JP4751029B2 - Gas shut-off device - Google Patents

Description

  The present invention relates to a gas shut-off device, and more particularly to a gas shut-off device to be incorporated in a gas meter having a safety function, provided with voltage detection means for a power battery.

  2. Description of the Related Art Conventionally, a gas meter is attached to a gas passage, and a gas shut-off device that shuts off the gas supply by closing a shut-off valve in an emergency is provided for the purpose of safe gas supply. In order to check that the gas shut-off device is activated, it is one of them to have means for detecting the voltage of the battery which is the power source of the gas meter (at least the power source of the gas shut-off device).

  In one example of the battery voltage detection means of the gas meter, when the gas flow rate measured by the flow sensor is abnormal, the cutoff valve is driven, and before the voltage detection circuit loses the ability of the battery to drive the cutoff valve, Is driving. However, in the conventional method, the voltage is measured when the battery load is passing only a small current of the control unit, so if there is an increase in internal resistance due to the end of the battery capacity or for some reason Even though the pulse characteristics of the large current deteriorates and the shut-off valve driving capability is lost, the voltage detection circuit cannot detect it.

  A gas shut-off device for solving such a problem has been proposed (see, for example, Patent Document 1). FIG. 4 is a diagram showing a circuit configuration relating to voltage detection in the gas cutoff device of Patent Document 1, in which 21 is a cutoff valve equivalent resistance as a pseudo resistance, 22 is a cutoff valve equivalent resistance operating circuit, 23 is a microcomputer, Reference numeral 24 denotes a voltage detector. According to the voltage detection method described in Patent Literature 1, when the voltage of the battery of the gas meter is checked by the microcomputer 23, the shut-off valve equivalent resistance operation circuit 22 is activated and the shut-off valve equivalent resistance 21 is energized, The same load is applied as when the shut-off valve is operated by the shut-off valve drive circuit, and the battery voltage is checked without operating the shut-off valve by the shut-off valve drive circuit. In this gas shut-off device, the shut-off valve is actuated by a shut-off signal output from the microcomputer in the event of an emergency, and the shut-off valve maintains the closed state. After the abnormality disappears, the shut-off valve is manually operated. It is structured to restart the gas supply by returning and opening the valve.

In addition, after removing the shut-off valve equivalent resistance and confirming the open / closed state of the valve, if the valve is open, the valve open signal is sent to the valve control circuit, and the voltage detection circuit is operated. A gas meter that checks the voltage of a battery has also been proposed (see, for example, Patent Document 2).
Japanese Patent Publication No. 4-23169 Japanese Patent Laid-Open No. 10-19629

  However, in the gas shut-off device using the shut-off valve equivalent resistance as in Patent Document 1, a large current equivalent to the shut-off valve drive flows through the shut-off valve equivalent resistance, which is a pseudo resistance of the shut-off valve, during voltage detection. Become. When such a circuit design is performed, the shut-off valve equivalent resistance operation circuit has a large number of parts, which causes an increase in cost. Furthermore, the current flowing through the pseudo-resistor and the current flowing through the exciting coil at the time of driving the valve differ depending on the difference between the resistance and inductance, the variation in resistance value, and the temperature characteristic in the shut-off valve equivalent resistance and the shut-off valve excitation coil. That is, the terminal voltage of the battery when a current is passed through the pseudo resistance and the terminal voltage of the battery during actual valve driving are different from each other, and the accuracy of battery voltage detection is reduced.

  In addition, the battery voltage detection method as described above, including the battery voltage detection method in the gas meter of Patent Document 2, is a voltage drop due to the voltage characteristics at the end of the remaining battery capacity in which the battery voltage gradually decreases, and a voltage at the time of driving the valve. Therefore, the monitoring interval is set every few hours. Therefore, in the normal case, safety can be ensured by the above-described detection. However, in the unlikely event that the battery itself is defective or the board is abnormal (circuit short circuit due to condensation), the above-described detection cannot ensure safety. there is a possibility. Furthermore, if the monitoring interval is long, if an unexpected abnormal condition occurs, a large current flows and the battery capacity decreases rapidly, causing the voltage to drop earlier than usual, without warning or closing before the monitoring timing. In addition, the safety function of the gas meter may not work. However, conversely, in the voltage check method according to the prior art, if the monitoring time is shortened, the current consumption increases.

  Further, in a gas meter that performs voltage detection by valve control as in Patent Document 2, it is necessary to perform control according to the open / closed state of the valve, such as sending a valve closing signal when the valve is closed and a valve opening signal when the valve is opened. That is, in such a gas meter, the control microcomputer needs to confirm the state of the valve before performing voltage detection.

