CN114730557A

CN114730557A - Silencer and household electrical appliance with same

Info

Publication number: CN114730557A
Application number: CN202080081124.0A
Authority: CN
Inventors: 渡部真德; 黑泽真理; 金内优; 菅原道太; 藁谷二郎; 千叶浩司
Original assignee: Hitachi Global Life Solutions Inc
Current assignee: Hitachi Global Life Solutions Inc
Priority date: 2019-11-28
Filing date: 2020-08-28
Publication date: 2022-07-08
Also published as: WO2021106296A1

Abstract

A muffler (201) is provided with a main body (210) that houses a plurality of sound tubes (202) having a hollow interior. An opening (211) for passing a housing (101a) of the motor (101) is formed in the center of the main body. Each sound tube has an open one end (A1) and a closed other end (A2), and is disposed such that the one end faces the opening and the other end faces the outer peripheral surface of the main body.

Description

Silencer and household electrical appliance with same

Technical Field

The present invention relates to a muffler and a household electrical appliance provided with the same.

Background

In mechanical devices, silencers are widely used as a means for reducing noise generated by a driving unit such as a motor. A muffler is a device that reduces the transmission of noise by sound absorption, reflection, interference, and the like. The silencer is classified into several types according to the silencing principle, and expansion type, interference type, resonance type, and the like are well known.

As a technique for using such a silencer in a home appliance, for example, techniques described in patent documents 1 and 2 are known. The above patent document describes the following structure: a resonance type silencer is mounted on a blower motor as a noise source of a dust collector, so that noise generated by the blower motor is reduced.

The muffler described in patent document 1 is configured such that the periphery of a housing of a motor is surrounded by a wall member, a cavity (acoustic pipe) for resonating acoustic waves is disposed outside the wall member, and acoustic waves radiated from the housing of the motor are guided from an opening at an end of the wall member to the inside of the cavity. On the other hand, the muffler described in patent document 2 is configured such that the periphery of the housing of the motor is surrounded by a wall member, a cavity (acoustic pipe) for resonating the acoustic wave is disposed outside the wall member, and the acoustic wave radiated from the housing of the motor is guided to the inside of the cavity through a hole provided in the wall member.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open No. 2006 and 314595

Patent document 2: japanese laid-open patent publication No. H07-031564

Disclosure of Invention

Problems to be solved by the invention

However, since the conventional resonance-type mufflers described in patent documents 1 and 2 have a wall member around the housing of the motor, the size of the entire muffler tends to be large, and it is difficult to achieve miniaturization.

The present invention has been made to solve the above-described problems, and a main object thereof is to provide a resonance type muffler that is reduced in size and noise generated by a motor, and a home appliance including the muffler.

Means for solving the problems

In order to achieve the above object, the present invention provides a muffler including a main body portion having a plurality of sound tubes each having a cavity therein, wherein an opening portion through which a housing of a motor passes is formed in a central portion of the main body portion, each of the sound tubes has one open end and the other closed end, and the one end is disposed in a direction toward the opening portion and the other end is disposed in a direction toward an outer peripheral surface of the main body portion.

Other schemes are described below.

The effects of the invention are as follows.

According to the present invention, it is possible to reduce noise generated by the motor while achieving miniaturization.

Drawings

Fig. 1 is a perspective view showing an external appearance of a washing machine as an example of a home appliance on which a muffler according to embodiment 1 is mounted.

Fig. 2 is a vertical sectional view showing an internal structure of a washing machine as an example of a home appliance on which the muffler of embodiment 1 is mounted.

Fig. 3 is a longitudinal sectional view showing a structure in the vicinity of a motor of the washing machine in an enlarged manner.

Fig. 4 is a perspective view showing the appearance of the muffler of embodiment 1.

Fig. 5 is a perspective view showing a structure in which the muffler of embodiment 1 is attached to a motor.

Fig. 6 is a vertical cross-sectional view showing a structure in which the muffler of embodiment 1 is attached to a motor.

Fig. 7 is a cross-sectional view showing a structure in which the muffler of embodiment 1 is attached to a motor.

Fig. 8 is a schematic view showing the shape of the sound pipe of the muffler of embodiment 1.

Fig. 9 is a waveform diagram showing the noise reduction effect of the muffler of embodiment 1.

Fig. 10 is a cross-sectional view showing the structure of a muffler of embodiment 2.

Fig. 11 is a cross-sectional view showing the structure of a muffler of embodiment 3.

Fig. 12 is a longitudinal sectional view showing the structure of a muffler according to embodiment 4.

Fig. 13 is a longitudinal sectional view showing the structure of a muffler according to embodiment 5.

Fig. 14 is a longitudinal sectional view showing the structure of a muffler according to embodiment 6.

Fig. 15A is a cross-sectional view showing the structure of the sound tube on the upper layer side in the muffler of embodiment 6.

Fig. 15B is a cross-sectional view showing the structure of the sound tube on the lower layer side in the muffler of embodiment 6.

Fig. 16 is a longitudinal sectional view showing the structure of a muffler according to embodiment 7.

Fig. 17A is a partially cutaway perspective view showing the structure of an upper side member of a muffler of embodiment 7.

Fig. 17B is a partially cut-away perspective view showing the structure of the bottom part (bottom) of the muffler of embodiment 7.

Fig. 18 is a cross-sectional view showing the structure of a muffler of embodiment 8.

Fig. 19A is a vertical sectional view showing an enlarged structure of a vicinity of a motor of a washing machine on which a muffler according to embodiment 9 is mounted.

Fig. 19B is a vertical sectional view showing a structure in which the muffler of embodiment 9 is attached to a motor.

Fig. 20A is a cross-sectional view showing a structure in which the muffler of embodiment 9 is attached to a motor.

Fig. 20B is a cross-sectional view showing a structure in which the muffler of the first modification of embodiment 9 is attached to a motor.

Fig. 20C is a cross-sectional view showing a structure in which the muffler of the second modification of embodiment 9 is attached to a motor.

Fig. 21A is a cross-sectional view showing a structure in which a muffler according to a third modification of embodiment 9 is attached to a motor.

Fig. 21B is a cross-sectional view showing a structure in which the muffler of the fourth modification of embodiment 9 is attached to a motor.

Fig. 21C is a cross-sectional view showing a structure in which the muffler of the fifth modification of embodiment 9 is attached to a motor.

Detailed Description

Hereinafter, an embodiment of the present invention (hereinafter, referred to as "the present embodiment") will be described in detail with reference to the drawings. The drawings are only schematic to the extent that the present invention can be fully understood. Therefore, the present invention is not limited to the illustrated examples. In the drawings, the same reference numerals are given to the common components and the same components, and redundant description thereof will be omitted.

[ embodiment 1]

Structure of household electrical appliance with silencer

The structure of a washing machine S, which is an example of a household appliance on which a muffler 201 (see fig. 3) of embodiment 1 is mounted, will be described below with reference to fig. 1 to 3. Fig. 1 is a perspective view showing an external appearance of a washing machine S as an example of a home appliance on which a muffler 201 according to embodiment 1 is mounted. Fig. 2 is a vertical sectional view showing an internal structure of the washing machine S as an example of a home appliance on which the muffler 201 is mounted. Fig. 3 is a longitudinal sectional view showing a structure in the vicinity of the motor 101 of the washing machine S in an enlarged manner. Here, a case where the washing machine S is a vertical washing machine dryer having a drying function will be described.

