JP2013015007A - Sound-insulation double floor and building - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance heavy floor impact sound insulating performance of a double floor used for a floor finishing structure in an RC house or the like.SOLUTION: A substrate panel of a double floor is formed in a hollow structure with high flexural rigidity, in which a hollow part communication hole 10 for connecting between a hollow part 14 and an underfloor air layer 2 is provided for cushioning of an impactive pressure increase in the underfloor air layer. As a result, the heavy floor impact sound insulating performance is significantly improved to decrease by 10 decibels or more with respect to a slab surface.

Description

  The present invention relates to a sound-insulating double floor having a good heavy-floor impact sound insulation performance and a building having the sound-insulating double floor.

In a conventional double floor structure of a conventional apartment, as shown in FIG. 39, a plurality of anti-vibration support legs 3 arranged on the floor base (concrete slab) allow a predetermined distance (underfloor air layer) from the slab. ), A base panel (particle board) 4b is supported, and a floor finish layer 5 is disposed on the base panel. Hereinafter, this is referred to as “conventional example”.
The double floor of this conventional example has a problem that the performance of blocking heavy floor impact sound (for example, sound generated on the lower floor when a child jumps) is low, and improvement has been desired.

One of the improvement methods is to increase the bending rigidity of the double-floor base panel 4b. For example, instead of the base panel of the conventional example, a flat particle board, (For example, refer to Patent Document 1). Hereinafter, this is referred to as “first prior art”.
Although this technology improves the heavy floor impact sound insulation performance to some extent, this performance is still not sufficient in the social rise of noise awareness.

A sound insulation double floor has been proposed in which the first prior art is developed to further improve the heavy floor impact sound (see FIG. 40). This structure is further improved by focusing on the directionality of the bending rigidity of the base panel 4 of Patent Document 1 that is a three-dimensional structure (see Patent Document 2). Hereinafter, this is referred to as “second prior art”.
This second prior art has been put into practical use, and the product has been certified by the Minister of Land, Infrastructure, Transport and Tourism to reduce the weight floor impact sound by 1 dB.
However, even with this second prior art, its performance is still not sufficient. In addition, the sound insulation double floor of the first prior art and the second prior art is the increase in the floor height of the building or the compression of the indoor space accompanying the increase in the double floor height 7h due to the increase in the thickness of the base panel 4. There are also drawbacks.

As another improvement example from another viewpoint, as shown in FIG. 41, there is a method of installing an air hole 27 in a joint portion between a double floor and a wall (see, for example, Non-Patent Documents 1 and 2). The air hole 27 reduces the function of the air spring by releasing the sealing degree of the underfloor air layer 2. As a result, resonance amplification by the spring of the underfloor air layer 2 that occurs in the conventional example is prevented, and the heavy floor impact sound blocking performance is improved.
However, although this method also shows a certain level of performance (a reduction amount of 0 dB) in Non-Patent Document 2, it has not yet achieved a sufficient shut-off performance. In addition, since the air holes 27 in this case are limited in installation location, depending on the room shape or the like, a sufficient installation location cannot be ensured, and there are other disadvantages such as entry of foreign matter into the gap. This is called the third prior art.

Patent Publication 2009-127248 Patent Publication 2003-227226

Japan Acoustic Material Association Acoustic Technology NO. 121 (vol.32no.1) March 2003 P22 2.2 Effects of gaps at the end of double floor Published by Engineering Books Co., Ltd. Housing Performance Display System, Japan Housing Performance Display Standard, Evaluation Method Standard, Technical Explanation 2001 P365 Figure 8-7

The present invention has been made in view of such a situation, and an object thereof is to provide a sound insulation double floor having a simple and lightweight structure with improved weight floor impact sound insulation performance and suppressed increase in height. To do.
Another object of the present invention is to provide a sound insulation double floor capable of adjusting the frequency band of the heavy floor impact sound to be interrupted.
Another object of the present invention is to provide a building having a sound insulation double floor.

  The present invention includes a floor base, a plurality of vibration isolation support legs installed on the floor base, and a floor base supported by the plurality of vibration isolation support legs at a predetermined height across an underfloor air layer, In the double floor composed of a floor finish layer laid on the upper surface of the floor foundation, the floor foundation is provided with a plurality of air holes for buffering the pressure of the underfloor air layer.

Further, the floor base is a box.
Moreover, it is good to drill the said air hole which connects the inside of the said box, and the said underfloor air layer in the lower surface or side surface of the said box, and buffers the pressure of the underfloor air layer.
In addition, it is preferable that a duct having a resonance frequency of the Helmholtz resonator of 16 Hz to 1000 Hz is provided inside the box body so that air passing through the air holes is passed.
In addition, a plurality of finishing layer communication holes may be formed on the upper surface of the box body to communicate the inside of the box body with the lowermost layer of the floor finishing layer and further buffer the pressure of the underfloor air layer.
Moreover, it is preferable that the lowermost layer of the floor finish layer has air permeability.
Also, piping may be laid inside the box.
Moreover, it is good to make a part of member which forms the said box so that attachment or detachment is possible, and to update the said piping.
Moreover, it is good to provide the space which compressed the height of the said box, and to lay piping in this space.
Moreover, it is good to arrange | position the said some box at predetermined intervals, and to lay piping in the clearance gap between the said boxes.

Moreover, this invention also provides the building characterized by providing said sound-insulation double floor.
Further, the floor base may have a structure in which a step around the water is eliminated.

  As described above, according to the present invention, since the plurality of air holes for buffering the pressure of the underfloor air layer are provided in the floor base, it is possible to improve the heavy floor impact sound blocking performance. Details of the effect will be described later.

