JP3173572B2 - 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 a heating device for an electric water heater for heating and boiling a contained liquid.

[0002]

2. Description of the Related Art A conventional heating system for an electric water heater or the like is as shown in FIGS.

[0003] Reference numeral 101 denotes a container for storing a liquid.
In the lower part of 1, a main heating element 102 for heating the liquid and a switchable automatic temperature controller 103 for controlling the main heating element 102.
And a temperature fuse 104.

Reference numeral 105 denotes a manual reset type temperature switch which is disposed above the full position of the container 101, and a body 107 for covering the outside of the container 101 is provided with a knob 107 for operating the manual reset type temperature switch 105. Provided. 108
Is an over-temperature prevention device provided to prevent an abnormal rise in temperature of the main heating element 102 together with the temperature fuse 104.

Next, an electric circuit will be described with reference to FIG. One end from the temperature fuse of power - Connect's 104 and a circuit connected to the main heating element 102 and the overheat protector 108 in series to the terminals always closed circuit thermostats 103, the normally closed circuit terminal Is connected to a normally open circuit terminal of the automatic temperature controller 103 via a manual reset type temperature switch 105, and a common terminal of the automatic temperature controller 103 is connected to a power supply.

With the above arrangement, when the water is put into the container 101 and the knob 107 is pushed to close the manual reset type temperature switch 105 and connected to the power source, the main heating element 102 is made up of the temperature fuse 104 and the overheat prevention device. 108, automatic temperature controller 1
03 is supplied with electricity through the container 10 to generate heat.
Heat the water in 1.

When the water is heated to reach the operating temperature of the automatic temperature controller 103, the automatic temperature controller 103 opens the normally closed circuit and closes the normally open circuit. In this state, electricity from the power supply is supplied to the temperature switch 105 of the manual reset type.
Is supplied via the main heating element 102, and the energized state of the main heating element 102 is further continued. When the water in the container 101 boils to generate steam, the temperature of the sensing surface of the manually reset type temperature switch 105 rapidly rises due to the steam, and the manually reset type temperature switch 105 operates to operate the main heating element. The supply of electricity to 102 is stopped and boiling stops.

[0008]

However, in the above-mentioned conventional structure, steam cannot be detected unless the mounting surface of the manual reset type temperature switch 105 is disposed above the full position of the container 101. There is a problem that the height of the container 101 is increased and the cost is increased.

The temperature of the steam is 100 ° C. on a flat ground, and exceeds this temperature.
Since the operating temperature cannot be set, it is usually necessary to set the upper limit to 98 ° C. including the variation in the operating temperature. This means that the boiling time is short, the hot water cannot be sufficiently boiled, and the temperature of the manual reset type temperature switch 105 cannot be reduced even if the delay in temperature detection due to the thermal mass of the sensing portion of the manual reset type temperature switch 105 is considered. Since the operating temperature is set close to the boiling temperature, there is a problem that a device for preventing an abnormal temperature rise of the temperature fuse 104 and the excessive temperature rise prevention device 108 is required, and the cost is further increased.

[0010]

In order to solve the above-mentioned problems, an electric water heater according to the present invention comprises a container for containing a liquid, a main heating element for heating the liquid in the container, and a main heating element. a thermostat for controlling the energization, the auxiliary heating elements
And a temperature switch connected in series
The auxiliary heating element is composed of a circuit connected in parallel with the node.
Close the container and partly receive the temperature switch.
It is those formed by-sensitive surface.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to a first aspect of the present invention provides a container for storing a liquid, a main heating element for heating the liquid in the container, and an automatic temperature controller for controlling the supply of electricity to the main heating element. , A circuit in which an auxiliary heating element and a temperature switch are connected in series.
Consisting of a circuit connected in parallel to the thermostat,
The auxiliary heating element is kept in close contact with the
Auxiliary heating element
Temperature rise and the temperature of water in the container.
So that boiling will surely occur even if the amount of water in the container changes.
it can.

