JPH036461A - Acceleration sensor - Google Patents
Acceleration sensorInfo
- Publication number
- JPH036461A JPH036461A JP14050789A JP14050789A JPH036461A JP H036461 A JPH036461 A JP H036461A JP 14050789 A JP14050789 A JP 14050789A JP 14050789 A JP14050789 A JP 14050789A JP H036461 A JPH036461 A JP H036461A
- Authority
- JP
- Japan
- Prior art keywords
- circuit
- piezoelectric
- conductive layer
- linear expansion
- vibrator
- 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
- 230000001133 acceleration Effects 0.000 title claims description 16
- 239000003990 capacitor Substances 0.000 claims abstract description 16
- 238000006243 chemical reaction Methods 0.000 claims description 5
- 230000007935 neutral effect Effects 0.000 claims description 5
- 230000003321 amplification Effects 0.000 claims description 3
- 238000003199 nucleic acid amplification method Methods 0.000 claims description 3
- 230000035945 sensitivity Effects 0.000 abstract description 6
- 230000000694 effects Effects 0.000 abstract description 4
- 230000001939 inductive effect Effects 0.000 abstract description 4
- 239000000853 adhesive Substances 0.000 abstract description 3
- 230000001070 adhesive effect Effects 0.000 abstract description 3
- 239000004020 conductor Substances 0.000 abstract description 3
- 229920005989 resin Polymers 0.000 description 15
- 239000011347 resin Substances 0.000 description 15
- 230000005669 field effect Effects 0.000 description 12
- 238000006073 displacement reaction Methods 0.000 description 7
- 239000000463 material Substances 0.000 description 7
- 238000010586 diagram Methods 0.000 description 6
- 230000006698 induction Effects 0.000 description 6
- 230000000903 blocking effect Effects 0.000 description 4
- 230000002265 prevention Effects 0.000 description 4
- 238000001514 detection method Methods 0.000 description 3
- 238000009413 insulation Methods 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- 229920000131 polyvinylidene Polymers 0.000 description 3
- 238000007639 printing Methods 0.000 description 3
- 230000005616 pyroelectricity Effects 0.000 description 3
- 239000000758 substrate Substances 0.000 description 3
- FCYVWWWTHPPJII-UHFFFAOYSA-N 2-methylidenepropanedinitrile Chemical compound N#CC(=C)C#N FCYVWWWTHPPJII-UHFFFAOYSA-N 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- XTXRWKRVRITETP-UHFFFAOYSA-N Vinyl acetate Chemical compound CC(=O)OC=C XTXRWKRVRITETP-UHFFFAOYSA-N 0.000 description 2
- 230000002159 abnormal effect Effects 0.000 description 2
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 229920006026 co-polymeric resin Polymers 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 2
- 238000000576 coating method Methods 0.000 description 2
- 229920001971 elastomer Polymers 0.000 description 2
- 239000012212 insulator Substances 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 239000003973 paint Substances 0.000 description 2
- 229920006324 polyoxymethylene Polymers 0.000 description 2
- 238000004544 sputter deposition Methods 0.000 description 2
- 238000007740 vapor deposition Methods 0.000 description 2
- 229920000049 Carbon (fiber) Polymers 0.000 description 1
- 239000002033 PVDF binder Substances 0.000 description 1
- 229930182556 Polyacetal Natural products 0.000 description 1
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000004917 carbon fiber Substances 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 229920001577 copolymer Polymers 0.000 description 1
- 230000004069 differentiation Effects 0.000 description 1
- NKZSPGSOXYXWQA-UHFFFAOYSA-N dioxido(oxo)titanium;lead(2+) Chemical class [Pb+2].[O-][Ti]([O-])=O NKZSPGSOXYXWQA-UHFFFAOYSA-N 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 229920006332 epoxy adhesive Polymers 0.000 description 1
- 239000003822 epoxy resin Substances 0.000 description 1
- 239000010408 film Substances 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 238000007747 plating Methods 0.000 description 1
- 229920000647 polyepoxide Polymers 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 229920002981 polyvinylidene fluoride Polymers 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 229920002050 silicone resin Polymers 0.000 description 1
- 230000006641 stabilisation Effects 0.000 description 1
- 238000011105 stabilization Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000002470 thermal conductor Substances 0.000 description 1
- 229920002803 thermoplastic polyurethane Polymers 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
- 229910000859 α-Fe Inorganic materials 0.000 description 1
Landscapes
- Pressure Sensors (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は圧電振動子を用いて加速度を検出する加速度セ
ンサに係り、特に、温度変化や電圧変動、電磁ノイズな
どの影響を受けに＜＜、車両搭載用として優れた低周波
用の加速度センサに関する。[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an acceleration sensor that detects acceleration using a piezoelectric vibrator, and is particularly sensitive to the effects of temperature changes, voltage fluctuations, electromagnetic noise, etc. , relates to a low-frequency acceleration sensor that is excellent for use in vehicles.
（先行技術〕
加速度は変位の２重微分で得られるので、低周波になる
ほど大きな変位でも実際の加速度は小さくなってくる。(Prior Art) Since acceleration is obtained by double differentiation of displacement, the lower the frequency, the smaller the actual acceleration even for a large displacement.
