JPH0319319Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to an electric water heater, particularly to a mounting structure for a heating element.

(Prior art) For electric water heaters, for example, Japanese Patent Application Laid-Open No. 58-104447
There is an idea shown in the publication. In this example, the heating element has a T-shape consisting of a heating element part and a mounting member provided below them, and the mounting member has heat-resistant packing such as silicone in a through hole formed in the bottom of the bottomed container. A retaining ring is attached from the outside and a biasing force is applied to attach the retaining ring to the bottom plate.

(Problems to be Solved by the Invention) However, the heating element has a relatively complicated T-shape, and there is a drawback that limescale adhering to the back surface of the heating element cannot be cleaned. Therefore, the purpose of this invention is to simplify the structure and facilitate cleaning.

(Means for solving the problem) The gist of this invention is that in an electric water heater that has a heating element that is provided below the upper case and serves as the bottom surface,
The heating element has a metal case that is approximately donut-shaped with a bottom in the center and has a protrusion that has a trapezoidal cross section so that there is no hidden area when viewed from the pouring spout side, and a back side of the protrusion of the metal case. The heater coil is housed in a recess corresponding to the protrusion, and includes a heater coil coated with an insulating material and fixed therein with an inorganic material.

(Function) Therefore, the heating element has a simple shape with an approximately donut-shaped protrusion with a bottom in the center, and there is no hiding place, and the heating element can be easily inserted by inserting a brush through the spout. can be easily washed and the above purpose can be achieved.

(Example) Hereinafter, an example of this invention will be described with reference to the drawings.

In FIGS. 1 to 3, the upper case 1a of the electric water heater has a substantially cylindrical shape, and has a spout 2 at the top.
is formed, and a lid 3 is screwed into the spout 2. 4 is a cover that wraps over the lid 3, and the upper case 1
It is screwed into a. In addition, this upper case 1a
The lower part is open, and a heating element 6 is attached to the opening as described below, forming the bottom surface and forming a water boiling chamber 5.

A screw 7 is formed on the lower outer periphery of the upper case 1a, and a lower case 1b is screwed to the lower case 1b, which is provided with a screw 8 that is screwed into the screw.

The lower case 1b has the screw 8 inside its opening.
is engraved, and a step 9 is formed in the middle part of the inside.
Further below, a bottom body 10 is integrated by welding and caulking the tip of a connecting rod 11.

The heating element 6 has a diameter almost equal to the lower diameter of the upper case 1a, and is disk-shaped, with a trapezoidal cross-section so that the center part is not hidden when viewed from the pouring port toward the water boiling chamber 5 side. It stands out. The heating element 6 has a metal case 13 on the outside, has a bottom 14 at the center, and has a substantially donut-shaped protrusion 15. On the opposite side of the water boiling chamber of the metal case 13, there is a protrusion 1 on the back side of the protrusion 15.
A heater coil 17 is disposed in the recess 16 corresponding to the recess 16 with a ceramic insulating material 18 interposed therebetween, and the entire recess 16 is filled with an inorganic material 19 such as cement. In addition, a support plate 2 for a temperature switch 20 such as a thermostat is mounted on the lower surface of the metal case 15 (on the side opposite to the water boiling room).
1 is attached. The support plate 21 is approximately disk-shaped and has the same diameter as the metal case 15, and the temperature switch 20 is attached through a hole 22 formed in the center.

The temperature switch 20 sets the temperature of the hot water to, for example, 90°C.
The temperature switch body 20a controls the temperature back and forth.
and a mounting piece 20b that wraps and supports the temperature switch main body 20a, and this mounting piece 20b and the support plate 21 are connected with screws 23.

At this time, one of the screws 23 supports the mounting piece 25 holding the temperature fuse 24.
The support plate 21 of the temperature switch 20 is attached to the back side of the metal case 13 of the heating element 6. The temperature fuse 24 is connected to the temperature switch 2.
The cutoff temperature is, for example, around 120°C.

The elastic ring 26 is ring-shaped and has a fitting groove 27 formed on its inner surface into which the outer peripheries of the metal case 13 and the support plate 21 fit.

The heating element 6 is integrated with a support plate 21 attached to the back surface of the metal case 13, an elastic ring 26 is fitted on the outer periphery, and then the lower case 1b is assembled.
By placing the upper case 1a on the stepped portion 9 of the lower case 1b, both cases 1a and 1b are removed.
Then, the metal case 13 and the like of the heating element 6 are clamped and attached. Note that both cases 1a and 1 are connected with screws 12.
b is fixed.

28 is a handle provided on the upper case 1a;
9 is an electric wire, and 30 is a plug for inserting a cigarette for an automobile.The connections with the heater coil 17, temperature switch 20, and temperature fuse 24 are as shown in FIG. When the heater coil 17 is inserted into the cigarette socket of the vehicle, electricity is applied to the heater coil 17 from the power source of the vehicle and the heater coil 17 is heated. 31 is an engagement piece provided on the bottom body 10 of the lower case 1b.

(Invention of the invention) As described above, according to this invention, the heating element has a simple shape with a protrusion that is approximately donut-shaped with a lower part in the center, and a place that is hidden when seen from the pouring spout. It is easy to clean using a brush with a handle.

Furthermore, since the protrusion is shaped like a donut, the surface area increases and heat conduction is good. Furthermore, structurally, the metal case of the heating element is a single piece, making it easy to manufacture and low in cost.

[Brief explanation of the drawing]

Fig. 1 is a half sectional view showing an embodiment of this invention, Fig. 2 is an enlarged sectional view of the main part, Fig. 3 is an exploded perspective view of the heating element and the mounting plate and elastic ring attached to its lower part. The figure is a circuit diagram of this invention. 1a... Upper case, 1b... Lower case, 6...
heating element, 13... metal case, 15... protrusion,
16... recess, 17... heater coil, 19...
Inorganic materials such as cement.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. In an electric water heater that has a heating element that is installed below the upper case and serves as the bottom surface, the heating element is approximately donut-shaped with a bottom in the center and has a hidden part when viewed from the spout side. A metal case having a protruding part having a trapezoidal cross-section so as not to disturb the metal case, and a metal case that is housed in a recess corresponding to the protruding part on the back side of the protruding part of the metal case, and fixed therein with an inorganic material. An electric water heater characterized by comprising a heater coil coated with an insulating material. 2. The electric water heater according to claim 1, wherein the inorganic material is made of cement.