JPS5853260B2 - Hot air heating device - Google Patents

Description

[Detailed Description of the Invention] This invention uses a positive temperature coefficient thermistor as a heating element,
The present invention relates to a hot air heating device that generates hot air.

BACKGROUND ART Conventionally, there has been a hot air heating device as shown in, for example, FIG. 8, as described in Vol. 19, No. 2 of Electronic Technology.

In this figure, 3 is a main body case, and an air suction port 29 is provided on one side of the main body case, and an air outlet 28 is provided on the opposite side.

31 is a casing for forming an air passage between the suction port 29 and the air outlet 28, 32 is a filter provided in the air passage near the suction port 29, and 4 is a casing for forming an air flow. A fan 11 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 28; 33 is a heating element 1 of the heating element 1;
A damper is provided between the fan 1 and the fan 4 to adjust the amount of air flowing to the heating element 11, and its angle can be continuously changed by rotating the rotating shaft 34 with an adjustment knob (not shown). It looks like this.

In the hot air heating device having such a configuration, when the fan 4 is rotated and a current is passed through the heating element 11, air is sucked through the suction port 29, dust is removed by the filter 32, and the air is passed through the damper 33 to the heating element 11. When the air passes through the air, it is heated and hot air is blown out from the air outlet 28.

At this time, the angle of the damper 33 is manually changed so that the heating element 11
By changing the amount of air flowing through the heating element 11, the amount of heat generated by the heating element 11 will also change, making it possible to adjust the temperature.

However, in such a hot-air heating system, the calorific value PW of the heating element 11 varies greatly depending on the amount of air passing through the heating element 11 Q (m''/m1n) as shown in FIG. 9, but it varies depending on the intake air temperature T1. It only changes slightly.

Also, the temperature T of the air blown from the suction port 28.

is approximately expressed by the following equation (1), To=0.047×P/Q+T1−...”・(1)
For example, when the air volume Q is 0.3 m''/min and the suction air temperature T1 is 20°C, the calorific value PM of the heating element 11 is the 9th
From the figure, it is about 300W, and the blown air temperature To is To=0.047×30010.3+2O−67CQ.

In addition, in this hot air heating device, when the intake air temperature T1 reaches 40°C, the calorific value P of the heating element 11 is determined from FIG.
becomes 280W, and the temperature of the blown air at that time is T.

becomes large as To=0.047X 28010.3+40=84guQ.

In this hot air generator, even when the suction air temperature T1 is 40°C ('Q), the blown air temperature T is the same as when the suction air temperature T2 is 20°C.

In order to make the air flow rate as low as 67CQ, it is necessary to set the air amount Q to 0.5 m/m-n or more as shown in FIG. 9, and the air amount must be changed by manually operating the adjustment knob.

In other words, if the ambient temperature changes, the adjustment knob must be manually operated in order to keep the blowing temperature constant, which is very troublesome.

Furthermore, when the hot air heating device described above is used in a narrow closed space (e.g., a yagura kotatsu) and the hot air generator is turned on from an atmosphere of 20°C, the air temperature inside the yagura kotatsu will have a calorific value P of 300.
0,3 heated to about 67CQ by W heating element 7
The air inside the tower is mixed and warmed by the m'/min air.

Then, the air temperature inside the tower gradually rises, and the temperature T1 of the intake air of the hot air heating device gradually rises.
As shown in the figure, although the calorific value P 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 Yagura Kotatsu, a temperature sensor is used to detect the air temperature inside the tower, and when the temperature exceeds a predetermined temperature, electricity is turned on to the heating element and fan. There is no choice but to take control to stop it.

On the other hand, electric tower kotatsu, which heat small enclosed spaces, use infrared lamps as heating elements.

A kotatsu using an infrared lamp uses a large amount of electricity from the time it starts up until a certain temperature, and when that temperature is exceeded (the set temperature value), it changes to a small amount of electricity and repeats this cycle to adjust the temperature inside the yagura kotatsu.

This method has the disadvantage that the temperature inside the Yagura Kotatsu varies greatly, making the person trying to stay warm uncomfortable.

Also, the thermostat etc. that adjust the temperature mentioned above is turned on.
When turned off, radio wave interference occurs, causing noise on televisions, radios, etc.

