JP4746047B2 - Planar heating element, electric heating board for floor heating, and electric heating board assembly for floor heating - Google Patents

Description

  The present invention relates to a planar heating element, an electric heating board for floor heating, and an electric heating board assembly for floor heating, and more particularly to an arrangement system of heating resistance wires used for the planar heating element.

  In recent years, floor heating systems that efficiently use heat radiation, conduction heat, and convection have attracted attention as means for heating the interior of buildings, in addition to stoves, fan heaters, and air conditioners. Since the floor heating system can uniformly warm the room in order to efficiently use the three ways of transferring heat, it is a quiet and clean heating system, so further demand is expected to increase in the future.

  Although the floor heating system may be composed of a single floor heating electric heating board, it is usually composed of a floor heating electric board assembly in which a plurality of floor heating electric boards are connected to each other. As a heating means used for an electric heating board for floor heating, for example, a planar heating element described in Japanese Patent No. 3463898 is known.

  FIG. 1 is a cross-sectional view of a conventional floor heating electric heating board cut along a plane parallel to the main surface. A planar heating element 130 is formed on the upper surface of the floor heating electric heating board 120. The planar heating element 130 includes a plurality of parallel circuits 141 to 144 in which a plurality of heating resistance wires 133 that generate heat when energized are connected in parallel. Each of the parallel circuits 141 to 144 extends in parallel while being adjacent to each other, and the adjacent parallel circuits are sequentially electrically connected in series via the electrodes 131a, 131d, 131b, 131e, and 131c to form a heater circuit. ing.

  In order to install the floor heating electric heating board, the floor heating electric heating boards are laid and fixed one by one on the joists or floor floor, and the floor material is laid thereon. A nailing area is required to fix the floor heating electric board to the floor base or to fix the flooring floor or the like on the floor heating electric board. For this reason, generally, a crosspiece 122 is fixed along the outer peripheral portion of the back surface of the sheet heating element 130, and a region where the crosspiece 122 is provided is a nail driving region 105.

  FIG. 2 is a plan view showing an example of an end portion of the floor heating electric heating board. The planar heating element has a width W in a direction orthogonal to the direction in which the parallel circuits 141 to 144 extend (hereinafter referred to as laying direction x) (hereinafter referred to as laying orthogonal direction y). However, as shown in FIG. 1, when the crosspiece 122 is arranged on the outer peripheral portion of the planar heating element 130 and the nail driving region 105 is formed, the heating resistance wire 133 cannot be arranged in the nail driving region 105 (hereinafter referred to as the nail driving region 105). The non-installation area 105 may be used instead of the nailing area.) For this reason, the area | region of the width | variety w which does not contain the non-installation area | region 105 of the planar heating element 130 was divided | segmented into area | region A141-A144 at equal intervals, and the parallel circuits 141-144 were arrange | positioned in each area | region A141-A144.

  In such a conventional heating resistor wire arrangement method, since the heating resistor wire cannot be arranged in the nail area of the outer peripheral portion extending parallel to the laying direction x of the planar heating element, the temperature of this area is The cold zone is likely to occur. In particular, when a plurality of floor heating electric boards are arranged side by side, the nailing areas are arranged adjacent to each other, so that the range in which the heating resistance lines cannot be arranged is expanded. For this reason, there is a possibility that the cold zone expands and the temperature drop also increases.

  An object of the present invention is to provide a planar heating element that can suppress a temperature drop in a non-installation region even when there is a non-installation region of a heating resistance wire.

  Another object of the present invention is to provide a floor heating electric board and a floor heating electric board assembly using such a planar heating element.

  The planar heating element of the present invention is a planar heating element provided with a plurality of parallel circuits in which a plurality of heating resistance wires that generate heat when energized are connected in parallel. Each parallel circuit extends in parallel while being adjacent to each other, and adjacent parallel circuits are sequentially electrically connected in series to form a heater circuit. A heating resistance line non-installation area is provided along at least one peripheral edge of the planar heating element extending in parallel with the parallel circuit. In each of the parallel circuits, in the direction orthogonal to the direction in which the parallel circuit extends, the entire width of the planar heating element including the non-installation region is W, the electric resistance of each parallel circuit is Ri, and the total electric resistance of the heater circuit is R. Sometimes it is arranged in a parallel circuit region having a width defined by (Ri / R) × W.

  Each parallel circuit is arranged in a parallel circuit region having a width obtained by allocating the entire width of the planar heating element including the non-installed region in proportion to the resistance ratio of each parallel circuit, that is, the heat generation ratio. Therefore, in the parallel circuit area including the non-installation area, the heating resistance line cannot be installed in the non-installation area itself, but by installing the heating resistance line in other areas, the average per unit area of each parallel circuit area It becomes possible to arrange the calorific value. In other words, although no heat is generated from the non-installation area, a decrease in temperature of the non-installation area can be suppressed by increasing the average heat generation amount per unit area in the vicinity area.

