JPH1127781A - Sound pressure microphone - Google Patents
Sound pressure microphoneInfo
- Publication number
- JPH1127781A JPH1127781A JP18082197A JP18082197A JPH1127781A JP H1127781 A JPH1127781 A JP H1127781A JP 18082197 A JP18082197 A JP 18082197A JP 18082197 A JP18082197 A JP 18082197A JP H1127781 A JPH1127781 A JP H1127781A
- Authority
- JP
- Japan
- Prior art keywords
- sintered metal
- hole
- metal body
- insulator
- output terminal
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000002184 metal Substances 0.000 claims abstract description 37
- 239000012212 insulator Substances 0.000 abstract description 14
- 230000002093 peripheral effect Effects 0.000 abstract description 10
- 239000000843 powder Substances 0.000 abstract description 5
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 abstract description 2
- 238000003754 machining Methods 0.000 abstract description 2
- 230000003068 static effect Effects 0.000 abstract description 2
- 239000006185 dispersion Substances 0.000 abstract 2
- 230000004888 barrier function Effects 0.000 abstract 1
- 230000035515 penetration Effects 0.000 abstract 1
- 238000013022 venting Methods 0.000 abstract 1
- 238000000034 method Methods 0.000 description 5
- 238000009423 ventilation Methods 0.000 description 4
- 239000000853 adhesive Substances 0.000 description 3
- 230000001070 adhesive effect Effects 0.000 description 3
- 239000000523 sample Substances 0.000 description 3
- 238000005192 partition Methods 0.000 description 2
- PYVHTIWHNXTVPF-UHFFFAOYSA-N F.F.F.F.C=C Chemical compound F.F.F.F.C=C PYVHTIWHNXTVPF-UHFFFAOYSA-N 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 239000011796 hollow space material Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 239000002923 metal particle Substances 0.000 description 1
- 239000002861 polymer material Substances 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000005245 sintering Methods 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R1/00—Details of transducers, loudspeakers or microphones
- H04R1/20—Arrangements for obtaining desired frequency or directional characteristics
- H04R1/22—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired frequency characteristic only
- H04R1/222—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired frequency characteristic only for microphones
Landscapes
- Obtaining Desirable Characteristics In Audible-Bandwidth Transducers (AREA)
Abstract
Description
【0001】[0001]
【発明の属する技術分野】本発明は、2マイクロホン法
を適用した音響インテンシティプローブに用いる音圧マ
イクロホンに関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sound pressure microphone used for a sound intensity probe to which a two-microphone method is applied.
【0002】[0002]
【従来の技術】2マイクロホン法を適用した音響インテ
ンシティプローブにおいては、特に2個のマイクロホン
間の低周波数領域での位相特性の差が、音響インテンシ
ティの測定精度に大きく影響する。このため、音響イン
テンシティプローブを製作する場合、個々のマイクロホ
ンの加工精度を上げて位相特性を揃えたり、多数のマイ
クロホンを作製し、その中から位相特性の揃った2個の
マイクロホンを選択している。2. Description of the Related Art In a sound intensity probe to which the two-microphone method is applied, a difference in phase characteristics between two microphones particularly in a low frequency region greatly affects the measurement accuracy of the sound intensity. For this reason, when manufacturing an acoustic intensity probe, the processing accuracy of each microphone is increased to make the phase characteristics uniform, or a number of microphones are made, and two microphones having the same phase characteristics are selected from among them. I have.
【0003】従来のコンデンサ型の音圧マイクロホンと
しては、図5に示すように、大気圧の変動があっても正
しい音圧が得られるように振動膜100の内外の静圧を
等しく保つため、マイクロホンの内側(背極部空間)1
01と外側(外界)を通気する非常に細い圧力平衡通路
103を隔壁となる絶縁体104に形成している。な
お、105は背極、106は出力端子、107は外周壁
である。As shown in FIG. 5, a conventional condenser-type sound pressure microphone is designed to maintain the same static pressure inside and outside the diaphragm 100 so that a correct sound pressure can be obtained even when the atmospheric pressure fluctuates. Inside of microphone (back space) 1
A very narrow pressure balance passage 103 that ventilates the outside (outside) from the outside is formed in an insulator 104 serving as a partition. In addition, 105 is a back pole, 106 is an output terminal, and 107 is an outer peripheral wall.
