JP2007265782A - Planar heating element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a planar heating element in which temperature distribution at the time of heat generation is nearly uniform regardless of the locations. <P>SOLUTION: The planar heating element 1 has a plate shape substrate 2 having electric insulation property, and electrodes 5, 6 and a heat generating part 7 are arranged on the electrode arrangement face 10 of this substrate 2. The heat generating part 7 is electrically connected to the electrodes 5, 6 and generates heat by flowing electric current to the electrodes 5, 6. In the planar heating element 1, the spacing D1 between the longitudinal parts 20b, 30b of the electrodes and the spacing D1 between the longitudinal parts 20d, 30d at the outer periphery side of the electrode arrangement face 10 are narrower than the spacing D2 between the central part 21a and the longitudinal parts 30b, 30d of the electrodes 5, 6. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a planar heating element that can be suitably used as a floor heating panel or the like.

  Conventionally, as disclosed in Patent Document 1 below, a planar heating element called a PTC heater (Positive Temperature Coefficient) has been used for a floor heating panel or the like. The PTC heater of the prior art has a pair of electrodes A and B arranged on the surface of the base material, and electrically connects a heating element having a characteristic that the electrical resistance value increases with increasing temperature to the electrodes A and B. It has been configured.

The above-described PTC heater generally has a characteristic that the amount of generated heat changes according to the increase or decrease of the distance between the electrodes A and B. Therefore, in the above-described planar heating element according to the prior art, the electrodes A and B are arranged almost evenly over the entire planar heating element or the electrodes A and B are suppressed in order to suppress the occurrence of uneven heat generation for each part. The intervals are substantially uniform regardless of the part.
JP-A-5-315053

  Many of the above-described planar heating elements are constructed side by side, and are referred to as “sane” in order to engage with other planar heating elements at the edge (outer peripheral portion) of the base material. Such a protrusion is provided, or a groove for engaging the protrusion is provided. For this reason, the conventional sheet heating element cannot provide electrodes near the outer periphery of the base material in order to provide protrusions and grooves, and the temperature near the outer periphery is lower than that at the center during heat generation. there were. Further, when a plurality of sheet heating elements of the prior art are arranged side by side, there is a problem that the vicinity of the joint between the sheet heating elements adjacent to each other becomes lower than the central portion of the sheet heating element.

  Therefore, an object of the present invention is to provide a planar heating element capable of generating heat so that the temperature distribution becomes substantially uniform regardless of the part.

  The invention according to claim 1, which is provided to solve the above-described problem, includes a plate-like base material having electrical insulation, and an electrode A disposed on an electrode arrangement surface constituting the base material, B and a heating element that is electrically connected to the electrodes A and B and generates heat when energized, and the distance between the electrodes A and B on the outer peripheral side of the electrode arrangement surface is The sheet heating element is narrower than the distance between the electrodes A and B on the center side of the electrode arrangement surface.

  In the sheet heating element of the present invention, since the distance between the electrodes A and B on the outer peripheral side of the electrode arrangement surface is narrower than the distance between the electrodes A and B on the center side of the electrode arrangement surface, the heat generation on the outer peripheral side of the electrode arrangement surface. The amount is larger than the calorific value at the center side. Therefore, in the sheet heating element of the present invention, the electrodes A and B may be arranged in order to provide a projection called “Sane” or a groove for engaging the projection on the outer peripheral end of the substrate. Even if it is not possible, the heat generated in the electrodes A and B arranged on the outer peripheral side of the electrode arrangement surface propagates to the outer peripheral end side of the electrode arrangement surface, and not only the central portion of the electrode arrangement surface and the vicinity thereof, It will be in the state heated substantially uniformly to the outer periphery end. Therefore, according to the present invention, it is possible to provide a planar heating element capable of generating heat so that the temperature distribution becomes substantially uniform regardless of the portion.

  The invention according to claim 2, which is provided based on similar findings, has a plate-like base material having electrical insulation, and an electrode A disposed on an electrode arrangement surface constituting the base material. , B and a heating element that is electrically connected to the electrodes A and B and generates heat when energized, passes through the center of the electrode arrangement surface, and is connected to the electrode A When a virtual line that is parallel or overlaps with the electrode A is assumed, the distance between the electrode A at a position distant from the virtual line and the electrode B facing the electrode A is the electrode A at a position on the virtual line or near the virtual line. The sheet heating element is narrower than the distance between the electrode A and the electrode B facing the electrode A.

