JP2008061674A - Vacuum cleaner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vacuum cleaner suppressing noise such as NZ noise, or prominent harsh sound generated from an electric blower, and low-frequency wind noise, in a simple constitution. <P>SOLUTION: A silencing means 24 for suppressing the operation noise of the electric blower 2 equipped in a cleaner body 1 includes a planar body 25 having a plurality of holes of specific shape in the thickness direction and fixed to an air passage wall face 26 in the cleaner body 1, a sound absorbing plate 27 laminated on the surface of the planar body 25, and a shielding space 29 by the specific-shaped holes held between the sound absorbing plate 27 and the air passage wall face 26. The shielding space 29 is thus formed with a pseudo swelling space to acoustic waves to provide silencing effects mainly in a low frequency zone, while the sound absorbing plate 27 can provide the silencing effects on noise of a specific frequency determined by the strength of the plate and the height of the shielding space and a high frequency zone, thus providing the silencing effects to the acoustic waves of a plurality of frequencies in a same area. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a vacuum cleaner provided with a silencer for reducing noise propagating with an air flow.

Conventionally, as this type of vacuum cleaner, the outer periphery of the electric blower is covered with a soundproofing cylinder, and a recess that becomes a resonance space is provided on the way to the exhaust port of the soundproofing cylinder, so that an NZ sound that is an annoying protruding sound, What suppresses noises, such as a low-frequency wind noise, is known (for example, refer patent document 1).
JP 2001-165097 A

  However, the conventional configuration requires a plurality of resonance spaces according to the operation mode of the electric blower, which leads to a complicated and large soundproof cylinder shape and is difficult to form an optimal resonance space due to the installation space. Had problems.

  The present invention solves the above-described conventional problems, and provides a vacuum cleaner that suppresses noise such as NZ noise, which is an annoying projecting sound generated from an electric blower, and low-frequency wind noise with a simple configuration. For the purpose.

  In order to solve the above-mentioned conventional problems, the vacuum cleaner of the present invention comprises a cleaner body, an electric blower provided in the cleaner body, and a silencer for suppressing operation noise of the electric blower, and the silencer The means has a plurality of holes of a specific shape in the thickness direction and is fixed to the air passage wall surface in the cleaner body through which operating noise propagates, and a sound absorbing plate laminated on the surface of the surface body, The sound absorbing plate and the air passage wall surface are constituted by a shielded space formed by a hole having a specific shape.

  As a result, the shielding space formed in the planar body forms a pseudo expansion space with respect to the sound wave, and a silencing effect in the low frequency range is mainly obtained and laminated on the surface of the planar body. The sound-absorbing plate can obtain a silencing effect for noise at a specific frequency and high frequency range determined by the strength of the plate and the height of the shielding space, and can silence the sound wave of multiple frequencies within the same area. An effect can be obtained.

  For example, if the dimensions and materials are designed to mute NZ sounds that are likely to be generated in the high frequency range, and the wind noise in the low frequency range in the shielding space of the planar body, The main noise generated can be reduced at the same time, and the vacuum cleaner can be operated without worrying about the sound. In particular, the noise reduction means can obtain a noise reduction effect as long as it is affixed to the wall surface of the air flow path where noise propagates, and it is necessary to create a new molded part that forms an air path such as a soundproof cylinder for noise countermeasures. Therefore, noise countermeasures can be easily implemented at low cost.

  The vacuum cleaner of the present invention can suppress noise such as NZ sound, which is an annoying protruding sound generated from an electric blower, and a low-frequency wind noise with a simple configuration.

  1st invention is equipped with the cleaner main body, the electric blower equipped in the cleaner main body, and the silencing means which suppresses the driving noise of an electric blower, The said silencing means has a plurality of holes of a specific shape in the thickness direction. It is sandwiched between a sheet-like body that is fixed to the air passage wall surface in the main body of the vacuum cleaner where operation noise is propagated, a sound-absorbing plate laminated on the surface of the sheet-like body, and the sound-absorbing plate and the air passage wall surface By using a vacuum cleaner composed of a shielded space with a hole of a specific shape, the shielded space formed in the planar body forms a pseudo expansion space with respect to sound waves, and is mainly low. A sound absorbing plate with a frequency range muffler effect is obtained, and the sound absorbing plate laminated on the surface of the planar body obtains a muffler effect for noise in a specific frequency and high frequency range determined by the strength of the plate and the height of the shielding space. Can be applied to sound waves of multiple frequencies within the same area. Effect can be obtained.

