JP7055701B2 - Gas meter - Google Patents

Description

The present invention relates to a gas meter.

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

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

The cutoff unit controls to open and close the cutoff valve provided in the middle of the gas flow path in the gas meter in response to the control signal from the microcomputer. The cutoff portion is composed of 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 to open and close the isolation 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 and supplies it to the pulse motor to rotate the pulse motor. As a result, the isolation valve is opened and closed.

Japanese Unexamined Patent Publication No. 2004-125569

Some conventional gas meters are equipped with a dedicated electronic circuit for confirming valve immobility to detect the immobility of the isolation valve. However, the valve immobility detection function that detects the immobility of the isolation valve detects valve disconnection, wiring mistakes, and failure of the IC that drives the valve, and detects whether the isolation valve operates but operates normally. Couldn't.

An object of the present invention is to provide a gas meter capable of detecting an abnormality in the operation of a isolation valve while reducing the manufacturing cost.

In order to solve the above problems and achieve the object, the invention according to claim 1 comprises a gas flow path, a isolation valve that shuts off the gas flow path when an abnormality occurs, and a drive unit that drives the shutoff valve. An acceleration sensor that detects the vibration of the isolation valve and outputs a vibration signal, a isolation valve abnormality detecting unit that detects an abnormality of the isolation valve based on the vibration signal of the acceleration sensor, and a predetermined acceleration pattern. The storage unit includes a storage unit to be registered, and the standard drive time of the isolation valve is registered in the storage unit as the predetermined acceleration pattern, and the isolation valve abnormality detection unit is the output time of the vibration signal. The drive time of the isolation valve is compared with the standard drive time registered in the storage unit, and when the vibration signal deviates from the predetermined acceleration pattern, it is determined that the isolation valve is abnormal. It is a gas meter characterized by.

The invention according to claim 2 includes, in the invention according to claim 1 , an extraction unit for extracting a signal in a frequency range corresponding to the drive frequency of the drive unit from the vibration signal of the acceleration sensor, and the storage. An amplitude value in a predetermined frequency range is registered as the predetermined acceleration pattern in the unit, and the shutoff valve abnormality detecting unit registers the signal in the frequency range extracted by the extraction unit and the storage unit. It is characterized by comparing with an amplitude value.

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

According to the third aspect of the present invention, in the invention according to the first or second aspect, when the isolation valve abnormality detecting unit determines that the isolation valve is abnormal, the isolation valve is abnormal. It is characterized by being provided with a notification means for notifying.

According to the first aspect of the present invention, the isolation valve abnormality detecting unit can detect the abnormality of the isolation valve based on the vibration signal output by the acceleration sensor. As a result, it is possible to eliminate the need for an electronic circuit for confirming valve immobility in the prior art, and thus it is possible to reduce the manufacturing cost.

It is an external perspective view which shows the gas meter which concerns on 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 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 which is a housing formed of a metal material such as aluminum or an aluminum alloy. The meter body 10 includes a gas inlet 11 for introducing gas at one end and a gas outlet 12 for discharging gas at the other end. The gas inlet 11 is connected to the gas supply source via an upstream pipe (not shown), and the gas outlet 12 is connected to the gas supply destination via a downstream pipe (not shown). Inside the meter body 10, a gas flow path (not shown) 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 rate sensor 3, a pressure sensor 4, an acceleration sensor 5, a stepping motor 6 (drive unit), a isolation valve 7, and a communication unit 8 (notification). Means) and a microcomputer 9 (hereinafter referred to as μCOM 9) are provided.

The display panel 13 is composed of an LCD or the like, and is provided on the front portion of the meter body 10. The display panel 13 displays the 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 measured value measured by the flow rate sensor 3. Further, the display panel 13 displays the state of the isolation valve 7 (that is normal, that it is abnormal (including deterioration)) according to the instruction of μCOM 9.