  According to such a configuration, even when the electrodes A and B cannot be disposed in the vicinity of the outer peripheral edge of the base material due to construction reasons or the like, heat is generated so that the temperature distribution on the electrode placement surface is substantially uniform regardless of the portion. A possible planar heating element can be provided.

  Invention of Claim 3 has the plate-shaped base material which has electrical insulation, and with respect to the electrodes A and B arranged on the electrode arrangement | positioning surface which comprises the said base material, and the said electrodes A and B And a heating element that is electrically connected and has a heating part that generates heat when energized, and is disposed at a position opposite to the electrode A at a position away from the center of the electrode arrangement surface. The planar heating element is characterized in that the distance from the electrode B is narrower than the distance between the electrode A on the center side of the electrode arrangement surface and the electrode B disposed at a position facing the electrode A.

  According to such a configuration, even when the electrodes A and B cannot be disposed in the vicinity of the outer peripheral edge of the base material due to construction reasons or the like, the temperature of the entire electrode arrangement surface is almost uniform due to the energization of the electrodes A and B. It is possible to provide a planar heating element that can have a substantially uniform temperature.

  Invention of Claim 4 has the plate-shaped base material which has electrical insulation, and with respect to the electrodes A and B arranged on the electrode arrangement | positioning surface which comprises the said base material, and the said electrodes A and B And a heating element that is electrically connected and generates heat when energized, the electrode arrangement surface is rectangular, and the electrodes A and B face each other along the short direction of the electrode arrangement surface A short region arranged in such a manner that the electrodes A and B are arranged so as to face each other along the longitudinal direction of the electrode arrangement surface, and the short region is a longitudinal direction of the electrode arrangement surface. Present at both ends, the longitudinal region is present in the middle in the longitudinal direction of the electrode placement surface, and the electrodes A and B are located at the center of the electrode placement surface relative to the short region present at both ends in the longitudinal direction of the electrode placement surface. The distance from the center of the electrode arrangement surface to the electrode A arranged in the short region is long from the center of the electrode arrangement surface. Longer than the distance to the electrode A disposed in the area, the electrode A in the lateral region, the distance B is a planar heating element, characterized in that narrower than the electrode A, interval B in the longitudinal region.

  Since the space | interval of the electrodes A and B in a longitudinal area is wider than the space | interval of the electrodes A and B in a short area | region, the planar heat generating body of this invention has less calorific value in a longitudinal area than a short area | region. However, in the planar heating element of the present invention, the electrodes A and B are not present in the region outside the longitudinal direction of the electrode arrangement surface from the short region, and the outer sides of the electrodes A and B are energized even when energized. This region is assumed not to generate heat and to be cooler than the longitudinal region. For this reason, when the electrodes A and B are energized, the heat generated in the short region is preferentially moved to the region outside the longitudinal direction of the electrode arrangement surface with respect to the short region, and the region is heated. Therefore, in the planar heating element of the present invention, when the electrodes A and B are energized, the temperature distribution in the longitudinal direction of the electrode arrangement surface will soon become uniform.

  In addition, since the sheet heating element of the present invention has a smaller amount of heat generation in the long region than in the short region, the heat generated in the long region is more than in the short region side (longitudinal direction of the sheet heating element). It is assumed that the sheet heating element moves preferentially in the short direction. Moreover, since the electrode heating surface of the planar heating element of the present invention is rectangular, the heat energy moves smoothly in the short direction even if the heat generation amount in the longitudinal region is small. Therefore, in the sheet heating element of the present invention, the temperature distribution in the short direction of the electrode arrangement surface becomes almost uniform soon after the electrodes A and B are energized.

  In the present invention, the shape of the planar heating element is rectangular, but the term “rectangular” as used herein is substantially “rectangular” such as a so-called chamfered or chamfered corner of the planar heating element. It includes all the concepts that are used.

  The invention according to claim 5 is the planar heating element according to any one of claims 1 to 3, characterized in that the heating portion has a resistance value that increases as the temperature rises.

