JP2019203815A - Gas meter - Google Patents

Abstract

To provide a gas meter which can detect an abnormality of operations of a cutoff valve while reducing the manufacturing cost.SOLUTION: A gas meter 1 includes: a gas flow passage; a cutoff valve 7 for cutting off the gas flow passage when an abnormality is happening; a driving unit 6 for driving the cutoff valve 7; an acceleration sensor 5 for outputting a vibration signal of the cutoff valve 7; and a cutoff valve abnormality detector 91 for detecting an abnormality of the cutoff valve 7 on the basis of the vibration signal of the acceleration sensor 5.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a gas meter.

  Conventionally, a gas meter that measures the amount of gas used and detects and reports a gas leak is known (see, for example, Patent Document 1). In the gas meter, a flow rate sensor, a pressure sensor, a seismic sensor, and a shut-off unit are connected to a microcomputer (hereinafter referred to as “microcomputer”).

  The microcomputer controls the entire gas meter. The microcomputer monitors the flow rate signal from the flow rate sensor, the pressure signal from the pressure sensor, and the seismic signal from the seismic sensor, and if it determines that an abnormality has occurred based on these signals, it controls the shut-off unit. Send a signal to shut off the gas flow path.

  The shut-off unit performs control to open and close a shut-off valve provided in the middle of the gas flow path in the gas meter in accordance with a control signal from the microcomputer. The shut-off unit includes a pattern generation circuit, a drive circuit, and a pulse motor.

  The pattern generation circuit generates a pattern signal for instructing the operation (forward rotation or reverse rotation) of the pulse motor, and supplies the pattern signal to the drive circuit.

  The drive circuit generates a voltage for normal rotation or reverse rotation of the pulse motor based on the pattern signal sent from the pattern generation circuit, and sends the voltage to the pulse motor. The pulse motor rotates according to the voltage sent from the drive circuit, and opens and closes the shut-off valve.

  In the conventional gas meter configured as described above, the microcomputer sends a control signal to the cutoff unit, so that the pulse generation circuit in the cutoff unit generates a pattern signal and supplies it to the drive circuit. The drive circuit generates a voltage corresponding to the pattern signal, supplies the voltage to the pulse motor, and rotates the pulse motor. Thereby, the shut-off valve is opened and closed.

Japanese Patent Application Laid-Open No. 2004-1255569

  Some conventional gas meters are equipped with a dedicated valve immobilization electronic circuit for detecting the immobility of the shut-off valve. However, the valve immobility detection function that detects the immobility of the shut-off valve detects valve disconnection, wiring errors, and failure of the IC that drives the valve, and detects whether the shut-off valve operates but operates normally. I couldn't.

  An object of the present invention is to provide a gas meter capable of detecting an abnormal operation of a shut-off valve while reducing the manufacturing cost.

  In order to solve the problems and achieve the object, the invention described in claim 1 includes a gas flow path, a shut-off valve that shuts off the gas flow path when an abnormality occurs, and a drive unit that drives the shut-off valve. An acceleration sensor that detects vibration of the shut-off valve and outputs a vibration signal; and a shut-off valve abnormality detection unit that detects an abnormality of the shut-off valve based on the vibration signal of the acceleration sensor. This is a featured gas meter.

  According to a second aspect of the present invention, there is provided the storage device according to the first aspect, wherein a predetermined acceleration pattern is registered, and the shut-off valve abnormality detection unit is configured to store the vibration signal of the acceleration sensor and the storage. When the vibration signal deviates from the predetermined acceleration pattern by comparing with the predetermined acceleration pattern registered in the section, it is determined that the shutoff valve is abnormal.

  According to a third aspect of the present invention, in the second aspect of the present invention, the storage device further includes an extraction unit that extracts a signal in a frequency range corresponding to a driving frequency of the driving unit from the vibration signal of the acceleration sensor. An amplitude value in a predetermined frequency range is registered as the predetermined acceleration pattern in the unit, and the shut-off valve abnormality detection unit is configured to register the signal in the frequency range extracted by the extraction unit and the storage unit. It is characterized by comparing the amplitude value.

  According to a fourth aspect of the present invention, in the invention according to the second or third aspect, a standard drive time of the cutoff valve is registered as the predetermined acceleration pattern in the storage unit, and the cutoff valve abnormality detection unit Is characterized in that the drive time of the shut-off valve is compared with the standard drive time registered in the storage unit.

