JPH0646661U - Water level detector for dishwasher - Google Patents
Water level detector for dishwasherInfo
- Publication number
- JPH0646661U JPH0646661U JP8404592U JP8404592U JPH0646661U JP H0646661 U JPH0646661 U JP H0646661U JP 8404592 U JP8404592 U JP 8404592U JP 8404592 U JP8404592 U JP 8404592U JP H0646661 U JPH0646661 U JP H0646661U
- Authority
- JP
- Japan
- Prior art keywords
- water level
- reference electrode
- electrode
- water
- level detection
- 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
Abstract
(57)【要約】
【目的】 小型で信頼性が高く、しかも安価な食器洗浄
機の水位検出装置を提供することである。
【構成】 洗浄槽２に連通する水溜部３には、その底面
近傍で同一高さに位置する基準電極９および比較電極１
０と、所望水位に位置する水位検知電極１１とが設けら
れている。基準電極９と比較電極１０との間の電位差
と、基準電極９と水位検出電極１１との間の電位差の相
対的な差が比較され、この差がなくなれば所望水位に達
したと判断されるようになっている。
(57) [Abstract] [Purpose] To provide a small, highly reliable and inexpensive water level detection device for a dishwasher. [Structure] In a water reservoir 3 communicating with a cleaning tank 2, a reference electrode 9 and a reference electrode 1 located at the same height in the vicinity of the bottom surface thereof.
0 and a water level detection electrode 11 located at a desired water level are provided. The relative difference between the potential difference between the reference electrode 9 and the comparison electrode 10 and the potential difference between the reference electrode 9 and the water level detection electrode 11 is compared. If this difference disappears, it is determined that the desired water level has been reached. It is like this.
Description
【０００１】[0001]
本考案は食器洗浄機の水位検出装置に関するものである。 The present invention relates to a water level detecting device for a dishwasher.
【０００２】[0002]
従来、食器洗浄機の水位検出装置としては、フロート式、圧力式あるいは電気 式のものがある。 前記フロート式のものとしては、洗浄槽に連通するフロート室内にフロートを 配設し、このフロートをその浮力により水位の変化に応じて昇降させて、フロー ト室内の所定水位に設けたマイクロスイッチ，リードスイッチ等をオン，オフさ せることにより、水位を検出するようにしたものがある。 しかし、このフロート式では、昇降動作を安定させるためにフロート自身を大 きくする必要があり、食器洗浄機自体が大型化するという問題点がある。 Conventionally, as a water level detecting device for a dishwasher, there are a float type, a pressure type and an electric type. As the float type, a float is installed in a float chamber communicating with the cleaning tank, and the float is moved up and down according to the change of the water level by its buoyancy, and a micro switch is installed at a predetermined water level in the float chamber. There is a device that detects the water level by turning on and off a reed switch. However, in this float type, it is necessary to enlarge the float itself in order to stabilize the lifting operation, and there is a problem that the dishwasher itself becomes large.
【０００３】 前記圧力式のものとしては、洗浄槽内に収容した洗浄水の所定位置での圧力を 検出することにより、この検出圧力値に基づいて水位を算出するようにしたもの がある。 しかし、この圧力式では、この圧力を検出するセンサ自体が高価である。As the pressure type, there is one in which the pressure of the wash water contained in the wash tank is detected at a predetermined position and the water level is calculated based on the detected pressure value. However, in this pressure type, the sensor itself for detecting this pressure is expensive.
