JPH08255672A - heater - Google Patents

Abstract

(57) [Summary] [Structure] A heating element 2 made of ceramics, which is a positive temperature coefficient thermistor, is extruded from the heater body 1 in the covering member 4 in a cord-shaped heater body 1 having electrical insulation and flexibility. Enclose in. The heating element 2 has a recess 11 in each electrode 7 that is connected to each power supply line 3 and that can hold the contact with each power supply line 3. [Effect] The contact between each power supply line 3 and each electrode 7 of the heating element 2 can be easily maintained, and the process for producing the heater body 1 can be simplified as compared with the conventional case.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heater which can prevent water from being frozen at a staying site by heating a staying site where water is collected, such as a water pipe.

[0002]

2. Description of the Related Art Conventionally, in order to prevent the freezing of water from a water pipe or the like, US Pat. No. 4072848 discloses a heating cable as a cord-shaped heater. As shown in FIG. 15, the heating cable includes a main body 51, which is a cable-shaped insulator made of a thermoplastic resin 54, and a rectangular parallelepiped heating element 52, which is a positive temperature coefficient thermistor. A plurality of them are enclosed along the above so as to have a predetermined interval. At this time, each electrode 56 of the heating element 52 is connected to each power supply line 53 via the solder 55.

[0003]

However, in the above-mentioned conventional configuration, since the respective electrodes 56 of the heating element 52 are connected to the respective power supply lines 53 through the solder 55, the respective electrodes 56 and the respective electrodes 56 are connected. Positioning is performed in advance so that the power supply line 53 is accurately brought into contact with each other, and the two are connected by the solder 55 while maintaining the contact state between the both. Therefore, there is a problem in that the connection takes time.

[0004]

In order to solve the above-mentioned problems, the heater according to claim 1 of the present invention is provided with a cord-shaped main body having electrical insulation and flexibility, and is a positive temperature coefficient thermistor. A plurality of heating elements made of certain ceramics,
A pair of power supply lines, which are provided in the main body at intervals from each other along the length direction of the main body, for supplying electric power to the heat generating body, are provided in the main body, and the heat generating body includes a pair of heat generating bodies. It is characterized in that the respective recesses each having an electrode are respectively formed so as to surround each power supply line along the circumferential direction.

A heater according to a second aspect of the present invention is characterized in that, in the heater according to the first aspect, each of the recesses is formed so as to surround each power supply line over the entire circumference.

[0006]

According to the constitutions of claims 1 and 2 of the present invention, since the main body has an electric insulation property, it is possible to energize the heating element from each power supply line while maintaining the electric insulation property between the respective power supply lines.
Further, since each heating element is provided along the length direction of the main body with a space therebetween, even if the heating element is made of hard ceramics, the main body having a cord-like flexibility is provided. It is possible to bend it.

As a result, even with respect to the curved surface of the body to be heated, the main body can be placed along the surface and the surface can be heated by each heating element, and each heating element is composed of a positive temperature coefficient thermistor. Therefore, it is possible to efficiently heat the low temperature portion that needs to be heated.

By the way, in the conventional heater, after accurately aligning each power supply line and each heating element, they are connected to each other via solder while maintaining the positional relationship between the two power supply lines. It took time to connect with each heating element.

However, in the above structure, since the respective power supply lines can be held in contact with the respective electrodes of the respective heating elements by the respective recesses formed in the respective heating elements, it is possible to save the time and effort for maintaining the contact state of the both. This makes it possible to further simplify the connection between the two.

[0010]

【Example】

[Embodiment 1] One embodiment of the present invention is shown as Embodiment 1 in FIG.
9 to FIG. 9 will be described below. 1 to 3
As shown in FIG. 3, the heater of the first embodiment has a flexible and long cord-shaped heater body 1 on which a plurality of heating elements 2 made of ceramics, which is a positive temperature coefficient thermistor that generates heat when energized, are provided. It has a predetermined interval in the length direction.

The above-mentioned cord shape means an electric wire shape having a circular or elliptical cross section or a strip shape having a rectangular cross section.
This type of heater serves as a water retention site of a water pipe or the like, and can heat the object to be heated having a curved surface along the surface thereof.
Of the above cord-shaped heaters, a band-shaped heater having a particularly rectangular cross-section is more preferable than a circular or elliptical cross-section because it can improve the adhesion to the object to be heated. From this, the following description will be made assuming that the heater main body 1 has a band shape.

