JPS5833492Y2 - Hot air generator - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a hot air generator that generates hot air using a positive temperature coefficient thermistor as a heating element.

BACKGROUND ART Conventionally, there has been a hot air generator as shown in FIG. 4, for example, as described in Denshi Gijutsu Vol. 19, No. 2.

In this figure, 21 is a main body case, and an air suction port 22 is provided on the negative side of the main body case, and an air outlet 23 is provided on the opposite side.

24 is a casing for forming an air passage between the suction port 22 and the air outlet 23; 25 is a filter provided in the air passage near the suction port 22; and 26 is a casing for forming an air flow. A fan 27 is a heating element made of a positive temperature coefficient thermistor having a honeycomb-shaped cavity provided in the air passage and near the air outlet 23; 28 is a heating element provided between the heating element 27 and the fan 26; , is a damper for adjusting the amount of air flowing to the heating element 21, and its angle can be continuously changed by rotating a rotary shaft 29 using an adjustment knob (not shown).

In the hot air generator configured as described above, when the fan 26 is rotated and a current is passed through the heating element 27, air is sucked in from the suction port 22, dust is removed by the filter 25, and heat is generated through the gap formed by the damper 18. When the air passes through the body 27, it is heated and hot air is blown out from the air outlet 23.

At this time, the angle of the damper 28 is manually changed so that the heating element 28
By changing the amount of air flowing through the heating element 21, the amount of heat generated by the heating element 21 will also change, making it possible to adjust the temperature.

However, in such a hot air generator, the calorific value P6iV) of the heating element 27 changes greatly depending on the amount of air Q (m37m1n) passing through the heating element 27, as shown in Fig. 5, but it changes slightly depending on the intake air temperature T1. Just do it.

For example, when the air volume Q is 0.3 m''/'tnin and the suction air temperature T1 is 20°C, the calorific value P (g) of the heating element 27 is approximately 300 (W) from FIG. ℃, the calorific value P of the heating element 17 becomes 280 (W) as shown in FIG. 5, and the calorific value P decreases only slightly.

In order to greatly change the calorific value P of the heating element 270 according to changes in the intake air temperature T1 in this hot air generator, manually operate the adjustment knob □ to rotate the damper 28 about the rotation shaft 29. The amount of air must be changed.

In other words, when the ambient temperature changes, the adjustment knob must be operated manually in order to significantly change the amount of heat generated.

In particular, when using the hot air generator described above in a narrow closed space, such as a kotatsu tower, turn on the hot air generator from an atmosphere of 20°C.
In this case, the air temperature inside the Yagura Kotatsu will have a calorific value P of 30
0.3m3/,tn heated by 0W heating element 27
The in air mixes and warms the air inside the tower.

In such a kotatsu, it is difficult to operate the damper at the right time, so the air temperature inside the tower gradually rises, and the temperature of the air sucked into the hot air generator also gradually rises, as shown in Figure 6. Although the calorific value gradually decreases, the change is small.

Therefore, the air temperature inside the tower increases rapidly, so in order to use this hot air generator as a tower kotatsu, a temperature sensor is used to detect the air temperature inside the tower, and when the temperature exceeds a predetermined temperature, the heating element 27 and fan There is no choice but to control the power supply to stop.

However, this would cause pulsations in the temperature of the hot air and generate radio noise, similar to the conventional infrared kotatsu, so the advantage of using a positive temperature coefficient thermistor would be lost.

Therefore, the present inventors first made the damper 28 automatically operate by driving the damper 29 with a thermally responsive element such as a bimetal that responds to the temperature of the gas to be heated, or by forming the damper 28 from a thermally responsive material. We came up with the idea of continuously and automatically controlling the calorific value of the heating element 270.

Furthermore, if the air passage is completely closed off by the damper 28 in the device shown in Fig. 4, the motor of the fan 26 will be overloaded, so a gap should be provided at the upper edge of the damper 28. There is a need.

