JP2010181128A - Determination device and determination method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a determination device and a determination method for reducing electric power consumption when a gas appliance use etc. <P>SOLUTION: A gas meter 40 includes a flow rate sensor 41, a differentiating circuit 42, an integrating circuit 43 and a microcomputer 44. When an electric signal from the flow rate sensor 41 exceeds predetermined output change, the differentiating circuit 42 outputs a first trigger signal. When the electric signals from the flow rate sensor 41 are integrated and the integrated amount reaches predetermined amount, the integrating circuit 43 outputs a second trigger signal. The microcomputer 44 determines whether the gas appliance with a governor is used and whether gas leakage occurs, in accordance with the input condition of the first and second trigger signals. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a determination device and a determination method.

  Conventionally, there has been proposed a gas appliance discriminating apparatus that determines whether or not a gas appliance in use is provided with a governor (see, for example, Patent Document 1).

JP 2005-265513 A

  The present applicant has invented the technique of Japanese Patent Application No. 2008-86022. In the present invention, based on the gas pressure, it is determined whether a gas appliance with a governor is used, a gas appliance without a governor is used, and whether a gas leak has occurred.

  However, in the case of the technology of Japanese Patent Application No. 2008-86022, it is necessary to perform a frequency analysis of the pressure waveform in order to determine the gas usage status such as whether a gas appliance with a governor has been used. This may lead to an increase in power consumption. In this specification, a part of the technology of Japanese Patent Application No. 2008-86022 is described. However, this description does not recognize the publicity of the technology of Japanese Patent Application No. 2008-86022.

  The present invention has been made to solve such a conventional problem, and an object of the present invention is to provide a determination device and a determination method capable of reducing power consumption when determining a gas usage state. It is to provide.

  The determination device of the present invention includes a flow sensor that outputs an electrical signal corresponding to the gas flow rate in the flow path, and a differentiating unit that outputs a first trigger signal when the electrical signal from the flow sensor exceeds a predetermined output change. Integrating means for outputting a second trigger signal when the electric signal from the flow sensor is integrated and the integrated amount reaches a predetermined amount, a first trigger signal from the differentiating means, and a second trigger signal from the integrating means And determining means for determining the gas usage status according to the input status.

  According to this determination device, when the electrical signal from the flow sensor exceeds a predetermined output change, the first trigger signal is output and the electrical signal from the flow sensor is integrated to reach the predetermined amount. In addition, the second trigger signal is output, and the gas usage status is determined according to the input status of the first trigger signal and the second trigger signal. Here, for example, when a gas appliance with a governor is not used, there is a tendency that a high-frequency component is not included in the flow waveform. On the other hand, when there is no gas leakage, the flow waveform tends to contain a lot of high frequency components. Further, since the first trigger signal is output when a predetermined output change occurs, the first trigger signal is output relatively early when the flow rate waveform includes many high frequency components. On the other hand, the second trigger signal is output when an overall flow rate increase occurs. Therefore, the gas usage status can be determined from the output status of the first trigger signal and the second trigger signal, and the power consumption can be reduced.

  In addition, the determination device of the present invention includes a pressure sensor that outputs an electric signal corresponding to the gas pressure in the flow path, a flow rate sensor that outputs an electric signal corresponding to the gas flow rate in the flow path, and an electric power from the pressure sensor. The integration that outputs the second trigger signal when the integrated amount reaches a predetermined amount by integrating the differentiating means that outputs the first trigger signal when the signal exceeds a predetermined output change and the electrical signal from the flow sensor. And a judging means for judging the gas usage status according to the input conditions of the first trigger signal from the differentiating means and the second trigger signal from the integrating means.

  According to this determination device, when the electrical signal from the pressure sensor exceeds a predetermined output change, the first trigger signal is output, and the electrical signal from the flow sensor is integrated to reach the predetermined amount. In addition, the second trigger signal is output, and the gas usage status is determined according to the input status of the first trigger signal and the second trigger signal. Here, for example, when the gas appliance with a governor is not used, the pressure waveform and the flow waveform tend not to include a high frequency component. On the other hand, when no gas leak occurs, the pressure waveform and the flow rate waveform tend to contain many high frequency components. Further, since the first trigger signal is output when a predetermined output change occurs, the first trigger signal is output relatively early when the pressure waveform includes many high frequency components. On the other hand, the second trigger signal is output when an overall flow rate increase occurs. Therefore, the gas usage status can be determined from the output status of the first trigger signal and the second trigger signal, and the power consumption can be reduced.

