JP3431125B2 - Gas meter - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas meter having a function of shutting off a gas flow path. 2. Description of the Related Art Some gas meters have a safety function of shutting off a gas flow path when an abnormality occurs using a microcomputer. One of the safety functions is a function of shutting off a gas flow path when an earthquake is detected by a seismic sensor. FIG. 6 is a block diagram showing a schematic configuration of a control system for performing a safety function of a conventional gas meter. This figure shows a case where a seismic device is used as a safety function. As shown in this figure, a conventional gas meter has a control unit 110 composed of a microcomputer or the like to send a seismic sensor 120 for sensing an earthquake and a gas flow path in accordance with the sensing result of the seismic device 120. A shutoff valve 130 for shutting off is connected and configured. In addition, the control unit 110 controls the
And an earthquake occurrence determining unit 140 that determines whether or not an earthquake has occurred based on the sensing result of zero.
And a shut-off valve driving circuit 150 that drives the shut-off valve 130 based on the result of the determination. [0004] The shutoff valve 130 has a coil serving as an electromagnet disposed therein, and the shutoff operation is performed by controlling the current flowing through this coil from the shutoff valve drive circuit 150. In a normal case, when the shutoff valve 130 is shut off by an earthquake, the user can manually reset the shutoff valve. [0005] However, in the conventional gas meter as described above, the shut-off valve used has a structure in which it operates according to the current flowing through the internal coil. Also, even when there is some shock other than an earthquake from the outside, an electromotive force is generated in the coil due to the shock, causing a current to flow, and the shut-off valve may malfunction. The conventional gas meter has a problem in that it cannot be distinguished whether the shutoff of the shutoff valve is caused by any impact other than the earthquake or caused by the earthquake. Further, in response to the importance of crisis management for recent earthquakes, it is necessary to carefully handle the return operation of the shut-off state of the shut-off valve. For example, if a gas meter management staff is not dispatched, It is also possible to take measures to prevent the shut-off valve from being returned. In view of this situation, it is necessary to clarify whether the shutoff of the shutoff valve is due to an earthquake or other temporary impact, and to control whether the shutoff state of the shutoff valve is maintained. This is very important. The present invention has been made in view of the above problems, and has as its object to discriminate whether or not the shutoff of a shutoff valve is caused by an impact other than an earthquake, and to shut off the shutoff valve accordingly. It is to provide a gas meter whose state can be controlled. The gas meter according to the first aspect of the present invention has a flow rate detecting means for detecting a flow rate of gas flowing through a gas flow path, a seismic sensing means capable of detecting an earthquake for each seismic intensity, and a plan.
And a coil for driving the plunger.
Seen, the shut-off valve for interrupting the gas flow path according to the action of an impact from the sensing results and the outside of the seismic section, the coil
Including a reed switch provided in the vicinity of
By detecting the leakage component of the magnetic field generated in the
Distinguish between earthquakes and external shocks other than earthquakes
And notifying means for notifying that the serial shutoff valve becomes blocked state by the impact from the outside, based on the detection result of the seismic means
Control to shut off the shutoff valve based on the
If the notification is made by the informing means, the shut-off valve is shut off.
The disconnection state is controlled to be releasable, and the notification by the
If this is not done, the seismic means shall be below the specified seismic intensity.
Only when the above earthquake is detected.
Shut- off valve control means for controlling the disconnection state so as not to be released . In this gas meter, the notification means (ie,
Reed provided near the coil that constitutes the shut-off valve
Switch) reduces the leakage component of the magnetic field generated in the coil.
Is detected. As a result, earthquakes and external
Shocks are distinguished from each other.
If a disconnection occurs, a notification to that effect is given. Shut-off valve
The control means controls the shut-off valve based on the detection result of the seismic
Control is performed to shut off
Is shut off, the shut-off state of the shut-off valve can be released.
If the notification is not given by the notification means
Means that if the seismic sensor detects an earthquake
Only when the shut-off state of the shut-off valve is
You. Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a sectional view showing a schematic configuration of a gas meter according to an embodiment of the present invention. This gas meter 1
Reference numeral 0 denotes a main body 11, an inlet 12A inserted into the main body 11 for receiving gas, and an outlet 12B for discharging gas.
