JP2022107368A - Muffler - Google Patents

Abstract

To improve sound reducing effects.SOLUTION: A muffler includes a casing 10, a first muffling unit 11 having a plurality of pairs of plate materials provided in spaced side by side relation to each other in the casing to form hollow and approximately rectangular parallelepiped muffling parts, and having a sound absorbing material provided on at least each one of faces of the pair of plate materials opposed to each other, and a second muffling unit 12 having a plurality of pairs of plate materials provided in spaced side by side relation to each other in the casing to form hollow and approximately rectangular parallelepiped muffling parts, and having a sound absorbing material provided on at least each one of the faces of the pair of plate materials opposed to each other, the first muffling unit and the second muffling unit being arranged in spaced relation to each other in a long axis direction of the casing. The long axis of each muffling part included in the first muffling unit is shifted from the axis of each muffling part included in the second muffling unit in a direction perpendicular to the long axis in a cross section including the long axis.SELECTED DRAWING: Figure 2

Description

The present invention relates to a silencer.

In large-scale ventilation equipment such as road tunnels, a large number of ventilation silencers may be used by stacking them in parallel on the cross section of the air passage (see, for example, Patent Document 1). Further, when a large sound reduction performance is required, two or more rows of silencers may be installed in the air flow direction to ensure the sound reduction performance (see, for example, Patent Document 2).

Japanese Unexamined Patent Publication No. 6-146845 Japanese Unexamined Patent Publication No. 2001-164922

When two or more rows of silencers are installed in the air flow direction, it is desired to improve the sound reduction effect.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a silencer capable of improving the sound reduction effect.

In the silencer according to the first aspect of the present invention, a casing and a plurality of pairs of plate members provided at intervals in the casing so as to form a hollow and substantially square-shaped silencer are arranged side by side. A first sound deadening unit in which a sound absorbing material is provided on at least one of the surfaces of the pair of plate materials facing each other is provided at intervals in the casing so as to form a hollow and substantially rectangular sound deadening portion. A second muffling unit in which a plurality of the pair of plate members are arranged side by side and a sound absorbing material is provided on at least one of the surfaces of the pair of plate members facing each other is provided with the first muffling unit. The second muffling unit is arranged at intervals in the long axis direction of the casing, and the long axis of each of the muffling portions included in the first muffling unit is the first in a cross section including the long axis. The long axis of any of the muffling portions included in the muffling unit 2 is deviated in the direction perpendicular to the long axis, and the cross section along the longitudinal direction of the casing is said to be perpendicular to the longitudinal direction. Each of the ranges of the internal space of the muffling unit included in the first muffling unit does not fall within the range of the internal space of any of the muffling units included in the second muffling unit.

According to this configuration, since the airflow inlet cannot be seen straight from the airflow outlet of the casing, the sound is refracted and the sound wave is attenuated between the first muffling unit and the second muffling unit. As a result, the sound reduction effect can be improved, and in particular, the sound reduction effect at a high frequency having a short wavelength can be improved.

The muffler according to the second aspect of the present invention is a muffler according to the first aspect, and is provided between the first muffling unit and the second muffling unit and induces an air flow. Further provided with a partition member.

According to this configuration, the air flow can be guided by the plurality of partition members, and the pressure loss can be suppressed.

The silencer according to the third aspect of the present invention is the silencer according to the second aspect, and the partition member has air permeability.

According to this configuration, the sound is diffused through the plurality of partition members, so that the sound reduction performance can be improved.

The silencer according to the fourth aspect of the present invention is the silencer according to the third aspect, and the partition member is a perforated plate or a plate formed of a porous material.

According to this configuration, the sound is diffused through the holes of the partition members, so that the sound reduction performance can be improved.

The silencer according to the fifth aspect of the present invention is the silencer according to the second aspect, and the partition member is not breathable.

According to this configuration, since the airflow does not pass through the partition member, it is possible to suppress the airflow noise when the airflow passes.

The silencer according to the sixth aspect of the present invention is the silencer according to the fifth aspect, and the partition member is made of a non-breathable but acoustically permeable material.

According to this configuration, since the low frequency band is transmitted, the sound is diffused between the first sound deadening unit and the second sound deadening unit, and the sound reduction effect can be improved.

The silencer according to the seventh aspect of the present invention is the silencer according to the sixth aspect, and the acoustically permeable material on which the partition member is formed transmits sound waves in a frequency band of 250 Hz or less. It is a material to be used.

According to this configuration, in the frequency band of 250 Hz or less, the sound is diffused between the first muffling unit and the second muffling unit, and the muffling effect can be improved.

The muffler according to the eighth aspect of the present invention is the muffler according to any one of the second to seventh aspects, and the partition member is the first muffling unit from the outlet of the muffling unit. It is provided so as to extend in the longitudinal direction of the casing toward the sound deadening unit of 2.

According to this configuration, by providing the partition member, the airflow is separated at the outlet of the first muffling unit and guided to the separate muffling portions of the second muffling unit.

The muffler according to the ninth aspect of the present invention is the muffler according to any one of the second to seventh aspects, and the partition member is the second one from the plate material of the first muffling unit. It is provided so as to extend in the longitudinal direction of the casing toward the sound deadening unit.

According to this configuration, the airflow discharged from the target muffling unit of the first muffling unit can be suppressed from interfering with the airflow discharged from the adjacent muffling unit by the partition member, and the pressure loss can be suppressed.

The muffler according to the tenth aspect of the present invention is the muffler according to any one of the second to seventh aspects, and the partition member uses the plate material of the first muffling unit to muffle the second. It is provided so as to extend towards one of the plate members of the unit.

According to this configuration, the airflow is guided to the second muffling unit by the partition member, so that the pressure loss can be reduced.

The muffler according to the eleventh aspect of the present invention is the muffler according to any one of the first to tenth aspects, and the first muffling unit is the plate material and the casing of the first muffling unit. In between, there is a shielding material that shields the inflow of air from the side opposite to the second muffling unit.

According to this configuration, the volume reduction can be made uniform.

The silencer according to the twelfth aspect of the present invention is the silencer according to the eleventh aspect, and the shielding material has an opening toward the second sound deadening unit so as to reduce or absorb sound.

According to this configuration, it is possible to reduce the sound while suppressing the influence of the air flow and reducing the pressure loss.

The muffler according to the thirteenth aspect of the present invention is the muffler according to any one of the first to twelve aspects, and the second muffling unit is the plate material and the casing of the second muffling unit. In between, there is a shielding material that shields the inflow of air from the side of the first sound deadening unit.

According to this configuration, it is possible to make the volume reduction uniform while suppressing the influence of the air flow and reducing the pressure loss.

The silencer according to the fourteenth aspect of the present invention is the silencer according to any one of the first to ninth aspects, and the shielding material is directed toward the first sound deadening unit so as to reduce or absorb sound. Or has an opening on the airflow outlet side of the second muffling unit.