  In the determination apparatus of the present invention, it is preferable that the determination unit is configured as one function of the microcomputer, and at least one of the differentiation unit and the integration unit is configured by a peripheral analog circuit outside the microcomputer.

  According to this determination apparatus, the determination unit is configured as one function of the microcomputer, and at least one of the differentiation unit and the integration unit is configured by a peripheral analog circuit outside the microcomputer. For this reason, when outputting at least one of the first and second trigger signals, there is no need for calculation, and the amount of calculation can be further reduced to reduce power consumption.

  A pressure switch that does not generate a first trigger signal when the gas pressure changes below a predetermined value, but outputs a first trigger signal when the gas pressure changes above a predetermined value, and an electrical signal corresponding to the gas flow rate in the flow path From the flow sensor to be output, the integration means for outputting the second trigger signal when the integrated amount reaches a predetermined amount by integrating the electrical signals from the flow sensor, the first trigger signal from the pressure switch, and the integration means And determining means for determining the gas usage status according to the input status of the second trigger signal.

  According to this determination apparatus, when the pressure switch outputs the first trigger signal due to a change in the gas pressure equal to or greater than a predetermined value, and when the integrated amount reaches the predetermined amount by integrating the electrical signals from the flow rate sensor, 2 trigger signals are output, and the gas usage status is determined according to the input status of the first trigger signal and the second trigger signal. Here, when the gas appliance with a governor is not used, the pressure waveform and the flow rate waveform tend not to include a high frequency component. On the other hand, when no gas leak occurs, the pressure waveform and the flow rate waveform tend to contain many high frequency components. Further, since the first trigger signal is output when a change in gas pressure of a predetermined value or more occurs, the first trigger signal is output relatively early when a high frequency component is included in the pressure waveform. On the other hand, the second trigger signal is output when an overall flow rate increase occurs. Therefore, the gas usage status can be determined from the output status of the first trigger signal and the second trigger signal, and the power consumption can be reduced.

  In the determination apparatus of the present invention, it is preferable that the determination unit is configured as one function of the microcomputer, and the integration unit is configured by a peripheral analog circuit outside the microcomputer.

  According to this determination apparatus, the determination means is configured as one function of the microcomputer, and the integration means is configured by a peripheral analog circuit outside the microcomputer. For this reason, when the second trigger signal is output, there is no need for calculation, and the amount of calculation can be further reduced to reduce power consumption.

  In the determination apparatus of the present invention, it is preferable that the determination unit determines that no gas leak has occurred when the second trigger signal is input after the first trigger signal is input. The gas leak here may be a concept meaning only a small amount of gas leak, or may be a concept meaning both a small amount and a large amount of gas leak.

  According to this determination apparatus, when the second trigger signal is input after the first trigger signal is input, it is determined that no gas leak has occurred. Here, when there is no gas leakage, the waveform tends to include many relatively high frequency components. For this reason, the first trigger signal tends to be output before the second trigger signal due to a relatively high frequency component. Therefore, in the above case, it can be determined that no gas leak has occurred, the possibility of gas leak can be eliminated, the amount of calculation can be reduced, and the power consumption can be reduced.

  In the determination apparatus of the present invention, it is preferable that the determination unit determines that the gas appliance with the governor is not used when the second trigger signal is input without inputting the first trigger signal.

  According to this determination apparatus, when the first trigger signal is not input and the second trigger signal is input, it is determined that the gas appliance with the governor is not used. Here, when the gas appliance with the governor is not used, the waveform tends not to include many high-frequency components. For this reason, the first trigger signal is not output, and the integrated value reaches a predetermined amount due to the increase in the overall flow rate, and only the second trigger signal tends to be output. Therefore, in the above case, by determining that the gas appliance with governor is not used, the possibility of using the gas appliance with governor can be eliminated, and the amount of calculation can be reduced and the power consumption can be reduced.

  In the determination apparatus of the present invention, the determination means does not input the first trigger signal, inputs the second trigger signal, and the average gas flow rate within a specified time after the second trigger signal is input is equal to or greater than the specified amount. If it is, it is preferable to determine that the gas is leaking.

  According to this determination apparatus, when the first trigger signal is not input, the second trigger signal is input, and the average gas flow rate within the specified time after the second trigger signal is input is equal to or greater than the specified amount, Judge as a leak. Here, when a gas leak occurs (especially when a large amount of gas leaks), the waveform tends not to contain many high-frequency components. Further, governorless gas appliances tend to have a flow rate that is not greater than a specific flow rate. For this reason, the first trigger signal is not output, the integrated value reaches a predetermined amount due to the overall flow rate increase, and only the second trigger signal is output, and the average gas flow rate within the specified time is equal to or greater than the specified amount. In some cases, it will no longer be a gas leak. Therefore, in the above case, it is possible to eliminate the possibility of using other governor-equipped gas appliances, etc., by determining that the gas is leaking, thereby reducing the amount of calculation and reducing power consumption. Furthermore, since the amount of calculation can be reduced, it is possible to quickly determine that there is a gas leak, and it is possible to quickly perform a security process or the like, so that safety can be further improved.

