JPH0536471A - Electric heater - Google Patents

Abstract

PURPOSE:To provide high-intensity radiation, high safety, and high-speed heating property in an electric heater used in a radiating type heater. CONSTITUTION:An electric heater is formed of a tape heating wire 1 which is an electric resistant heating element and an insulating heat resistant stick 2. By the structure in which the tape heating wire 1 is spirally wound on the insulating heat-resistant stick 2, high-intensity radiation can be provided, the dip by thermal expansion of the heating wire is prevented and high safety and high-speed heating property can be provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric heater used in electric cookers, electric heaters and the like.

[0002]

2. Description of the Related Art Most of electric heaters used in conventional cookers and heaters are sheathed heaters, quartz tube (or heat-resistant glass tube) heaters, mica heaters, or nichrome heaters.

A conventional electric heater will be described below. As shown in FIG. 4, the sheathed heater comprises a heating wire 11, an insulating agent 12, a sealing material 13, and a protective tube 14 in a rod shape. When energized, the surface temperature of the protective tube 14 is 700 to 8
It reaches 00 ° C and heats the object to be heated.

The quartz tube heater uses a quartz tube as the protective tube 14, and its basic structure is the same as that of the sheathed heater.

As shown in FIG. 5, the mica heater has a structure in which a heating wire 16 is wound around a mica plate 15 and further sandwiched and fixed by two mica plates 17 and 18. The heater wire connects the mica plate when energized. Heated to about 500 ° C,
The object to be heated is heated by the secondary radiation of the mica plate.

The nichrome heater has a structure in which a spiral nichrome wire 19 is fixed in a groove of a sintered body 20, as shown in FIG.

[0007]

However, in the sheath heater, the quartz heater and the mica heater, the heating wire 1
1 or 16 is covered with a suitable material for preventing disconnection due to insulation or corrosion or sagging due to heat, and the radiant energy from the heating wire 11 or 16 is hindered by the coating material and becomes small. there were.

In addition, since the nichrome heater which is a radiant surface has a linear shape, the nichrome heater has a small radiant energy, and the heat capacity of the sintered body is large, so that the rising characteristics are poor, and the heater is generally arranged on the upper surface. In the traditional box cooker, there is a problem that the heating wire hangs down due to heat.

The present invention solves the above problems, and securely holds a tape-shaped heating wire in an exposed state (bare state) so that radiant energy from the heating wire can be efficiently transmitted to an object to be heated. The purpose is to provide a secure, fast, fast heating heater.

[0010]

In order to achieve the above object, the present invention provides an electric heater of the present invention in which a tape-shaped heating wire, which is an electric resistance heating element, is spirally wound into a hollow or solid insulated heat-resistant rod. It has a wound structure.

[0011]

According to the present invention, the radiation surface of the tape-shaped heating wire having good radiation characteristics is exposed by the above-mentioned structure, and the radiant energy from the heating wire is efficiently transmitted to the object to be heated. Also, after winding a tape-shaped heating wire around the insulated heat resistant rod in a spiral shape,
When the heating wire is heated by energization, the spiral shape is maintained even after energization due to the transformation plasticity, the heating wire is fixed to the insulating heating rod, and sagging due to thermal expansion of the heater wire is prevented. Further, since the heater wire is not in contact with anything other than the insulated heat-resistant rod, heat loss due to heat conduction is small, and high efficiency and high-speed heat resistance can be obtained. Furthermore, when the insulated heat-resistant rod is hollow, the heat capacity of the rod becomes small, and the rapid heating property is further improved.

[0012]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

In FIGS. 1 and 2, 1 is a tape-shaped heating wire and 2 is an insulating heat-resistant rod. The tape-shaped heating wire 1
Each tape-shaped heating wire is spirally wound around the heat-resistant insulating rod 2 at a pitch such that insulation can be secured even by thermal expansion during energization. With the above configuration, the radiation surface 3 of the tape-shaped heating wire 1 having good radiation characteristics is exposed, and the radiant energy from the heating wire is efficiently transmitted to the object to be heated.
Further, since the tape-shaped heating wire 1 is not in contact with anything other than the insulating heat-resistant rod 2, the heat loss due to heat conduction is smaller and the heat capacity is smaller than that of the mica heater as shown in FIG. It can be heated to a high temperature, and high radiation can be obtained from Stefan-Boltzmann's law.

After the winding process, the tape-shaped heating wire 1
When is heated by electricity, the spiral shape is maintained even after electricity is applied due to transformation plasticity, the tape-shaped heating wire 1 is fixed to the insulating heat-resistant rod 2, and it is possible to prevent sagging due to thermal expansion of the heating wire at high temperature.

Further, as shown in FIG. 3, in the structure in which the tape-shaped heating wire 4 is wound around the hollow insulated heat-resistant rod 5, as shown in FIG.
The heat capacity of the heater can be further reduced as compared with the configuration of FIG. 2, and the rapid heating property of the heater is improved.

[0016]

As described above, according to the electric heater of the present invention, the following effects can be obtained. (1) Since the tape-shaped heating wire having good radiation characteristics is spirally wound around the insulated heat-resistant rod, the radiation surface of the heater is exposed and high radiation can be obtained. (2) With the above configuration, it is possible to prevent the heater from sagging due to thermal expansion of the heating wire when the heater is energized, and to obtain a highly safe heater. (3) With the configuration in which the tape-shaped heating wire is spirally wound around the hollow insulated heat-resistant rod, in addition to the above-mentioned effects, the heat capacity of the heater is further reduced, and a heater having high rapid heating property can be obtained.

[Brief description of drawings]

FIG. 1 is a plan view of an electric heater according to a first embodiment of the present invention.

FIG. 2 is a cutaway perspective view of a main part of FIG.

FIG. 3 is a cutaway perspective view of essential parts in a second embodiment of the present invention.

FIG. 4 is a schematic perspective view of a conventional sheathed heater.

FIG. 5 is a schematic perspective view of a conventional mica heater.

FIG. 6 is a schematic perspective view of a conventional mica heater.

[Explanation of symbols]

1 Tape-shaped heating wire 2 Insulation heat resistant rod 3 Radiation surface 5 Hollow insulation heat resistant rod

Claims (2)

[Claims] 1. An electric heater comprising a tape-shaped electric resistance heating element and a solid insulating heat-resistant rod, wherein the electric resistance heating element is spirally wound around the insulating heat-resistant rod. 2. The electric heater according to claim 1, wherein the insulated heat-resistant rod is hollow.