close

Вход

Забыли?

вход по аккаунту

?

JP2008263588

код для вставкиСкачать
Patent Translate
Powered by EPO and Google
Notice
This translation is machine-generated. It cannot be guaranteed that it is intelligible, accurate,
complete, reliable or fit for specific purposes. Critical decisions, such as commercially relevant or
financial decisions, should not be based on machine-translation output.
DESCRIPTION JP2008263588
PROBLEM TO BE SOLVED: To provide a sound collector suitable for performing acoustic analysis
with high accuracy, in which the influence of unnecessary reflected waves is further suppressed.
SOLUTION: A sound collecting hood having an opening at the front end and a sound reflecting
inner wall having a rotating surface shape having an opening at the front end and a focus behind
the opening, an inner space is formed, and a sound receiving surface A microphone disposed
forward and receiving a sound wave incident in the sound collecting hood, and a front surface
having an incident path of sound to the sound receiving surface from the rear end circumference
of the sound reflecting inner wall to the front of the sound receiving surface The acoustic wave
acting body is formed to have a shape surrounding the incident passage so as to be formed, and
extends toward the rear end side of the inner space, the acoustic wave acting body acting on the
acoustic wave incident on itself. The invention is characterized in that it is extended to the
outside of the diameter of the rear end of the sound reflecting inner wall. [Selected figure] Figure
3
Sound collector
[0001]
The present invention relates to a sound collector that collects sound with a parabolic hood.
[0002]
Conventionally, the surface to be inspected is hit with a striking tool such as a hammer, and the
sound generated by the impact (hereinafter referred to as striking sound) is collected by a
microphone and analyzed to be present inside the object to be tested. A hitting sound inspection
system for detecting defects such as hollows is known (see, for example, Non-Patent Document
03-05-2019
1
1).
[0003]
In the percussion sound inspection system described in the above-mentioned Non-Patent
Document 1, the collection of percussion sound is provided with a stethoscope type sound
collecting hood for disposing the microphone at the center and blocking the surrounding sound.
It is performed by a sound collector.
[0004]
By the way, since impulse sound such as hitting sound is not continuous sound, it is necessary to
collect an accurate acoustic signal in a short time.
[0005]
However, in the acoustic diagnosis of impulse sound, since the sound is reflected (including
irregular reflection) and reaches the sound collector at one time, accurate acoustic diagnosis may
be difficult.
[0006]
Therefore, the sound absorbing material is disposed on the back side of the sound collecting
hood, and it is difficult to cause interference between the sound waves by absorbing the sound
waves emitted from the inspection object and reflected by the inner wall surface 112 of the
sound collecting hood. It is conceivable to adopt the already proposed sound collector (see Patent
Document 1).
[0007]
FIG. 1 is a cross-sectional view of a sound collector already proposed by the present inventor.
[0008]
FIG. 1 shows the sound collector 100 in which the sound absorbing material 130 is disposed so
as to be surrounded by the sound reflecting wall 111 of the sound collecting hood 11 and the
inner wall surface 112 of the inner wall surface 112.
[0009]
Further, the inventor of the present invention has proposed a sound collector, which is an
03-05-2019
2
improvement of the sound collector 100 shown in FIG. 1 and is further improved in sound
collection performance with respect to the collection of impulse sound generated by striking an
inspection object. (See Patent Document 2).
[0010]
FIG. 2 is a cross-sectional view of the sound collector already proposed by the inventor.
[0011]
FIG. 2 shows a sound collector 200 provided with a sound absorbing material 230 formed in a
shape surrounding an incident path of sound to the sound receiving surface 121 of the
microphone 12 disposed in the sound collecting hood.
[0012]
In the sound collector 200 shown in FIG. 2, the sound absorbing material is more absorbed than
the sound wave reflected by the inner wall surface 112 of the sound collecting hood 11 without
obstructing the sound wave reflected by the sound reflecting wall 111 and reaching the sound
receiving surface 121. Since the light can be absorbed by 230, it is possible to make the
interference between the sound waves less likely to occur than the sound collector 100 shown in
FIG.
