JP2023111120A

JP2023111120A - sound pressure detector

Info

Publication number: JP2023111120A
Application number: JP2022012786A
Authority: JP
Inventors: 和哉滝本; Kazuya Takimoto; 貴裕目黒; Takahiro Meguro
Original assignee: Saginomiya Seisakusho Inc
Current assignee: Saginomiya Seisakusho Inc
Priority date: 2022-01-31
Filing date: 2022-01-31
Publication date: 2023-08-10

Abstract

To provide a sound pressure detection device capable of restraining deterioration in detection accuracy of sound pressure and output accuracy from a sound pressure sensor by possessing a substrate structure that is resistant to deformation caused by pressing force and temperature change.SOLUTION: A sound pressure detection device 100 includes a device housing 10, a sound propagation path 20 for propagating sound from the outside, a vent portion 30 provided on the outside of the device housing of the sound propagation path 20, a substrate 40 provided inside the device housing of the sound propagation path 20, a sound pressure sensor 50, and a cover 70 for closing an opening portion of the device housing 10. The device housing 10 is provided with at least a pair of fixing portions 16 which fix the substrate 40 and are spaced apart from each other, and the pitch L between one fixing portion 16 and the other fixing portion 16 is equal to 11.0 times or less of the plate thickness dimension t1 of the substrate 40.SELECTED DRAWING: Figure 1

Description

本発明は、音圧検出装置に関する。 The present invention relates to a sound pressure detection device.

従来、装置筐体と、カバーと、ベント部と、基板と、音圧センサと、を備えた音圧検出装置が知られている（例えば、特許文献１参照）。特許文献１に記載の音圧検出装置では、基板は、シールドプレートおよびＯリングを介して装置筐体の開口部内周端面に固定されている。音圧センサは、所望の音圧のみを計測し、周囲雑音を拾って精度が低下することを抑えるよう、装置筐体に設けられた音伝搬経路の延長線上で基板と密着して取り付けられている。 2. Description of the Related Art Conventionally, a sound pressure detection device including a device housing, a cover, a vent portion, a substrate, and a sound pressure sensor is known (see Patent Document 1, for example). In the sound pressure detection device described in Patent Document 1, the substrate is fixed to the inner peripheral end surface of the opening of the device housing via the shield plate and the O-ring. The sound pressure sensor measures only the desired sound pressure and is attached in close contact with the board on the extension line of the sound propagation path provided in the device housing so as to suppress the deterioration of accuracy due to picking up ambient noise. there is

特開２０２０－１１３８７４号公報JP 2020-113874 A

しかしながら、従来の音圧検出装置は、外部環境からの電磁ノイズの侵入を防止するためにシールドプレートを基板に密接させ、このシールドプレートがＯリングに当接して押圧力を支持しているが、電磁ノイズの影響が無いか小さい環境においてシールドプレートを省略した場合、基板がＯリングからの押圧力を受けることになり、基板が変形することで検出精度や音圧センサからの出力精度が低下する可能性がある。また、基板とシールドプレートおよび装置筐体との線膨張係数の相違により、周囲温度が変化した場合も同様に基板の変形が生じ検出、出力精度が低下する可能性があった。 However, in the conventional sound pressure detection device, the shield plate is brought into close contact with the substrate in order to prevent electromagnetic noise from entering from the external environment, and the shield plate contacts the O-ring to support the pressing force. If the shield plate is omitted in an environment where there is little or no electromagnetic noise, the board will receive pressure from the O-ring, and the deformation of the board will reduce the accuracy of detection and output from the sound pressure sensor. there is a possibility. In addition, due to the difference in coefficient of linear expansion between the substrate, the shield plate, and the housing of the device, the substrate may be deformed in the same way when the ambient temperature changes, resulting in deterioration in detection and output accuracy.

本発明は、押圧力や温度変化に対して変形し難い基板構造を有することで、音圧の検出精度や音圧センサからの出力精度の低下を抑制できる音圧検出装置を得ることを目的とする。 SUMMARY OF THE INVENTION An object of the present invention is to provide a sound pressure detection device capable of suppressing deterioration in sound pressure detection accuracy and output accuracy from a sound pressure sensor by having a substrate structure that is resistant to deformation due to pressing force and temperature changes. do.

上記課題を解決するために、本発明の音圧検出装置は、装置筐体と、前記装置筐体の内外に連通し外部からの音を伝搬させる音伝搬経路と、前記音伝搬経路の前記装置筐体内部側端部に設けられる基板と、前記基板に設けられる音圧センサと、前記装置筐体の開口部を閉じて筐体内部空間を形成するカバーと、を備えた音圧検出装置であって、前記装置筐体には、前記基板を固定する少なくとも一対の離間した固定部が設けられ、一方の前記固定部と他方の前記固定部との離間距離は、前記基板の板厚寸法の１１．０倍以下であることを特徴とする。 In order to solve the above problems, the sound pressure detection device of the present invention comprises: a device housing; a sound propagation path that communicates with the inside and outside of the device housing to propagate sound from the outside; A sound pressure detection device comprising: a substrate provided at the inner end of a housing; a sound pressure sensor provided on the substrate; and a cover closing an opening of the device housing to form an internal space of the housing. The apparatus housing is provided with at least a pair of spaced-apart fixing portions for fixing the substrate, and the distance between one of the fixing portions and the other of the fixing portions is equal to the thickness of the substrate. It is characterized by being 11.0 times or less.

このような本発明によれば、一対の固定部間の離間距離を、基板の板厚寸法の１１．０倍以下に設定したことで、基板の板厚を固定部の離間距離に対して相対的に厚くし、基板の剛性を向上させることができる。このため、従来のようにシールドプレートを省略した場合に基板がＯリングからの押圧力を受ける構成と比較して、基板の変形を抑制することができる。また、基板の板厚を固定部の離間距離に対して相対的に厚くすることで、周囲温度が変化した場合に、基板と、装置筐体との線膨張係数の相違により基板が変形することを抑制することができる。したがって、押圧力や温度変化に対して変形し難い基板構造を有することで、音圧の検出精度、音圧センサからの出力精度の低下を抑制できる音圧検出装置を得ることができる。 According to the present invention, the distance between the pair of fixing parts is set to 11.0 times or less of the board thickness dimension of the board. It is possible to increase the rigidity of the substrate by increasing the thickness of the substrate. Therefore, deformation of the substrate can be suppressed as compared with the conventional configuration in which the substrate receives the pressing force from the O-ring when the shield plate is omitted. Further, by increasing the thickness of the substrate relative to the separation distance between the fixed parts, the substrate can be deformed due to the difference in coefficient of linear expansion between the substrate and the device housing when the ambient temperature changes. can be suppressed. Therefore, it is possible to obtain a sound pressure detection device capable of suppressing deterioration in sound pressure detection accuracy and output accuracy from the sound pressure sensor by having a substrate structure that is resistant to deformation due to pressing force and temperature changes.

この際、前記基板は、前記基板の板厚方向に当接する環状の弾性部材を介して前記音伝搬経路の前記装置筐体内部側端部に取り付けられていることが好ましい。このような構成によれば、基板の板厚方向に当接する環状の弾性部材を介して基板を装置筐体に取り付けることができるので、基板と装置筐体とが密着することにより取り付け部分にすき間が生じることを防止し、当該部分から音伝搬経路内の音が漏れることを抑制し、センサ出力の低下を抑制することができる。そして、基板を装置筐体に取り付ける際の押圧力を弾性部材で吸収することができるので、弾性部材を用いない構成と比較して、基板に対して生じる押圧力を低減し、基板の変形を抑制することができる。 At this time, it is preferable that the substrate is attached to the end portion of the sound propagation path on the inner side of the apparatus housing via an annular elastic member that abuts on the substrate in the thickness direction. According to such a configuration, the substrate can be attached to the device housing via the annular elastic member that abuts on the substrate in the plate thickness direction. can be prevented from occurring, leakage of sound in the sound propagation path from the relevant portion can be suppressed, and a decrease in sensor output can be suppressed. Since the elastic member can absorb the pressing force when the substrate is attached to the housing of the device, the pressing force applied to the substrate can be reduced and deformation of the substrate can be prevented as compared with a configuration in which the elastic member is not used. can be suppressed.

また、前記装置筐体には、前記弾性部材の幅寸法よりも小さい幅寸法を有した凸部が設けられ、前記凸部が前記弾性部材の幅方向中間部に当接していることが好ましい。このような構成によれば、弾性部材の幅寸法よりも小さい幅寸法を有した凸部を、弾性部材の幅方向中間部に当接するようにしたことで、凸部を設けない構成と比較して、装置筐体と弾性部材との接触面積を小さくすることができる。このため、弾性部材が装置筐体から押圧された際の反力の発生範囲を小さくすることができ、当該反力による基板への影響を小さくして、基板が変形することを抑制することができる。 Further, it is preferable that the apparatus housing is provided with a convex portion having a width dimension smaller than that of the elastic member, and the convex portion is in contact with a widthwise intermediate portion of the elastic member. According to such a configuration, the protrusion having a width smaller than the width of the elastic member is brought into contact with the intermediate portion in the width direction of the elastic member. Therefore, the contact area between the device housing and the elastic member can be reduced. Therefore, it is possible to reduce the range in which the reaction force is generated when the elastic member is pressed by the device housing, and to reduce the influence of the reaction force on the substrate, thereby suppressing deformation of the substrate. can.