Furthermore, if a temperature controller such as a thermostat malfunctions,
The temperature inside the Yagura Kotatsu may become abnormally high and there is a risk of a fire.

The purpose of this invention is to eliminate the drawbacks of conventional hot air heating devices,
Regardless of the volume of the space, or whether it is an open or relatively narrow closed space, the amount of heat generated varies widely and automatically depending on the intake air temperature, that is, the air temperature in the closed space, and the outlet air temperature changes automatically. To provide a hot air heating device that not only maintains a constant temperature but also can arbitrarily change the set temperature.

That is, the present invention has an airflow passage, a heating element consisting of an airflow generation fan and a positive temperature coefficient thermistor installed in the passageway, and a bimetal that displaces depending on the temperature of the heated object heated by the heating element. , a damper that is fixed to the free end of the bimetal and automatically adjusts the air flow rate to the heating element according to the amount of displacement of the bimetal; This hot air heating device includes a temperature adjustment setting mechanism that includes a temperature adjustment setting tool that sets an operation start temperature within a predetermined range and a mounting plate that fixes the temperature adjustment setting tool.

An embodiment of the present invention will be described below based on a case where it is incorporated into a tower kotatsu.

In Fig. 1, 1 is a tower, and 2 is a hot air heating device installed under the top of the tower.

Figures 2 and 3 are a top view and a vertical sectional view of the hot air heating device, and in these figures, 3 is the main body case, 4 is the air flow generation fan, and 5 is the air flow generation fan 4. A drive motor 6 is a motor fixing plate attached to the main body case 3 in order to fix the drive motor 5, and partitions a space in which the fan 4 and the motor 5 are located, and also a space between the fan 4 and the motor 5. It has a fan suction lower.

Reference numeral 8 denotes a fan casing which forms an air flow passage with this motor fixing plate 6, 9 a fan outlet of this air flow passage, 10 a heater duct communicating with the fan outlet 9, and 11 an interior of this heater duct. This is a heating element consisting of a positive temperature coefficient thermistor installed in the airflow.This is a heating element that has a large number of circular, rectangular, polygonal, etc. ventilation holes, or a large number of flat, disk-shaped, etc., arranged parallel to the air flow. One or more of these are arranged in the heater duct 10.

Furthermore, since this heating element 11 is made of a positive temperature coefficient thermistor, as the air flow rate passing through the heating element increases, the amount of heat generated increases in proportion to it, and as the air flow rate decreases, the amount of heat generated also decreases, and the air flow rate becomes extremely small. When this happens, the amount of heat generated becomes extremely small.

An intermediate duct 12 is provided between the fan outlet 9 and the heater duct 10 and is connected by bending a predetermined length at a predetermined angle so that the centers of the fan outlet 9 and the heater duct 10 are shifted in the vertical direction. The inclined surface of the intermediate duct 12 facing the fan 4 is provided with an exhaust port, and 14 divides the air flow rate generated by the fan 4 to the exhaust port 13 to reduce the air flow rate to the heating element 11. An automatically adjusting damper 15 is disposed at a curved portion of the surface of the intermediate duct 12 on the side of the heating element 11 on which the exhaust port 13 is provided, the outer peripheral end is fixed, and the center is connected to the damper through the rotating shaft 16. A spiral-shaped bimetal connected to the damper 14 is displaced in proportion to the temperature of the air to be heated, and when the temperature exceeds a predetermined temperature, it applies rotational force to the rotating shaft 16, and the damper 14 is connected to the exhaust port 13. It is rotated in the direction of

17 is fixed to the intermediate duct 12 and the bimetal 1
5 and the intermediate duct 12, and has an adjustment mechanism mounting shaft 18 that protrudes outward at a position corresponding to the center of the bimetal 15.

Reference numeral 21 denotes a temperature control setting plate rotatably attached to the shaft 18 for mounting the adjustment mechanism, and an arcuate adjustment slit 23 having the same diameter as the bimetal 15 is provided in a portion corresponding to the outer peripheral end of the bimetal 15. There is.

Reference numeral 19 is a ring spring whose center is fixed to the shaft 18 between the mounting plate 17 and the temperature control setting plate 21, and whose side surface is arcuate, and has a ball holder 20 at a predetermined distance from the center.

