JP2000074496A - Heating tank with idle-burning preventive mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the factor of failure by connecting one of pair of electrodes arranged in a hot water tank with a voltage generating source and the other electrode with a current detecting circuit and controlling conduction of a water heater thereby simplifying the operation control arrangement of an apparatus. SOLUTION: An upper electrode 11 is arranged in proximity to a water temperature sensor 3 and closely to the full water level and a lower electrode 12 is arranged in proximity to a heater 2 and closely the bottom face in a hot water tank 1. The upper electrode 11 is connected with a voltage supply 13 and the lower electrode 12 is connected with an operation control section 20 through a current detecting circuit 14. When the water in the hot water tank 1 is at full level, the upper electrode 11 conducts with the lower electrode 12 and the current detecting circuit 14 detects a high current level. When it is at a reduced water level, the electrodes do not conduct and a low current level is detected. These current levels are inputted to the operation control section 20 and idle burning is prevented by interrupting conduction of the heater 2 when the water level is lower than the full water level.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water heating tank provided with an air-burn prevention mechanism for heating a washing water by assembling it in a sanitary washing device for a toilet bowl.

[0002]

2. Description of the Related Art FIG. 11 shows a schematic configuration of a conventional sanitary washing apparatus as a sketch. Reference numeral 1 in the figure denotes a hot water tank (water heating tank) for temporarily storing cleaning water supplied from a water supply pipe and heating it to an appropriate temperature. In the hot water tank 1, a heater (sheath heater) 2 for heating water is attached to a lower portion of a side wall, and a water temperature sensor 3 is attached to a top wall. In addition, a float switch 4 is provided on the top wall, which serves to detect the water level in the hot water tank 1 and to control the power supply to the heater 2 to prevent empty heating.

The cleaning hot water supplied to the hot water tank 1 through the water supply control valve 5, heated by the heater 2, and maintained at an appropriate temperature by the water temperature sensor 3 passes through the suction device 6 and the flow control valve 7 to be cleaned. The hot water is supplied to an injection nozzle 8 for injecting the hot water toward a local area. The other reference numerals in the figure are: 20 is an operation control unit of the sanitary washing device, 21 is an operation panel of the device, 22 is a water temperature setting circuit, 23 is an operation display unit that shows operation status by a lamp (LED), and 23a is a display Circuit.

As shown in FIG. 12, the float switch 4 holds a cylindrical float 4b loosely fitted to a vertically oriented core shaft 4a at a lowered position indicated by a chain line by a stopper 4c. When the float 4b is pushed up to the position indicated by the solid line with the rise of the water surface in the hot water tank 1, the magnet 4d attached to the inner peripheral surface of the float 4b is connected to the reed switch 4e attached to the core shaft 4a. Approach,
The float switch 4 is turned on to energize the heater 2.

[0005] However, if the sanitary washing device is once detached for cleaning the toilet or the like and then accidentally attached to the toilet in an inclined state, the float switch 4 is used for the water level in the hot water tank 1. Although the water level is lower than the water level when the water is full, the float 4b may be displaced up along the core axis 4a, and the float switch 4 may be turned on. If this happens, hot water tank 1
There is a high possibility that the air will be fired.

Therefore, a conventional sanitary washing device is shown in FIG.
As shown in (2), when the sanitary washing device is attached to the toilet in an inclined state, the inclination detector 24 for detecting the inclination is installed.

[0007]

However, when the inclination detector 24 is assembled in addition to the float switch 4, the cost of manufacturing the sanitary washing device increases and the structure of the operation control unit 20 becomes complicated. Combined with this, failure factors increase. Therefore, an object of the present invention is to provide a simpler air-fired alternative to the conventional float switch 4 and the tilt detector 24 in order to prepare the case where the sanitary washing device is attached to the toilet in an inclined state by mistake. An object of the present invention is to provide a water heating tank provided with a prevention mechanism.