And a gas pipe 12 as a gas flow path having
The gas pipe 12 includes, in order from the inlet 12A side, a shutoff valve 13 for shutting off a gas flow path in the event of an abnormality, and a flow rate detection unit 14 as flow rate detection means for detecting a flow rate of gas flowing through the gas flow path. Pressure sensor 1 for detecting the pressure of gas in a gas flow passage through a pressure guiding hole 17 provided in gas pipe 12
5 are arranged. The main body 11 further includes a seismic sensor 16 as a seismic means for detecting an earthquake, and a flow detecting unit 1.
4, a control unit 20 for inputting each output signal of the pressure sensor 15 and the seismic sensor 16 and controlling the shutoff valve 13 is provided. As the shut-off valve 13, a shut-off valve (also referred to as a two-way valve) capable of electrically selecting a shut-off state for shutting off the gas flow path and a return state for opening the gas flow path is used. FIGS. 2 and 3 show the shut-off valve 13 in FIG.
2 is a cross-sectional view showing the configuration of FIG. 2, FIG. 2 shows a return state, and FIG. 3 shows a cut-off state. In the following description, the opening 12a in the gas flow path in the gas pipe 12 and the shutoff valve 1
The positional relationship of 3 is described with the opening 12a side being the upper side and the shutoff valve 13 side being the lower side. The shut-off valve 13 has a housing 41 made of a magnetic material. The housing 41 has a cylindrical shape with a small diameter on the upper side and a cylindrical shape with a large diameter on the lower side. The upper end is open and the lower end is closed. A flange portion 42 is fixed outside a central portion of the housing 41 in the vertical direction. This flange portion 42 is fixed to the main body 11 in FIG. A cylindrical permanent magnet 43 is provided on the upper side of the housing 41, and a coil 44 serving as an electromagnet is provided on a lower side of the housing 41.
A reed switch 44 which is turned on / off according to the strength of the magnetic field is provided at a portion corresponding to the coil 44 outside the housing 41.
a is provided. Further, the permanent magnet 43 and the coil 44
The plunger 45 is inserted in the hollow part formed by this so that an axial movement is possible. This plunger 4
5 has an upper magnetic part 45a formed of a magnetic material and a lower nonmagnetic part 45b formed of a nonmagnetic material. The upper end of the plunger 45 protrudes from the upper end of the housing 41, and a rubber valve body 46 capable of closing the opening 12a is attached to the upper end of the plunger 45. A spring 47 is provided between the rubber valve body 46 and the flange portion 42 to urge the rubber valve body 46 upward. No current flows through the coil 44 of the shut-off valve 13 under normal conditions. Further, as shown in FIG. 2, the magnetic force of the permanent magnet 43 acts as shown by an arrow 48, the plunger 45 is retracted, and the opening 12a is opened. As a result, the gas passes through the opening 12a as indicated by the arrow 49. To shut off the shut-off valve 13, as shown in FIG. 3, a current is applied to the coil 44 to generate a magnetic field that cancels out the magnetic field generated by the permanent magnet 43. The magnetic force generated by the coil 44 is indicated by a broken arrow 50. Then
The plunger 45 projects by the force of the spring 47, and the opening 12 a is closed by the rubber valve body 46. On the other hand, in order to return the shut-off valve 13, a current in a direction opposite to that in the shut-off state is applied to the coil 44 to generate a magnetic field that strengthens the magnetic field generated by the permanent magnet 43. As a result, the plunger 45 is retracted by overcoming the force of the spring 47, and as a result, the opening 12
a is released. The current flowing through the coil 44 of the shutoff valve 13 is
Normally, it is controlled by a shut-off valve drive circuit 23 (FIG. 4), which will be described later. When a seismic sensor 16 senses an earthquake of a predetermined seismic intensity, a current flows and the device is cut off. However, when an external shock is applied in addition to the earthquake, an electromotive force is generated in the coil 44 irrespective of the control of the shut-off valve driving circuit 23, a current flows, and a magnetic field is generated.
