JP5724055B2 - Planar heating element - Google Patents

Description

  The present invention relates to a planar heating element that generates heat when supplied with electric power.

  2. Description of the Related Art Conventionally, for example, a sheet-like planar heating element that generates heat when supplied with electric power, such as a PTC (positive temperature coefficient) heater, is known.

  For example, a planar heating element described in Patent Document 1 includes two sheets of polyethylene terephthalate having electrical insulation, including a resistor composed of a layer of PTC ink having self-temperature control characteristics and an electrode electrically connected to the resistor. It is a waterproof structure that is covered (laminated) with a resin (PET) film. In order to supply power to the PTC ink layer laminated on two films, an electric wire (cable) connected to an external power source is electrically connected to the electrode through a grommet penetrating one PET film and the electrode. Is done. In order to seal the through hole of the PET film through which the eyelet penetrates, the whole eyelet is covered with a seal made of silicon resin or the like.

  As a method of electrically connecting an electrode laminated with two electrical insulating films and an external power source, a method that does not use eyelets is also conceivable. For example, a part of an electrode is exposed from between two electrical insulating films, and an electric wire is joined to the exposed part of the electrode through, for example, a fusing terminal, and an electric connection part between the electrode and the electric wire is formed with a resin package. The method of enclosing is mentioned.

JP-A-10-154574

  By the way, when high electrical insulation is required for a sheet heating element in which an electrode is sandwiched between two electrical insulating films and covered with a resistor, the electrical connection portion between the electrode and the electric wire is sufficiently insulated. There must be. In the case of the planar heating element described in Patent Document 1, it is necessary to increase the seal of silicon resin or the like that covers the entire eyelet. However, if the seal covering the whole eyelet is enlarged, the thickness of the planar heating element is partially increased, and the advantage of the planar heating element that it is thin is impaired. Since the resin package also needs to have a certain thickness in consideration of the possibility that bubbles can be generated inside, the advantage that the planar heating element is thin is impaired. Although it is conceivable to adjust the resin material and the molding conditions of the package so that bubbles do not occur in the resin package, in that case, the production of the planar heating element becomes complicated.

  Therefore, an object of the present invention is to provide a planar heating element having a structure that can easily have high electrical insulation without impairing the advantage of thinness.

In order to solve the above-mentioned problem, according to the first aspect of the present invention,
In a state where a part of the electrode electrically connected to the resistor is exposed, a resistor sheet in which the resistor is covered with an electrical insulating film, and
An electric wire electrically connected to the exposed portion of the electrode;
A pair of electrical insulating sheets arranged to sandwich the electrical connection portion of the electrode and the wire; and
A resin package enclosing the electrical connection portion and the pair of electrical insulation sheets;
The electrical connection portion and the pair of electrical insulation sheets in a state where the electrical insulation sheet is fixed to the resistance sheet via a notch or a notch formed in at least one of the electrical insulation sheet or the resistance sheet Is provided in the resin package.

According to a second aspect of the invention,
A part of the electrode is exposed from the edge of the notch formed in the resistance sheet,
The planar heating element according to the first aspect, in which the electrical insulating sheet is sandwiched between an edge of the notch and the electrical connection portion, is provided.

According to a third aspect of the invention,
The planar heating element according to the second aspect, in which the electrical insulating sheet is sandwiched between two opposing side edges of the notch and the electrical connection portion, is provided.

According to a fourth aspect of the invention,
A slit is formed on the side edge of the notch,
The electrical insulation sheet according to the third aspect, wherein the electrical insulation sheet is sandwiched between two opposing side edges of the notch and the electrical connection portion in a state where a part of the electrical insulation sheet passes through the slit. A planar heating element is provided.

According to a fifth aspect of the present invention,
The planar heating element according to any one of the first to fourth aspects, in which the electric wire is bent at least once in the resin package and extends from the electrical connection portion to the outside of the resin package. The

  In the present invention, a pair of electrical insulating sheets are arranged in the resin package so as to sandwich the electrical connection portion between the electrode and the electric wire. With this pair of electrical insulation sheets, it becomes possible to ensure the insulation of the electrical connection part in the thickness direction of the planar heating element, compared with the case where the insulation distance of the electrical connection part is ensured only with the resin package, The size (particularly the thickness) of the resin package can be reduced.

