JPH0758335B2 - Powder particle detector - Google Patents
Powder particle detectorInfo
- Publication number
- JPH0758335B2 JPH0758335B2 JP61153162A JP15316286A JPH0758335B2 JP H0758335 B2 JPH0758335 B2 JP H0758335B2 JP 61153162 A JP61153162 A JP 61153162A JP 15316286 A JP15316286 A JP 15316286A JP H0758335 B2 JPH0758335 B2 JP H0758335B2
- Authority
- JP
- Japan
- Prior art keywords
- electrode
- piezoelectric vibrator
- powder
- collector
- granular material
- 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.)
- Expired - Fee Related
Links
Landscapes
- Geophysics And Detection Of Objects (AREA)
Description
【発明の詳細な説明】 産業上の利用分野 本発明は、圧電振動子を用いた粉体，粒体等の有無検知
するための粉粒体検知装置に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a powder or granular material detection device for detecting the presence or absence of powder, granular material or the like using a piezoelectric vibrator.
従来の技術 近年、発振回路から発振電圧を受けて振動する圧電振動
子に粉体，粒体等の被検知物が接触すると、上記振動子
の振動が停止し、発振出力がなくなる原理を利用したセ
ンサが、粉粒体の有無検知に使われるようになってきた
（「圧電ブザー・発音体最新技術'85年版」編集委員会
編『圧電ブザー・発音体最新技術'85年版』1984年12月2
5日総合技術出版発行第２頁〜第15頁）。2. Description of the Related Art In recent years, when the piezoelectric vibrator vibrating by receiving an oscillating voltage from an oscillating circuit comes in contact with an object to be detected such as powder or particles, the vibration of the vibrator is stopped and the oscillation output is lost. Sensors have come to be used for detecting the presence or absence of powder particles ("Piezoelectric buzzer / sound generator latest technology '85 edition" edited by the editing committee, "Piezoelectric buzzer / sound generator latest technology '85 edition" December 1984 2
5th, Comprehensive Technology Publishing, pages 2 to 15).
以下に従来の粉粒体センサについて第２図〜第４図を用
いて説明する。第２図，第３図はそれぞれ従来の粉粒体
センサの斜視図およびそのA-A′矢視断面図、第４図は
そのブロック図である。図に示すように、圧電振動子１
は、たとえば非磁性金属薄板からなる振動板２上に薄板
状の圧電素子３を付着させたものである。圧電素子３上
には電極4,5が設けられている。なお、振動板２がこれ
らの電極4,5と対向する電極を兼ねている。これらから
なる圧電振動子１はケース６に保持される。The conventional powder / particle sensor will be described below with reference to FIGS. 2 to 4. 2 and 3 are a perspective view and a sectional view taken along the line AA 'of the conventional granular material sensor, respectively, and FIG. 4 is a block diagram thereof. As shown in the figure, the piezoelectric vibrator 1
Is a thin plate-shaped piezoelectric element 3 attached to a vibration plate 2 made of, for example, a non-magnetic metal thin plate. Electrodes 4 and 5 are provided on the piezoelectric element 3. The diaphragm 2 also serves as an electrode facing these electrodes 4 and 5. The piezoelectric vibrator 1 made of these is held in the case 6.
第５図はこの粉粒体センサを用いた装置の要部回路図で
ある。図に示すように、電極４は圧電振動子１を振動さ
せるための駆動電極であり、電極５は圧電振動子１の動
作により発生する電荷を発振用トランジスタ７のベース
へ帰還信号として取り出すための帰還電極である。圧電
振動子１はトランジスタ７などとにより自励発振回路を
構成し、基本共振周波数で発振するように回路定数が選
定されている。粉粒体が圧電振動子１に接触するとその
発振が停止するので、その動作状態により粉粒体の有無
を検出することができる。FIG. 5 is a circuit diagram of a main part of an apparatus using this powder / particle sensor. As shown in the figure, the electrode 4 is a drive electrode for vibrating the piezoelectric vibrator 1, and the electrode 5 is for extracting the electric charge generated by the operation of the piezoelectric vibrator 1 to the base of the oscillation transistor 7 as a feedback signal. It is a return electrode. The piezoelectric vibrator 1 constitutes a self-excited oscillation circuit with the transistor 7 and the like, and the circuit constants are selected so as to oscillate at the fundamental resonance frequency. When the powder or granular material comes into contact with the piezoelectric vibrator 1, its oscillation is stopped, so that the presence or absence of the powder or granular material can be detected by the operating state.
発明が解決しようとする問題点 しかしながら上記従来の装置では、圧電振動子の部品精
度のばらつきや、組立上のばらつきによって粉粒体が圧
電振動子に接触しても、その発振動作が停止せず、基本
周波数以外の共振周波数たとえば高調波が発生する。こ
の高調波はトランジスタにより増幅されるため、検出感
度に悪影響を及ぼすという問題点がある。DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, in the above-described conventional device, even if the powder or granular material comes into contact with the piezoelectric vibrator due to variations in component accuracy of the piezoelectric vibrator or variations in assembly, the oscillation operation does not stop. A resonance frequency other than the fundamental frequency, such as a harmonic, is generated. Since this harmonic is amplified by the transistor, there is a problem that detection sensitivity is adversely affected.
