JP7401090B2 - double floor structure - Google Patents

Description

The present invention relates to a double bed structure.

Patent Document 1 discloses a technology related to a sound-insulating double floor structure having a floor slab provided on the floor of a building and a floor surface laid upward from the top surface of the floor slab at a predetermined interval. ing. In this prior art, a dynamic damper is placed on the top surface of a floor slab. Further, the natural frequency of the dynamic damper is adjusted so that the vibration range in which vibration can be effectively damped is 44 Hz to 177 Hz.

Patent Document 2 discloses a technique related to a double floor having a space between a lower floor and an upper floor. In this prior art, a dynamic damper whose weight is elastically floating in the vertical direction is attached to the lower surface of the upper floor. Further, the natural frequency of the dynamic damper is set to 40 to 80 Hz.

Japanese Patent Application Publication No. 2007-205152 JP2013-256817A

A wooden slab double floor made of CLT (Cross Laminated Timber) or the like generates more vibrations such as heavy floor impact noise than a concrete slab double floor, and countermeasures are desired.

In view of the above facts, an object of the present invention is to suppress vibrations in a double floor made of wooden slabs.

A first aspect includes a double floor including a wooden slab and a flooring material supported at intervals on the slab, and a plurality of first vibration dampers installed on the lower surface of the flooring material. , and a plurality of second vibration dampers installed on the upper surface of the slab.

In the double floor structure of the first embodiment, the first vibration damper installed on the underside of the flooring reduces the vibration of the flooring, and the reduced vibration of the flooring is transmitted to the wooden slab, causing the slab to vibrate. do. In other words, the vibrations transmitted to the slab are reduced by the first vibration damper. Then, the vibration of the slab is reduced by the second vibration damper installed on the top surface of the wooden slab.

In this way, by installing the first vibration damper on the bottom surface of the flooring material to suppress the vibration of the flooring material and reducing the vibration transmitted to the wooden slab, the vibration of the slab can be reduced to the first vibration damper installed on the top surface. Vibration is effectively reduced by two anti-vibration dampers.

In a second aspect, the first vibration damper is adjusted to suppress vibrations at a natural frequency of heavy floor impact noise in the floor material, and the second vibration damper is adjusted to suppress vibrations at a natural frequency of heavy floor impact noise in the slab. The double bed structure according to the first aspect, wherein the double bed structure is adjusted to suppress vibrations at a natural frequency of.

In the double floor structure of the second aspect, the first vibration damper is adjusted to suppress the natural frequency vibration of the heavy floor impact sound in the floor material, and the second vibration damper is adjusted to suppress the vibration of the natural frequency of the heavy floor impact sound in the slab. Adjusted to suppress vibrations at natural frequencies. Therefore, even with a double floor made of wooden slabs, heavy floor impact noise can be effectively suppressed.

In a third aspect, the plurality of first vibration-proofing dampers are arranged in areas obtained by dividing the lower surface of the flooring material equally or approximately equally in a plan view, and the plurality of second vibration-proofing dampers are , the double floor structure according to the first aspect or the second aspect, wherein the double floor structure is arranged so as to suppress the vibration of the first mode of the natural frequency of the heavy floor impact sound in the slab.

In the double floor structure of the third aspect, the plurality of first vibration dampers are light in weight because they are arranged in areas divided into equal or approximately equal parts on the lower surface of the flooring material in plan view. Vibrations in the flooring are effectively suppressed, resulting in reduced vibrations transmitted to the slab. In addition, the plurality of second vibration dampers are arranged so as to suppress the vibration of the first mode of the natural frequency of the heavy floor impact sound in the slab, thereby effectively suppressing the vibration of the heavy floor impact sound in the slab. be done.

In a fourth aspect, the double floor structure according to any one of the first to third aspects, wherein the slab is made of a wood material in which sawn boards are laminated and bonded so that the fiber directions are perpendicular to each other. It is.

In the fourth aspect of the double floor structure, the wooden slab is made of wood material made by laminating and bonding sawn boards so that the fiber directions are perpendicular to each other, that is, cross laminated timber (CLT). Compared to the case where the slab is made of solid wood, the rigidity of the wooden slab is higher, so the vibration of the wooden slab is further reduced.

According to the present invention, vibrations of a double floor made of wooden slabs can be suppressed.

(A) is a sectional view of the double floor structure of this embodiment, and (B) is an enlarged sectional view of the slab in (A). FIG. 2 is a bottom view of the flooring material of FIG. 1 viewed from below. FIG. 2 is a top plan view of the slab of FIG. 1;

<Embodiment>
A double floor structure according to an embodiment of the present invention will be explained. Note that two orthogonal directions in the horizontal direction are referred to as the X direction and the Y direction, which are indicated by arrows X and Y, respectively. The vertical direction perpendicular to the X direction and the Y direction is the Z direction, and is indicated by an arrow Z. Further, the view from the Y direction is defined as a front view.

