JP2007186961A - Double structure of structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a double structure (a double floor structure and a double ceiling structure) efficiently reducing the impulsive sound of a heavy floor over a wide band and easily and positively constructed without making structural load to a structure excessive. <P>SOLUTION: The double floor structure 10 of the structure has a floor foundation bed 12 of the structure, a plurality of support legs 20 arranged on the floor foundation bed 12, and floor panels 13 supported facing the floor foundation bed 12 by the support legs 20. A plurality of dampers 30 each provided with a fixed layer 31 higher in Young's modulus than a viscoelastic body 32, on the surface of the viscoelastic body 32 is adhesively joined to the floor foundation bed 12, and the fixed layer 31 and the floor panel 13 are connected by screw spikes 35. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a double structure of a structure, and in particular, in a double floor structure or a double ceiling structure in which a floor base and a panel material of a structure are opposed to each other with a space therebetween, a heavy floor impact sound blocking performance. It relates to an improved structure.

  In apartment houses such as apartments and condominiums, as shown in FIG. 6 (a), a plurality of supports such as support legs 120 are arranged on a floor base 112 such as a concrete slab so that a predetermined height is achieved. A double floor structure 110 is widely used in which a floor panel 113 such as a particle board is supported across a space 116 and a finishing material such as a flooring material is laid on the floor panel 113. The support leg 120 is generally composed of a bolt 122 whose height is adjustable, and a support plate 121 and an elastic pedestal 123 that fit the bolt 122 above and below. Further, a double ceiling structure in which a ceiling panel such as a plaster board is opposed to the floor base 112 with a space therebetween and supported by a support such as a suspension bolt is also widely used.

  The double floor structure and the double ceiling structure can easily obtain a floor surface and a ceiling surface having a uniform height as compared with the direct bonding structure in which the floor panel or the ceiling panel is directly laid on the floor base. It is easy to let piping and wiring pass through and has excellent remodeling properties. Further, regarding the double floor structure 110, an appropriate elasticity is generated between the floor panel 113 and the floor base 112 by the elastic pedestal 123, so that an appropriate walking feeling can be obtained. There is an advantage that a direct impact to the base 112 can be prevented.

  However, the double floor structure and double ceiling structure may not be able to sufficiently block the floor impact sound on the upper and lower floors, especially heavy floor impact sound with a large impact force (for example, the sound of a person jumping on the upper floor and heavy objects) In some cases, the blocking performance against a drop impact sound, etc.) may be deteriorated by about 10 dB as compared with the direct attachment structure. The floor impact sound is roughly classified into the above-described heavy floor impact sound and a light floor impact sound with a small impact force (for example, a drop impact sound of a lightweight object such as metal tableware on the upper floor). The former is a sound wave generated when the entire floor panel vibrates, and the latter is a sound wave generated when the floor panel vibrates locally, both of which propagate through the floor base 112 to the lower floor or the like.

  Although the mechanism by which the heavy floor impact sound blocking performance is reduced in the double floor structure and the double ceiling structure as compared with the direct attachment structure is not completely clarified, for example, the general double floor structure 110 In this case, due to the resonance system (double structure resonance system) composed of various elements such as the elasticity of the elastic pedestal 123 constituting the double floor, the specific rigidity of the floor panel 113 and the ceiling panel, and the effect of the air spring by the space 116 It is thought to be caused by amplification of floor impact sound. In particular, it is said that when the impact sound in the 31.5 to 250 Hz band is significantly amplified, the interruption performance of the entire heavy floor impact sound is lowered.

Various attempts have been made in the past to reduce amplification of such heavy floor impact sound. Hereinafter, a double floor structure will be described as an example.
First, it is an attempt to suppress the generation of heavy impact sound by increasing the thickness of the floor base where vibrations propagate and the floor panel itself that generates vibrations. However, this measure is difficult to realize from the viewpoint of strength because the load on the floor base and floor panel, which are heavy structures, is excessive, and it is not possible to redesign these main structural members with respect to conventional structures. There is a problem that it is not easy.
The second is an attempt to reduce the effect of the air spring generated between the floor panel and the floor base by providing air vent holes around the floor panel of the double floor. However, when the floor area is increased, it is not easy to remove the air from the central portion, so the effect of the countermeasure is relatively reduced. Moreover, the hole provided in the circumference | surroundings of a floor panel becomes a problem on an architectural design.
Third, it is an attempt to reduce the vibration transmissibility between the floor panel and the floor base by lowering the hardness of the elastic pedestal 123 of the support leg 120. However, with such a countermeasure, the rigidity of the entire double floor structure is lowered, so that there is a risk that furniture or the like may be inclined.
Fourthly, in the double floor described in Patent Documents 1 and 2 below, as shown in FIG. 6 (b), it is in close contact with the back surface of the floor panel 113 or has a predetermined gap, such as a plastic foam. Attempts have been made to improve the soundproofing property of the floor impact sound by providing the porous material 131. In addition, in the double floor described in Patent Document 1, another sound absorber 132 made of a porous material is further placed on the floor base 112 to achieve acoustic attenuation of the floor impact sound to be propagated. .

