JPH06313541A - Warm-air heater - Google Patents

Abstract

PURPOSE:To retain a room temperature stably without being affected by the fluctuation of a power supply voltage by a method wherein the ignition phase control of an AC power supply is effected based on a phase control signal corresponding to the power supply voltage of an external AC power supply to impress a substantially constant AC voltage on a fan. CONSTITUTION:A power supply voltage detecting circuit 16 detects the power supply voltage of an external AC power supply and converts it into a corresponding low-voltage DC voltage and outputs it to a microcomputer 17 as a voltage detecting signal S. The microcomputer 17 converts the voltage detecting signal S through analog/digital conversion, compares the voltage of the AC power supply with a preset reference voltage, and thereby outputs a phase control signal CP to a voltage controller 24. The voltage control device 24 changes the phase angle of a trigger pulse based on the phase control signal to fix an AC voltage impressed to a fan motor 5. By this method, a warm-air temperature and the amount of warm-air become constant.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot air heater such as an oil fan heater and a gas fan heater.

[0002]

2. Description of the Related Art For example, in a hot air heater such as an oil fan heater, as disclosed in JP-A-3-20518, a combustion section for burning fuel, and combustion gas is supplied from the combustion section to exchange heat. It has a heat exchange section for performing the above and a blower for transmitting heat to the room. The air is taken in by the blower and blown out through the heat exchange section to heat the room.

The above-mentioned warm air heater has a control device for changing the combustion amount in the combustion section and the air flow amount of the blower according to the temperature difference between the room temperature and the set temperature, and always keeps the room temperature at the set temperature. It was supposed to be maintained.

[0004]

However, in the above-mentioned conventional hot air heater, when the power supply voltage fluctuates, the voltage applied to the fan motor that rotationally drives the fan (blades) of the blower also fluctuates, and the fan motor. The number of revolutions of the hot air changes and the temperature of the hot air blown from the hot air heater changes, and the amount of hot air changes, making it impossible to keep room temperature stable. There was a problem that it would rise abnormally.

Therefore, an object of the present invention is to provide a hot air heater having a high safety, which stably maintains the room temperature without being affected by the fluctuation of the power supply voltage.

[0006]

In order to solve the above problems, the present invention detects a power supply voltage of an external AC power source in a warm air heater having an AC driven blower for circulating hot air. Then, the detection means for outputting the detection signal and the phase control signal comparing means by comparing the detection signal with the preset reference voltage signal, and the ignition phase of the AC power supply based on the phase control signal. Control
And a voltage control means for applying a substantially constant AC voltage to the blower.

[0007]

According to the present invention, the detecting means detects the power source voltage of the external AC power source and outputs the detection signal to the comparing means. The comparison means outputs the phase control signal to the voltage control means by comparing the input detection signal with the reference voltage signal.

As a result, the voltage control means controls the ignition phase of the AC power source based on the phase control signal, and applies a substantially constant AC voltage to the blower.

Therefore, even if the AC power supply voltage fluctuates, the voltage applied to the blower becomes almost constant, fluctuations in the temperature of the circulating hot air, the amount of warm air, etc. are suppressed, and stable heating can be performed. At the same time, the temperature of the warm air heater is kept within a certain range, which improves safety.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will now be described with reference to the drawings.

FIG. 1 is an external perspective view of the oil fan heater, and FIG. 2 is a rear view of the oil fan heater.

The oil fan heater has an outer case 1, and an air suction port 3 having an air filter is provided on the back side of the outer case 1. Also, the outer case 1
A warm air outlet 4 communicating with the air inlet 3 is provided on the front side of the.

Inside the outer case 1, there is provided a warm air blower 5 for taking in indoor air through the air suction port 3 and blowing out warm air from the warm air outlet 4.

Further, in the outer case 1, a cartridge tank 6 for storing kerosene as a fuel, and an oil receiving tank 7 functioning as a buffer for stably supplying kerosene supplied from the cartridge tank to a combustion system described later. , A fuel pump 8 for supplying kerosene in the oil receiving tank 7 to a burner described later, a combustion blower 9 for supplying fresh combustion air to the burner described below, and a burner 10 for burning kerosene.
A combustion cylinder 11 functioning as a heat exchanger for efficiently extracting heat from the burning of kerosene in the burner 10, a blower guide case 12 for guiding the air from the warm air blower 5 to the vicinity of the combustion cylinder, and an oil A control device 13 that controls the entire fan heater, and a power supply voltage detection circuit 16 that detects the voltage of the AC power supply and outputs a power supply voltage detection signal to the control device 13.
And are provided.

An operation panel 14 is provided on the upper surface of the outer case 1, and a room temperature sensor 15 for measuring the room temperature is provided on the lower portion of the back surface.

FIG. 3 is a block diagram showing the basic configuration of the control device 13.

The control device 13 has a ROM (not shown) storing a control program, a RAM (not shown) storing various data, an A / D converter for performing analog / digital conversion, and the like, and is a micro controller for controlling the entire device. It has a computer (hereinafter referred to as a microcomputer) 17.

On the input side of the microcomputer 17, an operation switch 18 for operating / stopping the warm air heater, a temperature setter 19 for the user to set a desired room temperature,
A room temperature sensor 15, a power supply voltage detection circuit 16, a burner temperature sensor 20 that detects the temperature of the fuel vaporization section of the burner 10, and a flame detector FL that detects the presence or absence of a flame in the burner are connected.

