JP2001284028A - Thin and flexible heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thin and flexible heater which is equipped with a pair of electrodes and a thin exothermic body whose one end is connected to an electrode of one side and the other end is connected to an electrode of the other side and which exists extendedly between electrodes, and in which a thin exothermic body is formed by mixed paper composed of electro-conductive fiber, non-conducting fiber and binder, and in which a curving part and bending part are formed in the extending direction of the exothermic body, and in which a temperature unevenness in the orthogonal direction in the extending direction of the heater is alleviated. SOLUTION: This is a thin and flexible heater which is equipped with a pair of electrodes, and a thin exothermic body whose one end is connected to an electrode of one side and the other end is connected to an electrode of the other side and which exists extendedly between electrodes, and the exothermic body is mixed paper composed of electro-conductive fiber, non-conducting fiber and binder, and the exothermic body has a curving part in the way of extension, and the correlation coefficient of the ratio of curvature radius of outer periphery of the exothermic body at the curving part to that of inner periphery against the angle formed between the orientation of conductive fiber and extending direction of surface exothermic body is set at a positive value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a conductive fiber comprising a pair of electrodes, a planar heating element having one end connected to one electrode and the other end connected to the other electrode and extending between the electrodes. The present invention relates to a sheet heater in which a sheet heating element is formed by a mixed paper comprising non-conductive fibers and a binder.

[0002]

2. Description of the Related Art A pair of electrodes and a planar heating element having one end connected to one electrode and the other end connected to the other electrode and extending between the electrodes are provided. 2. Description of the Related Art A planar heater in which a planar heating element is formed by a mixed paper made of a binder is used for various heating devices. Depending on the heating device, a curved portion or a bent portion may be formed during the extension of the planar heating element.

[0003]

In a curved portion or a bent portion, the resistance at the outer edge is smaller than the resistance at the inner edge due to the difference between the outer edge length and the inner edge length of the sheet heating element. The current density at the inner edge is higher than the current density at the outer edge, the calorific value per unit area at the inner edge is larger than the calorific value per unit area at the outer edge, and the inner edge is It is hotter than the outer edge. As a result, in the curved portion or the bent portion, temperature unevenness occurs in a direction orthogonal to the extending direction of the planar heating element, and the comfort of the heating device is reduced. The present invention has been made in view of the above problems, and includes a pair of electrodes, and a planar heating element having one end connected to one electrode and the other end connected to the other electrode and extending between the electrodes, A planar heater in which a planar heating element is formed by a mixed paper made of conductive fibers, non-conductive fibers, and a binder, and a curved portion or a bent portion is formed on the way of extension of the planar heating element, An object of the present invention is to provide a planar heater in which temperature unevenness in a direction perpendicular to an extending direction of a planar heating element at a curved portion or a bent portion is reduced.

[0004]

According to the present invention, in order to solve the above-mentioned problems, a pair of electrodes, one end of which is connected to one electrode and the other end of which is connected to the other electrode, extend between the electrodes. A sheet heating element, wherein the sheet heating element is a mixed paper made of a conductive fiber, a non-conductive fiber, and a binder, and the sheet heating element has a curved portion in the course of extension; The ratio of the radius of curvature of the outer edge to the radius of curvature of the inner edge of the planar heating element at the portion,
Provided is a planar heater, wherein a correlation coefficient between the orientation of the conductive fiber in the curved portion and the angle formed by the extending direction of the planar heating element is set to a positive value. In a curved portion having a large ratio of the radius of curvature of the outer edge to the radius of curvature of the inner edge of the planar heating element, the ratio of the length of the outer edge to the length of the inner edge is large, and the ratio of the resistance value at the outer edge to the resistance value at the inner edge. The ratio of the current density at the inner edge to the current density at the outer edge is large, and the ratio of the calorific value per unit area at the inner edge to the calorific value per unit area at the outer edge is large. The ratio between the temperature and the temperature at the outer edge is large. If the orientation of the conductive fibers, that is, the angle between the extending direction of the conductive fibers and the extending direction of the sheet heating element, is increased in a curved portion having a large ratio of the temperature of the inner edge portion to the temperature of the outer edge portion, the current is increased. Since the conductive fibers tend to flow in the direction of orientation, the current flowing in the inner edge portion in the direction in which the planar heating element extends is bent in the direction of the outer edge portion, the current density at the outer edge increases, and the unit at the outer edge portion is increased. The calorific value per area increases, and the temperature of the outer edge increases. As a result, the temperature ratio between the inner edge portion and the outer edge portion decreases, and the temperature unevenness in the direction orthogonal to the extending direction of the planar heating element is reduced.

