JP2010053414A - Porous material, sound absorbing and insulating structure, electric equipment, vacuum cleaner and method for producing porous material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a porous material which can show sound absorption properties, sound insulation properties and vibration damping properties, though being made of sintered one material. <P>SOLUTION: The porous material 10 is formed by sintering metal powders having different particle sizes (metal powder 1 with large particle size and metal powder 2 with small particle size), and has air chambers A formed among the metal powders. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a porous material having sound absorption characteristics, sound insulation characteristics, and vibration suppression characteristics, and noise absorption and sound insulation that effectively reduce noise and vibration generated during operation of a movable body that is a vibration generation source using the porous material. The present invention relates to a structure, a vacuum cleaner and an electric device to which the sound absorbing and insulating structure is applied, and a method for producing a porous material.

  Conventionally, in order to provide sound absorption performance and sound insulation performance, a sintered porous body in which a metal powder is sintered and a plurality of pores (bubbles) are formed inside is known. As such, “a sintered porous body obtained by sintering metal powder, having a porosity of 50% to 99.5% by volume and a continuous porosity of 80%. There has been proposed a “sintered porous body” having a volume% of 100% to 100% and an average pore diameter of 0.001 μm to 100 μm (see, for example, Patent Document 1).

JP 2000-297334 A (page 7, FIG. 1)

  The sintered porous body described in Patent Document 1 has continuous pores (bubbles) formed therein because the material melts when the metal powder is sintered. However, since the void | hole formed is continuous, the coupling | bonding of metal materials became a weak thing. As a result, there has been a problem that the rigidity of the material itself after molding becomes weak and the structure is easily broken. In addition, the sintered porous body does not have a constant size and size of open cells, and since there is no reproducibility of the sound absorption coefficient, which is an important requirement for the pores formed, reliable sound absorption characteristics can be obtained. It also had the problem of not.

  The present invention has been made to solve the above-described problems, and is a porous material, a sound absorbing and insulating structure, an electric material that can be obtained from a single material having sintered sound absorbing characteristics, sound insulating characteristics, and vibration damping characteristics. It aims at providing the manufacturing method of an apparatus, a vacuum cleaner, and a porous material.

  The porous material according to the present invention is characterized in that metal powders having different particle sizes are sintered and an air chamber is formed between the metal powders. The sound absorbing and insulating structure according to the present invention is characterized in that the above-described porous material is molded into a predetermined size and shape. Furthermore, an electrical device according to the present invention is characterized in that the above-described sound absorbing and insulating structure is applied to members around a movable body that is a vibration generation source. Furthermore, the vacuum cleaner according to the present invention has a blower motor that drives an electric blower and a motor case that houses the blower motor, and the motor case is the sound absorbing and insulating structure according to claim 5. It is characterized by comprising.

  In the method for producing a porous material according to the present invention, a kneaded material is prepared by mixing a metal powder having a particle size of 10 μm to 50 μm with a raw material of ethyl carbamate or polyurethane, and the kneaded material is heated to a predetermined temperature. The raw material of the ethyl carbamate or polyurethane is melted by treatment at a predetermined pressure, and the metal powder is baked and hardened.

  According to the porous material of the present invention, it is possible to obtain sound absorption characteristics, sound insulation characteristics, and vibration suppression characteristics with one material obtained by sintering metal powders having different particle sizes. In addition, according to the sound absorbing and insulating structure according to the present invention, the sound absorbing and insulating structure has the sound absorbing characteristics, the sound insulating characteristics, and the vibration damping characteristics because it is made of the porous material described above. Furthermore, according to the vacuum cleaner according to the present invention, since the above-described sound absorbing and insulating structure is applied as a motor case, both the sound absorbing characteristics and the sound insulating characteristics can be secured and maintained, and the vibration damping characteristics can be maintained. Will also have. Furthermore, according to the electrical equipment according to the present invention, since the above-described sound absorbing and insulating structure is applied to the members around the movable body serving as the vibration generation source, both the sound absorbing characteristics and the sound insulating characteristics are improved. It will also have properties.

