JP2861699B2 - Electric heater - Google Patents

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 for an electric cooker or an electric heater.

[0002]

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

[0003] A conventional electric heater will be described below. As shown in FIG. 6, the sheathed heater is formed in a rod shape with a heating wire 11, an insulating material 12, a sealing material 13, and a protective tube 14. At the time of energization, the surface temperature of the protection tube 14 is 700 to 8
The temperature becomes 00 ° C. and the object to be heated is heated.

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

In the mica heater, a heating wire 16 is wound around a mica plate 15 as shown in FIG.
When energized, the heating wire heats the mica plate to about 500 ° C., and the object to be heated is heated by the secondary radiation of the mica plate.

The nichrome wire 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 sheathed heater and the quartz tube heater, the electric resistance heating element has a tubular shape, so that the projected radiation area cannot be large, and the radiation is transmitted in all directions (360 degrees). Therefore, there is a problem that the amount of radiation to the object to be heated is small, and the radiation amount differs between a portion opposed to the heater and a portion not facing the heater, resulting in poor distribution. Further, the sheathed heater has a problem that the protective tube is made of metal, and when used for a heater for a cooker, the metal tube is corroded by a corrosive substance such as salt at a high temperature. In addition, the mica heater has a problem that the radiation temperature from the mica plate is 500 ° C., which is lower than that of other heaters, so that the radiation amount is small.

On the other hand, the nichrome wire heater has the same problem as the sheathed heater because it is wound in a solenoid coil shape, and the heat of the heating wire is conducted to the sintered body,
In the case of a general box-type cooker having a poor start-up characteristic and a heater disposed on the upper surface, there is a problem that the heating wire hangs down due to heat. In addition, since the heating wire was bare, there was a problem that the wire corroded.

The present invention has been made to solve the above problems, and has as its first object to obtain a high radiation type heater having a high radiation amount and good rising characteristics.

A second object of the present invention is to provide a safe heater in which the electric resistance heating element is prevented from drooping without applying excessive stress to the electric resistance heating element.

[0013] A third object is to obtain a heater having high durability.

[0012]

According to the present invention, in order to achieve the first object, a tape-shaped electric resistance heating element having a thickness of several tens μm is used.

Further a second invention to achieve the purpose of the tape-shaped electrical resistance heating element, than the width of the tape-like electrical portions corresponding to the radiation surface of the resistance heating element the tape-shaped electrical resistance heating elements A holed insulator with a hole in a narrow width;
The thickness of the tape-shaped electric resistance heating element is set at a portion equal to or larger than the width of the tape-shaped electric resistance heating element and corresponding to the electric resistance heating element.
A grooved insulator having a deep groove, wherein the tape-shaped electric resistance heating element is inserted into the grooved insulation and covered with the holed insulation, and the electric resistance heating element is thermally expanded.
When extended, the groove of the grooved insulator and the hole
The tape-shaped electricity extends in the space surrounded by the insulator
The structure is such that thermal stress is not applied to the resistance heating element .

In order to achieve the third object, the present invention is configured such that the radiation surface of the tape-shaped electric resistance heating element of the electric heater having the above-mentioned structure is covered with an inorganic plate that transmits at least a part of infrared rays.

[0015]

According to the present invention, the use of the above-described tape-shaped electric resistance heating element having a small heat capacity and a large radiating area allows the heating element to be rapidly heated and a high radiation amount to be obtained.

The present invention further provides a groove of an insulator in which a tape-shaped electric resistance heating element is formed with a groove at a portion which is larger than the width of the tape-shaped electric resistance heating element and which corresponds to the tape-shaped electric resistance heating element. By covering the portion corresponding to the radiation surface of the tape-shaped electric resistance heating element with a perforated insulator having a width smaller than the width of the electric resistance heating element. Even when the resistance heating element expands due to thermal expansion, it extends only in the space surrounded by the groove of the grooved insulator and the insulator with the hole, and extends to the tape-shaped electric resistance heating element.
The tape-shaped electric resistance heating element without applying thermal stress
There is a configuration that does not go outside of the insulator.

Further, since the inorganic plate that transmits at least a part of the infrared ray is configured to protect the heating wire,
It can prevent corrosion of the electric resistance heating element due to a substance such as salt.

[0018]

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

[0019] (Embodiment 1) FIG. 1, 2 and 3, 1 is a tape-shaped electrical resistance heating element, 3 is the tape-shaped electrical resistance portion corresponding to the radiation surface of the tape-like electrical resistance heating elements 1 perforated insulator drilled 4 width narrower than the width of the heating element 1, 5 the tape-shaped conductive
It is a grooved insulator in which a groove 6 deeper than the thickness of the tape-shaped electric resistance heating element is provided at a portion corresponding to the electric resistance heating element that is equal to or larger than the width of the electric resistance heating element 1 .

As shown in FIG. 2, the foil-shaped electric resistance heating element 1 has a thickness of several tens μm and a width of 5 to 7 mm, and has an extremely small heat capacity as compared with a sheathed heater or a quartz tube heater.
In addition, since it has a tape shape, the projection radiation area is 3 to 6 times that of a tape.

