JPH06283257A - Flat heat generating body - Google Patents

Abstract

PURPOSE:To provide a flat heat generating body with high durability and uniform surface temperature by sandwiching a heat diffusing layer consisting of a metal heat generator element and a binder between inorganic insulating materials and uniting them by heating and pressing. CONSTITUTION:A binder 3 prepared by adding an inorganic adhesive to ceramic of such as aluminum nitride is applied to a metal heat generator element 1 to form a heat diffusing layer 4. The heat diffusing layer 4 is sandwiched between inorganic insulating materials 2 of such as mica, alumina, etc., and the resulting body is united by heating and pressing to give a panel heat generating body. Consequently, since the metal heat generator element 1 with high resistance is buried in the heat diffusing layer 4, no local heating occurs and the heat from the metal heat generator element 1 is diffused in the heat diffusing layer 4 which has high thermal conductivity and excellent electric insulation resistance. The heat diffused and made uniform is then transmitted immediately to the inorganic insulating materials 2 and the surface temperature is kept uniform and thus the durability of the panel heat generator is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat heating element used for cooking equipment, heating equipment and the like.

[0002]

2. Description of the Related Art Conventionally, as a plane heating element, (1) a structure in which a ribbon-shaped heating element is wound around a mica plate and mica plates are fastened with eyelets on both sides of the mica plate (2) Metal formed into a desired circuit shape A structure in which glass fibers are bonded to one or both sides of a foil heating element with an inorganic binder (see, for example, Japanese Utility Model Publication No. 51-10437) (3) Between a heat-resistant electrical insulating material composed of mica and an inorganic binder The heater element is positioned and integrated, and the outer surface is formed with an insulating coating layer of crystallized glass (see, for example, JP-A-4-36977).

[0003]

However, the structure of (1) in which the ribbon-shaped heating element is wound around the mica plate has a problem that the mica plate and the heating element are point-contacted with each other and are disconnected due to local heating. Yes, the structure of (2) in which glass fibers are bonded with an inorganic binder has problems such as low electrical insulation and heat resistance of glass fibers, and the insulating coating of crystallized glass in the case of (3). Layer is insulation resistant
Although excellent in heat shock resistance, the thermal conductivity of the crystallized glass was poor, so that the temperature distribution on the surface was not uniform and there was a problem in using it in a cooking appliance or the like.

The present invention is intended to solve the above problems, and an object thereof is to provide a flat heating element having excellent durability and having a uniform heating element surface temperature.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it provides a metal heating element, an inorganic insulating material made of mica powder or the like, and good thermal conductivity of aluminum nitride or the like and electrical insulation. And a binder made by adding an inorganic adhesive to powdery ceramics having excellent properties, the binder is applied to the entire surface of the metal heating element to form a heat diffusion layer, and The heat diffusion layer is laminated between them, and is heated and pressed to be integrally formed.

[0006]

With the above structure, since the metal heating element is embedded in the thermal diffusion layer, there is no local heating, and the heat from the metallic heating element is immediately conducted and diffused to the thermal diffusion layer, which is the inorganic insulating surface. The entire surface of the material can be heated to a uniform temperature.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG.

Reference numeral 1 denotes a metal heating element, which is made of a heat-resistant metal having a high resistivity such as ferritic stainless steel, nickel chrome, and iron chrome, and has a foil shape or a ribbon shape formed in a desired resistance value and shape. The foil is wrapped around a mica plate. Reference numeral 2 is an inorganic insulating material made of mica, alumina, aluminum nitride, glass ceramics or the like, and is formed in a plate shape. 4 is a thermal diffusion layer, which has excellent thermal conductivity,
The binder 3 in which an inorganic polymer such as polyborosiloxane or an inorganic adhesive (not shown) such as aluminum phosphate is added to powdered ceramics such as aluminum nitride or sialon having high electric insulation resistance is used for the metal heating. It is applied to the entire surface of the body element 1 to form a plate shape. This thermal diffusion layer 4 is overlaid between two inorganic insulating materials 2 and has a temperature of 15
It is heated and pressed by a hot press under the condition of around 0 ° C to be integrated.

The operation of this embodiment having the above structure will be described.

Since the metal heating element 1 having a high resistivity is embedded in the thermal diffusion layer 4, there is no local heating of the metal heating element 1, and the heat from the metal heating element 1 has a thermal conductivity. And is diffused in the thermal diffusion layer 4 with excellent electrical insulation resistance,
The uniform heat is immediately transferred to the inorganic insulating material 2 and the surface temperature is kept uniform, so that a flat heating element having excellent durability can be obtained.

[0011]

As described above, according to the present invention, an inorganic adhesive is applied to a metal heating element, an inorganic insulating material made of mica powder, etc., and powdered ceramics such as aluminum nitride having good heat conduction and excellent electric insulation. And a binder added, and the binder is applied to the entire surface of the metal heating element to form a thermal diffusion layer,
Since the thermal diffusion layer is laminated between two sheets of inorganic insulating material and is heated and pressed to be integrally formed, the metal heating element is buried in the thermal diffusion layer having excellent thermal conductivity and high electrical insulation resistance, and the metal heating element is heated. There is no local heating of the body element, and the heat from the metal heating element is diffused in the heat diffusion layer, and the uniform heat is immediately transferred to the inorganic insulating material. Even when the flat heating element using the inorganic insulating material is used for a cooking device or the like, the flat heating element can be quickly heated without unevenness in temperature, and the object to be heated can be deliciously cooked and grilled such as a grill can be provided.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of a flat heating element showing an embodiment of the present invention.

[Explanation of symbols]

 1 Metal heating element 2 Inorganic insulating material 3 Binder 4 Thermal diffusion layer

Claims (3)

[Claims] 1. An inorganic adhesive is applied to a metal heating element (1), an inorganic insulating material (2) made of mica powder, etc., and powdered ceramics such as aluminum nitride having good heat conduction and excellent electrical insulation. And the binder (3) added, and the binder (3) is applied to the entire surface of the metal heating element (1) to form a thermal diffusion layer (4). The heat-diffusing layer (4) is superposed between the above (1) and (2) and is heated and pressed to be integrally formed. 2. The flat heating element according to claim 1, wherein the inorganic adhesive is made of an inorganic polymer such as polyborosiloxane or aluminum phosphate. 3. The flat heating element according to claim 1, wherein a plate-shaped material such as glass ceramics, mica, alumina or aluminum nitride is used as the inorganic insulating material (2).