JP3167912B2 - Hot air heater - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a hot air heater such as a fan heater.

[0002]

2. Description of the Related Art For example, in the case of a fan heater, a burner and a blowing fan (convection fan) are provided in a main body case.
The indoor air is drawn into the warm air passage formed in the main body case by the blower fan, and it is heated by the combustion heat of the burner in the middle of the warm air passage, and the warm air is blown from the outlet of the warm air passage. It blows out indoors.

[0003] In this type of hot air heater, the intake or outlet of the hot air blowing passage may be blocked or clogged,
If the blower fan fails and stops operating, air will no longer flow in the hot air blower path, or the flow of air will be excessively low. As a result, there is a risk that the device may fail, and that excessively hot air may be blown out.

For this reason, in this type of hot air heater, a temperature sensor for detecting the temperature of the hot air blowing path by the burner is usually provided in the hot air blowing path, and the temperature detected by the temperature sensor becomes excessive. When the temperature becomes higher than a predetermined temperature set in advance, the burner is automatically extinguished and the heating operation is stopped.

[0005] When the airflow in the hot air passage is suddenly reduced, as in the case where the air inlet and outlet of the hot air passage are suddenly blocked or the blower fan does not operate, the hot air is blown off. Because the heating temperature of the air passage rises rapidly, even if the combustion of the burner is stopped when the temperature detected by the temperature sensor reaches the predetermined temperature, the temperature of the hot air air passage exceeds the predetermined temperature due to overshoot. It will rise to an excessively high temperature. On the other hand, when the blower fan is operating normally, but the filter is clogged by dust or the like, the degree of blockage of the inlet and outlet of the warm air blowing passage gradually increases, and in this state, Although the heating temperature of the hot air blowing path gradually increases to the predetermined temperature, if the combustion of the burner is stopped when it is detected that the temperature has increased to the predetermined temperature, the heating temperature does not increase to an excessively high temperature. When the blower fan stops operating, it is preferable to stop the heating operation as quickly as possible in order to prevent a failure of the device due to an excessively high temperature.

For this reason, in a conventional warm air heater, for example, as disclosed in Japanese Patent Application Laid-Open No. 6-123425, the amount of increase in the temperature detected by the temperature sensor per unit time is detected and the increase is detected. When the amount is equal to or more than a predetermined value and it is detected that a rapid temperature rise has occurred, the heating operation is stopped at that time, and the heating operation is stopped before the temperature reaches the predetermined temperature, whereby the excess In order to prevent the temperature from rising to a high temperature, if the amount of increase in the temperature detected by the temperature sensor is smaller than the predetermined value and the temperature rise is relatively gentle, the heating operation is performed when the detected temperature rises to the predetermined temperature. It has been proposed to stop the operation.

However, such a hot air heater has the following disadvantages.

That is, when the operation of the hot air heater is started in a low temperature state where the room or the hot air heater is sufficiently cooled, for example, the operation of the hot air heater in a cold region, generally, the desired operation of the blower fan is required. The rise to rotation speed is also bad. For this reason,
Even when the blower fan is normal and the inlet and outlet of the warm air passage are not suddenly closed, the temperature of the warm air passage often rises relatively sharply.

In such a state, if the room temperature or the like is increased to some extent by the heating operation of the warm air heater, a sufficient amount of indoor air can be flown into the warm air passage by the blower fan. In addition, since the temperature of the hot air blowing passage does not suddenly rise, it is not necessary to stop the heating operation of the hot air heater.

However, in the above-described conventional hot air heater,
When the heating operation is started in the low temperature state as described above, and the temperature of the hot air blowing path rises relatively rapidly by the amount of increase equal to or more than the predetermined value, the heating operation is stopped in the predetermined time. It will be.

Therefore, in the conventional warm air heater, when the heating operation is started in a low temperature state, it is not necessary to stop the heating operation originally, and even if the heating operation can be continued without any trouble, There was a disadvantage that the operation was stopped.

[0012]

SUMMARY OF THE INVENTION The present invention solves such inconvenience, and immediately stops the heating operation in an abnormal state in which the heating temperature of the hot air blowing passage rises to an excessively high temperature due to a failure of a blowing fan or the like. It is an object of the present invention to provide a hot-air heater capable of performing a heating operation without any trouble and in a state where the heating operation can be performed without any trouble, without unnecessarily stopping the heating operation.