JP-A-9-32246 Japanese Patent Laid-Open No. 10-2094

However, the porous sound-absorbing material used in the invention described in Patent Document 1 or 2 is effective for blocking a relatively high frequency sound, which is a main cause of a light floor impact sound, but has a relatively low weight. The effect was not sufficient from the viewpoint of blocking floor impact sound. In general, when the frequency ω of the floor impact sound and the resonance frequency ω _{0 of the} double structure are coincident or close to each other, the floor impact sound of such frequency is amplified by a high vibration transmissibility. Is based on a technology that suppresses the amplification of vibration by shifting the resonance frequency ω ₀ of the double structure to a low frequency by providing a porous material on the back surface of the floor panel and by separating it from the frequency ω of the floor impact sound. Yes.
However, the heavy floor impact sound generated by the double floor structure does not have only a specific frequency ω, and the frequency with a high sound pressure level is widely distributed over a wide band of 31.5 to 250 Hz. For this reason, even if the resonance frequency ω ₀ of the double floor structure is reduced and the amplification of the sound wave of the specific frequency ω can be suppressed, the vibration of another impact sound having a frequency close to the new ω ₀ Since the transmissibility increases conversely, it is difficult to suppress the heavy weight floor impact sound over a wide band by such a conventional method.

  Further, as in the double floor structure 110 described in Patent Document 1 (see FIG. 6B), when the sound absorber 132 is placed on the floor base 112, the sound absorber 132 and the floor panel are arranged depending on the arrangement of the sound absorber. It has been reported that the heavy floor impact sound is amplified in the space 116 formed between the control unit 113 and the shut-off performance.

  In addition, each subject in the above-described prior art aiming at reducing heavy floor impact sound is a problem that can occur in a double ceiling structure in which a floor base and a ceiling panel are separated from each other. Therefore, the present invention can effectively reduce heavy-weight floor impact sound over a wide band, and can be easily and surely constructed without increasing the structural load on the structure. The purpose is to provide a heavy floor structure and a double ceiling structure.

  The present invention does not shift the resonance frequency of the dual structure to the low frequency side, or absorb the heavy floor impact sound that propagates in space by the sound absorbing material and attenuate the sound by its viscous friction, but does not attenuate the floor panel or ceiling. By directly connecting panel materials such as panels to the floor base with a viscoelastic body with a high loss coefficient, the vibration transmission rate between the panel material and the floor base is reduced, and vibration generated in the panel material is promptly reduced. It was based on a completely new technical idea of attenuating and dissipating as thermal energy.

That is, the present invention
(1) A duplex structure having a floor base of the structure, a plurality of supports disposed above or below the floor base, and a panel member supported by the support to face the floor base. Structure,
A plurality of dampers provided with a fixed layer having a higher Young's modulus than the viscoelastic body on the surface of the viscoelastic body are joined to the floor base, and the fixed layer and the panel material are joined by a connector. A double structure characterized by:
(2) The fixed layer is a plate material laminated and bonded to the surface of the viscoelastic body, and the damper and the floor base are joined by an adhesive, as described in (1) above Double structure;
(3) The double structure according to (1) or (2) above, wherein the viscoelastic body is made of one or more of foamed plastic, rubber, elastomer, or fiber;
(4) The double structure according to any one of (1) to (3), wherein the connector is a screw nail that passes through the panel material and is inserted into the fixed layer;
Is the gist.

  According to the present invention, it is easy to make the height of the panel material uniform, and without damaging the advantage of the double structure that is excellent in the laying property of piping and wiring, between the panel material and the floor base. It is possible to reduce the vibration transmissibility and quickly attenuate the vibration generated in the panel material. In addition, the present invention provides a fixed layer having a high Young's modulus on the surface of the viscoelastic body and connects it to the floor panel, so that vibration generated in the floor panel is efficiently transmitted to the viscoelastic body of the damper. In addition, it is possible to suppress the resonance of the panel material and reduce the occurrence of heavy floor impact sound itself. Such vibration transmissibility reduction and resonance attenuation and suppression effects do not act only on sound waves of a specific frequency, but can block the entire heavy floor impact sound over a wide band of 31.5 to 250 Hz. .