  Each heating resistance line constituting each parallel circuit is preferably arranged in a heating resistance line area having a width obtained by dividing the width of the parallel circuit area of each parallel circuit by the number of heating resistance lines of each parallel circuit.

  An electric heating board for floor heating according to the present invention is an electric heating board for floor heating in which the above-described planar heating element is disposed on the upper surface. The electric heating board for floor heating is fixed to the nailable frame fixed to the back surface of the sheet heating element and the part surrounded by the frame frame on the back surface of the sheet heating element along at least the peripheral edge of the heating board. And a resin-made reinforcing member that is fixed to the back surface of the sheet heating element and includes an electrical connection portion between the power line and the sheet heating element. The reinforcing member is provided with a gap for accommodating the power line by bending it.

  The electric heating board assembly for floor heating according to the present invention is an electric heating board assembly for floor heating in which a plurality of floor heating electric heating boards are connected. Adjacent floor heating electric boards are electrically connected by power lines extending between the floor heating electric boards between peripheral edges extending in parallel with the parallel circuit and facing each other, and each electric heating board is They are connected by mechanical connecting means so as to be overlapped and folded. When opening the folded floor heating electric heating board and laying each floor heating electric heating board so that the opposing peripheral edges of each floor heating electric heating board are in contact with each other, the gap portion is an extra length portion of the power line. Can be stored.

  As described above, according to the present invention, it is possible to provide a planar heating element that can suppress a temperature drop in the non-installation region even when there is a non-installation region of the heating resistance wire. Moreover, according to this invention, the heating board for floor heating using this planar heating element and the heating board aggregate | assembly for floor heating can be provided.

It is sectional drawing cut | disconnected by the surface parallel to the main surface of the electric heating board for floor heating of a prior art. It is a top view which shows an example of the edge part of the electric heating board for floor heating. It is sectional drawing cut | disconnected by the surface parallel to the main surface of the electric heating board for floor heating which concerns on one Embodiment of this invention. It is sectional drawing cut | disconnected along line A-A 'of the electric heating board for floor heating shown in FIG. It is sectional drawing cut | disconnected along line B-B 'of the electric heating board for floor heating shown in FIG. It is a schematic diagram explaining the construction method of the electric heating board aggregate | assembly for floor heating. 2 is a cross-sectional view showing the inside of a reinforcing member 10 cut along a plane parallel to a main surface. FIG. It is the top view seen from the opposite side of the main surface in which the heat equalization board was provided of the electric heating board for floor heating shown in FIG. It is a fragmentary sectional view of the planar heating element along the A-A 'line of Drawing 7A. It is a figure for demonstrating the connection method of the power wire to a planar heating element. FIG. 7B is a partial detail view of the planar heating element shown in FIG. FIG. 7B is a partial detail view of the vicinity of part B of the planar heating element shown in FIG. 7A for explaining the arrangement pattern of each heating resistance line in the parallel circuit. FIG. 7B is a partial detail view of a planar heating element corresponding to the vicinity of portion B in FIG. 7A when the widths of the parallel circuit regions are different. FIG. 7B is a partial detail view of a planar heating element corresponding to the vicinity of portion B in FIG. 7A when the widths of the parallel circuit regions are different. It is a graph which shows the temperature distribution of the two electric heating boards for floor heating in Example 1. FIG. It is a graph which shows the temperature distribution of the two electric heating boards for floor heating in Example 2. FIG.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 3 is a cross-sectional view of the floor heating electric board according to the embodiment of the present invention, cut along a plane parallel to the main surface. 4A is a cross-sectional view taken along line A-A ′ of the floor heating electric heating board shown in FIG. 3, and FIG. 4B is a cross-sectional view taken along line B-B ′.

  The floor base on which the floor heating electric heating board 20 can be laid is not particularly limited, and examples thereof include a wooden floor base, a concrete floor base, and a dry sound insulation double floor. The floor material that can be laid on the floor heating electric heating board 20 is also not particularly limited, but floor heating tatami mat, floor heating wood floor material, plywood + carpet, and the like can be suitably used.

  A planar heating element 30 is disposed on the upper surface of the floor heating electric heating board 20. On the back surface of the sheet heating element 30, a crosspiece 22 is disposed along the peripheral edge of the floor heating electric heating board 20. The heat insulating material 21 and the resin reinforcing member 10 are fixed to a portion surrounded by the crosspiece 22 on the back surface of the planar heating element 30. The reinforcing member 10 includes an electrical connection portion between the power line 12 and the planar heating element 30. The upper surface of the sheet heating element 30 is covered with a soaking plate 24. A reinforcing sheet 25 is disposed on a part or the entire back surface of the floor heating electric heating board 20. Hereinafter, the structure of each part will be described in detail.

