JP2009009958A - Enclosure noise-reducing structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently reduce noises generated as a result of forced air cooling in an enclosure. <P>SOLUTION: The forced air cooling enclosure is made up of a structure that is constructed by combining first members (23, 42, 43, 47, 49 and 54) each having a given hardness and thickness and a plurality of through-holes with second members (25, 41, 44, 48, 50, 53 and 55) each having a given thickness and containing gaps or air bubbles formed continuously from the surface to the inside. The structure is so set on the opposed inner wall surfaces of the enclosure that the first members are opposite to each other. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a noise reduction structure for an electronic device that requires forced air cooling.

  Conventionally, this type of electronic device has a noise-reduction structure, for example, by blowing air from a fan 73 arranged to cool a unit 71 having an electronic circuit mounted on a frame 72, as shown in FIGS. The exhaust duct 70 for discharging to the outside of the housing is provided, and a sound absorbing material is further installed on the side wall of the exhaust duct 70 to reduce noise.

Japanese Utility Model Publication No. 2-42494

  However, the above-described conventional noise reduction structure of the electronic device is an exhaust duct in which a sound absorbing member is attached to the wind discharge side of the blower 73 prepared to cool the unit 71 having the electronic circuit mounted on the frame 72. The noise reduction measures are taken only in the L-shaped exhaust path 81 provided from the exhaust duct 70 to the exhaust port 61, and the noise generated inside the device is not sufficiently attenuated and is external to the device. There was a fault that it was easy to come out.

  Particularly recently, along with the higher integration and speeding up of electronic circuit elements, the amount of heat generated in the electronic circuit package has also increased, and this is in the direction of increasing the amount of rotation of the blower mounted in the housing. It was difficult to reduce noise.

  Therefore, the noise reduction structure for an electronic device according to the present invention aims to efficiently reduce noise generated inside the device to cool a unit having an electronic circuit mounted in a rack. It is what.

  The first noise reduction structure of the present invention has a predetermined hardness and thickness, a first member having a plurality of through holes, and a gap having a predetermined thickness and continuing from the surface to the inside. A structure formed by combining a second member containing bubbles is placed so that the first member faces each other with a predetermined space therebetween, and noise generated from a sound source in the housing is silenced. It is characterized by that.

  The second noise reduction structure of the present invention has a plurality of through holes, a first member having at least a characteristic of reflecting sound incident on a portion other than the through holes, and a predetermined high frequency of the incident sound. A structure formed by combining a second member having at least a property of absorbing a part of the component, and a sound source in the housing, wherein the first member is disposed so as to face each other with a predetermined space therebetween It is characterized in that the noise generated from the noise is reduced.

  The third noise reduction structure of the present invention has a predetermined hardness and thickness, a first member having a plurality of through holes, a predetermined thickness, and a gap or a continuous gap from the surface to the inside. A structure formed by combining a second member containing air bubbles is placed on opposing inner wall surfaces in the housing so that the first members face each other, and noise generated from a sound source in the housing It is characterized by quieting.

  The fourth noise reduction structure of the present invention has a plurality of through holes, a first member having at least a property of reflecting sound incident on a portion other than the through holes, and a predetermined high frequency of the incident sound. A structure formed by combining a second member having at least a property of absorbing a part of the component, and the first member is installed on opposite inner wall surfaces in the housing so as to face each other; The noise generated from the sound source in the housing is silenced.

  The fifth noise reduction structure of the present invention has a predetermined hardness and thickness, a first member having a plurality of through-holes, a gap having a predetermined thickness and continuous from the surface to the inside, or A structure formed by combining the second member containing bubbles is placed on the opposing inner wall surface portion other than the inner wall surface of the rear surface of the housing such that the first member faces each other. The structure is provided in a plurality of stages on the inner wall surface of the front surface of the body, and noise generated from a sound source in the housing is silenced.