Therefore, even when the amount of air flowing into the heating element 27 is minimal, a considerable amount of air flows in, and the wind speed is high, so the amount of heat exchanged with the heating element 27 is relatively large, and the amount of heat generated cannot be reduced much. Ta.

To improve this, an exhaust port is provided between the fan 26 and the heating element 27, and the damper 29 is installed between the position where the exhaust port is closed and the position where the air passage leading to the heating element 27 is closed. I came up with the idea of making it rotate.

That is, when the air passage is fully open and the exhaust port is closed, the heating element 27 generates the maximum amount of heat relative to the capacity of the blower 26, and when the exhaust port is fully open and the air passage is closed, no heat is generated. The amount of heat generated by the body 27 is minimized.

However, when manufacturing such a device, if an attempt is made to directly use the wall surface of the air passage to close the air passage with the damper 28, the damper 28 must be provided with some clearance between the wall surface and the damper 28. does not rotate smoothly.

The purpose of this invention is to solve the above problems, and by providing a gap closing part that protrudes inward at the closed position of the exhaust port, damper, and gas flow path and comes into contact with the peripheral edge of the damper, fan load fluctuations can be improved. By reducing the amount of heat generated by the heating element and making the flow rate of gas to the heating element accurate, the amount of heat generated by the heating element can be controlled widely and accurately according to the temperature of the heated gas, and energy is saved. It's about doing.

Therefore, the configuration of this invention is such that a gas flow generating fan and a gas flow generation fan are sequentially arranged between the suction port and the blowout port of the gas flow passage formed by communicating the suction port and the blowout port through the casing. a heating element made of a characteristic thermistor, an exhaust port located in the casing and located between the noan and the heating element, and a passage cross section of the gas flow passage provided in the gas flow passage and between the exhaust port and the gas flow passage on the side of the heating element. a damper that rotates according to the temperature of the gas to be heated and closes at each predetermined temperature; and a gap closing part that protrudes inside the casing wall at the closed position of the cross section of the gas flow path and that the peripheral edge of the damper abuts. It is something to be prepared for.

As for its effect, when the temperature of the gas to be heated is low and the exhaust port is closed by the damper, most of the gas flow rate generated by the fan passes through the heating element, so the amount of heat generated is extremely large.

As the temperature of the gas to be heated increases, the damper rotates and the panel air ports begin to open, and part of the gas flow rate generated by the fan is exhausted from the exhaust port without passing through the heating element, reducing the gas flow rate passing through the heating element. decreases, so the amount of heat generated by the heating element decreases.

Then, when the temperature of the gas to be heated exceeds a predetermined temperature, the damper rotates further, and the gap closing part and the damper come into contact, and the gas flow path to the heating element is reliably closed, and the leaking gas is almost transferred to the heating element. The amount of heat generated is minimal because it is not sent to
As a result, the amount of heat generated by the heating element can be automatically controlled accurately and widely in accordance with the temperature of the gas to be heated without fluctuations in the load on the fan, resulting in improved safety and energy savings.

This invention will be described below as an example of a heater, based on an example in which it is incorporated into a yagura kotatsu to heat the air in a relatively narrow, low-sealed space.

In FIG. 1, 1 is a tower, 2 is a casing that is provided under the top plate of the tower 1, and forms an air flow passage 12 that is a gas flow passage that communicates with the intake lower and the outlet 8; a fan that is provided in the air flow passage 12 on the intake lower side and generates an air flow in the air flow passage 12;
Reference numeral 4 denotes a heating element made of a positive temperature coefficient thermistor, which is provided in the airflow passage 12 on the side of the air outlet 8 and heats the airflow generated by the fan 3. This heating element 4 is a positive temperature coefficient thermistor. Because it consists of heating element 4
As the air flow rate increases, the amount of heat generated increases; as the air flow rate decreases, the amount of heat generated decreases; and when the air flow rate decreases to zero, the amount of heat generated becomes extremely small.

