Muffler

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

[Technical field]

[0001] The present invention relates to a silencer. [Background technology]

[0002] In large-scale ventilation facilities such as road tunnels, many ventilation silencers are sometimes stacked in parallel on the cross section of the air passage (see, for example, Patent Document 1). In addition, when a large noise reduction performance is required, two or more rows of silencers are installed in the air flow direction to ensure the noise reduction performance (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Unexamined Patent Publication No. 6-146845 [Patent Document 2] JP 2001-164922 A Summary of the Invention [Problem to be solved by the invention]

[0004] When two or more rows of silencers are installed in the air flow direction, it is desirable to improve the sound reduction effect.

[0005] The present invention has been made in consideration of the above problems, and has an object to provide a silencer that can improve the sound reduction effect. [Means for solving the problem]

[0006] A silencer according to a first aspect of the present invention includes a casing, a first silencer unit in which a pair of plate members spaced apart from each other are arranged in a plurality of rows in the casing to form a hollow, substantially rectangular parallelepiped-shaped silencer section, and a sound absorbing material is provided on at least one of the opposing surfaces of the pair of plate members, and a second silencer unit in which a pair of plate members spaced apart from each other are arranged in a plurality of rows in the casing to form a hollow, substantially rectangular parallelepiped-shaped silencer section, and a sound absorbing material is provided on at least one of the opposing surfaces of the pair of plate members, The first muffler unit and the second muffler unit are arranged at a distance from each other in the longitudinal direction of the casing, and the longitudinal axis of each muffler section included in the first muffler unit is shifted in a direction perpendicular to the longitudinal axis with respect to the longitudinal axis of any of the muffler sections included in the second muffler unit in a cross section including that longitudinal axis, and the range of the internal space of each of the muffler sections included in the first muffler unit does not fall within the range of the internal space of any of the muffler sections included in the second muffler unit in a direction perpendicular to the longitudinal direction in a cross section along the longitudinal direction of the casing.

[0007] With this configuration, the airflow inlet of the casing cannot be seen directly from the airflow outlet, so sound is refracted between the first and second silencing units, and the sound waves are attenuated. This improves the sound reduction effect, particularly for high-frequency sounds with short wavelengths.

[0008] A silencer according to a second aspect of the present invention is the silencer according to the first aspect, further comprising a plurality of partition members provided between the first silencer unit and the second silencer unit and guiding an airflow.

[0009] According to this configuration, the airflow can be guided by the multiple partition members, and pressure loss can be suppressed.

[0010] A noise eliminator according to a third aspect of the present invention is the noise eliminator according to the second aspect, wherein the partition member has air permeability.

[0011] According to this configuration, sound is diffused through a plurality of partition members, thereby improving sound reduction performance.

[0012] A noise suppressor according to a fourth aspect of the present invention is the noise suppressor according to the third aspect, wherein the partition member is a perforated plate or a plate formed of a porous material.

[0013] According to this configuration, sound is diffused through the holes in each of the partition members, thereby improving the sound reduction performance.

[0014] A noise eliminator according to a fifth aspect of the present invention is the noise eliminator according to the second aspect, wherein the partition member is non-permeable.

[0015] According to this configuration, since the air current does not pass through the partition member, it is possible to suppress the air current noise generated when the air current passes through.

[0016] A noise eliminator according to a sixth aspect of the present invention is the noise eliminator according to the fifth aspect, wherein the partition member is formed of a material that is not breathable but is acoustically transparent.

[0017] According to this configuration, since low frequency bands are transmitted, sound is diffused between the first and second sound-absorbing units, and the sound reduction effect can be improved.

[0018] A silencer according to a seventh aspect of the present invention is the silencer according to the sixth aspect, wherein the acoustically transparent material from which the partition member is formed is a material that transmits sound waves in a frequency band of 250 Hz or less.

[0019] According to this configuration, in the frequency band of 250 Hz or less, sound is diffused between the first and second silencing units, and the sound reduction effect can be improved.

[0020] A silencer according to an eighth aspect of the present invention is a silencer according to any one of the second to seventh aspects, wherein the partition member is arranged to extend in the longitudinal direction of the casing from the outlet of the muffling section of the first muffling unit toward the second muffling unit.

[0021] According to this configuration, by providing the partition member, the airflow is divided at the outlet of the first muffler unit and guided to separate muffler portions of the second muffler unit.

[0022] A silencer according to a ninth aspect of the present invention is a silencer according to any one of the second to seventh aspects, wherein the partition member is arranged to extend in the longitudinal direction of the casing from the plate material of the first silencer unit toward the second silencer unit.

[0023] According to this configuration, the partition member can prevent the airflow discharged from the target muffler section of the first muffler unit from interfering with the airflow discharged from the adjacent muffler section, thereby reducing pressure loss.

[0024] A silencer according to a tenth aspect of the present invention is a silencer according to any one of the second to seventh aspects, wherein the partition member is arranged to extend the plate material of the first silencer unit toward one of the plate materials of the second silencer unit.

[0025] According to this configuration, the airflow is guided to the second silencing unit by the partition member, so that pressure loss can be reduced.

[0026] A silencer according to an eleventh aspect of the present invention is a silencer according to any one of the first to tenth aspects, wherein the first silencer unit has a shielding material between the plate material of the first silencer unit and the casing, which shields air from entering from the side opposite the second silencer unit.

[0027] With this configuration, the sound volume reduction can be made uniform.

[0028] A noise absorbing device according to a twelfth aspect of the present invention is the noise absorbing device according to the eleventh aspect, wherein the shielding material has an opening facing the second noise absorbing unit so as to reduce or absorb sound.

[0029] According to this configuration, it is possible to reduce noise while suppressing the effect of airflow and reducing pressure loss.

[0030] A silencer according to a thirteenth aspect of the present invention is a silencer according to any one of the first to twelfth aspects, wherein the second silencer unit has a shielding material between the plate material of the second silencer unit and the casing, which shields air from entering from the side of the first silencer unit.

[0031] According to this configuration, it is possible to suppress the influence of the air flow, reduce pressure loss, and make the sound volume reduction uniform.

[0032] A noise absorbing device according to a fourteenth aspect of the present invention is a noise absorbing device according to any one of the first to ninth aspects, wherein the shielding material has an opening facing the first noise absorbing unit or on the airflow outlet side of the second noise absorbing unit so as to reduce or absorb sound.

[0033] According to this configuration, it is possible to reduce noise while suppressing the influence of airflow.

[0034] A silencer according to a fifteenth aspect of the present invention is the silencer according to the tenth aspect, wherein an end partition member among the plurality of partition members is arranged to extend the plate material at the end of the first silencer unit toward the plate material at the end of the second silencer unit, and the partition member has an opening.

[0035] This configuration can improve the sound reduction performance.

[0036] A silencer according to a sixteenth aspect of the present invention is the silencer according to any one of the second to seventh aspects, wherein the partition member is provided from an outlet of the muffling section of the first muffling unit toward an inlet of the muffling section of the second muffling unit.

[0037] According to this configuration, the airflow is guided by the partition plate at the airflow outlet of the primary silencer, where it is divided, and is guided to separate muffling sections of the second muffling unit.

