JP3063395B2 - Positive characteristic thermistor heating element - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positive temperature coefficient thermistor heating element used for heating a fluid such as air in a hot air heater or the like.

[0002]

2. Description of the Related Art Since a positive temperature coefficient thermistor is a semiconductor ceramic whose resistance value rises rapidly at a certain temperature, it has a self-temperature control action. It is generally well known that this is a convenient heating element because it does not change temperature and does not heat.

When this heating element is used as a heater for heating fluid such as air, the heating element can be used as a safe heater without red heating even when the passage of fluid is stopped. It is also well known that a heat sink is fixed to a positive temperature coefficient thermistor in order to increase the heat generation by increasing the heat dissipation, and that the effect can be sufficiently exhibited by increasing the surface area of the heat sink. Things.

FIG. 2 is a perspective view showing the structure of a heating element of the conventional PTC thermistor. Reference numeral 1 denotes a PTC thermistor having an electrode provided on a main plane. I have. Reference numeral 3 denotes a radiator formed by bending an aluminum thin plate into a waveform and fixing an electrode plate made of an aluminum plate on one surface by brazing or the like to serve as a conductive path. The other surface of the heat radiator 3 is closely fixed to both main planes of the characteristic thermistor 1.

When a voltage is applied to the two radiators 3 which also serve as a conduction path of the positive-characteristic thermistor heating element configured as described above, this voltage is applied to the positive-characteristic thermistor 1 to generate heat.
The generated heat is transmitted to the two radiators 3, and when a fluid such as air is supplied from one side, warm air can be obtained from the opposite side.

FIG. 3 is a perspective view showing another example of the conventional PTC thermistor heating element. Reference numeral 1 denotes a PTC thermistor having electrodes provided on both main planes, and a plurality of PTC thermistors are arranged adjacent to each other. ing. Reference numeral 4 denotes a radiator formed by processing aluminum by extrusion or the like. The radiator 4 is formed by tightly fixing the radiator 4 to both main planes of a plurality of PTC thermistors 1 arranged adjacent to each other. ing. The operation of the positive temperature coefficient thermistor heating element is the same as that of the conventional positive temperature coefficient thermistor heating element described with reference to FIG.

[0007]

However, in the above-mentioned conventional configuration, in order to increase the surface area of the heat radiators 3 and 4 in order to increase the calorific value, a method of enlarging the heat radiators 3 and 4 is disclosed. There is a method of increasing the heat capacity by increasing the thickness of the plates 3 and 4. In the method of increasing the size of the radiators 3 and 4, it is effective to increase the height in the height direction to increase the ventilation area rather than in the ventilation direction. .

However, the heat from the positive temperature coefficient thermistor 1 is transmitted from the surface to which the radiators 3 and 4 are fixed, and is transmitted to the entire radiators 3 and 4. At that time, when the air passes through the vent, the heat from the PTC thermistor 1 is transmitted to the entire radiators 3 and 4, and at the same time, the radiators 3 and 4 dissipate heat. It becomes lower than the near part, and the heat radiation effect becomes worse. This has the problem that the larger the heat radiators 3 and 4 are, the worse the effect becomes, and the heat generation cannot be increased for the shape effect.

Further, in the method of increasing the thickness of the plate, the heat conductivity is raised to solve the above problem so that heat is transmitted to the entire radiators 3 and 4. However, the weight is increased and the processing is difficult and the cost is reduced. There was a problem that it would be expensive.

An object of the present invention is to provide a highly reliable positive temperature coefficient thermistor heating element capable of maximizing the heat radiation effect of the heat radiator, generating a large amount of heat, and reducing the size and weight. It is intended for.

[0011]

In order to solve this problem, a positive temperature coefficient thermistor heating element according to the present invention includes a positive temperature coefficient thermistor having electrodes formed on both main planes and arranged singly or plurally adjacently. An aluminum plate whose thickness is changed at intervals is bent into a waveform so that the thick portion becomes one of the tops and a radiator formed by brazing an aluminum thin plate on each top, The radiator has a thicker top portion fixed to both main planes of the positive temperature coefficient thermistor.

