JPS61290684A - Manufacture of heatsensitive wire - 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 the Invention The present invention relates to a method for manufacturing a heat-sensitive wire for temperature detection used in planar heating devices such as electric blankets and electric carpets.

Conventional technology In general, a sheet heating device such as an electric blanket or an electric carpet has a cord-shaped heating wire and a heat-sensitive wire for temperature detection arranged in a meandering manner, and the heating wire detects the temperature of the sheet heating device. The function is to control the current flowing through the heating wire.

The structure of the heat-sensitive wire is as shown in FIG. 4, in which a heat-sensitive layer 9 having a negative temperature coefficient is provided around the outer periphery of a core thread 7 and an internal electrode 8 spirally wound around the outer periphery of the core thread 7.

After an external electrode 10 is spirally wound around the outer periphery of this heat-sensitive layer 9, a gap tape 11 is then wound around the outer periphery of the outer electrode 9, and an insulating jacket 12 is further provided.

The method for producing the heat-sensitive wire is shown below. ``First, the diameter Q is made of heat-resistant fiber such as polyester or heat-resistant polyamide.
, 4~(Copper around the outer circumference of the 18m core thread.

A metal conductor such as copper alloy or stainless steel with a thickness of 0.05 to 0.
A first step of obtaining a primary winding in which the internal electrode 8 processed into a ribbon shape of 1tm width Q, 5 to Q, 8m is wound in a spiral shape at a pitch of 5 to 10 times per 10111I11, and the outer periphery of the primary winding. A quaternary ammonium salt whose main component is polyvinyl chloride, which is added to improve temperature detection sensitivity.

A second step of coating the heat-sensitive layer 9 by extrusion molding a composition containing 1 to 5% by weight of a surfactant such as an imidazole compound or an oxazole compound, and coating the outer periphery of the heat-sensitive layer 9 with copper, copper alloy, stainless steel, etc. Conductor thickness 0.05 to 0.1 width α
The external electrode 10 processed into a ribbon shape of 6 to α8 is 101
No. 6, which is wound in a spiral shape with a pitch of 5 to 10 times per turn.
and polyethylene terephthalate and polyamide around the outer electrode 1o.

Thickness α0 made of a single substance such as aluminum or a composite material
A fourth step of wrapping tape-shaped intervening tapes 11 having a width of 3 to 8III+ in a spiral manner.

An insulating jacket 1 of polyvinyl chloride is placed around the outer circumference of the gap tape 11.
It consisted of a fifth step of covering No. 2 by extrusion molding.

Problems to be Solved by the Invention However, the structure of the conventional heat-sensitive wire and its manufacturing method have the following problems, and improvement thereof has been desired.

(1) The contact between the internal electrode 8 and the heat-sensitive layer 9 is such that the heat-sensitive layer 9 is coated on the outer peripheral surface of the internal electrode 8 by extrusion processing, so that sufficient adhesion reliability can be obtained; Since the contact between the outer electrode 10 and the heat-sensitive layer 9 is determined by the tension during the winding process of the outer electrode 10, it is easily subject to variations during manufacturing.
~(LlsaI, width α3~G, 8 strips are processed into a foil shape, so deformation and flaking are likely to occur. This may cause the B constant to become small or cause variations.

■) Since the structure has a gap between the heat-sensitive layer 9 and the intervening tape 11, the plasticizers and additives added to the heat-sensitive layer 9 are likely to bleed out, so it is difficult to prevent the plasticizer and additives from bleeding out after long-term use. In addition to a large change in impedance over time, the external electrode 1o tends to dig into the heat-sensitive layer 9 during compression or undergo bending fatigue, resulting in poor mechanical strength.

(3) In the process of winding the gap tape 11, the winding machine must be stopped every 500 to 800 meters of the heat-sensitive wire to connect the tape, and the next new tape must be connected immediately. If the winding speed is increased, the tape becomes more likely to break, resulting in poor work efficiency and increased manufacturing costs.

Means for Solving the Problems The present invention has been made to solve the problems of the conventional art, and includes a first step of winding internal electrodes around the outer circumference of the core thread, and a heat-sensitive layer around the outer circumferences of the inner electrodes. Immediately after wrapping a tape-shaped metal foil vertically around the outer periphery of this heat-sensitive layer, a third step involves wrapping an external electrode around the outer periphery of the metal foil, and a third step of wrapping the outer periphery of these metal foils. and a fourth step of covering with an insulating jacket.

Function The method for producing a thermosensitive wire of the present invention can be expected to have the following functions, and has great industrial utility value.

(1) By providing a metal foil between the heat-sensitive layer and the external electrode, contact reliability is increased, the B constant is increased, and migration of plasticizers and additives added to the heat-sensitive layer is prevented. .

(2) Improve flexibility by eliminating gaps around the outside of the heat-sensitive layer.

(3) Manufacturing man-hours can be reduced and workability can be improved.

Example DESCRIPTION OF THE PREFERRED EMBODIMENTS One implementation of the present invention will be described in detail below with reference to the drawings.

Figure 1 shows a structural diagram of a heat-sensitive wire manufactured based on the manufacturing method of the present invention. 1 is a wire made by twisting heat-resistant fibers such as polyester or polyamide to have a diameter of α4 to α8. The core thread 2 is copper or copper alloy wound spirally around the outer circumference of the core thread 1.