  In addition, since the electrical insulating sheet is fixed to the resistance sheet, the electrical insulating sheet does not move due to the flow of the molten resin when the resin package is manufactured through the mold. This eliminates the need for a means for fixing the electrical insulation sheet to the mold, and simply encapsulates a pair of electrical insulation sheets arranged so as to sandwich the electrical connection portion between the electrode and the electric wire in the resin package. Is possible.

  Accordingly, it is possible to provide a planar heating element having a structure that can easily have high electrical insulation without impairing the advantage of thinness.

The top view of a part of planar heating element of one embodiment concerning the present invention Sectional drawing of a part of planar heating element along the AA line shown in FIG. (A) is a top view of a part of the sheet heating element showing a state where the package is removed and the electric insulation sheet is attached / detached, and (B) is a sheet heat generation showing the state where the package is removed and the attachment / detachment state of the electric insulation sheet. Bottom view of body part (A) is a figure for demonstrating the preparation process of a planar heating element, (B) is a figure for demonstrating the post process of the process shown to (A). (A) is a figure for demonstrating the post process of the process shown to FIG. 4 (B), (B) is a figure for demonstrating the post process of the process shown to FIG. 5 (A). The figure for demonstrating the planar heating element of another embodiment which concerns on this invention.

  1st invention is the state which exposed the part of the electrode electrically connected to the resistor, the resistance sheet | seat with which the said resistor was coat | covered with the electrical insulation film, and the electric wire electrically connected to the exposed part of the said electrode And a pair of electrical insulation sheets arranged so as to sandwich the electrical connection portion of the electrode and the electric wire, and a resin package enclosing the electrical connection portion and the pair of electrical insulation sheets, the electrical insulation sheet Alternatively, the electrical connection portion and the pair of electrical insulation sheets are in the resin package in a state where the electrical insulation sheet is fixed to the resistance sheet via a notch or a notch formed in at least one of the resistance sheets. It is a planar heating element enclosed in the.

  According to 1st invention, a pair of electrical insulation sheet is arrange | positioned so that the electrical connection part of an electrode and an electric wire may be pinched | interposed in the resin package. With this pair of electrical insulation sheets, it becomes possible to ensure the insulation of the electrical connection part in the thickness direction of the planar heating element, compared with the case where the insulation distance of the electrical connection part is ensured only with the resin package, The size (particularly the thickness) of the resin package can be reduced.

  In addition, since the electrical insulating sheet is fixed to the resistance sheet, the electrical insulating sheet does not move due to the flow of the molten resin when the resin package is manufactured through the mold. This eliminates the need for a means for fixing the electrical insulation sheet to the mold, and simply encapsulates a pair of electrical insulation sheets arranged so as to sandwich the electrical connection portion between the electrode and the electric wire in the resin package. Is possible.

  Accordingly, it is possible to provide a planar heating element having a structure that can easily have high electrical insulation without impairing the advantage of thinness.

  In the second invention, a part of the electrode is exposed from an edge of the notch formed in the resistance sheet, and the electric insulating sheet is sandwiched between the edge of the notch and the electrical connection portion. It is the planar heating element of 1st invention. Thereby, an electrical insulation sheet can be fixed to a resistance sheet via the notch part formed in the resistance sheet.

  3rd invention is a planar heating element of 2nd invention by which the said electrical insulation sheet is clamped by the two side edges which the said notch part opposes, and the said electrical-connection part. Thereby, an electrical insulation sheet can be reliably fixed to a resistance sheet via the notch part formed in the resistance sheet.