According to this configuration, it is possible to reduce the sound while suppressing the influence of the air flow.

The silencer according to the fifteenth aspect of the present invention is the silencer according to the tenth aspect, and the partition member at the end of the plurality of partition members is the plate material at the end of the first silencer unit. , The partition member is provided so as to extend toward the plate material at the end of the second sound deadening unit, and the partition member has an opening.

According to this configuration, the sound reduction performance can be improved.

The muffler according to the sixteenth aspect of the present invention is the muffler according to any one of the second to seventh aspects, and the partition member is the first muffling unit from the outlet of the muffling unit. It is provided toward the entrance of the muffling unit of the muffling unit of 2.

According to this configuration, the airflow is guided to the partition plate at the airflow outlet of the primary silencer, the airflow is shunted, and is guided to the separate muffling portions of the second muffling unit.

The muffler according to the seventeenth aspect of the present invention is the muffler according to any one of the second to seventh aspects, and the partition member starts from the outlet of the muffling unit of the first muffling unit. The closer to the second muffling unit from the first muffling unit, the farther away from each other.

According to this configuration, the airflow is guided to the partition member and the airflow is separated. Further, it is possible to prevent the generation of vortices at the entrance of the secondary silencer and suppress the pressure loss.

The silencer according to the eighteenth aspect of the present invention is the silencer according to any one of the first to ninth aspects, and the distance between the first silencer unit and the second silencer unit is 0. .5 to 2 m.

According to this configuration, the volume reduction of the ventilation silencer can be supplemented in the band of 63, 125 Hz (about 45 to 180 Hz in the frequency range) in the octave band center frequency.

The silencer according to the nineteenth aspect of the present invention is the silencer according to any one of the first to eighteenth aspects, and the long axis of the silencer is perpendicular to the internal space of the silencer in the longitudinal direction. It is the intersection of the diagonal lines of the rectangle when cut with a simple cross section.

The muffler according to the twentieth aspect of the present invention is the muffler according to any one of the first to nineteenth aspects, in a cross section parallel to the long axis of the muffling unit, in a direction perpendicular to the long axis. The width of the internal space of the muffling unit of the first muffling unit in the direction perpendicular to the long axis is abbreviated as the width of the internal space of the muffling unit of the second muffling unit in the direction perpendicular to the long axis. It is the same.

According to one aspect of the present invention, since the airflow inlet of the casing cannot be seen straight from the airflow outlet, the sound is refracted and the sound wave is attenuated between the first muffling unit and the second muffling unit. As a result, the sound reduction effect can be improved, and in particular, the sound reduction effect at a high frequency having a short wavelength can be improved.

It is the schematic perspective view of the silencer which concerns on 1st Embodiment. FIG. 2 is a cross-sectional view taken along the line AA of FIG. It is sectional drawing of the BB cross section of FIG. It is sectional drawing of the CC cross section of FIG. It is a vertical cross-sectional view of the 1st muffling unit which concerns on the modification of 1st Embodiment. It is a vertical sectional view of the 2nd muffling unit which concerns on the modification of 1st Embodiment. It is a horizontal sectional view of the silencer which concerns on 2nd Embodiment. It is sectional drawing of the DD cross section of FIG. 7A. It is a horizontal sectional view of the silencer which concerns on 3rd Embodiment. It is a horizontal sectional view of the silencer which concerns on 4th Embodiment. It is a horizontal sectional view of the silencer which concerns on 5th Embodiment. It is a horizontal sectional view of the silencer which concerns on 6th Embodiment. It is a horizontal sectional view of the silencer which concerns on 7th Embodiment. It is a horizontal cross-sectional view of the shielding material of the 1st modification. It is a horizontal cross-sectional view of the shielding material of the 2nd modification. It is a horizontal cross-sectional view of the shielding material of the 3rd modification. It is a horizontal sectional view of the silencer which concerns on 8th Embodiment. It is a horizontal sectional view of the silencer which concerns on 9th Embodiment. It is a horizontal sectional view of the silencer which concerns on tenth embodiment. It is a horizontal sectional view of the silencer which concerns on eleventh embodiment. It is a horizontal sectional view of the silencer which concerns on 12th Embodiment. It is a horizontal sectional view of the silencer which concerns on 13th Embodiment.

Hereinafter, each embodiment will be described with reference to the drawings. However, more detailed explanation than necessary may be omitted. For example, detailed explanations of already well-known matters and duplicate explanations for substantially the same configuration may be omitted. This is to avoid unnecessary redundancy of the following description and to facilitate the understanding of those skilled in the art.

<First Embodiment>
First, the first embodiment will be described. FIG. 1 is a schematic perspective view of the silencer according to the first embodiment. 2 is a cross-sectional view taken along the line AA of FIG. 1. FIG. FIG. 3 is a cross-sectional view of the BB cross section of FIG. FIG. 4 is a cross-sectional view taken along the line CC of FIG. As shown in FIG. 1, the silencer 1 according to the first embodiment is provided in a hollow rectangular cuboid casing 10, a first silencer unit 11 provided in the casing 10, and inside the casing 10. The second muffling unit 12 is provided.

In each embodiment, as shown in FIG. 2, the airflow is assumed to flow in from the first muffling unit 11 side, the first muffling unit 11 is a primary silencer group on the upstream side of the airflow, and the second muffling is performed. The unit 12 will be described as a group of secondary silencers on the downstream side of the air flow. Further, in each embodiment, the airflow will be described as passing through the inlet of the primary silencer group, the outlet of the primary silencer group, the inlet of the secondary silencer group, and the outlet of the secondary silencer group in this order.

As shown in FIGS. 1 and 2, the first muffling unit 11 and the second muffling unit 12 are arranged at intervals in the long axis direction of the casing 10. As a result, the sound is widely diffused at the airflow outlet of the first muffling unit 11 as compared with the case where there is no space between the first muffling unit 11 and the second muffling unit 12, so that the muffling effect is improved. be able to.

As shown in FIGS. 2 and 3, the first muffling unit 11 includes muffling portions SL1 to SL4 provided in the casing 10. The sound deadening portion SL1 has a top plate U1 and a bottom plate B1, and has a pair of plate materials P1a and P1b having one end connected to the top plate U1 and the other end connected to the bottom plate B1. Similarly, the sound deadening portion SL2 has a top plate U2 and a bottom plate B2, and has a pair of plate materials P2a and P2b having one end connected to the top plate U2 and the other end connected to the bottom plate B2. Similarly, the sound deadening portion SL3 has a top plate U3 and a bottom plate B3, and has a pair of plate materials P3a and P3b whose one end is connected to the top plate U3 and the other end is connected to the bottom plate B3. Similarly, the sound deadening portion SL4 has a top plate U4 and a bottom plate B4, and has a plate material P4 having one end connected to the top plate U4 and the other end connected to the bottom plate B4. As an example, the muffling unit SL4 has a structure in which any one of the muffling units SL1 to SL3 is substantially vertically divided in half.