It is sectional drawing of the prototype floor of a model corresponding to Example 1. It is sectional drawing of the prototype floor of a model corresponding to Example 2. It is a graph of a heavy floor impact sound measurement result. 1 is a cross-sectional view of Example 1. FIG. It is sectional drawing for description which expanded the floor finish material of Example 1. FIG. It is the explanatory top view which looked at the floor finish layer of Example 1 from the upper part. FIG. 3 is a schematic diagram illustrating the function of the floor finish layer of Example 1. It is explanatory drawing of the base panel of Example 1, and piping. 6 is a cross-sectional view of Example 2. FIG. 6 is a cross-sectional view of Example 3. FIG. FIG. 10 is an explanatory diagram of one unit of Example 3. 6 is a sectional view of Example 4. FIG. It is explanatory drawing of piping of Example 4, and a foundation | substrate unit. 10 is a cross-sectional view of Example 5. FIG. 10 is a cross-sectional view of Example 6. FIG. 10 is a sectional view of Example 7. FIG. It is sectional drawing of modification 1bd. It is a schematic diagram explaining the function of the floor finishing layer of modification 1bd. It is sectional drawing of modification 1cd. It is an enlarged view explaining the function of the floor finishing layer of modification 1cd. It is a schematic diagram explaining the function of the floor finishing layer of modification 1cd. It is sectional drawing of the modification 1ae. It is sectional drawing of modification 1af. It is sectional drawing of the modification 2e. It is sectional drawing of the modification 2f. It is sectional drawing of the modification 3be. It is sectional drawing of modification 3cf. It is sectional drawing of modification 4be. It is sectional drawing of modification 4cf. It is sectional drawing of modification 5be. It is sectional drawing of modification 5cf. It is sectional drawing of modification 7bd. It is slab sectional drawing of Example 8. FIG. It is slab sectional drawing of a prior art example. FIG. 35 (a) is a schematic plan view for explaining a configuration example of the ninth embodiment of the present invention, and FIG. 35 (b) is a schematic sectional view for explaining a configuration example of the ninth embodiment of the present invention. is there. It is sectional drawing of a prior art example. It is sectional drawing of the prior art 2. FIG. It is sectional drawing of the prior art 3. FIG. It is explanatory drawing of the vertical deformation mechanism of a prior art example. It is explanatory drawing of the vertical deformation mechanism of Example 1. FIG. It is sectional drawing of the prototype floor of a prior art 1 corresponding | compatible model.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
First, terms used in this specification are defined as follows.
The “floor base” refers to a reinforced concrete slab 1 (see FIG. 1) used for a floor of a reinforced concrete structure or a steel structure building. The reinforced concrete slab includes ordinary concrete, lightweight concrete and ALC, and homogeneous slab and void slab.

  A “double floor” is a floor finish structure having an air layer on the floor base. The double floor is generally called a dry double floor or a dry sound insulation double floor, but here it is simply referred to as “double floor” in order to clearly distinguish it from the present invention. The cross-sectional double floor range is from the top of the floor base (slab) to the floor finish surface layer. This height is referred to as a double floor height 7h (see FIG. 6).

  The “sound insulation double floor” is a floor finishing structure according to the present invention in which a heavy floor impact sound insulation performance is added to a double floor, and is a structure that fits within a cross-sectional range of a double floor height of 7 h, similar to a double floor. It is.

  The “floor base” is a portion obtained by removing the floor finishing layer from the double floor or the sound insulation double floor. In general, the anti-vibration support legs 3 (refer to FIG. 1) and the base panel are generically referred to, but here, a discarded plywood (not shown) or a floor heating radiator (not shown) that is in close contact with the base panel is excluded from the floor base. Each of these elements is included in the floor finish layer.

  “Anti-Vibration Support Leg” 3 has an anti-vibration structure that is elastically deformed, has a length for maintaining a predetermined height, the length is adjustable, and a top panel and a supporting panel This is a structure having a support plate 3a (see FIG. 1) that fulfills the joining function, and is currently marketed in the assembled state. Here, in addition to this commercial product, there is no top support plate 3a, an extremely short length (when the space between the floor base and the base panel is small), a length that cannot be adjusted, a steel spring and rubber Including anti-vibration support means including those used in combination, these are referred to as “anti-vibration support legs”.

  The “base panel” generally refers to a flat particle board 4b as in the conventional example (see FIG. 39), but includes a three-dimensional panel with ribs and a hollow panel (see FIG. 40). Moreover, the material includes iron and concrete (including FRC) in addition to wood. The cross-sectional area is a portion obtained by removing the anti-vibration support legs 3 from the floor base.

  The “base unit” refers to one construction unit of a portion of the base panel excluding the upper face material when the floor base (the base panel) has a hollow structure or a three-dimensional structure.

  The “floor finishing layer” refers to from the top of the base panel to the floor finishing material surface layer. Therefore, a pneumatic buffer layer and a double-sided tape for bonding the same, or a floor heating radiator plate or a discarded plywood are also included in the floor finish layer (described later).

  The “soundproof flooring” is used for direct tensioning and refers to a flooring material in which a soundproof layer such as a nonwoven fabric is arranged on the back surface. "Soundproof flooring" is the most popular product among flooring materials for direct tension.

Next, the main mechanism of the present invention and the actual measurement result of the heavy floor impact sound will be described.
In the double floor of the conventional example or the like, the primary natural frequency (f: see formula (I)) is in the 63 Hz band. The light floor impact sound in which the frequency band (for example, 250 Hz band) is the determined frequency has high blocking performance. The floor impact sound of the double floor reduces the primary natural frequency (f), so that the blocking performance is improved even with the heavy floor impact sound.
Here, in order to decrease the primary natural frequency (f), (k) in the formula (I) is decreased (the spring of the entire double floor is softened), and (m) is increased (2). The weight per unit area (surface density) of the heavy bed is increased). Further, (k) is a spring obtained by combining the spring (ka) of the underfloor air layer and the anti-vibration support leg (kb), and for this spring (k), the total floor area is a factor (ka). Since it is dominant, the control of the air spring has a high contribution rate to floor impact noise reduction.

here,
f: Primary natural frequency of double floor (Hz)
k: Floor 1 m ² per synthesized spring constant of (N / m)
ka: spring constant of the underfloor air layer per 1 m ² of floor (N / m)
kb: spring constant (N / m) of the anti-vibration support leg per 1 m ^{2 of} floor
m: Mass of double bed per 1 m ² of floor (= Area density (kg / m ² ))
ρ: Air density (kg / m ³ )
c: Speed of sound (m / s)
h: thickness of the underfloor air layer (m)
It is.

  Further, according to the formula (I), when the thickness (h) of the underfloor air layer is increased, the spring (ka) constant is decreased, the primary natural frequency (f) is decreased, and the floor impact sound blocking performance is reduced. However, it causes a demerit of compressing the indoor space or increasing the floor height of the building. In the third prior art described above, by installing an air vent opening at the end of the floor to release the sealing degree of the underfloor air, the action of the spring (ka) of the underfloor air layer is reduced, and the air layer thickness is not increased. The effect of reducing the primary natural frequency (f) is the same as that obtained by reducing the constant of (ka). The present invention is also based on the same mechanism as the third prior art. In the present invention, the means for installing the air holes on the entire surface of the double floor eliminates the limitation of the installation location and the number of locations, and further reduces the action of the spring of the underfloor air layer.