[0005] In the present invention, there is provided a pair of electrodes, and a sheet heating element having one end connected to one electrode and the other end connected to the other electrode and extending between the electrodes, wherein the sheet heating element is conductive. Paper comprising a conductive fiber, a non-conductive fiber, and a binder, wherein the sheet heating element has a bent portion in the course of extension, an inner angle at the bent portion, and a conductive fiber at the bent portion. Provided is a planar heater, wherein a correlation coefficient between the orientation and an angle between the extending direction of the planar heating element is set to a negative value. The bent portion having a small inner angle has a large ratio of the outer edge length to the inner edge length, a large ratio of the resistance value at the outer edge portion to the resistance value at the inner edge portion, and a current density at the inner edge portion and a current at the outer edge portion. The ratio of the density is large, the ratio of the calorific value per unit area at the inner edge to the calorific value per unit area at the outer edge is large, and the ratio of the temperature of the inner edge to the temperature of the outer edge is large. In the bent portion where the ratio of the temperature of the inner edge to the temperature of the outer edge is large, the orientation of the conductive fibers,
That is, if the angle between the extending direction of the conductive fiber and the extending direction of the sheet heating element is increased, the current tends to flow in the orientation direction of the conductive fiber. The current flowing in the direction is bent toward the outer edge, the current density at the outer edge increases, the amount of heat generated per unit area at the outer edge increases, and the temperature at the outer edge increases. As a result, the temperature ratio between the inner edge portion and the outer edge portion decreases, and the temperature unevenness in the direction orthogonal to the extending direction of the planar heating element is reduced.

According to the present invention, there is provided a heating toilet seat provided with the planar heater according to the first or second aspect. The heating toilet seat provided with the planar heater has a reduced temperature unevenness in a direction orthogonal to the extending direction, so that a comfortable feeling of use can be given to the user.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A planar heater according to an embodiment of the present invention will be described. As shown in FIG. 1, the planar heater 1 includes a pair of electrodes 2a and 2b, a planar heating element having one end connected to the electrode 2a and the other end connected to the electrode 2b, and extending between the electrodes 2a and 2b. 3 is provided. The planar heating element 3 has three curved portions 3a, 3b, 3c in the middle of extension. Curved part 3
a, 3b, 3c has a plurality of inner arc R _1i, R _2i, R _3i, which are sequentially disposed toward the electrode 2a to 2b, outer arc R _1o, R _2o, are formed by the R _3o. The relationship between the radii of curvature of the respective arcs is R _2o / R _2i > R _1o / R _1i > R
_3o / R _3i is set. The sheet heating element 3 is formed of a mixed paper made of conductive fibers, non-conductive fibers, and a binder. The orientation of the conductive fiber, that is, the extending direction of the conductive fiber is in the direction indicated by an arrow α in FIG. 1, that is, in the direction orthogonal to the extending direction at the center of the extending direction of the curved portion 3 b of the planar heating element 3. Is set.

As shown in FIG. 2, the mixed paper is prepared by dispersing conductive fibers such as carbon fibers and non-conductive fibers such as pulp in water stored in a paper making tank 4 and previously disposing the mixed fibers in the paper making tank 4. While winding the roll-shaped net 5, the mixed conductive fiber and non-conductive fiber are scraped on the net 5, dehydrated, and a binder solution in which a binder is dissolved in a solvent is dropped and dried to manufacture. . The conductive fibers and the non-conductive fibers mixed by the mesh 5 wound at a predetermined speed are scraped off, so that the conductive fibers are oriented in the winding direction of the mesh 5 indicated by an arrow in FIG. In mixed paper, the resistance value per unit area has anisotropy, becomes minimum in the orientation direction of the conductive fiber, becomes maximum in the direction orthogonal to the orientation direction, and is continuous between the orientation direction and the orthogonal direction. Changes to By cutting out the sheet heating element 3 of FIG. 1 from the mixed paper whose winding direction is directed in the direction of the arrow α of FIG. 1, the plane in which the orientation of the conductive fibers is set in the direction of the arrow α of FIG. The heating element 3 can be obtained.

