, an elastic body 38, a second plate 40, and a weight 42 made of a material having a high specific gravity such as cast iron or steel plate.
The elastic body 38 is fixed between the first plate 36 and the second plate 40, and the first plate 36 is attached to the bracket 34 with screws or the like (not shown). Further, a weight 42 is fixed to the upper surface of the second plate 40 with screws or the like (not shown).
The elastic body 38 of the present embodiment is a columnar rubber. However, the material and shape are not particularly limited as long as it has springiness, and may be a metal spring (coil spring, leaf spring) or the like.

The type of rubber constituting the elastic body 38 is not particularly limited. For example, butyl rubber can be employed, and other rubbers can be appropriately selected according to the vibration damping properties.
The dynamic damper 32 is installed at a position where the vibration antinode is large (a position where the amplitude is large), but the position where the amplitude of the vibration antinode is the largest (peak position) or the amplitude where the vibration antinode is largest. It is preferable to install it close to the position.

  FIG. 3A is a plan view showing the floor frame 26 of the central building unit 12 among the three building units 12 connected in the direction of arrow A of the unit building 10 shown in FIG. FIG. 3B is a plan view of the floor frame 26 of the outer building unit 12 of the three connected building units 12 of the unit building 10 shown in FIG. .

The floor frame 26 of the building unit 12 shown in FIG. 3 (A) has a peak position P1 of the antinode of the primary mode vibration (of the floor beam 20) in order to reduce the vibration of the primary mode and the vibration of the secondary mode. The dynamic damper 32 is installed at the peak position P2 of the antinodes of the vibration in the secondary mode (the center portion in the longitudinal direction) and the intermediate portion between the center portion in the longitudinal direction of the floor girder 20 and the floor girder 22.
In FIG. 3, black circles indicate dynamic dampers 32 for reducing primary mode vibrations, and white circles indicate dynamic dampers 32 for reducing secondary mode vibrations.

By the way, in the floor frame 26, the floor beam 29 is attached to the peak position P1 of the antinode of the primary mode. Therefore, the dynamic damper 32 for reducing the vibration of the primary mode is the floor beam 29. 3 (A) and FIG. 6 (B), it is attached to the outer surface side of the large floor beam 20 (the side opposite to the side on which the small floor beam 29 is attached).
In addition, since the floor beam 26 is not attached to the peak position P2 of the antinode of the secondary mode in the floor frame 26, the dynamic damper 32 for reducing the vibration of the secondary mode is provided with the floor beam. 29, it is attached to the inner surface side of the floor girder 20 as shown in FIGS. 3 (A) and 6 (A).

  Further, in the building unit 12 shown in FIG. 3B, an outer wall panel (not shown) is attached to the outer surface of the floor girder 20 on the outer periphery side of the building (floor girder 20 on the lower side of FIG. 3B). Therefore, since the dynamic damper 32 interferes with the outer wall panel, it cannot be attached to the outer surface of the floor girder 20 on the outer peripheral side of the building. For this reason, in the building unit 12 shown in FIG. 3B, the dynamic damper 32 for reducing the vibration of the primary mode is attached to the inside of the floor girder 20 in the floor girder 20 on the outer periphery side of the building (FIG. 6 ( A) Reference) Since the floor beam 31 is attached to the peak position P1 of the vibration of the first-order mode, the dynamic damper 32 does not interfere with the floor beam 29. Are mounted as close as possible.

  As described above, when the floor beam 29 is attached to the peak position P1 of the antinode of the primary mode, the dynamic damper 32 is as shown by a solid line (black circle) in FIG. It may be attached to the right side of the floor beam 31 in the drawing, or may be attached to the left side of the floor beam 29 in the drawing as shown by a two-dot chain line in FIG.

Of course, in the dynamic damper 32 described above, the natural frequency is determined in accordance with the frequency of the vibration to be reduced. Incidentally, the vibration of the low frequency has a larger amplitude than the vibration of the high frequency, and the mass of the weight 42 necessary for reducing the vibration becomes large.
As an example, the dynamic damper 32 for reducing the vibration of the primary mode according to the present embodiment sets the spring constant of the elastic body 38 so that the weight 42 is 5.6 kg and the natural frequency is 120 Hz. Has been.

(Function)
Next, the effect | action of the unit building 10 of this embodiment is demonstrated.
In this embodiment, when an impact or the like is input to the floor material 27 on the second floor (arrow F), the floor girder 20 vibrates due to the impact, but the dynamic girder 32 reduces the vibration of the primary mode in the floor girder 20. In addition, the dynamic damper 32 for reducing the vibration in the secondary mode is installed on the floor girder 20, and each dynamic damper 32 is installed at the peak position of the vibration antinode, so that the primary mode of the floor girder 20 is And the vibration of the second mode are effectively reduced.