In FIG. 3, the vertical axis represents the sound pressure level of the heavy floor impact sound, and the horizontal axis represents the center frequency band. The impact source is a standard impact source (hereinafter referred to as a ball) defined in JIS A 1418-2, which reproduces the impact of a child jumping.
A solid line shows the measurement result of only a floor base (concrete slab 1) without a double floor. This is called a bare surface.
A dotted line is the double floor without an air hole which modeled patent document 1 shown in FIG. This is referred to as a first prior art compatible model.
A broken line is the sound-insulating double floor shown in FIG. 2 provided with air holes (hollow part communication holes 10) in the first prior art compatible model. This is called a model corresponding to the second embodiment (the second embodiment will be described later).
The alternate long and short dash line is the sound-insulating double floor shown in FIG. 1 provided with the finish layer communication hole 11 in the model corresponding to the second embodiment. This is called a model corresponding to the first embodiment (the first embodiment will be described later).
Each of these double floors actually measured has a surface density adjusting brick 25 attached inside, and is adjusted to the surface density corresponding to the example (about 50 kilograms per square meter).

  Moreover, the measurement of FIG. 3 was performed according to the content described in “Development of the 2011 Annual Meeting of the Architectural Institute of Japan (Kanto) Academic Lecture D-1 P219 Development of High Performance Sound Insulation Double Floor” by the present inventors. .

According to the graph of FIG. 3, the effect of the hollow portion communication hole 10 (compared to the first prior art model without this) was 8 and 7 decibels in the 125 · 250 Hz band. Further, when the finishing layer communication hole 11 was installed (compared to the model corresponding to the second embodiment without this), the effects of 7 and 4 dB were obtained in the 63 · 125 Hz band. These effects vary in the appearing frequency band and level depending on the factor (f) shown in Formula (I) and the air hole conditions (diameter, frequency, hole depth (neck)). However, in this graph, all of these air holes showed a significant effect on the heavy-floor impact sound insulation performance.
From these experiments, an embodiment in which this effect is easily realized in a general apartment will be described below.

<First embodiment>
A first embodiment will be described with reference to FIGS. In the figure, reference numeral 1 denotes a concrete slab serving as a floor base. Reference numeral 4 denotes a ground panel held by a vibration-proof support leg 3 disposed on the concrete slab 1. Reference numeral 5 denotes a floor finishing layer installed on the base panel. The first embodiment (double floor 7) includes an underfloor air layer 2, an anti-vibration support leg 3, a base panel 4, air holes (hollow part communication hole 10 and finishing layer communication hole 11) and finishing layer on a concrete slab. 5 is comprised. This height is called double floor height 7h.

The base panel 4 is made of a wood material, and the upper face member 12 and the lower face member 13 are firmly joined by a rib member 9 with a predetermined hollow portion height 14h therebetween, so that the bending rigidity is increased. ing. The lower face member 13 is provided with a hollow communication hole 10 as an air hole, and air can move between the underfloor air layer 2 and the hollow part 14 through the hole.
Further, a finishing layer communication hole 11 is provided in the upper face material 13, and air can be moved between the hollow portion 14 and the lowermost layer of the floor finishing layer 5 by this air hole. 5 is a floor finish layer, and the material is a soundproof flooring 6. As shown in the cross-sectional view of FIG. 7, the soundproofing flooring 6 is a wooden floor finishing material for direct tensioning to a slab, in which a sawtooth ZG is formed on the back surface of a wood plywood and a nonwoven fabric 26 is lined as a soundproofing layer. The soundproofing flooring 6 is a plate material having a small bending rigidity due to the saw-toothed ZG on the back surface. The nonwoven fabric 26 lined has elasticity and air permeability. In the first embodiment, the soundproofing flooring 6 is partially bonded to the base panel 4 (the upper surface material 12 thereof) with a double-sided adhesive tape 15 as an adhesive as shown in the plan view of FIG.

  The piping 8 shown in FIG. 4 is piping / wirings such as sanitary and electrical equipment, and as shown in FIG. 8 (an explanatory diagram of the base panel 4 and the piping 8 of the first embodiment), a notch in the rib. 16 penetrates the rib material 9 and is built in the base panel 4.

  Hereinafter, the mechanism etc. which block | interrupt a heavy floor impact sound are demonstrated regarding the sound insulation double floor of 1st Example comprised in this way.

  When the bending rigidity of the double floor base panel 4 is improved, the heavy floor impact sound blocking performance is improved. In the first embodiment, the bending rigidity of the base panel 4 is improved by adopting a hollow structure in which the three members of the upper face member 12, the lower face member 13, and the rib member 9 are firmly connected. Moreover, since these three members are firmly connected with a planar spread, a larger area is integrated in a vibrational manner. When an impact or concentrated load is applied to the double floor, the vertical deformation amount 22 is locally generated in the conventional example as shown in FIG. 39. However, in the case of the first embodiment, local deformation is difficult to occur due to the integration. The deformation amount 22 is relatively small (see FIG. 40). Therefore, when a weight impact by a ball is applied to the sound insulation double floor of the first embodiment, the pressure increase in the underfloor air layer 2 is smaller than that in the conventional example.

  When a pressure increase in the underfloor air layer 2 occurs due to a floor impact in the double floor, the double floor above the underfloor air layer 2 is pushed back upward. At that time, the mass of the double floor and the aforementioned air spring (constant is ka) resonate, and the resonance-amplified impact force is transmitted to the concrete slab 1. In the first embodiment, since the hollow portion communication hole 10 is opened in the lower face material 13, the underfloor air moves to the hollow portion 14 as the pressure of the underfloor air layer 2 increases. For this reason, the action of the air spring is hindered, the spring constant (ka) of the underfloor air layer 2 is apparently lowered, and the temporary natural frequency (f) is lowered, so that the heavy floor impact sound blocking performance is improved.

  The air that has entered through the hollow portion communication hole 10 moves upward from the finish layer communication hole 11 with an increase in pressure in the hollow portion 14. Due to the action of the finishing layer communication hole 11, the pressure of the hollow portion 14 does not exceed a suitable level, so that further movement of air from the underfloor air layer 2 through the hollow portion communication hole 11 becomes possible. Due to these two kinds of communication holes 10 and 11, in the first embodiment, the action of the spring of the underfloor air layer 2 is greatly reduced.

  The air that has moved upward from the finishing layer communication hole 11 gathers in the lowermost layer of the floor finishing layer 5 and pushes up the partially bonded soundproofing flooring 6 as shown in FIG. The deformation of the floor finishing layer 5 due to this pressure rise converges within a shocking (short) time and the deformation amount is small, so that the change as shown in the image diagram of FIG. There is no.

  In the sound insulation double floor of the first embodiment, the spring of the underfloor air layer 2 is freely controlled by the hollow portion communication hole 10, the finish layer communication hole 11, and the floor finish layer 5 that does not impede this function, and its adverse effect Is greatly eliminated. In addition, the first embodiment is expected to have a high weight floor impact sound blocking performance due to the synergistic effect of the bending rigidity improvement of the base panel 4 and the expansion of the integrated area and the air spring control.

