JP2005078803A - Sheet heating element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet heating element wherein safety measures are taken without using a fuse as an independent component. <P>SOLUTION: The sheet heating element 1 is equipped with a substrate 4, a plurality of electrode patterns 5 printed on the substrate 4, and a heating part 6 printed between the electrode patterns 5 in the substrate 4. A fuse part 7 made of a fusing material for cutting off current when current of an allowable value or more is made to flow is installed in an optional part in the vicinity of an end part to be connected to a power source in the electrode pattern, and the fuse part 7 is cut when current exceeding previously set flows. Consequently, installation of the additional independent fuse is made unnecessary, and complexity of fuse fitting work when it is independently provided, and break of the fuse are effectively prevented. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a planar heating element, and more particularly to a planar heating element that can automatically shut off a power supply when an excessive current flows.
[0002]
[Prior art]
Conventionally, as a heater used for floor heating or the like, a planar heater including an electrical planar heating element has been provided.
[0003]
That is, this planar heater includes at least a pair of electrode patterns and a conductive heat generating portion provided between the electrode patterns, and generates electricity by applying Joule heat to the heat generating portion. It functions as a heater. In recent years, a method of configuring the electrode pattern and the heat generating portion by printing a conductive material has begun to be adopted.
[0004]
By the way, in general, a heater is required to be equipped with a safety device such as a fuse in order to prevent abnormal heat generation in a heat generating portion and prevent an accident such as a fire.
[0005]
For example, FIG. 4 shows a planar heater 31 having a fuse. In the heater 31, a pair of electrode patterns 33 formed on a base material 32 and a plurality of heat generating portions 35 formed between the electrode patterns 33. And a fuse 34 between one electrode pattern 35 and the power source, so that when a current value of a certain level or more flows, the fuse 34 is activated to cut off the current. Yes.
[0006]
However, when such a fuse is provided, there is a problem that a work for mounting the fuse is necessary and a thickness corresponding to the fuse is generated in the part, and further, for example, the fuse is placed on the fuse. In such a case, there is a possibility that the fuse may be damaged, which may cause a problem that the safety measure becomes impossible.
[0007]
Thus, while safety measures to prevent accidents such as fires are indispensable, there are problems with the provision of fuses, but with electric planar heaters, a method to solve these problems Has never been proposed before.
[0008]
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a planar heating element that can take safety measures without using a fuse as an independent component.
[0009]
[Means for Solving the Problems]
The planar heating element of the present invention comprises a substrate, a plurality of electrode patterns printed on the substrate, and a heating part printed between the electrode patterns on the substrate. A fuse part made of a conductive fusing material that can be cut when a current exceeding an allowable value flows is formed at an arbitrary position near the end of the electrode pattern on the side connected to the power source. The fuse portion is cut when a current exceeding a preset value flows.
[0010]
In the planar heating element of the present invention, a fuse portion made of a conductive fusing material that can be cut when a current exceeding an allowable value is passed is formed in the vicinity of the end portion on the side connected to the power source in the electrode pattern. When a current exceeding a preset value flows, the fuse portion is cut off. Therefore, when a current more than necessary flows to the heat generating part due to some cause, the fuse part is cut and the supply of power is cut off.
[0011]
As described above, in the planar heating element of the present invention, a fuse part is formed in a part of the electrode pattern, and this part can function as a safety device. Therefore, a fuse as an independent part is used. It is possible to take safety measures without any troublesome work.
[0012]
Further, since the fuse portion is formed in the electrode pattern itself, the thickness of the electrode pattern and the thickness of the fuse portion can be made the same, and the fuse portion is also damaged when it gets on the fuse. Fear can also be avoided.
[0013]
【Example】
An embodiment of the planar heating element of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing the structure of the planar heating element of this embodiment. In the figure, reference numeral 1 denotes the sheet heating element of the present embodiment, and the sheet heating element 1 of the present embodiment is configured by covering the heating element body 2 with an insulating film material 3.
[0014]
Here, FIG. 2 is a diagram showing a plan view of the heating element body 2. In this embodiment, the heating element body 2 includes a base material 4 made of a non-conductive material. A pair of electrode patterns 5 printed with a conductive material such as silver is formed.
[0015]
