JPH0348873Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to heating wires used in electric blankets, electric sheets, electric carpets, warmers, winter clothing, etc.

[Conventional technology and its problems]

As shown in Fig. 3, a conventional heating wire has a core member a made of a heat-resistant material, an inner conductor b spirally wound around the core member a, and a coating covering the inner conductor b and the core member a. and a thermistor layer c whose electrical resistance differs depending on temperature changes, an outer conductor d spirally wound around the thermistor layer c, and an exterior insulator e covering the outer conductor d and the thermistor layer c; It was composed of. In addition, the inner conductor b and the outer conductor d
was made of a strip of copper wire or copper alloy with a thickness of approximately 0.08 mm.

Therefore, the inner conductor b and the outer conductor d are extremely susceptible to disconnection and are difficult to handle. Note that even if round wires are used instead of strips for the inner conductor b and outer conductor d, the diameter of the round wires is approximately
Wires with a diameter of 0.13 to about 0.14 mm are used, and they are also prone to breaking.

This invention solves these conventional problems and
The purpose is to provide a heating wire that is difficult to break.

[Means for solving problems]

In the heating wire according to the present invention, an internal conductor is spirally wound around a core member, and the internal conductor and the core member are covered with a thermistor layer whose electrical resistance differs depending on temperature changes, and In a heating wire in which an outer conductor is spirally wound around the thermistor layer and the outer conductor and the thermistor layer are covered with an exterior insulator; 1 reinforcing tape, a conductive strip-shaped first metal foil that is attached to both sides of the reinforcing tape and has a width that is the same or substantially the same as the width of the reinforcing tape;
In addition, the outer conductor is a belt-shaped second reinforcing tape made of a heat-resistant material, and the outer conductor is attached to both sides of the second reinforcing tape, and the width dimension thereof is the same as or equal to the width dimension of the reinforcing tape. This is a three-layer structure including a second metal foil in the form of a strip having substantially the same conductivity.

[Effect]

If configured as described above, the metal foils of the inner conductor and outer conductor, which are strip-shaped, are reinforced with the reinforcing tape, and have excellent strength, and each metal foil is difficult to break even when bent frequently. .

〔Example〕

Hereinafter, the present invention will be explained in detail based on drawings showing embodiments.

FIG. 1 shows a heating wire according to the present invention, which includes a core member 1 made of a heat-resistant material, an inner conductor 2 spirally wound around the core member 1, and the inner conductor 2 and the core. a thermistor layer 3 covering the member 1; an outer conductor 4 spirally wound around the thermistor layer 3;
It consists of an exterior insulator 5 that covers the external conductor 4 and thermistor layer 3.

Thus, the internal conductor 2 includes a first belt-shaped reinforcing tape 6 made of polyester, polyamide, etc., which is strong and has excellent heat resistance, and second belt-shaped metal foils 7, 7 attached to both sides of the reinforcing tape 6. Consisting of In other words, this internal conductor 2 is a three-layered body consisting of a pair of metal foils 7, 7 and a reinforcing tape 6. In this case, the width of the metal foils 7, 7 is set to be the same or approximately the same as the width of the reinforcing tape 6, as shown in FIG. Conductive materials such as Note that the metal foil 7 is attached to the reinforcing tape 6 by a heat fusion method, an adhesive medium method, or the like.

Further, the outer conductor 4 also includes a second reinforcing tape 6a and a pair of second metal foils 7, similar to the inner conductor 2 described above.
a, 7a, and is made into a three-layered body. In other words,
The reinforcing tape 6a is made of a strip of polyester, polyamide, etc., and the metal foil 7a is made of copper, whose width dimension is the same or approximately the same as that of the reinforcing tape 6a.
It consists of a strip of conductive metal such as copper alloy or aluminum.

The thermistor layer 3 has electrical resistance that changes depending on changes in temperature, and has so-called "thermistor characteristics." That is, this thermistor layer 3 is normally an insulator, and as the temperature rises, its electrical resistance decreases and it becomes a conductor.