[0012]

(Embodiment 1) A first embodiment of the present invention will be described below with reference to FIGS.

In FIG. 1, reference numeral 1 denotes a substantially cylindrical container for storing a liquid, and a main heating element 2 is attached to a lower end of the container 1. Reference numeral 3 denotes an automatic temperature controller, which controls energization of the main heating element 2. This automatic temperature controller 3 has two circuits, a normally closed circuit and a normally open circuit, and is inverted when the set operating temperature is reached.

Reference numeral 4 denotes a lead-out path, one end of which is disposed below the container 1, the other end of which is disposed in the discharge port 5 outside the body, and an electric pump 6 is provided during the introduction. Reference numeral 7 denotes an auxiliary heating element which is disposed below the side of the container 1 and extends at one end to constitute a sensing surface 9 of a manually reset type temperature switch 8 and a part of the sensing surface 9 is formed by a container. 1 and closely adhered. Reference numeral 10 denotes a knob for manually resetting the temperature switch 8 of a manual reset type, which is slidably attached to a body 11 disposed outside the container 1. Reference numeral 12 denotes a temperature fuse which is attached to the lower part of the container 1.

In the above configuration, a circuit will be described. A circuit in which the main heating element 2 and the automatic temperature controller 3 are arranged in series is connected to a power supply, and a series circuit of an auxiliary heating element 7 and a manual reset type temperature switch 8 is connected in parallel with the automatic temperature controller 3. It is composed.

Next, the operation of this embodiment will be described. When water is poured into the container 1 and the knob 10 is pressed to close the manual return type temperature switch 8 to close the circuit, and then connected to a power source, the main heating element 2 has the automatic temperature controller 3 in a closed state. The body 2 is energized and the water in the container 1 is heated. When the temperature of the mounting surface of the thermostat 3 rises and reaches the set temperature of the thermostat 3, the thermostat 3 operates and the contacts are opened.

In this state, the manual reset type temperature switch 8 is used.
Are closed, the main heating element 2 is further energized via the automatic temperature controller 3 and the auxiliary heating element 7, and the auxiliary heating element 7 is energized. Since the sensing surface 9 of the manual reset type temperature switch 8 is configured by extending a part of the auxiliary heating element 7, the temperature of the sensing surface 9 rises when the auxiliary heating element 7 is energized, and When the operating temperature of the return-type temperature switch 8 is reached, the manual return-type temperature switch 8 is operated, and the power supply to the auxiliary heating element 7 and the main heating element 2 is stopped. When the water channel 7 is closed by sliding the knob 11, the stopper 16 provided on a part of the knob 11 is inserted between the switch 14 and the button 15, and the switch 14 is pressed. Prevent operation.

Although the embodiment of the present invention has been described using an electric pump 5 as a tapping means, the same effect can be obtained by using a manual air pump. There is.

[0019]

As described above, according to the first aspect of the present invention, since the water temperature in the container is tracked , it is possible to prevent a change in the water amount.
And can reliably detect the temperature rise of the auxiliary heating element.
Therefore, a device for preventing abnormal temperature rise can be supplied at low cost.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an electric water heater showing one embodiment of the present invention.

FIG. 2 is an electric circuit diagram of the electric water heater.

FIG. 3 is a longitudinal sectional view of a conventional electric water heater.

FIG. 4 is an electric circuit diagram of the electric water heater.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Container 2 Main heating element 3 Automatic temperature controller 7 Auxiliary heating element 8 Manual reset type temperature switch 9 Sensitive surface

Claims (1)

(57) [Claims] 1. A container for accommodating a liquid, a main heating element for heating the liquid in the container, an automatic temperature controller for controlling energization of the main heating element, an auxiliary heating element and a temperature switch.
A circuit connected in a row is connected in parallel to the thermostat.
The auxiliary heating element is brought into close contact with the container.
Both are electric water heaters, some of which are sensitive to the temperature switch .