JP2016058269A - Heating element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a planar heating element capable of making intra-plane temperature distribution uniform even if the heating element is formed to have a different distance in which current flows.SOLUTION: On a sheet 100, a plurality of through-holes 102 are formed from an end 100A to an end 100B. The sheet 100 is formed in such a manner that a first edge 100C becomes shorter than a second edge 100D. Further, on the sheet 100, a region closer to the first edge 100C is defined as a short route part IS and a region closer to the second edge 100D is defined as a long route part OS. At such a time, a first opening rate that is a ratio of an area in which a film 101 is not formed in the short route part IS with respect to an area projected with the edge of the short route part IS becomes greater than a second opening rate that is a ratio of an area in which the film 101 is not formed in the long route part OS with respect to an area projected with the edge of the long route part OS.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a heating element that generates heat by electricity.

  2. Description of the Related Art Conventionally, for the purpose of heating and freezing prevention, it is known to arrange a heating element inside a heated toilet seat, a seat surface of an automobile seat, a seat surface of a chair, or a door knob.

  For example, there is a linear heating element as a heating element used for the above-mentioned use. Patent Document 1 discloses a linear heating element formed from a heating wire and an enameled wire composed of an enamel layer. This linear heating element includes a heating wire provided with an insulating layer on the outer periphery, a metal foil sandwiching the heating wire, and a waterproof insulating layer on the outer periphery of the metal foil.

  However, the linear heating element may be broken by use. And there exists a subject that it will not generate | occur | produce heat | fever if it disconnects at one place. For this reason, in recent years, planar heating elements that do not have the possibility of such disconnection are often used. For example, Patent Document 2 discloses that a resistor formed on a substrate by screen printing using ink containing conductive particles and a resistor formed by screen printing using ink containing a heat-resistant resin. A planar heating element having an insulating coating layer formed so as to cover the sheet is disclosed.

JP 2009-76438 A JP2011-227999A

  By the way, when the planar heating element shown in Patent Document 2 is used for a toilet seat, the heating element is arranged in a U shape from the root portion (hinge portion) of the toilet seat, and an electric flow is formed along the U shape. become. In this case, there is a difference in the distance of the current flowing in the U-shape between the area where the distance between the electrodes of the planar heating element is near and the area where it is far, so that a difference occurs in the amount of current per unit time and the temperature becomes uniform Don't be. That is, the region where the distance through which electricity flows is easier to warm up, and the region where the distance through which electricity flows is easier to warm up.

  The present invention has been made in view of such problems, and the purpose of the present invention is to make the in-plane temperature distribution uniform even when the planar heating element has a different current flowing distance. Is to provide a simple heating element.

  In order to solve the above problems, a heating element according to the present invention includes a sheet having a conductive film portion that generates heat by applying a voltage between one end and the other end, and the one end and the other end, respectively. A heating element including a pair of electrodes provided, wherein the sheet has a peripheral edge formed between the one end and the other end, and from the one end to the other end; The first peripheral edge portion is formed shorter than the second peripheral edge portion, and is formed on the first peripheral edge side and the short path portion formed on the first peripheral edge side. The first aperture ratio, which is a ratio of the area where the film portion is not formed in the short path portion to the area where the periphery of the short path portion is projected, is formed in parallel. The long path portion has an area projected from the periphery of the long path portion. Being larger than the second aperture ratio is the ratio of the area which is not the film portion formed Te.

  In the present invention as described above, the heating element includes a sheet and a pair of electrodes. The electrodes are respectively provided at one end and the other end of the sheet. The sheet has a conductive film portion that generates heat by applying a voltage between one end and the other end. Further, the periphery of the sheet is composed of one end and the other end, and a first peripheral edge and a second peripheral edge formed from the one end to the other end. Furthermore, the first peripheral edge is shorter than the second peripheral edge. Examples of the shape of the sheet include various shapes such as a U shape and a U shape.