  By the way, in this 1st Example, since the base panel 4 was made into the hollow structure, if the piping 8 is arrange | positioned on the slab 1 like a prior art example, the double floor height 7h will increase. Therefore, as shown in FIG. 8, the rib material 9 constituting the base panel 4 is partially lost, and the pipes 8 are laid in the hollow portion of the base panel 4 to avoid an increase in the double floor height. Moreover, although the lower surface material 13 and the rib material 9 were fixed with the adhesive agent and the screw, the upper surface material 12 and the rib material 9 were fixed only with the screw, and the renewability of the built-in piping 8 was considered.

  Generally, a discarded plywood (not shown) attached between the base panel 4 and the floor finishing layer 2 impairs the air vent function of the finishing layer communication hole 11. The main purpose of the discarded plywood is to prevent shear deformation (so-called misunderstanding) between the base panels 4 and to prevent deformation and damage of the finishing material. In the first embodiment, since the members constituting the base panel 4 are firmly connected as described above, shear deformation does not occur. For this reason, it is possible to omit the discarded plywood here. In addition, when providing a littering plywood for unevenness adjustment etc., it is necessary to provide the finishing layer communication hole 11 in the same position as the base panel 4.

<Second embodiment>
The second embodiment does not have the finishing layer communication hole 11 provided in the first embodiment. For this reason, the floor finish layer 5 is not particularly limited. This is different from the first embodiment. FIG. 9 shows a cross section thereof. The floor finish layer 5 is an example of composite flooring, and is directly attached to the upper face material 12 of the base panel 4. Moreover, you may provide a discarding plywood as needed, and there is no restriction | limiting in the method of discarding.

  The heavy floor impact sound blocking performance of the second embodiment is indicated by a broken line (model corresponding to the second embodiment) in the graph of FIG. The cutoff effect of the heavy floor impact sound that appears in the 125 and 250 hertz bands varies in frequency depending on the factor of the primary natural frequency (f) and the shape and frequency of the hollow communication hole. In the case of the second embodiment, by increasing the height 14h of the hollow portion, it is possible to achieve a heavy floor impact sound blocking effect up to a lower frequency. Further, the fact that the floor finishing layer 5 is not limited is also an excellent point of the second embodiment.

<Third embodiment>
The third embodiment is different from the first embodiment in the configuration of the base panel 4. FIG. 10 shows a cross section thereof. The base panel 4 is formed by unitizing the portion excluding the upper face material 12, and the units 24 are firmly connected to each other. In the connected unit 24, the upper face material 12 is firmly attached with screws 23. A form in which one unit 24 is taken out is shown in FIG. The unit 24 has a shape in which the height of the base panel 4 having a hollow structure or a three-dimensional structure is partially compressed, and the laying space 8b of the piping 8 is provided in the compressed portion.

  The third embodiment is slightly different from the first embodiment in the continuity of bending rigidity. For this reason, the area integrated vibrationally becomes small compared with these. However, the countermeasures against the air spring that governs the performance are the same as those in the first embodiment. The heavy floor impact sound blocking performance of the third embodiment is approximately the same as the one-dot chain line (model corresponding to the first embodiment) of the graph of FIG. Moreover, since this 3rd Example can distinguish the construction time of piping 8 and a double floor, it is excellent in workability, and the productivity improvement accompanying unitization is also anticipated.

<Fourth embodiment>
The fourth embodiment is further different in configuration from the base panel 4 of the third embodiment. FIG. 12 shows a cross section thereof. The base panel 4 is unitized except for the upper face material 12. The units 24 are firmly connected to each other by the upper face material 12 at a predetermined distance, and are integrated as a base panel 4. The piping 8 is disposed in the gap between the units 24. Since the joint portion between the upper face materials 12 (upper face material joint portion 31) is generally completed within the range of the base unit 24, the joint portion of the upper face material 12 does not undergo shear deformation (mistake), Discarding plywood can be omitted. Moreover, if a clearance is provided in the upper surface material joint portion 31, the upper surface material joint portion 31 functions as the combined portion 11b of the floor lower layer communication hole.

  Similar to the third embodiment, the fourth embodiment differs from the first embodiment in the continuity of bending rigidity, and the area integrated in vibration is slightly smaller than that in the first embodiment. However, since the countermeasure of the air spring is the same as that of the first embodiment, the heavy floor impact sound cutoff performance is substantially equivalent to the one-dot chain line (model corresponding to the first embodiment) of the graph of FIG. In the fourth embodiment, the workability of the double floor and the productivity of the parts are improved as in the third embodiment. Further, in the fourth embodiment, as shown in the perspective view of FIG. 13, since the pipes 8 are arranged in the gaps of the unit 24, only the portion where the piping space is required is spaced apart or no piping space is required. These parts can be brought into close contact with each other, and the space between the units 24 can be secured at a part where a piping space is required, and the degree of freedom in setting the width and position of the piping space is high.

<Fifth embodiment>
The fifth embodiment is further different from the first embodiment in the configuration of the base panel. FIG. 14 shows a cross section thereof. The base panel 4 does not have the lower face material 13, but this can be considered as a pattern in which the hollow communication hole 10 is maximized. Except this, it is almost the same as the first embodiment. In the fifth embodiment, since the lower face material is not provided, the upper face material 12 is supported by the vibration isolating support legs 3. The upper face member 12 can be supported by the rib member 9.

  When a ball, which is a standard impact source for measuring heavy floor impact sound, is dropped in the fifth embodiment, the underfloor air layer 2 is compressed as in the first embodiment. As the pressure rises, the air moves upward through the finishing layer communication hole 11 provided in the upper face member 12. Hereinafter, the mechanism is the same as in the first embodiment. The weight floor impact sound blocking performance of the seventh embodiment is substantially the same as that of the first embodiment.

<Sixth embodiment>
The sixth embodiment is different from the fifth embodiment described above in the shape of the rib material. FIG. 15 shows a cross section thereof. The base panel 4 includes an upper face member 12 and ribs 28 that prevent misalignment (prevent shear displacement), which are the minimum necessary rib members. Since the sixth embodiment also does not have the lower face material, the upper face material 12 is supported by the vibration isolation support leg 3, but the rib material (missing prevention rib 28) is the same as in the fifth embodiment. Can also be supported. Further, even if the rib material has a minimum size, it serves to prevent misunderstanding of the underlying panel (upper surface material 12), and therefore, the discarded plywood can be omitted.

  The heavy floor impact sound blocking performance of the sixth embodiment is an intermediate value between the conventional example (general double floor in FIG. 36) and the first embodiment. The sixth embodiment has a relatively large space for installing a flat pipe, and the construction procedure of the pipe and the double floor is the same as the conventional example. Therefore, the change from the conventional example to the sixth embodiment can be performed smoothly. . Further, the surface density is similar to that of the conventional example. The mechanism and effect of the finishing layer communication hole are the same as in the first embodiment.