As described above, a pair of plate members P1a and P1b, P2a and P2b, P3a and P3b provided at intervals in the casing 10 so as to form a hollow and substantially rectangular cuboid-shaped sound deadening portion are arranged. As an example, as shown in FIG. 3, a pair of plate members P1a, P1b, P2a, P2b, P3a, and P3b are provided substantially parallel to each other. Further, the plate material P4 is provided next to the plate material P1a at no interval as an example.

Further, sound absorbing materials S1a and S1b are provided on at least one of the surfaces of the pair of plate materials P1a and P1b facing each other. Similarly, sound absorbing materials of the pair of plate materials P2a and P2b are provided on at least one of the surfaces facing each other. S2a and S2b are provided. Further, similarly, sound absorbing materials S3a and S3b are provided on at least one of the surfaces of the pair of plate materials P3a and P3b facing each other. Further, the sound absorbing material S4 is provided on the surface of the plate material P4 corresponding to the inner surface of the casing 10.

Further, as shown in FIGS. 2 and 4, the second muffling unit 12 includes muffling portions SL5 to SL8 provided in the casing 10. The sound deadening portion SL5 has a top plate U5 and a bottom plate B5, and has a pair of plate materials P1a and P1b having one end connected to the top plate U5 and the other end connected to the bottom plate B5. Similarly, the sound deadening portion SL6 has a top plate U6 and a bottom plate B6, and has a pair of plate materials P6a and P6b having one end connected to the top plate U6 and the other end connected to the bottom plate B6. Similarly, the sound deadening portion SL3 has a top plate U7 and a bottom plate B7, and has a pair of plate materials P7a and P7b having one end connected to the top plate U7 and the other end connected to the bottom plate B7. Similarly, the sound deadening portion SL8 has a top plate U8 and a bottom plate B8, and has a plate material P8 having one end connected to the top plate U8 and the other end connected to the bottom plate B8. As an example, the sound deadening unit SL8 has a structure in which any one of the sound deadening units SL5 to SL7 is substantially vertically divided in half.

As described above, in the second sound deadening unit 12, a pair of plate members P5a and P5b, P6a and P6b, P7a and which are provided at intervals in the casing 10 so that hollow and substantially rectangular cuboid-shaped sound deadening portions are lined up. P7b are lined up. As an example, as shown in FIG. 4, a pair of plate members P5a, P5b, P6a, P6b, P7a, and P7b are provided substantially parallel to each other. Further, the plate material P8 is provided next to the plate material P7b at no interval as an example.

Further, sound absorbing materials S5a and S5b are provided on at least one of the surfaces of the pair of plate materials P5a and P5b facing each other. Similarly, sound absorbing materials of the pair of plate materials P6a and P6b are provided on at least one of the surfaces facing each other. S6a and S6b are provided. Further, similarly, sound absorbing materials S7a and S7b are provided on at least one of the surfaces of the pair of plate materials P7a and P7b facing each other. Further, the sound absorbing material S8 is provided on the surface of the plate material P8 opposite to the plate material P7b.

FIG. 2 shows the major axes AX1, AX2, and AX3 of the muffling units included in the first muffling unit 11. Further, the major axes AX4, AX5, and AX6 of the muffling units included in the second muffling unit 12 are shown. Here, the long axis of the muffling portion (also referred to as the axis of the ventilation path) is the intersection of the diagonal lines of a rectangle when the internal space of the muffling portion is cut by a cross section perpendicular to the longitudinal direction. As shown in FIG. 2, in the horizontal cross section parallel to the longitudinal direction of the casing, in the direction perpendicular to the longitudinal direction (direction parallel to the x-axis of FIG. 2), each of the muffling portions included in the first muffling unit 11 The major axes AX1, AX2, and AX3 are deviated from the major axes AX4, AX5, and AX6 of any of the muffling units included in the second muffling unit 12.

Further, as shown in FIG. 2, in the cross section along the longitudinal direction of the casing (here, as an example, the horizontal cross section), in the direction perpendicular to the longitudinal direction (direction parallel to the x-axis of FIG. 2), the first muffling unit Each of the ranges (x1a to x1b, x2a to x2b, x3a to x3b, x4a to x4b) of the internal space of the muffling unit included in 11 is the range of the internal space of any muffling unit included in the second muffling unit 12 (x1a to x1b, x2a to x2b, x3a to x3b, x4a to x4b). It does not fit in x5a to x5b, x6a to x6b, x7a to x7b, x8a to x8b).

Due to this configuration, the airflow inlet cannot be seen straight from the airflow outlet of the casing 10, so that the sound is refracted between the first muffling unit 11 and the second muffling unit 12 as shown by arrows A3 to A9 in FIG. Then the sound wave is attenuated. As a result, the sound reduction effect can be improved, and in particular, the sound reduction effect at a high frequency having a short wavelength can be improved.

That is, from the open surface side of the casing 10 on the muffling portion side of the second muffling unit 12 (that is, the outlet side of the air passage), along the major axes AX4, AX5, and AX6 of the muffling portion of the second muffling unit 12. When looking at the internal space of the muffling unit (when looking along the direction of arrow A1 in FIG. 2), the muffling unit of the first muffling unit 11 can be seen from any of the muffling units of the second muffling unit 12. You cannot see the entire internal space. As a result, between the first muffling unit 11 and the second muffling unit 12, the sound is refracted and the sound wave is attenuated as shown by arrows A3 to A9 in FIG. As a result, the sound reduction effect can be improved, and in particular, the sound reduction effect at a high frequency having a short wavelength can be improved.

In each embodiment, the width of the air passage of the muffling portion of the first muffling unit 11 and the width of the air passage of the muffling portion of the second muffling unit 12 are substantially the same. That is, in a cross section parallel to the long axis of the muffling unit (here, as an example, a horizontal cross section), on the long axis of the internal space of the muffling unit of the first muffling unit 11 in the direction perpendicular to the long axis of the muffling unit. The width in the vertical direction is substantially the same as the width in the direction perpendicular to the long axis of the internal space of the muffling portion of the second muffling unit 12.

