JP2008023010A - Vacuum cleaner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vacuum cleaner capable of reducing noise caused by the propagation of the vibration of a blower motor to a housing regardless of a temperature or a vibration frequency. <P>SOLUTION: The vacuum cleaner for supporting the fan case part 104 of the blower motor by a vibration isolating material 105 has a high polymer damping material 106 with a piezoelectric effect fixed to the front surface of the fan case part 104. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a vacuum cleaner that can reduce noise generated by vibration of a blower motor propagating to a housing.

Conventionally, as a technique of “attenuating vibration and noise of an electric blower and preventing air leakage from around the fan case”, a “ring-shaped elastic material made of rubber, foamed resin, etc., and having a center hole 1d” The annular part 1a and the flat belt-like band-like part 1b formed a buffer body 1 having a shape connected via a narrow connecting part 1c. Then, an adhesive layer for attachment to the fan case 4 is attached to one surface of the buffer body 1, and the annular portion 1 a can be used as a fan of the electric blower 3 simply by aligning and bonding the buffer body 1. While being bonded to the front surface portion 4 b of the case 4, the band-shaped portion 1 b is bonded to the outer peripheral portion 4 c of the fan case 4. Is proposed (Patent Document 1).
JP-A-8-154876 (Claim 1, Summary)

However, when the blower motor of the vacuum cleaner is operated, the temperature of the fan case may reach 100 degrees. At this time, if an elastic material such as rubber is used for noise reduction, the elastic material becomes soft as the temperature rises and vibrates together with the blower motor, so that the vibration damping effect cannot be fully exhibited. There was a problem that noise could not be reduced sufficiently.
Also, when rubber or foam material is used, it can only deal with one of the natural vibration frequencies of the object to be damped in terms of frequency characteristics, and when vibrations other than the natural vibration frequency occur, There was a problem that it was not possible to attenuate, and therefore the noise caused by this could not be reduced sufficiently.

  The present invention has been made in order to solve the above-described problems. An electric vacuum cleaner that can reduce noise generated by the vibration of a blower motor propagating to a housing regardless of temperature and vibration frequency. It is intended to obtain.

The vacuum cleaner according to the present invention is
A vacuum cleaner that supports the fan case part of the blower motor with a vibration isolator,
A polymer damping material having a piezoelectric effect is fixed to the front surface of the fan case portion.

  According to the vacuum cleaner of the present invention, noise generated by the vibration of the blower motor propagating to the housing even when the temperature of the fan case changes during operation or when vibrations other than the natural vibration frequency occur. Can be reduced.

Embodiment 1 FIG.
FIG. 1 illustrates a state in which the periphery of a blower motor is viewed from the side in the internal structure of the electric vacuum cleaner according to Embodiment 1 of the present invention.
In the internal structure of FIG. 1, a motor case 101 surrounds the motor, and a flow path wall 102 is provided in front of the motor.
The motor body has a rotor part 103 and a fan case part 104, and a suction port 107 is provided at the center of the front surface of the fan case part 104. Further, the side periphery of the fan case portion 104 is supported by a motor vibration isolator 105.
A dotted arrow indicates the direction of noise generation, and details will be described later with reference to FIG.

  Here, before the detailed description of FIG. 1, in order to facilitate the understanding of the present invention, the cause of the noise generated by the vibration of the blower motor propagating to the housing will be described.

FIG. 7 shows sound radiation characteristics based on acoustic intensity analysis results.
In FIG. 7, the direction of sound emission is indicated by the direction of the arrow, and the intensity of the sound is indicated by the length of the arrow.
The cause of the noise of the vacuum cleaner is mainly the blower motor. As shown in FIG. 7, the noise is radiated by dividing it into the front side (fan case part) and the rear side (rotor part) of the blower motor. I understand.
In addition, sound is transmitted and radiated from the front side (fan case part) of the blower motor, and the sound radiated from the opening diameter which is the suction port is less than the sound transmitted from the fan case surface. I understand.
Furthermore, it can be seen that the sound radiated from the rear side (rotor portion) of the blower motor is less likely to propagate in the direction of the front side (fan case portion) and radiates to the rear of the motor with fluid. Most of this sound is transmitted sound from the housing and radiated sound from the exhaust port.