例えば１６０ Ｈｚ 、 １０μｍの変位で加速度は
Ｉ Ｇ 、 ０．１６Ｈ２では１０ｍの変位量でＩＧと
なる。低周波の振動測定を行う場合、実際の変位はせい
ぜい１ｍ以下であり、例えば１．６ Ｈｚでは、０．１
Ｇで、ｌ ｃｍの変位となる。For example, at 160 Hz and a displacement of 10 μm, the acceleration is IG, and at 0.16H2, the acceleration is IG with a displacement of 10 m. When making low-frequency vibration measurements, the actual displacement is at most 1 m or less; for example, at 1.6 Hz, the displacement is 0.1 m or less.
G, resulting in a displacement of l cm.
従って、０，１〜１０Ｈｚの振動を測定するためには０
．１〜０．ＯＩＧの小さな加速度を測定できるものでな
ければならない。Therefore, in order to measure vibrations from 0.1 to 10Hz, 0.
．． 1~0. It must be able to measure small OIG accelerations.
本発明者等は低周波用の加速度センサを実願昭６３−１
０３６０２号として既に提案した。この加速度センサは
、圧電振動子を導電性樹脂、断熱体及び熱伝導体により
順次被覆し、これを絶縁性基台に取付けると共に、導電
性樹脂と導電性の熱伝導体との間に、外部誘導障害防止
用コンデンサを接続してなるもので、このように構成す
ることにより、圧電振動子を導電性樹脂により電磁シー
ルドしているので、電気的ノイズに影響されず、また断
熱体と熱伝導体により外部からの加熱あるいは冷却によ
る温度変化を大幅に緩和できるばかりでなく、絶縁性基
台により圧電振動子を被測定物から電気的に絶縁してい
るので、静電誘導やアース間電位などの誘導障害を受け
にくいと共に、導電性樹脂と導電性の熱伝導体との間に
外部誘導障害防止用コンデンサを接続しているので、外
部高周波ノイズをバイパスさせることができるため、低
周波低加速度の計測もより一層高精度に行うことができ
るという作用効果を奏する。The inventors of the present invention applied for a low-frequency acceleration sensor in 1983-1.
It has already been proposed as No. 03602. In this acceleration sensor, a piezoelectric vibrator is sequentially coated with a conductive resin, a heat insulator, and a heat conductor, and this is mounted on an insulating base. It is made by connecting a capacitor to prevent inductive disturbances. By configuring it in this way, the piezoelectric vibrator is electromagnetically shielded by conductive resin, so it is not affected by electrical noise, and it also has excellent insulation and thermal conductivity. Not only can the body significantly reduce temperature changes caused by external heating or cooling, but the insulating base electrically isolates the piezoelectric vibrator from the object being measured, reducing electrostatic induction, ground potential, etc. In addition to being less susceptible to inductive interference, an external inductive interference prevention capacitor is connected between the conductive resin and the conductive heat conductor, allowing external high frequency noise to be bypassed, thereby reducing low frequency and low acceleration. This has the advantage of being able to measure with even higher precision.
しかしながら」−記先行例にあっては、外部高周波ノイ
ズをバイパスさせるため、導電性樹脂と導電性の熱伝導
体との間に外部誘導障害防止用コンデンサを接続する必
要があり、それだけ構造が煩雑になるという課題がある
ばかりでなく、圧電振動子の出力を別設した信号処理、
信号安定化電子回路にケーブルにより接続することにな
り、構造が小形、コンパクトにできず、圧電振動子と電
子回路間で外部誘導障害を受りるおそれがあり、また、
圧電体がこれよりも線膨張率の小さい材料によって保持
されていないので、センサ感度の温度依存性を一定にで
きないという課題もある。However, in the previous example mentioned above, in order to bypass external high-frequency noise, it is necessary to connect an external induction failure prevention capacitor between the conductive resin and the conductive thermal conductor, which makes the structure complicated. Not only is there the issue of configuring the
Since it is connected to the signal stabilization electronic circuit by cable, the structure cannot be made small and compact, and there is a risk of external induction interference between the piezoelectric vibrator and the electronic circuit.
Since the piezoelectric body is not supported by a material with a coefficient of linear expansion smaller than this, there is also the problem that the temperature dependence of sensor sensitivity cannot be made constant.
本発明センサは上記の課題を解決するため、図示のよう
に圧電体１の両面に電極を設けて圧電振動子６を構成し
、この圧電振動子６を線膨張率の小さな回路基板７の一
面に接着し、この回路基板７の他面に信号処理電子回路
８を形成せしめ、全体を、内部導電層１０．断熱層９及
び外部導電層１１の３層で被覆してなる構成としたもの
である。In order to solve the above-mentioned problems, the sensor of the present invention has electrodes provided on both sides of a piezoelectric body 1 to form a piezoelectric vibrator 6 as shown in the figure, and this piezoelectric vibrator 6 is attached to one side of a circuit board 7 having a small coefficient of linear expansion. A signal processing electronic circuit 8 is formed on the other side of the circuit board 7, and the entire circuit board 7 is bonded to an internal conductive layer 10. It has a structure in which it is coated with three layers: a heat insulating layer 9 and an external conductive layer 11.