22 is a plurality of recesses provided at predetermined angles on the circumference of the temperature control setting plate 21 having the same radius as this ball receiver 20;
24 is a ball provided on the ball receiver 20; 25 is an outer peripheral end coupling shaft for fixing the outer peripheral end of the bimetal 15 to the temperature adjustment setting plate 21 at a predetermined position of the adjustment slit 23;
6 is a temperature adjustment lever attached to the temperature adjustment setting plate 21, and these ring springs 19% temperature adjustment setting plate 211 ball 24. The coupling shaft 25 and the temperature adjustment lever 26 constitute a temperature adjustment setting tool.

The temperature adjustment setting plate 21 is attached to the adjustment mechanism via a ball 24 in the ball holder 20 and the recess 22 of the ring spring 19, and is rotatable at a predetermined angle by a shaft 18, and receives a predetermined restoring force of the ring spring 19. and is fixed to the mounting plate 17.

27 is a main body exhaust port for air flow blown out from the exhaust port 13 provided in the main body case 3; 28 is a hot air outlet provided in the main body case 3 that communicates with the heater duct 10; 29 is a hot air outlet provided in the main body case 3; A main body suction port 30 provided in the main body case 3 is a shielding plate that communicates the exhaust port 13 with the main body exhaust port 27 and forms a suction passage from the main body suction port 29 to the fan 4.

Note that the bimetal 15 is disposed within this suction passage.

In the hot air kotatsu constructed as described above, air always comes into contact with the bimetal 15 from the main body suction port 29 through the suction passage composed of the motor fixing plate 6, the fan casing 8, and the shielding plate 20. However, the air is sucked in by the fan 4 from the fan suction lower.

At the start, the temperature inside the kotatsu is still low and the bimetal 15 is not deformed, so the damper 14 is connected to the exhaust port 1.
3 remains closed, and there is no flow of air exhausted from the exhaust port 13, and the maximum flow of air blown out through the heating element 11 is blown out from the hot air blowout port 28.

At this time, the amount of heat generated by the heating element 11 is at its maximum,
The temperature inside the kotatsu rises quickly, and since it is forced air, the internal temperature is also uniform. When the temperature inside the kotatsu exceeds a predetermined temperature, the damper 14 rotates in proportion to the temperature, and air is released from the exhaust port 13. The flow rate of air exhausted increases, and conversely the flow rate of air passing through the heating element 11 decreases.

Then, when the temperature rises to a certain value, the damper 14 rotates by a predetermined angle, completely closing the passage cross section of the intermediate duct 12, reducing the air flow rate to the heating element 11 to zero, and removing the entire air flow rate from the exhaust port 13. is exhausted.

In this state, the amount of heat generated by the heating element 11 is extremely small.

When the temperature inside the kotatsu falls, the damper 14 rotates in a direction that closes the exhaust port 13, and the flow rate of air passing through the heating element 11 increases, so that the amount of heat generated also increases.

The temperature is set by moving the outer peripheral end of the bimetal 15 by a predetermined angle using a temperature adjustment lever 26 provided on the temperature adjustment setting plate 21.

For example, the outer peripheral end of the bimetal 15 is set to a predetermined state (T
When the damper 14 starts to open the exhaust port 13 at a certain angle in the clockwise direction in FIG. 3, the damper 14 is restrained with the exhaust port 13 closed. , a predetermined torque corresponding to a predetermined angle ω is applied in the opposite direction, but the temperature adjustment setting plate 2
1 is subjected to a predetermined restraining force by the ring spring 19, so that the outer peripheral end of the bimetal 15 is fixed at a position moved by a predetermined angle θ0.

Therefore, the temperature of the air that is the object to be heated in the bimetal 15 is the sum of the temperature rise corresponding to the temperature change angle - of the bimetal 15 and the temperature T°C in a predetermined setting state (T
Since the bimetal 15 does not deform until +t)'C, the damper 14 keeps the exhaust port 13 closed and the entire air flow passes through the heat generating element 11, so the time when the amount of heat generation is at its maximum continues for a long time, and the After the temperature of the air that is heated exceeds (T10t)°C, the damper 14 begins to open the exhaust port 13 and the air flow rate to the heating element 11 decreases, so the amount of heat generated decreases, so the temperature inside the kotatsu decreases. Equilibrium occurs at a higher temperature than the predetermined set state.