  The object of the present invention is to reduce noise generated from the front side (fan case portion) of the blower motor, particularly noise from the fan case surface that emits strong sound, among the sound generation factors shown in FIG. Is.

Next, the description returns to FIG.
In FIG. 1, the polymer damping material 106 is fixed so as to cover the front surface of the fan case portion 104.
The polymer damping material 106 is a disc-shaped damping material with a hole in the center, and is fixed to the front side of the fan case 104 with a double-sided tape or the like so that the hole in the center and the suction port 107 are aligned. Let Since the fan case part may become hot during operation, it is desirable to use a double-sided tape or the like for fixing the polymer damping material 106 having heat resistance suitable for the temperature condition.
The size of the polymer damping material 106 is such that it can cover almost the entire front surface of the fan case portion 104. By doing in this way, among the noises emitted from the front surface of the fan case part 104, those emitted from other than the suction port 107 where the generation of noise is small are sufficiently reduced.
In addition, since a part of the motor vibration isolator 105 covers the end portion along the circumference of the front surface of the fan case part 104, it is not necessary to cover this part with the polymer damping material 106. .

Next, material characteristics of the polymer damping material 106 will be described.
As the polymer damping material 106 in the present invention, a polymer damping material having a piezoelectric effect is used. That is, when vibration is applied to the polymer damping material 106, vibration energy is finally converted into thermal energy by the piezoelectric effect, so that vibration can be attenuated.
As a polymer material having such a piezoelectric effect, for example, polyvinylidene fluoride (PVDF) is known.

Moreover, the polymer damping material used in the present invention has the following properties.
(1) Temperature characteristics Even if the surface temperature of a material that should be treated for vibration rises, the material does not soften. That is, the vibration damping characteristic does not change even when the temperature changes.
Therefore, unlike the conventionally used elastic body such as rubber, even if the temperature of the fan case unit 104 rises during operation, it is possible to obtain a stable and constant noise reduction effect.
(2) Frequency characteristics Since the polymer damping material does not have a specific frequency (natural frequency), it is not a specific frequency countermeasure, but a noise reduction effect over a wide frequency band, unlike when rubber or foam material is used. Can be demonstrated.
(3) Sound insulation effect The polymer damping material is a material in which a polymer material such as carbon and an organic and inorganic material are mixed in an arbitrary ratio. Metals and resin materials can be selected as the organic and inorganic materials, and the surface density can be arbitrarily formed.
The surface density is the weight per unit area, and by increasing the surface density, the rigidity per unit area can be increased and the sound insulation effect can be increased.
That is, by providing the polymer damping material 106 formed with a high surface density on the front surface of the fan case portion 104, the effect of covering the front surface of the fan case portion 104 with a sound insulating plate can be achieved.
As a result, a “sound insulation layer” for blocking sound transmission is formed on the front surface of the fan case portion 104, so that it is possible to effectively prevent transmitted sound and reduce transmitted sound radiated from the front surface of the fan motor. it can.

  By adhering the polymer damping material having the above characteristics to the front surface of the fan case part 104, vibration components having high frequencies can be suppressed by the damping material, and a significant damping effect of high-frequency vibrations is exhibited. can do. Further, by forming a “sound insulation layer” on the front surface of the fan case portion 104, it is possible to obtain an attenuation effect over the entire frequency band of noise.

As described above, according to the first embodiment,
Since the polymer damping material 106 having a piezoelectric effect is fixed to the front surface of the fan case portion 104, the blower motor can be used even when the temperature of the fan case changes during operation or vibrations other than the natural vibration frequency occur. The noise generated by the propagation of the vibration to the housing can be reduced.

