Soundproof structure

Abstract

Provided is a soundproof structure that is used for a blower, has a wide band from a low-frequency band, and has uniform soundproof performance. The soundproof structure is provided in an opening of the blower having a fan and a housing surrounding the fan and having the opening for passing wind generated by the fan. The soundproof structure has a box shape having an internal space, has a ventilation part for passing air from the opening, and has an opened part for connecting the ventilation part with the internal space on at least a portion of a surface where the ventilation part and the internal space are in contact with each other. When viewed in a direction perpendicular to the opening surface of the ventilation part, the internal space has a portion where the distance from the center position of the ventilation part to an outer shape position of the internal space varies.

Description

Soundproofing structure

[0001] The present invention relates to a soundproof structure.

[0002] 2. Description of the Related Art Fan-equipped blower devices used in outdoor units of air conditioners, fan devices for refrigerators, and the like are configured to discharge heated exhaust air from an exhaust port to the outside of the device.

[0003] In such a blower, the driving noise of the blower is released outside the device along with the exhaust air. To reduce this noise, blowers with fans, such as outdoor units for air conditioners, are required to be soundproofed while maintaining ventilation performance.

[0004] For example, Patent Document 1 describes a refrigerator including a fan device provided inside the refrigerator body, a bell-mouth forming member provided with a circular bell-mouth surrounding the fan of the fan device, and a Helmholtz resonator provided in the bell-mouth forming member near the bell-mouth.

[0005] Japanese Patent Application Publication No. 10-306972

[0006] The spectrum of noise generated by a blower often has a broadband, flat distribution that includes the low-frequency range of 1000 Hz or less. Therefore, soundproof structures used in blowers are required to have soundproofing performance that is as broadband as possible from the low-frequency range and as flat as possible. However, conventional soundproof structures have not been able to provide sufficient soundproofing effect.

[0007] The object of the present invention is to solve the problems of the above-mentioned conventional technology and to provide a soundproof structure to be used in a blower, which has flat soundproofing performance from the low frequency range to a wide band.

[0008] To solve this problem, the present invention has the following configurations. [1] A soundproof structure to be provided at an opening of a blower device having a fan and a housing surrounding the fan and having an opening for passing airflow generated by the fan, the soundproof structure having a box-like shape with an internal space, a ventilation section for passing airflow from the opening, and an open section communicating the ventilation section with the internal space on at least a portion of a surface where the ventilation section and the internal space meet, the soundproof structure having portions where the distance from the center of the ventilation section to the outer shape of the internal space varies when viewed from a direction perpendicular to the opening surface of the ventilation section. [2] The soundproof structure according to [1], wherein the outer shape of the internal space when viewed from a direction perpendicular to the opening surface of the ventilation section is a non-circular shape with at least a portion being linear. [3] The soundproof structure according to [1] or [2], wherein the outer shape of the internal space when viewed from a direction perpendicular to the opening surface of the ventilation section is a polygonal shape. [4] The soundproof structure according to [1] or [2], wherein the outer shape of the internal space when viewed from a direction perpendicular to the opening surface of the ventilation section is rectangular. [5] The soundproof structure according to any one of [1] to [4], wherein the area of ​​the ventilation section when viewed from a direction perpendicular to the opening surface of the ventilation section is equal to or larger than the area of ​​the opening of the housing. [6] The soundproof structure according to any one of [1] to [5], wherein the opening surface of the ventilation section is shaped like a circle. [7] The soundproof structure according to any one of [1] to [6], wherein the soundproof structure has a plurality of openings. [8] The soundproof structure has a sound-absorbing material that converts sound energy into thermal energy and absorbs sound, and is arranged in at least one of the internal space and a position covering the opening. [9] The soundproof structure according to any one of [1] to [7], wherein the internal space is unpartitioned and communicates with each other.

[10] The soundproof structure according to any one of [1] to [9], wherein the soundproof structure has a through-hole that communicates the internal space with the outside.

[11] The soundproof structure according to any one of [1] to

[10] , wherein the soundproof structure attached to the air blower entirely overlaps with the housing of the air blower when viewed from the direction of the rotation axis of the fan of the air blower.

[12] The soundproof structure according to any one of [1] to

[11] , wherein the opening of the air blower to which the soundproof structure is attached is an exhaust port.

[13] The soundproof structure according to any one of [1] to

[12] , wherein the soundproof structure has an attachment portion for a fan grill.

[14] The soundproof structure according to any one of [1] to

[13] , wherein the mounting portion of the fan grill is on the opposite side to the surface on which the soundproof structure is mounted to the air blower.

[0009] According to the present invention, it is possible to provide a soundproof structure for use in a blower, which has flat soundproofing performance from the low frequency range to a wide frequency band.