(composition)
First, the configuration of the double floor structure will be explained.

As shown in FIG. 1(A), the double floor structure 10 includes a double floor 20, a plurality of first vibration dampers 100, and a plurality of second vibration dampers 200. Note that in FIG. 1A, hatching indicating the cross section is omitted for easy viewing.

The double floor 20 is composed of a wooden slab 30 and flooring materials 40 supported on the slab 30 at intervals. In this embodiment, the wooden slab 30 is a wooden material made by laminating and bonding sawn boards 38 such that the fiber directions are perpendicular to each other, that is, a cross-laminated timber (CLT), as shown in FIG. 1(B). ). Note that the lower surface 34 of the slab 30 of this embodiment constitutes the ceiling surface of the lower floor 24.

The floor material 40 shown in FIG. 1(A) is made of particle board and is supported by support bolts 22. A sound insulating mat 50 is laid on the upper surface 42 of the flooring material 40. The sound insulating mat 50 of this embodiment is made of a rubber sheet material, but is not limited thereto. For example, it may be a sheet material made of urethane foam or the like. A plywood 52 made of white birch or the like and a tile carpet (not shown) are laid on the sound insulating mat 50.

The first vibration damper 100 is installed on the lower surface 44 of the flooring material 40. The first vibration damper 100 of this embodiment includes a leaf spring member 110 whose one end 112 is fixed to the lower surface 44 of the flooring 40, a weight part 120 provided at the other end 114 of the leaf spring member 110, A high damping rubber 122 provided on the upper part of the weight part 120 is provided. The first anti-vibration damper 100 is a damper that combines the damping effect of the movement of the leaf spring member 110 and the weight part 120, and the damping effect of absorbing the vibration of the floor material 40 by the high damping rubber 122. In addition, the first vibration damper 100 has the thickness and length of the leaf spring member 110 and the weight of the weight portion 120 adjusted so as to suppress the vibration of the natural frequency of the heavy floor impact sound in the flooring material 40. There is.

As shown in FIG. 2, the first vibration damper 100 is arranged in each region R obtained by dividing the lower surface 44 of the flooring material 40 into equal or substantially equal parts in plan view. To explain from another point of view, the first vibration damper 100 is arranged so as to have an equal area on the lower surface 44 of the flooring material 40. Note that the number of first vibration-proofing dampers 100 to be installed is determined according to this embodiment so that the total weight of the weight portions 120 of the plurality of first vibration-proofing dampers 100 becomes a predetermined ratio with respect to the effective mass of the flooring material 40. It is set to be between 15% and 25%.

As shown in FIG. 1(A), the second anti-vibration damper 200 is installed on the upper surface 32 of the slab 30. The second anti-vibration damper 200 of this embodiment is an iron weight damper having a leg portion 210 having spring properties fixed on the slab 30 and a weight portion 220 supported by the leg portion 210. In the second anti-vibration damper 200, the thickness and length of the leg portion 210, the weight of the weight portion 220, etc. are adjusted so as to suppress the vibration of the natural frequency of the heavy floor impact sound in the slab 30.

As shown in FIG. 3, the second anti-vibration damper 200 is arranged to suppress vibration in the first mode of the natural frequency of the heavy floor impact sound in the slab 30. Specifically, it is placed at a portion of the slab 30 that corresponds to the antinode of the amplitude of the primary mode. In this embodiment, the number of second anti-vibration dampers 200 to be installed is set such that the total weight of the weight portions 220 of the plurality of second anti-vibration dampers 200 is a predetermined ratio to the effective mass of the slab 30. It is set to be 20% to 30%.

Note that the natural frequency of the heavy floor impact sound is approximately 45 Hz to 90 Hz.

(action and effect)
Next, the functions and effects of this embodiment will be explained.

In the double floor structure 10 of this embodiment, the vibration of the flooring 140 is reduced by the first vibration damper 100 installed on the lower surface 44 of the flooring 40, and the reduced vibration of the flooring 40 is transferred to the wooden slab 30. and the slab 30 vibrates. In other words, the vibrations transmitted to the slab 30 are reduced by the first vibration damper 100. The second vibration damper 200 installed on the upper surface 42 of the wooden slab 30 reduces the vibration of the slab 30.

In this way, by installing the first vibration damper 100 on the lower surface 44 of the flooring material 40 to suppress the vibrations of the flooring material 40 and reducing the vibrations transmitted to the wooden slab 30, the vibrations of the slab 30 are reduced. The second vibration damper 200 installed on the upper surface 32 reduces the reduced vibration of the slab 30. Therefore, vibration of the slab 30 is effectively reduced.

