JPS5853479B2 - heating cloth - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a planar heating cloth, which minimizes the surface contact resistance between an electrode wire and a heating wire, and achieves stability with less fluctuation in electrical resistance in response to fluctuations in contact pressure. The purpose is to submit a surface heating cloth.

Conventionally, for surface heating elements that generate heat over a wide area, such as hot carpets, a large number of linear heating wires made by coating the fiber surface with a heating material such as carbon powder are arranged in parallel in one direction. On the other hand, by arranging electrode wires made of thin metal wires at intervals between heating surfaces in the orthogonal direction, and by weaving them together with cotton thread etc. to form a planar shape, the heating wires and electrode wires are intertwined with each other. Heat-generating cloth has been used in which the current applied to the wire is guided to each heat-generating wire through the above-mentioned confounding contact points and generates self-heating. It has the advantage of being easy to use, and is attracting particular attention from many quarters as an extremely excellent heating element.

However, the biggest problem with such heating fabrics is how to maintain stable electrical contact between the heating wires and the electrode wires. An important issue is how to prevent electrical contact defects caused by differences in the heating cloth, transient bending of the heating cloth, or changes in external pressure.

Of course, in order to eliminate these drawbacks, for example, as shown in FIGS. 1 and 2, an electrode wire 3 made of a thin copper wire 2 helically wound around the outer layer of a fiber core wire 1 is interlaced with a heating wire 4. method has been used.

That is, when the thin metal wires 2 are provided in a helical shape on the outer layer of the fiber core wire 1, the thin metal wires 3 have a spring force, so that when they are woven into the heating wire and entangled, they generate contact pressure with each other and come into contact. Therefore, the effect of reducing electrical contact resistance or preventing fluctuations can be expected.

However, on the other hand, the contact between the helically wound metal wire and the heating wire is only at the points where they intersect, so in order to increase the number of contact points and reduce the resistance, it is necessary to reduce the winding pitch of the metal wire. Alternatively, it became necessary to combine a large number of electrode wires and use them as one electrode band.

However, when an attempt is made to increase the number of contact points by decreasing the winding pitch of the thin metal wire, the spring elastic force of the thin metal wire naturally increases in proportion to the winding density, and as a result, when driving the electrode wire with a shirt bolt, the spring elasticity of the thin metal wire increases. The force exerted on the fabric causes tension fluctuations, making it impossible to obtain a heating cloth with stable electrical contact.

However, when it comes to forming an electrode band by combining a large number of thin metal wires helically wound around a fiber core wire at an optimal winding pitch, the cost increases as the number of composite wires increases, and the electrode This is by no means a preferable countermeasure because the ratio of the non-heat generating surface of the band to the total area of the heat generating cloth becomes large, impairing the uniform temperature distribution.

The present invention was arrived at through extensive research in consideration of the above-mentioned problems, and the gist of the invention is to provide a thin metal wire in a helical shape on an outer layer in which the surface of a fiber core wire is coated with a conductive material in advance. The present invention proposes a heating cloth in which electrode wires, heating wires, and aggregate fibers are woven together, and the present invention significantly improves the electrical contact between the electrode wires and the heating wires, and provides long-term durability. It has become possible to perform stable surface heating.

The present invention will be described in detail below based on Examples.

FIG. 3 shows the basic principle of the electrode wire constituting the present invention.

That is, a conductive coating 6 is provided on the surface of a linear fiber core 5, which is an electrical insulator, to add conductivity, and then a thin metal wire 7 is wound helically around the outer layer of the fiber core 5 to form an electrode. A line 8 is formed.

When such electrode wires are interwoven with heating wires to bring them into surface contact, a superior effect can be obtained compared to conventional methods.

That is, in the conventional method, the contact between the electrode wire and the heating wire is formed only at the surface contact point between the heating wire and the fine metal wire wound helically around a fiber core wire, which is an electrical insulator. The thin metal wire 7 wound in a helical manner maintains electrical contact with the core wire 5 of the fiber throughout its length via the conductive coating 6, so there is no electrical contact between the heating wire and the electrode wire when woven together. This occurs not only at the intersection of the heating wire surface and the helical thin metal wire surface, but also through the conductive coating on the heating wire surface and the fiber core wire surface.

As shown in FIG. 4, the present invention provides heating wires 11 and 11' formed by arranging a large number of such electrode wires 9 and 10 in parallel in the horizontal direction.
, 11"..., the aggregate fibers 12,
12'...13, 13', 13".

13"'... is braided in the vertical direction to form a planar heating cloth.

Therefore, the current passed through the electrode wires 9 and 10 is
7' and heating wires 11 and 11' through the conductive coatings 6 and 6' on the surface of the fiber core.

11"..., so in the present invention, the electrical contact resistance between the electrode wire and the heating wire is significantly reduced as a whole, and the external pressure on the heating cloth or the heat generation is reduced. It is possible to obtain an improved heat generating cloth that can eliminate instability in current flow due to disconnection of electrical contact points caused by bending of the cloth or the like.

Examples of the hindered fiber core wire of the electrode wire constituting the heating cloth of the present invention include polyester fibers such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; boron fibers such as 6-nylon, 6.6-nylon, and nylon-12; □ Cotton fiber; polypropylene fiber,
Synthetic yarns such as acrylonitrile fibers, cotton yarns, or bifilamentous composite fibers of synthetic yarns and cotton yarns are used.

Further, in order to provide a conductive coating on the fiber core wire, for example, the fiber core wire is impregnated with a conductive paint made by mixing conductive powder such as carbon copper with a resin binder, or the fiber core wire is coated and baked to form a conductive fiber. Conductive fibers are made by attaching a metal coating of nickel, copper, tin, etc. to the surface of the fiber core wire by means such as electroless plating or vapor deposition.

