JPH01310231A - Liquid fuel combustion device - Google Patents

Abstract

PURPOSE:To ensure safety by a method wherein according to the presence of the pulse signal of a time division driven signal from a display means by means of a microcomputer, a pressure solenoid to control the forced feed of fuel is controlled, and when a pulse signal is stopped, the pressure solenoid is turned OFF to stop combustion. CONSTITUTION:When a signal C is held in an Hi level state, charge is charged in a capacitor 32, a signal (a) exceeds a given voltage, and the signal (a) produces an Lo signal. When a signal a' produces an Lo signal, a signal (c) produces Lo irrespective of the state of a control signal B, a transistor 30 is turned OFF, and no energization to a pressure solenoid 21 is effected. When the pressure solenoid 21 is turned OFF, an air pressure generated with the aid of a motor 17 for combustion is disconnected, no pressure is exerted on the interior of a constant level gauge 8, injection of fuel through a needle 10a to a vaporizing cylinder 11 is stopped, and combustion is stopped. similarly, when the signal C is held in an Lo level state, a signal C' is held in an Hi state, and the pressure solenoid 21 is turned OFF.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to a safety device for a liquid fuel combustion device.

[Conventional technology]

FIG. 5 is a sectional view showing the configuration of a conventional liquid fuel combustion device.

In Fig. 5, 1 is a cartridge type fuel tank, 2
is a sub-tank, 3 is a water detector, 4 is an oil detector, 5 is a saucer, 6 is a water separation filter, 7 is an oil pipe, 8 is a constant oil surface sound,
9 is an electromagnetic pump, 10 is a fuel pipe, 10a is a needle, 11 is a carburetor cylinder, 12 is a preheating heater, 13 is a preheating detection thermistor, 14 is a burner head, 15 is a spark plug, 16 is a flame detector, 17 is a combustion 18 is a blower pipe, 1 is a cooling pipe, 20 is a pressure pipe, 21 is a pressure solenoid, 22 is an air volume control valve, 23 is a nozzle, and 24 is a rotation speed sensor.

In the above configuration, the vaporizer cylinder 11 is heated by the preheater 12.
When it is heated and reaches a predetermined temperature, the preheat detection thermistor 13 detects this temperature and the operation is started.

Then, the combustion motor 17 rotates and blows air into the blower pipe 18 and the cooling pipe 19 for a certain period of time to blow air into and out of the vaporizer cylinder 11, and then the electromagnetic pump 9, the spark plug 15, and the pressurizing solenoid 21 are energized. .

When the electromagnetic pump 9 is operated, the fuel stored in the sub tank 2 from the fuel tank 1 is transferred from the oil supply pipe 7 to the oil level regulator 8.
Further, the fuel in the leveler 8 is sent to the fuel pipe 1
0 to the needle 10a.

On the other hand, by energizing the pressure solenoid 21, the pressure pipe 2
Pressure P is applied to the oil level in the oil level regulator 8 through the nozzle 23 provided at the tip of the blower pipe 18.
Fuel is forcefully jetted from the needle 10a into the vaporization cylinder 11 by the airflow passing through the fuel cylinder 11, and is supplied in the form of mist.

The atomized fuel supplied into the vaporization tube 11 instantly vaporizes when it hits the heated inner wall surface of the vaporization tube 11 , and then passes through the nozzle 23 .
The mixture is mixed with air flowing in from the ignition plug 15 and ejected from the periphery of the burner head 14, and is ignited by discharge from the ignition plug 15 and combusts.

FIG. 6 is a block diagram showing part of the control circuit that controls the combustion operation.

In FIG. 6, 25 is a microcomputer (hereinafter referred to as microcomputer), which controls the combustion motor 17 using a motor control signal A. Further, the pressurizing solenoid 21 is controlled so that the air pressure generated by the combustion motor 17 is applied to the oil level at the constant oil level M8 through the pressurizing pipe 20. The pressurizing solenoid 21 is activated by the printing part signal B from the microcomputer 25.
6.

Furthermore, the microcomputer 25 generates a pulse signal C, and the IC2
7 to drive and control the display means 28 in a time-division manner. When the microcomputer 25 malfunctions or malfunctions called runaway, the control signal A for the combustion motor 17 and the control signal B for the pressurizing solenoid 21 remain output, making control impossible. At that time, the pulse signal of the drive signal C of the display means 28 stops and becomes either the rHiJ level or the rLoJ level, but only a part of the display means 28 lights up brightly and does not have any effect on the control parts. .