[0013]

According to the present invention, there is provided a main body case having a heater housed therein.
A warm air blowing passage formed in the main body case through the heater, and a blower fan that draws room air from an inlet of the warm air blowing passage and blows air from an outlet of the warm air blowing passage. ,
A temperature sensor disposed in the hot air blowing path to detect a heating temperature of the hot air blowing path by the heater; and the hot air flowing to stop the heating operation in a state where the temperature detected by the temperature sensor becomes excessively high. In a warm air heater equipped with operation control means for controlling the heater, a temperature rise grasping means for grasping a rise amount per unit time of a temperature detected by the temperature sensor during a heating operation, and grasping by the temperature rise grasping means. Temperature setting means for setting an excessively high stop temperature for stopping the heating operation by the operation control means in accordance with the temperature increase amount, wherein the temperature setting means sets the predetermined excessively high stop temperature to the predetermined value. Set so that the higher the temperature rise, the lower
The operation control means is configured to stop the heating operation when the temperature detected by the temperature sensor rises above the set excessively high stop temperature.

According to the present invention, the operation control means stops the heating operation when the temperature detected by the temperature sensor rises above the excessively high stop temperature set by the temperature setting means. In this case, the excessive hot stop temperature is
Since the temperature rise per unit time grasped by the temperature rise grasping means is set to be lower as the temperature rise per unit time is larger, the failure of the blower fan or the blockage of the inlet or outlet of the warm air blower passage causes the blower fan to operate. The excess high-temperature stop temperature is set to be lower as the flow of air in the hot-air blowing passage decreases and the heating temperature of the hot-air blowing passage by the heater easily rises sharply. Therefore,
If the blower fan fails or the intake or outlet of the warm air passage is blocked, the flow of air in the warm air passage tends to be insufficient, so that the lower excessively high temperature stop temperature is lowered. The heating operation is stopped by the operation control means when the temperature detected by the temperature sensor rises, and the heating operation is stopped more quickly as the temperature of the hot air blowing passage tends to become excessively high. Further, when the heating operation is started in a low temperature state such as room temperature, in the early stage of the heating operation, the amount of increase in the temperature detected by the temperature sensor is relatively large, and the excessive high-temperature stop temperature is relatively large. Although the temperature may be set lower, if the blower fan is normal and the air inlet or the outlet of the hot air blow path is less obstructed, the temperature of the hot air blow path rises relatively sharply. Is a temporary one at the beginning of the heating operation, so that the temperature of the hot air blowing passage does not rise to the excessively high temperature stop temperature due to sufficient air blowing by the blowing fan. Therefore, the operation control means does not stop the heating operation, and the heating operation is continued.

Thus, according to the present invention, in an abnormal state where the heating temperature of the hot air blowing passage rises to an excessively high temperature due to a failure of the blower fan or the like, the heating operation can be stopped quickly and troublesome. In a state where the heating operation can be performed without heating, the heating operation can be surely continued without unnecessarily stopping the heating operation.

In the present invention, the setting of the excessively high stop temperature by the temperature setting means may be performed, for example, only at the beginning of the heating operation, and thereafter, the set excessively high stop temperature may be maintained. In Although,
It is particularly preferable that the temperature setting means sets the excessively high-temperature stopping means while updating it from time to time according to the amount of temperature rise grasped by the temperature rise degree grasping means from the start of the heating operation.

According to this, while the heating operation is being continued, the intake port or the outlet port of the hot air blowing passage is suddenly excessively blocked, or the blower fan breaks down and stops, and the temperature rises. Even in the case where the temperature of the air blowing passage rises to an excessively high temperature, the amount of the temperature rise is determined as the temperature of the air flowing through the hot air blowing passage decreases and the temperature rises more easily. Since the excessively high stop temperature is set from moment to moment, the heating operation can be stopped at an appropriate speed according to the degree to which the flow of air in the hot air blowing passage is reduced.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a system configuration diagram of a hot air heater provided with a blower of the present embodiment, FIG. 2 is a perspective view of the hot air heater as viewed from the rear side, and FIG. FIG. 4 is a block diagram illustrating the operation of the main part of the hot air heater.

Referring to FIG. 1 and FIG. 2, the hot air heater of the present embodiment is a gas hot air heater, and a duct 2 (a hot air blowing path), The apparatus includes a blower fan 3 (convection fan), a gas burner 4 (heater), a duct 5, a gas supply pipe 6, and a control unit 7.