"Inspection technology", July 2002, pp. 41-45 (technical topics / architects / architects) Patent
No. 3223237 Patent Publication No. 2005-124032
[0013]
However, in the sound collector 200 shown in FIG. 2 as well, the sound wave incident on the
sound absorbing material 230 is reflected by the inner wall 112 of the sound collecting hood 11
as shown by arrow A in FIG. There is a problem that interference with the sound waves is
generated while being incident on the 12 sound receiving surfaces 121.
[0014]
An object of the present invention is to provide a sound collector suitable for performing acoustic
analysis with high accuracy, in which the influence of unnecessary reflected waves is further
suppressed.
03-05-2019
3
[0015]
In order to achieve the above object, a sound collector of the present invention is a sound
collecting hood having an opening at the front end and a sound reflecting inner wall in the form
of a rotating surface having a focus behind the opening. A microphone disposed in the sound
collecting hood with the sound receiving surface facing forward and receiving a sound wave
incident on the sound collecting hood, and a front face receiving the sound from around the rear
end of the sound reflecting inner wall It is formed to surround the incident passage so that an
incident passage of sound to the sound receiving surface is formed toward the front of the
surface, and it is incident on itself extending toward the rear end side of the internal space And a
sound wave acting body acting on a sound wave, wherein the sound wave working body extends
outward beyond the diameter of the rear end of the sound reflection inner wall.
[0016]
Here, the sound wave acting body is preferably made of a sound absorbing material having a
sound absorbing property, or the sound wave acting body includes a sound absorbing material
having a sound absorbing property and a diameter of a rear end of the sound reflecting inner
wall. It is also a preferable embodiment that it is composed of a sound reflecting material having
sound reflectivity that surrounds the periphery of the sound absorbing material outside.
[0017]
In the sound collector of the present invention, the sound wave acting body extends outward
beyond the diameter of the rear end of the sound reflecting inner wall, so the propagation path
of the sound wave incident on the sound wave acting body in the sound wave acting body is It
also gets longer.
Thereby, if the sound reflector is made of a sound absorbing material, the sound wave incident
on the sound reflector can be attenuated and then directed to the rear side of the sound receiving
surface of the microphone, and the sound wave action can be achieved. If the body is made of a
sound absorbing material and a sound reflecting material, the sound wave incident on the sound
absorbing material can be scattered by the sound reflecting material and directed to the back
side of the sound receiving surface of the microphone.
Therefore, according to the sound collector of the present invention, the influence of the
03-05-2019
4
reflected wave can be further suppressed.
[0018]
Further, it is preferable to provide a sound reflection ring which covers the peripheral edge
portion of the sound wave acting body which is continuous with the rear end of the sound
reflection inner wall and extends the rear end of the sound reflection inner wall.
[0019]
In order to accommodate the sound wave action body extended outside the diameter of the rear
end of the sound reflection inner wall of the conventional sound collection hood, a sound
collection hood in which the diameter of the rear end of the sound reflection inner wall of the
conventional sound collection hood is enlarged Although it is quick to use, if it is made in this
way, the sound reflection profile is different from the sound reflection profile on the conventional
sound reflection inner wall, and it becomes difficult to judge the effect.
In addition, the sound reflection inner wall retains the conventional sound reflection profile by
maintaining the conventional shape, and then the diameter of the sound reflection wall of the
sound collection hood behind the rear end of the sound reflection wall is the rear end of the
sound reflection inner wall The diameter of the sound reflecting wall may be narrowed at the
rear end of the sound reflecting wall.
However, this makes die cutting difficult and takes time for molding.