  Further, the sheet is provided with a short path portion and a long path portion that are formed in parallel. “Parallel” means that the region of the short path part and the region of the long path part are arranged so as not to intersect. The short path part is formed near the first peripheral part on the sheet, and the long path part is formed near the second peripheral part on the sheet. For this reason, the length from the anode to the cathode and along the first peripheral edge is always shorter in the short path than in the long path. Therefore, when electricity is passed from the anode to the cathode, the length of the circuit through which the current passes is different between the short path portion and the long path portion, and the amount of current flowing per unit time is different. As a result, a temperature difference occurs between the short path portion with a large amount of current per unit time and the short path portion with a small amount of current. Therefore, the first aperture ratio, which is the ratio of the area where the film portion is not formed in the short path portion to the area where the periphery of the short path portion is projected, is the long path relative to the area where the periphery of the long path portion is projected. It was made for it to become larger than the 2nd aperture ratio which is a ratio of the area in which the film part is not formed in the part.

  The first aperture ratio refers to a value obtained by dividing a region in the short path portion that is not provided with a film portion by an area projected from the periphery of the short path portion. The second aperture ratio refers to a value obtained by dividing a region in the long path portion that is not provided with a film portion by an area projected from the periphery of the long path portion. By making the first aperture ratio larger than the second aperture ratio, the ratio of the film part in the short path is reduced, and as a result, the amount of current flowing through the short path part per unit time is reduced. . As a result, the uneven temperature distribution in the surface can be eliminated.

  Furthermore, in the heating element according to the present invention, a plurality of through holes are formed in each of the short path part and the long path part, and the plurality of through holes formed in the part with respect to the area of the short path part. It is also preferable that the ratio of the total opening area is larger than the ratio of the total opening area of the plurality of through holes formed in the portion with respect to the area of the long path portion.

  The total opening area refers to the total area of the openings of the through holes. In this preferred embodiment, a plurality of through holes are formed in each of the short path portion and the long path portion. The ratio of the total opening area of the plurality of through holes formed in the short path portion to the area of the short path portion is the ratio of the plurality of through holes formed in the long path portion to the area of the long path portion. It is larger than the ratio of the total opening area. As a result, the amount of current flowing per unit time in the short path region can be kept low, and the in-plane temperature distribution can be made uniform.

  Further, in the heating element according to the present invention, the plurality of through holes are formed so that the respective opening areas are substantially the same, and the path is shorter than the number of the plurality of through holes formed in the long path portion. It is also preferable that the number of the plurality of through holes formed in the portion is large. Furthermore, in the heating element according to the present invention, it is also preferable that a plurality of through holes are formed in the short path portion, while no through holes are formed in the long path portion. In this preferred embodiment, by suppressing only the amount of current at a required location, the temperature distribution can be made uniform while maintaining the heat generation efficiency.

  ADVANTAGE OF THE INVENTION According to this invention, even when it is a shape where the distance which an electric current flows differs in a planar heat generating body, the heat generating body which can make uniform temperature distribution in a surface can be provided.

It is the plane schematic diagram which showed typically the heat generating body in embodiment of this invention. It is a plane schematic diagram which shows the other aspect of the heat generating body in embodiment of this invention. It is the figure which showed typically the electric current in the surface of the heat generating body in embodiment of this invention. It is a schematic diagram which shows the example of application of the heat generating body in embodiment of this invention. It is AA sectional drawing of FIG. It is a schematic diagram which shows the example of application of the heat generating body in embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In order to facilitate the understanding of the description, the same constituent elements in the drawings will be denoted by the same reference numerals as much as possible, and redundant description will be omitted.

  FIG. 1 is a diagram schematically showing a heating element according to the present invention. As shown in FIG. 1, the heating element 10 includes a sheet 100, and an anode 201 and a cathode 202 provided on the end portion 100 </ b> A and the end portion 100 </ b> B of the sheet 100.

  The periphery of the sheet 100 is formed of an end portion 100A, an end portion 100B, a first peripheral portion 100C, and a second peripheral portion 100D, and the first peripheral portion 100C is more than the second peripheral portion 100D. It has a short arc shape. In the following description, the first peripheral edge portion 100C is also referred to as an inner periphery, and the second peripheral edge portion 100D is also referred to as an outer periphery. In addition, the shape of the sheet 100 of the present invention is not limited to such an arc shape, but a shape in which the first peripheral edge portion 100C is shorter than the second peripheral edge portion 100D, in other words, an inner periphery is shorter than the outer periphery. If it is. For example, it can be formed according to uses such as a U-shape, a U-shape, or a corrugated shape, and the use includes toilet seats, seat surfaces of automobile seats, chair seat surfaces, and the like.