As shown in fig. 1 and 2, the washing machine S includes a housing 1, an outer tub 2 (see fig. 2) for storing washing water, a rotary tub 3 (see fig. 2), a drive motor 10 (see fig. 2), a blower 22 (see fig. 2), and the like. The outer tank 2 is built in the outer frame 1 and is supported by the outer frame 1 in a vibration-proof manner. The rotary tub 3 is a washing and dewatering tub for storing laundry such as clothes to be washed and dried, and is provided inside the outer tub 2. The rotary tub 3 is rotatably supported inside the outer tub 2. A stirring blade 4 for stirring and washing laundry is rotatably provided at the bottom of the rotary tub 3. The stirring blade 4 repeats normal rotation and reverse rotation during the washing operation and the drying operation. The stirring blade 4 rotates at a high speed together with the rotary tub 3 during the dehydration operation, and removes water contained in the laundry in the rotary tub 3. The drive motor 10 is provided inside the outer frame 1, and rotationally drives the stirring blade 4 and the rotary tub 3.

An outer cover 5 and a top cover 6 are provided on the upper portion of the outer frame 1. A handle 5a (see fig. 1) and an operation panel 54 are provided on the front side of the outer cover 5. The operation panel 54 is provided with an operation switch 52 (see fig. 1) and a display 53 (see fig. 1). The outer lid 5 is openably and closably provided on the top cover 6. An inner lid 34 is openably and closably provided on the upper part of the outer tub 2. A power switch 51 is provided on the front surface of the top cover 6. In the washing machine S, the laundry can be put into and taken out of the spin basket 3 by opening the outer lid 5 and the inner lid 34. A water supply unit 7 is provided inside the outer frame 1 and on the back side of the top cover 6. The water supply unit 7 includes a water supply tank (not shown) having a plurality of water passages therein, and supplies tap water or bath water flowing from the water supply hose connection port 8 to the outer tub 2. A detergent/softener feeding device 35 is provided on the front side of the top cover 6. The detergent and the softener are injected between the outer tub 2 and the spin tub 3 through the input hose 36.

Washing machine S includes drying mechanism 9 for drying laundry in rotary tub 3. The drying mechanism 9 performs circulation air supply and dehumidification of drying air. The drying mechanism 9 has a blower 22 for sending drying air to the drying air circulation passage. The drying mechanism 9 heats and dries the drying air by the electric heater 24 of the blower 22, and rotates an impeller 104 (see fig. 3) of the blower 22 by the motor 101, thereby conveying the drying air to the inside of the rotary tub 3 through the drying air circulation passage. Thereby, the drying mechanism 9 dries the laundry in the rotary tub 3. A fan or a blower is attached to a rotary shaft 102 (see fig. 3) of the motor 101 as necessary.

The drying air circulation path of the drying mechanism 9 includes a bottom circulation path 20 connected to the bottom of the outer tub 2 so as to communicate therewith, and a vertical dehumidification passage 21 extending upward from the bottom circulation path 20. The suction side of the blower 22 is connected to the upper side of the vertical dehumidification passage 21. The discharge side of the blower 22 is connected to the return connection circulation path 25 so as to communicate therewith. Further, a drying filter 45 is disposed between the blower 22 and the vertical dehumidification passage 21. The washing machine S prevents foreign matter from flowing into the blower 22 by the drying filter 45.

The return connection circulation path 25 has an upper bellows 23, and is connected to the upper portion of the outer tub 2 so as to communicate with the upper bellows 23. The bottom circulation path 20 has a lower bellows 26, and is connected to the bottom of the outer tub 2 via the lower bellows 26 in a communicating manner. The lower bellows 26 is connected to the bottom recess 31 of the outer tub 2.

The bottom recess 31 communicates with the wash water discharge passage 42 and the wash water circulation passage 43 via the lower communication pipe 41. A drain valve 44 is provided in the wash water discharge path 42. A foreign matter removal trap 32 is provided in the washing water circulation water passage 43. The drain valve 44 is closed during the washing operation and the drying operation. On the other hand, when the washing water is discharged, the drain valve 44 is opened to discharge the washing water and the rinse water stored in the outer tub 2 to the outside (outside of the apparatus) of the washing machine S from the washing water discharge passage 42. The washing water circulation water path 43 is connected to a washing water circulation water longitudinal water path 46. The washing water circulating water longitudinal water passage 46 rises along the outer surface of the outer tub 2, extends to the upper side of the rotary tub 3, and is connected to the washing thread end removing device 33 provided on the upper side of the rotary tub 3 in a communicating manner.

An air pipe 49 and an air trap 50 are provided near the bottom of the outer tub 2. The air pipe 49 is connected in communication with an air trap 50. A water level sensor 47 is connected to the upper end of the air pipe 49. The washing machine S detects the water level fluctuation inside the outer tub 2 by the water level sensor 47.

Washing machine S sprays (i.e., sprays) the washing water and the rinsing water stored in outer tub 2 from washing-water-circulation-water longitudinal water passage 46 into rotary tub 3 from washing-lint removing device 33, and injects them into rotary tub 3. At this time, the washing machine S detects the water level of the washing water and the rinsing water stored in the outer tub 2 by the water level sensor 47. The washing machine S performs washing and rinsing in the process of spraying water. Thus, the washing machine S performs washing and rinsing with a small amount of water.

In the washing machine S, for example, when the motor 101 rotates the impeller 104 (see fig. 3) of the blower 22, noise such as electromagnetic sound is generated by the motor 101. This noise is mainly radiated to the outside from the side of the casing 101a (see fig. 3 and 5) of the motor 101. In embodiment 1, in washing machine S, noise is reduced by attaching muffler 201 to the periphery of casing 101a (see fig. 3 and 5) of motor 101. This point will be described below with reference to fig. 3. Further, the muffler 201 has a resonance type structure.

As shown in fig. 3, an impeller 104 (fan) is attached to a rotary shaft 102 of a motor 101. The impeller 104 is covered by the fan housing 103. The fan housing 103 is provided with an air inlet 105. Washing machine S sucks air from air inlet portion 105 and circulates drying air through a drying air circulation path. The fan housing 103 is attached to the motor 101 via vibration-

proof rubbers

106, 107. A muffler 201 is attached to the periphery of the casing 101a of the motor 101. The washing machine S reduces noise such as electromagnetic sound generated by the motor 101 by the muffler 201.

In embodiment 1, washing machine S has a gap between muffler 201 and motor 101. Thus, although the sound insulation performance of washing machine S is reduced, the vibration transmitted from motor 101 to muffler 201 can be cut off. However, whether or not to provide the gap may be determined in consideration of the characteristics of noise generated by the motor 101, the characteristics of vibration, the material of the muffler 201, the cooling of the motor 101, and the like.

< Structure of muffler >

The structure of the muffler 201 will be described below with reference to fig. 4 to 7. Fig. 4 is a perspective view showing an appearance of the muffler 201. Fig. 5 is a perspective view showing a structure when the muffler 201 is attached to the motor 101. Fig. 6 is a vertical sectional view showing a structure when the muffler 201 is attached to the motor 101. Fig. 7 is a cross-sectional view showing a structure when the muffler 201 is attached to the motor 101.

As shown in fig. 4 to 7, the muffler 201 includes a main body portion 210 in which a plurality of sound tubes 202 each having a hollow inside are built. An opening 211 through which the housing 101a of the motor 101 passes is formed in the center of the body 210. The muffler 201 can be molded from a resin material.

As shown in fig. 6, each sound tube 202 has one open end a1 and the other closed end a 2. Each sound tube 202 is disposed in a direction (left-right direction in fig. 6) perpendicular to the axial direction of the opening 211 such that one end a1 faces the opening 211 and the other end a2 faces the outer peripheral surface of the body 210. Thus, a layer in which the plurality of acoustic tubes 202 are arranged on the same plane is formed inside the main body portion 210. The axial direction of the opening 211 is a direction (vertical direction in fig. 6) in which the housing 101a of the motor 101 passes through the opening 211.