[0008]

In order to achieve the above-mentioned object, a water heating tank provided with an empty heating prevention mechanism according to the present invention comprises a water heating tank at a lower portion in a tank provided with a water supply port and a tap hole. When the water in the tank rises to near the water level when the tank is full, both of the electrodes come into contact with water and fall below the water level when the water is full. When one or both of them are arranged in the tank so as to be separated from the water surface, a voltage generation source is connected to the one electrode, and a current flowing between the pair of electrodes is connected to the other electrode. A current detection circuit for measuring is connected, and a control circuit is provided for energizing the heater when the current detection circuit detects a current higher than a set level. One of the pair of electrodes may be disposed at an upper part in the tank, and the other may be disposed at a lower part. In addition, at least one of the pair of electrodes may be a conductive exterior member of the heater or the water temperature sensor. When the water heating tank is incorporated in a sanitary washing device for a toilet, a scan signal for an operation indicator lamp generated by an operation control unit of the device may be used as the voltage generation source. Then, an insulating component for protecting the operation control unit may be interposed in a circuit connecting the operation control unit and the electrode.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment in which the present invention is applied to a hot water tank of a sanitary washing device for a toilet bowl will be described.
This will be described with reference to FIGS. FIG. 1 is a diagram schematically showing the entire configuration of the sanitary washing device. The basic configuration is common to the conventional one shown in FIG. That is, 1 is a hot water tank (water heating tank), 2 is a heater (seed heater), 3 is a water temperature sensor, 5 is a water supply control valve, 6 is a suction device, 7 is a flow control valve, and 8 is hot water for washing. It is an injection nozzle. And 20, an operation control unit of the device;
21 is an operation panel, 22 is a water temperature setting circuit, 23 is an operation display section, and 23a is a display circuit.

Next, components different from those of the conventional apparatus shown in FIG. 11 will be described. First, in the hot water tank 1, a location near the water level at the time of full water close to the water temperature sensor (FIG. 4)
B), an upper electrode (electrode) 11 is provided, and a lower electrode (electrode) 12 is provided near the bottom surface close to the heater 2. The upper electrode 11 is connected to a power supply (voltage generation source) 13 for applying a voltage. Further, a current detection circuit 14 is interposed in a circuit for connecting the lower electrode 12 to the operation control unit 20.

In this embodiment, both electrodes 11, 12, which are made of small metal plates, a power supply 13, and a current detection circuit 14, constitute an idling prevention mechanism. The operation of the water supply control valve 5 is controlled based on an operation signal of an operation switch (not shown) provided on the operation panel 21.

Next, the operation of the idling prevention mechanism will be described. First, the operation when the sanitary washing device is correctly and horizontally attached to the toilet will be described with reference to FIGS. As shown in FIG. 4B, when the water surface in the hot water tank 1 has reached the full water level a that causes the upper electrode 11 to come into contact with water (that is, the water temperature sensor 3 comes into contact with water). As shown by arrows in FIG. 2, the upper electrode 11 and the lower electrode 12 are electrically connected through the water layer. Therefore, based on the electric conductivity of water, the current value detected by the current detection circuit 14 is As shown in graph A of FIG.

However, as shown in FIG. 4A, the water level in the hot water tank 1 falls below the upper electrode 11 (that is, the water temperature sensor 3 does not come into contact with water), and 3, the current value detected by the current detection circuit 14 is significantly smaller than the graph A as shown in the graph B of FIG. 3 based on the electric conductivity of the air on the water surface. Therefore, by inputting this current value to a control circuit (not shown) incorporated in the operation control unit 20, when the water level in the hot water tank 1 is lower than the full water level a, the power to the heater 2 is supplied. Can be stopped to prevent empty firing.

Next, the operation when the sanitary washing device is mistakenly attached to the toilet in an inclined state will be described with reference to FIGS. First, as shown in FIG. 5B, when the water level in the hot water tank 1 has reached the water level a when it is full, even if the hot water tank 1 is inclined as shown in FIG. Since 11 is in contact with water, the current detection circuit 14 detects the high-level current value shown in the graph A of FIG.