  In FIG. 1, when the region of the sheet 100 is divided by a boundary B that is a center line connecting the midpoint of the end portion 100A to the midpoint of the end portion 100B along the first peripheral portion 100C, the first peripheral portion The region on the 100C side is a short path portion IS, and the region on the second peripheral edge 100D side is a long path portion OS. Note that the short path portion IS and the long path portion OS are formed in parallel. “Parallel” refers to a state in which two formed regions are arranged so as not to intersect.

  Since the short path portion IS is formed closer to the first peripheral edge portion 100C than the long path portion OS, the length from the anode 201 to the cathode 202 and the length along the first peripheral edge portion 100C is The short path part IS is always shorter than the long path part OS. Here, for convenience of explanation, the boundary B between the short path portion IS and the long path portion OS is used as the center line. However, the boundary B between the short path portion IS and the long path portion OS in the present invention is the center line. Not limited. The short path portion IS may be an area formed near the first peripheral edge portion 100C and closer to the first peripheral edge portion 100C than the long path portion OS. Further, the long path portion OS may be a region that is formed closer to the second peripheral portion 100D and that is formed closer to the second peripheral portion 100D than the short path portion IS. That is, the short path portion IS may be formed so as to occupy about two thirds of the sheet 100 from the first peripheral edge portion 100C side. On the contrary, the long path portion OS is formed from the second peripheral edge portion 100D side. May be formed so as to occupy about two thirds.

  Each of the short path portion IS and the long path portion OS, which are regions formed on the sheet 100, has a conductive film 101 that generates heat when voltage is applied from the end portion 100A and the end portion 100B. The film 101 is formed, for example, by forming a sheet of resin obtained using a conductive material such as carbon-based powder. Note that the film 101 is not limited to such an embodiment, and may be formed of a sheet made of carbon fiber, for example.

  The heating element 10 generates heat by applying a voltage to the end portions 100 </ b> A and 100 </ b> B of the film 101 so that current flows in the plane. In the present embodiment, as an example, it is assumed that the anode 201 is formed at the end portion 100A and the cathode 202 is formed at the end portion 100B. That is, in this example, the current flows from the end portion 100A to the end portion 100B.

  A plurality of through holes 102 are formed in the film 101 from the end portion 100A to the end portion 100B. To what extent the through hole 102 is provided in the short path portion IS or the long path portion OS is expressed by the first aperture ratio or the second aperture ratio. The first aperture ratio is a value obtained by dividing the total opening area, which is the sum of the areas of the openings of the through holes 102 provided in the short path portion IS, by the area of the entire short path portion IS including the openings. The second aperture ratio is a value obtained by dividing the total opening area, which is the sum of the areas of the openings of the through holes 102 provided in the long path portion OS, by the area of the entire long path portion OS including the openings. Say. The plurality of through holes 102 are formed in the film 101 such that the first aperture ratio is larger than the second aperture ratio. That is, a larger number of through holes 102 are formed on the short path portion IS side and a smaller number of through holes are formed on the long path portion OS side than the short path portion IS side. The long path portion OS side includes a case where the through hole 102 is not formed.

  In the example of FIG. 1, the areas of the through holes 102 formed in the film 101 are all the same. Therefore, in this case, the fact that the first aperture ratio is larger than the second aperture ratio means that the number of the through holes 102 per unit area is shorter on the outer peripheral side of the short path portion IS, which is a region on the inner peripheral side of the sheet 100. It means that it is larger than the long path part OS which is the area of For example, even when the boundary B is not the center line but is provided on the inner peripheral side or the outer peripheral side, the inner peripheral region is more perforated per unit area than the outer peripheral region. Through-holes 102 are formed in the film 101 so that the number of 102 increases.