In addition, since the portion excluding the portion covered with the motor vibration isolator 105 and the suction port 107 on the front surface of the fan case portion 104 is almost entirely covered with the polymer damping material 106,
The noise emitted from the fan case front surface of the fan case part 104 can be sufficiently reduced.

In addition, since the polymer damping material 106 has a high surface density that can block the transmitted sound radiated from the front surface of the fan case portion 104,
By forming a “sound insulation layer” for blocking sound transmission, it is possible to effectively prevent transmitted sound and reduce transmitted sound radiated from the front surface of the fan motor.

Embodiment 2. FIG.
The upper part of FIG. 2 illustrates a state in which the periphery of the blower motor is viewed from the side in the internal structure of the electric vacuum cleaner according to Embodiment 2 of the present invention.
In the structure shown in the upper diagram of FIG. 2, the motor case 201 to the suction port 207 have the same configuration as the motor case 101 to the suction port 107 of FIG. 1 in the first embodiment. Instead, the sound absorbing material 208 is used. Hereinafter, the difference from the first embodiment will be mainly described.

The sound absorbing material 208 is formed in a disk shape with a hole in the center, and is fixed to the front side of the fan case portion 204 so that the hole in the center and the suction port 207 are aligned.
Further, the size of the sound absorbing material 208 is such that it can cover almost the entire front surface of the fan case portion 204 as in the first embodiment. By doing in this way, among the noises emitted from the front surface of the fan case unit 204, it is intended to block almost all the noises emitted from other than the suction port 207 with less noise generation.
In addition, since a part of the motor vibration isolator 205 covers the end portion along the circumference of the front surface of the fan case part 204, it is not necessary to cover this part with the sound absorbing material 208.

The lower diagram of FIG. 2 is an enlarged view of the periphery of the motor vibration isolator 205 in the upper diagram of FIG.
In the second embodiment, when the sound absorbing material 208 is fixed to the front surface of the fan case portion 204, the circumferential portion of the sound absorbing material 208 is connected to the motor vibration isolator 205 and the fan case without using a double-sided tape or the like. It is sandwiched and fixed by the portion 204.
This is because when the sound absorbing material 208 is fixed using a double-sided tape or the like, noise generated from the blower motor is reflected on the tape surface. In order for the sound absorbing material 208 to be sufficiently effective, it is desirable that noise is incident on the inside of the sound absorbing material 208 and the noise is reduced inside the sound absorbing material 208. A sufficient effect cannot be obtained.
Therefore, in the second embodiment, without using a double-sided tape or the like, the motor vibration isolator 205 supporting the side periphery of the fan case portion 204 and the fan case portion 204 are “sandwiched” as described above. The sound absorbing material 208 is fixed by the method.
In the first embodiment, the polymer damping material 106 is fixed with a double-sided tape or the like. However, the polymer damping material 106 has an effect as a sound insulating layer and does not transmit sound. Therefore, it is added that there is no need to be aware of the reduction in the sound absorption effect due to the reflection of sound, unlike the sound absorbing material 208 in the second embodiment.

For the same reason as that of the double-sided tape or the like, the surface of the sound absorbing material 208 is not subjected to surface treatment such as “film” formation, so that noise is reliably incident on the sound absorbing material 208.
In addition, in order to prevent the sound absorbing material 208 from being sucked into the motor, the sound absorbing material 208 is formed with a thickness that does not protrude from the front of the motor (suction port 207), or the hole in the center is Suppose that the aperture is wider than the suction port 207.

  The sound absorbing material 208 can be a fiber material using, for example, recycled PET material or recycled cloth. Thereby, even when the sound absorbing material 208 is ignited when the power source is short-circuited, it is possible to prevent the motor or the like from being burned by the self-extinguishing or melting of the sound absorbing material 208. Further, since the PET material is composed only of carbon, hydrogen, and oxygen, no harmful substances are generated even when burned, which is preferable from the viewpoint of safety.