  In the determination device of the present invention, it is preferable that the determination unit determines that an ignition error has occurred when the second trigger signal is not input within a predetermined time after the first trigger signal is input.

  According to this determination apparatus, if the second trigger signal is not input within a predetermined time after the first trigger signal is input, it is determined that an ignition error has occurred. Here, when an ignition error occurs, both the pressure waveform and the flow rate waveform tend to exhibit a large amplitude at a relatively high frequency, and the first trigger signal is output with a relatively high frequency component. However, as for the flow rate, the gas supply is interrupted only by showing a large amplitude at a relatively high frequency, and even if the flow rate is integrated, the predetermined amount is not reached and the second trigger signal is not output. Therefore, in the above case, it is not necessary to determine the use of a gas appliance with a governor by determining that it is an ignition mistake, and the amount of calculation can be reduced and the power consumption can be reduced.

  The determination method of the present invention includes a differentiation step of outputting a first trigger signal when an electrical signal from a flow sensor that outputs an electrical signal corresponding to a gas flow rate in a flow path exceeds a predetermined output change, and a flow rate. When the electrical signal from the sensor is integrated and the integrated amount reaches a predetermined amount, the integration step for outputting the second trigger signal, and the first trigger signal output in the differentiation step and the integration step are output. And a determination step of determining the gas usage status according to the input status of the second trigger signal.

  According to this determination method, when the electrical signal from the flow sensor exceeds a predetermined output change, the first trigger signal is output and the electrical signal from the flow sensor is integrated to reach the predetermined amount. In addition, the second trigger signal is output, and the gas usage status is determined according to the input status of the first trigger signal and the second trigger signal. Here, for example, when a gas appliance with a governor is not used, there is a tendency that a high-frequency component is not included in the flow waveform. On the other hand, when there is no gas leakage, the flow waveform tends to contain a lot of high frequency components. Further, since the first trigger signal is output when a predetermined output change occurs, the first trigger signal is output relatively early when the flow rate waveform includes many high frequency components. On the other hand, the second trigger signal is output when an overall flow rate increase occurs. Therefore, the gas usage status can be determined from the output status of the first trigger signal and the second trigger signal, and the power consumption can be reduced.

  Further, the determination method of the present invention includes a differentiation step of outputting a first trigger signal when the electrical signal from the pressure sensor that outputs an electrical signal corresponding to the gas pressure in the flow path exceeds a predetermined output change, The electric signal from the flow sensor that outputs the electric signal corresponding to the gas flow rate in the road is integrated, and when the integrated amount reaches a predetermined amount, the integration step for outputting the second trigger signal and the differential step for output And a determination step of determining a gas usage status according to the input status of the first trigger signal and the second trigger signal output in the integration step.

  According to this determination method, when the electrical signal from the pressure sensor exceeds a predetermined output change, the first trigger signal is output, and the electrical signal from the flow sensor is integrated to reach the predetermined amount. In addition, the second trigger signal is output, and the gas usage status is determined according to the input status of the first trigger signal and the second trigger signal. Here, for example, when the gas appliance with a governor is not used, the pressure waveform and the flow waveform tend not to include a high frequency component. On the other hand, when no gas leak occurs, the pressure waveform and the flow rate waveform tend to contain many high frequency components. Further, since the first trigger signal is output when a predetermined output change occurs, the first trigger signal is output relatively early when the pressure waveform includes many high frequency components. On the other hand, the second trigger signal is output when an overall flow rate increase occurs. Therefore, the gas usage status can be determined from the output status of the first trigger signal and the second trigger signal, and the power consumption can be reduced.

  Further, the determination method of the present invention includes a pressure switch that does not generate a first trigger signal when the gas pressure changes below a predetermined value and outputs a first trigger signal when the gas pressure changes above a predetermined value. The second trigger signal when the accumulated amount reaches a predetermined amount by integrating the electrical signals from the flow sensor that outputs the electrical signal corresponding to the gas flow rate in the flow path. And a determination step of determining the gas usage status according to the input status of the first trigger signal from the pressure switch and the second trigger signal from the integration means.