  The invention described in claim 5 is the invention according to any one of claims 1 to 4, wherein when the shut-off valve abnormality detection unit determines that the shut-off valve is abnormal, the shut-off valve An informing means for informing that the valve is abnormal is provided.

  According to the first aspect of the invention, the shut-off valve abnormality detection unit can detect an abnormality of the shut-off valve based on the vibration signal output by the acceleration sensor. As a result, the conventional electronic circuit for confirming the valve immobility can be dispensed with, and the manufacturing cost can be reduced.

It is an external appearance perspective view which shows the gas meter concerning one embodiment of this invention. It is a control block diagram of the gas meter. It is a flowchart which shows the processing content of the said gas meter.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an external perspective view showing a gas meter 1 according to an embodiment of the present invention.

  As shown in FIG. 1, the gas meter 1 includes a meter body 10 that is a casing formed of a metal material such as aluminum or an aluminum alloy. The meter body 10 includes a gas inlet 11 that introduces a gas to one end and a gas outlet 12 that discharges the gas to the other end. The gas inflow port 11 is connected to a gas supply source via an unillustrated upstream side pipe, and the gas outflow port 12 is connected to a gas supply destination via an unillustrated downstream side pipe. Inside the meter body 10, a gas flow path (not shown) extending from the gas inlet 11 to the gas outlet 12 is formed.

  Further, as shown in FIG. 2, the gas meter 1 includes a display panel 13 (notification means), a flow sensor 3, a pressure sensor 4, an acceleration sensor 5, a stepping motor 6 (drive unit), a shutoff valve 7, and a communication unit 8 (notification). Means) and a microcomputer 9 (hereinafter referred to as [mu] COM9).

  The display panel 13 is configured by an LCD or the like, and is provided in the front portion of the meter body 10. The display panel 13 displays information processed by the μCOM 9. As typical information displayed on the display panel 13, there is an integrated value (integrated flow rate) of the gas flow rate based on the measurement value measured by the flow rate sensor 3. Further, on the display panel 13, the state of the shut-off valve 7 (indicating that it is normal or abnormal (including deterioration)) is displayed according to the instruction of the μCOM 9.

  The flow sensor 3 is provided in a gas flow path inside the meter body 10. The flow sensor 3 measures the gas flow rate passing through the gas flow path and outputs a signal corresponding to the flow rate. A signal output from the flow sensor 3 is input to the μCOM 9. As the flow sensor 3, for example, an ultrasonic sensor or a flow sensor can be used.

  The pressure sensor 4 is provided in the gas flow path inside the meter body 10. The pressure sensor 4 measures the gas pressure in the gas flow path and outputs a signal corresponding to the pressure. A signal output from the pressure sensor 4 is input to the μCOM 9. As the pressure sensor 4, a piezoresistive type or a capacitance type sensor can be used.

  The shut-off valve 7 is provided in the gas flow path inside the meter body 10, and when the CPU 94 detects an abnormal signal from the flow sensor 3 or the pressure sensor 4, or when the acceleration sensor 5 detects seismic sensitivity. This is for blocking the gas flow path when an abnormality occurs. In this embodiment, a motor valve driven by a stepping motor 6 is used as the shutoff valve 7. The shut-off valve 7 is connected to the μCOM 9 via the stepping motor 6. The stepping motor 6 is driven according to a control signal from the μCOM 9 and drives the shut-off valve 7 with the driving force. The driving frequency of the stepping motor 6 of this embodiment is 200 Hz to 250 Hz.

  The communication unit 8 is for communicating with the μCOM 9 and external devices (setting device, meter-reading device and center device). The communication unit 8 is connected to the μCOM 9 via the communication I / F 80. The communication unit 8 includes terminals for inputting and outputting various signals (for example, an N line terminal for a telephone line, a terminal for connecting to a gas leak alarm, and a terminal for connecting to a carbon monoxide alarm). It consists of a terminal block and wireless communication equipment using radio waves and light. In addition, when the shut-off valve abnormality detection unit 91 described later determines that the shut-off valve 7 is abnormal (including deterioration), the communication unit 8 communicates to that effect to the external device.