  The heat insulating material 21 is used to suppress the heat generated from the planar heating element 30 from being transmitted to the back surface of the floor heating electric heating board 20 and to effectively transfer the heat to the floor material above the floor heating electric heating board 20. . As the heat insulating material 21, a material that is lightweight and has a high heat insulating effect and has heat resistance with respect to the normal use temperature of the floor heating electric heating board 20 is preferable. The heat insulating material 21 is made of, for example, a foamed resin such as foamed polyurethane, foamed polyethylene, or foamed polypropylene, a wood fiber molded body such as a hard wood fiber board or a lightweight wood fiber board, or a synthetic fiber such as polyester fiber or polyether ketone fiber. Made of felt mat.

  The pier 22 is formed of a light and strong material, for example, wood, plywood, lightweight plastic and the like. By providing the pier 22, the overall strength of the floor heating electric heating board 20 can be increased. The pier 22 is arranged in a frame shape on the outer periphery of the floor heating electric heating board 20, whereby the weight of the entire floor heating electric heating board 20 is reduced, deformation such as warpage due to its own weight is suppressed, and floor heating is performed. The installation workability of the electrical heating board 20 is improved.

  The pier 22 also has a function of securing an area for fixing the floor heating electric heating board 20 to the floor base. The floor heating electric heating board 20 is fixed to the floor base by, for example, nailing, screwing, adhesion, or fitting. When the floor heating electric heating board 20 is fixed, an area where the pier 22 is provided is used. By displaying the nailable area on the floor heating electric heating board 20, when the floor heating electric heating board 20 is fixed to the floor base by nailing or the like, it is used as an electric wiring or an electric component of the sheet heating element 30. It can prevent adverse effects. The area where the crosspiece 22 of the planar heating element 30 is fixed becomes a non-installation area 105 where a heating resistance wire (described later) cannot be installed.

  The heat equalizing plate 24 uniformly disperses the heat generated from the planar heating element 30 in the in-plane direction and transmits it to the flooring. The soaking plate 24 is formed of, for example, a metal foil or plate such as aluminum or copper. The soaking plate 24 is made of, for example, an aluminum plate having a thickness of 40 to 150 μm, and is attached to the surface of the planar heating element 30. By providing the soaking plate 24, the variation in the temperature distribution of the planar heating element 30 can be reduced.

  The reinforcing sheet 25 is fixed to the back surface of the floor heating electric heating board 20. The reinforcing sheet 25 is fixed to the lower surface of the reinforcing member 10, the heat insulating material 21, and the pier 22, improves the strength of the floor heating electric heating board 20, and protects the internal circuit of the floor heating electric heating board 20. Reinforcing sheet 25 is, for example, paper such as crepe paper, polypropylene (polyethylene, polyethylene, polyester, etc.), laminates of paper and paper, various plastic or asphalt waterproof sheets, bakelite (registered trademark), etc. It is made of a plastic plate, a metal plate such as tinplate, aluminum or stainless steel. The reinforcing sheet 25 can also be formed of a composite material of these materials.

  The shape of the reinforcing member 10 in the thickness direction is held by the rib 13 rising from the base body 15. A gap 14 is secured by a rib 13 inside the reinforcing member 10. A power line 12 for supplying power to the planar heating element 30 is accommodated in the gap portion 14. In order to secure a space for the lead wires 12 a to 12 c (see FIG. 8) branched from the power supply line 12 to rise toward the electrodes 31 a to 31 c (see FIG. 7A) provided on the planar heating element 30, the reinforcing member 10. Are provided with through holes 11a to 11c extending in the thickness direction.

  By adjoining the peripheral portions 28 extending in the laying direction x, a plurality of floor heating electric boards 20 can be used adjacently. A configuration in which a plurality of floor heating electric boards are connected is referred to as a floor heating electric board assembly 100 in this specification. The power line 12 extends between the adjacent floor heating electric heating boards 20 in the orthogonal direction y, and electrically connects the two floor heating electric heating boards 20. A hole 22 c is provided in the peripheral portion 28 of the floor heating electric heating board 20, and is connected to the hole 22 c of the adjacent floor heating electric heating board 20 by a connection band 27. As a result, the adjacent floor heating electric heating boards 20 are mechanically connected. An appropriate space is secured between the adjacent floor heating electric heating boards 20 by the connecting band 27, and the floor heating electric heating boards 20 can be easily overlapped and folded. The interval between the floor heating electric heating boards 20 can be adjusted by the length of the connecting band 27.

  Drawing 5 is a mimetic diagram explaining the construction method of the electric heating board aggregate for floor heating. First, as shown in the upper left diagram, the assembly 100 is carried into the room in a state where the assembly 100 is alternately folded at the connecting portion of the floor heating electric heating board 20. Next, as shown in the upper right view, the assembly 100 is stretched and developed. Next, as shown in the lower left figure, the assembly 100 is completely unfolded and laid on the floor base. Then, the connecting band 27 that connects the floor heating electric boards 20 is pulled up, and the space between the floor heating electric boards 20 is reduced so that the opposite peripheral edges 28 of the floor heating electric boards are in contact with each other. Then, the connecting band 27 is cut and removed. Through the above steps, the floor heating electric heating boards 20 are installed in close contact with each other, as shown in the lower right diagram, and the installation of the assembly 100 is completed.

