JPS62276329A - Combustion device - Google Patents

Abstract

PURPOSE:To prevent a supplying amount of oil from being increased due to a defect of trigger element and further prevent a flame from being generated at a discharging part by a method wherein a pulse signal is generated in response to an output from a combustion control part, a pulse generated from a pump driving circuit for driving an electromagnetic pump is supervised to discriminate if it is abnormal or not. CONSTITUTION:Since a diode 36 of a photo-coupler 35 is connected in parallel with a pump coil 18, a photo-transistor 37 is kept ON when a pulse is being applied to the pump coil 18, and the pulse signal is sent to an abnormal condition discriminating part D of a microcomputer E. A pulse width T1 at a normal condition is varied in response to an amount of combustion and in accordance with an instruction generated from a combustion control part A within the microcomputer E. A pulse width V1 is varied as indicated by V2 due to a disturbance in the circuit. Under an assumption of this disturbance and the like, the spacing T2 until a next pulse reaches is set in advance as follows. That is, T2<=T1-V.

Description

[Detailed Description of the Invention] 3. Detailed Description of the Invention Industrial Application Field The present invention relates to a combustion device that takes indoor air, burns kerosene, and releases the combustion gas indoors for heating. be.

2. Description of the Related Art Generally, as shown in FIG. 5, this type of combustion appliance has a burner 3, a hot air fan 4 and its motor 5, and a controller that controls all of these in a space surrounded by an external device and a stand 2. 6, and is configured such that indoor air A is mixed with combustion gas B by a blower motor, and the mixture is discharged from a looper 7 as warm air C at an appropriate temperature to be used for indoor heating.

As shown in FIG. 6, the burner 3 includes a vaporizer cylinder 8 that vaporizes kerosene for combustion, an electromagnetic pump 9 that supplies a certain amount of kerosene, and a burner motor unit 10 that sends combustion air. An ignition electrode 11 for igniting the vaporized kerosene, a flame rod 12 for monitoring the state of the combustion flame, and the like are provided. The circuit of the electromagnetic pump 9 is as shown in FIG. 7, and includes a diode 13, a resistor 14, and a resistor 14 connected to AC terminals a and b.
15, a capacitor 16, and a Zener diode 170 components are configured so that DC 140V and 12V are generated at the 0 point and the d point. A first thyristor 19 is connected to the coil 18 of the electromagnetic pump 9, and a second thyristor 21 is connected to the resistor 20, and these connection points are referred to as points e and f. A capacitor 21 and a resistor 22 are connected between points e and f.
The trigger element 23, the eight gate points of the Cyrisk 21, and the resistor 24 are connected between the points b. -Thyristor 19 of force tube 1
A transistor 26 of a photocoupler 25 to which a signal is emitted from the controller 6 is connected to the gate h of the resistor 2 between the gate h and the point d.
Connect through 7. Additionally, a resistor 29, a capacitor 30, and diodes 28 and 31 are connected as shown in FIG.

In this circuit, DC is always applied to the cyrisks 19 and 21 due to the DC generated from the AC terminals a and b.

During steady state, voltage is applied to point g through resistor 20 → point f → trigger element 23, so thyristor 21 is turned on.
in a state. However, since there is no signal from the controller 6, the thyristor 19 is turned off. Therefore, the capacitor 21 is charged with positive polarity on the 0 point side and negative polarity on the f point side. In this state, when a signal from the controller 6 enters the light emitting diode 28 in the form of a pulse signal, the transistor 26 turns on and hits the gate h, so the thyristor 19 turns on. In this state, the voltage at the 0 point suddenly drops and the charged load on the capacitor 21 is transferred from the resistor 22 to
Since discharge occurs in the circuit from point e to thyristor 19 to point b to thyristor 21 to point I, a reverse voltage is momentarily applied to thyristor 21, turning it off. This time the f point is positive, 0
The capacitor 21 starts charging when the point becomes negative, and the voltage of the capacitor 21 increases until the voltage of the trigger element 23 reaches the trigger voltage, and when the trigger is finally triggered, the thyristor 21 is turned on again. Therefore, this time, the charge of the capacitor 21 goes through a loop of point f -> thyristor 21 -> thyristor 19 -> point e -> resistor 22, and a reverse voltage is applied to thyristor 1q, turning it off. By repeating this, the electromagnetic pump 9 is operated, and kerosene is supplied to the vaporizing tube 8 to be vaporized and burned. The controller 6 then controls the on-off interval of the cyrisk 19 to make the combustion state stronger or weaker.

