JPH0521141A - Sheet heating element - Google Patents

Abstract

(57) [Summary] [Purpose] To obtain a planar heating element with no gaps that disturb heat transfer. [Structure] Oxide film 8 of electrical insulator on the heat transfer surface side of body 4
An insulating sheet 9 made of the metal sheet 7 coated with is applied to form a heat transfer surface. [Effect] Since electrical insulation is provided by the film of the heat transfer conductor of the insulating sheet, an insulating structure between the main body and the heat transfer conductor is not necessary, and heat transfer is hindered between the heat transfer conductor and the film. There are no gaps and the heat distribution on the heat transfer surface is uniform.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet heating element provided with a heat transfer conductor for uniformizing heat generation temperature on a heat transfer surface.

[0002]

2. Description of the Related Art A conventional sheet heating element is shown in FIG.
The configuration is as shown in. That is, the heat generating portion is enclosed in a bag by the insulating film 2 in which the nonwoven fabric 1 is laminated on the inner surface, and the flat body 4 is configured. The heat generating portion is composed of an electrode 5 fixed at a position opposite to the nonwoven fabric 1 forming the inner surface of the insulating film 2, and a heat generating element 6 that is energized by the electrodes 5 to generate heat. A heat transfer surface is formed by the metal film 10 having heat transfer property on one surface or both surfaces of the main body 4. The metal film 10 on the heat transfer surface is bonded to the insulating film 2 having the surface structure of the main body 4 by adhesion.

When the heating element 6 is energized through the electrode 5, the planar heating element having the above-described structure converts electric energy into heat energy and generates heat. The heat in the heating element 6 is transferred to the metal film 10 on the heating surface via the nonwoven fabric 1 and the insulating film 2. The metal film 10 absorbs heat variations due to local excessive heat generation in the heating element 6 and makes the heat distribution on the heat transfer surface uniform.

[0004]

In the conventional sheet heating element having the above-mentioned structure, the adhesive strength between the insulating film 2 and the metal film 10 is likely to be uneven in the manufacturing process, and the gap due to the uneven adhesive strength is generated. Was easily formed between the insulating film 2 and the metal film 10. Further, due to the difference in the coefficient of thermal expansion of each constituent member, a gap may be formed between the insulating film 2 and the metal film 10 by repeated use. This gap becomes a factor to make the heat transfer non-uniform, which hinders the temperature uniformity in the metal film 10.

The present invention has been made in order to solve such a conventional problem, and an object thereof is to obtain a planar heating element having no gap for disturbing heat transfer.

[0006]

In the sheet heating element according to the present invention, an insulating sheet made of a heat transfer conductor coated with an electric insulator is attached to the heat transfer surface side of the main body.

Another planar heating element according to the present invention is an insulation formed of a heat transfer conductor coated with an electric insulator on the heat transfer surface side of a main body having the structure of the electric insulator adhered to the heat transfer surface side. It is a sheet that has been attached.

Still another planar heating element according to the present invention is one in which an insulating sheet made of a heat transfer conductor coated with an electrical insulator is adhered to both the front and back of a main body having both front and back heat transfer surfaces. is there.

[0009]

In the sheet heating element according to the present invention, the electrical insulation is performed by the film of the heat transfer conductor of the insulating sheet, so that the insulating structure between the main body and the heat transfer conductor is not necessary and the heat transfer conductor Since there is no gap between the coatings that hinders the movement of heat, the heat distribution on the heat transfer surface becomes uniform.