Further, the first vibration damper 100 is adjusted to suppress the vibration of the natural frequency of the heavy floor impact sound in the floor material 40, and the second vibration damper 200 is adjusted to suppress the vibration of the natural frequency of the heavy floor impact sound in the slab 30. Adjusted to suppress vibration. Therefore, even with a double floor made of wooden slabs 30, the heavy floor impact sound that resonates on the lower floor 24 can be effectively suppressed.

Moreover, the plurality of first vibration dampers 100 are arranged in each region R obtained by dividing the lower surface 44 of the flooring material 40 into equal or substantially equal parts in plan view. Therefore, the vibrations of the lightweight flooring material 40 are effectively suppressed, so that the vibrations transmitted to the slab 30 are effectively suppressed. Furthermore, by arranging the plurality of second vibration dampers 200 to suppress the vibration of the first mode of the natural frequency of the heavy floor impact sound in the slab 30, the vibration of the slab 30 due to the heavy floor impact sound is effectively suppressed. is suppressed. Therefore, the heavy floor impact sound that resonates on the lower floor 24 is effectively suppressed.

In addition, the wooden slab 30 is constructed from a wooden material in which sawn boards 38 are laminated and bonded so that the fiber directions are perpendicular to each other, that is, cross laminated timber (CLT), so that the slab is constructed from solid wood. Since the rigidity of the wooden slab 30 is higher than that in the case where the wooden slab 30 is used, the vibration of the wooden slab 30 is reduced, and the heavy floor impact sound that resonates on the lower floor 24 is further suppressed.

Furthermore, the vibration of the flooring 40 is further reduced by the sound insulating mat placed on the upper surface 42 of the flooring 40. Therefore, the vibrations transmitted to the wooden slab 30 are further reduced. Therefore, the vibration of the slab 30 is further reduced by the second vibration damper 200 installed on the upper surface 32 of the wooden slab 30, so that the heavy floor impact noise is further suppressed.

In addition, it has been confirmed through actual measurements that the double floor 20 of this embodiment has performance of LH60 class against heavy floor impact noise.

In addition, the wooden slab 30 is lighter than a reinforced concrete slab, so it is easier to construct and can reduce the weight of the building. Furthermore, as described above, the heavy floor impact sound that resonates on the lower floor 24 is suppressed, so the wooden lower surface 34 can be exposed as a ceiling surface, improving the design.

<Others>
Note that the present invention is not limited to the above embodiments.

For example, the first anti-vibration damper 100 and the second anti-vibration damper 200 are not limited to the configurations of the above embodiments. Any configuration of the anti-vibration damper may be used. Further, the arrangement of the first anti-vibration damper 100 and the second anti-vibration damper 200 is not limited to the arrangement shown in FIGS. 2 and 3. The first anti-vibration damper 100 and the second anti-vibration damper 200 may be arranged in any manner.

Further, for example, in the above embodiment, the flooring material 40 is made of particle board, a sound insulating mat 50 is laid on the upper surface 42 of the flooring material 40, and on this sound insulating mat 50, a plywood 52 and tiles (not shown) are placed. Carpeted, but not limited to. The material constituting the flooring material 40 is not limited, and the material laid on the flooring material 40 is also not limited. Any structure may be used as long as it is a double floor of wooden slabs 30.

Further, for example, in the above embodiment, the slab 30 is made of a wood material in which the sawn boards 38 are laminated and bonded so that the fiber directions are perpendicular to each other, that is, cross laminated timber (CLT). It is not limited to this. The slab 30 may be made of, for example, a veneer laminated material (LVL (Laminated Veneer Lumber)), which is a shaft material made by laminating and bonding veneers with their fiber directions aligned, or may be made of solid wood. . The slab 30 may be made of wood.

Furthermore, the invention may be implemented in various ways without departing from the spirit of the invention.

10 double floor structure 20 double floor 30 slab 38 sawn board 40 flooring material 42 top surface 50 sound insulation mat 100 first vibration isolation damper 200 second vibration isolation damper
R area

Claims (2)

a double floor comprising a wooden slab and flooring supported at intervals above the slab;
a plurality of first vibration dampers installed on the lower surface of the flooring material to reduce vibrations of the flooring material ;
a plurality of second anti-vibration dampers that are arranged on the upper surface of the slab and reduce vibrations transmitted to the slab from the flooring material whose vibrations have been reduced by the first anti-vibration dampers;
Equipped with
The plurality of first anti-vibration dampers are arranged in each region divided into equal or substantially equal parts on the lower surface of the flooring material in a plan view,
The plurality of second vibration dampers are arranged to suppress vibration in the first mode of the natural frequency of the heavy floor impact sound in the slab.
Double floor structure. The slab is made of a wood material in which sawn boards are laminated and bonded so that the fiber directions are perpendicular to each other.
The double bed structure according to claim 1.