JP7435271B2 - Sound insulation structure - Google Patents

Description

The present invention relates to a sound insulation structure that absorbs vibrations caused by impact from heavy floors in buildings.

Conventionally, in order to absorb vibrations caused by heavy floor impact of ceiling boards that partition spaces in buildings, for example, the ceiling structure of a building described in Cited Document 1 and the vibration absorbing member described in Cited Document 2 have been known. There is.

In the ceiling structure of the building described in Cited Document 1, a dynamic damper made of a combination of a weight (mass body) and an elastic member (elastic body) is attached to the ceiling base material attached to the floor beam on the upper floor. . This dynamic damper is configured to elastically support a weight using its elastic member. As such an elastic member, for example, one containing rubber is used. The weight vibrates with the impact generated on the floor of the upper floor, thereby reducing the heavy floor impact sound propagating to the lower floor.

On the other hand, the vibration absorbing member described in Cited Document 2 includes a sheet-like elastic member containing at least one of glass wool and rock wool, and a weight fixed to the elastic member, and is arranged on the upper surface of a ceiling board. has been done. The weight and the portion of the elastic member that supports the weight each function as a dynamic damper, and the weight absorbs the vibration of the ceiling board by vibrating with the vibration of the ceiling board.

Further, as a performance standard for impact sound in a floor structure using such a vibration absorbing member, an L value (JIS A 1418) representing a sound insulation grade is generally used. The L value is set so that the floor impact sound level decreases as the frequency of the floor impact sound increases. The frequency band for determining the sound insulation grade for heavy floor impact sound is mostly the 63 Hz octave band center frequency band.

JP2006-342580A Japanese Patent Application Publication No. 2018-123669

However, when using the ceiling structure of a building described in Patent Document 1 or the vibration absorbing member described in Cited Document 2, vibrations in the frequency band targeted for vibration absorption cannot be sufficiently absorbed. The floor impact sound level may exceed the target L value. The reason for this is thought to be as follows.

That is, in the dynamic damper for the ceiling structure of a building described in Patent Document 1, rubber is used as the material of the elastic member. For example, compared to the case where glass wool or rock wool is used as the elastic member, the effective frequency width, which is the frequency width in which vibration can be effectively absorbed, is narrower and its maximum value is larger. In other words, this dynamic damper has steep resonance characteristics. Although such characteristics make it possible to absorb vibrations within a specific narrow range, there have been cases in which vibrations in the entire frequency band to be absorbed cannot be sufficiently suppressed (see FIGS. 3 and 2).

On the other hand, in the vibration absorbing member described in Patent Document 2, a material containing glass wool or rock wool is used as the material of the elastic member. In addition, compared to the case where rubber is used as the elastic member, for example, the effective frequency width is wider and the maximum value thereof is smaller. In other words, this vibration absorbing member has resonance characteristics that are gentle and have a wide base. Due to such characteristics, when the floor impact sound level reaches a maximum value within the frequency band to be absorbed, vibrations at that frequency may not be sufficiently suppressed (see FIGS. 3 and 2).

The present invention has been made in view of the above problems, and an object of the present invention is to provide a sound insulation structure that can absorb vibrations of a face material even more effectively.

In order to solve the above problem, a sound insulation structure according to the present invention is a sound insulation structure for absorbing vibrations in a building, and includes a panel, a support mechanism that supports the panel, and a support mechanism attached to the support mechanism. a first dynamic damper that absorbs vibrations of the support mechanism; and a second dynamic damper that is attached to the face material and absorbs vibrations of the face material, the first dynamic damper containing rubber and The second dynamic damper includes a first elastic member disposed in contact with the mechanism, and a first weight fixed to the first elastic member, and the second dynamic damper includes at least one of glass wool and rock wool. A second elastic member that includes a second elastic member and is disposed on the surface of the face material in contact with the second elastic member, and a second weight that is fixed to the second elastic member, and absorbs vibrations within a predetermined frequency band. The first dynamic damper has a natural frequency tuned to suppress a predetermined floor impact sound within the predetermined frequency band among the floor impact sound levels of vibrations absorbed by the second dynamic damper. It has a natural frequency tuned to absorb vibrations within a predetermined frequency band above the level.

In the sound insulation structure, the first dynamic damper includes a first elastic member disposed in contact with the support mechanism, and a first weight fixed to the first elastic member. The vibration transmitted to the support mechanism is transmitted to the first weight via the first elastic member, and the first weight vibrates. Therefore, a reaction force is transmitted from the first weight to the face material, and vibrations transmitted to the support mechanism can be attenuated by this reaction force, and as a result, the sound insulation properties of the sound insulation structure can be improved.

Further, the sound insulation structure includes a second dynamic damper in addition to the first dynamic damper. The second dynamic damper includes a second elastic member including at least one of glass wool and rock wool and disposed on the surface of the face material in contact with the second elastic member, and a second weight fixed to the second elastic member. and. Therefore, vibrations transmitted to the face material can be attenuated, and the sound insulation properties of the sound insulation structure can be improved. Here, since the second elastic member of the second dynamic damper includes at least one of glass wool and rock wool, the effective frequency width, which is a frequency width that can effectively absorb vibrations, is relatively large, and its maximum It has the characteristic that the value is relatively small. This characteristic is thought to be the cause, but when only the second dynamic damper is used, vibrations in the frequency band to be absorbed may not be sufficiently suppressed.