【０００４】 前記電気式のものとしては、例えば実開昭62─139462号に記載のように、洗浄 槽に連通するタンク内の所定水位に少なくとも一対の電極を設けるようにしたも のがある。このものでは、水位が上昇して電極間が通電された場合に、水位を検 出できるようになっている。 しかし、この電気式では、洗浄水に汚れ等により泡が発生した場合、この泡に より電極間が導通されて所定水位に達する前にこの水位に達していると判断され ることがある。また、洗浄水自身の汚れ、あるいは、電極の表面に形成された絶 縁被膜により、検出される電位差が変化して誤動作する恐れがある。 本考案は前記問題点に鑑み、小型で信頼性が高く、しかも安価な食器洗浄機の 水位検出装置を提供することを目的とする。As the electric type, for example, as disclosed in Japanese Utility Model Application Laid-Open No. 62-139462, at least a pair of electrodes is provided at a predetermined water level in a tank communicating with a cleaning tank. With this device, the water level can be detected when the water level rises and electricity is applied between the electrodes. However, in this electric system, when bubbles are generated in the wash water due to dirt or the like, it may be determined that the bubbles reach the water level before the electrodes reach the predetermined water level due to the conduction between the electrodes. In addition, the dirt of the cleaning water itself or the insulating film formed on the surface of the electrode may change the detected potential difference and cause malfunction. The present invention has been made in view of the above problems, and an object thereof is to provide a compact, highly reliable, and inexpensive water level detection device for a dishwasher.
【０００５】[0005]
本考案は前記目的を達成するため、洗浄槽に連通する水溜部に、その底面近傍 で同一高さに位置する基準電極および比較電極と、所望水位に位置する水位検知 電極とを設けて、基準電極と比較電極との間の電位差と、基準電極と水位検知電 極との間の電位差とを比較することにより、水位を検出するようにしたものであ る。 In order to achieve the above object, the present invention provides a water reservoir communicating with a cleaning tank with a reference electrode and a reference electrode located at the same height in the vicinity of the bottom surface thereof and a water level detection electrode located at a desired water level. The water level is detected by comparing the potential difference between the electrode and the reference electrode with the potential difference between the reference electrode and the water level detection electrode.
【０００６】[0006]
前記構成によれば、基準電極と比較電極との間の電位差と、基準電極と水位検 出電極との間の電位差の相対的な差を比較することにより、この差が小さくなれ ば所望水位に達したと判断する。これにより、たとえ洗浄水の水面に泡が発生し てこの泡により基準電極と水位検出電極とが導通したとしても、その電位差は比 較電極と基準電極との間の電位差と相違するので、正常な導通状態でないことが 判別される。 According to the above configuration, by comparing the potential difference between the reference electrode and the reference electrode and the relative difference in potential difference between the reference electrode and the water level detection electrode, if this difference becomes small, the desired water level is obtained. Judge that it has reached. As a result, even if bubbles are generated on the surface of the washing water and the bubbles cause conduction between the reference electrode and the water level detection electrode, the potential difference is different from the potential difference between the comparison electrode and the reference electrode. It is determined that it is not in a proper conduction state.
【０００７】[0007]
次に、本考案の一実施例について添付図面に従って説明する。 図１は食器洗浄機を示し、本体１内には洗浄槽２が形成されている。洗浄槽２ の下部は水溜部３となっており、この水溜部３から吸引管４が延びている。ポン プ５は、吸引管４内の洗浄水を流動させて前記吸引管４の先端に設けた噴霧ノズ ル６を介して食器かご７内の食器８に吹き付けることにより、循環させるように なっている。 Next, an embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 shows a dishwasher, and a washing tank 2 is formed in a main body 1. The lower part of the cleaning tank 2 is a water reservoir 3, and a suction pipe 4 extends from the water reservoir 3. The pump 5 is circulated by flowing the wash water in the suction pipe 4 and spraying it onto the dishes 8 in the dish basket 7 through the spray nozzle 6 provided at the tip of the suction pipe 4. There is.
【０００８】 ところで、前記水溜部３には、図１に示すように、洗浄水加熱用のヒータ３ａ と、合計３つの電極９，１０，１１を備えた水位検知装置とが設けられている。 基準電極９および比較電極１０は水溜部３の下面近傍の同一高さで、前記ヒータ ３ａの上方に配置され、水位検知電極１１は水溜部３上方側の所望水位に配置さ れている。By the way, as shown in FIG. 1, the water reservoir 3 is provided with a heater 3a for heating washing water and a water level detecting device having a total of three electrodes 9, 10, 11. The reference electrode 9 and the comparison electrode 10 are arranged at the same height near the lower surface of the water reservoir 3 and above the heater 3a, and the water level detection electrode 11 is arranged at a desired water level above the water reservoir 3.
