JPH10106725A - Sheet-like heater element and electric carpet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To change the temperature when used in a multistage condition by simple operation by arranging self-temperature control heater elements different in a Curie point of a PTC characteristic on both surfaces of an insulation sheet, and switching its current-carrying condition. SOLUTION: Self-temperature control heater elements 2A and 2B different in a Curie point of a PTC characteristic are arranged on both surfaces of a resin or ceramic insulation sheet 1, and the thickness of the sheet 1 is formed in a degree that insulation is held and heat conduction is not hindered. For example, the heater elements 2A and 2B are composed of carbon black or the like of polyethylene, polypropylene and a conductive particle, and are printed and formed by screen printing or the like, and electrodes are arranged in both end parts of a coating film. At least one of the heater elements 2A and 2B may be composed of plural divided surfaces having different Curie points according to its necessity. These sheet-like heating elements may be laminated in plural layers through the insulating sheet. Therefore, a quick temperature rise and an unpleasant feeling of a projecting-recessed shape can also be eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a planar heating element which can be suitably used as a heating element for home or business use.

[0002]

2. Description of the Related Art Conventionally, nichrome wire heaters and sheathed heaters have been mainly used as heaters for home electric heating equipment, and copper wires of about 0.14 mmφ have been used for electric carpets and heating panels. Used. When such a heating wire is used, for example, as a heater for an electric carpet, it is necessary to uniformly heat a relatively large area, and thus, as shown in FIG. After arranging the wire 11, a separate soaking plate 12 such as an aluminum plate having good heat conductivity is used. The use of the heat equalizing plate 12 can increase the heating area, but this method has disadvantages such as low energy efficiency, slow rising speed of rising temperature, and insufficient heat uniformity. In addition, for example, in the case of an electric carpet for heating, since heating is performed by arranging heating wires in a carpet fiber at regular intervals, inconvenience due to unevenness of the heating wires and insufficient heat uniformity are disadvantageous. There is.

Further, as a conventional method of heating an electric heater such as an electric blanket, a panel (desk) heater, or an electric carpet, a plastic thermistor is used as disclosed in Japanese Utility Model Publication No. 1-17161, for example. In the control temperature range, a temperature control switch is turned on and off by a signal current corresponding to the impedance of the temperature-sensitive layer, using a heating-temperature detection line in which a heating resistance wire and a temperature detection line are arranged via the temperature-sensitive layer. Those that control the heater temperature are known. In addition, using a temperature detection line dedicated to temperature control, in which a power supply line and a temperature detection line are arranged via the temperature sensitive layer, and separating the temperature detection used for temperature control from the heater wire, the DC voltage is applied to the temperature sensitive layer. There is also known a temperature control device which prevents the application of water and prevents the use of polyvinyl chloride, and is not affected by a change in humidity.

[0004] In the case of an electric carpet or electric blanket for heating as described above, a heat-temperature detection line in which a heating resistance line and a temperature detection line are arranged via a temperature-sensitive layer using a plastic thermistor is placed in a fiber. The method of arranging and heating at regular intervals improves the temperature control characteristics, but does not completely prevent the discomfort due to the uniformity of heat and unevenness due to the linear body. Further, the temperature control requires a temperature control circuit that turns on and off a switch function of the temperature control circuit by a signal current corresponding to the impedance of the temperature-sensitive layer thermistor.

In recent years, self-temperature control having so-called PTC characteristics has been achieved as a planar heating element which has improved heat uniformity, ensured uniformity of a heating surface in a heating device, and improved ease of temperature control at one time. Heating appliances using a mold heating element have been developed (see, for example, Japanese Patent Application Laid-Open No. 1-213978). That is, a heating layer (PTC heating layer) formed by dispersing conductive particles (for example, carbon black or metal particles) in a crystalline polymer compound having a positive temperature coefficient of electric resistance is widely spread on an insulating sheet. Since the PTC heat generating layer itself is a surface, it has high uniformity, a flat surface, and easy self-temperature control depending on the Curie point without using a special temperature control circuit. Is achieved.