[0038] A silencer according to a 17th aspect of the present invention is a silencer according to any one of the second to seventh aspects, wherein the partition members are arranged so that, starting from the outlet of the muffling section of the first muffling unit, the partition members become more distant from each other as they approach the second muffling unit from the first muffling unit.

[0039] According to this configuration, the airflow is guided to the partition member and divided into two parts. Furthermore, the generation of vortexes at the entrance of the secondary silencer can be prevented, and pressure loss can be reduced.

[0040] A silencer according to an eighteenth aspect of the present invention is the silencer according to any one of the first to ninth aspects, wherein a distance between the first and second silencer units is 0.5 to 2 m.

[0041] According to this configuration, it is possible to compensate for the sound reduction of the ventilation silencer in the octave band center frequency bands of 63 and 125 Hz (frequency range of approximately 45 to 180 Hz).

[0042] A silencer according to a 19th aspect of the present invention is a silencer according to any one of the first to eighteenth aspects, wherein the long axis of the silencer section is the intersection of diagonals of a rectangle obtained when the internal space of the silencer section is cut in a cross section perpendicular to the longitudinal direction.

[0043] A silencer according to a 20th aspect of the present invention is a silencer according to any one of the first to nineteenth aspects, wherein, in a cross section parallel to the long axis of the muffling part, the width of the internal space of the muffling part of the first muffling unit in a direction perpendicular to the long axis is approximately the same as the width of the internal space of the muffling part of the second muffling unit in a direction perpendicular to the long axis. Effect of the Invention

[0044] According to one aspect of the present invention, since the airflow inlet of the casing cannot be seen directly from the airflow outlet, the sound is refracted between the first and second silencing units, and the sound waves are attenuated. This improves the sound reduction effect, particularly for high-frequency sounds with short wavelengths. [Brief description of the drawings]

[0045] [Figure 1] FIG. 1 is a schematic perspective view of a silencer according to a first embodiment. [Diagram 2] FIG. 2 is a cross-sectional view taken along the line AA of FIG. [Diagram 3] FIG. 3 is a cross-sectional view taken along line BB in FIG. 2. [Figure 4] FIG. 3 is a cross-sectional view taken along line CC of FIG. 2. [Diagram 5] FIG. 4 is a vertical sectional view of a first silencer unit according to a modified example of the first embodiment. [Figure 6] FIG. 4 is a vertical sectional view of a second silencer unit according to a modified example of the first embodiment. [Figure 7A] FIG. 6 is a horizontal sectional view of a silencer according to a second embodiment. [Figure 7B] FIG. 7B is a cross-sectional view taken along line DD of FIG. 7A. [Figure 8] FIG. 11 is a horizontal sectional view of a silencer according to a third embodiment. [Figure 9] FIG. 11 is a horizontal sectional view of a silencer according to a fourth embodiment. [Figure 10] FIG. 13 is a horizontal sectional view of a silencer according to a fifth embodiment. [Figure 11] FIG. 13 is a horizontal sectional view of a silencer according to a sixth embodiment. [Figure 12] FIG. 13 is a horizontal sectional view of a silencer according to a seventh embodiment. [Figure 13A] FIG. 2 is a horizontal cross-sectional view of a shielding material according to a first modified example. [Figure 13B] FIG. 11 is a horizontal cross-sectional view of a shielding material according to a second modified example. [Figure 13C] FIG. 11 is a horizontal cross-sectional view of a shielding material according to a third modified example. [Figure 14]FIG. 13 is a horizontal cross-sectional view of a silencer according to an eighth embodiment. [Figure 15] FIG. 13 is a horizontal cross-sectional view of a silencer according to a ninth embodiment. [Figure 16] FIG. 23 is a horizontal cross-sectional view of a silencer according to a tenth embodiment. [Figure 17] FIG. 23 is a horizontal cross-sectional view of a silencer according to an eleventh embodiment. [Figure 18] FIG. 23 is a horizontal cross-sectional view of a silencer according to a twelfth embodiment. [Figure 19] FIG. 23 is a horizontal cross-sectional view of a silencer according to a thirteenth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0046] Hereinafter, each embodiment will be described with reference to the drawings. However, more detailed description than necessary may be omitted. For example, detailed description of already well-known matters or duplicate description of substantially the same configuration may be omitted. This is to avoid the following description becoming unnecessarily redundant and to facilitate understanding by those skilled in the art.

[0047] <First embodiment> First, the first embodiment will be described. Fig. 1 is a schematic perspective view of the silencer according to the first embodiment. Fig. 2 is a cross-sectional view of the AA section of Fig. 1. Fig. 3 is a cross-sectional view of the BB section of Fig. 2. Fig. 4 is a cross-sectional view of the CC section of Fig. 2. As shown in Fig. 1, the silencer 1 according to the first embodiment includes a hollow rectangular parallelepiped casing 10, a first silencer unit 11 provided in the casing 10, and a second silencer unit 12 provided in the casing 10.

[0048] In each embodiment, the airflow will be described as flowing in from the first silencer unit 11 side as shown in Fig. 2, the first silencer unit 11 being the primary silencer group on the upstream side of the airflow, and the second silencer unit 12 being the secondary silencer group on the downstream side of the airflow. Also, 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 that order.

[0049] 1 and 2, the first silencer unit 11 and the second silencer unit 12 are arranged with a gap in the longitudinal direction of the casing 10. As a result, compared to a case where there is no gap between the first silencer unit 11 and the second silencer unit 12, sound is diffused widely at the airflow outlet of the first silencer unit 11, thereby improving the sound reduction effect.

[0050] As shown in FIG. 2 and FIG. 3, the first muffling unit 11 includes muffling sections SL1 to SL4 provided in the casing 10. The muffling section SL1 has a top plate U1 and a bottom plate B1, and includes a pair of plate materials P1a and P1b, one end of which is connected to the top plate U1 and the other end of which is connected to the bottom plate B1. Similarly, the muffling section SL2 has a top plate U2 and a bottom plate B2, and includes a pair of plate materials P2a and P2b, one end of which is connected to the top plate U2 and the other end of which is connected to the bottom plate B2. Similarly, the muffling section SL3 has a top plate U3 and a bottom plate B3, and includes a pair of plate materials P3a and P3b, one end of which is connected to the top plate U3 and the other end of which is connected to the bottom plate B3. Similarly, the muffling section SL4 has a top plate U4 and a bottom plate B4, and includes a plate material P4, one end of which is connected to the top plate U4 and the other end of which is connected to the bottom plate B4. As an example, the muffling portion SL4 has a structure obtained by splitting any one of the muffling portions SL1 to SL3 in half substantially vertically.

[0051] In this manner, pairs of plate materials P1a and P1b, P2a and P2b, and P3a and P3b are arranged at intervals in the casing 10 so as to form a hollow, substantially rectangular parallelepiped sound absorbing section. As an example, as shown in Fig. 3, pairs of plate materials P1a, P1b, P2a, P2b, P3a, and P3b are arranged substantially parallel to each other. Also, as an example, plate material P4 is arranged next to plate material P1a with no interval therebetween.

