JPS6243096B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a control circuit for a combustor having an air leading type burner whose combustion amount changes depending on the amount of air supplied.

Conventional configuration and its problems A conventional control device for a hot-air heater, such as an oil fan heater, has a circuit configuration as shown in FIG. 33 is detected by a first comparator 34 and a second comparator 35, and relays 38,
39, and by switching the switching contacts 38a, 39a of the relays 38, 39, the rotation speed of the combustion blower 17a is controlled to be high, medium, or low. Therefore, according to this configuration,
If the setting is suddenly changed using the room temperature setting controller 33, there may be a sudden change from high-speed rotation to medium-speed rotation to low-speed rotation. In general, in this type of combustor, the quantitative balance between air and fuel in the burner section tends to be temporarily disrupted, and the amount of air rapidly decreases relative to the amount of vaporization, resulting in an excess of fuel and temporary yellow flame. This causes problems such as burning with smoke and soot, raising the temperature of the equipment itself, and damaging the equipment itself.

OBJECTS OF THE INVENTION The present invention has been made in view of the above problems, and is intended to prevent deterioration in combustion.

Structure of the Invention In order to achieve the above object, the present invention provides a control system that maintains the medium speed rotation for a certain period of time after a signal to switch to the low speed rotation is generated when the combustion blower switches from medium speed rotation to low speed rotation. This prevents a sudden change from high-speed rotation to medium-speed rotation to low-speed rotation as in the past, and reduces transient phenomena that result in excess fuel as much as possible, eliminating the negative effects caused by them.

DESCRIPTION OF EMBODIMENTS One embodiment will be described below with reference to FIGS. 1 and 2.

In FIG. 1, reference numeral 1 denotes a fuel tank, and fuel (petroleum) 2 in this fuel tank 1 is sucked up by a cylindrical lamp wick 3 by capillary action. Above wick 3
is connected to the right end of the lever 4 of the core up/down mechanism in FIG. 6
numeral 7 is a solenoid that holds the left end of the lever 4 above and below the wick while pushing the wick 3 upward at the same time as the ignition operation, and 7 is a cylindrical ventilation cylinder having a vent 8, which serves as a guide for the vertical slide of the wick 3. Reference numeral 9 is an outer fire pan having a large number of air holes 10, and reference numeral 11 is a cylindrical inner flame cylinder, which has a large number of primary air supply holes 12. 13
1 is a cylindrical outer flame cylinder having a large number of primary air supply holes 14, 15 is a cylindrical outer cylinder, and 16 is a cylindrical combustion cylinder, and the above 9 to 16 parts constitute a burner. 17 is a blower fan, and 17a is a blower motor, and these two parts constitute a combustion blower. Reference numeral 18 denotes a disc-shaped wind partition plate having a ventilation hole 19; 20, a blower guide; 21, a stand; 22, a stand 21 that covers the burner section and the blower fan 17;
The exterior case attached above has an inlet 23 near the blower fan 17 and an outlet 24 in a portion facing the opening of the blower guide 20. Reference numeral 25 indicates an ignition device, and 26 indicates a room temperature detection thermistor installed near the suction port 23, which is used as an example of a room temperature detection element.

Figure 2 shows the electrical circuit diagram of this combustion device.
7 is the power plug, 28 is the first lever 4 above and below the core.
The operating switch on the left side of the figure is opened by pressing, and the normally open contact port is connected to a circuit such as a solenoid 6, and the common contact A is connected to a power source. 29 is a power transformer, 30 is a diode bridge for full-wave rectification, 31 is a smoothing capacitor, 3
2 is a Zener diode for a stabilized power supply, 33 is a variable resistor for setting the room temperature, 34 and 35 are first and second comparators, and 36 has resistors 36a and 36b as bases.
This is a transistor connected to the comparator 34 via. A first relay 38 is connected to the collector of the transistor 36 and has a contact 38a.

50 is a third comparator whose input terminal is connected to the second comparator 35, and whose input is connected to the resistor 50.
They are connected to a stabilized power supply C and a ground G via terminals a and 50b, respectively. The output of the third comparator 50 is connected to a stabilized power supply C via a resistor 52 and a capacitor 51.
is connected to a fourth comparator 5 via a resistor 53.
4 input terminals are connected, and a fourth comparator 5
The input terminals of No. 4 are connected to the stabilized power supply C, ground G, and No. 4 through resistors 54a, 54b, and 54c, respectively.
is connected to the output terminal of the comparator 54. Further, the base of a transistor 37 is connected to the output of the fourth comparator 54 via a resistor 37a, and 39 is a second relay connected to the collector of the transistor 37 and has a switching contact 39a. Switching contact 39
The common contact C of a is connected to the normally open contact port of the operation switch 28, and the normally open contact H of the switching contact 39a is connected to the "weak" terminal of the blower motor 17a.

