JPH0789512B2 - Far infrared heater - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Application> The present invention relates to a heating element for a dryer, a panel heater for indoor heating,
The present invention relates to a far infrared heater used as various heating elements such as a heating element for a sauna.

<Prior Art> A conventional far-infrared heater uses a nichrome resistor as a heating element, insulates it with a heat-resistant insulating material such as mica, and further forms a far-infrared radiation layer on the surface of this heat-resistant insulating material. It was structured. Taking the far infrared heater disclosed in Japanese Patent Laid-Open No. 59-189576 as an example, as shown in FIGS. 3 and 4, the nichrome resistor 3 is formed in a meandering shape between the mica plates 1-2. Buried and nichrome resistor 3
Both ends were drawn out by terminals 4 and 5, and a far-infrared radiation layer 6 of high-purity white alumina having a film thickness of about 50 to 100 μm was formed on the surface of the mica 2.

In the far-infrared heater, an electric current is passed through the nichrome resistor 3 so that the far-infrared radiation layer 6 passes through the mica plate 2 at 250 ° C.
When heated and held to a surface temperature of approx.
It is stated that far infrared rays of μm or more can be obtained.

<Problems to be Solved by the Invention> As described above, the conventional far-infrared heater uses a nichrome resistor as a heating element, which is insulated with a heat-resistant insulating material such as mica. Since the structure has a far infrared radiation layer formed on the surface, there are the following problems.

(B) Insulation treatment such as burying the nichrome resistor in a heat-resistant insulating material such as mica is required, which makes manufacturing difficult.

(B) While the heat-resistant insulating material for embedding the nichrome resistor is made of mica, the far-infrared radiation layer is made of a ceramic different from this, so when forming the linear infrared radiation layer, the nichrome resistor is used. As a pretreatment, plasma aluminum metallikon treatment or the like must be applied to the surface of the mica in which the burial is embedded, which also causes a complicated manufacturing process.

(C) Since the heat generated in the nichrome resistor is transferred to the far-infrared radiation layer through the mica, the thermal efficiency and thermal responsiveness deteriorate.

(D) Since a nichrome resistor is used, the heating temperature is not constant and the far infrared radiation operation becomes unstable.

(E) If the heating temperature is stabilized to stabilize the far-infrared radiation operation, a temperature control circuit is required, which leads to an increase in the number of parts, an increase in size, and an increase in cost.

An object of the present invention is to provide a far infrared heater which is easy to manufacture.

Another object of the present invention is to provide a far infrared heater capable of stabilizing the far infrared radiation operation without requiring a temperature control circuit or the like.

Still another object of the present invention is to provide a far infrared heater having improved thermal efficiency and thermal response.

<Means for Solving the Problems> In order to solve the problems described above, the far infrared heater according to the present invention has a far infrared radiation layer formed on the surface of a positive temperature coefficient thermistor. The PTC thermistor includes a PTC element body and a pair of electrodes, and the PTC element body is formed in a flat plate shape having a predetermined thickness. The electrode is adhered to at least the surface and the side end surface of the PTC porcelain body on both sides in the thickness direction of the PTC porcelain body to form ohmic contact with the PTC porcelain body. There is. The far-infrared radiation layer is made of a ceramic material, and is formed by coating a far-infrared radiation substance on substantially the entire surface of the PTC thermistor including the surface of the electrode.

<Operation> In the far infrared heater having the above-described configuration, the far infrared radiation layer made of the same ceramic material may be formed on the positive temperature coefficient thermistor, so that the manufacturing and assembling is simplified.

Moreover, as is well known, the positive temperature coefficient thermistor has a self-temperature control function of rapidly increasing the resistance value at a certain specific temperature and automatically controlling the heat generation temperature of the self, so that for the far infrared radiation layer, By the constant temperature heat generation operation of the positive temperature coefficient thermistor itself, constant temperature heating can be provided without the need for a temperature control circuit and the far infrared radiation operation can be stabilized.

Further, since both the positive temperature coefficient thermistor and the far infrared ray emitting layer are made of a ceramic material, peeling or the like due to thermal strain does not occur between them. For this reason, heat conduction between the two is stably maintained for a long period of time.

Since the electrodes are formed on both sides of the PTC porcelain body in the thickness direction and are led to the side end faces of the PTC porcelain body, there are three bonding surfaces between the PTC porcelain body and the electrodes. As a result, the electrode contact area is increased and the electrode strength is increased.

