JP3120808B1 - Electric water heater - Google Patents

Abstract

An object of the present invention is to keep the electric water heater at a predetermined temperature even when a voltage drop or the like occurs. SOLUTION: When the temperature is kept at a predetermined temperature, when the temperature of the liquid does not rise even when the temperature of the liquid does not rise even if the temperature of the liquid does not rise even when the temperature of the heat retaining heater 4 is energized for a predetermined time, Heater 5
An electric water heater that is designed to energize the.

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 for heating and keeping water contained in a container.

[0002]

2. Description of the Related Art In general, an electric water heater is used in which water is kept at a desired temperature after boiling water. In FIG. 4, after boiling, for example, when the temperature is maintained at 85 ° C., if the water temperature is 85 ° C. or higher, the heat retaining heater is turned off. It keeps warm. When the temperature is less than about 80 ° C (it is generally detected at a temperature about 3 to 7 ° C lower than the heat retention temperature, but this time it will be explained at 5 ° C), it is determined that water has been added, and the heater is turned on to boil the water. Let it.

[0003]

However, in the above-mentioned conventional configuration, when the ambient temperature is low (for example, 5 ° C.) or when the commercial power supply is low (for example, 90 V), the required power for keeping the temperature is insufficient with the heat retaining heater. 85 ℃
Even if it is kept warm, the water temperature will be lower than 85 ° C, and the water temperature will continue to drop even if the warming heater is turned on.
It is determined that water has been added, the heater is turned on, and the water boils. There was a problem that simply increasing the electric power of the heat retaining heater would increase the cost of parts for controlling the heat retaining heater.

The present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to maintain a constant heat-retaining temperature at a lower cost under any circumstances.

[0005]

In order to achieve the above-mentioned object, one means of the present invention is to provide a heat-retaining heater by means of a heat-retaining means when the temperature is lower than a first predetermined temperature and higher than a second predetermined temperature. An electric water heater characterized in that the heater is energized by the heating energizing means when the temperature does not reach the first predetermined temperature or higher or the temperature of the liquid does not rise even when energized for a predetermined time.

[0006] With the above configuration, it is possible to keep the temperature kept close to the set temperature under any circumstances, so that hot water at a desired temperature can be obtained at any time with confidence.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 is a container for containing a liquid, and a temperature sensor for detecting the temperature of the liquid in the container.
And a heater for heating the liquid in the container, a heater for keeping the liquid in the container warm, a heating unit for supplying electricity to the heater, and a unit for supplying electricity to the heater . And keeping the liquid in the container warm
When maintaining the first predetermined temperature, which is the predetermined temperature of
The temperature detected by the temperature sensor is lower than the first predetermined temperature and
When the temperature is higher than the predetermined temperature, the heat-retaining heater is energized by the heat-retaining means to raise the temperature to the first predetermined temperature and maintain the temperature.
If the temperature is maintained and the temperature of the liquid does not rise above the first predetermined temperature or the temperature of the liquid does not rise even if the heat retaining heater is energized for a predetermined time at this time, the heater is energized by the heating energizing means. And an electric water heater.

According to a second aspect of the invention, when the temperature is lower than the first predetermined temperature and higher than the second predetermined temperature, the temperature does not become higher than the first predetermined temperature even if the heat retaining heater is energized for a predetermined time by the heat retaining energizing means. The electric water heater according to claim 1, wherein when the temperature of the liquid does not rise, the heating heater is energized from the first predetermined temperature to an arbitrary temperature lower than the boiling point by the heating energizing means.

According to a third aspect of the present invention, when the temperature is lower than the first predetermined temperature and higher than the second predetermined temperature, the temperature does not become higher than the first predetermined temperature even if the heat retaining heater is energized for a predetermined time by the heat retaining energizing means. If the temperature of the liquid does not rise, the heating heater is energized to the vicinity of the first predetermined temperature by the heating energizing means.

[0010]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a partial cross-sectional configuration diagram of an electric water heater of the present invention, FIG. 2 is a circuit configuration diagram, and FIG. 3 is a graph showing a relationship between water temperature and on / off of a heater.