  According to the method for producing a porous material according to the present invention, a plurality of air chambers in which the metal powder and the metal powder are not bonded together are forcibly formed. A quality material can be formed, and only the porous material has sound absorption characteristics, sound insulation characteristics and vibration suppression characteristics.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
Embodiment 1 FIG.
FIG. 1 is a schematic diagram for explaining a porous material 10 according to Embodiment 1 of the present invention. Based on FIG. 1, the structure of the porous material 10 is demonstrated. The porous material 10 is composed of a single sintered material, and the porous material 10 alone has all of sound absorption characteristics, sound insulation characteristics, and vibration damping characteristics. In addition, in the following drawings including FIG. 1, the relationship of the size of each component may be different from the actual one.

  As shown in FIG. 1, the porous material 10 is configured by baking and solidifying metal powder containing different particle sizes. The metal powder is a conductive material (for example, SUS (stainless steel), aluminum, gold, silver, etc.) having a particle size of 10 μm (micrometer) to 50 μm. Here, a case where the porous material 10 is composed of a large particle size metal powder 1 and a small particle size metal powder 2 is shown as an example. Further, the constituent ratio of the porous material 10 is such that the content rate of the small particle size metal powder 2 is larger than the content rate of the large particle size metal powder 1. By kneading the large particle size metal powder 1 and the small particle size metal powder 2 at such a ratio, a large number of air chambers (spaces) A are formed to constitute the porous material 10. .

  FIG. 2 is a schematic diagram for explaining the method for manufacturing the porous material 10 according to the first embodiment. Based on FIG. 2, the manufacturing method of the porous material 10 is demonstrated. As described above, the porous material 10 can be provided by one material obtained by sintering sound absorption, sound insulation and vibration suppression. This porous material 10 is formed by kneading and sintering metal powders (large particle size metal powder 1 and small particle size metal powder 2) containing different particle sizes in urethane resin or the like. The Therefore, the porous material 10 can secure the air chamber A necessary for sound absorption, can secure the specific gravity necessary for sound insulation, can convert vibration and acoustic energy into electric energy, and has sound absorption characteristics, sound insulation characteristics and vibration suppression characteristics. Will have the characteristics.

  First, a metal powder made into a granular powder of 10 μm to 50 μm is mixed with a raw material such as ethyl carbamate or polyurethane (urethane resin) (FIG. 2A). This kneaded material is sintered at a temperature of, for example, 300 ° C. or higher and a predetermined pressure (for example, 3 atmospheres or 4 atmospheres). By doing so, ethyl carbamate, polyurethane and the like are dissolved, and the metal powder is baked and hardened. The sintering temperature in this sintering process is a heating temperature before the metal powder starts to melt, and may be adjusted according to the metal material. Since the sintering process is performed at such a temperature, part of the contact portion between the metal powders is melted and partial baking (sintering) occurs (FIG. 2B). A plurality of air chambers A in which the metal powder and the metal powder are not bonded are forcibly formed by partial baking of the metal powder.

  Therefore, the porous material 10 is formed as one sintered material, and the porous material 10 alone has all the sound absorption characteristics, the sound insulation characteristics, and the vibration damping characteristics. In other words, the sound absorption characteristic can be realized by the air chamber A serving as a noise reduction space necessary for sound absorption, and the sound insulation characteristic is improved by the surface density as a material due to the sintered structure of the metal powder. It can be realized by ensuring the necessary specific gravity, and the vibration damping characteristic can be realized by the conductive material converting vibration and acoustic energy into electric energy.

  The air chamber A functioning as a silencing space can pass a fluid component (wind) generated by a blowing means such as a fan, so that it is possible to reduce sound and to secure a flow path for the fluid component. Can be provided inside or outside the product (for example, a vacuum cleaner or the like as described in detail in Embodiment 4). Moreover, since metal powder is kneaded with raw materials such as ethyl carbamate and polyurethane before foaming and then sintered, it can be easily molded into various shapes according to the use of the porous material 10. . Furthermore, since a large number of air chambers A are formed in the porous material 10, the porous material 10 is flexible and can be reduced in weight.