  For example, if the dimensions and materials are designed to mute NZ sounds that are likely to be generated in the high frequency range, and the wind noise in the low frequency range in the shielding space of the planar body, The main noise generated can be reduced at the same time, and the vacuum cleaner can be operated without worrying about the sound. In particular, the noise reduction means can obtain a noise reduction effect as long as it is affixed to the wall surface of the air flow path where noise propagates, and it is necessary to create a new molded part that forms an air path such as a soundproof cylinder for noise countermeasures. Therefore, noise countermeasures can be easily implemented at low cost.

  In the second invention, in particular, in the first invention, the sound absorbing plate laminated on the surface of the planar body is a membrane-like planar body, so that the density, tension and high shielding space of the membrane-like planar body are high. Since the noise of a specific frequency can be reduced by setting according to the frequency to be silenced, the NZ sound generated at the specific frequency by the electric blower can be effectively reduced, and the film-like planar body Since sound is transmitted through the shielded space, the acoustic energy of the sound wave can be attenuated by expanding or resonating in the shielded space. Therefore, 1 kHz or less generated when a large amount of air flows during operation of the electric blower The wind noise can be effectively silenced.

  According to a third invention, in particular, in the first invention, the sound absorbing plate laminated on the surface of the planar body is a porous planar body, so that the pores of the porous planar body have a high frequency range. Excellent noise absorption effect, and can muffle high frequency noise from electric blower in a wide range.

  According to a fourth aspect of the invention, in particular, in the first aspect of the invention, a layer of a porous planar body and a film-like body are simultaneously laminated on the surface of the planar body. This layer and the shielding space layer can simultaneously mute noises in a wide frequency range on the same plane, and a higher silencing effect can be obtained.

  In the fifth aspect of the invention, in particular, in any one of the first to fourth aspects of the invention, at least one of the planar body of the sound deadening means and the sound absorbing plate is sequentially changed in cross-sectional thickness in the air flow direction. Therefore, the depth of the shielded space of the planar body will be set widely, especially when the sound absorption by the sound absorbing plate, it will be able to handle a wide range of frequencies, when the operating condition of the electric blower changes, or due to the change in environmental temperature Even when a deviation occurs in the frequency characteristics of the sound wave, a plurality of pseudo depths of the shielding space of the planar body are set in a pseudo manner, so that a silencing effect can be stably obtained. Note that a greater effect can be obtained by sequentially changing the cross-sectional thicknesses of both the planar body and the sound absorbing plate.

  According to a sixth aspect of the invention, in particular, in the fifth aspect of the invention, the sequential change of the cross-sectional thickness in the air flow direction is simulated on the side closer to the sound source because the thicker portion is located on the upstream side of the air flow. Since a noise expansion space can be ensured by securing a general expansion space to reduce noise in the low frequency range and expanding the air path toward the downstream side, the noise reduction effect for noise in the low frequency range is further enhanced.

  In the seventh invention, in particular, in any one of the first to sixth inventions, by enclosing a gas other than air in at least a part of a shielded space formed by a hole having a specific shape, for example, the speed of sound is higher than that of air. By enclosing the slowing gas, the resonance frequency can be lowered while the shielding space has the same volume, so that an effect of increasing the shielding space can be obtained. It is possible to reduce the air flow rate of the electric blower due to the installation of the silencing means.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
1-5 has shown the vacuum cleaner in Embodiment 1 of this invention.