Conversely, when the temperature adjustment lever 26 is moved in the opposite direction to the above-mentioned direction by a predetermined angle of 0, the bimetal 15 changes the temperature of the air to be heated from (T-t)'C, and the damper 14 opens the exhaust port 13. Since the heat generation value decreases quickly,
The temperature inside the kotatsu equilibrates at a lower temperature than the predetermined setting state.

At this time, the temperature adjustment setting plate 2 is also controlled by the ring spring 19.
1 is subjected to a restraining force, so the temperature adjustment lever 26 remains fixed.

In this way, by moving the temperature adjustment lever 26 within a predetermined angular range, the outer peripheral end of the bimetal 15 can be given a displacement amount corresponding to a predetermined temperature increase to the bimetal 15 in advance. The temperature of air, which is a substance, can be set stepwise from a low temperature to a high temperature within a predetermined range.

However, depending on the outside air conditions, the equilibrium temperature inside the kotatsu will be slightly different even under the same setting, but as shown in FIG. 6, the temperature inside the kotatsu can be controlled in stages within a predetermined range with a constant load.

Since the heating element 11 is a positive temperature coefficient thermistor, it will never overheat, and if the temperature rises, the air flow rate passing through the heating element 11 will be reduced, so the heating element 11 itself will not generate abnormal heat and will be safe. It is.

In addition, even if the temperature inside the kotatsu gets cold due to people coming and going, the damper 14 linked to the bimetal 15 automatically adjusts the air flow rate and automatically increases the heating element, keeping the temperature inside the kotatsu constant. The structure is such that it maintains

Furthermore, since the amount of heat generated is continuously and automatically adjusted, the temperature change inside the kotatsu is less than that of conventional infrared kotatsu, and does not cause discomfort to the person trying to stay warm.

The characteristic graph in FIG. 7 shows temperature changes for the conventional infrared kotatsu b and the kotatsu a of the present invention when the load is constant.

Furthermore, since it does not have a temperature regulator such as a thermostat that can be turned ON or OFF, there is no interference with radio waves to televisions, radios, etc. that occurs with conventional infrared kotatsu.

Furthermore, since the air flow rate to each heating element is adjusted by having an exhaust port and a damper in the middle of the heating element, the amount of air generated by the fan is always constant, and the cooling effect of the fan motor is large, so the life span and other factors are not taken into account. It is designed.

Since the temperature adjustment setting plate 21 has an adjustment slit, it is possible to adjust the temperature of the outer peripheral edge of the bimetal 15 within a predetermined angular range by adjusting the variations in shape and performance that occur during the manufacture of the bimetal 15. It can be fixed to the setting plate 21 with an outer peripheral end coupling shaft.

In the above embodiment, the temperature adjustment setting plate 21 has a recess 2.
A plurality of recesses 22 and balls 24 are provided at each predetermined angle, but this angle and number are not limited, and in relation to the restraint force by the ring spring 19, it is not necessary to provide the recesses 22 and the balls 24, and conversely in this case. has the advantage that the temperature can be set continuously within a predetermined range.

Furthermore, the shape of the ring spring is not limited to the above embodiments, and any shape may be used as long as it is a plate spring of any shape or a spiral-shaped spring that restrains the temperature adjustment setting plate with a predetermined force and can rotate freely. .

Also, although the ring spring is fixed to the plate, the same function can be obtained by fixing it to the temperature control setting plate and providing a recess in the plate.

The plate is fixed to the intermediate duct, but it can be installed anywhere in a rigid place so that it will not get in the way even if the temperature control setting plate is moved within the specified range, and will not move to the extent that the function can be obtained. It may be fixed.

Furthermore, the damper is driven by applying rotational torque to the rotational axis of a spiral-shaped bimetal; however, the invention is not limited to this. Fix the central axis of the bimetal to the temperature control setting plate.

It is also possible to adjust the set temperature by giving a predetermined rotation angle to the central axis.

If the bimetal is provided in the air flow path between the fan and the exhaust port, the bimetal will always be in contact with air that has the same temperature as the air to be heated, so the temperature control will be able to follow it even better.

Furthermore, although the plate is installed between the bimetal and the temperature control setting plate, the installation position is not limited.

