JP2005135678A - Planar heating element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a user-friendly planar heating element, slim and long in a length direction, by alleviating unevenness of current loads generated in electrode wires, and also restraining voltage fall and unevenness of heat radiation along a length direction of the electrode wire, without going to the trouble of setting a number of lead wires. <P>SOLUTION: The planar heating element is provided with weft thread 8 at least including conductive thread for heating arranged at given intervals, warp thread 10 made of insulating thread braided with weft thread 8 in crossing at given intervals, a pair of electrode wires 6, 6 arranged so as to be electrically connected to either end of the weft thread, and an insulation coating layer 4 coating woven cloth 5 woven with the warp thread 8, the weft thread 10 and the electrode wires 6. Each of the pair of electrode wires 6 is structured of two or more rows of electrode wire units 6a, 6b separated by a given interval W2 along a length direction W of the weft thread 8. The electrode wire units 6a, 6b adjacent to each other of each electrode wire 6, 6 are connected to each other by a low-resistance lateral conductive wire 20 with a lower electric resistance than the weft thread 8 at a given interval L2 along a length direction of the electrode wire units. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a planar heating element, and more particularly to a planar heating element of a type in which electrodes are arranged in parallel and linear heating elements are arranged in parallel between the electrodes.

  Various types of planar heating elements are known, but classified into electrode shapes, there are a series electrode type planar heating element and a parallel electrode type planar heating element. In a series electrode type planar heating element, linear heating elements such as nichrome wire and metal foil are arranged in a meandering manner to form a surface, and a voltage is applied to both ends of the linear heating element, A linear heating element is caused to generate heat.

  There are two types of planar heating elements of the parallel electrode type. One is a type (pure planar type) in which a heating element made of a planar conductive film or the like is disposed between a pair of electrodes arranged in parallel. The other is a type (line surface type) in which linear heating elements are arranged in parallel between a pair of electrodes arranged in parallel.

  In the series electrode type planar heating element, when a part of the longitudinal direction of the linear heating element is cut, no current flows through the entire heating element and the function as a planar heating element is lost. Have. On the other hand, in the parallel electrode type planar heating element, even if a part of the planar heating element or the linear heating element is cut, a current flows to other heating elements, and the planar heating element is used as a planar heating element. The function can be maintained.

  However, in a pure planar type planar heating element, which is one of the parallel electrode types, the heating element generally generates a small amount of heat, and it is difficult to obtain a sufficient amount of heating. In addition, in this pure planar type planar heating element, if a part of the planar heating element is damaged, the electric field concentrates around the damaged part and excessive current flows, causing abnormal heat generation. There is a problem that is likely to occur.

  On the other hand, in the linear surface type heating element, since a linear heating element is used, a relatively large calorific value can be obtained. In addition, even if one of the linear heating elements is cut off, no current flows through the cut-off heating element, and only heat is not generated, and the electric field concentrates on the other linear heating elements. There is no fever and continues to generate heat normally.

  In view of this, a line-type planar heating element with parallel electrodes is preferably used in various fields. In a conventional linear surface type planar heating element, for example, as shown in Patent Document 1, a woven fabric in which warp yarns and weft yarns are closely woven is covered with a resin film. Electrode wires are connected to both ends of the weft in parallel with the warp. These electrode wires also become part of the woven fabric and are covered with a resin film. For example, as shown in Patent Document 2, each electrode wire is composed of a plurality of conductive wires, and these conductive wires are connected in a honeycomb shape.

  However, even such an electrode wire structure has a problem that a large amount of current flows through the conductive wire of the electrode wire closest to the heat generation side, and the load is large. In other words, the upper limit of the amount of current that can be passed through the electrode wire is limited by the capacity of the conductive wire of the electrode wire closest to the heat generation side, and a voltage drop occurs along the electrode wire in the planar heating element. Therefore, when the length of the planar heating element in the electrode line direction is increased, there is a problem that heat generation at an end portion far from the power source is reduced. Therefore, there is also a problem that it is difficult to make the planar heating element too long.

  Such a problem cannot be solved even if the number of conductive wires constituting each electrode line is increased. This is because even if the number of electrode wires is simply increased, it is not possible to eliminate the situation where a large amount of current flows through the conductive wire of the electrode wire closest to the heat generation side and the load is large.

In addition, in order to prevent a voltage drop along the longitudinal direction of the electrode wire, providing lead wire take-out portions at a predetermined interval along the longitudinal direction of the planar heating element increases the number of lead wires. Depending on the use of the heating element, the usability becomes worse.
Japanese Utility Model Publication No. 62-40389 Japanese Patent Publication No.1-30265

  The present invention has been made in view of such a situation, and reduces the non-uniformity of the current load generated in the electrode wire, and also suppresses the voltage drop and the non-uniformity of heat generation along the longitudinal direction of the electrode wire. An object of the present invention is to provide a planar heating element that is elongated in the longitudinal direction and excellent in usability.

Means for Solving the Problems and Effects of the Invention

In order to achieve the above object, a planar heating element according to the present invention comprises:
A weft thread including at least a conductive thread for heat generation and disposed at a predetermined interval;
A warp yarn made of an insulating yarn, arranged to be knitted at a predetermined interval across the weft yarn, and
A pair of electrode wires respectively disposed so as to be electrically connected to both ends of the weft,
An insulating coating layer covering the woven fabric woven with the weft, warp and electrode wires;
Have
Each of the pair of electrode lines is configured in units of two or more electrode lines separated by a predetermined distance along the longitudinal direction of the weft yarn,
The electrode line units adjacent to each other in each electrode line are connected to each other by a low resistance lateral conductive line having a lower electrical resistance than the conductive yarn for heat generation at a predetermined interval along the longitudinal direction of the electrode line unit. It is characterized by being.
In the present invention, the weft may not include only the heat-generating conductive yarn but may include insulating yarns arranged at a predetermined arrangement interval. Further, an insulating yarn may be woven into the heat generating conductive yarn.

  The planar heating element according to the present invention is a so-called line-type planar heating element of a parallel electrode type. Therefore, even if a part of the planar heating element is damaged and a part of the linear heating element (heating conductive yarn) constituting at least a part of the weft is cut, other heating conductive An electric current is supplied to the yarn to maintain heat generation. In addition, the cut conductive yarn for heat generation of the weft does not generate heat because no current flows, the voltage applied to the conductive yarn for heat generation of the other weft does not change, and abnormal heat generation occurs. There is no fear.

  Further, in the planar heating element according to the present invention, each of the pair of electrode lines is configured in units of two or more electrode lines separated by a predetermined distance along the longitudinal direction of the weft yarn. In addition, the electrode line units adjacent to each other in each electrode line are connected to each other by a low resistance horizontal conductive line having a lower electrical resistance than the weft at predetermined intervals along the longitudinal direction of the electrode line unit. For this reason, even if a voltage drop occurs along the electrode line unit on the side close to the heat generating part (inside), the initial voltage is set inside through the electrode line unit on the side far from the heat generating part (outside) and the low resistance lateral conductive line. Is supplied to each electrode line unit to suppress the voltage drop. This also means reducing the current load on the inner electrode line unit.

  That is, in the present invention, since the current flows also in the outer electrode line unit, the current load on the inner electrode line unit can be reduced. This means that the planar heating element can be made longer in the longitudinal direction of the electrode wire than before, and the usability of the planar heating element can be improved.

  In addition, in the present invention, it is not necessary to provide lead wire take-out portions at predetermined intervals along the longitudinal direction of the planar heating element, so there is no need to increase the number of lead wires, and the usability is improved in that respect as well.

  For this reason, in the present invention, the non-uniformity of the current load generated in the electrode wire is reduced, and also the voltage drop and the non-uniformity of heat generation along the longitudinal direction of the electrode wire are suppressed, without providing a large number of lead wires. A planar heating element that is elongated in the longitudinal direction and excellent in usability can be provided.

  In the present invention, each electrode line unit may be a single conductive line or a plurality of conductive lines. When each electrode line unit is constituted by a plurality of conductive lines, it is preferably constituted by a plurality of low resistance vertical conductive lines that are woven and connected in a honeycomb shape in the width direction.

  A plurality of low resistance vertical conductive lines woven in a honeycomb shape and connected in the width direction can be ideally handled as a single low resistance conductive line having a large cross-sectional area. However, in reality, among the plurality of low-resistance vertical conductive lines, the current flowing through the innermost conductive line is the largest.

  In the present invention, two or more electrode line units are formed, and a voltage is supplied to the inner electrode line units at predetermined intervals in the longitudinal direction through the outer electrode line units and the low-resistance lateral conductive lines. For this reason, even if a voltage drop occurs due to power consumption along the longitudinal direction of the inner electrode line unit, the voltage drop does not affect the outer electrode line unit. It is possible to recover.

Hereinafter, the present invention will be described based on embodiments shown in the drawings.
FIG. 1 is a plan view of an essential part of a sheet heating element according to an embodiment of the present invention,
FIG. 2 is a cross-sectional view of an essential part taken along line II-II shown in FIG.
3 is an enlarged view of a main part of the electrode line unit shown in FIG.
FIG. 4 is a schematic diagram showing a voltage drop along the longitudinal direction of each electrode line.

  As shown in FIGS. 1 and 2, the planar heating element 2 according to one embodiment of the present invention has transparent insulating coating layers 4, 4, and the weft yarn is between these insulating coating layers 4, 4. A woven fabric 5 composed of 8 and warp yarn 10 is sandwiched. The weft 8 of the woven fabric 5 is composed of a heat-generating conductive yarn and, if necessary, a yarn including an insulating yarn. The heat-generating conductive yarn constituting the weft 8 is, for example, one in which the outer periphery of an insulating filament is covered with a conductive paint. The heat generating conductive yarn may be a single wire or a stranded wire. The material of the insulating filament is not particularly limited, and examples thereof include polyester, cotton, nylon, and glass fiber. As the conductive paint, for example, a positive temperature characteristic (PTC) type conductive paint having a high temperature dependency obtained by mixing conductive particles is used.

  The PTC-type conductive paint is not particularly limited as long as the resistance increases as the temperature increases, and a good self-temperature control function is exhibited. For example, metal particles, carbon particles (carbon black particles, graphite carbon) Particles, graphite particles) and the like containing conductive particles are used. As the conductive particles, carbon particles are preferably used.

  If an insulating filament is immersed in such a conductive paint and dried, the conductive yarn constituting the weft 8 of this embodiment can be obtained. The electric resistance value of the conductive yarn is approximately 500 to 10,000 Ω / cm.

  In the present embodiment, the warp yarns 10 extend along the longitudinal direction L of the planar heating element 2, are arranged at predetermined intervals along the width direction W orthogonal to the longitudinal direction L, and are composed of insulating yarns. .

  The insulating yarn constituting the warp yarn 10 is constituted by an insulating filament used as a core material of the same conductive yarn except that it is not covered with a conductive paint, for example. Further, for example, a metal wire with an insulating coating may be used. The warp yarn 10 may also be a single wire or a stranded wire.

  A pair of electrode wires 6 are arranged along the longitudinal direction L of the woven fabric 5 at both ends of the weft 8 in the width direction W. Each electrode line 6 is composed of two or more rows of electrode line units 6 a and 6 b that are separated by a predetermined interval W 2 along the longitudinal direction W of the weft 8. The electrode line units 6a and 6b that are adjacent to each other in each electrode line 6 are arranged at a predetermined interval L2 along the longitudinal direction L of the electrode line units 6a and 6b, and have a low resistance lateral conductive line 20 having a lower electrical resistance than the weft thread 8. Are connected to each other. The lower the electrical resistance value of the low resistance lateral conductive wire 20, the better, and it is usually 5 Ω / cm or less, preferably 1 Ω / cm or less.

  As shown in FIG. 3, each electrode line unit 6a (same for 6b) is composed of a plurality of low resistance vertical conductive lines 30 that are woven in a honeycomb shape and connected in the width direction W. The low resistance vertical conductive wire 30 is preferably made of a metal thread. Moreover, it is preferable that the low resistance lateral conductive wire 20 is also made of a metal thread.

The low resistance longitudinal conductive wire 30 is knitted integrally with the woven fabric 5 at both ends of the woven fabric 5, constitutes an electrode wire unit 6a or 6b, and is electrically connected to each weft yarn 8. Further, as shown in FIG. 1, the low-resistance lateral conductive line 20 is knitted into a woven fabric 5 so that the electrode line units 6a and 6b adjacent to each other in each electrode line 6 are connected to the electrode line units 6a and 6b. Connections are made along the longitudinal direction L at a predetermined interval L2. The low resistance lateral conductive line 20 electrically connects only the adjacent electrode line units 6a and 6b, and the electrode lines 6 and 6 positioned on the left and right in the width direction W of the planar heating element 2 are not connected to each other. Is knitted into the woven fabric 5.
The lower the electrical resistance value of the low resistance vertical conductive wire 30, the better, and it is usually 5 Ω / cm or less, preferably 1 Ω / cm or less.

  The metal yarn which is a preferred form constituting the low resistance conductive wire 20 or 30 is made of, for example, copper, iron, stainless steel or the like. The metal yarn may be a single wire or a stranded wire. The wire diameter of the metal yarn is substantially the same as that of the warp yarn 10 and the weft yarn 8, and is preferably 10 to 1000 μm.

  In the present embodiment, the distance L1 between the adjacent wefts 8 in the woven fabric 5 is preferably 0.01 to 50 mm. Moreover, the space | interval W1 between the adjacent warp 10 in the woven fabric 5 becomes like this. Preferably it is 0.01-50 mm.

  If the arrangement interval L1 of the weft yarns 8 is too narrow, the amount of heat generated per unit area tends to be too large, and if the arrangement interval L1 of the weft yarns 8 is too wide, the heat generation capacity of the entire planar heating element tends to decrease. is there. In addition, since the warp yarn 10 hardly contributes to heat generation, the arrangement interval W1 of the warp yarn 10 can be made wider than the arrangement interval L1 of the weft yarn 8 as long as the strength as the woven fabric 5 can be maintained. However, considering the workability of forming the woven fabric 5 of the weft yarn 8 and the warp yarn 10, the arrangement interval W1 of the weft yarn and the arrangement interval L1 of the warp yarn should be substantially the same.

  Although the space | interval L2 between the low resistance horizontal conductive lines 20 is not specifically limited, Preferably it is 10-50000 mm, More preferably, it is 50-30000 mm. If the distance L2 is too narrow, the knitting work tends to be complicated, and if it is too wide, the effect of the present invention tends to be small. However, L2> L1 is preferable.

  The separation distance W2 between the adjacent electrode line units 6a and 6b in each electrode line is preferably 1 to 50 mm, more preferably 5 to 30 mm. If the separation distance W2 is too small, it is the same as increasing the width of one electrode line unit 6a, and the effect of the present invention tends to be reduced. If the separation width W2 is too wide, it contributes to heat generation. The width of the difficult part is widened and the material is wasted.

  As shown in FIG. 2, the woven fabric 5 composed of the warp yarn 10, the weft yarn 8, and the electrode wire 6 (including the low resistance transverse conductive wire 20) is covered with a transparent or opaque insulating coating layer 4. The insulating coating layer 4 is not particularly limited, and is composed of, for example, a vinyl chloride sheet, a PET sheet, a polyolefin sheet, a polyurethane sheet, an acrylic sheet, or the like.

A method for coating the woven fabric 5 with the insulating coating layer 4 is not particularly limited, and examples thereof include a method using an adhesive and a method using thermal fusion. When an adhesive is used, a polyurethane or epoxy resin adhesive is preferably used as the adhesive.
In addition, the insulating coating layer 4 of the planar heating element 2 in the above-described embodiment may be a single layer film, but may be composed of, for example, a multilayer film of a vinyl chloride sheet and a polyethylene terephthalate (PET) sheet. When the insulating coating layer 4 is composed of a multilayer film of a vinyl chloride sheet and a PET sheet, the inside is preferably composed of a vinyl chloride sheet and the outside is composed of a PET sheet. By disposing the PET sheet on the outside, it is possible to effectively prevent the penetration of liquid from the outside. In addition, by arranging a relatively flexible vinyl chloride sheet on the inner side, it becomes easy to heat-seal with a woven fabric serving as a heating element, and damage to the outer PET sheet can be prevented. Can be compensated with. The multilayer film can be manufactured by, for example, a thermal lamination method.

  A lead wire 22 for connecting to a power source is connected to an end portion in the longitudinal direction L of the inner electrode wire unit 6a in each electrode wire 6. The voltage applied between the pair of electrode wires 6 via the lead wire 22 is not particularly limited, but is, for example, 250 volts or less. When a voltage is applied between the electrode wires 6, a current flows in the longitudinal direction W of the weft 8, and the weft 8 generates heat. In this embodiment, the space between the inner electrode line units 6a is a main heat generating portion. The heating temperature of the heating part in the planar heating element is preferably about 80 ° C. or less, although it depends on the material of the insulating coating layer 4.

  The planar heating element 2 according to the present embodiment is a parallel electrode type, and is a so-called linear surface type heating element. Therefore, even if a part of the planar heating element is damaged and a part of the linear heating element composed of the weft yarn 8 is cut, current is supplied to the other weft yarns 8 to maintain the heat generation. it can. Further, the cut weft 8 does not generate heat because no current flows, the voltage applied to the other weft 8 does not change, and there is no possibility of abnormal heat generation.

  Moreover, in the planar heating element 2 according to the present embodiment, each of the pair of electrode wires 6 and 6 is configured by two or more rows of electrode wire units 6 a and 6 b that are separated by a predetermined distance along the longitudinal direction W of the weft 8. It is. In addition, the electrode line units 6a and 6b adjacent to each other in each electrode line 6 have a low resistance lateral conductivity having a lower electric resistance than the weft 8 at a predetermined interval L2 along the longitudinal direction L of the electrode line units 6a and 6b. The lines 20 are connected to each other.

  For this reason, as shown in FIG. 4, even if a voltage drop occurs along the longitudinal direction L of the electrode line unit 6a on the side (inner side) close to the heat generating part, the electrode line on the side farther from the heat generating part (outer side) An initial voltage is supplied to the inner electrode line unit 6a through the unit 6b and the low-resistance lateral conductive line 20 to suppress a voltage drop. This also means that the current load on the inner electrode line unit 6a is reduced.

  That is, in this embodiment, since the current also flows through the outer electrode line unit 6b, the current load on the inner electrode line unit 6a can be reduced. This means that the planar heating element 2 can be made longer in the longitudinal direction L than before, and the usability of the planar heating element 2 can be improved.

  In addition, in the present embodiment, there is no need to provide lead wire take-out portions at predetermined intervals along the longitudinal direction of the planar heating element 2, so there is no need to increase the number of lead wires 22, and in that respect, it is easy to use. improves.

  For this reason, in this embodiment, the non-uniformity of the current load generated in the electrode wire 6 is reduced, and also the voltage drop and the non-uniformity of heat generation along the longitudinal direction L of the electrode wire 6 are suppressed, and the lead wire 22 is Without providing a large number, it is possible to provide a planar heating element 2 that is elongated in the longitudinal direction L and excellent in usability.

  The present invention is not limited to the above-described embodiment, and can be variously modified within the scope of the present invention.

  The use of the sheet heating element according to the present invention is not particularly limited. For example, heating or heat insulation of a floor covering, a mat, a floor of a constant temperature warehouse, a concrete structure, a tank, etc., or melting snow, defrosting, melting ice, freezing It can be used for a wide variety of purposes such as prevention, kitchen, bathroom, toilet, and bathroom heating.

FIG. 1 is a plan view of an essential part of a planar heating element according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of an essential part taken along line II-II shown in FIG. FIG. 3 is an enlarged view of a main part of each electrode line shown in FIG. FIG. 4 is a schematic diagram showing a voltage drop along the longitudinal direction of each electrode line.

Explanation of symbols

DESCRIPTION OF SYMBOLS 2 ... Planar heating element 4 ... Insulation coating layer 5 ... Woven cloth 6 ... Electrode wire 6a ... Electrode wire unit 6b ... Electrode wire unit 8 ... Weft yarn 10 ... Warp yarn 20 ... Low resistance transverse conductive wire 22 ... Lead wire 30 ... Low resistance Vertical conductive wire

Claims (3)

A weft thread including at least a conductive thread for heat generation and disposed at a predetermined interval;
A warp yarn made of an insulating yarn, arranged to be knitted at a predetermined interval across the weft yarn, and
A pair of electrode wires respectively disposed so as to be electrically connected to both ends of the weft,
An insulating coating layer covering the woven fabric woven with the weft, warp and electrode wires;
Have
Each of the pair of electrode lines is configured in units of two or more electrode lines separated by a predetermined distance along the longitudinal direction of the weft yarn,
The electrode line units adjacent to each other in each electrode line are connected to each other by a low resistance lateral conductive line having a lower electrical resistance than the conductive yarn for heat generation at a predetermined interval along the longitudinal direction of the electrode line unit. A sheet heating element. 2. The planar heating element according to claim 1, wherein each of the electrode line units includes a plurality of low-resistance longitudinal conductive lines, and the conductive lines are woven in a honeycomb shape and connected in the longitudinal direction of the weft yarn. The planar heating element according to claim 1, wherein the weft yarn includes an insulating yarn in addition to the conductive yarn for heat generation.

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