Each of the heating elements 2 has a length of 8.0 mm, for example.
, 6.0 mm in width and 1.6 mm in height, and in the shape of a rectangular parallelepiped, 20 pieces are placed at equal intervals in the heater body 1 per 1 m of the heater body 1, and the commercial voltage is applied when the outside air temperature is -20 ° C. Is set so that the total power consumption of each heating element 2 is about 18 W per unit length, for example, 1 m when an alternating current of 100 V is applied.

The heater body 1 has a covering member 4 made of vinyl chloride resin having an electric insulation property. Further, in order to supply electric power to the heating element 2, the heater body 1 is arranged in the longitudinal direction of the heater body 1. It is provided with a pair of flexible power supply lines 3 arranged in parallel. Therefore, the heating elements 2 are connected to the power supply lines 3 so as to be electrically parallel to each other at predetermined intervals between the power supply lines 3.

The feed line 3 is a braided wire in which thin copper wires are twisted together. Therefore, since the heater main body 1 of the present embodiment is easily bent and no restoring force is generated even when it is bent, the heater main body 1 of the present embodiment can supply water along the axial direction even if the water pipe has a large curvature, that is, a small diameter. It can be spirally wound around the outer peripheral surface of the pipe without difficulty, and the heater main body 1 can be brought into close contact with the curved part of the water pipe along the lengthwise direction of the water pipe. It is possible to efficiently heat a water pipe.

Further, as shown in FIG. 2, an electric supply cord 6 is soldered to one end of the feeder line 3. The electric supply cord 6 supplies electric power to each heating element 2 when connected to an AC power source.

As shown in FIG. 4, the heating element 2 is formed with a recess 11 along the lengthwise direction of the heater body 1 so that the power feeding wires 3 can be inserted and held therein. There is. The recesses 11 are formed on both side surfaces of the heating element 2 in the lengthwise direction of the heater body 1.

At this time, the depth and width of each recess 11 are set to be slightly larger than the diameter of the power supply line 3, for example, 0.2 mm, and the electrode 7 is formed on the inner peripheral surface of each recess 11. Has been formed.

As a method of forming each of the electrodes 7, one is to apply a silver paste (made by Degussa Co.) for forming an ohmic contact electrode to each inner peripheral surface of the heating element 2 and then to apply the heating element 2. A method of heating at 560 ° C. for 5 minutes may be mentioned. On the other hand, electrode layers are formed on the entire surface of the heating element 2 by electroless plating, and thereafter, electrode layers on the upper and lower surfaces and side surfaces not required as electrodes are formed. There is a method of removing by polishing.

Next, a method of enclosing the heating unit 10 including the heating elements 2 and the power supply lines 3 in the heater body 1 will be described. First, each power supply line 3 is inserted into each recess 11 of each heating element 2, and then fixed to each electrode 7 with a conductive adhesive to electrically connect the two and fix each other.

Thereafter, as shown in FIG. 5, the heating unit 10 having the heating elements 2 is enclosed in the heater body 1 when the heater body 1 is formed into a cord shape by extrusion molding. In this extrusion molding step, the thermoplastic resin 4'is extruded from each nozzle 8 in the direction of A along the both surfaces of each heating element 2 with a constant extrusion pressure, and the heating unit 10 is covered to form the thermoplastic resin 4 '. The heater body 1 in which the heating unit 10 is enclosed in the covering member 4 made of the resin 4'is formed. Thus, the heat generating unit 10 is sealed in the heater body 1 and electrically insulated from the outside by the covering member 4.

As described above, in the above method, since the heat generating unit 10 can be continuously enclosed in the heater body 1 by extrusion molding of the thermoplastic resin 4 ', the heat generating unit 10 having no particular length limitation is enclosed. The heater body 1 can be easily manufactured. For example, the heater body 1 can be easily set to have a length of 100 m or more.

By the way, in the conventional heater, as shown in FIG. 15, each electrode 5 formed on each heating element 52 is formed.
The surface of No. 6 was connected to each power supply line 53 by soldering via solder 55. This manufacturing process, such as soldering, takes time and effort to connect the two with the solder 55 while maintaining the state where the power supply line 53 is in contact with or close to the surface of the electrode 56.

However, in the above embodiment, the heating element 2
When it is connected to each of the power supply lines 3, it becomes easy to maintain the aligned state by the concave portion 11, so that the manufacturing process can be simplified.