  Since the present invention is a system in which a plurality of dampers for coupling the floor base and the panel material are provided, the weight impact sound can be efficiently reduced even for a large panel area by increasing the number of dampers. The double structure according to the present invention can obtain the same effect when applied to a double ceiling structure as well as a double ceiling structure.

  The damper used in the present invention is characterized in that a fixed layer having a higher Young's modulus is provided on the surface of a viscoelastic body and is bonded to a panel material. Thereby, the vibration of the panel material caused by the heavy floor impact is directly transmitted to the fixed layer, and the vibration damping effect by the viscoelastic body can be fully enjoyed.

  Furthermore, since the present invention is formed by connecting the fixed layer and the panel material with a connecting tool having a predetermined length, the floor base has partial unevenness (unevenness) or the height of the damper. Even if there are variations, the fixing layer and the panel material can be reliably bonded by adjusting the attachment depth of the coupling tool. Thereby, the mechanical coupling | bonding of a panel material and a damper does not become inadequate, and the uniform interruption | blocking performance with respect to a heavy floor impact sound can be given to the whole panel material.

  Hereinafter, the best mode for carrying out the double structure of a structure according to the present invention will be specifically described with reference to the drawings. FIG. 1 is an explanatory view of a double floor structure according to a first embodiment of the present invention, in which FIG. 1 (a) is a plan view and FIG. 1 (b) is a bb cross-sectional view thereof. Moreover, the enlarged view of the circle | round | yen X of FIG.1 (b) is shown in FIG. 10 is a double floor structure according to the present embodiment, 12 is a floor base, 20 is a support leg as an example of a support disposed on the floor base, and 13 is a panel material supported opposite to the floor base 12. An example floor panel, 30 is a damper for connecting the floor base 12 and the floor panel 13, and 35 is a screw nail as an example of a connector.

The structure according to the present invention is not particularly limited as long as it has a floor base 12 and a panel material facing the floor base 12 and is intended to reduce heavy floor impact sound. Of apartments and apartments.
Generally, a slab material having a thickness of about 200 mm is used for the floor base 12, but a structure obtained by other methods and the floor base 12 may be used.

  As the floor panel 13 having a double floor structure, a particle board obtained by crushing wood into small pieces and hot compression molding with an adhesive, or an MDF board obtained by making wood into a fiber shape and press-molding at a high temperature are generally used. On the upper surface side of the floor panel 13, a flooring material, a finishing material such as a carpet or a tatami mat (not shown in FIG. 1), a sound insulating sheet, and the like are laid.

  The double floor structure 10 has a plurality of support legs 20 standing on a floor base 12 at a predetermined interval and a floor panel 13 placed horizontally thereon. Furthermore, a damper 30 is provided in the space 16 formed between the floor base 12 and the floor panel 13, and the floor panel 13 and the damper 30 are mechanically coupled via screw nails 35, The floor base 12 is bonded and bonded by an adhesive layer 33. The floor panel 13 is divided into a plurality of sheets from the viewpoint of manufacturing and construction. As a load path that increases the level of the floor panel 13 and efficiently transmits the load applied to the floor panel 13 to the support leg 20, a joist member 15 combined with a prism is provided on the support leg 20 as necessary. The floor panel 13 may be placed side by side. Note that the joist member 15 is not shown in FIG.

The specific configuration of the support used in the present invention is not particularly limited. In the double floor structure, a double ceiling is used by using support legs 20 that are arranged on the floor base 12 and on which the floor panel 13 is placed. In the structure, it is common to use suspension bolts provided below the floor base 12 to suspend and hold the ceiling panel 43. In the double floor structure 10 according to the present embodiment, the support leg 20 may be composed of, for example, a bolt 22 whose height can be adjusted, and a support plate 21 and an elastic base 23 on which the bolt 22 is fitted at the top and bottom. . The elastic pedestal 23 made of a rubber material or the like may have a predetermined elasticity by adjusting the hardness of the material. Further, the support legs 20 are arranged at a predetermined interval with respect to the floor panel 13.
FIG. 1 shows a configuration in which the support legs 20 are arranged in a lattice point and the damper 30 is arranged at the center (face center) of each lattice. However, the number and position of the support legs 20 and the dampers 30 are not limited to this.
In this way, by providing the damper 30 in the central portion of the section of the panel surrounded by the plurality of support legs 20 arranged in a lattice point shape, the central portion corresponding to the antinode of the primary vibration (odd-order vibration) of the panel is provided. Large vibrations are received by the damper 30, and such vibrations can be attenuated efficiently.

