JP2727156B2 - Heater wire - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heater wire used for a planar heating element such as an electric carpet, and more particularly to a one-wire type heater wire.

[0002]

2. Description of the Related Art Conventionally, a heater wire is used for a sheet heating element such as an electric blanket or an electric carpet laid on a cloth such as a carpet. A function for controlling the temperature of the planar heating element is provided to the heater wire. Depending on the structure of the heater wire, a one-wire heater wire (hereinafter referred to as a one-wire heater wire) and a two-wire heater wire ( This is hereinafter referred to as a two-wire heater wire). The one-wire heater wire has a structure in which a heat generating portion and a temperature detecting portion are combined into one wire. On the other hand, the two-wire type heater wire has a structure in which a heat generating portion and a temperature detecting portion are respectively divided into two wires of a heater wire and a temperature sensing wire, and these two wires function as a pair. Depending on the length of the heater wire used, a one-wire heater wire is mainly used for the electric blanket, and a two-wire heater wire is mainly used for the electric carpet.

The structure of a conventional one-wire heater wire will be described in detail with reference to FIG. The one-wire heater wire 8a is formed by winding one or a plurality of heat generating wires 2 in a spiral shape at a constant pitch around the outer periphery of a winding core 1 made of glass fiber or polyester fiber.
A polyamide resin such as 1, nylon-12 or the like is extruded and coated in a tubular shape to provide a fusion layer 10, and then a fusion layer 1 is formed.
A nickel wire 6 serving also as a temperature detection wire and a signal wire is spirally wound at a constant pitch width around the outer periphery of the wire 0, and a polyvinyl chloride resin or the like is extruded in a tube shape on the outermost layer to form a sheath 7
Is provided.

The nickel wire used for the single-wire heater wire 8a has a characteristic that the temperature coefficient of resistance changes linearly with temperature (temperature coefficient of resistance 3.8 to 4.5 × 10 ^-3 ). The temperature control of the sheet heating element detects the temperature over the entire length of the laid heater wire as a change in the resistance of the nickel wire,
Temperature control is performed as an average temperature over the entire length of the heater wire.

Next, the structure of the two-wire heater wire will be described in detail with reference to FIG. First, the heater wires (heating portions) in FIG. 3A will be described. The heater wire 20 is formed by winding one or more heating wires 2 in a spiral shape at a constant pitch around the outer periphery of a core 1 made of glass fiber or the like. It has a structure in which a sheath 7 is provided by extrusion. A temperature sensing wire (temperature sensing unit) 40 shown in FIG. 3B is formed by winding a lower winding conductor 31 made of copper or a copper alloy around the outer periphery of the core 1 to form a winding electrode. The body is extruded into a tube to provide a temperature-sensitive layer 32, and an outer winding conductor 33 made of copper or a copper alloy is provided on the outer periphery thereof.
Is wound to form a winding electrode, and a sheath 7 is provided on the outer periphery by extruding a polyvinyl chloride resin or the like into a tube shape. The polymer thermosensitive material used for the thermosensitive layer 32 is a plastic thermistor formed by using a thermoplastic resin such as polyvinyl chloride as a base material and adding a substance imparting ion conductivity to the base material. Note that a surfactant made of a quaternary ammonium perchlorate is generally used as the ion-conductivity imparting substance.

The sheet heating element uses the heater wire 20 as a heating portion, and uses an electronic controller and a temperature sensing line 40 in combination for controlling the temperature of the heating portion. The temperature sensing line 40 has a characteristic that the rate of change of the impedance characteristic with respect to temperature (temperature dependence of impedance, thermistor B constant) of the temperature sensing layer 32 is constant, and the temperature is controlled using this characteristic. .

[0007] It is possible to use a nickel wire for the winding electrode of the upper winding conductor of the plastic thermistor layer to which a substance imparting ionic conductivity is added. Apply and detect the change. Therefore, when the nickel wire is wound immediately above the ion-conductive plastic thermistor layer, the direct current component flows through the plastic thermistor layer to the winding electrode of the lower winding conductor, and the carrier ion of the ion-conductive substance of the plastic thermistor layer. Causes the polarization phenomenon, the impedance characteristic gradually changes during use, and the temperature-dependent gradient of the impedance becomes small. Therefore, when an ion-conductive plastic thermistor layer is interposed, a temperature control method in which an impedance change due to an alternating current is detected and a direct current component is superimposed thereon cannot be used.

