JP3177628B2 - Capacitive level sensor - Google Patents
Capacitive level sensorInfo
- Publication number
- JP3177628B2 JP3177628B2 JP13629795A JP13629795A JP3177628B2 JP 3177628 B2 JP3177628 B2 JP 3177628B2 JP 13629795 A JP13629795 A JP 13629795A JP 13629795 A JP13629795 A JP 13629795A JP 3177628 B2 JP3177628 B2 JP 3177628B2
- Authority
- JP
- Japan
- Prior art keywords
- electrode
- outer electrode
- level sensor
- connecting rod
- inner electrode
- 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
- Measurement Of Levels Of Liquids Or Fluent Solid Materials (AREA)
Description
【０００１】[0001]
【産業上の利用分野】この発明は静電容量式レベルセン
サの応答性の向上に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in responsiveness of a capacitance type level sensor.
【０００２】[0002]
【従来の技術及び発明が解決しようとする課題】従来の
静電容量式レベルセンサ（以下単にレベルセンサと言
う）１は図２に示すように、円筒状の内電極２と外電極
３とが同心に対向して配され、それら両電極がそれぞれ
を貫通する円柱状の連結棒４により結合される。このレ
ベルセンサ１は液位を測定しようとする槽の底面５から
僅かな距離Δだけ離して垂直に取付けられている。液位
ｈの変化に応じて、両電極間の静電容量が変化するの
で、その静電容量を測定することによって液位ｈを検出
できる。定常状態では両電極２，３間及び内電極２内の
液位は外電極３の外側の槽の液位ｈに等しい。液位ｈが
Ｈ＋Δ（Ｈは電極の長さ）より小さい場合に、槽の液位
ｈが変化すると、センサ１内部の液体は両電極の周面に
孔が無く、両電極の下側からのみ出入りするので、レベ
ルセンサ１内の液位が測定すべき槽の液位ｈに一致する
までに時間がかかる。特に両電極間の液位は電極間隔が
狭いので特に時間がかかる。即ち、このセンサは応答性
がよくない問題がある。2. Description of the Related Art As shown in FIG. 2, a conventional capacitance type level sensor (hereinafter simply referred to as a level sensor) 1 has a cylindrical inner electrode 2 and an outer electrode 3. The electrodes are concentrically opposed to each other, and the two electrodes are connected by a cylindrical connecting rod 4 penetrating therethrough. The level sensor 1 is mounted vertically at a slight distance Δ from the bottom surface 5 of the tank whose liquid level is to be measured. Since the capacitance between the two electrodes changes according to the change in the liquid level h, the liquid level h can be detected by measuring the capacitance. In a steady state, the liquid level between the two electrodes 2 and 3 and inside the inner electrode 2 is equal to the liquid level h in the tank outside the outer electrode 3. When the liquid level h is smaller than H + Δ (H is the length of the electrode), when the liquid level h of the tank changes, the liquid inside the sensor 1 has no holes in the peripheral surfaces of both electrodes, and only from the lower side of both electrodes. Since it enters and exits, it takes time until the liquid level in the level sensor 1 matches the liquid level h of the tank to be measured. In particular, the liquid level between the two electrodes takes a long time because the distance between the electrodes is small. That is, this sensor has a problem of poor response.
【０００３】そこで、応答性を改善するために、図３に
示すように液位ｈが変動する位置に流通孔３ａ，３ｂを
設けて、両電極間の液体を電極の下側のみでなく、この
流通孔を通じても出入りできるようにしたものがある。
しかし、そのために液位ｈ対静電容量の直線性が低下す
る問題が生じる。この発明の目的は、液位対静電容量の
直線性を損なうことなく応答性を向上しようとするもの
である。In order to improve the responsiveness, flow holes 3a and 3b are provided at positions where the liquid level h fluctuates as shown in FIG. There are some which can enter and exit through this circulation hole.
However, this causes a problem that the linearity between the liquid level h and the capacitance is reduced. An object of the present invention is to improve responsiveness without impairing the linearity of liquid level versus capacitance.
【０００４】[0004]
（１）請求項１の発明は、連結棒が両端解放の筒状体と
され、その周壁を貫通する流通孔が、内電極と外電極で
挟まれた区間に形成されているものである。 （２）請求項２の発明は、連結棒が、外電極の外径より
長く形成され、内電極及び外電極共通の軸線と直交し、
内電極及び外電極それぞれの左右の側壁を貫通して取付
けられ、流通孔が内電極及び外電極の間の区間に加え
て、内電極で囲まれた区間にも形成されているものであ
る。(1) According to the first aspect of the present invention, the connecting rod is a tubular body having both ends open, and a flow hole penetrating the peripheral wall is formed in a section sandwiched between the inner electrode and the outer electrode. (2) In the invention of claim 2, the connecting rod is formed to be longer than the outer diameter of the outer electrode, and is orthogonal to the common axis of the inner electrode and the outer electrode.
