JPS594552Y2 - heat generating device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heating device using a barium titanate semiconductor ceramic heating element (hereinafter referred to as a positive characteristic ceramic heating element) having a positive temperature coefficient of resistance.

As is well known, positive characteristic porcelain heating elements have a self-temperature control function that automatically controls self-heating by rapidly increasing electrical resistance when a certain temperature is reached, and unlike nichrome heating elements, there is no danger of overheating. Since it is safe and highly reliable, it has been widely used as a heat source in various heat generating devices.

Positive characteristic porcelain heating elements are generally formed in the form of pellets, but in the form of pellets - the heat output per element is small, and heat sources such as hair dryers, hot air blowers, clothes dryers, etc. that generate several hundred watts or more can be used. When used as a device, the number of elements used increases, which is disadvantageous in terms of performance and cost.

In order to eliminate these drawbacks, as shown in FIG. 1, a large number of through holes 2 are provided in the thickness direction of the positive characteristic porcelain body 1, and electrodes 3 and 4 are provided on the surface where the through holes 2 are opened. Honeycomb-shaped positive temperature porcelain heating elements have been proposed.

This honeycomb-shaped positive characteristic porcelain heating element has a very large effective surface area per unit volume, and by allowing fluid such as air to pass directly through the through holes 2, efficient heat dissipation can be obtained. It is possible to generate more than several hundred watts of heat per element, which was not possible with conventional devices, and it is also possible to extract hot air with excellent temperature rise characteristics, making it possible to generate heat of several hundred watts or more per element, which was not possible with conventional devices. It has become widely used as a heat source for capacitive products.

An object of the present invention is to provide a large-capacity heat generating device in which the above-mentioned honeycomb-shaped PTC porcelain heat generating element further increases the heat generation amount.

In order to achieve the above object, the heat generating device according to the present invention provides a positive temperature characteristics porcelain heating element having a large number of through holes, on at least one surface of which the through holes are opened, a large number of holes that diagonally communicate with the through holes. It is characterized by comprising a heat radiator having a through hole.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The content of the present invention will be described in detail below with reference to the accompanying drawings, which are examples.

FIG. 2 shows a sectional view of the heat generating device according to the present invention.

In the figure, numerals 5 and 6 are honeycomb-shaped positive characteristic porcelain heating elements.

In this embodiment, as shown in FIG. 1, a large number of through holes 2 are provided in the thickness direction of a disk-shaped positive characteristic porcelain body 1, and on the surface where the through holes 2 are opened, It is configured as a honeycomb-shaped positive characteristic porcelain heating element provided with electrodes 3 and 4.

It is preferable that the PTC porcelain heating elements 5 and 6 have a Curie temperature Tc in a high temperature range of, for example, 220° C. or higher.

That is, when the calorific value of the positive characteristic porcelain heating elements 5 and 6 is W, the heat radiation coefficient is C, the Curie temperature is Tc, and the ambient temperature is Ta, W = C (TC - Ta)... (■ ) is established, and the temperature difference (Tc
This is because the larger the value of -Ta), the larger the amount of heat generated W can be obtained.

Further, the positive characteristic porcelain heating elements 5 and 6 may be singular, but as shown in the embodiment, when increasing the heat generation amount by using two or more, the porcelain heating elements 5 and 6 may be arranged on the leeward side with respect to the air blowing direction P1. If the Curie temperature Tc of the PTC porcelain heating element 6 is set to a higher value than the Curie temperature Tc of the PTC porcelain heating element 5 located upwind, a larger amount of heat generation can be obtained.

As is well known, the Curie temperature Tc is the barium titanate B
By substituting a portion of Ba in aTiO3 with lead Pb, it can be easily moved to a high temperature range.

7.8 is a heat radiator, which is made of a material with excellent heat resistance and thermal conductivity, such as a metal material such as aluminum or Beriya porcelain, and has a shape approximately equal to the outer shape of the positive characteristic porcelain heating element 5°6. It is formed into a plate shape.

The heat sinks 7 and 8 have a large number of through holes 9 and 10 diagonally provided in the thickness direction, and these through holes 9 and 10 are diagonally arranged with respect to the through holes 2 of the PTC porcelain heating elements 5 and 6. The heat sinks 7 and 8 are placed in contact with the electrode-formed surfaces of the PTC ceramic heat generating bodies 5 and 6 so as to communicate with each other.