Here, the first dynamic damper has a frequency band that is preset as exceeding a predetermined floor impact sound level within the predetermined frequency band among the floor impact sound levels of the vibrations absorbed by the second dynamic damper. It has a natural frequency tuned to absorb the vibrations within. Therefore, vibrations that exceed a predetermined floor impact sound level even if absorbed by the second dynamic damper can be further absorbed by the first dynamic damper. Therefore, vibrations within the building can be absorbed more effectively.

Furthermore, since the second elastic member includes at least one of glass wool and rock wool, the second elastic member can be constructed at a relatively low cost, and the second elastic member improves the heat insulation performance of the face material. can be done. Furthermore, compared to the case where rubber is used as the material, it is cheaper and can absorb vibrations in a wider frequency band.

Here, the floor impact sound level of vibrations transmitted to the surface materials in a building tends to be large in a relatively small frequency band. On the other hand, it is difficult to provide the first dynamic damper with vibration absorption characteristics over a wide range of effective frequencies. Therefore, by making the natural frequency of the first dynamic damper smaller than the center frequency of the predetermined frequency band, vibrations in the relatively small frequency band can be effectively absorbed.

In the sound insulation structure, the panel material constitutes a ceiling in the building, and the support mechanisms extend along a first direction and are spaced apart from each other along a second direction orthogonal to the first direction. The second dynamic damper includes a plurality of field edges fixed to the upper surface of the panel material in a state where the field edges are arranged as follows, and a field edge support arranged above the field edges and supporting the field edges. , it is preferable that the first dynamic damper is disposed between the adjacent field edges on the upper surface of the panel material, and the first dynamic damper is attached to the field edge support.

According to this configuration, since the second dynamic damper is disposed between the adjacent field edges, by suppressing the second dynamic damper from protruding above the field edge, the second dynamic damper is arranged above the field edge. It is possible to secure an installation area for the first dynamic damper with respect to the located field fence. Therefore, it is possible to realize a sound insulation structure that is compact as a whole.

In the sound insulation structure, it is preferable that the second dynamic damper is provided at an intersection of the field edge and the field edge.

According to this configuration, the second dynamic damper is provided in the area between the field edges, and the first dynamic damper is provided on the field edge, so that both dampers can be arranged evenly on the surface material. Furthermore, the first dynamic damper is disposed at a location with high rigidity in the support mechanism, and the vibration absorption performance of the first dynamic damper can be effectively exhibited. For these reasons, vibrations of the face material can be efficiently absorbed.

As explained above, according to the sound insulation structure of the present invention, vibrations of the face material can be absorbed even more effectively.

2 is a graph showing the relationship between the narrow band display of the floor impact sound level of the heavy floor impact sound transmitted to the ceiling board and the L value grade curve in a state where the heavy floor impact sound is absorbed by the first and second dynamic dampers. . It is a graph showing the resonance distribution (distribution of resonance magnification with respect to frequency) of the 1st dynamic damper which comprises the sound insulation structure of this invention. It is a graph showing resonance distribution of the 2nd dynamic damper which constitutes the above-mentioned sound insulation structure. It is a perspective view showing the whole structure of the said sound insulation structure. FIG. 5 is an enlarged view of FIG. 4. It is a longitudinal cross-sectional view of the said sound insulation structure. 7 is a sectional view taken along line VII-VII of FIG. 6. FIG. It is a side view showing the vibration-proof hanging tool attached to the said sound insulation structure. 9 is a sectional view taken along line IX-IX in FIG. 8. FIG. FIG. 7 is a diagram corresponding to FIG. 6 of a sound insulation structure according to a second embodiment of the present invention. 11 is a sectional view taken along line XI-XI in FIG. 10. FIG. FIG. 7 is a diagram corresponding to FIG. 6 of a sound insulation structure according to a third embodiment of the present invention. 13 is a sectional view taken along line XIII-XIII in FIG. 12. FIG.

[First embodiment]
Hereinafter, a sound insulation floor structure 100 to which the sound insulation structure 1 according to the first embodiment of the present invention is applied will be described in detail with reference to the drawings.

This sound insulating floor structure 100 is used, for example, in general steel-framed offices, hotels, and the like.

Specifically, as shown in FIGS. 6 and 7, this sound insulating floor structure 100 includes a floor material that constitutes the floor portion of the upper floor, and a plurality of beam members 7 that extend in one direction and support this floor material. , a ceiling support beam 6 that extends in a direction perpendicular to one direction and is fixed between adjacent beam members 7, and is suspended from the ceiling support beam 6, forming the ceiling of the lower floor and absorbing the vibrations of the ceiling. A sound insulation structure 1 including a mechanism for. Hereinafter, one direction will be referred to as a front-rear direction, and a direction perpendicular to the one direction will be referred to as a left-right direction.

