JPH11339934A - Flexible heating element and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flexible heating element capable of enhancing a product yield and a manufacturing method therefor by ensuring a stability of feeding by preventing excessive heating caused by a local deformation of a flat heating element and certainly carrying out electric and mechanical connection between the heating element and the electrode. SOLUTION: Fiber materials forming a heating element member 1 and a band-like electrode 2 are intertwined each other and are electrically connected and a covering material 3 is filled in a space between fiber materials of the heating element member 1 and the band-like electrode 2 and is solidified to be mechanically connected. The covering material 3 operates as a damper against a local deformation and a space interval of the respective fiber material of the heating element member 1 and the band-like electrode 2 is kept constant to avoid reduction in resistance.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet heating element,
The present invention relates to a flexible heating element having flexibility or flexibility and a method for manufacturing the same.

[0002]

2. Description of the Related Art As a planar heating element having flexibility or flexibility, a heating element in which a conductive powder such as carbon is dispersed and solidified in a resin such as ethylene tetrafluoride is known. When such a planar heating element is bent or deformed by applying a local pressure, the distance between the conductive powders in the bent portion or the pressure deformed portion becomes small, and the resistance value becomes low. Due to the flow of electric current, overheating was locally caused, shortening the life of the product and causing a fire.

Further, in the conventional electrical and mechanical connection between the sheet heating element and the electrode, a metal foil such as copper is used as an electrode, and the metal foil is sewn with a metal wire such as a copper wire. It was connected to the heating element by riveting, riveting, or bolting through a holding plate. However, in connection by sewing or riveting, when viewed electrically, they are only in point contact with each other. In addition, electrical contact failures occur due to the inefficient use, and the connection by bolting is easy to cause the local overheating described above. Therefore, the attachment of the electrodes to the conventional planar heating element has an unstable power supply performance, which has been a factor that significantly reduces the product yield.

[0004]

SUMMARY OF THE INVENTION According to the present invention, even if a sheet heating element is bent or a local pressure is applied, local overheating is reliably prevented from occurring and the durability is improved. And avoid the risk of fire,
Provided is a flexible heating element and a method of manufacturing the same, which can ensure stable power supply performance by ensuring electrical and mechanical connection between a planar heating element and an electrode, thereby improving product yield. What you want to do.

[0005]

SUMMARY OF THE INVENTION A flexible heating element according to the present invention comprises a heating member formed in a mat shape or a sheet shape by a fibrous heating material which generates heat when energized, and each of the heating members facing each other. A pair of strip-shaped electrodes respectively disposed on the side portions and each formed of a fibrous conductive material having good conductivity, and a heat-generating member and a pair formed of a heat-resistant resin material having flexibility or flexibility; And a covering member formed so as to include the band-shaped electrode therein.

The heat-generating member and the strip-shaped electrode are electrically connected to each other when the fibrous materials forming the respective members are intertwined with each other, and the covering member fills and solidifies the space of the heat-generating member and the fibrous material of the strip-shaped electrode. The connection is made mechanically. Thereby, this flexible heating element is electrically connected without separately providing an electrical connection means between the heating member and the strip electrode, and the covering member serves as a damper against bending and local pressure. In operation, the distance between the fibrous materials of the heating member and the strip electrode is kept constant to avoid a decrease in the resistance value, thereby preventing local overheating and a fire caused thereby.

[0007] The flexible heating element according to the present invention also includes:
The heat-generating member may be constituted by at least two heat-generating sheets laminated on each other, and each strip-shaped electrode may be arranged between two heat-generating sheets adjacent to each other. With this, the strip-shaped electrode makes the electrical connection more secure by entanglement of the fibrous conductive material with the fibrous heat-generating material of the heat-generating sheet adjacent to both surfaces thereof,
The heating member and the strip-shaped electrode are prevented from being separated by the covering member.

