JPH0559725B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an electric water heater for heating and keeping a stored liquid warm.

Conventional technology Conventional electric water heaters of this type include, for example, the Jikosho
As shown in Japanese Patent No. 59-31148, it had a structure as shown in FIG. That is, 1 is an exterior body, 2 is a bottomed cylindrical container provided in the exterior body 1, and a band-shaped heating element 3 is wrapped around the lower outer peripheral side of this container 2. 3, a vertically elongated water level gauge 4 was provided on the cylindrical outer wall of the container 2, and a see-through window 5 was provided in the exterior body 1 corresponding to the water level gauge 4.

Problems to be Solved by the Invention However, in such a conventional configuration, since the band-shaped heating element 3 is wrapped around the lower outer circumferential surface of the container 2, the water level gauge 4 is inevitably attached to the heating element 3. It must be located in the upper part and attached to the cylindrical outer wall of the container 2, and as a result, even though a considerable amount of contained liquid remains in the container 2, the water amount display area is visible to the transparent window 5. had become limited. In addition, if the liquid stored in the container 2 is used too much, a part of the band-shaped heating element 3 will be exposed and the heating will become dry, which poses a safety problem, and the function of displaying the amount of water will be halved. Not only did it work, but it was also extremely difficult to use. As an improvement on the above-mentioned one, for example, as seen in Japanese Utility Model Publication No. 59-34421, there is one in which the water level gauge 4 is derived from the bottom of the container 2, but in this,
When cleaning the inside of the container 2, dirt and debris tend to accumulate in the outlet, and there is also a problem in that the heating element runs dry.

The present invention solves these problems,
The object of the present invention is to provide an electric water heater having a water level gauge that is easy to use and clean.

Means for Solving the Problems In order to solve the above problems, the present invention provides an exterior body, a bottomed cylindrical container having a heat transfer plate disposed inside the exterior body and protruding from the bottom surface, and a heat transfer plate. The bottom of the container is equipped with a heat-generating plate attached to the back side of the plate via an insulating material, and the protrusion on the bottom of the container is cut into a D-shape, and an outlet to the water level gauge is provided in the lower part of the side wall of the container corresponding to this cut. It was established.

Effect According to the above configuration, the water level gauge can be arbitrarily provided at the lowermost end of the cylindrical outer wall of the container, and this water level gauge can be cut into the approximately D shape of the bottom protrusion of the container to which the heating plate is attached. By locating the outlet of the water level gauge into the container at the lowest end of the side wall of the container, the water level display range is widened, and the outlet has a protrusion toward the inside of the container. Even if there is a problem, a space is secured by the D-cut, making it easy to reach when cleaning, and as a result, an electric water heater with a water level gauge that is easy to use and clean can be obtained.

Embodiment Hereinafter, an embodiment of the present invention will be described based on FIGS. 1 to 4. In the figure, reference numeral 6 denotes a heat exchanger plate whose central portion protrudes upward in a substantially D-shape to form an outer circumferential side edge 7, and has a temperature detection surface 9 on the lower surface of the D-cut circumferential side edge 8. , and by fixing the outer edge to the lower end of the cylinder liquid-tightly by means such as welding,
A metal container 10 is formed. 11 is container 1
It is an exterior body that encloses 0 through space.

On the lower surface of the heat transfer plate 6 described above, a heating plate 12 in which a first heating wire and a second heating wire of low power, which will be described later, are integrally wound is stacked between upper and lower insulating plates 13 and 14. A first heat diffusion plate 15 having good thermal conductivity is disposed on the upper surface of the upper insulating plate 13. Further, the heat generating plate 12 has a through hole in the center, and a pressing allowance is provided on the lower surface of the heat transfer plate 6 by a second heat diffusion plate 17 having good thermal conductivity and a backing material 18 having an outer peripheral side part 16. In this state, it is fixedly built-in by spot welding or the like to form a heating element.

Note that the backing material 18 is provided with a notch 21 of an appropriate size on the D-cut outer peripheral side. Further, a substantially Z-shaped container fitting 23 for fixing a heat shield plate 22, which will be described later, is fixed to this backing material 18. Further, the D-cut portion of the approximately D-shaped protrusion of the container 10 is located in the direction of the water level gauge 24 provided on the cylindrical outer wall of the container 10. 32
is a waterproof fitting 32 which is attached to the container 10 in a state where it penetrates into the container 10 and communicates with the water level gauge 24.

Further, the lead line of the heat generating plate 12 is located at a portion facing a substantially D-shaped D-cut portion of the bottom protrusion of the container 10.

Further, a heat shield plate 22 is provided below the heating element portion, and a square hole portion of an appropriate size is provided in this heat shield plate 22 to correspond to the notch 21 of the backing material 18. ing. Further, a temperature controller 25 is installed in the center of this heat shield plate 22 by a mounting spring 26.
The temperature-sensitive reed switch 27 and the temperature fuse 28 are integrated with a good heat conductive material, and are temporarily assembled using presser springs 29 at positions corresponding to the notches 21 of the backing material 18, and furthermore, the wiring stand 30 is fixed. There is. This therefore allows major wiring work to be carried out. Moreover, this heat shield plate 22
A temperature controller 25 and a temperature-sensitive reed switch 27 integrated with the temperature controller 25 are attached to the bottom of the container 23 via the container fitting 23.
The heat receiving portions of the temperature fuse 28 and the temperature fuse 28 are fixed to each other by a mounting bracket 31 so as to be in close contact with each other.