Problems to be Solved by the Invention However, in the circuit of this combustion device, the thyristor 19.
21, trigger element 23, resistor 20, capacitor 21
If these characteristics change even slightly, the amount of fuel discharged from the bonder 9 will change significantly.

For example, if the withstand voltage of Cyrisk 19 becomes less than the voltage at the 0 point, it will automatically turn on even without a trigger signal, and the number of pulses will become extremely large. Also, resistance 2
If the value of o becomes large for some reason, the capacitor 21
Since the current supply to the thyristor 21 is delayed and the turn-on of the thyristor 21 is delayed, the ON time of the thyristor 19 is extended, resulting in a large amount of oil being supplied. That is, the amount of kerosene supplied increases both when the number of pulses increases and when the number of pulses increases. For this reason, the burner motor 10
Since the rotational speed of the bar 7 does not change, the length of the fire inside the burner increases, and in some cases, flame may erupt from the bar 7 as shown in FIG. The opposite oil may still decrease, in which case the flame lot 12 will detect it. However, if there are many flames, the flame loft will not detect abnormalities and may become dangerous as described above.There are no special devices or sensors to prevent these, and quality may be affected. I was only looking forward to improvement. FIG. 8 shows such a state. The solid line in the figure is the pump coil/l under normal conditions.
This is the waveform of the number of pulses added to /1B. That is, 1 during the pulse
1. The pulse interval (frequency) is tl. If the thyristor 19 has a low breakdown voltage and turns on only when the 0 point voltage is high in the shaped waveform, the thyristor 19 will oscillate at the same frequency as the power supply frequency, and the pulse interval will decrease as shown by the dotted line t2 in the figure. Further, when the resistance 20 becomes large, the width increases to fto indicated by the dashed dotted line Y2 in FIG.

The present invention has been made in view of these points, and is aimed at improving safety.

Means for Solving the Problems In order to achieve the above object, the present invention includes a combustion control section A that controls combustion as shown in FIG. 1, and a pulse signal is generated based on the output from this combustion control section A. The pulse generator B, the pump drive circuit C that drives the electromagnetic pump based on the pulse signal from the pulse generator B, and the pulses from the pulse generator B and the pump drive circuit C are monitored to determine whether there is an abnormality. This configuration includes an abnormality determination section that determines whether the

With the above-described configuration, the present invention can prevent abnormal oscillation or expansion during pulses due to component failure, noise, etc.
Since this is detected and combustion is stopped, flame does not come out from the hot air outlet, etc., so it can be used with peace of mind.

Embodiment Below, one embodiment of the present invention will be described based on the drawings. FIG. 2 shows the pump drive circuit C and combustion control section A shown in FIG. 1.
It also shows the abnormality determination section. Here, the combustion control section A and the abnormality determination section are operated by a microcomputer E.
It is connected to an AC power source via a DC converter 33.

The pump drive circuit C has a series circuit of a resistor 34 and a light emitting diode 36 of a photocoupler 35 connected in parallel to the pump coil 18 of the conventional example shown in FIG. ,
D).

The reference numeral 39 indicates all load groups such as fan motors, and the others are the same as the conventional example shown in FIG. 7, so a description thereof will be omitted.

In the above configuration, the operation of the pump drive circuit C is the same as the conventional example shown in FIG. 7, but since the diode 36 of the photocoupler 35 is connected in parallel to the pump coil 18, a pulse is applied to the pump When this happens, the phototransistor 37 is in the N state, and its pulse signal is sent to the abnormality determination section of the microcomputer E. Here, as shown in FIG. 3, the pulse interval during normal operation is T1, and the period during the pulse is indicated by ■1, which is indicated by a solid line. Among these, T1 varies depending on the amount of combustion, and follows an instruction issued from the combustion control section A in the microcomputer E. Further, v1 during the pulse differs like v2 due to circuit variations and the like. Therefore, as shown in FIG. 3, in consideration of this variation, etc., the interval T2 until the next pulse arrives is set in advance as follows.