In the flexible heating element according to the present invention, a pair of strip-shaped electrodes are inserted into respective slits formed on respective sides of the heating member facing each other, and a portion of the heating member separated by each slit is separated. It is also possible to adopt a configuration in which each of the band electrodes is sewn together with a fixing thread. Thereby, the mechanical and electrical connection between the strip electrode and the heat generating member can be further ensured.

Further, in the flexible heating element according to the present invention, the covering member may contain ceramic powder and / or titanium powder, thereby causing the covering member to act as a member for generating far-infrared rays and generating far-infrared rays. As a body, it is possible to perform more efficiently than the heating effect.

The method of manufacturing a flexible heating element according to the present invention provides good heat conductivity to each of mutually facing sides of a heating member formed in a mat shape or a sheet shape by a fibrous heating material which generates heat when energized. A pair of strip-shaped electrodes each formed of a fibrous conductive material having the same are provided, and a solution of a flexible or flexible heat-resistant resin material containing a cross-linking agent is added to a heating member provided with the strip-shaped electrodes. The solution is injected and impregnated, and the resin material solution impregnated in the heat generating member is heated to form a preformed heat generating layer. At the same time, a solution of the same resin material as described above is poured into a mold having a size and shape corresponding to a desired heating element, and the resin material is heated to form a preform coating layer. Next, a preforming heat generating layer is arranged on the preforming heat generating layer in the mold, and a solution of the same resin material as described above is poured into the mold and heated. A coating member is formed by forming a layer similar to the preformed coating layer and integrating the preformed coating layer and the preformed heat generating layer.

Forming the preformed heat-generating layer by impregnating the heat-generating member provided with the strip-shaped electrodes with a solution of a resin material can achieve the electrical and mechanical connection between the heat-generating member and the strip-shaped electrode at this time. Therefore, it is possible to avoid a situation where the positional relationship between the two is shifted in a subsequent process and the electrical and mechanical connections are impaired. Therefore, in extreme case, by performing this step reliably, the product yield can be reduced to 100%.
It becomes possible to be close to. In addition, placing the preformed heating layer after forming the preformed coating layer in the mold, and injecting a solution of the resin material to form the coating member is performed by disposing the heating member and the strip-shaped electrode in the coating member. Is securely arranged at a predetermined position, and the heating member and the strip-shaped electrode are reliably protected by the covering member.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 << Flexible Heating Element >> As shown in FIGS. 1 and 2, a flexible heating element according to an embodiment of the present invention has a mat-shaped or sheet-shaped heating member 1 and a heating member 1 opposed to each other. It is composed of a pair of strip-shaped electrodes 2 and 2 disposed on each side, respectively, and a covering member 3 formed so as to enclose or enclose the heating member 1 and the pair of strip-shaped electrodes 2 and 2 therein. .

The heat generating member 1 is formed of a fibrous heat generating material that generates heat when energized. The fibrous heat generating material has a certain resistance value, has a fibrous whisker on at least its outer surface, can be entangled with the fibrous conductive material of the strip electrode 2 described later, and Any material can be used as long as it can withstand the temperature at which the heating element generates heat. However,
As a suitable fibrous heating material, a pitch-based carbon fiber “Donacarb S (trade name)” developed by Osaka Gas Co., Ltd.
Carbon felt obtained by appropriately changing the carbon content of the above, or a material obtained by adhering and mixing a metal powder such as titanium or titanium carbide with glass fiber can be used.

Each of the strip electrodes 2 is formed by forming a sheet or film of a fibrous conductive material into a strip. The fibrous conductive material has good conductivity, has a fibrous whisker on at least its outer surface, can be entangled with the fibrous heat generating material of the heat generating member 1, and has at least the present flexible heat generating element. Any material can be used as long as it can withstand the temperature at which it generates heat. However, as a suitable fibrous conductive material, a carbon paper formed with a small interval between fibers, which is a form of the above-mentioned pitch-based carbon fiber "Donacarbo-S", or the pitch-based carbon fiber as a raw material substrate, "CNP nickel mat (trade name)" developed by Osaka Gas Co., Ltd., which has been subjected to nickel plating, can be used.

