JPS59104022A - Gas accident preventing device - Google Patents

Abstract

PURPOSE:To automatically shut off the supply of gas during vibration, such as earthquake, during which the use of gas is dangerous, by installing a vibration- sensitive device which is able to detect vibration by convert the vibration magnitude into a direct electric signal. CONSTITUTION:A vibration-sensitive device 19 is constituted such that a weight piece 69 is located to the forward end of an elastic plate 68 protruding from a stand 67, a strain gauge 70, of which a resistance value is varied when bending and torsion strain are exerted on a film having CuNi or Si foil laminated on a thin foil-shaped resin or paper, is adhered to said elastic plate 68, when said elastic plate 68 oscillates resulting from vibration, the strain gauge 70 is enabled to detect strain vibration as a change in a current flowing through said strain gauge 70. Thus, when vibration is exerted on the vibration-sensitive device 19, the strain gauge 70 senses it, a current change amount enters the reset input of a flip flop 73. When the current peak voltage even slightly exceeds the motion input voltage of the flip flop 73, the flip flop 73 is operated, an output terminal 74 maintains a low level, and an electromagnetic valve is closed even if flame is burning in a normal condition, resulting in the shut-off of the supply of gas.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a gas accident prevention device.In recent years, the trend in gas accidents has been to seal houses and switch to natural gas, resulting in oxygen deficiency accidents, gas leaks, and gas accidents. Gas explosion accidents, where gas filled in a room due to suicide or the like explodes for some reason, are becoming more prominent, and there is also a strong need to prevent fires caused by gas in use due to earthquakes.

The inventor has discovered that in the flame of gas combustion appliances, certain types of ions exist in a plasma state in a fixed direction of movement, and as a result, the flame is electrically conductive and has a rectifying effect, and the ions Focusing on the fact that the state of flame generation is greatly influenced by the oxygen content of the combustion atmosphere, we measured the state of this flame electrically.
By supplying gas to the downstream side of the gas supply path by energizing the solenoid valve placed upstream of the gas supply path (preferably outdoors) only when the flame is burning normally, oxygen deficiency accidents and gas leak accidents such as those mentioned above can be prevented. The company has manufactured a gas accident prevention device that prevents gas accidents.

Another object of the present invention is that conventional devices for shutting off gas supply due to earthquakes cannot always obtain the desired sensitivity due to differences in the installation location and structure of buildings. Direct vibration! : We have manufactured a gas accident prevention device that can automatically cut off the gas supply in the event of vibrations such as earthquakes that make gas usage dangerous, using highly reliable and versatile vibration sensors that can detect electrical signals.

Hereinafter, the present invention will be described in detail based on an embodiment shown in the accompanying drawings.

In the figure, reference numeral 1 indicates a gas supply source, and the figure shows a propane gas cylinder, but in the case of city gas, the end of an outdoor pipe or the outlet of a gas meter may be regarded as the gas supply source 1. A gas supply path 2 is connected to this gas supply source 1,
As in the conventional case, a gas combustion appliance 7 is connected to the tip thereof to form a gas supply system.

An electromagnetic valve 3 is disposed upstream of the gas supply source 1, which normally closes the gas supply passage 2 and opens the gas supply passage 2 only when energized to supply gas to the downstream side.

A switch 4 interlocked with the appliance plug 5 of the gas combustion appliance 7 is disposed so that the switch 4 can detect that the appliance plug 5 has moved to the ignition position. This switch 4 is a switch 81. which is turned ON when the appliance tap 5 is opened, closed, or ignited in conjunction with the movement (mainly rotation) of the knob 6 or appliance tap 5.
S2 and S3, each switch Si, 82.83 is ON, 0FF-'C- is not set so that the moving position of the appliance stopper 5 can be detected.