5 is the fan 3 and the heating element 4 of the air flow passage 12;
An exhaust port 6 located in the middle of the casing 2 is rotatable by a predetermined angle about the end of the exhaust port 5 on the side of the heating element 4 as a fulcrum, and the air circulation on the side of the heating element 4 is The passage 120 is a damper that adjusts the cross section of the passage by dividing the air flow rate to the heating element 4 to the exhaust port 5.

FIG. 2 is an enlarged perspective view showing the structure of the damper 6 and the exhaust port in detail, with a portion of the damper 6 and the exhaust port cut away.

In this figure, reference numeral 9 denotes a spiral-shaped bimetal whose outer circumferential end is fixed and which moves according to the temperature of the air inside the tower kotatsu, which is the gas to be heated, and whose center is connected to the damper 6 by a rotating shaft 10.

When the temperature of the heated air exceeds a first predetermined temperature, the bimetal 9 rotates the damper 6 about the rotary shaft 10 in a direction that opens the exhaust port 5 at a constant angle relative to the temperature difference. When the temperature further rises to a second predetermined temperature, a frame-shaped gap closing plate 11, which is provided in the air flow passage 12 and protrudes from the inner side of the wall of the casing 2 and serves as a gap closing portion, and the damper 6
is rotated until the peripheral edge portions of the heat generating element 4 come into contact with each other, thereby closing the passage cross section of the air flow passage 12 on the side of the heat generating element 4, and approximately adjusting the air flow rate to the heat generating element 4.

Further, this gap closing plate 11 is provided at a position such that the damper 6 in the passage cross-sectional closed position of the air flow passage 12 and the damper 6 in the closed position of the exhaust port 5 form an acute angle. is smaller than the damper 6, and the peripheral edge of the damper 6 comes into contact with the gap closing plate.

Further, the shape of the opening surface of the exhaust port 5 is designed to be relatively smaller than the shape of the damper.

In the warm air kotatsu configured as described above, at the start, the temperature inside the kotatsu is still low, and the bimetal 9 is not deformed, so the damper 6 does not rotate, and the fish discharge eye 5 is blocked by the damper 6, so that the air is exhausted. There is no flow of air exhausted from the opening 5, and the flow of air blown out through the heating element 4 is maximum, so the amount of heat generated by the heating element 40 is maximum, the temperature inside the kotatsu rises quickly, and forced air is Therefore, the internal temperature is also uniform.

When the temperature of the kotatsu gradually rises and reaches a first predetermined value or higher, the damper 6 gradually rotates, and the flow rate of air exhausted from the exhaust port 5 increases in proportion to the temperature rise, and conversely, the air flow rate passes through the heating element 4. As a result, the flow rate of air blown out from the outlet 8 decreases, and the amount of heat generated also decreases.

Furthermore, when the temperature inside the kotatsu falls, the damper 6 follows the decrease in the amount of deformation of the bimetal 9 and rotates in the opposite direction to the above, so the flow rate of air passing through the heating element 4 increases, and the amount of heat generated increases. becomes.

When the temperature inside the kotatsu reaches the second predetermined temperature, the damper 6 comes into close contact with the gap closing plate 11 provided in the air flow passage, and all of the air flow is exhausted from the exhaust port 5, and the air flow to the heating element 4 is reduced. Since there is no leakage, the amount of heat generated is minimal.

Note that since the damper 6 contacts the gap closing plate 11 at an acute angle with respect to the closed position of the exhaust port 5, the relationship between the displacement of the bimetal 9 and the air temperature inside the kotatsu is approximately linear.
Furthermore, the force of the bimetal 9 when the damper 6 is pressed against the gap closing plate 11 is large, which has the advantage of further reducing air leakage.

However, since the heating element 4 is a thermistor with a positive temperature coefficient, it never overheats, and since it is designed so that the flow rate of air passing through the heating element 4 decreases when the temperature rises, the heating element itself does not generate abnormal heat. It's safe.

Furthermore, even if the temperature inside the kotatsu cools down due to people coming and going, the damper 6 automatically adjusts the air flow accordingly and automatically increases the amount of heat generated, so that the temperature inside the kotatsu is always kept constant. There is.

