JP4144157B2 - Sheet heater - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sheet heater including a mixed paper made of conductive fibers, non-conductive fibers, and a binder, and a plurality of electrodes attached to the mixed paper.
[0002]
[Prior art]
As shown in FIG. 1, a sheet heater 3 including a mixed paper 1 made of conductive fibers, non-conductive fibers, and a binder, and a pair of electrodes 2 attached to the mixed paper 1 is a heating element of a heating toilet seat. It is used as Since the heating toilet seat is horseshoe-shaped, the mixed paper 1 between the electrodes 2 is curved.
[0003]
[Problems to be solved by the invention]
Since the length of the outer edge 1a of the curved mixed paper 1 is larger than the length of the inner edge 1b, the resistance value between the electrodes 2 at the outer edge portion of the mixed paper 1 is larger than the resistance value between the electrodes 2 at the inner edge portion. is there. As a result, when a voltage is applied between the electrodes 2, the current density at the outer edge of the mixed paper 1 becomes smaller than the current density at the inner edge, and the amount of heat generated per unit area of the outer edge of the mixed paper 1 is reduced to the inner edge. The amount of heat generated per unit area becomes small, resulting in uneven temperature in the planar heater 3, and the comfort of the heated toilet seat is impaired.
The present invention has been made in view of the above problems, and includes a mixed paper composed of conductive fibers, non-conductive fibers, and a binder, and a plurality of electrodes attached to the mixed paper, and extends between the electrodes. An object of the present invention is to provide a planar heater in which the mixed paper to be curved is curved, and the occurrence of temperature unevenness is suppressed.
[0004]
[Means for Solving the Problems]
In the present invention, in order to solve the above-mentioned problem, a mixed paper made of conductive fibers, non-conductive fibers, and a binder, and a plurality of electrodes attached to the mixed paper are provided and extend between the electrodes. The mixed paper is curved and the curve is formed by a plurality of arcs, and the conductive fibers are oriented in a direction that bisects the central angle of the arc having the smallest radius of curvature in the plurality of arcs. A planar heater is provided.
When the curve of the mixed paper is formed by a plurality of arcs, a portion where a plurality of arcs having the smallest curvature radius in the arc exists is the most tightly bent portion. Therefore, in this part, the difference in length between the inner edge and the outer edge of the mixed paper is maximized, the difference in current density between the inner edge and the outer edge is maximized, and the difference in heat generation per unit area between the inner edge and the outer edge is obtained. The temperature unevenness of the planar heater is maximized. If the conductive fibers are oriented in the direction that bisects the central angle of the arc with the smallest radius of curvature, the inner edge will be mixed paper at the point where the temperature difference between the inner edge and the outer edge becomes the maximum. The current flowing in the extending direction is induced in the direction of the outer edge, and the current density of the outer edge is increased. As a result, the current density difference between the inner edge portion and the outer edge portion decreases, the difference in heat generation per unit area between the inner edge portion and the outer edge portion decreases, and the occurrence of temperature unevenness in the planar heater is suppressed.
[0005]
The present invention comprises a mixed paper composed of conductive fibers, non-conductive fibers and a binder, and a plurality of electrodes attached to the mixed paper, and the mixed paper extending between the electrodes is curved as a whole. A planar heater, wherein the curved line is formed by a plurality of straight lines, and conductive fibers are oriented in a direction that bisects the smallest inner angle among the inner angles of the intersections of the plurality of straight lines. provide.
When the mixed paper extending between the electrodes is curved as a whole and the curve is formed by a plurality of straight lines, the portion where the smallest inner angle exists among the inner angles of the intersections of the plurality of straight lines is the most bent. It is a hard part. Therefore, in this part, the difference in length between the inner edge and the outer edge of the mixed paper is maximized, the difference in current density between the inner edge and the outer edge is maximized, and the difference in heat generation per unit area between the inner edge and the outer edge is obtained. The temperature unevenness of the planar heater is maximized. If the conductive fibers are oriented in the direction that bisects the smallest inner angle, the inner edge is made to extend in the direction in which the mixed paper extends in the region where the temperature difference between the inner edge and the outer edge where the bending is most severe is greatest. The flowing current is induced in the direction of the outer edge, and the current density at the outer edge increases. As a result, the current density difference between the inner edge portion and the outer edge portion decreases, the difference in heat generation per unit area between the inner edge portion and the outer edge portion decreases, and the occurrence of temperature unevenness in the planar heater is suppressed.
[0006]
In the present invention, there is provided a heating toilet seat comprising the planar heater.
A heated toilet seat including a planar heater in which occurrence of temperature unevenness is suppressed has high comfort.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
A planar heater according to an embodiment of the present invention will be described.
As shown in FIG. 2, the planar heater 13 includes a mixed paper 11 made of conductive fibers, nonconductive fibers, and a binder, and a pair of electrodes 12 attached to the mixed paper 11. The mixed paper 11 between the electrodes 12 is curved. The curve is formed by a plurality of arcs. The conductive fibers are oriented in a direction that bisects the central angle θ of the arc R having the smallest radius of curvature in the arcs, that is, in the direction indicated by the arrow α in FIG.
[0008]