11 The above-mentioned switch 4 will be explained in more detail with reference to FIG. The common contact side of 83 is grounded, and each other power side contact is connected to the power input terminal 31 via resistors R4, R5, and R6, and the output terminals 32, 33, and 34 are branched and connected. When each switch Sl, S2, 83 is turned on, each output terminal 32
．． When the output voltages of 33 and 34 become low level, the ignition signal is output from the output terminal 32, the appliance stopper open signal is output from the output terminal 33, and the appliance stopper open signal is output from the output terminal 34. When the appliance stopper 5 is moved to the ignition position by the switch 4 set to , the one-shot multivibrator circuit 12 generates a / pulse signal. This one-shot multivibrator circuit 12 has an input terminal 35 connected to an output terminal 32 of the switching circuit 11, an inverter 36, a resistor I(7, an inverter 37
and the output of this inverter 37 is connected to an AND circuit 38.
, and the other end of the capacitor C2 whose negative end is grounded is connected to the branch point between the resistor R7 and the inverter 37, and furthermore, the other end of the capacitor C2 is connected to the branch point between the resistor R7 and the inverter 36. is connected to the other end of the AND circuit 38, and only a pulse signal having a width set by the time constant of the resistor R7 and the capacitor C2 is output from the output terminal 39 of the AND circuit 38. .

And the one-shot multi-bye break circuit 12
The generated pulse signal drives the solenoid valve 3 disposed upstream of the gas supply path 2, and energizes the solenoid valve 3 only for a time corresponding to 3 of the pulse signal to supply gas to the gas supply path 2.
Further, the ignition device 9 is driven by the pulse signal. That is, the output terminal 39 of the one-shot multivibrator circuit 12 is branched, and the branch-blade side is connected to the electromagnetic valve 3 via the OR circuit 17 and the AND circuit 18, and the other branch side is connected to the ignition device 9 that performs spark discharge. It becomes connected to. When I want to do this, when I change the appliance stopper 5 from the open position to the ignition position, the switch S3 is turned on, a pulse signal is generated in the one-shot multivibrator circuit 12, and the solenoid valve 3 is activated only for a time corresponding to the width of this pulse signal. Electricity is applied, during which time gas is supplied to the downstream side, and the ignition device 9 ignites the gas combustion appliance 7 at the location. In addition, in this case, in case of Iai where the distance of gas supply path 2 is long,
It is preferable that the ignition device 9 generates a spark in synchronization with the falling edge of the pulse signal.

Note that the output terminal 33 of the switching circuit 11 shown in FIG. 3 is connected to one end of the NAND circuit 16 shown in FIG. For example, in the case of a two-burner stove, the output terminal 34 energizes the solenoid valve 3 only when one side is in use and the other is in the closed state of the appliance stopper 5, so that only one side of the stove can be used. It is connected to the t-OR circuit 17 via an inverter 66.

On the other hand, at least one of the two electrodes to which a DC voltage or an AC voltage is applied is inserted into the flame F of the gas combustion appliance 7, and the current value flowing between the two electrodes is set to a preset upper limit. The solenoid valve 3 is controlled depending on whether or not the value is within the lower limit value and greater than or equal to the lower limit value.

In the illustrated example, the two electrodes are an electrode 8 inserted into the flame F and a gas combustion appliance 7 (burner part), as clearly shown in FIGS. Normal pressure is applied between the flame F and the gas combustion appliance 7, but it is theoretically possible that either side of the two electrodes may be at a high potential, or that the two electrodes may be inserted side by side into the flame F. . In the illustrated example, the one in Figure ≠ applies an AC voltage, and the power input to the input terminal 4o of the application power supply circuit 13 is a DC voltage because the output of the power supply circuit 10 described later is DC. Inverter 41, 42, resistor R7, R8 and capacitor C3
The combination of the inverter 43 and the transistors 44 and 45 generates an alternating current wave in the primary winding of the transformer 46, and the alternating current wave is generated in the secondary winding of the transformer 46. One output end of the transformer 46 is connected to the output terminal 64 via a resistor R9, and the other output end is connected to the output terminal 59. One side output terminal 64 of this application power supply circuit 13 is connected to the gas combustion appliance 7, and the other side output terminal 59 is grounded. Also, the fifth
In the case of DC in the figure, the application power supply circuit 13 is connected to the transformer 46
The secondary winding of the diode 65 and the smoothing capacitor c5
and the surface output terminal 64.59 via the resistor R11.