As shown in fig. 7, the main body portion 210 of the muffler 201 is formed in a disc shape in a plan view. The opening 211 is formed in a circular shape in a central portion of the main body 210 in a plan view. Therefore, main body 210 of muffler 201 has an annular shape in plan view. The inner diameter of the opening 211 is slightly larger than the diameter of the casing 101a of the motor 101. The acoustic pipes 202 are radially arranged around an opening center 211o (see fig. 7). That is, each acoustic tube 202 is arranged to linearly extend in the normal direction with respect to the circular surface of the opening 211.

In such a muffler 201, when the muffler 201 is attached to the motor 101, the plurality of sound tubes 202 are arranged so as to surround the periphery of the casing 101a of the motor 101. One end a1 (see fig. 6) of the opening of each sound tube 202 faces the casing 101 a.

In the muffler 201, the sound wave radiated from the side surface of the casing 101a of the motor 101 is incident into the sound tube 202 from the open one end a1 (see fig. 6), and is then reflected by the closed other end a2 (see fig. 6) of the sound tube 202. At this time, the muffler 201 can use the sound wave (reflected wave) reflected at the other end a2 to cancel the sound wave (incident wave) incident from the one end a 1. Therefore, the muffler 201 can reduce noise generated by the motor 101.

As shown in fig. 8, the sound tube 202 has a depth length D, a width W, and a height H. Fig. 8 is a diagram showing the shape of the acoustic pipe 202. In fig. 8, the upper right oblique side of the sound tube 202 is the direction of the opening 211.

As shown in fig. 8, in the present embodiment, the acoustic tube 202 has a rectangular parallelepiped shape. The opening 211 of the acoustic pipe 202 has a rectangular cross-sectional shape in the axial direction (vertical direction in fig. 6).

In the present embodiment, the depth length D of the sound tube 202 is set to a length within a range of "(λ × 1/4) ± 10 (%)" with respect to the wavelength λ of the sound wave of the sound attenuation target frequency. That is, the depth D of the sound tube 202 is set to have a length of "(λ × 1/4)" as the center, a lower limit of "(λ × 1/4) -10 (%)" and an upper limit of "(λ × 1/4) +10 (%)". "± 10 (%)" is an allowable value when the depth length D is set.

In the muffler 201, the reflected wave reflected by the other end a2 (see fig. 6) is shifted in phase (wavelength) from the incident wave (sound wave radiated from the motor 101) incident from the one end a1 (see fig. 6) of the opening by 1/2. Therefore, the reflected wave and the incident wave are in opposite phases. Since the muffler 201 can act so as to cancel the reflected wave and the incident wave, the incident wave (the acoustic wave radiated from the motor 101) can be muffled. As a result, the muffler 201 can more efficiently reduce the noise generated by the motor 101.

The width W and height H of the sound tube 202 may be set so that the sound wave of the sound attenuation target frequency becomes a plane wave (i.e., a wave having a wave surface on a plane perpendicular to the traveling direction of the wave) inside the sound tube 202. Therefore, for example, the width W and the height H of the sound tube 202 may be set to be equal to or less than (λ × 1/2) the wavelength λ of the sound wave corresponding to the sound attenuation target frequency. The silencer 201 configured as described above forms (realizes) a plane wave inside each sound tube 202, and can cancel out noise. Thus, the muffler 201 can efficiently reduce noise generated by the motor 101.

However, the shape of the acoustic pipe 202 is determined according to the restriction conditions such as the size of the motor 101, the frequency of the noise to be muffled (the frequency of the frequency band to be muffled), and the space of the home appliance to which the motor 101 is attached. The number of the acoustic pipes 202 is also determined by the restriction conditions such as the size of the motor 101, the frequency of the noise to be reduced, and the space of the home appliance to which the motor 101 is attached.

Fig. 9 is a waveform diagram showing the noise reduction effect of the muffler 201. The motor 101 having the muffler 201 attached thereto is driven to rotate, and the noise at that time is measured, thereby obtaining the waveform diagram of fig. 9. In fig. 9, the horizontal axis represents frequency [ Hz ] and the vertical axis represents noise level [ dBA ]. Here, "dBA" is a unit representing the a characteristic sound pressure level. The "a characteristic" is a frequency weighting characteristic used in the measurement of the noise meter in consideration of human hearing. From the waveform diagram of fig. 9, it is clear that the muffler 201 reduces noise in the vicinity of the frequency R to be muffled.

In particular, the silencer 201 is configured to form (realize) plane waves inside each sound tube 202, and thereby can cancel noise more effectively. Thus, the muffler 201 can further efficiently reduce noise generated by the motor 101.

In addition, when the axial length of the motor 101 is long, there is a possibility that the plane wave does not stand (is realized) in the axial length of the motor 101 (that is, the height of each layer constituted by the plurality of acoustic pipes 202) depending on the frequency of the noise to be suppressed. In this case, the silencer 201 has the multilayer sound tube 202, and thus plane waves can be established (realized) in each layer. In the present embodiment, the muffler 201 has a structure in which two layers are stacked in the vertical direction. However, the number of layers (number of layers) of the acoustic pipe 202 is not limited to two, and may be changed according to the size of the motor 101, the frequency of noise to be suppressed, and the like.

The muffler 201 having the structure of the multi-layered sound tube 202 can reduce noise generated by the motor 101 at each layer. The muffler 201 of this configuration can change the frequency to be muffled in each layer as in the muffler 201C (see fig. 12) of embodiment 4 described below and the muffler 201D (see fig. 13) of embodiment 5 described below.

As described above, in embodiment 1, washing machine S has a gap between muffler 201 and motor 101. That is, the muffler 201 provides a gap between the main body portion 210 and the casing 101a of the motor 101. Thereby, the muffler 201 can cut off the vibration transmitted from the motor 101.

The gap may be filled with a vibration-proof member (not shown) made of a relatively soft material such as rubber or gel. That is, the muffler 201 may be configured such that a vibration isolation member (not shown) is disposed at one end a1 (see fig. 6) of the sound tube 202 of the body 210. Such a muffler 201 can improve sound insulation by a vibration-proof member (not shown) while suppressing vibration transmitted from the motor 101 by the vibration-proof member (not shown). Therefore, the muffler 201 can reduce both vibration and noise generated by the motor 101.

< main characteristics of muffler >

(1) As shown in fig. 4 to 7, the muffler 201 according to embodiment 1 includes a main body portion 210 in which a plurality of sound tubes 202 each having a hollow space therein are built. An opening 211 through which the housing 101a of the motor 101 passes is formed in the center of the body 210. Each of the acoustic pipes 202 has one open end a1 (see fig. 6) and the other closed end a2 (see fig. 6). The sound tubes 202 are arranged such that one end a1 faces the opening 211 and the other end a2 faces the outer peripheral surface of the body 210.

In the muffler 201 of embodiment 1, when the muffler 201 is attached to the motor 101, the plurality of sound tubes 202 are arranged so as to surround the casing 101a of the motor 101. One end a1 (see fig. 6) of the opening of each sound tube 202 faces the casing 101 a.

The acoustic muffler 201 can use the sound wave (reflected wave) reflected by the other end a2 (see fig. 6) to cancel the sound wave (incident wave) incident from the one end a1 (see fig. 6). Therefore, the muffler 201 can reduce noise generated by the motor 101. Unlike the conventional resonance-type silencer described in patent documents 1 and 2, for example, the silencer 201 according to embodiment 1 does not have a wall member around the housing of the motor. Therefore, the muffler 201 of embodiment 1 can be reduced in size as compared with a conventional resonance-type muffler.

(2) As shown in fig. 7, the main body portion 210 of the muffler 201 according to embodiment 1 is formed in a disc shape in a plan view. The opening 211 is formed in a circular shape in a central portion of the main body 210 in a plan view. The acoustic pipes 202 are radially arranged around an opening center 211o (see fig. 7).