An internal electrode made of stainless steel or the like; 3 a heat-sensitive layer coated around the outer periphery of the core thread 1 and the internal electrode 2; and 4 a heat-sensitive layer made of a composition of polyvinyl chloride and a quaternary ammonium salt; 4 a heat-sensitive layer 3; Tape-shaped metal foil such as aluminum foil, stainless steel foil, copper foil, etc.

Reference numeral 5 designates an external electrode made of copper, mixed gold, stainless steel, etc., which is wound around the outer periphery of the metal foil 4, and reference numeral 6 designates an insulating jacket that covers all of these.

FIG. 2 shows the temperature dependence characteristics of the impedance of heat-sensitive wires constructed according to the conventional example and the manufacturing method of the present invention.

FIG. 3 shows the impedance change characteristics over time of heat-sensitive wires constructed according to the conventional example and the manufacturing method of the present invention when subjected to heat aging at a high temperature of 110°C.

As is clear from the structure shown in FIG. 1, the heat-sensitive wire of the present invention can be obtained by the following manufacturing method.

First step: An internal electrode is spirally wound around the outer periphery of the core yarn 1 at a pitch of 5 to 10 times per 10+o+ to obtain a bobbin for the primary winding.

Second step: While loosening the bobbin of the primary winding, the heat-sensitive layer 3 is coated to a thickness of I:
Coated by extrusion molding to L2~α4■, outer diameter accuracy ±α05■.

Third Step This step is the main part of the present invention and the most important operation. First, a thickness CL is applied to the outer periphery of the heat-sensitive layer 3 obtained in the second step.
A metal foil 4 of aluminum foil slit into a tape shape with a width of 4 to 61 m and a width of 0.06 to 0.03 wa is fed through a guide jig and then wound vertically and vice versa.9 Immediately after this winding, an external electrode 5 is The metal foil 4 attached vertically and sub-couplings is wound while being fixed by a winding machine that winds it in a spiral shape. If the external electrode 5 is not wrapped immediately after the metal foil 4 is attached and wrapped around the heat-sensitive layer B, gaps will be created in the vertical and sub-portions of the metal foil 4, #1 will become loose, and the gap effect will be lost, and the external electrode 5 will be Since a problem arises in which the nozzle of the winding machine is clogged with the metal foil 4 and the winding process cannot be carried out, the manufacturing method for obtaining the structure of this embodiment is impossible except in this third step.

Fourth step: An insulating jacket 6 of polyvinyl chloride is placed around the outer periphery of the metal foil 4 and external electrode 5 obtained in the fifth step to a thickness of Q, 3 to α8 wa.
+Extrusion molding coating with thickness accuracy ±[105m.

By making the heat-sensitive wire in the above manufacturing process, by providing the metal foil 4 vertically between the heat-sensitive layer 3 and the external electrode 5 immediately before wrapping the external electrode 5, the metal foil 4 is attached to the heat-sensitive layer 6. The temperature dependence of the impedance becomes large as shown in Fig. 2, that is, the B constant becomes large, and the temperature detection sensitivity can be improved.
In addition to making it possible to improve characteristics such as reducing the change in impedance over time and improving flexibility compared to conventional examples, the number of manufacturing steps is less than that of conventional examples, and because the metal foil 4 is wound vertically and sub-wise, it is possible to reduce the amount of force required. Since the metal foil 4 is not added to the metal foil 4, there is no need to cut it during the winding process, and the connection work can be performed every 2000 to 3000 m.
It can be manufactured at a lower cost and is expected to significantly improve work efficiency than conventional methods.

Effects of the Invention As described above, the heat-sensitive wire manufactured by the manufacturing method of the present invention has the following effects and has great industrial utility value.

(1) The thermal wire has high temperature detection sensitivity and changes in characteristics can be minimized, so it is highly reliable during long-term use.

(2) A heat-sensitive wire with excellent bending fatigue resistance can be obtained.

(3) It is possible to reduce the number of man-hours and improve workability, making it possible to reduce manufacturing costs.

[Brief explanation of the drawing]

FIG. 1 is a structural diagram of a heat-sensitive wire obtained by a method of manufacturing a heat-sensitive wire according to an embodiment of the present invention, and FIGS. 2 and 3 show impedances of an embodiment of the present invention and an embodiment of a conventional example, respectively. Temperature dependence characteristic diagram and impedance change characteristic diagram over time, 4th
The figure shows a structural diagram of a conventional heat-sensitive wire. 1... Core thread, 2... Internal electrode. 3...Thermosensitive layer, 4...Metal foil. 5... External electrode, 6... Insulating jacket.

Claims (1)

[Claims] A first step of spirally winding an internal electrode (2) around the outer periphery of a core yarn (1) of heat-resistant fiber to obtain a primary winding, and having a negative temperature coefficient around the outer periphery of the primary winding. Heat sensitive layer (3)
Immediately after wrapping a tape-shaped metal foil (4) vertically and vertically around the outer periphery of the heat-sensitive layer (3), an external electrode ( 5) in a spiral shape; and a fourth step of extruding and covering the outer periphery of the metal foil (4) and the external electrode (5) with an insulating jacket (6). A method of manufacturing a heat-sensitive wire.