As shown in FIG. 3, the mixed paper 11 has a roll shape in which conductive fibers such as carbon fibers and non-conductive fibers such as pulp are dispersed in water stored in the paper tank 14, and is disposed in advance in the paper tank 14. The mixed conductive and non-conductive fibers are wound on the mesh 15 while the mesh 15 is wound up, dehydrated, and a binder solution in which the binder is dissolved in a solvent is dropped and dried. Since the mixed conductive fibers and non-conductive fibers are wound up by the mesh 15 wound at a predetermined speed, the conductive fibers are oriented in the winding direction of the mesh 15 indicated by arrows in FIG. Therefore, if the mixed paper 11 is cut by making the direction of the arrow α in FIG. 2 coincide with the winding direction at the time of manufacture, the conductive fibers can be oriented in the direction of the arrow α in FIG.
[0009]
The portion where the arc R is present is the portion where the curve is most severe. Therefore, at this part, the difference between the lengths of the outer edge and the inner edge of the mixed paper 11 is maximized, the current density difference between the outer edge portion 11a and the inner edge portion 11b is maximized, and the unit area of the outer edge portion 11a and the inner edge portion 11b per unit area. The difference in calorific value is maximized, and the temperature unevenness of the planar heater 13 is maximized. However, since the conductive fibers are oriented in a direction that bisects the central angle θ of the arc R, a broken line in FIG. 2 shows a portion where the temperature difference between the outer edge portion 11a and the inner edge portion 11b is the largest. The current flowing in the extending direction of the mixed paper 11 through the inner edge portion 11b as shown by the arrow is bent in the direction of orientation of the conductive fibers, and is guided in the direction of the outer edge portion 11a as shown by the solid line arrow in FIG. The current density of the outer edge part 11a increases. As a result, the difference in current density between the outer edge portion 11a and the inner edge portion 11b is reduced, the difference in heat generation per unit area between the outer edge portion 11a and the inner edge portion 11b is reduced, and the occurrence of temperature unevenness in the planar heater 13 is suppressed. .
[0010]
As shown in FIG. 4, when the mixed paper 11 is curved as a whole and the curve is formed by a plurality of straight lines, the smallest inner angle Θ among the inner angles of the intersections of the plurality of straight lines is divided into two equal parts. The conductive fibers may be oriented in the direction, that is, the direction indicated by the arrow β in FIG. The portion where the inner angle Θ is present is the portion with the most bending. Accordingly, in this portion, the difference in heat generation per unit area between the outer edge portion 11a and the inner edge portion 11b of the mixed paper 11 is maximized, and the temperature unevenness of the planar heater 13 is maximized. However, if the conductive fibers are oriented in a direction that bisects the circular angle Θ, the portion where the temperature difference between the outer edge portion 11a and the inner edge portion 11b is the most bent is shown by a broken line arrow in FIG. Thus, the current flowing in the extending direction of the mixed paper 11 through the inner edge portion 11b is bent in the orientation direction of the conductive fiber and is guided in the direction of the outer edge portion 11a as shown by the solid line arrow in FIG. Current density increases. As a result, the difference in current density between the outer edge portion 11a and the inner edge portion 11b is reduced, the difference in heat generation per unit area between the outer edge portion 11a and the inner edge portion 11b is reduced, and the occurrence of temperature unevenness in the planar heater 13 is suppressed. .
[0011]
If the said planar heater is used as a heat generating body of a heating toilet seat, high comfort will be provided to a heating toilet seat.
[0012]
In the above embodiment, the number of electrodes is two, but three or more electrodes may be provided. When the mixed paper between the electrodes facing each other is curved as a whole, the occurrence of temperature unevenness can be suppressed in the same manner as in the above embodiment.
The application symmetry of the planar heater is not limited to the heating toilet seat. You may use for the heating of the seat part of a chair, a rug, etc.
[0013]
【The invention's effect】
As can be seen from the above description, when the mixed paper is curved with a plurality of arcs, the conductive fiber is oriented in the direction that bisects the central angle of the arc with the smallest radius of curvature, so that the most bending is achieved. In the region where the temperature difference between the tight inner edge portion and the outer edge portion becomes maximum, the temperature difference can be reduced, and the occurrence of temperature unevenness in the planar heater can be suppressed.
[Brief description of the drawings]
FIG. 1 is a plan view of a planar heater having a conventional structure.
FIG. 2 is a plan view of a planar heater according to an embodiment of the present invention.
FIG. 3 is a diagram showing a process for producing a carbon fiber mixed paper.
FIG. 4 is a partial plan view of a planar heater according to an embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1,11 Mixed paper 2,12 Electrode 3,13 Planar heater 14 Paper basket 15 Net

Claims (3)

A mixed paper composed of conductive fibers, non-conductive fibers, and a binder, and a plurality of electrodes attached to the mixed paper, the mixed paper extending between the electrodes is curved, and the curvature is a plurality of A planar heater formed of an arc, wherein conductive fibers are oriented in a direction that bisects a central angle of the arc having the smallest radius of curvature in the plurality of arcs. A mixed paper composed of conductive fibers, non-conductive fibers, and a binder, and a plurality of electrodes attached to the mixed paper, the mixed paper extending between the electrodes is curved as a whole, and the curved A planar heater which is formed by a plurality of straight lines, and in which conductive fibers are oriented in a direction which bisects the smallest inner angle among the inner angles of the intersections of the plurality of straight lines. A heating toilet seat comprising the planar heater according to claim 1.

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