JPH0747002B2 - Electric water heater - Google Patents

Description

Description: <Industrial field of application> The present invention relates to an electric water heater for heating water contained in a container.

<Prior Art> A conventional electric water heater of this type, for example, as shown in FIG.
Alternatively, as shown in Fig. A, the float 65 is used to indicate the "full" position at the full-water display position of the mounting frame 64 attached to the outer case 63 in order to see the water level in the container 61.

<Problems to be solved by the invention> However, in such a configuration as described above, it is difficult to tell whether or not the water is full by only markings, and even if the water is poured above the full water position, the water in the container is heated. There was a risk that hot water would spill out of the discharge port when boiling.

The present invention is to solve such a problem, and an object of the present invention is to provide an electric water heater capable of reliably detecting an abnormality when a dangerous water level is reached, stopping heat generation, and giving a warning to notify a danger. To do.

<Means for Solving the Problem> In order to solve the above problems, the present invention provides a container that stores water, a heating element that heats water in the container, and a control element that controls energization of the heating element. And a water level pipe that is connected to the container and indicates the water level in the container, and is provided on the water level pipe.
If the water level detecting means for detecting whether or not the water level has reached a dangerous water level, a notifying means for notifying by sound or light, and the water level detected by the water level detecting means only immediately after the application of the AC power source is less than the dangerous water level The control means is turned on, and when the dangerous water level is reached, the control element is turned off until the water level becomes lower than the dangerous water level, and the notification means is operated.

<Operation> According to the above configuration, even if the water rises from below the dangerous water level to the dangerous water level due to thermal expansion during heating, it is possible to prevent the heating element from being erroneously stopped from heating, and before the AC power is applied. It is possible to solve problems such as hot water spouting from the discharge port due to too much water coming from, and burns and the table becoming dirty.

<Example> An example of the present invention will be described below with reference to FIGS. 1 to 4.

FIG. 1 is a sectional view of this embodiment, and FIG. 2 is a sectional view of a main part of FIG. In FIGS. 1 and 2, 1 is a container for containing water, 2 is a water level pipe that is connected to the container 1 and indicates the water level in the container 1, and 3 is a lower L type that connects the container 1 and the water level pipe 2 at the bottom. A water pipe 4 is an upper part L connecting the container 1 and the water level pipe 2 at the upper part.
Shaped water pipes, 5 are in the water level pipe 2, floats floating above the water surface,
A restriction piece 6 is a part of the upper L-shaped water pipe 4 and controls the movement of the float 5. m shows the same height as the mark 62 of the full water display shown in FIG. 6, l shows the dangerous water level above the height m of the full water display mark (here, 10 mm), and the light emitting diode is located at this position. 42 and phototransistor 43 are attached.

FIG. 3 shows the appearance of the electric water heater of the present embodiment. 10 is an outer case, 11 is a handle, 12 is a lid, 13 is a base, 14 is a full water notification lamp, 15 is a water supply notification lamp, 16 Is a boiling water lamp, 17 is a heat retention lamp, and 18 is a reboil switch.

FIG. 4 is a circuit diagram of the present embodiment. In FIG. 4, 31 is an AC power source applied to the circuit by connecting a power cable (not shown) of a water heater to an outlet, and 32 is a resistor.
DC power source composed of 33, diode 34, electrolytic capacitor 35, and Zener diode 36, 37 is a heating element for heating water in the container 1, 38 is a control element for controlling energization of the heating element 37, which is a relay contact 39 and a relay. It is composed of a coil 40. 41
Is a water level detecting means composed of a light emitting diode 42, a phototransistor 43, and resistors 44 and 45 shown in FIG.
Reference numeral 6 is a notification means composed of a piezoelectric buzzer 47, a light emitting diode 48 as a full water notification lamp, resistors 49 and 50, and 51 is a control means composed of a microcomputer 52, a transistor 53 and a resistor 54.

FIG. 5 is a flow chart of the ROM of the microcomputer 52 immediately after the application of the AC power supply 31, and the operation of this embodiment will be described according to this flow chart. First, the AC power source 31 is applied to the water level detection means 41.
Operates (step 1). At this time, the water level detecting means 41 determines whether or not the float 5 shown in FIG. 2 has reached the dangerous water level 1 or below (step 2). Float 5 is dangerous water level l
Phototransistor 43 is a light emitting diode if
The light of 42 is detected and turned on, and the "L" signal is sent to the microcomputer 52. When the "L" signal is input to the microcomputer 52, the "H" signal is output to the transistor 53, the transistor 53 is turned on (step 3), current flows through the relay coil 40, the relay contact 39 is closed, and the heating element 37 is generated. To heat. When the float 5 reaches the dangerous water level 1 in step 2, the phototransistor 43 does not turn on because the light of the light emitting diode 42 is blocked and sends a "H" signal to the microcomputer 52. When this "H" signal is input to the microcomputer 52, the "L" signal is output to the transistor 53 to turn off the heating element 37 (step 4), and the piezoelectric buzzer 47 of the notification means 46 receives "H", ". The L "repeat signal is continuously sent to the light emitting diode 42 until the float 5 is below the critical water level (step 5).

<Effects of the Invention> As is apparent from the above embodiments, according to the present invention, when the water reaches the critical water level, it is possible to stop the heating of the heating element until the water reaches the critical water level. Moreover, since the control means operates only immediately after the AC power is applied depending on the signal from the detection means, even if the dangerous water level is reached due to the thermal expansion of water during the heating of the container, neither the control means nor the notification means operates. Accurate full water detection is possible. As a result, it is possible to provide a safe and easy-to-use electric water heater with a simple structure without the risk of burns or the like due to hot water spillage.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing the configuration of an embodiment of the present invention, FIG. 2 is a detailed cross-sectional view of the essential parts in FIG. 1, and FIG. 3 is a perspective view showing the appearance of the electric water heater in the same embodiment. FIG. 4 is a circuit diagram of the same embodiment, FIG. 5 is a flow chart for explaining the operation of the same embodiment, and FIG. 6 is a diagram showing an example of water level display means of a conventional electric water heater. 1 ... Container, 2 ... Water level pipe, 3 ... Lower L-shaped water pipe, 4 ... Upper L
Mold water pipe, 5 ... Float, 37 ... Heating element for heating water in container 1, 38 ... Control element for controlling energization of heating element 37, 42, 4
3 ... Light-emitting diode and phototransistor constituting water level detection means, 46 ... Notification means.

Claims (1)

[Claims] 1. A container for containing water, a heating element for heating water in the container, a control element for controlling energization of the heating element, a water level tube indicating a water level in the container, and the water level tube. The water level detection means provided in the upper part, which detects whether or not the water level has reached a dangerous water level, the notification means which notifies by sound or light, and the water level detection means only immediately after the AC power is applied. If the water level is lower than the dangerous water level, the control element is turned on, and if the water level reaches the dangerous water level, the control element is turned off until the water level becomes lower than the dangerous water level, and the electric water heater equipped with the control means is operated. .