  The μCOM 9 includes an input unit 92, an output unit 93, a CPU 94, a storage unit 95, and a shut-off valve abnormality detection unit 91 that is executed by a command from the CPU 94, and functions as a control unit that controls the entire gas meter 1. The μCOM 9 is mounted on, for example, a control board (not shown).

  Further, the gas meter 1 includes an acceleration sensor 5 that detects the vibration and vibration of the shutoff valve 7 and outputs a vibration signal. The vibration signal output from the acceleration sensor 5 is input to the μCOM 9. Specifically, when the acceleration sensor 5 detects the vibration of the shut-off valve 7, the μCOM 9 detects a bandpass filter (not shown) other than the signal component in the frequency range corresponding to the driving frequency of the stepping motor 6 from the input vibration signal. It is removed by the extraction unit). In this way, when the signal component in the unnecessary frequency range is removed by the bandpass filter, when the shut-off valve abnormality detection unit 91 determines the state of the shut-off valve 7, the installation location of the gas meter 1 (the ground condition and Make it less susceptible to vibration from trains). Alternatively, the μCOM 9 may obtain a signal in a predetermined frequency range by performing a fast Fourier transform (FFT) on the input vibration signal. Further, the CPU 94 measures the output time of the vibration signal output by the acceleration sensor 5 (drive time of the shutoff valve 7). A valve shut-off abnormality detector 91 described later detects an abnormality (including deterioration) in the operation of the shut-off valve 7 based on a signal in a predetermined frequency range obtained by the CPU 94 and the drive time of the shut-off valve 7.

  In the storage unit 95, an amplitude value in a predetermined frequency range as a predetermined acceleration pattern and a standard driving time of the shut-off valve 7 are registered. The amplitude value in a predetermined frequency range to be registered is obtained as follows. That is, the shut-off valve 7 is operated at the time of initial setting, and the CPU 94 obtains a vibration signal from which the driving frequency component corresponding to the driving frequency of the stepping motor 6 is removed from the input vibration signal by a band pass filter, and is removed. The CPU 94 performs a fast Fourier transform (FFT) on the vibration signal to obtain an amplitude value in a predetermined frequency range. The CPU 94 registers the obtained amplitude value in the predetermined frequency range in the storage unit 95. Further, the CPU 94 registers a predetermined range based on the obtained amplitude value in the predetermined frequency range in the storage unit 95. In the present embodiment, the value obtained by operating the shutoff valve 7 at the initial setting is registered in the storage unit 95 as the predetermined acceleration pattern, but the present invention is not limited to this. . As the predetermined acceleration pattern, a predetermined design value or a predetermined driving time (standard driving time) of the shut-off valve 7 may be registered.

  When the shut-off valve 7 is opened or closed, the shut-off valve abnormality detection unit 91 compares the frequency range signal obtained from the vibration signal of the shut-off valve 7 with the amplitude value in the registered predetermined frequency range. To do. And when the signal of the calculated | required frequency range corresponds with the amplitude value in the registered predetermined frequency range, and the measured drive time of the cutoff valve 7 corresponds with the registered standard drive time, it determines with it being normal. Also, when the signal of the obtained frequency range does not match the amplitude value in the registered predetermined frequency range (when the signal of the obtained frequency range deviates from the amplitude value in the registered predetermined frequency range) or measured If the drive time of the shut-off valve 7 does not coincide with the registered standard drive time, it is determined that there is an abnormality (including deterioration).

  Further, the signal within the determined frequency range is within the range based on the registered amplitude value in the predetermined frequency range, and the measured driving time of the shut-off valve 7 is within the range based on the registered standard driving time. If it is, it may be determined as normal. Or when the signal of the obtained frequency range is out of the range based on the amplitude value in the registered predetermined frequency range (when the signal of the obtained frequency range is out of the amplitude value in the registered predetermined frequency range) ), Or when the measured driving time of the shut-off valve 7 is out of the range based on the registered standard driving time, it may be determined as abnormal (including deterioration).