Further, since the far-infrared radiation layer is formed by coating the surface of the PTC porcelain body with the far-infrared radiation substance, the far-infrared radiation layer may form a gap with the PTC porcelain body. No, but close contact. Therefore, the heat generated in the positive temperature coefficient thermistor can be directly transferred to the far-infrared radiation layer, and the heat conduction efficiency and the thermal response can be improved. In addition, despite the existence of the electrode, the difference in the electrode thickness is filled by applying the far-infrared radiation substance, and the far-infrared radiation layer is adhered to the positive characteristic porcelain body without forming a gap. Can be made. Therefore, the heat generated in the positive temperature coefficient thermistor can be directly transferred to the far-infrared radiation layer, and the heat conduction efficiency and the thermal response can be improved.

Since the far-infrared radiation substance is applied to the surface of the positive-characteristics ceramic body including the surfaces of the electrodes formed by being extended to both sides in the thickness direction of the positive-characteristics ceramic body, the far-infrared radiation layer is used as an electrode. It becomes a protective layer against the above, and the durability of the electrode is improved.

Moreover, the electrodes are at both ends in the length direction of the PTC porcelain body,
The far-infrared radiation layer is applied to almost the entire surface of the positive temperature coefficient thermistor by depositing it over the entire width so that almost the entire surface between the electrodes constitutes a heating surface. Therefore, heat can be generated on the entire surface of the PTC thermistor, and almost all of the heat generated on the entire surface can be directly conducted to the far infrared radiation layer. As a result, the surface of the positive temperature coefficient thermistor can be maximally utilized as a heat generating surface, and the heat thus generated can be conducted to the far infrared radiation layer with high efficiency.

Since the far-infrared radiation substance is applied to the surface of the PTC porcelain body including the surface of the electrode adhered to the surface in the thickness direction of the PTC porcelain body, the far-infrared radiation layer serves as a protective layer for the electrodes. , The durability of the electrode is improved. As a result, as a result, the ohmic contact characteristics between the PTC porcelain body and the electrodes are stably maintained for a long period of time, and stable far-infrared radiation operation is ensured.

Moreover, since it is led out to the side end surface of the PTC porcelain body, a far infrared radiation layer is applied to almost the entire surface of the PTC thermistor to increase the heat generation amount and the heat transfer efficiency. It is possible to supply power to the positive temperature coefficient thermistor through the electrode portion led out to the side end surface of the positive temperature coefficient ceramic body without adversely affecting the structure.

<Example> FIG. 1 is a perspective view of a far infrared heater according to the present invention, and FIG. 2 is a sectional view thereof. Reference numeral 7 denotes a PTC thermistor, which has a structure in which a pair of electrodes 72 and 73 in ohmic contact are adhered to both ends of a PTC porcelain body 71 formed in a flat plate shape in the longitudinal direction. With this structure, almost the entire surface exposed between the electrodes 72 and 73 operates as a heat generating surface.
The electrodes 72 and 73 are formed on both sides of the PTC porcelain body 71 in the thickness direction, and are led out to the side end faces of the PTC porcelain body 71.

Reference numeral 8 denotes a far infrared radiation layer deposited and formed on one surface of the positive temperature coefficient thermistor 7 in the thickness direction. The far-infrared radiation layer 8 shown in the embodiment includes a far-infrared radiation substance as a positive temperature coefficient thermistor 7.
It is formed by directly applying to the surface of. 9 is a power supply.

The far-infrared heater having the above-mentioned configuration can be manufactured and assembled simply by forming the far-infrared radiation layer 8 made of the same ceramic material on the PTC thermistor 7.

Moreover, as is well known, the positive temperature coefficient thermistor 7 has a self-temperature control function of rapidly increasing the resistance value at a certain specific temperature and automatically controlling the heat generation temperature of the self. By the constant temperature heat generation operation of the positive temperature coefficient thermistor 7 itself, constant temperature heating can be applied without the need for a temperature control circuit or the like, and the far infrared radiation operation can be stabilized.

Further, since both the positive temperature coefficient thermistor 7 and the far infrared radiation layer 8 are made of a ceramic material, peeling or the like due to thermal strain does not occur between them. For this reason, heat conduction between the two is stably maintained for a long period of time.

Further, the electrodes 72, 73 are formed by being adhered to both sides in the thickness direction of the PTC porcelain body 71, and are led out to the side end faces of the PTC porcelain body 71. Electrodes 72, 73
There are at least two bonding surfaces with and the electrode contact area increases, and the electrode strength increases.

Further, since the far infrared radiation layer 8 is formed by coating the surface of the PTC porcelain body 71 with a far infrared radiation substance,
The far-infrared radiation layer 8 adheres to the PTC porcelain body 71 without forming a gap. Therefore, the heat generated in the positive temperature coefficient thermistor 7 can be directly transferred to the far-infrared radiation layer 8, and the heat conduction efficiency and the thermal response can be improved. Further, despite the presence of the electrodes 72 and 73, the difference in electrode thickness is filled by applying a far infrared radiation substance, and a gap is formed between the far infrared radiation layer 8 and the positive temperature coefficient ceramic body 71. It can be brought into close contact without causing it. Therefore, the heat generated in the positive temperature coefficient thermistor 7 can be directly transferred to the far-infrared radiation layer 8, and the heat conduction efficiency and the thermal response can be improved.

