JP3827395B2 - Gas shut-off control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a gas shut-off control device that detects that a gas shut-off device mounted on a gas meter shuts off a gas passage due to an impact in order to ensure the safety of gas use.
[0002]
[Prior art]
The gas meter is equipped with a gas shut-off device that shuts off the gas passage when an abnormal state in use of the gas is detected, thereby ensuring safety in use of the gas. The shut-off valve operated by the gas shut-off device to shut off the gas passage is configured as an electromagnetic valve as shown in FIG.
[0003]
In FIG. 7, the shutoff valve 10 drives the movable rod 32 in the forward and reverse directions depending on the direction of the excitation current applied to the excitation coil 31, and the gas passage is opened and closed by the valve 33 attached to the movable rod 32. Switch to the state.
[0004]
When there is no abnormality in the gas shut-off device, the shut-off valve 10 is kept open, and when an abnormality such as a gas leak, pressure abnormality, or earthquake is detected, the gas shut-off device excites the shut-off valve 10. An exciting current is applied to the coil 31 and the gas passage is closed by the valve 33. In this way, the shutoff valve 10 is electrically controlled, but when a strong impact is applied to the gas meter on which the gas shutoff device is mounted, the permanent magnet 35 holding the valve 33 in the open state by the impact. In some cases, the movable rod 32 moves away from the magnet, moves from the inside of the exciting coil 31 in the closing direction, and shuts off the shock that puts the valve 33 in the closing state.
[0005]
When the movable rod 32 moves from the open state due to an impact, a back electromotive force is generated in the excitation coil 31 due to electromagnetic induction. By detecting this, the shut-off valve 10 is closed due to the impact. The state of this shock interruption can be detected and displayed on an alarm indicator provided in the gas meter or notified to the centralized monitoring center.
[0006]
[Problems to be solved by the invention]
However, when the impact cutoff is detected from the signal generated by the impact cutoff, there is a problem that an erroneous detection of the impact cutoff occurs due to detection of this as a signal due to the impact cutoff due to the entry of external noise or the like.
[0007]
An object of the present invention is to provide a gas cutoff control device capable of accurately detecting the closing operation of a cutoff valve due to an impact.
[0008]
[Means for Solving the Problems]
According to the present invention, when an impact is applied to a gas shut-off device having an electromagnetic valve for switching a gas passage between an open state and a closed state, the movable rod of the electromagnetic valve held in the open state moves to the closed state. In the gas cutoff control device that detects the impact cutoff of the gas cutoff device by detecting the pulse signal generated in the excitation coil of the solenoid valve due to the impact cutoff,
In order to discriminate between the impact interception detection unit that outputs as an impact interception detection signal when a pulsed signal of a predetermined voltage or more is input, and the specific signal generated when the movable rod moves, the values of voltage and pulse width are set. An opening / closing control unit having a determination processing means for comparing a preset comparison value with the impact cutoff detection signal to determine whether the signal is due to impact cutoff or noise is provided,
The opening and closing control unit, the a signal is determined by the impact interrupted by two comparison value determination processing means, and when it is confirmed that is a plugging condition, and features a TURMERIC row processing such alarm output To do.
[0009]
According to the above configuration, the open / close control unit detects the impact cutoff by judging the impact cutoff detection signal input from the impact cutoff detection unit from the voltage and the pulse width. Since not only the pulse signal generated in the excitation coil of the solenoid valve due to the impact cutoff, but also the noise signal that is excited by the excitation coil due to the external noise may be input to the impact cutoff detector. The switching control unit distinguishes the pulse signal input from the impact shut-off detection unit from the noise based on the voltage and pulse width peculiar to the impact shut-off signal. To accurately determine the state of the impact cutoff.
[0010]
In the above configuration, by providing a low-pass filter for removing a noise component in the signal input unit of the impact cutoff detection unit, the state where the impact cutoff detection unit outputs noise to the open / close control unit as an impact cutoff detection signal is reduced. More accurate detection of impact interruption can be performed.
[0011]
In addition, by configuring both ends of the electromagnetic coil to ground with resistors, voltage components affected by noise such as counter electromotive force generated by the magnetic field generated in the excitation coil due to high voltage due to noise or the like are generated by the resistors. Since it is grounded, magnetic energy is not accumulated, and it is possible to suppress erroneous detection of a noise signal generated by the back electromotive force as an impact cutoff signal.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings for understanding of the present invention. The following embodiment is an example embodying the present invention, and does not limit the technical scope of the present invention.
[0013]
FIG. 1 is a configuration diagram showing a configuration of a gas cutoff control device according to an embodiment of the present invention. The gas cutoff control device 1 is configured to shut off by an impact and a valve drive unit 2 that opens and closes a cutoff valve (electromagnetic valve) 10. An impact shutoff detection unit 6 that detects a signal that the valve 10 shuts off the gas passage, and an open / close control unit 4 that controls the operation of the valve drive unit 2 associated with the abnormality detection and controls a series of processing operations associated with the impact shutoff operation. And a valve opening / closing determination unit 5 that detects the closing state of the shutoff valve 10 and a valve opening / closing display unit 8 that displays an alarm that the shutoff valve 10 has been closed.