  The sixth noise reduction structure of the present invention has a predetermined hardness and thickness, a first member having a plurality of through holes, a predetermined thickness, and a gap or a continuous gap from the surface to the inside. A first structure formed by combining a second member containing air bubbles, and a frame structure capable of integrally configuring a plurality of fans; and further, the first member and the second member And a second structure formed including the first structure and the first member formed on each other with a predetermined space therebetween, so that noise generated from a sound source in the housing is silenced. It is characterized by.

  The seventh noise reduction structure of the present invention has a predetermined hardness and thickness, a first member having a plurality of through holes, a predetermined thickness, and a gap or a continuous gap from the surface to the inside. A second member containing air bubbles and a structure formed so that the second member is sandwiched between the first members are disposed so that one of the first members faces each other with a predetermined space therebetween The noise generated from the sound source in the housing is silenced.

  The eighth noise reduction structure of the present invention has a plurality of through holes, a first member having at least a property of reflecting sound incident on a portion other than the through holes, and a predetermined high frequency of the incident sound. A second member having at least a property of absorbing a part of the component, and a structure formed so as to sandwich the second member between the first member, and the first member is separated from the first member by a predetermined space. The members are installed so as to face each other, and noise generated from a sound source in the housing is silenced.

According to the present invention, noise generated in the housing can be efficiently reduced in the housing.

Next, a first embodiment of the electronic device casing of the present invention will be described with reference to FIGS.
FIG. 1 is an external perspective view of an electronic device casing, FIG. 2 is an internal configuration example of a functional unit in which an electronic board for each function is mounted on the electronic device casing of FIG. 1, and FIG. FIG. 4 is a diagram for explaining the relationship between the air flow generated in the electronic device casing by the fan and the noise, and FIG. 5 is installed on the fan unit and the bottom of the casing. FIG. 6 is a diagram for explaining a state in which sound is absorbed by a sound absorbing material installed at an opposite position.

  First, the configuration of a device mounted on the electronic device casing 1 will be described with reference to FIGS. 1 and 2.

  In FIG. 1, an optical device 3 and an HDD 4 that are storage devices are mounted on an upper portion of an electronic device housing 1. An intake port 2 is provided around the upper part of the electronic device casing 1. A functional unit having an electronic circuit designed for each predetermined function can be mounted in the central portion of the housing. By mounting the functional unit 5 corresponding to the function required for the electronic device casing 1, it is possible to realize the function required for the electronic device casing 1. A fan unit 6 including a plurality of fans 7 is mounted on the lower part of the electronic device casing 1.

  Next, an example of the internal configuration of the functional unit 5 will be described with reference to FIG. The functional unit 5 can be implemented in the electronic device casing 1 to realize a predetermined function. A fan 7 is mounted on the top of the functional unit 5, and an electronic circuit board 8 having various functions is connected to and mounted on the main board 9.

  Next, the configuration of the noise reduction member including the sound absorption member attached to the lower part of the fan unit 6 and the electronic device casing 1 will be described with reference to FIG.

  First, the fan unit 6 is a noise reduction member including a plurality of fans 7, frames 20 and 22, and a sound absorbing member 21. The frames 20 and 22 have a sturdy structure made of metal, and the fan 7 is attached integrally. Specifically, when the fan 7 is attached to the frames 20 and 22, a member having flexibility such as rubber may be sandwiched between the fan and the frame, and the fan may be attached to the case integrally with screws or the like. Further, through holes are provided at predetermined intervals at positions other than the opening of the fan 7 to be attached. The sound absorbing member 21 is formed so as to fill the gaps between the fans 7 attached to the frames 20 and 22 and between the fans 7 and the frames 20 and 21.

  Next, the noise reducing member including the sound absorbing member 25 includes the punching metal 23 and the sound absorbing member 21. The punching metal 23 is made of a material having high hardness and specific gravity, such as metal, and has through holes with predetermined intervals and sizes. This has the effect of suppressing vibrations and will be referred to as a damping member. The sound absorbing member 21 is made of a fibrous material such as glass wool or a porous material such as a foamed resin containing continuous bubbles. A casing cover 23 made of punching metal is attached to the bottom surface of the casing 1.