[0008]

In order to control the temperature of the planar heating element, the amount of heat generated from the laid heater wires is measured over the entire length, and the amount of change as the average temperature of the entire length of the heater wires is detected. Has been done. Large-sized planar heating elements using long heater wires, for example, electric carpets for 2 tatami mats and 3 tatami mats have become mainstream, and the length of heater wires to be laid is inevitably long. . Since the single-wire type heater wire has a small temperature coefficient of resistance of 3.8 to 4.5 × 10 ⁻³ of the nickel wire, the longer the length of the heater wire, the smaller the rate of change in resistance of the nickel wire with respect to temperature change. Therefore, the sensitivity as a temperature detection line is deteriorated, and a local temperature change cannot be detected. As a result, almost no heater wire is used for a large planar heating element having a long strip, and for example, a two-wire type is widely used for an electric carpet.

On the other hand, the two-wire type heater wire has a heater wire (heat generating portion) and a temperature sensing wire (temperature detecting portion) individually as described above, and is used as a pair. The workability of laying wires to was poor. Further, the temperature-sensitive detection line having the temperature-sensitive layer is set at a high temperature (eg, 120 ° C.) for a long time (eg,
0) When used, the copper wire used as the winding electrode reacts with the plasticizer and various stabilizers in the thermosensitive layer to reduce the carrier density and increase the impedance of the thermosensitive layer,
Temperature changes cannot be detected sensitively. Further, since a surfactant is used, there is a disadvantage that the rate of change of impedance with respect to humidity change is large.

In a one-wire heater wire, nylon-11,
Various methods have been proposed in which a polyamide fusion fault is also used as a temperature-sensitive layer by utilizing the temperature dependence of the impedance of a polyamide resin such as nylon-12, and the thermistor B constant caused by the hygroscopicity of the polyamide resin has been proposed. Has not been put to practical use because of the large fluctuation range of.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and has a simple structure without greatly changing the structure of a conventional one-wire heater wire.
A new temperature-sensitive layer resin (plastic thermistor) used for the temperature-sensitive detection wire of the two-wire heater wire, a large thermistor B constant, excellent responsiveness to changes in ambient temperature, and excellent copper and copper alloys The purpose of the present invention is to provide a heater wire which does not decrease in carrier density even when exposed for a long time in the presence of a heating element wire composed of copper or a copper ion eluted from a metal conductor and has excellent environmental resistance such as moisture absorption resistance. And

[0012]

In order to achieve the above-mentioned object, the present invention is to provide a heating element in which a heating element wire is spirally wound around an outer periphery of a winding core at a constant pitch, and a polyolefin oxide is added to the outer periphery of the heating element wire. A temperature-sensitive layer 3 is prepared by adding a high-ionic conductive polymer electrolyte in which lithium is dissolved to a polyvinyl chloride resin, and a signal line formed of a metal conductor 4 is provided at a constant pitch on the outer periphery of the temperature-sensitive layer 3. And spirally wound with
A winding layer 5 made of a heat-resistant plastic tape is provided on the outer periphery, and a temperature detecting wire made of a nickel wire 6 is wound around the outer periphery of the winding layer 5 in a spiral at a constant pitch. 7 is provided in the heater wire.

The heating element wire 2 is generally a copper wire or a copper alloy wire, but may be a nickel-plated copper wire or a nickel-plated copper alloy wire obtained by plating these with nickel. The polymer solid electrolyte exhibiting high ionic conductivity obtained by dissolving lithium perchlorate (LiClO ₄ ) in the polyolefin oxide-[— (CH ₂ ) m—O—] n- (where m, n = 2 to ₄ ) is It is a conductivity-imparting agent. As the polyolefin oxide, polyethylene oxide or polypropylene oxide is used. Further, as the polyvinyl chloride resin, polyvinyl chloride resin (PVC), polyvinyl chloride admixture or the like is used. The metal conductor 4 is generally a copper wire or a copper alloy wire, but may be a nickel-plated copper wire, a nickel-plated copper alloy wire, or a stainless steel wire obtained by plating these. Each of the strands may be a round wire or a flat wire. In general, copper and copper alloy react with the plasticizer in the temperature-sensitive layer at high temperatures as described above, copper ions are eluted, react with carriers that contribute to ion conduction, and impedance characteristics decrease. The element wire 2 and / or the metal conductor 4 are preferably a nickel-plated copper wire or a nickel-plated copper alloy wire. The material of the tape of the heat-resistant plastic tape winding layer 5 may be any material that is excellent in electrical insulation and thermally strong, and may be a synthetic resin film such as a polyethylene terephthalate film, a polyetherimide film, or a polyphenylsulfone. A film or the like is used, but is not particularly limited. In consideration of economy and versatility, polyethylene terephthalate tape is preferable. Further, it is preferable that the heat-resistant plastic tape winding layer 5 is formed by longitudinal application or lap winding of a fixed width. Further, the sheath 7 is made of a polyvinyl chloride resin, for example, PVC, a polyvinyl chloride mixture or the like.