[0052] Also, sound absorbing materials S1a, S1b are provided on at least one of the surfaces of the pair of plate materials P1a, P1b facing each other, and similarly, sound absorbing materials S2a, S2b are provided on at least one of the surfaces of the pair of plate materials P2a, P2b facing each other.Furthermore, sound absorbing materials S3a, S3b are provided on at least one of the surfaces of the pair of plate materials P3a, P3b facing each other.Furthermore, sound absorbing material S4 is provided on the surface of plate material P4 that corresponds to the inner surface of the casing 10.

[0053] As shown in Figs. 2 and 4, the second muffling unit 12 includes muffling sections SL5 to SL8 provided in the casing 10. The muffling section SL5 has a top plate U5 and a bottom plate B5, and includes a pair of plate materials P1a and P1b, one end of which is connected to the top plate U5 and the other end of which is connected to the bottom plate B5. Similarly, the muffling section SL6 has a top plate U6 and a bottom plate B6, and includes a pair of plate materials P6a and P6b, one end of which is connected to the top plate U6 and the other end of which is connected to the bottom plate B6. Similarly, the muffling section SL3 has a top plate U7 and a bottom plate B7, and includes a pair of plate materials P7a and P7b, one end of which is connected to the top plate U7 and the other end of which is connected to the bottom plate B7. Similarly, the muffling section SL8 has a top plate U8 and a bottom plate B8, and includes a plate material P8, one end of which is connected to the top plate U8 and the other end of which is connected to the bottom plate B8. As an example, the muffling portion SL8 has a structure obtained by splitting any one of the muffling portions SL5 to SL7 in half substantially vertically.

[0054] Thus, in the second muffler unit 12, pairs of plate materials P5a and P5b, P6a and P6b, and P7a and P7b are arranged at intervals in the casing 10 so that hollow, substantially rectangular parallelepiped mufflers are arranged side by side. As an example, as shown in Fig. 4, pairs of plate materials P5a, P5b, P6a, P6b, P7a, and P7b are arranged substantially parallel to each other. Also, as an example, plate material P8 is arranged next to plate material P7b with no interval therebetween.

[0055] 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, and similarly, sound absorbing materials S6a and S6b are provided on at least one of the surfaces of the pair of plate materials P6a and P6b facing each other.Further, 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, sound absorbing material S8 is provided on the surface of plate material P8 opposite plate material P7b.

[0056] 2 shows the long axes AX1, AX2, and AX3 of the muffling parts included in the first muffling unit 11. Also, the long axes AX4, AX5, and AX6 of the muffling parts included in the second muffling unit 12 are shown. Here, the long axis of the muffling part (also called the axis of the ventilation passage) is the intersection of the diagonals of a rectangle when the internal space of the muffling part is cut in a cross section perpendicular to the longitudinal direction. As shown in FIG. 2, in a horizontal cross section parallel to the longitudinal direction of the casing, the long axes AX1, AX2, and AX3 of the muffling parts included in the first muffling unit 11 are offset from the long axes AX4, AX5, and AX6 of all the muffling parts included in the second muffling unit 12 in the direction perpendicular to the longitudinal direction (the direction parallel to the x-axis in FIG. 2).

[0057] Furthermore, as shown in Figure 2, in a cross section along the longitudinal direction of the casing (here, a horizontal cross section as an example), in a direction perpendicular to the longitudinal direction (a direction parallel to the x-axis in Figure 2), the ranges of the internal space of the muffling parts included in the first muffling unit 11 (x1a-x1b, x2a-x2b, x3a-x3b, x4a-x4b) do not fall within the ranges of the internal space of any of the muffling parts included in the second muffling unit 12 (x5a-x5b, x6a-x6b, x7a-x7b, x8a-x8b).

[0058] With this configuration, the airflow inlet of the casing 10 cannot be seen directly from the airflow outlet, so sound is refracted and attenuated between the first silencer unit 11 and the second silencer unit 12 as shown by arrows A3 to A9 in Fig. 2. This improves the sound reduction effect, particularly at high frequencies with short wavelengths.

[0059] That is, when the internal space of the muffling part of the second muffling unit 12 is viewed from the open surface side of the casing 10 on the muffling part side of the second muffling unit 12 (i.e., the outlet side of the air passage) along the long axes AX4, AX5, and AX6 of the muffling part of the second muffling unit 12 (viewed along the direction of arrow A1 in FIG. 2), the entire internal space of the muffling part of the first muffling unit 11 cannot be seen from any of the muffling parts of the second muffling unit 12. As a result, sound is refracted between the first muffling unit 11 and the second muffling unit 12 as shown by arrows A3 to A9 in FIG. 2, and the sound waves are attenuated. This improves the sound reduction effect, particularly at high frequencies with short wavelengths.

[0060] In each embodiment, the width of the air passage of the muffling part of the first muffling unit 11 is approximately the same as the width of the air passage of the muffling part of the second muffling unit 12. That is, in a cross section parallel to the long axis of the muffling part (a horizontal cross section here as an example), the width of the internal space of the muffling part of the first muffling unit 11 in a direction perpendicular to the long axis of the muffling part is approximately the same as the width of the internal space of the muffling part of the second muffling unit 12 in a direction perpendicular to the long axis.

[0061] <Distance between the first silencing unit 11 and the second silencing unit 12> If the expanded flow passage portion between the first silencer unit 11 and the second silencer unit 12 (i.e., between the silencers) is regarded as an expansion chamber of an expansion type silencer, the sound reduction effect is maximized when the length of this section is set to 1 / 4 of the wavelength λ of the sound to be reduced. As an additional effect aimed at this effect, it is desirable to set the distance L between the first silencer unit 11 and the second silencer unit 12 to about 1 / 4 of the wavelength λ when the sound to be reduced is limited. For example, the dominant frequency component of a blower is often in a band around 125 Hz, but the reduction in sound volume of a sound-absorbing ventilation silencer is not very large. Therefore, if you want to reduce the sound velocity v=340 m / s and f=125 Hz at an air temperature of 15°C, aiming at this band, it is considered to set λ / 4=(v / f) / 4=340 / 125 / 4=0.68 m. From this, in order to generally compensate for the sound volume reduction of the ventilation silencer in the octave band center frequency band of 63 and 125 Hz (frequency range of about 45 to 180 Hz), the distance L between the first silencing unit 11 and the second silencing unit 12 is desirably about 0.5 to 2 m, when calculated as above. Note that in each of the following embodiments, the distance L between the first silencing unit 11 and the second silencing unit 12 may also be about 0.5 to 2 m.

[0062] As described above, the silencer 1 according to the first embodiment includes a casing, a first silencer unit in which a pair of plate members spaced apart from each other are arranged in the casing so as to form a hollow, substantially rectangular parallelepiped silencer section, and a sound absorbing material is provided on at least one of the opposing surfaces of the pair of partition plates, and a second silencer unit in which a pair of plate members spaced apart from each other are arranged in the casing so as to form a hollow, substantially rectangular parallelepiped silencer section, and a sound absorbing material is provided on at least one of the opposing surfaces of the pair of plate members, and the first silencer unit The first and second silencing units are disposed at an interval in the longitudinal direction of the casing, and the longitudinal axis of each silencing section included in the first silencing unit is offset from the longitudinal axis of any of the silencing sections included in the second silencing unit in a direction perpendicular to the longitudinal axis in a horizontal cross section including the longitudinal axis, and the range of the internal space of each of the silencing sections included in the first silencing unit does not fall within the range of the internal space of any of the silencing sections included in the second silencing unit in a direction perpendicular to the longitudinal direction in a horizontal cross section parallel to the longitudinal direction of the casing.

