JP3967281B2 - Hot air heater - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a hot air heater using electricity, gas, or oil as a heat source.
[0002]
[Prior art]
In recent years, fan heaters have been equipped with safety devices against overheating and falling, and there is no risk of burns even if they are touched by hands. The structure is located in the lower part of the front of the main body, and warm air travels over the floor surface and warms from the feet, so that there is an advantage that extremely ideal heating for the cold head heat is obtained.
[0003]
However, the fan heater as described above has a structure in which hot air is blown out along the floor surface. Therefore, if an elderly person or a child gets too close to the hot air outlet, the clothes overheat. There is a risk of low temperature burns. In such a case, it is desirable to immediately stop the operation of the fan heater.
[0004]
As a conventional hot air heater, Patent Document 1 discloses a hot air outlet provided on a front plate of an apparatus main body, a radiation sensor provided below and near the floor, and an output from the radiation sensor. And a controller that controls the heating output, effectively detects the radiant heat from the floor near the living space and controls the heating output effectively, and when an obstacle is placed in front of the equipment body It is disclosed that the backflow of hot air is sensitively detected and the amount of combustion is controlled before the temperature of the obstacle itself becomes high.
[0005]
Patent Document 2 discloses a safety device in which a non-contact type temperature detecting element such as a pyroelectric type is provided on the entire surface of a heater, and the operation of the heater is stopped when an obstacle approaches the front of the heater. It is disclosed.
[0006]
In Patent Document 3, an object distance sensor is attached in the vicinity of a hot air outlet provided at the lower front surface of the fan heater body, and the object distance sensor detects an object within a certain distance. A fan heater is disclosed in which a timer is activated by an output and the operation of the fan heater is stopped or a combustion amount is reduced by a limit output of the timer.
[0007]
[Patent Document 1]
JP-A-8-327057 (see abstract)
[Patent Document 2]
Japanese Utility Model Publication No. 58-108319 (refer to the specification, line 1 line 11 to line 15)
[Patent Document 3]
Japanese Patent Laid-Open No. 11-257752 (refer to claim 1, abstract)
[0008]
[Problems to be solved by the invention]
By the way, even if an object is detected in the fan heater as described above, if the object simply passes through the place or leaves the place in a relatively short time, the operation of the fan heater is immediately stopped. Is not preferred for use.
[0009]
However, in the fan heaters disclosed in Patent Documents 1 and 2, since the backflow of hot air is sensitively detected, the object simply passes through the place or leaves the place in a relatively short time. However, there is a risk of stopping the operation of the fan heater. In addition, since one temperature sensor (radiation sensor or non-contact type temperature detection element) is used for both room temperature detection and obstacle detection, changes in room temperature, environmental conditions around the blower (for example, dust on the filter) However, there is a problem that accurate detection is not always possible depending on changes in lighting and the like, and further on the installation state of the hot air heater.
[0010]
Further, in Patent Document 3, since the obstacle is detected by the distance sensor, the operation is stopped even when a relatively low temperature hot air is blown out and there is no risk of a burn regardless of the hot air blowing temperature. There is a drawback.
[0011]
In view of the above, the present invention constantly monitors the presence or absence of an object ahead, stops the operation only when it is dangerous, or reduces the heating output so that the safety can be improved. It is for the purpose of provision.
[0018]
[Means for Solving the Problems]
In order to achieve the above object, in the hot air heater according to the present invention, the device main body, the hot air outlet provided in the front plate of the device main body, and the device main body provided in the vicinity of the hot air outlet of the front plate A temperature sensor that detects the temperature of hot air that flows back to the device body due to an obstacle located in front of the room, a room temperature detection sensor that detects the indoor air temperature, and a control unit that controls heating output, the control unit Has a heating output smaller than a normal heating output when the temperature difference detected by the temperature sensor and the room temperature detection sensor continues for a first time at a value equal to or greater than the first value, When a temperature difference equal to or greater than a second value smaller than the value is continued for a second time longer than the first time, the temperature is once returned to the original heating output, and the above cycle is repeated again a plurality of times. When the second is repeated a plurality of times Characterized by stopping the heating output when the temperature difference is not eliminated over. According to the above configuration, the state of the obstacle can be reliably monitored in the heating output state, and the safety can be improved while maintaining the heating operation more satisfactorily .
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of an oil fan heater equipped with a liquid fuel combustion device as a hot air heater according to the present invention will be described with reference to the drawings. FIG. 1 is a front perspective view of an oil fan heater equipped with a liquid fuel combustion apparatus, and FIG. 2 is a side sectional view of the same.