As can be understood from FIG. 1, the orientation of the conductive fibers at the center of the extending direction of the curved portion 3a and the extending direction of the sheet heating element 3, that is, the sheet heating element 3 shown by a dashed line in FIG. The angle θ ₁ between the central point of the width of the curved line 3 and the direction along the envelope line formed by the smooth curve, the orientation of the conductive fiber at the center of the extending direction of the curved portion 3 b, and the extending direction of the sheet heating element 3. Angle θ ₂ ,
The angle θ ₃ between the orientation of the conductive fiber at the center of the bending portion 3 c in the extending direction and the extending direction of the planar heating element ₃ is θ ₂ > θ ₁ >.
It meets the θ ₃ the relationship. As can be seen from the above description, in the planar heater 1, R _2o / R _2i > R _1o / R _1i
> R _3o / R _3i and θ ₂ > θ ₁ > θ ₃ . That is, in the planar heater 1, the ratio between the radius of curvature of the outer edge and the radius of curvature of the inner edge of the planar heating element in the curved portion, the orientation of the conductive fibers in the curved portion, and the extending direction of the planar heating element are described. The correlation coefficient with the angle made is set to a positive value. The ratio between the radius of curvature of the outer edge and the radius of curvature of the inner edge of the planar heating element in the curved portion, and the angle between the orientation of the conductive fiber in the curved portion and the extending direction of the planar heating element. The relationship need not necessarily be straight.

When a voltage is applied between the electrodes 2a and 2b, a current flows in the direction in which the sheet heating element 3 extends. R _2o / R _2i > R
_{Since 1o} / _R1i > _R3o / _R3i , the ratio of the length of the outer edge to the inner edge is curved portion 3b> curved portion 3a> curved portion 3c, and the ratio of the resistance value at the outer edge portion to the resistance value at the inner edge portion is Curved portion 3b> curved portion 3a> curved portion 3c, and the ratio of the current density at the inner edge to the current density at the outer edge is curved portion 3b> curved portion 3a> curved portion 3.
c, and the ratio of the calorific value per unit area at the inner edge to the calorific value per unit area at the outer edge is curved portion 3b> curved portion 3a> curved portion 3c, where the temperature of the inner edge portion and the temperature of the outer edge portion are The ratio is as follows: curved portion 3b> curved portion 3a> curved portion 3c. Therefore, the temperature unevenness in the direction orthogonal to the extending direction of the planar heating element 3 is as follows: the curved portion 3b> the curved portion 3a> the curved portion 3c. However, in the planar heating element 3, θ ₂ > θ ₁ > θ ₃ and the current tends to flow in the extending direction of the conductive fiber. The degree to which the flowing current is bent in the direction of the outer edge is as follows: curved portion 3b> curved portion 3a> curved portion 3c. As a result, the amount of increase in the current density at the outer edge caused by the current flowing through the inner edge in the direction in which the planar heating element 3 extends is bent toward the outer edge is such that the curved portion 3b> the curved portion 3a> the curved portion 3c, the amount of increase in the amount of heat generated per unit area at the outer edge caused by the current flowing through the inner edge in the direction in which the planar heating element 3 extends is bent toward the outer edge. Part 3a> curved part 3c, and the amount of temperature rise of the outer edge caused by the current flowing through the inner edge in the direction in which the planar heating element 3 extends is bent toward the outer edge is curved part 3b> curved part 3a >
It becomes the curved portion 3c. As a result, the temperature unevenness caused by the curvature of the planar heating element 3 in the direction orthogonal to the extending direction of the planar heating element 3 depends on the angle between the orientation of the conductive fibers and the extending direction of the planar heating element. It is alleviated by the redistribution of the temperature distribution in the direction perpendicular to the direction in which the planar heating element 3 extends.

As shown in FIG. 3, when the sheet heating element 3 has bent portions 3a ', 3b', and 3c 'in the middle of extension, the inner angle で at the bent portion and the bent portion The orientation of the conductive fibers in the portion and the extending direction of the sheet heating element, that is, the direction along the envelope connecting the center points of the width of the sheet heating element 3 indicated by dashed lines in FIG. 3 with a smooth curve. What is necessary is just to set the correlation coefficient between the direction along and the angle formed with the direction to a negative value. The smaller the inner angle の of the bent portion, the greater the ratio of the outer edge to the inner edge length, the greater the ratio of the resistance value at the outer edge to the resistance value at the inner edge, the current density at the inner edge and the current at the outer edge The ratio of the density is large, the ratio of the calorific value per unit area at the inner edge to the calorific value per unit area at the outer edge is large, and the ratio of the temperature of the inner edge to the temperature of the outer edge is large. The temperature unevenness in the direction orthogonal to the extending direction of the third member 3 increases. However, since the correlation coefficient between the inner angle Θ at the bent portion and the angle between the orientation of the conductive fiber at the bent portion and the extending direction of the planar heating element is negative, the inner angle で at the bent portion is The smaller the angle, the larger the angle between the orientation of the conductive fiber at the bent portion and the extending direction of the planar heating element, and the current flowing in the inner edge portion in the extending direction of the planar heating element 3 is bent toward the outer edge portion. The degree of increase in the current density at the outer edge caused by the current flowing through the inner edge portion in the direction in which the sheet heating element 3 extends is bent toward the outer edge portion is large. The amount of heat generated per unit area at the outer edge caused by the current flowing in the extending direction of the body 3 being bent toward the outer edge is large, and the inner edge is extended in the direction in which the planar heating element 3 extends. Temperature caused by the current flowing to the outer edge being bent in the direction of the outer edge The amount of rise is large. As a result, the temperature unevenness in the direction perpendicular to the extending direction of the planar heating element 3 caused by the bending of the planar heating element 3 is as follows:
It is alleviated by the redistribution of the temperature distribution in the direction orthogonal to the extending direction of the sheet heating element 3 caused by the angle between the orientation of the conductive fibers and the extending direction of the sheet heating element. The relationship between the inner angle で at the bent portion and the angle between the orientation of the conductive fiber at the bent portion and the extending direction of the planar heating element does not necessarily have to be a straight line.