<Seventh embodiment>
As shown in FIG. 16, the seventh embodiment differs from the conventional example shown in FIG. 1 in the finishing layer communication holes 11 and the floor finishing layer 5. In FIG. 16, in order to prevent misunderstanding of the base panel 4, the anti-vibration support legs 3 are arranged at the base panel joint part (general arrangement called common support legs), and the support plate of the anti-vibration support leg top part 3 a and the base The panel 4 is firmly joined, and the discarded plywood is omitted. Generally, since this portion is joined to the support plate and the base panel through a buffer material such as thin butyl rubber by a non-rigid method, a discarded plywood is provided to prevent mistakes. In the seventh embodiment as well, when the discarded plywood is provided in this way, it is necessary to consider such as providing a hole at the same position so as not to hinder the effect of the finish layer communication hole 11.

  The heavy floor impact sound blocking performance of the seventh embodiment is an intermediate value between the conventional example and the first embodiment. In the seventh embodiment, the area of the plane installation space and the construction procedure are the same as those in the conventional example, and therefore the change from the conventional example to the seventh embodiment can be performed smoothly. Further, the surface density is similar to that of the conventional example. The mechanism and effect of the finishing layer communication hole are the same as in the first embodiment, and the limitation of the air vent installation location, which is a problem in the third prior art, is completely canceled in the seventh embodiment.

<Modification 1bd>
In the modified example 1bd (the meaning of the symbols b and d will be described later), which is a change pattern of the first example, the floor finish layer 5 is different from the first example as shown in FIG. As the surface finishing material, a carpet is adopted as the breathable floor finishing material 20. Moreover, the felt which has air permeability and moderate elasticity is used as the foundation | substrate 20a (refer FIG. 18).
The weight floor impact sound blocking mechanism of the modified example 1bd is the same as that of the first embodiment. That is, when the ball is dropped, the underfloor air layer 2 is compressed as in the first embodiment, and the air flows into the hollow portion 14 of the base panel. It moves upwards by the finish layer communication hole 11 provided in.
In the modified example 1bd, the air that has moved upward passes through the breathable floor finish 20 and is released into the living room as shown in FIG. The heavy floor impact sound insulation performance is approximately the same as that of the first embodiment, although it depends on the air permeability of the floor finish layer. Hereinafter, the soundproof flooring that is the floor finish layer of the first embodiment is referred to as a finish pattern a, and the breathable floor finish material of this modified example 1bd is referred to as a finish pattern b.

  Here, the symbol given to the modification indicates the number of the embodiment based on the Arabic numeral, the next alphabet represents the type of the finishing layer, and the last alphabet represents the material of the base panel. Here, regarding the finishing layer, a is a soundproof flooring, b is a breathable floor finish (carpet), and c is a breathable material (described later). Regarding the material of the base panel, d is wood, e is fiber reinforced mortar, and f is an iron plate. Therefore, the above-mentioned modified example 1bd is a modified example from the first example, and shows that the finishing layer is a breathable floor finish and the base panel is wood. In the first to seventh embodiments described above, the finishing layer is a (soundproof flooring), and the base panel is d (wood).

<Modification 1cd>
In the modified example 1cd, the floor finish layer 5 is different from that of the first embodiment as shown in FIG. The composite flooring 17 of the surface finishing material is a floor finishing material that has been most frequently used in recent years, in which thin wood is pasted on the surface of a non-breathable plywood. The discarded plywood 21 (see FIG. 20) located in the immediately lower layer has the purpose of improving the workability of the composite flooring 17 and improving the walking feeling, but can be omitted as appropriate. The air pressure buffer layer 19 located immediately below the discarded plywood 21 is made of a material (here, non-woven fabric) having appropriate elasticity and air permeability. In this modified example 1cd, the nonwoven fabric is adhered to the entire surface of the base panel 4, but can be partially adhered in the same manner as in the first embodiment shown in FIG.

  When a ball, which is a standard impact source for measuring heavy floor impact sound, is dropped on the modified example 1cd, the underfloor air layer 2 is compressed and into the hollow portion 14 of the base panel 4 as in the first and second embodiments. Air flows in. As the pressure rises, the air in the hollow portion 14 moves to the pneumatic buffer layer 19 through the finishing layer communication hole 11 provided in the upper face material 13. At this time, the pneumatic buffer layer 19h can reduce the shocking pressure rise coming from below by increasing its thickness. The air pressure buffer layer 19 can be partially bonded as shown in FIG. 21, and exhibits a higher air pressure buffering effect depending on the surface density of the surface material. The weight floor impact sound insulation performance of the modified example 1cd differs depending on the thickness, hardness (elasticity), air permeability, and bonding method of the air pressure buffer layer, but is almost the same as that of the first embodiment. Hereinafter, the modified 1cd floor finish layer combining the composite flooring and the buffer layer is referred to as a finish pattern c.

<Modification 1ae>
In the modified example 1ae, the material of the base panel 4 is different from that of the first embodiment as shown in FIG. Here, the part except the upper surface material 12 of the base panel 4 is unitized, and a raw material is a fiber reinforcement mortar (henceforth, FRC). The heavy floor impact sound blocking mechanism is the same as that of the first embodiment, but the surface density, which is the weight of the double floor, can be easily adjusted by adjusting the thickness of the FRC, and the unit 24 is suitable for sound insulation design requirements. Is easy to produce. The weight floor impact sound blocking performance of the modified example 1ae is equivalent to that of the first embodiment if the surface density is the same, and the performance improves as the surface density increases.

<Modification 1af>
In the modified example 1af, as shown in FIG. 23, the material of the base panel 4 is different from that of the first example. Also here, the part except the upper surface material 12 of the base panel 4 is unitized, and a raw material is an iron plate. The heavy floor impact sound blocking mechanism is the same as in the first embodiment. In the case of an iron plate, it is easy to form the neck of each communication hole (the depth of the hole of the Helmholtz resonator) as necessary. The weight floor impact sound blocking performance of the modified example 1af is approximately the same as that of the first embodiment as long as the surface density is the same. Hereinafter, the material of the unit part of the base panel made of an iron plate is referred to as a material pattern f.

<Other modifications of the first embodiment>
In the first embodiment, there are three types of abc finishing patterns and three types of def material patterns. Of the nine types of modifications, 1ad, 1ae, 1af, 1bd, 1be, 1bf, 1cd, 1ce, and 1cf, illustrations and descriptions are omitted except for the above-described and illustrated modifications 1bd, 1cd, 1ae, and 1af.

<Variation of the second embodiment>
In the second embodiment, there is no particular limitation on the floor finish. For this reason, there are three types of variations in the second embodiment, the base material pattern abc, and since a is described in the second embodiment, the variations are 2e and 2f.