  ADVANTAGE OF THE INVENTION According to this invention, a heat-emitting part does not become high temperature too much, and can provide the planar heating element excellent in safety | security.

  The planar heating element according to any one of claims 1 to 5 has an engagement portion that can be engaged with another member on an outer periphery of the electrode arrangement surface, and the electrode arrangement surface is more than the engagement portion. A configuration in which the electrodes A and B are arranged on the center side of each of them may be adopted.

  According to such a configuration, it is possible to provide a planar heating element having a substantially uniform temperature distribution on the electrode arrangement surface regardless of the portion and having excellent workability.

  ADVANTAGE OF THE INVENTION According to this invention, the planar heat generating body with which temperature distribution at the time of heat_generation | fever is substantially uniform irrespective of a site | part can be provided.

(First embodiment)
Next, the planar heating element according to the first embodiment of the present invention will be described in detail with reference to the drawings. In FIG. 1, 1 is a planar heating element of this embodiment. The planar heating element 1 is mainly used as a flooring material for floor heating. As shown in FIG. 1, electrodes 5 and 6 (electrodes) are formed on one surface (electrode arrangement surface 10) of the substrate 2. A, B) and the heat generating part 7 are provided.

  The base material 2 is made of a material having electrical insulating properties such as wood. The base material 2 is a plate-like body having a substantially rectangular shape in plan view as shown in FIG. The base material 2 has an electrode arrangement surface 10 on which the electrodes 5 and 6 and the heat generating part 7 are arranged. Moreover, the base material 2 has the convex part 11 which protruded toward the outer side on one edge surface extended along a longitudinal direction, and the groove-shaped recessed part 12 which can be engaged with the convex part 11 on the other edge surface. Have. The convex portion 11 and the concave portion 12 function as an engaging means when a plurality of the planar heating elements 1 are arranged in the short direction. That is, the planar heating element 1 has the convex portions 11 provided on the edge surface of the base material 2 as shown in FIG. 1C at positions adjacent to the width direction (short direction) of the base material 2. It can construct in the state engaged with the recessed part 12 of the other planar heating element 1 to be done.

  The electrodes 5 and 6 are each made of a material having excellent conductivity, and are arranged on the electrode arrangement surface 10 of the substrate 2. More specifically, the electrodes 5 and 6 are formed by, for example, spraying a metal or an alloy such as copper, silver, aluminum, or nickel on the electrode arrangement surface 10 of the substrate 2, or forming the above-described metal or alloy into a paste form. This is formed by printing and baking on the electrode arrangement surface 10. The electrodes 5 and 6 are surface-treated by plating or the like as necessary.

  As shown in FIG. 2, the electrode 5 is roughly divided into an outer peripheral side electrode part 20 and an inner peripheral side electrode part 21. The outer peripheral side electrode portion 20 is further divided into a portion extending along the short side of the substrate 2 (short portions 20a and 20c) and a portion extending along the long side of the substrate 2 (longitudinal portions 20b and 20d). Separated. The outer peripheral side electrode part 20 is continuous in the order of the short part 20a → the long part 20b → the short part 20c → the long part 20d, and the gap between the short part 20a and the long part 20d is discontinuous. . The short portions 20 a and 20 c and the long portions 20 b and 20 d are provided at positions separated from the outer peripheral end of the substrate 2 by a distance d. A power source (not shown) is connected to the end of the short part 20a.

  Moreover, the inner peripheral side electrode part 21 has the center part 21a and the short part 21b. The central portion 21a is provided substantially in parallel with the longitudinal portions 20b and 20d at an intermediate position between the longitudinal portions 20b and 20d of the outer peripheral side electrode portion 20, that is, at a substantially central portion of the base member 2. That is, the central portion 21a exists on the virtual line L1 when assuming a virtual line L1 that passes through the center C of the electrode arrangement surface 10 of the substrate 2 and is parallel to the longitudinal portions 20b and 20d. . The distance between the central portion 21a and the longitudinal portions 20b and 20d of the outer peripheral side electrode portion 20 is D. The short part 21 b is a part that connects the center part 21 a and the long part 20 b described above, and extends substantially in parallel to the short part 20 c constituting the outer peripheral side electrode part 20.