The duct 2 has an intake port 8 for taking in room air at the back of the main body case 1 and an outlet 9 for warm air at the lower front part of the main body case 1. An air filter 10 is detachably attached to the intake port 8 to prevent dust and dirt from flowing into the duct 2.
A movable louver 11 for adjusting the opening degree is attached to the outlet 9, and a gad motor 12 for driving the movable louver 11 is provided. A temperature sensor 13 for detecting a heating temperature in the duct 2 by the gas burner 4 is provided on an inner wall near the intake port 8 of the duct 2, and the temperature sensor 13 sends a signal indicating the detected temperature to a control unit. 7 is output. The temperature sensor 13
Is provided at a position where the air sucked into the duct 2 does not directly hit.

The blower fan 3 has a fan motor 14 whose number of revolutions changes in proportion to the supplied current, and rotating blades 15 driven to rotate by the fan motor 14.
The indoor air s is sucked into the duct 2 from the intake port 8 by the rotation of 5. Then, the sucked room air s is mixed with the combustion exhaust gas h of the gas burner 4 incorporated in the duct 2 and heated, and is blown out from the outlet 9 as warm air m. The blower fan 3 is provided with a rotation speed sensor 16 for detecting the rotation speed. The rotation speed sensor 16 is configured by a Hall IC that generates a predetermined number of pulses for each rotation of the fan motor 14, and provides its output to the control unit 7.

Gas burner 4 incorporated in duct 2
Has a combustion plate 18 disposed in a combustion cylinder 17 and an ignition electrode 19 for igniting an air-fuel mixture disposed downstream of the combustion plate 18. The combustion cylinder 17 of the gas burner 4 is arranged in the duct 2, and the combustion exhaust h is discharged into the duct 2 outside the combustion cylinder 17. Further, a thermocouple 20 for detecting abnormal combustion is disposed downstream of the combustion plate 18, and the thermocouple 20 is exposed to the combustion flame of the gas burner 4 to generate an electromotive force, which is transmitted to the control unit 7. Output to

The duct 5 is a passage for supplying the indoor air s and the fuel gas to the gas burner 4.
The main body case 1 has an intake port 21 for room air s which communicates with the inside of the combustion cylinder 17 and is defined in the duct 2 and is incorporated in the main body case 1 and opened on the back surface of the main body case 1. On the way from the intake port 21 of the duct 5 to the gas burner 4,
A nozzle 22 attached to the tip of the gas supply pipe 6 is introduced. The indoor air s is sucked into the duct 5 from the air inlet 21 by the rotation of the blower fan 3, and the sucked indoor air s is ejected from the nozzle 22 of the gas supply pipe 6 in the process of reaching the gas burner 4. The mixture with the gas is supplied to the gas burner 4. In addition, the intake port 21
Is covered by an air filter 10 together with the intake port 8 of the duct 2. A room temperature sensor 23 composed of a thermistor is provided at a position near the air inlet 21 inside the duct 5.
The room temperature sensor 23 outputs an electric output corresponding to the room temperature to the control unit 7.

In the gas supply pipe 6 in which the nozzle 22 is introduced into the duct 5, electromagnetic valves 24, 25 and a proportional valve 26 are arranged in this order from the upstream side.

The solenoid valves 24 and 25 allow the fuel gas to pass in the direction of the nozzle 22 when the valve is opened by energization, and block the passage of the fuel gas when the valve is closed by stopping the energization.

The proportional valve 25 is a valve whose opening increases in accordance with the magnitude of the energizing current, and the energizing current is proportional to the amount of gas supplied to the gas burner 4.

An operation switch 27 is provided on the upper surface of the main body case 1.
A room temperature setting switch 2 is provided inside an opening / closing lid 1a (see FIG. 2) provided on the upper surface of the main body case 1.
8 and a filter lamp 29 are provided.

The ON / OFF operation of the operation switch 27 instructs the control unit 7 to start or end the heating operation.

The room temperature setting switch 28 is an operation switch for setting the room temperature, and instructs the control unit 7 to raise or lower the set room temperature by, for example, 1 ° C. by a predetermined operation.

The filter lamp 29 notifies the user of the necessity of cleaning the air filter 10 by lighting.

Referring to FIG. 3, the control unit 7 is constituted by using a microcomputer or the like, and has a functional configuration as an operation control unit 30 (operation control means), a temperature rise grasping unit 31 ( Temperature rise grasping means) and a temperature setting section 32 (temperature setting means).