On the other hand, in electric equipment such as a steam generator and a hair dryer, in which the fluid load (water, wind, etc.) fluctuates, when the fluid load is reduced, the heating value of the heater is automatically reduced to save energy and save casing. For the purpose of preventing excessive temperature rise, for example, a heater using a heater in which two PTC elements having different Curie points are adhered to both sides of a heating plate through which a fluid comes into contact via an insulating plate is known. JP-A-61-151987).

[0007]

The self-temperature control type heating element having the above-mentioned PTC characteristics, when it is used as a planar heating element for a heating device or the like, is easy to control the uniformity, uniformity and temperature. Although many advantages are provided in terms of performance, the control temperature depends on the Curie point and does not directly depend on the voltage fluctuation, so that it is not always easy to change the use temperature according to the environment.

An object of the present invention is to provide a planar heating element using a self-temperature control type heating element having PTC characteristics as a heat source, wherein the temperature during use can be changed in multiple steps by a simple operation. Obtaining a heating element. Another object of the present invention is to obtain an electric carpet having such a planar heating element as a heat source.

[0009]

A planar heating element according to the present invention for solving the above-mentioned problems is basically composed of an insulating sheet and self-temperature-controlled heating elements having different Curie points of PTC characteristics arranged on both surfaces thereof. And a means for switching the state of energization to the self-temperature control heating element, whereby two or more stages of temperature control can be performed.

That is, as described above, according to the present invention, in an electric device such as a steam generator or a hair dryer in which a fluid load (water, wind, etc.) fluctuates, a Curie point is provided on both sides of a hot plate through which fluid contacts and passes. Two different PTC elements are attached to each other, thereby automatically reducing the amount of heat generated by the heater to save energy and prevent overheating of the casing. It is intended to be applied to temperature control of electric equipment having a self-temperature control heating element having a heat source as a heat source. With a simple main operation of switching the energized state, such as switching of switches, it is possible to easily obtain two-stage temperature with one sheet heating element. Is enabled (planar heating element according to claim 1).

Further, the use of the self-temperature control type heating element having the PTC characteristic makes it possible to quickly raise the temperature of the sheet heating element by a large inrush current, and to form a thin sheet or pattern by printing or the like. Since it can be arranged on the insulating sheet surface, there is no discomfort due to unevenness as in the case of the wire heater, and it is possible to easily increase the heat generation area. Furthermore, since the heating element in the form of a film is a self-heating type heating element, it can be maintained at a constant temperature, so that there is an advantage that temperature uniformity can be achieved.

[0012] In a preferred aspect of the present invention, in the planar heating element, at least one of the self-temperature control heating elements disposed on both surfaces is divided into two or more, and each of the divided self-temperature control heating elements is divided into two or more. There is further provided a means for switching a state of energization to the heating element. Each of the divided self-temperature control heating elements may be the same self-temperature control heating element having the same Curie point, or may include a self-temperature control heating element having a different Curie point. 2-4
Surface heating element).

[0013] One side and / or both sides of the insulating sheet
By arranging a self-temperature control heating element composed of independent divisions each of which is divided or more, it is possible to easily obtain a required area and two or more kinds of temperatures by switching the front and back of the planar heating element and individual surfaces. Therefore, temperature control adapted to the use environment can be easily achieved. Still another aspect of the sheet heating element of the present invention is characterized in that the above-described sheet heating element is laminated in a plurality of layers via an insulating sheet, and an insulating sheet is further disposed on the uppermost surface and the lowermost surface. (A planar heating element according to claims 5 and 6). In this case,
Finer temperature control becomes possible.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a sheet heating element according to the present invention will be described below in detail with reference to the drawings and tables. 1 and 2 show a basic embodiment of a planar heating element according to the present invention. A self-temperature controlled heating element 2 having different PTC characteristic Curie points on both surfaces of an insulating sheet 1 as a base material. , 2 are arranged. Insulation sheet 1
The material may be, for example, an insulating resin sheet material such as polyester or polyimide, or a ceramic sheet material such as alumina, cordierite, or mullite.The thickness needs to maintain insulation and not hinder heat conduction. For example, when used as a heat source for an electric carpet product, the thinnest sheet satisfying the above conditions and having a thickness of 34 μm is used.