Further, the first heating wire 19 is connected to a temperature controller 25.
, the second heating wire 20 is connected to a temperature-sensitive reed switch 27.
are connected to each other by an electrical circuit to form a parallel circuit, and a temperature fuse 28 is further connected in series to form an electric water heater.

In the above configuration, a liquid is stored in the container 10,
When electricity starts, the heat generating plate 12 is heated, the heat is sufficiently diffused by the first heat diffusion plate 15 via the insulating plate 13, and the heat is transferred to the liquid via the heat transfer plate 6. At the same time, heat is also diffused toward the outer peripheral side through the second heat diffusion plate 17. The heat transferred to the backing material 18 by the second heat diffusion plate 17 is transferred to the outer peripheral side and is used to heat the liquid.

As described above, since the members constituting the heat exchanger plate 6 and the heating element part of the container 10 are partially D-cut in a substantially D shape, the D-cut circumferential edge 8 allows the distance between the component parts to be Position regulation becomes reliable, and in particular, it becomes easy and reliable to secure the insulation distance between the heating wire lead-out portion from the heating panel 12 and the second heat diffusion plate 17 and the backing material 18, and the ease of assembly is improved. can.
Furthermore, assuming that the inner diameter d of the bottom protrusion of the container 10 is constant, in order to improve temperature correlation with the liquid and safety in the event of an abnormality, it is necessary to integrate the heat-receiving part of the temperature-sensitive reed switch 27 and the temperature fuse 28. and container 10
It is necessary to increase the contact area with the temperature detection surface 9 on the bottom surface of the heat transfer surface, but in the conventional circular heat transfer surface protrusion, the diameter d of this protrusion must be made small. Heat transfer plate 6
This greatly reduces the projected area of the surface of the protrusion, which increases the wattage density and shortens the life of the heating element. Moreover, by making it substantially D-shaped, the contact area can be expanded with a slight reduction in the projected area, and the temperature correlation with the liquid temperature can be highly accurate. In addition, by forming the approximately D-shape, compared to the conventional circular shape, the contact area remains the same, that is, the distance a from the center point of the protrusion to the D-cut remains unchanged, and the projection of the protrusion of the heat exchanger plate 6 The area can be increased by increasing the diameter d, and as a result, the watt density can be reduced, and the life of the heating element can also be extended.

Also, since the first heat diffusion plate 15 is added between the insulating plate 15 on the heat generating plate 12 and the heat transfer plate 6,
Even in the dry cooking state, the generated heat can be sufficiently diffused and conducted to the heat exchanger plate 6, and as a result, local heating does not occur, so that discoloration of the surface of the heat exchanger plate 6 can be reduced. In addition, sufficient heat diffusion occurs, so the heat conduction area is expanded.
As a result, it is also possible to improve heating efficiency.

Further, since the outlet to the water level gauge 24 can be installed near the lowermost end of the outer wall of the container 10 corresponding to the D-cut portion of the protrusion of the container 10, the water amount display range can be widened.

Further, since the D-cut portion of the approximately D-shaped protrusion of the container 10 is located in the direction of the water level gauge 24, when cleaning the bottom surface of the container 10, the waterproof metal fitting 32
Even if there is a protrusion on the inner surface of the container 10, it does not become an obstacle, and as a result, cleaning efficiency is improved.

Effects of the Invention As is clear from the above embodiments, in the electric water heater of the present invention, the protruding portion on the bottom of the container is cut into a substantially D-shape, and an outlet for the water level gauge is provided in the lower part of the side wall of the container corresponding to the cut portion. With this configuration, the water amount display range is widened, and even if there is a protrusion inward of the container at the outlet,
The D-cut secures space, makes it easier to access when cleaning, and improves usability, so it has great practical value.

[Brief explanation of drawings]

Fig. 1 is an enlarged view of the main parts of an electric water heater according to an embodiment of the present invention, in which a is a vertical sectional view, b is a partial sectional view showing the heating element, and Fig. 2 is an enlarged view of the electric water heater according to an embodiment of the present invention. Figure 3 is an exploded perspective view of the heating element of the water heater, Figure 4 is a plan view showing the temporarily assembled state of the heat shield plate of the water heater, and Figure 5 is a conventional electric water heater. It is a longitudinal cross-sectional view of the vessel. 6...Heat transfer plate, 10...Container, 11...Exterior body, 12...Heating plate, 24...Water level gauge.

Claims (1)

[Claims] 1 comprising an exterior body, a bottomed cylindrical container disposed within the exterior body and having a heat exchanger plate protruding from the bottom surface, and a heat generating plate attached to the back side of the heat exchanger plate via an insulating material, An electric water heater in which the bottom protrusion of the container is cut into a substantially D-shape, and an outlet to a water level gauge is provided in a lower part of the side wall of the container corresponding to the cut.