JP3122959B2 - Electric water heater - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric water heater capable of heating and keeping water contained in a container and purifying the water.

[0002]

2. Description of the Related Art In recent years, electric water heaters have been used not only as simple household items that can simply heat and heat water but also as means for converting water into delicious water in urban areas. Hereinafter, a conventional electric water heater will be described with reference to the drawings. FIG. 4 is a partial cross-sectional block diagram showing a configuration of a conventional electric water heater. In the figure, it comprises a container 2 of the upper surface opening and closing port for accommodating a liquid 18 such as water to the inside of the main body container 1, covering the upper in the lid 3. Further, a discharge port 9 for discharging the liquid 18 inside the container 2 is provided at an upper part of the main body container 1.
And a motor 1 through a discharge port 6 provided on the bottom surface of the container 2.
A water passage is formed up to the discharge port 9 via the electric pump 7 driven by 3 and the water pipe 8. The outer bottom of the container 2 is provided with a heating source 4 for heating the liquid 18 and a temperature sensor 5 for detecting the temperature of the liquid 18. Also, the main body container 1
An operation knob 14 and a variable resistor 15 operated by the operation are provided in the vicinity of the discharge port 9 above. Further, the control means 19 for controlling the operation of the whole electric water heater is provided with the main body container 1.
The control means 19 includes a temperature detecting means 11 for detecting the temperature of the liquid 18 by the temperature sensor 5, and temperature information detected by the temperature detecting means 11. Heating and insulation control means 10 for controlling the energization of the heating source 4 to control the heating or insulation operation based on the
And drive circuit means 12 for driving the motor 7 for rotating the electric pump 7.

The operation of the above configuration will be described. The control means 19 controls the connection of the heating source 4 to a commercial AC power supply 17 to heat the liquid 18 filled in the container 2, and the temperature of the liquid 18 is constantly detected by the temperature sensor 5. After the boiling, the temperature is controlled to be a predetermined temperature. Also, in response to a user's request for pumping by rotating the operation knob 14, a drive voltage corresponding to the rotational position of the variable resistor 15 is applied to the motor 13, and the rotation drives the electric pump 7 to discharge liquid. . In this case, at the rotation position when the operation knob 14 is not rotated, the motor drive voltage is equal to or lower than the starting voltage of the motor 13 and the motor 13 does not rotate. The drive voltage rises due to the rotation, and the motor 13 rotates. At this time, as the rotation angle of the operation knob 14 increases, the drive voltage increases, the rotation speed of the motor 13 increases, and the discharge amount of pumping increases. Further, when the operator releases the hand after rotating the operation knob 14, the motor 13 is automatically returned to the position before the operation by a spring or the like, and the motor 13 is stopped.

[0004]

In such a conventional electric water heater, the boiling state must be continued for a long time in order to remove the calcium component in the water to such an extent that it does not matter. And there was the problem of spending power.

An object of the present invention is to solve the above-mentioned problems, and an object of the present invention is to provide an electric water heater capable of removing unnecessary substances such as calcium components without continuing a boiling state for a long time.

[0006]

In order to achieve the above object, the present invention provides a container for containing a liquid, a heating source for heating and keeping the liquid, and a sensor for detecting the temperature of the liquid. A temperature detecting element, a filtering means for removing unnecessary substances in the liquid, a circulating means for forcibly circulating the liquid through the filtering means , and a predetermined temperature or less during water heating.
When it reaches above, circulation is completed by boiling for a certain period of time
The circulation means is driven so that the amount of circulation is
To the liquid volume in the container detected from the temperature detected by the temperature detection element.
Accordingly, the larger the liquid volume, the more circulation per unit time.
An electric water heater that is controlled to be increased the amount, Yunie
If the temperature reaches or exceeds the specified temperature during the curing, the boiling point is maintained for a specified period of time.
Drive the circulation means so as to complete the circulation by rising,
The amount of circulation was detected from the detected temperature of the temperature detecting element.
Depending on the liquid volume in the container, the larger the liquid volume,
An electric water heater that controls the circulation amount per unit time to be large .