The shut-off valve 13 may be in a shut-off state. The reed switch 44a operates by detecting the leakage component of the magnetic field generated in the coil 44 when the shut-off valve 13 receives an external impact as described above, and the shut-off valve 13 is shut off by the external impact. Then, an impact cutoff signal for notifying the user of the occurrence is output to the control unit 20 (FIG. 1). In addition,
The reed switch 44a corresponds to a notification unit in the present invention. FIG. 4 is a block diagram showing the configuration of the control unit 20 and its periphery in FIG. As shown in the figure, the gas meter 10 further includes a display unit 25 composed of an LED (light emitting diode) and the like, a communication control unit 26 for notifying various information to an automatic meter reading center, and a shut-off valve 13. And a valve return operation section 27 for returning. Then, the control unit 20 includes the shutoff valve 13 and the flow rate detecting unit 1.
4, the pressure sensor 15, the seismic sensor 16, the display unit 25, the communication control unit 26, and the valve return operation unit 27 are connected. The control unit 20 is constituted by, for example, a microcomputer.
A flow rate calculating unit 21 for calculating a flow rate and an integrated flow rate based on the output signal of No. 4, a flow rate calculating unit 21, a safety function unit 22 for detecting an abnormality based on each output signal of the pressure sensor 15 and the seismic sensor 16, A shutoff valve drive circuit 23 that drives the shutoff valve 13 under the control of the safety function unit 22 is provided. The seismic sensor 16 operates when an earthquake occurs, and is configured to be able to sense the seismic intensity of a plurality of earthquakes. Then, the seismic device 16 outputs a seismic signal according to the seismic intensity of the earthquake to the safety function unit 22 of the control unit 20. For example, the seismic sensor 16 outputs a signal 16a when detecting an earthquake of seismic intensity 4 and outputs signals 16a and 16b when detecting an earthquake of seismic intensity 5 to detect an earthquake of seismic intensity 6. In this case, signals 16a to 16c are output. As a seismic sensing mechanism of the seismic device 16, for example, a steel ball is arranged on a plate-like support plate disposed horizontally, and when a steel ball moves by a certain value or more due to earthquake motion, an electric contact is made. Are turned on and off, and this state is detected as a signal (pulse). The valve return operating section 27 is used to manually return the shut-off valve 13 to its original state, and is constituted by, for example, a push button switch or the like. When the normal shutoff is performed, the user of the gas meter 10 can return the shutoff state of the shutoff valve 13 to the original state by operating the valve return operation unit 27. ing. The integrated flow rate calculated by the flow rate calculation section 21 is displayed on the display section 25 and sent to the communication control section 26. The communication control unit 26 sends information on the integrated flow rate to the automatic meter reading center via a communication line such as a telephone line or wirelessly. The safety function unit 22 activates the shut-off valve when a gas flow rate exceeding a predetermined amount is detected, when the gas flow rate is detected for a predetermined period or more, or when the gas pressure drops below a predetermined value. By controlling the circuit 23 to drive the shut-off valve 13 to cut off the gas flow path, an alarm display such as blinking of an LED is displayed on the display unit 25 and the automatic meter reading center is notified via the communication control unit 26 to that effect. It has become. It should be noted that whether to display an alarm on the display unit 25 and to notify the automatic meter reading center can be set individually.
(Random access memory) as a flag. Further, when an earthquake is detected by the seismic sensor 16, the safety function unit 22 controls the shut-off valve driving circuit 23 to drive the shut-off valve 13 to shut off the gas flow path according to a procedure described later. The cutoff state is controlled. For example, when the impact cutoff signal 13a is input from the reed switch 44a (FIGS. 2 and 3) of the shutoff valve 13, the safety function unit 22 can release the shutoff state of the shutoff valve 13 (the valve return operating unit 27). (In a state where it can be released by an operation from the user), the control is performed so that the normal shutoff is performed.