【0004】[0004]
【発明が解決しようとする課題】しかし、圧力平衡通路
103は、非常に細くて空気の粘性抵抗が大きく音響抵
抗として作用するため、高い周波数の場合には圧力平衡
通路103を通して振動膜100の内側に影響を与える
ことは少ないが、低い周波数の場合には振動膜100の
内側に影響を与える。従って、音圧を測定する場合、圧
力平衡通路103を設けることにより、直接振動膜10
0の外側から振動膜100にかかる音圧以外に、圧力平
衡通路103を通して振動膜100の内側からも振動膜
100に音圧がかかることになり、位相特性が乱れる原
因となる。However, since the pressure balancing passage 103 is very thin and has a large viscous resistance to the air and acts as an acoustic resistance, the inside of the diaphragm 100 passes through the pressure balancing passage 103 at a high frequency. , But at a low frequency, the inside of the diaphragm 100 is affected. Therefore, when measuring the sound pressure, the provision of the pressure equilibrium passage 103 makes it possible to directly
In addition to the sound pressure applied to the diaphragm 100 from the outside of 0, the sound pressure is also applied to the diaphragm 100 from the inside of the diaphragm 100 through the pressure equilibrium passage 103, which causes the phase characteristic to be disturbed.
【0005】そこで、どの周波数域からどの程度の影響
が出るかは、圧力平衡通路103の形状によって決まる
ため、マイクロホン間の位相特性の差を小さくするに
は、対となるマイクロホンの圧力平衡通路103が同一
形状になるように加工精度のばらつきを小さくすること
が必要になる。しかしながら、低い周波数の場合におい
て、所望の位相特性を満足する程度に圧力平衡通路10
3を加工するには高い加工精度を必要とするため容易で
はなく、しかも対となるマイクロホンについて同一形状
に圧力平衡通路103を加工するのは困難である。[0005] Since the frequency range and the degree of influence are determined by the shape of the pressure balance passage 103, in order to reduce the difference in phase characteristics between the microphones, the pressure balance passage 103 of the paired microphones must be reduced. It is necessary to reduce the variation in the processing accuracy so as to have the same shape. However, in the case of a low frequency, the pressure equilibrium passage 10 is sufficient to satisfy the desired phase characteristic.
It is not easy to machine 3 because it requires a high machining accuracy, and it is difficult to machine the pressure balancing passage 103 into the same shape for the paired microphones.
【0006】本発明は、従来の技術が有するこのような
問題点に鑑みてなされたものであり、その目的とすると
ころは、マイクロホンの低域周波数の位相特性のばらつ
きが小さく、特別な加工精度を必要としない音圧マイク
ロホンを提案しようとするものである。The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to reduce the variation in the phase characteristics of the low-frequency band of a microphone and achieve a special processing accuracy. It is intended to propose a sound pressure microphone that does not require a microphone.
【0007】[0007]
【課題を解決するための手段】上記課題を解決すべく本
発明は、背極部空間と外界とを音響抵抗体を介して通気
させたものである。SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is to ventilate the space between the back pole and the outside through an acoustic resistor.
【0008】前記音響抵抗体は、多孔質の焼結金属で形
成することができる。[0008] The acoustic resistor may be formed of a porous sintered metal.
【0009】[0009]
【発明の実施の形態】以下に本発明の実施の形態を添付
図面に基づいて説明する。ここで、図1は本発明に係る
音圧マイクロホンの概要断面図、図2は焼結金属体の取
付状態を示す断面図、図3は出力端子の雌部材の分解斜
視図、図4は焼結金属体の他の取付状態を示す断面図で
ある。Embodiments of the present invention will be described below with reference to the accompanying drawings. Here, FIG. 1 is a schematic sectional view of a sound pressure microphone according to the present invention, FIG. 2 is a sectional view showing a mounted state of a sintered metal body, FIG. 3 is an exploded perspective view of a female member of an output terminal, and FIG. It is sectional drawing which shows the other attachment states of a binding metal body.
【0010】本発明に係る音圧マイクロホンは、図1に
示すように、コンデンサ型のマイクロホンで、円筒状の
外周壁1の開口端部に振動膜2を取り付け、この振動膜
2に対向するように背極3を外周壁1内に配置し、背極
3に出力端子4を接続し、背極部空間5を形成すべく隔
壁として中心に貫通孔6aを設けた絶縁体6を外周壁1
に取り付け、更に絶縁体6の貫通孔6aと貫通孔6aに
遊装する出力端子4とで形成する間隙7を音響抵抗体と
しての焼結金属体8によって塞ぐことにより構成されて
いる。As shown in FIG. 1, the sound pressure microphone according to the present invention is a condenser type microphone, in which a diaphragm 2 is attached to an open end of a cylindrical outer peripheral wall 1 so as to face the diaphragm 2. A back electrode 3 is disposed in the outer peripheral wall 1, an output terminal 4 is connected to the back electrode 3, and an insulator 6 provided with a through hole 6 a at the center as a partition to form a back electrode space 5 is formed on the outer peripheral wall 1.