[0010] 1 is a perspective view conceptually showing an example of a soundproof structure of the present invention installed in an air blower. It is a front view of FIG. 1. It is a cross-sectional view taken along line A-A of FIG. 2. It is a cross-sectional view taken along line B-B of FIG. 3. It is a conceptual diagram for explaining the action of the soundproof structure of the present invention. It is a cross-sectional view conceptually showing another example of a soundproof structure of the present invention. It is a cross-sectional view conceptually showing another example of a soundproof structure of the present invention. It is a cross-sectional view conceptually showing another example of a soundproof structure of the present invention. It is a cross-sectional view conceptually showing another example of a soundproof structure of the present invention. It is a perspective view conceptually showing another example of a soundproof structure of the present invention installed in an air blower. It is a cross-sectional view of the soundproof structure shown in FIG. 10. It is a perspective view conceptually showing another example of a soundproof structure of the present invention installed in an air blower. It is a cross-sectional view of the soundproof structure shown in FIG. 12. It is a cross-sectional view conceptually showing another example of a soundproof structure of the present invention. It is a cross-sectional view conceptually showing another example of a soundproof structure of the present invention. It is a cross-sectional view conceptually showing another example of a soundproof structure of the present invention. It is a cross-sectional view conceptually showing another example of a soundproof structure of the present invention installed in an air blower. Fig. 1 is a cross-sectional view conceptually showing a state in which an example of the soundproof structure of the present invention is installed on another example of a blower. Fig. 2 is a graph showing the relationship between frequency and silencing volume. Fig. 3 is a graph showing the relationship between frequency and silencing volume. Fig. 4 is a graph showing the relationship between frequency and silencing volume. Fig. 5 is a graph showing the relationship between frequency and silencing volume. Fig. 6 is a cross-sectional view conceptually showing a state in which a soundproof structure of a comparative example is installed on a blower.

[0011] The present invention will be described in detail below. The following description of the components will be based on a representative embodiment of the present invention, but the present invention is not limited to such an embodiment.

[0012] In this specification, a numerical range expressed using "to" means a range that includes the numerical values ​​before and after "to" as the lower and upper limits.

[0013] In this specification, the terms "orthogonal," "perpendicular," and "parallel" include the range of error acceptable in the technical field to which the present invention pertains. For example, "orthogonal," "perpendicular," and "parallel" mean that the error is within a range of less than ±10° from the strict orthogonal, perpendicular, or parallel, and the error from the strict orthogonal, perpendicular, or parallel is preferably 5° or less, and more preferably 3° or less.

[0014] In this specification, the terms "same" and the like include a margin of error generally accepted in the technical field.

[0015] [Soundproof structure] The soundproof structure of the present invention is a soundproof structure provided at an opening of a blower device having a fan and a housing surrounding the fan and having an opening for passing air generated by the fan, wherein the soundproof structure is box-shaped with an internal space, has a ventilation section for passing air from the opening, and has an open section connecting the ventilation section to the internal space on at least a part of the surface where the ventilation section and the internal space meet, and when viewed from a direction perpendicular to the opening surface of the ventilation section, the internal space has portions where the distance from the center position of the ventilation section to the outer shape position of the internal space varies.

[0016] The configuration of the soundproof structure of the present invention will be described with reference to the drawings.

[0017] Fig. 1 is a perspective view showing an example of a soundproof structure of the present invention installed in a blower. Fig. 2 is a front view of Fig. 1. Fig. 3 is a cross-sectional view taken along line A-A in Fig. 2. Fig. 4 is a cross-sectional view taken along line B-B in Fig. 3.

[0018] The soundproof structure 10 shown in Fig. 1 is provided in an opening 106 of a housing 104 of a blower 100, through which air from the fan 102 passes. In the example shown in Fig. 1, the opening 106 is an exhaust port through which air from the fan 102 is discharged, and the soundproof structure 10 is disposed on the outer surface of the housing 104 where the exhaust port is provided. Note that the blades of the fan 102 are not shown in Fig. 1.

[0019] 1, the opening 106 in the blower device 100 is open so as to pass air in the direction of the rotation axis of the fan 102. The cross section of the opening 106 perpendicular to the direction of the rotation axis has a substantially circular shape.

[0020] There are no particular limitations on the type of blower device 100, as long as it has a fan 102 and a housing 104 surrounding the fan 102, and the housing 104 has an opening 106 for passing air generated by the rotation of the fan 102. Examples of blower device 100 include outdoor units for air conditioners, cooling fans for devices (computers, servers, electronic devices, medical devices, office equipment, home appliances, etc.), axial fans and air conditioning systems for mobility radiators, cooling towers in factories and power plants, air exchangers for buildings and shopping malls, etc., air and heat exchangers in agricultural greenhouses, ventilation and dust exhaust systems within factories, and spot cooler systems using fans.

[0021] The illustrated blower device 100 is an example of an outdoor unit for an air conditioner, and has a heat exchanger 108 on the surface opposite the back (opening 106) and on a side. The heat exchanger 108 has many fine slit-like through-holes, so air is drawn into the blower device 100 through the heat exchanger 108 (through-holes) on the back and side. The heat exchanger 108 is a heat exchanger having a conventionally known configuration.

[0022] In the example blower 100 shown in Fig. 3, the opening 106 is substantially circular, and its center substantially coincides with the rotation axis of the fan. The example blower 100 shown in Fig. 3 also has a bell mouth 110 disposed in the opening 106. The bell mouth 110 is a cylindrical member whose diameter changes in the direction of the rotation axis of the fan, with the diameter of the end on the fan 102 side substantially coinciding with the outer diameter of the blades of the fan 102 and the diameter of the end on the opening 106 side substantially coinciding with the diameter of the opening 106.

[0023] Although not shown in the illustrated example, the blower 100 may have a fan grill or the like. The fan grill may be disposed between the opening 106 and the soundproof structure 10, or may be disposed on the surface of the soundproof structure 10 opposite to the blower 100 side, as in the example shown in Fig. 18 described later.

[0024] The opening 106 of the blower 100 may be an exhaust port for discharging the air generated by the fan 102, or an intake port for drawing in air. That is, the soundproof structure 10 may be disposed on the exhaust port side of the blower 100, on the intake port side, or on both the exhaust port side and the intake port side.