Also, the switching contact 38a of the first relay 38
The normally closed contact G is connected to the "strong" terminal of the blower motor 17a, and the normally open contact G is connected to the "core" terminal. 40 is a diode whose cathode is connected to the collector of the transistor 37, and whose anode is connected to the comparator 34 via resistors 36b and 36a, respectively.
and connected to the base of transistor 36.

41 is a transistor whose base is a resistor 41a,
41b to a stabilized power supply c, the collector of which is connected to the cathode of a light emitting diode 42 used as an example of a light emitting device,
The anode of is connected to the full-wave rectified power supply d via the resistor 42a.
It is connected to the. The diode 43 has a cathode connected to the collector of the transistor 36, and an anode connected to the stabilized power supply c and the base of the transistor 41 via resistors 41b and 41a.
Furthermore, the base of the transistor 43 is a resistor 43a,
43b, the collector thereof is connected to the cathode of a light emitting diode 44, and the anode of the light emitting diode 44 is connected to a resistor 44a.
It is connected to a full-wave rectified power supply d via. The anode of the diode 45 is connected to the anode of the diode 43, and the cathode of the diode 45 is connected to the collector of the transistor 48. The diode 46 has an anode connected to the stabilized power supply c and the base of the transistor 43 via resistors 43b and 43a, and a cathode connected to the transistor 48.
connected to the collector.

The light emitting diode 47 has an anode connected to a full-wave rectified power supply d via a resistor 47a, and a cathode connected to a power supply ground G. Note that the emitters of the transistors 36, 37, 41, and 43 are also all connected to the power source G.

FIG. 3 shows the light emitting diodes 42, 44, 4
7, which are provided on the front surface of the exterior case 22, and below which is a variable resistor 33 (not shown).
A lever is provided.

In FIG. 3, the light-emitting diodes 42, 44, and 47 are shaded in the lighting state, and those without the hatching are in the off-state. 44 is provided at the bottom, 42 is provided at the top,
This explanation will be discussed in detail later.

The operation of the above configuration will be explained below.
First, connect the power plug 27 shown in Fig. 2 to the power outlet, and then push down the left side of the fulcrum of the lever 4 above and below the core shown in Fig. 1, the operation switch 28 shown in Fig. 2 will be closed, the operation will start, and the ignition will start. Device 25 is energized. At this time, since the lamp wick 3 is pushed out above the outer fire pan 9 by the lever 4,
The wick 3 is ignited and combustion begins.

Since the solenoid 6 is also energized, its suction action holds the levers 4 above and below the wick in a depressed state, and combustion continues. At the same time, the blower motor 17a is also energized, and the blower fan 17 rotates.
The wind is blown downward along the blow guide 20. The wind blown out at this time causes the wind partition plate 18 to
Due to the ventilate effect that occurs downward, combustion exhaust gas from the burner is sucked in as shown by the broken line, mixes with the air from the blower fan 17, and is converted into warm air to the air outlet 2.
On the other hand, combustion air is forced to be sucked and supplied to the burner through the vent port 8 due to the ventilate effect.

Then, the ignition device 25 is stopped after a certain period of time (a thermostat, not shown, is interposed in the energizing path), so that the ignition state shifts to the combustion state.

If the room temperature setting is set to 20°C using the variable resistor 33, the temperature of the thermistor 26 for room temperature detection is sufficiently lower than 20°C at the start of combustion indoors in winter, so the resistance value of the thermistor 26 is big. Therefore, since the potential of the + inputs of the comparators 34 and 35 is lower than that of the - input, their respective outputs become Lo, transistors 36 and 37 are also turned off, and relays 38 and 39 are also de-energized, and as shown in Fig. 2, the blower motor 17a is energized to the "strong" terminal.