T2≦TI −V2 Note that the above v2 is determined by adjusting with the resistor 20 to absorb variations in the pump oscillation circuit C and variations in the pump mechanism, and varies from pump to pump. Therefore, the largest width is set as the limit and this is set as v2.

Next, the operation of the microcomputer 32 in determining the pulse signal of the output transistor 37 of the pulse detection photocoupler 35 to the pump coil 18 will be explained using FIG.

First, when the pump drive circuit C starts operating and the first pulse is input, the voltage V during this pulse is checked. During this pulse, do nothing in particular until V becomes V2V5 (1). In addition to the above condition (1), the interval T until the next pulse arrives is compared with the basic T2. That is, T≦T2 ・・・・・・・・・・・・・・・ (We are monitoring whether it becomes 2 or not. And if this T is shorter than T2,
In other words, as long as either condition (2) or condition (1) above is satisfied, the pulses in between are counted as a count and are integrated.Then, T2 itself is counted, and condition (1) or ('2) is satisfied. If the number of times T2 that satisfies T2 is less than 10, clear the work up to that point, start checking the pulse again, and repeat the actions up to now, but T2
When 10 times have elapsed, count the number of pulses so far, and if this pulse has elapsed, for example, 5 times or more, combustion is stopped.

If it is less than 4 times, clear all pulse and T2 counts so far and continue combustion. Then, clear the number of pulses and T2 so far and make everything operate from the beginning.

Here, 10 times or 5 times is an assumption, but in reality, the level is determined by the degree of flame discharge.

To detect pulses within this normal pulse interval T1,
If there is an abnormality even once, the combustion can be stopped, but in reality, there are also pulses caused by noise, and at this level, the flame will not reach the point where it is ejected, so the combustion will stop. There is no need to stop. Therefore, it is effective to continue for about 10 cycles and then judge whether or not there is an abnormality.

Also, regarding the pulse width v2, compared to the specified vl,
Since it can be detected, it has become possible to detect abnormal pulse widths.

According to the present invention, as is clear from the description of the embodiments above,
For example, the breakdown voltage of thyristor 19.21 is poor, or resistor 20.
22. An increase in the amount of oil supplied due to a defect in the capacitor 21 or trigger element 23 can be prevented in advance, and flames can be prevented from forming in the exhaust section.8 Also, as in the present invention, flames can be prevented from blowing out. One possible method for this is to install a temperature-sensitive element such as a thermistor or thermostat in a part of the exhaust port or the looper and stop the operation due to a temperature rise. Detection is possible, and extremely high safety is ensured.

Note that even if the pulse interval becomes narrow for some reason, it can be detected if the pulse interval is detected, for example, when 3 out of 10 detections fall between TI-v2.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a combustion device according to an embodiment of the present invention, Fig. 2 is a circuit diagram of the main parts, Fig. 3 is an explanatory diagram of the pulse I-res waveform, and Fig. 4 is a diagram for explaining the operation. Flowchart, FIG. 5 is a sectional view of the hot air fan according to the present invention, FIG. 6 is an explanatory diagram of the structure of its burner section, FIG. 7 is a circuit diagram showing a conventional example, and FIG. 8 is an explanatory diagram of its pulse waveform. . A: Combustion control section, B: Pulse generating section, C: Pump drive circuit, D: Pulse abnormality determination section, 18... electromagnetic pump. Name of agent: Patent attorney Toshio Nakao and one other person A-
-- Burning Disaster "Shinto B--Eleventh Pulse Life City C--Pump D-Pulse Viscousity" Foot/3-January Bossif. Figure 1 Figure 2 r Figure 4 Figure 5 Figure 6 Figure 7 Jυ Figure 8

Claims (2)

[Claims] (1) A combustion control section, a pulse generation section that generates pulses based on the output from this combustion control section, a pump drive circuit that drives an electromagnetic pump based on the pulses from this pulse generation section, and a pump drive circuit Also, monitor the pulse from the pulse generator, do not measure the pulse for a period slightly longer than the time when the pulse is applied to the electromagnetic pump, and then measure until the next pulse is applied, This combustion device includes a pulse abnormality determination unit that stops combustion when the number of abnormalities obtained by repeating this measurement several times exceeds a certain value. (2) The combustion apparatus according to claim 1, wherein the abnormality measured by the abnormality determining section is either the pulse width V_2 or the interval T_2 until the next pulse is applied, or both.