  For example, the shut-off valve abnormality detection unit 91 determines that it is abnormal (including deterioration) that the shut-off valve 7 is not completely opened or closed when the shut-off valve 7 operates. As an example of the determination element, when the signal in the obtained frequency range is out of the amplitude value in the registered predetermined frequency range (when the signal is out of the range based on the amplitude value in the registered predetermined frequency range) It is assumed that a decrease in current due to a short circuit inside the coil and an increase in excitation-side impedance including the coil (such as a pseudo contact between the connector part and the solder part) reduced the magnetic field. In addition, when the measured drive time of the shut-off valve is out of the range based on the standard drive time registered in the storage unit, it is assumed that the mechanical movement amount of the shut-off valve 7 is small. In other words, when the signal in the obtained frequency range deviates from the amplitude value in the registered predetermined frequency range (when deviated from the range based on the amplitude value in the registered predetermined frequency range) or measured When the drive time of the shut-off valve 7 is out of the range based on the standard drive time registered in the storage unit 95, it is assumed that the shut-off valve 7 is not operating normally. In these cases, the shut-off valve abnormality detection unit 91 determines that the shut-off valve 7 is abnormal (including deterioration).

  Next, the operation of the CPU 94 mounted on the gas meter 1 will be described. FIG. 3 is a flowchart showing the processing contents of the CPU 94 mounted on the gas meter 1. As shown in FIG. 3, first, when the open / close signal of the shut-off valve 7 is ON (YES in step S1), the CPU 94 detects the vibration of the shut-off valve 7 and detects the vibration signal of the shut-off valve 7. Start output. The CPU 94 starts reading the vibration signal output from the acceleration sensor 5 (step S2). When the open / close signal of the shut-off valve 7 is OFF (NO in step S1), the process returns to START, and the CPU 94 determines ON / OFF of the open / close signal of the shut-off valve 7 again.

  After step S2, the CPU 94 determines ON / OFF of the open / close signal of the shutoff valve 7 (step S3). When the open / close signal of the shutoff valve 7 is ON (YES in step S3), the CPU 94 continues to read the vibration signal of the shutoff valve 7 output from the acceleration sensor 5 and when the open / close signal of the shutoff valve 7 is OFF ( In step S3, the CPU 94 stops reading the vibration signal of the acceleration sensor 5 (step S4), and proceeds to step S5. That is, the CPU 94 continues to read the vibration signal of the cutoff valve 7 output from the acceleration sensor 5 while the open / close signal of the cutoff valve 7 is ON.

  In step S5, when the shut-off valve 7 is opened or closed, the frequency range signal obtained from the vibration signal of the shut-off valve 7 output by the acceleration sensor 5, the amplitude value in the registered predetermined frequency range, and , And the measured driving time of the shut-off valve 7 is compared with the standard driving time registered in the storage unit 95. Then, the standard drive registered in the storage unit 95 is within the range in which the signal of the obtained frequency range is based on the amplitude value in the registered predetermined frequency range, and the measured drive time of the shut-off valve 7 If it is within the range based on time (NO in step S6), it is determined that the shutoff valve 7 is normal (step S7), and the process is terminated. Further, when the signal of the obtained frequency range is out of the range based on the amplitude value in the registered predetermined frequency range, or the measured driving time of the shut-off valve 7 is the standard registered in the storage unit 95. If it is out of the range based on the drive time (YES in step S6), it is determined that the shutoff valve 7 is abnormal (including deterioration) (step S8), and the process is terminated.

  Here, after it is determined that the shutoff valve 7 is normal in step S <b> 7, the CPU 94 displays that fact on the display panel 13. In step S8, after determining that the shutoff valve 7 is abnormal (including deterioration), the CPU 94 displays a message to that effect on the display panel 13. That is, the display on the display panel 13 is changed depending on the state of the shutoff valve 7. Further, after determining that the shut-off valve 7 is normal in step S <b> 7, the CPU 94 communicates that fact to the outside via the communication unit 8. In step S7, after it is determined that the shut-off valve 7 is abnormal (including deterioration), the fact is communicated to the outside via the communication unit 8.

  According to the above-described embodiment, the cutoff valve abnormality detection unit 91 can detect an abnormality of the cutoff valve 7 based on the vibration signal output from the acceleration sensor 5. As a result, the conventional electronic circuit for confirming the valve immobility can be dispensed with, and the manufacturing cost can be reduced.

  In addition, a storage unit 95 in which an amplitude value in a predetermined frequency range as a predetermined acceleration pattern is registered, and the shutoff valve abnormality detection unit 91 includes a vibration signal of the acceleration sensor 5 and a predetermined acceleration registered in the storage unit 95. When the vibration signal deviates from a predetermined acceleration pattern by comparing with the pattern, it is determined that the shutoff valve 7 is abnormal. According to this, the cutoff valve abnormality detection part 91 can detect the abnormality of the cutoff valve 7 with high accuracy.