  In the first embodiment, an example is shown in which the porous material 10 is composed of two metal powders having different particle sizes (a large particle size metal powder 1 and a small particle size metal powder 2). However, the porous material 10 may be composed of three or more metal powders having different particle sizes. Moreover, it is good also as a thing from which the particle size of all the metal powders differs. Furthermore, the porous material 10 may be composed of the same kind of metal powder or may be composed of different kinds of metal powder. And when comprising the porous material 10 with a different kind of metal powder, you may make it divide a kind for every particle size, for example.

Embodiment 2. FIG.
FIG. 3 is a schematic diagram for explaining a porous material 10a according to Embodiment 2 of the present invention. Based on FIG. 3, the structure of the porous material 10a is demonstrated. The porous material 10a is composed of one sintered material, and the porous material 10a alone has all of sound absorption characteristics, sound insulation characteristics, and vibration damping characteristics. This porous material 10a is different from the porous material 10 according to the first embodiment in that a piezoelectric powder material that expresses piezoelectric performance (hereinafter referred to as piezoelectric material 3) is kneaded. In the second embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and differences from the first embodiment will be mainly described.

As shown in FIG. 3, the porous material 10a expresses piezoelectricity such as metal powder and piezoelectric material 3 (for example, carbon, lead zirconate titanate (PZT), mica, etc.) having different particle sizes. Any material may be baked and hardened. The piezoelectric material 3 is a powder material having a particle size of 10 μm to 50 μm, like the metal powder. Here, an example is shown in which the porous material 10 a is composed of a large particle size metal powder 1, a small particle size metal powder 2, and a piezoelectric material 3. The constituent ratio of the porous material 10a is such that the content of the small particle size metal powder 2 is higher than the content of the large particle size metal powder 1 and the piezoelectric material 3. Large particle size metal powder 1 in such a ratio, by kneading a small particle size metal powder 2 and the piezoelectric material 3 to form a large number of air chambers A _1, since the structure of the porous material 10a is there.

FIG. 4 is a schematic diagram for explaining a method for manufacturing the porous material 10a according to the second embodiment. Based on FIG. 4, the manufacturing method of the porous material 10a is demonstrated. As described above, the porous material 10a can be provided by one material obtained by sintering sound absorption, sound insulation and vibration suppression. The porous material 10a is formed by kneading and sintering metal powders having different particle sizes (large particle size metal powder 1 and small particle size metal powder 2) and piezoelectric material 3 in urethane resin or the like. The Accordingly, the porous material 10a can ensure the air chamber A ₁ required for sound absorption, can be secured density required for sound insulation, vibration by the piezoelectric material 3 can be converted into heat energy, sound-absorbing characteristics, sound insulation properties and It will have damping characteristics. That is, the porous material 10 a has further improved vibration damping characteristics compared to the porous material 10.

  First, a metal powder made into a granular powder of 10 μm to 50 μm and further a piezoelectric material 3 are mixed with raw materials such as ethyl carbamate or polyurethane (FIG. 4A). The kneaded material is sintered at a predetermined temperature, for example, a temperature of 300 ° C. or higher, and a predetermined pressure (for example, 3 atmospheres or 4 atmospheres). By doing so, ethyl carbamate, polyurethane, and the like are dissolved, and the metal powder and the piezoelectric material 3 are baked and hardened. The sintering temperature in this sintering process is a heating temperature before the metal powder and the piezoelectric material 3 start to melt, and may be adjusted according to the metal material and the piezoelectric material 3. Since the sintering process is performed at such a temperature, the metal powders, the metal powder and the piezoelectric material 3, and the contact portions between the piezoelectric materials 3 are partially dissolved and partially baked (sintered). Occurs (FIG. 4B).