[0010]

【Example】

Example 1. FIG. 1 is a sectional view of a sheet heating element showing an embodiment of the present invention. In the planar heating element of the illustrated example, the heat generating portion is a bag by joining the insulating film 2 forming the non-heat transfer surface side having the nonwoven fabric 1 laminated on the inner surface and the nonwoven fabric 3 forming the heat transfer surface side. The main body 4 having a flat shape is formed. The heat generating portion is composed of an electrode 5 fixed at a position opposite to the nonwoven fabric 1 forming the inner surface of the insulating film 2, and a heat generating element 6 which is energized by the electrodes 5 to generate heat.
The heat transfer surface side of the main body 4 is composed of the non-woven fabric 3, and the non-conductive oxide film 8 is formed on the surface of the heat conductive metal sheet 7 on the non-woven fabric 3 so that the insulating sheet 9 is adhered. The heat transfer surface is configured.

The insulating sheet 9 on the heat transfer surface is a sheet in which the heat transfer conductor is covered with an electrical insulator in terms of its structure, and may be, for example, an alumite surface-treated aluminum foil.

The sheet heating element having the above-mentioned structure is made up of the insulating sheet 9
Since there is a non-conductive oxide film 8 on the side, an insulating structure is not required on the heat transfer surface side of the main body 4 side, and there is a change with time in the manufacturing process between the metal sheet 7 and the oxide film 8. The heat generated in the heating element 6 is transferred to the metal sheet 7 through the non-woven fabric 3 and the oxide film 8, and the metal sheet 7 is locally excessive in the heating element 6. It absorbs variations in heat due to heat generation, etc., and makes the heat distribution on the heat transfer surface uniform.

Most basically, the non-woven fabric 3 on the heat transfer surface side of the main body 4 may be eliminated and the insulating sheet 9 may be directly attached to the heat transfer surface side of the heat generating element 6, whereby a gap is formed. Without being able to do so, it is possible to achieve uniform heat distribution on the heat transfer surface.

Example 2. FIG. 2 is a cross-sectional view of a sheet heating element showing another embodiment of the present invention. In this sheet heating element, the main body 4 is made of only the nonwoven fabric 1 and the heating portion is in a bag. In addition, an insulating sheet 9 obtained by forming a non-conductive oxide film 8 on the surface of a metal sheet 7 having heat conductivity is adhered.

This sheet heating element has both heat transfer surfaces,
Since the non-conductive oxide film 8 is provided on the insulating sheet 9 side, no insulating structure is required on the body 4 side. Of course, since there is no gap between the metal sheet 7 and the oxide film 8 that is a factor that hinders heat transfer during the manufacturing process or due to changes over time, the heat generated by the heat-generating element 6 is generated between the nonwoven fabric 1 and the oxide film 8. After that, the heat is transmitted to the metal sheets 7 on both sides, and each metal sheet 7 absorbs heat variations due to local excessive heat generation or the like in the heating element 6, and makes the heat distribution on the heat transfer surface uniform.

[0016]

As is apparent from the above description of the embodiments, according to the present invention, the electrical insulation is performed by the film of the heat transfer conductor of the insulating sheet, so that the insulating structure between the main body and the heat transfer conductor is formed. Is unnecessary, the configuration is simple, and since there is no gap between the heat transfer conductor and the film that hinders the movement of heat, the heat distribution on the heat transfer surface becomes uniform.

[Brief description of drawings]

FIG. 1 is a sectional view of a planar heating element according to an embodiment of the present invention.

FIG. 2 is a sectional view of a planar heating element according to another embodiment of the present invention.

FIG. 3 is a sectional view showing a configuration of a conventional sheet heating element.

[Explanation of symbols]

1 non-woven fabric 3 non-woven fabric 4 body 5 electrodes 6 heating element 7 metal sheet 8 oxide film 9 Insulation sheet

Claims (3)

[Claims] 1. A sheet-like heat generation characterized in that an insulating sheet made of a heat-transfer conductor coated with an electric insulator is adhered to the heat-transfer surface side of a planar main body made of a heat-generating element which generates heat when energized by electrodes. body. 2. The sheet heating element according to claim 1, wherein a structure of an electric insulator is adhered to the heat transfer surface side of the main body. 3. The heat transfer surface of the main body is on both front and back surfaces.
Alternatively, the sheet heating element according to claim 2.