Since the far-infrared radiation substance 8 is applied to the surface of the positive-characteristic magnetic body 71 including the surfaces of the electrodes 72 and 73 formed by being extended to both surfaces in the thickness direction of the positive-characteristic ceramic body 71, The far-infrared radiation layer 8 serves as a protective layer for the electrodes 72 and 73,
The durability of 73 is improved. As a result, the ohmic contact characteristics between the PTC porcelain body 71 and the electrodes 72 and 73 are stably maintained for a long period of time, and stable far-infrared radiation operation is ensured.

Since the far-infrared radiation layer 8 is directly applied to the surface of the positive temperature coefficient thermistor 7 which is a heat generating surface, the heat generated in the positive temperature coefficient thermistor 7 is directly transmitted to the far infrared radiation layer 8. The heat conduction efficiency and the thermal response can be improved.

Moreover, the electrodes 72, 73 are formed on both ends of the positive-characteristic porcelain body 71 in the longitudinal direction so that almost the entire surface between the electrodes 72-73 constitutes a heat-generating surface, and is formed over the entire width thereof. The far-infrared radiation layer 8 is directly applied to almost the entire surface of the positive temperature coefficient thermistor 7. Therefore, heat can be generated on the entire surface of the positive temperature coefficient thermistor 7, and almost all of the heat generated on the entire surface can be directly conducted to the far infrared radiation layer 8. As a result, the surface of the positive temperature coefficient thermistor 7 can be maximally utilized as a heat generating surface, and the heat thus generated can be conducted to the far infrared radiation layer 8 with high efficiency.

Since the electrodes 72 and 73 are led out to the side end surface of the PTC porcelain body 71, almost all of the surface of the PTC thermistor 7 is
In the structure in which the far-infrared radiation layer 8 is directly adhered and laminated to increase the heat generation amount and improve the heat conduction efficiency, the side end surface of the PTC porcelain body 71 is not adversely affected to the structure. Power can be supplied to the PTC thermistor 7 through the led-out portions of the electrodes 72 and 73.

<Effects of the Invention> As described above, according to the present invention, the following effects can be obtained.

(A) It is possible to provide a far-infrared heater that is extremely easy to manufacture and assemble.

(B) A far-infrared heater capable of stabilizing the far-infrared radiation operation by heating the far-infrared radiation layer at a constant temperature without requiring a temperature control circuit or the like can be provided.

(C) A far infrared heater having a large electrode contact area and high electrode strength can be provided.

(D) Utilizing the far-infrared radiation layer as a protective layer for the electrode, improving the durability of the electrode, maintaining the ohmic contact property between the positive-characteristic porcelain body and the electrode stably for a long time, and ensuring a stable long-distance It is possible to provide a far-infrared heater capable of ensuring infrared radiation operation.

(E) Despite the existence of the electrode, the difference in electrode thickness is filled by applying a far infrared ray emitting substance, and the far infrared ray emitting layer is formed without forming a gap between the positive characteristic ceramic body. It is possible to provide a far-infrared heater which is closely adhered and has improved thermal efficiency and thermal response.

(F) It is possible to provide a far-infrared heater capable of maximally utilizing the surface of the positive temperature coefficient thermistor as a heat-generating surface and conducting the heat thus generated to the far-infrared radiation layer with high efficiency.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a far infrared heater according to the present invention, FIG. 2 is a sectional view of the same, and FIG. 3 is a far infrared heater disclosed in Japanese Patent Laid-Open No. 59-189576. 4 is a partial sectional view of the same. 7: Positive characteristic thermistor 8: Far infrared radiation layer

Continuation of the front page (56) References JP-A-60-32278 (JP, A) JP-A-55-54035 (JP, A) Actually opened 59-93095 (JP, U)

Claims (1)

[Claims] 1. A far-infrared heater having a far-infrared radiation layer formed on the surface of a PTC thermistor, wherein the PTC thermistor includes a PTC porcelain body and a pair of electrodes. The PTC porcelain body is formed in a flat plate shape having a predetermined thickness, and the electrodes are provided at both ends in the length direction of the PTC porcelain body with almost the entire surface between the electrodes being a heating surface. As a whole, the positive characteristic porcelain body is adhered to at least the surface and the side end surface of the positive characteristic porcelain body over the entire width thereof in the thickness direction of the positive characteristic porcelain body, and the ohmic property with the positive characteristic porcelain body. Forming a contact, wherein the far-infrared radiation layer is made of a ceramic material, and is formed by coating a far-infrared radiation substance on substantially the entire surface of the positive temperature coefficient thermistor including the surface of the electrode. Features far infrared heat .