When electricity is applied as described above, electricity [8 and gas combustion appliance 7]
By applying a voltage of about 70 to 70 V between the
A minute current of about 9 milliamps flows. Therefore, this minute current is amplified by the amplifier circuit 14 and input to the determination circuit 15.

The amplifier circuit 14 has an input terminal 47 that connects the electrode 8, and the current input from this input terminal 47 is connected to the resistor RIO.
The voltage changes through the voltage, is smoothed by a capacitor C4, is amplified by a buffer amplifier consisting of a differential amplifier circuit 48, and is output to an output terminal 49. Note that, in the case of direct current, the capacitor C4 in this amplifier circuit 14 serves to alleviate sudden changes in current due to the influence of wind or the like.

Further, the determination circuit 15 includes a pair of variable resistors 52 and 53 connected in parallel to the power input terminal 51, and the output of the variable resistors is connected to one end of each of the pair of comparator circuits 54 and 55, One comparator circuit 54 selects a lower limit current value, and the other comparator circuit 55 selects an upper limit current value using variable resistors 52 and 53, respectively, so that they can be set as base currents. The other end of both comparator circuits 54 and 55 is connected to the output terminal 4 of the amplifier circuit 14.
9, the output of one comparator circuit 54 is connected to one side of an AND circuit 57, and the output of the other comparator circuit 55 is connected to the other side of the AND circuit 57 via an inverter 56. However, the signal is outputted to the output terminal 58 connected to the output of the AND circuit 57 only when the signal input to the input terminal 50 is within the upper limit value and greater than the lower limit value preset by both variable resistors 52 and 53. None.

The output terminal 58 of the determination circuit 15 is connected to the solenoid valve 3 via a NOR circuit 17 and an AND circuit 18. Note that this output terminal 58 is connected to the other end of the aforementioned NAND circuit 16, and the output terminal of this NAND circuit 16 is connected to the buzzer 21. A warning indicator such as a warning light 22 is connected. Also,
A vibration sensor 19, a centralized gas control panel 20, etc. are connected to another input terminal of the AND circuit 18, so that gas supply can be cut off by another device. In addition to the solenoid valve 3, an 8i device driven by gas, such as a gas lamp 24 and ventilation M25, can be connected to the output end of the valve 18.

As shown in Figure O, the vibration sensor 19 has a weight 69 disposed at the tip of an elastic plate 68 protruding from a base 67.
8, make a thin strip of resin or paper and apply 0uN on top of it.
i. A strain gauge 70 whose resistance value changes when bending or torsional strain is applied to a film made of laminated layers of Si, and when the elastic plate 68 shakes due to vibration, the strain gauge 70 absorbs the strain vibration. None can be detected as a change in the current passing through the strain gauge 70. This strain gauge 70 is connected in series with a power input terminal 76 together with a resistor R18.
A differential amplifier circuit 71 amplifies the signal from which relatively slow voltage fluctuations such as temperature changes are removed by passing through a time constant circuit of a capacitor C6 and a resistor R12. This amplification degree is
Since it is determined by the ratio of the resistors R13 and R14, by making the resistor R14 variable, the desired amplified signal can be transmitted to the differential amplifier circuit 71.
You get the output of And this signal is connected to resistors 15 and 16.
and a differential amplifier circuit 72) are synthesized by diodes 77 and 78, respectively.
This combined signal is connected to the reset input of the flip-flop 73, and the above-mentioned ignition pulse signal is input to the set input of this flip-flop.

