JP3309018B2 - 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 the shape of the bottom of an electric water heater for heating and keeping a liquid stored therein.

[0002]

2. Description of the Related Art In a conventional electric water heater, the configuration of the bottom surface of a container is as shown in FIG. That is, in the drawing, the container 51 is formed so that its central portion protrudes upward. On the back surface of the container bottom surface 52, an annular heating element 53 is provided. The heat generating element 53 is mounted in a state in which a heat diffusion plate 54 having good thermal conductivity and an outer peripheral edge on the lower surface of the bottom surface 52 and a back member 55 are pressed against each other. Also the bottom 5
A control sensor 58 is attached to the back surface of the upper convex portion 56 so as to be in close contact therewith, thereby detecting the temperature of the bottom surface 52 and controlling the energization of the heating element 53.

Hereinafter, a conventional electric water heater will be described. 1 example of a schematic configuration of a conventional electric water heater is as shown in FIG. 5, 50 body, 51 containers of top opening disposed in the body 50, 5 3 heating the liquid in the container Heating element.

[0004]

In such a conventional structure, since the upper convex portion 56 is formed flat, the liquid in the container is poured when the heating element 53 is energized, and the bottom portion is formed. If a small amount of hot water remains, the upper convex portion 56
In some cases, water droplets may remain attached. At this time, even if the heating element 53 is energized and the temperature of the bottom surface 52 rises significantly, the temperature of the upper convex portion 56, which is the sensing surface of the sensor 58, does not rise due to the attached water droplets. The temperature of the actual bottom surface 52 is lower. Further, the power is supplied to the heating element 53, and the temperature of the bottom surface 52 further rises to be in an empty state.

When the water droplets adhering to the upper surface convex portion 56 evaporate due to the heat of the temperature rise of the bottom surface 52, the sensor 58
For the first time, the abnormal heat of the bottom surface 52 can be detected. Therefore, the power supply to the heating element 53 is stopped, and the baking is stopped after a while from the state of the bottom surface 52.

As a result, it takes time for the sensor 58 to properly detect the temperature of the bottom surface 52, and the container may be discolored due to empty space, or the reliability of other electric components may be adversely affected by the temperature rise. In addition, it requires unnecessary electricity, is uneconomical, and has problems in durability and safety.

The present invention solves such a conventional problem. A sensor can accurately detect the temperature of the bottom surface and appropriately control the energization state of the heating element, so that the temperature in the container can always be appropriately detected. It is another object of the present invention to provide an electric water heater that is excellent in durability, safety and economical efficiency without baking.

[0008]

In order to achieve the above-mentioned object, a first means of the present invention is to provide a liquid container for storing a liquid on a bottom surface thereof.
With a water inlet that forms an outlet for liquid to the outside
To form a protrusion, thereby mounting a heating element for heating the receiving liquid to the rear surface of the container bottom, the seam plate for supporting the lower surface portion of the heating element is provided to control energization of the heating element When the sensor Ru provided on the convex portion below the container bottom
In both cases, a slope is provided so that no water droplets remain on the protrusion.
In this case, an electric water heater having the seam plate and the inclined portion of the convex portion fixed by welding or the like.

A second aspect of the present invention is an electric water heater according to claim 1, wherein the sensor is mounted so as to be shifted from a center portion of the container to a side of a water inlet provided at a bottom portion of the container.

[0010]

According to the first means, a convex portion is provided on the bottom surface of the container, a sensor for controlling the energization of the heating element is mounted on the rear surface of the convex portion, and an inclined portion is formed on the convex portion so that no water droplet remains. Setting
Due to the girder structure, as the liquid in the container decreases, the water droplets on the convex portion are pulled by the inclined portion due to the surface tension, and the water droplets on the convex portion flow downward. As a result, no water droplet remains. Further, even when water droplets remain on the bottom of the container, there is no water droplet on the convex portion which is the sensing surface of the sensor, so that the sensor can accurately detect the temperature of the bottom surface and appropriately control the energized state of the heating element.