In FIG. 1, a container 2 having an upper surface opening is provided in a main container 1, and lids 3 for covering an upper portion of the container 2 are arranged. Further, a heater 4 for heating the water inside the container 2, a warming heater 5 for heating and keeping the water warm, and a temperature sensor 6 for detecting the temperature of the water inside the container 2 are arranged below. The signal from the temperature sensor 6 is input to the temperature detecting means 7 to detect the water temperature. The opening and closing of the heating heater 4 and the heat retaining heater 5 are controlled by a heating current supplying means 8 and a heat retaining current supplying means 9, respectively. The control unit 10 controls the energization of the heating energizing unit 8 and the heat-retaining energizing unit 9 based on the temperature data from the temperature detecting unit 7 and the input of the operation unit 11, and displays on the display unit 14.

The operation unit 11 comprises a heat retention setting switch 12 as a heat retention setting means and a reboil switch 13 for boiling water. The heat retention setting switch 12 is set at 98 ° C., 85
It is composed of a push switch, a changeover switch, etc., which can set the heat retention temperature of 60 ° C. or 60 ° C. The display unit 14 includes a boiling LED 14a for displaying that the water is being heated and about 98 b.
98 heat retention LED that indicates that the temperature is set to ℃
14b, an 85-warming LED 14c that indicates that the temperature is set to about 85 ° C., and a 60-heating LED 14d that indicates that the temperature is set to about 60 ° C.

The overall operation of the electric water heater configured as described above will be described with reference to FIGS. In FIG. 2, the microcomputer 16 controls the relay 8 and the triac 9 to determine the amount of power to the heater 4 and the heater 5.

On the other hand, the resistance value of the temperature sensor 6 such as a thermistor mounted in pressure contact with the container 2 changes depending on the temperature of the water in the container 2. Then, the resistance value ratio of the resistor 7a connected in series with the temperature sensor 6 changes and is input as a voltage change to the A / D converter 7h. 16 is input as temperature data. The voltage determined by the resistors 7b and 7c is also input to the A / D converter 7h, and determines the initial setting temperature (about 95 ° C., the initial value of the 98 temperature data) at the time of 98 temperature keeping. The voltage determined by the resistors 7d and 7e determines the temperature (about 85 ° C.) at the time of keeping the temperature at 85. The voltage determined by the resistors 7f and 7g determines the temperature (approximately 60 ° C.) when the temperature is kept at 60. Further, the heat retention setting switch 12 and the reboiler switch 13 are connected to the microcomputer 1.
6 are input to each of the LEDs 14a to 14
d is connected to the output of the microcomputer 16.

When the water is boiled, the microcomputer 16 operates the relay 8 and the triac 9 to turn on the heater 4 and the heater 5. After boiling, add 9
When keeping the temperature at 8 ° C., the microcomputer 13 is 98
In order to detect the temperature, the triac 9 is operated for three minutes, and then the triac 9 is operated for three minutes. The triac 9 is controlled so as to keep the temperature at a temperature lower by 2 ° C. than the temperature data value from the temperature detecting means 7 at that time, and the heater 5 Is controlled. When the temperature is kept warm, the reboil switch 11 is pressed or the temperature is kept several degrees lower than the temperature keeping temperature (generally, the temperature is set to about 3 to 7 degrees lower than the temperature keeping temperature.
When the temperature decreases, the microcomputer 13 sets the boiling LE
D14a is turned on, the relay 8 and the triac 9 are operated, and the heater 4 and the heater 5 are energized until boiling.

When the heat insulation setting switch 12 is pressed once, the heat insulation setting is set to 85, and each time the switch 12 is pressed, the heat insulation setting switch 60 changes to the heat insulation setting 98, the heat insulation setting 85, and the heat insulation LED 12b, the heat insulation LED 12c, and the heat insulation LED 12c, respectively. Warm LED
12d lights up.