Therefore, when vibration is applied to the vibration sensor 19, the strain gauge 70 senses it, and the amount of change at that time is input to the reset input of the flip-flop 73. If the peak voltage at that time exceeds the operating input voltage of the flip-flop 73, the flip-flop 73 is activated and the output terminal 74 is activated.
is kept at a low level, and the output terminal 74 will not go to a high level again unless the next ignition pulse signal arrives. This output terminal 74 is connected to one input of the AND circuit 18, and even if the flame F is burning normally, the solenoid valve 3 is closed and the gas supply is cut off.

Note that 10 in the figure is a power supply circuit for supplying power to each of the above-mentioned circuits, and has a configuration as shown in FIG. 2. Plug 23
are connected to a transformer 28 via a fuse 26.18g switch 27, which transformer 28 has a diode 29.
29 and a capacitor C1 are connected together, which is the same as in the conventional power supply circuit, but in this embodiment, a battery 30 and a start switch 63 are provided as a secondary power source. A current that constantly charges the battery 3o flows from one output terminal through the diode 60 and the resistor R3, although it is lower than the other output terminal of the transformer 28. One output end of the transformer 28 is connected to the anode of the thyristor 5OR2 via the diode 60 and the resistor R3, and the other output end is connected to the anode of the thyristor 5OR2.
Connected to the anode of OR1, both thyristors 5ORI, 5
The cathode of CR2 is connected to the power output terminal 62 via the regulator 61, and the gates of both thyristors 5ORI and 5OR2 are connected to a high potential via the starting switch 63, and the starting switch 63 is manually operated to switch once. s4. When s5 is turned on, thyristor S OR1 is turned on.
A constant voltage is output to the power output terminal 62. Also, once a power outage occurs, the start switch 63 is manually turned ON/OFF.
If not, thyristor 5ORI will be turned on, and if the start switch 63 is turned on during a power outage, thyristor 5OR2 will be turned on/off.
The current from the battery 30 side is output to the power output terminal 62, so that gas can be used by the battery 30 even during a power outage, and when the power outage ends, the start switch 6 is turned on.
Unless the solenoid valve 3 is operated manually, the power is not automatically resupplied and the solenoid valve 3 is not opened.

Next, the operation of this embodiment will be explained.

It is assumed that the plug 23 is inserted into the power outlet, the start switch 63 is turned ON once, and the device of the present invention is ready for operation.

First, it is assumed that the appliance stopper 5 is moved from the closed position to the open position and to the ignition position. Then, as described above, the switch S3 is turned on, the solenoid valve 3 is opened by the pulse signal, and the ignition device ignites.

At this time, even if ignition fails for some reason and flame F is not produced, the solenoid valve 3 is only opened for a period of time corresponding to the width of the pulse signal, so there is no risk of raw gas flowing out subsequently. Normally, the device plug 5 returns to the open position when the user releases the device due to spring force or the like, but even if it is held at the ignition position, the solenoid valve 3 will not continue to open unless a flame F is generated.

When the ignition is performed by the operation of the device plug 5, the current is passed from the electrode 8 to the electromagnetic valve 3 via the amplifier circuit 14 and the determination circuit 15.

However, the current flowing through the electrode 8 changes depending on the combustion state and whether or not the electrode 8 is short-circuited. Therefore, when the electrode 8 is short-circuited and the current flowing through the electrode 8 exceeds a set upper limit value, the determination circuit 15 stops the energization to the solenoid valve 3, and also stops the electricity flowing to the electromagnetic valve 3 due to lack of oxygen in the combustion air. When the current flowing through the solenoid valve 3 falls below the set lower limit, the energization to the solenoid valve 3 is similarly stopped and the gas supply is stopped. Note that at this time, since the appliance stopper 5 is normally in the open position, the inputs to the NAND circuit 16 are both at low level, and the buzzer 21. The warning light 22 etc. is energized to issue an alarm.