[0025] 2 to 4, the soundproof structure 10 is a component that includes a box-shaped casing 12 having a ventilation section 16 that penetrates from one side to the other and that allows air to pass through from an opening 106, and an internal space 14 that is provided surrounding the periphery of the ventilation section 16, and that has an opening 18 that connects the internal space 14 to the ventilation section 16 on at least a portion of the surface where the ventilation section 16 and the internal space 14 meet. Specifically, in the soundproof structure 10 of the example shown in FIGS. 2 to 4, the casing 12 is substantially rectangular parallelepiped-shaped with an internal space, and is formed with the ventilation section 16 that penetrates in the direction of the rotation axis of the fan 102 when installed and has a substantially circular cross section, and an inner wall member is provided on a portion of the side of the ventilation section 16 that separates the ventilation section 16 from the internal space 14 of the casing 12, and the internal space 14 and the ventilation section 16 are connected by the opening 18 where no inner wall member is provided.

[0026] In other words, the soundproof structure 10 has a substantially rectangular shape with a substantially circular through hole provided in the approximate center, and includes two plate members 50 arranged spaced apart from each other, four side plate members 52 extending from one plate member 50 to the other plate member 50 on each of the four sides of the plate members 50 in a direction perpendicular to the main surface, and four inner wall members 54 extending from one plate member 50 to the other plate member 50 along a portion of the edge of the through hole in the plate members 50 in a direction perpendicular to the main surface. The four inner wall members 54 are arranged at equal intervals along the edge of the through hole in the plate members 50. In the example shown in FIG. 4 , the inner wall members 54 are arranged on the left-right and top-bottom edges of the through hole in the plate members 50. As a result, the soundproof structure 10 has an internal space 14 surrounded by two plate members 50, four side plate members 52, and four inner wall members 54, a ventilation section 16 that passes through from the through hole of one plate member 50 to the through hole of the other plate member 50, and openings 18 that are formed between the inner wall members 54 and communicate between the internal space 14 and the ventilation section 16. In the example shown in Figure 4, the openings 18 are formed at four locations diagonally around the edge of the through hole in the plate member 50.

[0027] As shown in Fig. 4 , when the soundproof structure 10 is viewed from a direction perpendicular to the opening of the ventilation section 16 (a direction perpendicular to the plane of the paper in Fig. 4 ), the outer shape of the internal space 14 is rectangular (quadrilateral). In this case, as shown in Fig. 5 , for example, the distance in the diagonal direction from the center position of the ventilation section 16 (the center position of the through hole in the plate member 50) to the outer position of the internal space 14 (the position of the side plate member 52) is different from the distance in the left-right or up-down direction from the center position of the ventilation section 16 to the outer position of the internal space 14. Therefore, the internal space 14 has portions where the distance from the center position of the ventilation section 16 (the center position of the through hole in the plate member 50) to the outer position of the internal space 14 (the position of the side plate member 52) is different.

[0028] As shown in Figures 2 and 3, this soundproof structure 10 is disposed so that the direction perpendicular to the opening surface of the ventilation section 16 is approximately aligned with the direction of the rotational axis of the fan 102 of the air blower 100. When viewed from a direction perpendicular to the opening surface of the ventilation section 16, the soundproof structure 10 is disposed so that the center of the ventilation section 16 is approximately aligned with the rotational axis of the fan 102 of the air blower 100. Therefore, the internal space 14 has portions where the distance from the rotational axis of the fan 102 to the outer periphery of the internal space 14 varies. In a preferred embodiment, when viewed from a direction perpendicular to the opening surface of the ventilation section 16, the area of ​​the ventilation section 16 of the soundproof structure 10 is equal to or greater than the area of ​​the opening 106 of the air blower 100. Therefore, the air discharged from the opening 106 of the air blower 100 is not blocked and is discharged to the outside through the ventilation section 16.

[0029] At this time, at least a portion of the sound generated by the fan 102 of the blower device 100 passes through the opening 106, the ventilation section 16, and the open section 18 of the soundproof structure 10 into the internal space 14. The sound that enters the internal space 14 is damped by resonance within the internal space 14 and by sound-absorbing materials, etc., as described below. Since the internal space 14 has regions where the distance from the center of the ventilation section 16 to the outer edge of the internal space 14 varies, for example, a damping effect can be obtained for lower frequency sounds in the diagonal direction of the internal space 14 (the direction from one corner of the internal space 14 through the ventilation section 16 to the corner diagonally opposite), and a damping effect can be obtained for higher frequency sounds in the direction where the shortest distance is from the ventilation section 16 (inner wall member 54) to the outer edge of the internal space 14 (side panel member 52). In the present invention, the distance from the ventilation section 16 to the outer edge of the internal space 14 (side plate member 52) in the radial direction passing through the center of the ventilation section 16 and the length between the walls (the length from the side plate member 52 to the side plate member 52, and the length from the inner wall member 54 to the side plate member 52) vary depending on the direction, so that it is possible to prevent strong resonance at a specific frequency and increase the sound deadening effect only at that frequency, thereby achieving flat sound deadening. Therefore, the soundproof structure 10 of the present invention can achieve flat sound deadening effect over a wide frequency range from low frequencies.

[0030] In the example shown in Fig. 4, no other components are disposed within the internal space 14, but this is not limiting, and a sound-absorbing material 20 may be disposed within the internal space 14, as in the soundproof structure 10b shown in Fig. 6. The sound-absorbing material 20 is a material that absorbs sound by converting sound energy into thermal energy. By providing the sound-absorbing material 20 within the internal space 14, sound can be more effectively attenuated, and a wide-band, flat sound-attenuation effect can be obtained.