また、前記音伝搬経路の前記装置筐体内部側端部には、前記基板の板厚方向を載置方向として前記基板が載置される基板載置部と、前記載置方向に凹み前記弾性部材が前記載置方向に設置される装着部と、が形成され、前記装着部には、前記基板載置部を超えない範囲で前記載置方向の前記基板載置部側に突出する凸部が設けられ、前記凸部は、前記弾性部材の幅寸法よりも小さい幅寸法を有し、前記弾性部材における前記載置方向一方側の面に全周に渡って当接するように設けられ、前記基板載置部から前記凸部の頂部までの前記載置方向の寸法は、前記装着部に設置された前記弾性部材の前記載置方向の寸法以下に設定されていることが好ましい。このような構成によれば、基板載置部から凸部の頂部までの載置方向の寸法を、弾性部材の載置方向の寸法以下、すなわち弾性部材の厚さ以下に設定したので、弾性部材を装着した際、弾性部材の凸部と当接する面と反対側の面が、基板載置部よりも載置方向に突出するか、基板載置部と同一平面上となるので、基板は必ず弾性部材を圧縮、もしくは弾性部材に当接することができる。また、基板載置部から凸部の頂部までの載置方向の寸法を、弾性部材の厚さ以下に規定することにより、取付状態によらずに弾性部材を一定の圧縮量にして基板を固定することができる。また、装着部には、見かけ上溝部が形成されることになる為、凸部に押圧されて弾性部材が変形しても、変形した弾性部材の一部を溝内に逃がすことができる。 Further, at the end portion of the sound propagation path on the inner side of the device housing, a substrate mounting portion on which the substrate is mounted with the plate thickness direction of the substrate as the mounting direction, and the elastic portion recessed in the mounting direction. A mounting portion in which a member is installed in the mounting direction is formed, and the mounting portion has a convex portion protruding toward the substrate mounting portion in the mounting direction within a range not exceeding the substrate mounting portion. is provided, and the convex portion has a width dimension smaller than that of the elastic member, and is provided so as to abut on the surface of the elastic member on one side in the mounting direction over the entire circumference, It is preferable that the dimension in the mounting direction from the substrate mounting portion to the top of the projection is set to be equal to or less than the dimension in the mounting direction of the elastic member installed in the mounting portion. According to this configuration, the dimension in the mounting direction from the substrate mounting portion to the top of the projection is set to be equal to or less than the dimension in the mounting direction of the elastic member, that is, equal to or less than the thickness of the elastic member. When the elastic member is attached, the surface of the elastic member opposite to the surface that abuts on the convex portion protrudes in the mounting direction from the substrate mounting portion, or is on the same plane as the substrate mounting portion. The elastic member can be compressed or abutted against the elastic member. In addition, by setting the dimension in the mounting direction from the substrate mounting portion to the top of the convex portion to be equal to or less than the thickness of the elastic member, the elastic member is compressed by a constant amount regardless of the mounting state, and the substrate is fixed. can do. Moreover, since the groove is apparently formed in the mounting portion, even if the elastic member is deformed by being pressed by the projection, part of the deformed elastic member can escape into the groove.

また、前記装置筐体の内部には、前記音伝搬経路の前記装置筐体内部側の開口部の周囲と前記基板との間に前記弾性部材が設けられ、前記固定部が前記音伝搬経路の前記装置筐体内部側開口部の先端部の径方向外側近傍に設けられていることが好ましい。このような構成によれば、固定部が音伝搬経路の装置筐体内部側開口部の先端部の径方向外側近傍に設けられていることで、各固定部を基板の中心側にできるだけ近づけ、一対の固定部の離間距離を小さくすることができる。これにより、当該離間距離に対する基板の板厚寸法を相対的に大きくすることができ、基板の剛性を向上させることができる。また、上述の離間距離と基板の板厚寸法の関係を満たすための基板の板厚を、当該離間距離が大きい構成と比較して薄くすることができ、音圧検出装置の大型化を抑制することができる。 Further, inside the device housing, the elastic member is provided between the substrate and the periphery of the opening of the sound propagation path on the inner side of the device housing, and the fixing portion is the sound propagation path. It is preferable that it is provided in the vicinity of the radially outer side of the tip portion of the inside opening of the apparatus housing. According to such a configuration, since the fixing portion is provided near the radially outer side of the tip portion of the opening on the inner side of the device housing of the sound propagation path, each fixing portion is brought as close to the center side of the substrate as possible, The separation distance between the pair of fixing parts can be reduced. As a result, the board thickness dimension of the board can be relatively increased with respect to the separation distance, and the rigidity of the board can be improved. In addition, the thickness of the substrate for satisfying the relationship between the separation distance and the thickness dimension of the substrate can be made thinner compared to a configuration in which the separation distance is large, thereby suppressing an increase in the size of the sound pressure detection device. be able to.

また、前記基板は、前記音伝搬経路の前記装置筐体内部側開口部の先端部を塞いで設けられ、前記基板には前記音伝搬経路と前記筐体内部空間とを連通する微小な通気孔が少なくとも１つ以上設けられていることが好ましい。このような構成によれば、音伝搬経路の装置筐体内部側開口部の先端部を塞ぐ基板には、音伝搬経路と筐体内部空間とを連通する微小な通気孔が設けられているので、音伝搬経路の気圧と筐体内部空間の気圧とが等しくなり、筐体内部空間で結露が発生することを防止することができる。 Further, the substrate is provided so as to close a tip portion of the opening of the sound propagation path on the inner side of the device housing, and the substrate has a minute air hole communicating the sound propagation path and the interior space of the housing. is preferably provided at least one or more. According to this configuration, the substrate that closes the tip of the opening of the sound propagation path on the inner side of the device housing is provided with a minute air hole that communicates the sound propagation path with the space inside the housing. , the air pressure in the sound propagation path and the air pressure in the internal space of the housing become equal, and the occurrence of dew condensation in the internal space of the housing can be prevented.

本発明によれば、押圧力や温度変化に対して変形し難い基板構造を有することで、音圧の検出精度や音圧センサからの出力精度の低下を抑制できる音圧検出装置を得ることができる。 According to the present invention, it is possible to obtain a sound pressure detection device capable of suppressing deterioration in sound pressure detection accuracy and output accuracy from a sound pressure sensor by having a substrate structure that is resistant to deformation due to pressing force and temperature changes. can.

本発明の一実施形態にかかる音圧検出装置の断面図。1 is a cross-sectional view of a sound pressure detection device according to an embodiment of the present invention; FIG. （Ａ）は、前記音圧検出装置の装置筐体の正面図であり、（Ｂ）は、（Ａ）のＡ－Ａ線矢視断面図。(A) is a front view of a housing of the sound pressure detection device, and (B) is a cross-sectional view taken along the line AA of (A). 図２（Ａ）のＢ－Ｂ線矢視断面図。A cross-sectional view taken along the line BB in FIG. 2(A). （Ａ）は、基板を固定する前の音圧計測装置の部分拡大図であり、（Ｂ）は、基板を固定した後の音圧検出装置の部分拡大図。(A) is a partially enlarged view of the sound pressure measuring device before fixing the substrate, and (B) is a partially enlarged view of the sound pressure detecting device after fixing the substrate. 前記基板の実装面の正面図。The front view of the mounting surface of the said board|substrate. （Ａ）前記音圧検出装置の分解斜視図であり、（Ｂ）は、前記装置筐体に基板を取り付けた状態の音圧検出装置を背面側から見た斜視図。(A) is an exploded perspective view of the sound pressure detection device, and (B) is a perspective view of the sound pressure detection device in a state in which a substrate is attached to the device housing as viewed from the rear side.

以下、本発明の実施形態を図１～図６に基づいて説明する。図１は、本発明の一実施形態にかかる音圧検出装置１００の断面図である。図２（Ａ）は、前記音圧検出装置１００の装置筐体１０の正面図であり、図２（Ｂ）は、図２（Ａ）のＡ－Ａ線矢視断面図である。図３は、図２（Ａ）のＢ－Ｂ線矢視断面図である。 An embodiment of the present invention will be described below with reference to FIGS. 1 to 6. FIG. FIG. 1 is a cross-sectional view of a sound pressure detection device 100 according to one embodiment of the invention. 2(A) is a front view of the device housing 10 of the sound pressure detection device 100, and FIG. 2(B) is a cross-sectional view taken along line AA of FIG. 2(A). FIG. 3 is a cross-sectional view taken along line BB of FIG. 2(A).

なお、図面において、矢印Ｘ、矢印Ｙ、矢印Ｚは、互いに直交する方向であり、本実施形態では、装置筐体１０の一方の側面から他方の側面に向かう方向を矢印Ｘで示し、矢印Ｘを「左右方向Ｘ」と記す。そして、左右方向Ｘの左側を「左側Ｘ１」と記し、右側を「右側Ｘ２」と記す。また、装置筐体１０の左右方向Ｘに直交する方向を矢印Ｙで示し、矢印Ｙを「前後方向Ｙ」と記す。そして、前後方向Ｙの前側を「正面側Ｙ１」と記し、後側を「背面側Ｙ２」と記す。また、左右方向Ｘおよび前後方向Ｙに直行する方向を矢印Ｚで示し、「上下方向Ｚ」と記す。また、上下方向Ｚの上側を「上側Ｚ１」、下側を「下側Ｚ２」と記す。 In the drawings, arrow X, arrow Y, and arrow Z are directions perpendicular to each other. is referred to as "left-right direction X". The left side in the horizontal direction X is referred to as "left side X1", and the right side as "right side X2". A direction perpendicular to the left-right direction X of the device housing 10 is indicated by an arrow Y, and the arrow Y is referred to as a "front-rear direction Y". The front side in the front-rear direction Y is referred to as "front side Y1", and the rear side is referred to as "back side Y2". A direction perpendicular to the left-right direction X and the front-rear direction Y is indicated by an arrow Z, and is referred to as a "vertical direction Z". Also, the upper side in the vertical direction Z is referred to as "upper side Z1", and the lower side is referred to as "lower side Z2".