  Next, with reference to FIG. 4 and FIG. 5, the air flow generated in the electronic device casing 1 by the fan and the noise reduction will be described.

  First, with reference to FIG. 4, the flow of air in the electronic device casing 1 due to the intake of a fan installed in the electronic device casing 1 will be described. In the electronic device casing 1, the air was sucked in from the air inlet 2 by the fan 7 attached to the upper side inside the functional unit 5 or the fan 7 attached to the lower part of the electronic device casing 1. The air takes down heat generated from an electronic circuit or the like inside the functional unit and flows downward, and is further drawn by the fan 7 of the fan unit 6 at the bottom of the electronic device casing 1. The portion having the through holes of the frames 20 and 22 attached to the fan unit 6 and the sound absorbing member 21 are not provided in the opening of the fan 7, and the air flow is hardly impaired. The air drawn in by the fan unit 6 passes through a predetermined space provided between the fan unit 6, a punching metal 23 attached to the bottom of the electronic device casing 1, and a sound absorbing member 25. Exhaust from the exhaust port 8 through.

  Next, the silencing of noise generated inside the electronic device casing 1 will be described. The noise reduction member 21 including the sound absorbing member 21 and the frames 20 and 22 having through holes provided in the fan unit 6 is formed in the vicinity of the fan 7, and noise generated from the fan 7 configured in the fan unit is approached. Absorb with. Furthermore, it is vibrated by an elastic body such as rubber attached between the fan 7 and the frames 20 and 22, and the generation of noise is also suppressed. Further, air flowing in the housing is collected in a space between the punching metal 23 and the sound absorbing member 25 that is provided with a predetermined space between the fan unit 6 and the sound absorbing member 25. A part of the noise is absorbed by the sound absorbing members 21 and 25 due to the diffuse reflection of noise between the opposing silencer members in the path until the air flow including the noise reaches the exhaust port 8. In addition, when the housing cover on the bottom surface of the electronic device housing 1 is configured by the punching metal 24, some noise is also generated from the housing bottom surface cover 24 formed of the punching metal of the electronic device housing 1. Discharged. This exhausts noise generated inside the electronic device casing 1 not only from the exhaust port 8 but also from the through-hole of the casing bottom cover 24, thereby reducing the muffled noise.

  Next, a specific state in which noise is reduced will be described with reference to FIG. A similar noise reduction member 30 is installed at a position facing the noise reduction member 30 formed of the vibration damping member 23 and the sound absorption member 21 made of punching metal or the like with a predetermined space therebetween. The sound that has entered the portion other than the through hole of the other punching metal facing the predetermined space is reflected, and a part of the sound enters the portion of the through hole of the opposing punching metal and enters the sound absorbing member 21. Further, a part of the light is incident on and reflected from a portion other than the opposing punching metal through hole. By repeating the above operation at random, the frequency of sound incident on the sound absorbing member 21 is increased and the sound absorption efficiency is increased.

  Further, although not shown in the drawings, in the punching metal 23 and the sound absorbing member 21 forming the noise reduction member 30, when the punching metal 23 is attached to another surface where the punching metal 23 is not combined, it is newly attached. Since the reflection of the sound to the sound absorbing material 21 also occurs on the surface, the frequency of the sound incident on the sound absorbing member 21 is further increased and the sound absorption efficiency is increased.

  Next, the difference in sound absorption to the sound absorbing member due to noise frequency components will be described. When sound is incident on the damping member 23 made of punching metal or the like, the sound reaching the portion other than the through hole is reflected, but from the through hole, a fibrous material such as glass wool or a foamed resin having continuous air bubbles, etc. The sound incident on the member 21 made of the porous material causes viscous friction of the air on the surface of the porous material fibers and bubbles, and a part of the sound energy is converted into thermal energy. Is attenuated. This sound attenuation effect is generally remarkable for high-frequency sounds. These attenuation operations are combined and repeated to reduce the overall noise level. Since the high frequency component sound is more likely to propagate air than the low frequency component sound, the noise reduction effect is high when reduced.