[0031] 6, the sound-absorbing material 20 is configured to be disposed over substantially the entire interior space 14, but this is not limiting, and the sound-absorbing material 20 may be configured to be disposed in only a portion of the interior space 14. The sound-absorbing material 20 may also be disposed in a position that covers the opening 18 of the ventilation section 16 that connects the interior space 14 to the ventilation section 16, or may be disposed both within the interior space 14 and in a position that covers the opening 18. The sound-absorbing material 20 may also be divided into multiple pieces and disposed within the interior space 14.

[0032] As the sound absorbing material 20, any conventionally known sound absorbing material can be appropriately used. For example, foam, foam material (urethane foam (e.g., Calmflex F manufactured by Inoac Corporation, urethane foam manufactured by Hikari Corporation, etc.), soft urethane foam, ceramic particle sintered material, phenol foam, melamine foam, polyamide foam, etc.), nonwoven fabric sound absorbing material (microfiber nonwoven fabric (e.g., Thinsulate manufactured by 3M), polyester nonwoven fabric (e.g., White Q-on manufactured by Tokyo Bouon Co., Ltd., QonPET manufactured by Bridgestone KBG Corporation, Micro Q-on manufactured by Taihei Felt Kogyo Co., Ltd., etc.), Various known sound-absorbing materials can be used, including Chromat, and these products are also available in a two-layer structure consisting of a thin, high-density surface nonwoven fabric and a low-density backing nonwoven fabric), plastic nonwoven fabrics such as acrylic fiber nonwoven fabrics, natural fiber nonwoven fabrics such as wool and felt, metal nonwoven fabrics, and glass nonwoven fabrics), as well as woven fabrics and other materials containing minute air bubbles (glass wool, rock wool, nanofiber-based fiber sound-absorbing materials (silica nanofiber, acrylic nanofiber (for example, XAI manufactured by Mitsubishi Chemical Corporation)).

[0033] Furthermore, a thin structure with high flow resistance, such as a high-density thin nonwoven or woven fabric or a structure with minute through holes such as punched metal, can be arranged particularly at the interface of the open portion 18, and sufficient acoustic resistance can be provided with a thin structure. Such a thin structure with high flow resistance can be arranged in the open portion 18, and sound-absorbing material 20 can also be arranged in the interior space 14.

[0034] In the examples shown in FIGS. 7 to 17 described later, the sound absorbing material 20 may also be disposed in the interior space 14 and / or in a position that covers the open portion 18 .

[0035] In the example shown in Fig. 4, the soundproof structure 10 has four openings 18 connecting the internal space 14 and the ventilation section 16, but this is not limiting. For example, as in the soundproof structure 10c shown in Fig. 7, the entire surface where the ventilation section 16 and the internal space 14 come into contact may be an opening 18. In other words, the soundproof structure 10c does not have an inner wall member 54. Alternatively, the soundproof structure may have one opening 18 where a portion of the surface where the ventilation section 16 and the internal space 14 come into contact is closed, or may have two openings 18, three openings 18, or five or more openings 18, as in the soundproof structure 10d shown in Fig. 8.

[0036] 4 and 8, the plurality of open portions 18 have the same size, but this is not limited thereto, and the plurality of open portions 18 may have different sizes. Also, in the examples shown in Fig. 4 and 8, the intervals between adjacent open portions 18 in the circumferential direction are constant, but this is not limited thereto, and the intervals between open portions 18 may be different.

[0037] 4, when viewed from a direction perpendicular to the opening surface of the ventilation section 16, the openings 18 are formed at four diagonal edges of the ventilation section 16. However, this is not limited to this configuration and the openings 18 may be formed at any circumferential position around the ventilation section 16. A configuration in which the openings 18 are formed at diagonal edges of the ventilation section 16 is preferable because it increases the length between the walls in the diagonal direction passing through the center of the ventilation section 16 within the internal space 14, thereby more suitably achieving a flat sound-deadening effect from low frequencies to a wide band. Furthermore, this configuration is not limited to this, and a configuration in which the openings face each other can be preferable because it increases the length between the walls.

[0038] 4, the outer shape of the internal space 14 of the soundproof structure 10 is substantially square when viewed from a direction perpendicular to the opening surface of the ventilation section 16, but is not limited to this. The outer shape of the internal space 14 of the soundproof structure 10 can be various shapes such as rectangular, polygonal, circular, elliptical, or irregular, as long as it has portions that are different distances from the center position of the ventilation section 16 when viewed from a direction perpendicular to the opening surface of the ventilation section 16. When viewed from a direction perpendicular to the opening surface of the ventilation section 16, the outer shape of the internal space 14 of the soundproof structure 10 is preferably at least partially linear and non-circular, more preferably polygonal, and even more preferably quadrangular (rectangular).

[0039] Specifically, for example, as in a soundproof structure 10e shown in Fig. 9, the outer shape of the internal space 14 of the soundproof structure 10e may be rectangular when viewed from a direction perpendicular to the opening surface of the ventilation section 16. In the example shown in Fig. 9, the outer shape of the casing 12e when viewed from a direction perpendicular to the opening surface of the ventilation section 16 is rectangular.

[0040] Furthermore, the external shape of the internal space 14 of the soundproof structure 10 when viewed from a direction perpendicular to the opening surface of the ventilation section 16 may be polygonal. For example, in the soundproof structure 10g shown in Figures 10 and 11, the external shape of the internal space 14 of the soundproof structure 10e when viewed from a direction perpendicular to the opening surface of the ventilation section 16 is a regular pentagon. In the example shown in Figures 10 and 11, the external shape of the casing 12g when viewed from a direction perpendicular to the opening surface of the ventilation section 16 is a regular pentagon.