Further, a plurality of heat generating portions 6 that are also printed with a conductive material such as silver are formed by printing between the pair of electrode patterns 5 in the base material 4. The electrode pattern 5 can be energized.
[0016]
With this configuration, by supplying power to the electrode pattern 5, Joule heat is generated in the heat generating part 6, thereby increasing the temperature of the heat generating part 6 and functioning as a heater.
[0017]
Next, in this embodiment, a fuse portion 7 is formed in the vicinity of the end portion on the side connected to the power supply side in either or one of the pair of electrode patterns 5, and the fuse portion 7 is safely It is a device.
[0018]
Here, the fuse portion 7 will be described. FIG. 3 is an enlarged plan view showing the vicinity of the fuse portion 7 in the electrode pattern 5. As shown in FIG. In FIG. 5, the part which forms the fuse part 7 is cut | disconnected by arbitrary length. Along with that, a conductive fusing material having the property of burning out when a current exceeding the allowable value is passed through the cut portion, specifically, a conductive fusing material such as nickel or a lead alloy, An arbitrary width is printed, whereby a fuse portion 7 is formed on a part of the electrode pattern 5 (in FIG. 3, the fuse portion 7 is painted black for easy understanding).
[0019]
As a result, when a current exceeding a preset value flows through the fuse portion 7, the fuse portion 7 is burned out, thereby making it possible to cut off the supply of power.
[0020]
Next, the operation of the sheet heating element 1 of the present embodiment configured as described above will be described. When power is connected to the pair of electrode patterns 5 via lead wires and the like, and power is supplied to the electrode patterns 5. First, electricity flows through the heat generating part 6, whereby Joule heat is generated in the heat generating part 6 and it can function as a heater.
[0021]
When the value of the current flowing to the heat generating portion 6 side exceeds a preset value for some reason, the fuse portion 7 formed in the electrode pattern 5 is burned out as described above, and the heat generating portion 6 is thereby discharged. Therefore, it is possible to prevent accidents such as fires.
[0022]
Therefore, in the sheet heating element 1 of the present embodiment, it is possible to prevent an abnormal heat generation of the heat generating portion and prevent an accident such as a fire without separately providing a fuse.
[0023]
In addition, the width dimension and length dimension of the said fuse part 7 to form are not specifically limited, It sets according to the allowable electric current value.
[0024]
FIG. 2 shows the case where the fuse portion 7 is formed on both of the pair of electrode patterns 5, but it is not always necessary to form the fuse portion 7 on both of the pair of electrode patterns 5, and one of the electrode patterns is formed. Only the fuse portion 7 may be formed.
[0025]
【The invention's effect】
The planar heating element of the present invention is implemented in the form described above, and has the effects described below.
[0026]
In the planar heating element of the present invention, a fuse portion made of a conductive fusing material that can be cut when a current exceeding an allowable value is passed is printed in the vicinity of the end of the electrode pattern on the side connected to the power source. When the current that exceeds the preset value flows, the fuse part is cut, so that when more current than necessary flows to the heating part side for some reason Is configured such that the fuse portion is cut and the supply of power is cut off.
[0027]
Thus, in the planar heating element of the present invention, the fuse portion is formed in the electrode pattern, and this fuse portion can be made to function as a safety device, so that without using a fuse as an independent component, It is also possible to take safety measures without going through troublesome work.
[0028]
Further, since the fuse portion is formed in the electrode pattern itself, the thickness of the electrode pattern and the thickness of the fuse portion can be made the same, and the fuse portion is also damaged when it gets on the fuse. Fear can also be avoided.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing the structure of an embodiment of a planar heating element of the present invention.
FIG. 2 is a plan view for explaining a heating element body in an embodiment of the planar heating element of the present invention.
FIG. 3 is a plan view for explaining a fuse portion in an embodiment of the planar heating element of the present invention.
FIG. 4 is a view for explaining a conventional planar heater provided with fuses independently.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Planar heat generating body 2 Heat generating body main body 3 Insulating film 4 Base material 5 Electrode pattern 6 Heat generating part 7 Fuse part

Claims (1)

A substrate (4);
A plurality of electrode patterns (5) printed on the substrate (4);
In a sheet heating element (1) comprising a heating part (6) printed between the electrode patterns (5) in the substrate (4), the electrode pattern (5) on the side connected to the power source A fuse part (7) made of a conductive fusing material that can be cut when an electric current exceeding an allowable value is applied to an arbitrary position in the vicinity of the end part is formed, thereby exceeding a preset value. A planar heating element characterized in that the fuse portion (7) is cut when a current flows.

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