【０００９】 前記電極９，１０間および９，１１間の電位差を検出するための回路は、図２ に示すようになっている。基準電極９はアースされている。一方、比較電極１０ は抵抗Ｒ1を介してアース接続されるとともに、抵抗Ｒ2を介して電極ＶDに接続 され、水位検知電極１１は抵抗Ｒ3を介して電源ＶDに接続されている。前記比較 電極１０と抵抗Ｒ2の間はバッファを構成する第１オペアンプ１２の（＋）入力 端子に接続され、前記水位検知電極１１と抵抗Ｒ3の間は同じくバッファを構成 する第２オペアンプ１３の（＋）入力端子に接続されている。前記第１オペアン プ１２の出力端子は、抵抗Ｒ4を介して減算回路を構成する第３オペアンプ１４ の（＋）入力端子に接続されている。一方、第２オペアンプ１３の出力端子は、 抵抗Ｒ5を介して前記第３オペアンプ１４の（−）入力端子に接続されている。 そして、この第３オペアンプ１４の（−）入力端子は抵抗Ｒ6を介してアース接 続され、出力端子は図示しないマイクロコンピュータのＡ／Ｄ入力ポートに接続 されている。また、第３オペアンプ１４の（＋）入力端子と、第３オペアンプ１ ４の出力端子との間にはフィードバック用の抵抗Ｒ7が接続されている。A circuit for detecting the potential difference between the electrodes 9 and 10 and between the electrodes 9 and 11 is as shown in FIG. The reference electrode 9 is grounded. On the other hand, the reference electrode 10 is grounded via the resistor R 1 and connected to the electrode V D via the resistor R 2 , and the water level detection electrode 11 is connected to the power source V D via the resistor R 3 . . The reference electrode 10 and the resistor R 2 are connected to the (+) input terminal of the first operational amplifier 12 which forms a buffer, and the water level detection electrode 11 and the resistor R 3 also form a second operational amplifier 13 which also forms a buffer. It is connected to the (+) input terminal of. The output terminal of the first operational amplifier 12 is connected to the (+) input terminal of the third operational amplifier 14 1 forming the subtraction circuit via the resistor R 4 . On the other hand, the output terminal of the second operational amplifier 13 is connected to the (−) input terminal of the third operational amplifier 14 via the resistor R 5 . Then, the third operational amplifier 14 (-) input terminal is grounded connected via a resistor R 6, and an output terminal connected to the A / D input port of a microcomputer (not shown). A feedback resistor R 7 is connected between the (+) input terminal of the third operational amplifier 14 and the output terminal of the third operational amplifier 14.
【００１０】 前記構成の水位検出装置では、水溜部３に洗浄水が注水されると、まず、比較 電極１０が基準電極９に導通してアースされるため、第１オペアンプ１２の（＋ ）入力端子に入力されている電圧値が水の抵抗値に応じた電圧値まで低下する。 その後、水位が水位検知電極１１に達すれば、この水位検知電極１１も前記基準 電極９を介してアースされるので、第２オペアンプ１３の（＋）入力端子に入力 されている電圧値も水の抵抗値に応じた電圧値まで低下する。このように、各電 極９，１０間および９，１１間では、共に洗浄水を介して電圧が降下するので、 ほぼ等しい値となる。したがって、第３オペアンプ１４では電位差がないと判断 され、マイクロコンピュータでは前記第３オペアンプ１４からの入力値に基づい て所望の水位が得られたと判断して注水を停止する。In the water level detecting device having the above-described configuration, when washing water is poured into the water reservoir 3, first, the comparison electrode 10 is electrically connected to the reference electrode 9 and grounded, so that the (+) input of the first operational amplifier 12 is input. The voltage value input to the terminal drops to the voltage value corresponding to the resistance value of water. After that, when the water level reaches the water level detection electrode 11, the water level detection electrode 11 is also grounded via the reference electrode 9, so that the voltage value input to the (+) input terminal of the second operational amplifier 13 is also water. It decreases to the voltage value according to the resistance value. In this way, the voltage drops between the electrodes 9 and 10 and between the electrodes 9 and 11 through the wash water, and therefore the values are substantially equal. Therefore, the third operational amplifier 14 determines that there is no potential difference, and the microcomputer determines that the desired water level has been obtained based on the input value from the third operational amplifier 14 and stops water injection.