本発明では電子回路８中に外部誘導障害防止用コンデン
サを組込むことによりそれだけ構造が簡便になり、該コ
ンデンサの設置に苦慮することがないばかりでなく、圧
電振動子６の出力を信号処理電子回路８に接続するに際
してケーブルを別設する必要もないので、構造が小形、
コンパクトにでき、圧電振動子６と電子回路８間で外部
誘導障害を受けるおそれがないし、また圧電体１がこれ
より線膨張率の小さい材料によって保持されているので
、センサ感度の温度依存性を一定にできることになる。In the present invention, by incorporating an external induction interference prevention capacitor into the electronic circuit 8, the structure is simplified and there is no need to worry about installing the capacitor. There is no need to install a separate cable when connecting to 8, so the structure is compact and
It can be made compact, there is no risk of external induction interference occurring between the piezoelectric vibrator 6 and the electronic circuit 8, and since the piezoelectric body 1 is held by a material with a smaller linear expansion coefficient, the temperature dependence of the sensor sensitivity can be reduced. This will be possible to a certain extent.
以下図面に基いて本発明の詳細な説明する。 The present invention will be described in detail below based on the drawings.
第１図は本発明センサの一実施例の構成を示す概略断面
図、第２図は本実施例の外観を示す斜視図、第３図は本
実施例における構成の説明用斜視図である。FIG. 1 is a schematic sectional view showing the structure of an embodiment of the sensor of the present invention, FIG. 2 is a perspective view showing the appearance of this embodiment, and FIG. 3 is a perspective view for explaining the structure of this embodiment.
第３図ｔａ＋ 、 （ｂｌ 、第４図中、１は圧電体で
ある。Fig. 3 ta+, (bl) In Fig. 4, 1 is a piezoelectric material.
圧電体１としては体積固有抵抗が２０℃で１０′２〜１
０′６Ωｃｍの範囲にある、厚さ１０〜５００μｍの圧
電樹脂シートである。The piezoelectric material 1 has a volume resistivity of 10'2 to 1 at 20°C.
It is a piezoelectric resin sheet with a thickness of 10 to 500 μm and in the range of 0'6 Ωcm.
例えば、高分子圧電体では、ＰＶＤＦ＝ポリフッカビニ
リデン樹脂やＰ （ＶＤＣＮ／ＶＣＡ）＝ポリ （ビニ
リデンシアナイド／酢酸ビニル）共重合樹脂などであり
、高分子複合系では、ＰＺＴ−チタン酸ジルコン酸鉛・
ＰＯＭ−ポリアセタール樹脂・ＮＢＲ−アクリルニトリ
ル・ブタジェン共重合ゴム・カーボンからなる組成物の
圧電体である。ゴムは加硫することで耐久性を向上でき
る。For example, in polymeric piezoelectric materials, PVDF=polyvinylidene resin and P (VDCN/VCA)=poly(vinylidene cyanide/vinyl acetate) copolymer resin, etc., and in polymer composite systems, PZT-zirconate titanate resin. lead·
It is a piezoelectric body made of a composition consisting of POM-polyacetal resin, NBR-acrylonitrile-butadiene copolymer rubber, and carbon. The durability of rubber can be improved by vulcanizing it.
ＰＣＴ−カルシウム置換型チタン酸鉛、ｕ−ＰＯＭ−ウ
レタン変性ポリアセタール樹脂からなる組成物の圧電体
でもよい。A piezoelectric body made of a composition consisting of PCT-calcium-substituted lead titanate and u-POM-urethane modified polyacetal resin may be used.
圧電体の両面には、蒸着、スパッタ、導電塗料の印刷等
の手段に依って電極が設けられて圧電振動子６が構成さ
れるが、例えば、圧電体１の一面に一対の正、負電極２
，３を設け、他面に中立電極４を設けた構造の圧電振動
子６ （第３図参照）にすると、焦電性を減じるのに効
果がある。この効果は、正、負電極２，３の面積を等し
くすると更に高められる。The piezoelectric vibrator 6 is constructed by providing electrodes on both sides of the piezoelectric body by means such as vapor deposition, sputtering, or printing with conductive paint. 2
, 3 and a neutral electrode 4 on the other surface (see FIG. 3) is effective in reducing pyroelectricity. This effect is further enhanced when the areas of the positive and negative electrodes 2 and 3 are made equal.
また、圧電体１の一面の中心側に正電極２を。In addition, a positive electrode 2 is placed on the center side of one surface of the piezoelectric body 1.
外側に負電極３を配置すると、電気ノイズ低減に効果が
ある。Placing the negative electrode 3 on the outside is effective in reducing electrical noise.
尚、内側正電極２と外側負電極３の間には、電気的絶縁
帯が設けられることは勿論である。It goes without saying that an electrically insulating band is provided between the inner positive electrode 2 and the outer negative electrode 3.
この圧電振動子６ば線膨張率の小さい回路基板７の一面
に接着されており、この回路基板７の他面には信号処理
電子回路８が形成されている。This piezoelectric vibrator 6 is bonded to one side of a circuit board 7 having a small coefficient of linear expansion, and a signal processing electronic circuit 8 is formed on the other side of this circuit board 7.
回路基板７としては、線膨張率が５ｘｌＯ−５／’ｃ以
下で高い剛性を有するガラスエポキシ樹脂、セラミック
（アルミナ、シリコンウェーハーなと）、金属等が用い
られる。As the circuit board 7, glass epoxy resin, ceramic (alumina, silicon wafer, etc.), metal, etc., which has a coefficient of linear expansion of 5xlO-5/'c or less and high rigidity, is used.
圧電体１上の正、負電極２，３を電子回路８に接続する
ために、接続回路が形成される。接続回路は、ワイヤー
ボンデングによるリード線の接続、蒸着やスパッタ等に
よる薄膜形成、厚膜回路印刷、導電塗装等の方法で形成
される。A connection circuit is formed to connect the positive and negative electrodes 2, 3 on the piezoelectric body 1 to the electronic circuit 8. The connection circuit is formed by connecting lead wires by wire bonding, forming a thin film by vapor deposition, sputtering, etc., thick film circuit printing, conductive coating, or the like.