[0041] Furthermore, when the external shape of the internal space 14 of the soundproof structure 10 is polygonal when viewed from a direction perpendicular to the opening of the ventilation section 16, it does not need to be a regular polygon, and the lengths of the sides of the polygon may be different. For example, in the soundproof structure 10h shown in Figures 12 and 13, the external shape of the internal space 14 of the soundproof structure 10h when viewed from a direction perpendicular to the opening of the ventilation section 16 is octagonal, with long and short sides alternately combined. In the example shown in Figures 12 and 13, the external shape of the casing 12h when viewed from a direction perpendicular to the opening of the ventilation section 16 is also octagonal. In other words, the external shape of the internal space 14 of the soundproof structure 10h is quadrangular with C-chamfered corners.

[0042] In addition, in the example shown in Figure 4, etc., when viewed from a direction perpendicular to the opening surface of the ventilation section 16, the center position of the ventilation section 16 is configured to be located at a position that approximately coincides with the center position of the outer shape of the internal space 14, but this is not limited to this.

[0043] For example, in a soundproof structure 10f shown in Fig. 14, the outer shape of the internal space 14 is rectangular when viewed from a direction perpendicular to the opening surface of the ventilation section 16, and the ventilation section 16 is provided at a position offset from the center position of the outer shape of the internal space 14. In other words, the ventilation section 16 is provided at an eccentric position with respect to the casing 12f of the soundproof structure 10f. By providing the ventilation section 16 at an eccentric position in this manner, the difference in the length between the walls in the internal space 14 (the length between the walls in the radial direction passing through the center of the ventilation section 16) between different directions becomes larger, which is preferable in that a flat sound deadening effect can be obtained from the low frequency range to a wide band.

[0044] 15 shows a soundproof structure 10i in which the internal space 14 has a circular outer shape when viewed from a direction perpendicular to the opening of the ventilation section 16, and the ventilation section 16 is provided at a position offset from the center of the outer shape of the internal space 14. In other words, the ventilation section 16 is provided at an eccentric position with respect to the casing 12i of the soundproof structure 10i. In this way, even if the internal space 14 has a circular outer shape, by providing the ventilation section 16 at an eccentric position, it is possible to achieve a configuration in which there are regions where the distance from the center of the ventilation section 16 to the outer shape of the internal space 14 varies when viewed from a direction perpendicular to the opening of the ventilation section 16.

[0045] In the example shown in FIG. 4 and the like, the internal space is configured to be continuous without being partitioned in the circumferential direction, but the present invention is not limited to this.

[0046] As in a soundproof structure 10j shown in Fig. 16 , a casing 12j may have a partition member 22 that separates the internal space 14. The soundproof structure 10j shown in Fig. 16 has partition members 22 connected to side plate members 52 and inner wall members 54 on both the upper and lower sides of the ventilation section 16 in Fig. 16 . Thus, in the soundproof structure 10j, the internal space 14 is separated into two by the two partition members 22. Providing the partition members 22 can ensure the rigidity of the soundproof structure 10j.

[0047] In the example shown in FIG. 16, the internal space 14 is configured to be divided into two sections, but this is not limitative, and the internal space 14 may be divided into three or more sections.

[0048] Furthermore, when the internal space 14 is divided, the volumes of the divided internal spaces may be the same or different.

[0049] In addition, in the example shown in Figure 16, the partition members 22 are configured to be provided on both the upper and lower sides of the ventilation section 16, but this is not limited to this, and the partition members 22 may be provided at any position within the internal space 14.

[0050] From the viewpoint of obtaining a flat sound deadening effect over a wide frequency range from the low frequency range, it is preferable that the internal space is continuous and not partitioned in the circumferential direction.

[0051] 17, a casing 12k may have pillar members 24 that hold the plate members 50 at a predetermined distance from each other without dividing the internal space 14. The soundproof structure 10k shown in Fig. 17 has pillar members 24 at left-right symmetrical positions above the ventilation section 16 and at left-right symmetrical positions below the ventilation section 16 within the internal space 14.

[0052] By providing the pillar members 24, the rigidity of the soundproof structure 10k can be ensured while maintaining the circumferential communication of the internal space.

[0053] 4 and the like, the shape of the opening surface of the ventilation section 16 when viewed from a direction perpendicular to the opening surface of the ventilation section 16 is circular, but is not limited to this and may be various shapes such as rectangular, polygonal, elliptical, irregular, etc. Note that, since the ventilation section 16 is arranged so as to overlap the opening 106 of the blower device 100 through which the air generated by the fan 102 passes, from the viewpoint of not blocking the air from the fan 102 and ensuring the size of the internal space 14, it is preferable that the shape of the opening surface of the ventilation section 16 is circular.

[0054] Furthermore, from the viewpoint of not blocking the wind from fan 102, it is preferable that the area of ​​ventilation section 16 when viewed from a direction perpendicular to the opening surface of ventilation section 16 is equal to or larger than the area of ​​opening 106 of housing 104 of blower device 100. In other words, when viewed from a direction perpendicular to the opening surface of ventilation section 16, if opening 106 of housing 104 is circular and the opening surface of ventilation section 16 is also circular, it is preferable that the diameter of ventilation section 16 is equal to or larger than the diameter of opening 106.