The operation control unit 30 includes an operation start / end instruction by an operation switch 27, an instruction of a set room temperature by a room temperature setting switch 28, a detected room temperature by a room temperature sensor 23, a detected rotation speed of the blower fan 3 by a rotation speed sensor 16, Based on the output of the thermocouple 20, the detected temperature of the duct 2 by the temperature sensor 13, the excessively high stop temperature set by the temperature setting unit 32 as described later, etc., the fan motor 14, the proportional valve 26, the solenoid valves 24, 25, The operation of the hot air heater is controlled by controlling the ignition electrode 19, the filter lamp 29, and the like. Details of this control will be described later.

The temperature rise grasping unit 31 obtains the amount of temperature rise in the duct 2 per unit time from time to time based on the temperature detected by the temperature sensor 13.

The temperature setting unit 32 determines an excessively high temperature stop temperature for stopping the heating operation of the warm air heater by the operation control unit 30 in the excessively high temperature state in the duct 2 by the temperature rise grasping unit 31. The temperature is set according to the amount of rise, and the set value of the excessively high stop temperature is updated each time the amount of temperature rise is obtained by the temperature rise grasping unit 31. In this case, the temperature setting unit 32, for example, calculates the temperature rise amount per unit time (for example, 1 s) obtained by the temperature rise grasping unit 31 (hereinafter, referred to by a reference symbol Δt).
However, if Δt ≦ 1 deg, the excessive high-temperature stop temperature is set to 80 °
If C is 1 deg <Δt ≦ 2 deg, the excessively high stop temperature is set to 70 ° C., and if Δt> 2 deg, the temperature is set to 60 ° C. Accordingly, the temperature setting unit 32 sets the excessively high stop temperature lower as the amount of temperature rise per unit time in the duct 2 is larger. Hereinafter, the above set values of the excessively high stop temperature of 80 ° C., 70 ° C., and 60 ° C. are referred to as T ₁ ,
_They are called T ₂ and T ₃ .

The excessive high-temperature stop temperature set as described above is higher than the temperature in the duct 2 in the normal heating operation state of the hot air heater.

Next, the operation of the warm air heater of this embodiment will be described.

When the user turns on the operation switch 27, the operation is started under the control of the operation control unit 30 of the control unit 9 accordingly. At this time, the control unit 9
The operation control unit 30 energizes the solenoid valves 24 and 25 to open them, and further energizes the proportional valve 26 with a predetermined energizing amount to supply a predetermined amount of fuel gas to the gas burner 4. Further, the operation control unit 30 controls the energization of the fan motor 14 so as to rotate the blower fan 3 at a predetermined number of revolutions, and draws air into the ducts 2 and 5. In this state, the operation control unit 30 monitors the output of the thermocouple 20 while monitoring the output of the thermocouple 20.
9, the gas burner 4 is ignited and its combustion is started.

When the combustion of the gas burner 4 is started in this way, the operation control unit 30 determines the required combustion of the gas burner 4 to match them based on the detected room temperature of the room temperature sensor 23 and the room temperature set by the room temperature setting switch 28. The amount is calculated every moment, and the proportional valve 26 is energized and the rotation speed of the blower fan 3 is controlled to a required target rotation speed so as to burn the gas burner 4 with the calculated required combustion amount.

As a result, warm air is blown from the outlet 9 of the duct 2 so that the room temperature matches the set room temperature, and the heating operation of the warm air heater is performed.

On the other hand, in such a heating operation, the temperature rise in the duct 2 per unit time Δt from the start of the heating operation is obtained from the temperature detected by the temperature sensor 13 by the temperature rise grasping unit 31 from time to time. The excessive high-temperature stop temperature T ₁ or T ₂ according to the obtained temperature increase Δt.
Alternatively, T ₃ is set while being updated from time to time by the temperature setting unit 32. During the heating operation, the operation control unit 3
0 is always the temperature detected by the temperature sensor 13, and compares the excess hot shutdown temperatures T ₁ or T ₂ or T ₃ is currently set, the detected temperature is excessively hot shutdown temperatures T ₁ or T ₂ or T _When an excessively high temperature of _three or more is reached, the solenoid valves 24 and 25 are closed to extinguish the gas burner 4 and forcibly stop the heating operation in order to prevent a failure or the like of the hot air heater. Further, after a predetermined time or when the detected temperature in the duct 2 decreases to the predetermined temperature, the fan motor 14 is stopped and the rotation of the blower fan 3 is stopped.