Therefore, as described above, by providing the sound reflection ring that covers the peripheral
edge portion continuous with the rear end of the sound reflection inner wall and extends the rear
end of the sound reflection inner wall, the rear of the sound reflection inner wall of the
conventional sound collecting hood is provided. The sound collector of the present invention can
be easily embodied without losing portability by producing the same shape as the conventional
sound reflecting inner wall while accommodating the sound wave acting body extended to the
outside of the diameter of the end. be able to.
Further, by providing such a sound reflection ring, it is possible to easily store the sound wave
acting body extended to the outside of the diameter of the rear end of the sound reflection inner
03-05-2019
5
wall inside the sound collection hood.
[0020]
Furthermore, it is also a preferable aspect that the above-mentioned sound reflection ring is
removably disposed, and the above-mentioned sonic acting body is removably accommodated
behind the above-mentioned internal space.
[0021]
In this way, the acoustic wave effector can be easily replaced.
[0022]
Here, it is preferable that the above-mentioned sound reflection material is a shape in which the
shape of the cross section is a shape in which the apexes of triangles are connected.
[0023]
When the sound reflecting material has such a shape, sound waves can be scattered with a
simple structure.
[0024]
In addition, it is also a preferable embodiment to include a partition wall disposed in front of the
sound receiving surface to isolate at least the rear region of the internal space including the
sound receiving surface from the outside of the sound collecting hood.
[0025]
If such a partition is provided in a sound collector that does not have a sound wave acting body
that forms an incident passage of sound to the sound receiving surface of the microphone in the
sound collection hood, the inner wall surface of the sound collector 1 hood and the partition
Although the sound collection performance is extremely degraded by the standing waves
generated by the multiple reflections of the sound waves between the two, in the sound collector
of the present invention, the deterioration of the sound collection performance is suppressed by
the presence of the sound acting body, Even if such a partition is used, the antifouling property
of the sound receiving surface of the microphone can be improved without sacrificing the sound
collecting performance so much.
03-05-2019
6
[0026]
Here, it is preferable that the above-mentioned partition is a partition which consists of a sheet
which has sound permeability, or it is also a desirable mode that it is a partition which consists of
a sheet which has air permeability.
[0027]
When the partition wall has sound permeability or air permeability, the reduction in sound
collection performance can be further reduced.
[0028]
According to the present invention, it is possible to provide a sound collector suitable for
performing acoustic analysis with high accuracy, in which the influence of reflected waves is
further suppressed.
[0029]
Hereinafter, embodiments of the present invention will be described.
[0030]
FIG. 3 is a cross-sectional view of a first embodiment of a sound collector of the present
invention.
Among the members shown in FIG. 3, members of the same type as the members shown in FIGS.
1 and 2 have the same reference numerals as the reference numerals attached to the members
shown in FIGS.
[0031]
The sound collector 1 of this embodiment shown in FIG. 3 includes a sound collecting hood 11
for collecting sound, a microphone 12 inserted into a hole 113 formed in the center back side of
the sound collecting hood 11, and a sound collecting hood Sound-reflecting sound reflecting the
peripheral portion of the glass wool 13 and the peripheral portion of the glass wool 13 which is
fitted between the sound-absorbing material storage wall 112 of FIG. 11 and the microphone 12;
The ring 14 is configured.
03-05-2019
7
[0032]
The sound collecting hood 11 is composed of a sound reflecting inner wall 111 of a rotating
surface shape having a focal point behind the opening 114 and a sound absorbing material
storage wall 112 of a cylindrical shape, and the sound reflecting ring 14 is a sound of the glass
wool 13. The rear end of the sound reflection inner wall 111 is extended so as to cover the
peripheral edge portion continuous with the rear end of the reflection inner wall 111.
[0033]
In this sound collector 1, the sound absorbing material 13 is removably accommodated on the
back side in the sound collecting hood, and the sound reflecting ring 14 also has the sound
collecting hood 11 although illustration of the mechanism is omitted. The sound reflecting inner
wall 111 is removably disposed.
[0034]
The microphone 12 is configured of a sound receiving surface 121 and a main body 122.