<Distance between the first muffling unit 11 and the second muffling unit 12>
Assuming that the expansion chamber of the flow path between the first muffling unit 11 and the second muffling unit 12 (that is, between the silencers) is regarded as the expansion chamber of the inflatable muffler, the length of this section is the wavelength of the sound for which the sound is desired to be reduced. The sound reduction effect is maximized when it is set to 1/4 of λ. Aiming at this effect, as an incidental effect, the distance L between the first muffling unit 11 and the second muffling unit 12 is set to about 1/4 of the wavelength λ when the sound to be reduced is limited. Is desirable. For example, the predominant frequency component of the blower is often in the band around 125 Hz, but the volume reduction of the sound absorbing type ventilation silencer is not so large. Therefore, if you want to reduce the speed of sound v = 340 m / s and f = 125 Hz at a temperature of 15 ° C, aiming at this band, set λ / 4 = (v / f) / 4 = 340/125/4 = 0.68 m. Can be considered. From this, in order to supplement the volume reduction of the ventilation silencer in the band of 63, 125 Hz (about 45 to 180 Hz in the frequency range) in the octave band center frequency, the first muffling unit 11 and the first muffling unit 11 and the first muffling unit are calculated as described above. It is desirable that the distance L between the two muffling units 12 and the muffling unit 12 is about 0.5 to 2 m. In each of the following embodiments, the distance L between the first muffling unit 11 and the second muffling unit 12 may be about 0.5 to 2 m.

As described above, in the silencer 1 according to the first embodiment, a plurality of pairs of plate members provided at intervals in the casing so as to form a hollow and substantially rectangular sound deadening portion are arranged side by side. A space is provided in the casing so that the first sound deadening unit in which the sound absorbing material is provided on at least one of the surfaces of the pair of partition plates facing each other and the hollow and substantially rectangular sound deadening portion are lined up. A second sound deadening unit is provided in which a plurality of a pair of plate materials provided are arranged side by side, and a sound absorbing material is provided on at least one of the surfaces of the pair of plate materials facing each other, and the first sound deadening unit is provided. The unit and the second muffling unit are arranged at intervals in the long axis direction of the casing, and the long axes of the muffling portions included in the first muffling unit have a horizontal cross section including the long axis. In the direction perpendicular to the long axis, it is deviated from the long axis of any of the muffling portions included in the second muffling unit, and is perpendicular to the longitudinal direction in the horizontal cross section parallel to the longitudinal direction of the casing. In any direction, the range of the internal space of the muffling unit included in the first muffling unit does not fall within the range of the internal space of any muffling unit included in the second muffling unit.

According to this configuration, since the airflow inlet cannot be seen straight from the airflow outlet of the casing 10, sound is generated between the first muffling unit 11 and the second muffling unit 12 as shown by arrows A3 to A9 in FIG. Refracts and the sound wave is attenuated. As a result, the sound reduction effect can be improved, and in particular, the sound reduction effect at a high frequency having a short wavelength can be improved.

<Modified example of the first embodiment>
Subsequently, a modified example of the first embodiment will be described. The silencer 1a according to the modified example of the first embodiment corresponds to a stack of three silencers 1 according to the first embodiment in the vertical direction. FIG. 5 is a vertical cross-sectional view of the first muffling unit according to a modified example of the first embodiment. FIG. 6 is a vertical cross-sectional view of the second muffling unit according to the modified example of the first embodiment. As shown in FIG. 5, the silencer 1a according to the modified example of the first embodiment includes a casing 10b and a first silencer unit 11a provided in the casing 10b.

As shown in FIG. 5, in the first muffling unit 11a according to the modified example of the first embodiment, four horizontally arranged muffling portions are vertically stacked in three stages in the casing 10b. Each of the sound deadening portions includes one bottom plate B11 to B34, one plate material P14, P24, P34 or a pair of plate materials P11a to P33b provided substantially vertically on the bottom plates B11 to B34, and the plate materials P11a to P34. It has one top plate U11 to U34 provided on the top. Sound absorbing materials S11a to S33b are provided on the surfaces of the pair of plate materials P11a to P33b facing each other, and the sound absorbing materials S14 and S24 are provided on the surfaces of one plate material P14, P24 and P34 facing the inner surface of the casing 10b. , S34 is provided.

As shown in FIG. 6, the silencer 1a according to the modified example of the first embodiment further includes a second silencer unit 12a provided in the casing 10b.

As shown in FIG. 6, four horizontally arranged sound deadening portions are vertically stacked in three stages in the casing 10b. Each of the sound deadening portions includes one bottom plate B15 to B38, one plate material P18, P28, P38 or a pair of plate materials P15a to P37b provided substantially vertically on the bottom plates B15 to B38, and the plate materials P15a to P38. It has one top plate U15 to U38 provided on the top. Sound absorbing materials S15a to S37b are provided on the surfaces of the pair of plate materials P15a to P37b facing each other, and the sound absorbing materials S18 and S28 are provided on the surfaces of one plate material P18, P28 and P38 facing the inner surface of the casing 10b. , S38 are provided.

In this way, the sound deadening portions may be stacked in a plurality of stages in the vertical direction.

<Second embodiment>
Subsequently, the second embodiment will be described. FIG. 7A is a horizontal sectional view of the silencer according to the second embodiment. FIG. 7B is a cross-sectional view of the DD cross section of FIG. 7A. As shown in FIGS. 7A and 7B, the silencer 1b according to the second embodiment has a first silencer unit 11 and a second silencer as compared with the silencer 1 according to the first embodiment of FIG. A plurality of partition members D1, D2, and D3 provided between the units 12 and inducing an air flow are further provided. The partition members D1, D2, and D3 according to the present embodiment have air permeability, and are perforated plates as an example.

The partition members D1, D2, and D3 are provided so as to extend from the outlet of the muffling portion of the first muffling unit 11 toward the second muffling unit 12 in the longitudinal direction of the casing 10. In the present embodiment, as an example thereof, the partition member D1 is connected to the plate material P5b and / or the plate material P6a, the partition member D2 is connected to the plate material P6b and / or the plate material P7a, and the partition member D3 is connected to the plate material P7b and / or. It is connected to the plate material P8. That is, the partition members D1, D2, and D3 are provided, for example, so as to extend the plate members P5b to P8 of the muffling portion of the second muffling unit 12 in the longitudinal direction of the casing 10 toward the first muffling unit 11. There is.

By providing the partition member D1 in this way, the airflow is divided (here, equally divided as an example) at the outlet R1 of the muffling portion of the first muffling unit 11 as shown by arrows A12 and A13, and the second It is guided to the separate muffling parts of the muffling unit. Similarly, by providing the partition members D2 and D3, the airflow is separated at the outlet of the muffling portion of the first muffling unit 11 as shown by arrows A14 and A15 and arrows A16 and A17 (here, as an example, etc.). (Divided) and guided to separate muffling units of the second muffling unit.

On the other hand, as shown by the arrow A18, the sound is widely diffused through the plurality of holes of the partition member D1, so that the sound reduction effect can be improved. Similarly, as shown by arrows A19 and A20, the sound is widely diffused through the plurality of holes of the partition members D2 and D3, so that the sound reduction effect can be improved.

The partition member is not limited to the perforated plate, and may be a plate formed of a porous material such as a metal fiber plate, or may be formed of a material that transmits sound waves.