In the muffler 201 of embodiment 1, when the muffler 201 is attached to the motor 101, the plurality of sound tubes 202 are arranged to radially surround the periphery of the casing 101a of the motor 101. Therefore, the muffler 201 can efficiently guide the sound waves radiated from the casing 101a of the motor 101 to the respective sound tubes 202. Thus, the muffler 201 can efficiently reduce noise generated by the motor 101.

(3) The depth length D (see fig. 8), which is the length from the one end a1 (see fig. 6) to the other end a2 (see fig. 6), of each sound tube 202 of the muffler 201 according to embodiment 1 may be a length in the range of (λ × 1/4) ± 10 (%) with respect to the wavelength λ of the sound wave of the sound-deadening target frequency.

The muffler 201 according to embodiment 1 can shift 1/2 the phase (wavelength) of the incident wave (the sound wave radiated from the motor 101) incident from the one end a1 (see fig. 6) and the reflected wave reflected from the other end a2 (see fig. 6). That is, the muffler 201 can make the reflected wave and the incident wave have opposite phases. Such a silencer 201 can act so as to cancel the reflected wave and the incident wave. Thereby, the muffler 201 can attenuate an incident wave (acoustic wave radiated from the motor 101). As a result, the muffler 201 can further efficiently reduce noise generated by the motor 101.

(4) As shown in fig. 8, in each sound tube 202 of the silencer 201 according to embodiment 1, the cross-sectional shape of the opening 211 in the axial direction may be a rectangular shape. The width W (see fig. 8) of each sound tube 202 of the silencer 201 may be set to be equal to or smaller than (λ × 1/2) with respect to the wavelength λ of the sound wave of the sound-damping target frequency. The height H (see fig. 8) of each sound tube 202 of the silencer 201 may be set to be equal to or less than (λ × 1/2) with respect to the wavelength λ of the sound wave of the silencing target frequency.

The silencer 201 according to embodiment 1 as described above can form (realize) plane waves inside each acoustic pipe 202, and can cancel out noise. Thus, the muffler 201 can further efficiently reduce noise generated by the motor 101.

(5) As shown in fig. 4 to 7, the main body portion 210 of the muffler 201 according to embodiment 1 may have a plurality of layers in which a plurality of sound tubes 202 are arranged in the axial direction of the opening 211.

The muffler 201 of the present embodiment can reduce noise generated by the motor 101 on a per-layer basis. The muffler 201 can change the frequency of the sound to be muffled for each layer.

(6) As shown in fig. 6, the main body 210 of the muffler 201 according to embodiment 1 may be configured such that the casing 101a of the motor 101 is separated from the one end a1 (see fig. 6) of the sound tube 202 when the casing 101a of the motor 101 passes through the opening 211.

The muffler 201 of the present embodiment can cut off the vibration transmitted from the motor 101 by the gap formed between the body portion 210 and the casing 101a of the motor 101.

(7) In the body portion 210 of the muffler 201 according to embodiment 1, a vibration isolation member (not shown) may be disposed at one end a1 (see fig. 6) of the sound tube 202.

The muffler 201 of the present embodiment can improve sound insulation by the vibration isolation member (not shown) while suppressing vibration transmitted from the motor 101 by the vibration isolation member (not shown). Therefore, the muffler 201 can reduce both vibration and noise generated by the motor 101.

As described above, according to the muffler 201 of embodiment 1, it is possible to reduce noise generated by the motor 101 while achieving downsizing.

[ embodiment 2]

The structure of muffler 201A according to embodiment 2 will be described below with reference to fig. 10. Fig. 10 is a cross-sectional view showing the structure of a muffler 201A according to embodiment 2. Fig. 10 shows the structure of the muffler 201A when not attached to the motor 101.

As shown in fig. 10, muffler 201A according to embodiment 2 is different from muffler 201 (see fig. 7) according to embodiment 1 in that: the body section 210 has an acoustic tube 202A instead of the acoustic tube 202.

The sound tube 202A has a rectangular cross-sectional shape in the longitudinal direction (direction perpendicular to the paper plane), and is arranged to turn around the opening 211 linearly. That is, the sound tube 202A has a rectangular longitudinal sectional shape and is arranged to linearly extend in the clockwise direction or the counterclockwise direction (clockwise direction in the example shown in fig. 10).

The muffler 201A of embodiment 2 can reduce the outer diameter of the muffler 201A while keeping the dimension of the depth L of the center portion of the sound pipe 202A unchanged (i.e., without changing the frequency to be muffled). Therefore, muffler 201A of embodiment 2 can be made smaller than muffler 201 of embodiment 1 (see fig. 7).

The frequency to be silenced is determined by the depth L of the center. Therefore, the center depth length L is increased at a low frequency, and is decreased at a high frequency. Therefore, by providing the sound pipe 202A in the muffler 201A of embodiment 2, even when the same frequency as that of the muffler 201 of embodiment 1 is set as the frequency to be muffled, the overall shape of the muffler 201A can be made smaller than that of the muffler 201 of embodiment 1.

In the muffler 201A according to embodiment 2, the depth of each sound tube 202A differs between the one inner wall surface 301A and the other inner wall surface 301 b. The depth L12 of the other side inner wall surface 301b is longer than the depth L11 of the one side inner wall surface 301 a. Such a muffler 201A can provide a mufflable frequency in a range corresponding to the difference between the depth length L12 and the depth length L11. That is, such a muffler 201A can expand the range of the frequency of the sound-deadening object.

[ embodiment 3]

Next, the structure of muffler 201B according to embodiment 3 will be described with reference to fig. 11. Fig. 11 is a cross-sectional view showing the structure of a muffler 201B according to embodiment 3. Fig. 11 shows the structure of the muffler 201B when not attached to the motor 101.

As shown in fig. 11, muffler 201B according to embodiment 3 is different from muffler 201A (see fig. 10) according to embodiment 2 in that: the body section 210 has an acoustic tube 202B instead of the acoustic tube 202A.

The sound tube 202B has a rectangular cross-sectional shape in the longitudinal direction (direction perpendicular to the paper surface), and is arranged to turn around the opening 211 in an arc shape. That is, the acoustic pipe 202B has a rectangular longitudinal cross-sectional shape, and is disposed so as to extend in a clockwise direction or a counterclockwise direction (in the example shown in fig. 11, the clockwise direction) while curving inward in an arc shape.

Like the muffler 201A of embodiment 2, the muffler 201A of embodiment 2 can reduce the outer diameter of the muffler 201B while keeping the dimension of the depth L of the center portion of the sound pipe 202B unchanged (i.e., without changing the frequency to be muffled). Therefore, like muffler 201A of embodiment 2, muffler 201B of embodiment 3 can be made smaller than muffler 201 of embodiment 1 (see fig. 7).

Further, in the muffler 201B of embodiment 3, since the sound pipe 202B is formed in a shape curved inward in an arc shape, the sound pipe 202B can be formed at a higher density than the muffler 201A of embodiment 2. Therefore, muffler 201B of embodiment 3 can improve noise reduction performance more than muffler 201A of embodiment 2.

Further, in the muffler 201B of embodiment 3, the depth of each sound tube 202B is different between the one side inner wall surface 302a and the other side inner wall surface 302B, as in the muffler 201A of embodiment 2. The depth L22 of the other side inner wall surface 302b is longer than the depth L21 of the one side inner wall surface 302 a. Such a muffler 201B can set the mufflable frequency to a range corresponding to the difference between the depth length L22 and the depth length L21. That is, like muffler 201A of embodiment 2, muffler 201B can expand the range of frequencies to be muffled.