The present invention has been made in view of the above circumstances, and does not require a shut-off valve equivalent resistance, a shut-off valve equivalent resistance operation circuit, can reduce costs by reducing the number of parts and mounting costs, and Gas shutoff that shuts off the gas passage with a solenoid valve that can accurately detect the voltage of the battery with simple control regardless of the shutoff state of the solenoid valve without affecting the normal use of gas consumers The object is to provide a device.

  Another object of the present invention is to provide a gas shut-off device that can detect an unexpected voltage drop such as a battery failure at an early stage and shut off the gas passage without consuming battery capacity wastefully. Objective.

In order to solve the above-described problems, the present invention is constituted by the following technical means.
A first technical means is a gas shut-off device comprising a solenoid valve for shutting off a gas in a gas passage, and driving the solenoid valve using a battery as a power source to shut off the gas, the solenoid valve driving circuit driving the solenoid valve When, and a control unit for controlling the electromagnetic valve driving circuit, before SL and a voltage detection circuit that detect the voltage drop of the battery, the said solenoid valve is a stepper motor valve which is driven by a stepping motor, wherein The controller controls the electromagnetic valve so as to drive the stepping motor valve by a number of steps that substantially does not close or open when detecting a voltage drop of the battery in a state where the electromagnetic valve driving circuit is operated. The driving circuit is controlled .

A second technical means is the first technical means, wherein the voltage detection circuit, a short detection interval than the interval of the detection, and in a state of not operating the electromagnetic valve driving circuit, detecting the voltage drop of the battery It has the means to have further.

According to the first technical means of the present invention, the shut-off valve equivalent resistance and the shut-off valve equivalent resistance operation circuit are unnecessary, the cost can be reduced by reducing the number of parts and the mounting cost, and the solenoid valve drive circuit Since the current actually flows, the accuracy of voltage detection is improved, leading to improvement in reliability. Furthermore, according to the first technical means of the present invention, the battery voltage drop can be detected regardless of the shut-off state of the solenoid valve, so that the detection control is simple and the solenoid valve is kept stopped. Since detection can be performed, the normal use of the gas consumer is not affected, and the function as a gas meter is not impaired.

  According to the second technical means of the present invention, an unexpected voltage drop such as a battery failure can be detected at an early stage by monitoring in a short cycle, and the battery capacity is wasted for monitoring with no load. There is no longer to do.

  FIG. 1 is a diagram showing a circuit configuration example of a gas meter provided with a gas cutoff device according to an embodiment of the present invention, in which 1 is a gas meter, 2 is a gas meter body, 3 is a gas passage, 4 is a solenoid valve, Reference numeral 5 denotes a control unit, 6 denotes a battery, 7 denotes a solenoid valve drive circuit, 8 denotes a voltage detection circuit, and 9 denotes a display unit such as a display panel. However, in FIG. 1, for the sake of simplification, sensors and circuits relating to flow measurement, which are the main part of the gas meter 1, and sensors and circuits relating to safety functions such as gas pressure drop and earthquake detection are not illustrated. What is necessary is just to prepare according to a usage form.

  The gas shut-off device according to an embodiment of the present invention uses a battery 6 as a power source, and includes a solenoid valve 4, a control unit 5, a solenoid valve drive circuit 7, and a voltage detection circuit 8. In addition, since the battery 6 is common to the above-described sensors and circuits related to the flow rate measurement in the gas meter 1, the voltage detection target is widened as a power source for performing valve control linked to abnormal flow rate detection and the like. Although it is preferable, a power supply battery different from the battery related to the flow rate measurement may be used as long as it is a power supply for at least a circuit related to driving of the solenoid valve 4.

  The solenoid valve 4 is a shut-off valve for shutting off the gas passage 3 at the upstream side of the gas meter main body 2 or a flow rate sensor (not shown), and may be any one that can be electromagnetically closed. Although it is preferable that the electromagnetic valve 4 can be opened, the opening operation may be performed by a user or a gas manager. The position where the electromagnetic valve 4 is provided may be on the downstream side of the flow rate sensor, but it is preferably on the upstream side because the sensor may detect pulsation even when the flow rate is stopped. The solenoid valve drive circuit 7 is a circuit for driving the solenoid valve 4 and is controlled by the control unit 5. The voltage detection circuit 8 is a circuit that detects a voltage drop of the battery 6 when the electromagnetic valve drive circuit 7 is operated and transmits the voltage drop to the control unit 5. The voltage detection circuit 8 detects that the voltage is less than a predetermined drive voltage based on the minimum drive voltage value of the electromagnetic valve 4.