  As shown in FIG. 3 (A), it is most effective to install all the dynamic dampers 32 at the peak positions of vibration antinodes. However, as shown in FIG. Even if the mounting position is not completely coincident with the peak position of the vibration antinode, if it is arranged as close as possible so as not to interfere with the floor beam 29, it is comparable to the case where it is installed at the peak position of the vibration antinode. Vibration reduction effect is obtained.

  For this reason, vibration (vibration propagation sound) propagated from the second floor floor girder 20 to the first floor ceiling girder 16, the pillar 14, and the first floor ceiling material 31, and the second floor floor material 27 and the first floor Both vibrations (drum sounds) transmitted to the ceiling material 31 on the first floor through the air between the ceiling material 31 can be effectively suppressed.

  As shown in FIG. 1, when three building units 12 are connected to form a room without a pillar 14 in the center, the floor girder 20 arranged on the center side of the room is connected to the floor girder 20 on the outer wall side. Although it is easy to vibrate in comparison, since the dynamic damper 32 is provided on the floor girder 20 arranged on the center side of the room as in this embodiment, vibration propagation to the first floor can be effectively suppressed.

  In view of the effect of vibration reduction, it is most preferable to attach the dynamic damper 32 at the peak position of the vibration antinode, so that the dynamic damper 32 is preferentially attached at the peak position of the vibration antinode. If it is unavoidable, attach it as close as possible to the peak position of the vibration belly.

  Between the central building unit 12 and the outer building unit 12, as shown in FIG. 6C, a gap is formed between the floor beam 20 of the central building unit 12 and the floor beam 20 of the outer building unit 12. Since the space between the two floor beams 20 is a dead space, the dynamic damper 32 can be installed on the outer surface of the floor beam 20 without interfering with other members.

  In this embodiment, as an example, the natural frequency of the dynamic damper 32 that reduces the vibration of the primary mode is set to 120 Hz. However, the natural frequency 120 Hz is an example, and the natural frequency of the dynamic damper 32 is set to this value. It is not limited. It goes without saying that the natural frequency can be changed by the weight of the weight 42, the spring constant of the elastic body 38, tan δ, and the like.

[Other Embodiments]
In the building unit 12 of the above embodiment, the pitch dimension L of the floor girder 22 on one side and the floor girder on the other side in the longitudinal direction of the floor frame 26 is 3 m. ~ As shown in Fig. 12, "3.5P unit", "4P unit", "4.5P unit", "5P unit", "5.5P unit", "6P unit", etc. One having a floor frame 26 is conceivable. In any unit of the floor frame 26, the pitch dimension of the floor beam 22 and the floor beam 29 and the pitch dimension of the floor beam 29 and the floor beam 29 are 50 cm each, and the floor beam 29 is equally spaced. Is arranged.

  For example, in the floor frame 26 of “3.5P unit” shown in FIG. 7, a dynamic damper (black circle) 32 that reduces vibration in the primary mode, a dynamic damper (white circle) 32 that reduces vibration in the secondary mode, Three types of dynamic dampers (triangles) 32 that reduce the vibration of the tertiary mode are installed on the floor girder 20.

  In the floor frame 26 of the “3.5P unit” shown in FIG. 7, the peak position P1 of the antinode of the primary mode and the peak position P2 of the antinode of the secondary mode are respectively the connecting positions of the floor beams 29. Therefore, the dynamic damper (black circle) 32 that reduces the vibration of the primary mode and the dynamic damper (white circle) 32 that reduces the vibration of the secondary mode do not interfere with the floor beam 29 and do not interfere with the floor beam 20. It is installed at the peak position of the vibration belly inside.

On the other hand, the dynamic damper (triangle) 32 for reducing the vibration of the third-order mode is close to the connection position of the peak position P3 of the vibration of the third-order mode and the floor beam 29. Are arranged so as to coincide with the peak position P3 of the antinode of the third-order mode on the outside of the large floor beam 20 so as not to interfere with the floor beam 29.
In addition, since there are three antinodes of the vibration in the tertiary mode, it is most preferable to install dynamic dampers (triangles) 32 at each of the three locations. However, if there are two locations as in this embodiment, A sufficient effect can be obtained.

  In addition, also in the “4P unit”, “4.5P unit”, and “5P unit” shown in FIGS. 8 to 10, the dynamic damper 32 is installed at the peak position of the vibration mode of each of the floor beams 20. Therefore, each vibration of the primary mode, the secondary mode, and the tertiary mode of the floor girder 20 can be effectively reduced.