  As shown in FIG. 1, an electric blower 2 is provided in the cleaner body 1, and a dust bag 4 is detachably incorporated in the dust collection chamber 3 in the front half of the cleaner body 1. Furthermore, the suction part 5 provided in the front part of the cleaner body 1 is connected to the hose 6 in communication with the dust bag 4, and the other end of the hose 6 is connected to the extension pipe 7 and the suction tool 8. It is a configuration. That is, dust or the like on the floor surface is sucked from the suction tool 8 by the suction force of the electric blower 2, separated from the suction airflow by the dust bag 4, and stored.

  Further, an exhaust port 9 of the main body is provided at the rear of the cleaner body 1, and air is discharged through an exhaust filter 10 (FIG. 2) incorporated in the exhaust port 9. Furthermore, the air passage wall surface inside the rear of the cleaner body 1 is equipped with a silencer 24, and the noise transmitted along with the air flow from the electric blower 2 is suppressed from being attenuated in the process of passing through the silencer 24. It is.

  Next, the periphery of the electric blower 2 will be described with reference to FIG.

  The electric blower 2 includes an impeller, an air guide, an electric motor, and the like as is conventionally known, and is entirely surrounded by a soundproof cylinder 21 formed of a hard resin, and is incorporated in the cleaner body 1. The air discharged from the exhaust port 20 flows to the exhaust port 9 of the cleaner body 1 through the exhaust port 22 of the soundproof cylinder 21.

  Furthermore, a sound absorbing material 23 such as felt and urethane foam having open cells is appropriately attached or installed on the soundproof cylinder 21 and the inner wall of the cleaner body 1.

  As shown in FIGS. 2 and 3, the silencer 24 is provided at two locations inside the vacuum cleaner main body 1 and has a plurality of holes 28 having a specific shape in the thickness direction, and driving noise. The sheet-like body 25 that is stuck and fixed to the air passage wall surface 26 in the cleaner body 1 in which the noise propagates, the sound absorbing plate 27 that is laminated and fixed to the surface of the sheet body 25, and the sound absorbing plate 27 and the air passage wall surface 26 It has the shielding space 29 by the hole of the specific shape pinched | interposed.

  When a sound wave is in contact with the silencer 24 having this configuration, when the sound wave comes into contact with the sound absorbing plate 27, the sound absorbing plate 27 is vibrated by the acoustic energy, and the acoustic energy is consumed by the internal friction at the time of vibration. The sound of a specific frequency is muted by the material and tension of the. Here, when the non-breathable membranous planar body 30 is pasted and fixed as the sound absorbing plate 27, the mass M (kg) per unit area of the membranous planar body 30 and the height of the shielding space 29, In other words, the thickness L (m) of the planar body 25 is effective for resonating with the sound of the frequency f (Hz) expressed by substituting into the following equation.

f = (C / 2π) × √ (ρ / M / L)
f: Frequency (Hz)
C: Speed of sound in air (m / s)
ρ: Air density (kg / m ³ )
M: Mass per unit area of the membrane-like planar body (kg)
L: Depth of shielding space (m)
By using this effect, it is possible to reduce noise focused on a specific frequency, and to obtain an effect on the silencing of noise protruding at a specific frequency, such as NZ sound generated during operation of the electric blower 2. Can do.

  In addition, it is preferable to use the film-like planar body as the sound absorbing plate 27 according to the frequency of noise for which a soft resin film such as a vinyl sheet or a metal film is to be silenced.

  In addition, as shown in FIG. 4, in the case where a porous planar body is attached as a sound absorbing plate 27 instead of a non-breathable film-shaped planar body, There are capillaries and continuous cavities, and when noise is transmitted to the inside, acoustic energy is converted to thermal energy and attenuated by the viscosity of the air in the small holes and cavities, friction, and vibration of fine fibrous objects. In the method, noise in a high frequency range can be reduced widely and easily, so that noise in a high frequency range including NZ sounds derived from the operation of the electric blower 2 can be effectively reduced. It is to be noted that the use of glass wool, rock wool, felt, foamed resin, fiber material or the like as the porous planar body 31 is effective for noise reduction.