  As shown in FIG. 1, the electrode 6 is arranged so as to be substantially parallel to the outer peripheral side electrode portion 20 of the electrode 5 on the center side of the electrode arrangement surface 10. More specifically, the electrode 6 includes short portions 30a and 30c extending parallel to the short portions 20a and 20c of the electrode 5, and a long portion 30b extending parallel to the long portions 20b and 20d of the electrode 5. , 30d. The electrode 6 is continuous in the order of the long portion 30b → the short portion 30a → the long portion 30d → the short portion 30c, and the gap between the long portion 30b and the short portion 30c is discontinuous. Further, the short portion 21b of the electrode 5 described above crosses the approximate center of the discontinuous portion between the long portion 30b and the short portion 30c. A power source (not shown) is connected to the end portion of the longitudinal portion 30b.

  The short portions 30a and 30c of the electrode 6 are also provided at positions that are separated from the short portions 20a and 20c of the electrode 5 toward the center C by a distance D1. Further, the longitudinal portions 30b and 30d of the electrode 6 are provided at positions deviating from the longitudinal portions 20b and 20d of the electrode 5 toward the center C side of the electrode arrangement surface 10 of the substrate 2 by a distance D1. Further, the long portions 30 b and 30 d are provided at positions that are distant from the center portion 21 a of the electrode 5 on the outer side in the short direction of the electrode arrangement surface 10 by a distance D2.

  The distance D1 between the long portions 30b, 30d of the electrode 6 and the long portions 20b, 20d of the electrode 5 is shorter than the distance D2 between the long portions 30b, 30d of the electrode 6 and the central portion 21a of the electrode 5 (D1 < D2). That is, in the planar heating element 1, the distance D1 between the electrodes 5 and 6 on the end side of the electrode arrangement surface 10 is narrower than the distance D2 between the electrodes 5 and 6 on the center C side of the electrode arrangement surface 10. In other words, assuming a virtual line L1 passing through the center C of the electrode arrangement surface 10, the longitudinal portions 20b and 20d of the electrode 5 located at a position away from the virtual line L1 and the longitudinal portions of the electrodes 6 adjacent thereto. A distance D1 between 30b and 30d is narrower than a distance D2 between the central portion 21a of the electrode 5 passing on the virtual line L1 and the longitudinal portions 30b and 30d of the electrode 6 adjacent thereto.

  The heat generating portion 7 is generally called a PTC thermistor or the like, has conductivity, and has a characteristic of generating heat when energized. Moreover, the heat generating part 7 also has a characteristic that the resistance value increases as the temperature rises. The heat generating part 7 is electrically connected to the electrodes 5 and 6 described above, and generates heat when a current flows between the electrodes 5 and 6.

  The heat generating portion 7 can be formed using, for example, a resin material mixed with conductive particles such as carbon. Similarly to the electrodes 5 and 6, the heat generating part 7 can be formed into a shape by a method such as a method of printing and baking on the base material 2 by screen printing or the like, or an extrusion method. Although not shown in FIG. 2, the heat generating portion 7 is disposed substantially uniformly between the electrodes 5 and 6 regardless of the portion as shown by hatching in FIGS. , 6 are electrically connected. Therefore, the resistance value between the electrodes 5 and 6 varies depending on the distance between the electrodes 5 and 6.

  More specifically, as described above, the distance D1 between the regions A1 and A2 between the longitudinal portions 20b and 20d of the electrode 5 and the longitudinal portions 30b and 30d of the electrode 6 adjacent thereto is the central portion of the electrode 5. It is narrower than a distance D2 between regions A3 and A4 formed between 21a and the longitudinal portions 30b and 30d of the electrode 6. Therefore, in the sheet heating element 1, the electric resistances of the regions A3 and A4 are larger than the electric resistances of the regions A1 and A2 existing on the outer peripheral side of the electrode arrangement surface 10. Therefore, immediately after energization of the electrodes 5 and 6, the sheet heating element 1 has both ends than A3 and A4 at the center in the width direction (short direction) of the sheet heating element 1 as shown in FIG. The areas A1 and A2 in the vicinity of the part tend to become high temperature.