The flow rate sensor 3 is provided in the gas flow path inside the meter body 10. The flow rate sensor 3 measures the gas flow rate passing through the gas flow path and outputs a signal corresponding to the flow rate. The signal output from the flow rate sensor 3 is input to μCOM 9. As the flow rate sensor 3, for example, an ultrasonic sensor, a flow sensor, or the like 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. The signal output from the pressure sensor 4 is input to μCOM 9. As the pressure sensor 4, a sensor such as a piezo resistance type or a capacitance type can be used.

The isolation 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 rate sensor 3 or the pressure sensor 4, or when the acceleration sensor 5 detects a seismic sensory, etc. This is to shut off the gas flow path when an abnormality occurs. As the shutoff valve 7, a motor valve driven by a stepping motor 6 is used in the present embodiment. The isolation valve 7 is connected to the μCOM 9 via a stepping motor 6. The stepping motor 6 is driven in response to a control signal from the μCOM 9, and the driving force thereof drives the isolation valve 7. The drive 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 an external device (setting device, meter reading device, center device). The communication unit 8 is connected to the μCOM 9 via the communication I / F80. The communication unit 8 includes terminals for inputting / 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 that uses radio waves and light. Further, when the isolation valve abnormality detecting unit 91, which will be described later, determines that the isolation valve 7 is abnormal (including deterioration), the communication unit 8 communicates to that effect with an external device.

The μCOM 9 has an input unit 92, an output unit 93, a CPU 94, a storage unit 95, and a isolation valve abnormality detection unit 91 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 vibration and vibration sensitivity of the isolation valve 7 and outputs a vibration signal. The vibration signal output from the acceleration sensor 5 is input to μCOM 9. Specifically, when the acceleration sensor 5 detects the vibration of the shutoff valve 7, the μCOM 9 is a bandpass filter (not shown) except for the signal components in the frequency range corresponding to the drive frequency of the stepping motor 6 from the input vibration signal. It is removed by the extraction unit). In this way, the bandpass filter removes unnecessary signal components in the frequency range, so that when the isolation valve abnormality detection unit 91 determines the state of the isolation valve 7, the installation location of the gas meter 1 (ground condition, etc.) It is less susceptible to the effects of train vibration). 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 (driving time of the isolation valve 7) of the vibration signal output by the acceleration sensor 5. The valve disconnection abnormality detection unit 91, which will be described later, detects an abnormality (including deterioration) in the operation of the isolation valve 7 based on a signal in a predetermined frequency range obtained by the CPU 94 and a drive time of the isolation valve 7.

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

The isolation valve abnormality detection unit 91 compares the signal in the frequency range obtained from the vibration signal of the isolation valve 7 with the amplitude value in the registered predetermined frequency range when the isolation valve 7 operates to open or close. do. When the signal in the obtained frequency range matches the amplitude value in the registered predetermined frequency range and the measured drive time of the isolation valve 7 matches the registered standard drive time, it is determined to be normal. In addition, when the signal in the obtained frequency range does not match the amplitude value in the registered predetermined frequency range (when the signal in the obtained frequency range deviates from the amplitude value in the registered predetermined frequency range), measurement is performed. If the drive time of the shutoff valve 7 does not match the registered standard drive time, it is determined to be abnormal (including deterioration).

Further, the signal in the obtained frequency range is within the range based on the amplitude value in the registered predetermined frequency range, and the measured drive time of the isolation valve 7 is within the range based on the registered standard drive time. If it is, it may be judged to be normal. Or, when the signal in the obtained frequency range deviates from the range based on the amplitude value in the registered predetermined frequency range (when the signal in the obtained frequency range deviates from the amplitude value in the registered predetermined frequency range). ) Or, if the measured drive time of the shutoff valve 7 deviates from the range based on the registered standard drive time, it may be determined to be abnormal (including deterioration).