[0055] 1, 2, 10, and 12, it is preferable that the soundproof structure 10 attached to the air blower 100 entirely overlaps with the housing 104 of the air blower 100 when viewed from the direction of the rotation axis of the fan 102 of the air blower 100. In other words, it is preferable that the soundproof structure 10 does not protrude from the housing 104 of the air blower 100 when viewed from the direction of the rotation axis of the fan 102 of the air blower 100.

[0056] Here, in the present invention, the soundproof structure preferably has a mounting portion for the fan grill, and the mounting portion for the fan grill is preferably located on the opposite side to the surface on which the soundproof structure is mounted to the air blower.

[0057] FIG. 18 is a cross-sectional view conceptually showing another example of a soundproof structure of the present invention installed in a blower.

[0058] 18, soundproof structure 10 is installed on air blower 100, and fan grill 120 is attached to the side of soundproof structure 10 opposite to the side attached to air blower 100. That is, air blower 100, soundproof structure 10, and fan grill 120 are arranged in this order.

[0059] This allows the distance between the blower device 100 and the fan grill 120 to be greater than when the fan grill 120 is attached directly to the blower device 100, thereby suppressing wind noise when the wind generated from the blower device 100 (fan 102) passes through the fan grill 120.

[0060] The fan grill 120 prevents people or foreign objects from coming into contact with the rotating fan 102, and / or rectifies the discharged air. There are no particular limitations on the type of fan grill 120, and any conventional fan grill known in the art that is suitable for the air blower 100 can be used.

[0061] Here, the dimensions of each part of the soundproof structure, such as the dimensions of the ventilation section and the dimensions of the internal space, may be set appropriately depending on the air blower 100 to which the soundproof structure is attached.

[0062] In the example shown in FIG. 3 etc., an outdoor unit for an air conditioner is shown as the blower device 100, but as mentioned above, the invention is not limited to this and can be applied to various blower devices.

[0063] 19 shows an example in which the blower device 100b is an axial flow fan, and the soundproof structure 10 is disposed at an opening 106 of the axial flow fan. The housing 104 of the blower device 100b has an opening 106 that penetrates in the direction of the rotation axis of the fan 102 and passes the air generated by the fan 102. The soundproof structure 10 may be disposed on either the intake side or the exhaust side of the opening 106, but is preferably disposed on the exhaust side in order to obtain a greater soundproofing effect.

[0064] Here, the soundproof structure of the present invention may have a through hole that connects the internal space with the outside. For example, the soundproof structure 10 may have a through hole on the surface of the casing 12 opposite the ventilation section 16 (side panel member 52, hereinafter also referred to as the back surface). By opening a through hole on the back surface, the acoustic characteristics including resonance in the internal space 14 of the soundproof structure change, making it possible to adjust the frequency band to be silenced. Furthermore, by providing a mechanism for opening and closing the through hole, it becomes possible to configure the soundproof structure so that the frequency band to be silenced can be changed.

[0065] Furthermore, by arranging the through-holes below the soundproof structure 10 when it is installed on the air blower 100, it becomes possible to discharge water, dust, and the like that have entered the internal space 14 of the soundproof structure 10 to the outside, which also has the effect of improving environmental compatibility with outdoor environments. In this case, by not arranging the sound-absorbing material 20 around the through-holes and by providing cutouts that serve as water flow paths toward the through-holes, it becomes possible to make it easier for water to be discharged to the outside.

[0066] Materials for forming the members (plate members 50, side plate members 52, inner wall members 54, partition members 22, and pillar members 24) that make up the casing 12 of the soundproof structure 10 include metal materials, resin materials, reinforced plastic materials, and carbon fiber. Examples of metal materials include aluminum, titanium, magnesium, tungsten, iron, steel, chromium, chromium molybdenum, nichrome molybdenum, zinc-plated steel sheet, and alloys of these. The surfaces of these materials may be subjected to an anti-rust treatment. Examples of resin materials include acrylic resin (PMMA), polymethyl methacrylate, polycarbonate, polyamide, polyarylate, polyetherimide, polyacetal, polyetheretherketone, polyphenylene sulfide, polysulfone, polyethylene terephthalate, polybutylene terephthalate (PET), polyimide, triacetyl cellulose (TAC), polypropylene (PP), polyethylene (PE), polystyrene (PS), ABS resin (acrylonitrile, butadiene, styrene copolymer synthetic resin), flame-retardant ABS resin, ASA resin (acrylonitrile, styrene, acrylate copolymer synthetic resin), PVC (polyvinyl chloride) resin, and PLA (polylactic acid) resin. Examples of reinforced plastic materials include carbon fiber reinforced plastics (CFRP) and glass fiber reinforced plastics (GFRP).

[0067] From the viewpoints of weight reduction and ease of molding, it is preferable to use a resin material as the material for the housing. Furthermore, from the viewpoint of sound insulation in the low-frequency range, it is preferable to use a material with high rigidity. Furthermore, it is desirable to use a metal material, particularly for environmental compatibility in outdoor environments. By using a metal material coated with anti-rust paint, it is possible to achieve high durability in wind, rain, and extremely high and low temperature environments.

[0068] It is desirable that these materials are non-combustible, flame-retardant, and self-extinguishing. It is also desirable that the entire soundproof structure be non-combustible, flame-retardant, and self-extinguishing.

[0069] The soundproof structure of the present invention has been described in detail above, but the present invention is not limited to the above examples, and various improvements and modifications may be made within the scope of the gist of the present invention.

[0070] The present invention will be described in more detail below with reference to examples. The materials, amounts used, ratios, treatment contents, treatment procedures, etc. shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the examples shown below.