Therefore, if the combustion device continues to burn and is used in a closed state for a long time without the user noticing an abnormality, it is assumed that incomplete combustion will occur. Even in such an incomplete combustion state, the microcomputer 25 has failed or stopped operating, and even if the information of the sensor signal N is input to the microcomputer 25, combustion cannot be stopped.

[Problem to be solved by the invention]

Conventional liquid fuel combustion devices do not stop combustion when the microcomputer 25 fails or stops operating, but continue combustion, which can lead to incomplete combustion in some cases, which is extremely dangerous. there were.

This invention is capable of ensuring safety by stopping the operation of the combustion device when the microcomputer becomes uncontrollable due to malfunction or runaway, and the output signal of the microcomputer stops changing. The purpose is to obtain equipment.

[Means to solve the problem]

The liquid fuel combustion device according to the present invention determines whether there is a pulse signal of the time division drive signal of the display means by the microcomputer.
Control the pressure solenoid that controls the pressure feeding of fuel by fI + lJ, and when the pulse signal stops, turn the pressure solenoid OFF.
' F is used to stop combustion.

[Effect]

In the liquid fuel combustion device according to the present invention, when the pulse signal for time-divisionally driving the display means stops changing, the pressurizing solenoid is turned OFF regardless of the pressurizing solenoid control signal from the microcomputer, and the The air pressure applied to the oil leveler is cut off, fuel supply is stopped, and combustion is stopped.

〔Example〕

An embodiment of the present invention will be described below.

The basic configuration of the liquid fuel combustion device in this example is almost the same as the configuration shown in FIG. do.

FIG. 1 is a circuit diagram of an embodiment of the present invention.

In FIG. 1, reference numeral 17 denotes a combustion motor, and its rotational speed is controlled by fM Onsougo A of a microcomputer 25 (hereinafter referred to as microcomputer) via a solid state relay 29.

As in the conventional example shown in FIG. 5, fuel is pumped up by an electromagnetic pump 7, and a level regulator 8 configured to maintain a constant oil level.
Maintain a constant oil level inside.

Pressure solenoid 21 (is driven via transistor 30 by a control signal from microcomputer 25).

When voltage is applied to the pressure solenoid 21, the oil level regulator 8
Air pressure generated by the rotation of the combustion motor 17 is applied through the pressurizing pipe 20, and the fuel is sent from the needle 10a to the vaporization cylinder 11, where it is combusted.

The microcomputer 25 outputs a pulse signal CL, and displays temperature information, time information, etc. on the display means 28 by time division driving.

The pulse signals C to G of the microcomputer 25 are finger-driven pulse signals of the display means 28, and are, for example, regular waveforms of the duty signal 115'.

The pulse signals H to L of the microcomputer 25 are signals for driving the segments of the display means 28, and output display signals in synchronization with the corresponding digit signals C to G.

The inverter IC31 is an element for amplifying the digit signals C to G and the segment signals H to L.

The signal C is output from the microcomputer 25 at a duty cycle 115, and becomes an inverted signal C' at an inverter IC31.

FIG. 2 is a pulse waveform diagram of signal C and signal C'.

When the microcomputer 25 is operating normally, the signal C is controlled by a program stored in the memory inside the microcontroller 25 so that it has a pulse waveform.

For example, in a certain step of the program, the signal C is set to rHi.
The signal C is output to the J level, and the signal C is output to the rL and oJ levels at a step after a predetermined time has elapsed.

In FIG. 1, when the signal C reaches the rLoJ level, the charge in the capacitor 32 is discharged, and the signal I does not rise above a predetermined voltage even if the signal C becomes rHiJ for a certain period of time.

The inverter 33 is an oven collector type IC, and the signal I' is open.

When the signal C' reaches the rLoJ level, the charge in the capacitor 34 flows into the signal C', and the signal port receives the signal C' for a certain period of time.
Even if becomes rHiJ, the voltage does not exceed the predetermined voltage.

The inverter 35 is an open collector type IC, and the signal port' is open.