However, as shown in FIG. 5A, when the water level in the hot water tank 1 is in the lowered water level b when the water level in the hot water tank 1 is lowered, the upper electrode 11 does not touch the water level, so that the current detection circuit 14 Surely detects the low-level current value shown in the graph B of FIG. Accordingly, also in this case, when the current value is reported to the control circuit, when the inside of the hot water tank 1 is in a water-reduced state, the power supply to the heater 2 can be reliably stopped to prevent idling.

FIG. 6 shows a second embodiment of the present invention. The difference from the first embodiment lies in that the scan signal branched from the display circuit 23a and amplified by the buffer amplifier 25 is replaced by the power supply 13 of the first embodiment.

In order to protect the operation control unit 20 and to insulate the electrodes 11 and 12 from the operation control unit 20,
As shown in FIG. 6, it is preferable that an insulating component such as a capacitor 26 and a transformer is interposed in a circuit that constitutes the idling prevention mechanism. The operation of the empty firing prevention mechanism of this embodiment is as follows.
According to the first embodiment.

Next, FIGS. 7 to 9 show a third embodiment of the present invention. The difference from the second embodiment is that the pair of upper electrode 11 and lower electrode 12 are omitted, and instead, the conductive members constituting the water temperature sensor 3 and the heater 2 are used as the electrodes.

That is, as shown in FIG.
Is used as a substitute for the upper electrode 11. In the figure, 3b is a thermistor coated with glass, and 3c is a lead wire. Also, as shown in FIG.
Metal protective tube 2 constituting heater (seeds heater) 2
a serves as a substitute for the lower electrode 12. A heater wire 2b embedded in an insulating material 2c is accommodated in the protective tube 2a.

Then, as shown in FIG. 7, the upper electrode 1
A connection circuit is provided between the protection tube 3a also serving as 1 and the voltage generation source 13 (23a), and a connection circuit between the protection tube 2a also serving as the lower electrode 12 and the current detection circuit 14. The operation of this embodiment is similar to that of the first embodiment.

By the way, according to the circuit configuration of this embodiment, the performance of the insulating material 2c may deteriorate with time due to the heat generated by the heater 2.
The AC 100 V supplied to b may be applied to the operation control unit 20. However, as shown in the circuit diagram of FIG. 6, operation control is performed by interposing an insulating component such as a capacitor 26 in a circuit connecting each of the upper electrode 3a and the lower electrode 2a and the operation control unit 20. The part 20 can be reliably protected.

Next, FIG. 10 shows a fourth embodiment of the present invention. The difference from the third embodiment is that the lower electrode
In this embodiment, the lower electrode 12 similar to that of the first embodiment is used without using the protection tube 2a of the heater 2. by this,
The protection measures for the operation control unit 20, which are required in the third embodiment, are not required.

Incidentally, in the configuration shown in each of the above embodiments,
The object of the present invention is achieved even if the structure of the details is changed as appropriate. For example, the pair of electrodes 11 and 12 may be provided side by side at a predetermined interval in the vicinity of the full water level a, instead of the two upper and lower locations in the hot water tank 1. Further, the form of the two electrodes 11 and 12 and the location of attachment to the hot water tank 1 are not limited to those shown in the drawings. The conductive members forming the heater 2 and the water temperature sensor 3 are not limited to the protection tubes 2a and 3a.
A metal fitting for attaching to the hot water tank 1 may be used. And the hot water tank 1 is not limited to the one for the sanitary washing device.

[0024]

As is clear from the above description, the water heating tank provided with the idle-heating prevention mechanism according to the present invention has the following practically excellent effects. (A) As in the prior art described at the beginning, the problem that the float switch for detecting the water level in the hot water tank malfunctions when the hot water tank is installed at an angle can be solved. (B) It is not necessary to provide a means for detecting the inclination of the hot water tank to cope with this problem of malfunction. (C) In the case of a hot water tank for a sanitary washing device, if a scan signal for an operation indicator lamp is used as a power supply for energizing a pair of electrodes, the configuration of the operation control unit can be simplified accordingly. (D) If at least one of the pair of electrodes is replaced with a heater and a metal protection tube of a water temperature sensor which are components of the hot water tank, the configuration of the hot water tank can be simplified accordingly. (E) When the protection tube of the heater is used as an electrode,
Even if the electric insulation of the heater deteriorates with time, the operation control unit of the sanitary washing device is reliably protected by the insulating parts.