  According to this determination method, when the pressure switch outputs the first trigger signal due to a change in the gas pressure equal to or greater than a predetermined value, and when the integrated amount reaches a predetermined amount by integrating the electrical signals from the flow rate sensor, 2 trigger signals are output, and the gas usage status is determined according to the input status of the first trigger signal and the second trigger signal. Here, for example, when the gas appliance with a governor is not used, the pressure waveform and the flow waveform tend not to include a high frequency component. On the other hand, when no gas leak occurs, the pressure waveform and the flow rate waveform tend to contain many high frequency components. Further, since the first trigger signal is output when a change in gas pressure of a predetermined value or more occurs, the first trigger signal is output relatively early when a high frequency component is included in the pressure waveform. On the other hand, the second trigger signal is output when an overall flow rate increase occurs. Therefore, the gas usage status can be determined from the output status of the first trigger signal and the second trigger signal, and the power consumption can be reduced.

  In the above, the gas usage status means that the gas appliance with governor is not used, the gas appliance with governor and the gas appliance without governor are not used, the gas does not leak, the gas appliance without governor and the gas leak The use of a gas appliance with a governor, the use of a gas appliance with a governor and a gas appliance without a governor, the presence of a gas leak, the use of a gas leak and a gas appliance without a governor It is a concept that means at least one of being any one, using a gas appliance having an electronic control function, not using a gas appliance having an electronic control function, and being an ignition mistake. The electronic control function refers to a function of controlling the gas combustion amount by finely adjusting the gas amount by automatic control such as PID.

  According to the present invention, it is possible to provide a determination device and a determination method capable of reducing power consumption when determining a gas usage state.

It is a lineblock diagram of a gas supply system containing a measuring device concerning an embodiment of the present invention. FIG. 2 is a side sectional view showing an example of the governor shown in FIG. 1. It is a lineblock diagram of the gas meter concerning the embodiment of the present invention. It is a graph which shows the mode of the flow volume change when starting use of the gas appliance with a governor. It is the schematic which shows the mode of supply of the fuel gas in a gas appliance without a governor. It is a graph which shows the mode of the flow volume change at the time of gas leak. It is a flowchart which shows the judgment method of the gas meter which concerns on this embodiment. It is a flowchart which shows the detail of the 1st judgment process (S3) shown in FIG. It is a graph which shows an example of spectrum data, (a) shows at the time of use of the gas appliance with a governor, (b) shows at the time of use of a gas appliance without a governor, (c) shows the time of gas leak occurrence. . It is a flowchart which shows the detail of the 2nd judgment process (S6) shown in FIG. It is a block diagram of the gas meter which concerns on 2nd Embodiment of this invention. It is a block diagram of the gas meter which concerns on 3rd Embodiment of this invention. It is a graph which shows the waveform of the flow volume and pressure at the time of ignition mistake.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the drawings. FIG. 1 is a configuration diagram of a gas supply system including a measuring device according to an embodiment of the present invention. The gas supply system 1 supplies fuel gas to each gas appliance 10, and includes a plurality of gas appliances 10, a gas supply source regulator 20, pipes 31 and 32, a gas meter (measuring device) 40, and the like. It has. In the example shown in FIG. 1, the gas meter 40 is given as an example of a measuring device.

  The adjuster 20 adjusts the fuel gas from the upstream to a predetermined pressure and flows it through the first pipe 31. The adjuster 20 has a configuration in which, for example, the fuel gas is adjusted to a pressure of about 2.9 kPa and flows through the first pipe 31. The first pipe 31 connects the regulator 20 and the gas meter 40. The second pipe 32 is a pipe that connects the gas meter 40 and the gas appliance 10. The gas meter 40 measures the flow rate of the fuel gas and displays the integrated flow rate. In such a gas supply system 1, a flow path connected to the first pipe 31 and the second pipe 32 is formed in the gas meter 40, and the fuel gas flowing through the regulator 20 flows from the first pipe 31 to the gas meter 40, And the gas appliance 10 is reached through the second pipe 32 and burned in the gas appliance 10.

  The gas appliance 10 generally includes a shut-off valve 12, a governor 13, and a burner 14. The shut-off valve 12 is a valve provided in the gas appliance 10. The governor 13 has a governor inner valve 13a, and adjusts the pressure of the gas supplied to the burner 14 of the gas appliance 10 by the opening degree of the governor inner valve 13a. The pressure-adjusted fuel gas reaches the burner 14 through the nozzle 13b at the tip of the governor 13 and burns. Note that not all the gas appliances 10 have the governor 13, and some gas appliances 10 do not have the governor 13 such as a gas stove.