When the signal C is normally a pulse wave, both the signal I' and the signal port' are open, and the pressurizing solenoid 21 is ft1.
Controlled by lJa signal B.

When the microcomputer 25 stops operating normally due to a failure or a phenomenon called runaway, programs stored in the internal memory cannot be executed.

In that case, the signal C becomes a pulse wave, and as shown in FIG.
As shown in the figure, it remains at the "LO" level.

When the signal C is held at r)iiJ level as shown in FIG. 3, the capacitor 32 is charged with charge in FIG.
A No. 3 A becomes higher than the predetermined voltage, and signal A becomes "T, o-
! It becomes a signal.

When the signal A' becomes the "LO" signal, the signal becomes "LO" regardless of the state of the control signal B, the transistor 30 is turned off, and the pressurizing solenoid 21 is de-energized.

When the pressurizing solenoid 21 turns OFF, the combustion motor 17
The air pressure generated by this is interrupted, and no pressure is applied within the oil level regulator 8, and the injection of fuel from the needle 10a into the vaporization tube 11 is stopped, and combustion is stopped.

As shown in FIG. 4, when the signal C is held at the rLoJ level, the signal C' is held at the rHiJ state.

In FIG. 1, when the signal C' is held in the r Hi J state,
The capacitor 34 is charged with electric charge through the resistor 38, and the signal port becomes equal to or higher than a predetermined voltage.

When the signal port becomes a predetermined voltage or higher, the signal port' becomes rLoJ, and the signal becomes "LO" regardless of the state of control &1!14'a No. B, the transistor 30 is turned off, and the pressure solenoid j: 21 turns OFF.

,! When the Jl pressure solenoid 21FF is turned on, the combustion motor
At step 17, the air pressure generated is interrupted from being applied to the oil level regulator 8, and the injection of fuel from the needle 10a is stopped.
Combustion stops.

That is, when the pulse signal C of the microcomputer 25 is normally output, the pressurizing solenoid 21 is controlled by the control signal B of the microcomputer 25, and the pulse signal C of the microcomputer 25 is kept constant at the I"HiJ or "LO" level. In this case, the pressurizing solenoid 21 is OFF regardless of the control signal B of the microcomputer 25.

, combustion stops.

Note that the signal M is a control signal for each part of the combustion device, the signal N is a signal from various sensors of the combustion device, and the signal P is a switch signal of the combustion device.

〔Effect of the invention〕

As described above, according to the present invention, the pressure solenoid that controls the air pressure applied to the oil level of the oil level regulator is controlled by the presence or absence of a pulse signal from the microcomputer for time-divisionally driving the display means, Since the pressurizing solenoid is turned OFF to stop combustion when the pulse signal stops, it will act as a safety device when the microcomputer breaks down or malfunctions, resulting in a highly safe device.

[Brief Description of the Drawings] Fig. 1 is a circuit diagram of an embodiment of the present invention, Fig. 2 is a signal C
Figures 3 and 4 show the pulse waveform diagrams of signal C and signal C' when the microcomputer fails or becomes inoperable.
FIG. 5 is a sectional view showing the configuration of a conventional liquid fuel combustion device, and FIG. 6 is a circuit diagram of the same conventional control device. In the figure, 8 is an oil level regulator, 17 is a combustion motor, 18 is a blower pipe, 20 is a pressurizing pipe, 21 is a pressurizing solenoid, 25 is a microcomputer, 28 is a display means, and A. B is a control signal, and CG is a digit signal (pulse signal). Note that the same reference numerals in the figures indicate the same or equivalent parts. Agent Masuo Oiwa (2 others):? 111EF Fig. 2 Fang Fig. 3 Fig. Fang Fig. 4 Fig. Fang Fig. 6

Claims (1)

[Claims] A blower pipe that guides combustion air to the combustion section, a pressurizing pipe that applies air pressure in the blower pipe to the oil level of the oil level regulator, and a pressurizing solenoid that controls the air pressure acting on the pressurizing pipe.
In a device having a control microcomputer and a display means driven in time division by a pulse signal from the microcomputer, a pressurizing solenoid is controlled depending on the presence or absence of a pulse signal from the microcomputer, and the pulse signal is stopped. The liquid fuel combustion device is configured to turn off the pressurizing solenoid to stop combustion when