JPH084717Y2 - Flexible heater - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is used as a heating element such as a temperature-sensing ship device or a floor heating device that is attached to a desired part of the body to heat the part, and is bent. The present invention relates to a flexible heater that can be freely deformed.

[Conventional technology]

As shown in FIG. 3, a heater using a positive temperature coefficient thermistor having a temperature-resistance characteristic in which the resistance value sharply increases at the Curie point Tc is proposed as a heating element. When the temperature of the positive temperature coefficient thermistor reaches the Curie point Tc, the resistance value sharply increases and the amount of electricity is reduced, and further temperature rise is stopped.On the other hand, when the temperature decreases and becomes lower than the Curie point Tc, The energization amount increases as the resistance value decreases, and the temperature rises again to the Curie point Tc. Due to such self-control, the temperature of the PTC thermistor is almost at the Curie point.
It is kept near Tc and is prevented from being overheated to a temperature higher than the Curie point Tc. Therefore, when the positive temperature coefficient thermistor is used as the heating element, the overheat prevention circuit and the temperature adjustment circuit are unnecessary, and the fluctuation range of the temperature of the heater can be sufficiently narrowed.

As such a heater, for example, as shown in FIG. 4, a plurality of through holes 12 in the thickness direction are provided in an insulating substrate 11, and a positive temperature coefficient thermistor 13 is inserted into each through hole 12 to perform the above insulation. By sandwiching the substrate 11 with a pair of conductive plates 14 and 15, each positive temperature coefficient thermistor 13 is brought into contact with both conductive plates 14 and 15 by the conductive spring material 16, and further, both conductive plates 14 and 15 are insulated from the outside by a pair. It is proposed that the plates 17 and 18 cling to each other and transfer the heat generated by the positive temperature coefficient thermistor 13 to the outside through the insulating plates 17 and 18 (Japanese Patent Laid-Open No. 48-49038). Kimiko Sho 5
(See JP 4-24357).

However, in the above heater, since the insulating substrate 11 and the insulating plates 17 and 18 are formed of a hard material such as phenol resin and epoxy resin, it is possible to freely deform the heater depending on the application, for example. It has become difficult.
Therefore, its application is for floor heating heaters, panel heaters, etc.
It is limited to those used in flat form.

Therefore, in order to make it deformable, a plurality of PTC thermistors are sandwiched by a pair of flexible wire mesh electrodes, and the gaps between the PTC thermistors are filled with a flexible resin having insulation and heat resistance. A flexible heater has been proposed (see Japanese Utility Model Publication No. 46-4612).

[Problems to be solved by the device]

However, in the above-mentioned conventional heater having flexibility, since the wire netting electrode comes into contact with each positive temperature coefficient thermistor by a wire rod, it is necessary to connect each positive temperature coefficient thermistor and the wire netting electrode with solder or adhesive. is there. On the other hand, when the two are connected in this way, the flexibility of the heater itself is reduced.

Moreover, even when both are connected as described above,
Since the thin wire rod of the wire mesh electrode is connected to the positive temperature coefficient thermistor, a defective connection between the positive temperature coefficient thermistor and the wire mesh electrode is likely to occur due to repeated use accompanied by deformation. Also,
To improve the connection between the PTC thermistor and the wire mesh electrode, if the solder layer or adhesive layer provided at these connection parts is thickened, the heater becomes thicker and the flexibility of the heater is significantly reduced. It will also be done. Further, the wire mesh electrode itself is likely to be broken due to the repeated deformation of the heater. Further, the PTC thermistor and the wire mesh electrode are easily displaced relative to each other due to the deformation of the heater, which causes the connection failure between the PTC thermistor and the wire mesh electrode.
And the wire breakage of the wire mesh electrode is promoted.

Further, in the structure having the above-mentioned wire netting electrode, since the wire rod of the wire netting electrode partially exists on the flexible resin in which the positive temperature coefficient thermistor is embedded and the positive temperature coefficient thermistor, there is a difference in thermal conductivity. The temperature of the heater surface tends to be non-uniform between the portion where the wire is present and the portion where the wire is not present. Therefore, each part of the heating target cannot be heated uniformly. This problem is also the same as when the insulating resin layer is provided on the surface of the wire mesh electrode.