本実施形態に係る音圧検出装置１００は、音源（例えば、スピーカ等）の近くに配置されて、音源が正常に機能しているか否かを検出するために用いられる。音圧検出装置１００は、例えば、踏切の警報音や、横断歩道の誘導用音声などの検出に用いられる。図１に示すように、音圧検出装置１００は、箱状の装置筐体１０と、外部からの音を伝搬させる音伝搬経路２０と、音伝搬経路２０の外部側に設けられるベント部３０と、音伝搬経路２０の内部側に設けられる基板４０と、基板４０に設けられる音圧センサ５０と、基板４０の板厚方向に当接する弾性部材６０と、装置筐体１０に設けられた開口部を閉じて筐体内部空間１０ｃ１を形成するカバー７０と、を備えている。 The sound pressure detection device 100 according to this embodiment is placed near a sound source (for example, a speaker or the like) and used to detect whether the sound source is functioning normally. The sound pressure detection device 100 is used, for example, to detect railroad crossing warning sounds and crosswalk guidance sounds. As shown in FIG. 1, the sound pressure detection device 100 includes a box-shaped device housing 10, a sound propagation path 20 for propagating sound from the outside, and a vent portion 30 provided on the outside of the sound propagation path 20. , a substrate 40 provided inside the sound propagation path 20, a sound pressure sensor 50 provided on the substrate 40, an elastic member 60 abutting on the substrate 40 in the plate thickness direction, and an opening provided in the device housing 10. and a cover 70 that closes the housing interior space 10c1.

装置筐体１０は、防水性の確保や外部環境からの保護のために、音圧検出装置１００を構成する各部品を収容している。図２に示すように、装置筐体１０の背面側Ｙ２の壁部には、雌ねじ１０ａと、溝部１０ｂと、開口部１０ｃと、が形成されている。雌ねじ１０ａは、カバー７０を装置筐体１０に固定する際にボルト１１を締め込む部分であり、装置筐体１０の背面側Ｙ２の壁部の四隅に形成されている。溝部１０ｂは、Ｏリング等のシール部材１２を配置するための溝であり、装置筐体１０の背面視で円形に形成されている。開口部１０ｃは、溝部１０ｂの内縁よりも内側部分に当該溝部１０ｂの内縁に沿って略円形に形成され、装置筐体１０の内外に連通するように開口している。この開口部１０ｃは、後述するカバー７０によって、閉塞されるようになっており、カバー７０に閉塞された状態では、開口部１０ｃの内部に、筐体内部空間１０ｃ１が形成されるようになっている。装置筐体１０の下側Ｚ２の壁部には、図１に示すように、上下方向Ｚに開口する引出口１０ｄが形成されており、この引出口１０ｄには、音圧信号を出力するためのケーブル１３が、取付部材１３ａを介して取り付けられている。 The device housing 10 accommodates each component that constitutes the sound pressure detection device 100 in order to ensure waterproofness and protect it from the external environment. As shown in FIG. 2, the wall portion of the device housing 10 on the rear side Y2 is formed with a female screw 10a, a groove portion 10b, and an opening portion 10c. The female screws 10a are portions for tightening the bolts 11 when fixing the cover 70 to the device housing 10, and are formed at the four corners of the wall of the device housing 10 on the rear side Y2. The groove portion 10b is a groove for disposing a sealing member 12 such as an O-ring, and is formed in a circular shape when the apparatus housing 10 is viewed from the rear. The opening 10c is formed in a substantially circular shape inside the inner edge of the groove 10b along the inner edge of the groove 10b, and opens to communicate with the inside and outside of the apparatus housing 10. As shown in FIG. The opening 10c is closed by a cover 70, which will be described later. When the cover 70 is closed, a housing internal space 10c1 is formed inside the opening 10c. there is As shown in FIG. 1, the wall portion of the lower side Z2 of the apparatus housing 10 is formed with an outlet 10d that opens in the vertical direction Z. The outlet 10d is provided for outputting a sound pressure signal. is attached via an attachment member 13a.

装置筐体１０の正面側Ｙ１の壁部には、背面側Ｙ２に立ち上がり、前後方向Ｙに貫通する円筒状の円筒壁部１４が形成されている。円筒壁部１４の背面側Ｙ２の端部（装置筐体１０内部側端部）には、前後方向Ｙ（板厚方向、載置方向）に基板４０を設置するための基板載置部１７が形成されている。また、円筒壁部１４の背面側Ｙ２の端部における基板載置部１７の内周側には、基板載置部１７の正面側Ｙ１側（載置方向）に弾性部材６０を設置するための装着部１５が形成されている。装着部１５は、図２（Ａ）に示すように、装置筐体１０の背面視で円形に形成されている。装着部１５の内径寸法は、後述する弾性部材６０が脱落することがないように、当該弾性部材６０の外径寸法よりも小さく設定されている。また、装着部１５の外形寸法は、弾性部材６０が乗り上げることがないように、弾性部材６０の外径寸法よりも大きく設定されている。 A cylindrical wall portion 14 is formed on the wall portion of the front side Y1 of the apparatus housing 10 so as to stand up on the rear side Y2 and penetrate in the front-rear direction Y. As shown in FIG. At the end of the cylindrical wall portion 14 on the back side Y2 (the end on the inside of the apparatus housing 10), there is a substrate placement portion 17 for placing the substrate 40 in the front-rear direction Y (plate thickness direction, placement direction). formed. Further, on the inner peripheral side of the substrate mounting portion 17 at the end portion of the back side Y2 of the cylindrical wall portion 14, an elastic member 60 for installing the elastic member 60 on the front side Y1 side (mounting direction) of the substrate mounting portion 17 is provided. A mounting portion 15 is formed. As shown in FIG. 2A, the mounting portion 15 is formed in a circular shape when the device housing 10 is viewed from the rear. The inner diameter of the mounting portion 15 is set smaller than the outer diameter of the elastic member 60 to prevent the later-described elastic member 60 from falling off. In addition, the external dimension of the mounting portion 15 is set larger than the external diameter dimension of the elastic member 60 so that the elastic member 60 does not ride on it.

装着部１５には、基板載置部１７より正面側Ｙ１方向へ一段凹んだ段差部が形成されている。すなわち、装着部１５は、正面側Ｙ１方向（載置方向）に凹んで形成されている。装着部１５には、背面側Ｙ２（載置方向基板載置部１７側）に、基板載置部１７を超えない範囲で突出する凸部１５ａが設けられている。このため、凸部１５ａの周囲は相対的に正面側Ｙ１方向に凹み、当該部分は凹部１５ｂを構成している。凸部１５ａおよび凹部１５ｂは、図２（Ａ）に示すように、装置筐体１０の背面視で円形に形成されている。凸部１５ａの幅寸法ｓ１は、図４（Ａ）に示すように、弾性部材６０の幅寸法ｓ２よりも小さく設定されており、この凸部１５ａの頂部は、弾性部材６０の正面側Ｙ１の面（載置方向一方側の面）の幅方向中間部に全周に渡って当接するようになっている。凹部１５ｂは、弾性部材６０が変形する際にその変形した弾性部材６０の一部を逃がす部分であり、その深さ、すなわち凸部１５ａの頂部から凹部１５ｂの底部までの寸法は、図４（Ｂ）に示す弾性部材６０の変形代ｓ４以上に設定されている。また、基板載置部１７から凸部１５ａの頂部までの寸法ｓ３（載置方向の寸法、高低差、または部品寸法ともいう）は、弾性部材６０の厚さｔ２（装着部１５に設置された弾性部材６０の載置方向の寸法）以下に設定されている。 The mounting portion 15 is formed with a stepped portion that is recessed one step in the front side Y1 direction from the substrate mounting portion 17 . That is, the mounting portion 15 is recessed in the front side Y1 direction (mounting direction). The mounting portion 15 is provided with a convex portion 15 a protruding within a range not exceeding the substrate mounting portion 17 on the rear side Y2 (the substrate mounting portion 17 side in the mounting direction). Therefore, the periphery of the convex portion 15a is relatively recessed in the front side Y1 direction, and this portion constitutes a concave portion 15b. As shown in FIG. 2A, the convex portion 15a and the concave portion 15b are formed in a circular shape when the apparatus housing 10 is viewed from the rear. The width dimension s1 of the projection 15a is set smaller than the width dimension s2 of the elastic member 60, as shown in FIG. It abuts on the width direction intermediate portion of the surface (the surface on one side in the mounting direction) over the entire circumference. The recessed portion 15b is a portion that allows part of the deformed elastic member 60 to escape when the elastic member 60 is deformed. It is set to be greater than or equal to the deformation allowance s4 of the elastic member 60 shown in B). In addition, the dimension s3 from the substrate mounting portion 17 to the top of the convex portion 15a (also referred to as the dimension in the mounting direction, height difference, or component dimension) is the thickness t2 of the elastic member 60 ( dimension of the elastic member 60 in the mounting direction).