[0020]
In FIG. 1, 1 is a device main body, 2 is a lower part of a front plate 7 of the device main body, a hot air outlet provided with a louver for guiding hot air, and 3 is an operation disposed on the front side of the upper surface of the main body. The display unit 4 is a louver that blows out hot air in a downward direction, and 5 is a fuel tank that also has a main body lid. The exterior body of the apparatus main body 1 is configured such that a front plate 7 that covers the front surface, an upper surface plate 8 that covers the upper surface, and a back plate 9 that covers the side surfaces and the rear surface are fixed on the mounting table 10.
[0021]
In FIG. 2, 11 is a convection fan as a blowing means attached to the hot air intake on the back side of the apparatus main body, 12 is a fan motor of the convection fan, 13 is an air intake provided on the back of the apparatus main body 1, 14 is a combustion chamber, and 15 is a burner below the combustion chamber. The combustion chamber 14 and the burner 15 constitute a heat generating part of the hot air heater. The heating capacity of the heat generating portion is changed by controlling each component of the fuel path shown in FIG.
[0022]
FIG. 3 is a schematic view of the fuel path. In FIG. 3, 5 is a fuel tank that can be removed from the main body, 19 is an ignition heater, 20 is a flame sensor as flame detection means disposed above the burner, 21 is an electromagnetic pump as a pump for sending fuel in the fuel tank, 22 Is a vaporizer that heats the fuel from the electromagnetic pump to turn it into vaporized gas, and 15 is a burner that jets vaporized gas from the vaporizer through a nozzle, mixes it with combustion air, and burns it. Although not shown, the vaporizer 22 is provided with a solenoid valve that opens and closes the nozzle and a vaporizer heater that heats the vaporizer.
[0023]
Reference numeral 24 denotes a first (oil feeding side) connecting means for connecting the fuel tank 5 and the combustion section when the fuel tank is mounted on the main body, and includes a tank-side connection joint 24a and a combustion joint-side connection joint receiver 24b. Consists of Reference numeral 25 denotes a second (return oil side) connecting means for connecting the oil tank and the vaporizer and returning the unburned gas to the oil tank 5 when the oil tank is attached to the main body, and the tank side connection joint 25a. And a connection joint receiver 25b on the combustion part side.
[0024]
The oil supply side connecting means 24 is provided with an air valve 26 for sending air into the path. The air valve 26 is driven to open and close by a solenoid. Further, a pipe 27 is provided between the first connecting means 24 and the electromagnetic pump 21 of the fuel tank 5, a pipe 28 is provided between the electromagnetic pump 21 and the vaporizer 22, and a return oil is provided between the vaporizer 22 and the second connecting means 25. They are connected by a pipe 29.
[0025]
In FIG. 2, reference numeral 31 denotes a temperature sensor, which is provided below the hot air outlet 3 of the front plate 7. Reference numeral 32 denotes a room temperature thermistor as a room temperature detection sensor provided in the vicinity of the air intake port 13. The temperature sensor 31 and the room temperature thermistor 32 detect the temperature by utilizing the fact that the resistance value changes depending on the temperature received by the temperature sensing unit.
[0026]
FIG. 4 is a cross-sectional view showing the mounting structure of the temperature sensor 31. As shown in the figure, an opening 33 is formed in the lower part of the front plate 7 of the apparatus body, and a cylindrical holder 34 for holding the temperature sensor 31 from the inside is fitted into this opening. The end side is attached to the mounting bracket 35 on the apparatus main body side. A heat insulating sealing material 36 is provided around the holder 34 to prevent the heat detected by the temperature sensor 31 from escaping and to secure a gap with the front plate 7. A protective cover 37 that protects the temperature sensor 31 is disposed on the outer side of the holder 34 so as to enclose the temperature sensor 31.
[0027]
FIG. 5 is a control block diagram of the present embodiment. As shown in the figure, the control unit 30 is configured by a general microcomputer and includes a CPU, a RAM, and a ROM therein. The control unit 30 is connected to the input side of the temperature setting switch 3a of the operation display unit 3, the temperature sensor 31, and the room temperature thermistor 32, and connected to the output side of the heat generating unit 38, so that the temperature sensor 31 and the room temperature thermistor 32 are connected. The output of the heat generating part is controlled by the output.
[0028]
In the oil fan heater having the above configuration, the liquid fuel accommodated in the fuel tank 5 is guided to the vaporizer 22 via the oil feed pipe 28 by the electromagnetic pump 21 for fuel pressure feeding, and the vaporizer provided in the vaporizer 22 is provided. The supplied liquid fuel is vaporized by a heater (not shown). The fuel gas vaporized by the carburetor 22 is jetted vigorously from the nozzle, introduced into the burner 15 together with combustion air, and combusted at the flame port, and the air in the combustion chamber is heated.
