JPS6218921Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heating unit that heats gas or liquid using a positive temperature coefficient thermistor element.

Conventionally, as shown in FIG. 1, this type of heating unit has been made by forming a honeycomb shape by providing a large number of through holes 2, . Ohmic electrodes 3 and 4 are provided, and power is supplied to these electrodes 3 and 4 to cause the positive characteristic porcelain 1 to generate heat, and the fan 5
A honeycomb type heater configured to heat the fluid by flowing it through the through holes 2, ..., 2;
Alternatively, although not specifically shown, a large number of thin positive characteristic porcelain plates each having an electrode on two opposing circumferential surfaces are arranged parallel to each other, and air or liquid is passed between them to heat them. Ladder type heaters and the like are known.

However, in the honeycomb type heater as described above, the direction of the flow of air and the direction of the voltage applied to the positive characteristic porcelain 1 by the electrodes 3 and 4 are the same. The temperature distribution between electrodes 3 and 4 is as shown by curve Wo in Figure 2.
While the temperature at the middle of the electrode becomes high, when the fan 5 sends the wind W in the direction from the electrodes 3 to 4, the lower temperature wind passes through, as shown by the curve _W1 . The temperature between AB of the positive characteristic porcelain 1 from the electrode 3 to the intermediate part becomes lower than the temperature of the part between BC, and the peak temperature shifts to the exhaust part (the part between BC). For this reason, the resistance of the part between BC increases and the voltage concentrates in that part, a so-called pinch effect, which causes most of the heat generation.
This occurs only in the area between BC, and the area between AB does not make a sufficient contribution as a heating element, resulting in a disadvantage of low heat generation efficiency.

Further, as the wind speed of the wind W sent from the fan 5 increases, the resistance of the positive characteristic porcelain 1 decreases, the flowing current increases, and the amount of heat generated increases, but when the wind speed exceeds a predetermined value. Then, the resistance value of the positive characteristic porcelain 1 becomes unstable around its Curie point, and the power consumption periodically fluctuates, so-called power oscillation occurs, and the wind sent out from the positive characteristic porcelain 1 increases. The disadvantage was that the temperature of the

Furthermore, in the hot air heater of FIG. 1, since the shape and dimensions of the positive characteristic porcelain 1 are fixed, it is difficult to adjust the power of the positive characteristic porcelain 1.

The present invention was made to solve the above-mentioned drawbacks, and its purpose is to adjust the power by changing the number of fins that contact per unit length of the electrode plate by using an electrode plate with corrugated fins attached. The objective is to suppress the occurrence of pinch effects and power oscillations in the positive temperature coefficient thermistor substrate.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

In Fig. 3, 11 and 11 are corrugated fins made by bending thin metal plates having a substantially constant width into a wave shape, 12 and 12 are fin covers of these corrugated fins 11 and 11, and 13 and 13 are fins with good thermal conductivity. A pair of electrode plates made of metal plates, 1
4 and 14 are plate-shaped positive temperature coefficient thermistor substrates, and 15 is an insulating spacer into which these positive temperature coefficient thermistor substrates 14 and 14 are fitted.

The above corrugated fins 11 and 11 are 0.1mm to 0.5
It is made of an aluminum plate having a thickness of mm, and its wave heads 16, 16, . . . are rounded.

On the other hand, the electrode plates 13, 13 are made of a material such as copper or brass, and have tab terminals 17, 17 at one end.
has been established.

In the embodiment shown in FIG. 3, as shown in FIG. 4, the corrugated fin 11 is attached to the electrode plate 13 by a roughly U-shaped fin cover 12 that fits over the corrugated fin 11.

Both ends of the fin cover 12 are approximately 90 degrees outward.
The electrode plate 1 is placed on the bent portions 21, 21.
The fin cover 12 is fixed to the electrode plate 13 by bending the cut and raised pieces 22, 22 provided at the fin cover 12, and the corrugated fin 11 is fixed between the fin cover 12 and the electrode plate 13.

As shown in FIG. 5, the pair of electrode plates 13, 13 with the corrugated fins 11 attached thereto by the fin covers 12 are inserted into the holes 23, 23 of the insulating spacer 15, as shown in FIG. The electrode plates 13, 13 are inserted into the electrode films 24, 2 of the PTC thermistor substrates 14, 14.
4 and 24, 24, the above electrode plate 1
Projecting pieces 25, 25 projecting from sides different from the projecting sides of the tab terminals 17, 17 of No. 3, 13 and the opposite side thereof.
and the round holes 26 provided in 25, 25, respectively, and the protrusions 25, 25 and 25 of the insulating spacer 15
Protrusions 27, 27 and 2 provided at opposite positions of 25
Eyelets 29 are inserted and fixed into the round holes 28, 28 and 28, 28 of 7, 27, respectively.

In the warm air heater having the above configuration, the pitch of the corrugated fins 11, 11 is selected to be, for example, 2 mm to 4 mm in the standard type, and as shown in FIG. Both ends of the corrugated fin 11 are stretched in the direction of arrow Ar1, and the pitch is set to, for example, 5 mm or more.

In addition, in a high-power hot air heater, both ends of the corrugated fin 11 are connected as shown in FIG. 6b.
Compress in the direction of arrow Ar2, and adjust the pitch to 1 mm, for example.
degree.

If you do the above, the positive temperature coefficient thermistor board 1
The number of fins of the corrugated fins 11, 11 that contact per unit length of the electrode films 24, 24 and the electrode plates 13, 13 that are in close contact with the electrode films 24, 24, 24, 24 changes, and a hot air heater with the desired power can be obtained. It will be done.

Furthermore, the direction of the fluid passing through the corrugated fins 11, 11 and the direction of the current flowing in the thickness direction of the positive temperature coefficient thermistor substrates 14, 14 are perpendicular to each other, and problems such as pinch effect and power vibration do not occur.

As detailed above, the present invention changes the number of fins per unit length of the electrode plate by changing the pitch of the fins of the electrode plate to which the corrugated fins are attached. Power can be easily adjusted by expanding and contracting.

In addition, since the direction of the fluid passing through the corrugated fins is almost perpendicular to the direction of the current flowing in the thickness direction of the PTC thermistor substrate, it is possible to suppress the pinch effect and power vibration that occur in the PTC thermistor substrate. can.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of a conventional hot air heater, Fig. 2 is an explanatory diagram of the operation of Fig. 1, Fig. 3 is an explanatory diagram of the hot air heater according to the present invention, and Fig. 4 is an explanatory diagram of the installation of a corrugated fin. , FIG. 5 is an exploded perspective view of FIG. 3, and FIGS. 6a and 6b are illustrations of adjusting the pitch of the corrugated fins. DESCRIPTION OF SYMBOLS 11... Corrugated fin, 12... Fin cover, 13... Electrode plate, 14... Positive temperature coefficient thermistor substrate, 15... Insulating spacer, 24... Electrode film.

Claims (1)

[Scope of utility model registration request] A corrugated fin, which is made by bending a thin metal plate having a substantially constant width into a wave shape, is inserted into a fin cover having a roughly U-shape, and is attached to one main surface of a pair of electrode plates made of a metal plate with good thermal conductivity. The other main surface of these electrode surfaces is brought into close contact with the electrode films formed on both main surfaces of a plate-shaped PTC thermistor substrate, the PTC thermistor substrate is sandwiched between the electrode plates, and the corrugated fin is compressed. Alternatively, the hot air heater is characterized in that the fins are extended and fitted into the fin cover to adjust the power by changing the number of fins that come into contact with each unit length of the electrode plate.