Although the planar heater according to the present invention can be used for various heating devices, in particular, when used for a heating toilet seat, it suppresses the occurrence of temperature unevenness in a direction perpendicular to the extending direction of the toilet seat. Therefore, the comfort of the toilet seat can be greatly improved.

[0013]

As can be seen from the above description, a curved portion having a large ratio of the radius of curvature of the outer edge to the radius of curvature of the inner edge of the planar heating element has a large ratio of the length of the outer edge to the length of the inner edge. The ratio of the resistance value at the inner edge to the resistance value at the inner edge is large, the ratio of the current density at the inner edge to the current density at the outer edge is large, and the heat generation per unit area at the inner edge and the unit area at the outer edge The ratio of the calorific value per hit is large, and the ratio of the temperature of the inner edge to the temperature of the outer edge is large. If the orientation of the conductive fibers, that is, the angle between the extending direction of the conductive fibers and the extending direction of the sheet heating element, is increased in a curved portion having a large ratio of the temperature of the inner edge portion to the temperature of the outer edge portion, the current is increased. Since the conductive fibers tend to flow in the direction of orientation, the current flowing in the inner edge portion in the direction in which the planar heating element extends is bent in the direction of the outer edge portion, the current density at the outer edge increases, and the unit at the outer edge portion is increased. The calorific value per area increases, and the temperature of the outer edge increases. As a result, the temperature ratio between the inner edge portion and the outer edge portion decreases, and the temperature unevenness in the direction orthogonal to the extending direction of the planar heating element is reduced.

[Brief description of the drawings]

FIG. 1 is a plan view of a planar heater according to an embodiment of the present invention.

FIG. 2 is a view showing a manufacturing process of a mixed paper.

FIG. 3 is a plan view showing a modification of the planar heater of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sheet heater 2a, 2b Electrode 3 Sheet heating element 4 Paper tank 5 Net

Continued on the front page (72) Inventor Yumiko Kataoka 2-1-1, Nakajima, Kokurakita-ku, Kitakyushu-shi, Fukuoka F-term (reference) in Tohoku Kiki Co., Ltd. 3K034 AA05 AA09 AA20 AA34 BC29 CA26 CA32 HA04 HA10 3K092 PP20 QA06 QB16 QB17 QB33 QC25 RF02 RF13 RF17 RF22 VV22

Claims (3)

[Claims] An electronic device comprising: a pair of electrodes; and a planar heating element having one end connected to one electrode and the other end connected to the other electrode and extending between the electrodes, wherein the planar heating element includes conductive fibers and A mixed paper made of a non-conductive fiber and a binder, wherein the sheet heating element has a curved portion in the course of extension, and a radius of curvature of an outer edge and an inner edge of the sheet heating element at the curved portion. Wherein the correlation coefficient between the ratio of the conductive fiber and the angle between the orientation of the conductive fiber in the curved portion and the extending direction of the planar heating element is set to a positive value. . 2. A semiconductor device comprising: a pair of electrodes; and a sheet heating element having one end connected to one electrode and the other end connected to the other electrode and extending between the electrodes. It is a mixed paper made of a non-conductive fiber and a binder, and the sheet heating element has a bent portion in the course of extension, and an inner angle at the bent portion,
A planar heater, wherein a correlation coefficient between the orientation of the conductive fiber at the bent portion and the angle between the extending direction of the planar heating element is set to a negative value. 3. A heating toilet seat comprising the planar heater according to claim 1.