Considering the function of controlling the temperature of the sheet heating element, it is preferable that the single-wire heater wire of the present invention is formed by directly winding the metal conductor 4 and the nickel wire 6 on the temperature-sensitive layer 3. However, when the metal conductor 4 and the nickel wire 6 come into contact with each other, a DC component for detecting a change in resistance of the nickel wire with respect to temperature flows through the temperature-sensitive layer 3 to the lower winding conductor 2 and polarizes ion carriers in the temperature-sensitive layer. Therefore, it is necessary to completely separate the metal conductor 4 and the nickel wire 6 electrically. In order to faithfully detect a change in the impedance of the thermosensitive layer 3, the metal conductor 4 needs to be wound directly above and directly above the thermosensitive layer 3 in electrical contact. On the other hand, nickel wire 6
It is not always necessary to completely contact the thermosensitive layer 3 and wind it. Therefore, the metal conductor 4 is wound immediately above the heat-sensitive layer, and the nickel wire 6 is interposed with a heat-resistant plastic tape wound layer 5 to prevent contact with the metal conductor 4. The wire 6 is wound.

[0015]

The temperature change rate of the impedance detected by the temperature-sensitive layer 3 of the heater wire of the present invention is in a low temperature region (about 20 to 50 ° C.).
And a high temperature region (about 50 to 120 ° C.).
This is because the conduction mechanism of ionic conduction of the plastic thermistor of the temperature-sensitive layer 3 is different, and is represented by the capacitive reactance of the temperature-sensitive layer 3 in a low-temperature region and by the volume resistivity in a high-temperature region. Since the change of the capacitive reactance with respect to the temperature is small, it is not suitable for use in temperature control. On the other hand, since the change in the volume resistivity with respect to the temperature is large, it is suitable for use in temperature control. The resistance of the nickel wire 6 changes at a substantially constant rate from the low temperature region to the high temperature region (change rate of the temperature coefficient of resistance). Therefore, the heater wire of the present invention controls the temperature in the low temperature region by using the rate of change of the temperature coefficient of resistance of the nickel wire 6, and when the high temperature region and local abnormal heat generation occur, the volume specific resistance of the temperature sensitive layer 3 is increased. That is, since temperature control is performed based on the rate of change in impedance, it is possible to detect temperature with higher sensitivity. Further, the heater wire of the present invention differs from the conventional two-wire heater wire in that
Since the structure is such that the temperature detection line composed of the heating section, the temperature-sensitive layer, and the nickel wire is integrated on the two heater lines, it is not necessary to use the conventional heater line and the temperature detection line. The work of laying wires on the heating elements was improved, the temperature-sensitive layer and the nickel wire could be used together, local heat generation could be detected with high sensitivity, and a highly reliable one-wire control method became possible.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. Note that the present invention is not limited to the present embodiment. FIG. 1 is a perspective view showing the structure of a heater wire according to one embodiment of the present invention, and FIGS. 4 and 5 are graphs showing the impedance characteristics of a temperature-sensitive layer and the resistance characteristics of a nickel wire of the heater wire according to the first embodiment. .

Embodiment 1 Manufacturing of a heater wire will be described with reference to FIG. Outer diameter 0.
A heating wire 2 composed of 0.14 mmφ × 2 nickel-plated copper wires is spirally wound at a pitch of 0.60 mm around a winding core 1 made of a 45 mm polyester resin fiber twisted yarn to produce a wire. It was wound on a bobbin (not shown). Next, a wire is drawn out from the bobbin, and a PVC admixture obtained by adding a solid polymer electrolyte obtained by dissolving lithium perchlorate in polyethylene oxide as an ionic conductivity-imparting agent to the outer periphery of the wire is subjected to a head temperature of 220. The extruder was extruded into a tube using an extruder having a cylinder temperature of 220 ° C. and a temperature-sensitive layer 3 having an outer diameter of 0.120 mm was provided. Next, a signal wire 4 composed of two nickel-plated copper wires of 0.13 mmφ × 2 was spirally wound around the outer periphery of the thermosensitive layer 3 at a winding pitch of 0.20 mm. Next, a 1/16 wrap of a polyester tape having a thickness of 0.016 mm and a width of 6.0 mm is wound around the outer periphery to form a heat-resistant plastic tape winding layer 5.
A 0.09 mmφ nickel wire 6 is spirally wound at a pitch of 0.20 mm. Finally, a PVC mixture is extruded in a tube shape on the outer periphery to provide a sheath 7, and a finish outer diameter is 2.35 m.
m of the single-wire heater wire 8 for an electric carpet was manufactured. The specification of this one-wire heater wire 8 is for 1 tatami mat, 100V-200W-
It is 29.5m (full wave specification).