More specifically, when the temperature in the duct 2 at the temperature sensor 13 is normal in a state where the blower fan 3 is normal and the air filter 10 is not clogged or the like, the room temperature at the start of operation is very small. When the temperature is not low, for example, as shown by a solid line a in FIG. 4, the temperature gradually rises from the start of combustion of the gas burner 4 and finally reaches an equilibrium temperature corresponding to the set room temperature (which is higher than the set room temperature). Reach.

In this case, in the early stage of the combustion of the gas burner 4,
The rise Δt per unit time of the detected temperature of the temperature sensor 13 grasped by the temperature rise grasping unit 31 is 1 deg <Δ
When t ≦ 2 deg, the excessive high-temperature stop temperature becomes T ₂ (70
° C> T ₁ ), but shortly thereafter the excessive hot shutdown temperature is set to the highest T ₃ (80 ° C). In this case, regardless of which of the excessively high stop temperatures T ₂ and T ₃ is set, the temperature detected by the temperature sensor 13 (the temperature in the duct 2) becomes the excessively high stop temperature T ₂ or T _3. This is not the case, and the heating operation is continued.

Also, even in a normal state, in a low temperature state where the room temperature at the start of operation is considerably low, the starting performance of the fan motor 12 is reduced. As shown by, a relatively sharp rise occurs in the early stage of combustion of the gas burner 4 as compared with the case of the solid line a, but thereafter, the temperature gradually rises toward the solid line a and finally reaches the equilibrium temperature.

In this case, in the initial stage of the combustion of the gas burner 4, the amount of increase Δt per unit time of the temperature detected by the temperature sensor 13 grasped by the temperature rise grasping section 31 is Δt>
The temperature may become 2 deg, and the excessive high-temperature stop temperature may be set to the lowest T ₁ (60 ° C.) by the temperature setting unit 32, but thereafter, the excessive high-temperature stop temperature becomes T ₂ (70 ° C.).
C) and T ₁ (80 ° C.). Also in this case, the temperature detected by the temperature sensor 13 (temperature in the duct 2) is over-hot shutdown temperature T ₁ through T ₃ or more and not become, the heating operation is continued.

On the other hand, when it is assumed that the room temperature at the start of combustion of the gas burner 4 is the same as the case indicated by the solid line a, the fan motor 14 fails and becomes inoperable, or the air filter 10 In a state in which clogging has occurred and air cannot flow in the duct 2 or the flow of the air is extremely small, the heat of combustion of the gas burner 4 is accumulated in the duct 2. The temperature in the duct 2 at the location causes a continuous and rapid rise, for example as shown by the solid line c in FIG.
Note that such a rapid temperature rise occurs similarly as shown by the broken line d in the figure even when the room temperature at the start of combustion of the gas burner 4 is as low as the case of the solid line b. This also occurs when the outlet 9 and the inlet 8 of the duct 2 are closed.

In this case, in the early stage of the combustion of the gas burner 4,
The amount of increase Δt per unit time of the temperature detected by the temperature sensor 13 grasped by the temperature rise grasping section 31 is equal to the gas burner 4.
Δt> 2 deg continuously from the start of the combustion of, and therefore the excessively high stop temperature set by the temperature setting unit 32 is continuously the lowest T ₁ (60 ° C.). Then, the temperature detected by the temperature sensor 13 rises above the set excessively high temperature stop temperature T ₁ (60 ° C.), and therefore, the operation control unit 30 stops the operation of the hot air heater as described above. Let me know. At this time, the excessive high temperature stop temperature T ₁ (60 °
C) is the lowest, so that the temperature detected by the temperature sensor 13 reaches the excessively high-temperature stop temperature T ₁ (60 ° C.) in a short time after the combustion of the gas burner 4 starts (in FIG. 4, at times t _C and t _C) .
t _D ) Therefore, the stop of the heating operation by the operation control unit 30 is quickly performed. This avoids a situation in which the temperature inside the duct 2 suddenly rises to an excessively high temperature state.

Further, for example, during the normal heating operation, the fan motor 14 breaks down and the blower fan 15 stops, or the outlet 9 and the inlet 8 of the duct 2 are blocked by some shielding. In such a case, for example, as shown by a virtual line e in FIG. 4, the temperature in the duct 2 rapidly rises. In this case, the temperature setting unit 32 immediately sets the lowest excessive high-temperature stop temperature T ₁ (60 ° C.) due to the rapid temperature rise in the duct 2. Therefore, when the temperature detected by the temperature sensor 13 rises to the lowest excessive high-temperature stop temperature T ₁ (60 ° C.), the operation control unit 3
When 0, the heating operation is stopped, and a situation in which the temperature in the duct 2 rapidly rises to an excessively high temperature state is quickly avoided.