  As described above, when the floor heating electric heating board 20 is folded, a space is provided between the floor heating electric heating board 20 and the floor heating electric heating board 20 so as to be in close contact with the adjacent floor heating electric heating board 20 after installation. Therefore, as shown in FIG. 6, in the gap portion 14 of the reinforcing member 10, the extra length portion of the power line 12 that is generated when the floor heating electric heating boards 20 are in close contact with each other, the power line 12 is bent like a broken line. There is room for storage by deforming.

  The planar heating element 30 is composed of a plurality of heating resistance wires made of carbon fiber. The thickness of the planar heating element 30 is preferably 2 mm or less, more preferably 0.8 mm or less. Examples of the planar heating element 30 include, for example, a fiber reinforced resin molded article disclosed in Japanese Patent Application Laid-Open No. 8-207191. A fiber reinforced resin molded product is a fiber made of glass epoxy after connecting conductive fibers and electrodes at both ends of a network structure formed by joining intersections of non-conductive fibers and conductive fibers made of carbon fibers. It is formed by laminating a resin film for insulation such as a reinforced prepreg sheet and a polyester film.

  FIG. 7A is a plan view of the floor heating electric heating board shown in FIG. 3 as viewed from the opposite side of the main surface on which the heat equalizing plate is provided. FIG. 7B is a partial cross-sectional view of the planar heating element along the line A-A ′ in FIG. 7A. FIG. 7B shows the image upside down. In FIG. 7A, strictly speaking, a crosspiece and a heating resistance line are not displayed, but are illustrated for convenience of explanation. The planar heating element 30 has heating resistance lines 32a to 32e, 33a to 33e, 34a to 34e, and 35a to 35e that have a certain length and are arranged linearly and in parallel with each other. In FIG. 7A, the planar heating element 30 matches the planar dimension of the floor heating electric heating board 20. The heating resistance wires 32a to 35e are sandwiched between rectangular fiber reinforced prepregs 2 and 4. A resin film 1 is laminated on the fiber reinforced prepreg 2, and a soaking plate 24 is laminated thereon. A resin film 5 is laminated on the fiber reinforced prepreg 4.

  The heating resistance wires 32a to 35e generate heat when energized. The heating resistance lines 32a to 32e are connected in parallel between the electrode 31a and the electrode 31d, and form one parallel circuit 41 that connects the electrode 31a and the electrode 31d. The heating resistance lines 33a to 33e are connected in parallel between the electrode 31d and the electrode 31b, and form one parallel circuit 42 that connects the electrode 31d and the electrode 31b. The heating resistance lines 34a to 34e are connected in parallel between the electrode 31b and the electrode 31e, and form one parallel circuit 43 that connects the electrode 31b and the electrode 31e. The heating resistance lines 35a to 35e are connected in parallel between the electrode 31e and the electrode 31c, and form one parallel circuit 44 that connects the electrode 31e and the electrode 31c. As described above, the parallel circuits extend in parallel while being adjacent to each other, and the adjacent parallel circuits are sequentially electrically connected in series to form a heater circuit. An overheat prevention device (not shown) such as a thermostat may be provided between the electrode 31a and the power supply line 12, and this may be built in the floor heating electric heating board 20.

  The number of heat generating resistance lines constituting the parallel circuits 41 to 44 is not particularly limited, but is preferably about 3 to 12. The number of parallel circuits is not particularly limited, but it is desirable to configure a heater circuit by connecting 4 to 8 parallel circuits in series.

  In addition, it replaces with the structure which folds between the both ends of the electric heating board 20 for floor heating via the electrodes 31d and 31e which are not connected to the power supply line 12, and it does not provide the electrodes 31d and 31e, but generates heat resistance. It is also possible to adopt a configuration in which the line itself is folded back.

  The heating resistance wires 32a to 35e are all composed of carbon fibers having the same diameter. The carbon fiber is excellent in durability and is a material suitable for the heating resistance wires 32a to 35e. The heating resistance wires 32a to 35e may be formed of nichrome wires, or a carbon-based conductive paint can be applied and formed using a printing technique.

  An electrode 31b serving as a central electrical connection is provided at a central position where the number of parallel circuits connected in series is equal, that is, between the parallel circuit 42 and the parallel circuit 43. For this reason, the parallel circuits (the set of parallel circuits 41 and 42 and the set of parallel circuits 43 and 44) on both sides of the electrode 31b are electrically connected between the electrode 31b and the corresponding end (electrodes 31a and 31c). The resistances are made equal to each other.