  In the gas shut-off device and the gas meter 1 equipped with the device having the above-described configuration, the voltage detection circuit is in a state in which the electromagnetic valve drive circuit 7 is controlled by the control unit 5 and the electromagnetic valve 4 is driven during voltage detection. 8 is used to check the voltage of the battery 6. That is, the shut-off valve equivalent circuit and the shut-off valve equivalent resistance operation circuit are unnecessary, and the battery voltage at that time is checked by actually operating the solenoid valve drive circuit 7 (solenoid valve drive) at the time of detection. The check timing may be set every few hours, for example.

  FIG. 2 is a diagram showing a circuit configuration example of a main part related to battery voltage detection in the gas cutoff device of FIG. 1, in which 14 is a motor valve as an example of the electromagnetic valve 4, and 15 is an example of the control unit 5. Reference numeral 17 denotes a solenoid valve drive IC (IC: semiconductor integrated circuit) as an example of the solenoid valve drive circuit 7, and reference numeral 18 denotes a voltage detector (VD) as an example of the voltage detection circuit 8.

  In the circuit configuration illustrated in FIG. 2, when detecting the battery voltage, the microcomputer 15 sends a signal (electromagnetic valve drive IC control signal) from the PO terminal to the electromagnetic valve drive IC 17 at a predetermined timing (timing for voltage detection). By outputting and further controlling the PO1 and PO2 terminals, the solenoid valve drive IC 17 outputs a drive signal from the OUT1, OUT2, OUT3, and OUT4 terminals to the valve excitation coil of the motor valve 14 to flow current. The voltage detector 18 detects the voltage of the battery at this time. The voltage detector 18 may also be controlled by the microcomputer 15. For example, the microcomputer 15 outputs a detection command signal to the voltage detector 18 together with the detection start signal, so that the voltage detector 18 detects the voltage. You just have to do it. When the voltage detector 18 detects that the battery voltage is lower than a predetermined voltage, the voltage detector 18 outputs a detection signal (voltage drop detection signal) to the terminal PI of the microcomputer 15. As described above, when the voltage is detected, the voltage of the battery is checked by the voltage detector 18 when the electromagnetic valve driving IC 17 is controlled by the microcomputer 15, that is, in a state where the current is actually passed through the valve exciting coil.

  The microcomputer 15 that has received the voltage drop detection signal from the terminal PI outputs a signal for controlling the solenoid valve driving IC 17 from the PO, PO1, and PO2 terminals. In response to this control signal, the electromagnetic valve drive IC 17 outputs a drive signal from the OUT1, OUT2, OUT3, and OUT4 terminals to the valve excitation coil of the motor valve 14 to cause a current to flow to drive the motor valve 14 and close it.

  As described above, in the gas shut-off device according to the present embodiment, the shut-off valve equivalent resistance 21 and the shut-off valve equivalent resistance operation circuit 22 described with reference to FIG. 4 are unnecessary, and the solenoid valve drive circuit is actually operated at the time of detection (solenoid valve). The battery voltage at that time is checked. Therefore, according to the present embodiment, the cost can be reduced by reducing the number of parts and the mounting cost, and the current is actually supplied to the solenoid valve drive circuit (here, to the valve exciting coil). Increases the accuracy and leads to improved reliability.

  As another embodiment, the present invention may further include another voltage detection circuit in order to detect a voltage drop in a short period such as a battery failure. Another voltage detection circuit (hereinafter referred to as a second voltage detection circuit) added here detects a battery voltage drop at a detection interval shorter than the detection interval in the voltage detection circuit 8 in the above-described embodiment. , A circuit to be transmitted to the control unit 5, and its circuit configuration is not limited. However, the second voltage detection circuit is a circuit for detecting the voltage of the battery at the time of opening without performing the detection in the state where the electromagnetic valve driving circuit 7 is operated like the voltage detection circuit 8. In addition, the check timing (the above-described short detection interval) may be set to a constant interval such as 10 minutes.

  Such second voltage detection is performed by the voltage detection circuit 8 and the voltage detector 18 described in FIGS. 1 and 2, that is, voltage detection is performed by a common circuit because the number of components is small. This is preferable because it is advantageous in terms of circuit configuration. In such an embodiment, when the voltage is detected, the voltage detection circuit 8 controls the voltage detection circuit 8 by the control unit 5 to check the voltage of the battery 6, but at this time, the solenoid valve drive circuit 7 is not controlled. . The check timing at this time may also be a fixed interval such as 10 minutes.

  Further, according to the present embodiment, by monitoring the voltage at the time of opening in a short cycle, a voltage drop such as an unexpected sudden drop in voltage such as a battery failure can be detected early, and safety can be ensured. Moreover, in this embodiment, since the monitoring is performed with no load, the battery capacity is not wasted.