  However, in the sheet heating element 1, the electrode 6 does not exist in the regions A 5 and A 6 outside the width direction (short direction) of the electrode arrangement surface 10 with respect to the long portions 20 b and 20 d of the electrode 5. Immediately after energization, the temperature is low as shown in FIG. 3A, and the temperature difference between the regions A1 and A5 and between the regions A2 and A6 is larger than the temperature difference between the regions A1 and A3 and between the regions A1 and A4. Become. Therefore, after a while after the energization of the electrodes 5 and 6, the heat energy generated in the regions A 1 and A 2 is a region A 5 on the outer side in the width direction of the electrode placement surface 10 from the region A 3 and A 4 side of the central portion of the electrode placement surface 10. It moves preferentially to the A6 side, and the temperature distribution in the width direction of the electrode arrangement surface 10 becomes almost uniform soon as shown in FIG.

  Further, the sheet heating element 1 has the short portions 20a, 20c of the electrode 5 and the short portions 30a, 30c of the electrode 6 facing each other at both ends in the longitudinal direction, and the short portions 21b of the electrode 5 and the electrodes 6 It arrange | positions so that the short part 30c may oppose. Therefore, immediately after the energization of the electrodes 5 and 6, the sheet heating element 1 has a region B1 between the short portions 20a and 30a, a region B2 between the short portions 20c and 30c, and a portion between the short portions 21b and 30c. The region B3 generates heat.

  Here, the distance between the electrodes 5 and 6 in the regions B1, B2 and B3 is D1, and is shorter than the distance D2 between the electrodes 5 and 6 in the regions A3 and A4. Further, as described above, in the sheet heating element 1, the heating parts 7 are arranged substantially uniformly regardless of the part. Therefore, as shown in FIG. 4A, when energization to the electrodes 5 and 6 is started, the temperatures of the regions B1, B2, and B3 become higher than those of the regions A3 and A4.

  On the other hand, in the regions B4 and B5 on the outer side in the longitudinal direction of the electrode arrangement surface 10 with respect to the short portions 20a and 20c, the electrodes 6 are not provided as in the regions A5 and A6 described above. It does not generate fever. Therefore, the temperatures of the regions B4 and B5 immediately after the energization of the electrodes 5 and 6 are lower than those of the regions B1, B2, and B3 and the regions A3 and A4 as shown in FIG. That is, immediately after the energization of the electrodes 5 and 6 is started, the temperature difference between the regions B1, B2, and B3 and the regions B4 and B5 is larger than the temperature difference between the regions B1, B2, and B3 and the regions A3 and A4. Therefore, after a while after the energization of the electrodes 5 and 6, the heat energy generated in the regions B 1, B 2 and B 3 is a region outside the longitudinal direction of the electrode placement surface 10 from the region A 3, A 4 side of the central portion of the electrode placement surface 10. Move preferentially to B4 and B5. Therefore, in the sheet heating element 1, the temperature distribution in the width direction of the electrode arrangement surface 10 becomes substantially uniform as shown in FIG. 4B shortly after the electrodes 5 and 6 are energized.

  In the planar heating element 1 of the present embodiment, the distance between the electrodes 5 and 6 on the outer peripheral side of the electrode arrangement surface 10 is narrower than the distance between the electrodes 5 and 6 on the center C side of the electrode arrangement surface 10. That is, when assuming the imaginary line L1 passing through the center C of the electrode arrangement surface 10, the planar heating element 1 has an interval D1 between the electrode 5 located away from the imaginary line L1 and the electrode 6 adjacent thereto. The distance D2 between the electrode 5 on the virtual line L1 and the electrode 6 adjacent thereto is narrower. Therefore, the heat generation amount on the outer peripheral side of the electrode arrangement surface 10 is larger than the heat generation amount on the center C side. Therefore, in the sheet heating element 1 according to the present embodiment, the electrodes 5 and 6 are arranged on the outer peripheral end (edge surface) side of the base material 2 due to construction reasons such as the areas A5 and A6 and the areas B4 and B5. Even if there is a portion that is not, heat generated in the electrodes 5 and 6 disposed on the outer peripheral side of the electrode arrangement surface 10 soon after the energization to the electrodes 5 and 6 propagates to the outer peripheral end side of the electrode arrangement surface 10, The entire electrode placement surface 10 is heated substantially uniformly.