The heating element 2 is a positive temperature coefficient thermistor P.
It consists of a ceramic having TC (Positive Temperature Coefficient) characteristics, for example, a ceramic semiconductor whose main raw material is barium titanate, and has a low resistance from room temperature to the Curie temperature Tc (rapid change temperature), but when it exceeds the Curie temperature Tc. It is a heat-sensitive element having a characteristic that the resistance value sharply increases.

Due to the above characteristics, when a voltage is applied to the heating element 2 at a low temperature below the Curie temperature Tc, a large current flows because the resistance value is small at first because of the low temperature. The temperature rises. On the other hand, when the temperature exceeds the Curie temperature Tc, the resistance value sharply increases,
As the flowing current value decreases and the amount of heat generation decreases,
The temperature does not rise above a certain temperature, and the temperature is kept stable. That is, the heating element 2 has a self-temperature control function. For this reason, the heating element 2 can omit the temperature control circuit and the overheat prevention circuit, can be downsized, and has no fear of ignition due to local overheating.

The Curie temperature Tc of the heating element 2 can be set within the range of about -15 to 250 ° C. depending on the material composition, and the Curie temperature Tc of the heating element 2 of this embodiment is set.
Is set to 40 ° C to 50 ° C according to the mutual distance between the heating elements 2 or the size of the heater body 1, and a positive temperature is set in a temperature range from a predetermined temperature to the maximum heating temperature of the heating element 2. It is set to have characteristics.

As described above, in the heater body 1, the resistance values of the individual heating elements 2 arranged at the predetermined intervals rapidly increase (or decrease) in accordance with the temperature of the outside air. That is, in an area where the outside air temperature around the water pipe is lower than room temperature, for example, at a portion below the freezing point temperature, the resistance value of the heating element 2 located at that portion becomes small, current easily flows, and the water pipe is heated, Freezing of water inside the water pipe is prevented.

On the other hand, in a portion where the outside air temperature around the water pipe is high, the resistance value of the heating element 2 located in that portion is increased, the flowing current is reduced and the calorific value is reduced, and a constant temperature is maintained and heat is generated. The power consumption of the body 2 can be reduced.

The heater body 1 is made of a thermoplastic resin 4'having electrical insulation, flexibility, and weather resistance as the covering member 4, for example, vinyl chloride resin, and has a length of 1000 m and a width of 16.2 mm. , With a thickness of 3.9 mm. The weather resistance is excellent in heat resistance and cold resistance, for example, heating at about 50 ° C and -10 ° C.
It is a property that changes little in physical properties even after repeated cooling.

In the above method, the heating element 2 is connected to each of the feeder lines 3.
While pulling out the heating units 10 respectively connected to the heating units 10, the heating units 2 are sealed in the heater body 1 while the heating elements 2 are pressed against the power supply lines 3 by the thermoplastic resin 4 ′ melted at the time of extrusion molding.

From the above, in the above method, since the heating element unit 10 is pulled out, tension is generated in each power supply line 3, and therefore each power supply line 3 is held in parallel with each other at a predetermined interval and each power supply line 3 is maintained. Since it can be sealed in the heater body 1 while ensuring the electrical insulation between the heating elements 3, the heating unit 10 in which the heating element 2 is connected to each power supply line 3 can be easily and automatically manufactured.

In the above, as an example of the shape of the heating element 2, an example of the heating element having the recesses 11 through which the power supply lines 3 can be inserted from both side surfaces of the heating element 2 along the length direction of the heater body 1. However, the present invention is not limited to this, and as another example, as shown in FIG. 6A, the width of the recess 11 is smaller than the thickness of the power supply line 3 at the opening end of the recess 11,
The cross-section may be tapered so that the depth increases as the depth of the recess 11 increases.

Further, as shown in FIG. 6B, the recess 11
Has a width of 3 mm at both ends of the heater body 1 in the longitudinal direction.
The opening may be formed so that it is smaller than the thickness of the concave portion and gradually increases toward the inside of the concave portion 11.

Due to the shape of the recess 11 as described above,
Once the flexible power supply line 3 is inserted into each recess 11, there is an effect of preventing each power supply line 3 from being separated from the heating element 2 due to an impact from the outside.