<Third embodiment>
Subsequently, the third embodiment will be described. In the first and second embodiments, it is an object to improve the sound reduction performance of high frequency, but in the third embodiment, in addition to that, it is an object to suppress an increase in pressure loss. FIG. 8 is a horizontal sectional view of the silencer according to the third embodiment. As shown in FIG. 8, in the silencer 1c according to the third embodiment, the positions of the partition members D4, D5, and D6 are changed as compared with the silencer 1b according to the second embodiment of FIG. 7A. It has become. Specifically, for example, the partition member D4 is connected to the plate material P4 and / or the plate material P1a, the partition member D5 is connected to the plate material P1b and / or the plate material P2a, and the partition member D6 is connected to the plate material P2b and / or the plate material P3a. It is connected to the. As described above, the partition members D4, D5, and D6 are provided so as to extend from the plate material of the first sound deadening unit toward the second sound deadening unit 12 in the longitudinal direction of the casing 10.

As a result, as shown in the region R2, the partition member D4 prevents the airflow discharged from the target muffling unit of the first muffling unit (primary silencer group) 11 from interfering with the airflow discharged from the adjacent muffling unit. It can be suppressed by, and the pressure loss is suppressed. Further, since the partition members D4, D5, and D6 have holes, the sound emitted from the outlet of the first muffling unit (primary silencer group) 11 is widely diffused through the holes of the partition members D4, D5, and D6. The sound reduction effect can be improved.

In FIG. 8, the flow of airflow is indicated by arrows A21 to A27. As shown by arrows A22 and A23 in FIG. 8, the airflow discharged from the target muffling unit of the first muffling unit (primary silencer group) 11 is diffused, and the second muffling unit (secondary silencer group) It flows into a plurality of muffling units of twelve.

<Fourth Embodiment>
Subsequently, the fourth embodiment will be described. In the second embodiment, the partition member has breathability, but in the fourth embodiment, the partition member does not have breathability. FIG. 9 is a horizontal sectional view of the silencer according to the fourth embodiment. As shown in FIG. 9, the partition members D11, D12, and D13 in the silencer 1d according to the fourth embodiment are not breathable. As a result, the partition members D11, D12, and D13 have an advantage that airflow noise is not generated unlike the perforated plate. For example, the partition members D11, D12, and D13 are, for example, non-breathable plates (metal plates), and if they are metal plates, they have the advantages of high rigidity and easy installation.

As shown by arrows A31 and A32 in FIG. 9, the partition members D11, D12, and D13 divide the wind at the outlet of the first muffling unit (primary silencer group) 11 (for example, evenly divided).

<Fifth Embodiment>
Subsequently, the fifth embodiment will be described. In the third embodiment, the partition member has breathability, but in the fifth embodiment, the partition member does not have breathability. FIG. 10 is a horizontal sectional view of the silencer according to the fifth embodiment. As shown in FIG. 10, D21, D22, and D23 in the silencer 1e according to the fifth embodiment are not breathable. As a result, the partition members D21, D22, and D23 have an advantage that airflow noise is not generated unlike the perforated plate. For example, the partition members D21, D22, and D23 are, for example, non-breathable plates (metal plates), and if they are metal plates, they have the advantages of high rigidity and easy installation.

As shown by arrows A33 and A34 in FIG. 10, the airflow discharged from the target muffling unit of the first muffling unit (primary silencer group) 11 is the second muffling unit (secondary silencer group) 12-2. It is divided into two sound deadening parts and flows in.

Similar to the third embodiment, the partition member D21, prevents the airflow discharged from the target muffling unit of the first muffling unit (primary silencer group) 11 from interfering with the airflow discharged from the adjacent muffling unit. It can be suppressed by 22 and 23, and the pressure loss is suppressed.

<Modification example of partition member>
Even if the partition members D11, D12, D13 according to the fourth embodiment and the partition members D21, D22, D23 according to the fifth embodiment are made of a material having no air permeability but having acoustic transparency. It may be, for example, a non-breathable but acoustically permeable membrane. As a result, since the low frequency band is transmitted, the sound is diffused between the primary silencer group and the secondary silencer group as in the case where the perforated plate is installed, and the sound reduction effect can be improved. Here, the material having acoustic transparency is preferably a material that well transmits sound waves in a (relatively low) frequency band of 250 Hz or less. As a result, in the frequency band of 250 Hz or less, the sound is diffused between the primary silencer group and the secondary silencer group, and the sound reduction effect can be improved. Therefore, it is effective to install such a material (for example, a film-like material) depending on the frequency characteristic of the volume reduction required for the silencer group.

<Sixth Embodiment>
Subsequently, the sixth embodiment will be described. In the third embodiment of FIG. 8, the partition member is provided substantially parallel to the long axis of the silencer, but in the sixth embodiment, the silencer of the first silencer unit (primary silencer group) 11 The difference is that the partition member is provided diagonally with respect to the long axis of the silencer so as to connect the plate material and the plate material of the silencer of the second silencer unit (secondary silencer group) 12. As a result, the airflow discharged from the muffler of the first muffling unit can be guided only to the muffler of the second muffling unit associated with one-to-one.

FIG. 11 is a horizontal sectional view of the silencer according to the sixth embodiment. As shown in FIG. 11, the silencer 1f according to the sixth embodiment includes partition members D31, D32, D33, and D34. A partition member D31 is provided obliquely with respect to the long axis of the silencer so as to connect the plate material P1a of the silencer of the first silencer unit 11 and the plate material P5a of the silencer of the second silencer unit 12. Similarly, the partition member D32 is provided obliquely with respect to the long axis of the silencer so as to connect the plate material P1b of the silencer of the first silencer unit 11 and the plate material P5b of the silencer of the second silencer unit 12. There is. Similarly, a partition member D33 is provided obliquely with respect to the long axis of the silencer so as to connect the plate material P2b of the silencer of the first silencer unit 11 and the plate material P6b of the silencer of the second silencer unit 12. There is. Similarly, a partition member D34 is provided obliquely with respect to the long axis of the silencer so as to connect the plate material P3b of the silencer of the first silencer unit 11 and the plate material P7b of the silencer of the second silencer unit 12. There is. As described above, the partition members D31 to D34 are provided so as to extend the plate material of the first sound deadening unit 11 toward one of the plate materials of the second sound deadening unit 12. As a result, the airflow is guided to the second muffling unit 12 by the partition members D31 to D34, so that the pressure loss can be reduced.

The first muffling unit 11 of the muffling device 1f according to the sixth embodiment is provided with a shielding material H1 whose inside is filled so that airflow does not flow into the shielding material H1. As described above, the first muffling unit 11 shields the inflow of air from the side opposite to the second muffling unit 12 between the plate material P1a at the end of the first muffling unit 11 and the casing 10. It has material H1.