【００１１】 ここで、洗浄水の水面に汚れ等により泡が発生した場合、所望水位に達する前 に、この泡により基準電極９と水位検知電極１１との間が導通される。しかしな がら、泡の電気抵抗は洗浄水の電気抵抗に比べて大きいため、第２オペアンプ１ ３に入力される電圧値は第１オペアンプ１２に入力される電圧値に比べて低下し ない。したがって、第３オペアンプ１４では、第１オペアンプ１２からの入力値 と第２オペアンプ１３からの入力値との間に差を出力する。マイクロコンピュー タでは、第３オペアンプ１４からの出力値に基づいて洗浄水が所望水位に達して いないと判断して注水を続行する。その後、前述のように第３オペアンプ１４で 入力電圧に差がなくなった時点で注水を停止する。Here, when bubbles are generated on the surface of the wash water due to dirt or the like, the bubbles establish electrical connection between the reference electrode 9 and the water level detection electrode 11 before the desired water level is reached. However, since the electric resistance of bubbles is larger than the electric resistance of washing water, the voltage value input to the second operational amplifier 13 does not decrease compared to the voltage value input to the first operational amplifier 12. Therefore, the third operational amplifier 14 outputs the difference between the input value from the first operational amplifier 12 and the input value from the second operational amplifier 13. The microcomputer determines that the wash water has not reached the desired water level based on the output value from the third operational amplifier 14 and continues water injection. After that, as described above, the water injection is stopped when the input voltage of the third operational amplifier 14 has no difference.
【００１２】 このように、前記水位検出装置では、洗浄水の水面に泡が発生しても、各電極 間の電位差を検出するようにしているので、誤動作することがない。そして、前 記電極が洗浄水によって汚れ、たとえ表面に絶縁被膜が形成されたとしても、各 電極間の電位差は相対的に変化して一定関係を維持するので、従来のように早期 に測定不能となることはない。As described above, in the water level detecting device, even if bubbles are generated on the surface of the wash water, the potential difference between the electrodes is detected, so that no malfunction occurs. Even if the electrodes are contaminated with cleaning water and an insulating film is formed on the surface, the potential difference between the electrodes changes relatively and maintains a constant relationship, which makes it impossible to measure quickly as in the past. It never becomes.
【００１３】 また、洗浄中に水漏れ等のトラブルが発生して水位が低下した場合には、まず 、基準電極９と水位検出電極１１との間が絶縁状態となった後、基準電極９と比 較電極１０との間が絶縁状態となる。したがって、各電極間の電位差の変化が生 じるので、この状態をも検出することができ、ブザー等の報知手段を設けたり、 ヒータ３ａへの通電を停止したりすれば、空焚き等の心配もなくなる。When a trouble such as water leakage occurs during cleaning and the water level is lowered, first, the reference electrode 9 and the water level detection electrode 11 are electrically insulated, and then the reference electrode 9 is disconnected. An insulation state is formed between the comparison electrode 10 and the comparison electrode 10. Therefore, since a change in the potential difference between the electrodes occurs, it is possible to detect this state as well, and by providing a notification means such as a buzzer or by stopping the energization of the heater 3a, it is possible to detect that the heater 3a is not heated. No worries.
