JPH07161456A - Heat generating sheet - Google Patents

Abstract

PURPOSE:To provide a heat generating sheet with flexibility, bendable-ness, and tensile strength by combinedly weaving a heat generating wire composed by winding a wire-state metallic heating element on a stringlike insulating wire and an insulating wire composed of a fiber. CONSTITUTION:A heat generating wire 12 is formed by winding, for instance, a heating body 22 composed of a stainless wire having an outer diameter of 70mum at a pitch of 0.47mm on a heating-element-winding insulating wire 21 having an outer diameter of 0.7mm. The heating-element-winding insulating wire 21 uses a stranded wire composed of 65% polyester and 35% cotton or a stranded wire of an Aramid fiber and a glass fiber, etc. A plane-like heating element is formed by arraying an insulating wire 14 as a warp and alternately placing the wire 12 and an insulating wire 11 as a weft to the insulating wire 14 to combinedly weave them. The insulating wires 11 and 14 are to have material structure as that of the heating-element-winding insulating wire 21. An electrode wire 13 is arranged as a warp in a given position of the plane-like heating element. The electrode wire 13 is formed by spirally close-winding the belt of tin-plated copper foil on a polyester fiber.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat generating sheet for a sheet heating element, and more particularly to a seat heater for an automobile, an electric blanket, a hot carpet, floor heating, a snow melting heater and the like.

[0002]

2. Description of the Related Art Conventionally, for example, Japanese Utility Model Publication No. 62-40391 and Japanese Utility Model Publication No. 58-18578 have electric carpets in which cord-shaped heater wires are arranged in a meandering manner at predetermined intervals. In addition, as a method of using a film as a substrate, a film coated with carbon, a self-controlled element (Japanese Patent Publication No. 3-42681) in which carbon and resin are mixed is sandwiched between films with a non-woven fabric, and metal foil is etched. Some are processed with a heating element and sandwiched between films.

Further, as the woven fabric type described in the present invention, a fiber coated with carbon as a heating wire, a metal monofilament or a twisted wire is used,
Those using a single fiber mix of metal and fiber are provided as sheet heating elements.

[0004]

However, when the above cord heater is used, cord heaters having an outer diameter of about 0.5 to 2 mm are usually arranged at a meandering pitch of about 5 to 30 cm, so that the cord portion lacks flexibility. Not only does it cause a sense of discomfort, but the arrangement pitch is large, which causes local heat generation only in the cord portion.

In the case where a film is used as a substrate, it is necessary to use a film having a small elongation in order to give the strength of the heating element by the film, which causes the most problems in flexibility. In particular, when it is attached to a seat heater for an automobile, a sound peculiar to the film is generated and the seating feeling is impaired. In addition, when carbon is used, the change over time is also a problem.

Further, in the case of the woven cloth type, carbon coating on the fibers is problematic in that it lacks in bending resistance and changes over time, and the heating wire obtained by mixing the single fibers of metal and fibers is formed by the contact resistance of the single metal fibers. The resistance value is large when pulled and loosened, and changes by 30 to 50%. Further, those using a metal monofilament or a stranded wire have a very low specific resistance value, so that the heating wire itself becomes thin and is weak in terms of strength.

Therefore, the present invention solves the above-mentioned drawbacks and provides a heat generating sheet which has sufficient strength against bending and pulling, is highly flexible, and can stably and uniformly generate heat. is there.

[0008]

[Means for Solving the Problems] As means for solving the above-mentioned problems, a wire-shaped or foil-shaped strip of metal to be a heating element is spirally formed around a thread-shaped insulated wire having heat resistance and strength. By winding it around to form a heating wire, and interweaving this linear heating wire with natural or synthetic fibers as an insulating wire to form a planar heating element, the planar heating element is bent or pulled, and cut even when compressed. It is a heat-generating sheet which eliminates the above-mentioned disadvantages, is highly flexible, and can stably and uniformly generate heat on the entire surface.

[0009]

According to the above-mentioned features of the present invention, since the wire-shaped heating wire is formed by spirally winding a metal wire or foil band, the heating element follows the bending and pulling,
Since the insulated wire serving as the winding core has strength, the defect of disconnection can be eliminated. Further, since the heating element itself is also formed by spirally winding a metal linear or foil band, the length can be 1.5 to 5 times as long as when the heating element is linearly arranged. That is, the cross-sectional area of the heating element itself is 1.5
It is possible to increase up to 5 times, the strength is strong, and the heat generation amount per unit surface area that most affects the life of the heater is 1/2 to 1/12, making it a safe and long-life heater. It is possible to obtain a uniform heat generation.