[0035]
The glass wool 13 has an insertion hole 13 a for inserting the main body 122 of the microphone
12 in the central portion, and has a sound absorbing property which extends outside the
diameter of the rear end of the sound reflection ring 14. .
The glass wool 13 corresponds to an example of the sound absorbing material in the present
invention.
[0036]
In this sound collector 1, the sound reflection ring 14 is removable as described above, in
preparation for replacement in the case where the glass wool 13 extended to the outside beyond
the diameter of the rear end of the sound reflection ring 14 is deteriorated. .
In order to accommodate the glass wool 13 extended outside the diameter of the rear end of the
03-05-2019
8
sound reflection inner wall of the conventional sound collection hood shown in FIG. 2, the
diameter of the rear end of the sound reflection inner wall of the conventional sound collection
hood is enlarged Although it is quick to use a sound hood, this makes the sound reflection profile
different from the sound reflection profile on the conventional sound reflection inner wall,
making it difficult to judge the effect.
In addition, the sound reflection inner wall retains the conventional sound reflection profile by
maintaining the conventional shape, and then the diameter of the sound reflection wall of the
sound collection hood behind the rear end of the sound reflection wall is the rear end of the
sound reflection inner wall It is conceivable to make the diameter larger than the diameter of the
rear end, that is, to make the shape of the rear end of the sound reflection wall constricted, but
this makes die cutting difficult and takes time for molding.
Therefore, in the sound collector 1, a sound reflection ring 14 is provided to cover the peripheral
edge portion continuous with the rear end of the sound reflection inner wall 111 and extend the
rear end of the sound reflection inner wall 111. Since the same shape as the conventional sound
reflecting inner wall is created while accommodating the glass wool 13 extended to the outside
beyond the diameter of the rear end of the sound reflecting inner wall, this sound collector 1 can
be easily made without lowering the portability. It can be embodied.
In addition, by providing such a sound reflection ring 14, it is possible to easily store the glass
wool 13 expanded to the outside of the diameter of the rear end of the sound reflection inner
wall 111 inside the sound collection hood.
[0037]
FIG. 4 and FIG. 5 are diagrams showing the range in which sound can be collected by the sound
collector of this embodiment.
[0038]
In FIG. 4 and FIG. 5, the directivity for every frequency (from 1 kHz to 16 kHz) of the sound
collector 1 of this embodiment is shown.
[0039]
Here, FIG. 6 and FIG. 7 are diagrams showing the range in which sound can be collected by the
conventional sound collector.
03-05-2019
9
[0040]
6 and 7 show directivity of each of the conventional sound collectors 200 shown in FIG. 2 for
each frequency (from 1 kHz to 16 kHz).
[0041]
From FIG. 4, FIG. 5, FIG. 6, and FIG. 7, in the sound collector 1 of this embodiment, the side lobes
recognized at 9 kHz and 10 kHz in the conventional sound collector 200 are good as the effects
of the present invention. It can be confirmed that it is suppressed.
[0042]
FIG. 8 is a graph showing the frequency characteristics of the sound collector of this embodiment
and a conventional type sound collector.
[0043]
In FIG. 8, the relative sensitivity for each frequency in the sound collector 1 of the present
embodiment is indicated by 'dia mark', and the relative sensitivity for each frequency in the
conventional sound collector 200 shown in FIG. It is done.
From FIG. 8, by making the glass wool 13 into a shape extending outward beyond the diameter of
the rear end of the sound reflection ring 14, the sensitivity of the microphone 12 is leveled and
the frequency characteristics are flattened as compared with the prior art. Is shown.
[0044]
As described above, in the sound collector 1 of the present embodiment, the glass wool 13 is
expanded to the outside of the diameter of the rear end of the sound reflection ring 14 so that
this glass wool of the sound wave incident on the glass wool 13 As the propagation path in the
inside becomes longer, the incident sound wave can be attenuated more, and it can pass behind
the sound receiving surface 121 of the microphone 12 as shown by the arrow A shown in FIG. .
