JPS61269883A - Surface heater - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is used as a heat source for appliances that utilize electrical energy, such as heaters, cookers, and dryers. This relates to a surface heater in which a heater element with a smooth surface is fixed to a hollow substrate.

BACKGROUND OF THE INVENTION In recent years, surface heaters have come into the spotlight as heating elements that meet the demands for thinning devices and uniform heating, and various surface heaters as shown below have been developed.

(1) One that has a structure in which a heater is wound around an insulating substrate such as mica.

(2) It has an integrated structure in which a conductive pattern is formed on an alumina substrate using a conductive paste such as tungsten, and an alumina substrate is further provided on top of the conductive pattern.

(3) A laminated structure in which a conductive pattern is formed between organic films such as silicon or polyimide.However, the surface heater of (1) has poor heat transfer to the object to be heated, and the heater is sealed. However, there were problems with moisture resistance. Further, in the case of the surface heater (2), the strength of the electric extraction portion is weak and the heat capacity is large, so the start-up time is long. Furthermore, in the case of the surface heater (3), the actual situation is that the heat resistance temperature is low and there are problems with life characteristics.

Therefore, in order to solve the above problem, JP-A-5B-22
A planar heater using a hollow substrate as shown in Japanese Patent No. 5592 has been proposed.

In addition, the present inventors have further improved the planar heater using the hollow substrate described above, and have proposed a new planar heater using a heater element made of a smooth mesh metal foil. In the planar heater proposed by the present inventors, a heater coating layer made of hollow material is provided on a hollow substrate, and a heater element made of a smooth mesh metal foil and a heater element made of a smooth mesh-like metal foil are placed in the heater coating layer. It had a structure in which a part of the electrical outlet terminal board connected to the heater element was buried, and the material of the heater element was 5US430.

Problems to be Solved by the Invention In the planar heater having the above-described structure, the characteristics of the completed planar heater differ significantly depending on the material used for the heater element.

Among these, the heater element's compatibility with the hollow substrate and heater coating layer, the processability of the heater element, Setting resistance value, board size, etc. are significantly affected. In particular, when 5US430 is used as the material for the heater element, it is difficult to fabricate a planar heater with a small area due to its low volume resistivity, and the resistance temperature coefficient is large, so the set resistance value varies widely depending on the atmospheric conditions. Setting the power consumption was extremely complicated.

The present invention solves the above-mentioned problems and aims to provide a surface heater with a wide range of applications.

Means for Solving the Problems In order to solve the above problems, the present invention provides
0-19.00%, Si is 2.00-3. OO%
, C is 0.07% or less, Mn is o, so% or less, P is 0
．． A heater element made of a smooth mesh-like metal foil made of an alloy having S of 0.04% or less, S of 0.03% or less, and the balance being Fe is fixed to a hollow substrate with a heater coating layer.

Function Generally speaking, materials that have a large specific volume resistivity, a small temperature coefficient of resistance, a high heat resistance, and can be formed into foils are considered good materials for the heater elements used in surface heaters. In addition, in the present invention, since the heater element is firmly attached to the hollow substrate, it is necessary to match the expansion coefficient with that of the hollow substrate.

Furthermore, since the heater element of the present invention is a smooth mesh-like metal foil, it must be able to obtain a flat surface without cracking or deforming during processing. Therefore, it is necessary to use a material with high elongation. As a material to satisfy the above characteristics, Cr is 18.
00-19.00%.

si is 2.00 to 3.00%, C is 0.0796 or less,
Mu is o, so% or less, P is 0.04% or less.

An alloy in which S is 0.03% or less and the balance is Fe is considered suitable.

EXAMPLE Hereinafter, an example of the present invention will be described based on FIGS. 1 and 2. In FIG. 1, as a metal substrate 1a,
A hollow substrate 1 was prepared using a steel plate for hollow holes, and an insulating hollow layer 1b made of a hollow material whose main component is high-insulating glass frit was formed on this metal substrate 1a.

In addition, as shown in Fig. 2, the material is 18% Cr,
00-19, 00%, Si is 2.00-3.0
0%, C 0.07% or less, Mn 0.50% or less, P
The heater element 2 is made of a smooth mesh-like metal foil made of an alloy in which S is 0.04% or less, S is 0.03% or less, and the balance is Fe, and the same alloy as this heater element 2 is used as the material. The heater element 2 was prepared by connecting the used electrical output terminal plates 3 made of smooth metal foil by spot welding.

A thin layer of hollow slip was applied onto the hollow substrate 1 prepared by the above method, and the heater element 2 connected to the electrical outlet terminal plate 3 was placed in an undried state, and a similar slip was applied thereon.

After drying this, it is heat-treated at 80°C, and the heater element 2 is embedded in the heater coating layer 4 made of hollow material whose main component is the glass frit.
The heater element 2 was closely fixed on the hollow substrate 1 to complete the surface heater of the present invention having the structure shown in FIG. 1.

The completed surface heater has a volume resistivity of 96μΩ・crn(a
-1 (SUS4
Approximately 1.6 times that when using 30 (SUS430 is 60
μΩ・LMat 20°C), and the power consumption setting range has been greatly improved. The temperature coefficient of resistance is still 42×10
Approximately 3A (at -67℃ using 5US430)
SUS430 is 179 x 10 7°C), so there is less change in the set resistance value in the operating atmosphere, making it very easy to set the power consumption. In addition, the average coefficient of thermal expansion is 10.3 x 107°C (0 to 100°C), which matches well with the insulating hollow layer 1b in the hollow substrate 1 and the heater coating layer 4, and has excellent thermal shock properties. It is something that becomes something.

Effects of the Invention As described above, according to the present invention, Cr is 18.00 to 19
．． 00%, si 2.00-3.00%, C 0.07
% or less, Mn is 0.50% or less, P is 0.04% or less,
The heater element is made of a smooth mesh metal foil made of an alloy with S content of 0.03% or less and the balance is Fe, and is fixed to the hollow substrate with a heater coating layer, so it has a high volume resistivity and It is possible to provide a surface heater with a small resistance temperature coefficient, good matching with the hollow layer, and excellent thermal shock resistance.

[Brief explanation of the drawing]

FIG. 1 is an enlarged sectional view of a main part of a surface heater showing an embodiment of the present invention, and FIG. 2 is a front view showing a heater element of the same heater. 1... Hollow board, 2... Heater element, 4... Heater coating layer.

Claims (1)

[Claims] Cr: 18.00-19.00%, Si: 2.00-3
．． 00%, C is 0.07% or less, Mn is 0.50% or less, P is 0.04% or less, S is 0.03% or less, and the balance is Fe.
A surface heater characterized in that a heater element made of a smooth mesh metal foil made of an alloy is fixed to a hollow substrate with a heater coating layer.