And a gap 7 formed between the through-hole 6a of the insulator 6 and the output terminal 4 loosely mounted in the through-hole 6a is closed by a sintered metal body 8 as an acoustic resistor.
【0011】焼結金属体8は、円柱状でその軸芯に貫通
孔8aを形成し、この貫通孔8aに出力端子4を嵌合
し、絶縁体6に当接して間隙7を塞いでいる。なお、出
力端子4などに接続するバイアス用直流電圧源や外周壁
1に連結するケース体などについては、図示を省略して
いる。The sintered metal body 8 is cylindrical and has a through hole 8a formed in the axis thereof, and the output terminal 4 is fitted into the through hole 8a and abuts on the insulator 6 to close the gap 7. . A DC voltage source for bias connected to the output terminal 4 and the like and a case connected to the outer peripheral wall 1 are not shown.
【0012】焼結金属体8は、背極部空間5と外界とを
通気させるために、従来の音圧マイクロホンに用いられ
ている圧力平衡通路103に替えて、多数の連続通気孔
を有する多孔質の部材である。焼結金属体8には、ステ
ンレス粉体やブロンズ粉体などの金属粉体が原料粉末と
して用いられる。The sintered metal body 8 is made of a porous material having a large number of continuous ventilation holes in place of the pressure equilibrium passage 103 used in the conventional sound pressure microphone in order to ventilate the back electrode space 5 and the outside world. It is a quality member. For the sintered metal body 8, a metal powder such as a stainless steel powder or a bronze powder is used as a raw material powder.
【0013】そして、焼結金属体8内の多数の通気孔1
つ1つの大きさや形状はそれぞれ異なるが、焼結金属体
8全体を圧力平衡通路として考えた場合の平均的な空気
の粘性抵抗は、複数の焼結金属体8間においてもほぼ等
しくなる。A large number of air holes 1 in the sintered metal body 8
Although the size and shape of each sintered metal body 8 are different from each other, the average viscous resistance of air when the entire sintered metal body 8 is considered as a pressure equilibrium passage is substantially equal between the plurality of sintered metal bodies 8.
【0014】その結果として、音圧マイクロホンの低域
周波数の位相特性のばらつきが少なくなる。また、圧力
平衡通路としての孔や溝は必要なくなり、特別な加工精
度は必要としない。As a result, variations in the phase characteristics of the sound pressure microphone at low frequencies are reduced. Further, holes and grooves as pressure equalizing passages are not required, and no special processing accuracy is required.
【0015】また、音響抵抗体としては、焼結金属体8
と同様の構造を有するセラミックの焼結部材、高分子材
料や4ふっ化エチレン連続多孔質体のシートなどを用い
てもよい。As the acoustic resistor, a sintered metal body 8 is used.
A ceramic sintered member having the same structure as described above, a polymer material, a sheet of a continuous porous body of ethylene tetrafluoride, or the like may be used.
【0016】焼結金属体8の取付方法としては、図2に
示すように、焼結金属体8の貫通孔8aに背極3と一体
に形成した出力端子4の雄部材4aを嵌挿し、次いで雄
部材4aを出力端子4の雌部材4bに螺合して、焼結金
属体8を雄部材4aの外周に形成した係止部4cと絶縁
体6とで挟むようにして行う。As shown in FIG. 2, a male member 4a of the output terminal 4 formed integrally with the back electrode 3 is inserted into a through hole 8a of the sintered metal body 8, as shown in FIG. Next, the male member 4a is screwed into the female member 4b of the output terminal 4, and the sintered metal body 8 is sandwiched between the locking portion 4c formed on the outer periphery of the male member 4a and the insulator 6.
【0017】出力端子4の雌部材4bは、雄部材4aが
螺合することにより絶縁体6に当接して固定される。な
お、焼結金属体8の外径は、絶縁体6の貫通孔6aの内
径よりも大きめになっている。The female member 4b of the output terminal 4 is fixed in contact with the insulator 6 by screwing the male member 4a. The outer diameter of the sintered metal body 8 is larger than the inner diameter of the through hole 6a of the insulator 6.
【0018】また、雌部材4bは、図3に示すように、
貫通孔4dを形成して絶縁体6の貫通孔6aに下方から
嵌合する嵌合部材4eと、貫通孔4fを形成した押えリ
ング4gと、貫通孔4hの内周面にねじを切った盲管の
端子部材4iとからなる。The female member 4b is, as shown in FIG.