  As another embodiment of the present invention, in battery voltage detection, it is preferable that the solenoid valve 4 is shut off so as not to affect the normal use of the gas consumer. In this embodiment, referring to FIG. 1 again, when the controller 5 detects a voltage drop of the battery 6 when the solenoid valve drive circuit 7 is operated, the solenoid valve 4 is substantially closed or opened. The solenoid valve drive circuit 7 is controlled so as not to valve. In the present embodiment, in this way, a current equivalent to that when the valve is actually driven flows while the state of the electromagnetic valve 4 (open / closed state) is maintained without confirming the state of the electromagnetic valve 4 by the control unit 5. So that it is controlled.

Next, a more specific configuration example of the present embodiment will be described with reference to FIG.
FIG. 3 is a cross-sectional view showing an outline of a stepping motor valve used in a gas cutoff device according to another embodiment of the present invention, and is a view showing an outline of a stepping valve used as a motor valve in the circuit configuration example of FIG. is there. In the figure, 14a is a valve body, 14b is a shaft, and 14c is a stepping motor.

  As an example of the stepping motor valve (stepping motor drive valve) 14, a valve body 14a, a shaft 14b, and a stepping motor 14c are provided as main parts. For example, although not shown in detail, a male screw is engraved on the shaft 14b, this male screw is screwed with a female screw provided on the valve body 14a, and projects into the base plate of the stepping motor 14c. The rotation of the shaft 14b is linearly moved by the rotation of the valve body 14a because the rotation of the valve body 14a is regulated by slidably fitting with the rotation stop portion provided on the valve body 14a by the provided guide rod or the like. Is converted to

Next, a method for controlling the stepping motor valve in this configuration example will be described.
The stepping motor valve 14 is driven by outputting a pulse from the microcomputer 15 to the electromagnetic valve driving IC 17. If the stepping motor valve 14 is set to rotate once in 48 steps (stroke is 1.5 mm), the stroke in one step is 0.03125 mm. When the valve is actually closed, for example, 176 steps (stroke is 5.5 mm) are set.

  In this embodiment, when the battery voltage is detected, the electromagnetic valve drive IC 17 is controlled only for one step. In this case, theoretically, as described above, there is a possibility that the valve body 14a (and the shaft 14b) may move two steps (0.0625 mm) in the stroke direction (the arrow direction in FIG. 3). The valve stop position is held by the structure of the motor valve 14. The control of the electromagnetic valve drive IC 17 is not limited to control of only one step, but may be control of only the number of steps so that the motor valve 14 is not substantially closed or opened as described above, such as control of only a few steps. That's fine.

  According to this embodiment, since the voltage of the battery can be detected regardless of the shut-off state (open / close state) of the solenoid valve, detection control is simple. In the present embodiment, means for checking the open / close state of the electromagnetic valve in the above-described embodiment is also unnecessary. Further, according to the present embodiment, detection can be performed while the valve stop state is maintained, the normal use of the gas consumer is not affected, and the function as a gas meter is not impaired.

It is a figure showing an example of circuit composition of a gas meter provided with a gas interception device concerning one embodiment of the present invention. It is a figure which shows the circuit structural example of the principal part in connection with the battery voltage detection in the gas cutoff device of FIG. It is sectional drawing which shows the outline of the stepping motor valve used in the gas cutoff device which concerns on other embodiment of this invention. It is a figure which shows the circuit structure regarding the voltage detection in the gas interruption | blocking apparatus of patent document 1. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Gas meter, 2 ... Gas meter main body, 3 ... Gas passage, 4 ... Solenoid valve, 5 ... Control part, 6 ... Battery, 7 ... Solenoid valve drive circuit, 8 ... Voltage detection circuit, 9 ... Display part, 14 ... Motor valve (Stepping motor valve), 14a ... valve body, 14b ... shaft, 14c ... stepping motor, 15 ... microcomputer, 17 ... solenoid valve drive IC, 18 ... voltage detector.

Claims (2)

A gas shut-off device comprising a solenoid valve for shutting off gas in a gas passage, and driving the solenoid valve using a battery as a power source to shut off the gas,
Wherein comprising a solenoid valve driving circuit for driving the electromagnetic valve, and a control unit for controlling the electromagnetic valve driving circuit, a voltage detection circuit that detect the voltage drop of the previous SL cells, and
The electromagnetic valve is a stepping motor valve driven by a stepping motor;
The control unit detects the voltage drop of the battery in a state where the electromagnetic valve driving circuit is operated, and drives the stepping motor valve by the number of steps that does not substantially close or open the stepping motor valve. A gas shut-off device that controls a valve drive circuit . It said voltage detection circuit, a short detection interval than the interval of the detection, and in a state of not operating the electromagnetic valve driving circuit according to claim 1, characterized in that it comprises means that detect the voltage drop of the battery, further The gas shut-off device according to 1.

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