JP3109282B2 - 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 kettle for heating and keeping a liquid contained in a container, which prevents the liquid from being cooked.

[0002]

2. Description of the Related Art Conventionally, the detection of an empty bake of an electric water heater of this type has been performed as shown in FIG.

[0003] That is, a heating means 2 for heating a liquid in a container is brought into contact with a bottomed cylindrical container 1,
The temperature detecting means 3 composed of a temperature sensing element 3a abutted on the sensor and an AD converter 3b for converting the output into an electric signal detects the temperature inside the container. When the temperature detecting means 3 detects a predetermined temperature or less and starts heating, the driving means 5 is driven to energize the energizing means 4 to start heating the heating means 2. When the heating means 2 starts heating, the measuring means 7 calculates the rate of change of the temperature of the liquid in the container based on the output of the temperature detecting means 3, and when the temperature exceeds a predetermined value, the heating means 2 is stopped and the notification means 8 is turned on. Had been driven.

[0004]

However, in such a conventional configuration, the presence or absence of the liquid in the container is detected only when heating is started. For this reason, for example, even if the liquid in the container is emptied by hot water while keeping the temperature, the empty container is kept warm for a long time.

An object of the present invention is to solve the above-mentioned problems, and it is an object of the present invention to detect the presence or absence of water at the end of tapping when the liquid in the container is discharged, and to immediately notify that the water has run out.

[0006]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides a container for containing a liquid, heating means for heating the liquid in the container, and a temperature detector for detecting the temperature of the liquid in the container. Means, hot-water detecting means for detecting that the liquid in the container has been discharged to the outside, energizing means for energizing the heating means, notifying means for notifying to the outside that there is no liquid in the container, Drive means for driving the energizing means until a first predetermined time elapses after the detection means detects the end of hot water, and a temperature until a second predetermined time elapses after the hot water detection means detects the end of hot water. When the rise value is equal to or more than a predetermined value, the apparatus is provided with a measuring means for driving the notifying means.

[0007]

According to the present invention, by means of the above-mentioned solution means, when the liquid is reduced due to hot water, the empty baking is detected each time, so that it is possible to make the apparatus efficient and convenient without keeping the temperature empty. .

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a block diagram of an electric water heater according to an embodiment of the present invention. Reference numeral 1 denotes a container for accommodating a liquid, 2 denotes a heating means for contacting the container and heating the liquid in the container, and 3 denotes the container. Temperature detecting means 4 which is in contact with 1 and detects the temperature of the liquid in the container 4 is an energizing means for energizing the heating means 2.

Reference numeral 9 denotes a tapping detecting means for detecting that the liquid in the container 1 is discharged, and in this embodiment, when the tapping means constituted by the tapping means by an electric pump shown in 10 is driven, the electric power is supplied to the tapping means. The end of hot water is detected by inputting a signal.

Reference numeral 5 denotes a driving means, and 7 denotes a measuring means. When the hot water detecting means 9 detects the end of the hot water, the driving means 5 causes the energizing means 4 to operate for a first predetermined time (in this embodiment, The measurement means 7 measures the temperature rise when a second predetermined time (in this embodiment, 25 seconds) elapses from the end of tapping. When the measuring means 7 detects that the measured temperature difference is equal to or more than a predetermined value (4 ° C. in this embodiment), it drives the notifying means 8 to detect that there is no liquid in the container.

FIG. 2 is a circuit diagram of an electric water heater showing one embodiment of the present invention. In the figure, reference numeral 11 denotes an AC power supply. The heating means 2 includes a first heating element 2a for heating the liquid in the container and a second heating element 2b for heating and keeping the liquid in the container at a lower heating power than the first heating element 2a. . The energizing means 4 includes a relay contact 4 connected in series with each heating element of the heating means 2 and an AC power supply 11.
a and 4b, and relay coils 4c and 4d for controlling the relay contacts 4a and 4b. A current flows through the relay coils to close the relay contacts.