A plurality of metal powders, metal powder and piezoelectric material 3, and piezoelectric material 3 are not bonded to each other due to partial baking of metal powders, metal powder and piezoelectric material 3, and piezoelectric material 3. The air chamber A ₁ is forcibly formed. Therefore, the porous material 10a is formed as one sintered material, and has all of the sound absorption characteristics, the sound insulation characteristics, and the vibration damping characteristics only by the porous material 10a. In other words, the sound absorption characteristic can be realized by the air chamber A ₁ serving as a sound deadening space necessary for sound absorption, and the sound insulation characteristic has a surface density as a material due to the sintered structure of the metal powder and the piezoelectric material 3. It can be realized by improving and securing a specific gravity necessary for sound insulation, and the vibration damping characteristic can be realized by the conductive material converting vibration into electric energy and the piezoelectric material 3 converting vibration into heat energy.

The air chamber A ₁ functioning as a sound deadening space can also pass a fluid component (wind) generated by a blowing means such as a fan, so that sound can be reduced and a fluid component flow path must be secured. Can be provided inside and outside of a product (for example, a vacuum cleaner or the like as described in detail in Embodiment 4). Moreover, since metal powder is kneaded with raw materials such as ethyl carbamate and polyurethane before foaming and then sintered, it can be easily molded into various shapes depending on the use of the porous material 10a. .

Further, since the piezoelectric material 3 is kneaded in the porous material 10a, the piezoelectric material 3 is vibrated in contact with each other by vibrating the porous material 10a itself that has been sintered with vibration and acoustic energy after sintering. The piezoelectric effect is expressed. This piezoelectric effect is due to vibration-to-heat conversion that converts vibration and vibration of acoustic energy into thermal energy. That is, the porous material 10a can convert the generated vibration and acoustic energy into thermal energy and consume the vibration and acoustic energy. Therefore, the porous material 10 a has a more effective damping characteristic compared to the porous material 10. Further, since the porous material 10a is a number of the air chamber A ₁ is formed, it is flexible, it is also possible to achieve a weight reduction.

  In the second embodiment, the porous material 10a is composed of two metal powders having different particle sizes (a large particle size metal powder 1 and a small particle size metal powder 2) and a piezoelectric material 3 having the same particle size. Although the case where it comprises is shown as an example, the porous material 10a may be composed of three or more metal powders having different particle diameters and two or more piezoelectric materials 3 having different particle diameters. Further, the particle diameters of all the metal powders and the piezoelectric material 3 may be different. Furthermore, the porous material 10a may be composed of the same type of metal powder and the same type of piezoelectric material 3, or may be composed of different types of metal powder and different types of piezoelectric material 3. When the porous material 10a is composed of different types of metal powder and different types of piezoelectric material 3, the types may be divided for each particle size, for example.

Embodiment 3 FIG.
FIG. 5 is a perspective view showing a schematic configuration of the sound absorbing and insulating structure 20 according to Embodiment 3 of the present invention. Based on FIG. 5, the configuration of the sound absorbing and insulating structure 20 will be described. The sound absorbing and insulating structure 20 is configured by molding the porous material 10 according to the first embodiment or the porous material 10a according to the second embodiment into a predetermined size and shape. It has damping characteristics. The porous material 10 and the porous material 10a having such characteristics are the plate material of the case and the bottom plate of the case of a device that generates vibration (for example, a device such as a vacuum cleaner, a compressor, and a washing dryer). Suitable for use as.

  Here, the case where the sound absorbing and insulating structure 20 is configured by assembling the porous material 10 or the porous material 10a into a case is shown as an example. By assembling the porous material 10 or the porous material 10a in this manner, the sound absorbing and insulating structure 20 can be used as a motor case. If the sound absorbing and insulating structure 20 is used as a motor case, the sound absorbing and insulating structure 20 functions as a soundproof wall, and sound radiation generated from the motor can be attenuated before being emitted to the outside of the sound absorbing and insulating structure 20. It becomes possible. In addition, since the sound absorbing and insulating structure 20 has vibration damping characteristics, it is also possible to attenuate vibration along with sound.