  Next, the noise reduction structure of the second embodiment of the present invention will be described.

  Referring to FIG. 6, all inner wall surfaces of the electronic device casing 1 are provided with a noise reduction member in which a vibration damping member such as punching metal and a sound absorbing member made of a porous material are combined. It is attached to the inner wall surface. Silencing members made up of a damping member and a sound absorbing member are attached to all opposing inner wall surfaces in the housing. A silencing member comprising the damping member 42 and the sound absorbing member 41 and a silencing member comprising the damping member 43 and the sound absorbing member 44 are respectively attached to the opposing wall surfaces of the housing. A noise reducing member consisting of the vibration damping member 47 and the sound absorbing member 48 and a noise reducing member consisting of the vibration suppressing member 49 and the sound absorbing member 50 are respectively attached to the opposite wall surfaces of the casing. A silencing member comprising the damping member 23 and the sound absorbing member 25 and a silencing member comprising the damping member 54 and the sound absorbing member 53 are respectively attached to the opposing wall surfaces of the casing. Here, it is desirable that the noise reduction member is attached so as not to cause a gap as much as possible at the adjacent boundary of the inner wall of the housing.

  In terms of operation, noise is absorbed by the sound absorbing member while being diffusely reflected between the noise reducing members attached to the opposite wall surface portions, and the noise is similarly obtained between the noise reducing members attached to other wall surface portions. Is absorbed while being irregularly reflected. The specific noise absorbing operation is the same as that shown in FIG.

  Next, a noise reduction structure according to a third embodiment of the present invention will be described. In the second embodiment described above, the case where the noise reduction member is attached to all opposing inner wall surfaces of the housing has been described. However, in the third embodiment, a part of the inner wall surface of the device housing has The case where the noise reduction member is not attached will be described. On the rear side of the housing, the noise reduction member composed of the vibration damping member 25 and the sound absorbing member 26 is not installed. The reason is to facilitate the operation of connecting or disconnecting cables such as a network interface in the electronic device casing 1. For this reason, the noise reduction member of the present invention is not attached to the back surface of the housing 1, and the noise reduction member of the present invention is double-attached to the front wall portion which is the opposite inner wall surface portion.

In Example 3, since the noise reduction member of the present invention is not installed on the rear surface of the casing of the device, the noise reduction member of the present invention is overlapped on the front surface of the device casing having a relative positional relationship to compensate for it. The sound is attenuated between the silencer members that are installed in duplicate.
By discharging sound from the wall on the rear surface of the housing of the device in which the noise reduction member of the present invention is not installed, the sound is discharged to the rear rather than the sound leaking to the front for the user located in the front of the device Is preferred.

  In this embodiment, the example in which the air is sucked in from the upper side of the casing and is exhausted downward has been described. However, the air can be sucked in from the lower side of the casing and exhausted upward. Similarly, the relationship between intake and exhaust can be applied in the left-right direction.

It is a figure which shows the flow of the air from the exterior of the housing | casing of 1st Embodiment. It is a figure for demonstrating the internal structure of the functional unit mounted in the housing | casing of 1st Embodiment. It is a figure which shows the structure of the fan unit and the noise reduction member inside the housing | casing of 1st Embodiment. It is a figure explaining the flow of the air inside the housing | casing of 1st Embodiment, and the flow of noise. It is a figure for demonstrating the mode of attenuation | damping or absorption of the noise between the opposing silencing members in 1st, 2nd, 3rd embodiment. It is a figure for demonstrating the structure inside the housing | casing of 2nd, 3rd Embodiment. It is the external appearance perspective view and whole sectional view of the conventional case for forced air cooling. It is detailed sectional drawing of the exhaust duct part of the conventional housing | casing for forced air cooling.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,60 Electronic device housing | casing 2,74 Intake port 3, 4 Recording device 5 Functional unit 6 which has an electronic circuit Fan unit 7, 73 Fan 8, 61 Exhaust port 10 Electronic circuit board 11 Motherboard 40, 46, 51, 52, 45 Housing cover 21, 25, 41, 44, 48, 50, 53, 55, 82, 83 Sound absorbing member 23, 24, 42, 43, 47, 49, 54 Punching metal 30 Silent member 31 Noise 33 Through hole 70 Exhaust duct 71 Unit 72 Frame 80 Cavity resonance chamber 81 Exhaust passage