As described above, according to the second embodiment,
Since the sound absorbing material 208 is formed on the front surface of the fan case portion 204, and the sound absorbing material 208 is sandwiched and fixed between the motor vibration isolator 205 and the fan case portion 204,
The noise can be reliably incident on the sound absorbing material 208 without being reflected, and the noise reduction effect can be reliably exhibited.

Further, since the sound absorbing material 208 is formed so as to cover a portion of the front surface of the fan case portion 204 excluding the portion covered with the motor vibration isolating material 205 and the suction port 207.
The noise emitted from the fan case front surface of the fan case portion 204 can be sufficiently reduced.

  In addition, since the sound absorbing material 208 is made of a fiber material using a PET material, a recycled cloth or the like, even if the sound absorbing material 208 is ignited when the power source is short-circuited, the sound absorbing material 208 self-extinguishes or melts, so that the motor etc. Can prevent burning. Further, since the PET material is composed only of carbon, hydrogen, and oxygen, no harmful substances are generated even if burnt, and this is preferable from the viewpoint of safety.

Embodiment 3 FIG.
The upper part of FIG. 3 illustrates a state in which the periphery of the blower motor is viewed from the side in the internal structure of the electric vacuum cleaner according to Embodiment 3 of the present invention.
In the structure shown in the upper diagram of FIG. 3, the motor case 301 to the sound absorbing material 308 have substantially the same configuration as the motor case 201 to the sound absorbing material 208 of FIG. 2 in the second embodiment, but the shape of the fan case portion 304 is Is different. Hereinafter, the difference from the second embodiment will be mainly described.

In FIG. 3, an air chamber is provided between the fan case portion 304 and the sound absorbing material 308 so that a plurality of mountain-shaped convex portions 309 are provided on the front surface of the fan case portion 304 and the convex portion 309 is covered with the sound absorbing material 308. ing. In general, when noise passes through the air layer, the sound pressure level is generated according to the distance, so that an acoustic attenuation effect is obtained by the air chamber around the convex portion 309.
That is, with the above configuration, the noise attenuation effect by the sound absorbing material 308 and the acoustic attenuation effect by the air chamber can be obtained at the same time, so the noise reduction effect is further enhanced.

If the height of the convex portion 309 is extremely high, the sound absorbing material 308 is positioned in front of the suction port 307, which is not preferable from the viewpoint of preventing the sound absorbing material 308 from being sucked. Moreover, if the height of the convex portion 309 is extremely high, the sound absorbing material 308 is easily peeled off from the surface of the fan case portion 304.
Therefore, it is desirable to stop the height of the convex portion 309 to such an extent that the sound absorbing material 308 is not positioned in front of the suction port 307.

As in the second embodiment, the sound absorbing material 308 is fixed by sandwiching the circumferential portion of the sound absorbing material 308 between the motor vibration isolating material 305 and the fan case portion 304. The reason is the same as that described in the second embodiment, and sound is reflected on the tape surface when fixed using a double-sided tape or the like.
In addition, the material, size, and the like of the sound absorbing material 308 are not particularly different from the sound absorbing material 208 in the second embodiment.

  In Embodiment 3, the convex portion 309 has a mountain shape, but is not limited thereto, and may be formed in a columnar shape or a triangular pyramid shape, for example. That is, as described above, if the air chamber can be formed around the convex portion 309, the sound attenuation effect by the air chamber can be obtained, and therefore the shape of the convex portion 309 can be arbitrary. Similarly, the number of convex portions 309 can be arbitrarily configured.

As described above, according to the third embodiment,
Since the convex portion 309 is provided on the front surface of the fan case portion 304, the sound absorbing material 308 is formed so as to cover the convex portion 309, and an air chamber is provided between the sound absorbing material 308 and the convex portion 309.
The noise attenuation effect by the sound absorbing material 308 and the sound attenuation effect by the air chamber can be obtained at the same time, and the noise reduction effect is further enhanced.