円筒壁部１４の背面側Ｙ２の端部（音伝搬経路２０の装置筐体１０内部側開口部の先端部）、すなわち装着部１５における左右方向Ｘの両端部には、図２（Ａ）に示すように、それぞれ左右方向Ｘに延びて装置筐体１０の背面側Ｙ２の壁部に接続される一対の接続板部１４ａが形成されている。そして、各々の接続板部１４ａには、基板４０を装置筐体１０に固定するための固定部１６がそれぞれ形成されている。すなわち、装置筐体１０には、基板４０を固定する少なくとも一対の離間した固定部１６が設けられている。固定部１６は、接続板部１４ａの背面側Ｙ２の板面における円筒壁部１４寄りの位置に形成されている。すなわち、固定部１６は、音伝搬経路２０の装置筐体１０内部側開口部の先端部の径方向外側近傍に設けられている。この固定部１６は、基板４０を装置筐体１０に固定する際のねじ１６ａ（図６（Ａ）、（Ｂ）参照）を締め込むための雌ねじで構成されている。 At the end of the cylindrical wall portion 14 on the back side Y2 (the tip of the opening of the sound propagation path 20 on the inner side of the device housing 10), that is, at both ends of the mounting portion 15 in the left-right direction X, as shown in FIG. As shown, a pair of connection plate portions 14a extending in the left-right direction X and connected to the wall portion on the rear side Y2 of the apparatus housing 10 are formed. A fixing portion 16 for fixing the substrate 40 to the apparatus housing 10 is formed on each connection plate portion 14a. That is, the apparatus housing 10 is provided with at least a pair of spaced-apart fixing portions 16 for fixing the substrate 40 . The fixing portion 16 is formed at a position near the cylindrical wall portion 14 on the back side Y2 plate surface of the connection plate portion 14a. That is, the fixing portion 16 is provided near the radially outer side of the tip portion of the opening of the sound propagation path 20 on the inner side of the apparatus housing 10 . The fixing portion 16 is composed of a female screw for tightening a screw 16a (see FIGS. 6A and 6B) for fixing the board 40 to the apparatus housing 10. As shown in FIG.

基板４０を固定部１６にねじ１６ａで締め付ける際の締め付け量（すなわち、締め付けトルク）や温度変化による装置筐体１０および基板４０の線膨張係数の違い等の理由により、基板４０の変形量、弾性部材６０の変形量、および弾性部材６０の変形の過多による反力が左右されることとなっていることから、一方の固定部１６と他方の固定部１６とのピッチＬ（離間距離、図２（Ａ）、図５参照）は、基板４０の板厚寸法ｔ１（図１参照）に対して相対的に小さくなるように調整することが好ましい。換言すると、ピッチＬに対する基板４０の前後方向Ｙの板厚寸法ｔ１を相対的に大きくすることが好ましい。すなわち、固定部１６のピッチＬと基板４０の板厚寸法ｔ１との比Ｌ／ｔが小さいほど、基板４０の変形量を小さくすることができる。具体的には、Ｌ＝１９ｍｍの場合、ｔ＝１．６ｍｍで比Ｌ／ｔが１１．８の場合よりもｔ＝３．２ｍｍで比Ｌ／ｔが５．９の場合の方が、基板４０の変形量を小さくすることができる。そこで、本実施形態では、一方の固定部１６と他方の固定部１６とのピッチＬは、基板４０の板厚寸法ｔ１の１１．０倍以下に設定され、好ましくは、板厚寸法ｔ１の８．０倍以下に設定されている。 Due to factors such as the tightening amount (that is, tightening torque) when tightening the substrate 40 to the fixing portion 16 with the screw 16a, and the difference in the coefficient of linear expansion between the device housing 10 and the substrate 40 due to temperature changes, the amount of deformation and elasticity of the substrate 40 may vary. Since the amount of deformation of the member 60 and the reaction force due to excessive deformation of the elastic member 60 are affected, the pitch L (separation distance, FIG. 2 (A), see FIG. 5) is preferably adjusted to be relatively small with respect to the plate thickness dimension t1 of the substrate 40 (see FIG. 1). In other words, it is preferable to make the thickness dimension t1 of the substrate 40 in the front-rear direction Y relative to the pitch L relatively large. That is, the smaller the ratio L/t between the pitch L of the fixed portions 16 and the thickness dimension t1 of the substrate 40, the smaller the deformation amount of the substrate 40 can be. Specifically, when L = 19 mm, the substrate when t = 3.2 mm and the ratio L/t is 5.9 is better than when t = 1.6 mm and the ratio L/t is 11.8. The amount of deformation of 40 can be reduced. Therefore, in the present embodiment, the pitch L between one fixing portion 16 and the other fixing portion 16 is set to 11.0 times or less the thickness dimension t1 of the substrate 40, preferably 8 times the thickness dimension t1. It is set to 0 times or less.

なお、本実施形態では、固定部１６は上述のように一対の雌ねじで構成したが、雌ねじの他に、装置筐体１０側若しくは基板４０側から延在する爪で引っ掛けるようにして装置筐体１０と基板４０とを固定する固定部１６としてもよいし、爪による引掛け、または、ねじ、爪の組合せを用いて固定部１６を構成してもよい。さらには、円筒壁部１４の背面側Ｙ２の端面に開口部の全周に渡り接着剤を塗布し、この接着剤を塗布する部分を固定部１６としてもよいし、粘着シートや両面テープ等を貼り付けるなどして基板４０を装置筐体１０に固定してもよい。また、本実施形態では、固定部１６は、一対設けることとしたが、一対以上の固定部１６を設けて基板４０を三点支持する等してもよい。また、本実施形態では、基板載置部１７と、固定部１６と、接続板部１４ａとは、同一平面上とすることがのぞましい。このような構成にすることにより、基板４０の固定時に、基板４０に不所望な応力が負荷され初期状態から基板４０が変形してしまうことを回避することができる。 In the present embodiment, the fixing portion 16 is configured by a pair of internal threads as described above, but in addition to the internal threads, the fixing portion 16 may be hooked by a claw extending from the device housing 10 side or the substrate 40 side. The fixing portion 16 may be used to fix the substrate 40 to the substrate 10. Alternatively, the fixing portion 16 may be configured by hooking with a nail or by using a combination of a screw and a nail. Furthermore, an adhesive may be applied to the end surface of the back side Y2 of the cylindrical wall 14 over the entire circumference of the opening, and the portion to which the adhesive is applied may be used as the fixed portion 16, or an adhesive sheet, double-sided tape, or the like may be applied. The substrate 40 may be fixed to the device housing 10 by pasting or the like. Further, in the present embodiment, a pair of fixing portions 16 are provided, but more than one pair of fixing portions 16 may be provided to support the substrate 40 at three points. Further, in this embodiment, it is preferable that the substrate mounting portion 17, the fixing portion 16, and the connection plate portion 14a are on the same plane. With such a configuration, it is possible to avoid deformation of the substrate 40 from its initial state due to undesired stress being applied to the substrate 40 when the substrate 40 is fixed.

円筒壁部１４の内壁面には、図１に示すように、ベント部３０の後述するベントボディ３１の外壁面に形成された雄ねじ３１ａと螺合する雌ねじ１４ｂが形成されている。そして、円筒壁部１４の内側は、前後方向Ｙに延びる直線上の空間を形成しており、この空間は、装置筐体１０の内外に連通し外部からの音を伝搬させる音伝搬経路２０を構成している。すなわち、円筒壁部１４は、音伝搬経路２０の周囲を囲んでいる。また、円筒壁部１４の背面側Ｙ２の先端部は、音伝搬経路の装置筐体１０内部側開口部の先端部を構成している。なお、本実施形態では、円筒壁部１４が音伝搬経路２０の周囲を囲むようにしたが、例えば、装置筐体１０の正面側Ｙ１の壁部を肉厚とし、その肉厚の壁部に前後方向Ｙに貫通する貫通孔を形成することで、当該貫通孔を音伝搬経路２０とし、円筒壁部１４を省略することも可能である。この場合、肉厚の壁部の背面側Ｙ２の端部に上述の基板載置部１７および装着部１５を形成し、音伝搬経路２０の装置筐体１０内部側開口部の先端部の径方向外側近傍に固定部１６を設ければよい。 As shown in FIG. 1, the inner wall surface of the cylindrical wall portion 14 is formed with a female thread 14b that engages with a male thread 31a formed on the outer wall surface of a vent body 31 of the vent portion 30, which will be described later. The inside of the cylindrical wall portion 14 forms a linear space extending in the front-rear direction Y, and this space forms a sound propagation path 20 that communicates with the inside and outside of the device housing 10 and propagates sound from the outside. Configure. That is, the cylindrical wall portion 14 surrounds the sound propagation path 20 . The tip of the cylindrical wall portion 14 on the back side Y2 constitutes the tip of the opening of the sound propagation path on the inner side of the device housing 10 . In the present embodiment, the cylindrical wall portion 14 surrounds the sound propagation path 20. However, for example, the wall portion on the front side Y1 of the device housing 10 is made thick, and the thick wall portion By forming a through-hole penetrating in the front-rear direction Y, it is possible to use the through-hole as the sound propagation path 20 and omit the cylindrical wall portion 14 . In this case, the substrate mounting portion 17 and the mounting portion 15 are formed at the end of the thick wall portion on the back side Y2, and the sound propagation path 20 is formed at the end portion of the opening on the inner side of the device housing 10 in the radial direction. A fixing portion 16 may be provided near the outside.