The isolation valve abnormality detection unit 91 determines, for example, that the isolation valve 7 does not completely open or close when it operates is an abnormality (including deterioration). As an example of the judgment factor, when the signal in the obtained frequency range deviates from the registered amplitude value in the predetermined frequency range (when it deviates from the range based on the amplitude value in the registered predetermined frequency range). It is assumed that the short circuit inside the coil and the decrease in the current due to the increase in the excitation side impedance including the coil (pseudo-contact between the connector part and the solder part, etc.) reduced the magnetic field. Further, when the measured drive time of the isolation 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 isolation valve 7 is small. That is, when the signal in the obtained frequency range deviates from the registered amplitude value in the predetermined frequency range (when it deviates from the range based on the registered amplitude value in the predetermined frequency range), it is measured. If the drive time of the isolation valve 7 deviates from the range based on the standard drive time registered in the storage unit 95, it is assumed that the isolation valve 7 is not operating normally. In these cases, the isolation valve abnormality detection unit 91 determines that the isolation 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 isolation valve 7 is ON (YES in step S1), the acceleration sensor 5 detects the vibration of the isolation valve 7 and the vibration signal of the isolation valve 7 is transmitted. Start output. The CPU 94 starts reading the vibration signal output by the acceleration sensor 5 (step S2). When the on-off signal of the isolation valve 7 is OFF (NO in step S1), the process returns to START, and the CPU 94 again determines ON / OFF of the on-off signal of the isolation valve 7.

After step S2, the CPU 94 determines ON / OFF of the open / close signal of the isolation 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 (YES). In step S3 NO), 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 isolation valve 7 output from the acceleration sensor 5 while the open / close signal of the isolation valve 7 is ON.

In step S5, when the isolation valve 7 operates to open or close, the signal in the frequency range obtained from the vibration signal of the isolation valve 7 output by the acceleration sensor 5, and the amplitude value in the registered predetermined frequency range are used. , And compare the measured drive time of the shutoff valve 7 with the standard drive time registered in the storage unit 95. Then, the signal in the obtained frequency range is within the range based on the amplitude value in the registered predetermined frequency range, and the measured drive time of the isolation valve 7 is the standard drive registered in the storage unit 95. If it is within the time-based range (NO in step S6), it is determined that the isolation valve 7 is normal (step S7), and the process is terminated. Further, when the signal in the obtained frequency range deviates from the range based on the amplitude value in the registered predetermined frequency range, or the measured drive time of the isolation valve 7 is a standard registered in the storage unit 95. If the frequency deviates from the range based on the drive time (YES in step S6), it is determined that the isolation valve 7 is abnormal (including deterioration) (step S8), and the process ends.

Here, after the isolation valve 7 is determined to be normal in step S7, the CPU 94 displays that fact on the display panel 13. Further, after the shutoff valve 7 is determined to be abnormal (including deterioration) in step S8, the CPU 94 displays that fact on the display panel 13. That is, the display on the display panel 13 is changed depending on the state of the isolation valve 7. Further, after the shutoff valve 7 is determined to be normal in step S7, the CPU 94 communicates to that effect to the outside via the communication unit 8. Further, after the isolation valve 7 is determined to be abnormal (including deterioration) in step S7, the fact is communicated to the outside via the communication unit 8.

According to the above-described embodiment, the isolation valve abnormality detecting unit 91 can detect the abnormality of the isolation valve 7 based on the vibration signal output by the acceleration sensor 5. As a result, it is possible to eliminate the need for an electronic circuit for confirming valve immobility in the prior art, and thus it is possible to reduce the manufacturing cost.

Further, a storage unit 95 for registering an amplitude value in a predetermined frequency range as a predetermined acceleration pattern is provided, and the shutoff valve abnormality detecting 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 the predetermined acceleration pattern by comparing with the pattern, the shutoff valve 7 is determined to be abnormal. According to this, the isolation valve abnormality detecting unit 91 can accurately detect the abnormality of the isolation valve 7.