  In the floor heating electric heating board 20 of the present embodiment, the entire parallel circuits 41 to 44 can be energized between the electrode 31a and the electrode 31c as one series circuit (operation pattern 1). It is also possible to energize the set of parallel circuits 41 and 42 as a series circuit between the electrodes 31a and 31b, and at the same time energize the set of parallel circuits 43 and 44 as another series circuit between the electrodes 31b and 31c. There is (operation pattern 2). The two operation modes can be easily switched by switching the connection of the electrode 31b to the power source.

  Such an operation mode switching method is effective when the floor heating electric heating board 20 is used at different power supply voltages. Since the heat generation amount is proportional to the square of the voltage, if the power supply voltage is different, the heat generation amount of the floor heating electric heating board 20 is greatly different, which is not preferable. However, although the power supply voltage varies depending on the country, it can be roughly divided into a 100V system and a 200V system. Therefore, it is sufficient if the amount of heat generated can be controlled to the same level with respect to both power supply voltages.

When the resistance value between the electrodes 31a and 31b and the resistance value of the parallel circuit between the electrodes 31b and 31c are R, the resistance value of the planar heating element 30 in the operation pattern 1 is 2R. Since the heat generation amount is obtained by V ² / R with respect to the voltage V and the resistance R, if the operation pattern 1 is selected with respect to the power supply voltage of 200 [V], the heat generation amount is P = 200 ² / 2R = 20000 / R. On the other hand, in the operation pattern 2, the resistance R of the planar heating element 30 is 1 / {(1 / R) + (1 / R)} = R because the resistance R circuit is provided in parallel in two rows. / 2. If the operation pattern 2 is selected with respect to a power supply voltage of 100 [V], the calorific value is P = 100 ² / (R / 2) = 20000 / R, theoretically 100 [V] power supply voltage and 200 [V]. The same calorific value is obtained for the power supply voltage of V]. In this way, the amount of heat generated can be made equal by simply changing the electrode connected to the power supply line between when the applied voltage is 100 [V] and when it is 200 [V].

  In order to enable the operation pattern 2, it is necessary to use the electrode 31 b as a central electrical connection portion. Therefore, the electrode 31 b is advantageously provided on the same side as the electrodes 31 a and 31 c. Therefore, the number of parallel circuits is desirably an even number, and in order to align the electric resistances on both sides of the central electrical connection portion, the arrangement of the heating resistor lines in each parallel circuit and each parallel circuit is laid through the central electrical connection portion. It is desirable that the line is symmetrical about the center line c extending in x.

  Electrode 31a-31e is comprised from metal foil pieces, such as copper and aluminum, for example. Connection portions 36a to 36c connected to the power supply line 12 are provided on the electrodes 31a to 31c, respectively.

  Referring to FIG. 7B, the electrodes 31a to 31e are formed so as to cover the heating resistance lines 32a to 35e from one side (FIG. 7B shows only the electrode 31b. The same applies to other members). Metal wire meshes 3a to 3c are laminated on the electrodes 31a to 31c, respectively. The metal wire meshes 3a to 3c are composed of metal fibers, metal fiber fabrics, punching metal, expanded metal, metal mesh belts, and the like. The metal wire meshes 3a to 3c have an effect of fixing solder as connection means when the lead wire 12a (see FIG. 8) connected to the power supply line 12 is connected to the electrodes 31a to 31c.

  Through holes 4a to 4c are formed at positions near the electrodes 31a to 31c of the fiber reinforced prepreg 4 in order to make electrical connection between the power line 12 and the electrodes 31a to 31c. The through holes 4a to 4c have a diameter of about 5 to 50 mm. The resin film 5 laminated on the fiber reinforced prepreg 4 also has through holes 5a to 5c having a size including the through holes 4a to 4c.

  FIG. 8 is a diagram for explaining a method of connecting the power supply line to the planar heating element. First, the planar heating element 30 is placed on the floor heating electric heating board 20 so that the through holes 4a to 4c provided in the fiber reinforced prepreg 4 face the through holes 11a to 11c provided in the reinforcing member 10, respectively. Include. In the figure, only the through holes 4a and 11a are shown, and the following description will be given for the through holes 4a and 11a, but the same applies to the through holes 4b, 4c, 11b and 11c. Next, the lead wire 12a connected to the power supply line 12 is connected to the electrode 31a by the solder 6 through the through holes 4a and 11a. The solder 6 is firmly connected to the electrode 31a by the anchor effect of the metal wire mesh 3a provided on the electrode 31a. Although it is conceivable that the electrode 31a is not provided and the heating resistance wire is connected only through the metal wire mesh 3a, there is a possibility that the resin penetrates from the fiber reinforced prepreg 2 and covers the metal wire mesh 3a at the time of molding. Therefore, a configuration in which the electrode 31a is provided and the metal wire mesh 3a is laminated thereon is preferable.

  Thereafter, by filling the through hole 11a provided in the reinforcing member 10 with the resin 7, the lead wire 12a connected to the power supply line 12 can be firmly connected to the planar heating element 30 and waterproofed. Examples of the resin 7 that fills the through hole 11a include thermosetting resins such as epoxy resins and silicone resins, and thermoplastic resins such as polypropylene.