Similarly, the second muffling unit 12 of the muffler 1f according to the sixth embodiment is provided with a shielding material H2 whose inside is filled so that airflow does not flow into the shielding material H2. There is. In this way, the second muffling unit 12 has a shielding material H2 that shields the inflow of air from the side of the first muffling unit 11 between the plate material P7b at the end of the second muffling unit 12 and the casing 10. Has. Since there is no mixture of silencers SL4 and SL8 (also referred to as half-split silencers) having a size half that of the others in the third embodiment, the volume reduction can be made uniform.

However, when the separation distance L of the silencer group is small and the wind speed at the outlet of the primary silencer group is high, the airflow interferes with the partition members D32, D33, and D34 provided between the silencer groups in the region R3, and the airflow Generated sound may occur.

<7th Embodiment>
Subsequently, the seventh embodiment will be described. In the sixth embodiment, when the separation distance L of the silencer group is small and the wind speed at the outlet of the primary silencer group is high, the airflow interferes with the partition members D32, D33, and D34 provided between the silencer groups. Airflow generation noise may occur. On the other hand, in the seventh embodiment, the separation distance L of the silencer group is made longer than a predetermined reference distance so that the silencer group is provided between the silencer groups with respect to the long axis of the silencer of the first silencer unit. Reduce the angle of the partition member. As a result, the angle of entry of the airflow into the partition member is reduced, and interference with the partition member is reduced.

FIG. 12 is a horizontal sectional view of the silencer according to the seventh embodiment. As shown in FIG. 12, in the silencer 1g according to the seventh embodiment, partition members D35, D36, D37, and D38 are provided between the silencer groups. The partition members D35, D36, D37, and D38 are perforated plates as an example. As shown in FIG. 12, as represented by the region R4, the approach angle of the airflow to the partition members D36, D37, and D38 becomes small, and the generation of airflow noise due to interference with the partition member is suppressed. Further, since the amount of airflow leaking through the partition members D35, D36, D37, and D38 is reduced, the diffusion of the airflow is suppressed, and the interference with the airflow (also referred to as silencer airflow) flowing out from the adjacent silencer is suppressed. be able to. Similar to the sixth embodiment, the silencer 1g according to the seventh embodiment is provided with the shielding materials H1 and H2 filled in the inside so that the airflow does not flow into the shielding materials H1 and H2. It has become. As a result, since there is no mixture of silencers (also referred to as half-split silencers) having a size half that of the first to fifth embodiments, the volume reduction can be made uniform.

<About the deformation example of the shielding material>
Next, a modified example of the shielding material will be described. FIG. 13A is a horizontal cross-sectional view of the shielding material of the first modification. The shielding material H1a of the first modification may be provided in place of the shielding material H1 of FIG. 11 or FIG. As shown in FIG. 13A, the shielding material H1a of the first modification is a side branch provided with an opening facing in the direction between the silencer groups, and can enhance the sound reduction performance of a specific frequency component. The side branch is an example of an auxiliary silencer.

FIG. 13B is a horizontal cross-sectional view of the shielding material of the second modified example. The shielding material H1b of the second modification may be provided in place of the shielding material H1 of FIG. 11 or FIG. As shown in FIG. 13B, the shielding material H1b of the second modification is a resonator provided with an opening facing in the direction between the silencer groups, and can enhance the sound reduction performance of a specific frequency component. The resonator is an example of an auxiliary silencer.

FIG. 13C is a horizontal cross-sectional view of the shielding material of the third modified example. The shielding material H1c of the third modification may be provided in place of the shielding material H1 of FIG. 11 or FIG. As shown in FIG. 13C, the shielding material H1 of the third modification has an opening in the direction between the silencer groups, and the shielding material H1c of the third modification is filled with the sound absorbing material S41. As a result, the sound absorption performance is improved.
Further, instead of the sound insulating material H2, the sound insulating materials H1a to H1c of the first to third modified examples may be provided.

The openings of the shielding materials H1a to H1c and H2 (that is, the inlet of the sound wave) are installed on either the inlet side of the primary silencer group, between the primary silencer group and the secondary silencer group, or on the airflow outlet side of the secondary silencer group. You may. However, if wind hits the openings to the shielding materials H1a and H1b that function as auxiliary silencers, airflow generation noise is generated and the sound reduction performance of the auxiliary silencer deteriorates. Therefore, between the primary silencer group and the secondary silencer group (for example). , Between the partition plate and the casing 10) and the airflow outlet side of the secondary silencer group, it is desirable that the position is not affected by the airflow.
As described above, the shielding materials H1a to H1c preferably have an opening toward the second sound deadening unit 12 so as to reduce or absorb sound. As a result, the sound can be reduced while suppressing the influence of the air flow. Further, the shielding material H2 preferably has an opening toward the first sound deadening unit 11 or on the airflow outlet side of the second sound deadening unit 12 so as to reduce or absorb sound. As a result, the sound can be reduced while suppressing the influence of the air flow.

<8th Embodiment>
Subsequently, the eighth embodiment will be described. In the sixth embodiment, there is a possibility that the airflow may interfere with the perforated plate provided between the primary silencer and the secondary silencer to generate an airflow generation sound. On the other hand, in the eighth embodiment, the partition member has no holes in order to suppress the interference between the perforated plate and the airflow to generate an airflow generation sound.

FIG. 14 is a horizontal sectional view of the silencer according to the eighth embodiment. As shown in FIG. 14, the silencer 1h according to the eighth embodiment is provided with partition members D41 and D42 having no holes between the silencer groups. As a result, since there are no holes in the partition members D41 and D42, the diffusion of the airflow is suppressed, and the airflow flowing out from the muffling part of the target and the airflow flowing out from the muffling part adjacent to the muffling part of the target are prevented from interfering with each other. Can be eliminated.

Further, in the silencer 1h according to the eighth embodiment, a shielding material H3 is provided between the primary silencer and the silencer group, and the surface of the shielding material H3 is formed on the partition member D41 between the silencer groups. It is almost parallel. Further, in the silencer 1h according to the eighth embodiment, a shielding material H4 is provided between the secondary silencer and the silencer group, and the surface of the shielding material H4 between the silencer groups is the partition member D42. It is almost parallel. Further, similarly to the sixth and seventh embodiments, the silencer 1h according to the eighth embodiment is filled with the shielding materials H3 and H4, and the airflow flows into the shielding materials H3 and H4. It is designed not to. As a result, since there is no mixture of silencers (half-split silencers) having a size half that of the first to fifth embodiments, the volume reduction can be made uniform.

<9th embodiment>
Subsequently, the ninth embodiment will be described. FIG. 15 is a horizontal sectional view of the silencer according to the ninth embodiment. In the silencer 1i according to the ninth embodiment, the shielding material H3 is provided between the shielding material H11 on the primary silencer side and the silencer group as compared with the silencer 1h according to the eighth embodiment of FIG. It is divided into a hollow shielding material H12, and the partition member H12 is different in that a sound wave inlet portion H121 is provided. The sound wave inlet portion H121 has a hole so that sound waves can flow in, and a part of the sound insulating material H11 may be a sound absorbing material, or is surrounded by a partition member H12, a casing 10, and a sound insulating material H11. The space may be filled with a sound absorbing material.

