JPH044590A - Self temp controlling heat emitting element - Google Patents

Abstract

PURPOSE:To lessen dispersion in manufacturing and stabilize the amount of heat emission by winding electrode conductors on a pair of insulative core threads at different pitches, and thereby forming electrodes. CONSTITUTION:Electrode conductors 2-1, 2-2 are wound on a pair of insulative core threads 1'' at different pitches. The core thread 1'' shall preferably be an all-aromatic type polyester thread which has a high strength and is insulative. The electrode conductor 2-1 obtained by applying Sn plating to Cu alloy as one of the metal conductors followed by winding of three such plated conductors at a pitch P1 and the other electrode conductor 2-2 obtained by alike winding four Sn plated conductors on the core thread 1'' as the other metal conductor at a pitch P2 constitute a pair of electrodes. A PTC resin layer 3 is subjected to extrusion shaping process followed by heat resisting process using bridging method, and the resultant is covered with an insulation layer 4 through extrusion molding process. Thereby dispersion in manufacturing can be lessened, and the amount of heat emission be stabilized.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention comprises a flexible heating element used in electric carpets and electric blankets, specifically a wire-shaped heating wire,
The present invention relates to a self-temperature-controlled heating element having a configuration in which a conductive material having a positive temperature coefficient (PTC) is provided between a pair of electrodes.

(Prior technology) A resistance material made of a crystalline polymer material such as low-density polyethylene with conductive particles such as carbon or graphite dispersed therein is extruded simultaneously with a pair of electrode conductors, and heat resistance is improved through a crosslinking reaction. After application, there are heating elements made by also extruding the insulating material.

In addition, considering the purpose of use in electric carpets and electric blankets, the electrode conductor structure is
No. 91, JP-A No. 59-132191, etc., which, as shown in Fig.
An electrode conductor 2 made of a copper alloy or the like is spirally wound around the PTC resin layer 3 so that a pair of electrode configuration A is buried in the PTC resin layer 3, so that the electrode conductor 2 is not disconnected due to bending such as stepping on or bending. It has a difficult configuration. In addition, other
4 in the figure indicates an insulating layer.

(Problems to be Solved by the Present Invention) However, in the above method, when the electrode conductor 2 is spirally wound around the insulating core string 1, the manner in which the electrodes face each other is not constant, and due to manufacturing variations. There was a problem in that the heating resistance value varied widely.

Specifically, in this type of heating element, as shown in Fig. 4, the electrode conductor 2' wound spirally around the insulating core thread 1' is a conductor with a circular cross section, as required. The reason for this is that it has an advantage in bending performance compared to a flat ribbon-shaped conductor as shown in Figure 3, and that this type of heating element is particularly useful when used in long lengths. In this case, the current value flowing through the electrode conductor 2' cannot be ignored, and as a countermeasure, the number of conductors may be increased, or conversely, the voltage under the electrode conductor 2' may be used to obtain a predetermined overall calorific value. This is because it is relatively easy to reduce the number of conductors, and P
This is based on the reason that it is much easier than changing the composition design of the resistance value characteristics of the TC resin layer 3.

However, since the electrode conductors are spiral-shaped, as shown in FIG. 6
As shown in the figure, the current path B' flowing through the PTC resin layer 3 is different in the case of a pitch P where they do not face each other at right angles, and the resistance value (heat amount ) was different.

Even if the method of facing each other is adjusted and matched at the beginning of work, there will always be variations due to expansion and contraction of the core thread 1, variations in the tension balance between a pair of threads, etc. .

As described above, when a pair of electrode conductors is conventionally wound using the same material and at the same pitch, there is a problem that variations in the way they face each other cannot be ignored at each portion in the length direction.

The present invention has been proposed in view of the above, and its purpose is to reduce manufacturing variations even in a structure in which a pair of electrode conductors face each other, and to stabilize the amount of heat generated. An object of the present invention is to provide a temperature-controlled heating element.

(Means for Solving the Problems) The present invention provides a self-temperature-controlled heating element in which a pair of electrode conductors is covered with a resistance material in which conductive particles such as carbon are mixed and dispersed in a polymer material. The above object is achieved by configuring the pair of electrode conductors by winding the electrode conductors around the core yarn at different pitches.

(Function) The present invention is constructed as described above, and the way the pair of conductor electrodes face each other is different from each other so that they always face each other randomly when viewed microscopically to avoid manufacturing variations. If you look at it by winding it and averaging it, it will appear to be a stable face-to-face.

(Embodiment) FIG. 1 shows an embodiment of the present invention. In the present invention, electrode conductors 2-1 and 2-2 are wound at different pitches around a pair of insulating core threads I11. ing.

In this case, the core yarn 1''' is a fully aromatic polyester yarn (trade name: Pectran 1000 de
) is used, and Sn0.3χ is used as one metal conductor.
The electrode conductor 2-1 is made of copper alloy 0.14+wm with Sn plating and wound with three wires arranged at a pitch of 1.4+mm P, and the other metal conductor is 1000mm.
Same as the core thread 11 of de, 4 Sn-plated wires of 0.14m+w are arranged at a pitch of 1. Electrode conductor 2 wound around om■P8
-2 are used as a pair of electrodes, a PTC resin layer 3 is extruded, heat-resistant treatment is performed by crosslinking, and then an insulating layer 4 is covered by extrusion molding.

In this way, in the example, the current path B° is random no matter where you look at it, and in the example, the current path B° is random every 14 m + m (PHxto turns, pg x 14 turns) in the length direction. For example, if you use an 18 m, 80 W heating wire for an electric blanket, this 14
The unbalance of heat generation within 90 degrees does not pose a problem at all, and stable characteristics can be obtained as shown in FIG. 2.

Also, in the examples, the reason why the number of conductors was different from 3 to 4 was to prevent the resistance value of the smaller pitch from becoming too large, in addition to supporting random facing. be.

(Effects of the Invention) As described above, according to the present invention, in a self-temperature-controlled heating element in which a pair of electrode conductors are covered with a resistance material in which conductive particles such as carbon are mixed and dispersed in a polymer material, Since the pair of electrode conductors are formed by winding the electrode conductors around an insulating core thread at different pitches, manufacturing variations can be reduced, so a heating element with a stable calorific value can be produced.

In addition, compared to the case where the electrode conductors are wound closely together with almost no gaps, the amount of conductor used is less, which is not only advantageous in terms of cost, but also the amount of heat generated depending on the pitch, number, and -electrode conductor resistance value. Another advantage is that design adjustments such as these can be made regardless of the PTC resin material.

Furthermore, since an appropriate uneven shape is formed on the electrode surface, the adhesion to the PTC resin is less likely to change due to thermal expansion of the electrode conductor.

[Brief explanation of drawings]

FIG. 1 is a partial sectional view of an embodiment of the present invention, FIG. 2 is a characteristic diagram of the present invention, FIG. 3 is a conventional example, and FIG. 4 is another conventional example.
FIG. 5 is a sectional view taken along the line A--I in FIG. 4, and FIG. 6 is a sectional view taken along the line A--I of another embodiment. 1°゛ ... Core yarn 2-1.2-2 ... Electrode conductor 3 ... PTC resin layer 4 ... - Insulating layer Fig. 1 Fig. 3 Fig. 5 Fig. 6

Claims (1)

[Scope of Claims] A self-temperature-controlled heating element in which a pair of electrode conductors is covered with a resistance material in which conductive particles such as carbon are mixed and dispersed in a polymer material, in which each electrode conductor is attached to an insulating core thread. A self-temperature-controlled heating element characterized in that the pair of electrode conductors are wound at different pitches.