Further, in the above, as the shape of the heating element 2,
Although an example of the rectangular parallelepiped shape is given, the shape is not particularly limited to this, and a shape in which the corners of both side surfaces of the heating element 2 are chamfered in the length direction of the heater body 1 can also be used. In this case, the shape becomes as shown in FIGS. 7A and 7B, and it is possible to alleviate the occurrence of the breakage of the corner due to an unexpected impact from the outside when the heater body 1 is manufactured.

As another example of the shape of the heating element 2, FIG.
As shown in, the both sides of the heater body 1 are spindle-shaped with respect to the length direction, that is, the thickness of the heating element 2 on the front side and the rear side of the heater body 1 in the longitudinal direction is Examples include thinned shapes. The new effect of this shape will be described below.

When the heating element 2 is enclosed in the heater body 1 by the extrusion molding of the thermoplastic resin 4 ', the thermoplastic resin 4'is sandwiched between the heating element 2 and is more elastically compressed. It

When the thermoplastic resin is elastically compressed in this way, when the heating element has a rectangular parallelepiped shape, the elastic compression is transmitted along the surface of the heating element rearward of the extruding direction of the heating element along with the extrusion. To be done. As a result, in the heater body after the heating element is extruded, the thermoplastic resin may elastically expand to form a convex portion on the heater body.

However, in the case of the shape of the heating element 2, since the rear side and the front side of the heating element 2 are formed to be thin with respect to the extrusion direction A, the rear side and the thin side of the heating element 2 are thinned. Since the space where the thermoplastic resin 4'can be present on the front side becomes large, transmission of the elastic compression of the thermoplastic resin 4'to the rear at the time of extruding the heating element 2 is relaxed. As a result, it is possible to prevent the thermoplastic resin 4 ′ from elastically expanding to form a convex portion on the heater body 1.

In addition, as shown in FIGS. 9 (a) and 9 (b), the heating element 2 may have recesses 11 on the upper and lower surfaces thereof, through which the power supply lines 3 are inserted.

[Embodiment 2] Another embodiment of the present invention will be described below as Embodiment 2 with reference to FIGS. 10 to 13. In addition, the same member numbers are given to the respective members having the same functions as those in the first embodiment, and the description thereof will be omitted. In the heater of the second embodiment, as shown in FIGS. 10 and 11, in the heater body 1, instead of the heating element 2 described in the first embodiment, each power supply line 3 is arranged in the length direction of the heater body 1. A heating element 21 having a through hole 22 that can penetrate therethrough is used. At this time, the electrodes 71 are formed on the inner peripheral surface of each through hole 22.

As a method for forming the electrode 71 in this way, a method similar to the method described in Embodiment 1 is used, in which the silver paste is applied to the inner peripheral surface and then fixed by heating, or electroless plating. There is a method in which an electrode layer is formed on the entire surface of the heating element 21 by means of, and each of the above-mentioned electrodes 71 is formed by a method of polishing an unnecessary portion as an electrode.

However, in the case of the heating element 21, since it is not easy to apply the silver paste to the inner peripheral surface of each through hole 22, an electrode layer is formed on the entire surface by electroless plating, and the through hole 22 is formed. It is desirable to remove the parts other than the inner peripheral surface by polishing.

Each through hole 2 of the heating element 21
Each of the power supply lines 3 is inserted along the electrode 71 formed on the inner surface of 2 to connect the both. The above two may be connected and fixed to each other by a conductive adhesive.

In the configuration of the second embodiment, the power feeding line 53 and the electrode 56 are aligned as in the conventional case, and it is not a labor-intensive work such as connecting through solder while maintaining the positional relationship between the two, and the penetration is performed. Since the contact state between the power supply line 3 and the electrode 71 can be more easily maintained by the hole 22, the alignment between the two can be facilitated and a more reliable connection between the both can be achieved.

In the case of the second embodiment, a method of connecting the power supply lines 3 to the entire surface of each electrode 71 on the inner peripheral surface of each through hole 22 of the heating element 21 with a conductive adhesive, A method is conceivable in which only the central portion of each electrode 71 on the peripheral surface is connected to each feeder line 3 by a conductive adhesive. At this time, since the power supply lines 3 are bound at both ends of the respective through holes 22, the above methods are the same in the degree of freedom of each power supply line 3.