Further, the sound tube 202B of the muffler 201B according to embodiment 3 extends in an arcuate shape curved inward, and the other end a2 of the closed end is shaped so as to be orthogonal to the direction in which the sound tube 202B extends. The sound tube 202B of the muffler 201B of embodiment 3 can have a larger difference between the depth length L22 and the depth length L21 than the sound tube 202A of the muffler 201A of embodiment 2. Further, the depth length of the sound tube 202B of the muffler 201B according to embodiment 3 gradually increases (changes) from the one side inner wall surface 302a to the other side inner wall surface 302B. Thus, the muffler 201B of embodiment 3 can have a wider mufflable frequency range than the muffler 201A of embodiment 2, and can further expand the range of the frequency to be muffled.

The shape of the other end portion a2 of the acoustic pipe 202B is not limited to the illustrated example. In embodiment 3, the other end portion a2 is orthogonal to the direction in which the sound tube 202B extends, but may be parallel to the surface of the open one end portion a 1. However, in this case, the depth length of the sound tube 202B is the same as the depth length L of the center portion at any position from the one side inner wall surface 302a to the other side inner wall surface 302B, and therefore the frequency band of the frequency to be muffled by the muffler 201B of embodiment 3 is single.

[ embodiment 4]

Next, the structure of muffler 201C according to embodiment 4 will be described with reference to fig. 12. Fig. 12 is a vertical sectional view showing the structure of a muffler 201C according to embodiment 4.

As shown in fig. 12, a silencer 201C according to embodiment 4 is different from the silencer 201 (see fig. 6) according to embodiment 1 in that: the depth length of each sound tube 202C differs between upper inner wall surface 202Ca and lower inner wall surface 202 Cb. In embodiment 4, the muffler 201D has two layers, an upper acoustic pipe 202Da and a lower acoustic pipe 202Db, and the depth length of the lower inner wall surface 202Cb is longer than the depth length of the upper inner wall surface 202Ca in each layer.

In embodiment 4, the other end portion a2 of the acoustic pipe 202C is formed as a straight line obliquely inclined surface in a vertical cross section. However, the other end portion a2 may be formed as a surface curved in an arc shape or a stepped surface in a longitudinal cross section, for example.

Like the muffler of the other embodiments, the muffler 201C of embodiment 4 can be reduced in size and reduce noise generated by the motor 101. Further, in muffler 201C according to embodiment 4, since the depth of each sound tube 202C is different between upper inner wall surface 202Ca and lower inner wall surface 202Cb, the mufflable frequencies can be set to a range, and the range of the muffled frequencies can be expanded. The number of layers (number of layers) of the acoustic pipe 202C is not limited to two, and may be changed according to the size of the motor 101, the frequency of noise reduction (the frequency of a frequency band to be reduced in noise), and the like.

[ embodiment 5]

The structure of muffler 201D according to embodiment 5 will be described below with reference to fig. 13. Fig. 13 is a longitudinal sectional view showing the structure of a muffler 201D according to embodiment 5.

As shown in fig. 13, a silencer 201D according to embodiment 5 is different from the silencer 201 (see fig. 6) according to embodiment 1 in that: the depth length of each sound tube 202D differs depending on the layer. In embodiment 5, the muffler 201D has two layers, that is, the sound tube 202Da and the sound tube 202Db, and the depth length of the sound tube 202Da is longer than the depth length of the sound tube 202 Db.

In embodiment 5, the other end portion a2 of the acoustic pipe 202D is formed as a straight surface disposed in the vertical direction in a vertical cross-sectional view. However, the other end portion a2 may be formed as a straight surface inclined obliquely, for example, as in the muffler 201C of embodiment 4. The other end portion a2 may be formed as a curved surface in an arc shape or a stepped surface in a vertical cross section.

Like the muffler of the other embodiments, the muffler 201D of embodiment 5 can be reduced in size and reduce noise generated by the motor 101. Further, in the muffler 201D according to embodiment 5, since the depth of each sound pipe 202D differs depending on the layer, the mufflable frequencies can be set in a range, and the range of the frequencies to be muffled can be expanded. The number of layers (number of layers) of the acoustic pipe 202D is not limited to two, and may be changed according to the size of the motor 101, the frequency of the noise to be suppressed (the frequency of the frequency band to be suppressed), and the like.

[ embodiment 6]

Next, the structure of a muffler 201E according to embodiment 6 will be described with reference to fig. 14, 15A, and 15B. Fig. 14 is a vertical sectional view showing the structure of a muffler 201E according to embodiment 6. Fig. 15A is a cross-sectional view showing the structure of the sound tube 202Ea on the upper layer side in the muffler 201E. Fig. 15B is a cross-sectional view showing the structure of the sound tube 202Eb on the lower layer side in the muffler 201E.

As shown in fig. 14, 15A, and 15B, a muffler 201E according to embodiment 6 is different from muffler 201 (see fig. 3) according to embodiment 1 in that: there is a cooling portion 206 for cooling the motor 101.

As shown in fig. 14, in embodiment 6, a muffler 201E has a two-layer sound pipe 202E of an upper sound pipe 202Ea and a lower sound pipe 202Eb, and the upper sound pipe 202Ea has a cooling portion 206.

As shown in fig. 15A, the cooling unit 206 includes an acoustic pipe 202Ea, an intake port 203, an exhaust port 204, and a partition plate 205. When the muffler 201E is attached to the motor 101, the acoustic pipe 202Ea is formed in a circular pipe shape so as to surround the periphery of the casing 101a of the motor 101. The acoustic pipe 202Ea functions as a passage through which air sucked from the air inlet 203 passes. The acoustic pipe 202Ea is partitioned by a partition plate 205 into a space on the intake port 203 side and a space on the exhaust port 204 side.

The cooling unit 206 takes in air for cooling the motor 101 from the air inlet 203, passes through the acoustic pipe 202Ea, and then is discharged from the air outlet 204. At this time, the cooling unit 206 cools the outer peripheral surface of the casing 101a of the motor 101 by passing air through the acoustic pipe 202 Ea.

As shown in fig. 15B, the layer of the lower sound tube 202Eb has the same structure as the muffler 201 (see fig. 7) of embodiment 1. Therefore, the description is omitted here.

The muffler 201E according to embodiment 6 can reduce noise generated by the motor 101 while cooling the motor 101.

[ embodiment 7]

Next, the structure of muffler 201F according to embodiment 7 will be described with reference to fig. 16, 17A, and 17B. Fig. 16 is a vertical sectional view showing the structure of a muffler 201F according to embodiment 7. Fig. 17A is a partially cutaway perspective view showing the structure of the upper side member 210a of the muffler 201F. Fig. 17B is a partially cut-away perspective view showing the structure of the bottom part 210B (bottom) of the muffler 201F.

As shown in fig. 16, 17A, and 17B, a muffler 201F according to embodiment 7 is different from mufflers according to other embodiments in that: the bottom (bottom member 210b) of body portion 210 has a detachable structure.

As shown in fig. 16, in embodiment 7, body portion 210 of muffler 201F is configured to be separable into upper member 210a and bottom member 210 b. Further, the cross-sectional shape of the muffler 201F in the lateral direction is the same as that of the muffler 201 shown in fig. 7.

Body portion 210 of muffler 201F can be divided into upper member 210a and bottom member 210 b. The upper member 210a and the bottom member 210b can be formed by punching with a die in the axial direction of the opening 211. Therefore, the muffler 201F can be easily manufactured. Like the silencer of the other embodiments, the silencer 201F of embodiment 7 can be reduced in size and reduce noise generated by the motor 101.

In addition, in the case where a circular flange is provided on the bottom of the motor 101, the flange may be used instead of the bottom member 210 b. In this case, the bottom member 210b can be removed.

[ embodiment 8]

Next, the structure of muffler 201G according to embodiment 8 will be described with reference to fig. 18. Fig. 18 is a cross-sectional view showing the structure of a muffler 201G according to embodiment 8.