Next, the arrangement pattern of the heating resistance lines will be described. FIG. 9 is a partial detailed view of the planar heating element shown in FIG. 7A in the vicinity of portion B in FIG. Each of the parallel circuits 41 to 44 has a full width W in the laying-orthogonal direction y of the planar heating element 30, an electrical resistance Ri (where i = 41 to 44) of each parallel circuit 41 to 44, and an overall electrical resistance R ( That is, for the sum of the electrical resistances of the parallel circuits 41 to 44),
wi = (Ri / R) × W (Formula 1)
Are arranged in parallel circuit areas A41 to A44 having widths w41 to w44 defined by The total width W of the heating element 30 includes the width of the non-installation area 105.

  First, as a simple example, consider a case where the widths w41 to w44 of the parallel circuit regions A41 to A44 are all the same. In this case, the electric resistances R41 to R44 of the parallel circuits 41 to 44 are all the same from the equation (1). Although the parallel circuit area A41 includes the non-installation area 105 of the heat generation resistance line generated by arranging the crosspiece 22, the parallel circuit 41 cannot be arranged in the non-installation area 105. For this reason, the heating resistance lines 32a to 32e are concentrated in the area of the width w41 'excluding the non-installation area 105 in the parallel circuit area A41. That is, the heating resistance lines 32a to 32e are arranged at an arrangement pitch smaller than the arrangement pitch of the heating resistance lines 33a to 33e installed in the parallel circuit region A42. Since the electric resistances R41 and R42 of the parallel circuits 41 and 42 are the same, the amount of heat generated in the parallel circuit region A41 is equal to the amount of heat generated in the parallel circuit region A42. Similarly, the amount of heat generated in the parallel circuit region A43 is equal to the amount of heat generated in the parallel circuit region A44. Eventually, the amount of heat generated in each parallel circuit region A41 to A44 is all equal. Since the widths w41 to w44 of the parallel circuit areas A41 to A44 are all equal, the average heat generation amount per unit area of the parallel circuit areas A41 to A44 is equal. In this way, even if the parallel circuit regions A41 and A44 include an area where a part of the heating resistance lines cannot be installed, the heating resistance lines are arranged so as to satisfy the formula (1) by arranging the heating resistance lines densely. It can arrange | position and can equalize the heat_generation | fever of the planar heating element 30. FIG.

  FIG. 10 is a partial detail view of the vicinity of part B of the planar heating element shown in FIG. 7A for explaining the arrangement pattern of each heating resistance line in the parallel circuit. The heating resistance line regions (a11 to a45) and the non-installation area 105 overlap, and all of the heating resistance lines that cannot be arranged are arranged in the heat generation resistance line area that can be arranged near the non-installation area. That is, a part of the heating resistance lines constituting each parallel circuit is disposed in the heating resistance line area having a width obtained by dividing the width of the parallel circuit area of each parallel circuit by the number of heating resistance lines of each parallel circuit. . However, the remaining heating resistance lines to be allocated to the heating line area that at least partially overlaps the non-installation area are arranged in the heating line area near the non-installation area. Specifically, the parallel circuit region A41 is divided into five regions a11 to a15, and the heating resistance lines 32b to 32e are disposed in the corresponding regions a12 to a15. However, since the heating resistance line 32a cannot be arranged in the corresponding area a11, it is arranged with the heating resistance line 32b in the adjacent area a12 near the non-installation area 105. The same applies to the heating resistance line 35e in the parallel circuit region A44. In this arrangement pattern, not only the average heat generation amount per unit area of the parallel circuit regions A41 to A44 is equal, but also the average heat generation amount per unit area of the regions a13 to a15 in the parallel circuit region A41, and the parallel circuit region A44. Among them, the average heat generation amount per unit area of the regions a41 to a43 is equal to that of the parallel circuit regions A42 and A43, and the heat generation of the planar heating element 30 can be further equalized. Further, since the heat quantity necessary for the non-installation area 105 can be supplied from the adjacent area a12, the temperature drop can be minimized.

  In the present embodiment, the heating resistance wire non-installation region 105 is provided along both peripheral portions 28 extending in the laying direction x. However, a configuration in which only one peripheral portion 28 is provided is also possible. In this case, in the area where the non-installation area is not provided, the heating resistance lines may be arranged at the same pitch as the central portion.

  Next, when the widths w41 to w44 of the parallel circuit regions are different, first, the electric resistances R41 to R44 are calculated by the equation (1). From the equation (1), the electrical resistances R41 to R44 are values proportional to the widths w41 to w44 of the corresponding parallel circuit regions A41 to A44, and thus the electrical resistances R41 to R44 are also different. There are two methods for making the electrical resistances R41 to R44 different from each other. One is a method in which the resistance value per unit length of each heating resistance line is made different for each of the parallel circuit regions A41 to A44. Specifically, the thickness of the heating resistance line in each parallel circuit is all or It is possible to change partly. For example, in an embodiment described later, the heating resistance wire of 3000 filaments may be changed to a heating resistance wire of 1000 filaments or 6000 filaments.