The flooring material includes a steel plate 105 provided on the beam member 7, a deck plate part 103 folded up and fixed on the steel plate 105, a subfloor material 101 that covers the deck plate part 103 from above, a steel plate 105 and It has a concrete material 107 filled between the deck plate part 103 and the subfloor material 101. Hereinafter, the steel plate 105 and the deck plate portion 103 will be collectively referred to as a deck plate.

As shown in FIG. 7, the deck plate is made of a thin steel plate with a corrugated cross-sectional view, and bears the load generated on the subfloor material 101 during concrete pouring. Since a well-known deck plate is used as the deck plate, detailed description thereof will be omitted here.

The concrete material 107 is concrete cast on site. Additionally, reinforcing bars are embedded in the concrete material 107 to improve strength.

In this embodiment, the beam member 7 is a steel material having a web and a pair of upper and lower flanges 7a, 7a provided at both upper and lower ends of the web. On the upper flange 7a of the beam member 7, a steel plate 105 of the deck plate is fixed by welding (for example, spot welding) or the like.

As shown in FIG. 7, the ceiling support beam 6 includes a web 6c, a pair of upper and lower flanges 6a, 6a provided at both the upper and lower ends of the web 6c, and one side in the front and rear direction of each flange 6a, 6a (in this embodiment, a pair of lips 6b, 6b extending in a direction toward each other from the end (front side). The ceiling support beam 6 is set smaller in height than the beam member 7, and is fixed to the beam member 7 between a pair of flanges 7a, 7a of the beam member 7.

Both longitudinal (left and right) ends of the ceiling support beam 6 are fixed to adjacent beam members 7, 7, respectively. Specifically, with the longitudinal end of the ceiling support beam 6 disposed between the upper and lower flanges 7a of the beam member 7, the lower flange 6a of the ceiling support beam 6 and the bottom of the beam member 7 are arranged. The side flange 7a is connected via bolts or the like. Note that the method for connecting the ceiling support beam 6 and the beam member 7 is not limited to a method using bolts or the like, but may also be welding or the like.

As shown in FIGS. 4 and 5, the sound insulation structure 1 is fixed to a ceiling board 8 made of gypsum board or the like (corresponding to the "face material" of the present invention) and a ceiling support beam 6, and supports the ceiling board 8. , a first dynamic damper 30 attached to the support mechanism 3 , and a second dynamic damper 20 attached to the ceiling board 8 .

The ceiling board 8 is a plate-like member extending in the horizontal direction, and is suspended from the ceiling support beam 6 by the support mechanism 3. Further, a board that can be used as the ceiling board 8 is not limited to a gypsum board, and may be a wooden board, for example.

As shown in FIGS. 4 and 5, the support mechanism 3 includes a plurality of roof edges 5 arranged parallel to each other and fixed to the upper surface of the ceiling board 8, and a plurality of roof edges 5 arranged above the roof edge 5 and perpendicular to the roof edge 5. A plurality of field edge supports 4 are arranged as shown in FIG. We are prepared.

In the present embodiment, the field edge 5 is a rectangular bar-shaped (cylindrical member having a substantially quadrangular cross-sectional view) that extends along the front-rear direction (corresponding to the "first direction" of the present invention). The plurality of field edges 5 are fixed to the upper surface of the ceiling board 8 while being spaced apart from each other in the left-right direction (corresponding to the "second direction" of the present invention). The field edge 5 is attached to the field edge receiver 4 via a field edge support 50, as shown in FIG. Note that the field edge 5 may be arranged so as to extend along the left-right direction. In this case, field edge receivers 4, which will be described later, are arranged so as to extend in the front-rear direction.

As shown in FIGS. 8 and 9, the field edge 5 has locking grooves 5a, 5a for locking the field edge support 50 along the longitudinal direction (back and forth direction) on both left and right sides thereof. It is formed by stretching. Note that FIG. 9 represents a cross-sectional view taken along lines IX-A and IX-B in FIG. 8.

The field edge support 50 includes an upper surface portion, a pair of locking portions 50a, 50a extending from both ends of the upper surface portion in the left-right direction and capable of engaging with the locking grooves 5a of the field edge 5, and a pair of locking portions 50a, 50a extending from the upper surface portion. It has a claw portion that locks onto the field edge receiver 4.

The field edge support 50 is locked to the field edge 5 by engagement between the locking portions 50a, 50a and the locking grooves 5a, 5a.

The claw portion is formed by rising above the plate member and bending forward. The field edge support 50 can be locked to the field edge support 4 by sandwiching the later-described upper flange of the field edge support 4 between the claw portion and the plate member.

In this embodiment, as shown in FIGS. 5 and 7, the field support 4 is a channel steel that opens in the rear direction and extends in the left-right direction, and is spaced apart from each other in the front-rear direction. It is suspended from member 7. Specifically, the field edge receiver 4 includes a web 41 extending in the left-right direction, and a pair of upper and lower flanges 40 extending rearward from the upper and lower edges of the web 41. Note that the direction in which the field edge receiver 4 opens does not necessarily have to be in the rear direction, but may be in the front direction.