  In the present embodiment, the shape of the floor panel 13 is a rectangular plate with the vertical direction in FIG. 1A as the longitudinal direction, and the supporting legs 20 are arranged on each of the four legs along the opposing long sides. Three dampers 30 are arranged on the center line of the floor panel 13 in the short direction. On the other hand, for example, the support legs 20 may be arranged on the center line in the short direction of the floor panel 13, and the arrangement pattern of the support legs 20 and / or the dampers 30 may be other than the lattice points.

Hereinafter, the configuration and function of the damper 30 which is a characteristic component of the present invention will be described in detail.
The damper 30 is characterized in that a fixed layer 31 having a higher Young's modulus than that of the viscoelastic body is provided on the surface of the viscoelastic body 32. A specific configuration of the damper 30 is illustrated in a perspective view in FIG. The fixing layer 31 provided on the surface of the viscoelastic body 32 may be any material as long as it can mechanically connect the floor panel 13 and the viscoelastic body 32 with sufficient strength by a connector such as a screw nail 35. May be formed by attaching a plate material such as wood having a predetermined thickness to the viscoelastic body 32 with an adhesive or the like, or may be provided by improving the Young's modulus by thermosetting the surface side of the viscoelastic body 32 or the like. Good. In the latter case, it is also preferable to embed a metal insert or the like on the surface of the cured viscoelastic body 32 to increase the bonding force with the connector. In addition, as an example of a material that has good adhesiveness to the viscoelastic body 32 and can obtain a high bonding force with the screw nail 35, paper and plastic are pulverized and mixed, and then hot pressed to thermally press the cloth material onto the surface. Can be mentioned.

  The fixed layer 31 may be a single plate as shown in FIG. 3A, or may be a plurality of block members that are separated from each other as shown in FIG. Further, the width dimension w and the depth dimension d of the fixed layer 31 are not limited to these, and may have a width and a depth dimension large enough to cover the viscoelastic body 32 as shown in FIG. .

The viscoelastic body 32 mechanically couples the floor base 12 and the floor panel 13 to give a loss coefficient η to the resonance system of the double floor structure 10 and to suppress the vibration itself of the floor panel 13 itself. It also has a function to By increasing the loss factor η, even when a heavy floor impact having a frequency equal to the resonance frequency ω ₀ of the double floor structure 10 is applied to the floor panel 13, the floor panel 13 and the floor base 12 are not affected. The vibration transmissibility is reduced, and the generated vibration energy is quickly converted into heat energy and dissipated.
In order to improve the performance of blocking heavy floor impact sound, the loss coefficient η of the viscoelastic body 32 is preferably as high as possible, and is preferably 0.4 or more. Further, the Young's modulus of the viscoelastic body 32 is made as small as possible, and this is equivalent to the Young's modulus of air (= 1.4 × 10 ⁵ [N / m ² ]) or in the range of about 5 to 6 times that, that is, 2 × 10. By setting ^{5 to} 9 × 10 ⁵ [N / m ² ], the resonance frequency ω ₀ of the double floor structure 10 is not substantially shifted to the high frequency side.

  As a specific material of the viscoelastic body 32, any one or more of foamed plastic, rubber, elastomer or fiber can be used. Silicon rubber can be used as the rubber, and fiber-based porous materials such as glass wool and rock wool can be used as the fiber. Among these, low repulsion foamed polyethylene and other foamed plastics are preferable from the viewpoint of having a high loss factor with respect to vibration with a large amplitude such as a heavy floor impact sound. Foamed plastics also have the advantage that a desired Young's modulus can be achieved by adjusting the expansion ratio.

  Examples of preferable foamed plastics include polyolefin resin extruded foams described in JP-A No. 2003-165858. Specifically, a polyethylene or polypropylene resin extruded foam having an apparent density of 90 g / L or less is preferable. Further, the extruded foam may be laminated and laminated to adjust the thickness. Further, those having an open cell ratio of 40 to 100% are particularly suitable. In addition, the said open cell rate means the value calculated | required by the procedure C of ASTM-D2856-70.