The covering member 3 has flexibility or flexibility, can withstand at least the temperature at which the present flexible heating element generates heat, and has a fibrous heating material of the heating member 1 and a fibrous conductive material of the strip electrode 2. Any resin material can be applied as long as it can enclose and integrate the heating member 1 and the strip-shaped electrode 2 by filling and solidifying the space of the material, but from the viewpoint of availability and raw material cost. From
Preferably, silicon is used.

In the flexible heating element of the present invention configured as described above, the heating member 1 and the strip-shaped electrode 2 are electrically connected to each other by entanglement of the fibrous materials forming the respective members. As a result, not only the conventional parts for sewing such as sewing, riveting, and bolting but also the work steps for providing the parts can be omitted, and a sufficient connection area for transmitting required power can be secured. And electrically stable contact can be performed for a long period of time, and in addition, product yield can be significantly improved.

The heating member 1 and the strip electrode 2 are mechanically connected by filling the space of the fibrous material with the covering member 3 and solidifying it. For this reason, when the flexible heating element is bent or deformed by applying a local pressure, the interval between the fibers of the fibrous heating material forming the heating member 1 is determined such that the covering member 3 is interposed therebetween. As a result, the space at the time of non-deformation is substantially maintained, and the resistance value at that portion does not decrease. It can be reliably prevented.

[0018]

Embodiment 2 << Laminated Flexible Heating Element >> FIG. 3 is a view showing a flexible heating element according to another embodiment of the present invention, wherein at least two heat generating members 1 described in the above embodiment are stacked on each other. And the same configuration as that of the above-described embodiment except that a pair of strip-shaped electrodes 2 and 2 are disposed between two adjacent heat-generating sheets 1a and 1b, respectively. I have.

In the flexible heating element of this embodiment, the strip-shaped electrodes 2 are electrically connected to each other by entanglement of the fibrous conductive materials of the strip-shaped electrodes 2 with the fibrous heating materials of the heat-generating sheets 1a and 1b adjacent to both surfaces thereof. Therefore, the electrical connection between the two can be made more reliable. In addition, the strip electrode 2 is a heating sheet 1
Since the belt-shaped electrode 2 and the heat-generating sheets 1a and 1b are separated from each other during the enclosing operation into the covering member 3, the electrical connection therebetween is impaired. This has the further advantage that it can be reliably prevented from being performed.

[0020]

Embodiment 3 FIG. 4 is a view showing a flexible heating element according to still another embodiment of the present invention.
The configuration is the same as that of the above-described embodiment except that the means for attaching to the second embodiment is different.

Each of the strip electrodes 2 is inserted into a slit 4 formed on each side of the heat generating member 1 facing each other, and separated by the slits 4 using fixing threads 5. By suturing the heat generating member 1 at a position corresponding to the band-shaped electrode 2, each band-shaped electrode 2 is sewn into the separated portion of the heat generating member 1 and attached.

By sewing between the heating member 1 and each of the strip-shaped electrodes 2 with the fixing thread 5, the mechanical and electrical connection between the heating member 1 and each of the strip-shaped electrodes 2 can be reliably performed. In addition, the possibility that the connection between the two is impaired by external vibration, deformation stress, or the like is reliably avoided. Here, the material of the fixing thread 5 is the belt-like electrode 2 and the heating member 1.
Any member can be applied as long as the member can be attached to the base member, but preferably, a conductive member is used so that an electrical connection can also be made by a fixing thread 5 interposed therebetween. Is used.

[0023]

Embodiment 4 << Far-infrared ray generating type flexible heating element >> FIG. 5 is a view showing a flexible heating element according to still another embodiment of the present invention. Except that the titanium powder 6 is included, the configuration is the same as that of the above-described embodiment 1, 2, or 3. Ceramic powder mixed in the covering member 3 and / or
Alternatively, the amount and distribution of the titanium powder 6 are not particularly limited, but are usually mixed so as to be uniformly distributed as a whole.