In the case where the convex portion on the bottom surface is exposed to a boiling state by the second means, the position of the convex portion on the bottom surface is shifted from the center of the container so that the boiling water droplet on the bottom surface hits the side surface of the container. However, since the center is shifted, the water drops do not concentrate and the water drops hardly accumulate.

[0012]

(Embodiment 1) An embodiment of the present invention will be described below with reference to the drawings. 1 to 3 , reference numeral 1 denotes an outer case, on which an inlet frame 2 is placed. Reference numeral 3 denotes a container having an upper surface opening arranged in the main body 1, reference numeral 4 denotes a lid covering the opening of the container 3, and reference numeral 5 denotes a heating element for heating the liquid in the container.

The lid 5 is pivotally supported by a hinge 2 a behind the spout 2, and seals the container 3. Numeral 7 operates a push plate 8 by a pump to send air into the container 3 and draw out the liquid in the container 3 to the outside of the body. Reference numeral 9 denotes a water inlet that forms a liquid outlet from the inside of the container 3 to the outside, and reference numeral 10 denotes a water inlet path that leads from the container 3 to the outside of the container. Also, 11
Is a base constituting the lower part of the vessel.

Next, in FIG. 3, the container 3 is formed by fixing the outer peripheral portion of a peripheral edge 12a to the lower end of the cylindrical body in a watertight manner by welding or the like. The heating element 5 is mounted on the bottom surface 12 via a heat conductive plate 13 made of, for example, an aluminum plate, an aluminum-plated steel plate, or the like having a good thermal conductivity. On the lower surface of the heat generating element 5, a heat diffusing plate 15 of good conductivity and relatively deformable made of an aluminum plate or the like having the outer periphery of the flat plate fitted to the inner wall of the peripheral edge 12a of the bottom surface 12 is arranged. . The heat conducting plate 13, the heating element 5 and the heat diffusing plate 15 have a central portion protruding upward, and a rigid and high heat conductive seam plate 16 such as a surface-treated steel plate having a through hole at the outer peripheral side and the center is formed. Provided.

[0015] Figure 3 between where the bottom surface substantially central is provided with a protrusion 18 serving as the sensing part of the sensor 17 bottom section 12
It provided an inclined portion 19 toward the convex portion 18 as the convex portion
No water droplets remained on 18. The bottom surface 12
A pressing force is applied to the lower surface of the container 3, and the bottom of the container 3 is held and fixed by welding or the like. The inclined portion 19 is brought into close contact by welding or the like in order to bring the heating element 5 into closer contact with the container bottom surface 12. The sensor 17 indirectly measures the liquid temperature in the container 2 based on the temperature of the bottom surface 12 and controls the energization state of the heating element 5 to control the liquid temperature. Reference numeral 20 denotes a control board for controlling the heating element 5 by a signal from the sensor 17.

In the above configuration, when the heating element 5 of the electric water heater is energized, the liquid in the container 3 is poured and the liquid in the container is reduced. It will be exposed first. It will not remain water droplets on the protrusion 18 since the provided inclined slope portion 19 to further. Therefore, the sensor 17 can accurately detect the temperature of the bottom surface 12 and appropriately control the energized state of the heating element 5.

Further, since the heating element 5 is held by the seam plate 16 and fixed by welding or the like between the inclined surface portion 19 and the bottom surface portion 12 of the container 3, the radiant heat of the heating element 5 is transmitted to the sensor 17. Can be prevented.

[0018] (Example 2) Next, a second embodiment of the present invention will be described with reference to FIG.
In the embodiment of the present invention, the center a of the container 3 and the center b of the convex portion 18 on the bottom of the container are shifted to the water inlet 9.