  FIG. 2 is a side sectional view showing an example of the governor 13 shown in FIG. In addition, in FIG. 2, only an example of the governor 13 is shown, and the configuration of the governor 13 is not limited to that shown in FIG. Further, the governor 13 shown in FIG. 2 is illustrated with the nozzle 13b shown in FIG. 1 omitted.

  As shown in FIG. 2, the governor 13 uses a part of the internal space formed by the outer wall 13c and the governor cap 13d as a gas flow path. Such a governor 13 includes a diaphragm 13e, an adjustment spring 13f, and an adjustment screw 13g in the internal space in addition to the governor inner valve 13a.

  The diaphragm 13 e is a film-like member that partitions the internal space of the governor 13. A governor inner valve 13a is attached to the diaphragm 13e on one side (flow channel side). Further, an adjustment spring 13f is attached to the other side (side not functioning as a flow path) of the diaphragm 13e. The adjustment spring 13f has a diaphragm 13e attached to one end and an adjustment screw 13g attached to the other end. The adjustment screw 13g is structured to be fixed to the inner wall of the governor 13 in which the thread groove is formed, and the compression rate of the adjustment spring 13f can be changed by changing the fixing position with the thread groove. Further, the adjusting screw 13g is not exposed to the outside, and has a structure covered with a governor cap 13d.

  The outer wall 13c of the governor 13 is formed with an air hole 13h that communicates with the other side of the diaphragm 13e. For this reason, the other side of the diaphragm 13e is air pressure. Further, in the example shown in FIG. 2, the governor inner valve 13a has a hemispherical shape, and the opening ratio of the passage port 13i can be controlled by vertical movement.

  In such a governor 13, when the gas pressure on the gas inlet side increases, the diaphragm 13e is pushed up, and at the same time, the governor inner valve 13a attached to the diaphragm 13e is also raised. Thereby, the opening ratio of the passage port 13i becomes small, and the gas flow rate decreases. On the other hand, when the gas pressure on the gas inlet side is lowered, the diaphragm 13e is lowered, and at the same time, the governor inner valve 13a attached to the diaphragm 13e is also lowered. Thereby, the opening ratio of the passage port 13i increases, and the gas flow rate increases. In this manner, the governor 13 adjusts the downstream pressure by keeping the downstream flow rate constant with respect to the upstream pressure fluctuation.

  FIG. 3 is a configuration diagram of the gas meter 40 according to the embodiment of the present invention. As shown in FIG. 3, the gas meter 40 according to the present embodiment includes a flow rate sensor 41, a differentiation circuit (differentiation means) 42, an integration circuit (integration means) 43, and a microcomputer (determination means) 44. .

  The flow sensor 41 is installed in the flow path in the gas meter 40 and detects the gas flow rate in the flow path. When the gas meter 40 according to the present embodiment is a gas meter equipped with a thermal sensor such as a flow sensor, the gas meter 40 includes a heater that generates a temperature distribution and a thermopile that generates a signal corresponding to the temperature distribution. The flow sensor 41 is not limited to a thermal sensor, and may be constituted by other sensors.

  The differentiation circuit 42 outputs a first trigger signal when the electrical signal from the flow sensor 41 exceeds a predetermined output change. The differentiation circuit 42 is configured as a peripheral analog circuit of the microcomputer 44. Further, the integrating circuit 43 outputs a second trigger signal when the electric signal from the flow sensor 41 is integrated and the integrated amount reaches a predetermined amount. Similarly to the differentiation circuit 42, the integration circuit 43 is also configured as a peripheral analog circuit of the microcomputer 44.

  In this embodiment, the signal from the flow sensor 41 in FIG. 3 is directly input to the differentiation circuit 42, the integration circuit 43, and the microcomputer 44, and the outputs of the differentiation circuit 42 and the integration circuit 43 are also directly input to the microcomputer 44. However, in some cases, other elements such as an amplifier may be added between the two. Here, other elements added between the two include a peak hold circuit. In other words, it is possible to prevent the first trigger signal from becoming unstable by providing a circuit for temporarily fixing the amplitude signal, such as a peak hold circuit, in the subsequent stage of the differentiation circuit 42. Further, by providing a circuit that outputs the pulse output by comparing the integration amount, such as a comparator circuit, at the subsequent stage of the integration circuit 43, the integration amount can be set by the comparator circuit, and the hysteresis is provided to make the second trigger signal unstable. It is because it can prevent becoming.

  Further, in the present embodiment, the number of flow sensors 41 is one, but at least one of the flow sensors input to the differentiation circuit 42, the integration circuit 43, and the microcomputer 44 may be provided separately.

