JPH08167470A - Heating device - Google Patents

Abstract

PURPOSE: To provide a heating device which can maintain the insulation, gives no fear of electric shock and can safely stop the power feeding function even in the final period of the service life of a heating body. CONSTITUTION: This heating device 4 is composed of a sheath heater 1 to be a heating body to heat a liquid; a water pipe to pass the liquid; and a heat conductive metal part 3 to integrally connect the heating body 1 and the water pipe. By covering the water pipe 2 by an electric insulating member 7 and a metal pipe 8, the water pipe 2 is electrically insulated from the metal part 3, and furthermore, this heating device 4 is installed to the other structure of an apparatus by electrically insulating through an electric insulator.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating device for an electric water heater which heats and keeps hot water.

[0002]

2. Description of the Related Art A conventional heating device of this type is shown in FIG.
As shown in an external plan view of a conventional heating device, a sheathed heater 1 which is a heating element for heating a liquid, a water pipe 9 through which the liquid passes, and a heat conductive metal for integrally connecting the sheathed heater 1 and the water pipe 9 to each other. There is a heating device 10 composed of the portion 3 and a water pipe 9 that uses a metal pipe that is an electrically conductive material (see, for example, JP-A-5-312406).
As shown in FIG. 4 which is a side partial sectional view showing the state in which the heating device is attached to the electric water heater, the heating device 10 is generally attached directly to another structure 5 of the electric water heater or other device.

[0003]

In the conventional heating device, in the case of an electric water heater or the like which uses water as the liquid to be heated, the sheath heater 1 deteriorates the insulation performance of the electric insulating material at the end of its life, and the insulation resistance decreases. In addition, since a short circuit phenomenon (hereinafter referred to as a dielectric breakdown state) occurs between the electric charging part in the sheathed heater 1 and the metal sheath, and the water pipe 9 made of a metal pipe is electrically connected. There is a fear of being electrocuted through the water passing through 9, and since it also conducts from the heating device 10 to the other structural body 5 of the equipment, there is a fear of being electrocuted by the user from the equipment such as the electric water heater. There was a problem.

An object of the present invention is to safely stop the energizing function even at the end of life.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and a heating element for heating a liquid, a water passage through which the liquid passes, and the heating element and the water passage are integrally connected. By constructing a heating device from a heat conductive metal part, and further covering the water pipe with an electrical insulating material and a metal pipe,
The water pipe is electrically insulated from the metal part.

Further, it is safer if the heating device is electrically insulated and attached to another structure of the apparatus through an electric insulator.

[0007]

[Function] With such a structure, the metal part at the normal time has the heat generated by the heating element on both the water passage side and the non-water passage side.
Heat is efficiently transferred to the water pipe to heat the liquid. Even if the heating element breaks in a dielectric breakdown state at the end of its life, the water pipe insulated with an electric insulating material and covered with a metal pipe is heated between the electric charging part and the water flowing part, and hence the electric charging part. It acts to maintain insulation between liquids. The electrical insulator also electrically insulates the heating device from other structures of the equipment.

[0008]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an external plan view of a heating device according to an embodiment of the present invention, and FIG. 2 is a side partial cross-sectional view showing a state in which the heating device is attached to an electric water heater.

In FIG. 1, a sheathed heater 1 which is a heating element for heating a liquid, a water pipe 2 made of metal such as stainless steel for passing a liquid, and an electric insulating material 7 for covering the water pipe 2 are provided.
Then, a metal tube 8 made of a metal such as stainless steel, which covers the electric insulating material 7, is integrally connected by a metal portion 3 made of a heat-conductive aluminum alloy or the like to form the heating device 4.

In FIG. 2, the heating device 4 is electrically insulated and attached to another structure 5 of the electric water heater via an electric insulator 6 formed of an electric insulating material.

Next, the operation of the above configuration will be described.

When the sheath heater 1 is energized, heat is generated, and the heat heats the water pipe 2 through the metal portion 3. A liquid flows inside the water flow pipe 2, and the amount of heat required to heat the liquid flows from the sheath heater 1 through the metal portion 3 to the metal pipe 8,
It is supplied to the inside of the water pipe 2 via the electric insulating material 7.

The heating liquid and the sheath heater 1 are electrically insulating materials 7
Even if the sheathing heater 1 is used for a long period of time and the sheath heater 1 is broken in a dielectric breakdown state at the end of its life, the electric charging section will be electrically insulated regardless of the insulation state of the sheathed heater 1. Insulation from the electric water heater is maintained, and the heating device 4 is connected to the other structure 5 of the electric water heater.
Therefore, the heating device stops the energizing function in a safe state without being electrically shocked by the user of the electric water heater.

[0014]

As described above, according to the present invention, heating is performed from the sheath heater which is a heating element for heating the liquid, the water pipe through which the liquid passes, and the heat conductive metal portion which integrally connects the heating element and the water pipe. Since the device is configured, normally, the metal portion efficiently transfers the heat generated by the heating element to the water passage tube and the water passage side to heat the liquid. In addition, since the water pipe is electrically insulated and reinforced with a metal pipe, even if the heating element is disconnected at the end of its life due to insulation breakdown, electrical insulation is provided between the electric charging part and the heating liquid when the heating element is disconnected. In addition to being maintained, the heating device is electrically insulated and attached to another structure of the device through an electric insulator, so that the user does not get an electric shock even when the heating element is disconnected at the end of life,
In a safe state, there is an effect that it is possible to provide a heating device in which the energized state is stopped.

[Brief description of drawings]

FIG. 1 is an external plan view of a heating device according to an embodiment of the present invention.

FIG. 2 is a schematic side partial cross-sectional view showing a state in which the heating device is attached to an electric water heater.

FIG. 3 is an external plan view of a conventional heating device.

FIG. 4 is a schematic side partial cross-sectional view showing a state in which the heating device is attached to an electric water heater.

[Explanation of symbols]

 1 Heating Element (Season Heater) 2 Water Pipe 3 Metal Part 4 Heating Device 5 Other Structure 6 Electrical Insulator 7 Electrical Insulation Material 8 Metal Pipe

Claims (2)

[Claims] 1. A heating element (1) for heating a liquid, a water pipe (2) through which the liquid passes, and a heat-conducting metal part (3) integrally connecting the heating element (1) and the water pipe (2). ) And the water pipe (2) is covered with an electric insulating material (7), and the electric insulating material (7) is covered with a metal pipe (8). 2. Heating according to claim 1, characterized in that said heating device (4) is electrically insulated from the other structure (5) of the device via an electrical insulator (6). apparatus.