The field edge support 4 is further divided into a field edge support 4A to which the first dynamic damper 30 is attached, and a field edge support 4B to which the vibration isolating hanger 2 is attached. In the following, if it is necessary to distinguish between the two, they will be referred to as the field receiver 4A and the field receiver 4B, respectively, and if there is no need to distinguish between the two, they will simply be collectively referred to as the field receiver 4.

Insertion holes (not shown) through which bolts 34 can be inserted are formed in the web 41 of the field edge receiver 4A at predetermined intervals in the left-right direction. The first dynamic damper 30 is attached to the web 41 via these bolts 34 and the insertion holes.

An insertion hole (not shown) through which the hanging bolt 12 can be inserted is formed in the upper flange 40 of the field edge receiver 4B. With the suspension bolt 12 inserted into this insertion hole, the flange 40 is sandwiched between a pair of upper and lower nuts 19, so that the field edge support 4B is suspended from the vibration isolating hanger 2.

As shown in FIGS. 5 and 7, the vibration isolating hanger 2 includes a beam mounting member 10 attached to the beam member 7, a vibration isolating rubber 11 attached to this beam mounting member 10, and this vibration isolating rubber 11. The suspension bolt 12 is supported by the suspension bolt 12.

The beam attachment member 10 includes an arrangement surface 15 on which the vibration isolating rubber 11 is arranged, and a pair of attachment parts 16 for attaching the arrangement surface 15 to the beam member 7 so that the arrangement surface 15 projects forward from the beam member 7. 16. The mounting portions 16 are erected from both ends of the placement surface 15 in the left-right direction and can be engaged with the ceiling support beams 6 .

The arrangement surface 15 is a flat plate material, and an insertion hole (not shown) through which the suspension bolt 12 can be inserted is formed in the arrangement surface 15 so as to pass through the arrangement surface 15 in the vertical direction. As shown in FIGS. 5 and 8, the hanging bolt 12 is provided on the vibration isolating rubber 11 in a state in which it passes through the vibration isolating rubber 11 placed on the placement surface 15 and the insertion hole of the placement surface 15 in the vertical direction. It is screwed into a nut 18. Therefore, the load generated on the hanging bolt 12 acts in a direction that compresses the vibration isolating rubber 11 between it and the placement surface 15.

The first dynamic damper 30 is fixed to the field edge support 4 in a state of protruding forward so as to fit within the height dimension (vertical dimension) of the support mechanism 3.

Specifically, the first dynamic damper 30 includes a mounting plate 33 attached to the web 41 of the field bridge 4, a first elastic member 32 extending forward from the mounting plate 33, and a distal end portion of the first elastic member 32. It has a first weight 31 attached thereto.

By doing so, it is possible to prevent the first dynamic damper 30 from getting in the way when installing piping, heat insulating material, sound absorbing material, etc. in the sound insulating floor structure 100.

Further, the first dynamic damper 30 is arranged at each intersection between the field edge receiver 4A and the field edge 5 in the field edge receiver 4A. In this way, the second dynamic damper 20 is provided between the field edges 5, and the first dynamic damper 30 is provided on the field edge 5, so that both dampers 20, 30 can be arranged evenly on the surface material. Can be done. Furthermore, the first dynamic damper 30 is disposed at a location with high rigidity in the support mechanism 3, and the vibration absorption performance of the first dynamic damper 30 can be effectively exhibited.

The resonance distribution (distribution of resonance magnification with respect to frequency) of the first dynamic damper 30 has characteristics as shown in FIG. 2. Specifically, the effective frequency width d1 of the first dynamic damper 30 is smaller than the effective frequency width d2 of the second dynamic damper 20, and the local maximum value f1 of the resonance magnification of the first dynamic damper 30 is smaller than the effective frequency width d2 of the second dynamic damper 20. It is smaller than the maximum value f2. Further, the natural frequency t1 of the first dynamic damper 30 is set to be smaller than the center frequency (63 Hz) of the frequency band T and larger than the lowest frequency (45 Hz) of the frequency band T. Furthermore, the range of the frequency band S of vibrations that is the target of vibration absorption by the first dynamic damper 30 is narrower than the range of the frequency band T of vibrations that is the target of vibration absorption of the second dynamic damper 20 . Furthermore, the center frequency of the frequency band S set for the first dynamic damper 30 is lower than the center frequency of the frequency band T set for the second dynamic damper 20. In other words, the first dynamic damper 30 is configured to effectively absorb vibrations on the relatively low frequency side of the frequency band T. With this configuration, when the floor impact sound level is relatively high on the low frequency side of the impact sound, the first dynamic damper 30 can effectively absorb vibrations on the relatively low frequency side that cannot be sufficiently absorbed by the second dynamic damper 20. can be absorbed.

The first weight 31 is made of a material having a higher specific gravity than the field support 4 in order to effectively absorb vibrations. Specifically, the first weight 31 is made of steel or iron.

The first elastic member 32 is configured such that the local maximum value f1 (see FIG. 2) of the resonance distribution of the first dynamic damper 30 is relatively larger (the local maximum value f1 is larger than the local maximum value f2 of the resonance distribution of the second dynamic damper 20). molded from synthetic rubber or the like so as to increase the size of the material.