本発明は上記従来の問題点を解決するもので、部品や組
立上のばらつきによる影響を少なくし安定した感度で粉
粒体を検出できる粉粒体検知装置を提供することを目的
とする。The present invention solves the above-mentioned conventional problems, and an object of the present invention is to provide a powdery or granular material detection device capable of detecting powdery or granular materials with a stable sensitivity by reducing the influence of variations in parts and assembly.
問題点を解決するための手段 この目的を達成するために本発明の粉粒体検知装置は、
駆動用電極、帰還用電極および接地用電極を備え、かつ
粉粒体の接触の有無を検出する圧電振動子の前記帰還用
電極を抵抗を介して電源端子に接続し、さらにコレクタ
が負荷抵抗を介して前記電源端子に接続され、かつエミ
ッタが接地された発振用トランジスタのベースに抵抗を
介して前記帰還用電極を接続し、前記コレクタに出力端
子を設け、同出力端子と接地点間に電圧分割手段を設
け、その分割電圧発生点に前記駆動用電極を接続すると
ともに、前記トランジスタのコレクタと前記帰還用電極
との間にコンデンサを接続してなるものである。Means for Solving the Problems In order to achieve this object, the particulate matter detection device of the present invention is
The piezoelectric vibrator is equipped with a drive electrode, a return electrode, and a ground electrode, and the return electrode of the piezoelectric vibrator that detects the presence or absence of contact with the powder or granular material is connected to a power supply terminal via a resistor. Is connected to the power supply terminal and the emitter is grounded, the feedback electrode is connected via a resistor to the base of the oscillation transistor, the collector is provided with an output terminal, and a voltage is provided between the output terminal and the ground point. A dividing means is provided, the driving electrode is connected to the division voltage generating point, and a capacitor is connected between the collector of the transistor and the feedback electrode.
作用 この高周波バイパス用コンデンサは、圧電振動子が基本
共振周波数以外の高い共振周波数で発振することを抑圧
する。Action This high-frequency bypass capacitor suppresses the piezoelectric vibrator from oscillating at a high resonance frequency other than the fundamental resonance frequency.
実施例 以下に本発明の一実施例について図面を参照しながら説
明する。第１図は本発明の一実施例における粉粒体検知
装置の要部回路図である。Embodiment An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a circuit diagram of a main part of a powdery or granular material detecting device according to an embodiment of the present invention.
図に示すように、この装置は、圧電振動素子３、駆動用
の電極４、帰還用の電極５、接地用電極である振動板２
および粉粒体の接触の有無を検出する圧電振動子１を有
する三端子型の圧電振動子を用いたものである。そし
て、電源端子に、抵抗を介して圧電振動子１の帰還用の
電極５と負荷抵抗を介して発振用トランジスタ７のコレ
クタとがそれぞれ接続され、前記コレクタに出力端子を
設けている。また、前記出力端子とアース間に抵抗9,10
からなる抵抗電圧分割手段を設け、その分割電圧発生点
に圧電振動子１の駆動用の電極４を接続している。As shown in the figure, this device includes a piezoelectric vibrating element 3, a driving electrode 4, a feedback electrode 5, and a diaphragm 2 which is a ground electrode.
And a three-terminal type piezoelectric vibrator having a piezoelectric vibrator 1 for detecting the presence / absence of contact of powder and granular material. The power supply terminal is connected to the feedback electrode 5 of the piezoelectric vibrator 1 via a resistor and the collector of the oscillation transistor 7 via a load resistance, and the collector is provided with an output terminal. In addition, a resistor 9,10 is connected between the output terminal and ground.
Is provided, and the driving electrode 4 of the piezoelectric vibrator 1 is connected to the division voltage generation point.
そして、トランジスタ７のコレクタと圧電振動子１の帰
還用の電極５との間には、コンデンサ11が接続されてい
る。A capacitor 11 is connected between the collector of the transistor 7 and the feedback electrode 5 of the piezoelectric vibrator 1.
この装置の発振は、第５図に示した従来例と同様にして
行われる。Oscillation of this device is performed in the same manner as the conventional example shown in FIG.
コンデンサ11がトランジスタ７のコレクタと圧電振動子
１の電極との間に接続されているので、圧電振動子１の
部品精度や組立上のばらつきなどによって生じる、発振
周波数の高調波成分は、このコンデンサ11をバイパス
し、トランジスタ７のベースへ帰還されることが少なく
なる。このため、不要な発振動作が抑圧され、粉粒体の
有無を確実に検出することができる。Since the capacitor 11 is connected between the collector of the transistor 7 and the electrode of the piezoelectric vibrator 1, the harmonic component of the oscillation frequency, which is caused by the component accuracy of the piezoelectric vibrator 1 and the variation in assembly, is generated by this capacitor. Bypassing 11 makes it less likely to be fed back to the base of transistor 7. Therefore, unnecessary oscillation operation is suppressed, and it is possible to reliably detect the presence or absence of powder or granular material.