[0063] With this configuration, since the airflow inlet of the casing 10 cannot be seen directly from the airflow outlet, sound is refracted and attenuated between the first and second silencing units 11 and 12 as shown by arrows A3 to A9 in Fig. 2. This improves the sound reduction effect, particularly at high frequencies with short wavelengths.

[0064] <Modification of the first embodiment> Next, a modified example of the first embodiment will be described. The silencer 1a according to the modified example of the first embodiment corresponds to three silencers 1 according to the first embodiment stacked vertically. FIG. 5 is a vertical cross-sectional view of a first silencer unit according to the modified example of the first embodiment. FIG. 6 is a vertical cross-sectional view of a second silencer 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.

[0065] As shown in Fig. 5, the first muffling unit 11a according to the modification of the first embodiment has four muffling sections arranged horizontally and stacked vertically in three stages inside the casing 10b. Each muffling section has one bottom plate B11-B34, one plate P14, P24, P34 or a pair of plates P11a-P33b arranged substantially vertically on the bottom plate B11-B34, and one top plate U11-U34 arranged on the plate P11a-P34. Sound absorbing materials S11a-S33b are provided on the mutually opposing surfaces of the pair of plates P11a-P33b, and sound absorbing materials S14, S24, S34 are provided on the surface of one of the plates P14, P24, P34 facing the inner surface of the casing 10b.

[0066] 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 within the casing 10b.

[0067] As shown in Fig. 6, four sound absorbing units are arranged horizontally and vertically in three tiers in the casing 10b. Each sound absorbing unit has a bottom plate B15-B38, a plate P18, P28, P38 or a pair of plates P15a-P37b arranged substantially vertically on the bottom plate B15-B38, and a top plate U15-U38 arranged on the plate P15a-P38. Sound absorbing materials S15a-S37b are provided on the opposing surfaces of the pair of plates P15a-P37b, and sound absorbing materials S18, S28, S38 are provided on the surface of one of the plates P18, P28, P38 facing the inner surface of the casing 10b.

[0068] In this manner, the sound absorbing parts may be stacked in multiple stages in the vertical direction.

[0069] <Second embodiment> Next, the second embodiment will be described. Fig. 7A is a horizontal cross-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 further includes a plurality of partition members D1, D2, and D3 that are provided between the first silencer unit 11 and the second silencer unit 12 and guide the airflow, as compared with the silencer 1 according to the first embodiment of Fig. 2. The partition members D1, D2, and D3 according to this embodiment have air permeability, and are, for example, perforated plates.

[0070] The partition members D1, D2, and D3 are provided so as to extend in the longitudinal direction of the casing 10 from the outlet of the muffling section of the first muffling unit 11 toward the second muffling unit 12. In the present embodiment, as an example, 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 the plate material P8. That is, as an example, the partition members D1, D2, and D3 are provided so as to extend the plate materials P5b to P8 of the muffling section of the second muffling unit 12 in the longitudinal direction of the casing 10 toward the first muffling unit 11.

[0071] By providing the partition member D1 in this manner, the airflow splits (here, equally divided, as an example) at the outlet R1 of the muffling section of the first muffling unit 11, as shown by arrows A12 and A13, and is guided to separate muffling sections of the second muffling unit. Similarly, by providing the partition members D2 and D3, the airflow splits (here, equally divided, as an example) at the outlet R1 of the muffling section of the first muffling unit 11, as shown by arrows A14 and A15 and arrows A16 and A17, and is guided to separate muffling sections of the second muffling unit.

[0072] On the other hand, as shown by arrow A18, the sound is widely diffused through the multiple holes in partition member D1, improving the sound reduction effect. Similarly, as shown by arrows A19 and A20, the sound is widely diffused through the multiple holes in partition members D2 and D3, improving the sound reduction effect.

[0073] The partition member is not limited to a perforated plate, but may be a plate made of a porous material such as a metal fiber plate, or may be made of a material that transmits sound waves.

[0074] <Third embodiment> Next, the third embodiment will be described. In the first and second embodiments, the objective is to improve the high-frequency sound reduction performance, but in the third embodiment, the objective is to suppress the increase in pressure loss in addition to the above. FIG. 8 is a horizontal cross-sectional view of a silencer according to the third embodiment. As shown in FIG. 8, the silencer 1c according to the third embodiment is different from the silencer 1b according to the second embodiment of FIG. 7A in that the positions of the partition members D4, D5, and D6 are changed. 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. In this way, the partition members D4, D5, and D6 are provided so as to extend in the longitudinal direction of the casing 10 from the plate material of the first silencer unit toward the second silencer unit 12.

[0075] As a result, as shown in region R2, the partition member D4 can prevent the airflow discharged from the target muffler section of the first muffler unit (primary silencer group) 11 from interfering with the airflow discharged from the adjacent muffler section, thereby reducing pressure loss. Also, since the partition members D4, D5, and D6 have holes, the sound emitted from the outlet of the first muffler unit (primary silencer group) 11 diffuses widely through the holes in the partition members D4, D5, and D6, improving the sound reduction effect.

[0076] In Fig. 8, the flow of air currents is indicated by arrows A21 to A27. As indicated by arrows A22 and A23 in Fig. 8, the air currents discharged from the target muffler section of the first muffler unit (primary silencer group) 11 diffuse and flow into the multiple muffler sections of the second muffler unit (secondary silencer group) 12.

[0077] <Fourth embodiment> Next, the fourth embodiment will be described. In the second embodiment, the partition member has air permeability, but in the fourth embodiment, the partition member does not have air permeability. FIG. 9 is a horizontal cross-sectional view of a 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 have no air permeability. This has the advantage that the partition members D11, D12, and D13 do not generate airflow noise, unlike perforated plates. For example, the partition members D11, D12, and D13 are, for example, air-permeable plates (metal plates), and metal plates have the advantage of being highly rigid and easy to install.

[0078] As shown by arrows A31 and A32 in FIG. 9, the airflow is divided (eg, evenly divided) at the outlet of the first silencer unit (primary silencer group) 11 by the partition members D11, D12, and D13.

[0079] <Fifth embodiment> Next, the fifth embodiment will be described. In the third embodiment, the partition member has air permeability, but in the fifth embodiment, the partition member does not have air permeability. FIG. 10 is a horizontal cross-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 have no air permeability. This has the advantage that the partition members D21, D22, and D23 do not generate airflow noise as in the case of a porous plate. For example, the partition members D21, D22, and D23 are, for example, plates (metal plates) that have no air permeability, and metal plates have the advantage of being highly rigid and easy to install.

[0080] As shown by arrows A33 and A34 in FIG. 10, the airflow discharged from the target silencing section of the first silencing unit (primary silencer group) 11 splits and flows into two silencing sections of the second silencing unit (secondary silencer group) 12.