  Further, although the differentiating circuit 42 is used as the differentiating means, the differentiating means is not limited to the differentiating circuit 42 as long as it can output a flow rate change, and may be a circuit that mainly extracts a high frequency such as a high-pass filter.

  The microcomputer 44 controls the entire gas meter 40 and performs flow rate integration control, display control, cutoff valve cutoff control, and the like. In the present embodiment, the microcomputer 44 has a function of determining the use of the gas appliance 10 with the governor, the use of the gas appliance 10 without the governor, and the occurrence of gas leakage.

  Here, the determination principle of the use of the gas appliance 10 with the governor by the microcomputer 44 will be described. FIG. 4 is a graph showing how the flow rate changes when the use of the gas appliance 10 with the governor is started. In FIG. 4, the vertical axis represents the output voltage (V) from the flow sensor 41 according to the flow rate, and the horizontal axis represents the elapsed time since the use of the gas appliance 10 with the governor was started. FIG. 4 shows a graph when the flow sensor 41 is a flow sensor.

  When the use of the gas appliance 10 with the governor is started, the flow rate becomes stable after showing the predetermined vibration shown in FIG. Specifically, immediately after the start of use of the gas appliance 10 with the governor, the output voltage once shows about “0.3” V (see reference sign a1), and then shows about “−0.2” V (reference sign). a2). After that, the output voltage shows about “0.3” V (see symbol a3), and then shows about “−0.27” V (see symbol a4). Thereafter, while the amplitude gradually decreases, the waveform repeatedly oscillates and finally becomes stable at an output voltage of about “0.2” V.

  The reason why such a flow rate vibration is generated is that an adjustment spring 13 f is provided in the governor 13. That is, when use of the gas appliance 10 with the governor is started, the adjustment spring 13f vibrates and the governor inner valve 13a also vibrates. As a result, the opening ratio of the passage port 13i also changes in small increments and decreases, and as a result, the flow rate waveform contains a lot of relatively high frequency components.

  FIG. 5 is a schematic view showing a state of supply of fuel gas in the governorless gas appliance 10. As shown in FIG. 5, when the governorless gas appliance 10 is used, the fuel gas reaches the burner 14 and the like from the second pipe 32 through the nozzle holder 100. Here, when a gas having a flow velocity flows into the nozzle holder 100, the flow rate does not decrease suddenly due to the inertial force, but the gas is compressed and the pressure rises. Thereafter, the inflow flow velocity becomes small (in some cases, a reverse flow) due to the increased pressure, and the pressure decreases. By repeating such a change in the flow velocity, vibration of the flow rate is generated.

  As described above, the flow rate vibrates between the use of the gas appliance with governor 10 and the use of the gas appliance 10 without governor. However, the flow rate waveform when using the gas appliance with governor 10 tends to include more frequency components than when using the gas appliance 10 without governor.

  First, in the case of the gas appliance 10 without a governor, there is no adjustment spring 13f, and only the vibration due to the gas inflow inertia force to the nozzle holder 100 is generated. On the other hand, even the gas appliance 10 with the governor has the nozzle holder 100, and vibration due to the gas inflow inertia force to the nozzle holder 100 is generated. In addition to this, the governor-equipped gas appliance 10 has a governor 13 to which vibration due to the adjustment spring 13f is added. As a result, the gas appliance 10 with the governor includes a higher frequency component than the gas appliance 10 without the governor.

  FIG. 6 is a graph showing how the flow rate changes when a gas leaks. In FIG. 6, the vertical axis represents the output voltage (V) from the flow sensor 41 according to the flow rate, and the horizontal axis represents the elapsed time since the gas leak occurred.

  As shown in FIG. 6, when a gas leak occurs, the flow rate shows a temporary vibration, but the vibration is relatively gentle. As described above, in the case of gas leakage, neither the vibration of the adjustment spring 13f nor the vibration due to the compressibility of the nozzle holder 100 occurs, so that no clear vibration as shown in FIG. It contains almost no ingredients.

  As described above, there is a characteristic difference in the flow rate waveform between the start of use of the gas appliance 10 with governor, the start of use of the gas appliance 10 without governor, and the occurrence of gas leakage. Moreover, the above-described features occur within a few seconds at the maximum from the start of use of the gas appliance 10 or the occurrence of gas leakage. Therefore, the microcomputer 44 can determine the use of the gas appliance 10 with the governor in a short time from the above characteristics.

  However, when determining the use of the gas appliance 10 with the governor, the use of the gas appliance 10 without the governor, and the occurrence of gas leakage based on the above characteristics, the calculation amount of the microcomputer 44 increases and the power consumption increases. End up. In particular, the gas meter 40 must be driven by a battery for 10 years, and the lower the power consumption, the better.