[0071] [Comparative Example 1] Acrylic plates (thickness 5 mm) were cut using a laser cutter, and the cut acrylic plates were combined to produce a soundproof structure in which the outer shape of the internal space was circular, and when viewed from a direction perpendicular to the opening surface of the ventilation section, the distance from the center position of the ventilation section to the outer shape of the internal space was constant (see Figure 26).

[0072] Specifically, the soundproof structure had a circular interior space with a diameter of 550 mm, a ventilator with a diameter of 430 mm, and a height of 110 mm in the direction perpendicular to the opening of the ventilator (the height of the interior space was 100 mm). Acrylic plates (inner wall members) were arranged at 45° intervals in four directions (top, bottom, left, and right) on the surface where the ventilator and interior space meet, providing four openings. The area ratio of the openings to the inner wall members was 1:1.

[0073] Furthermore, sound-absorbing material was placed throughout the entire interior space. Micromat (manufactured by Taihei Felt Kogyo Co., Ltd.) was used as the sound-absorbing material. The flow resistance of this sound-absorbing material was determined by sound absorption coefficient evaluation, and the average flow resistance was 1000 Rayls / m.

[0074] Comparative Example 2 A soundproof structure was produced in the same manner as in Comparative Example 1, except that the height of the soundproof structure in the direction perpendicular to the opening face of the ventilation section was 60 mm (the height of the internal space was 50 mm).

[0075] [Example 1] Acrylic plates (thickness 5 mm) were cut using a laser cutter, and the cut acrylic plates were combined to produce a soundproof structure in which the outer shape of the internal space was rectangular, and when viewed from a direction perpendicular to the opening surface of the ventilation section, the internal space had portions where the distance from the center position of the ventilation section to the outer shape position of the internal space varied.

[0076] Specifically, the soundproof structure had a rectangular interior space measuring 425 mm x 525 mm, a ventilator diameter of 430 mm, and a height perpendicular to the opening of the ventilator of 110 mm (the height of the interior space being 100 mm). Acrylic plates (inner wall members) were arranged at 45° intervals in four directions (top, bottom, left, and right) on the surface where the ventilator and interior space meet, providing four openings. In other words, the openings were arranged diagonally. The area ratio of the openings to the interior wall members was 1:1. The volume of the interior space in Example 1 was approximately the same as that of Comparative Example 1.

[0077] As in Comparative Example 1, sound absorbing materials (micromats) were placed in almost the entire interior space.

[0078] Example 2 A soundproof structure was produced in the same manner as in Example 1, except that the height of the soundproof structure in the direction perpendicular to the opening face of the ventilation section was 60 mm (the height of the internal space was 50 mm).

[0079] [Evaluation] An air conditioning outdoor unit (Daikin air conditioner outdoor unit R22ZES) was placed in a semi-anechoic chamber. The fan was rotated at a rotation speed of 1000 rpm, and the sound volume was measured. Measurements were taken by placing microphones at a position with a radius of 1.14 m and a height of 1.14 m, centered on the fan shaft of the outdoor unit. The front of the exhaust port was set to 0°, and measurements were taken with eight microphones surrounding the outdoor unit at 45° intervals. The sound pressure values ​​measured by each microphone were designated p1 to p8, and their energy (the squared value of the sound pressure p1 2 ~p8 2 ) was used as the noise level (p1 2 +p2 2 +...+p8 2 ) The frequency band was measured and evaluated for each 1 / 3 octave band.

[0080] First, the noise spectrum of the original outdoor unit was measured without installing the soundproof structure. Next, the noise spectrum after installing the soundproof structures of each Example and Comparative Example to the outdoor unit was measured, and the noise spectrum was subtracted from the noise spectrum of the original outdoor unit to evaluate the soundproofing performance (quantity of soundproofing (dB)) of each soundproof structure.

[0081] FIG. 20 shows a graph comparing the measurement results of the sound deadening volume between Example 1 and Comparative Example 1, both of which have the same height of 100 mm, and FIG. 21 shows a graph comparing the measurement results of the sound deadening volume between Example 2 and Comparative Example 2, both of which have the same height of 50 mm.

[0082] 20 and 21 show that the example of the present invention has less variation in the amount of attenuation at each frequency compared to the comparative example, and that the amount of attenuation is higher in the low frequency range around 450 Hz. From the above, it can be seen that the soundproof structure of the present invention has a flat sound pressure in the frequency range typical of noise generated by fans, and can achieve higher sound attenuation performance against loud noises from low frequencies compared to the comparative example.

[0083] [Example 3] A soundproof structure was fabricated in the same manner as in Example 1, except that the outer shape of the internal space when viewed from a direction perpendicular to the opening face of the ventilation section was a regular pentagon, as shown in Figure 11. The distance from the center of the pentagon to each vertex was 315 mm.

[0084] [Evaluation] The sound deadening performance (amount of deadening (dB)) of the soundproof structure was evaluated in the same manner as above. The results are shown in Fig. 22. Fig. 22 is a graph comparing the measurement results of the amount of deadening in Example 3 and Comparative Example 1.

[0085] From FIG. 22, it can be seen that in Example 3 of the present invention, the variation in the amount of silencing for each frequency is smaller than in Comparative Example 1, and the amount of silencing is higher in the low frequency range around 450 Hz.

[0086] [Example 4] A soundproof structure was fabricated in the same manner as in Example 1, except that the external shape of the internal space when viewed from a direction perpendicular to the opening face of the ventilation section was made octagonal, as shown in Figure 13. Specifically, each of the four corners of the rectangular structure of Example 1 was made into an octagonal structure with a C-chamfered shape, with sides 20 mm long.