[0081] As in the third embodiment, the partition members D21, 22, and 23 can prevent the airflow discharged from the target muffler section of the first muffler unit (primary silencer group) 11 from interfering with the airflow discharged from the adjacent muffler section, thereby reducing pressure loss.

[0082] <Modifications of Partition Member> The partition members D11, D12, and D13 according to the fourth embodiment and the partition members D21, D22, and D23 according to the fifth embodiment may be formed of a material that is not breathable but has acoustic transparency, for example, a film that is not breathable but has acoustic transparency. As a result, the low frequency band is transmitted, so sound is diffused between the primary silencer group and the secondary silencer group in the same way as when a perforated plate is installed, and the sound reduction effect can be improved. Here, the acoustically transparent material is preferably a material that transmits well 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, sound is diffused between the primary silencer group and the secondary silencer group, and the sound reduction effect can be improved. Therefore, depending on the frequency characteristics of the sound reduction required for the silencer group, it is effective to install such a material (for example, a film-like material).

[0083] Sixth embodiment Next, 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 partition member is provided obliquely to the long axis of the silencer so as to connect the plate material of the silencer of the first silencer unit (primary silencer group) 11 and the plate material of the silencer of the second silencer unit (secondary silencer group) 12. This makes it possible to guide the airflow discharged from the silencer of the first silencer unit only to the silencer of the second silencer unit that is associated with it one-to-one.

[0084] FIG. 11 is a horizontal cross-sectional view of a silencer according to a sixth embodiment. As shown in FIG. 11, the silencer 1f according to the sixth embodiment includes partition members D31, D32, D33, and D34. The 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. Similarly, the 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. Similarly, a partition member D34 is provided obliquely with respect to the long axis of the muffler so as to connect the plate material P3b of the muffler of the first muffler unit 11 and the plate material P7b of the muffler of the second muffler unit 12. In this manner, the partition members D31 to D34 are provided so as to extend the plate material of the first muffler unit 11 toward one of the plate materials of the second muffler unit 12. As a result, the airflow is guided to the second muffler unit 12 by the partition members D31 to D34, thereby reducing pressure loss.

[0085] The first silencer unit 11 of the silencer 1f according to the sixth embodiment is provided with a shielding material H1 filled inside, so that air does not flow into the shielding material H1. In this way, the first silencer unit 11 has the shielding material H1 between the plate material P1a at the end of the first silencer unit 11 and the casing 10, which blocks the inflow of air from the opposite side to the second silencer unit 12.

[0086] Similarly, the second silencing unit 12 of the silencer 1f according to the sixth embodiment is provided with a filled shielding material H2, which prevents air from flowing into the shielding material H2. In this manner, the second silencing unit 12 has the shielding material H2 between the plate material P7b at the end of the second silencing unit 12 and the casing 10, which shields air from flowing in from the first silencing unit 11 side. Since there is no mixture of silencing sections SL4 and SL8 (also called half silencers) that are half the size of the others in the third embodiment, it is possible to make the sound volume reduction uniform.

[0087] However, if the separation distance L between the silencer groups is small and the wind speed at the outlet of the primary silencer group is fast, the airflow in region R3 may interfere with the partition members D32, D33, and D34 provided between the silencer groups, resulting in airflow noise.

[0088] Seventh embodiment Next, the seventh embodiment will be described. In the sixth embodiment, when the separation distance L between the silencer groups is small and the wind speed at the outlet of the primary silencer group is high, the airflow may interfere with the partition members D32, D33, and D34 provided between the silencer groups, causing airflow noise. In contrast, in the seventh embodiment, the separation distance L between the silencer groups is made longer than a predetermined reference distance, thereby reducing the angle of the partition member provided between the silencer groups with respect to the major axis of the silencer of the first silencer unit. This reduces the angle at which the airflow enters the partition member, reducing interference with the partition member.

[0089] FIG. 12 is a horizontal cross-sectional view of the silencer according to the seventh embodiment. As shown in FIG. 12, the silencer 1g according to the seventh embodiment is provided with partition members D35, D36, D37, and D38 between the silencer groups. The partition members D35, D36, D37, and D38 are perforated plates, for 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 is small, suppressing the generation of airflow noise due to interference with the partition members. Furthermore, 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 interference with the airflow (also called the silencer airflow) flowing out from the adjacent silencer can be suppressed. As in the sixth embodiment, the silencer 1g according to the seventh embodiment is provided with shielding materials H1 and H2 whose insides are filled, so that the airflow does not flow into the shielding materials H1 and H2. As a result, compared to the first to fifth embodiments, there is no mixture of sound absorbing parts (also called half silencers) that are half the size, so that the sound volume reduction can be made uniform.

[0090] <Modifications of shielding materials> Next, modified examples of the shielding material will be described. Fig. 13A is a horizontal cross-sectional view of a first modified shielding material. The first modified shielding material H1a may be provided in place of the shielding material H1 of Fig. 11 or 12. As shown in Fig. 13A, the first modified shielding material H1a is a side branch provided with an opening facing in the direction between the silencer groups, and can improve the sound reduction performance of a specific frequency component. The side branch is an example of an auxiliary silencer.

[0091] Fig. 13B is a horizontal cross-sectional view of the shielding material of the second modification. The shielding material H1b of the second modification may be provided instead of the shielding material H1 of Fig. 11 or Fig. 12. As shown in Fig. 13B, the shielding material H1b of the second modification is a resonator provided with an opening facing the direction between the silencer groups, and can improve the sound reduction performance of a specific frequency component. The resonator is an example of an auxiliary silencer.

[0092] Fig. 13C is a horizontal cross-sectional view of the shielding material of the third modification. The shielding material H1c of the third modification may be provided in place of the shielding material H1 of Fig. 11 or 12. 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 a sound-absorbing material S41, thereby improving the sound-absorbing performance. Moreover, sound insulating materials H1a to H1c according to the first to third modified examples may be provided in place of the sound insulating material H2.

[0093] The openings of the shielding materials H1a to H1c and H2 (i.e., the inlets of the sound waves) may be located on 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. However, if wind hits the openings of the shielding materials H1a and H1b that function as auxiliary silencers, airflow-generated noise will be generated and the sound reduction performance of the auxiliary silencer will decrease, so it is preferable to locate them in a position that is not affected by airflow, such as between the primary silencer group and the secondary silencer group (for example, between the partition plate and the casing 10) or on the airflow outlet side of the secondary silencer group. In this way, it is preferable that the shielding materials H1a to H1c have an opening facing the second silencing unit 12 so as to reduce or absorb sound. This makes it possible to reduce sound while suppressing the influence of airflow. Also, it is preferable that the shielding material H2 has an opening facing the first silencing unit 11 or on the airflow outlet side of the second silencing unit 12 so as to reduce or absorb sound. This makes it possible to reduce sound while suppressing the influence of airflow.

[0094] <Eighth embodiment> Next, 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, generating airflow noise. In contrast, in the eighth embodiment, the partition member is made without holes in order to suppress the airflow from interfering with the perforated plate and generating airflow noise.

[0095] Fig. 14 is a horizontal cross-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 without holes between the silencer groups. As a result, since the partition members D41 and D42 have no holes, the diffusion of the airflow is suppressed, and it is possible to eliminate interference between the airflow flowing out from the target muffling section and the airflow flowing out from the muffling section adjacent to the target muffling section.

