JPH0327551Y2 - - 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 to apply a biasing force, and the retaining ring is attached to the bottom plate. The temperature of the heating element is controlled by a thermostat, which is located inside the heating element and its head touches the top plate to detect the temperature of the hot water in the container. However, the thermostat 26 is arranged through a through hole 20 in the center of the heat generating member 16.

(Problem to be solved by the invention) However, although the thermostat is located very close to the heat-generating member and its temperature-sensitive surface is mounted so that it is easy to detect the temperature of the water, the temperature of the heat-generating member is It has the disadvantage that it is located nearby and is easily heated by the heat generating member, the temperature cannot be accurately detected, and the operating temperature tends to vary.

Therefore, the purpose of this invention is to make the temperature switch unaffected by the heat generated by the heating element.

(Means for solving the problem) The gist of this invention is that in an electric water heater that has a heating element that is installed below the upper case and serves as the bottom of the boiling chamber, the heating element has a lower part in the center. The center of the metal case includes a metal case having a protrusion formed in a substantially donut shape, and a heater coil disposed in a recess formed on the back side of the protrusion with an insulating material interposed therebetween. This is because a temperature switch is attached to the lower part of the tank, opposite to the water boiling chamber.

(Function) Therefore, a temperature switch is attached to the lower central part of the metal case on the side opposite to the water boiling chamber, and the hot water in the water boiling chamber is detected, and the heater coil is housed in the lower part. Since it is separated from the recess, the influence of heat can be reduced, and the above object 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 pouring spout 2. 4 is a cover that wraps around the top of lid 3, and upper case 1
It is screwed into a.

The lower part of the upper case 1a is open, and a heating element 6 is attached to the opening as described below, forming a bottom surface and a water boiling chamber 5. Further, 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 7.

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 that is approximately equal to the lower diameter of the upper case 1a, has a disk shape, and has a central portion protruding toward the water boiling chamber 5 side. The heating element 6 has a metal case 13 on the outside, has a lower part 14 in the center, and has a substantially doughnut-shaped protrusion 15. On the opposite side of the metal case 13 to the water boiling chamber, a recess 16 is formed on the back side of the protrusion 15 and corresponds to the protrusion 15. A heater coil 17 is disposed in the recess 16 with a ceramic insulating material 18 interposed therebetween, and an inorganic material 19 such as cement is disposed therebetween.
is packed into the entire recess 16. Also,
A support plate 21 for a temperature switch 20 such as a thermostat is attached to the lower surface of the metal case 15 (on the side opposite to the water boiling chamber). The support plate 21 is approximately disk-shaped and has the same diameter as the metal case 15, and a 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.
It consists of a temperature switch main body 20a and a mounting piece 20b that wraps and supports the temperature switch main body 20 at the front and rear, and the 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 provided at a position remote from the temperature switch 20, so that the influence of heat is reduced, and its cutoff temperature can be set to a low temperature of, for example, around 120°C, which is advantageous from a safety standpoint.

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;
Reference numeral 9 indicates an electric wire, and 30 indicates a plug for inserting a cigarette into 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.

In the above-described configuration, when the plug 30 is attached to an automobile cigarette socket, the heater coil 17 is energized and water is boiled in the water boiling chamber 5. Then, the temperature is determined by the temperature switch 20.
The temperature is controlled at around 100°C.

(Effects of the invention) As described above, according to this invention, the temperature switch is located relatively far from the heater coil,
The effect of heat is small and the temperature of hot water can be detected accurately.

Further, it has the advantage that it is not necessary to use a material with high heat resistance for the temperature switch.

[Brief explanation of drawings]

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, 14...Bottom, 2
0...Temperature switch, 24...Temperature fuse.

Claims (1)

[Scope of Claim for Utility Model Registration] In an electric water heater that has a heating element that is installed below the upper case and serves as the bottom of the boiling chamber, the heating element is a protrusion that is approximately donut-shaped and has a lower part in the center. and a heater coil disposed with an insulating material interposed in a recess formed on the back side of the protrusion, and a counter-boiling chamber in the central lower part of the metal case. An electric water heater characterized by a temperature switch attached to the side.