回路形成に先だって、圧電体１の端面に露出している中
立電極４と電気的に短絡するのを避けるため、当該部分
は絶縁体１２でコートされる。そして圧電振動子６の正
、負電極２．３は、それぞれ回路基板７の一面に形成さ
れた正、負電極用パターン１５ 、１６に、正、負電極
用リードパターン１３１４で接続され、（第３図参照）
、更にこれらの正負電極用パターン１５ 、１６はスル
ーポール１７ 、１８で回路基板７の他面に形成された
信号処理電子回路８に接続されている。２４は負電極用
パターン１６と一体に形成された回路基準電位電極であ
る。Prior to circuit formation, this portion is coated with an insulator 12 in order to avoid electrical short-circuiting with the neutral electrode 4 exposed on the end face of the piezoelectric body 1. The positive and negative electrodes 2.3 of the piezoelectric vibrator 6 are connected to positive and negative electrode patterns 15 and 16 formed on one surface of the circuit board 7, respectively, by positive and negative electrode lead patterns 1314. (See Figure 3)
Further, these positive and negative electrode patterns 15 and 16 are connected to a signal processing electronic circuit 8 formed on the other surface of the circuit board 7 through through poles 17 and 18. 24 is a circuit reference potential electrode formed integrally with the negative electrode pattern 16.
信号処理電子回路８は、例えば第１図示のように回路基
板７，７ａに分けて形成してもよ＜、１９は当該電子回
路８を構成する部品である。The signal processing electronic circuit 8 may be formed separately on circuit boards 7 and 7a, for example, as shown in the first diagram. Reference numeral 19 denotes a component constituting the electronic circuit 8.
信号処理電子回路８は例えば第４図示のようにインピー
ダンス変換部２０．フィルタ部２１．ミューティング部
２２、増幅部２３および電源回路３０より構成されてい
る。The signal processing electronic circuit 8 includes, for example, an impedance conversion section 20 .as shown in FIG. 4 . Filter section 21. It is composed of a muting section 22, an amplification section 23, and a power supply circuit 30.
インピーダンス変換部２０の電界効果トランジスタＱ１
に１〜１００ＧΩのゲート抵抗Ｒを挿入することで、焦
電性による出力のドリフトが低減され、温度変化に対し
て安定した出力が得られる。Field effect transistor Q1 of impedance conversion section 20
By inserting a gate resistor R of 1 to 100 GΩ in , output drift due to pyroelectricity is reduced, and stable output can be obtained against temperature changes.
フィルタ部２１の定数は、最低測定周波数によって決定
されるバイパス・フィルタのカッ１−オフ周波数から算
出される。The constant of the filter section 21 is calculated from the cut-off frequency of the bypass filter determined by the lowest measured frequency.
フィルタ部２１の後段にはミューティング部２２を接続
し、電源投入直後の出力立ち上がりを早くする。A muting section 22 is connected after the filter section 21 to speed up the output rise immediately after power is turned on.
回路基板７の振動子６側には回路基準電位電極２４を設
け、高インピーダンスの圧電体１を電磁ノイズから保護
する。A circuit reference potential electrode 24 is provided on the vibrator 6 side of the circuit board 7 to protect the high impedance piezoelectric body 1 from electromagnetic noise.
センサ外との接続線（電源線、信号線など）には貫通コ
ンデンサ２５ 、２６ 、２７を挿入し、外部高岡ノイ
ズが回路部に入らないように保護する。Feedthrough capacitors 25, 26, and 27 are inserted into the connection lines to the outside of the sensor (power supply lines, signal lines, etc.) to protect the circuit from external Takaoka noise.
増幅部２３には温度補償回路２８が組み合わせられ、環
境温度の変化に対して安定な感度が得られると共に利得
調整回路２９も設けられ、これにより出力信号■、の大
きさが調整される。The amplifier section 23 is combined with a temperature compensation circuit 28 to obtain stable sensitivity to changes in environmental temperature, and is also provided with a gain adjustment circuit 29, which adjusts the magnitude of the output signal (2).
電源回路３０は耐逆電圧用素子を挿入、異常な逆方向電
圧に対して回路を保護する。A reverse voltage withstand element is inserted into the power supply circuit 30 to protect the circuit against abnormal reverse voltage.
また、瞬低・瞬断対策用回路を挿入し、異常な電圧の低
下や切断に対して回路の動作を保護する。In addition, a voltage drop/interruption countermeasure circuit is inserted to protect circuit operation against abnormal voltage drops or disconnections.
３２ 、３３はそれぞれケーブル及びコネクタである。32 and 33 are a cable and a connector, respectively.
以上の構成によると、圧電体１が、自身よりも線膨張率
の小さい材料の回路基板７によって保持されるので、モ
ンサ感度の温度依存性を一定にすることができる。According to the above configuration, the piezoelectric body 1 is held by the circuit board 7 made of a material having a coefficient of linear expansion smaller than that of the piezoelectric body 1, so that the temperature dependence of the Monsa sensitivity can be made constant.
基板７上には、振動子６を固定しない側に部品１９を実
装するなど、ハイブリッド化した電子回路８を形成する
ことができる。A hybrid electronic circuit 8 can be formed on the substrate 7 by mounting components 19 on the side to which the vibrator 6 is not fixed.