Therefore, when fixing each power supply line 3 to the entire inner peripheral surface of each recess 11 of the heating element 2 of the first embodiment with a conductive adhesive, each of the heating elements 21 of the second embodiment has. The method of connecting each power supply line 3 to the through hole 22 and the degree of freedom of each power supply line 3 are the same.

However, in the case where the power supply lines 3 are partially fixed to the central portion of the inner peripheral surface of the respective recesses 11 described in the first embodiment with a conductive adhesive, the lengthwise direction of the heater body 1 of the recesses 11 is reduced. Since each power supply line 3 can be slightly moved at both ends, the degree of freedom of each power supply line 3 is higher than that when each power supply line 3 is connected to each through hole 22 of the heating element 21 described in the second embodiment. There is an effect that it becomes large and has excellent flexibility.

Furthermore, when connecting each of the power supply lines 3 to the heating element 21, each of the power supply lines 3 may be fixed by further soldering. In this case, stronger connection strength can be exerted against the stress generated by the bending of the power supply line 3 when the heater body 1 is spirally wound around the water pipe or pressure-bonded along the length direction of the water pipe. So
The structure can be made stronger against bending.

With this, it is possible to further prevent the occurrence of defects in the connection portion between the heating element 21 and the power supply line 3, and the state where the heating element 21 and the power supply line 3 are electrically connected more reliably. Therefore, it becomes possible to heat the water pipe efficiently and more reliably.

In the above, as the shape of the heating element 21, the example of the heating element 21 provided with the through holes penetrating the power supply lines 3 along the length direction of the heater body 1 has been given, but the shape is not particularly limited thereto. As another example, instead of the conventional rectangular parallelepiped shape, along the length direction of the heater body 1,
FIG. 12 shows a shape in which the corners of both sides of the heating element 21 are chamfered, and FIG. 13 shows a shape in which both sides are spindle-shaped. The effect of the shape of the heating element 21 is the same as the effect of the shape of the heating element 2 described in the first embodiment.

[Embodiment 3] Still another embodiment of the present invention will be described below as Embodiment 3 with reference to FIG. The members having the same functions as those in the first and second embodiments are designated by the same member numbers, and the description thereof will be omitted. In the heater of this embodiment, as shown in FIG.
The heat generating unit 13 including the electrode 7 and the power supply line 3 is formed in the same manner as in the first and second embodiments, but the heat generating unit 13 is not entirely covered, and the heat generating unit 13 is exposed on one side. The heater main body 12 is formed so as to be held in this state.

In this case, an adhesive tape or an adhesive material (not shown) is provided on the back side of the power supply line 3. The power supply line 3 and the heater body 12 are fixed to each other by the adhesive tape or the adhesive material, and the heat generating unit 13 is held in the heater body 12 in a stable form.

In the structure of this embodiment, the heat generating unit 13 is provided on only one surface of the heater body 12. As a result, the resin surface of the heater body 12 opposite to the heat generating unit 13 is formed by the covering member 40, and the resin surface is spirally wound around the outer peripheral surface of the water pipe along the axial direction of the water pipe. When covered with glass wool or insulating tape from above, the heater main body 12 is covered as compared with the case where the entire surface of the heating unit 13 is covered because the convex portions are concentrated on only one surface.
Is easy to bend.

Therefore, the heater body 12 of the present embodiment.
Even if it is a water pipe having a large curvature, that is, a small diameter, it can be spirally wound around the outer peripheral surface of the water pipe along its axial direction without difficulty. Further, instead of spirally winding the water pipe as described above, the water pipe may be coated so as to be crimped to the water pipe along the length direction of the water pipe.

Further, one surface of the heating element 2 is not covered with the covering member 40. As a result, the heating element 2 more quickly responds to changes in the outside air temperature and changes its resistance value faster. Therefore, the water pipe can be quickly heated, and the freezing of water in the water pipe can be prevented.

The above-mentioned embodiments do not limit the present invention, and various modifications can be made within the scope of the invention. For example, although an example in which a vinyl chloride resin is used as the material of the covering member 4 described in the above examples is given, the present invention is not limited to this, and melting or deformation due to the heat generation temperature of the heating element 2 does not occur, and the above It is possible to use a resin material or a rubber material whose physical properties change little even if the heating by the heating element 2 and the cooling by the outside air temperature below the freezing point temperature are repeated.