[Means for solving the problem]

In order to solve the above problems, the flexible heater according to the present invention has an insulating flexible support and electrodes at both ends, and these electrodes are exposed on the opposite surfaces of the flexible support plate. A plurality of positive temperature coefficient thermistors as heat sources embedded in the flexible support plate, and the electrodes of each positive temperature coefficient thermistor in contact with the surfaces of the flexible support plate and the above-mentioned electrodes. And a pair of flexible conductive layers that are respectively provided so as to cover the surface of each of the PTC thermistors and supply electric power to the PTC thermistors. The flexible coating layer is characterized in that it is provided with a flexible coating layer in which the portions covering the pair of flexible conductive layers are connected to each other by coating the side surfaces of the flexible support plate.

[Action]

According to the above configuration, the electrodes of the plurality of positive temperature coefficient thermistors embedded in the flexible support plate and the flexible conductive layer are in contact with each other on the electrode surface and the flexibility facing the electrode surface. Since it is performed with a sufficiently wide surface of the conductive layer, a sufficient contact area between the both can be secured. Therefore, it is possible to surely conduct electricity between the positive temperature coefficient thermistor and the flexible conductive layer without connecting them with a conductive adhesive or the like, that is, without impairing the flexibility of the flexible heater. Further, the flexible conductive layer is unlikely to break. Further, since the portions of the flexible coating layer coating the flexible conductive layer are connected by the coating portion for the side surface portion of the flexible support plate, the flexible heater was deformed into a desired shape. Even at this time, it is possible to prevent the flexible conductive layer from being separated from the electrode of the PTC thermistor. For this reason, the present flexible heater has good flexibility and can reliably prevent generation of power supply failure to the PTC thermistor during repeated use accompanied by deformation.

Further, since the flexible conductive layer is provided on the opposite surfaces of the flexible supporting plate so as to cover this surface and the surface of the electrode of each PTC thermistor, the flexible supporting plate and each PTC thermistor are provided. The flexible conductive layer is uniformly present between the electrode and the flexible coating layer, and substantially uniform heat conduction is performed during the above period. Thereby, each part of the heating target can be heated uniformly.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

As shown in FIGS. 1 and 2, the flexible heater includes a flexible support plate 1 made of a material having electrical insulation and flexibility such as rubber. ,
A plurality of positive temperature coefficient thermistors 2, 2 ... Are regularly arranged vertically and horizontally and embedded. Electrodes 3 and 4 are formed on the upper and lower ends of each positive temperature coefficient thermistor 2 by coating or the like, and the electrodes 3 and 4 are exposed on the upper and lower surfaces, which are the opposite surfaces of the flexible support plate 1. ing.

Conductive films 5 and 6 as flexible conductive layers are formed on the opposite surfaces of the flexible support plate 1, for example, aluminum,
It is formed by depositing a metal such as silver, and the conductive film 5 is in contact with each electrode 3 and the conductive film 6 is in contact with each electrode 4.

The surfaces of the conductive films 5 and 6 are covered with a flexible coating layer 7 made of a material having electrical insulation and flexibility such as rubber. As is clear from FIGS. 1 and 2, the side surface of the flexible support plate 1 is also covered with the flexible coating layer 7. That is, the conductive films 5 and 6
The flexible coating layer 7 that covers the surface of the flexible support plate 1 is connected by coating the side surface portion of the flexible support plate 1. The lead wires 8 and 9 are drawn out from the conductive films 5 and 6 through the flexible coating layer 7 and connected to a power source (not shown).

In the above configuration, when the power is turned on, a current flows through each positive temperature coefficient thermistor 2 through the lead wires 8 and 9, the conductive films 5 and 6, and the electrodes 3 and 4, and each positive temperature coefficient thermistor 2 starts to generate heat. To do. As described above, when the temperature of each positive temperature coefficient thermistor 2 exceeds the Curie point Tc, the temperature rise is further stopped, while when the temperature falls, the energization amount increases and the temperature rises. Due to such self-control, the positive temperature coefficient thermistor 2 can maintain its temperature within a narrow fluctuation range near the Curie point Tc without providing an overheat prevention circuit and a temperature adjustment circuit.

The heat of the PTC thermistor 2.2 is conductive film 5.
The heat transferred to the surface of the flexible coating layer 7 via 6 and transferred to the surface of the flexible coating layer 7 is used for heating a desired part of the body or floor heating.

As described above, in the flexible heater, since the flexible support plate 1, the conductive films 5 and 6 and the flexible coating layer 7 can be deformed, the flexible heater can be used by bending it into a desired shape. it can.