  According to a fourth aspect of the present invention, a slit is formed at a side edge of the cutout portion, and the two side edges of the cutout portion that face each other and the electrical connection in a state where a part of the electrical insulating sheet passes through the slit. The sheet heating element according to the third aspect of the present invention, wherein the electrical insulating sheet is sandwiched between the portions. The electrical insulating sheet can be firmly fixed to the resistance sheet by the slit.

  According to a fifth aspect of the present invention, in the sheet heating according to any one of the first to fourth aspects, the electric wire is bent at least once in the resin package and extends from the electrical connection portion to the outside of the resin package. Is the body. Thereby, the disconnection in the electrical connection part of the electrode and electric wire which arises when an electric wire is pulled can be suppressed.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the following embodiments.

  FIG. 1 shows a part of a planar heating element according to an embodiment of the present invention. FIG. 2 shows a cross section of the planar heating element along the line AA shown in FIG.

  As shown in FIG. 1 and FIG. 2, the planar heating element 10 includes a resistor 12 that generates heat upon receiving power, an electrode 14 that is electrically connected to the resistor 12, and the resistor 12 and the electrode 14. It has a resistance sheet 18 including two electrically insulating films 16a and 16b that are sandwiched and covered (laminated).

  The resistor 12 is configured by, for example, a PTC (positive temperature coefficient) ink layer formed on the surface of the electrical insulating film 16a. Since the resistor 12 composed of the PTC ink layer has a self-temperature control characteristic, that is, a property that the resistance rapidly increases when a predetermined temperature is exceeded, it is possible to suppress excessive heating by the planar heating element 10. it can.

  The electrode 14 has, for example, a thin strip shape and is made of a conductive material (for example, copper) having flexibility.

  The electrical insulating films 16a and 16b are made of, for example, polyethylene terephthalate resin (PET) having flexibility and electrical insulation. The electrical insulating films 16a and 16b are coated (laminated) with the resistor 12 and the electrode 14 sandwiched therebetween. The electrical insulation films 16a and 16b are bonded or heat-sealed in a state where the resistor 12 and the electrode 14 are sandwiched, whereby a resistance sheet 18 that waterproofs the resistor 12 is configured.

  The sheet heating element 10 also includes an electric wire 20 that connects the electrode 14 and an external power source (not shown), and a hot melt resin package 24 that encloses an electrical connection portion 22 between the electrode 14 and the electric wire 20. . The electric wire 20 is, for example, a lead wire coated with an insulating material. The hot melt resin package 24 will be described later in detail, but is formed by molding. The hot melt resin used for the package 24 is an electrically insulating resin that has fluidity when heated.

  As shown in FIG. 3A, which is a top view of the sheet heating element 10 with the package 24 removed, and FIG. 3B, which is a bottom view, one end 14a of the electrode 14 is exposed from the resistance sheet 18. The electric wire 20 is electrically connected. The electrical connection between the electric wire 20 and the one end 14a of the electrode 14 is performed by, for example, solder bonding or fusing (via a fusing terminal).

  The electric wire 20 is disposed along the surface of the electrical insulating film 16b of the resistance sheet 18 (not disposed along the surface of the electrical insulating film 16a).

  Specifically, the resistance sheet 18 includes a cutout portion 18b formed by cutting from one side end 18a, and one end 14a of the electrode 14 is exposed from the leading edge 18c of the cutout portion 18b. . As shown in FIG. 1, the electric wire 20 extends substantially in parallel to the side end 18a of the resistance sheet 18 from the electrical connection portion 22, and then bends about 90 degrees toward the side end 18a. That is, the electric wire 20 is bent at least once in the package 24 and extends from the electrical connection portion 22 toward the outside of the package 24. Thereby, compared with the case where the electric wire 20 extends outside the package 24 without being bent in the package 24, the disconnection between the electrode 14 and the electric wire 20 caused by the pulling of the electric wire 20 can be suppressed.