The ceramic powder and / or titanium powder 6 mixed in the coating member 3 generates far-infrared rays when electricity is supplied to the heating member 1 through the band-shaped electrode 2 to further enhance the heating effect. it can. In the figure,
Although the laminated type flexible heating element of the second embodiment described with reference to FIG. 3 is shown as an example, ceramic powder and / or ceramic powder is applied to the covering member 3 of the flexible heating element of the first embodiment of FIGS. It will be easily understood that far infrared rays can be similarly generated by applying the titanium powder 6.

[0025]

Embodiment 5 << Method of Manufacturing Flexible Heating Element >> A method of manufacturing a flexible heating element according to the present invention is shown in FIG.
As shown in (1), a pair of strip-shaped electrodes 2 and 2 are disposed on each side of the heat generating member 1 facing each other. A solution 7 of silicon or other flexible or flexible heat-resistant resin material containing a cross-linking agent that will eventually form the covering member 3 is applied to the heat-generating member 1 on which the strip electrodes 2 are disposed.
Is injected and impregnated, and the preform heat generating layer H is formed by heating and solidifying the resin material solution 7.

At this time, the heating member 1 and the strip electrode 2
Until the solution 7 of the resin material is injected and solidified.
It is preferable to use a pressing means such as a pressing plate (not shown) or the like to maintain a state in which appropriate pressure is applied from the mutually opposing surfaces, so that the gap between the heating member 1 and the strip electrode 2 is separated. Thus, it is possible to reliably prevent the electrical connection from being damaged.

Along with or after the formation of the preforming heat generating layer H, a resin material solution 7 is poured into a mold 8 corresponding to the desired shape and shape of the heat generating element, and heated, thereby obtaining a [B] of FIG. As shown in the figure, the preformed coating layer L is formed. This preformed coating layer L is formed so as to constitute the lower (or upper) portion of the coating member 3 of the flexible heating element shown in FIG.

Next, as shown in FIG. 6C, after the preformed heat generating layer H is disposed on the preformed coating layer L formed in the mold 8, the resin material solution 7 is injected again, and the heating is performed. As a result, as shown in [D] of FIG. 6, at the same time as forming the upper (or lower) portion of the covering member 3 of the flexible heating element, the preforming heating layer H and the preforming coating are formed. The layer L is integrated in a state of being included or enclosed in the covering member 3. For this reason, the crosslinking at the time of molding the preformed heat generating layer H and the preformed coating layer L is usually terminated in an incomplete state.

The electrical and mechanical connection between the heat-generating member 1 and the strip-shaped electrode 2 is substantially performed by impregnating the heat-generating member 1 on which the strip-shaped electrode 2 is disposed with a resin material solution 7. Since the process is performed at the time when H is formed, it is possible to reliably avoid a deviation in the positional relationship between the two in a subsequent process.
In addition, the arrangement position of the heat generating member 1 and the strip-shaped electrode 2 in the covering member 3 is surely set to a predetermined intermediate position by integrating the whole including the preformed heating layer H after forming the preformed covering layer L. Therefore, it is possible to reliably prevent the heat generating member 1 and the strip-shaped electrode 2 from being displaced and exposed to the outside to cause an electric shock, a short circuit, a deterioration of the member, and the like.

The description of the above-described manufacturing method will be described with reference to FIGS.
The method of manufacturing the flexible heating element according to the first embodiment described with reference to FIG. 1 is not described in detail in order to avoid redundancy, but the heating sheet 1 is used instead of the heating member 1.
a, 1b, and the strip-shaped electrode 2 is connected to the heat generating sheets 1a, 1b.
By injecting and solidifying the resin material solution 7 while being sandwiched therebetween, the method for manufacturing the flexible heating element of Embodiment 2 described with reference to FIG.
It is easily understood by those skilled in the art that the method of manufacturing the flexible heating element according to the third embodiment described with reference to FIG. 4 can be realized by using a solution of a resin material mixed with ceramic powder and / or titanium powder 6 as the method. Like.