Then, the blower motor 17a and the blower fan 17 rotate at high speed, thereby increasing the ventilating effect below the air partition plate 18, thereby increasing the amount of air supplied to the burner section, especially the fuel vaporization section of the lamp wick 3, This increases the amount of fuel vaporized, resulting in maximum combustion. At this time, the light emitting diode 47 is lit, and since the transistors 41 and 43 are also in the ON state, the light emitting diodes 42 and 44 are also lit, resulting in the state shown in FIG. 3c. Next, as shown in Figure 4, "strong" combustion continues and the room temperature becomes about 2 degrees Celsius below the set temperature.
When the temperature reaches a relatively low temperature, the resistance value of the thermistor 26 becomes small, the potential of the + input of the comparator 34 becomes higher than that of the - input, and the output switches from "Lo" to "Hi". Then transistor 36 turns on and relay 3
8 is energized, the switching contact 38a switches from heat to heat, and the blower motor 17a changes from "strong" to "medium".
The rotation speed changes to medium speed. When this happens, the burner will have a medium combustion rate. At this time, since the transistor 36 is on, the current flowing to the base of the transistor 41 via the diode 43 is cut off, so the transistor 41 is turned off, and the light emitting diode 42 is turned off, resulting in the state shown in FIG. 3b. .
When "medium" combustion continues and the room temperature rises and the temperature of the thermistor 26 reaches the set temperature, the resistance value of the thermistor 26 decreases, the potential of the + input of the comparator 35 becomes higher than the - input, and the output increases. Switching from "Lo" to "Hi", transistor 37 is turned on, transistors 41 and 43 are turned off by diodes 45 and 46, respectively, and light emitting diodes 42 and 44 are turned off, resulting in the weak state shown in FIG. 3a.

At the same time, the potential of the input of the third comparator 50 becomes higher than the potential of the input, and the output switches from "Hi" to "Lo". Then, charging of the capacitor 51 starts, and after a certain period of time, the fourth comparator 5
When the potential of the input 4 becomes higher than the potential of the input, the output switches from "Lo" to "Hi", the transistor 37 turns on, the relay 39 is energized, and the switching contact 39a switches from H-N to H-H. Then, the blower motor 17a switches from "medium" to "weak", resulting in a weak combustion amount. At this time, the transistor 36 is turned on because the base current is cut off by the diode 40, and the relay 38 is also de-energized. Then, when "weak" combustion continues and the room temperature becomes about 1°C lower than the set temperature, the + input of the comparator 35 becomes lower than the - input, the output becomes "Lo", and the third comparator 50 becomes "Hi". Therefore, the output of the fourth comparator 54 becomes "Lo", the transistor 37 is turned off, and the relay 39 becomes de-energized. Also, since the output of the comparator 34 is "Hi", the base current of the transistor 36 is cut off by the diode 40. Therefore, the transistor 36 is turned on again, the relay 38 is energized, and the switching contact 39 is turned on.
H becomes H, the switching contact 38a becomes H H, and the blower motor 17a becomes ``MID''.
Further, the light emitting diode is also in the state shown in FIG. 3b, resulting in a medium combustion amount. The following operations are repeated to automatically control the room temperature to a nearly constant state.

Effects of the Invention According to the present invention, room temperature control is performed by switching the combustion amount in three stages: "strong,""medium," and "weak." The air blower switches to "strong" after a certain period of time after the switching signal is generated, so even if the conventional room temperature setting controller is suddenly changed, the combustion amount will suddenly switch from "strong" to "weak". Since the temperature changes from "medium" to "weak" after a certain period of time, transient phenomena of excessive combustion can be minimized and deterioration of combustion can be prevented.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view of a combustor in one embodiment of the present invention, Fig. 2 is its electrical circuit diagram, and Figs. 3 a to c.
4 is a front view of a display section showing the combustion amount, and FIG. 4 is an electric circuit diagram of a conventional example. 1... Tank, 3... Light wick, 4... Lever, 6
...Solenoid, 17...Blower fan (combustion blower), 17a...Blower motor, 25...Ignition heater, 26...Thermistor (room temperature detection element) 33
...Variable resistor (room temperature setting controller), 34,3
5, 50, 54... Comparator, 38, 39... Relay, 38a, 39a... Relay switching contact, 42,
44, 47... Light emitting diode (light emitter), 51
...Capacitor for timer circuit.

Claims (1)

[Scope of Claims] 1. A burner whose combustion amount is varied depending on the rotation speed of a combustion blower, a room temperature detection element that detects room temperature,
and a control circuit that controls the rotation speed of the combustion blower to be high, medium, or low based on the difference between the room temperature detected by the room temperature detection element and the set room temperature set by the room temperature setting controller, When the combustion blower switches from an intermediate rotation speed to a low rotation speed, the combustor is configured to maintain the intermediate rotation speed for a certain period of time after the control signal is generated, and then switch to the low rotation speed after a certain period of time. Control device. 2 The combustion blower has a configuration in which one light emitter lights up when it rotates at low speed, two light emitters light up when it rotates at medium speed, and three light emitters light up when it rotates at high speed, and it switches from medium speed rotation to low speed rotation. In the case where the control signal is generated, the lighting of two light emitters is immediately switched to lighting of one light emitter, and only in this case, one light emitter is lit even during mid-rotation.Claim 1 A control device for a combustor as described in Section 1.