Embodiment 4.
FIG. 6 is a longitudinal sectional view showing a schematic configuration of a vacuum cleaner 30 which is an example of the electric device according to the fourth embodiment of the present invention. Based on FIG. 6, the vacuum cleaner 30 as an example of an electric equipment is demonstrated. The electric vacuum cleaner 30 has a sound absorbing characteristic, a sound insulating characteristic, and a vibration damping characteristic by using the sound absorbing and insulating structure 20 according to the third embodiment. That is, the electric vacuum cleaner 30 can reduce the sound and vibration generated from the blower motor 33 by housing the blower motor 33 installed therein in the sound absorbing and insulating structure 20.

  The vacuum cleaner 30 is provided in a dust collection chamber 31 in which a dust collection bag for collecting dust is accommodated and a rear side (downstream side) of the dust collection chamber 31, and generates an air flow for suctioning the dust. An electric blower 32 and a blower motor 33 that drives the electric blower 32 are housed in a housing 35. The electric blower 32 and the blower motor 33 are further accommodated in the sound absorbing and insulating structure 20 in the housing 35. Further, an exhaust port 34 for discharging an air flow is formed on the back surface of the housing 35. Although not shown, the vacuum cleaner 30 has a front wheel at the front lower part of the housing 35, a rear wheel at the rear lower part, and a control means and a cord reel for controlling the drive of the blower motor 33 inside the housing 35. A chamber or the like is provided and includes a bellows-like intake pipe, a suction pipe, and a suction brush.

Next, the operation of the electric vacuum cleaner 30 will be described.
When a power switch (not shown) of the vacuum cleaner 30 is turned on, the blower motor 33 is driven and the electric blower 32 is rotated. Dust on the floor or the like is sucked together with air by a suction brush and sucked into the dust collecting chamber 31. The blower motor 33 rotates at a high speed, and vibration is generated with the rotation. The blower motor 33 is supported in the housing 35 by the sound absorbing and insulating structure 20. Therefore, the vibration generated from the blower motor 33 directly propagates to the sound absorbing and insulating structure 20. In addition, vibration noise is also generated with this vibration.

  Therefore, the blower motor 33 is accommodated in the sound absorbing and insulating structure 20 in order to reduce the vibration energy and the acoustic energy. Since the sound absorbing and insulating structure 20 has the characteristics as described in the third embodiment, vibration generated by rotation of the blower motor 33 and vibration sound generated along with the vibration can be effectively reduced. It becomes possible. That is, the sound absorbing and insulating structure 20 functions as a soundproof wall around the blower motor 33. Therefore, the sound absorption and sound insulation of the vibration sound radiated from the blower motor 33 are performed at the same time, and the sound radiation from the blower motor 33 can be attenuated before being radiated to the outside of the electric vacuum cleaner 30.

吸遮sound structure 20 is formed of a porous material 10a according to the porous material 10 or the second embodiment according to the first embodiment, a large number of air chambers A or air chamber A ₁ is formed. Therefore, the sound absorbing and insulating structure 20 can pass air. In the vacuum cleaner 30, since the sound absorbing and insulating structure 20 can pass air, the air flow path is secured at the same time without separately forming an air flow path for the air flowing in the housing 35. It will be. Therefore, according to the vacuum cleaner 30, securing the flow path of the air sucked by the blower motor 33 and securing the suction power of the vacuum cleaner 30 can be realized at the same time.

  As described above, if the sound absorbing and insulating structure 20 composed of the porous material 10 or the porous material 10a is used as the motor case of the blower motor 33, both the sound absorbing characteristics and the sound insulating characteristics can be secured and maintained. Thus, noise countermeasures for the blower motor 33 can be effectively realized. In addition, since the sound absorbing and insulating structure 20 also has vibration damping characteristics, not only noise countermeasures but also vibration countermeasures of the vacuum cleaner 30 can be effectively realized. Furthermore, since the sound absorbing and insulating structure 20 is lightweight, an increase in the weight of the electric vacuum cleaner 30 itself can be suppressed.