In response to the result of the detection in step 6, the shut-off state of the shut-off valve 13 is controlled so that the shut-off state cannot be released (the state cannot be released by the operation of the valve return operation unit 27). More specifically, when the impact cutoff signal 13a is not input, the safety function unit 22
Is controlled such that the shut-off state of the shut-off valve 13 cannot be released only when an earthquake having a seismic intensity 6 or more is detected. As described above, the safety function unit 22 and the shut-off valve drive circuit 23 correspond to the shut-off valve control unit in the present invention. Next, referring to the block diagram shown in FIG. 4, the operation of the gas meter 10 according to the present embodiment will be described with reference to the flowchart shown in FIG. . In the normal state, the controller 20 calculates the flow rate in the gas pipe 12 based on the detection result from the flow rate detector 14 (step S101). In this normal state, the safety function unit 22 of the control unit 20
It is determined whether or not a seismic signal has been input from (step S
102), here, if no seismic signal has been input (step S102; N), this determination is repeated. On the other hand, when a seismic signal is input from the seismic device 16 (step S102; Y), the safety function unit 22 of the control unit 20
First, it is determined whether or not the signal included in the input seismic signal is only the signal 16a that has detected the seismic intensity 4 (step S103). Here, the signal 16a which detected the seismic intensity 4
If it is only (step S103; Y), the safety function unit 22 recognizes that an earthquake of seismic intensity 4 has occurred (step S104), and displays, for example, a warning on the display unit 25 that an earthquake of seismic intensity 4 has occurred. After performing the alarm processing such as
01 to the normal state. If the signal included in the input seismic signal is not only the signal 16a for which the seismic intensity 4 is detected (step S103; N), the signal included in the input seismic signal is 4 detected signal 16a and seismic intensity 5
It is determined whether there is only a signal with the signal 16b that has detected (step S105). Here, the seismic signal is seismic intensity 4
If there are only signals 16a and 16b that have detected the seismic intensity 5 (step S105; Y), the safety function unit 22
For example, the display unit 25 performs an alarm process such as an alarm display indicating that an earthquake of seismic intensity 5 has occurred, controls the shut-off valve drive circuit 23 to bring the shut-off valve 13 into a resettable shut-off state, and normally shuts off the gas flow path. (Step S106). Here, if a predetermined operation for returning the shutoff valve 13 is not performed from the valve return operation unit 27 (Step S107; N), the shutoff state is continued. On the other hand, when a predetermined operation for returning the shutoff valve 13 is performed in the valve return operation unit 27 and a return signal is input from the valve return operation unit 27 to the safety function unit 22 (step S107; Y), Safety function section 22
Controls the shut-off valve drive circuit 23 to release the shut-off state of the shut-off valve 13 (step S108), sets the shut-off valve 13 to the return state, and shifts to the normal state of step S101. If the seismic signal includes not only the signals 16a and 16b detecting the seismic intensity 4 and the seismic intensity 5 but also the signal 16c detecting the seismic intensity 6 (step S10).
5; N), the safety function unit 22 determines that there is an earthquake with a seismic intensity of 6 or more (Step S109), and further determines whether or not the shock shutoff signal 13a is input from the shutoff valve 13 (Step S110). Here, if the impact cutoff signal 13a has not been input (step S110; N),
The safety function unit 22 performs an alarm process such as displaying an alarm indicating that an earthquake of seismic intensity 6 has occurred on the display unit 25 and notifying the automatic metering center by the communication control unit 26, and controls the shutoff valve drive circuit 23. Then, the shut-off valve 13 is set to a non-returnable cut-off state in which the cut-off valve 13 cannot be released by an operation from the valve return operation unit 27 (step S111). In this case, when the non-return operation is interrupted, the control personnel of the gas meter 10 is dispatched to perform the operation of restoring the shut-off valve 13, so that the shut-off valve 13 is brought into the reset state. On the other hand, when the shock cutoff signal 13a is input from the shutoff valve 13 to the safety function unit 22 (step S1).
10; Y), the safety function unit 22 determines that an impact has been interrupted (step S112), performs an alarm process such as displaying an alarm on the display unit 25 that the impact has been interrupted, and then performs a valve return operation. It is determined whether a predetermined operation for returning the shut-off valve 13 from the unit 27 has been performed (step S11).
3). Here, unless a predetermined operation for returning the shut-off valve 13 is performed from the valve return operation section 27 (step S
113; N), and continue the impact cutoff state. On the other hand, when a predetermined operation for returning the shut-off valve 13 is performed in the valve return operation unit 27 and a return signal is input to the safety function unit 22 (step S113; Y), the safety function unit 22
Controls the shut-off valve drive circuit 23 to release the impact shut-off state of the shut-off valve 13 (step S114), and returns the shut-off valve 13 to the return state to shift to the normal state of step S101. As described above, according to the gas meter 10 of the present embodiment, the reed switch 44a for notifying that the shut-off valve 13 has been shocked (FIGS. 2 and 3).