[0007]

SUMMARY OF invention as the following, the liquid volume in the kettle
Depending on the volume of liquid per unit time
And circulate for a certain period of time until boiling is complete.
Ensures complete circulation and removes unnecessary substances
It is controlled to be.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the electric water heater of the present invention will be described below with reference to the drawings. FIG. 1 is a partial sectional block diagram showing the configuration of the present embodiment. The same components as those of the conventional example shown in FIG. 4 are denoted by the same reference numerals, and detailed description is omitted. The present invention differs from the conventional example in that a switch 20 is provided in the middle of the water channel to branch the water channel, and one of the branches is connected to the discharge port 9 and the other is connected to the circulation discharge port 22. The switching device 20 includes a valve 21, and switches and connects the water guide pipe 8 to one of the discharge port 9 and the circulation discharge port 22. When the operation knob 14 is not operated, the valve 2
Reference numeral 1 denotes a state in which the water channel is switched to the circulation discharge port 22. When the operation knob 14 is rotated for the pumping operation, the valve 21 is driven so that the water channel is switched to the discharge port 9. I have. Further, a filtration device 23 for filtering unnecessary substances such as a calcium component is provided below the circulation discharge port 22.
The liquid discharged from the circulation discharge port 22 is filtered.
Further, the control unit 19 determines the circulation time corresponding to the liquid volume with the volume detection unit 25 for detecting the volume of the liquid in the container 2, and rotates the electric pump 7 at a predetermined amount of circulation per unit time. A circulation control unit 24 for controlling the drive circuit unit 12.

The interrelationship and operation of the above components will be described. When the container 2 is filled with the liquid 18 and a power switch (not shown) is turned on, the control circuit 19 energizes the heating source 4 and starts heating. In addition, the temperature of the liquid is
And the temperature detection means 11, and further detects the amount of liquid from the temperature rise gradient value per unit time. Now
Assuming that the amount of liquid per unit time passing through the filtration device 23 is constant, the circulation time is increased if the amount of liquid in the container 2 is large in order for the filtration device 23 to sufficiently remove unnecessary substances such as calcium components. There is a need to. Therefore, the control means 19 determines the required circulation time corresponding to the volume of the liquid by the circulation control means 24, and starts circulation at a constant circulation amount per predetermined unit time. When the circulation time has elapsed, the circulation is stopped. When the heating proceeds and boils, the heating is stopped and the operation shifts to a warming operation. The boiling of the liquid can be detected when the temperature rise gradient value per unit time of the liquid becomes equal to or less than a predetermined value.

FIG. 2 is an electric circuit diagram showing the configuration of the electric water heater of this embodiment . In the figure, a microcomputer (hereinafter, referred to as a microcomputer) 30 is a main device for realizing the temperature detecting means 11, the capacity detecting means 25, the heating and heat controlling means 10, and the circulation controlling means 24 in the control means 19 shown in FIG. . The microcomputer 30 detects the temperature of the liquid from the change in the thermal resistance of the temperature sensor 5. Further, based on the temperature information, the amount of liquid in the container 2 is detected from the temperature rise gradient value per unit time of water. In addition, the transistor 25 is turned on through the resistor 26, the heater 4a is connected to the commercial AC power supply 17 through the relay contact 22a to energize the transistor 25, and the transistor 28 is turned on through the resistor 29, and the heater is heated by the thyristor 23. 4b is connected to a commercial AC power supply and energized to control heating or heat retention. The diode 24 is a surge voltage absorbing diode when the transistor 25 is turned off.

The drive circuit means 12 for driving the motor 13 comprises resistors 32, 34, 36, a variable resistor 33, a transistor 35, a Zener diode 38 and an amplifier 37. The operation knob 14 is a means for changing the number of rotations of the motor 13. The rotation of the operation knob 14 moves the slider of the variable resistor 33, and the drive voltage of the motor 13 is changed according to the input voltage of the amplifier 37. Change, motor 13
Changes the number of revolutions. At the position of the slider before the operation knob 14 is rotated, the output voltage of the drive circuit 12 is set to a low voltage that is not enough to drive the motor 13. When the operation knob 14 is rotated, the drive voltage is reduced. Ascends and the motor 13 rotates.