回路基板７，７ａは更にきょう体と固定される。The circuit boards 7, 7a are further fixed to the housing.
固定に際して、シリコン樹脂、ウレタン樹脂などの軟質
接着剤を用いると、両者の線膨張率差による歪を吸収で
きる利点がある。When fixing, using a soft adhesive such as silicone resin or urethane resin has the advantage of being able to absorb distortion due to the difference in linear expansion coefficient between the two.
第５図は本発明における電子回路３０の一例を示す接続
図で、６は圧電振動子、Ｖｃは回路基準電位、Ｒ１はソ
ース抵抗、Ｖｃ（は電圧端、Ｒはゲート抵抗、Ｑ、はイ
ンピーダンス変換用電界効果トランジスタ、Ｔ、は直流
電圧阻止用コンデンサＣＩと抵抗Ｒ２とよりなる第１時
定数回路、Ｔ２は直流電圧阻止用コンデンサＣ２と抵抗
Ｒ３とよりなる第２時定数回路で、これらの第１．第２
時定数回路Ｔ ＋ 、 Ｔ ２はフィルタ部を構成する
。Ａ Ｉ’ 、 Ａ ｚは初段、後段アンプ、Ｒ３’
、Ｒ，＋ 、Ｒｈ 、Ｒ７は０
それぞれ利得調整回路２９を構成する初段、後段アンプ
Ａ ＋ 、 Ａ ｚのゲイン設定用抵抗で、温度補償
回路２８は図示していない。Ｑ２．Ｑ、はそれぞれ抵抗
Ｒ２，Ｒ５に並列に抵抗した第１．第２スイツチング用
電界効果トランジスタ、Ｄｌ、Ｄ２はダイオード、Ｍｃ
はミューティング回路２２である。FIG. 5 is a connection diagram showing an example of the electronic circuit 30 according to the present invention, where 6 is a piezoelectric vibrator, Vc is a circuit reference potential, R1 is a source resistance, Vc (is a voltage terminal, R is a gate resistance, and Q is an impedance. The conversion field effect transistor T is a first time constant circuit consisting of a DC voltage blocking capacitor CI and a resistor R2, and T2 is a second time constant circuit consisting of a DC voltage blocking capacitor C2 and a resistor R3. 1st. 2nd
The time constant circuits T + and T 2 constitute a filter section. A I', A z are first stage, second stage amplifier, R3'
, R. Q2. Q, is the first resistor resistor R2 and R5, respectively. Second switching field effect transistor, Dl and D2 are diodes, Mc
is the muting circuit 22.
ミューティング回路Ｍｃより出力される電界効果トラン
ジスタＱ２．Ｑ３のオン、オフ用信号Ｍ ＋ 。Field effect transistor Q2 outputted from muting circuit Mc. Signal M + for turning on and off Q3.
Ｍ２は第６図示のように電源投入直後同時に出力される
が、停止する時期については先にＭｌが停止し、一定期
間後Ｍ２が停止するように形成される。As shown in FIG. 6, M2 is output at the same time immediately after the power is turned on, but M1 is stopped first and M2 is stopped after a certain period of time.
電源投入直後、基準電位Ｖｃより高電圧に設定されたミ
ューティング信号Ｍ、、Ｍ、がミューティング回路Ｍｃ
よりダイオードＤＩ、Ｄ２に印加すると、電界効果トラ
ンジスタＱ２．Ｑ、はダイオードリーク電流によりゲー
ト、ソース間電圧ＶＣＳ−〇■となり、オンする。一定
期間１．．１２の後ミューティング信号Ｍ、、Ｍ、が基
準電位Ｖｃより電界効果トランジスタピンチオフ電圧以
下に低くなると電界効果トランジスタＱ、、Ｑ、はそれ
ぞれオフする。ここで電界効果トランジスタＱ２゜Ｑ、
のオン設定時間ｔＩ＋ｔ２は１．＜１２に設定される。Immediately after the power is turned on, the muting signals M, , M, which are set to a higher voltage than the reference potential Vc, are applied to the muting circuit Mc.
When applied to the diodes DI, D2, the field effect transistor Q2. Q becomes the gate-source voltage VCS-〇■ due to diode leakage current, and turns on. For a certain period of time 1. ．． After 12, when the muting signals M, , M, become lower than the reference potential Vc to below the field effect transistor pinch-off voltage, the field effect transistors Q, , Q, respectively turn off. Here, the field effect transistor Q2゜Q,
The ON setting time tI+t2 is 1. <12.
このような構成において電源を投入すると、インピーダ
ンス変換用電界効果トランジスタＱ１およびアンプＡ、
、Ａ２に電源電圧Ｖｃｃが印加される。同時に、ミュー
ティング回路Ｍｃが作動し第１時定数回路Ｔ１の抵抗Ｒ
２に並列に接続されたスイッチング用電界効果トランジ
スタＱ２がダイオードＤ、を介してミューティング信号
Ｍ１により設定時間ｔ１オンし、その後オフせしめられ
る。When the power is turned on in such a configuration, the impedance conversion field effect transistor Q1 and the amplifier A,
, A2 are applied with power supply voltage Vcc. At the same time, the muting circuit Mc is activated and the resistance R of the first time constant circuit T1 is
The switching field effect transistor Q2 connected in parallel with the switching field effect transistor Q2 is turned on for a set time t1 by the muting signal M1 via the diode D, and then turned off.