  Therefore, the gas meter 40 according to the present embodiment includes the differentiating circuit 42 and the integrating circuit 43, and based on the trigger signal output from these, the use of the gas appliance 10 with the governor or the use of the gas appliance 10 without the governor is used. And the process of determining whether a gas leak has occurred is reduced.

  FIG. 7 is a flowchart showing a determination method of the gas meter 40 according to the present embodiment. Note that the processing shown in FIG. 7 is executed when the flow rate detected by the flow rate sensor 41 is zero. That is, it is executed when only a flow rate equal to or lower than the lowest flow rate (for example, 1.5 L / hr) that can be measured by the electrical signal from the flow rate sensor 41 flows in the gas flow path. Then, the process is executed until a time of about several seconds elapses after the flow rate is changed from zero to over zero.

  As shown in FIG. 7, in a state where the flow rate detected by the flow rate sensor 41 is zero, the microcomputer 44 first determines whether or not the first trigger signal is input prior to the second trigger signal (S1). ). When it is determined that the first trigger signal is input before the second trigger signal (S1: YES), the microcomputer 44 determines that there is no gas leakage (S2).

  Here, the reason why the microcomputer 44 determines that there is no gas leakage is as follows. When a gas leak occurs, as shown in FIG. 6, the flow waveform tends to include many low frequency components and not many high frequency components. However, when the first trigger signal is input prior to the second trigger signal, for example, as shown in FIG. 4, a predetermined output change occurs due to a high frequency component, and the first trigger signal is quickly transmitted from the differentiation circuit 42. Is output to. As described above, when the first trigger signal is input before the second trigger signal, there is a high possibility that the gas appliance 10 with the governor is used, and even if an error or the like is taken into consideration, at least gas leakage does not occur. It can be judged.

  In this embodiment, it is determined that there is no gas leakage in step S2. However, it may be determined that the gas appliance 10 with the governor is used, or the gas appliance 10 with the governor and the gas appliance 10 without the governor are used. You may decide that it is either use. More specifically, whether or not the first trigger signal is output is determined by the multiplier of the differentiation circuit 42. For this reason, unless the gas appliance 10 with a governor is used, the multiplier of the differentiation circuit 42 is set so that the first trigger signal is not output prior to the second trigger signal. It can be determined that it is in use. Similarly, the multiplier of the differentiating circuit 42 is set so that the first trigger signal is not output before the second trigger signal unless the gas instrument 10 with the governor is used or the gas instrument 10 without the governor is used. Thus, it can be determined in step S2 that either the use of the gas appliance 10 with the governor or the use of the gas appliance 10 without the governor is used.

  After step S2, the microcomputer 44 executes a first determination process (S3). In this process, the microcomputer 44 determines whether the gas appliance 10 with governor is used or the gas appliance 10 without governor is used. Then, the process shown in FIG. 7 ends. In the first determination process in step S3, since the possibility of gas leakage is excluded, the amount of calculation is reduced and power consumption is reduced.

  When it is determined that the first trigger signal is not input before the second trigger signal (S1: NO), the microcomputer 44 does not input the first trigger signal but inputs only the second trigger signal. Whether or not (S4). When the first trigger signal is input or the second trigger signal is not input (S4: NO), the process proceeds to step S1. When it is determined that the first trigger signal is not input and only the second trigger signal is input (S4: YES), the microcomputer 44 determines that the gas appliance with governor 10 is not used (S5).

  Here, the reason why the microcomputer 44 determines that the gas appliance 10 with the governor is not used is as follows. When the governor-equipped gas appliance 10 is used, the flow waveform tends to include a lot of high-frequency components as shown in FIG. However, the case where the first trigger signal is not input and only the second trigger signal is input is a case where a predetermined output change does not occur because the flow rate waveform does not include a high frequency component as shown in FIG. 6, for example. . As described above, when the first trigger signal is not input and only the second trigger signal is input, there is a high possibility of gas leakage, and at least the use of the gas appliance 10 with the governor is used even if an error is taken into consideration. It can be judged that it is not.

  In this embodiment, it is determined that the gas appliance 10 with the governor is not used in step S5, but it may be determined that the gas leak is present, or either the gas leak or the gas appliance 10 without the governor is used. You may judge that there is. More specifically, whether or not the first trigger signal is output is determined by the multiplier of the differentiation circuit 42. For this reason, only in the case of using the gas appliance 10 with governor and the gas appliance 10 without governor, by setting the multiplier of the differentiating circuit 42 so that the first trigger signal is output, the gas leakage is detected in step S5. It can be judged that there is. Similarly, only in the case of using the gas appliance 10 with the governor, by setting the multiplier of the differentiating circuit 42 so that the first trigger signal is output, in step S5, the gas leakage and the use of the gas appliance 10 without the governor are used. It can be judged that it is either.