  In addition, an extraction unit that extracts a signal in a frequency range corresponding to the driving frequency of the stepping motor 6 (drive unit) from the vibration signal of the acceleration sensor 5 is provided, and the storage unit 95 has a predetermined acceleration pattern in a predetermined frequency range. The amplitude value is registered, and the signal in the frequency range extracted by the band pass filter (extraction unit) is compared with the amplitude value registered in the storage unit 95. According to this, an unnecessary frequency range signal is removed by a band pass filter (extraction unit), and a signal of a driving frequency component of the stepping motor 6 is extracted. Noise caused by the installation location is removed, and when the shut-off valve abnormality detection unit 91 determines the state of the shut-off valve 7, it is difficult to be affected by the place where the gas meter 1 is installed (ground conditions or vibration due to the train). The abnormality of the shut-off valve 7 can be detected with high accuracy.

  Further, the storage unit 95 registers the standard drive time of the shut-off valve 7 as a predetermined acceleration pattern, and compares the drive time of the shut-off valve 7 with the standard drive time registered in the storage unit 95. According to this, the abnormality of the shutoff valve 7 can be detected with high accuracy.

  In addition, when the shut-off valve abnormality detection unit 91 determines that the shut-off valve 7 is abnormal, it is provided with notification means for notifying that the shut-off valve 7 is abnormal. When the shut-off valve abnormality detection unit 91 determines that the shut-off valve 7 is abnormal (including deterioration), the CPU 94 may instruct the display panel 13 to display an abnormality, or the CPU 94 However, the communication unit 8 may be instructed to communicate to the outside that it is abnormal. That is, the notification unit may be configured by the CPU 94 and the display panel 13, or may be configured by the CPU 94 and the communication unit 8. According to this, it is possible to promptly inform the consumer of the abnormality (including deterioration) of the shutoff valve 7 and to ensure the safety of the consumer.

  In addition, the best configuration, method and the like for carrying out the present invention have been disclosed in the above description, but the present invention is not limited to this. That is, the invention has been illustrated and described primarily with respect to particular embodiments, but may be configured for the above-described embodiments without departing from the scope and spirit of the invention. Various modifications can be made by those skilled in the art in terms of materials, quantity, and other detailed configurations. Therefore, the description limiting the shape, material, etc. disclosed above is an example for easy understanding of the present invention, and does not limit the present invention. The description by the name of the member which remove | excluded the limitation of one part or all of such is included in this invention.

1 Gas Meter 5 Acceleration Sensor 6 Stepping Motor (Driver)
7 Shut-off valve 91 Shut-off valve abnormality detection unit 95 Storage unit

Claims (5)

A gas flow path;
A shut-off valve that shuts off the gas flow path when an abnormality occurs;
A drive unit for driving the shut-off valve;
An acceleration sensor that detects vibration of the shutoff valve and outputs a vibration signal;
A gas meter comprising: a shut-off valve abnormality detection unit that detects an abnormality of the shut-off valve based on the vibration signal of the acceleration sensor. A storage unit in which a predetermined acceleration pattern is registered;
The shut-off valve abnormality detection unit compares the vibration signal of the acceleration sensor with the predetermined acceleration pattern registered in the storage unit, and when the vibration signal deviates from the predetermined acceleration pattern, The gas meter according to claim 1, wherein the shutoff valve is determined to be abnormal. An extraction unit that extracts a signal in a frequency range corresponding to the drive frequency of the drive unit from the vibration signal of the acceleration sensor;
In the storage unit, an amplitude value in a predetermined frequency range is registered as the predetermined acceleration pattern,
The gas meter according to claim 2, wherein the shut-off valve abnormality detection unit compares the signal in the frequency range extracted by the extraction unit with the amplitude value registered in the storage unit. In the storage unit, a standard driving time of the shut-off valve is registered as the predetermined acceleration pattern,
The gas meter according to claim 2 or 3, wherein the shut-off valve abnormality detection unit compares a drive time of the shut-off valve with the standard drive time registered in the storage unit.   The said shut-off valve abnormality detection part is provided with the alerting | reporting means which alert | reports that the said shut-off valve is abnormal, when it judges that the said shut-off valve is abnormal. A gas meter according to claim 1.

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