Ideally, the surface electrical resistance of the conductive coating on the fiber core wire thus obtained should be as small as possible, but it is effective when the surface electrical resistance is equal to or lower than the surface electrical resistance of the heating wire. .

In the past, it was undesirable for the fiber core to harden significantly due to the provision of the above-mentioned conductive coating. Therefore, in order to obtain the above-mentioned sufficient conductivity and maintain the flexibility of the fiber, the thickness of the conductive coating must be increased. It is preferable that the thickness is 100 μm or less.

Furthermore, the heat-generating wire according to the present invention refers to synthetic fibers such as polyester fibers, cotton threads, or composite fibers of synthetic fibers and cotton threads, which are impregnated with a heat-generating paint, such as a paint made by kneading carbon powder with a heat-resistant resin. Alternatively, a metal or metal oxide coating is applied by means such as electroless plating or vapor deposition to form a thin heating wire. An electrically insulating fiber, made of cotton thread, for example, that is inserted in parallel with the wires to shape the planar heating cloth.

Example 1 65 strands of polyester fiber and 35φ of cotton yarn were used as the fiber core wire of the electrode wire.
A conductive coating with a thickness of 100 μm is formed by impregnating the fiber core with an acrylic resin paint mixed with carbon powder and baking it to form a rectangular copper metal cross section with a width of 0.3 mm. The thin wire was wound helically at a pitch of 0.5 m+n to form an electrode wire.

The electrical resistance of the conductive coating on the surface of the fiber core of the obtained electrode wire was 20 Ω/cm in the length direction of the fiber core, and the electrode wire was used as a heating wire made of polyester fiber coated with carbon paint and a cotton yarn. When the fabric was woven together with aggregate fibers to form a heating cloth as shown in Figure 4, the electrical contact resistance between the heating wire and the electrode wire was reduced to 1/10 or less compared to the conventional method.

Example 2 A polyamide fiber was used as the fiber core wire of the electrode wire, and its surface was coated with a conductive coating of nickel of 5 Ω per 1 cm of length by electroless plating, and a copper wire with an outer diameter of 0.1 mm was placed on the outer periphery. 0.
The electrode wire was wound helically at a pitch of 4trvn.

Furthermore, a heating cloth was formed using the electrode wire, heating wire, and aggregate fibers in the same manner as in Example 1, and a test was conducted on changes in electrical resistance due to changes in external pressure. For a pressure change of 5 hours per 1 cm of cloth surface, the contact electrical resistance between the heating wire and the electrode wire changed by 2 degrees, but for the heating cloth of the present invention, the electrical resistance changed by less than 0.2%. Characteristics were significantly improved.

The thickness of the conductive film above the button was 50 μm.

Example 3 Polyester 65q/) and cotton thread 35 for the fiber core wire of the electrode wire
A rectangular copper metal with a width of 0.2 rrvn and a thickness of 0.021 rrrn is formed on the outer periphery by using a double yarn composite fiber of φ and vapor-depositing tin on its surface to form a conductive coating of 30 Ω per 1 crn length. A thin wire was wound helically at a pitch of 0.5 rran to obtain an electrode wire.

The electrode wire, the heating wire, and the aggregate fibers were made into a heating cloth in the same manner as in Example 1, and the heating cloth was energized to repeat the heating cycle of 120°C 300 times to establish the electrical connection between the heating wire and the electrode wire. When testing the change in contact resistance, it was found to be 0 compared to the initial value.
．． Although the variation was limited to 6φ or less, a similar test using a conventional heating cloth showed a variation of 5%.

That is, as explained in the principle drawings and examples, the present invention consists of a core wire made by coating the surface of a fiber with a conductive material and a thin metal wire provided in a helical shape to form an electrode wire, a heating wire and an aggregate fiber. Since the heating cloth is made by interweaving the electrode wire and the heating wire, it is possible to reduce the surface contact resistance between the electrode wire and the heating wire, and to reduce changes in the surface contact resistance due to fluctuations in contact pressure.

Furthermore, since an improved heating cloth can be obtained even if the thickness of the conductive coating is 100 μm or less for the fiber core wire coated with a conductive material, the present invention does not impair its original flexibility as a heating cloth. There is no need to particularly increase the winding density of the fine metal wires, so it is possible to optimally adjust the tension when braiding with a loom or knitting machine, so the heat generating fabric obtained by the present invention has an extremely high structure. It can be made into a flexible heating cloth that maintains a stable shape.

Therefore, by using the heat generating fabric of the present invention in hot carpets, hot seats, etc., stable heat generation can be easily achieved over a long period of time, which is advantageous.

[Brief explanation of the drawing]

Figure 1 is an external view showing the structure of the electrode wires woven into the heat-generating cloth in the conventional method, Figure 2 is a plan view showing part of the weaving style of the electrode wires and heat-generating wires in the conventional method, and Figure 3 is the book. FIG. 4 is an external view showing the structure of the electrode wire according to the invention, and a plan view showing the weaving of the heating cloth according to the invention. 5... Fiber core wire, 6... Conductive coating,
7...Thin metal wire, 8,9,10...Electrode wire, 11.11'11"...Heating wire, 12,
12', 13,13'. 13", 131... Aggregate fiber.

Claims (1)

[Claims] 1. A heating cloth characterized in that a core wire formed by coating the surface of the fibers with a conductive material is provided with thin metal wires in a helical shape to serve as electrode wires, and interwoven with heating wires and aggregate fibers.