As shown in fig. 18, a silencer 201G according to embodiment 8 is different from silencers according to other embodiments in that: the main body 210G is formed in a plate shape having a cross shape in a plan view. Opening 211G is formed in a circular shape in a central portion of main body 210G in a plan view. Moreover, the acoustic tubes are arranged so as to be divided into the acoustic tube 202Ga in the first direction and the acoustic tube 202Gb in the second direction orthogonal to the first direction, and the acoustic tubes in the same direction are arranged so as to be parallel to each other.

Like the muffler of the other embodiments, the muffler 201G of embodiment 8 can be reduced in size and reduce noise generated by the motor 101.

[ embodiment 9]

Next, the structure of the muffler 1201 according to embodiment 9 will be described with reference to fig. 19A, 19B, and 20A. Fig. 19A is an enlarged longitudinal sectional view showing a structure in the vicinity of the motor 101 of the washing machine S on which the muffler 1201 of embodiment 9 is mounted. Fig. 19B is a vertical sectional view showing a structure when the muffler 1201 is attached to the motor 101. Fig. 20A is a cross-sectional view showing a structure when the muffler 1201 is attached to the motor 101.

As shown in fig. 19A, the fan housing 103 is attached to the motor 101 via the main body 1210 of the muffler 1201. The fan housing 103 and the muffler 1201 are connected to each other with screws or the like via vibration-proof rubbers 1072. The main body 1210 of the muffler 1201 and the motor 101 are fixed to each other via a vibration-proof rubber 1071 provided on a motor flange 1011 of the motor 101. Motor 101 is attached to fan casing 103 via vibration-proof rubber 106 in the vicinity of the base of rotary shaft 102. The muffler 1201 forms an acoustic space 1202 by the main body portion 1210, the motor flange portion 1011, and the vibration-proof rubber 1071. In washing machine S (see fig. 1), noise such as electromagnetic sound generated by motor 101 is reduced by muffler 1201, and unbalanced vibration of the shaft generated by motor 101 is reduced by vibration-proof rubber 1071.

In embodiment 9, washing machine S is provided with a gap between muffler 1201 and motor 101. Thus, although the sound insulation performance of washing machine S is reduced, the vibration transmitted from motor 101 to muffler 1201 side can be cut off. However, whether or not to provide the gap may be determined in consideration of the characteristics of noise generated by the motor 101, the characteristics of vibration, the material of the muffler 1201, the cooling of the motor 101, and the like.

As shown in fig. 19B, the muffler 1201 includes a plurality of acoustic spaces 1202 each having a hollow interior and formed by the main body 1210, the motor flange 1011, and the vibration-proof rubber 1071. As shown in fig. 20A, the acoustic space 1202 is formed to be partitioned in the axial direction by a wall 1221 from the central direction opening 1211 of the main body portion 1210 to the vicinity of the outer peripheral surface of the main body portion 1210. In the present embodiment, the wall 1221 is formed so that its width increases from the central opening 1211 of the body 1210 toward the outer peripheral surface of the body 1210. Thus, the width W of each acoustic space 1202 is substantially constant in the direction from the center-direction opening 1211 toward the outer peripheral surface of the main body 1210. A central opening 1211 through which the housing 101a of the motor 101 passes is formed in the central portion of the main body 1210. The muffler 1201 can be molded from a resin material.

As shown in fig. 19B, each acoustic space 1202 has one end a1 that is open and the other end a2 that is closed. Each acoustic space 1202 is disposed in a direction (left-right direction in fig. 19B) orthogonal to the axial direction of the central direction opening 1211 such that one end a1 faces the central direction opening 1211 and the other end a2 faces the outer peripheral surface of the main body 1210. Thus, a plurality of acoustic spaces 1202 are formed in the same plane inside the main body 1210. The axial direction of the central opening 1211 is a direction (vertical direction in fig. 19B) in which the housing 101a of the motor 101 passes through the central opening 1211. The bottom surface of the main body 1210 is entirely open.

As shown in fig. 20A, the main body 1210 of the muffler 1201 is formed in an annular shape in a plan view. The central opening 1211 is formed in a circular shape in a central portion of the main body 1210 in a plan view. The inner diameter of the central opening 1211 is slightly larger than the diameter of the casing 101a of the motor 101. The acoustic spaces 1202 are radially arranged around the center of the central opening 1211. That is, each acoustic space 1202 is arranged to linearly extend in the normal direction with respect to the circular surface of the central direction opening 1211.

In such a muffler 1201, when the muffler 1201 is attached to the motor 101, the plurality of acoustic spaces 1202 are arranged to surround the periphery of the casing 101a of the motor 101. One end a1 (see fig. 19B) of the opening of each acoustic space 1202 faces the casing 101 a.

In the acoustic muffler 1201, sound waves radiated from the side surface of the casing 101a of the motor 101 enter the interior of the acoustic space 1202 from one open end a1 (see fig. 19B), and are then reflected by the other closed end a2 (see fig. 19B) of the acoustic space 1202. At this time, the muffler 1201 can use the sound wave (reflected wave) reflected by the other end a2 to cancel the sound wave (incident wave) incident from the one end a 1. Therefore, the muffler 1201 can reduce noise generated by the motor 101.

As shown in fig. 19B and 20A, the acoustic space 1202 is formed by the main body 1210, the vibration-proof rubber 1071, and the motor collar 1011, and has a depth length D (see fig. 19B), a width W (see fig. 20A), and a height H (see fig. 19B). The depth length D of the acoustic space 1202 (i.e., the length of the acoustic space 1202 from the one end a1 (see fig. 19B) to the other end a2 (see fig. 19B)) can be set to be approximately 1/4 as the wavelength of the sound wave with respect to the sound attenuation target frequency. Specifically, the depth length D of the acoustic space 1202 may be a length in a range of (λ × 1/4) ± 10 (%) with respect to the wavelength λ of the sound wave of the sound attenuation target frequency.

Such a silencer 1201 can shift 1/2 the phase (wavelength) of an incident wave (an acoustic wave radiated from the motor 101) incident from one end a1 (see fig. 19B) of the opening and a reflected wave reflected from the other end a2 (see fig. 19B). Therefore, the silencer 1201 can make the incident wave and the reflected wave have opposite phases. Such a silencer 1201 can act so that the reflected wave and the incident wave cancel each other. Thus, the muffler 1201 can muffle the incident wave (the acoustic wave radiated from the motor 101). The muffler 1201 can reduce vibration such as shaft imbalance generated by the motor 101 by the vibration isolation rubber 1071.

Further, the width W and the height H of the acoustic space 1202 may be set such that, inside the acoustic space 1202, the acoustic wave of the sound attenuation target frequency becomes a plane wave (i.e., a wave whose wave surface is on a plane perpendicular to the traveling direction of the wave). Therefore, for example, the width W and the height H of the acoustic space 1202 may be set to be equal to or smaller than (λ × 1/2) with respect to the wavelength λ of the sound wave of the sound attenuation target frequency. The silencer 1201 configured as described above forms (realizes) plane waves in the interior of each acoustic space 1202, and can cancel out noise. Thus, the muffler 1201 can efficiently reduce noise generated by the motor 101.

However, the shape of the acoustic space 1202 is determined by the restriction conditions such as the size of the motor 101, the frequency of the noise to be muffled (the frequency of the frequency band to be muffled), and the space of the home appliance to which the motor 101 is attached. The number of acoustic spaces 1202 is also determined by the restriction conditions such as the size of the motor 101, the frequency of the noise to be reduced, and the space of the home appliance to which the motor 101 is attached.

The muffler 1201 of embodiment 9 (see fig. 20A) can be deformed as shown in fig. 20B to 21C, for example. The structure of each modified example will be described below with reference to fig. 20B to 21C.