On the other hand, on the output side of the microcomputer 17, an electric heater 21 for heating the fuel vaporization portion of the burner 10, an igniter 22 for igniting the vaporized fuel, a burner motor 9M for driving the combustion blower 9, and a fuel pump. 8. Digital display 23 and fan motor 5 for displaying room temperature and set temperature
A voltage control device 24 for applying a substantially constant drive voltage to M is connected.

As the burner motor 9M and the fan motor 5M, an AC motor such as a shading motor is used.

The operation switch 18, the temperature setting device 19 and the digital display 23 are provided on the operation panel 14.

FIG. 4 shows a flowchart of the initial operation of the warm air heater.

When the microcomputer 17 detects that the operation switch 18 has been turned on, the electric heater 21 is energized to heat the fuel vaporization section of the burner 10. When the burner temperature sensor 20 detects that the temperature of the burner vaporization section has reached a temperature suitable for vaporizing kerosene as fuel and preheating is completed, the microcomputer 17 operates the burner motor 9M to pre-purge the burner 10 ( Step S1).

When the prepurge is completed, the microcomputer 17 operates the igniter 22 for a predetermined time. At the same time, the microcomputer 17 sends the fan motor 5 through the voltage control circuit 24.
By starting M, the warm air blower is operated, and further, the fuel pump is started and fuel supply is started.

As a result, when the combustion air is supplied to the burner 10 and the fuel is supplied to the vaporizing portion of the burner 10, the fuel is vaporized, mixed with the combustion air, and then ignited by the igniter 22. (Step S2).

After that, the microcomputer 17 detects the ignition by the output signal of the flame detector FL (step S
3) A normal heating operation for performing combustion control, hot air flow rate control, etc. is started (step S4).

FIG. 5 shows a block diagram of a voltage control system for applying a substantially constant drive voltage to the fan motor 5M.

The power supply voltage detection circuit 16 is provided with a step-down transformer TR for stepping down the voltage of an external AC power supply (100 V), a diode D and a capacitor C for rectifying and outputting the stepped down power supply voltage. The power supply voltage of the AC power supply is detected, converted into a corresponding low-voltage DC voltage, and output to the microcomputer 17 as a voltage detection signal S.

The microcomputer 17 performs analog / digital conversion of the voltage detection signal S by the A / D converter and compares the voltage of the AC power supply with a preset reference voltage,
The phase control signal CP is output to the voltage controller 24.

The voltage control device 24 changes the phase angle α (see FIG. 6D) of the trigger pulse based on the phase control signal to make the AC voltage applied to the fan motor 5M constant.

More specifically, as shown in FIG. 6A, when the phase angle at the reference voltage VREF is αREF,
When the voltage V of the actual AC power supply is higher than the reference voltage VREF (V> VREF), the phase angle αH is set to αH> αREF, and the voltage V5M applied to the fan motor 5M is controlled to be V5M = VREF. To do.

When the actual voltage V of the AC power supply is lower than the reference voltage VREF (V <VREF), the phase angle αL
Is set to αL <αREF, and the voltage V5M applied to the fan motor 5M is controlled so that V5M = VREF.

As a result, the rotation speed of the fan motor 5M is not affected by the voltage fluctuation of the AC power supply, and the hot air temperature and the hot air amount are constant, so that stable heating operation can be performed. Further, since the temperature of the warm air heater is also constant, heating of the warm air heater is eliminated and safety is improved.

In the above description, the case where the phase angle to be controlled as a function of the fluctuation amount of the power supply voltage is obtained on a one-to-one basis has been described. Is stored as a table,
It is also possible to set the same phase angle control amount for the power supply voltage within a predetermined fluctuation range.

[0035]

According to the present invention, the voltage control means performs the ignition phase control of the AC power supply based on the detected phase control signal corresponding to the power supply voltage of the external AC power supply, so that the blower is substantially constant. Since the AC voltage is applied, the voltage applied to the blower is almost constant even if the AC power supply voltage fluctuates,
Fluctuations such as the temperature of the circulating hot air and the amount of hot air are suppressed,
Since stable heating can be performed and the temperature of the warm air heater is kept within a certain range, safety is improved.

[Brief description of drawings]

FIG. 1 is an external perspective view of a warm air heater.

FIG. 2 is an explanatory diagram of an internal structure of a warm air heater.

FIG. 3 is a block diagram showing a schematic configuration of a control device.

FIG. 4 is a flowchart of an initial operation of the warm air heater.

FIG. 5 is a configuration block diagram of a voltage control system.

FIG. 6 is a diagram illustrating an operation of a voltage control system.

[Explanation of symbols]

 1 Outer Case 2 Air Filter 3 Air Suction Port 4 Hot Air Blowout 5 Hot Air Blower 5M Fan Motor 6 Cartridge Tank 7 Oil Receiving Tank 8 Fuel Pump 9 Combustion Blower 9M Burner Motor 10 Burner 11 Combustion Tube 12 Blower Guide Case 13 Control Device 14 Operation panel 15 Room temperature sensor 16 Power supply voltage detection circuit 17 Microcomputer 18 Operating switch 19 Temperature setting device 20 Burner temperature sensor 21 Electric heater 22 Igniter 23 Digital display 24 Voltage control device

Claims (1)

[Claims] 1. A hot-air heater having an AC-driven blower for circulating hot air, said detection means detecting a power supply voltage of an external AC power supply and outputting a detection signal, said detection signal. And a comparison means for outputting a phase control signal by comparing a preset reference voltage signal, and performing an ignition phase control of the AC power supply based on the phase control signal, and a substantially constant AC voltage to the blower. A hot-air heater including: a voltage control unit that applies a voltage.