The self-temperature controlled heating elements 2 and 2 having PTC characteristics disposed on both sides of the insulating sheet 1 may be manufactured by a conventionally known method, and have a thickness of, for example, about 10 μm. It is baked and formed on both surfaces of the insulating sheet 1 as a film by a technique such as screen printing, transfer printing, or ink jet printing. Further, electrodes 3 made of Ag, Cu, Ni or the like are provided at both ends of the film. As an example, the self-temperature control type heating elements 2 and 2 may be made of, for example, polyethylene, which is a first polymer, and a first polymer having a melting point or heat distortion temperature incompatible with the first polymer that is not completely compatible with the first polymer. Can be obtained by using a molding material obtained by kneading polypropylene as the second polymer having a melting point higher than the above and carbon black as the conductive particles. By mainly adjusting the amount of conductive particles to be added, for example, self-heating elements A to D having different Curie points (temperatures) T (T _{1 to} T ₄ ) as shown in FIG. 14 can be obtained.

FIG. 3 shows the sheet heating elements 2 and 2 shown in FIGS.
The power supply to the sheet heating elements 2 and 2 is selectively switched by turning on and off the switches S and S. The Curie temperatures T of the sheet heating elements 2 and 2 are different, and the temperature of the sheet heating elements can be easily switched only by switching the switches S and S. That is,
When the Curie point T ₁ of the self-temperature control type heating element 2 (A) on the front side and the Curie point T ₂ of the self-temperature control type heating element 2 (B) on the rear side, the self-temperature control type heat generation on the front side is obtained. rapidly resistor body a is can be kept from rapidly resistance increases characteristic exceeds Curie point T ₁ in the constant temperature zone, also self temperature control type heating elements of the rear B also exceeds the Curie point T ₂ Increases and is maintained in a constant temperature range. Therefore, it is understood from the circuit diagram that two-stage temperatures can be easily obtained as needed by switching the switches S and S.

FIGS. 4 and 5 show another embodiment of the planar heating element according to the present invention, which is different from the one shown in FIGS. Independently 3
They differ in that they are divided. As shown in the circuit diagram of FIG. 6, each of the independent self-temperature controlled heating elements is further provided with an individual switch Sa.
Therefore, by switching the individual switches, the required area and two kinds of temperatures can be easily obtained from the front and back surfaces and the individual surfaces.

FIGS. 7 and 8 show still another embodiment of the sheet heating element according to the present invention, which is different from those shown in FIGS. 4 and 5 in that the heating element is divided into front and back surfaces and individual surfaces. The temperature-controlled heating elements 2 and 2 are self-temperature-controlled heating elements configured to have different Curie points as needed. That is, in the example of FIG. 7, three self temperature control type heating member 2 on the front side are all Curie point T ₁ is a temperature self-regulating heating element A, three self-temperature control type back side the heating element 2, the two left and right is a self temperature control type heating member B is a Curie point T _2, the middle ones are self temperature control type heating member C is the Curie point T _3.
In the example of FIG. 8, among the three surface side of the self temperature control type heating member 2, one is a temperature self-regulating heating element A is a Curie point T _1, the other two Curie point a T ₂ a self temperature control type heating elements B, of the self temperature control type heating member 2 three of the back side, one has Curie point T ₂
A self temperature control type heating member B is, the other two are a self temperature control type heating member C is the Curie point T _3. Thus, the required area and three types of temperatures can be easily obtained from the front and back surfaces and the individual surfaces.

[0019] Figure 9 further shows an another embodiment, divided into three temperature self-regulating heating element A is the same Curie point T ₁ to the back surface of the upper insulating sheet 1a of the planar heating element according to the present invention Then, they are independently formed (first layer), and thereafter, similarly, two layers and three layers are formed to form a multilayer. The Curie point of the self-temperature control type heating element of each of the multilayered layers (one layer, two layers, three layers,...) Is different, and in this example, the second layer has a Curie point T ₂ of self-temperature control. is a type heating element B, 3-layer is a self temperature control type heating member C is the Curie point T _3. Then, an insulating sheet 1d is disposed in the lowermost layer. As shown in the circuit diagram of FIG. 10, by switching individual switches (Sa, Sb, Sc), the area and various temperatures (T _1. T _2. T ₃ ....
・) Can be easily obtained.