At the interface between the heat radiating elements 7 and 8 and the positive characteristic ceramic heating elements 5 and 6,
In order to increase the thermal conductivity between the two, it is desirable to use a thermal binder such as grease or a resilient thermally conductive material.

In addition, when the heat sinks 7 and 8 are made of a metal material such as aluminum, and it is necessary to ensure electrical insulation between the electrodes 3 and 4 of the positive characteristic ceramic heating elements 5 and 6 and the heat sinks 7 and 8. It is necessary to interpose a heat-resistant insulator with excellent thermal conductivity at the interface between the two.

Further, in this embodiment, the heat sinks 5 and 6 have through holes 9° and 10°.
Therefore, the through holes (9-2-10-2) of the positive characteristic porcelain heating elements 5, 6 and the heat radiating element 7°8 create a zigzag shape. A through path is formed.

However, the directions of the through holes 9.10 of the heat sinks 5, 6 may be parallel to each other.

The aperture ratio of the through holes 9 and 10, that is, the ratio of the area of the through holes 9 and 10 to the total cross-sectional area of the heat sinks 7 and 8, is
．． It is preferable to select a value slightly larger than the aperture ratio of the through-holes 2 of the positive characteristic ceramic heating elements 5 and 6 in consideration of the windage loss with respect to the fluid flowing through the inside.

Reference numeral 11 denotes a cylindrical body that houses the positive characteristic ceramic heating elements 5, 6 and the heat radiators 7, 8, and can also function as a blower tube or a heat radiator tube.

12 is a blower fan. As described above, the heat generating device according to the present invention has a large number of through holes 9, 10 communicating with the through holes 2 on at least one side of the positive characteristic ceramic heating elements 5, 6 where the through holes 2 are opened. Since the heat sinks 7 and 8 are provided, the effective surface area per unit volume of the heat sinks 7.8 is very large, and by allowing fluid such as air to flow directly through the through holes 2, 9.10, highly efficient heat dissipation can be achieved. can get.

As a result, the heat radiation coefficient C in the above-mentioned formula (1) increases, and the amount of heat generated W increases even more.

Moreover, since the through holes 9, 10 of the heat sinks 7, 8 are communicated obliquely with the through holes 2 of the PTC porcelain heating elements 5, 6, air flows through each through hole 9, 10.2. are stirred and mixed, the heat exchange efficiency between the positive characteristic ceramic heating elements 5, 6 and the heat radiating element 7.8 and the fluid is improved, and the amount of heat generated is further increased.

Furthermore, as shown in the embodiment, when the heat radiator 7 or 8 is placed upwind from the PTC porcelain heating element 5 or 6, the heat radiator 7 or 8 applies a preheating effect to the blown air. Thermal shock to the positive characteristic porcelain heating elements 5 and 6 is alleviated, and the amount of heat generated increases.

As described above, in the heat generating device according to the present invention, a positive temperature characteristic ceramic heating element having a large number of through holes has a large number of through holes that diagonally communicate with the through holes on at least one side where the through holes are opened. Since the heat dissipation body is characterized by having a heat dissipation body, it is possible to provide a heat generating device that has a high heat dissipation coefficient and heat exchange efficiency, and therefore generates a large amount of heat.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a honeycomb-shaped PTC porcelain heating element, and FIG. 2 is a sectional view of the heating device according to the present invention in a state of use. 1... Positive characteristic porcelain element, 2... Through hole, 3, 4... Electrode, 5, 6... Positive characteristic porcelain heating element, 7 , 8... Heat sink, 9°10...
...Through hole.

Claims (3)

[Scope of utility model registration request] (1) A positive characteristic porcelain heating element having a large number of through holes is provided with a heat radiator having a large number of through holes that diagonally communicate with the through holes on at least one side where the through holes are opened. A heat generating device. (2) The heat generating device according to claim 1, wherein a plurality of the heat radiating bodies and the positive characteristic ceramic heat generating bodies are each provided. (3) The heating device according to claim 1 or 2, wherein the heat radiator is provided in front of the PTC porcelain heating element with respect to the air blowing direction.