JPH05103725A - Electric water boiler - Google Patents

Abstract

PURPOSE:To prevent a drop in the durability of a vessel, and improve a convenience for use, for example, in such a way as allowing liquid to be again boiled quickly, in an electric water boiler used for heating liquid in the vessel and thermally insulating the heated liquid. CONSTITUTION:A temperature detecting device 5 laid on the outer surface of the bottom center of a vessel 1 is constituted of a thermo-sensitive plate 8 having an upper flat section and a lower U-shaped recess section, a temperature sensor 10 mounted on the recess section via an insulation 9, and an insulation 11 closing the periphery of the recess section via a gap. Then, the termosensitive plate 8 laid on the insulation 11 is press fitted to the bottom outside of the vessel 1 via the insulation 11 with a fitting spring. As a result, the thermal capacity of the plate 8 can be reduced and the vessel 1 is hardly exposed to the radiation heat of the plate 8 or heat generation body, thereby making it possible to keep the temperature of the vessel 1 and temperature detected with the sensor 10 nearly equal to each other. According to this construction, an excessive temperature fluctuation in the vessel 1 can properly be detected, and the deterioration thereof due to overheating can be prevented. Also, it is possible to quickly cope with necessity for again boiling water.

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 that heats and keeps a contained liquid.

[0002]

2. Description of the Related Art A conventional electric water heater will be described below.

As shown in FIGS. 4 and 5, a heating element having a through hole in the central portion is pressed by a back plate and fixed to the outer surface of the bottom portion of the bottomed cylindrical container 1 provided inside the exterior body 2. A temperature detecting device 14 is arranged on the outer surface of the bottom center of the container 1. Reference numeral 4 denotes a control board that controls the energization of the heating element 3 with an electric signal from the temperature detection device 14. Temperature detector 1
Reference numeral 4 denotes a heat sensitive plate 15 formed of a cylindrical metal having a flat surface on the upper surface and a through hole on the side surface, a temperature sensor 10 mounted on the through hole through an insulating material 9, and a heat insulating plate supporting the heat sensitive plate 15. The heat sensitive plate 15 made of the material 16 and placed on the heat insulating material 16 was pressure-bonded to the bottom surface of the container 1 via the heat insulating material 16 by the mounting spring 13.

[0004]

However, in the above-mentioned conventional configuration, the temperature of the temperature sensor 10 is detected when the temperature of the container 1 in which the heat capacity of the heat-sensitive plate 15 is large and abruptly changes, for example, when boiling a small amount of water or when boiling the rice. There is a problem that the container 1 is overheated and discolored or the durability is deteriorated, and even when water is added during the heat retention to boil water, the temperature detection of the temperature sensor 10 is delayed and immediately. It had a problem that the water did not boil.

The present invention solves the above-mentioned problems of the prior art. It prevents heating in response to a sudden temperature change in the container, does not deteriorate the durability of the container, and is easy to reheat. The purpose is to provide a good electric water heater.

[0006]

In order to achieve this object, an electric water heater according to the present invention comprises a temperature detecting device disposed on the outer surface of the center of the bottom of a container, a flat portion on the upper portion and a U-shaped recess on the lower portion. The heat-sensitive plate mounted on the heat-insulating material includes a formed heat-sensitive plate, a temperature sensor mounted in the recess of the heat-sensitive plate through an insulating material, and a heat-insulating material that covers the periphery of the recess by providing a gap with the heat-sensitive plate. Is attached to the outer surface of the bottom of the container via a heat insulating material and crimped with a spring, and the heat sensitive plate is supported by the protrusion formed on the upper surface of the heat insulating material so that a gap is provided between the heat sensitive plate and the heat insulating material. It has a structure.

[0007]

With this structure, the temperature sensor is less likely to receive the radiant heat of the heating element, the temperature of the container and the temperature detected by the temperature sensor are close to each other, and the conductive heat to the heat insulating material is reduced.
The temperature of the heat sensitive plate is close to the temperature of the container, and a rapid temperature change in the container can be detected accurately.

[0008]

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

1 to 3 showing an embodiment of the present invention, the same parts as those of the conventional example are designated by the same reference numerals and the description thereof will be omitted.

As shown in FIGS. 1 to 3, the temperature detecting device 5 disposed on the outer surface of the center of the bottom of the container 1 is formed of a plate member integrally with a flat portion 6 on the upper portion and a U-shaped recess 7 on the lower portion. The heat sensitive plate 8 formed, the temperature sensor 10 such as a thermistor mounted in the U-shaped recess 7 via the insulating material 9, and the heat insulating material 11 covering the periphery of the U-shaped recess 7 with a gap. It is a thing.

The projection 12 formed on the upper surface of the heat insulating material 11 supports the heat sensitive plate 8 so that a gap is provided between the heat sensitive plate 8 and the heat insulating material 11. The temperature detecting device 5 in which the heat sensitive plate 8 is placed on the heat insulating material 11 is pressure-bonded to the outer surface of the bottom of the container 1 by the mounting spring 13 via the heat insulating material 11.