03-05-2019
10
Therefore, according to the sound collector 1 of this embodiment, the influence by the reflected
wave reflected by the sound absorbing material storage wall 112 of the sound collection hood 11
can be suppressed, and it can contribute to highly accurate acoustic analysis.
[0045]
In the present embodiment, the case where the glass wool 13 is accommodated in the sound
collecting hood 11 has been described as an example, but the present invention is not limited to
this, and any other material may be used as long as it has sound absorbing properties. You may
use.
[0046]
Next, a second embodiment of the sound collector of the present invention will be described.
[0047]
FIG. 9 is a cross-sectional view of a sound collector according to a second embodiment.
Among the members shown in FIG. 9, members of the same type as the members shown in FIG. 3
are given the same reference numerals as the reference numerals shown in FIG.
[0048]
The difference between the sound collector 2 according to the second embodiment shown in FIG.
9 and the sound collector 1 according to the first embodiment shown in FIG. 3 is that in the
sound collector 1 according to the first embodiment In the sound collector 2 of the second
embodiment, only the glass wool 13 is accommodated in the sound collecting hood 11, and the
sound is surrounded by the glass wool 13 and the sound of the glass wool 13. The point is that
the reflective aluminum wool 23 is accommodated in the sound collecting hood 11.
Further, in the sound collector 2 of the second embodiment, the aluminum wool 23 surrounds
the glass wool 13 outside the diameter of the rear end of the sound reflection ring 14, and in this
way, sound reflection is achieved. The influence of the reflected wave can be further suppressed
as compared with the sound collector 200 shown in FIG. 2 in which only the glass wool 13 is
03-05-2019
11
provided inside the diameter of the rear end of the ring 14.
The aluminum wool 23 corresponds to an example of the reflective material in the present
invention.
[0049]
FIG. 10 is a view showing the X-X 'cross section of the sound collector shown in FIG.
[0050]
FIG. 10 shows that sound absorbing aluminum wool 23 surrounds sound absorbing glass wool
13.
Further, FIG. 10 shows that the shape of the cross section of the aluminum wool 23 is a shape in
which the apexes of substantially equilateral triangles are connected.
[0051]
In the sound collector 2 of the present embodiment, by surrounding the glass wool 13 with the
aluminum wool 23 whose cross section is formed by connecting the apexes of equilateral
triangles, the sound wave incident from the front face of the glass wool 13 has a simple
structure. It can be scattered more reliably and can be directed to the rear side of the sound
receiving surface 122 of the microphone 12.
[0052]
FIG. 11 and FIG. 12 are diagrams showing the range in which sound can be collected by the
sound collector of this embodiment.
[0053]
11 and 12 show directivity for each frequency (from 1 kHz to 16 kHz) of the sound collector 2 of
the present embodiment, which is comparable to that of the conventional sound collector 200. It
can be confirmed that the directivity is secured.
03-05-2019
12
[0054]
FIG. 13 is a graph showing the frequency characteristics of the sound collector of this
embodiment and the conventional sound collector.
[0055]
In FIG. 13, the relative sensitivity for each frequency in the sound collector 2 of the present
embodiment is indicated by 'dia mark', and the relative sensitivity for each frequency in the
conventional sound collector 200 shown in FIG. It is done.
From FIG. 13, in addition to the glass wool 13, the sensitivity of the microphone is improved by
providing the sound reflective aluminum wool 23 surrounding the glass wool 13 outside the
diameter of the rear end of the sound reflection ring 14. It is shown that the frequency
characteristic is also flattened while being leveled in comparison.
[0056]
As described above, in the sound collector 2 of the present embodiment, the glass wool 13 and
the aluminum wool 23 having sound reflectivity that surrounds the glass wool 13 outside the
diameter of the rear end of the sound reflection ring 14 The sound wave that has been incident
on the glass wool 13 from the front surface can be more reliably scattered by the aluminum wool
23 and directed to the rear of the sound receiving surface 122 of the microphone 12.