A pair of insertion holes (not shown) through which bolts 34 can be inserted are formed in the mounting plate 33. The mounting plate 33 is fixed to the field edge support 4 by inserting the bolts 34 into the insertion holes in a state where this insertion hole and the insertion hole formed in the web 41 of the field edge support 4 overlap. It has become.

As shown in FIGS. 5 to 7, the second dynamic damper 20 includes a sheet-like second elastic member 22 having elastic force, and a plurality of (four in this embodiment) fixed to the second elastic member 22. It has a second weight 24, a first locking sheet 26, and a second locking sheet 27, and is within a preset frequency band T (see FIGS. 1 and 3) generated within the building. It has a natural frequency tuned to absorb vibrations at

The natural frequency t2 (see FIG. 3) of the second dynamic damper 20 of this embodiment is tuned to absorb vibration within a predetermined frequency band T centered around 63 Hz in order to reduce heavy floor impact noise. has been done. In other words, the second dynamic damper 20 is designed to vibrate in synchronization with vibrations in a predetermined frequency band T centered around 63 Hz. Specifically, for each second elastic member 22, the density of the second elastic member 22 is set to 60 kg/m3 or more (for example, 85 kg/m3), and the thickness dimension (vertical dimension) is set to about 12 mm. Four weight bodies 24a each weighing 250 g are fixed to the second elastic member 22 in rows in the front, back, left and right directions. The weight body 24a is made of steel or iron, and has a rectangular parallelepiped shape with dimensions of about 50 mm in the front-rear direction and horizontal direction, and about 12 mm in height. In the second dynamic damper 20 of this embodiment, the vibration within the frequency band T via the second elastic member 22 is determined as the distance between adjacent weights 24 or the distance from the weight 24 to the end surface of the second elastic member 22. The distance at which the light can be appropriately propagated to the second weight 24 is set to 30 mm.

As shown in FIG. 3, the resonance distribution (distribution of resonance magnification with respect to frequency) of the second dynamic damper 20 has a local maximum value f2 of the resonance magnification near the natural frequency t2, and the frequency of the impact sound is the same as the natural frequency t2. It shows a characteristic that the resonance magnification decreases as the distance from the point increases. Furthermore, in this embodiment, the resonance distribution of the second dynamic damper 20 includes a predetermined frequency band T centered at 63 Hz.

Further, the second dynamic damper 20 is arranged between adjacent field edges 5, as shown in FIGS. 4 to 6.

The second elastic member 22 is a member that supports the second weight 24 so that the second weight 24 can vibrate with the vibration of the ceiling board 8, and is in contact with the ceiling board 8. It is placed so as to extend along the upper surface of 8.

Moreover, in this embodiment, as the second elastic member 22, a material formed by compressing glass wool into a sheet shape is used. As a result, the second dynamic damper 20 has a characteristic that its effective frequency width d2 (see FIG. 3) is relatively large (the effective frequency width d2 is larger than the effective frequency width d1 of the first dynamic damper 30). . Although the second elastic member 22 is made of glass wool in this embodiment, when the second elastic member 22 contains at least one of glass wool and rock wool, it has the above characteristics.

Further, as shown in FIG. 9, the horizontal dimension of the second elastic member 22 is set to a value smaller than the distance between adjacent field edges 5, and the left and right edges of the second elastic member 22 are A gap is formed between the field edge 5 and the field edge 5, respectively. This is to prevent vibration of the second elastic member 22 from being inhibited due to contact between the second elastic member 22 and the field edge 5.

The second weight 24 includes a weight main body 24a having a higher specific gravity than the second elastic member 22, and an adhesive layer 24b interposed between the weight main body 24a and the second elastic member 22 to bond them together. The adhesive layer 24b is formed on the entire surface of the weight body 24a on the second elastic member 22 side. This adhesive layer 24b is formed, for example, by applying an adhesive to the surface of the weight body 24a and then bonding it onto the second elastic member 22.

In addition, the second weights 24 are fixed to the upper surface of the second elastic member 22 at positions spaced apart from each other by a predetermined distance (in this embodiment, the above-mentioned distance of 30 mm) in order to prevent interference with each other. has been done.

The first locking sheet 26 includes a main body portion 26a that extends in the left-right direction and is bonded to the upper surface of the second elastic member 22, and a pair of extension portions 26b that extend outward from both end surfaces of the second elastic member 22 in the left-right direction. , 26b.

The second locking sheet 27 includes a main body portion 27a that extends in the left-right direction and is bonded to the lower surface of the second elastic member 22, and a pair of extension portions 27b that extend outward from both end surfaces of the second elastic member 22 in the left-right direction. It is made up of.

As the first locking sheet 26 and the second locking sheet 27, for example, a tape in which an adhesive is applied to one surface of a base material and the one surface serves as an adhesive surface is used. Further, two of the first locking sheets 26 and the second locking sheets 27 are respectively arranged in a state that they are spaced apart from each other along the front-rear direction of the second elastic member 22.