[0096] Furthermore, 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 approximately parallel to the partition member D41 between the silencer group. In addition, 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 is approximately parallel to the partition member D42 between the silencer group. As in the sixth and seventh embodiments, in the silencer 1h according to the eighth embodiment, the insides of the shielding materials H3 and H4 are filled, and airflow does not flow into the shielding materials H3 and H4. As a result, there is no mixture of muffling parts (half silencers) that are half the size compared to the first to fifth embodiments, so that the sound reduction can be made uniform.

[0097] <Ninth embodiment> Next, the ninth embodiment will be described. Fig. 15 is a horizontal cross-sectional view of the silencer according to the ninth embodiment. The silencer 1i according to the ninth embodiment is different from the silencer 1h according to the eighth embodiment in Fig. 14 in that the insulating material H3 is divided into the insulating material H11 on the primary silencer side and the hollow insulating material H12 provided between the silencer group, and the partition member H12 is provided with a sound wave inlet portion H121. The sound wave inlet portion H121 has a hole so that sound waves can flow in, and a part of the sound insulation material H11 may be a sound absorbing material, or the space surrounded by the partition member H12, the casing 10, and the sound insulation material H11 may be filled with a sound absorbing material.

[0098] Furthermore, the silencer 1i according to the ninth embodiment differs from the silencer 1h according to the eighth embodiment in FIG. 14 in that the insulating material H4 is divided into the insulating material H13 on the secondary silencer side and the partition member H14 provided between the silencer group, and the partition member H14 is provided with a sound wave inlet portion H141. The sound wave inlet portion H141 has a hole so that sound waves can flow in, and a part of the sound insulation material H13 may be a sound absorbing material, or the space surrounded by the partition member H14, the casing 10, and the sound insulation material H13 may be filled with a sound absorbing material. In this way, the partition members H12 and H14 at the ends of the multiple partition members are provided so as to extend the plate material at the end of the first silencer unit 11 toward the plate material at the end of the second silencer unit, and the partition members H12 and H14 have openings. This can improve the sound reduction performance.

[0099] In addition, performance may be improved by installing an auxiliary silencer such as a resonator between the partition members H12, H14 and the casing 10. In this way, since an auxiliary silencer (for example, a resonator) is provided, it is possible to improve sound reduction performance.

[0100] The shielding material H11 may also be added as a resonator volume. An auxiliary silencer may be installed on the shielding material H11 and used in conjunction with the auxiliary silencer of the shielding material. An auxiliary silencer may be provided in the shielding material H11 and used in conjunction with the auxiliary silencer in the partition member H12. Similarly, an auxiliary silencer may be provided in the shielding material H13 and used in conjunction with the auxiliary silencer in the partition member H14.

[0101] <Tenth embodiment> Next, the tenth embodiment will be described. Fig. 16 is a horizontal cross-sectional view of the silencer according to the tenth embodiment. The silencer 1j according to the tenth embodiment is different from the silencer 1i according to the ninth embodiment in Fig. 15 in that the partition members D51, D52, and D53 having air permeability are provided at an angle to the long axis of the muffling section and at a position that equally divides the airflow at the airflow outlet of the primary silencer. In this way, the partition members D51, D52, and D53 are provided from the outlet of the muffling section of the first muffling unit 11 toward the inlet of the muffling section of the second muffling unit 12. As a result, the airflow is guided by the partition members D51, D52, and D53 at the airflow outlet of the primary silencer, divided, and guided to separate muffling sections of the second muffling unit 12. Here, the partition members D51, D52, and D53 are, for example, perforated plates or plates formed of porous materials.

[0102] As in the ninth embodiment, in the silencer 1j according to the tenth embodiment, the insides of the shielding materials H11 and H13 are filled, and airflow does not flow into the shielding materials H11 and H13. As a result, compared to the first to fifth embodiments, there is no mixture of sound absorbing parts (half silencers) that are half the size, and sound volume reduction can be made uniform.

[0103] <Eleventh embodiment> Next, an eleventh embodiment will be described. Fig. 17 is a horizontal cross-sectional view of a silencer according to the eleventh embodiment. In the silencer 1k according to the eleventh embodiment, compared to the silencer 1j according to the tenth embodiment in Fig. 16, air-permeable partition members D54 and D55 are additionally provided on one side and the other side of the inner surface of the casing 10, respectively. Here, the partition members D54 and D55 are, for example, perforated plates or plates formed of a porous material. As a result, compared to the silencer 1j according to the tenth embodiment, the partition members D54 and D55 can further suppress unnecessary diffusion of the airflow, and as a result, the pressure loss of the airflow can be suppressed.

[0104] <Twelfth embodiment> Next, a twelfth embodiment will be described. Fig. 18 is a horizontal cross-sectional view of a silencer according to the twelfth embodiment. Compared to the silencer 1b according to the second embodiment in Fig. 7A, the silencer 1l according to the twelfth embodiment does not have the partition members D1-D3, and is provided with non-permeable partition members G1a-G4. The partition members G1a and G1b are provided approximately at the center of the silencer outlet of the first silencer unit 11 so as to correspond to two sides of a triangle in the horizontal cross section.

[0105] Specifically, the partition member G1a is provided from the outlet of the muffling part of the first muffling unit 11 toward the surface of the sound absorbing material S5b of the muffling part SL5 of the second muffling unit 12, and / or toward the surface of the sound absorbing material S6a of the muffling part SL6 adjacent to the muffling part SL5 of the second muffling unit 12. In this way, the partition members G1a and G1b are provided so that they are spaced apart from each other from the outlet of the muffling part of the first muffling unit 11 toward the second muffling unit 12. This allows the airflow to be guided to the partition members G1a and G1b and split into separate airflows. Furthermore, vortex generation at the inlet of the secondary silencer can be prevented, and pressure loss can be reduced.

[0106] In this embodiment, the partition members G1a and G1b are disposed at the approximate center of the outlet of the primary silencer in the horizontal cross section. This allows the airflow to be guided to the partition members G1a and G1b and to be divided approximately evenly. The pair of partition members G2a and G2b and the pair of partition members G3a and G3b are also provided in the same positional relationship as the pair of partition members G1a and G1b.

[0107] Also, the air passage does not suddenly narrow at the inlet of the secondary silencer, and pressure loss can be reduced. The partition members G1a to G4 do not have to be flat, and may be curved to match the flow. This can reduce pressure loss. Also, increasing the distance between the first silencing unit 11 and the second silencing unit 12 can reduce pressure loss.

[0108] 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 member G4 and the casing 10 may be used as a resonator or the like.

[0109] <Thirteenth embodiment> Next, the thirteenth embodiment will be described. Fig. 19 is a horizontal cross-sectional view of the silencer according to the thirteenth embodiment. The silencer 1m according to the thirteenth embodiment is different from the silencer 1l according to the twelfth embodiment in Fig. 12 in that the partition members G1a to G4 are removed and partition members G5a to G8 having air permeability are provided. Here, the partition members G5a to G8 are, for example, perforated plates or plates made of a porous material. The triangular prism-shaped space between the partition members G1a to G1b is hollow. This causes a sudden acoustic contraction at the entrance of the secondary silencer group, thereby improving sound reduction.