The damper 30 including the viscoelastic body 32 has a fixed layer 31 formed on the front surface side and an adhesive layer 33 formed on the back surface side. In the present invention, the “surface” side refers to the surface on the opposite side of the floor base 12.
The damper 30 is coupled to the floor panel 13 on the front surface side via a connector, and is coupled to the floor base 12 on the back surface side via an adhesive layer 33. As a result, the double floor structure 10 can increase the loss coefficient η without substantially shifting the resonance frequency ω ₀ to both the low frequency side and the high frequency side. Reduction can be realized.

  The coupling tool exemplified by the screw nail 35 can be used without particular limitation as long as it can couple the floor panel 13 and the fixed layer 31 and resonate them together. For example, in addition to the above-described mechanical fasteners such as screw nails (coarse thread screws) and bolts, a thick wet adhesive such as GL bond or mortar can be used. Screw nails are particularly preferably used because they do not require pilot holes, are excellent in workability, and have a binding force of about five times that of ordinary nails.

In the fixed layer 31 of the damper 30, the arrangement of the connection points 34 connected to the floor panel 13 by the screw nails 35 is shown in FIG. 3. When a normal screw nail 35 is used as a coupling tool, it is preferable that each damper 30 is coupled to the floor panel 13 at three or more locations. Thereby, vibration can be efficiently transmitted from the floor panel 13 to the damper 30, and the vibration can be attenuated by viscoelastic deformation of the entire viscoelastic body 32.
In addition, when there are too few coupling | bonding locations of the floor panel 13 and the fixed layer 31, it may become difficult to transmit the resonance of the floor panel 13 to the viscoelastic body 32 sufficiently. In this case, since the rigidity of the fixed layer 31 cannot be sufficiently imparted to the floor panel 13, it may be difficult to suppress the vibration of the entire floor panel 13 and reduce the generation of heavy floor impact sound. .
On the other hand, from the viewpoint of reducing the number of construction steps, it is preferable to reduce the number of screw nails 35. From the balance between them, the screw nails 35 that connect the fixing layer 31 and the floor panel 13 are 3 per damper 30. It is preferable to use ~ 5. In addition, the arrangement of the coupling points 34 is most excellent in the mechanical balance when a pattern corresponding to each of the third to fifth eyes of the dice is used.

The shape of the viscoelastic body 32 may be an arbitrary shape such as a columnar shape, a pyramid shape, a cone shape, a truncated pyramid shape, and a truncated cone shape in addition to the prismatic shape shown in each drawing of FIG. Moreover, when making the damper 30 into prismatic shape shown to Fig.3 (a), it does not specifically limit about the width dimension w and the depth dimension d, It is suitable to set it as about 200-250 mm.
About the cross-sectional area and the number of the viscoelastic bodies 32, it is preferable that the following relational expression (i) is satisfied, so that the resonance frequency ω ₀ of the double floor structure 10 is not substantially changed. However, in the following equation, the viscoelastic body 32 is columnar, the cross-sectional area is constant regardless of the height, and the viscoelastic bodies 32 have the same dimensions. A is the total floor area, s is the cross-sectional area of the viscoelastic body 32, n is the number of viscoelastic bodies 32 (ie, dampers 30), E is the Young's modulus of the viscoelastic body 32, and ρ ₀ is the density of air in the space 16. , C ₀ is the speed of sound in the air.
(Equation 1)
sn / A = ρ ₀ c ₀ ² / (E + ρ ₀ c ₀ ² ) (i);
In addition, if the width dimension w or the depth dimension d of the viscoelastic body 32 is remarkably small, the connectivity with the floor panel 13 is inferior, and if it is remarkably large, it becomes difficult to flexibly cope with the problem of unevenness described later. A preferred height dimension h will be described later along with the problem of unevenness.

  In addition to the adhesive layer 33 shown in each drawing of FIG. 3, for example, the damper 30 is joined to the floor base 12 by forming a wedge-shaped unevenness on the upper surface of the floor base 12 and piercing and fixing the back surface of the viscoelastic body 32. Such mechanical joining may be used. From the viewpoint that the viscoelastic body 32 made of a porous body or the like is uniformly bonded to the floor base 12 and the construction is easy, a sheet material such as kraft paper is bonded and bonded to the back surface of the viscoelastic body 32, It is preferable to join the sheet material and the upper surface of the floor base 12 with an adhesive layer 33. As the adhesive used for the adhesive layer 33, an organic adhesive such as urethane or cellulose, or an inorganic adhesive such as GL bond or mortar can be suitably used.