In the above configuration, when the liquid in the container 3 is reduced by pouring the liquid in the container 3 when the heating element 4 of the electric water heater is energized, the convexity of the bottom surface 12, which is the sensing surface of the sensor 17, is obtained. The part 18 will be exposed first. However, since the center of the container 3 and the center of the convex portion 18 of the sensor 17 mounting portion on the bottom surface 12 are shifted to the water inlet 9 side, when the convex portion 18 is exposed, water droplets are smoothly pulled, and No water droplets remain on the projections 18. Further, when the bottom surface 12 is exposed and the boiling is continued, the splash of water droplets from the side surface of the container 3 does not collect at the center b, and the water droplets do not accumulate on the convex portions 18 of the container bottom surface 12. Therefore, the sensor 17 can accurately detect the temperature of the bottom surface 12 and control the energized state of the heating element 5.

[0020] Next in the Summary of the invention of claim 2, wherein Te with <br/> you described with reference to FIG. As shown in FIG. 4 , the position of the convex portion 18 on the bottom surface 12 of the container 3 is attached to the heating element 5.

In the above configuration, when the heating element 5 of the electric water heater is energized, if the liquid in the container decreases, the convex portion 18 of the bottom surface 12, which is the sensing surface of the sensor 17, is exposed. In the process of further exposing the bottom surface 12, the bottom surface 1
Since the mounting portion of the second sensor 17 is displaced from the center of the container and is close to the heating element 5, the temperature of the convex portion 18 of the bottom surface 12 quickly rises, and the sensor 17 detects the temperature of the bottom surface 12 and energizes the heating element 5. Can be stopped.

In the structure of the first and second embodiments, the container 3
By subjecting the bottom surface 12 of the container including the inner surface or the convex portion and the inclined surface portion 19 to a surface treatment with a water-repellent paint, water droplets can be further reduced.

[0023]

As described above , according to the present invention, the projection is first exposed during the process of decreasing the liquid in the container. Although the bottom surface of the container is exposed first, water droplets flow on the inclined portion of the convex portion of the sensor mounting portion, so that no water droplets remain. Therefore, even when a little water remains on the bottom of the container, there is no water droplet on the convex portion, so that the sensor can accurately detect the temperature of the bottom surface and appropriately control the energization state of the heating element. Therefore, if the heating element is energized at this time, the sensor can immediately detect an abnormal temperature rise on the bottom surface and stop energizing the heating element.

Accordingly, the baking is not performed, and the electric capacity required conventionally can be saved. In addition, the temperature rise of the heating element can be reduced abnormally, preventing discoloration due to the temperature rise inside the container and adversely affecting the built-in electric parts, safety and durability without insulation failure and disconnection failure, and economical It is possible to provide a high-quality electric water heater having excellent properties.

[Brief description of the drawings]

FIG. 1 is a full vertical sectional view of an electric water heater according to a first embodiment of the present invention.

FIG. 2 is an external perspective view of the electric water heater.

FIG. 3 is a sectional view of a main part of the electric water heater according to the first and second embodiments of the present invention.

FIG. 4 is an enlarged sectional view of a main part of an electric water heater showing the gist of the invention described in claim 2 of the present invention.

FIG. 5 is a longitudinal sectional view of a main part showing an example of a conventional electric water heater.

[Explanation of symbols]

 3 Container 4 Heating Element 9 Outlet 12 Container Bottom 17 Sensor 18 Convex 19 Slope

Continued on the front page (72) Inventor Kaoru Maekawa 1006 Kazuma Kadoma, Kazuma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (56) References JP-U 4-125822 (JP, U) JP-A 59-37032 (JP) , U) (58) Fields surveyed (Int. Cl. ⁷ , DB name) A47J 27/21

Claims (2)

(57) [Claims] 1. A liquid to the outside is provided on a bottom surface of a container for storing a liquid.
Provided with a water guide opening forming the outlet of the body, to form a convex portion, with mounting a heating element for heating the receiving liquid to the rear surface of the container bottom, the seam plate for supporting the lower surface portion of the heating element provided, Rutotomoni provided a sensor for controlling the energization of the heating element on the convex portion below the container bottom, wherein
An electric water heater in which an inclined portion is provided so that no water droplet remains on the convex portion, and the seam plate and the inclined portion are fixed by welding or the like. 2. The electric water heater according to claim 1, wherein the sensor is displaced from a center of the container to a side of a water inlet provided at a bottom of the container.