Thereby, according to the sound collector 2 of this embodiment, since the influence by a
reflected wave can be suppressed, highly accurate acoustic analysis is attained.
[0057]
Moreover, although the example which used the aluminum wool 23 which has sound reflectivity
was mentioned and demonstrated in this embodiment, this invention is not limited to this, If it is
a material which has sound reflectivity, resin, wood, It may be cork, rubber or the like, and the
cross section is not limited to an equilateral triangle, and this may be an equilateral triangle in
cross section and may be a connection of apexes forming base angles, and further, The cross
section may be semicircular, and the end points of the strings may be connected to each other.
03-05-2019
13
[0058]
In the sound collector 1 according to the first embodiment of the sound collector of the present
invention and the sound collector 2 according to the second embodiment of the present
invention, the sound reflection ring 14 for extending the sound reflection inner wall 111 is
provided. Although the present invention has been described by way of example, the sound
collector of the present invention is not limited to this embodiment.
[0059]
Here, FIG. 14 is a cross-sectional view of a third embodiment and a fourth embodiment of the
sound collector of the present invention.
[0060]
The sound collector 3 of 3rd Embodiment is shown by Fig.14 (a), and in the 1st embodiment
shown in FIG. 3, the extension part by the sound reflection ring 14 is the sound collector 3 of 3rd
Embodiment. In the figure, it is shown that it is integrally molded as a part of the sound
collecting hood 11.
Further, FIG. 14 (b) shows the sound collector 4 of the fourth embodiment, and in the second
embodiment shown in FIG. 9, the extended portion by the sound reflection ring 14 corresponds
to the sound collection of the fourth embodiment. The container 4 is shown as being integrally
molded as part of the sound collecting hood 11.
Thus, even if the portion corresponding to the sound reflecting ring 14 is integrally formed as a
part of the sound collecting hood 11, the basic effect of the present invention is not diminished.
[0061]
Here, FIG. 15 is an external perspective view of the sound collector in a state in which the sheet
is put on the opening surface of the sound collection hood.
The same type as shown in FIG. 1 as shown in FIG. 15 is given the same reference numeral as
03-05-2019
14
that shown in FIG.
[0062]
The sound collector 5 which is 5th Embodiment of the sound collector of this invention which
covered the polyvinyl chloride sheet 15 on the opening surface of the sound collection hood 11
of the sound collector 1 of 1st Embodiment is shown by FIG. It is done.
[0063]
The vinyl chloride sheet 15 has a thickness of 0.1 mm which is cut to a size enough to cover the
opening surface of the sound collecting hood 11 with a margin, and the end of the vinyl chloride
sheet 15 Are attached to the sound collecting hood 11 by a frame 16 having a diameter slightly
longer than the diameter of the opening of the sound collector 1 hood 11, which can be fitted
around the opening periphery of the sound collecting hood 11.
For this reason, in the sound collector 5 of this embodiment, the replacement of the vinyl
chloride sheet 15 can be easily performed.
[0064]
Here, FIG. 16 is a diagram showing the sound collecting performance of the sound collector of
the first embodiment by frequency.
[0065]
FIG. 16 shows a voltage waveform output from the sound collector 1 when the tone burst having
a duration of 2 ms is collected by the sound collector 1 which is the sound collector of the first
embodiment.
[0066]
FIG. 17 is a diagram illustrating the sound collection performance of the sound collector of the
fifth embodiment by frequency.
[0067]
FIG. 17 shows a voltage waveform output from the sound collector 5 when the same tone burst
03-05-2019
15
as the tone burst used to obtain the voltage waveform of FIG. 16 is collected by the sound
collector 5.
[0068]
The voltage waveform output from the sound collector 5 shown in FIG. 17 is somewhat
comparable with the voltage waveform output from the sound collector 1 shown in FIG. It can be
seen that a sound pressure waveform is obtained.