It is mounted so as to penetrate the left and right side walls of the inner electrode and the outer electrode, and the flow hole is formed not only in the section between the inner electrode and the outer electrode, but also in a section surrounded by the inner electrode.
【０００５】（３）請求項３の発明は、連結棒が外電極
の半径より短く形成され、複数の連結棒が軸線に対して
放射方向に、上方から見て等角間隔に配されているもの
である。 （４）請求項４の発明は、連結棒が円筒状に形成されて
いるものである。 （５）請求項５の発明は、前記（３）項において、複数
の連結棒は、軸線方向の取付位置が順にずらされている
ものである。(3) According to a third aspect of the present invention, the connecting rods are formed to be shorter than the radius of the outer electrode, and the plurality of connecting rods are arranged radially with respect to the axis and at regular intervals when viewed from above. Things. (4) According to the invention of claim 4, the connecting rod is formed in a cylindrical shape. (5) In the invention of claim 5, in the above-mentioned item (3), the mounting positions of the plurality of connecting rods in the axial direction are sequentially shifted.
【０００６】[0006]
【実施例】この発明の実施例を図１に、図２，図３と対
応する部分に同じ符号を付けて示し、重複説明を省略す
る。この発明では、連結棒４が両端解放の筒状体とさ
れ、その周壁を貫通する流通孔４ｂが、内電極２と外電
極３で挟まれた区間に形成される。DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention is shown in FIG. 1 by assigning the same reference numerals to parts corresponding to those in FIGS. In the present invention, the connecting rod 4 is a tubular body having both ends open, and a flow hole 4b penetrating the peripheral wall is formed in a section sandwiched between the inner electrode 2 and the outer electrode 3.
【０００７】図１Ａ，Ｂの例では、連結棒４が、外電極
３の外径より長く形成され、内電極及び外電極共通の軸
線Ｌと直交し、両電極それぞれの左右の側壁を貫通して
取付けられ、流通孔４ｃが内電極２で囲まれた区間にも
形成される（請求項２）。図１Ｃ，Ｄの例では、連結棒
４は外電極３の半径より短く形成され、２個（一般には
複数個）が軸線Ｌに対して放射方向に取付けられる。そ
の場合、上方から見て連結棒が軸線Ｌに対して等角間隔
（３個の場合は１２０°間隔）に設けると、構造的にも
安定し、経年的な形状の歪を少なくできる。In the example shown in FIGS. 1A and 1B, the connecting rod 4 is formed to be longer than the outer diameter of the outer electrode 3, is perpendicular to the axis L common to the inner electrode and the outer electrode, and penetrates the right and left side walls of both electrodes. The flow hole 4c is also formed in a section surrounded by the inner electrode 2 (claim 2). In the example shown in FIGS. 1C and 1D, the connecting rod 4 is formed shorter than the radius of the outer electrode 3, and two (generally a plurality) of the connecting rods are attached in the radial direction with respect to the axis L. In this case, when the connecting rods are provided at regular intervals with respect to the axis L when viewed from above (in the case of three, at 120 ° intervals), the structure is stable and the distortion of the shape over time can be reduced.
【０００８】図１のレベルセンサでは液体が連結棒４の
中心孔４ａ，流通孔４ｂ（４ｃ）を出入りできるので、
図２の従来例に比べて応答性がよい。また、図３の従来
例のように、外電極３に直接流通孔３ａを設ける必要が
ないので、液位対静電容量の直線性が流通孔３ａによっ
て損なわれることはない。場合によっては、図１Ｃ，Ｄ
の複数の連結棒４を電極の同じ高さの位置ではなく、順
にずらせて、直線性を更に向上させるようにしてもよい
（請求項５）。連結棒４を円筒状とするのが、連結棒４
及びこれに嵌合される両電極の加工（孔の形成）が容易
となるので望ましい（請求項４）。In the level sensor shown in FIG. 1, the liquid can enter and exit the center hole 4a and the communication hole 4b (4c) of the connecting rod 4.
Responsiveness is better than the conventional example of FIG. Further, unlike the conventional example shown in FIG. 3, since there is no need to directly provide the flow hole 3a in the outer electrode 3, the linearity of the liquid level versus the capacitance is not impaired by the flow hole 3a. In some cases, FIGS.
The plurality of connecting rods 4 may be shifted not at the same height position of the electrodes but in order to further improve the linearity (claim 5). The connecting rod 4 is formed in a cylindrical shape.
Further, it is desirable because processing (formation of a hole) of both electrodes fitted to the electrode becomes easy (claim 4).