ベント部３０は、音伝搬経路２０の正面側Ｙ１（装置筐体１０外部側）に設けられている。ベント部３０は、音伝搬経路２０を覆う部材であり、防水性、防塵性、および通気性を有している。このベント部３０は、円筒状のベントボディ３１と、ベントボディ３１の正面側Ｙ１の端部から径方向外方に突出する円柱状のキャップ部３２と、を備えている。ベントボディ３１の外周面には、雄ねじ３１ａが形成されている。ベントボディ３１の内側は、装置筐体１０の円筒壁部１４と同様に音伝搬経路２０を構成するようになっている。 The vent portion 30 is provided on the front side Y1 of the sound propagation path 20 (on the outside of the device housing 10). The vent part 30 is a member that covers the sound propagation path 20 and has waterproofness, dustproofness, and air permeability. The vent portion 30 includes a cylindrical vent body 31 and a columnar cap portion 32 protruding radially outward from the end of the vent body 31 on the front side Y1. A male thread 31 a is formed on the outer peripheral surface of the vent body 31 . The inside of the vent body 31 constitutes a sound propagation path 20 like the cylindrical wall portion 14 of the device housing 10 .

キャップ部３２には、周方向に複数形成され、それぞれ中心部に向かって径方向に貫通し、内外と連通する第一貫通孔３２ａと、中心部に形成され、各第一貫通孔３２ａとベントボディ３１の内側の空間とを連通し、前後方向Ｙに貫通する第二貫通孔３２ｂと、が形成されている。ベント部３０を装置筐体１０に取り付ける際には、ベントボディ３１の外周壁における正面側Ｙ１の端部に封止用の押さえリング３３を装着した状態で、雄ねじ３１ａを円筒壁部１４の内側の雌ねじ１４ｂに締め込むことで、ベント部３０が装置筐体１０に固定されるようになっている。 In the cap portion 32, a plurality of first through holes 32a are formed in the circumferential direction and each penetrates in the radial direction toward the center portion and communicates with the inside and outside. A second through hole 32b that penetrates in the front-rear direction Y and communicates with the space inside the body 31 is formed. When the vent portion 30 is attached to the device housing 10, the external thread 31a is inserted into the inner side of the cylindrical wall portion 14 with the pressing ring 33 for sealing attached to the end of the outer peripheral wall of the vent body 31 on the front side Y1. The vent portion 30 is fixed to the apparatus housing 10 by tightening the female screw 14b.

基板４０は、上述の基板載置部１７に、基板４０の前後方向Ｙ（板厚方向）に当接する環状の弾性部材６０を介して取り付けられ、音伝搬経路２０の装置筐体１０内部側開口部の先端部を塞いで設けられている。この基板４０は、図５に示すように、正面視八角形の板状に形成されている。基板４０は、音圧を検知する音圧センサ５０や信号読み出し用のＩＣチップ（不図示）が実装されたプリント基板である。基板４０の中心には、音伝搬経路２０と連通し、音波を通過させる貫通孔４０ａが前後方向Ｙ（板厚方向）に貫通形成されている。貫通孔４０ａの上側Ｚ１には、音伝搬経路２０と筐体内部空間１０ｃ１とを連通する微小な通気孔４０ｂが少なくとも１つ以上設けられている。通気孔４０ｂは、音伝搬経路２０と筐体内部空間１０ｃ１との圧力を等しくするための孔であり、調湿機能を有している。一般的な電子回路基板のスルーホールの穴径は、電子部品のリード線の線径に対応させるために０．８～１．０ｍｍとされるところ、本実施形態では、一般的な穴径では、音伝搬経路２０を伝搬してきた音が音圧センサ５０で拾いきれず、センサ出力が低下し誤差となってしまう為、通気孔４０ｂの穴径は０．３ｍｍ程度に設定されている。 The substrate 40 is attached to the above-described substrate mounting portion 17 via an annular elastic member 60 that abuts on the substrate 40 in the front-rear direction Y (plate thickness direction). It is provided to close the tip of the part. As shown in FIG. 5, the substrate 40 is formed in an octagonal plate shape when viewed from the front. The substrate 40 is a printed circuit board on which a sound pressure sensor 50 for detecting sound pressure and an IC chip (not shown) for signal readout are mounted. A through-hole 40a that communicates with the sound propagation path 20 and allows sound waves to pass is formed through the center of the substrate 40 in the front-rear direction Y (thickness direction). At least one or more minute vent holes 40b are provided on the upper side Z1 of the through hole 40a to communicate the sound propagation path 20 and the housing internal space 10c1. The ventilation hole 40b is a hole for equalizing the pressure between the sound propagation path 20 and the housing internal space 10c1, and has a humidity control function. The hole diameter of a through hole of a general electronic circuit board is set to 0.8 to 1.0 mm in order to correspond to the wire diameter of the lead wire of an electronic component. Since the sound propagated through the sound propagation path 20 cannot be picked up by the sound pressure sensor 50 and the sensor output is reduced, resulting in an error, the hole diameter of the ventilation hole 40b is set to about 0.3 mm.

基板４０の上側Ｚ１部分には、コネクタ部４１が設置されており、このコネクタ部４１には、ケーブル１３の信号線１３ｂが接続されるようになっている。そして、基板４０の左右方向Ｘの両端部には、前後方向Ｙ（板厚方向）に貫通する一対のねじ通し穴４０ｃが貫通形成されている。このねじ通し穴４０ｃは、上述の固定部１６に締め込まれるねじ１６ａを通す穴であり、基板４０を装置筐体１０に取り付ける際には、図６（Ａ）および図６（Ｂ）に示すように、このねじ通し穴４０ｃの中心軸が固定部１６の中心軸と同軸となるように基板４０を配置し、ねじ１６ａによって締め付け固定するようになっている。音圧センサ５０は、貫通孔４０ａの背面側Ｙ２の端部を閉塞するように、基板４０の背面側Ｙ２の板面（実装面）に配置されている。音圧センサ５０には、例えば、静電容量型のＭＥＭＳ音響センサチップが用いられる。ＭＥＭＳ音響センサチップは、ＭＥＭＳ（micro electro- mechanical system）技術を用いて半導体基板に形成された小型の音響センサである。 A connector portion 41 is installed on the upper side Z1 portion of the substrate 40, and the signal line 13b of the cable 13 is connected to the connector portion 41. As shown in FIG. At both ends of the substrate 40 in the left-right direction X, a pair of screw holes 40c are formed through the substrate 40 in the front-rear direction Y (thickness direction). This screw through hole 40c is a hole through which the screw 16a to be tightened to the fixing portion 16 described above is passed. As shown, the substrate 40 is arranged so that the central axis of the screw through hole 40c is coaxial with the central axis of the fixing portion 16, and is fixed by tightening the screws 16a. The sound pressure sensor 50 is arranged on the plate surface (mounting surface) of the substrate 40 on the back side Y2 so as to close the end of the through hole 40a on the back side Y2. For example, a capacitive MEMS acoustic sensor chip is used for the sound pressure sensor 50 . A MEMS acoustic sensor chip is a small acoustic sensor formed on a semiconductor substrate using MEMS (micro electro-mechanical system) technology.

弾性部材６０は、基板４０を装置筐体１０に取り付ける際に基板４０と装着部１５との間に介在する部材であり、基板４０に対する前後方向Ｙ（板厚方向）の押圧力を吸収するように、前後方向Ｙに変形代ｓ４を備えたブチルゴムを用いて、平面視円環状（環状）に形成されている。弾性部材６０は、幅寸法ｓ２が前後方向Ｙの寸法よりも大きく設定されており、これにより、図４（Ａ）に示すように断面形状が長方形の平板状に形成されている。この弾性部材６０は、図４（Ａ）、（Ｂ）に示すように、音伝搬経路２０の背面側Ｙ２（装置筐体１０内部側）の開口部の周囲と基板４０との間に配置されるようになっている。基板４０が装着部１５に取り付けられた状態では、弾性部材６０は、正面側Ｙ１に押されて、変形するようになっている。この際、装着部１５と基板４０との隙間を弾性部材６０が塞ぐようになっている。すなわち、弾性部材６０は、音伝搬経路２０の内側を塞いで設けられている。このように基板４０が基板載置部１７に当接する様な載置において、基板載置部１７から凸部１５ａの頂部までの寸法ｓ３を設定することにより、弾性部材６０の圧縮量が一定となる様基板４０を固定することができる。このような構成により、音伝搬経路２０から筐体内部空間１０ｃ１への音漏れが防止され、当該音漏れによる音圧センサ５０への入力減衰を原因としたセンサ出力の低下や、当該音漏れによる音の回折を原因とした音圧センサの出力誤差が防止されている。 The elastic member 60 is a member interposed between the substrate 40 and the mounting portion 15 when the substrate 40 is attached to the apparatus housing 10, and is configured to absorb the pressing force in the front-rear direction Y (thickness direction) of the substrate 40. In addition, butyl rubber having a deformation margin s4 in the front-rear direction Y is used to form an annular (annular) shape in a plan view. The width dimension s2 of the elastic member 60 is set to be larger than the dimension in the front-rear direction Y, so that the elastic member 60 has a rectangular flat plate shape in cross section as shown in FIG. 4(A). As shown in FIGS. 4A and 4B, the elastic member 60 is arranged between the substrate 40 and the periphery of the opening of the sound propagation path 20 on the back side Y2 (inside the device housing 10). It has become so. When the substrate 40 is attached to the mounting portion 15, the elastic member 60 is pushed toward the front side Y1 and deformed. At this time, the elastic member 60 closes the gap between the mounting portion 15 and the substrate 40 . That is, the elastic member 60 is provided so as to block the inside of the sound propagation path 20 . By setting the dimension s3 from the substrate mounting portion 17 to the top of the projection 15a when the substrate 40 is placed in contact with the substrate mounting portion 17, the amount of compression of the elastic member 60 can be kept constant. The substrate 40 can be fixed as follows. With such a configuration, sound leakage from the sound propagation path 20 to the housing internal space 10c1 is prevented, and the sensor output decreases due to the input attenuation to the sound pressure sensor 50 due to the sound leakage, and the sound leakage An output error of the sound pressure sensor caused by sound diffraction is prevented.