Further, when there is vibration from the ground, etc., the output terminal 74 of the vibration sensor 19 becomes low level, so the solenoid valve 3 is closed via the AND circuit 18. Furthermore, if the central gas control panel 20 prevents the AND circuit 18 from outputting a signal to open the solenoid valve 3 at night or when going out, the gas can be prevented from being used by children or the like.

Furthermore, when the gas is finished being used and the appliance stopper 5 is closed, the combustion stops, so the output signal from the determination circuit 15 becomes low level and the solenoid valve 3 is closed.

The gas accident prevention device of the present invention has the above-described configuration and operation, and since the solenoid valve 3 is opened due to normal combustion of gas as determined by the judgment circuit 15, gas is supplied if the conditions for normal combustion of gas are not met. Therefore, a highly reliable gas accident prevention device can be provided. Actually, opening the solenoid valve 3 during normal combustion is different from closing the valve when an abnormality is detected, and even if there is a failure, the failure will only occur on the safe side where gas is not supplied. be. In addition, since this judgment circuit 15 prevents malfunctions due to short circuits of the electrodes at the upper limit of the current value, safety can be ensured even if the electrodes 8 come into contact with the gas combustion appliance 7 or there is a short circuit due to foreign matter such as boiling over. . .

In particular, this judgment circuit 15 detects oxygen deficiency at the lower limit of the current value and stops combustion. It has an unprecedented and revolutionary effect of preventing such occurrences.

Furthermore, as an exception to the device of the present invention which opens the solenoid valve 3 only during normal combustion, the one-shot multivibrator circuit 12 temporarily opens the solenoid valve 3 at the time of ignition. There is no outflow of gas even if it is kept in position, and the outflow of gas necessary for ignition can be reliably limited to a short period of time.

Furthermore, since the device of the present invention detects vibrations directly as an electric signal using the strain gauge 70, vibrations can be detected reliably, and the sensitivity can be easily increased by electrical processing such as making the resistor R14 variable. Since it can be adjusted, the sensitivity can be adjusted according to the actual installation location, and it has excellent versatility.

[Brief explanation of the drawing]

The drawings show one embodiment of the gas accident prevention device of the present invention. Fig. 1 is a front view including block wiring, Fig. 2 is a power supply circuit wiring diagram, and Fig. 3 is a switch, switching circuit, and one-shot multi Figure 6 is a wiring diagram of the vibrator circuit section, Figure 6 is a wiring diagram of the application power supply circuit, amplification circuit, and judgment circuit, Figure S is a wiring diagram of the application power supply circuit and amplifier circuit section showing another embodiment. FIG. 2 is a perspective view including a wiring diagram of the vibration sensor. 1-Gas supply source 2-Gas supply path 3-Solenoid valve 4-Switch 5-Appliance stopper 6-Knob
7 ~ Gas combustion appliance 8 ~ Electrode 9 ~ Ignition device
10 ~ Power supply circuit 11 ~ Switching circuit 12
~One shot 1-Multi-vi break circuit 13~
Application voltage circuit 14 ~ Amplification circuit 15 ~ Judgment circuit 16 ~ NAND circuit 17 ~ OR circuit
18 ~ AND circuit 19 ~ Vibration sensor 70 ~ Strain gauge representative person

Claims (1)

[Claims] When the appliance stopper is moved to the ignition position by a switch linked to the appliance stopper, a one-shot multivibrator circuit generates a pulse signal, and this pulse signal causes an electromagnetic switch disposed upstream of the gas supply path to be activated. The valve is driven to supply gas only for a time corresponding to the width of the pulse signal, and the ignition device is driven by the pulse signal. At least one of the two applied electrodes is inserted, and the solenoid valve is opened depending on whether the current value flowing between the two electrodes is within a preset upper limit value and greater than a lower limit value. None.Furthermore, the gas accident prevention device is configured to control the solenoid valve using a vibration sensor that electrically detects vibrations using a strain gauge whose resistance value changes depending on changes in strain.