Therefore, when a current is passed through the internal conductor 2 of the heating wire configured as described above, the internal conductor 2 generates heat,
(In other words, the internal conductor 2 becomes a heating element.) And,
Due to this heat generation, the temperature of the thermistor layer 3 increases, the electrical resistance of the thermistor layer 3 decreases, and the thermistor layer 3 becomes a conductor. Therefore, since a leakage current flows from the inner conductor 2 to the outer conductor 4 via the thermistor layer 3 (that is, the outer conductor 4 becomes a detection conductor), this leakage current is detected and the inner conductor 2 If the current to the heating wire is stopped and the temperature of the heating wire does not rise above a predetermined temperature, and the temperature of the heating wire falls,
If a current is made to flow through the internal conductor 2 again and the temperature is set to rise, the temperature of this heating wire will be maintained within a certain range. Conversely, it is also possible to freely set the current to flow in the outer conductor 4 and the leakage current to flow in the inner conductor 2. In addition, as mentioned above, if either the internal conductor 2 or the external conductor 4 becomes a heating conductor and the other is in the detection state,
This is an electric heating method called the "single line method".
In addition, as for the heating method of the heating wire, the "single wire method"
There is another type called the ``two-wire type.'' In other words, this "two-wire type" is wired so that both the inner conductor 2 and the outer conductor 4 become heat generating conductors or sensing conductors, and like the "single-wire type",
The temperature of the heating wire is set to be maintained within a certain range.

[Effect of idea]

Since the present invention is constructed as described above, it produces the following effects.

The metal foils 7, 7 of the inner conductor 2 are reinforced with reinforcing tape 6, and the outer conductor 4 is reinforced with the metal foils 7, 7.
a and 7a are reinforced with reinforcing tape 6a, respectively.
It has excellent strength, and therefore, when this heating wire is used for electric blankets, electric blankets, etc., even if the electric blankets, etc. are folded or bent to remove dust and dirt, The conductors 3 and 4 of this heating wire do not break, and the service life of the electric blanket or the like can be extended.

Further, the width dimension of the first reinforcing tape 6 and the width dimension of the first metal foils 7, 7 are set to be the same or substantially the same,
In addition, since the width of the second reinforcing tape 6a and the width of the second metal foils 7a, 7a are set to be the same or substantially the same, it is easy to attach the metal foil to each reinforcing tape. If the metal foil is not attached to the reinforcing tape in a misaligned manner and each conductor is wound at a fixed pitch, the metal foil will also be wound at a fixed pitch, causing malfunctions due to local temperature rises. Never.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway plan view of essential parts showing an embodiment of the present invention, and FIG. 2 is an enlarged cross-sectional view of an internal conductor. FIG. 3 is a partially cutaway plan view of essential parts showing a conventional example. DESCRIPTION OF SYMBOLS 1... Core member, 2... Internal conductor, 3... Thermistor layer, 5... Exterior insulator, 6, 6a... Reinforcement tape, 7, 7a... Metal foil.

Claims (1)

[Claims for Utility Model Registration] An internal conductor 2 is spirally wound around a core member 1, and the internal conductor 2 and the core member 1 are connected by a thermistor layer 3 whose electrical resistance differs depending on temperature changes. In the heating wire in which the outer conductor 4 is spirally wound around the thermistor layer 3 and the outer conductor 4 and the thermistor layer 3 are covered with an exterior insulator 5, the above-mentioned internal The conductor 2 is connected to a first reinforcing tape 6 made of a heat-resistant material in the form of a strip, and a conductive strip 6 attached to both sides of the reinforcing tape 6 and having the same or substantially the same width as the reinforcing tape 6. first metal foil 7,
7 and the outer conductor 4.
, a belt-shaped second reinforcing tape 6a made of a heat-resistant material,
Conductive strip-shaped second metal foils 7a, 7a attached to both sides of the second reinforcing tape 6a and having the same or substantially the same width as the reinforcing tape 6a.
A heating wire characterized by having a three-layer structure of and.