Is provided, it is possible to clearly distinguish whether the shut-off valve 13 has been cut off by an earthquake or cut off by the action of an external impact other than the earthquake. In addition, the safety function unit 22 sets the shut-off state of the shut-off valve 13 to the normal shut-off that can be released according to the detection result from the seismic sensor 16 that can detect a plurality of seismic intensities and the notification result from the reed switch 44a. Or whether the shut-off state of the shut-off valve 13 is set to an unrecoverable non-releasable shut-off state.
Can be controlled without waste to ensure that the shut-off state of the shut-off valve 13 cannot be released only when a large earthquake with a seismic intensity of 6 or more occurs, without unnecessarily making it impossible to return and shut off due to an external impact. . In this way, it is possible to distinguish whether or not the shut-off of the shut-off valve 13 is caused by an impact other than the earthquake, and it is possible to control the shut-off state of the shut-off valve accordingly. It can be improved and convenience is improved. The present invention is not limited to the above-described embodiment, but can be variously changed within an equivalent range. For example, in the above-described embodiment, a seismic sensor 16 that can sense a plurality of seismic intensities is used, but it may be one that senses only an earthquake of a predetermined seismic intensity or higher. Further, in the above-described embodiment, only when the seismic sensor 16 senses an earthquake with a seismic intensity of 6 or more, the non-returnable cutoff is set. It may be changed. As described above, according to the gas meter of the present invention , the shut-off valve control means is based on the sensing result of the seismic sensing means.
Control to shut off the shut-off valve based on the
Releases the shut-off state of the shut-off valve when notified by
Control if possible and the notification by the notification means is not made
If the seismic sensor detects an earthquake with a seismic intensity
Controlling the shut-off status of the shut-off valve so that it cannot be released only when
Since the way, interruption of the shut-off valve is distinguished whether seemingly caused by the impact of the non-seismic, it is possible to control the cut-off state of the shut-off valve according to the distinction, the safety function in the event of an earthquake This has the effect of being able to be improved and the convenience being improved. Also, shut-off valve is
Unnecessarily unremovable shutoff due to impact
If an earthquake of a specified seismic intensity or higher occurs,
It is not possible to release the shut-off state of the shut-off valve securely without waste.
There is an effect that control is possible. [0036]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view showing a schematic configuration of a gas meter according to an embodiment of the present invention. FIG. 2 is a sectional view showing a configuration of a shut-off valve in FIG. FIG. 3 is a sectional view showing a configuration of a shut-off valve in FIG. 1; FIG. 4 is a block diagram showing a configuration of a control unit and its periphery in FIG. 1; FIG. 5 is a flowchart showing an operation of the control unit in FIG. 1 when an earthquake is detected. FIG. 6 is a block diagram showing a schematic configuration of a conventional gas meter. [Description of Signs] 10 Gas meter 12 Gas pipe 13 Shutoff valve 14 Flow rate detection unit 15 Pressure sensor 16 Seismic sensor 20 Control unit 21 Flow rate calculation unit 22 Safety function unit 23 Shutoff valve drive circuit 25 Display unit 26 Communication control unit 27 Valve return Operation unit 44a Reed switch

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-9-53970 (JP, A) JP-A-4-39481 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01F 1/00-9/02

Claims (1)

(57) [Claims 1] A flow rate detecting means for detecting a flow rate of a gas flowing through a gas flow path, a seismic means capable of detecting an earthquake for each seismic intensity , a plunger and driving the plunger. Carp for
Including wherein the Le, a shutoff valve that shuts off the gas flow path according to the action of an impact from the sensing results and the outside of the seismic means, the reed switch provided in proximity position of the coil
To detect the leakage component of the magnetic field generated in the coil
To distinguish between earthquakes and external shocks other than earthquakes
And a notifying unit for notifying that the shut-off valve has been shut off by an external impact, and shutting off the shut-off valve based on a sensing result of the seismic sensing unit.
Control and the notification by the notification means is performed.
In the event that the shut-off state of the shut-off valve is released,
And when the notification by the notification means is not made,
Indicates that the seismic sensor detects an earthquake of a predetermined seismic intensity or higher.
Only in the case where the shut-off state of the shut-off valve cannot be released
Gas meter being characterized in that a shut-off valve control means for controlling.