[0110] At the outlet of the primary silencer group, the airflow is guided by the pair of partition members G1a and G1b, G2a and G2b, and G3a and G3b, and the airflow is divided evenly. In addition, since there is no sudden narrowing at the inlet of the secondary silencer group, pressure loss can be reduced.

[0111] The partition members G5a to G8 may be curved to match the flow, instead of being flat. This can reduce pressure loss. Also, increasing the distance between the first silencing unit 11 and the second silencing unit 12 can reduce pressure loss.

[0112] <Modification 1 of each embodiment> The partition members D1 to D55 and G1a to G8 may be deformed to have curved surfaces in accordance with the airflow, thereby reducing pressure loss.

[0113] <Modification 2 of each embodiment> Although the long axis of each muffling part included in the first muffling unit is shifted horizontally with respect to the long axis of each muffling part included in the first muffling unit, this is not limiting, and they may be shifted vertically. In the case of vertical shifting, the long axis of each muffling part included in the first muffling unit is shifted with respect to the long axis of any muffling part included in the second muffling unit in a direction perpendicular to the long axis in a vertical cross section including the long axis. Furthermore, in a vertical cross section along the longitudinal direction of the casing 10, the range of the internal space of each muffling part included in the first muffling unit does not fall within the range of the internal space of any muffling part included in the second muffling unit in a direction perpendicular to the longitudinal direction.

[0114] <Modification 3 of each embodiment> The secondary silencer group may be arranged at a position rotated around the major axis (axis of airflow) of the muffling section of the primary silencer group with respect to the primary silencer group.

[0115] <Modification 4 of each embodiment> The primary silencer group and the secondary silencer group may be shifted in their relative positions by any combination of horizontal, vertical and rotation.

[0116] In each embodiment and all of the above-mentioned modified examples 1 to 4, the primary silencer group and the secondary silencer group are arranged so that when the air passages of the silencers of the primary silencer group are extended along the major axis, they do not overlap with the inlets of the silencers of the secondary silencer group. More preferably, the primary silencer group and the secondary silencer group are arranged so that when the air passages of the primary silencer group are each extended along the major axis, they do not overlap at all with any inlets of the secondary silencer group.

[0117] In each embodiment and all of the above-mentioned variations 1 to 4, each sound-absorbing section has been described as having a top plate and a bottom plate, but this is not limited thereto, and the top plate and bottom plate may be omitted, and the plate material constituting the sound-absorbing section may extend from the inner bottom surface of the casing to the inner top surface.

[0118] As described above, the present invention is not limited to the above-described embodiment as it is, and in the implementation stage, the components can be modified and embodied without departing from the gist of the invention. In addition, various inventions can be formed by appropriately combining the multiple components disclosed in the above-described embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, components from different embodiments may be appropriately combined. [Explanation of symbols]

[0119] 1~1m silencer 10 Casing 11, 11a First silencer unit 12, 12a Second silencer unit B1~B8 Bottom plate U1~U8 Top plate D1~D55, H12, H14 Partition members H1~H4, H11, H13 Shielding material H121, H141 Sound wave inlet P11a~P38 Plate material S11a~S38 Sound absorbing material SL1~SL8 Silencer

Claims

1. A casing; a first sound-absorbing unit including a pair of plate members arranged at a distance from each other within the casing to form a hollow, substantially rectangular parallelepiped sound-absorbing section, and a sound-absorbing material provided on at least one of the opposing surfaces of the pair of plate members; a second sound-absorbing unit including a pair of plate members arranged at a distance from each other within the casing to form a hollow, substantially rectangular parallelepiped sound-absorbing section, and a sound-absorbing material provided on at least one of the opposing surfaces of the pair of plate members; a plurality of partition members provided between the first and second muffler units and guiding an air flow, the partition members having air permeability; Equipped with The first silencer unit and the second silencer unit are arranged at an interval in a longitudinal direction of the casing, a long axis of each of the muffling sections included in the first muffling unit is shifted in a direction perpendicular to the long axis with respect to a long axis of any of the muffling sections included in the second muffling unit in a cross section including the long axis, In a cross section along the longitudinal direction of the casing, in a direction perpendicular to the longitudinal direction, the range of the internal space of the muffling section included in the first muffling unit does not fall within the range of the internal space of any of the muffling sections included in the second muffling unit. Silencer.

2. The partition member is a perforated plate or a plate made of a porous material.

2. The silencer of claim 1.

3. A casing, a first sound-absorbing unit including a pair of plate members arranged at a distance from each other within the casing to form a hollow, substantially rectangular parallelepiped sound-absorbing section, and a sound-absorbing material provided on at least one of the opposing surfaces of the pair of plate members; a second sound-absorbing unit including a pair of plate members arranged at a distance from each other within the casing to form a hollow, substantially rectangular parallelepiped sound-absorbing section, and a sound-absorbing material provided on at least one of the opposing surfaces of the pair of plate members; a plurality of partition members provided between the first and second sound-absorbing units and guiding an airflow, the partition members being non-breathable and made of a material that is non-breathable but acoustically transparent; Equipped with The first silencer unit and the second silencer unit are arranged at an interval in a longitudinal direction of the casing, a long axis of each of the muffling sections included in the first muffling unit is shifted in a direction perpendicular to the long axis with respect to a long axis of any of the muffling sections included in the second muffling unit in a cross section including the long axis, In a cross section along the longitudinal direction of the casing, in a direction perpendicular to the longitudinal direction, the range of the internal space of the muffling section included in the first muffling unit does not fall within the range of the internal space of any of the muffling sections included in the second muffling unit. Silencer.

4. The acoustically transparent material from which the partition member is formed is a material that transmits sound waves in a frequency band of 250 Hz or less.

4. The silencer of claim 3.

5. A casing, a first sound-absorbing unit including a pair of plate members arranged at a distance from each other within the casing to form a hollow, substantially rectangular parallelepiped sound-absorbing section, and a sound-absorbing material provided on at least one of the opposing surfaces of the pair of plate members; a second sound-absorbing unit including a pair of plate members arranged at a distance from each other within the casing to form a hollow, substantially rectangular parallelepiped sound-absorbing section, and a sound-absorbing material provided on at least one of the opposing surfaces of the pair of plate members; a plurality of partition members provided between the first and second muffler units to guide an airflow, the partition members being provided so as to extend in a longitudinal direction of the casing from an outlet of the muffler section of the first muffler unit toward the second muffler unit; Equipped with The first silencer unit and the second silencer unit are arranged at an interval in a longitudinal direction of the casing, a long axis of each of the muffling sections included in the first muffling unit is shifted in a direction perpendicular to the long axis with respect to a long axis of any of the muffling sections included in the second muffling unit in a cross section including the long axis, In a cross section along the longitudinal direction of the casing, in a direction perpendicular to the longitudinal direction, the range of the internal space of the muffling section included in the first muffling unit does not fall within the range of the internal space of any of the muffling sections included in the second muffling unit. Silencer.

6. The partition member is provided so as to extend in the longitudinal direction of the casing from the plate member of the first silencing unit toward the second silencing unit. A silencer according to any one of claims 1 to 4.