A through hole (not shown) passing through the front and back of each of these parts is formed in each overlapping part of the first locking sheet 26 (extension part 26b) and the second locking sheet 27 (extension part 27b). ing.

Here, a temporary locking member 28 is provided on the field edge 5 for locking the first locking sheet 26 and the second locking sheet 27 by inserting it into the through holes of the extension portions 26b and 27b. It is provided.

The temporary fixing member 28 is for temporarily fixing the second dynamic damper 20 to the edge 5 by locking the extension parts 26b and 27b. As shown in FIG. 9, the temporary fixing member 28 includes a substrate extending in the left-right direction, a pair of extending portions extending downward from both edges of the base material, and extending diagonally upward from the lower edge of each extending portion. It has a locking protrusion 28a.

The temporary fixing member 28 is attached to the field edge 5 in a state where the board is placed on the upper surface of the field edge 5 with each extending portion extending along both sides of the field edge 5 in the width direction (horizontal direction). A plurality of temporary fixing members 28 are provided so as to be spaced apart from each other along the longitudinal direction (front-back direction) of the field edge 5.

With the extension part 26b of the first locking sheet 26 and the extension part 27b of the second locking sheet 27 overlapped, the locking protrusion 28a of the temporary locking member 28 is inserted into the insertion hole. By doing so, the first locking sheet 26 and the second locking sheet 27 can be locked to the edge 5. Thereby, the second dynamic damper 20 can be temporarily fixed to the support mechanism.

In this state, by pushing up the second dynamic damper 20 from below with the ceiling board 8, the second dynamic damper 20 can be placed on the upper surface of the ceiling board 8.

(Operation of sound insulation structure)
The natural frequency t2 of the second dynamic damper 20 is tuned to match the center frequency of a predetermined frequency band T in order to absorb vibrations within the frequency band T. Therefore, the resonance distribution of the second dynamic damper 20 has a local maximum value f2 of the resonance magnification at the natural frequency t2. In this embodiment, the resonance distribution of the second dynamic damper 20 has a local maximum value f2 of the resonance magnification at 63 Hz, and is designed to absorb vibrations within the frequency band T, that is, heavy floor impact sound.

However, even if the second dynamic damper 20 is used to absorb the heavy floor impact sound in the frequency band T, the floor impact sound level may not locally satisfy the performance standard of the target L value. In the following, as shown in Fig. 1, when there is a local maximum value P of the floor impact sound level that exceeds the target L value at a frequency between the lowest frequency and the center frequency (63Hz) of the frequency band T. I will explain about it. Note that the L value is measured based on "Method for measuring floor impact sound level at building sites" (JIS A 1418).

In order to absorb the floor impact sound level at such a maximum value P, the first dynamic damper 30 is tuned to have a natural frequency that resonates with the frequency at the maximum value P. Specifically, the natural frequency t1 of the first dynamic damper 30 is approximately equal to the frequency at the local maximum value P.

By configuring the first dynamic damper 30 and the second dynamic damper 20 as described above, vibrations in the frequency band T can be widely absorbed by the second dynamic damper 20 having a relatively large effective frequency width d2. Vibration at a frequency (maximum value P) that could not be absorbed sufficiently by the first elastic member 32 having a relatively large maximum value f1 of the resonance magnification of the resonance distribution can be effectively absorbed by the first elastic member 32.

As a result, as shown by the broken line in FIG. 1, the floor impact sound level at the maximum value P can be reduced so as to satisfy the performance standard at the target L value.

(effect)
According to the sound insulation structure 1 according to the present embodiment, the first dynamic damper 30 includes the first elastic member 32 that includes rubber and is disposed in contact with the support mechanism 3, and is fixed to the first elastic member 32. Since the vibration transmitted to the support mechanism 3 is transmitted to the first weight 31 via the first elastic member 32, the first weight 31 vibrates. Therefore, a reaction force is transmitted from the first weight 31 to the ceiling board 8, and vibrations transmitted to the support mechanism 3 can be attenuated by this reaction force, and as a result, the sound insulation performance of the sound insulation structure 1 can be improved.

Further, the sound insulation structure 1 includes a second dynamic damper 20 in addition to the first dynamic damper 30. The second dynamic damper 20 includes a second elastic member 22 that includes at least one of glass wool and rock wool and is disposed on the surface of the ceiling board 8 in contact with it, and a second elastic member 22 that is fixed to the second elastic member 22. A weight 24 is provided. Therefore, vibrations transmitted to the ceiling board 8 can be attenuated, and the sound insulation properties of the sound insulation structure 1 can be improved. Here, since the second elastic member 22 of the second dynamic damper 20 includes at least one of glass wool and rock wool, the effective frequency width, which is a frequency width that can effectively absorb vibrations, is relatively large. It has a characteristic that its local maximum value f2 is relatively small. This characteristic is considered to be the cause, but when only the second dynamic damper 20 is used, vibrations in the frequency band T to be absorbed may not be sufficiently suppressed.