In the drive circuit 12, when the level of the output terminal A of the microcomputer 30 is at the "low" level, the base of the transistor 35 is connected to the "low" level via the resistor 36, and the variable resistor 33 slides. The input voltage of the amplifier 37 is determined by the output voltage of the variable resistor 33 set by the operation knob 14, and the drive voltage of the motor 13 is set by the setting lower than the emitter voltage connected to the variable resistor 33. Outputs a voltage equal to the output voltage. On the other hand, when the level of the output terminal A is at the "high" level, the base voltage of the transistor 35 is set to the Zener voltage VZ of the Zener diode 38, and the input voltage to the amplifier 37 is constant by the emitter follow circuit configuration of the transistor 35. (VZ-VBE).
VBE is a voltage between the base and the emitter of the transistor 35.

The operation of the above configuration will be described. First,
When water is poured into the container 2 and the commercial AC power supply 17 is connected, the microcomputer 30 closes the relay contact 22a, conducts the thyristor 23, and initializes the level of the output terminal A to the "low" level. In this state, the heating source 4 is switched to the commercial AC power supply 17.
To start heating. As the water temperature rises, the resistance value of the temperature sensor 5 changes.
Detects the temperature of the water and calculates the temperature rise gradient value of the water temperature per unit time to obtain the amount of water in the container 2. The circulation time required for filtration is determined for this amount of water, and the microcomputer 3
The level of the output terminal A of 0 is set to the “high” level, and circulation is started. The motor 13 is rotated by receiving a voltage (VZ-VBE). Further, the circulation time is determined based on the filtration capacity of the filtration device 23 so that the circulation time becomes longer as the amount of water is larger. When the circulation time elapses, the level of the output terminal A of the microcomputer 30 is set to the "low" level, and the pump 30 is brought into a standby state for requesting pumping. Operation knob 1
When the motor 4 is not operated, the motor 13 stops. When the temperature of the temperature sensor 5 becomes higher than the predetermined temperature, the microcomputer 30 always detects the liquid temperature by the temperature sensor 5, and when the temperature rise gradient value per unit time becomes lower than the predetermined value, the water in the container 2 boils. And both the relay contact 22a and the thyristor 23 are turned off. After that, thyristor 2
3 is turned on or off in accordance with the water temperature to keep the temperature at a predetermined temperature.

As described above, the microcomputer 30 calculates the amount of water from the temperature rise gradient value, determines a longer circulation time as the amount of water increases, circulates the water through the filtration device 23, and circulates the water until the water boils. By completion, unnecessary substances such as calcium components have been sufficiently removed at the time of boiling, and there is no need to continue boiling.

Further, in this embodiment, the electric circuit diagram shown in FIG. 3 is used . The same components as those shown in FIG. 2 are denoted by the same reference numerals, and description thereof will be omitted. Also,
If the entire configuration is illustrated, it will be the same as that of FIG. In FIG. 3, the circulation control executed by the microcomputer 30 is characterized by the output of the output terminals a to d. In FIG.
By setting the output level of one terminal a by switching from a "low" level to a "high" level, only one type of motor rotation speed during circulation is determined, but the output of a plurality of output terminals a to d is determined. The level is determined, and the number of rotations of the motor 13 is switched to a plurality of number of rotations according to the combination of the levels. The “high” or “low” level of the output terminals a to d is given to the base of the transistor 35 via the resistors 39, 40, 41, and 42, respectively. Output terminals a to d
And the resistance values of the resistors 39 to 42.
Therefore, there is a feature that the drive voltage applied to the motor 13 can be set in a plurality of stages.

The operation of the drive circuit 20 in the above configuration will be described. Now, when the levels of the output terminals a, b, c and d of the microcomputer 30 are all "low" levels,
The transistor 35 becomes non-conductive, and a voltage corresponding to the slider position of the variable resistor 33 by the operation knob 14 is applied to the amplifier 3.
7 and is in a pumping request waiting state. When any one of the output terminals a, b, c and d is at the “high” level, for example, when the output terminal a is at the “high” level, the divided voltage V of the resistor 36 and the resistor 39 is obtained.
a is applied to the base of the transistor 35 and the motor 13
Is applied with a voltage (Va-VBE). Here the resistance 39
42 are set to different values from each other, and the voltage applied to the motor 13 can be changed in various ways by the combination of the output levels of the output terminals a to d. That is, the amount of circulation of the electric pump 7 per unit time can be changed in various ways.