As a characteristic test of the heater wire of Example 1 of the present invention, a temperature-impedance characteristic of the thermosensitive layer and a temperature-resistance characteristic of the nickel wire were measured. The measurement method was as follows: a 29.6 m length was sampled from the single-wire heater wire 8 manufactured in Example 1 as a test sample, and then the sample was left in a thermostat having a temperature range of 0 to 120 ° C. At intervals, after each temperature stabilizes 1
After an hour, the impedance of the thermosensitive layer and the resistance of the nickel wire were measured. The results are shown in Table 1 below and FIGS.

[0019]

[Table 1]

As is apparent from the graph of FIG. 5, since the temperature coefficient of resistance of the nickel wire shows a constant value depending on the purity of the material, the resistance increase of the nickel wire increases linearly in proportion to the temperature. On the other hand, the change in impedance of the thermosensitive layer shown in the graph of FIG. 4 is determined by the electrical properties of the material constituting the thermosensitive layer, that is, the temperature dependence of the capacitance reactance and the volume resistivity. It can be seen that the volume resistivity component greatly contributes in the high temperature region. Therefore, in the low temperature region (20 to 50 ° C.), the temperature is controlled using the change in the resistance of the nickel wire, and in the high temperature region (50 to 120 ° C.) and when the heat is confined and locally heated to a high temperature, the temperature-sensitive layer Temperature control is performed using the temperature change of the impedance.

[0021]

The heater wire according to the present invention is a one-wire heater wire having a structure in which the heat generating portion and the temperature detecting portion are integrated into one wire. Therefore, compared to the conventional two-wire type heater wire, only one wire is required, so that it is economical. In addition, when manufacturing the planar heating element, the work of laying the base material can be performed efficiently. Further, the present invention can be preferably applied to an electric carpet requiring a long heater wire, which cannot be applied to a conventional one-wire heater wire. Further, the heater wire of the present invention has an advantage that the temperature change at the time of abnormal temperature rise can be detected more quickly because the detection portion is constructed in the upper layer portion of the heat generating portion. In addition, the temperature detection function of the heater wire is duplicated with the temperature sensitive layer and the nickel wire, and by using these functions for the input of the temperature control circuit,
A planar heating element such as an electric carpet having high accuracy and high reliability can be manufactured at low cost. Therefore, the effect that contributes to the industry is extremely large.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a structure of a heater wire according to an embodiment of the present invention.

FIG. 2 is a perspective view showing the structure of a conventional one-wire heater wire.

FIG. 3 is a schematic view showing a structure of a conventional two-wire heater wire. (A) is a perspective view which shows the structure of a heater wire.
(B) is a perspective view showing the structure of the temperature sensing line.

FIG. 4 is a graph showing impedance characteristics of a heater wire (temperature-sensitive layer) of Example 1.

FIG. 5 is a graph showing resistance characteristics of a heater wire (nickel wire) of Example 1.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Winding core 2 Heating wire 3 Thermosensitive layer 4 Metal conductor (signal wire) 5 Heat-resistant plastic tape winding layer 6 Nickel wire (temperature detection wire) 7 Sheath 8 Heater wire

Continuation of the front page (56) References JP-A-7-6687 (JP, A) JP-A-7-216174 (JP, A) JP-A-7-216173 (JP, A) JP-A-4-132187 (JP) JP-A-4-28192 (JP, A) JP-A-61-117279 (JP, U) JP-A-4-40493 (JP, U) JP-B 5-72081 (JP, B2)

Claims (5)

(57) [Claims] A heating element wire is spirally wound around an outer circumference of a winding core at a constant pitch, and a polymer solid electrolyte having high ionic conductivity in which lithium perchlorate is dissolved in polyolefin oxide is wound on the outer circumference. A temperature-sensitive layer 3 added to a polyvinyl chloride resin is provided, and a signal line made of a metal conductor 4 is spirally wound at a constant pitch around the outer circumference of the temperature-sensitive layer 3. Winding layer 5
Then, a nickel wire 6 is provided around the outer periphery of the tape winding layer 5.
A heater wire comprising a spirally wound temperature detecting wire formed of a constant pitch and a sheath 7 provided on the outermost layer. 2. The heater wire according to claim 1, wherein the heating element wire 2 is a round wire or a flat wire of a copper wire, a copper alloy wire, a nickel-plated copper wire, a nickel-plated copper alloy wire. . 3. The heater wire according to claim 1, wherein the polyolefin oxide is polyethylene oxide or polypropylene oxide. 4. The metal conductor 4 comprises a round wire or a flat wire of a copper wire, a copper alloy wire, a nickel-plated copper wire, a nickel-plated copper alloy wire, or a stainless steel wire. The heater wire according to 2 or 3. 5. The wound layer of the heat-resistant plastic tape 5.
5. The heater wire according to claim 1, wherein the heater wire is formed by vertically adding polyester tape or lap winding of a fixed width.