また、第２時定数回路Ｔ２の抵抗Ｒ５に並列に接続され
たスイッチング用電界効果トランジスタＱ３もダイオー
ドＤ２を介してミューティング信号Ｍ２により設定時間
ｔ２オンし、その後オフせしめられる。Furthermore, the switching field effect transistor Q3 connected in parallel to the resistor R5 of the second time constant circuit T2 is also turned on for a set time t2 by the muting signal M2 via the diode D2, and then turned off.
本動作により第１時定数回路Ｔ、にて、１．期間Ｒｚ＝
ＯΩとなり直流阻止用コンデンサＣ１は速やかに所定の
電圧迄充電される。ｔ１期間後第１
２
１時定数回路Ｔ１は正規の時定数にてインピーダンス変
換されたセンサ検出信号出力Ｖｓを初段アンプＡ、へ伝
達する。This operation causes the first time constant circuit T to perform 1. Period Rz=
0Ω, and the DC blocking capacitor C1 is quickly charged to a predetermined voltage. After the t1 period, the 1 2 1 time constant circuit T1 transmits the impedance-converted sensor detection signal output Vs to the first stage amplifier A using a regular time constant.
同様に、第２時定数回路Ｔ２にて、ｔ２期期間１＃ＯΩ
となり、直流阻止用コンデンサＣ２は基準電位Ｖｃに対
する初段アンプＡ１の直流オフセント電圧変動に対し速
やかに充電される。ｔ２期間後第２時定数回路Ｔ２は正
規の時定数にて初段アンプＡ１にて増幅されたセンサ検
出信号出力■を後段アンプＡ２へ伝達する。Similarly, in the second time constant circuit T2, during the t2 period 1#OΩ
Therefore, the DC blocking capacitor C2 is quickly charged against the DC offset voltage fluctuation of the first stage amplifier A1 with respect to the reference potential Vc. After the period t2, the second time constant circuit T2 transmits the sensor detection signal output (2) amplified by the first stage amplifier A1 to the second stage amplifier A2 at a regular time constant.
上記の動作結果、センサアンプ出力信号Ｖｏは、電源投
入後ｔ２期間、基準電位Ｖｃとなり、その後安定したセ
ンサ検出信号増幅出力信号となり、入力応答の七トリン
グ時間送れを短くすることが可能となる。As a result of the above operation, the sensor amplifier output signal Vo becomes the reference potential Vc for a period t2 after the power is turned on, and then becomes a stable sensor detection signal amplified output signal, making it possible to shorten the seven-tring time delay of the input response.
例えば、低域カットオフ周波数を０．１ Ｈｚ程度に設
定した場合、本発明センサアンプでは、出力安定に必要
となる時間は、約６秒となる。For example, when the low cutoff frequency is set to about 0.1 Hz, the sensor amplifier of the present invention requires about 6 seconds to stabilize its output.
圧電振動子６．及び回路基板７，７ａは内部導電層１０
．断熱層９及び外部導電層１１よりなるきょう体３１内
に収納される。３２は各貫通コンデンサ２５〜２７に接
続されたケーブル、３３はケーブル３２に接続されたコ
ネクタである。Piezoelectric vibrator6. and the circuit board 7, 7a has an internal conductive layer 10
．． It is housed in a housing 31 consisting of a heat insulating layer 9 and an external conductive layer 11. 32 is a cable connected to each feedthrough capacitor 25 to 27, and 33 is a connector connected to the cable 32.
振動子６および電子回路８を電磁ノイズから保護するた
めに全体は内部導電層１０で囲まれ、導電層１０は電子
回路８の信号グランドと接続される。In order to protect the vibrator 6 and the electronic circuit 8 from electromagnetic noise, the whole is surrounded by an internal conductive layer 10, and the conductive layer 10 is connected to the signal ground of the electronic circuit 8.
内部導電層１０は、カーボンもしぐは／およびカーボン
ファイバーを混合した導電樹脂、樹脂メツキ、導電塗装
などで形成される。The internal conductive layer 10 is formed of a conductive resin mixed with carbon and/or carbon fiber, resin plating, conductive coating, or the like.
また、フェライト混合により、併せて高周波もシールド
することができる。Furthermore, by mixing ferrite, high frequencies can also be shielded.
圧電体ｌの焦電効果によって出力ゼロドリフトの起こる
のを防止するために、断熱層９で全体が囲まれる。断熱
層９は、ヒダのついた樹脂成型体や、発泡樹脂体などで
形成される。In order to prevent output zero drift from occurring due to the pyroelectric effect of the piezoelectric material 1, the entire structure is surrounded by a heat insulating layer 9. The heat insulating layer 9 is formed of a pleated resin molded body, a foamed resin body, or the like.
また、高周波電磁波の影響を除去するために、貫通コン
デンサ２５〜２７の接地端子と接続した、外部導電層１
１が金属などで形成され被測定物に接地される。In addition, in order to eliminate the influence of high-frequency electromagnetic waves, the outer conductive layer 1 is connected to the ground terminals of the feedthrough capacitors 25 to 27.
1 is made of metal or the like and is grounded to the object to be measured.
本発明を具体的に示すと、圧電体ｌとして、ＰＩ３
４
（ＶＤＣＮ／ＶＣＡ）−ポリ （ビニリデンシアナイド
／酢酸ビニル）共重合樹脂を用いた。To specifically illustrate the present invention, a PI3 4 (VDCN/VCA)-poly(vinylidene cyanide/vinyl acetate) copolymer resin was used as the piezoelectric body 1.