Additionally, because the amount of heat generated is continuously and automatically adjusted, there are fewer changes in the temperature inside the kotatsu than with conventional infrared kotatsu, which does not cause discomfort to those seeking warmth.

Furthermore, since the air flow rate passing through the heating element 4 is controlled by the exhaust port 5 and the damper 6 between the fan 3 and the heating element 4, the air volume generated by the fan 3 is always constant and there is no load fluctuation. The cooling effect of the fan motor is also great, and its lifespan is long enough.

Note that in the above embodiment, a frame-shaped gap closing plate is provided which has a damper shape and has a relatively smaller hole than the damper. The same effect can be obtained by forming a protruding portion.

That is, as shown in FIG. 3, the passage cross-sectional shape of the casing, which forms the heating element side air flow passage at a predetermined angle with respect to the damper rotation center, has a configuration in which the damper shape is relatively smaller.

This method has the advantage of reducing the number of parts and manufacturing steps.

In addition, if a damper-shaped gap-closing plate is provided around the opening of the exhaust port 5 and has a frame-shaped hole that is relatively smaller than the damper, leakage of airflow when the exhaust port is closed can be prevented, thereby reducing the temperature. The rise characteristics are even better.

In addition, if the frame-shaped gap closing plate is made of a flexible material, or flexible materials are attached to the gap closing plate or around the exhaust port, or flexible materials are attached to both sides of the damper, The airtightness between the damper and the airflow passage becomes even better.

Although the above-mentioned embodiment relates to a kotatsu, the same effect can be obtained in other hot and wind generating devices such as a heat insulator, a dryer, etc., and the gas to be heated may be other than air.

This idea is based on the above explanation, and by providing an exhaust port, a damper, and a gap closing part in the gas flow path between the fan and the heating element, the load fluctuation of the fan motor is reduced, and the gas flow to the heating element side is reduced. Since the passageway is reliably closed and less gas leaks to the heating element, the safety and life of the motor are improved, temperature control can be reliably performed, and energy savings can be achieved.

[Brief explanation of drawings]

The figures all show one embodiment of the present invention, and Fig. 1 is a longitudinal sectional view, Fig. 2 is an enlarged perspective view with a partial cutout of the casing portion where the damper is attached, and Fig. 3 is a portion of the casing. 4 is a longitudinal sectional view of a conventional device, and FIGS. 5 and 6 are characteristic diagrams of a positive temperature coefficient thermistor. In the figure, 2 is a casing, 3 is a fan for generating airflow, 4 is a heating element, 5 is an exhaust port, 6 is a damper 10 is a rotating shaft,
11 is a gap closing plate, and 12 is an air flow path. The same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Claims for Utility Model Registration] (1) A gas flow generating device arranged in sequence between the inlet and the outlet of a gas flow passage formed by communicating the inlet and the outlet through a casing. A heating element comprising a fan and a positive temperature coefficient thermistor, an exhaust port located between the fan and the heating element and provided in the casing, and a gas flow path provided in the gas flow passage between the exhaust port and the heating element side. A damper that rotates the passage cross section according to the temperature of the heated gas and closes at a predetermined temperature, and protrudes inside the casing wall at a closed position of the gas flow passage cross section, and a peripheral edge of the damper abuts. A hot air generator equipped with a gap closing section. (η A gap closing part is provided so that the damper when the exhaust port is in the closed position and the damper when the gas flow passage is closed by rotating according to the temperature of the heated gas form an acute angle. Claims for registration of a utility model The temperature generating device according to item (1). (3) Claims for registration of a utility model characterized in that the wall portion of the casing projects toward the gas flow passage side and serves as a gap closing portion. The hot air generating device according to item (1) or item (2). (4) Utility model registration claim No. The hot air generating device according to any one of items 1) to (3). (5) Scope of the utility model registration claim, characterized in that the part of the damper that comes into contact with the gap closing part is made of a flexible material. The hot air generator according to any one of items (1) to (3).