【０００９】[0009]
【発明の効果】以上述べたように、この発明では連結棒
４を中心孔４ａをもつ筒状体とし、その側壁に流通孔４
ｂ（４ｃ）を設けたので、センサ内部への液体の出入り
が容易となり、応答性を向上できる。この発明では、従
来のように外電極３に直接流通孔３ａを設けることは無
いので、流通孔３ａによって直線性を損なうことはな
い。As described above, according to the present invention, the connecting rod 4 is formed into a cylindrical body having the center hole 4a, and the side wall of the connecting rod 4 has the flow hole 4a.
Since b (4c) is provided, the liquid can easily enter and exit the inside of the sensor, and the responsiveness can be improved. According to the present invention, the flow hole 3a is not directly provided in the outer electrode 3 as in the prior art, so that the flow hole 3a does not impair the linearity.
【図１】Ａ及びＢはそれぞれこの発明の実施例を示す斜
視図及び断面図、Ｃ及びＤはそれぞれこの発明の他の実
施例を示す斜視図及び断面図。1A and 1B are respectively a perspective view and a sectional view showing an embodiment of the present invention, and C and D are respectively a perspective view and a sectional view showing another embodiment of the present invention.
【図２】Ａ及びＢはそれぞれ従来の静電容量式レベルセ
ンサの一例を示す斜視図及び断面図。FIGS. 2A and 2B are a perspective view and a cross-sectional view, respectively, showing an example of a conventional capacitance type level sensor.
【図３】Ａ及びＢはそれぞれ従来の静電容量式レベルセ
ンサの他の例を示す斜視図及び断面図。FIGS. 3A and 3B are a perspective view and a cross-sectional view, respectively, showing another example of a conventional capacitance type level sensor.
Claims (5)
対向して配され、それら両電極がそれぞれを貫通する連
結棒により連結されている静電容量式レベルセンサにお
いて、 前記連結棒が両端解放の筒状体とされ、その周壁を貫通
する流通孔が、前記内電極と外電極で挟まれた区間に形
成されていることを特徴とする静電容量式レベルセン
サ。1. An electrostatic capacitance level sensor in which a cylindrical inner electrode and an outer electrode are concentrically arranged close to and opposed to each other, and both electrodes are connected by connecting rods penetrating therethrough. Is a cylindrical body open at both ends, and a flow hole penetrating the peripheral wall is formed in a section sandwiched between the inner electrode and the outer electrode.
外電極の外径より長く形成され、前記内電極及び外電極
共通の軸線と直交し、その内電極及び外電極それぞれの
左右の側壁を貫通して取付けられ、前記流通孔が前記内
電極及び外電極の間の区間に加えて、前記内電極で囲ま
れた区間に形成されていることを特徴とする静電容量式
レベルセンサ。2. The inner rod according to claim 1, wherein the connecting rod is formed to be longer than an outer diameter of the outer electrode, is perpendicular to an axis common to the inner electrode and the outer electrode, and has left and right side walls of the inner electrode and the outer electrode. Wherein the flow hole is formed in a section surrounded by the inner electrode in addition to a section between the inner electrode and the outer electrode.
電極の半径より短く形成され、複数の前記連結棒が軸線
に対して放射方向に、上方から見て等角間隔に配されて
いることを特徴とする静電容量式レベルセンサ。3. The connecting rod according to claim 1, wherein the connecting rod is formed to be shorter than a radius of the outer electrode, and the plurality of connecting rods are arranged in a radial direction with respect to an axis and at regular intervals when viewed from above. A capacitance type level sensor characterized by the above-mentioned.
であることを特徴とする静電容量式レベルセンサ。4. The capacitance level sensor according to claim 1, wherein the connecting rod is cylindrical.
は、軸線方向の取付位置が順にずらされていることを特
徴とする静電容量式レベルセンサ。5. The capacitance type level sensor according to claim 3, wherein the mounting positions of the plurality of connecting rods in the axial direction are sequentially shifted.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13629795A JP3177628B2 (en) | 1995-06-02 | 1995-06-02 | Capacitive level sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13629795A JP3177628B2 (en) | 1995-06-02 | 1995-06-02 | Capacitive level sensor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH08327435A JPH08327435A (en) | 1996-12-13 |
| JP3177628B2 true JP3177628B2 (en) | 2001-06-18 |
Family
ID=15171893
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP13629795A Expired - Fee Related JP3177628B2 (en) | 1995-06-02 | 1995-06-02 | Capacitive level sensor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3177628B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2016121898A (en) * | 2014-12-24 | 2016-07-07 | 株式会社鷺宮製作所 | Liquid detector, compressor, and air conditioner |
-
1995
- 1995-06-02 JP JP13629795A patent/JP3177628B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH08327435A (en) | 1996-12-13 |
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