  As shown in FIG. 2, the electrical connection portion 22 between the electrode 14 and the electric wire 20 is provided between two electrical insulation sheets 26 and 28 having electrical insulation properties in order to secure an insulation distance (spatial distance). It is arranged to be sandwiched. In a preferred example, the two electrical insulating sheets 26 and 28 are arranged in the thickness direction of the planar heating element 10 and in close proximity to the electrical connection portion 22 in a state of being parallel to each other. The two electrical insulating sheets 26 and 28 are at least partially enclosed in the package 24. These electrical insulating sheets 26 and 28 are made of, for example, polyethylene terephthalate resin (PET) having flexibility.

  As shown in FIG. 1, the electrical insulating sheet 26 has a quadrangular shape, and is enclosed (held) in the package 24 with one surface exposed to the outside of the package 24. A method for enclosing the electrical insulating sheet 26 in the package 24 will be described later.

  On the other hand, the electrical insulating sheet 28 is enclosed (held) by the package 24 and is fixed to the resistance sheet 18. The reason why the electrical insulating sheet 28 is fixed to the resistance sheet 18 will be described later.

  Specifically, the electrical insulating sheet 28 is fixed to the resistance sheet 18 through a notch 18 b formed in the resistance sheet 18. Therefore, the notch 18b includes two side edges 18d separated by a distance W1 substantially orthogonal to the side edge 18a of the resistance sheet 18 and a tip edge 18c separated by a distance D1 from the side edge 18a of the resistance sheet 18. Prepare. That is, the notch 18b has a shape having a width W1 and a depth D1.

  In order to correspond to such a notch 18b, the electrical insulating sheet 28 is configured in a substantially rectangular shape having a width W2 that is larger than W1 and a depth D2 that is smaller than D1.

  As shown in FIGS. 3A and 3B, the electrical insulating sheet 28 is disposed on the electrical insulating film 16b with the side end 28a in the width direction exceeding the side edge 18d of the notch 18b. And the center part pinched | interposed into the two side ends 28a is fixed to the resistance sheet 18 by being arrange | positioned with respect to the electrical-connection part 22 at the electrical insulation film 16a side. That is, the electrical insulating sheet 28 is sandwiched between the electrical connection portion 22 and the resistance sheet 18 through the notch 18b.

  Further, the front end (end on the mounting direction side of the electrical insulating sheet 28) 28b of the electrical insulating sheet 28 comes into contact with the leading edge 18c of the notched portion 18b, so that the electrical insulating sheet 28 is related to the depth D1 direction of the notched portion 18b. Is positioned.

  Furthermore, since the depth D2 of the electrical insulation sheet 28 is smaller than the depth D1 of the notch 18b, the electrical insulation sheet 28 is fixed to the resistance sheet 18 without protruding from the outline of the resistance sheet 18, and the package 24 will be covered. Thereby, the insulation of the electrical connection part 22 becomes more reliable.

  In order to prevent the electric insulating sheet 28 fixed to the resistance sheet 18 from moving in the width W1 direction of the notch 18b, the electric insulating sheet 28 protrudes with a width smaller than the width W1 of the notch 18b. It is preferable to provide the part 28c. As shown in FIG. 3B, the protruding portion 28 c of the electrical insulating sheet 28 is disposed on the electrical insulating film 16 a side of the resistive sheet 18 when the electrical insulating sheet 28 is fixed to the resistive sheet 18. . In addition, this protrusion part 28c has the effect of ensuring the distance to the horizontal direction from the electrical connection part 22, and extending the horizontal insulation distance of the planar heating element 10. FIG.

  In addition, in order to firmly fix the electrical insulating sheet 28 to the resistance sheet 18, a slit (small notch) 18 e may be formed on the side edge 18 d of the notch 18 b of the resistance sheet 18. As shown in FIG. 3 (A) and FIG. 3 (B), through this slit 18e, a corner (on the slit 18e side) on the rear end side (the end side opposite to the front end 28b) of the electrical insulating sheet 28 is provided. Is disposed on the side of the electrical insulation film 16 a of the resistance sheet 18, whereby the electrical insulation sheet 28 is firmly fixed to the resistance sheet 18. In the drawing, the slit 18e is formed only on one side edge 18d of the notch 18b, but may be formed on both side edges 18d.