発明の効果 本発明は、圧電振動子を使用した粉粒体検知装置におい
て、発振回路のトランジスタのコレクタと圧電振動子の
帰還用の電極との間に高調波バイパス用のコンデンサを
接続しているので、基本周波数以外の周波数で発振する
おそれがなくなり、粉粒体に対して安定した検出感度を
得ることができる。EFFECTS OF THE INVENTION The present invention relates to a powder or granular material detecting device using a piezoelectric vibrator, in which a harmonic bypass capacitor is connected between the collector of the transistor of the oscillation circuit and the feedback electrode of the piezoelectric vibrator. Therefore, there is no possibility of oscillating at a frequency other than the fundamental frequency, and stable detection sensitivity can be obtained for the granular material.
第１図は本発明の一実施例における粉粒体検知装置の要
部回路図、第２図は粉粒体センサの一例の斜視図、第３
図はそのA-A′断面図、第４図は粉粒体検知装置の要部
ブロック図、第５図はその従来例の要部回路図である。 １……圧電振動子、２……振動板、３……圧電振動素
子、４……駆動用の電極、５……帰還用の電極、７……
トランジスタ。FIG. 1 is a circuit diagram of a main part of a powder or granular material detection device according to an embodiment of the present invention, and FIG. 2 is a perspective view of an example of the powder or granular material sensor.
FIG. 4 is a sectional view taken along the line AA ', FIG. 4 is a block diagram of a main part of a powdery or granular material detecting device, and FIG. 1 ... Piezoelectric vibrator, 2 ... Vibration plate, 3 ... Piezoelectric vibrating element, 4 ... Driving electrode, 5 ... Return electrode, 7 ...
Transistor.
Claims (1)
を備え、かつ粉粒体の接触の有無を検出する圧電振動子
の前記帰還用電極を抵抗を介して電源端子に接続し、さ
らにコレクタが負荷抵抗を介して前記電源端子に接続さ
れ、かつエミッタが接地された発振用トランジスタのベ
ースに抵抗を介して前記帰還用電極を接続し、前記コレ
クタに出力端子を設け、同出力端子と接地点間に電圧分
割手段を設け、その分割電圧発生点に前記駆動用電極を
接続するとともに、前記トランジスタのコレクタと前記
帰還用電極との間にコンデンサを接続してなることを特
徴とする粉粒体検知装置。1. A piezoelectric vibrator comprising a drive electrode, a return electrode, and a ground electrode, wherein the return electrode of a piezoelectric vibrator for detecting the presence / absence of contact of powder or granular material is connected to a power supply terminal via a resistor, and A collector is connected to the power supply terminal via a load resistor, and an emitter is grounded, the feedback electrode is connected to the base of the oscillation transistor via a resistor, and the collector is provided with an output terminal. A powder dividing means is provided between ground points, the driving electrode is connected to the divided voltage generating point, and a capacitor is connected between the collector of the transistor and the feedback electrode. Particle detection device.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61153162A JPH0758335B2 (en) | 1986-06-30 | 1986-06-30 | Powder particle detector |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61153162A JPH0758335B2 (en) | 1986-06-30 | 1986-06-30 | Powder particle detector |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS638582A JPS638582A (en) | 1988-01-14 |
| JPH0758335B2 true JPH0758335B2 (en) | 1995-06-21 |
Family
ID=15556397
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61153162A Expired - Fee Related JPH0758335B2 (en) | 1986-06-30 | 1986-06-30 | Powder particle detector |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0758335B2 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0875742B1 (en) * | 1997-04-30 | 2007-12-19 | Endress + Hauser GmbH + Co. KG | Device for determining/monitoring of a predefined liquid level in a container |
| US6138507A (en) * | 1997-04-30 | 2000-10-31 | Endress + Hauser Gmbh + Co. | Apparatus for establishing and/or monitoring a predetermined filling level in a container through controlled transducer phase and impedance |
| DE59712962D1 (en) * | 1997-04-30 | 2008-10-02 | Endress & Hauser Gmbh & Co Kg | Arrangement for detecting and / or monitoring a predetermined level in a container |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58153329U (en) * | 1982-03-31 | 1983-10-13 | 日本特殊陶業株式会社 | Piezoelectric oscillation circuit for liquid detection |
| JPS59147256A (en) * | 1983-02-10 | 1984-08-23 | Tdk Corp | Piezoelectric sensor |
-
1986
- 1986-06-30 JP JP61153162A patent/JPH0758335B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPS638582A (en) | 1988-01-14 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |