JPH1197160A - Sheet heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet heater in which an electrode wire does not protrude to outside the surface of a sheet heater element, which can be constructed at a low cost, ensures easy controllability for the temperature, is highly flexible, and can be installed along that part of a member to be heated where the radius of curvature is small. SOLUTION: As part of warps of fiber 5 constituting a woven cloth 6 a plurality of electrode groups 4a each consisting of a plurality of copper wires 4 are laid at a specified spacing and woven together with wefts 5a of fiber, an a carbon conductive material 7 is attached to the cloth thus formed, and the oversurface and undersurface of the carbon series coating are covered with silicone resin layer 3, and electrode terminals 8 are installed at the ends of each electrode group 4a. It may also be acceptable that glass cloth is adhered to at least either of the oversurface and undersurface of the silicone resin layer 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a planar heating element used for household electric appliances such as electric mats and electric blankets, and various heating apparatuses such as floor heating and snow melting equipment.

[0002]

2. Description of the Related Art A conventional planar heating element is disclosed in, for example,
As shown in -142154, a printing electrode made of silver paste or the like is provided in the vicinity of opposite sides of a heating element which is formed by processing a carbon fiber into a sheet shape so as to be able to conduct electricity,
An electric wire for conduction is led out from the printed electrode, and the entire surface is covered with a water-resistant and waterproof resin layer.

[0003]

However, in the conventional sheet heating element, a printing electrode made of silver paste or the like is provided near both sides of the sheet heating element facing each other. If the sheet-like heating element on the outer surface rubs against the external member to which it is attached and the waterproof resin layer breaks, the printed electrode also breaks in a relatively short time.

[0004] Further, since the portion on which the printed electrode is provided must be flat and relatively hard, the flexibility of the formed planar heating element is reduced at least in the portion.
For example, when used for a heating blanket or the like, a sense of incongruity occurs in the portion where the flexibility is reduced.

Further, since a portion formed by processing the carbon fiber into a sheet shape is configured to be energized, and this portion is used as a heat generating portion, not only the flexibility is low but the cost is increased, but also the temperature rise of the carbon fiber is reduced. There is a problem that the temperature is not proportional to the current value, and if the current value exceeds a certain current value, the temperature rises sharply, so that the temperature control is difficult.

[0006] Further, the conventional planar heating element has its entire surface covered with a water-resistant and waterproof polyolefin resin layer. When the sheet heating element is used together with a metal tile or the like, it is necessary to attach the sheet heating element to the lower surface of the metal tile via an elastic body. Accordingly, in this case, the waterproof resin layer and the elastic body are provided between the metal roof tile and the sheet heating element.
There is a problem in that thermal conductivity to metal tiles and the like of the sheet heating element is reduced due to heavy interposition. Further, the waterproof resin layer is formed to be relatively thick so as to be able to withstand the internal heating element to a certain degree against friction or the like applied from the outside. Has reduced flexibility. When the elastic body is further laminated on the sheet heating element, the flexibility is further reduced. Therefore, the sheet heating element is provided along a portion of a metal tile having a relatively small radius of curvature. There is a problem that you can not do.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object that the electrode wires do not protrude out of the surface of the planar heating element, the cost is relatively low, and the temperature control is easy. Another object of the present invention is to provide a planar heating element.

Another object of the present invention is to provide a surface having excellent thermal conductivity with respect to a member to be heated such as a metal roof tile and having excellent flexibility which can be provided along a portion having a small radius of curvature of the member to be heated. To provide a heating element in the form of a plate.

[0009]

In order to achieve the above-mentioned object, the planar heating element of the present invention uses a narrow flexible fiber as a part of the warp or weft fiber constituting the woven fabric. A plurality of conductive electrode strips having a property are arranged at predetermined intervals, woven together with the fiber yarns, and a carbon-based conductive material is applied to the woven fabric thus woven by coating or impregnation. The upper and lower surfaces of the conductive material are directly and integrally coated with a silicone resin layer, and electrode terminals are attached to the ends of each electrode strip.

As described above, since the conductive electrode band having a narrow width and flexibility is woven together with the fiber yarns, the electrode band does not protrude outside from the woven fabric serving as the heat generating portion. It does not rub against the member and break before other parts. In addition, since carbon-based conductive materials are attached to the woven fabric and these are heated by energization, the temperature is easily controlled at a lower cost than in the conventional example using carbon fibers. Further, the woven portion of the heating element formed by weaving the conductive electrode strip having a narrow width with the fiber yarn has excellent flexibility, and the silicone resin layer coated on the woven portion is provided. Is also excellent in elasticity, so that the sheet heating element of the present invention has excellent elasticity and flexibility as a whole. Therefore, the silicone resin layer performs both functions of the waterproof resin layer and the elastic body used when the conventional planar heating element is attached to the member to be heated. It is also possible to improve the position and follow the small radius of curvature of the member to be heated.

In the planar heating element of the present invention, when forming a woven fabric using a fiber yarn previously impregnated with a carbon-based conductive material, a warp fiber yarn or a weft fiber yarn constituting the woven fabric is used. A plurality of narrow conductive electrode strips are arranged at predetermined intervals as a part of the woven fabric and woven together with the fiber yarns. Silicone resin layers are directly and integrally formed on the upper and lower surfaces of the woven fabric thus formed. And an electrode terminal is attached to an end of each of the electrode strips.

In this sheet heating element, a fiber yarn pre-impregnated with a carbon-based conductive material is used.
A planar heating element having more excellent elasticity and flexibility than the above-described case can be obtained, so that the heat generating property is excellent, and the followability to the member to be heated can be improved.

[0013] Preferably, a conductive wire group in which conductive wires having the same diameter as that of the warp or weft fiber yarns is used as the conductive electrode strip, and the weft fiber line intersecting these conductive wire groups is used. Or it is braiding a vertical fiber wire to the conductive wire group.

[0014] Thus, since the conductive wire group serving as the electrode is braided together with the warp fiber yarn or the weft fiber yarn, the flexibility is further improved as compared with the above case.

[0015] Preferably, glass cloth is integrally coated and adhered to at least one of the upper surface and the lower surface of the silicone resin layer which is coated on the upper and lower surfaces of the woven fabric. In addition to the above performance, a sheet heating element having excellent fire resistance can be obtained.

[0016]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a plan view showing a planar heating element 1 according to a first embodiment of the present invention, partially cut away and partially enlarged.
FIG. 2 is a longitudinal sectional view taken along line AA of FIG.

In the sheet heating element 1 shown in FIG. 1, the sheet heating portion 2 has an outer periphery, as shown in FIG.
It is covered with.

The sheet-like heat generating section 2 comprises a copper wire 4 for an electrode,
5a and carbon-based conductive paint 7
And an electrode terminal 8 is attached to the electrode wire 4.

When weaving the woven fabric 6, first, the warp yarns are aligned at equal intervals. At this time, the electrode copper wire 4 and the cotton yarn 5 are used as the warp lines. A plurality of, for example, five, copper wires 4 having substantially the same thickness as the cotton thread 5 are grouped as a group 4a as the electrode copper wires 4, and a plurality of such copper wire groups 4a are formed at predetermined intervals. It is arranged between the cotton yarns 5. In the example shown in the figure, four copper wire groups 4a are adopted, and are aligned so that 60 cotton threads 5 exist between five adjacent copper wire groups 4a. Then, a cotton yarn having the same thickness as the cotton yarn 5 used as the warp is used as the weft 5a between the warps thus aligned, and braided to obtain a known plain-woven fabric.

Next, the carbon-based conductive paint 7 is adhered to the woven fabric 6 obtained as described above. As the carbon-based conductive paint, for example, a paint containing 10 to 30% by weight of carbon black in a dissolved thermoplastic resin is used. As a method for attaching the carbon-based conductive paint to the woven cloth, the woven cloth 6 is passed through a molten conductive paint tank, whereby the woven cloth 6 is impregnated with the carbon-based conductive paint 7. Will be done.

Next, the carbon-based conductive paint 7 attached to the woven fabric 6 is dried, and the electrode terminals 8 are fixed to the ends of the copper wire groups 4a by welding or the like. Thereafter, these are covered with the electrically insulating resin 3.

Lastly, two electrode terminals 8 located at every other one of the four electrode terminals 8 are connected to lead wires 9a,
The terminals 9b are connected to each other, and a lead wire derived from one terminal of each lead wire is connected to an outlet 10, and this outlet is connected to an external power supply.

When the outlet 10 of the planar heating element 1 formed as described above is connected to an external power source (not shown), the electrode copper wire group 4 is connected to the electrode adjacent to the electrode copper wire group 4 via the carbon-based conductive paint 7. A current flows through the copper wire group 4 for use, and the carbon-based conductive paint 7 generates heat.

The heat generation temperature of the sheet heating element 1, the time required for predetermined heat generation, and the power consumption required for the heat generation are determined by the carbon black content ratio of the carbon-based conductive paint 7 or the adhesion density (thickness) to the woven fabric 6. ) Or by changing the inter-fiber density of the woven fabric. For example, in the sheet heating element of the present invention, the outer dimensions of the heating element are 230 m.
The power consumption is 66 W at mx 1000 mm, and the time required to raise the temperature by 30 ° C. with respect to the outside air temperature (ambient temperature) is extremely short, about 6 minutes.

In the above-described embodiment, as the configuration of the heat-generating portion, an example is shown in which the copper wire 4 for the electrode is formed into a group 4a of five copper wires 5 having substantially the same thickness as the cotton thread 5. Is not limited to five, but may be plural, preferably from 4 to 8
It is a book. Thereby, even if one of them is cut off for some reason, the other remaining copper wires can function as electrodes. Also, instead of the electrode copper wire group 4a, a highly flexible band having a width substantially equal to that of the group of electrode copper wires can be used. In this case, the band is braided as a single warp with a weft. It is needless to say that a wire or band having another conductivity can be used instead of the copper wire for the electrode. It is needless to say that a fine stranded copper wire having a similar cross section to the illustrated copper wire can be used as the electrode copper wire 4. Further, in the above embodiment of the present invention, the woven fabric is formed by arranging the electrode copper wires 4 as vertical lines, but unlike this, it is possible to arrange these as horizontal lines to form the woven fabric. That is, detailed description is not required.

The width of the electrode strip composed of the electrode copper wire group or the electrode strip is preferably 3 to 7 mm, and is arranged at an interval of 40 to 80 mm with respect to the woven fabric. As a result, the amount of current flowing through the electrode strip can be increased, and the width of the carbon-based conductive material sandwiched between the adjacent electrodes can be made relatively narrow. Efficiency can be improved.

In the illustrated embodiment, four electrode copper wires 4a are provided on the sheet heating element, but the number is not particularly limited as long as the number is two or more. In any case, the connection is made such that adjacent electrode copper wire groups 4a are different electrodes.

In the above embodiment, after the woven fabric 6 is formed, the woven fabric is passed through a melted resin containing a carbon-based conductive material to impregnate the woven fabric. Can be attached to the woven fabric by coating or the like.

It is also preferable that the cotton yarn constituting the woven fabric is preliminarily impregnated with a carbon-based conductive material so as to be attached thereto, and the woven fabric is woven as described above using the thus impregnated cotton yarn. It is. In this case, the step of impregnating the carbon-based conductive material after weaving the woven fabric as described above is unnecessary, but if necessary, the step of impregnating can be supplemented. Needless to say, other fiber yarns can be used instead of the cotton yarns.

In the present invention, the silicone resin layer 3 is used as the electrically insulating resin layer 3 covering the above-mentioned planar heating portion 2. Although the properties of the silicone resin vary depending on the molar ratio between the organic group and silicon, a resin having a relatively large molar ratio and high elasticity is used here. Further, by using a methyl group as the organic group, it is possible to make the layer extremely excellent in heat resistance. Further, since the silicone resin is extremely excellent in electrical insulation, the use of the silicone resin as the electrical insulating resin layer 3 as described above ensures that the electrode copper wire 4 is electrically insulated from other portions. At the same time, it is possible to obtain a planar heating element having a high flexibility due to the elasticity of the silicone resin. And
When this planar heating element is used for heating a member to be heated such as a metal roof tile, there is no need to separately provide an elastic material for absorbing shock between the two.

In order to cover the upper and lower surfaces of the planar heating section 2 with the silicone resin layer 3, a solution-like silicone resin layer is applied, impregnated or molded on the upper and lower surfaces of the planar heating section 2 formed as described above. And then heat-curing.

The thickness of the silicone resin layer 3 is set at 10 μm in consideration of the thermal conductivity of the heat generated from the sheet-shaped heat generating portion 2 to the outside and the cushioning property when used together with the member to be heated. It is appropriately determined within the range of 10 and several millimeters. If necessary, the thickness of the silicone resin layer 3 is made thicker in the upper and lower portions of the electrode copper wire 4 and thinner in other portions, so that the electrode copper wire 4 is sufficiently protected from external force, and the other portions are sufficiently protected. Good thermal conductivity can be achieved.

In the second embodiment of the present invention, as shown in FIG. 3, a glass cloth 11 is bonded to the outer surface of the silicon resin layer 3 on the upper and lower surfaces of the planar heating element of the first embodiment. I have. The glass cloth 11 is formed by weaving long fiber glass yarns, and is preferably a glass cloth woven from a PVC-coated glass yarn. In this case, a desired printed pattern can be printed thereon. The glass cloth 11 is bonded to the silicone resin layer 3 via an adhesive, but a preferred adhesive is a silicone resin adhesive.

In this embodiment, since the glass cloth 8 is nonflammable and has extremely excellent heat resistance and fire resistance, it can be used as a curtain for heating. In this case, by applying a desired print pattern to the glass cloth woven with the glass yarn coated with PVC as described above, a non-combustible curtain having decorativeness of a desired design can be obtained.

Although not shown, the glass cloth 11 may be provided on only one of the upper and lower surfaces of the planar heating element of the first embodiment.

[0037]

As apparent from the above description, in the planar heating element of the present invention, the conductive electrode strip (conductive wire group, conductive strip) is braided together with the fiber yarn to form a woven fabric. Since the upper and lower surfaces of the electrode strip are directly and integrally coated with a silicone resin layer having excellent electrical insulation, the electrode strip does not protrude outside from the woven fabric serving as the heat generating portion, and the external It does not rub against the member and break before other parts. In addition, since carbon-based conductive materials are attached to the woven fabric and these are heated by energization, the temperature can be easily controlled at lower cost than in the conventional example using carbon fibers.

Further, the woven portion of the heating element formed by weaving the conductive electrode strip having a narrow width with the fiber yarn has excellent flexibility, and the silicone resin layer coated thereon is formed. Is also excellent in elasticity, so that the sheet heating element of the present invention has excellent elasticity and flexibility as a whole.
Therefore, since the silicone resin layer performs both functions of the waterproof resin layer and the elastic body used when the conventional planar heating element is attached to the member to be heated, the heat transfer to the member to be heated is improved. In addition, it is possible to additionally arrange the member to be heated so as to follow the small radius of curvature.

Further, when the sheet heating element is made of a fiber yarn impregnated with a carbon-based conductive material in advance, the sheet heating element having more excellent elasticity and flexibility than the above case is used. It can be a body, has excellent heat conductivity, and has good followability to a member to be heated.

Furthermore, when the glass cloth is integrally coated and adhered to at least one of the upper surface and the lower surface of the silicone resin layer coated on the upper and lower surfaces of the woven fabric, the fire resistance is improved. Excellent.

[Brief description of the drawings]

FIG. 1 is a plan view showing a planar heating element according to a preferred embodiment of the present invention, partially cut away.

FIG. 2 is a cross-sectional view taken along line AA of FIG.

FIG. 3 is a cross-sectional view of a sheet heating element according to a second embodiment of the present invention, which is similar to FIG. 2;

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 sheet heating element 2 sheet heating section 3 silicone resin layer 4 electrode copper wire 4 a electrode copper wire group 5 cotton thread 5 a weft thread 6 woven cloth 7 carbon-based conductive paint 8 electrode terminal 11 glass cloth

Claims (4)

[Claims] 1. A plurality of narrow and flexible conductive electrode strips are arranged at predetermined intervals as a part of a warp fiber thread or a weft fiber thread constituting a woven fabric. A carbon-based conductive material is adhered to the woven fabric woven in this manner, and the upper and lower surfaces of the conductive material are directly and integrally coated with silicone resin layers. A sheet heating element characterized in that an electrode terminal is attached to the heating element. 2. When forming a woven fabric using a fiber yarn previously impregnated with a carbon-based conductive material, a conductive material having a narrow width is used as a part of the warp fiber yarn or the weft fiber yarn constituting the woven fabric. A plurality of electrode strips are arranged at predetermined intervals, woven together with the fiber yarns, and the upper and lower surfaces of the woven fabric thus formed are directly and integrally covered with a silicone resin layer. A sheet heating element characterized in that an electrode terminal is attached to an end of the sheet heating element. 3. The electrode strip comprises a conductive wire group in which conductive wires having the same diameter as the warp fiber yarn or the weft fiber yarn are collected, and the weft fiber line or the warp fiber intersecting these conductive wire groups. 3. The planar heating element according to claim 1, wherein the wire is braided with respect to the conductive wire group. 4. A glass cloth is integrally coated and adhered to at least one of an upper surface and a lower surface of the silicone resin layer coated on upper and lower surfaces of the woven fabric. The sheet heating element according to any one of claims 1 to 3.