FIGS. 11 and 12 show still another embodiment of the sheet heating element according to the present invention, which is different from the one shown in FIG. Is an example in the case of using different Curie points. For the same reason as described in the embodiment shown in FIGS. 7 and 8, it is possible to easily perform fine temperature control as necessary by switching each layer and individual switches.

As an example of using the sheet heating element according to the present invention,
For example, when used for an electric carpet product, the surface temperature of a normal electric carpet needs to be in a range of 20 ° C. to 50 ° C., and four types of self-temperature control type heating elements 2 having different Curie temperatures T at this time. The self-temperature control type heating elements A to D are used, and the Curie temperatures T thereof are T ₁ : 20 ° C., T ₂ : 30 ° C., T ₃ : 40 ° C.
T ₄ : 50 ° C. is considered.

[0022]

As described above, in the sheet heating element according to the present invention, the self-temperature control heating elements having different Curie points of the PTC characteristics are arranged on both sides of the insulating sheet. It is possible to raise the temperature quickly, and because it can be arranged on the insulating sheet surface thinly and in a pattern by printing or the like, there is no uneven discomfort like in the case of a wire heater, and
The heat generating area can be large, and the heat generating element can be easily and reliably maintained at a constant temperature because of the self-temperature control type heat generating element. In addition to the effect, a unique effect that a required temperature can be easily obtained by a simple main operation (switch switching operation) is obtained. Further, in a preferred embodiment of the present invention, by forming the self-temperature control type heating element in multiple layers and individual divisions, an effect that more fine temperature control can be obtained is obtained.

[Brief description of the drawings]

FIG. 1 is an explanatory perspective view showing an embodiment of a sheet heating element according to the present invention.

FIG. 2 is an explanatory sectional view of the sheet heating element shown in FIG. 1;

FIG. 3 is an explanatory circuit diagram used for the sheet heating element shown in FIG. 1;

FIG. 4 is an explanatory perspective view showing another embodiment of the sheet heating element according to the present invention.

FIG. 5 is an explanatory cross-sectional view of the sheet heating element shown in FIG. 4;

6 is an explanatory circuit diagram used for the sheet heating element shown in FIG. 4;

FIG. 7 is an explanatory sectional view showing still another embodiment of the sheet heating element according to the present invention.

FIG. 8 is an explanatory sectional view showing still another embodiment of the sheet heating element according to the present invention.

FIG. 9 is an explanatory cross-sectional view showing still another embodiment of the sheet heating element according to the present invention.

10 is an explanatory circuit diagram used for the sheet heating element shown in FIG. 9;

FIG. 11 is an explanatory sectional view showing still another embodiment of the sheet heating element according to the present invention.

FIG. 12 is an explanatory cross-sectional view showing still another embodiment of the sheet heating element according to the present invention.

FIG. 13 is a perspective view illustrating a conventional electric carpet.

FIG. 14 is a graph showing resistance-temperature characteristics of a self-temperature control type heating element.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Insulating sheet, 2 ... Self-temperature control type heating element (things with different Curie points T are shown as A to D), 3 ...
T (T _{1 to} T ₄ ): Curie point (temperature).

Claims (7)

[Claims] 1. An insulating sheet and PTs disposed on both sides thereof
A self-temperature controlled heating element having a different C-Curie point of the C characteristic;
Means for switching the energization state to the self-temperature control heating element, thereby enabling two or more stages of temperature control. 2. At least one of the self-temperature control heating elements arranged on both sides is divided into two or more, and
2. The sheet heating element according to claim 1, further comprising means for switching a state of energization to each of the divided self-temperature control heating elements. 3. The planar state according to claim 2, wherein said divided individual self-temperature control heating elements arranged on one surface of the insulating sheet are self-temperature control heating elements having the same Curie point. Heating element. 4. The planar state according to claim 2, wherein said divided individual self-temperature control heating elements arranged on one side of the insulating sheet include self-temperature control heating elements having different Curie points. Heating element. 5. A sheet heating element, wherein a plurality of the sheet heating elements according to claim 1 are laminated via an insulating sheet. 6. The planar heating element according to claim 5, wherein insulating sheets are further arranged on the uppermost surface and the lowermost surface. 7. An electric carpet having the sheet heating element according to claim 1 as a heating source.