< first modification of embodiment 9 >

Fig. 20B is a cross-sectional view showing the structure of a muffler 1201A of a first modification of embodiment 9. Fig. 20B shows the structure of the muffler 1201A when not mounted to the motor 101.

As shown in fig. 20B, a muffler 1201A of the first modification of embodiment 9 is different from the muffler 1201 of embodiment 9 (see fig. 20A) in that: an acoustic space 1202A is formed inside the body portion 1210 instead of the acoustic space 1202.

Like the acoustic space 1202 (see fig. 20A) of the muffler 1201 of embodiment 9, the acoustic space 1202A of the muffler 1201A of the first modification is radially arranged around the center of the central direction opening 1211. However, the acoustic space 1202A of the muffler 1201A of the first modification is different from the acoustic space 1202 (see fig. 20A) of the muffler 1201 of embodiment 9, and the width of each acoustic space 1202 is formed so as to expand from the central direction opening 1211 toward the outer peripheral surface of the body portion 1210 from the width W1 to the width W2. That is, the acoustic space 1202A is formed such that the width of one end portion a1 (see fig. 19B) is a width W1 and the width of the other end portion a2 (see fig. 19B) is a width W2 larger than the width W1 so that the closed other end portion a2 (see fig. 19B) is larger than the open one end portion a1 (see fig. 19B).

In the first modification, the wall 1221a that partitions each acoustic space 1202A of the main body 1210 is formed to have the same width (constant thickness) in the normal direction of the opening. The muffler 1201A of the first modification can expand the width of the acoustic space 1202A from the central direction opening 1211 toward the outer peripheral surface of the main body portion 1210, as compared with the acoustic space 1202 (see fig. 20A) of the muffler 1201 of embodiment 9. Therefore, the muffler 1201A of the first modification can increase the amount of sound waves incident into the acoustic space 1202A, and can improve the muffling effect.

Second modification of embodiment 9

Fig. 20C is a cross-sectional view showing the structure of a muffler 1201B of a second modification of embodiment 9. Fig. 20C shows the structure of the muffler 1201B when not attached to the motor 101.

As shown in fig. 20C, a muffler 1201B according to a second modification of embodiment 9 is different from the muffler 1201A (see fig. 20B) according to the first modification in that: an acoustic space 1202B is formed inside the body portion 1210 instead of the acoustic space 1202A.

In the second modification, the wall 1222 partitioning each acoustic space 1202B of the main body 1210 is formed to have the same width (constant thickness) and to be spiral (i.e., to be rotated) around the center of the main body 1210. The muffler 1201B of the second modification has a rectangular cross-sectional shape in the longitudinal direction (direction perpendicular to the paper plane) of the acoustic space 1202B, and is arranged to turn around the central opening 1211 in an arc shape. That is, the acoustic space 1202B of the muffler 1201B of the second modification has a rectangular longitudinal sectional shape and is arranged to extend in a clockwise direction or a counterclockwise direction (clockwise direction in the example shown in fig. 20C) while being curved inward in an arc shape. The width of the entrance of the acoustic space 1202B is a width W1, and the width of the wall on the back side is a width W2 larger than the width W1.

The muffler 1201B of the second modification can reduce the outer diameter of the muffler 1201B while maintaining the dimension of the depth length D1 (corresponding to the depth length D in fig. 19B) of the acoustic space 1202B (i.e., without changing the sound-deadening target frequency). Therefore, the muffler 1201B of the second modification can be smaller than the muffler 1201 of embodiment 9 (see fig. 19B). In other words, the muffler 1201B of the second modification can perform low-frequency sound attenuation with the same outer diameter as the muffler 1201 of embodiment 9 (see fig. 19B).

< third modification of embodiment 9 >

Fig. 21A is a cross-sectional view showing the structure of a muffler 1201C according to a third modification of embodiment 9. Fig. 21A shows the structure of a muffler 1201C when not attached to the motor 101.

As shown in fig. 21A, a muffler 1201C according to a third modification of embodiment 9 is different from the muffler 1201 of embodiment 9 (see fig. 20A) in that: an acoustic space 1202C is formed inside the body portion 1210 instead of the acoustic space 1202.

Acoustic space 1202C of muffler 1201C of the third modification is different from muffler 1201 of embodiment 9 (see fig. 20A) in that: the main separator 1231 is provided inside. The body partition 1231 is a portion that protrudes inward from the wall on the back side of the acoustic space 1202C and is formed to extend in the axial direction (the mounting direction of the motor 101). The main separator 1231 has a plate-like shape and is radially formed around the center of the main body 1210. The length D2 of the body partition 1231 is shorter than the depth length D of the acoustic space 1202C (i.e., the length from one end a1 (see fig. 19B) to the other end a2 (see fig. 19B)).

As compared with the muffler 1201 of embodiment 9 (see fig. 20A), the muffler 1201C of the third modification can muffle not only sound waves having a frequency corresponding to the depth length D of the acoustic space 1202C, but also sound waves having a frequency corresponding to the length D2 of the body partition 1231. For example, when the length D2 of the body partition 1231 is 1/2 of the depth length D of the acoustic space 1202C, the silencer 1201C of the third modification can silence sound waves at a frequency 2 times that of the silencer 1201 (see fig. 20A) of embodiment 9.

< fourth modification of embodiment 9 >

Fig. 21B is a cross-sectional view showing the structure of a muffler 1201D according to a fourth modification of embodiment 9. Fig. 21B shows the structure of the muffler 1201D when not attached to the motor 101.

As shown in fig. 21B, a muffler 1201D according to a fourth modification of embodiment 9 is different from the muffler 1201A (see fig. 21B) according to the first modification of embodiment 9 in that: an acoustic space 1202D is formed inside the body portion 1210 instead of the acoustic space 1202A.

Acoustic space 1202D of muffler 1201D of the fourth modification is different from muffler 1201A of the first modification (see fig. 20B) in that: the main separator 1231 is provided inside the muffler 1201C (see fig. 20A) of the third modification. As compared with the muffler 1201A of the first modification (see fig. 21B), the muffler 1201D of the fourth modification can muffle not only the sound wave of a frequency corresponding to the depth length D of the acoustic space 1202D but also the sound wave of a frequency corresponding to the length D2 of the body partition 1231.

< fifth modification of embodiment 9 >

Fig. 21C is a cross-sectional view showing the structure of a muffler 1201E according to a fifth modification of embodiment 9. Fig. 21C shows the structure of the muffler 1201E when not attached to the motor 101.

As shown in fig. 21C, a muffler 1201E according to a fifth modification of embodiment 9 is different from a muffler 1201B (see fig. 20C) according to a second modification of embodiment 9 in that: an acoustic space 1202E is formed inside the body portion 1210 instead of the acoustic space 1202B.

Acoustic space 1202E of muffler 1201E of the fifth modification is different from muffler 1201B of the second modification (see fig. 20C) in that: the main separator 1232 is provided inside. The body partition 1232 is a portion that protrudes inward from the wall on the back side of the acoustic space 1202E and is formed to extend in the axial direction (the mounting direction of the motor 101). The main separator 1232 has a plate-like shape and is formed to rotate around the center of the main body 1210. The length D3 of the body partition 1232 is shorter than the depth length D1 of the acoustic space 1202E (i.e., the length from the one end portion a1 (see fig. 19B) to the other end portion a2 (see fig. 19B)).

As compared with the muffler 1201B of the second modification (see fig. 20C), the muffler 1201E of the fifth modification can muffle not only the sound wave of the frequency corresponding to the depth length D1 of the acoustic space 1202E but also the sound wave of the frequency corresponding to the length D3 of the main partition 1232. For example, when the length D3 of the body partition 1232 is 1/2 of the depth length D1 of the acoustic space 1202E, the muffler 1201E of the fifth modification can perform sound attenuation of sound waves of a frequency 2 times that of the muffler 1201B (see fig. 20C) of the second modification.