  Further, the sheet heating element 1 is configured such that the heating unit 7 has a resistance value that increases as the temperature rises. Therefore, the sheet heating element 1 is excellent in safety because the heat generating portion 7 does not become excessively high in temperature.

  The planar heating element 1 of this embodiment has a convex part 11 and a concave part 12 on the outer periphery of the electrode arrangement surface 10, and these are engaging parts that can be engaged with other members or other planar heating element 1. Function. Therefore, the planar heating element 1 is excellent in workability.

In the present embodiment, the example in which the convex portion 11 and the concave portion 12 are provided only on the edge surface extending in the longitudinal direction (length direction) of the substrate 2 is illustrated, but the present invention is not limited to this. Further, a configuration in which the convex portion 11 and the concave portion 12 are provided on the edge surface extending in the short direction (width direction) may be employed.
(Second Embodiment)
Then, the planar heating element concerning 2nd Embodiment of this invention is demonstrated in detail, referring drawings. In addition, since the planar heating element of this embodiment has a part of the configuration in common with the planar heating element 1 of the above-described embodiment, the same reference numerals are given to the common parts, and detailed description is omitted. . Moreover, in FIG. 6, the heat generating part 7 is not shown and is omitted.

  In FIG. 5, 50 is a planar heating element of this embodiment. The planar heating element 50 is provided with a pair of electrodes 51 and 52 (electrodes A and B) on the electrode arrangement surface 10 of the substrate 2 in the same manner as the planar heating element 1 described above. Thus, the heat generating portion 7 is electrically connected. The planar heating element 50 is different from the electrodes 5 and 6 described above in the shape and arrangement of the electrodes 51 and 52.

  More specifically, the electrodes 51 and 52 are made of a material having excellent conductivity such as a metal or an alloy such as copper, silver, aluminum, nickel, etc., like the electrodes 5 and 6 described above. . As shown in FIG. 5, the electrodes 51 and 52 each have a substantially “U” shape when viewed from the front.

  More specifically, the electrode 51 has short portions 51a and 51c extending along the short direction (width direction) of the substrate 2 and a long portion 51b extending along the long direction (length direction). And it is set as the structure continuous in order of the short part 51a-> longitudinal part 51b-> short part 51c. The short parts 51a and 51c are present at positions separated from the longitudinal ends of the base material 2 (upper and lower ends in FIG. 6) by a distance d toward the center C side. Further, the short portions 51a and 51c exist at positions separated from the virtual line L2 passing through the center C and the center C of the base material 2 and parallel to the short side of the base material 2 by an interval y.

  On the other hand, the long portion 51b is arranged at a position deviated from the one end side (left side in FIG. 6) of the base material 2 to the center C side by a distance d. Further, the longitudinal portion 51b exists at a position separated from the virtual line L3 passing through the center C and the center C of the substrate 2 and parallel to the long side of the substrate 2 by an interval x. The distance x between the long portion 51b and the center C and the virtual line L3 is narrower than the distance y between the short portions 51a and 51c and the center and the virtual line L2 (x <y).

  The electrode 52 has short portions 52a and 52c extending along the short direction (width direction) of the base material 2, and a long portion 52b extending along the long direction (length direction), and the short portion 52a. It is set as the structure continued in order of → longitudinal part 52b → short part 52c. The short parts 52a and 52c are arranged in parallel to the short parts 51a and 51c at positions spaced apart from the short parts 51a and 51c of the electrode 51 by the distance Y toward the center C side, respectively. Therefore, the electrodes 51 and 52 are arranged such that the short parts 51a and 52a face each other and the short parts 51c and 52c face each other. Further, the long portion 52b is arranged at a position deviated to the center C side by a distance d from the other end side in the short side direction of the substrate 2 (right side in FIG. 6). Thus, the electrodes 51 and 52 are arranged such that the longitudinal portions 51b and 52b face each other with an interval X therebetween.