  Furthermore, in the shielded space 29 formed between the air passage wall surface 26 and the sound absorbing plate 27, the noise is transmitted to the sound absorbing plate 27 when the noise is in contact with the silencer 24. The acoustic energy is attenuated in the shielding space 29 by acting as an expansion space or a resonance space. In general, by providing such an expansion space, it is possible to reduce noise in a low-frequency region having a long wavelength. When the shielding space 29 is cylindrical as in the present embodiment, the depth of the shielding space 29 is reduced. Based on L (m), the frequency f (Hz) to be reduced can be set by the following equation.

f = C / 2 / L
f: Frequency (Hz)
C: Speed of sound in air (m / s)
L: Depth of shielding space (m)
By utilizing this effect, it is possible to reduce wind noise of 1 kHz or less generated when a large amount of air flows during operation of the electric blower 2.

  In the present embodiment, the shielding space 29 has a cylindrical shape. However, an optimum silencing effect can be obtained by designing according to a frequency band to be silenced such as a prismatic shape or a rectangular parallelepiped shape.

  Further, as shown in FIG. 5, when the film-like planar body 30 and the porous planar body 31 are simultaneously laminated on the planar body 25 as the sound absorbing plate 27, the electric blower 2 of the vacuum cleaner on the same plane. It is possible to widely reduce the noise generated during operation, and it is possible to achieve significant noise reduction.

  Since the silencing means 24 in the present embodiment can easily obtain a silencing effect with a simple configuration that is simply fixed to the air passage wall surface 26 through which the noise propagates, the structural parts in the vacuum cleaner body 1 of the electric blower are noisy. Compared to designing with a countermeasure configuration, it can be realized at a low cost without causing a complicated structure.

(Embodiment 2)
6-9 has shown the vacuum cleaner in Embodiment 2 of this invention. Since the basic configuration is the same as that of the first embodiment, the same elements are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIGS. 6 and 7, the planar body 25 of the silencer 24 has the thickness of the cross section parallel to the air flow direction sequentially changing (continuously in the present embodiment). As a result, the depth of the hole 28 opened in the planar body 25 also changes sequentially. The planar body 25 is affixed to and fixed to the air passage wall surface 26, and the sound absorbing plate 27 is laminated and fixed to the surface of the planar body 25, thereby forming a shielding space 29 having a plurality of depths. The configuration of the silencer 24 can also be adopted for the other silencer 24 (in the present embodiment, the silencer installed in the vertical direction).

  The shielded spaces 29 having a plurality of depths can expand the frequency range of noise that can be silenced, and further increase the silencing effect, and the rotational speed of the impeller of the electric blower 2 varies depending on the cleaning mode of the electric vacuum cleaner. Thus, even if the frequency characteristic of noise changes, a silencing effect can be stably obtained. Further, the electric motor of the electric blower 2 changes in the heat generation temperature depending on the number of rotations, and as a result, the sound velocity C (m / s) in the air slightly changes, and this also changes the frequency characteristics of noise. Even in such a case, since the shielding space 29 having a plurality of depths is provided, the sound can be stably silenced.

  Furthermore, in the present embodiment, by positioning the thicker side of the planar body 25 on the upstream side of the air flow close to the noise source, the larger side of the shielded space 29 serving as an expansion space against noise is reduced in noise. By approaching the source, noise in the low frequency range is silenced immediately after it is generated, and the thickness of the planar body 25 decreases further downstream, so that the air flow path expands. In order to secure the expansion space, the sound energy is attenuated, so that the silencing effect is further enhanced.

  Further, as shown in FIGS. 8 and 9, the same effect can be obtained even when the thickness of the sound absorbing plate 27 is changed continuously or stepwise instead of sequentially changing the thickness of the cross section of the planar body 25. In addition, by combining the cross-sectional thickness changes of the planar body 25 and the sound absorbing plate 27, the frequency band in which the noise reduction effect can be obtained is further expanded. When the film-like planar body 30 is used as the sound absorbing plate 27, the same effect can be obtained by changing the thickness or strength of the film-like planar body 30 stepwise or continuously.