[0029]
Then, as shown in FIG. 2, the convection fan 11 attached to the fan motor 12 provided on the back of the main body warms the indoor air sucked through the filter together with the heated air and combustion gas in the combustion chamber 14. It blows out into the room from the outlet 2 as wind.
[0030]
On the other hand, the frame sensor 20 provided slightly above the flame outlet detects a flame current caused by the combustion flame. When a flame current exceeding a preset value is detected, the fan motor 12 is energized, and accordingly the convection fan 11 is energized. Rotates, and the air sucked from the room is blown into the room from the air outlet 2 as warm air.
[0031]
At this time, the control unit 30 controls the control unit 30 based on the difference between the desired temperature (set temperature) and the temperature of the indoor air that is in the vicinity of the air suction port by the room temperature thermistor 32 and is sucked by the convection fan 11. The heating output is controlled in the range from strong to weak to OFF based on the command from the front, but at the same time, the temperature sensor 31 on the front plate detects the ambient temperature, and the temperature difference between that temperature and the temperature detected by the room temperature thermistor 32 Is equal to or higher than a predetermined value (for example, the temperature difference is 10 ° C. or higher), the control for stopping or reducing the heating output is performed. Moreover, if the said temperature difference is below a predetermined value (for example, temperature difference is 5 degrees C or less), normal heating output control will be performed.
[0032]
The present inventor placed a rectangular parallelepiped obstacle of 200 mm in length and 200 mm in width in the vicinity of 30 cm in front of the outlet of the hot air heater, for example, the temperature rise of the obstacle when heated at a heating output of 3 kW Comparison was made between the comparative example in which the heating output was controlled only by detecting the temperature sensor 31 and the present embodiment in which the temperature sensor 31 and the room temperature thermistor 32 were provided for detection and the heating output was controlled. As a result, in the comparative example, it was operated with strong heating until the surface temperature of the obstacle rose to a maximum of 80 ° C., and the situation of the front obstacle was hardly detected.
[0033]
On the other hand, in the present embodiment, the temperature rises in a short time by the warm air from the warm air outlet 3 flowing back to the device body 1 side, the temperature rise is detected by the temperature sensor 31, and the room temperature thermistor 32 Depending on the difference between the values detected by the temperature sensor 31, the heating output could be reduced or stopped.
[0034]
FIG. 6 shows the relationship between the distance from the hot air heater to the obstacle (horizontal axis) and the temperature difference (vertical axis) detected by the temperature sensor 31 and the room temperature thermistor 32. As shown in the figure, the temperature difference is large when the distance is short, and the temperature is small when the distance is far, and the distance and the temperature difference are in an inversely proportional relationship.
[0035]
Further, according to the experiment by the present inventor, for example, when an obstacle is placed in a place where the heating output of the main body is 3 kW and the distance is 30 cm, the obstacle surface temperature is 65 ° C. when the obstacle is placed continuously for 5 minutes. The detected temperature of the temperature sensor 31 on the front plate 7 was 32 ° C., the detected temperature of the room temperature thermistor 32 was 22 ° C., and the difference between the detected temperature of the temperature sensor 31 and the detected temperature of the room temperature thermistor 32 was 10 ° C.
[0036]
Therefore, the control shown in FIG. 7 is performed as a reference example of the present invention . That is, as shown in the control flowchart of FIG. 7, after setting the temperature with the temperature setting knob at the start of operation, when the heating operation is started, the temperature is detected by the temperature sensor 31 and the room temperature thermistor 32, The controller 30 determines whether or not the temperature difference is 10 ° C. or higher. When the temperature difference is smaller than 10 ° C. as a result of the determination, the operation is performed with the normal heating capacity. When the temperature difference is 10 ° C. or more, the detected temperatures from the temperature sensor 31 and the room temperature thermistor 32 are read. It is determined whether or not the temperature difference of 10 ° C. or more is maintained for a predetermined time (for example, 3 minutes or more). As a result, when the temperature difference of 10 ° C. or more is maintained for a predetermined time (for example, 3 minutes or more), the heating output is stopped. Further, when the temperature difference becomes lower than 10 ° C. within the predetermined time, the operation of reading the detected temperatures from the temperature sensor 31 and the room temperature thermistor 32 is repeated while operating with the normal heating capacity.
[0037]
As described above, the heating output is controlled when the temperature difference detected between the temperature sensor 31 and the room temperature thermistor 32 is equal to or greater than a predetermined value. When the temperature difference is smaller than the predetermined value, the dangerous temperature is reached. If there is an object in front of the equipment body, the object simply passes through the place or leaves the place in a relatively short time. The output is not controlled, and operation in the normal state is possible.