  Another method is a method in which the number of heating resistance lines is made different for each of the parallel circuit regions A41 to A44. FIG. 11 is a diagram for explaining the arrangement pattern of the heating resistance lines when the number of heating resistance lines is changed according to the width of the parallel circuit area when the widths of the parallel circuit areas are different. FIG. 3 is a partial detail view of a planar heating element corresponding to the vicinity of a portion. It is assumed that the ratio of the width w41 of the parallel circuit region A41 and the width w42 of the parallel circuit region A42 is 7: 4. Therefore, from the equation (1), the resistance ratio of the resistor R41 of the parallel circuit 41 and the resistor R42 of the parallel circuit 42 is 7: 4. In order to realize this resistance ratio, as shown in the figure, the parallel circuit region A41 has four heating resistor wires having the same diameter, and the parallel circuit region A42 has seven wires having the same diameter as the four heating resistor wires. The heating resistance wire is provided.

  The above can be paraphrased as follows. That is, when the number of heating resistance lines in the parallel circuit region is reduced, the electrical resistance increases in inverse proportion to the number, and as a result, the width of the parallel circuit region becomes larger from the equation (1). Since the number of heating resistance lines itself is also reduced, it is possible to secure a large area width of each heating resistance line by the synergistic effect of both. As a result, it is possible to dispose the heating resistance wire in the region including the non-installation region. In this arrangement pattern, the heating resistance lines can be arranged in all the areas a11 to a14, b11 to b17, c11 to c17, and d11 to d14 of the parallel circuit areas A41 to A44.

  As described above, it may be difficult to evenly arrange the heating resistance lines in the area adjacent to the non-installation area. However, in this embodiment, by reducing the number of heating resistance lines in the parallel circuit area including the non-installation area, it is possible to increase the sharing width of each heating resistance line, so it is possible to widen the interval between the heating resistance lines. It becomes. For this reason, in this arrangement pattern, not only the average heat generation amount per unit area of the parallel circuit regions A41 to A44 is equal, but also the average heat generation amount per unit area of each region obtained by equally dividing the parallel circuit region. Thus, the heat generated by the planar heating element 30 can be further equalized.

  If the width of the crosspiece 22 is reduced, the heating resistance wire 32a can be easily arranged in the region a11, which is more effective. However, even when the heat generation resistance wire 32a cannot be arranged in the region a11, the same effect can be obtained by installing two heat generation resistance wires in a region adjacent to the non-installation region as shown in FIG.

Example 1
First, a planar heating element including parallel circuits 41 and 44 in which four heating resistance wires are connected in parallel and parallel circuits 42 and 43 in which seven heating resistance wires are connected in parallel was created. The planar heating element created in this example is the same as that shown in FIG. 7A, but the number and arrangement of the heating resistance lines constituting the parallel circuits 41 to 44 are as shown in FIG.

  First, the width of each parallel circuit region was obtained as shown in Table 1 from Equation (1), and each heating resistance line was arranged so that the parallel circuits 41 to 44 were arranged in the corresponding parallel circuit regions A41 to A44. As the heating resistance wire, a carbon fiber (Toray T300 3000 filament) having a resistance value per meter of 153 Ω / m was used. Of the areas obtained by dividing the parallel circuit areas A41 and A44 into four equal parts, the areas a11 and d14 have nail areas with a width of 30 mm, and there was no room for arranging the heating resistance wires, so two heat generations were made in the areas a12 and d13. A resistance wire was placed. One heating resistance wire was arranged in each other region.

  Next, a heating resistance wire was sandwiched from above and below by a glass fiber braid having a mesh opening of 5 mm, and a mesh-like braid having an intersection point joined by a thermoplastic resin was produced. The assembled fabric was cut to a length of 1720 mm, and adjacent parallel circuits were sequentially electrically connected by a copper foil tape having a width of 15 mm to form a predetermined parallel circuit and a series circuit. Thereafter, the braid was sandwiched from above and below with a prepreg in which a glass fiber fabric was impregnated with an epoxy resin to form a laminate. On the upper side of the laminate, an Alpet in which an aluminum plate having a thickness of 100 μm and a PET film having a thickness of 100 μm were bonded together was placed so that the PET film was on the laminate side. Further, a PET film having a thickness of 50 μm was placed on the lower side of the laminate, and the epoxy resin was cured by heating while applying pressure. As described above, a planar heating element having a length of 1820 mm, a width of 455 mm, and a thickness of 0.5 mm, in which the heating resistance lines were linearly and parallelly arranged with a length of 1690 mm, was obtained.