Examples of the rubber material of the covering members 4 and 40 are butyl rubber, natural rubber, butadiene rubber, ethylene-propylene rubber, chloroprene rubber, isoprene rubber, styrene-butadiene rubber, acrylic rubber, chlorosulfonated rubber and silicone. Examples thereof include rubber, fluorosilicone rubber, fluororesin rubber and the like.

Examples of resin materials for the covering members 4 and 40 include polyolefin resins such as polyethylene and polypropylene, polyurethane resins, poly-4-methylpentene-1, silicone resins, fluororesins,
Examples thereof include polycarbonate resin, polyamide resin, polyphenylene oxide resin, polybutylene terephthalate, polyethylene terephthalate, and polyimide resin.

The construction of each of the above-mentioned embodiments can be applied to any water pipe, but in particular, a water pipe made of a casting such as iron used in the cold regions of southern Tohoku and Shinshu. Most preferably used for.

This is because the water pipe is also used to heat the water pipe itself by flowing a high current when the water therein freezes, and to melt the frozen water by the heat generation. Therefore, since it has a large thermal conductivity, the heat from the heater bodies 1 and 12 of each of the above-described embodiments, which makes line contact, is efficiently transmitted to the entire water pipe.

In the structure of the above-mentioned embodiment, an example in which a water pipe, which is a retention area of water, is used as the object to be heated by the heater of the present invention has been given, but the invention is not particularly limited to this. Used by adhering to the outer surface of the pump, sprinkler, water tank, drainage port, U-shaped water sealing part of the drainage pipe, etc. directly in the ground, directly putting it in water, under the side of the track or the surface of the road It is also possible to embed it in and use it. By burying the heater below the center line of the road and using it, it is possible to improve the visibility of the center line during snowfall.

[0063]

According to the heater of the present invention, a plurality of heating elements are provided in the heater body, and a pair of power supply lines for supplying power to the heating elements are provided in the heater body. Each recess having each electrode of the body is formed so as to surround each power supply line along the circumferential direction.

Therefore, in the above-mentioned structure, it is possible to eliminate the labor-consuming work of aligning the power supply line and the electrode and connecting them via solder while maintaining the positional relationship between the two, as in the conventional case, and to use each recess. Since the contact state between the power supply line and the electrode can be easily maintained, the alignment between the two becomes easy.

As a result, in the above structure, each power supply line can be held in each recess, so that each power supply line can be firmly connected to the heating element, and the process for manufacturing the heater body is simplified as compared with the prior art. It has the effect of being able to.

[Brief description of drawings]

FIG. 1 is a fragmentary perspective view of a heater according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of the heater.

3 is a cross-sectional view taken along the line I-I of the heater shown in FIG.

FIG. 4 is a perspective view showing a shape of a heating element and electrodes in the heater.

FIG. 5 is an explanatory diagram of extrusion molding of the heater.

FIG. 6 is a perspective view of another modification showing the shape of the heating element in the heater.

FIG. 7 is a perspective view of another modification showing the shape of a heating element in the heater.

FIG. 8 is a perspective view of another modification showing the shape of the heating element in the heater.

FIG. 9 is a perspective view of another modification showing the shape of the heating element in the heater.

FIG. 10 is a fragmentary perspective view showing a heater according to a second embodiment of the present invention.

FIG. 11 is a perspective view showing a shape of a heating element and electrodes in the heater.

FIG. 12 is a perspective view of another modification showing the shape of the heating element in the heater.

FIG. 13 is a perspective view of another modification showing the shape of the heating element in the heater.

FIG. 14 is an explanatory diagram showing Embodiment 3 of the heater of the present invention.

FIG. 15 is an explanatory diagram of a conventional heater.

FIG. 16 is an explanatory diagram of extrusion molding of the heater.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heater main body 2 Heating element 3 Power supply line 4 Covering member 6 Electric supply cord 7 Electrode 11 Recess 22 Through hole

Claims (2)

[Claims] 1. A main body having electrical insulation and flexibility is provided in a cord shape, and a plurality of heating elements made of ceramics, which are positive temperature coefficient thermistors, are spaced from each other along the length direction of the main body. Is provided in the main body, and a pair of power supply lines for respectively supplying power to the heating elements are provided in the main body, and the recesses having the electrodes of the heating elements are provided in the heating element in the circumferential direction. A heater characterized in that each is formed so as to surround along. 2. The heater according to claim 1, wherein each of the recesses surrounds each of the power supply lines,
A heater characterized by being formed respectively.