The present invention is not limited to the above-described embodiments, and includes various modifications. For example, the above-described embodiments have been described in detail to explain the present invention easily and understandably, and are not limited to having all the configurations described. Further, a part of the structure of the embodiment may be replaced with another structure, and another structure may be added to the structure of the embodiment. Further, addition, deletion, and replacement of another configuration can be performed on a part of each configuration.

In the above-described embodiments, an example in which a household electrical appliance is a washing machine is explained. However, the present invention may be applied to household appliances having a motor for driving a fan, a blower, or the like, and to household appliances other than washing machines (for example, household appliances such as a vacuum cleaner, a refrigerator, and an air conditioner).

Description of the symbols

1-outer frame, 2-outer tank, 3-rotary tank, 4-stirring blade, 5-outer cover, 5 a-handle, 6-top cover, 7-water supply unit, 8-water supply hose connection port, 9-drying mechanism, 10-driving motor, 20-bottom circulation path, 21-longitudinal passage for dehumidification, 22-blower, 23-upper corrugated hose, 24-electric heater, 25-return connection circulation path, 26-lower corrugated hose, 31-bottom depression, 32-foreign matter removal trap, 33-washing thread end removal device, 34-inner cover, 35-input device, 41-lower communication pipe, 42-washing water discharge path, 43-washing water circulation path, 44-drain valve, 45-drying filter, 46-washing water circulation longitudinal path, 47-water level sensor, 49-air pipe, 50-air trap, 51-power switch, 52-operation switch, 53-display, 54-operation panel, 101-motor, 101A-housing, 102-rotation axis, 103-fan housing, 104-impeller, 105-air inlet section, 106, 107, 1071, 1072-vibration isolation rubber, 201A, 201B, 201C, 201D, 201E, 201F, 201G-silencer, 202A, 202B, 202C, 202D, 202Da, 202Db, 202Ea, 202Eb, 202Ga, 202 Gb-sound tube, 202 Ca-upper inner wall surface, 202 Cb-lower inner wall surface, 203-air inlet, 204-air outlet, 205-divider, 206-cooling section, 210G-body section, 210 a-upper member, 210B-bottom member (bottom section), 211G-opening section, 211 o-opening section center, 301A, 302A-one side inner wall surface, 301B, 302B-the other side inner wall surface, 1011-motor flange, 1201, a, B, 211C, D, 1201E-silencer, 1202A, 1202B, 1202C, 1202D, 1202E-acoustic space, 1210-body, 1221a, 1222-wall, 1231, 1232-body partition, 1211-central direction opening, a 1-one end, a 2-the other end, D, D1-depth length (length), D2, D3-length, H-height, L-central portion depth length, L11, L12, L21, L22-depth length, R-sound deadening object frequency R, S-washing machine (household appliance), W-width, λ -wavelength.

Claims

1. A silencer is characterized in that the silencer is provided with a silencer body,

a main body part having a plurality of sound tubes with cavities inside,

an opening for passing a motor housing is formed in the center of the main body,

each of the acoustic pipes has one open end and the other closed end, and,

the one end portion is disposed in a direction toward the opening portion, and the other end portion is disposed in a direction toward an outer peripheral surface of the body portion.

2. The muffler of claim 1,

the main body portion is formed in a disc shape in a plan view,

the opening is formed in a circular shape in a central portion of the main body in a plan view,

the acoustic pipes are radially arranged around the center of the opening.

3. The muffler of claim 1,

the main body portion is formed in a disc shape in a plan view,

each of the acoustic pipes is arranged to linearly turn around the opening.

4. The muffler of claim 1,

the main body portion is formed in a disc shape in a plan view,

each of the acoustic pipes is arranged to turn around the opening in an arc shape.

5. The muffler of claim 1,

the main body is formed in a plate shape having a cross shape in a plan view,

each of the above-described sound tubes is arranged so as to be divided into a sound tube in a first direction and a sound tube in a second direction orthogonal to the first direction, and the sound tubes in the same direction are arranged so as to be parallel to each other.

6. The muffler of claim 1,

the length of each of the acoustic pipes from the one end portion to the other end portion is a length in a range of (λ × 1/4) ± 10 (%) with respect to the wavelength λ of the acoustic wave of the frequency to be muffled.

7. The muffler of claim 1,

the width of each of the acoustic pipes is equal to or less than (λ × 1/2) a wavelength λ of the acoustic wave at the sound attenuation target frequency.

8. The muffler of claim 1,

the height of each acoustic pipe is equal to or less than (λ × 1/2) the wavelength λ of the acoustic wave at the frequency of the sound-deadening object.

9. The muffler of claim 1,

in each of the acoustic pipes, the opening has a rectangular cross-sectional shape in the axial direction.

10. The muffler of claim 3,

the length of each of the acoustic pipes from the one end portion to the other end portion is different between the inner wall surface on one side and the inner wall surface on the other side.

11. The muffler of claim 1,

the length of each of the acoustic tubes from the one end portion to the other end portion is different between an upper inner wall surface and a lower inner wall surface.

12. The muffler of claim 1,

the body portion has a plurality of layers in which the plurality of acoustic pipes are arranged in the axial direction of the opening portion.

13. The muffler of claim 12,

the length of each of the acoustic pipes from the one end portion to the other end portion differs depending on the layer.

14. The muffler of claim 12,

the motor has a cooling unit for cooling the motor.

15. The muffler of claim 1,

the main body has a detachable bottom.

16. The muffler of claim 1,

in the main body portion, when the housing of the motor passes through the opening portion, the housing of the motor is separated from one end portion of the acoustic pipe.

17. The muffler of claim 16,

a vibration-proof member is disposed at one end of the acoustic pipe of the body.

18. A silencer is characterized in that the silencer is provided with a silencer body,

comprises an annular main body part with an opening at the bottom and a cavity inside,

a central opening for passing a motor case is formed in a central portion of the main body,

a plurality of acoustic spaces are formed in the main body portion,

the acoustic space is formed so as to be axially partitioned from the central opening of the main body to the vicinity of the outer peripheral surface of the main body.

19. The muffler of claim 18,

the opening in the bottom surface of the main body is closed by a part of the motor and a vibration-proof rubber.

20. The muffler of claim 18,

the central opening is formed in a circular shape in a central portion of the main body in a plan view,

each of the acoustic spaces is radially arranged around the center of the central opening.

21. The muffler of claim 20,

the width of each of the acoustic spaces is constant in a direction from the central direction opening toward the outer peripheral surface of the main body.

22. The muffler of claim 20,

the width of each of the acoustic spaces is increased from the central opening toward the outer peripheral surface of the main body.

23. The muffler of claim 18,

each of the acoustic spaces is arranged to turn around the central opening in an arc shape.

24. The muffler of claim 18,

the length of each of the above-described acoustic spaces from one end portion to the other end portion is a length in a range of (λ × 1/4) ± 10 (%) with respect to the wavelength λ of the sound wave of the sound attenuation target frequency.

25. The muffler of claim 18,

the width of each of the acoustic spaces is equal to or less than (λ × 1/2) with respect to the wavelength λ of the sound wave of the sound attenuation target frequency.

26. The muffler of claim 18,

the height of each of the acoustic spaces is equal to or less than (λ × 1/2) with respect to the wavelength λ of the sound wave of the sound attenuation target frequency.

27. The muffler of claim 18,

each of the above-mentioned acoustic spaces has a body partition formed to be elongated in the axial direction inside,

the length of the main partition is shorter than the length of the acoustic space from one end portion to the other end portion.

28. A home appliance is characterized by comprising:

a motor; and

the muffler of claim 1 attached to the motor.

29. The household electrical appliance of claim 28,

the household appliance is formed as a washing machine.