A fitting member 4e formed from below to form a through hole 4d and fits into the through hole 6a of the insulator 6, a press ring 4g formed with a through hole 4f, and a blind thread formed on the inner peripheral surface of the through hole 4h. And a tube terminal member 4i.
【0019】出力端子4の雄部材4aを出力端子4の雌
部材4bに螺合することにより、焼結金属体8が間隙7
を塞いで背極部空間5と外界との圧力平衡通路として機
能すると共に、背極3から雌部材4bまでを電気的に接
続することができる。By screwing the male member 4a of the output terminal 4 into the female member 4b of the output terminal 4, the sintered metal body 8
And functions as a pressure equilibrium passage between the back pole space 5 and the outside world, and can electrically connect the back pole 3 to the female member 4b.
【0020】このように焼結金属体8を係止部4cと絶
縁体6とで挟んで固定するので、接着剤を必要とせず、
焼結金属体8の通気孔が接着剤により閉塞されず、結果
として焼結金属体8の音響抵抗のばらつきの発生を防止
することができる。As described above, since the sintered metal body 8 is fixed by sandwiching it between the locking portion 4c and the insulator 6, no adhesive is required.
The ventilation holes of the sintered metal body 8 are not closed by the adhesive, and as a result, it is possible to prevent the variation in acoustic resistance of the sintered metal body 8 from occurring.
【0021】また、焼結金属体の他の取付方法として
は、図4に示すように、背極3と一体に円筒状の出力端
子10を形成し、この出力端子10の中空部11に円柱
状の焼結金属体12を嵌装した後に、出力端子10を絶
縁体6の貫通孔6aに嵌挿させて行うことができる。な
お、13は出力端子10の先端部に螺着した電極であ
る。As another mounting method of the sintered metal body, as shown in FIG. 4, a cylindrical output terminal 10 is formed integrally with the back electrode 3, and a circular portion 11 is formed in the hollow portion 11 of the output terminal 10. After the columnar sintered metal body 12 is fitted, the output terminal 10 can be fitted into the through-hole 6 a of the insulator 6. Reference numeral 13 denotes an electrode screwed to the tip of the output terminal 10.
【0022】出力端子10の壁部10aには、背極部空
間5と中空部11を連通する複数の貫通孔10b、焼結
金属体12を当接させて位置決めさせる段部10c、中
空部11と外界を連通する複数の貫通孔10dが形成さ
れている。The wall 10a of the output terminal 10 has a plurality of through-holes 10b communicating the back electrode space 5 and the hollow portion 11, a step portion 10c for bringing the sintered metal body 12 into contact with and positioning, and a hollow portion 11a. And a plurality of through-holes 10d communicating with the outside world.
【0023】なお、円柱状の焼結金属体12は、金属製
の円筒部材の内部に金属粒体を充填した状態で所定温度
で焼結して形成したものである。また、出力端子10の
中空部11に焼結金属体12を嵌装する際には、焼結金
属体12の外周面と出力端子10の内周面との間に不要
な隙間ができないようにこの部分に接着剤等でシールを
施している。The cylindrical sintered metal body 12 is formed by sintering at a predetermined temperature in a state where a metal cylindrical member is filled with metal particles. When the sintered metal body 12 is fitted into the hollow portion 11 of the output terminal 10, an unnecessary gap is not formed between the outer peripheral surface of the sintered metal body 12 and the inner peripheral surface of the output terminal 10. This part is sealed with an adhesive or the like.
【0024】このように焼結金属体12を嵌装した出力
端子10を絶縁体6の貫通孔6aに嵌挿させることによ
り、背極部空間5と外界との間で、貫通孔10b、中空
部11、焼結金属体12、中空部11及び貫通孔10d
を介して所望な通気状態が保たれることになる。By inserting the output terminal 10 with the sintered metal body 12 fitted therein into the through-hole 6a of the insulator 6, the through-hole 10b and the hollow space are formed between the back electrode space 5 and the outside world. Part 11, sintered metal body 12, hollow part 11, and through hole 10d
Thus, a desired ventilation state is maintained.
【0025】図4に示す焼結金属体12の取付方法によ
れば、図2に示す焼結金属体8の取付方法と比較して、
より小型のマイクロホンに適用することが容易となる。According to the method of mounting the sintered metal body 12 shown in FIG. 4, compared to the method of mounting the sintered metal body 8 shown in FIG.
It becomes easy to apply to a smaller microphone.