[0087] [Evaluation] The sound deadening performance (amount of deadening (dB)) of the soundproof structure was evaluated in the same manner as above. The results are shown in Fig. 23. Fig. 23 is a graph comparing the measurement results of the amount of deadening for Example 4, Example 1, and Comparative Example 1.

[0088] 23 shows that Example 4 of the present invention has less variation in the amount of attenuation at each frequency than Comparative Example 1, and that the amount of attenuation is higher in the low frequency range around 450 Hz. Furthermore, Example 4 obtains a sound deadening spectrum similar to that of Example 1, and it can be seen that a polygonal soundproof structure can obtain higher sound deadening performance than the soundproof structure of Comparative Example 1 (circular shape).

[0089] Example 5 A soundproof structure was produced in the same manner as in Example 1, except that no inner wall member was provided and all surfaces where the ventilation section and the internal space come into contact were open.

[0090] Comparative Example 3 A soundproof structure was produced in the same manner as in Comparative Example 1, except that no inner wall member was provided and all surfaces where the ventilation section and the internal space come into contact were open.

[0091] [Evaluation] In the same manner as above, the soundproofing performance (quantity of sound deadening (dB)) of the soundproof structures of Example 5 and Comparative Example 3 was evaluated. The results are shown in Fig. 24. Fig. 24 is a graph comparing the measurement results of the quantity of sound deadening of Example 5 and Comparative Example 3.

[0092] 24 shows that in Example 5 and Comparative Example 3, all surfaces where the ventilation section and the internal space come into contact are open, and therefore the frequency band in which sound deadening performance is exhibited is shifted overall to the higher frequency side compared to Example 1 and Comparative Example 1. Even in this case, Example 5 shows less variation in the amount of sound deadening at each frequency compared to Comparative Example 3, and the amount of sound deadening in the low frequency range is higher.

[0093] Example 6 A soundproof structure was produced in the same manner as in Example 1, except that no sound-absorbing material was used.

[0094] Comparative Example 4 A soundproof structure was produced in the same manner as in Comparative Example 1, except that no sound-absorbing material was used.

[0095] [Evaluation] In the same manner as above, the soundproofing performance (quantity of sound deadening (dB)) of the soundproof structures of Example 6 and Comparative Example 4 was evaluated. The results are shown in Fig. 25. Fig. 25 is a graph comparing the measurement results of the quantity of sound deadening of Example 6 and Comparative Example 4.

[0096] 25, it can be seen that in Example 6, the variation in the amount of attenuation at each frequency is smaller than in Comparative Example 4, and the amount of attenuation in the low frequency range is higher. The above results clearly show the effects of the present invention.

[0097] 10, 10b to 10k Soundproof structure 12, 12e to 12k Casing 14 Internal space 16 Ventilation section 18 Open section 20 Sound absorbing material 22 Partition member 24 Pillar member 50 Plate member 52 Side plate member 54 Inner wall member 100 Blower device 102 Fan 104 Housing 106 Opening 120 Fan grill

Claims

1. A soundproofing structure provided at an opening of a blower having a fan and a housing surrounding the fan and having an opening for passing air generated by the fan, wherein the soundproofing structure is box-shaped with an internal space, has a ventilation section for passing air from the opening, and has an open section that connects the ventilation section to the internal space on at least a part of the surface where the ventilation section and the internal space meet, and when viewed from a direction perpendicular to the opening surface of the ventilation section, the internal space has parts where the distance from the center position of the ventilation section to the outer shape position of the internal space varies.

2. The soundproof structure according to claim 1, wherein the outer shape of the internal space when viewed from a direction perpendicular to the opening face of the ventilation section is a non-circular shape with at least a portion being linear.

3. A soundproof structure according to claim 1 or 2, wherein the outer shape of the internal space when viewed from a direction perpendicular to the opening face of the ventilation section is polygonal.

4. A soundproof structure according to claim 1 or 2, wherein the outer shape of the internal space when viewed from a direction perpendicular to the opening face of the ventilation section is rectangular.

5. A soundproof structure according to claim 1 or 2, wherein the area of ​​the ventilation section when viewed from a direction perpendicular to the opening surface of the ventilation section is equal to or larger than the area of ​​the opening of the housing.

6. A soundproof structure according to claim 1 or 2, wherein the opening of the ventilation section has a circular shape.

7. A soundproof structure according to claim 1 or 2, which has a plurality of said open portions.

8. A soundproof structure according to claim 1 or 2, comprising a sound-absorbing material that is arranged in at least one of the interior space and a position that covers the open portion, and that absorbs sound by converting sound energy into thermal energy.

9. A soundproof structure according to claim 1 or 2, wherein the spaces within the interior space are not partitioned but are interconnected.

10. A soundproof structure according to claim 1 or 2, wherein the soundproof structure has a through hole that connects the internal space with the outside.

11. A soundproof structure as described in claim 1 or 2, wherein the soundproof structure attached to the blower device overlaps entirely with the housing of the blower device when viewed from the direction of the rotation axis of the fan of the blower device.

12. The soundproof structure according to claim 1 or 2, wherein the opening of the air blower to which the soundproof structure is attached is an exhaust port.

13. The soundproof structure according to claim 1 or 2, wherein the soundproof structure has a mounting portion for a fan grill.

14. A soundproof structure according to claim 1 or 2, wherein the mounting portion of the fan grill is on the opposite side to the surface on which the soundproof structure is mounted to the air blower.

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