Here, the first dynamic damper 30 has a predetermined frequency that exceeds a predetermined floor impact sound level within a predetermined frequency band T, out of the floor impact sound level of vibrations absorbed by the second dynamic damper 20. It has a natural frequency tuned to absorb vibrations within band S. Therefore, vibrations that are absorbed by the first dynamic damper 30 but still exceed a predetermined floor impact sound level can be further absorbed by the second dynamic damper 20. Therefore, vibrations within the building can be absorbed more effectively.

Further, since the second elastic member 22 includes at least one of glass wool and rock wool, the second elastic member 22 can be constructed at a relatively low cost, and the second elastic member 22 can be used to support the ceiling board 8. The insulation performance can be improved. Furthermore, compared to the case where rubber is used as the material, it is cheaper and can absorb vibrations in a wider frequency band.

Here, the floor impact sound level of vibration transmitted to the ceiling board 8 in the building tends to be large in a relatively low frequency band. On the other hand, the effective frequency width d1 of the first dynamic damper 30 is smaller than the effective frequency width d2 of the second dynamic damper 20, as described above, and it is difficult to provide vibration absorption performance over a wide range. Therefore, as in the sound insulation structure 1 of the present embodiment, by making the natural frequency of the first dynamic damper 30 smaller than the center frequency (63Hz) of the predetermined frequency band T, the relatively low frequency band within the frequency band T is Vibration inside S can be effectively absorbed.

Furthermore, since the second dynamic damper 20 is disposed between the adjacent field edges 5, by suppressing the upward protrusion of the second dynamic damper 20, the field edge 5 is positioned above the field edge 5. It is possible to secure an installation area for the first dynamic damper 30 with respect to the field edge receiver 4. Therefore, it is possible to realize the sound insulation structure 1 which is compact as a whole.

Further, by providing the second dynamic damper 20 in the area between the field edges 5 and the first dynamic damper 30 on the field edge 5, it is possible to arrange both dampers 20, 30 evenly on the ceiling board 8. can. Furthermore, the first dynamic damper 30 is disposed at a location with high rigidity in the support mechanism 3, and the vibration absorption performance of the first dynamic damper 30 can be effectively exhibited. Therefore, vibrations of the ceiling board 8 can be efficiently absorbed.

[Second embodiment]
The second embodiment of the present invention will be described focusing on the differences from the first embodiment.

Although the sound insulating floor structure 100 of the first embodiment uses a flooring material having a deck plate, the type of flooring material is not limited to this. For example, in the sound insulation floor structure 200 of the second embodiment, as shown in FIGS. 10 and 11, a floor material having a sound insulation floor panel 203 with high sound insulation performance is used.

This flooring material includes a subflooring material 101 and a sound insulating floor panel 203 that supports the subflooring material 101.

The sound insulating floor panel 203 includes an extruded cement board 204 in which a hollow part 204a penetrating in the left-right direction is formed, and a sand-like inorganic material 205 filled in the hollow part 204a so as to be able to move slightly.

Note that in the second embodiment, the beam member 7 is fixed to the sound insulating floor panel 203 via bolts or the like.

(effect)
According to this sound insulating floor structure 200, it has high rigidity, and the sand-like inorganic material 205 moves slightly when vibrations occur due to propagation of floor impact sound, thereby canceling out the vibrations. Therefore, compared to a floor panel made of general ALC, it is possible to improve the performance of blocking heavy floor impact noise.

[Third embodiment]
The sound insulation structure according to the third embodiment of the present invention will be described with a focus on the differences from the first embodiment and the second embodiment.

In the sound insulation floor structure 100 of the first embodiment, a floor material having a deck plate is used as described above, and in the sound insulation floor structure 200 of the second embodiment, a floor material having a sound insulation floor panel 203 is used. Furthermore, in the first and second embodiments, the beam member 7 made of steel is used to support the flooring material 101. On the other hand, the sound insulating floor structure 300 of the third embodiment is different from the first and second embodiments in that a subfloor material 101 as a floor material is supported by a wooden support member.

Further, in the first and second embodiments, the sound insulation structure 1 is suspended via the ceiling support beam 6. On the other hand, the third embodiment differs in that the sound insulation structure 1 is directly suspended from a wooden support member.

Specifically, the floor material of the sound insulating floor structure 300 includes a subfloor material 101 and a support member that supports the subfloor material 101, as shown in FIGS. 12 and 13.

The support members include a plurality of wooden beams 307 that extend in the left-right direction and support the flooring material 101, joists 303 that connect adjacent wooden beams 307 and support the flooring material 101 together with the wooden beams 307, and the wooden beams 307. A hanging member 308 that is fixed to and suspends the sound insulation structure 1 is provided.

The wooden beam 307 is made of, for example, a wooden square, and is formed to have a rectangular cross-section. The wooden beams 307 are arranged spaced apart from each other along the front-rear direction. Receiving members 305 that receive the front and back ends of the joists 303 from below and from the left and right are formed at the upper portions of the opposing sides of the adjacent wooden beams 307, protruding in directions facing each other.