In FIG. 3, for example, when the heat retention is set to 85 ° C. (98 or 60 or any other temperature may be used), the microcomputer 16 operates the triac 9 until the temperature reaches 85 ° C. after boiling. Is stopped, and when the temperature reaches 85 ° C., the buzzer 15 notifies the user.
The triac 9 is turned on when the temperature becomes lower than the heat retention temperature, and turned off when the temperature exceeds the heat retention temperature, thereby maintaining the heat retention. When the temperature is kept in a place where the ambient temperature is extremely low, or when the power supply voltage is low and the heat retention power is low, even if the water temperature falls below the heat retention temperature and the triac 9 is turned on, it can be set for a predetermined time (1 minute to 10 hours, As one embodiment, for example, 1
(Time) If the temperature does not exceed the heat retention temperature even if the power is supplied, or if the temperature data from the temperature detecting means 7 continues to decrease even if the triac 9 is turned on, the microcomputer 16 controls the heating heater 4 through the heating / current supplying means 8. Turn on near the heat retention temperature.

In the present embodiment, the heater 4 is continuously energized. However, on-off energization is performed, and phase control is performed by using a semiconductor control element (thyristor, triac, power transistor, IGBT, etc.) for the heating energizing means 8. It is obvious that increasing the temperature while controlling the temperature is also included in the present invention.

In this embodiment, the heater 4 is turned off at the heat retaining temperature. However, the present invention can be applied to a case where the heater 4 is turned on at a temperature exceeding the heat retaining temperature and up to a predetermined temperature up to boiling, or stopped at a temperature several degrees below the heat retaining temperature. It is obvious that it is included.

[0020]

As described above, according to the present invention, the temperature is maintained in a place where the ambient temperature is extremely low, or the temperature is lowered when the power supply voltage is low, and it is determined that water has been added. You can start boiling water and prevent it from boiling in the meantime, and you can keep warming near the set warming temperature in any situation, so you can always get hot water at your favorite temperature with confidence .

[Brief description of the drawings]

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

FIG. 2 is a circuit configuration diagram of the electric water heater.

FIG. 3 is a graph showing the relationship between the water temperature of the electric water heater and the on / off state of the heater.

FIG. 4 shows the water temperature of the conventional electric water heater and the ON / OFF of the heater.
Graph showing off relationship

[Explanation of symbols]

 2 Container 4 Heater 5 Insulation heater 6 Temperature sensor 7 Temperature detection means 8 Heating and energizing means 9 Heating and energizing means 10 Control means 11 Operating part 12 Heat insulation setting switch 13 Reboiler switch 14 Display part 16 Microcomputer

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) A47J 27/21 101 A47J 27/00 109

Claims (3)

(57) [Claims] 1. A a container containing a liquid, the liquid in the container
A temperature sensor for detecting a body temperature, a heater for heating the liquid in the container, a heater for keeping the liquid in the container, a heating means for supplying electricity to the heater, and a heater for supplying electricity to the heater . With heat-retaining means for energizing
And a first place where the liquid in the container is kept at a predetermined temperature for keeping the temperature.
When the temperature is maintained at a constant temperature, when the temperature detected by the temperature sensor is lower than the first predetermined temperature and higher than the second predetermined temperature, the heat-retaining heater is energized by the heat-retaining means to generate the first predetermined temperature.
Temperature to maintain the heat retention temperature, and
An electric water heater characterized in that the heater is energized by the heating energizing means when the temperature does not reach the first predetermined temperature or higher or the temperature of the liquid does not rise even when the heat retaining heater is energized for a predetermined time. 2. When the temperature is lower than the first predetermined temperature and higher than the second predetermined temperature, the temperature does not reach the first predetermined temperature or the temperature of the liquid even when the heat retaining heater is energized for a predetermined time. The first electric water heater according to claim 1, wherein when the temperature does not rise, the heater is energized from the first predetermined temperature to an arbitrary temperature lower than the boiling point by the heating energizing means. 3. When the temperature is lower than the first predetermined temperature and higher than the second predetermined temperature, the temperature does not become equal to or higher than the first predetermined temperature or the temperature of the liquid even when the heat retaining heater is energized for a predetermined time. 2. A first electric water heater according to claim 1, wherein when the temperature does not rise, the heating heater is energized to a vicinity of the first predetermined temperature by the heating energizing means.