[0038]
Further, even when a towel or laundry is applied to the hot air outlet 3 or the temperature sensor 31 detects an abnormal temperature due to some reason on the front plate 7 of the main body, the heating output can be stopped, and safety is improved. Can be improved.
[0039]
FIG. 8 is a control flowchart showing another reference example of the present invention. As shown in the figure, when the heating operation is started after the temperature is set with the temperature setting knob at the start of operation, the temperature is detected by the temperature sensor 31 and the room temperature thermistor 32, and the control unit 30 It is determined whether the temperature difference is 10 ° C. or higher. When the temperature difference is smaller than 10 ° C. as a result of the determination, the operation is performed with the normal heating capacity. When the temperature difference is 10 ° C. or more, the detected temperatures from the temperature sensor 31 and the room temperature thermistor 32 are read. It is determined whether or not the temperature difference of 10 ° C. or more is maintained for a predetermined time (for example, 3 minutes or more). As a result, when the temperature difference of 10 ° C. or more is maintained for a predetermined time (for example, 3 minutes or more), the heating output is reduced or minimized than usual. And the operation which reads the detected temperature from the temperature sensor 31 and the room temperature thermistor 32 is repeated again, and if the temperature difference is 3 degreeC or more even if 10 minutes pass, a heating operation will be stopped.
[0040]
In the present invention, in the control flowchart of FIG. 8, if the temperature difference between the detected temperatures from the temperature sensor 31 and the room temperature thermistor 32 is 3 ° C. or more even after 10 minutes, the heating operation is immediately stopped. Instead of stopping immediately, it is once returned to the strong combustion or the original heating output, and again it is determined whether the temperature by the temperature sensor 31 and the room temperature thermistor 32 is 10 ° C. or higher, and the temperature difference is When the temperature difference is 10 ° C or higher, if the temperature difference of 10 ° C or higher continues for a predetermined time (for example, 3 minutes or more), the heating output is made smaller or smaller than usual, and the temperature difference of 3 ° C or higher continues for 10 minutes or more. Make a decision. This cycle is repeated a plurality of times (for example, twice), and the heating output is controlled to be stopped only when the above-mentioned state is not resolved .
[0041]
In the control flow of FIG. 8, the determination as to whether or not “10 ° C. or higher” and the determination as to “3 ° C. or higher” are merely examples, and are not limited thereto. The judgment values (“10 ° C.” and “3 ° C.”) in the two steps may be the same value.
[0042]
Further, the present invention is not limited to the above-described embodiment, and it is needless to say that corrections and changes can be made within the scope of the present invention. For example, in the above embodiment, the oil fan heater equipped with the liquid fuel combustion apparatus has been described. However, the present invention is not limited to this, and the present invention can of course be applied to a gas fan heater or an electric fan heater. Further, the room temperature thermistor is not limited to the one provided in the apparatus main body, and may be one mounted on a remote controller.
[0043]
【The invention's effect】
As described above, according to the hot air heater according to the present invention, the heating output is based on the detected temperature from the temperature sensor provided in the vicinity of the hot air outlet and the room temperature thermistor for detecting the indoor air temperature. Since the control is performed, the presence or absence of an object ahead is always monitored, and the operation is stopped only when it is dangerous, so that safety can be improved.
[Brief description of the drawings]
1 is a front perspective view of a petroleum fan heater equipped with a liquid fuel combustion apparatus according to an embodiment of the present invention. FIG. 2 is a side sectional view of FIG. 1. FIG. 3 is a schematic view of a fuel path of FIG. FIG. 4 is a cross-sectional view showing a temperature sensor mounting structure. FIG. 5 is a control block diagram of the present invention. FIG. 6 is a diagram showing a distance (horizontal axis) from a hot air heater to an obstacle, a temperature sensor 31 and a room temperature thermistor 32. FIG. 7 is a control flowchart showing a reference example of the present invention. FIG. 8 is a control flowchart showing another reference example of the present invention.

Claims (1)

The temperature of the hot air that flows back to the device main body due to the obstacle located at the front of the device main body, the warm air outlet provided on the front plate of the device main body, and the hot air outlet on the front plate A temperature sensor for detecting, a room temperature detection sensor for detecting an indoor air temperature, and a control unit for controlling a heating output, wherein the control unit has a temperature difference detected between the temperature sensor and the room temperature detection sensor, When the heating time is continued for the first time at the first value or more, the heating output is made smaller than the normal heating output, and the temperature difference equal to or more than the second value smaller than the first value is the first time. When it is continued for a longer second time, it is once returned to the original heating output , the above cycle is repeated a plurality of times, and the temperature difference equal to or greater than the second value is resolved when the above cycle is repeated a plurality of times. especially to stop the heating output if it does not Warm air heater to.

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