JP2563525B2 - Electric water heater - Google Patents

Description

TECHNICAL FIELD The present invention relates to an electric water heater that heats and keeps a liquid contained in a container heated.

2. Description of the Related Art Generally, an electric water heater which can be heated by putting water in a container and applying a power source has a structure as shown in FIGS. 4 and 5, for example. That is, as shown in FIG. 5, the marking 2 is provided on the inside of the container 1 at the full water level, or at the full water display position of the mounting frame 4 attached to the outer case 3 to see the water level inside the container 1, as shown in FIG. "Full water" was displayed.

However, in the above-described conventional configuration, whether or not water is full is indicated only by the inscription 2, which makes it difficult to understand, and furthermore, the water in the container 1 is heated even if water is injected at a position higher than the full water position. As a result, at the time of boiling, there is a possibility that hot water may be spilled from the discharge port due to thermal expansion of water.

The present invention solves such a problem and does not start heating when water enters above the first detection position when the power is turned on.
To provide an electric water heater capable of reliably detecting an abnormality when water is added to a position higher than the second detection position except when power is turned on, stopping the heating of a heating element, and giving a warning to notify a danger. That is the purpose.

Means for Solving the Problems In order to solve the above problems, the electric water heater of the present invention,
A heating element that heats the liquid in the container, a control element that controls energization of the heating element, a water level tube that is connected to the container and that indicates the water level in the container, and a first detection part above the water level tube. A first water level detecting means provided at a position and a second water level detecting means provided above the first water level detecting means at a second detection position.
Water level detecting means, an informing means for informing by sound or light, the water level is detected by the first water level detecting means when the power is turned on, and the water level is detected by the second water level detecting means otherwise. If the detected water level reaches the set height of each water level detecting means, the control element is turned off and the informing means is operated until it becomes lower than the set height.

Action According to the above configuration, when the heating at the time of turning on the power is started, if the water level is higher than the first detection position (full water position),
The first water level detection means detects full water and notifies it. Also,
After the power is turned on, the second unit is placed in consideration of the thermal expansion of water.
Since the full water level detection means is used to detect full water, when the first water level detection means detects a safe water amount, there is a case where the water level rises due to thermal expansion of water due to heating. There is no need to judge that the water is full, and only water that has been added during heating and the water level rises more than the thermal expansion of water will be detected, and as a result,
Malfunctions can be reliably prevented, and the problem of boiling water from the discharge port at the time of boiling, which was a problem when heating with too much water as in the past, is eliminated, thus causing burns, Problems such as dirtying the table can be prevented in advance.

Embodiment One embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows the structure of the main part of an electric water heater according to an embodiment of the present invention. In FIG.
Is a container for containing the liquid, and the container 5 is provided on the side of the container 5.
A water level pipe 6 indicating the water level inside is connected. Reference numeral 7 denotes a first water level detecting means which is provided above the water level tube 6 and which is installed at a position (referred to as a first detection position) where the water does not spill out from the discharge port during boiling due to thermal expansion of the water. The water level detecting means 7 is composed of a photodiode 7a and a phototransistor 7b. 8 is a position above the first water level detecting means 7 that does not spill from the discharge port even during boiling (second
The second water level detecting means 8 is provided at a detection position (1), and the second water level detecting means 8 is composed of a photodiode 8a and a phototransistor 8b. Reference numeral 9 is a float which is in the water level tube 6 and which floats and sinks depending on the amount of liquid in the container 5. Reference numeral 16 is a heating element for heating the container 5 containing the liquid, and 10 is a control element for energizing the heating element 16. Reference numeral 11 is a notification means for notifying the outside that the position is above the detection position. Reference numeral 12 is a control means for driving the control element 10 and the notification means 11, and the control means 12 turns on / off the phototransistors 7b, 8b of the first water level detection means 7 and the second water level detection means 8. It is to determine whether the water level in the container 5 is equal to or higher than the detection position.