<Modification 2e>
In the modification 2e, as shown in FIG. 24, the material of the base panel 4 is different from that of the second embodiment and uses FRC. The heavy floor impact sound blocking mechanism is the same as in the second embodiment, but the surface density, which is the weight of the double floor, can be easily adjusted by adjusting the thickness of the FRC member. The unit 24 of weight) is easy to produce. The weight floor impact sound blocking performance of the modified example 2e is equivalent to that of the second embodiment if the surface density is the same, but the performance improves as the surface density increases.

<Modification 2f>
In the modification 2f, as shown in FIG. 25, the material of the base panel 4 is different from that of the second embodiment, and an iron plate is used. The heavy floor impact sound blocking mechanism is the same as in the second embodiment. Further, in the case of an iron plate, it is easy to produce a unit 24 suitable for a sound insulation design requirement by taking advantage of good workability such as formation of a neck of each communication hole 10. The weight floor impact sound blocking performance of the modified example 2f is equivalent to that of the second embodiment if the surface density is the same, but the performance improves as the surface density increases.

<Modification of the third embodiment>
As variations of the third embodiment, there are three types of abc finishing patterns and three types of def material patterns. There are eight types of modifications 3ae, 3af, 3bd, 3be, 3bf, 3cd, 3ce and 3cf (3ad in the third embodiment). Two typical examples are shown below together with the drawings. These heavy floor impact sound blocking performances are as high as those of the third embodiment, and the following two examples further improve the workability on site and the productivity by industrialization.

<Modification 3be>
The modified example 3be is an example in which the floor finishing layer 5 is changed to the pattern b (breathable floor finishing material) and the base panel material is changed to the pattern e (FRC) in the third embodiment (see FIG. 26).

<Modification 3cf>
Modification 3cf is an example in which the floor finishing layer 5 is changed to the pattern c (pneumatic buffer layer + composite flooring) and the base panel material is changed to the pattern f (iron plate) in the third embodiment (see FIG. 27). .

<Modification of Fourth Embodiment>
Similarly to the third embodiment, the fourth embodiment may have three types of abc finishing patterns and three types of def material patterns. The variations are eight types of combinations ae, af, bd, be, bf, cd, ce and cf (in the fourth embodiment, a combination of a and d). Two typical examples of this combination are shown below with illustrations. These heavy floor impact sound insulation performances are equivalent to those of the fourth embodiment. In the fourth example, the workability of piping is high, but the following two examples are expected to further improve productivity by industrialization.

<Modification 4be>
The modification 4be is an example in which the floor finish layer 5 is changed to the pattern b (breathable floor finish) and the base panel material is changed to the pattern e (FRC) in the fourth embodiment (see FIG. 28).

<Modification 4cf>
Modification 4cf is an example in which the floor finishing layer 5 is changed to the pattern c (pneumatic buffer layer + composite flooring) and the base panel material is changed to the pattern f (iron plate) in the fourth embodiment (see FIG. 29). .

<Modification of the fifth embodiment>
Similarly to the fourth embodiment, the fifth embodiment may have three types of abc finishing patterns and three types of def material patterns. The variations are eight types of combinations ae, af, bd, be, bf, cd, ce, and cf (in the fifth embodiment, a combination of a and d). Two typical examples of this combination are shown below with illustrations.

<Modification 5be>
Modification 5be is an example in which the floor finishing layer 5 is changed to the pattern b (breathable floor finishing material) and the base panel material is changed to the pattern e (FRC) in the fifth embodiment (see FIG. 30). The heavy floor impact sound blocking performance is equivalent to that of the fifth embodiment. In the modified example 5be, since there is almost no lower face material, FRC can be adopted even in a design with a low surface density, and productivity can be improved by industrialization.

<Modification 5cf>
The modified example 5cf is an example in which the floor finish layer 5 is changed to the pattern c (pneumatic buffer layer + composite flooring) and the base panel material is changed to the pattern f (iron plate) in the fifth embodiment (see FIG. 31). . The heavy floor impact sound blocking performance is equivalent to that of the fifth embodiment. In the modified example 5cf, since a commercially available mold steel can be used, it is easy to ensure productivity in trial production and non-mass production.

<Modification of the sixth embodiment>
In the sixth embodiment, the material of the base panel portion is only d (woody system). For this reason, there are two types of variations, modified example 6bd and modified example 6cd, for each finishing pattern (not shown).

<Modification of the seventh embodiment>
In the seventh embodiment, as in the sixth embodiment, the base panel is only d (woody system). For this reason, there are two types of variations, that is, a modified example 7bd and a modified example 7cd for each finish pattern. FIG. 32 shows the simplest seventh embodiment, but the simplest modification 7bd among them is shown in FIG. This 7bd is the closest to the conventional example in the present invention, and there are many parts that can follow the design and construction method of the conventional example.

<Eighth embodiment>
The eighth embodiment is a house using the sound insulation double floor according to the present invention. An example of the cross section of the slab is shown in FIG. The conventional slab cross-section is barrier-free to flatten the floor of the unit bath and the floor of the dwelling unit, fits the drain pipe of the unit bath, secures the slab thickness required for the structure and the floor impact sound insulation performance of the double floor part From this point of view, it has a portion (water level difference portion 30) where the height of the upper surface of the slab, which is the floor base, is lowered.
This slab cross section is barrier-free, and has a unit bath washing area height of 32 h (for example, 250 mm) necessary for fitting the drainage pipe, a slab thickness (for example, 200 mm) necessary for the structure of the stepped portion 30 around the water, and double From the viewpoint of securing a thickness (for example, 280 mm) necessary for floor impact sound in the slab directly under the floor, the shape shown in FIG. 34 is often obtained.
However, in the house provided with the sound insulation double floor according to the present invention, the floor impact sound insulation performance is secured by the sound insulation double floor, so that the slab thickness can be reduced. The slab cross section shown in FIG. 35 is obtained by making use of this reduction, making the total slab thickness in the dwelling unit the minimum necessary in structure, and omitting the water level difference. In this way, if there are no steps around the water, there is an advantage that the degree of freedom for remodeling in the future will improve.

  As described above, in the double floor, when a heavy floor impact force is applied, the pressure of the underfloor air layer is shockedly increased. At that time, in the sound insulation double floor according to the present invention, the air in the underfloor air layer moves upward by a plurality of air holes and the like (such as gaps between the floor substrates) provided in the floor substrate. Due to the movement of the air, the shock pressure rise in the underfloor air layer is buffered (abrupt rise is reduced).

  The pressure buffering of the underfloor air layer achieved in this way reduces the action of the air spring as in the third prior art, and as a result, the primary natural frequency of the double floor is lowered. Resonance amplification is reduced, and the target heavy floor impact sound cutoff performance is improved.