  Note that the present invention is not limited to such an embodiment. For example, as illustrated in FIG. 2, the opening area of the through hole 102 is the same as the number of the through holes 102 in the short path portion IS and the long path portion OS. Including a plurality of patterns. In other words, in the heating element 10A, the through holes 102 formed in the film 101 are divided into a through hole 102A having a large opening area, a through hole 102B having a medium opening area, and a through hole having a small opening area. And 102C. The through holes 102A to 102C are formed so that the total opening area per unit area of the short path portion IS is larger than the total opening area per unit area of the long path portion OS.

  In addition, in the example of FIG. 1, since the through-hole 102 is represented typically, it represents larger than an actual embodiment. Actually, it is desirable that the through hole 102 is formed of a fine hole. Moreover, although the through-hole 102 is represented by circular shape, it is not limited to this, An ellipse, a polygon, a slit shape, etc. may be sufficient. Moreover, what is provided in the sheet | seat 100 is not limited to a hole, What is necessary is just the nonelectroconductive area | region in which the film 101 is not provided. For example, instead of forming the through hole 102, a resin or the like may be embedded in the sheet 100. In this case, the first aperture ratio is the ratio of the area of the short path portion IS including the non-conductive region to the total area of the non-conductive region formed in the short path portion IS. The 2 aperture ratio may be a ratio of the area of the long path portion OS including the nonconductive region to the total area of the nonconductive region formed in the long path portion OS.

  Next, the flow of current in the film 101 is schematically shown using FIG. The arrow in the figure indicates a circuit through which a current passes. In this example, since the number of the through holes 102 is small in the long path portion OS, the current flowing out from the end portion 100A can reach the end portion 100B with almost no collision with the through hole 102 (arrow 30A). Therefore, the current is hardly affected by the through hole 102 in the long path portion OS.

  On the other hand, in the short path portion IS, the current flowing out from the end portion 100A cannot pass through the opening portion of the through hole 102 until it reaches the end portion 100B, and thus proceeds around the through hole 102 (arrow) 30B). For this reason, in the short path part IS, the circuit becomes longer by the length of the detour, and the distance through which the current passes is longer than the length of the circuit from the original end part 100A to the end part 100B. As a result, the amount of current that flows through the short path portion IS per unit time becomes smaller than when there is no through hole 102.

  Here, since the through hole 102 passes through the sheet 100, electricity does not pass through the through hole 102. That is, the current flowing on the film 101 bypasses the through hole 102. For this reason, in the region where the through hole 102 is formed, a circuit through which a current passes is formed longer by this detour. Therefore, in the region where the through hole 102 is formed, the current amount per unit time is reduced, and as a result, the heat generation amount is reduced.

  In the case of a conventional planar heating element, the short path portion IS having a short distance from the anode to the cathode has a shorter circuit through which current flows than the long path portion OS, and the amount of current flowing per unit time is large. For this reason, the temperature of the short path portion IS is likely to increase as compared with the long path portion OS. That is, when a voltage is applied to the anode, the temperature of the short path portion IS rises higher than that of the long path portion OS, and the in-plane temperature distribution is uneven.

  Therefore, in the sheet 100, the through holes 102 are provided more in the short path portion IS that is a region where the amount of current per unit time is larger than in the long path portion OS, and the second aperture ratio is more than the first aperture ratio. I tried to get bigger. Thereby, the unevenness of the temperature distribution on the sheet 100 was controlled.

  By providing the through holes 102 in such a distribution that the first aperture ratio is larger than the second aperture ratio, the amount of current passing through the short path portion IS and the long path portion OS per unit time is adjusted. . Desirably, the through holes 102 are formed in such a distribution that the amount of current flowing per unit time between the long path portion OS and the short path portion IS is equal. As a result, the in-plane temperature distribution of the film 101 can be adjusted. In particular, by making the opening areas of the respective through holes 102 the same, the temperature distribution of the long path portion OS and the short path portion IS can be adjusted depending on the number of holes.

  Further, the through hole 102 may not be formed in the long path portion OS. Thus, the overall temperature distribution can be adjusted by adjusting only the amount of current flowing per unit time in the short path portion IS without reducing the amount of current flowing per unit time in the long path portion OS. .