Embodiment 4 FIG.
FIG. 4 illustrates a state in which the periphery of the blower motor is viewed from the side in the internal structure of the electric vacuum cleaner according to Embodiment 4 of the present invention.
In the structure shown in FIG. 4, the motor case 401 to the suction port 407 are the same as the motor case 101 to the suction port 107 of FIG. 1 in the first embodiment, but the polymer damping material 406 is further replaced by a sound absorbing material 408. The covering point is different. Hereinafter, the difference from the first embodiment will be mainly described.

In FIG. 4, as in the first embodiment, a polymer damping material 406 is fixed to the front surface of the fan case portion 404, and the front surface of the polymer damping material 406 is further covered with a sound absorbing material 408.
The sound absorbing material 408 is formed in a disk shape having a hole in the center, and is fixed to the front side of the fan case portion 404 so that the hole in the center and the suction port 407 are aligned.
The size of the sound absorbing material 408 may be substantially the same as the size of the polymer damping material 406, or the hole provided in the center portion is made larger than the hole in the center portion of the polymer damping material 406, so The surface area may be smaller than that of the vibrating material 406.
From the viewpoint of reliably preventing noise, it is desirable to cover the entire front surface of the polymer damping material 406 with the sound absorbing material 408. However, a sufficient noise reduction effect can be obtained with the polymer damping material 406 alone. For example, the sound absorbing material 408 may be used in an auxiliary manner.

The sound absorbing material 408 is fixed by sandwiching the circumferential portion of the sound absorbing material 408 between the motor vibration isolating material 405 and the fan case portion 404 as in the second embodiment. The reason is the same as that described in the second embodiment, and sound is reflected on the tape surface when fixed using a double-sided tape or the like.
In addition, the material, size, and the like of the sound absorbing material 408 are not particularly different from the sound absorbing material 208 in the second embodiment.

FIG. 5 is a side sectional view of the housing of the vacuum cleaner, and shows an example when the configuration shown in FIGS. 1 to 4 is installed in the vacuum cleaner housing. FIG. 5 illustrates the case where the sound absorbing material is fixed to the front surface of the fan case (corresponding to FIG. 2).
In FIG. 5, the motor case 501 to the sound absorbing material 508 have the same configuration as the motor case 201 to the sound absorbing material 208 of FIG.
The vacuum cleaner in FIG. 5 is entirely covered with a cleaner casing 510, a dust collecting portion 511 is formed in the front of the casing, and the configuration shown in FIGS. Installed.
The air in the dust collection part 511 flows into the blower motor part via the suction port 507.
Further, a total exhaust port 512 is provided at the rear of the cleaner casing 510.
The dotted line arrow represents the sound propagation direction.

FIG. 6 is a graph showing measurement results of noise characteristics before and after mounting a polymer damping material or a sound absorbing material which is a noise countermeasure member in the present invention.
The vertical axis in FIG. 6 represents the sound pressure level (dB) of the noise emitted from the blower motor.
The horizontal axis in FIG. 6 represents the frequency (Hz) of noise generated from the blower motor.

The graph represented by the solid line in FIG. 6 shows the noise characteristics before the noise countermeasure member is mounted. As shown in the graph, the noise before mounting the noise countermeasure member has a first peak in the frequency band of the sound transmission component (N component), and the fan rotation component (NZ) due to the higher-order divided vibration component. Component) has a second peak.
The graph represented by the dotted line in FIG. 6 shows the noise characteristics after the noise countermeasure member is mounted. As shown in the graph, it can be seen that the noise after the noise countermeasure member is mounted is such that the peak vibration of the NZ component is surely attenuated and the peak of the vibration of the N component is lowered.
It should be noted that the same effect as that of the graph represented by the dotted line in FIG. 6 can be obtained in any of the configurations of the first to fourth embodiments.

As described above, according to the fourth embodiment,
Since the sound absorbing material 408 covering the front side of the polymer damping material 406 is provided and the sound absorbing material 408 is sandwiched and fixed between the motor vibration damping material 405 and the fan case portion 404,
A greater noise reduction effect can be obtained than when the polymer damping material 406 and the sound absorbing material 408 are used alone.