なお、弾性部材６０は、ブチルゴムに限らず、シリコンパッキンや高密度の発泡ウレタン等で構成してもよい。また、本実施形態では、弾性部材６０は、装着部１５と基板４０とに挟み込まれた状態で装置筐体１０に固定されるようにしたが、例えば、弾性部材６０の片面に接着剤を塗布する、粘着シートや両面テープ等を貼り付けるなどして弾性部材６０を装置筐体１０に固定してもよい。また、弾性部材６０は、本実施形態のような平板円環状のいわゆる平パッキンで構成してもよいし、シリコーン等のコーキング材等を用いて構成してもよい。弾性部材６０は、平面視円環状（環状）としたが、これは音伝搬経路２０の背面側Ｙ２開口部の平面形状に基づいた形状であれば、平面視円環状に限定されない。すなわち、音伝搬経路２０の背面側Ｙ２開口部の端部に対して周方向全周に渡り当接するとともに、基板４０に当接し、音伝搬経路２０の背面側Ｙ２開口部を周方向全周に渡り封止できる形状であれば、音伝搬経路２０からの音漏れ防止効果を維持することができる。 The elastic member 60 is not limited to butyl rubber, and may be made of silicon packing, high density urethane foam, or the like. Further, in the present embodiment, the elastic member 60 is fixed to the apparatus housing 10 while being sandwiched between the mounting portion 15 and the substrate 40. Alternatively, the elastic member 60 may be fixed to the apparatus housing 10 by attaching an adhesive sheet, double-sided tape, or the like. Further, the elastic member 60 may be composed of a so-called flat packing having a flat annular shape as in the present embodiment, or may be composed of a caulking material such as silicone. Although the elastic member 60 is annular in plan view, it is not limited to an annular shape in plan view as long as the shape is based on the planar shape of the back side Y2 opening of the sound propagation path 20 . That is, it abuts against the end portion of the back side Y2 opening of the sound propagation path 20 along the entire circumferential direction and also contacts the substrate 40, so that the back side Y2 opening of the sound propagation path 20 extends along the entire circumferential direction. With a shape that allows transition sealing, the effect of preventing sound leakage from the sound propagation path 20 can be maintained.

また、弾性部材６０は、その断面形状を、本実施形態のように平板状にせず、円形状に形成してもよい。弾性部材６０の断面形状を平板状にする場合には、弾性部材６０と基板４０との接触面積を増大させることができるので、基板４０を正面側Ｙ１に押し付けた際の反力を大きくすることができ、基板４０が弾性部材６０に接触した状態を安定して維持することができる。一方、弾性部材６０の断面形状を円形状にする場合には、弾性部材６０と基板４０との接触面積を低減させることができるので、基板４０を正面側Ｙ１に押し付けた際の反力を小さくすることができ、基板４０の変形リスクを低減することができる。 Also, the cross-sectional shape of the elastic member 60 may be circular rather than flat as in the present embodiment. When the elastic member 60 has a flat cross-sectional shape, the contact area between the elastic member 60 and the substrate 40 can be increased, so that the reaction force when the substrate 40 is pressed against the front side Y1 can be increased. , and the substrate 40 can be stably maintained in contact with the elastic member 60 . On the other hand, when the cross-sectional shape of the elastic member 60 is circular, the contact area between the elastic member 60 and the substrate 40 can be reduced. and the deformation risk of the substrate 40 can be reduced.

カバー７０は、装置筐体１０の開口部１０ｃを閉塞する蓋部材である。このカバー７０は、装置筐体１０の開口部１０ｃの外縁に沿う外縁を備えた板状の部材である。カバー７０が装置筐体１０に固定されると、開口部１０ｃが閉じられて基板４０の背面側Ｙ２（音伝搬経路２０と反対側）に筐体内部空間１０ｃ１が形成されるようになっている。なお、カバー７０は、板状の部材に限らず、例えば前述のベント部３０の様に開口部１０ｃにねじ固定可能なねじ込み式の蓋であってもよい。また、カバー７０には、開口部１０ｃに挿入され係合爪により嵌合する円筒部と、背面側Ｙ２に張り出したフランジ部を設け、当該フランジ部でシール部材１２により密封できる構造であってもよい。 The cover 70 is a lid member that closes the opening 10 c of the device housing 10 . The cover 70 is a plate-shaped member having an outer edge along the outer edge of the opening 10c of the device housing 10. As shown in FIG. When the cover 70 is fixed to the device housing 10, the opening 10c is closed to form a housing internal space 10c1 on the rear side Y2 of the substrate 40 (the side opposite to the sound propagation path 20). . Note that the cover 70 is not limited to a plate-like member, and may be, for example, a screw-type lid that can be screw-fixed to the opening 10c like the vent 30 described above. Further, the cover 70 is provided with a cylindrical portion that is inserted into the opening 10c and fitted by the engaging claws, and a flange portion that protrudes toward the back side Y2, and the flange portion can be sealed by the sealing member 12. good.

本実施形態にかかる音圧検出装置１００は、以下の手順で組み立てられる。先ず、図１に示すように、ベント部３０に押さえリング３３を取り付けた状態で、円筒壁部１４の雌ねじ１４ｂに雄ねじ３１ａを締め込んでベント部３０を装置筐体１０に取り付ける。また、装置筐体１０の引出口１０ｄに取付部材１３ａを介してケーブル１３を取り付ける。次に、図６（Ａ）に示すように、弾性部材６０を装置筐体１０の背面側Ｙ２に配置し、図１に示すように、弾性部材６０の正面側Ｙ１の面を装着部１５の凸部１５ａの背面側Ｙ２の面に近づけていき、当該面に当接させる。この際、凸部１５ａの頂部が弾性部材６０の幅方向中央部に当接するようにする。次に、基板４０を装置筐体１０の背面側Ｙ２に配置し、図１に示すように、基板４０の正面側Ｙ１の面を弾性部材６０の背面側Ｙ２の面に近づけていき、当該面に当接させる。そして、基板４０のねじ通し穴４０ｃの中心軸と固定部１６の中心軸とが同軸となるようにし、ねじ１６ａを固定部１６に締め込むことで、基板４０を装置筐体１０に固定する。この際、図４（Ｂ）に示すように、基板４０の正面側Ｙ１の面は、基板載置部１７の面に当接するとともに、弾性部材６０の背面側Ｙ２の面に当接し且つ弾性部材６０を正面側Ｙ１に向かって押圧するようになっている。弾性部材６０は、基板４０に押圧されることで押しつぶされて変形している。そして、このように基板４０が装置筐体１０に固定された状態では、装着部１５と基板４０との隙間を弾性部材６０が塞ぐようになっている。 The sound pressure detection device 100 according to this embodiment is assembled in the following procedure. First, as shown in FIG. 1, the vent portion 30 is attached to the apparatus housing 10 by tightening the male screw 31a into the female screw 14b of the cylindrical wall portion 14 with the retaining ring 33 attached to the vent portion 30. As shown in FIG. Also, the cable 13 is attached to the outlet 10d of the device housing 10 via the attachment member 13a. Next, as shown in FIG. 6A, the elastic member 60 is arranged on the rear side Y2 of the apparatus housing 10, and the surface of the front side Y1 of the elastic member 60 is attached to the mounting portion 15 as shown in FIG. It is brought closer to the surface of the rear side Y2 of the convex portion 15a and brought into contact with the surface. At this time, the top of the convex portion 15a is brought into contact with the central portion of the elastic member 60 in the width direction. Next, the substrate 40 is placed on the rear side Y2 of the device housing 10, and as shown in FIG. abut on. Then, the substrate 40 is fixed to the device housing 10 by tightening the screw 16a into the fixing portion 16 so that the central axis of the screw hole 40c of the substrate 40 and the central axis of the fixing portion 16 are coaxial. At this time, as shown in FIG. 4B, the surface of the substrate 40 on the front side Y1 is in contact with the surface of the substrate mounting portion 17 and the surface of the elastic member 60 on the rear side Y2, and the surface of the elastic member 60 is in contact with the elastic member. 60 is pressed toward the front side Y1. The elastic member 60 is crushed and deformed by being pressed by the substrate 40 . In the state in which the substrate 40 is fixed to the device housing 10 in this way, the elastic member 60 closes the gap between the mounting portion 15 and the substrate 40 .