A flexible heat generating sheet that conforms to the contour of the body of a person who is seated, such as a seat heater for automobile seats, can be obtained, and the electric resistance value does not fluctuate greatly even in a use condition with constant bending and pulling.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below based on the specific embodiment shown in FIG. 1 of the accompanying drawings. Here, an example of a seat heater for a car seat will be described. As shown in the figure, the heat generating sheet 1 has a heat generating portion 3 formed between the electrode portions 2 and 2.

The heat generating sheet 1 for automobile seats is usually controlled at around 35 ° C. and is for relatively low temperatures, and the constituent material can be for low temperatures. In the high temperature heat generating sheet, the insulated wire 21 for winding the heating element, which is a constituent material, or the insulated wire is used.
A twisted yarn such as aramid fiber or glass fiber may be used for 11 and 14. First, a twisted yarn of synthetic fiber of 65% polyester and 35% cotton with an outer diameter of 0.7 mm is used for the insulated wire 21 for winding the heating element. By containing 35% of cotton yarn, the twisted yarn surface becomes fluffy, and it has the effect of preventing the wound heating element from shifting due to usage conditions.

A stainless resistance heating wire having an outer diameter of 70 μm is wound as a heating element 22 on the heating element winding insulating wire 21 at a pitch of 0.47 mm to form a heating wire 12. If the width of the heat generating part of the heat generating sheet 1 is set to 250 mm, it means that about 1.3 m of resistance heating wire is wound between them, and when arranging a stainless single wire in a straight line, the outer diameter is about 30 μm. It is possible to use a heating element 2.3 times longer, 5.2 times longer in length and 12 times larger in surface area.

As the electrode wire 13, a strip of copper foil obtained by tin-plating polyester fiber is closely wound in a spiral shape. When the electrode wire 13 is formed in this manner, all of the main constituent materials of the woven fabric have the same degree of elongation, and even if the woven fabric is woven with the same tension, a smooth woven fabric sheet can be manufactured. Furthermore, the same twisted yarn or cotton twisted yarn as the synthetic fiber used as the heating element winding insulated wire 21 is used for the insulated wire 14.

As the sheet heating element, in order to prevent short-circuiting between the heating wires 12, the heating wires 12 and the insulating wires 11 are alternately arranged and interwoven with the warp insulating wires 14 and the electrode wires 13. Further, the arrangement pitch of the heating wires 12 can be changed by changing the number of the insulating wires 11 between the heating wires 12, and the amount of heat generated by the planar heating element can be changed. If the above-mentioned heating wire 12 is 240Ω per 250 mm and 12 V is applied, the heat generation amount per heating wire 12 is
It becomes 0.6W, and if the arrangement pitch of the heating wires 12 is 4mm, it becomes 2
30W heat generating sheet for automobile seats of 50mm x 200mm 1
Can be provided.

In the currently used seat heater for automobile seats, a cord heater having an outer diameter of about 1 mm is arranged on a urethane sponge with a length of about 3 m in the above size. With 50 heating wires 12 and a total length of 12.5 m, the area of the heating part 3 will be much larger, the temperature of the heating wires 12 will be lower, and there will be no fear of local heat generation. It is possible.

[0017]

Industrial Applicability As described above, the present invention is a heating sheet in which a string-shaped heating wire in which a heating element is spirally wound is woven with a twisted yarn, and therefore is flexible against bending and pulling, and the heating element is flexible. There is no danger of disconnection, uniform heat generation on the surface can be obtained, and it is durable because it uses a metal resistance heating element, and the breathability is good because the sheet heating element itself is woven There is.

[Brief description of drawings]

FIG. 1 is a three-view drawing of a front view of a heat generating sheet of the present invention, an enlargement of a main part thereof, and a detailed view of a heat generating line.

[Explanation of symbols]

 1 ... Heating sheet 2 ... Electrode part 3 ... Heating part 11 ... Insulation wire 12 ... Heating wire 13 ... Electrode wire 14 ... Insulation wire 21 ... Insulation wire for winding heating element 22 ... Heating element

Claims (2)

[Claims] 1. A planar heating element, comprising a filament-shaped insulating wire having heat resistance and strength, and a metal wire or foil-shaped band to be the heating element, which is spirally wound with a heating wire and a natural heating wire. A heat-generating sheet, characterized in that an electric circuit is formed by attaching an electrode wire to a woven fabric in which synthetic fibers are interwoven as an insulating wire. 2. The heat generating sheet according to claim 1, wherein a wire-shaped or foil-shaped strip of metal to be an electrode wire is spirally wound around a thread-shaped insulating wire like the heat-generating wire to form an electric circuit. .