In a state where dust and the like gradually adhere to the air filter 10 during operation, for example, the temperature in the duct 2 rises as shown by a solid line f and a broken line g in FIG. In this case, if the increase in the temperature detected by the temperature sensor 13 to the excess hot shutdown temperature T ₂ or T ₃ is set corresponding to the temperature rise amount Δt per unit momentary time at elevated temperatures, operation control The heating operation is stopped by the unit 30. In a state in which dust gradually adheres to the air filter 10 as described above, the temperature inside the duct 2 does not suddenly increase to an excessively high temperature. until it is detected that reaches over hot shutdown temperature T ₂ or T _3, it is possible to perform the operation.

Since the operation is not stopped at the excessively high temperature stop temperature T ₁ set low, the operation is performed in a state where dust is slightly attached to the air filter 10 (a state where it is not necessary to stop the combustion). There is no inconvenience of stopping.

Furthermore, if the filter lamp 29 is turned on or blinks when the temperature rises to near the high excessive high-temperature stop temperature T ₂ or T _3, an abnormality such as a fan lock (rotation of the blower fan 3) or the like can be avoided. Filter lamp 2
Since the light 9 does not light or blink, only the necessity of cleaning the air filter 10 can be accurately notified to the user.

As described above, according to the hot air heater of the present embodiment, the temperature in the duct 2 rapidly rises to an excessively high temperature due to the failure of the blower fan 4 or the sudden clogging of the air filter 10. In such a case, the heating operation is stopped immediately to prevent the hot-air heater from being damaged due to an excessively high temperature, and the heating operation cannot be performed without any trouble. The heating operation can be continued without stopping the heating operation as necessary.

In the present embodiment, the excessively high stop temperature set in accordance with the temperature rise Δt in the duct 2 is set to T ₁ to T _1.
3 , the excessively high temperature stop temperature corresponding to the temperature increase Δt is continuously changed in accordance with the temperature increase Δt (however, as the temperature increase Δt is larger, the excessively high (To lower the temperature).

In this embodiment, the gas burner 4 is used as a heater. However, the present invention can be applied to a petroleum hot air heater or an electric heater as a heater. Of course.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram of a hot air heater according to an embodiment of the present invention.

FIG. 2 is a perspective view of the warm air heater of FIG. 1 as viewed from the rear side.

FIG. 3 is a block diagram of a main part of the hot air heater of FIG. 1;

FIG. 4 is a diagram for explaining the operation of the main part of the warm air heater of FIG. 1;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Body case, 2 ... Duct (hot air blowing path), 3 ... Blow fan, 4 ... Gas burner (heater), 13 ... Temperature sensor, 30 ... Operation control part (operation control means), 31 ... Temperature rise grasping part (Temperature rise grasping means), 32 ... Temperature setting section (Temperature setting means).

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) F24H 3/04 305 F23N 5/14 370 F23N 5/24 104

Claims (2)

(57) [Claims] 1. A main body case in which a heater is housed, a hot air blowing passage formed in the main body case through the heater, and room air is sucked from an air inlet of the hot air blowing passage. hand,
A blower fan that blows air from an outlet of the hot air blowing path, a temperature sensor disposed in the hot air blowing path to detect a heating temperature of the hot air blowing path by the heater, and a temperature detected by the temperature sensor. An operation control means for controlling the hot air heater to stop the heating operation in an excessively high temperature state.In a hot air heater, the amount of increase in the temperature detected by the temperature sensor per unit time during the heating operation is determined. Temperature rise grasping means for grasping, and temperature setting means for setting an excessively high stop temperature for stopping the heating operation by the operation control means according to the temperature rise amount grasped by the temperature rise grasping means, The temperature setting means sets the predetermined excessively high stop temperature to be lower as the temperature rise amount is larger, and the operation control means sets the excessively high temperature at which the temperature detected by the temperature sensor is set. A hot-air heater configured to stop the heating operation when the temperature rises above a stop temperature. 2. The temperature setting means sets the excessively high temperature stop means while updating it from time to time according to the amount of temperature rise grasped from time to time by the temperature rise degree grasping means from the start of the heating operation. A hot air heater.