Although the temperature adjustment lever is fixed at right angles to the plane of the temperature adjustment setting plate, it is not limited to this, and may be installed parallel or any other way, or it may be integrally formed with the temperature adjustment setting plate. It may be any mechanism as long as it can be easily operated by the user.

Driving the damper is not limited to a spiral-shaped bimetal; the disadvantage is that the shape of the bimetal must be large to achieve the desired function; however, one end of the plate-shaped bimetal is connected to the damper, and the other end is used for temperature adjustment and setting. It may also be fixed to a board.

By the way, in the above description, the case where this invention is used for a yagura kotatsu was explained, but it goes without saying that it can be used for other heaters as well.

As explained above, in this invention, the heating element consists of a positive temperature coefficient thermistor, and air is forcibly sent to the heating element, and a damper is operated depending on the temperature, so that the amount of air blown can be varied. Since the flow rate is maximum, the amount of heat generated is maximum, and since it is forced air, the temperature rises quickly and uniformly, and when the temperature exceeds a predetermined temperature, the damper automatically changes the air flow rate to the heating element, reducing the amount of heat generated. Since it changes continuously, it provides comfortable warmth with little temperature change even in a narrow closed space, and the temperature at which the damper starts to operate can be set arbitrarily within a specified range by giving a specified displacement to the bimetal, so it is possible to heat the object to be heated. It is possible to provide a highly safe hot air heating device that can set the temperature arbitrarily and does not cause radio wave interference.

[Brief explanation of drawings]

Figure 1 is a vertical cross-sectional view of this device installed in a Yagura Kotatsu.
Figure 2 is an enlarged top view of this device, Figure 3 is III of Figure 2.
-I sectional view, Figure 4 is the IV-ff sectional view of Figure 2,
The figure is a side view of Fig. 4, Fig. 6 is a graph showing the temperature change with respect to time when the load is constant, and Fig. 7 is a graph showing the temperature change with respect to time when the load is constant. Comparative characteristic diagrams for kotatsu; Figure 8 is a vertical cross-sectional view of a conventional hot air heating device; Figure 9 is a characteristic diagram of the amount of air passing through a positive temperature coefficient thermistor heating element and the amount of heat generated; Figure 10 is a diagram of the conventional It is a characteristic diagram showing the relationship between the temperature inside the kotatsu and the amount of heat generated with respect to time when the hot air heating device is installed in the kotatsu. In the figure, 4 is a fan for generating airflow, 5 is a motor, 1
1 is a heating element, 12 is an intermediate duct, 13 is an exhaust port, 14 is a damper, 15 is a bimetal, 17 is a mounting plate, 19 is a ring spring, 21 is a temperature adjustment setting plate, 23 is an adjustment slit, 24 is a ball, 25 is the coupling shaft, and 26 is the temperature control lever. Note that the same reference numerals in the figures indicate the same parts.

Claims (1)

[Scope of Claims] 1. A heating element having an airflow passage and consisting of an airflow generation fan and a positive temperature coefficient thermistor provided in the passageway, and a heating element that is displaced according to the temperature of the heated object heated by the heating element. a damper that is fixed to the free end of the bimetal and automatically adjusts the air flow rate to the heating element according to the displacement of the bimetal, and a damper that is fixed to the fixed end of the bimetal;
It is characterized by comprising a temperature adjustment setting mechanism that includes a temperature adjustment setting tool that sets the operation start temperature of the damper within a predetermined range by applying displacement to the bimetal in advance, and a mounting plate that fixes the temperature adjustment setting tool. Hot air heating equipment. 2 A bimetal is formed into a spiral shape, its fixed end is fixed to a temperature adjustment setting plate by a connecting shaft, and by rotating this temperature adjustment setting plate, a displacement is given to the bimetal in advance, and this temperature adjustment setting plate is 2. The hot air heating device according to claim 1, wherein the temperature adjustment setting tool includes a spring for fixing the temperature adjustment setting tool to the mounting plate. 3. Claims characterized in that an adjustment slit of a predetermined distance and a predetermined width is provided in the temperature adjustment setting plate, and the connection position at which the fixed end of the bimetal is fixed to the temperature adjustment setting plate by a connecting shaft can be adjusted. The hot air heating device according to item 2.