【0026】[0026]
【発明の効果】以上説明したように本発明によれば、背
極部空間と外界とを音響抵抗体を介して通気させること
により、圧力平衡通路の替わりとなり、特別な加工精度
を必要とせず、マイクロホンの低周波数領域の位相特性
のばらつきを低減することができる。As described above, according to the present invention, the space between the back pole portion and the outside world is ventilated through the acoustic resistor, thereby replacing the pressure equilibrium passage and requiring no special processing accuracy. In addition, variations in the phase characteristics of the microphone in the low frequency region can be reduced.
【0027】また、音響抵抗体として多数の連続通気孔
を有する焼結金属体を用いることにより、マイクロホン
の低周波数領域の位相特性のばらつきを一段と低減する
ことができる。Further, by using a sintered metal body having a large number of continuous ventilation holes as the acoustic resistor, it is possible to further reduce the variation in the phase characteristics of the microphone in the low frequency region.
【図1】本発明に係る音圧マイクロホンの概要断面図FIG. 1 is a schematic sectional view of a sound pressure microphone according to the present invention.
【図2】焼結金属体の取付状態を示す断面図FIG. 2 is a cross-sectional view showing a mounted state of a sintered metal body.
【図3】出力端子の雌部材の分解斜視図FIG. 3 is an exploded perspective view of a female member of the output terminal.
【図4】焼結金属体の他の取付状態を示す断面図FIG. 4 is a sectional view showing another mounting state of the sintered metal body.
【図5】従来の音圧マイクロホンの概要断面図FIG. 5 is a schematic sectional view of a conventional sound pressure microphone.
1…外周壁、2…振動膜、3…背極、4,10…出力端
子、5…背極部空間、6…絶縁体、7…間隙、8,12
…焼結金属体(音響抵抗体)。DESCRIPTION OF SYMBOLS 1 ... Outer peripheral wall, 2 ... Vibration film, 3 ... Back electrode, 4, 10 ... Output terminal, 5 ... Back electrode space, 6 ... Insulator, 7 ... Gap, 8, 12
... Sintered metal body (acoustic resistor).
───────────────────────────────────────────────────── フロントページの続き (72)発明者 林 義一 東京都八王子市大和田町3丁目4番21号 株式会社国立音響研究所内 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yoshikazu Hayashi 3-4-2-21 Owada-cho, Hachioji-shi, Tokyo Inside the National Acoustic Research Institute
Claims (2)
て通気させたことを特徴とする音圧マイクロホン。1. A sound pressure microphone wherein the back pole space and the outside world are ventilated through an acoustic resistor.
形成した請求項1記載の音圧マイクロホン。2. The sound pressure microphone according to claim 1, wherein said acoustic resistor is formed of a porous sintered metal.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP18082197A JPH1127781A (en) | 1997-07-07 | 1997-07-07 | Sound pressure microphone |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP18082197A JPH1127781A (en) | 1997-07-07 | 1997-07-07 | Sound pressure microphone |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH1127781A true JPH1127781A (en) | 1999-01-29 |
Family
ID=16089953
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP18082197A Pending JPH1127781A (en) | 1997-07-07 | 1997-07-07 | Sound pressure microphone |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH1127781A (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2011176613A (en) * | 2010-02-24 | 2011-09-08 | Audio Technica Corp | Unidirectional condenser microphone |
WO2015084491A1 (en) * | 2013-12-05 | 2015-06-11 | Apple Inc. | Pressure vent for speaker or microphone modules |
US9668038B2 (en) | 2011-03-30 | 2017-05-30 | Kaetel Systems Gmbh | Loudspeaker |
-
1997
- 1997-07-07 JP JP18082197A patent/JPH1127781A/en active Pending
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2011176613A (en) * | 2010-02-24 | 2011-09-08 | Audio Technica Corp | Unidirectional condenser microphone |
US9668038B2 (en) | 2011-03-30 | 2017-05-30 | Kaetel Systems Gmbh | Loudspeaker |
EP2692151B1 (en) * | 2011-03-30 | 2018-01-10 | Kaetel Systems GmbH | Electret microphone |
US10469924B2 (en) | 2011-03-30 | 2019-11-05 | Kaetel Systems Gmbh | Method and apparatus for capturing and rendering an audio scene |
US11259101B2 (en) | 2011-03-30 | 2022-02-22 | Kaetel Systems Gmbh | Method and apparatus for capturing and rendering an audio scene |
WO2015084491A1 (en) * | 2013-12-05 | 2015-06-11 | Apple Inc. | Pressure vent for speaker or microphone modules |
US9363587B2 (en) | 2013-12-05 | 2016-06-07 | Apple Inc. | Pressure vent for speaker or microphone modules |
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