Moreover, in this invention, the raw material which has air permeability can be employ | adopted for the lowest layer of a floor finishing layer. This means that the floor finish layer can be made of carpet or soundproof flooring or the bottom layer of the floor finish layer can be a breathable material such as nonwoven fabric or felt.
Of these, the carpet is described here representatively of a breathable floor finish, and has a function of releasing the air moving upward from the underfloor air layer to the atmosphere. In addition, the floor finish layer in which the soundproofing flooring or the lowermost layer is a nonwoven fabric or felt can be expected to store air moving upward from the underfloor air layer in the lowermost layer. By these actions, the effect of buffering the pressure of the underfloor air layer is enhanced.

Further, in the present invention, when floor bases are firmly connected to each other in an entire room or an area of 5 m ² or more and integrated vibrationally, the vertical deformation due to heavy floor impact is wider than that in FIG. 39 of the conventional example. Acting on the supporting leg (see FIG. 40). For this reason, it becomes possible to make the vibration-proof structure of each “vibration-proof support leg” softer, and a synergistic effect appears in the heavy-weight floor impact sound blocking performance.

Further, as apparent from the above description, the present invention has the following effects.
(1) Since the base panel is provided with a plurality of air holes for buffering the pressure of the underfloor air layer, or the gap between the floor base (panels) is air permeable, the spring of the underfloor air layer Since the function is reduced and the resonance amplification caused by the air spring is eliminated, the heavy floor impact sound insulation performance is improved.
(2) In addition, when adjacent floor foundations are firmly connected in the whole room or with an area of 5 m ² or more, and integrated vibrationally, the amount of vertical deformation can be reduced or the vibration-proofing support legs can be made flexible, and the weight can be reduced. A synergistic effect with the above (1) can be expected in the floor impact sound insulation performance.
(3) Since the necessary blocking performance can be sufficiently secured by the effect on the floor impact sound, it is possible to reduce the concrete slab that is the floor base.
(4) By reducing the slab, the reduction of structures such as beam columns and bearing walls that support the slab is promoted, which is effective in reducing construction costs and carbon dioxide emissions or saving resources.
(5) Conventionally, there are many existing buildings that are forced to be dismantled due to the low floor impact sound insulation performance, but this sound insulation double floor expands the possibility of reusing existing buildings.

<Ninth embodiment>
FIGS. 35A and 35B are a schematic plan view and a schematic cross-sectional view showing an example of a sound-insulating double floor according to the ninth embodiment of the present invention. In FIGS. 35 (a) and 35 (b), the same or corresponding parts as those in the above-described embodiments are denoted by the same reference numerals.

In the figure, the base panel 4 has an upper surface material 12 made of a flat plate and a lower surface material 13 made of a flat plate with a predetermined distance (hollow portion height) through a plurality of ribs 90 that are substantially cross-shaped columns. 14h). Here, the ribs 90 are arranged at predetermined intervals in the horizontal direction and the vertical direction between the upper face material 12 and the lower face material 13, and firmly connect the upper face material 12 and the lower face material 13. ing. Further, in the base panel 4, a hollow portion that is a gap between the upper face member 12 and the lower face member 13 is closed by a wall member (not shown), a baseboard (not shown), or the like. The overall configuration is a box. A floor finish layer 5 made of, for example, composite flooring is provided on the upper surface of the base panel 4.
As the rib 90, in addition to a woody material such as a laminated material or a solid material, a metal (for example, a lightweight steel base material such as LGS) or a concrete material (for example, a concrete such as FRC) used in the above-described embodiments is used. Molded products) or resin-based materials (for example, foamed plastics) can be used.

  Here, when the base panel 4 is installed in the room, the base panel 4 is constructed depending on a method of constructing an opening such as a partition wall or a sill with an adjacent room and a fitting condition of piping penetrating from the outside. Although a part of the box may open, the calculation of the Helmholtz resonator resonance frequency (resonance frequency) is a virtual partition set in consideration of the duct pitch even when the opening area of the box is large. Based on the above. On the other hand, when the opening area of the box is small, it is calculated to be slightly higher than actual, but it can be calculated as having no opening. As described above, the sound insulation double floor according to the ninth embodiment can be treated as a resonator (resonator / resonance box) in the same manner as the sound insulation double floor according to each embodiment described above. Think of it as a large box.

  In addition, the foundation panel 4 is supported by the anti-vibration support legs 3 in a state where it floats by a predetermined distance from the concrete slab 1, whereby an underfloor air layer 2 is formed between the concrete slab 1 and the foundation panel 4. Provided. Here, the anti-vibration support leg top portion 3 a attached to the upper part of the anti-vibration support leg 3 is disposed inside the base panel 4 and is screwed to the lower face member 13, so that the anti-vibration support leg 3 is The anti-vibration support leg 3 is fixed to the base panel 4, thereby supporting the base panel 4 on the concrete slab 1.

  A plurality of hollow communication holes 10 are perforated at predetermined intervals in the horizontal direction and the vertical direction in the lower face material 13 of the base panel 4, and a duct 94 is provided in each hollow communication hole 10. 4 is inserted from the hollow part side. The longitudinal dimension of the duct 94 is such that the length of the portion protruding from the lower face member 13 is set to about 3/4 of the hollow portion height 14h, and the plurality of ducts 94 are provided. The dimensions of the resonance frequency (resonance frequency) of the Helmholtz resonator of the base panel 4 are set to an arbitrary value of 16 Hz to 1000 Hz.

  According to the configuration of the ninth embodiment as described above, the resonance frequency of the Helmholtz resonator of the base panel 4 can be adjusted by the diameter and length of the duct 94 as is well known. When the diameter of the hollow communication hole 10 is defined, the resonance frequency of the Helmholtz resonator can be set by the length of the duct 94. The frequency characteristics of the floor impact sound can be changed by changing the resonance frequency of the Helmholtz resonator. For this reason, it is possible to further improve the floor impact sound insulation performance by selecting a duct shape that matches the conditions of the double floor.

  Specifically, according to the example described in “Development of the Japan Society for Noise Control Engineering, April 2012 Spring Research Presentation P157 High-performance dry sound insulation double floor” by the present inventors, the duct By changing the length from 20 mm to 65 mm, it was possible to increase the heavy floor impact sound blocking performance by 2 dB. In this case, the resonance frequency of the Helmholtz resonator is changed from 58 Hz to 37 Hz with the change in the length of the duct.