[0012]

According to this structure, when a voltage is applied to the PTC thermistor to allow air to pass through the ventilation section of the radiator, the PTC thermistor generates heat, and the heat is transmitted to the air through the ventilation section of the radiator, and the temperature is reduced. Heating by wind is possible, and the shape of the radiator is thinner toward the far side of the heat-generating part. A thermistor heating element is obtained.

[0013]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a PTC thermistor heating element according to an embodiment of the present invention. FIG. 1 is a perspective view showing the configuration of a positive temperature coefficient thermistor heating element according to the embodiment. In FIG. 1, reference numeral 1 denotes a square positive temperature coefficient thermistor provided with electrodes (not shown) formed by aluminum spraying on both surfaces. A plurality is arranged adjacent to each other. Reference numeral 2 denotes a radiator, which is formed by bending an aluminum plate whose thickness is changed at equal intervals by pressing or the like into a waveform, so that a thick portion 2a and a thin portion 2b become the respective top portions. The upper and lower aluminum plates 2c are formed by brazing. Further, the plate thickness is constituted within two times the thickness of the thin portion 2b, a thick portion of the plate thickness with respect to the height H ₁ between the respective tops of the thick portion 2a of the aluminum plate is bent in the waveform relationship height of H ₂ 2a is configured as _{H 2 = 1 / 2H 1 MAX} . The heat radiator 2 thus configured is arranged so that the thick portion 2a side of the heat radiator 2 is in contact with both main planes of the positive temperature coefficient thermistor 1 and is fixed by an adhesive.

The operation principle of the positive temperature coefficient thermistor heating element of the present invention configured as described above will be described below. When a voltage is applied to each of the two radiators 2, the radiators 2 serve as conductive paths, and a voltage is applied to the positive temperature coefficient thermistor 1 to generate heat. The heat is transmitted to the aluminum thin plate 2c forming the radiator 2, and further transmitted from the top of the thicker side 2a of the aluminum plate bent into a wave to the opposite top 2b. At this time, when air is allowed to pass through the radiator 2, the heat at the top of the thicker side 2 a of the corrugated plate of the radiator 2 radiates heat at the same time as radiating heat because the thickness of the portion fixed to the thin plate is increased. The heat is transmitted to the top of the side 2b, and only the heat radiation is performed on the top side 2b having a small thickness. As a result, warm air can be taken out from the entire radiator 2, and the amount of heat generated can be increased.

Further, the thickness is increased only in necessary portions by the above configuration, and the other portions are reduced in thickness, so that the heat radiator 2 does not become too heavy, and the size and weight can be reduced. At the same time, high efficiency can be realized.

[0016]

As described above, the positive temperature coefficient thermistor heating element according to the present invention can efficiently transmit heat to the end of the heat radiator by changing the plate thickness of the heat radiator, resulting in a large heat generation. In addition to being able to obtain a stable amount,
An excellent positive temperature coefficient thermistor heating element which is small and lightweight can be realized by the configuration of the heat radiator in which only the necessary portion is thickened.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a positive temperature coefficient thermistor heating element according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a conventional PTC thermistor heating element.

FIG. 3 is a perspective view showing a conventional positive temperature coefficient thermistor heating element.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Positive characteristic thermistor 2 Heat radiator 2a Thick part 2b Thin part 2c Aluminum thin plate

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H05B 3/14 F24H 3/04 303

Claims (1)

(57) [Claims] 1. A positive temperature coefficient thermistor having electrodes formed on both main planes and disposed adjacent to each other, and an aluminum plate whose thickness is changed at equal intervals is bent into a waveform to form a thick portion. It consists of a radiator formed by brazing a thin aluminum plate on each of the tops, and the top side of the radiator with a thicker plate is fixed to both main planes of the positive temperature coefficient thermistor. A positive temperature coefficient thermistor heating element.