The joist 303 is fixed to a wooden beam 307. Specifically, both ends of the joist 303 in the longitudinal direction (front-back direction) are fitted into each receiving member 305, respectively. The joists 303 support the subfloor material 101 while being in contact with the lower surface of the subfloor material 101.

The hanging member 308 is a rod-shaped member that extends in the vertical direction. The upper end of the hanging member 308 is fixed to the left and right sides of the wooden beam 307 via metal fittings or the like. Furthermore, a sound-insulating field frame receiver 4 is fixed to the lower end of the hanging member 308 via bolts or the like. In this way, the sound insulation structure 1 is suspended from the wooden beam 307 via the hanging member 308.

(effect)
According to the sound insulation floor structure 300 according to the third embodiment, even in a wooden house, it is possible to improve the insulation performance of heavy floor impact sound while ensuring the wooden feel.

(Modified example)
The above embodiments are merely illustrative of preferred specific examples of the present invention, and the scope to which the present invention is applied is not limited to the above embodiments.

For example, the sound insulation structure 1 according to the above embodiment is provided in the sound insulation floor structure of each room in order to absorb vibrations between vertically adjacent rooms in a building, but the sound insulation structure 1 is installed in each room. The structure is not limited to a sound insulating floor structure of a room, but may be a wall that separates horizontally adjacent rooms, for example.

In the above embodiment, the second dynamic damper 20 is configured to absorb vibrations in the frequency band T centered around the frequency of 63 Hz in order to reduce heavy floor impact noise, but the second dynamic damper 20 is capable of absorbing vibrations. The frequency band of vibrations is not limited to this, and the structure may be such that vibrations in other frequency bands (for example, light floor impact sound) can be absorbed.

In the above embodiment, the first dynamic damper 30 is fixed to the web 41 of the field support 4A, but the place where the first dynamic damper 30 can be fixed is not limited to the web 41, and may be the flange 40. .

In the above embodiment, the first dynamic damper 30 and the vibration isolating hanger 2 are provided on the separate field edge receivers 4A and 4B, but the first dynamic damper 30 and the vibration isolating hanger 2 are provided on the separate field edge receivers 4. It is not necessary to provide them, and they may be provided in the same field fence 4.

In the above embodiment, four second weights 24 are arranged for one second dynamic damper 20, but the number of second weights 24 that can be arranged for one second dynamic damper 20 is limited to four. It can be set as appropriate.

In the above embodiment, the second dynamic damper 20 is configured to have the second weights 24 on the upper surface of the second elastic member 22, but each second weight 24 is placed on the opposite side of the second elastic member 22. A lid member may be further provided to cover the inside. Thereby, interference between each second weight 24 and the support mechanism 3 can be suppressed.

In the second embodiment, the second dynamic damper 20 is suspended via the ceiling support beam 6 as in the first embodiment, but the method for suspending the second dynamic damper 20 is not limited to this. For example, as in the third embodiment, the second dynamic damper 20 may be directly suspended from the beam member 7 using the hanging member 308 without providing the ceiling support beam 6. In this case, the upper end of the hanging member 308 can be fixed to the lower flange 7a of the beam member 7 in a vertically penetrating state.

It goes without saying that various other design changes are possible within the scope of the claims of the present invention.

1 Sound insulation structure 3 Support mechanism 4 Field edge support 5 Field edge 8 Ceiling board (surface material)
20 Second dynamic damper 22 Second elastic member 24 Second weight 30 First dynamic damper 32 First elastic member 34 First weight

Claims (4)

A sound insulation structure for absorbing vibrations within a building,
Surface material and
a support mechanism that supports the surface material;
a first dynamic damper that is attached to the support mechanism and absorbs vibrations of the support mechanism;
a second dynamic damper that is attached to the face material and absorbs vibrations of the face material,
The first dynamic damper includes a first elastic member containing rubber and disposed in contact with the support mechanism, and a first weight fixed to the first elastic member,
The second dynamic damper includes a second elastic member that includes at least one of glass wool and rock wool and is disposed on the surface of the face material in contact with the second elastic member, and a second elastic member that is fixed to the second elastic member. a weight, and has a natural frequency tuned to absorb vibrations within a predetermined frequency band,
The first dynamic damper is configured to reduce the floor impact sound level of vibrations absorbed by the second dynamic damper within a predetermined frequency band that exceeds a predetermined floor impact sound level within the predetermined frequency band. A sound-insulating structure with a natural frequency tuned to absorb vibrations. The sound insulation structure according to claim 1,
The sound insulation structure has a natural frequency of the first dynamic damper that is lower than a center frequency of the predetermined frequency band. The sound insulation structure according to claim 1 or 2,
The surface material constitutes a ceiling in the building,
The support mechanism includes a plurality of fields fixed to the top surface of the panel material, extending along a first direction and spaced apart from each other along a second direction orthogonal to the first direction. a field edge, and a field edge support disposed above the field edge and supporting the field edge,
The second dynamic damper is arranged between the adjacent field edges on the upper surface of the panel material,
The first dynamic damper has a sound insulation structure attached to the field edge receiver. The sound insulation structure according to claim 3, wherein the second dynamic damper is provided at an intersection of the field edge and the field edge.

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