Therefore, according to the sound collector 5 of the present embodiment, it is possible to prevent
the contamination of the microphone disposed in the sound collecting hood without sacrificing
the acoustic analysis with high accuracy.
[0069]
FIG. 18 is a view showing the sound collecting performance of the sound collector of the sixth
embodiment of the sound collector of the present invention according to frequency.
Here, too, the same tone burst as used in obtaining the result shown in FIG. 16 is used.
[0070]
In FIG. 18, in place of the vinyl chloride sheet 15, the sound collection performance obtained by
the sound collector obtained by covering the opening surface of the sound collection hood 11
with a 0.1 mm thick polystyrene sheet having air permeability is the frequency. It is shown
separately and shows a waveform that is better than the voltage waveform shown in FIG.
[0071]
Therefore, according to the sound collector of the sixth embodiment, it is possible to ensure
acoustic analysis with higher accuracy than the sound collector of the fifth embodiment.
[0072]
03-05-2019
16
In the present embodiment, an example in which a polystyrene sheet is used as the air-permeable
partition is described, but the present invention is not limited to this as long as it has airpermeability, and a sound collecting hood is used. The position of the partition wall in the inside
is not limited to the opening as long as it is on the front side of the sound receiving surface of the
microphone.
Further, although the case where the partition wall is detachable to the sound collecting hood has
been described as an example, the present invention is not limited to this, and even if the
partition wall is fixed to the sound collecting hood Although the effect is not reduced, and
further, an example in which glass wool is adopted as the sound absorbing material has been
described, the present invention is not limited to this as long as it has a sound absorbing
function.
Further, the partition wall is not limited to a flat surface and may be a curved surface or the like.
[0073]
In addition, a mesh-like or grid-like guard may be provided on the surface of the partition wall or
on the front side of the partition wall to prevent breakage of the partition wall.
[0074]
It is sectional drawing of the sound collector already proposed by this inventor.
It is sectional drawing of the sound collector already proposed by this inventor.
It is sectional drawing of 1st Embodiment of the sound collector of this invention.
It is a figure showing the range which can be collected by the sound collector of this
embodiment.
It is a figure showing the range which can be collected by the sound collector of this
03-05-2019
17
embodiment.
It is a figure showing the range which can be sound-collected with the conventional sound
collector.
It is a figure showing the range which can be sound-collected with the conventional sound
collector.
It is a graph showing the frequency characteristics of the sound collector of this embodiment and
a conventional type sound collector.
It is sectional drawing of the sound collector which is 2nd Embodiment.
It is a figure which shows the X-X 'cross section of the sound collector shown in FIG.
It is a figure showing the range which can be sound-collected with the sound collector of 2nd
Embodiment.
It is a figure showing the range which can be sound-collected with the sound collector of 2nd
Embodiment.
It is a graph showing the frequency characteristics of the sound collector of 2nd Embodiment,
and a conventional type sound collector.
It is sectional drawing of 3rd Embodiment and 4th Embodiment of the sound collector of this
invention.
It is an external appearance perspective view of the sound collector in the state where the sheet
was put on the opening side of the sound collection hood.
03-05-2019
18
It is a figure which shows the sound collection performance of the sound collector of 1st
Embodiment according to a frequency.
It is a figure which shows the sound collection performance of the sound collector of 5th
Embodiment according to a frequency.
It is a figure which shows the sound collection performance of the sound collector of 6th
Embodiment according to a frequency.
Explanation of sign
[0075]
1, 2, 3, 4, 5 sound collector 11 sound collection hood 111 sound reflection inner wall 112 sound
absorption material storage wall 113 hole 114 opening 12 microphone 121 sound receiving
surface 122 main body 13 glass wool 14 sound reflection ring 15 polyvinyl chloride sheet 16
frame 23 Aluminum wool A arrow
03-05-2019
19
Документ
Категория
Без категории
Просмотров
0
Размер файла
29 Кб
Теги
jp2008263588
1/--страниц
Пожаловаться на содержимое документа