The temperature detecting means 3 comprises a temperature sensing element 3a for converting a temperature into a resistance value, and an AD converter 3b for converting a divided voltage value between the temperature sensing element 3a and the resistance into a binary code. ing.

Reference numeral 10 denotes a tapping means, and reference numeral 12 denotes a tapping switch. When the tapping switch 12 is turned on, a motor 10a for driving an electric pump is driven. The transistor 10b is turned on when the motor 10a is driven, and outputs a signal to the hot water detecting means 9.

Reference numeral 8 denotes a notifying means for notifying that there is no water in the container by using the LED 8a or the buzzer 8b when the temperature difference measured by the measuring means 7 exceeds a predetermined value.

Reference numeral 13 denotes a microcomputer (hereinafter abbreviated as "microcomputer") which executes a program to realize a control method of the driving means 5, the measuring means 7 and the hot water detecting means 9.

FIG. 3 is a flow chart of the burn-out detection portion of the program stored in the microcomputer according to the present invention, and the operation will be described with reference to FIG.

In this part, it is first detected in step 21 whether or not the tapping has been completed. If the hot water is being discharged or no hot water is being discharged, the process ends without detecting the empty burning. When the end of tapping is detected, the energizing means 4 is driven in step 22. Next, at step 23, the temperature at this time is detected to start measuring the temperature rise. In step 24, step 22
Waits for the first predetermined time to elapse of the energizing time of the energizing means 4 driven by the controller, and stops the energizing means 4 when the predetermined time elapses, and waits until the second predetermined time elapses in step 25. When the second predetermined time has elapsed, the temperature at this time is measured (step 26), and the difference from the temperature measured in step 23 is compared with a predetermined value (step 27). If it is smaller than the predetermined value in step 27, the burn-out detection is terminated.

With the above configuration, the present invention can be easily realized. Further, in the present embodiment, the empty baking detection is not performed in the first heating after the power is turned on. However, it is possible to easily cope with this by excluding the step 21 only when the power is turned on.

In this embodiment, the method of detecting the end of hot water supply is described as immediately after the end of hot water supply. However, when the hot water is supplied intermittently, in order to prevent the detection of idle burning every time, the start of hot water supply is detected. It is also possible to use a control method in which it is determined that tapping is completed when it is confirmed that there is no tapping operation for a predetermined time.

Further, the control of the heating means for energizing for a predetermined time and the heating means for heating after a predetermined time can be such that only the first heating element or both the first and second heating elements are energized.

[0022]

As is clear from the above embodiment, according to the present invention, when the tapping operation is completed, the heating means is energized for a specific period of time to perform idle burning detection. However, it is possible to provide a safe and easy-to-use electric water heater.

[Brief description of the drawings]

FIG. 1 is a specific block diagram of an electric water heater in one embodiment of the present invention.

FIG. 2 is a specific circuit diagram of the electric water heater in the embodiment.

FIG. 3 is a flowchart showing the operation of a microcomputer program in the electric water heater.

FIG. 4 is a block diagram of an electric water heater in a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Container 2 Heating means 3 Temperature detection means 4 Current supply means 5 Driving means 7 Measurement means 8 Notification means 9 Hot water detection means

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) A47J 27/21 A47J 41/00

Claims (1)

(57) [Claims] 1. A container for accommodating a liquid, a heating unit for heating the liquid in the container, a temperature detecting unit for detecting a temperature of the liquid in the container, and that the liquid in the container is discharged to the outside. Hot water detecting means for detecting the presence of water, an energizing means for energizing the heating means, a notifying means for notifying that there is no liquid in the container, and a first predetermined time after the hot water detecting means detects the end of the hot water And a driving unit for driving the energizing unit until the temperature rise value during the second predetermined time elapses after the hot water detection unit detects completion of the hot water is equal to or more than a predetermined value. Electric water heater with measuring means.