[Brief description of the drawings]

FIG. 1 shows a first embodiment in which the present invention is applied to a sanitary washing device for a toilet bowl, and is a sketch drawing of the overall configuration of the sanitary washing device.

FIG. 2 is a circuit diagram of a current supply and current detection circuit between a pair of electrodes according to the first embodiment;

FIG. 3 is a graph comparing the amount of electricity between two electrodes when a pair of electrodes are in contact with water in a hot water tank and when only one is in contact with water in the hot water tank. is there.

FIG. 4 is an explanatory diagram of a positional relationship between a water surface in the tank and an upper electrode when the hot water tank is installed horizontally.

FIG. 5 is an explanatory diagram of a positional relationship between a water surface in the tank and an upper electrode when the hot water tank is installed inclined.

FIG. 6 is a view corresponding to FIG. 1, showing a second embodiment of the present invention.

FIG. 7 shows a third embodiment of the present invention, and is a longitudinal sectional view of a hot water tank.

FIG. 8 is a partial vertical sectional view of the water temperature sensor according to the first embodiment;

FIG. 9 is a partial vertical sectional view of the heater according to the third embodiment.

FIG. 10 is a longitudinal sectional view of a hot water tank, showing a fourth embodiment of the present invention.

FIG. 11 is a diagram corresponding to FIG. 1, showing a conventional example.

FIG. 12 is a partially cutaway side view of the float switch.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hot water tank (water heating tank) 2 Heater 2a Protective tube (conductive sheathing material also serving as electrode) 2b Heater wire 2c Insulating material 3 Water temperature sensor 3a Protective tube (conductive sheathing material also serving as electrode) 3b Thermistor 3c Lead Line 4 Float switch 4a Core shaft 4b Float 4c Stopper 4d Magnet 4e Reed switch 5 Water supply control valve 6 Suction device 7 Flow control valve 8 Injection nozzle 11 Upper electrode (electrode) 12 Lower electrode (electrode) 13 Power supply (voltage source) 14 Current detection circuit 20 Operation control unit 21 Operation panel 22 Water temperature setting circuit 23 Operation display unit 24 Tilt detector 25 Buffer amplifier 26 Capacitor (insulation parts) a Water level when full b Water level when water is reduced

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Hiroyuki Adachi 1 Aichi-cho, Kasugai-shi, Aichi, Japan Aichi Electric Co., Ltd.

Claims (5)

[Claims] 1. In a tank provided with a water supply port and a tap hole,
When a heater for water heating is provided at the lower part and a water temperature sensor is provided at the upper part, when a pair of electrodes touch the water when the water in the tank rises to near the water level when the tank is full, both electrodes come in contact with water and become full. When the water level falls below the water level, one or both of them are arranged in the tank so as to be separated from the water surface, a voltage source is connected to the one electrode, and the other electrode is between the pair of electrodes. When a current detection circuit that measures the current flowing through is connected, and the current detection circuit detects a current equal to or higher than a set level,
A water heating tank provided with an empty heating prevention mechanism, wherein a control circuit for energizing the heater is provided. 2. The water heating tank according to claim 1, wherein one of the pair of electrodes is disposed in an upper part of the tank, and the other is disposed in a lower part of the tank. 3. The water heating system according to claim 1, wherein at least one of the pair of electrodes uses a conductive exterior member of the heater or the water temperature sensor. For tank. 4. The water heating tank is incorporated in a sanitary washing device for a toilet bowl, and the voltage generation source is a scan signal for an operation display lamp generated by an operation control unit of the device. A water heating tank provided with the idle-heating prevention mechanism according to claim 1. 5. The water provided with an idle-heating prevention mechanism according to claim 4, wherein an insulating component for protecting the operation control unit is interposed in a circuit connecting the operation control unit and the electrode. Heating tank.