Further, in the silencer 1i according to the ninth embodiment, the shielding material H4 is between the shielding material H13 on the secondary silencer side and the silencer group as compared with the silencer 1h according to the eighth embodiment of FIG. It is divided into the partition members H14 provided, and the partition member H14 is different in that the sound wave inlet portion H141 is provided. The sound wave inlet portion H141 has a hole so that sound waves can flow in, and a part of the sound insulating material H13 may be a sound absorbing material, or is surrounded by a partition member H14, a casing 10, and a sound insulating material H13. The space may be filled with a sound absorbing material. As described above, the partition members H12 and H14 at the ends of the plurality of partition members are provided so as to extend the plate material at the end of the first sound deadening unit 11 toward the plate material at the end of the second sound deadening unit 11. The partition members H12 and H14 have openings. Thereby, the sound reduction performance can be improved.

An auxiliary silencer such as a resonator may be installed between the partition members H12 and H14 and the casing 10 to increase the performance. As a result, since an auxiliary silencer (for example, a resonator) is provided, the sound reduction performance can be improved.

The shielding material H11 may be added as the volume of the resonator and used together. An auxiliary silencer may be installed on the shielding material H11 and used in combination with the auxiliary silencer of the shielding material. An auxiliary silencer may be installed on the shielding material H11 and used in combination with the auxiliary silencer of the partition member H12. Similarly, an auxiliary silencer may be installed on the shielding material H13 and used in combination with the auxiliary silencer of the partition member H14.

<10th Embodiment>
Subsequently, the tenth embodiment will be described. FIG. 16 is a horizontal sectional view of the silencer according to the tenth embodiment. In the silencer 1j according to the tenth embodiment, the partition members D51, D52, and D53 having air permeability are oblique to the long axis of the silencer as compared with the silencer 1i according to the ninth embodiment of FIG. The difference is that they are provided at positions that equally divide the airflow at the airflow outlet of the primary silencer. As described above, the partition members D51, D52, and D53 are provided from the outlet of the muffling portion of the first muffling unit 11 toward the entrance of the muffling portion of the second muffling unit 12. As a result, the airflow is guided to the partition members D51, D52, and D53 at the airflow outlet of the primary silencer, and the airflow is shunted and guided to separate muffling units of the second muffling unit 12. Here, the partition members D51, D52, and D53 are, for example, a porous plate or a plate formed of a porous material.

Further, similarly to the ninth embodiment, the silencer 1j according to the tenth embodiment is filled with the shielding materials H11 and H13 inside so that the airflow does not flow into the shielding materials H11 and H13. It has become. As a result, since there is no mixture of silencers (half-split silencers) having a size half that of the first to fifth embodiments, the volume reduction can be made uniform.

<11th Embodiment>
Subsequently, the eleventh embodiment will be described. FIG. 17 is a horizontal sectional view of the silencer according to the eleventh embodiment. In the silencer 1k according to the eleventh embodiment, the partition members D54 and D55 having air permeability are one side of the inner side surface of the casing 10, respectively, as compared with the silencer 1j according to the tenth embodiment of FIG. It is additionally provided on the other side. Here, the partition members D54 and D55 are, for example, a porous plate or a plate formed of a porous material. As a result, as compared with the silencer 1j according to the tenth embodiment, the partition members D54 and D55 can further suppress the extra diffusion of the airflow, and as a result, the pressure loss of the airflow can be suppressed. ..

<12th Embodiment>
Subsequently, the twelfth embodiment will be described. FIG. 18 is a horizontal sectional view of the silencer according to the twelfth embodiment. Compared to the muffler 1b according to the second embodiment of FIG. 7A, the muffler 1l according to the twelfth embodiment is provided with the partition members D1 to D3 and the non-breathable partition members G1a to G4. ing. Partition members G1a and G1b are provided substantially in the center of the outlet of the muffler of the first muffling unit 11 so as to correspond to two triangular sides in the horizontal cross section.

Specifically, the partition member G1a is provided from the outlet of the muffling portion of the first muffling unit 11 toward the surface of the sound absorbing material S5b of the muffling portion SL5 of the second muffling unit 12 and / or the first. The sound deadening unit 12 of 2 is provided toward the surface of the sound absorbing material S6a of the sound deadening unit SL6 next to the sound deadening unit SL5. As described above, the partition members G1a and G1b are provided so as to be separated from each other as the first muffling unit 11 approaches the second muffling unit 12 starting from the outlet of the muffling portion of the first muffling unit 11. .. As a result, the airflow is guided to the partition members G1a and G1b, and the airflow is separated. Further, the generation of vortices at the inlet of the secondary silencer can be prevented, and the pressure loss can be reduced.

In this embodiment, the partition members G1a and G1b are arranged at substantially the center of the outlet in the horizontal cross section at the position of the outlet of the primary silencer. As a result, the airflow is guided to the partition members G1a and G1b, and the airflow is divided substantially evenly. The set of partition members G2a and G2b and the set of partition members G3a and G3b are also provided in the same positional relationship as the set of partition members G1a and G1b.

Further, the air passage does not suddenly shrink at the inlet of the secondary silencer, and the pressure loss can be reduced. The partition members G1a to G4 may be curved surfaces that match the flow, instead of being flat. Thereby, the pressure loss can be reduced. Further, it is possible to reduce the pressure loss by increasing the distance between the first muffling unit 11 and the second muffling unit 12.

The space sandwiched between the partition members G1a and G1b, the space sandwiched between the partition members G2a and G2b, the space sandwiched between the partition members G3a and G3b, and the space sandwiched between the partition members G4 and the casing 10 are resonators. You may use it for such purposes.

<13th Embodiment>
Subsequently, the thirteenth embodiment will be described. FIG. 19 is a horizontal sectional view of the silencer according to the thirteenth embodiment. Compared to the muffler 1l according to the twelfth embodiment of FIG. 12, the muffler 1m according to the thirteenth embodiment is provided with the partition members G1a to G4 excluding the partition members G1a to G4 and having breathable partition members G5a to G8. ing. Here, the partition members G5a to G8 are, for example, a porous plate or a plate formed of a porous material. The triangular columnar space in which the partition members G1a to G1b are sandwiched is hollow. As a result, the volume is reduced acoustically at the entrance of the secondary silence group, so that the volume reduction can be improved.

At the outlet of the primary silencer group, the airflow is guided by a set of partition members G1a and G1b, a set of G2a and G2b, and a set of G3a and G3b, and the airflow is evenly shunted. Further, since there is no sudden reduction in the inlet of the secondary silencer group, the pressure loss can be reduced.