Here, the unevenness which may occur on the floor base 12 will be described. As schematically shown in FIGS. 1A, 1 </ b> B, and 2, the floor base 12 has unevenness 14 that is an uneven portion with respect to land that is a flat portion in terms of construction accuracy. It is hard to avoid. The height of the non-land 14 is about 20 mm at the maximum in general reinforced concrete apartments and apartments. That is, if the height of the space 16 formed between the floor base 12 and the floor panel 13 on the land that is the reference plane for the height of the floor base 12 is H [mm], the space 16 is formed above the non-land 14. The height of the space to be obtained is H−the maximum height [mm] of the assumed unevenness to H + the maximum height [mm] of the assumed unevenness (except H [mm]).
Here, when the height of the damper 30 is set to H [mm], the damper 30 is accommodated in the space 16 in a flat land portion or a concave uneven portion, and thus the floor panel 13 placed on the support leg 20 is placed. The damper 30 is not compressed by the floor base 12. On the other hand, when the damper 30 is provided in the convex uneven portion 14, the height of the space 16 is less than this, and therefore when the floor panel 13 is placed on the support leg 20, The damper 30 is compressed by the floor base 12. Then, the viscoelastic body 32 of the damper 30 is compressed by the dead weight of the floor panel 13, but when the amount of compression is large, the floor panel 13 is pushed upward at the contact portion with the damper 30, and the land 14 A local swell of the floor panel 13 occurs in a portion corresponding to. Such local swell of the floor panel 13 is problematic because it reduces the flatness of the floor. The ratio between the compression amount of the viscoelastic body 32 and the rising amount of the floor panel 13 is determined by the Young's modulus of both, and even if the Young's modulus of the viscoelastic body 32 is lowered to the same level as air, the rising of the floor panel 13 is increased. It cannot be zero.

  Therefore, in order to eliminate such inconvenience, in the present invention, the height h [mm] of the damper 30 is set to one of the maximum heights [mm] to H [mm] of the assumed non-land. Thus, the height of the convex unevenness 14 is absorbed, and the strong compression of the damper 30 can be more reliably avoided. That is, for example, in the double floor structure 10 according to the present embodiment, when the actual height of the convex unevenness 14 generated on the floor base 12 is 5 mm, the height of the damper 30 is assumed to be H-. By setting the maximum unevenness height [mm] to H-5 [mm], the damper 30 and the floor panel 13 are not in direct contact with each other, or the damper 30 is not compressed. Further, in particular, by setting the height of the damper 30 to the H-estimated maximum non-land height [mm], any normal non-land 14 height generated in a general reinforced concrete apartment or the like is absorbed. be able to. In addition, the maximum height of the assumed unevenness is 20 mm or less normally, Preferably it is 10 mm or less.

In the double floor structure 10 according to the present invention, the damper 30 and the floor panel 13 are mechanically coupled to each other by a connector, and the vibration of the floor panel 13 is transmitted to the viscoelastic body 32 through the fixed layer 31. . Therefore, even if the fixed layer 31 of the damper 30 and the floor panel 13 are not in direct contact with each other, it is possible to couple them using a connector represented by the screw nail 35. When the connector is a screw nail 35, it is preferable that the length of the screw nail 35 driven from above the floor panel 13 reaches at least the center of the thickness of the fixed layer 31. Even if the tip of the screwed nail 35 that has been driven penetrates the fixed layer 31 and reaches the inside of the viscoelastic body 32, the vibration damping performance of the viscoelastic body 32 is not deteriorated. Therefore, when using a screw nail 35 as a connecting tool,
(1) (the thickness of the floor panel 13 + the thickness of the fixed layer 31 × 0.5) mm or more, so that the bonding strength sufficient when the height h of the damper 30 is equal to the height H of the space 16 Can be obtained;
(2) The damper 30 provided on the land portion of the floor base 12 by setting the thickness to be equal to or greater than (thickness of the floor panel 13 + thickness of the fixed layer 31 × 0.5 + presumed maximum height of the unevenness). Can be bonded to the floor panel 13 with sufficient strength;
(3) The thickness of the floor panel 13 + the thickness of the fixed layer 31 × 0.5 + 2 × the assumed maximum non-land height) mm or more, so that the damper 30 has a concave non-land surface of the floor base 12. Even when it is provided in the part, it can be bonded to the floor panel 13 with sufficient strength.