Further, the contact between the electrode 3 of each positive temperature coefficient thermistor 2 and the conductive films 5 and 6 is caused by contacting the surface of the electrode 3 and the electrode 3
Since it is performed by the sufficiently wide surface of the conductive films 5 and 6 facing the surface of the above, it is possible to secure a sufficient contact area between the both. Therefore, it is possible to surely conduct electricity between the electrode 3 and the conductive films 5 and 6 without connecting them with a conductive adhesive or the like, that is, without impairing the flexibility of the flexible heater. Further, the conductive films 5 and 6 are unlikely to break. Furthermore, since the portions of the flexible coating layer 7 that coat the conductive films 5 and 6 are connected by the coating portion for the side surface portion of the flexible support plate 1, the flexible heater can be formed into a desired shape. Even when it is deformed, it is possible to prevent the conductive films 5 and 6 from being separated from the electrode 3. For this reason, the present flexible heater has good flexibility and can reliably prevent generation of power supply failure to each PTC thermistor 2 in repeated use accompanied by deformation. .

Further, since the conductive films 5 and 6 are provided on the surfaces of the flexible supporting plate 1 which face each other so as to cover this surface and the surfaces of the electrodes 3 of the respective positive temperature coefficient thermistors 2, the flexible supporting plate 1 is provided. Also, the conductive films 5 and 6 are uniformly present between the electrode 3 of the positive temperature coefficient thermistor 2 and the flexible coating layer 7, and substantially uniform heat conduction is performed during the above period. As a result, each part of the object to be heated can be heated almost uniformly.

[Effect of device]

The flexible heater according to the present invention is, as described above,
Having a flexible support plate having an insulating property and electrodes at both ends,
A plurality of PTC thermistors as heat sources embedded in the flexible support plate so that these electrodes are exposed at the opposite surfaces of the flexible support plate, and the electrodes of each PTC thermistor are brought into contact with each other to ensure flexibility. A pair of flexible conductive layers provided on opposite surfaces of the support plate so as to cover this surface and the surface of each of the above electrodes and supplying electric power to each of the positive temperature coefficient thermistors, and having an insulating property. A flexible coating in which the portions covering the pair of flexible conductive layers are connected by coating the pair of flexible conductive layers and the side surface of the flexible support plate. And a layer.

As a result, a sufficient contact area can be secured in the contact between the electrodes of the plurality of positive temperature coefficient thermistors embedded in the flexible support plate and the flexible conductive layer. Therefore,
It is possible to surely conduct electricity between the PTC thermistor electrode and the flexible conductive layer without connecting them with a conductive adhesive or the like, that is, without impairing the flexibility of the flexible heater. Further, the flexible conductive layer is unlikely to break.
Further, since the portions of the flexible coating layer coating the flexible conductive layer are connected to each other by the coating portion for the side surface portion of the flexible support plate, the flexible heater was deformed into a desired shape. Even at this time, it is possible to prevent the flexible conductive layer from being separated from the electrode of the PTC thermistor. As a result, good flexibility is ensured, and it is possible to reliably prevent generation of power supply failure to the positive temperature coefficient thermistor during repeated use with deformation.

Further, the flexible conductive layer is uniformly present between the flexible support plate and the electrodes of each PTC thermistor and the flexible coating layer, and the heat conduction is substantially uniform between the above. Is done. As a result, it is possible to uniformly heat each part of the object to be heated.

[Brief description of drawings]

1 and 2 show an embodiment of the present invention, in which FIG. 1 is a vertical sectional partial view of a flexible heater, and FIG.
The figure is a perspective view showing a part of the flexible heater,
FIG. 3 is a graph showing the relationship between the temperature and the resistivity of the positive temperature coefficient thermistor, and FIG. 4 is a schematic vertical sectional view of a conventional example. 1 is a flexible support plate, 2 is a positive temperature coefficient thermistor, 3 is an electrode,
Reference numerals 5 and 6 are conductive films (flexible conductive layers), and 7 is a flexible coating layer.

Claims (1)

[Scope of utility model registration request] 1. A flexible support plate having an insulating property and electrodes at both ends thereof, the electrodes being embedded in the flexible support plate so as to be exposed at opposite surfaces of the flexible support plate. A plurality of positive temperature coefficient thermistors as heat sources, and the electrodes of the positive temperature coefficient thermistors are in contact with each other. A pair of flexible conductive layers for supplying power to the characteristic thermistor and an insulating material, and by covering the pair of flexible conductive layers and the side surface of the flexible support plate, A flexible heater, comprising: a flexible coating layer in which portions covering the pair of flexible conductive layers are connected to each other.