Further, as shown in FIG. 1, the tape-shaped electric resistance heating element 1 is inserted into the groove 6 of the grooved insulator, and holes other than the radiation surface 2 of the tape-shaped electric resistance heating element 1 are formed. When the tape-like electric resistance heating element 1 is expanded by thermal expansion as shown in FIG. 3 by covering with the insulator 3 with a groove, the groove 6 of the insulator 5 with a groove and the insulator with a hole are formed. The tape-shaped electric resistance heating element can be extended outside the insulator without applying thermal stress to the tape-shaped electric resistance heating element because it is configured to extend freely only in the space surrounded by 3 and not to go out of the insulation. It is possible to obtain a safe heater that is prevented from hanging down.

In FIG. 4A, the width ts of the hole 4 of the insulator 3 with a hole is equal to the width of the tape-shaped electric resistance heating element 1.
Is the width of W, the width of the groove 6 of the grooved insulator 5 is tb, and the depth is d, as long as the relationship of the following expression is satisfied, the tape-shaped electric member is formed as shown in FIG. The resistance heating element 1 does not go out of the space surrounded by the groove 6 of the grooved insulator 5 and the holed insulator 3.

[0023]

(Equation 1)

For example, the width of the tape-shaped electric resistance heating element 1 is W = 6 mm, the width of the groove 6 of the grooved insulator 5 is tb = 7 mm,
When the depth is d = 2 mm, the width t of the hole 4 of the holed insulator 3
s may be 4.3 mm or less.

Embodiment 2 FIG. 5 shows another embodiment of the present invention. 1 is a tape-shaped electric resistance heating element, 2 is an insulator with holes, 5 is an insulator with grooves, and 7 is an inorganic plate that transmits at least a part of infrared rays.

The above configuration is the same as that of the electric heater of the first embodiment except that the radiation surface 2 of the tape-shaped electric resistance heating element 1 is covered with an inorganic plate 7 made of heat-resistant glass or ceramic that transmits at least a part of infrared rays. It is possible to obtain a high radiation amount and to prevent the electric resistance heating element from sagging. As described above, the tape-shaped electric resistance heating element 1
Since the radiation surface 2 is covered with the inorganic plate 7 that transmits at least a part of infrared rays, it is possible to prevent the electric resistance heating element from being corroded by salt during food cooking.

[0027]

According to the electric heater of the present invention as described above, the following effects can be obtained.

(1) Since a large tape-shaped electric resistance heating element having a small heat capacity and a large radiating area is used, a quick heat property and a high radiation amount can be obtained.

[0029] (2) the tape of the tape-like electrical resistance heating elements
Inserted into the groove of the insulator with a groove in the portion corresponding to the tape-like electrical resistance heating elements above the width of the looped electrical resistive heating element, which corresponds to a radiation surface of the tape-shaped electrical resistance heating element portion Is covered with a perforated insulator having a width smaller than the width of the electric resistance heating element, so that even when the tape-shaped electric resistance heating element is expanded by thermal expansion, the grooved insulation is provided. To obtain a safe heater that extends only in the space surrounded by the groove of the body and the insulator with the hole, without applying thermal stress to the tape-shaped electric resistance heating element and preventing the electric resistance heating element from hanging down. Can be.

(3) Since the radiation surface of the tape-shaped electric resistance heating element of the electric heater is covered with an inorganic plate that transmits at least a part of infrared rays, corrosion of the electric resistance heating element by a substance such as salt is prevented. And a highly durable heater can be realized.

[Brief description of the drawings]

FIG. 1 is an assembly view showing a configuration of an electric heater according to an embodiment of the present invention.

FIG. 2 is a perspective view of a tape-shaped electric resistance heating element according to one embodiment of the present invention.

FIG. 3 is a perspective view of a tape-shaped electric resistance heating element support portion of the electric heater in the embodiment of FIG. 1;

FIG. 4 is a detailed perspective view of a tape-shaped electric resistance heating element in the embodiment of FIG. 1;

FIG. 5 is an assembly view showing a configuration of an electric heater according to another embodiment of the present invention.

FIG. 6 is a sectional view of a conventional sheathed heater.

FIG. 7 is a perspective view of a conventional mica heater.

FIG. 8 is a perspective view of a conventional nichrome heater.

[Explanation of symbols]

1 Tape-shaped electric resistance heating element 2 Radiation surface 3 Insulator with hole 4 Hole 5 Insulator with groove 6 Groove 7 Inorganic plate

Claims (2)

(57) [Claims] 1. A tape-shaped electric resistance heating element, and a perforated insulator in which a portion corresponding to a radiation surface of the electric resistance heating element is perforated with a width smaller than a width of the tape-shaped electric resistance heating element.
The tape-shaped electric resistance heating element is applied to a portion which is equal to or larger than the width of the tape-shaped electric resistance heating element and corresponds to the tape-shaped electric resistance heating element.
The tape-like electric resistance heating element is inserted into the grooved insulation and covered with the holed insulation, and the electric resistance heating element is
The grooved insulator even when extended by thermal expansion
An electric heater extending in a space surrounded by the groove and the insulator with holes . 2. The electric heater according to claim 1, wherein the radiation surface of the tape-shaped electric resistance heating element is covered with an inorganic plate or a ceramic plate that transmits at least a part of infrared rays.