  From here, the manufacturing method of the planar heating element 10 of one Embodiment which concerns on this invention is demonstrated.

  As shown in FIGS. 4A and 4B, a notch 18 b is formed in the side end 18 a of the resistance sheet 18, and one end 14 a of the electrode 14 is exposed to the outside of the resistance sheet 18. Moreover, the slit 18e is formed in the side edge 18d of the notch 18b.

  Next, as shown in FIG. 5A, the electric wire 20 is disposed along the electric insulating film 16b of the resistance sheet 18, and the electric wire 20 and the exposed one end 14a of the electrode 14 are electrically connected (electrical connection). Part 22 is formed). Subsequently, as described above, the electrical insulating sheet 28 is fixed (temporarily fixed) to the resistance sheet 18 through the notch 18b (in addition, through the slit 18e).

  Subsequently, as shown in FIG. 5B, the resistance sheet 18 to which the electrical insulating sheet 28 is temporarily fixed is set in the mold 40 in order to form the package 24. The resistance sheet 18 is set in the mold 40 with the electrical insulating film 16b facing downward. The electrical insulating sheet 26 is placed on the bottom surface of the cavity 40 a of the mold 40. In addition, the electrical insulating sheet 26 is produced in substantially the same shape as the shape of the bottom surface of the cavity 40a of the mold 40.

  After the mold 40 is closed as shown in FIG. 5B, the molten hot melt resin is poured into the cavity 40a. At this time, since the electrical insulating sheet 26 has substantially the same shape as the bottom surface of the cavity 40a of the mold 40, it hardly moves due to the flow of the molten hot melt resin. On the other hand, since the electrical insulation sheet 28 is also temporarily fixed to the resistance sheet 18, it does not move due to the flow of the molten hot melt resin. Therefore, if the molten hot melt resin is filled in the cavity 40a of the mold 40 and then cooled to cure the hot melt resin in the cavity 40a of the mold 40, as shown in FIG. The package 24 enclosing the electrical insulating sheets 26 and 28 in a state where the 22 is preferably sandwiched is completed.

  As described above, according to the present embodiment, the two electrical insulating sheets 26 and 28 are arranged in the package 24 so as to sandwich the electrical connection portion 22 between the electrode 14 and the electric wire 20. By using the electrical insulating sheets 26 and 28, it is possible to ensure insulation of the electrical connection portion 22 in the thickness direction of the planar heating element 10, and therefore, an insulation distance of the electrical connection portion 22 is secured only by the package 24. No need to do. As a result, the size of the package 24, particularly the thickness of the package 24, can be reduced.

  Further, since the electrical insulating sheet 28 is fixed to the resistance sheet 18, when the hot melt resin package 24 is manufactured through the mold 40, the electrical insulating sheet 28 moves due to the flow of the molten hot melt resin. There is nothing. This eliminates the need for a means for fixing the electrical insulating sheet 28 to the mold 40, and it is possible to simply enclose the electrical insulating sheets 26 and 28 in a state where the electrical connecting portion 22 is sandwiched in the package 24. It becomes possible.

  Therefore, it is possible to provide the planar heating element 10 having a structure that can easily have high electrical insulation without impairing the advantage of thinness.

  In addition, supplementally, the electrical connection portion 22 between the electrode 14 and the electric wire 20 can be obtained by changing the size of the electrical insulating sheets 26 and 28 without increasing the thickness of the planar heating element 10 in the thickness direction. An insulation distance can be secured.

  Although the present invention has been described with reference to the above-described embodiment, the present invention is not limited to the above-described embodiment.

  For example, the shape of the notch 18b for fixing the electrical insulating sheet 28 to the resistance sheet 18 is not limited to the shape shown in FIG. Moreover, the notch part 18b for fixing may be formed in the electrical insulation sheet 28 instead of the resistance sheet 18, or may be formed in both.

  FIG. 6 shows a sheet heating element according to another embodiment of the present invention.