【００１４】[0014]
以上の説明から明らかなように、本考案に係る食器洗浄機の水位検出装置によ れば、比較電極、基準電極および水位検出電極を設けただけの構造であるので、 従来の水位検出用フロートのように水溜部の占有スペースが大きくなることがな く、必要最小限に抑えることが可能となる。 また、前記電極は圧力センサを設ける場合に比べて非常に安価である。 さらに、比較電極と基準電極との間の電位差を基準電極と水位検出電極との間 の電位差と比較するようにしているので、水面に泡が発生して基準電極と水位検 出電極とが導通したとしても、水位が上昇していると誤って検出されてしまうこ とがない。しかも、洗浄時には前記各電極は水没して一様に汚れるので、従来の 電気式のもののように早期に検出不能となることがない上、水漏れ等の異常によ り水位が低下したことも検出可能である。 As is clear from the above description, the water level detecting device for the dishwasher according to the present invention has the structure in which only the reference electrode, the reference electrode and the water level detecting electrode are provided, and thus the conventional float for detecting the water level is used. As in the above, the space occupied by the water reservoir does not become large, and it is possible to minimize it to the necessary minimum. Also, the electrodes are much cheaper than when a pressure sensor is provided. Further, since the potential difference between the reference electrode and the reference electrode is compared with the potential difference between the reference electrode and the water level detection electrode, bubbles are generated on the water surface and the reference electrode and the water level detection electrode are electrically connected. Even if you do, you will not be mistakenly detected that the water level is rising. Moreover, since each electrode is submerged in water and uniformly soiled during cleaning, it does not become undetectable as early as the conventional electric type, and the water level may drop due to an abnormality such as water leakage. It can be detected.
【図１】 本実施例に係る食器洗浄機の正面断面図であ
る。FIG. 1 is a front cross-sectional view of a dishwasher according to this embodiment.
【図２】 図１の水位検出装置の回路図である。FIG. 2 is a circuit diagram of the water level detection device of FIG.
２…洗浄槽、３…水溜部、９…基準電極、１０…比較電
極、１１…水位検知電極。2 ... cleaning tank, 3 ... water reservoir, 9 ... reference electrode, 10 ... comparison electrode, 11 ... water level detection electrode.
Claims (1)
傍で同一高さに位置する基準電極および比較電極と、所
望水位に位置する水位検知電極とを設けて、基準電極と
比較電極との間の電位差と、基準電極と水位検知電極と
の間の電位差とを比較することにより、水位を検出する
ようにしたことを特徴とする食器洗浄機の水位検出装
置。1. A water reservoir communicating with a cleaning tank is provided with a reference electrode and a reference electrode located at the same height in the vicinity of the bottom surface thereof, and a water level detection electrode located at a desired water level. A water level detection device for a dishwasher, wherein the water level is detected by comparing the potential difference between the reference electrode and the water level detection electrode.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8404592U JPH0646661U (en) | 1992-12-07 | 1992-12-07 | Water level detector for dishwasher |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8404592U JPH0646661U (en) | 1992-12-07 | 1992-12-07 | Water level detector for dishwasher |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0646661U true JPH0646661U (en) | 1994-06-28 |
Family
ID=13819543
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP8404592U Pending JPH0646661U (en) | 1992-12-07 | 1992-12-07 | Water level detector for dishwasher |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0646661U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2020114526A (en) * | 2020-04-27 | 2020-07-30 | 三菱電機株式会社 | Dishwasher |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS62117591A (en) * | 1985-11-18 | 1987-05-29 | 株式会社東芝 | Water level measuring apparatus of washing machine |
-
1992
- 1992-12-07 JP JP8404592U patent/JPH0646661U/en active Pending
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS62117591A (en) * | 1985-11-18 | 1987-05-29 | 株式会社東芝 | Water level measuring apparatus of washing machine |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2020114526A (en) * | 2020-04-27 | 2020-07-30 | 三菱電機株式会社 | Dishwasher |
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