この圧電体１を、厚さ２０μｍ直径１９酊の円板状に形
成した。This piezoelectric body 1 was formed into a disk shape with a thickness of 20 μm and a diameter of 19 μm.
圧電体１の一面に直径１３．５φの正電極２、内径１４
φ外形１９φの負電極３を、他面には全面に中立電極４
を導電塗料の印刷によって設は振動子６とした。A positive electrode 2 with a diameter of 13.5φ and an inner diameter of 14 are placed on one surface of the piezoelectric body 1.
A negative electrode 3 with an outer diameter of 19φ is placed on the other side, and a neutral electrode 4 is placed on the entire surface on the other side.
The vibrator 6 was created by printing conductive paint.
振動子６を、ハイブリッド化された電子回路８を搭載し
た厚さ０．８ ＋＋＋＋ 、 ２３ｍ１角のアルミナ基
板にエポキシ系接着剤を用いて接着した。The vibrator 6 was bonded using an epoxy adhesive to an alumina substrate having a thickness of 0.8 ++++ and a size of 23 square meters on which a hybrid electronic circuit 8 was mounted.
ハイブリッド化された電子回路８には、接続回路と、信
号処理回路と、電源回路とを設けた。The hybridized electronic circuit 8 was provided with a connection circuit, a signal processing circuit, and a power supply circuit.
前記の基板を、導電性樹脂層１０と、絶縁性を有する断
熱性樹脂層９と、金属層１１の３層からなるきょう体３
１に納め、本発明のセンサを完成させた。The above-mentioned substrate is formed into a housing 3 consisting of three layers: a conductive resin layer 10, an insulating heat-insulating resin layer 9, and a metal layer 11.
1 and completed the sensor of the present invention.
上述の説明より理解されるように本発明によれば、圧電
体１の両面に電゛極を設けて圧電振動子６を構成し、こ
の圧電振動子６を線膨張率の小さな回路基板７の一面に
接着し、この回路基板７の他面に信号処理電子回路８を
形成せしめ、全体を、内部導電層１０．断熱層９及び外
部導電層１１の３層で被覆してなるので、焦電性による
出力のドリフトを低減でき、温度変化に対して安定した
出力Ｖ。As can be understood from the above description, according to the present invention, electrodes are provided on both sides of the piezoelectric body 1 to constitute the piezoelectric vibrator 6, and the piezoelectric vibrator 6 is mounted on a circuit board 7 having a small coefficient of linear expansion. A signal processing electronic circuit 8 is formed on the other side of the circuit board 7, and the entire circuit board 7 is bonded to an inner conductive layer 10. Since it is coated with three layers, the heat insulating layer 9 and the external conductive layer 11, output drift due to pyroelectricity can be reduced, and the output V is stable against temperature changes.
を得ることができる。また、圧電体１よりも線膨張率の
小さい回路基板７により圧電振動子６を保持したので、
センサ感度の温度依存性を一定にすることができると共
に回路基板７を内部導電層１０゜断熱層９及び外部導電
層１１の３層に固定するに際し軟質接着剤を用いること
により回路基板７と３層の線膨張率差による歪を吸収で
きる。更に振動子６及び回路基板７の全体が、電子回路
８の信号グランドに接続された内部導電層１０により被
覆されているので、電磁ノイズから保護することができ
るばかりでなく、貫通コンデンサ２５〜２７の接地端子
に外部導電層１１を接続することにより高周波電磁波の
影響を除去することができる。また、電子回路８中に外
部誘導障害防止用コンデンサを組込むことによりそれだ
け構造が簡便になり、小形。can be obtained. Furthermore, since the piezoelectric vibrator 6 is held by the circuit board 7 which has a smaller coefficient of linear expansion than the piezoelectric body 1,
The temperature dependence of the sensor sensitivity can be made constant, and the circuit boards 7 and 3 can be fixed by using a soft adhesive when fixing the circuit board 7 to the three layers of the inner conductive layer 10°, the heat insulation layer 9, and the outer conductive layer 11. It can absorb the strain caused by the difference in linear expansion coefficient of the layers. Furthermore, since the vibrator 6 and the circuit board 7 are entirely covered with an internal conductive layer 10 connected to the signal ground of the electronic circuit 8, they are not only protected from electromagnetic noise but also protected from feedthrough capacitors 25 to 27. The influence of high frequency electromagnetic waves can be removed by connecting the external conductive layer 11 to the ground terminal. Furthermore, by incorporating an external induction interference prevention capacitor into the electronic circuit 8, the structure becomes simpler and more compact.
コンパクトにできる等の効果を奏する。It has the advantage of being compact.
５ ６5 6
第１図は本発明センサの一実施例の構成を示す図、第４
図は本実施例における信号処理電子回路の一構成例を示
す接続図、第５図は本発明における電子回路の一例を示
す接続図、第６図はその動作説明図である。
１・・・・・・圧電体、２．３・・・・・・正、負電極
、４・・・・・・中立電極、６・・・・・・圧電振動子
、７，７ａ・・・・・・回路基板、８・・・・・・信号
処理電子回路、９・・・・・・断熱層、１ｏ。
１１・・・・・・内、外部導電層。
７
４５８−
手
続
補
正
書
（方式）
％式％
発明の名称
加速度センサ
３゜
補正をする者
事件との関係 特許出願人
６０５ 三菱油化株式会社
４゜
代
理
人
住
所
口１４３東京都大田区山王２丁目１番８号平成１年９月
２６日
（発送口）FIG. 1 is a diagram showing the configuration of an embodiment of the sensor of the present invention, and FIG.