  In the sheet heating element 110 shown in FIG. 6, the electrical insulating sheet 128 has a pair of notches 128d at the front end 128b, while the resistance sheet 118 has a pair of notches 118b at the side end 118a. The pair of cutout portions 128d of the electrical insulation sheet 128 and the pair of cutout portions 118b of the resistance sheet 118 have substantially the same width as the thickness of the electrical insulation sheet 128. A part of the electrode 114 of the resistance sheet 118 is exposed from the side end 118a portion between the pair of notches 118b.

  As shown in FIG. 6, the electrical insulation sheet 128 can be fixed to the resistance sheet 118 by engaging the pair of notches 128 d of the electrical insulation sheet 128 and the pair of notches 118 b of the resistance sheet 118. it can.

  In this case, as shown in FIG. 6, the package 124 is formed in a state where almost half of the package 124 is located outside the side end 118 a of the resistance sheet 118, but a part of the resistance sheet 118 is included in the package 124. If sealed, the structural strength of the planar heating element 110 is sufficiently secured.

  Thus, in the broad sense, the present invention is such that the electrical insulation sheet is fixed to the resistance sheet through a notch formed in at least one of the electrical insulation sheet or the resistance sheet. As long as it is a notch that can be fixed to the sheet, the shape of the notch is not limited. Specifically, any shape of cutout is possible as long as the electrical insulating sheet can be sandwiched between the electrical connection portion of the electrode and the electric wire and the edge of the cutout.

  In the case of the above-described embodiment, as shown in FIG. 2, one electrical insulation sheet 28 is fixed to the resistance sheet 18, but the other electrical insulation sheet 26 is not fixed to the resistance sheet 18. The present invention is not limited to this. Both of the pair of electrical insulating sheets arranged so as to sandwich the electrical connection portion between the electrode and the electric wire may be fixed to the resistance sheet.

  Furthermore, in the case of the above-described embodiment, the electrical insulating sheet is fixed to the resistance sheet via a cutout portion formed by deleting a part of the resistance sheet, but the present invention is not limited to this. For example, it is possible to cut at least one of the electrical insulating sheet or the resistance sheet (form a cut portion) and fix the electrical insulating sheet to the resistance sheet via the cut portion.

  The planar heating element according to the present invention is excellent in electrical insulation and thin, and therefore can be applied to various applications and various fields such as warming a battery of an electric vehicle.

DESCRIPTION OF SYMBOLS 10 Planar heating element 12 Resistor 14 Electrode 16a Electrical insulation film 16b Electrical insulation film 18 Resistance sheet 18b Notch part 20 Electric wire 22 Electrical connection part 24 Package 26 Electrical insulation sheet 28 Electrical insulation sheet

Claims (5)

In a state where a part of the electrode electrically connected to the resistor is exposed, a resistor sheet in which the resistor is covered with an electrical insulating film, and
An electric wire electrically connected to the exposed portion of the electrode;
A pair of electrical insulating sheets arranged to sandwich the electrical connection portion of the electrode and the wire; and
A resin package enclosing the electrical connection portion and the pair of electrical insulation sheets;
The electrical connection portion and the pair of electrical insulation sheets in a state where the electrical insulation sheet is fixed to the resistance sheet via a notch or a notch formed in at least one of the electrical insulation sheet or the resistance sheet Is a sheet heating element enclosed in the resin package. A part of the electrode is exposed from the edge of the notch formed in the resistance sheet,
The planar heating element according to claim 1, wherein the electrical insulating sheet is sandwiched between an edge of the notch and the electrical connection portion.   The planar heating element according to claim 2, wherein the electrical insulating sheet is sandwiched between two opposing side edges of the notch and the electrical connection portion. A slit is formed on the side edge of the notch,
4. The surface according to claim 3, wherein the electrical insulation sheet is sandwiched between two side edges of the cutout portion facing each other and the electrical connection portion in a state where a part of the electrical insulation sheet passes through the slit. Heating element.   The planar heating element according to any one of claims 1 to 4, wherein the electric wire is bent at least once in the resin package and extends from the electrical connection portion to the outside of the resin package.

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