7. A casing; a first sound-absorbing unit including a pair of plate members arranged at a distance from each other within the casing to form a hollow, substantially rectangular parallelepiped sound-absorbing section, and a sound-absorbing material provided on at least one of the opposing surfaces of the pair of plate members; a second sound-absorbing unit including a pair of plate members arranged at a distance from each other within the casing to form a hollow, substantially rectangular parallelepiped sound-absorbing section, and a sound-absorbing material provided on at least one of the opposing surfaces of the pair of plate members; a plurality of partition members provided between the first and second muffler units to guide airflow, the partition members being provided so as to extend the plate material of the first muffler unit toward one of the plate materials of the second muffler unit; Equipped with The first silencer unit and the second silencer unit are arranged at an interval in a longitudinal direction of the casing, a long axis of each of the muffling sections included in the first muffling unit is shifted in a direction perpendicular to the long axis with respect to a long axis of any of the muffling sections included in the second muffling unit in a cross section including the long axis, In a cross section along the longitudinal direction of the casing, in a direction perpendicular to the longitudinal direction, the range of the internal space of the muffling section included in the first muffling unit does not fall within the range of the internal space of any of the muffling sections included in the second muffling unit. Silencer.

8. A casing, a first sound-absorbing unit including a pair of plate members arranged at a distance from each other within the casing to form a hollow, substantially rectangular parallelepiped sound-absorbing section, and a sound-absorbing material provided on at least one of the opposing surfaces of the pair of plate members; a second sound-absorbing unit including a pair of plate members arranged at a distance from each other within the casing to form a hollow, substantially rectangular parallelepiped sound-absorbing section, and a sound-absorbing material provided on at least one of the opposing surfaces of the pair of plate members; Equipped with The first silencer unit and the second silencer unit are arranged at an interval in a longitudinal direction of the casing, a long axis of each of the muffling sections included in the first muffling unit is shifted in a direction perpendicular to the long axis with respect to a long axis of any of the muffling sections included in the second muffling unit in a cross section including the long axis, the first silencing unit has a shielding material between the plate material of the first silencing unit and the casing, the shielding material blocking air from entering from the opposite side to the second silencing unit; In a cross section along the longitudinal direction of the casing, in a direction perpendicular to the longitudinal direction, the range of the internal space of the muffling section included in the first muffling unit does not fall within the range of the internal space of any of the muffling sections included in the second muffling unit. Silencer.

9. The shielding material has an opening toward the second sound-absorbing unit so as to reduce or absorb sound.

9. The silencer of claim 8.

10. A casing; a first sound-absorbing unit including a pair of plate members arranged at a distance from each other within the casing to form a hollow, substantially rectangular parallelepiped sound-absorbing section, and a sound-absorbing material provided on at least one of the opposing surfaces of the pair of plate members; a second sound-absorbing unit including a pair of plate members arranged at a distance from each other within the casing to form a hollow, substantially rectangular parallelepiped sound-absorbing section, and a sound-absorbing material provided on at least one of the opposing surfaces of the pair of plate members; Equipped with The first silencer unit and the second silencer unit are arranged at an interval in a longitudinal direction of the casing, a long axis of each of the muffling sections included in the first muffling unit is shifted in a direction perpendicular to the long axis with respect to a long axis of any of the muffling sections included in the second muffling unit in a cross section including the long axis, the second silencing unit has a shielding material between the plate material of the second silencing unit and the casing, the shielding material blocking air from entering from the first silencing unit side; In a cross section along the longitudinal direction of the casing, in a direction perpendicular to the longitudinal direction, the range of the internal space of the muffling section included in the first muffling unit does not fall within the range of the internal space of any of the muffling sections included in the second muffling unit. Silencer.

11. The shielding material has an opening toward the first silencing unit or on the airflow outlet side of the second silencing unit so as to reduce or absorb sound.

11. The silencer of claim 10.

12. Among the plurality of partition members, the end partition members are provided so as to extend the plate material at the end of the first silencing unit toward the plate material at the end of the second silencing unit, and the partition members have openings.

8. The silencer of claim 7.

13. A casing; a first sound-absorbing unit including a pair of plate members arranged at a distance from each other within the casing to form a hollow, substantially rectangular parallelepiped sound-absorbing section, and a sound-absorbing material provided on at least one of the opposing surfaces of the pair of plate members; a second sound-absorbing unit including a pair of plate members arranged at a distance from each other within the casing to form a hollow, substantially rectangular parallelepiped sound-absorbing section, and a sound-absorbing material provided on at least one of the opposing surfaces of the pair of plate members; a plurality of partition members provided between the first and second muffler units and guiding an airflow, the partition members being provided from an outlet of the muffler section of the first muffler unit toward an inlet of the muffler section of the second muffler unit; Equipped with The first silencer unit and the second silencer unit are arranged at an interval in a longitudinal direction of the casing, a long axis of each of the muffling sections included in the first muffling unit is shifted in a direction perpendicular to the long axis with respect to a long axis of any of the muffling sections included in the second muffling unit in a cross section including the long axis, In a cross section along the longitudinal direction of the casing, in a direction perpendicular to the longitudinal direction, the range of the internal space of the muffling section included in the first muffling unit does not fall within the range of the internal space of any of the muffling sections included in the second muffling unit. Silencer.

14. A housing, a first sound-absorbing unit including a pair of plate members arranged at a distance from each other within the casing to form a hollow, substantially rectangular parallelepiped sound-absorbing section, and a sound-absorbing material provided on at least one of the opposing surfaces of the pair of plate members; a second sound-absorbing unit including a pair of plate members arranged at a distance from each other within the casing to form a hollow, substantially rectangular parallelepiped sound-absorbing section, and a sound-absorbing material provided on at least one of the opposing surfaces of the pair of plate members; a plurality of partition members provided between the first and second muffler units and guiding an airflow, the partition members being provided so as to be spaced apart from each other as they approach the second muffler unit from the first muffler unit, starting from an outlet of the muffler section of the first muffler unit; Equipped with The first silencer unit and the second silencer unit are arranged at an interval in a longitudinal direction of the casing, a long axis of each of the muffling sections included in the first muffling unit is shifted in a direction perpendicular to the long axis with respect to a long axis of any of the muffling sections included in the second muffling unit in a cross section including the long axis, In a cross section along the longitudinal direction of the casing, in a direction perpendicular to the longitudinal direction, the range of the internal space of the muffling section included in the first muffling unit does not fall within the range of the internal space of any of the muffling sections included in the second muffling unit. Silencer.

15. The distance between the first and second muffling units is 0.5 to 2 m. A silencer according to any one of claims 1 to 14.

16. The long axis of the muffling section is an intersection of diagonals of a rectangle when the internal space of the muffling section is cut in a cross section perpendicular to the longitudinal direction. A silencer according to any one of claims 1 to 15.

17. In a cross section parallel to the major axis of the muffling part, a width of an internal space of the muffling part of the first muffling unit in a direction perpendicular to the major axis is substantially the same as a width of an internal space of the muffling part of the second muffling unit in a direction perpendicular to the major axis. A silencer according to any one of claims 1 to 16.

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