  Note that the opening area of the through hole 102 can be configured to be larger in the short path portion IS than in the long path portion OS. In this case, the temperature distribution can be adjusted by gradually increasing the size of the holes from the long path portion OS toward the short path portion IS while maintaining the same number of the through holes 102.

  Then, the application example of the heat generating body 10 of this invention is shown in FIGS. 4 is a schematic view showing an example in which the heating element 10 is used for a toilet seat, and FIG. 5 is a cross-sectional view taken along line AA of FIG. As shown in the figure, when the heating element 10 is used for the toilet seat TS, it is arranged in a U-shape along the shape of the toilet seat TS, and the power source P provided in the toilet seat device T is connected to the end portions 100A and 100B. Connected. Moreover, as shown in FIG. 5, the heat generating body 10 is curved and arranged along the cross-sectional shape of the toilet seat TS. In such a toilet seat TS, in the conventional heating element, the temperature of the short path portion IS becomes high, and the temperature of the long path portion OS does not increase so much. On the other hand, in the heating element 10, the temperature distribution between the short path portion IS and the long path portion OS can be made uniform by adjusting the amount of current between the short path portion IS and the long path portion OS.

  FIG. 6 is a schematic plan view showing an example in which the heating element 10 is used for a seating surface S of a seat used in an automobile or the like. When the heating element 10 is used for the seating surface S, it is arranged in a U-shape or a U-shape along the shape of the seating surface S, and is connected to the power source P provided outside the seating surface S from the end portions 100A and 100B. Is done. In such a seat surface S, as in the case of the toilet seat TS, in the conventional heating element, the temperature of the short path portion IS is high and the temperature of the long path portion OS is not so increased. On the other hand, in the heating element 10, the temperature distribution between the short path portion IS and the long path portion OS can be made uniform by adjusting the amount of current between the short path portion IS and the long path portion OS.

  The embodiments of the present invention have been described above with reference to specific examples. However, the present invention is not limited to these specific examples. In other words, those specific examples that have been appropriately modified by those skilled in the art are also included in the scope of the present invention as long as they have the characteristics of the present invention. For example, the elements included in each of the specific examples described above and their arrangement, materials, conditions, shapes, sizes, and the like are not limited to those illustrated, but can be changed as appropriate. Moreover, each element with which each embodiment mentioned above is provided can be combined as long as technically possible, and the combination of these is also included in the scope of the present invention as long as it includes the features of the present invention.

10, 10A, 10B: Heating element 30A, 30B: Current 100: Sheet 100A, 100B: End part 100C: First peripheral part 100D: Second peripheral part 101: Film 102: Through hole

Claims (5)

A heating element comprising a sheet having a conductive film portion that generates heat when a voltage is applied between one end and the other end, and a pair of electrodes provided on the one end and the other end, respectively. And
The sheet is
The periphery consists of the one end and the other end, and a first periphery and a second periphery formed from the one end to the other end,
The first peripheral edge is formed shorter than the second peripheral edge,
The short path part formed on the first peripheral part side and the long path part formed on the second peripheral part side are formed in parallel,
The first aperture ratio, which is the ratio of the area where the film part is not formed in the short path part to the area where the periphery of the short path part is projected, is relative to the area where the periphery of the long path part is projected. In the long path portion, the heating element is larger than a second opening ratio which is a ratio of an area where the film portion is not formed. A plurality of through holes are formed in each of the short path portion and the long path portion,
The ratio of the total opening area of the plurality of through holes formed in the part to the area of the short path part is the total opening area of the plurality of through holes formed in the part to the area of the long path part. The heating element according to claim 1, wherein the ratio is greater than The plurality of through holes are formed so that the respective opening areas are substantially the same,
The heating element according to claim 2, wherein the number of the plurality of through holes formed in the short path portion is larger than the number of the plurality of through holes formed in the long path portion.   The heating element according to claim 2, wherein an opening area of the through hole formed in the short path portion is larger than an opening area of the through hole formed in the long path portion.   The heating element according to claim 1, wherein a plurality of through holes are formed in the short path portion, but no through holes are formed in the long path portion.

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