In addition, in the “5.5P unit” and “6P unit” shown in FIGS. 11 and 12, a dynamic damper (× mark) 32 for reducing the vibration of the fourth-order mode is further installed on the floor girder 20. Yes. The floor small beam 29 is not connected to the antinode peak position P4 of the fourth-order mode vibration. Therefore, the dynamic damper (x mark) 32 for reducing the vibration of the fourth-order mode is the antinode on the inner side of the floor large beam 20. At the peak position P4. In addition, the other dynamic damper 32 that reduces the vibration in the first to third modes is installed at the peak position of the antinode on the outside of the floor girder 20.
Therefore, in the “5.5P unit” and the “6P unit” shown in FIGS. 11 and 12, each vibration of the primary beam, the second mode, the third mode, and the fourth mode of the floor beam 20 is effectively prevented. Can be reduced.

In this way, in any unit, the dynamic damper 32 is installed in the vicinity of the peak position of the vibration antinode and the peak position of the vibration antinode, so that the vibration of each order mode is effective. Can be reduced.
In the example shown in FIG. 3B, the peak position P1 of the vibration in the primary mode is the central portion in the longitudinal direction of the floor girder 20; It appears at a position different from the longitudinal central portion of the floor girder 20.

  When the dynamic damper 32 is attached to the inside of the floor girder 20 when the vibration peak position overlaps with the floor girder 29 connected to a portion other than the longitudinal center portion of the floor girder 20, for example, As shown by a two-dot chain line in FIG. 12, the dynamic damper 32 is placed closer to the center side in the longitudinal direction of the large beam of the floor, which is easy to deform, than the end of the small beam 29 in the longitudinal direction of the large beam of the floor, which is highly rigid and difficult to deform. It is preferable to attach a round dynamic damper 32 that suppresses secondary mode vibration and a triangular dynamic damper 32 that suppresses tertiary mode vibration.

  In addition, in the building unit 12 shown in FIG. 12, the peak position P3 of the third mode vibration is located in the center in the longitudinal direction of the floor beam 20 and overlaps with the peak position P1 of the first mode vibration. 12, a dynamic damper (triangle) 32 for reducing third-order mode vibration may be disposed inside the floor large beam 20 and close to the floor small beam 29. 3 embodiment).

  In the building unit (3.5P unit) 12 shown in FIG. 7, only the dynamic damper 32 that reduces the vibration of the first mode is installed at the center in the longitudinal direction of the floor beam 20, and the vibration of the third mode is performed. Although the dynamic damper 32 to be reduced is omitted, as shown in FIG. 6C, the dynamic damper 32 that reduces the vibration of the third mode can be installed on the outer surface of the web of the floor girder 20. In this case, the dynamic damper 32 for reducing the vibration in the third mode can be attached using the bolt 35 for attaching the dynamic damper 32 for reducing the vibration in the first mode and the hole formed in the web through which the bolt 35 passes. The bolt 35 and the hole for attaching the dynamic damper 32 for reducing the vibration in the third mode are not required separately, and the number of parts and the number of processing are reduced.

  In the present embodiment, the dynamic damper 32 is attached to the floor girder 20 via the bracket 34. However, the dynamic damper 32 may be attached to the lower flange of the floor girder 20 with screws or the like as shown in FIG.

  In the present embodiment, the dynamic damper 32 is attached to the girder-side floor girder 20. However, the dynamic damper 32 may be attached to the wive-side floor girder 20 in order to suppress vibration of the wife-side floor girder 20. .

The dynamic damper 32 appropriately sets the value of tan δ, which is a characteristic of the elastic body 38, that is, the value of the vector phase difference (angle) between the dynamic spring constant and the loss spring constant of the elastic body 38, It becomes possible to exert a damping action in a wide frequency band.
As a result, it is possible to effectively suppress the heavy impact sound defined in JIS A 1418-2, the lightweight impact sound defined in JIS A 1418-1, the sound generated by pedestrian walking, and the like. .

  In the present embodiment, the dynamic damper 32 is provided on each of the two floor beams 20 arranged on the center side of the room on the second floor. However, the intermediate portion in the longitudinal direction of the two floor beams 20 is not shown in the drawing. When the dynamic dampers 32 are connected to each other and function as a single beam, the effect of the present invention can be obtained even if the dynamic damper 32 is installed only on one of the floor beams 20.

  Since both ends of the floor girder 20 are the parts having the highest rigidity due to the columns 14 connected, even if the dynamic damper 32 is installed on the outside of the floor girder 29 in the longitudinal direction of the floor girder 29 closest to both ends, the dynamic The vibration reduction effect of the damper 32 is difficult to obtain.

[Second Embodiment]
Next, the dynamic damper 32 according to the second embodiment will be described with reference to FIGS. 14 and 15. In addition, the same code | symbol is attached | subjected to the same structure as 1st Embodiment, and the description is abbreviate | omitted.

As shown in FIGS. 14 and 15, the dynamic damper 32 of the present embodiment is provided with two protrusions 44 as vibration suppressing means on the lower surface of the first plate 36.
The protrusions 44 are provided on both ends of the first plate 36 in the longitudinal direction of the beam, and are formed in a range corresponding to a portion where the elastic body 38 is fixed to the first plate 36.