なお、本実施形態では、基板４０を装置筐体１０に固定する際に、弾性部材６０を押しつぶして基板４０の正面側Ｙ１の面を基板載置部１７の背面側Ｙ２の面に当接させることとしたが、基板４０の正面側Ｙ１の面は、基板載置部１７の背面側Ｙ２の面に当接していなくてもよい。すなわち、基板４０の正面側Ｙ１の面が弾性部材６０に密着していれば、基板４０と基板載置部１７との間にすき間が生じていてもよい。このため、弾性部材６０も必ずしも変形させる必要はなく、弾性部材６０の変形代ｓ４が０、ずなわち、圧縮せず装着部１５および基板４０に当接している状態であっても、基板４０と基板載置部１７との間にすき間が生じているような状態であってもよい。よって、設計の際は、このように弾性部材６０と基板４０との間にすき間が生じないよう、凸部１５ａの高さや弾性部材６０の厚さを調整する、ねじ１６ａの締め込み量を調節する等すればよい。そして、基板４０を装置筐体１０に固定した後、基板４０のコネクタ部４１に信号線１３ｂを接続させ、その後カバー７０で開口部１０ｃを閉じる。このようにして、音圧検出装置１００が完成する。 In the present embodiment, when the substrate 40 is fixed to the apparatus housing 10, the elastic member 60 is crushed to bring the surface of the front side Y1 of the substrate 40 into contact with the surface of the back side Y2 of the substrate mounting portion 17. However, the surface of the substrate 40 on the front side Y1 does not have to be in contact with the surface of the substrate mounting portion 17 on the back side Y2. That is, as long as the surface of the substrate 40 on the front side Y1 is in close contact with the elastic member 60 , a gap may be formed between the substrate 40 and the substrate mounting portion 17 . For this reason, the elastic member 60 does not necessarily need to be deformed either. and the substrate mounting portion 17 may be in a state in which a gap is generated. Therefore, when designing, the height of the projection 15a and the thickness of the elastic member 60 are adjusted, and the amount of tightening of the screw 16a is adjusted so that a gap does not occur between the elastic member 60 and the substrate 40. and so on. After fixing the substrate 40 to the device housing 10 , the signal line 13 b is connected to the connector portion 41 of the substrate 40 , and then the opening 10 c is closed with the cover 70 . Thus, the sound pressure detection device 100 is completed.

本実施形態によれば、音圧検出装置１００は、装置筐体１０と、装置筐体１０の内外に連通し外部からの音を伝搬させる音伝搬経路２０と、音伝搬経路２０の背面側Ｙ２（装置筐体１０内部側端部）に設けられる基板４０と、基板４０に設けられる音圧センサ５０と、装置筐体１０の開口部を閉じて筐体内部空間１０ｃ１を形成するカバー７０と、を備えた音圧検出装置１００であって、装置筐体１０には、基板４０を固定する少なくとも一対の離間した固定部１６が設けられ、一方の固定部１６と他方の固定部１６とのピッチＬ（離間距離）は、基板４０の板厚寸法ｔ１の１１．０倍以下である。 According to this embodiment, the sound pressure detection device 100 includes the device housing 10, the sound propagation path 20 that communicates with the inside and outside of the device housing 10 and propagates sound from the outside, and the rear side Y2 of the sound propagation path 20. A substrate 40 provided at (the inner end of the device housing 10), a sound pressure sensor 50 provided on the substrate 40, a cover 70 closing the opening of the device housing 10 to form the housing internal space 10c1, In the sound pressure detection device 100 having a L (spacing distance) is 11.0 times or less the thickness dimension t1 of the substrate 40 .

このような本発明によれば、一対の固定部間のピッチＬを、基板４０の板厚寸法ｔ１の１１．０倍以下に設定したことで、基板４０の板厚を固定部１６のピッチＬに対して相対的に厚くし、基板４０の剛性を向上させることができる。このため、従来のようにシールドプレートを省略した場合に基板４０がＯリングからの押圧力を受ける構成と比較して、基板４０の変形を抑制することができる。また、基板４０の板厚を固定部１６のピッチＬに対して相対的に厚くすることで、周囲温度が変化した場合に、基板４０と、装置筐体１０との線膨張係数の相違により基板４０が変形することを抑制することができる。したがって、押圧力や温度変化に対して変形し難い基板４０構造を有することで、音圧の検出精度、音圧センサ５０からの出力精度の低下を抑制できる音圧検出装置１００を得ることができる。 According to the present invention, the pitch L between the pair of fixed portions is set to 11.0 times or less of the plate thickness dimension t1 of the substrate 40, so that the plate thickness of the substrate 40 is reduced to the pitch L , the rigidity of the substrate 40 can be improved. Therefore, deformation of the substrate 40 can be suppressed as compared with the conventional configuration in which the substrate 40 receives the pressing force from the O-ring when the shield plate is omitted. In addition, by increasing the thickness of the substrate 40 relative to the pitch L of the fixed portions 16, the substrate 40 may be deformed due to the difference in coefficient of linear expansion between the substrate 40 and the device housing 10 when the ambient temperature changes. Deformation of 40 can be suppressed. Therefore, it is possible to obtain the sound pressure detection device 100 capable of suppressing deterioration in sound pressure detection accuracy and output accuracy from the sound pressure sensor 50 by having the structure of the substrate 40 that is resistant to deformation due to pressing force and temperature changes. .

また、本実施形態では、基板４０は、基板４０の前後方向Ｙに当接する環状の弾性部材６０を介して装置筐体１０に取り付けられている。このため、基板４０の板厚方向に当接する環状の弾性部材６０を介して基板４０を装置筐体１０に取り付けることができるので、基板４０と装置筐体１０とが密着することにより取り付け部分にすき間が生じることを防止し、当該部分から音伝搬経路２０内の音が漏れることを抑制し、センサ出力の低下を抑制することができる。そして、基板４０を装置筐体１０に取り付ける際の押圧力を弾性部材６０で吸収することができるので、弾性部材６０を用いない構成と比較して、基板４０に対して生じる押圧力を低減し、基板４０の変形を抑制することができる。 Further, in the present embodiment, the substrate 40 is attached to the device housing 10 via an annular elastic member 60 that abuts on the substrate 40 in the front-rear direction Y. As shown in FIG. Therefore, since the substrate 40 can be attached to the device housing 10 via the annular elastic member 60 that abuts on the substrate 40 in the plate thickness direction, the substrate 40 and the device housing 10 are in close contact with each other, so that the mounting portion can be secured. It is possible to prevent the occurrence of a gap, suppress leakage of sound in the sound propagation path 20 from the relevant portion, and suppress a decrease in sensor output. Since the elastic member 60 can absorb the pressing force applied when the substrate 40 is attached to the device housing 10, the pressing force applied to the substrate 40 can be reduced as compared with a configuration in which the elastic member 60 is not used. , deformation of the substrate 40 can be suppressed.

また、弾性部材６０の幅寸法ｓ２よりも小さい幅寸法ｓ１を有した凸部１５ａを、弾性部材６０の幅方向中間部に当接するようにしたことで、凸部１５ａを設けない構成と比較して、装置筐体１０と弾性部材６０との接触面積を小さくすることができる。このため、弾性部材６０が装置筐体１０から押圧された際の反力の発生範囲を小さくすることができ、当該反力による基板４０への影響を小さくして、基板４０が変形することを抑制することができる。 In addition, since the convex portion 15a having the width s1 smaller than the width s2 of the elastic member 60 is brought into contact with the widthwise middle portion of the elastic member 60, the structure can be compared with a configuration in which the convex portion 15a is not provided. Therefore, the contact area between the device housing 10 and the elastic member 60 can be reduced. Therefore, when the elastic member 60 is pressed by the apparatus housing 10, the range of reaction force generated can be reduced, and the influence of the reaction force on the substrate 40 is reduced, thereby preventing the substrate 40 from being deformed. can be suppressed.

また、基板載置部１７から凸部１５ａの頂部までの寸法ｓ３を、弾性部材６０の厚さｔ２以下に設定したので、凸部１５ａに押圧された弾性部材６０は、基板載置部１７から凸部１５ａの頂部までの寸法ｓ３（部品寸法）で圧縮量が決定されるので、取付状態によらずに一定の圧縮量が確保できる。この際、凸部１５ａに隣り合う凹部１５ｂが形成されるので、押圧された弾性部材６０の一部を凹部１５ｂに逃がすことができる。そのため、弾性部材６０が装置筐体１０から押圧された際の反力による基板４０への影響を小さくすることができる。したがって、弾性部材６０が装置筐体１０から押圧された際の反力による基板４０の変形を抑制することができる。 In addition, since the dimension s3 from the substrate mounting portion 17 to the top of the convex portion 15a is set to be equal to or less than the thickness t2 of the elastic member 60, the elastic member 60 pressed by the convex portion 15a is Since the amount of compression is determined by the dimension s3 (component dimension) to the top of the projection 15a, a constant amount of compression can be secured regardless of the mounting state. At this time, since the concave portion 15b adjacent to the convex portion 15a is formed, part of the pressed elastic member 60 can escape to the concave portion 15b. Therefore, the influence of the reaction force when the elastic member 60 is pressed from the device housing 10 on the substrate 40 can be reduced. Therefore, deformation of the substrate 40 due to the reaction force when the elastic member 60 is pressed from the device housing 10 can be suppressed.

