JP2561528Y2 - Flat heater - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat heater used for an electric stove or the like.

[0002]

2. Description of the Related Art Conventionally, this type of heat source has a sheathed heater welded to a metal (for example, stainless steel) cover (for example, Japanese Utility Model Application Laid-Open No. 61-30991). In recent years, there has been an example in which a heating resistance wire is inserted into a groove formed in a ceramic body (for example, Japanese Utility Model Application Laid-Open No. 64-13689).

[0003]

The former conventional product uses a sheathed heater as a heat source and thus has a poor quick-heating property, and uses a metal (for example, stainless steel) cover. If the cover is heated to a temperature of not less than ℃, the cover is oxidized and discolored (tempered), so that the appearance becomes unsightly and the cover is deformed by heating. The latter conventional product does not have such a drawback, but because the heating resistance wire is inserted in the groove formed in the ceramic body, the heat conductivity is poor, the quick heat property is insufficient, and the heating resistance wire is insufficient. When the temperature rises to a high temperature, air or moisture enters from outside, the oxidation is accelerated, and the heating resistance wire locally becomes abnormally high in temperature, causing a problem of disconnection.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has a heating element made of a metal foil sandwiched between two ceramic plates made of a nitride ceramic. No heater unit, flat heater fixed to metal mounting plate with inorganic adhesive,
Further, in the heater unit, two ceramic plates are closely attached by brazing at a predetermined distance from the outer periphery of the heating element and a predetermined position.

[0005]

In the above flat heater, since the ceramic plate is made of a nitride ceramic and has heat resistance, there is no discoloration or deformation, and the heat conductivity is good, so that it has fast heat.

[0006] The two ceramic plates are brought into close contact by brazing at a predetermined distance from the outer periphery and a predetermined position of the heat element made of a metal foil, so that the heat element is sandwiched between the ceramic plates. The conductivity is improved and the heating element does not reach a high temperature. In addition, since they are closely adhered by brazing, air and moisture do not enter from the outside, and the oxidation of the heat element is not promoted because the oxidation is not promoted. Therefore, the flat heater does not easily break.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS.

In FIG. 1, reference numeral 1 denotes a ceramic plate on a disk, which is made of a nitride ceramic (for example, alumina nitride). Reference numeral 2 denotes a metal foil body, which is a metal foil body etched or pressed into a predetermined pattern. The heat element 2 is sandwiched between the two ceramic plates 1 and 1. 2a
Is a terminal electrode, which is provided at both ends of the heating element 2. 2b is a terminal electrode lead wire, which is connected to the terminal electrode 2a. Reference numeral 3 denotes a brazing material made of nickel, and 3a denotes a brazing portion. As shown by a broken line in FIG.
Is provided between the two ceramic plates 1 at a predetermined distance (for example, 3 mm) from the outer periphery and a predetermined position.
Reference numeral 4 denotes a heater unit. The heater unit 4 is coated with a stop-off (not shown) for preventing the brazing material 3 from flowing to the heat element 2 side during brazing, and a predetermined distance from the outer periphery of the heat element 2 and a predetermined position. Is placed, and the two ceramic plates 1 and 1 are brazed using a brazing material 3 (heated at 1100 ° C. for 10 minutes in a hydrogen reduction furnace) and adhered and integrated. 5 is an inorganic adhesive, 6 is a metal mounting plate, and the heater unit 4 is fixed to the mounting plate 6 with the inorganic adhesive 5.

Next, the operation of this embodiment will be described.

In the above flat heater, since the ceramic plate 1 is made of a nitride ceramic and has heat resistance, there is no discoloration or deformation. In addition, because of good thermal conductivity, fast heat (time required to reach a surface temperature of 500 ° C .;
Minute, devised product 0.8 minutes).

Since the two ceramic plates 1 and 1 are adhered to each other by brazing at a predetermined distance from the outer periphery and a predetermined position of the heating element 2 made of a metal foil, the heating element 2 is made of two ceramic plates. Since it is sandwiched between 1 and 1, the thermal conductivity is improved and the heat element 2 does not reach an abnormally high temperature. Further, since the outer periphery of the heater unit 4 is closely attached by brazing, air and moisture do not enter from the outside. For this reason, the heating element 2
Since oxidation is not promoted, the temperature does not locally rise to an abnormally high level, and the wire is not easily broken. Also, since the surface of the ceramic plate 1 is usually smooth, the heat element 2 is smooth against expansion and contraction when energized.

The inorganic adhesive 5 serves not only for bonding the mounting plate 6 but also as a cushioning material when a pot or the like is placed thereon. The mounting plate 6 also serves to reinforce the heater unit 4.

[0013]

According to the present invention, in the flat heater, the two ceramic plates are brought into close contact by brazing at a predetermined distance from the outer periphery of the heating element made of a metal foil body and a predetermined position. Since the air and moisture do not enter the heating element, the oxidation of the heat element is not promoted, so that the heating element does not locally reach an abnormally high temperature and does not easily break.
Therefore, there is an effect that a flat heater having heat resistance and quick heat resistance and not easily breaking can be provided.

[Brief description of the drawings]

FIG. 1 is a side sectional view of a flat heater according to an embodiment of the present invention.

FIG. 2 is a plan sectional view of the flat heater according to the embodiment of the present invention;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ceramic plate 2 Heat element 4 Heater unit 5 Inorganic adhesive 6 Mounting plate

Claims (1)

(57) [Scope of request for utility model registration] 1. A heater unit (4) in which a heating element (2) made of a metal foil is sandwiched between two ceramic plates (1) made of a nitride-based ceramic. The unit (4) is provided with two ceramic plates at a predetermined distance from the outer periphery of the heat element (2) and a predetermined position.
A flat heater characterized in that (1) and (1) are brought into close contact by brazing, and the heater unit (4) is fixed to a metal mounting plate (6) with an inorganic adhesive (5).