JPH0218558B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a thermal heater wire used in an electric heating device such as a planar heating device. Conventionally, temperature detection wires, heater wires, thermosensitive heater wires, etc. used in planar heating devices are configured as shown in FIG. That is, the first electrode conductor 2 is formed in a spiral shape on the core yarn 1, and then the polymer heat-sensitive layer 3, the second electrode conductor 4, and the insulating jacket 5 are formed in this order. In the case of a heater wire, at least one of the electrode conductors is used as a heating wire, and the polymer heat-sensitive layer is used as a temperature fuse. In the case of a temperature detection line, the impedance change due to the temperature of the polymer heat-sensitive layer is detected and used as a temperature sensor. In this method, the sensor and heater are made of separate wires, and is called a two-wire method. On the other hand, in the case of a thermosensitive heater wire, one of the inner and outer electrodes is a heating element wire, and the other is a signal wire, which not only detects impedance changes due to the temperature of the polymer heat-sensitive layer, but also serves as a temperature fuse in the event of abnormal temperature rise. This also serves as This is called the one-line method. These systems have both a temperature control function and a local overheating detection function, but the amount of heat generated per length is constant, and the temperature distribution changes with changes in the wiring pattern. Therefore, the local overheat detection function is insufficient, and its characteristics largely depend on the B constant of the sensor and the wiring pattern. Also, as the system becomes larger and the length of use increases, the local sensing capability will decrease. Therefore, the present invention provides a heat-sensitive heater wire that has a self-temperature-controllable heat generating layer and that does not cause local overheating at all. Hereinafter, embodiments will be described in detail with reference to the drawings. FIG. 2 shows an embodiment of the present invention.
A first electrode conductor 6, an inner functional layer 7, a second electrode conductor 8, an outer functional layer 9, a third electrode conductor 10, and an insulating jacket 5 are sequentially formed on the core thread 1. this house,
The inner functional layer 7 is a polymer thermosensitive layer or a heat-melting insulating layer, and the outer functional layer 9 is a self-temperature controllable layer.
Use PTC heating layer. (Here, PTC refers to a large positive temperature coefficient of resistance.) The conductor for the first electrode can also be constructed with a metal wire core like a general electric wire, and as shown in Figure 2, the conductor for the first electrode can be constructed with a metal wire as the core. It may also be wrapped with metal foil. The heating layer can have a self-temperature control function by using a polymer composition containing a particulate conductive agent mainly composed of carbon black. Specifically, a positive temperature heating element composition having a large positive temperature coefficient at the crystal transformation point can be constructed by combining a crystalline polymer and carbon black.
For example, resins used for this include polyolefins such as polyethylene-vinyl acetate copolymer, polyethylene-ethyl acrylate copolymer, polyethylene, polypropylene, polyamide, polyvinylidene halide, polyester, etc., and each resin has a temperature close to its crystal transformation point. shows a sharp positive temperature coefficient. Resistance stability can be imparted to these polymers by chemical crosslinking, electron beam crosslinking, or the like. Since the heat generating layer is disposed between the inner and outer electrodes of 0.3 to 0.5 mm, a composition having a high specific resistance may be used, and a positive resistance temperature coefficient characteristic for self-temperature controllability can be easily obtained. On the other hand, for the polymer temperature sensitive layer, a polymer composition called a plastic thermistor that changes ionic conduction, electronic conduction, capacitance, etc. depending on temperature may be used; nylon composition, polyvinyl chloride composition, etc. It is generally made from a polyvinyl chloride-vinyl acetate copolymer composition. When operating as a heat-melting insulating layer, a crystalline polymer having a melting point higher than the self-control temperature of the heat generating layer, such as a nylon composition or polyolefin, may be used. Polyethylene-vinyl acetate copolymer and ethylene-ethyl acrylate are suitable as heat-generating layer materials that have a self-control point between 60°C and 80°C as heaters for electric heating devices. A crystalline polymer having a melting point of about .degree. C. to 200.degree. C. is preferable, and polyethylene, polyamide, polyester, etc. are suitable. By configuring the thermal heater wire as described above, a highly safe system as shown in the table can be configured. The table shows the safety of the temperature sensor/heater system.

【table】

[Table] By using the thermal heater wire of the present invention,
The following remarkable effects can be achieved. (1) Since the sensor and heater are integrated, wiring is easy and local overheating does not occur. (2) Since heat is consumed and only the low temperature areas are heated, energy-saving heating can be achieved. (3) Highly safe, providing peace of mind against abnormal overheating and local overheating. The present invention provides a high degree of safety to a wide surface heater using a single heat-sensitive heater wire, and provides an excellent heater in which safety is not compromised by the width or length of the heater wire. It is of great industrial value.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a conventional example, and FIG. 2 is a block diagram of an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Core thread, 5... Insulating outer jacket, 6... First electrode conductor, 7... Inner functional layer, 8... Second electrode conductor, 9... Outer functional layer, 10... Third Conductor for 3 electrodes.

Claims (1)

[Claims] 1. A first electrode conductor, an inner functional layer, and a second electrode conductor on the core thread.
An electrode conductor, an outer functional layer, a third electrode conductor, and an insulating jacket are sequentially provided with concentric cross sections, the inner functional layer is a polymeric temperature sensitive layer or a thermofusible insulating layer, and the outer functional layer is The self-temperature-controlling PTC heating layer serves as a thermal heater wire. 2. The thermal heater wire according to claim 1, wherein the polymer thermosensitive layer is a thermosensitive material that can extract temperature changes as impedance changes. 3. The thermal heater wire according to claim 2, wherein the impedance change is based on a change in any one of ionic conductivity, dielectric constant, and electronic conductivity. 4. The thermal heater wire according to claim 1, wherein the inner functional layer is made of a crystalline polymer having a melting point higher than the self-control temperature of the heat generating layer. 5. The thermal heater wire according to claim 4, wherein the crystalline polymer is made of a nylon composition.