  FIG. 4 is an explanatory diagram showing a construction procedure of the double floor structure 10 according to the present embodiment. FIG. 2A is a front view of the floor base 12 having the local convex unevenness 14 and the support legs 20 disposed thereon. The floor panel 13 is placed on the support leg 20 and provided to face the floor base 12. The support leg 20 includes a support plate 21, a bolt 22, and an elastic pedestal 23, and is formed between the floor panel 13 and the floor base 12 by adjusting the fitting depth between the bolt 22 and the elastic pedestal 23. The space 16 is set to a predetermined height (H [mm]). It is assumed that the height of the non-land 14 is 5 [mm], and therefore the height of the space 16 ′ formed above the non-land 14 is H-5 [mm].

Next, as shown in FIG. 4B, the damper 30 is composed of a fixed layer 31, a viscoelastic body 32, and an adhesive layer 33, and has a height h = H−the assumed maximum uneven height: 10 [mm]. Are bonded to the floor base 12 and accommodated in the spaces 16 and 16 ′, and the floor panel 13 (or a joist member (not shown) provided on the lower surface thereof) is placed on the support plate 21 of the support leg 20 from above. As a result, gaps 17 and 17 ′ having a height of 10 mm are formed between the floor panel 13 and the damper 30 in the land portion of the floor base 12 and 5 mm in the non-land portion.
From this state, as shown in FIG. 3C, three screw nails 35 are driven from above the floor panel 13 for each damper 30 to join the fixed layer 31 and the floor panel 13 together. The length of the screw nail 35 is the thickness of the floor panel 13 + the thickness of the fixed layer 31 +10 so that the floor panel 13 and the fixed layer 31 can be coupled with a sufficient strength via the gap 17 of 10 [mm] at the maximum. [Mm].
Finally, as shown in FIG. 4D, the finishing material 18 is laid on the floor panel 13, and the construction of the double floor structure 10 is completed.

  By constructing the double floor structure 10 by the above method, the floor panel 13 and the damper 30 are floated even when the unevenness 14 is generated in the floor base 12, that is, a state where it is mechanically cut off. On the contrary, the damper 30 pushes up the floor panel 13 to reduce its flatness, and a double floor having a uniform height can be obtained.

  Further, according to the double floor structure 10 according to the present embodiment, it is not necessary to accurately raise the damper 30 when laying. That is, even if the height of the gap 17 (17 ′) formed above each damper 30 is different, the floor panel 13 and the damper 30 can be coupled by the screw nails 35, so that the construction is extremely easy. is there. Furthermore, since the floor panel 13 and the fixed layer 31 of the damper 30 are mechanically firmly connected by the three screw nails 35, the vibration of the entire floor panel 13 which is the main cause of the heavy floor impact sound is efficiently generated. Input to the viscoelastic body 32. The viscoelastic body 32 having a high loss coefficient η reduces the vibration transmissibility between the floor panel 13 and the floor base 12 to suppress the generation of heavy floor impact sound, and to quickly attenuate the suppressed vibration. Can do.

In order to confirm the effect of blocking the heavy floor impact sound by the double floor structure 10 according to the present embodiment shown in FIG. 4, a test body having different dampers 30 was produced, and the sound source room on the floor and the floor on the lower floor were manufactured. A comparative experiment of floor impact sound was conducted using an experimental building partitioned into a sound receiving room.
The floor base 12 uses a 150 [mm] thick slab surface, the sound source room floor panel 13 uses a 20 [mm] MDF board, and the finishing material 18 has a sound insulation sheet of 6 [mm] and 12 [mm]. The flooring material of] was laminated and used. The height of the space 16 between the floor base and the floor panel was 137 [mm].
On the other hand, as the viscoelastic body 32, a foamed plastic having a thickness of 120 [mm], a loss coefficient η = 0.2, a Young's modulus E = 5 × 10 ⁵ [N / m ² ] (product name: Miraplank, manufactured by JSP Corporation) Layer flex), a 10-mm thick paper-plastic hybrid board material (manufactured by Akos Kogyo Co., Ltd., trade name: bite polyboard) as the fixed layer 31, and a thickness obtained by applying a urethane adhesive to the lower surface as the adhesive layer 33 Using 0.2 [mm] kraft paper, each was bonded and laminated with a urethane adhesive to obtain a damper 30. The damper 30 has a prismatic shape of 250 mm square, and is arranged so that the total horizontal sectional area is approximately 20% of the total floor area.

  Further, the floor panel 13 and the fixed layer 31 were connected using three coarse thread screws of φ3.8 [mm] × length 41 [mm] for each damper. The coarse thread screw was provided on the diagonal line of the fixed layer 31 at the center and both side 130 [mm] width positions.