[0014]
The shut-off valve 10 is configured as an electromagnetic valve as shown in FIG. 7 and is supplied from the battery 3 by switching control of the four transistors 7a to 7d constituting the bridge circuit by the open / close control unit 4. The direction in which the excitation current is applied to the excitation coil 31 of the cutoff valve 10 is controlled, and the gas passage can be switched between a closed state and an opened state. The open / close control unit 4 is configured to receive a detection signal from an abnormality detector (not shown) that detects an abnormality such as a gas flow rate, pressure, or earthquake vibration, and when the abnormality detection signal is input. An operation signal is given to the bases of the transistors 7a and 7b in order to close the shut-off valve 10. When the transistors 7a and 7b operate, the exciting current _ic is applied to the exciting coil 31 of the shut-off valve 10, and the shut-off valve 10 closes and shuts off the gas passage, so that the closed state is self-maintained. When the open state is restored by canceling the abnormality, the opening / closing control unit 4 gives an operation signal to the transistors 7c and 7d, so that the exciting current _io is applied to the exciting coil 31, and the shutoff valve 10 is opened. This open state is self-maintained, and the open state is maintained in normal times.
[0015]
When an impact is applied to the gas meter equipped with the gas shut-off control device 1 having the above configuration for some reason, if a strong impact is applied to the shut-off valve 10, the movable magnet is held in an open state by the permanent magnet 35 shown in FIG. The rod 32 is detached from the exciting coil 31 in the closing direction. When the movable rod 32 moves in the excitation coil 31 in a state where no excitation current is applied to the excitation coil 31, a back electromotive force is generated in the electromagnetic coil 31 due to electromagnetic induction. The component of the back electromotive force larger than the voltage of the battery 3 is recirculated through the diodes 9a to 9d connected in antiparallel to the transistors 7a to 7d, and is released to the ground. It is input to the impact cutoff detector 6.
[0016]
The impact cutoff detector 6 is configured as shown in FIG. 3, and when a voltage higher than a predetermined value divided by the resistors 13 and 14 is input to the base of the transistor 12, the collector and the emitter are electrically connected. Therefore, when the signal generated by the impact shutoff of the shutoff valve 10 is equal to or higher than the predetermined voltage, the transistor 12 conducts, and this state is input to the open / close control unit 4 as an impact shutoff detection signal.
[0017]
As shown in FIG. 2 (a), the opening / closing control unit 4 performs a determination process based on a voltage value and a pulse width (time) with respect to the impact cutoff detection signal input by the conduction of the transistor 12 of the impact cutoff detection unit 6. The noise signal as shown in FIG. 2B is identified. This determination process determines whether or not the voltage of the signal input from the impact cutoff detector 6 is greater than a predetermined value V _{0 and} whether or not the pulse width is greater than a predetermined value t ₀ . If the pulse width t ₂ is smaller than the predetermined pulse width t ₀ even if the voltage V ₂ is larger than the predetermined voltage V ₀ as in the noise signal shown in FIG. As shown in FIG. 2A, the impact cutoff detection signal has a voltage V ₁ and a pulse width t _{1 which} are specific signals generated when the movable rod 32 moves in the exciting coil 31, and the predetermined value The signal corresponding to V ₀ and t ₀ is determined as an impact cutoff detection signal. With this processing operation, it is possible to distinguish between noise and an impact cutoff detection signal, and it is possible to prevent an erroneous determination that determines that noise is an impact cutoff detection signal.
[0018]
After the opening / closing control unit 4 detects the impact cutoff detection signal, when the valve opening / closing determination unit 5 confirms that the cutoff valve 10 is closed, the cutoff valve 10 is closed on the valve opening / closing display unit 8. Display. In the valve open / close determination unit 5, the shutoff valve 10 is closed by means such as a change in inductance of the exciting coil 31 due to the movement of the movable rod 32 in the exciting coil 31, or a position detection of the valve 33 by a sensor. When it is detected that this is the case, a shutoff determination signal is input to the valve opening / closing control unit 4. The state in which the shut-off valve 10 shuts off the gas passage is due to the mechanical operation due to the shock and the electric control operation due to the detection of abnormalities such as the gas flow rate and pressure. The user provides a sudden gas shut-off in the gas meter. It can be known by warning display such as LED, LCD etc. In addition, it is possible to notify the centralized monitoring center through a telephone line simultaneously with the alarm display.
[0019]
By providing a low-pass filter 11 as shown in FIG. 4 at the input part of the shock cutoff detector 6, the signal due to the noise above the cutoff frequency of the low-pass filter 11 can be detected. Can be prevented, so that the false detection of the impact cutoff detection can be reduced.