In addition, dust and dust adhere to and accumulate on the surface of the sound absorbing and insulating structure 20, so that the air chamber A or the air chamber A ₁ is blocked, and the sound deadening space necessary for sound absorption cannot be maintained. is there. Thus, when it becomes impossible to ensure the sound deadening space, the temperature of the blower motor 33 may be abnormally increased. Therefore, a temperature sensor for detecting the temperature of the blower motor 33 is provided, and when the temperature sensor detects an abnormal temperature rise, it is determined that the space in the sound absorbing and insulating structure 20 is blocked, and the blower motor 33 is detected. It is desirable to take measures such as forcibly stopping the rotation of the device or informing a warning (for example, voice or display).

  In the fourth embodiment, the case where the sound absorbing and insulating structure 20 is used as a shape like a motor case has been described as an example. However, the shape of the sound absorbing and insulating structure 20 is not particularly limited. For example, a use form in which the sound absorbing and insulating structure 20 is formed in a plate shape and the blower motor 33 is mounted thereon may be employed. In the fourth embodiment, the vacuum cleaner 30 has been described as an example of an electric device. However, the present invention is not limited to this, and an electric device (for example, a compressor or a washing dryer) that generates vibrations is not limited thereto. I just need it. When the sound absorbing and insulating structure 20 is applied to a compressor, the sound absorbing and insulating structure 20 may be provided under the compressor or surrounding the periphery. Moreover, when applying the sound-absorbing / insulating structure 20 to a washing / drying machine, the motor may be provided so as to surround the sound-absorbing / insulating structure 20.

4 is a schematic diagram for explaining a porous material according to Embodiment 1. FIG. 5 is a schematic diagram for explaining a method for manufacturing a porous material according to Embodiment 1. FIG. 6 is a schematic diagram for explaining a porous material according to Embodiment 2. FIG. 6 is a schematic diagram for explaining a method for manufacturing a porous material according to Embodiment 2. FIG. FIG. 5 is a perspective view showing a schematic configuration of a sound absorbing and insulating structure according to a third embodiment. It is a longitudinal cross-sectional view which shows schematic structure of the vacuum cleaner which is an example of the electric equipment which concerns on Embodiment 4.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Large particle size metal powder, 2 Small particle size metal powder, 3 Piezoelectric material, 10 Porous material, 10a Porous material, 20 Sound absorption and insulation structure, 30 Vacuum cleaner, 31 Dust collection chamber, 32 Electric blower, 33 blower motor, 34 exhaust port, 35 housing.

Claims (9)

A porous material characterized in that metal powders having different particle sizes are sintered and an air chamber is formed between the metal powders. The porous material according to claim 1, wherein a particle diameter of the metal powder is in a range of 10 to 50 μm. The porous material according to claim 1, wherein a piezoelectric powder material that exhibits piezoelectric performance is sintered together with the metal powder. The porous material according to claim 3, wherein the piezoelectric powder material has a particle size in a range of 10 to 50 μm. A sound-absorbing and insulating structure characterized by molding the porous material according to any one of claims 1 to 4 into a predetermined size and shape. An electrical apparatus comprising the sound absorbing and insulating structure according to claim 5 applied to a member around a movable body serving as a vibration generation source. A blower motor for driving an electric blower;
A motor case that houses the blower motor,
The motor case is
It is comprised with the sound-absorption sound insulation structure of the said Claim 5. The vacuum cleaner characterized by the above-mentioned. Mixing a raw material of ethyl carbamate or polyurethane with metal powder having a particle size of 10 μm to 50 μm to create a kneaded material,
A method for producing a porous material, characterized in that the kneaded material is treated at a predetermined temperature and a predetermined pressure to melt the ethyl carbamate or polyurethane raw material, and the metal powder is baked and hardened. The method for producing a porous material according to claim 8, wherein a piezoelectric powder material that exhibits piezoelectric performance together with the metal powder is mixed with the ethyl carbamate or polyurethane raw material.

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