Claims (13)

A first member having a predetermined hardness and thickness and having a plurality of through holes;
A second member having a predetermined thickness and including gaps or bubbles continuous from the surface to the inside;
A structure formed by combining
The first members are installed so as to face each other with a predetermined space therebetween,
Silencing structure characterized by silencing noise generated from a sound source in a housing. A first member having a plurality of through holes and having at least a property of reflecting sound incident on a portion other than the through holes;
A second member having at least a characteristic of absorbing a part of a predetermined high-frequency component of the incident sound;
A structure formed by combining
The first members are installed so as to face each other with a predetermined space therebetween,
Silencing structure characterized by silencing noise generated from a sound source in a housing. A first member having a predetermined hardness and thickness and having a plurality of through holes;
A second member having a predetermined thickness and including gaps or bubbles continuous from the surface to the inside;
A structure formed by combining
The first members are installed on opposite inner wall surfaces in the housing so as to face each other,
Silencing structure characterized by silencing noise generated from a sound source in a housing. A first member having a plurality of through holes and having at least a property of reflecting sound incident on a portion other than the through holes;
A second member having at least a characteristic of absorbing a part of a predetermined high-frequency component of the incident sound;
A structure formed by combining
The first members are installed on opposite inner wall surfaces in the housing so as to face each other,
Silencing structure characterized by silencing noise generated from a sound source in a housing. The silence structure according to claim 3, wherein the structure is installed on all inner wall surfaces facing each other in the housing. The noise-reducing structure according to claim 4, wherein the structure is installed on all inner wall surfaces facing each other in the housing. The structure is installed on all inner wall surfaces facing each other except for a part of the surface in the housing, and the structure is overlapped on the inner wall facing the part of the surface. The silencing structure according to claim 3. The structure is installed on all inner wall surfaces facing each other except for a part of the surface in the housing, and the structure is overlapped on the inner wall surface facing the part of the surface. The silencing structure according to claim 4, characterized in that it is characterized. A first member having a predetermined hardness and thickness and having a plurality of through holes;
A second member having a predetermined thickness and including gaps or bubbles continuous from the surface to the inside;
A structure formed by combining
The first members are installed on opposing inner wall surfaces other than the inner wall surface of the rear surface of the housing so as to face each other, and further, the structure is installed in a plurality of stages on the inner wall surface of the front surface of the housing,
Silencing structure characterized by silencing noise generated from a sound source in a housing. A first member having a predetermined hardness and thickness and having a plurality of through holes;
A second member having a predetermined thickness and including gaps or bubbles continuous from the surface to the inside;
A first structure formed by combining
It has a frame structure that can be configured integrally with multiple fans,
A second structure formed including the first member and the second member;
The first member formed on each of the first member and the second member is opposed to each other with a predetermined space therebetween.
Silencing structure characterized by silencing noise generated from a sound source in a housing. The silence structure according to claim 10, wherein the first structure and the second structure are installed near an exhaust port of the housing. A first member having a predetermined hardness and thickness and having a plurality of through holes;
A second member having a predetermined thickness and including gaps or bubbles continuous from the surface to the inside;
A structure formed so that the second member is sandwiched between the first members,
One of the first members is placed opposite to each other with a predetermined space therebetween,
Silencing structure characterized by silencing noise generated from a sound source in a housing. A first member having a plurality of through holes and having at least a property of reflecting sound incident on a portion other than the through holes;
A second member having at least a characteristic of absorbing a part of a predetermined high-frequency component of the incident sound;
A structure formed so that the second member is sandwiched between the first members,
One of the first members is placed opposite to each other with a predetermined space therebetween,
Silencing structure characterized by silencing noise generated from a sound source in a housing.

Images