また、固定部１６が音伝搬経路２０の装置筐体１０内部側開口部の先端部の径方向外側近傍に設けられていることで、各固定部１６を基板４０の中心側にできるだけ近づけ、一対の固定部１６のピッチＬを小さくすることができる。これにより、当該ピッチＬに対する基板４０の板厚寸法ｔ１を相対的に大きくすることができ、基板４０の剛性を向上させることができる。また、上述のピッチＬと基板４０の板厚寸法ｔ１の関係を満たすための基板４０の板厚を、当該ピッチＬが大きい構成と比較して薄くすることができ、音圧検出装置１００の大型化を抑制することができる。 Further, since the fixing portions 16 are provided in the vicinity of the radial direction outside of the tip portion of the opening on the inner side of the device housing 10 of the sound propagation path 20, each fixing portion 16 is brought as close to the center side of the substrate 40 as possible, and the pair of , the pitch L of the fixing portion 16 can be reduced. Accordingly, the thickness dimension t1 of the substrate 40 can be relatively increased with respect to the pitch L, and the rigidity of the substrate 40 can be improved. Further, the thickness of the substrate 40 for satisfying the above-described relationship between the pitch L and the thickness dimension t1 of the substrate 40 can be made thinner than in a configuration where the pitch L is large. It is possible to suppress

また、音伝搬経路２０の装置筐体１０内部側開口部の先端部を塞ぐ基板４０に、音伝搬経路２０と筐体内部空間１０ｃ１とを連通する微小な通気孔４０ｂを設けたので、音伝搬経路２０の気圧と、筐体内部空間１０ｃ１の気圧とが等しくなり、筐体内部空間１０ｃ１で結露が発生することを防止することができる。 In addition, since the substrate 40 that closes the tip of the opening of the sound propagation path 20 on the inner side of the device housing 10 is provided with a minute air hole 40b that communicates the sound propagation path 20 with the housing inner space 10c1, sound propagation The air pressure in the path 20 and the air pressure in the housing internal space 10c1 become equal, and the occurrence of dew condensation in the housing internal space 10c1 can be prevented.

以上、本発明の実施形態について図面を参照して詳述してきたが、具体的な構成はこれらの実施形態に限られるものではなく、本発明の要旨を逸脱しない範囲の設計変更等があっても本発明に含まれる。本実施形態では、円筒壁部１４の背面側Ｙ２の端部、すなわち装着部１５における左右方向Ｘの両端部に一対の接続板部１４ａを形成し、各々の接続板部１４ａには、基板４０を装置筐体１０に固定するための雌ねじである固定部１６を形成した。しかしながら、固定部の種類および配置は、これに限られない。例えば、円筒壁部１４の背面側Ｙ２の端面と、基板４０の正面側Ｙ１の面と、を接着材で接着し、この接着部分を固定部としてもよい。 Although the embodiments of the present invention have been described in detail above with reference to the drawings, the specific configuration is not limited to these embodiments, and design changes and the like may be made without departing from the gist of the present invention. is also included in the present invention. In this embodiment, a pair of connection plate portions 14a are formed at the end portion of the cylindrical wall portion 14 on the back side Y2, that is, at both end portions of the mounting portion 15 in the left-right direction X. A fixing portion 16 which is a female screw for fixing to the apparatus housing 10 is formed. However, the type and arrangement of the fixing portion are not limited to this. For example, the end surface of the cylindrical wall portion 14 on the back side Y2 and the surface of the substrate 40 on the front side Y1 may be bonded with an adhesive, and this bonded portion may be used as the fixed portion.

また、弾性部材６０の正面側Ｙ１の面を円筒壁部１４の背面側Ｙ２の端部に接着し、弾性部材６０の背面側Ｙ２の面と、基板４０の正面側Ｙ１の面と、を接着剤で接着し、この接着部分を固定部としてもよい。この場合、弾性部材６０の内径寸法が離間寸法Ｌ（本実施形態におけるピッチＬ）となるが、上述のように装着部１５の外形寸法は、弾性部材６０が乗り上げることがないように、弾性部材６０の外径寸法よりも大きく設定されているので、本実施形態のように装着部１５の左右方向Ｘに延びる接続板部１４ａに固定部１６を形成する場合よりも、弾性部材６０の内径寸法、すなわち離間寸法Ｌを小さくすることができる。具体的には、本実施形態の固定部１６のピッチＬをＬ＝１９ｍｍとすると、ｔ＝１．６ｍｍで比Ｌ／ｔが１１．８、ｔ＝３．２ｍｍで比Ｌ／ｔが５．９となるのに対し、弾性部材６０の内径寸法を離間寸法Ｌとした場合、Ｌ＝１２ｍｍとすると、ｔ＝１．６ｍｍで比Ｌ／ｔが７．５、ｔ＝３．２で比Ｌ／ｔが３．７とすることができる。このため、離間寸法Ｌに対する基板４０の板厚寸法ｔ１をより一層、相対的に大きくすることができる。 In addition, the front side Y1 surface of the elastic member 60 is adhered to the end portion of the rear side Y2 of the cylindrical wall portion 14, and the rear side Y2 surface of the elastic member 60 and the front side Y1 surface of the substrate 40 are adhered. It may be adhered with an adhesive and this adhered portion may be used as the fixed portion. In this case, the inner diameter dimension of the elastic member 60 is the separation dimension L (pitch L in this embodiment), but the outer dimension of the mounting portion 15 is set so that the elastic member 60 does not ride on it as described above. Since the outer diameter of the elastic member 60 is set to be larger than the outer diameter of the elastic member 60, the inner diameter of the elastic member 60 is larger than that in the case where the fixing portion 16 is formed on the connecting plate portion 14a extending in the left-right direction X of the mounting portion 15 as in the present embodiment. That is, the separation dimension L can be reduced. Specifically, if the pitch L of the fixing portion 16 in this embodiment is L=19 mm, the ratio L/t is 11.8 at t=1.6 mm, and the ratio L/t is 5.0 at t=3.2 mm. 9. On the other hand, if the inner diameter dimension of the elastic member 60 is the spacing dimension L, and L = 12 mm, the ratio L / t is 7.5 at t = 1.6 mm, and the ratio L / t is 7.5 at t = 3.2. /t can be 3.7. Therefore, the plate thickness dimension t1 of the substrate 40 with respect to the separation dimension L can be relatively increased.

ｔ１板厚寸法
Ｌピッチ（離間距離）
１００音圧検出装置
１０装置筐体
１６固定部
１７基板載置部
２０音伝搬経路
３０ベント部
４０基板
５０音圧センサ
６０弾性部材
７０カバー t1 Plate thickness dimension L Pitch (separation distance)
100 Sound pressure detection device 10 Device housing 16 Fixing part 17 Substrate mounting part 20 Sound propagation path 30 Vent part 40 Substrate 50 Sound pressure sensor 60 Elastic member 70 Cover

Claims

a device housing, a sound propagation path that communicates with the inside and outside of the device housing and propagates sound from the outside, a substrate provided at an end portion of the sound propagation path on the inner side of the device housing, and a substrate provided on the substrate A sound pressure detection device comprising a sound pressure sensor and a cover that closes an opening of the device housing to form an internal space of the housing,
The apparatus housing is provided with at least a pair of spaced apart fixing portions for fixing the substrate, and the separation distance between one of the fixing portions and the other of the fixing portions is 11.0 times the thickness of the substrate. A sound pressure detection device characterized by being less than double.

2. The sound according to claim 1, wherein the substrate is attached to an end portion of the sound propagation path on the inner side of the apparatus housing via an annular elastic member that abuts on the substrate in the thickness direction. Pressure detection device.

The device housing is provided with a convex portion having a width dimension smaller than the width dimension of the elastic member,
3. The sound pressure detecting device according to claim 2, wherein the convex portion is in contact with a widthwise intermediate portion of the elastic member.

At the end portion of the sound propagation path on the inner side of the device housing, a substrate mounting portion on which the substrate is mounted with the thickness direction of the substrate as the mounting direction, and the elastic member recessed in the mounting direction are provided. A mounting portion installed in the mounting direction is formed,
The mounting portion is provided with a convex portion projecting toward the substrate mounting portion side in the mounting direction within a range not exceeding the substrate mounting portion,
The convex portion has a width dimension smaller than the width dimension of the elastic member, and is provided so as to abut on the surface of the elastic member on one side in the mounting direction over the entire circumference,
A dimension in the mounting direction from the substrate mounting portion to the top of the convex portion is set to be equal to or smaller than a dimension in the mounting direction of the elastic member installed in the mounting portion. Item 3. The sound pressure detection device according to item 2.

The elastic member is provided inside the device housing between the substrate and the periphery of the opening of the sound propagation path on the inner side of the device housing,
5. The sound pressure according to any one of claims 2 to 4, wherein the fixed portion is provided near the radially outer side of the tip of the opening on the inner side of the device housing of the sound propagation path. detection device.

The substrate is provided so as to close the tip of the opening of the sound propagation path on the inside of the device housing, and the substrate has at least a minute air hole that communicates the sound propagation path with the space inside the housing. 6. The sound pressure detection device according to claim 1, wherein one or more are provided.