Here, the Helmholtz resonator resonance frequency is a resonance frequency calculation value of a so-called (general) Helmholtz type sound absorption structure, and cannot be applied as it is to the sound insulation double floor. Because the space that is the target of sound absorption assumed by the Helmholtz type sound absorption structure is the underfloor air layer of this sound insulation double floor, the floor impact sound that this sound insulation double floor attempts to sound is measured. The propagation space is not the underfloor air layer but the indoor space of the lower floor, the air sound that the Helmholtz type sound absorption structure is the sound absorption object, and the floor impact sound that the sound insulation double floor is the sound insulation object This is because of a large difference. Furthermore, since the air pressure (or sound pressure) generated in the underfloor air layer propagates through the concrete slab 1 and is measured as the floor impact sound of the lower floor, the floor impact sound is caused by the structure of the concrete slab 1 and the like. The frequency characteristics change.
From the above, it is necessary to consider the resonance frequency of the Helmholtz resonator as a reference value when adjusting the frequency characteristics of the floor impact sound of the lower floor.

Thus, according to the ninth embodiment, the resonance frequency of the Helmholtz resonator as the entire base panel 4 is adjusted by adjusting the length, diameter, pitch of the duct 94 or the volume of the hollow portion of the base panel 4. Since it can be controlled, it is possible to construct a sound insulation double floor that matches the frequency band of the target impact sound to be cut off.
Here, the resonance frequency of the Helmholtz resonator can be calculated by the following equation (II).

here,
f ₀ : Helmholtz resonator resonance frequency (resonance frequency) (Hz)
C: Speed of light (m / S)
S: Duct cross-sectional area (m ² )
L: Effective length of the duct (m: Value obtained by correcting the actual length slightly longer)
V: Volume of the box (m ³ )
It is.

In addition, in each Example and modification mentioned above, although the shape of the hollow part communication hole 10 is made into circular, other shapes, for example, square, ellipse, etc., are also employable. In that case, the cross-sectional shape of the duct 94 is preferably matched with the shape of the hollow communication hole 10 with which the duct 94 communicates.
In addition, the configurations and modifications of the embodiments described above can be applied in appropriate combinations within a consistent range.

  The sound-insulated double floor of the present invention can be efficiently constructed by being assembled or manufactured in a factory, and can be expected to be used industrially (particularly in the manufacturing industry). In addition, by ensuring sound insulation with a double floor, it is possible to slim down the building structure and save resources as the slab thickness decreases, so it can be expected to be used in the construction industry.

1 Reinforced concrete slab 1h Thickness of slab 2 Underfloor air layer 2h Underfloor air layer height 3 Anti-vibration support leg 4 Ground panel 4b Ground panel (for example, particle board)
5 Floor finishing layer 6 Soundproof flooring 7 Double floor 7h Double floor height 8 Piping 8b Piping space 9 Rib material 10 Hollow part communication hole 11 Finishing layer communication hole 11b Combined upper surface material joint part and finishing layer communication hole Part 12 Upper face material 12b Upper face material (for example, veneer plate 15 mm thick)
13 Lower face material 13b Lower face material (for example, veneer plate 15 mm thick)
14 hollow part 14h hollow part height 15 double-sided adhesive tape 16 rib cutout part 17 composite flooring 18 carpet 19 pneumatic cushioning layer 19h pneumatic cushioning layer thickness 20 breathable floor finish 20b base felt 21 thrown plywood 22 vertical deformation Quantity 23 Unit connecting bolt 24 Ground unit 25 Brick for adjusting surface density 26 Non-woven fabric 27 Air hole 28 Misalignment prevention rib 29 Sound insulation double floor 30 Water level difference part 31 Upper face material joint part 32 Unit bath 32h Unit bath washing place height 94 Duct

The present invention includes a floor base, a plurality of vibration isolation support legs installed on the floor base, and a floor base supported by the plurality of vibration isolation support legs at a predetermined height across an underfloor air layer, In the double floor composed of a floor finishing layer laid on the upper surface of the floor substrate, the floor substrate is formed of a box, and the lower surface or side surface of the box communicates with the interior of the box and the underfloor air layer. A plurality of air holes for buffering the pressure of the underfloor air layer are formed, and air that passes through the plurality of air holes is passed through the inside of the box, so that the resonance frequency of the Helmholtz resonator is 16 Hz to 1000 Hz. A plurality of ducts that are any one of the above are provided to change the frequency characteristics of the floor impact sound .

Also, piping may be laid inside the box.
Moreover, it is good to make a part of member which forms the said box so that attachment or detachment is possible, and to update the said piping.
Moreover, it is good to provide the space which compressed the height of the said box, and to lay piping in this space.
Moreover, it is good to arrange | position the said some box at predetermined intervals, and to lay piping in the clearance gap between the said boxes.

As described above, according to the present invention, the plurality of air holes for buffering the pressure of the underfloor air layer are formed in the floor base, and the air passing through each of the plurality of air holes is passed through the resonance of the Helmholtz resonator. Since the frequency characteristic of the floor impact sound is changed by providing a plurality of ducts having a frequency of 16 Hz to 1000 Hz , the heavy floor impact sound blocking performance can be enhanced. Details of the effect will be described later.

Claims (12)

A floor base, a plurality of anti-vibration support legs installed on the floor base, a floor base supported by the plurality of anti-vibration support legs at a predetermined height across an underfloor air layer, and the floor base In the double floor consisting of the floor finish layer laid on the upper surface,
A sound-insulating double floor comprising a plurality of air holes for buffering the pressure of the underfloor air layer in the floor base.   The sound insulation double floor according to claim 1, wherein the floor foundation is a box.   The said air hole which permeate | transmits the inside of the said box and the said underfloor air layer, and buffered the pressure of the underfloor air layer was drilled in the lower surface or side surface of the said box. Soundproof double floor.   The sound-insulating double floor according to claim 3, wherein a duct having a resonance frequency of a Helmholtz resonator of 16 Hz to 1000 Hz is provided inside the box body so that air passing through the air holes is passed through the box body.   The upper surface of the box body is provided with a plurality of finishing layer communication holes that further communicate the inside of the box body and the lowermost layer of the floor finishing layer to further buffer the pressure of the underfloor air layer. The sound-insulating double floor according to claim 2. The sound insulation double floor according to claim 5, wherein a lowermost layer of the floor finish layer has air permeability.   The sound insulation double floor according to any one of claims 2 to 5, wherein piping is laid inside the box.   The sound-insulating double floor according to claim 7, wherein a part of the member forming the box is detachably formed so that the piping can be updated.   The sound-insulating double floor according to any one of claims 2 to 5, wherein a space in which the height of the box body is partially compressed is provided, and piping is laid in the space.   The sound insulation double floor according to any one of claims 2 to 5, wherein a plurality of boxes are arranged at predetermined intervals, and piping is laid in a gap between the boxes.   A building comprising the sound-insulating double floor according to any one of claims 1 to 10.   The building according to claim 11, wherein the floor base has a structure in which a step around the water is eliminated.