The test specimen was hit with the floor panel 13 of the sound source room by a bang machine for generating heavy floor impact sound, and the sound pressure level of the generated floor impact sound was measured with the microphone of the sound receiving room and analyzed with the sound receiving device. did. The method for measuring the floor impact sound level was performed in accordance with the provisions of JIS A1418 (method for measuring the floor impact sound level at the building site).
As a result of the comparison experiment, the test body according to the present embodiment is 1.5 dB in the 63 Hz band, about 5 dB in the 125 Hz band, and about 4 dB in the 250 Hz band as a result of the comparison experiment. Sound reduction effect was recognized. That is, it can be said that the double floor structure 10 of the present invention can provide a significant blocking effect of a heavy floor impact sound over a wide band.

  FIG. 5 is a front view for explaining a double ceiling structure 40 according to the second embodiment of the present invention. A ceiling panel 43 such as a plaster board formed by pasting paper on the hardened gypsum is suspended and supported by a suspension bolt 50 and is provided to face the floor base 12. A plurality of dampers 30 bonded and bonded by the adhesive layer 33 are provided on the lower surface of the floor base 12, and the dampers 30 are formed on the viscoelastic body 32 and the surface thereof (corresponding to the lower surface side in the present embodiment). It is composed of a fixed layer 31. The fixed layer 31 and the ceiling panel 43 are fixed by three screw nails 35, respectively. In addition, a vinyl cloth 48 is laid on the lower surface of the ceiling panel 43 to improve the design as viewed from the lower floor.

  Generally, in the double ceiling structure 40, when heavy floor impact sound generated on the upper floor is transmitted to the lower floor through the floor base 12, it is amplified in the space 16 between the floor base 12 and the ceiling panel 43, and the ceiling panel. It becomes a problem that the whole 43 is vibrated and air is propagated to a lower-level person as a sound with a high sound pressure level. However, according to the double ceiling structure 40 according to the present embodiment, the presence of the damper 30 reduces the vibration transmission rate between the floor base 12 and the ceiling panel 43, and transmits the transmitted vibration to the viscoelastic body 32. Since it can be quickly attenuated by viscoelastic deformation, it is possible to obtain a particularly high barrier property against heavy floor impact sound.

  Furthermore, according to the double ceiling structure 40 according to the present embodiment, the coupling between the ceiling panel 43 and the damper 30 is not broken even when the floor base 12 has a concave uneven surface. On the contrary, even when the floor base 12 has the convex unevenness 14, there is no possibility that the damper 30 and the ceiling panel 43 are in direct contact with each other and push it downward, and the flatness of the ceiling panel 43 can be maintained high. It is. That is, since it is not necessary to finely adjust the height of the damper 30 with high accuracy, the workability is excellent, and the ceiling panel 43 and the floor base 12 can be mechanically and reliably coupled.

It is explanatory drawing of the double floor structure concerning 1st embodiment of this invention, (a) is a top view, (b) is the sectional drawing. It is the elements on larger scale of FIG.1 (b). It is a perspective view which shows the specific structure of a damper. It is explanatory drawing which shows the construction procedure of a double floor structure. It is explanatory drawing of the double ceiling structure concerning 2nd embodiment of this invention. It is explanatory drawing of the conventional double floor structure.

Explanation of symbols

Double floor structure 10,110
Floor base 12,112
Floor panel 13, 113
Inland 14
Space 16, 16 ', 116
Gap 17, 17 '
Support legs 20, 120
Support plate 21, 121
Bolt 22, 122
Elastic base 23, 123
Damper 30
Fixed layer 31
Viscoelastic body 32
Adhesive layer 33
Screw nails 35
Double ceiling structure 40
Ceiling panel 43
Hanging bolt 5

Claims (4)

It is a double structure of a structure having a floor base of the structure, a plurality of supports arranged above or below the floor base, and a panel member supported by the support to face the floor base. And
A plurality of dampers provided with a fixed layer having a higher Young's modulus than the viscoelastic body on the surface of the viscoelastic body are joined to the floor base, and the fixed layer and the panel material are joined by a connector. Double structure characterized by 2. The double structure according to claim 1, wherein the fixed layer is a plate material laminated and bonded to the surface of the viscoelastic body, and the damper and the floor base are bonded to each other by an adhesive. The double structure according to claim 1 or 2, wherein the viscoelastic body is made of one or more of foamed plastic, rubber, elastomer, and fiber. The double structure according to any one of claims 1 to 3, wherein the connector is a screw nail that passes through the panel member and is inserted into the fixing layer.

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