Further, the storage unit 95 is provided with an extraction unit that extracts a signal in a frequency range corresponding to the drive frequency of the stepping motor 6 (drive unit) from the vibration signal of the acceleration sensor 5, 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 bandpass filter (extracting unit) is compared with the amplitude value registered in the storage unit 95. According to this, the band pass filter (extractor) removes the signal in the unnecessary frequency range and extracts the signal of the drive frequency component of the stepping motor 6, thereby causing the ground condition, vibration caused by the train, etc. Noise caused by the installation location is removed, and when the isolation valve abnormality detection unit 91 determines the state of the isolation valve 7, it is less likely to be affected by the installation location (ground condition or vibration caused by the train) of the gas meter 1. It is possible to detect the abnormality of the isolation valve 7 with high accuracy.

Further, the standard drive time of the isolation valve 7 is registered in the storage unit 95 as a predetermined acceleration pattern, and the drive time of the isolation valve 7 is compared with the standard drive time registered in the storage unit 95. According to this, the abnormality of the isolation valve 7 can be detected with high accuracy.

Further, when the isolation valve abnormality detecting unit 91 determines that the isolation valve 7 is abnormal, it is provided with a notification means for notifying that the isolation valve 7 is abnormal. When the isolation valve abnormality detection unit 91 determines that the isolation valve 7 is abnormal (including deterioration), the CPU 94 may instruct the display panel 13 to indicate that the abnormality is abnormal, or the CPU 94 may be instructed. However, the communication unit 8 may instruct the communication unit 8 to communicate to the outside to the effect that it is abnormal. That is, the notification means may be composed of the CPU 94 and the display panel 13, or may be composed of the CPU 94 and the communication unit 8. According to this, it is possible to promptly notify the consumer of the abnormality (including deterioration) of the isolation valve 7, and it is possible to ensure the safety of the consumer.

In addition, the best configuration, method, and the like for carrying out the present invention are disclosed in the above description, but the present invention is not limited thereto. That is, the present invention is primarily illustrated and described with respect to a particular embodiment, but without departing from the scope of the technical idea and object of the present invention, with respect to the embodiments described above. Various modifications can be made by those skilled in the art in terms of material, quantity, and other detailed configurations. Therefore, the description limiting the shapes, materials, etc. disclosed above is merely an example for facilitating the understanding of the present invention, and does not limit the present invention. Therefore, those shapes, materials, etc. The description by the name of the member excluding a part or all of the limitation such as is included in the present invention.

1 Gas meter 5 Accelerometer 6 Stepping motor (drive unit)
7 Isolation valve 91 Isolation valve abnormality detection unit 95 Storage unit

Claims (3)

Gas flow path and
A isolation valve that shuts off the gas flow path when an abnormality occurs,
A drive unit that drives the isolation valve and
An accelerometer that detects the vibration of the isolation valve and outputs a vibration signal,
A isolation valve abnormality detection unit that detects an abnormality in the isolation valve based on the vibration signal of the acceleration sensor, and a isolation valve abnormality detection unit.
Equipped with a storage unit in which a predetermined acceleration pattern is registered,
The standard drive time of the isolation valve is registered in the storage unit as the predetermined acceleration pattern.
The isolation valve abnormality detecting unit compares the driving time of the isolation valve, which is the output time of the vibration signal, with the standard driving time registered in the storage unit, and the vibration signal has the predetermined acceleration pattern. A gas meter characterized in that the shutoff valve is determined to be abnormal when it deviates from the above . It is provided with 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.
An amplitude value in a predetermined frequency range is registered in the storage unit as the predetermined acceleration pattern.
The gas meter according to claim 1 , wherein the isolation valve abnormality detecting unit compares a signal in the frequency range extracted by the extraction unit with the amplitude value registered in the storage unit. Any of claims 1 or 2 , wherein the isolation valve abnormality detecting unit is provided with a notification means for notifying that the isolation valve is abnormal when it is determined that the isolation valve is abnormal. The gas meter described in item 1.

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