[0020]
The low-pass filter 11 can also be configured by a simple circuit as shown in FIG. As shown in FIG. 5, the noise component having a frequency exceeding this is caused by the cutoff frequency determined by the value of the capacitor 15 connected to the signal input to the base of the transistor 12 and the value of the resistor 13. Since the signal generated by the impact interception can be passed, the input of the signal due to noise or the like from the impact interception detection unit 6 to the open / close control unit 4 is reduced. Detection is possible.
[0021]
FIG. 6 shows a configuration in which the exciting coil 31 of the shut-off valve 10 is provided with resistors 16 and 17 that are grounded at both ends, and is configured to reduce erroneous detection of impact shut-off due to noise or the like.
[0022]
When a high voltage due to noise or the like is applied to the shutoff valve 10, a magnetic field is generated in the excitation coil 31, and a counter electromotive force is generated in the excitation coil 31 due to this magnetic field. Although the voltage component larger than the voltage of the battery 3 of the back electromotive force is grounded by the recirculation of the diodes 9a to 9d, the voltage component smaller than the voltage of the battery 3 is input to the impact cutoff detection unit 6, so that the detection of the impact cutoff is performed. Cause false detection. Further, the back electromotive force generated due to noise or the like is accumulated as magnetic energy in the exciting coil 31, which also causes false detection. Therefore, as shown in FIG. 6, the back electromotive force generated in the exciting coil 31 is released to the ground by connecting both ends of the exciting coil 31 to the ground by the resistors 16 and 17, so that the back electromotive force generated by noise or the like is generated. The false detection of the impact cutoff detection by electric power is reduced, and the impact cutoff detection can be performed more accurately.
[0023]
【The invention's effect】
As described above, according to the present invention, the opening / closing control unit detects the impact cutoff by judging the impact cutoff signal input from the impact cutoff detection unit based on the voltage and the pulse width. It is possible to discriminate between the input signal due to the impact cutoff and the signal due to noise, etc., reducing false detection of erroneously judging noise etc. as the impact cutoff detection signal, and accurately determining the cutoff state of the cutoff valve due to impact be able to.
[0024]
In addition, by providing a low-pass filter that removes noise components in the signal input part of the impact cutoff detection unit, the state where the impact cutoff detection unit outputs noise to the open / close control unit as an impact cutoff detection signal is reduced, and a more accurate impact Blockage can be detected.
[0025]
Furthermore, by configuring both ends of the solenoid valve to ground with resistors, the coil back electromotive force generated by the magnetic field generated in the exciting coil due to high voltage due to noise or the like is grounded by the resistor, so that the magnetic energy is reduced. The noise signal generated by the back electromotive force is prevented from being erroneously detected as an impact cutoff detection signal without being accumulated.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing a configuration of a gas cutoff control device according to an embodiment of the present invention.
FIG. 2 is a waveform diagram for explaining discrimination between an impact cutoff signal (a) and a noise signal (b).
FIG. 3 is a circuit diagram showing a configuration of an impact cutoff detector.
FIG. 4 is a block diagram showing a configuration in which a low-pass filter is provided in the impact cutoff detection unit.
FIG. 5 is a circuit diagram showing a configuration of an impact cutoff detector provided with a low-pass filter.
FIG. 6 is a circuit diagram showing a configuration in which a noise countermeasure resistor is provided on the shut-off valve.
FIG. 7 is a cross-sectional view showing a configuration of a shut-off valve.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Gas interruption | blocking control apparatus 4 Opening / closing control part 6 Impact interruption | blocking detection part 10 Shut-off valve (solenoid valve)
11 Low-pass filter 16, 17 Resistor 31 Excitation coil

Claims (3)

When an impact is applied to a gas shut-off device equipped with an electromagnetic valve that switches the gas passage between the open state and the closed state, the movable rod of the solenoid valve held in the open state is moved to the closed state due to the impact cutoff. In the gas cutoff control device that detects the impact cutoff of the gas cutoff device by detecting the pulse signal generated in the excitation coil of the solenoid valve,
In order to discriminate between the impact interception detection unit that outputs as an impact interception detection signal when a pulsed signal of a predetermined voltage or more is input, and the specific signal generated when the movable rod moves, the values of voltage and pulse width are set. An opening / closing control unit having a determination processing means for comparing a preset comparison value with the impact cutoff detection signal to determine whether the signal is due to impact cutoff or noise is provided,
The opening and closing control unit, the a signal is determined by the impact interrupted by two comparison value determination processing means, and when it is confirmed that is a plugging condition, and features a TURMERIC row processing such alarm output Gas shut-off control device.   The gas cutoff control device according to claim 1, wherein a low-pass filter for removing a noise component is provided in a signal input portion of the impact cutoff detection unit.   The gas cutoff control device according to claim 1, wherein both ends of the exciting coil are grounded by resistors.

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