FIG. 2 shows a concrete circuit diagram of the electric water heater in one embodiment of the present invention. In FIG.
Is an AC power supply and 148 is a DC power supply. 15 is a microcomputer (hereinafter referred to as a microcomputer), and this microcomputer 15
Is an input of the outputs of the first water level detection means 7 and the second water level detection means 8 and outputs the outputs to the control element 10 and the notification means 11. In the first water level detection means 7 and the second water level detection means 8, when the floats 9 reach their respective detection positions, the floats 9 block the light from the photodiodes 7a, 8a, and the phototransistors 7b, 8b are turned off. Since it is turned off, "H" is input to the microcomputer 15. On the other hand, if the float 9 has not reached each detection position,
Since the phototransistors 7b and 8b receive the light from the photodiodes 7a and 8a and are turned on, "L" is input to the microcomputer 15.

The control element 10 is composed of a relay contact 10a, a relay coil 10b, and a transistor 10c.
When "H" is input to the transistor 10c via 0d, a current flows through the relay coil 10b. As a result, the relay contact 10a is closed and the heating element 16 is energized.
Further, the notification means 11 is an LED 11a for displaying when the water is full and a buzzer 11
It is constituted by b and is driven by a command of the microcomputer 15 when full water is detected.

FIG. 3 shows a flowchart of the main part of the microcomputer, and the operation will be described based on this flowchart. First, immediately after turning on the power, in step 2, the first
Input the output of the water level detection means 7 in
Then, it is judged from the input data whether or not the first detection position has been reached, and if the first detection position has not been reached, the process proceeds to step 7, while if the first detection position has been reached, , It is judged that the amount of water is full and the control element 10 of the heating element 16 is kept off in step 4, the notification means 11 is turned on in step 5, and the next step shown in step 6 in the full mode Go to. If the first detection position has not been reached in step 3, the control element 10 of the heating element 16 is turned on in step 7, and the process proceeds to the next step shown in step 6.

After the power is turned on, the output of the second water level detecting means 8 is input in step 8, and it is determined in step 9 whether or not the second detection position has been reached based on the input data. If has reached the second detection position, the process proceeds to step 4 to detect full water, and the heating element 16
The control element 10 is turned off. On the other hand, if the second detection position has not been reached, the process proceeds to step 10. Then, in the heating mode, the control element 10 of the heating element 16 is turned on, while in the heat retention mode, the control element 10 of the heating element 16 is turned off and the process proceeds to the next step shown in step 6.

As described above, according to this embodiment, it is possible to easily prevent heating when the water level is above the full water position.

EFFECTS OF THE INVENTION As is clear from the description of the above embodiments, according to the present invention, heating is not started if the water level exceeds the full water position when the power is turned on, and after the power is turned on, there is a risk of spilling during boiling. When water is added to the position, the control element that controls the energization of the heating element is turned off to stop heating, so there is a problem when heating with too much water as in the past. It is possible to reliably prevent the hot water from spilling from the discharge port when boiling.
At this time, since the notification is given by the notification means to notify the danger, it is possible to provide a safer electric water heater.

[Brief description of drawings]

FIG. 1 is a block diagram showing the construction of the main part of an electric water heater showing an embodiment of the present invention, FIG. 2 is a specific circuit diagram of the electric water heater, and FIG. FIG. 4 is a flowchart showing a program, FIG. 4 is a partially cutaway perspective view of a conventional electric water heater, and FIG. 5 is an enlarged view of a portion A in FIG. 5 ... Container, 6 ... Water level tube, 7 ... First water level detecting means, 8 ... Second water level detecting means, 10 ... Heating element control element, 11 ... Notification means, 12 ... Control Means, 15 ... Microcomputer, 16 ... Heating element.

Claims (1)

(57) [Claims] 1. A heating element for heating a liquid in a container, a control element for controlling energization of the heating element, a water level pipe connected to the container and indicating a water level in the container, and an upper part of the water level pipe. Water level detection means provided at a first detection position of the second water level detection means, a second water level detection means provided at a second detection position above the first water level detection means, and notification by sound or light. And the first water level detection means detects the water level when the power is turned on, and the second water level detection means otherwise detects the water level, and the detected water level is set by each water level detection means. An electric water heater comprising: a control means for turning off the control element and operating the notification means until the height reaches a predetermined height.