  The shape and size of the protrusion 44 can be set as appropriate within a range where the effects of the present invention can be achieved. That is, the shape and size of the protrusion 44 are set such that the protrusion 44 is pressed against the bracket 34 in a state where the first plate 36 is fixed to the bracket 34 with the bolt 46 and the nut 48.

  In the present embodiment, the first plate 36 is fixed to the bracket 34 with bolts 46 and nuts 48, so that the first plate 36 is opposite to the bolt side of the first plate 36 and has the elastic body 38 fixed thereto. Since the protrusion 44 provided in the range corresponding to the fixing portion of the elastic body 38 is pressed against the bracket 34, the portion of the first plate 36 opposite to the bolt side is securely grounded to the bracket 34. The first plate 36 is suppressed from vibrating in a direction in which the portion opposite to the bolt side approaches and separates from the bracket 34.

  For this reason, in the present embodiment, in the fixed state, the bracket-side first plate 36 can be prevented from functioning independently as a metal elastic body independently of the bracket 34, and the viscoelastic characteristics of the elastic body 38 can be reduced. Can be sufficiently exerted to obtain the inherent damping performance of the elastic body. Thereby, a desired attenuation characteristic can be exhibited in a wide frequency band.

[Other Embodiments]
The unit building 10 of the above embodiment is a unit building composed of a plurality of building units 12, but the present invention is not only a unit structure building but also a building having another structure such as a steel frame structure or a wooden frame structure. For example, it is also effective in suppressing vibration of propagation in the wall of the frame structure.
The building to which the present invention is applied is not limited to a general house but may be a commercial facility.

In the above embodiment, an example in which the damper is installed on the floor beam is shown, but the damper is not limited to the floor beam, and may be installed on the ceiling beam.
The damper of the above embodiment is a dynamic damper configured to include an elastic body and a weight (mass body). However, a known damper other than the dynamic damper can be used as long as vibration can be suppressed. The damper may be an active damper that is electrically controlled.

10 unit building (building)
12 Building unit 14 Pillar 20 Floor girder
29 Floor beam (beam)
32 Dynamic damper (Damper, 1st damper, 2nd damper)
36 First plate (first member)
38 Elastic body 40 Second plate (second member)
42 weight

Claims (10)

A girder connected to the pillar,
A plurality of small beams spanned between the one large beam facing the other and the other large beam;
A building with
The small beam connected to a position that becomes an antinode of vibration of the large beam,
A building in which a damper for suppressing vibration is installed on the opposite side to the small beam, which is connected to a position that becomes an antinode of vibration of the large beam. A girder connected to the pillar,
A plurality of small beams spanned between the one large beam facing the other and the other large beam;
A building with
The small beam connected to a position that becomes an antinode of vibration of the large beam,
A building in which a damper for suppressing vibration is installed on the large beam in the vicinity of the small beam connected to the position where the small beam is connected and to a position where the vibration of the large beam becomes antinode. A first damper that suppresses vibrations of the first order mode;
A second damper for suppressing vibration of a second order mode having a vibration frequency different from that of the first order mode;
With
In the portion where the vibration antinode of the first order mode overlaps with the antinode vibration of the second order mode, either the first damper or the second damper is the large beam. It is installed on the opposite side of the small beam connected to the position where vibration is caused, and one of the first damper and the second damper is on the side where the small beam is connected, and the large beam A building that is installed in the vicinity of the beam connected to a position that becomes an antinode of vibration. The small beam connected to the portion that becomes the antinode of the vibration that appears at a position different from the longitudinal central portion of the large beam,
4. The damper according to claim 2, further comprising: the damper that is installed on a side of the large beam to which the small beam is connected and close to a longitudinal central portion side of the small beam. building. Having the small beam connected to the longitudinal center of the large beam;
4. The building according to claim 2, wherein the damper is installed on a side of the large beam to which the small beam is connected and on one side or the other side in the longitudinal direction of the large beam.   The building according to any one of claims 1 to 5, wherein the girder on which the damper is installed is a floor girder of two or more floors.   The building according to any one of claims 1 to 6, wherein the damper is installed on the girder beam.   The building according to claim 7, wherein the damper is installed in each of the one large beam and the other large beam facing each other on the girder side.   The said damper is comprised by connecting several building units and is installed in the clearance gap between the said large beam of the said one building unit, and the said large beam of the other building unit, The Claim 1 and Claim The building according to any one of claims 3 to 8.   The damper includes a first member used for connection to the girder, an elastic body connected to the first member, and a second member connected to a position different from the first member of the elastic body. The building of any one of Claims 1-9 which is a dynamic damper provided with the member of this, and the weight connected to a said 2nd member.

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