FIG. 5 is a connection diagram showing an example of the configuration of the signal processing electronic circuit in this embodiment, FIG. 5 is a connection diagram showing an example of the electronic circuit in the present invention, and FIG. 6 is an explanatory diagram of its operation. 1... Piezoelectric substance, 2.3... Positive and negative electrodes, 4... Neutral electrode, 6... Piezoelectric vibrator, 7, 7a... ... Circuit board, 8 ... Signal processing electronic circuit, 9 ... Heat insulation layer, 1o. 11... Inner and outer conductive layers. 7 458- Procedural amendment (method) % formula % Name of the invention Acceleration sensor 3゜Relationship with the case of the person making the amendment Patent applicant 605 Mitsubishi Yuka Co., Ltd. 4゜ Agent address 143 Sanno 2-chome, Ota-ku, Tokyo No. 1 No. 8 September 26, 1999 (Shipping port)
Claims (3)
成し、この圧電振動子６を線膨張率の小さな回路基板７
の一面に接着し、この回路基板７の他面に信号処理電子
回路８を形成せしめ、全体を、内部導電層１０，断熱層
９及び外部導電層１１の３層で被覆してなる加速度セン
サ。(1) Electrodes are provided on both sides of the piezoelectric body 1 to form a piezoelectric vibrator 6, and this piezoelectric vibrator 6 is connected to a circuit board 7 with a small coefficient of linear expansion.
An acceleration sensor is formed by adhering to one side of the circuit board 7, forming a signal processing electronic circuit 8 on the other side of the circuit board 7, and covering the entire body with three layers: an inner conductive layer 10, a heat insulating layer 9, and an outer conductive layer 11.
極２，３を設け、その他面に中立電極４を設けてなる請
求項第１項記載の加速度センサ。(2) The acceleration sensor according to claim 1, wherein the piezoelectric vibrator 6 has a pair of positive and negative electrodes 2 and 3 provided on one surface of the piezoelectric body 1, and a neutral electrode 4 provided on the other surface.
インピーダンス変換部２０，フィルタ部２１，増幅部２
３をこの順に接続し、フィルタ部２１と増幅部２３間に
、ミューテイング部２２を接続すると共に、これら各部
を作動せしめる電源回路３０を設け、増幅部２３の出力
及び電源回路３０の入力、信号グランドにそれぞれ貫通
コンデンサ２６，２５，２７を接続せしめてなる請求項
第１項，第２項のいずれかに記載の加速度センサ。(3) The signal processing electronic circuit 8 applies the output of the piezoelectric vibrator 6 to
Impedance conversion section 20, filter section 21, amplifier section 2
3 are connected in this order, and the muting section 22 is connected between the filter section 21 and the amplification section 23, and a power supply circuit 30 for operating these sections is provided, and the output of the amplification section 23, the input of the power supply circuit 30, and the signal 3. The acceleration sensor according to claim 1, wherein feedthrough capacitors (26, 25, 27) are connected to the ground, respectively.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14050789A JPH036461A (en) | 1989-06-02 | 1989-06-02 | Acceleration sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14050789A JPH036461A (en) | 1989-06-02 | 1989-06-02 | Acceleration sensor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH036461A true JPH036461A (en) | 1991-01-11 |
Family
ID=15270257
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP14050789A Pending JPH036461A (en) | 1989-06-02 | 1989-06-02 | Acceleration sensor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH036461A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5679897A (en) * | 1995-07-25 | 1997-10-21 | Matsushita Electric Industrial Co., Ltd. | Piezoelectric type acceleration sensor with metallic case and resin package |
| JP2009053087A (en) * | 2007-08-28 | 2009-03-12 | Yamaha Corp | Motion sensor and method for manufacturing the same |
| WO2011024576A1 (en) * | 2009-08-31 | 2011-03-03 | 日立オートモティブシステムズ株式会社 | Capacitance type physical quantity sensor and angular velocity sensor |
| CN108489577A (en) * | 2018-03-26 | 2018-09-04 | 温州大学 | A kind of micro-mass sensor |
-
1989
- 1989-06-02 JP JP14050789A patent/JPH036461A/en active Pending
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5679897A (en) * | 1995-07-25 | 1997-10-21 | Matsushita Electric Industrial Co., Ltd. | Piezoelectric type acceleration sensor with metallic case and resin package |
| JP2009053087A (en) * | 2007-08-28 | 2009-03-12 | Yamaha Corp | Motion sensor and method for manufacturing the same |
| WO2011024576A1 (en) * | 2009-08-31 | 2011-03-03 | 日立オートモティブシステムズ株式会社 | Capacitance type physical quantity sensor and angular velocity sensor |
| JP2011053020A (en) * | 2009-08-31 | 2011-03-17 | Hitachi Automotive Systems Ltd | Capacitance type physical quantity sensor and angular velocity sensor |
| US8836348B2 (en) | 2009-08-31 | 2014-09-16 | Hitachi Automotive Systems, Ltd. | Electrostatic capacitance type physical quantity sensor and angular velocity sensor |
| CN108489577A (en) * | 2018-03-26 | 2018-09-04 | 温州大学 | A kind of micro-mass sensor |
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