(Embodiment 3)
FIG. 10 shows the silencer of the electric vacuum cleaner according to Embodiment 3 of the present invention. Since the basic configuration is the same as that of the first embodiment, the same elements are denoted by the same reference numerals and description thereof is omitted.

  In the present embodiment, a gas other than air is sealed in a part or all of the shielded space 29. In practice, it is difficult to inject gas directly into the shielded space 29. By injecting the injected elastic hollow body 32 into the shielding space 29, a desired configuration can be obtained.

  Here, when a gas having a low sound velocity with respect to the air is enclosed in the elastic hollow body 32, the frequency range in which the sound can be silenced in the shielded space 29 is lowered, and the effect equivalent to increasing the depth of the shielded space 29 is achieved. Is obtained. For example, as the gas whose sound speed is slower than that of air, argon, chlorine, and the like can be cited. By inserting the elastic hollow body 32 enclosing these into the shielded space 29, it is possible to reduce noise in a lower frequency range.

  As a result, in order to reduce noise in the low frequency range, a large expansion space is required. As a result, the air flow path in the vacuum cleaner main body 1 of the vacuum cleaner is narrowed, and air volume is reduced instead of noise reduction. Although it may be lowered, the present embodiment makes it possible to reduce the size of the shielding space 29, and to achieve both the silencing effect and the suction performance of the vacuum cleaner.

  As described above, the electric vacuum cleaner according to the present invention can suppress noise such as NZ sound, which is an annoying protruding sound generated from an electric blower, and low-frequency wind noise with a simple configuration. It can be used for various types of vacuum cleaners such as commercial vacuum cleaners.

Whole structure figure of the vacuum cleaner in Embodiment 1 of this invention Sectional drawing which shows the structure in the vacuum cleaner main body of the same vacuum cleaner (A) Plan view of the silencer in the vacuum cleaner (b) Side sectional view of the silencer Side sectional view which shows the other structure of the muffling means in the same vacuum cleaner Side sectional view which shows further another structure of the muffling means in the same vacuum cleaner Sectional drawing which shows the structure in the vacuum cleaner main body of the vacuum cleaner in Embodiment 2 of this invention. (A) Plan view of the silencer in the vacuum cleaner (b) Side sectional view of the silencer Side sectional view which shows the other structure of the muffling means in the same vacuum cleaner Side sectional view which shows further another structure of the muffling means in the same vacuum cleaner (A) Top view which shows the silencer of the vacuum cleaner in Embodiment 3 of this invention (b) Side sectional view of the silencer

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vacuum cleaner main body 2 Electric blower 24 Silencer 25 Planar body 26 Air channel wall surface 27 Sound absorbing plate 28 Hole 29 Shielding space 30 Film-shaped planar body 31 Porous planar body

Claims (7)

A vacuum cleaner main body, an electric blower provided in the vacuum cleaner main body, and a silencing means for suppressing operation noise of the electric blower, wherein the silencing means has a plurality of holes having a specific shape in the thickness direction, and driving noise. The surface is fixed to the wall surface of the air passage inside the cleaner body, the sound absorbing plate is laminated on the surface of the surface, and is shielded by a hole with a specific shape sandwiched between the sound absorbing plate and the air passage wall surface. And a vacuum cleaner having a space. The vacuum cleaner according to claim 1, wherein the sound absorbing plate laminated on the surface of the planar body is a film-shaped planar body. The vacuum cleaner according to claim 1, wherein the sound absorbing plate laminated on the surface of the planar body is a porous planar body. The vacuum cleaner according to claim 1, wherein a film-like planar body and a porous planar body are simultaneously laminated on the surface of the planar body. The vacuum cleaner according to any one of claims 1 to 4, wherein at least one of the planar body and the sound absorbing plate of the sound deadening means sequentially changes in cross-sectional thickness in the air flow direction. 6. The electric vacuum cleaner according to claim 5, wherein a portion having a large thickness is located on the upstream side of the air flow in the sequential change of the cross-sectional thickness in the air flow direction. The electric vacuum cleaner according to any one of claims 1 to 6, wherein a gas other than air is sealed in at least a part of a shielding space formed by a hole having a specific shape.

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