The operation of the above configuration will be described below. When water is poured into the container 2 and connected to the commercial AC power supply 17, the microcomputer 30 closes the relay contact 22a, conducts the thyristor 23, and initializes the output terminals a to d so that all levels become low. Set. With this setting, heating of water starts. At this time, unless the operation knob 14 is operated, the slider of the variable resistor 33 is located on the low potential side, and the motor 13 does not rotate. Microcomputer 3
A value of 0 is detected by detecting the water temperature by the temperature sensor 5 and calculating the amount of water in the container 2 from the temperature rise gradient value per unit time of the water temperature. The larger the amount of water, the higher the driving voltage of the motor 13 is output. The signals are output by combining the levels of the terminals a to d. That is, the combination of the output levels of the output terminals a to d is set such that the larger the amount of water, the greater the amount of circulation per unit time. Then , the circulation time is set to a predetermined fixed time irrespective of the amount of water, and the start point of the circulation is set to a high water temperature at which the filtration efficiency is high. After the circulation time has elapsed, the output terminals a to d
The circulation is stopped by setting all levels of the “low” level. After the end of the circulation, the microcomputer 30 determines that the water in the container has boiled since the temperature rise gradient per unit time of the water temperature has become equal to or less than the predetermined value, and opens both the relay contact 22a and the thyristor 23. After that, the thyristor 23 is turned on or off to keep the water in the container 2 at a predetermined temperature.

As described above, according to the electric water heater of this embodiment, the amount of water in the container 2 is measured, and the larger the amount of water, the higher the drive voltage of the motor 13 to increase the amount of circulation per unit time. In addition, by circulating for a predetermined period of time at a high water temperature, unnecessary substances such as calcium components can be sufficiently removed by a circulating operation for a predetermined period of time at a temperature with high filtration efficiency.

[0019]

As is apparent from the above embodiments, a container for containing a liquid, a heating source for heating and keeping the liquid, a temperature detecting element for detecting the temperature of the liquid, and a liquid Filtration means for removing unnecessary substances therein, circulation means for forcibly circulating the liquid through the filtration means , and a predetermined temperature when the temperature reaches or exceeds a predetermined value during water heating.
The circulation is completed so that the circulation is completed before boiling for a certain period of time.
Means for detecting the temperature of the temperature detecting element.
Liquid volume in the container detected from the
The larger the volume, the larger the amount of circulation per unit time
By controlling the electric water heater to be at a liquid temperature equal to or higher than a predetermined value during heating to boiling, for a predetermined period of time,
By driving the circulation means so that the circulation amount per unit time increases as the liquid volume increases, and by controlling the circulation to complete by boiling, the total circulation amount required for the liquid volume is secured. Te, to sufficiently remove unwanted substances such as chlorine components, and, since its operations are completed before boiling extra boiling continued unnecessary.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional block diagram showing the configuration of an embodiment of an electric water heater according to the present invention.

FIG. 2 is an electric circuit diagram showing a configuration of control means of a reference example in the electric water heater.

FIG. 3 is an electric circuit diagram showing a configuration of a control unit of the embodiment in the electric water heater.

FIG. 4 is a partial cross-sectional block diagram showing a configuration of a conventional electric water heater.

[Explanation of symbols]

 2 container 4 heating source 5 temperature detection element 7 electric pump (circulation means) 13 motor (circulation means) 18 liquid 19 control means 20 switching means (circulation means) 21 circulation discharge port (circulation means) 22 filtration device (filtration means)

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-6-22852 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) A47J 27/21 101

Claims (1)

(57) [Claims] 1. A container for accommodating a liquid, a heating source for heating and maintaining the temperature of the liquid, a temperature detecting element for detecting a temperature of the liquid, and a filtering means for removing unnecessary substances in the liquid. and circulation means for forcibly circulating the liquid by way of said filter means, predetermined temperature than in the kettle
When it reaches above, circulation is completed by boiling for a certain period of time
The circulation means is driven so that the amount of circulation is
To the liquid volume in the container detected from the temperature detected by the temperature detection element.
Accordingly, the larger the liquid volume, the more circulation per unit time.
Electric water heater that controls to increase the amount.