JPS6215791A - Positive resistance temperature coefficient heat generating body - 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 relates to a positive resistance temperature coefficient heating element (hereinafter referred to as a PTC heating element) useful as a heating appliance, a general heating device, and the like.

2. Prior Art It has been known that a resistor composition in which conductive fine powder is dispersed in a crystalline polymer exhibits remarkable PTC characteristics, and this composition has been used to create a heating element with self-temperature control. configuring is in progress.

Then, a PTC heating element was developed, which includes a thin PTC resistor made of the above composition and a pair of electrode bodies provided to apply a voltage in the thickness direction of the resistor.

Problems to be Solved by the Invention Specific problems to be solved by the present invention will be explained below. Although the phenomenon of resistor destruction due to voltage concentration does not occur in thin-walled PTC resistors, unexpectedly large voltage gradients and temperature distributions exist between the electrodes of the heating element when subjected to large heat loads, and local resistance of the resistor composition There are problems in that thermal deterioration and thermal conduction loss occur due to temperature rise. There is also the problem that the thin PTC resistor deteriorates due to deterioration of the electrode body due to oxidation, moisture in the air, and high heat due to voltage application.

Means for Solving the Problems In order to solve the above problems, the present invention provides a thin positive resistance temperature coefficient resistor whose main component is a composition in which conductive fine powder is dispersed in a crystalline polymer, and a thin positive resistance temperature coefficient resistor having a thickness of It is characterized by having a pair of electrode bodies installed to apply a voltage in the horizontal direction, and having a heat-uniforming plate with excellent thermal conductivity adhered to the lower side of an electrically insulating exterior material that covers the electrode bodies. .

Effect The effect of the technical means in this positive resistance temperature coefficient heating element is as follows. When a voltage is applied to the heating element,
Due to variations in the composition of the resistor layer, variations in the contact resistance between the electrode body and the thin PTC resistor, etc., temperature non-uniformity is observed in the PTC heating element. By disposing a heat equalizing plate with excellent thermal conductivity to equalize these non-uniformities, it is possible to equalize the heat generation temperature of the entire system. Furthermore, since the thin PTC resistor and the electrode body can be isolated from the outside air by the sheathing material, deterioration of the electrode body due to oxidation and deterioration of the thin PTC resistor due to moisture etc. can be prevented. Furthermore, since an electrically insulating exterior material is disposed between the electrode body and the heat soaking plate, insulation between the two can be maintained.

EXAMPLES Hereinafter, examples of the present invention will be explained based on FIGS. 1 to 3.

(Example 1) FIG. 1 shows a top view of a PTC heating element in a first example of the present invention. In Figure 1, 4 is the thickness 0
．． It is a thin PTC resistor with a 3π shoulder, and 5a and 5b are metal plate electrode bodies whose width is one inch longer than the thin PTC resistor 4. The electrode bodies 5a and 5b are located 2 from the end face of the PTC resistor 4.
The creepage distance is the sum of one location in the width direction and one location in the thickness direction, which is 2.3 meters. Thus, on the outside of the product, a polyester film having a heat-sensitive resin layer having heat resistance is formed on one side to provide electrical insulation for the exterior. ) 6a and 6b are formed, and a pressure-sensitive adhesive layer is provided on the surface of the exterior material 6b that comes into contact with the heat equalizing plate 7, and the surface is brought into close contact with the heat equalizing plate 7.

With the PTC heating element configured as described above, by using the heat equalizing plate 7, it is possible to uniformize the unevenness of the temperature distribution of the heating element itself.

(Embodiment 2) FIG. 2 is a top view of a PTC heating element showing a second embodiment of the present invention. In the same figure, 4 is a thin PTC resistor, 5
Reference numerals a and 5b denote electrode bodies, 6a and 6b exterior materials using heat-sealable polyester films, and 7 a heat-uniforming plate, all of which are the same as those shown in FIG.

The difference from FIG. 1 is that a film 8 of aluminum foil or aluminum film having excellent thermal conductivity is formed on the outer surface of the exterior material 6a. As described above, by covering the upper circumference of the PTC heating element with metal, it is possible to make the temperature distribution uniform and improve thermal diffusivity.

In addition, as shown in FIG. 3, in both the first and second embodiments, the PTC heating element may be formed at any number of locations on the heating plate 7.

Effects of the Invention As described above, the present invention provides a high-output PTC heating element in which the disadvantages of the conventional thin-walled PTC heating element, such as uneven temperature distribution and voltage concentration, are solved. Further, according to the present invention, the exterior material prevents deterioration of the electrode body due to oxidation and deterioration of the thin PTC resistor due to moisture, etc., and improves electrical insulation.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a positive resistance temperature coefficient heating element in a first embodiment of the present invention, Fig. 2 is a sectional view of a positive resistance temperature coefficient heating element in a second embodiment of the invention, and Fig. 3 is a sectional view of a positive resistance temperature coefficient heating element in a second embodiment of the present invention. FIG. 7 is a sectional view showing another embodiment of the temperature coefficient heating element. 4...Thin positive resistance temperature coefficient resistor, 5a, 5b
...electrode body, e a, , e b...
・Exterior material, 7...Heating plate.

Claims (1)

[Claims] It is equipped with a thin-walled positive resistance temperature coefficient resistor whose main component is a composition in which conductive fine powder is dispersed in a crystalline polymer, and a pair of electrode bodies provided to apply a voltage in the thickness direction of the resistor. A positive resistance temperature coefficient heating element characterized by having a heat equalizing plate with excellent thermal conductivity adhered to the underside of an electrically insulating exterior material covering the body.