On the other hand, when manufacturing the flexible heating element of the third embodiment described with reference to FIG. 4, first, the slits 4 are respectively formed on the respective sides of the heat generating member 1 facing each other. After inserting the strip-shaped electrodes 2 into the respective members, the portions separated by the slits 4 of the heat-generating member 1 are sewn together with the band-shaped electrodes 2 using the fixing thread 5 so that the band-shaped electrodes 2 are mechanically attached to the heat-generating member 1. It is also easily understood by those skilled in the art that the connection is made by electrical connection.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a flexible heating element according to an embodiment of the present invention.

FIG. 2 is a schematic partial enlarged sectional view of the flexible heating element shown in FIG.

FIG. 3 is a view similar to FIG. 1 showing a flexible heating element according to another embodiment of the present invention.

FIG. 4 is a view similar to FIG. 1 showing a flexible heating element according to still another embodiment of the present invention, in which a covering member is indicated by a temporary wire;

FIG. 5 is a view similar to FIG. 2 showing a flexible heating element according to still another embodiment of the present invention.

FIG. 6 is a view illustrating a method of manufacturing a flexible heating element according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heat generating member 1a, 1b Heating sheet 2 Strip electrode 3 Covering member 4 Slit 5 Fixed thread 6 Ceramic powder and / or titanium powder 7 Resin material solution 8 Mold H Pre-formed heat generating layer L Pre-formed coating layer

Claims (8)

[Claims] 1. A heating member formed in a mat shape or a sheet shape by a fibrous heating material which generates heat when energized, and provided on both sides of the heating member facing each other and having good conductivity. And a pair of strip-shaped electrodes each formed of a fibrous conductive material having: and a heat-resistant resin material having flexibility or flexibility and formed so as to include the heating member and the pair of strip-shaped electrodes therein. A flexible heating element comprising: a coated member. 2. The heat generating member comprises at least two heat generating sheets stacked on each other, and each of the strip electrodes is disposed between two heat generating sheets adjacent to each other. Item 7. The flexible heating element according to Item 1. 3. A pair of strip-shaped electrodes are respectively inserted into slits formed on respective sides of the heat-generating member facing each other, and a portion of the heat-generating member separated by each slit is fixed to each band-shaped electrode by a fixing thread. The flexible heating element according to claim 1, wherein the flexible heating element is sewn together. 4. The coating member comprises a ceramic powder and / or
4. The flexible heating element according to claim 1, further comprising titanium powder. 5. A mat-shaped or sheet-shaped heat generating member formed of a fibrous heat generating material that generates heat when energized by a fibrous conductive material having good conductivity on each of mutually facing sides. A pair of strip-shaped electrodes is disposed, and a heat-generating member provided with the strip-shaped electrodes is impregnated with a solution of a flexible or flexible heat-resistant resin material containing a crosslinking agent by impregnating the heat-generating member. The preformed heat generating layer is formed by heating the solution of the resin material impregnated in the resin material, and the solution of the resin material is poured into a mold having a size and shape corresponding to a desired heating element, and the resin material is heated and preformed. Forming a molded coating layer, arranging a preformed heating layer on the preformed coating layer in the mold, injecting a solution of the resin material into the mold and heating to form a preformed heating layer of the preformed heating layer. On the opposite side, a layer similar to the preformed coating layer A method for manufacturing a flexible heating element, comprising forming a covering member by forming and integrating a preformed coating layer and a preformed heat generating layer. 6. The heat-generating member comprises at least two heat-generating sheets stacked on each other, and each of the strip electrodes is disposed between two heat-generating sheets adjacent to each other. Item 6. The production method according to Item 5. 7. The pair of strip-shaped electrodes are formed with slits on respective sides of the heat-generating member facing each other, and inserted into each of the slits, and then separated by the slits. 6. The manufacturing method according to claim 5, wherein the portion between the heat generating member and each of the belt-shaped electrodes is attached by sewing with a fixing thread. 8. The method according to claim 8, wherein the covering member comprises ceramic powder and / or
The method for producing a flexible heating element according to claim 5, wherein the method further comprises titanium powder.