The state which looked at the blower motor periphery from the side among the internal structures of the vacuum cleaner which concerns on Embodiment 1 is illustrated. The state which looked at the blower motor periphery from the side among the internal structures of the vacuum cleaner which concerns on Embodiment 2 is illustrated. The state which looked at the blower motor periphery from the side among the internal structures of the vacuum cleaner which concerns on Embodiment 3 is illustrated. The state which looked at the blower motor periphery from the side among the internal structures of the vacuum cleaner which concerns on Embodiment 4 is illustrated. An example at the time of installing the structure shown in FIGS. 1-4 in a vacuum cleaner housing | casing is shown. It is a graph which shows the measurement result of the noise characteristic before and behind mounting | wearing with a polymer damping material or a sound absorbing material. The sound radiation characteristic is shown by the sound intensity analysis result.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Motor case, 102 Channel wall, 103 Rotor part, 104 Fan case part, 105 Motor damping material, 106 Polymer damping material, 107 Suction port, 201 Motor case, 202 Channel wall, 203 Rotor part, 204 Fan Case part, 205 Motor vibration isolator, 207 Suction port, 208 Sound absorbing material, 301 Motor case, 302 Channel wall, 303 Rotor part, 304 Fan case part, 305 Motor vibration isolator, 307 Suction port, 308 Sound absorber, 309 Convex part, 401 Motor case, 402 Flow path wall, 403 Rotor part, 404 Fan case part, 405 Motor vibration isolator, 406 Polymer damping material, 407 Suction port, 408 Sound absorbing material, 501 Motor case, 503 Rotor part, 504 Fan case, 505 Motor vibration isolator, 507 Suction port, 508 Sound absorbing material 510 cleaner housing 511 dust collecting unit, 512 total outlet.

Claims (10)

A vacuum cleaner that supports the fan case part of the blower motor with a vibration isolator,
A vacuum cleaner characterized in that a polymer damping material having a piezoelectric effect is fixed to the front surface of the fan case portion. The polymer damping material is
The vacuum cleaner according to claim 1, wherein the vacuum cleaner is formed so as to cover a portion of the front surface of the fan case portion other than a portion covered with the vibration isolating material. The polymer damping material is
The vacuum cleaner according to claim 2, wherein the vacuum cleaner is formed so as to cover a portion of the front surface of the fan case portion other than the suction port of the fan case portion. The polymer damping material is
The vacuum cleaner according to any one of claims 1 to 3, wherein the vacuum cleaner is formed with a surface density capable of blocking transmitted sound radiated from a front surface of the fan case portion. Provide a sound absorbing material covering the front side of the polymer damping material,
The vacuum cleaner according to any one of claims 1 to 4, wherein the sound absorbing material is sandwiched and fixed between the vibration isolating material and the fan case portion. A vacuum cleaner that supports the fan case part of the blower motor with a vibration isolator,
A sound absorbing material is formed on the front surface of the fan case part,
The vacuum cleaner, wherein the sound absorbing material is sandwiched and fixed between the vibration proof material and the fan case portion. The sound absorbing material is
The vacuum cleaner according to claim 6, wherein the vacuum cleaner is formed so as to cover a portion of the front surface of the fan case portion other than a portion covered with the vibration isolating material. The sound absorbing material is
The vacuum cleaner according to claim 7, wherein the vacuum cleaner is formed so as to cover a portion of the front surface of the fan case portion other than the suction port of the fan case portion. A convex part is provided on the front surface of the fan case part,
The said sound-absorbing material is formed so that this convex part may be covered, and the air chamber was provided between the said sound-absorbing material and this convex part, The Claim 6 thru | or 8 characterized by the above-mentioned. Electric vacuum cleaner. The vacuum cleaner according to any one of claims 5 to 9, wherein the sound absorbing material is made of a fiber material using a PET material, a recycled cloth, or the like.

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