The partition members G5a to G8 may be curved surfaces that match the flow, instead of being flat. Thereby, the pressure loss can be reduced. Further, it is possible to reduce the pressure loss by increasing the distance between the first muffling unit 11 and the second muffling unit 12.

<Modification 1 of each embodiment>
The partition members D1 to D55 and G1a to G8 may be deformed according to the air flow to form a curved surface. Thereby, the pressure loss can be reduced.

<Modification 2 of each embodiment>
The long axis of each muffling unit included in the first muffling unit is shifted horizontally with respect to the long axis of each muffling unit included in the first muffling unit, but the present invention is not limited to this, and the long axis of each muffling unit may be shifted vertically. .. When vertically displaced, the long axis of each muffling unit included in the first muffling unit is included in the second muffling unit in the direction perpendicular to the long axis in the vertical cross section including the long axis. It is deviated from the long axis of any muffling part. Further, in a vertical cross section along the longitudinal direction of the casing 10 in a direction perpendicular to the longitudinal direction, each range of the internal space of the muffling portion included in the first muffling unit is included in any of the second muffling units. It does not fit in the range of the internal space of the muffling part.

<Modification 3 of each embodiment>
The secondary silencer group may be arranged at a position rotated around the long axis (airflow axis) of the muffling portion of the primary silencer group with respect to the primary silencer group.

<Modification 4 of each embodiment>
The primary silencer group and the secondary silencer group may be arbitrarily combined horizontally, vertically, and rotated to shift their relative positions to each other.

In each embodiment and all of the above modifications 1 to 4, when the air passage of the silencer of the primary silencer group is extended along the long axis, it does not exactly overlap the inlet of the silencer of the secondary silencer group. A primary silencer group and a secondary silencer group are arranged. More preferably, the primary silencer group and the secondary silencer group are arranged so as not to overlap any of the inlets of the secondary silencer group when each of the air passages of the primary silencer group is extended along the long axis. ing.

In addition, in each embodiment and all of the above-mentioned modifications 1 to 4, it has been described that each sound deadening portion has a top plate and a bottom plate, but the present invention is not limited to this, and the top plate and the bottom plate are removed. The plate material constituting the sound deadening portion may extend from the inner bottom surface of the casing to the inner top surface.

As described above, the present invention is not limited to the above-described embodiment as it is, and at the implementation stage, the components can be modified and embodied within a range that does not deviate from the gist thereof. In addition, various inventions can be formed by an appropriate combination of the plurality of components disclosed in the above-described embodiment. For example, some components may be removed from all the components shown in the embodiments. Further, components over different embodiments may be combined as appropriate.

1 to 1 m Silencer 10 Casing 11, 11a First silencer unit 12, 12a Second silencer unit B1 to B8 Bottom plate U1 to U8 Top plate D1 to D55, H12, H14 Partition members H1 to H4, H11, H13 Shielding material H121, H141 Sound wave inlet P11a to P38 Plate material S11a to S38 Sound absorbing material SL1 to SL8 Silencer

Claims (20)

Casing and
A plurality of pairs of plate materials provided at intervals in the casing so as to form a hollow and substantially rectangular cuboid-shaped sound deadening portion are arranged, and a sound absorbing material is provided on at least one of the surfaces of the pair of plate materials facing each other. The first muffling unit provided with
A plurality of pairs of plate materials provided at intervals in the casing so as to form a hollow and substantially rectangular cuboid-shaped sound deadening portion are arranged, and a sound absorbing material is provided on at least one of the surfaces of the pair of plate materials facing each other. The second muffling unit provided with
With
The first muffling unit and the second muffling unit are arranged at intervals in the long axis direction of the casing.
The long axis of each muffling unit included in the first muffling unit is perpendicular to the long axis of any muffling unit included in the second muffling unit in the cross section including the long axis. It is off in the direction
In a cross section along the longitudinal direction of the casing and in a direction perpendicular to the longitudinal direction, each range of the internal space of the muffling unit included in the first muffling unit is any muffling contained in the second muffling unit. A silencer that does not fit within the internal space of the unit. The silencer according to claim 1, further comprising a plurality of partition members provided between the first silencer unit and the second silencer unit and inducing an air flow. The silencer according to claim 2, wherein the partition member has air permeability. The silencer according to claim 3, wherein the partition member is a porous plate or a plate made of a porous material. The silencer according to claim 2, wherein the partition member is not breathable. The silencer according to claim 5, wherein the partition member is made of a non-breathable but acoustically permeable material. The silencer according to claim 6, wherein the acoustically transmissive material on which the partition member is formed is a material that transmits sound waves in a frequency band of 250 Hz or less. Any one of claims 2 to 7, wherein the partition member is provided so as to extend in the longitudinal direction of the casing from the outlet of the muffling unit of the first muffling unit toward the second muffling unit. The silencer described in the section. The partition member is provided in any one of claims 2 to 7 so as to extend from the plate material of the first sound deadening unit toward the second sound deadening unit in the longitudinal direction of the casing. Described silencer. The partition member according to any one of claims 2 to 7, wherein the plate material of the first sound deadening unit is provided so as to extend toward one of the plate materials of the second sound deadening unit. Silencer. The first muffling unit has a shielding material between the plate material of the first muffling unit and the casing, which shields the inflow of air from the side opposite to the second muffling unit. The silencer according to any one of 10. The silencer according to claim 11, wherein the shielding material has an opening toward the second silencer unit so as to reduce or absorb sound. The second muffling unit has a shielding material for shielding the inflow of air from the side of the first muffling unit between the plate material of the second muffling unit and the casing. The silencer according to any one item. The silencer according to claim 13, wherein the shielding material has an opening toward the first silencer unit or on the airflow outlet side of the second silencer unit so as to reduce or absorb sound. The end partition member among the plurality of partition members is provided so as to extend the plate material at the end of the first sound deadening unit toward the plate material at the end of the second sound deadening unit. The silencer according to claim 10, wherein the member has an opening. The sound deadening member according to any one of claims 2 to 7, wherein the partition member is provided from the outlet of the sound deadening unit of the first sound deadening unit toward the entrance of the sound deadening unit of the second sound deadening unit. vessel. 2. The silencer according to any one item. The silencer according to any one of claims 1 to 17, wherein the distance between the first silencer unit and the second silencer unit is 0.5 to 2 m. The silencer according to any one of claims 1 to 18, wherein the long axis of the silencer is an intersection of rectangular diagonal lines when the internal space of the silencer is cut by a cross section perpendicular to the longitudinal direction. In the cross section parallel to the long axis of the muffling unit, the width of the internal space of the muffling unit of the first muffling unit in the direction perpendicular to the long axis in the direction perpendicular to the long axis is the second muffling. The silencer according to any one of claims 1 to 19, which is substantially the same as the width of the internal space of the silencer of the unit in the direction perpendicular to the major axis.

Images