  Next, a pedestal having a width of 30 mm and a thickness of 8.5 mm was attached to the outer periphery of the surface of the sheet heating element on which the aluminum plate was not attached. Furthermore, an insulating material made of foamed polypropylene having a thickness of 8.5 mm (foaming ratio 12 times) was attached to the portion surrounded by the pier. And the resin-made reinforcement member of FIG. 6 was attached to the connection part with the power supply of a planar heating element, and the power wire was attached to the electrode. After that, crepe paper was pasted on the pier and the heat insulating material, an aluminum plate having a thickness of 0.4 mm was pasted on the reinforcing member, and a lid was formed to form an electric heating board for floor heating. Two electric heating boards for floor heating are arranged and fixed on the floor base with the aluminum plate of the sheet heating element facing up, and a 12 mm thick plywood that simulates flooring is placed on the floor heating element. A voltage of 200 V was applied under the environment. At that time, the plywood surface temperature was controlled to be about 30 ° C., and the temperature distribution in the width direction (laying orthogonal direction y) of the plywood surface was measured.

  As a result, as shown in FIG. 13, the temperature drop at the joint between the two electric heating boards for floor heating was suppressed to about 1 ° C., and floor heating with few cold zones was realized.

(Example 2)
Similar to Example 1, a planar heating element including parallel circuits 41 and 44 in which four heating resistance wires are connected in parallel and parallel circuits 42 and 43 in which seven heating resistance wires are connected in parallel was created. In this embodiment, the width of the pier was set to a small value of 15 mm. For this reason, as shown in FIG. 11, one heating resistor line could be arranged in all of the parallel circuit regions A41 and A44 divided into four equal regions and the parallel circuit regions A42 and A43 divided into seven equal regions. . Other preparation methods and measurement methods are the same as those in the first embodiment.

  As a result, as shown in FIG. 14, the temperature drop at the joint between the two electric heating boards was further suppressed to about 0.5 ° C., and floor heating with almost no cold zone was realized.

Claims (7)

A planar heating element comprising a plurality of parallel circuits in which a plurality of heating resistance wires that generate heat when energized are connected in parallel,
Each parallel circuit extends in parallel while adjacent to each other, and the adjacent parallel circuits are sequentially electrically connected in series to constitute a heater circuit,
A non-installation area of the heating resistance wire is provided along at least one peripheral edge of the planar heating element extending in parallel with the parallel circuit,
Each of the parallel circuits has a width W of the planar heating element including the non-installation region in a direction orthogonal to a direction in which the parallel circuit extends, Ri, an electric resistance of each parallel circuit, and a total electric power of the heater circuit. A planar heating element disposed in a parallel circuit region having a width defined by (Ri / R) × W, where R is resistance.   Each heating resistance line constituting each parallel circuit is disposed in a heating resistance line area having a width obtained by dividing the width of the parallel circuit area of each parallel circuit by the number of the heating resistance lines of each parallel circuit. Item 2. The sheet heating element according to Item 1. A part of the heating resistance line constituting each parallel circuit is arranged in a heating resistance line area having a width obtained by dividing the width of the parallel circuit area of each parallel circuit by the number of the heating resistance lines of each parallel circuit,
The remaining heating resistance lines to be assigned to the heating line area at least partially overlapping the non-installation area are arranged in the heating line area in the vicinity of the non-installation area,
The planar heating element according to claim 1. Some of the parallel circuits have a larger width than the other parallel circuits;
2. The planar heating element according to claim 1, wherein the parallel circuit having the large width includes a smaller number of the heating resistance wires than the other parallel circuits. The even number of parallel circuits are provided,
A central electrical connection is provided at a central position where the number of the parallel circuits connected in series is equal,
The parallel circuits on both sides of the central electrical connection portion are configured such that the total electrical resistance between the central electrical connection portion and the corresponding end portion is equal to each other and can be energized as a series circuit independent of each other. Being
The planar heating element according to claim 1. An electric heating board for floor heating in which the planar heating element according to claim 1 is disposed on an upper surface,
A nailable pier fixed to the back surface of the planar heating element along at least the peripheral edge of the electric heating board;
A heat insulating material fixed to a portion surrounded by the pier on the back surface of the planar heating element;
A resin reinforcing member fixed to the back surface of the planar heating element and including an electrical connection between the power line and the planar heating element;
Have
The reinforcing member is an electric heating board for floor heating, which includes a gap portion for bending and storing the power line. A floor heating electric board assembly in which a plurality of floor heating electric boards according to claim 6 are connected,
The adjacent floor heating electric heating boards are electrically connected by the power line extending between the floor heating electric heating boards between the peripheral edges extending in parallel with the parallel circuit and facing each other, and It is connected by mechanical connecting means so that the electric heating boards are stacked and folded,
When opening the folded floor heating electric heating board and laying each floor heating electric heating board so that the opposing peripheral portions of each floor heating electric heating board are in contact with each other, the gap portion is a surplus of the power line. The long part can be stored,
Electric heating board assembly for floor heating.

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