  Although omitted in FIG. 6 between the electrodes 51 and 52 described above, as shown by hatching in FIG. 5, a heat generating portion 7 made of a PTC thermistor is disposed, whereby the electrodes 51 and 52 are connected to each other. Electrically connected. The heat generating part 7 is disposed substantially uniformly between the electrodes 51 and 52 regardless of the part, and electrically connects both the electrodes 51 and 52. Therefore, the resistance value between the electrodes 51 and 52 varies depending on the distance between the electrodes 51 and 52.

  More specifically, in the electrodes 51 and 52, the distance Y between the short parts 51a and 52a and the area P1 and P2 between the short parts 51c and 52c is the distance X between the long parts 51b and 52b. Narrow enough. Therefore, in the sheet heating element 50, the electric resistances of the regions P1 and P2 are sufficiently smaller than the electric resistance of the region P3. Therefore, as soon as energization of the electrodes 51 and 52 is started, the sheet heating element 50 is present at both ends in the longitudinal direction from the center P side region P3 of the sheet heating element 50 as shown in FIG. The regions P1 and P2 have a higher temperature.

  Here, in the planar heating element 50 of the present embodiment, the electrode 52 does not exist in the regions P4 and P5 outside the electrode arrangement surface 10 with respect to the short portions 51a and 51c of the electrode 51. Therefore, immediately after the energization of the electrodes 51 and 52 is started, the regions P4 and P5 existing at both ends in the longitudinal direction are lower in temperature than the region P3 in the central portion of the sheet heating element 50 as shown in FIG. become. That is, immediately after energization of the electrode 51, the temperature difference between the regions P1, P2 and the regions P4, P5 is larger than the temperature difference between the regions P1, P2 and the region P3. Therefore, in the sheet heating element 50, after a while after the energization of the electrodes 51 and 52, the thermal energy generated in the regions P1 and P2 moves preferentially to the regions P4 and P5 side, and soon shown in FIG. Thus, the temperature distribution in the longitudinal direction of the electrode arrangement surface 10 becomes substantially uniform.

  On the other hand, the planar heating element 50 has a smaller amount of heat generation in the region P3 than in the regions P1 and P2. Therefore, the heat generated in the region P3 is directed to the region P6 side formed on the outer side in the width direction of the base member 2 with respect to the longitudinal portion 51b of the electrode 51 and to the longitudinal portion 52b of the electrode 52 than the regions P1 and P2 side. On the other hand, it is assumed that it moves preferentially toward the region P7 formed on the outer side in the width direction of the substrate. Further, in the sheet heating element 50, since the base material 2 is rectangular and the length in the width direction (short direction) is shorter than the length in the length direction (longitudinal direction), the amount of heat generated in the region P3 is small. However, the thermal energy moves smoothly to the region P6 and the region P7 side. Accordingly, in the sheet heating element 50, the regions P6 and P7 are at a low temperature as shown in FIG. 8A just after the electrodes 51 and 52 are energized, but the regions as shown in FIG. P6 and P7 also have a high temperature as in the region P3. Therefore, the planar heating element 50 has a substantially uniform temperature distribution in the short direction of the electrode arrangement surface 10 when the electrodes 51 and 52 are energized.

  As described above, even if the planar heating element 50 of the present embodiment cannot arrange the electrodes 51 and 52 in the vicinity of the outer peripheral edge of the base material 2 due to construction reasons, as in the regions P4 to P7, Heat is generated so that the temperature distribution on the electrode arrangement surface 10 is substantially uniform regardless of the part. Therefore, if the planar heating element 50 of this embodiment is constructed, the joint portion of the planar heating element 50 can also generate heat similarly to other parts.