The operation of the electric water heater constructed as above will be described below. When the liquid is stored in the container 1 and the energization is started, the heating element 3 is heated to heat the liquid in the container 1, and the temperature detected by the temperature detecting device 5 arranged at the bottom of the container 1 also rises.

At this time, since the heat-sensitive plate 8 holding the temperature sensor 10 via the insulating material 9 is formed of a plate material, the heat-sensitive plate 8 has a small heat capacity and the conduction heat from the container 1 is
Immediately transmitted to the temperature sensor 10. Moreover, since the U-shaped concave portion 7 of the heat sensitive plate 8 holding the temperature sensor 10 has its peripheral portion covered with the heat insulating material 11, the temperature detecting device 5
The U-shaped concave portion 7 is not directly subjected to the radiant heat of the heating element 3 arranged on the peripheral portion of the.

A protrusion 12 formed on the upper surface of the heat insulating material 11
Since a gap is provided between the heat-sensitive plate 8 and the heat-sensitive plate 8, the conduction heat from the heat-sensitive plate 8 to the heat insulating material 11 is limited, and the heat-sensitive plate 8
As for the temperature of 1, the value closer to the bottom surface temperature of the container 1 can be detected.

The temperature sensor 1 thus detected
When the temperature of 0 reaches the set temperature, the control board 4 stops energizing the heating element 3.

When a cold liquid such as water is poured into the container 1 while keeping the temperature thereof, the temperature of the container 1 is lowered, and the temperature of the temperature detecting device 5 mounted on the bottom surface of the container 1 is lowered, so that the control board 4 is removed. Electricity is again supplied to the heating element 3 via the heater, and reheating can be performed immediately.

As described above, according to the present embodiment, the temperature detecting device 5 disposed on the outer surface of the center of the bottom of the container 1 includes the heat sensitive plate 8 having the flat portion on the upper portion and the U-shaped recess on the lower portion. , A temperature sensor 10 mounted in the recess via an insulating material 9,
By providing a heat insulating material 11 that covers the periphery of the recess with a gap, and by crimping with a mounting spring 13 on the bottom surface of the container 1,
The heat capacity of the heat sensitive plate 8 is reduced, and the heat sensitive plate 8 serves as the heating element 3.
The radiant heat can be hardly received and the temperature can be detected by following the rapid temperature change in the container 1 quickly, so that the overheat can be prevented, the durability of the container 1 is not deteriorated, and the reheating process can be quickly performed.

Further, the projection 12 formed on the upper surface of the heat insulating material 9
Since the heat sensitive plate 8 is supported by and a gap is provided between the heat sensitive plate 8 and the heat insulating material 9, the heat conduction to the heat insulating material 9 becomes small, and the temperature of the heat sensitive plate 8 is received closer to the temperature of the container 1. You can feel it.

[0019]

As is apparent from the above description of the embodiments, the present invention provides a temperature detecting device disposed on the outer surface of the center of the bottom of the container, a flat portion on the upper portion and a U-shaped concave portion on the lower portion. The heat-sensitive plate, the temperature sensor mounted in the recess of the heat-sensitive plate through an insulating material, and the heat-insulating material that covers the periphery of the recess by providing a gap with the recess of the heat-sensitive plate, and mount the heat-sensitive plate on the heat-insulating material. A structure in which it is attached to the outer surface of the bottom of the container via a heat insulating material and crimped with a spring, and a protrusion formed on the upper surface of the heat insulating material supports the heat sensitive plate, and a gap is provided between the heat sensitive plate and the heat insulating material. As a result, it is possible to realize an excellent electric water heater that prevents overheating in response to a sudden temperature change in the container, does not deteriorate the durability of the container, and is easy to re-heat the water.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a temperature detecting device for an electric water heater according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view of a temperature detecting device of the electric water heater.

FIG. 3 is a schematic sectional view of the electric water heater.

FIG. 4 is a schematic sectional view of a conventional electric water heater.

FIG. 5 is an exploded perspective view of the temperature detecting device of the electric water heater.

[Explanation of symbols]

 8 Heat Sensitive Plate 9 Insulation Material 10 Temperature Sensor 11 Heat Insulation Material 12 Projection

Claims (2)

[Claims] 1. A bottomed cylindrical container provided in an outer package, a heating element having a through hole in the center fixed to the outer surface of the bottom of the container, and a temperature disposed on the outer surface of the center of the bottom of the container. An electric water heater equipped with a detection device and a control board for controlling energization of a heating element with an electric signal from the temperature detection device, wherein the temperature detection device has a flat portion in an upper portion and a U-shape in a lower portion. A heat sensitive plate having a concave portion, a temperature sensor attached to the concave portion of the heat sensitive plate via an insulating material, and a heat insulating material which covers the circumference of the concave portion with a gap between the heat sensitive plate and the heat sensitive plate is provided on the heat insulating material. An electric water heater in which the mounted heat-sensitive plate is attached to the outer surface of the bottom of the container via the heat insulating material and pressed by a spring. 2. The electric water heater according to claim 1, wherein the heat sensitive plate is supported by a protrusion formed on the upper surface of the heat insulating material, and a gap is provided between the heat sensitive plate and the heat insulating material.