BRIEF DESCRIPTION OF THE DRAWINGS (a) is a perspective view which shows the planar heating element concerning 1st Embodiment of this invention, (b) is AA sectional drawing of (a), (c) is planar heating shown in (a). It is a disassembled sectional view which shows the construction state of a body. It is a front view which shows the planar heat generating body concerning 1st Embodiment of this invention. It is a graph which shows the temperature distribution of the transversal direction of the planar heating element concerning 1st Embodiment of this invention, (a) is the temperature distribution in the initial stage of electricity supply, (b) is the temperature distribution after a while after electricity supply. Is shown. It is a graph which shows the temperature distribution of the longitudinal direction of the planar heating element concerning 1st Embodiment of this invention, (a) is the temperature distribution in the initial stage of electricity supply, (b) is the temperature distribution after a while after electricity supply. It is shown. It is a perspective view which shows the planar heating element concerning 2nd Embodiment of this invention. It is a front view which shows the planar heating element concerning 2nd Embodiment of this invention. It is a graph which shows the temperature distribution of the longitudinal direction of the planar heating element concerning 2nd Embodiment of this invention, (a) is the temperature distribution in the initial stage of energization, (b) is the temperature distribution after a while after energization. It is shown. It is a graph which shows the temperature distribution of the transversal direction of the planar heating element concerning 2nd Embodiment of this invention, (a) is the temperature distribution in the initial stage of electricity supply, (b) is the temperature distribution after a while after electricity supply. Is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,50 Planar heat generating body 2 Base material 5, 6, 51, 52 Electrode 7 Heat generating part 20 Outer peripheral side electrode part 20a, 20c Short side part 20b, 20d Longer part 21 Inner peripheral side electrode part 21a Central part 21b, 30a, 30c, 51a, 51c, 52a, 52c Short part 30b, 30d, 51b, 52b Longitudinal part C Center L1-L3 Virtual line A1-A6 Area B1-B5 Area D1, D2 Width d Interval P1, P2 area (short area) )
P3 area (longitudinal area)
P4 to P7 area

Claims (6)

  It has a plate-like base material having electrical insulation, and is electrically connected to the electrodes A and B arranged on the electrode arrangement surface constituting the base material, and the electrodes A and B, for energization A planar heating element having a heat generating portion that generates heat, wherein the distance between the electrodes A and B on the outer peripheral side of the electrode arrangement surface is narrower than the distance between the electrodes A and B on the center side of the electrode arrangement surface. Characteristic planar heating element.   It has a plate-like base material having electrical insulation, and is electrically connected to the electrodes A and B arranged on the electrode arrangement surface constituting the base material, and the electrodes A and B, for energization A heating element having a heat generating part that generates heat, and is separated from the virtual line when assuming a virtual line passing through the center of the electrode arrangement surface and parallel to the electrode A or overlapping with the electrode A The distance between the electrode A at the position and the electrode B facing the electrode A is narrower than the distance between the electrode A at the position on or near the virtual line and the electrode B facing the electrode A. Planar heating element.   It has a plate-like base material having electrical insulation, and is electrically connected to the electrodes A and B arranged on the electrode arrangement surface constituting the base material, and the electrodes A and B, for energization A heating element having a heat generating part that generates heat, and the distance between the electrode A at a position away from the center of the electrode arrangement surface and the electrode B arranged at a position facing the electrode A is an electrode arrangement. A planar heating element characterized by being narrower than the distance between the electrode A on the center side of the surface and the electrode B disposed at a position facing the electrode A.   It has a plate-like base material having electrical insulation, and is electrically connected to the electrodes A and B arranged on the electrode arrangement surface constituting the base material, and the electrodes A and B, for energization And a heat generating part that generates heat, and a short region in which the electrode arrangement surface is rectangular and the electrodes A and B face each other along the short direction of the electrode arrangement surface And a longitudinal region arranged so that the electrodes A and B face each other along the longitudinal direction of the electrode arrangement surface, the short region exists at both ends in the longitudinal direction of the electrode arrangement surface, and the longitudinal region is It exists in the longitudinal direction intermediate part of the electrode arrangement surface, and the electrodes A and B are present on the center side of the electrode arrangement surface from the short region existing on both ends in the longitudinal direction of the electrode arrangement surface. The distance from the center of the surface to the electrode A arranged in the short region is from the center of the electrode arrangement surface to the electrode A arranged in the long region. Longer than the interval, the electrode A in the lateral region, distance B is, sheet heating element, characterized in that narrower than the electrode A, interval B in the longitudinal region.   The sheet heating element according to any one of claims 1 to 4, wherein the heating portion has a resistance value that increases with an increase in temperature.   The electrode arrangement surface has an engagement portion engageable with another member on the outer periphery, and electrodes A and B are arranged on the center side of the electrode arrangement surface with respect to the engagement portion. The planar heating element as described in any one of 1-5.

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