  In addition, a piping state changes with each household. For this reason, whether or not the first trigger signal is output also varies depending on the piping state. Therefore, when determining gas leakage in step S5, the following two methods may be performed. The first is a method of setting a multiplier of the differentiation circuit 42 so that a part of the gas leak cannot be judged properly in a certain household, but the gas leak can be appropriately judged in another household. This is because, by this method, when the first trigger signal is not input and the second trigger signal is input, it can always be determined that there is a gas leak.

  The second is a method in which the multiplier of the differentiation circuit 42 is set so that a gas leak is appropriately determined for a certain household, but other than the gas leak is determined for another household. is there. By this method, when the first trigger signal is not input and the second trigger signal is input, it may not be a gas leak, but it is determined that there is a gas leak in consideration of safety, and a safety process is performed. Is it possible to do it?

  In the case where it is difficult to determine a part of the gas leak in a certain household as described above, and a case where a gas leak other than the gas leak is determined to be a gas leak, a detailed determination process (described later) is performed after step S5. By executing the second determination process shown in step S8, it is possible to reduce the possibility that a part of the gas leak will be missed and the possibility that it is determined that there is a gas leak other than the gas leak.

  After step S5, the microcomputer 44 determines whether the average flow rate during a specified time (for example, 0.3 to 2 seconds) after the second trigger signal is input is a specified amount (for example, 100 L / hr as an average flow rate) or more. It is determined whether or not (S6). If it is determined that the amount is greater than the specified amount (S6: YES), the microcomputer 44 determines that there is a gas leak (step S7). Then, the process shown in FIG. 7 ends. If it is determined that there is a gas leak, the microcomputer 44 executes a security process such as shutting off the shutoff valve.

  Here, when a gas leak occurs (especially when a large amount of gas leaks), the waveform tends not to contain many high-frequency components. Further, the governorless gas appliance 10 tends to have a flow rate not greater than a specific flow rate. For this reason, after it is determined that the gas appliance 10 with the governor is not used, if the average gas flow rate within the specified time is equal to or more than the specified amount, the gas leakage is no longer necessary. In particular, a large amount of gas leakage has a high degree of danger, and in the flowchart shown in FIG. 7, the gas leakage is determined without performing detailed processing such as the first determination processing (S3) and the second determination processing (S8) described later. As a result, it is possible to execute an immediate security process, and the safety of the gas supply system 1 as shown in FIG. 1 can be improved.

  In step S6, the gas leakage is determined based on the average flow rate, but is not limited thereto, and may be determined based on the integrated flow rate within a specified time. This is because the integrated flow rate can also be handled as an average flow rate by dividing by the specified time.

  By the way, when it is determined in step S6 that the average flow rate is less than the prescribed amount (S6: NO), the microcomputer 44 executes a second determination process (S8). In this process, the microcomputer 44 determines in detail whether the gas appliance 10 without governor is used or a gas leak. Then, the process shown in FIG. 7 ends. In the second determination process in step S8, since the possibility of using the gas appliance 10 with the governor is excluded, the calculation amount is reduced and the power consumption is reduced.

  Here, as described with reference to FIGS. 4 to 6, the characteristic of the flow rate waveform occurs within a few seconds at the maximum from the start of use of the gas appliance 10 or the occurrence of gas leakage. Therefore, it is desirable that the process shown in FIG. 7 is terminated when a time of several seconds has elapsed since the flow rate has exceeded zero.

  FIG. 8 is a flowchart showing details of the first determination process (S3) shown in FIG. As shown in FIG. 8, in the first determination process, the microcomputer 44 performs a Fourier transform on the flow rate waveform (S11). As a result, the microcomputer 44 generates spectrum data indicating the correlation between the frequency and the amplitude. And the microcomputer 44 judges whether the amplitude value of a high frequency component is more than a 1st predetermined amplitude value among spectrum data (S12).

  FIG. 9 is a graph showing an example of spectrum data, where (a) shows the use of the gas appliance 10 with governor and (b) shows the use of the gas appliance 10 without governor. The spectral data shown in FIG. 9 is a Fourier transform of the pressure waveform, but there is a certain correlation between pressure and flow rate, and the characteristics of frequency and amplitude are similar. The spectrum data obtained by Fourier transforming the waveform is shown.

  As shown to Fig.9 (a), when the gas appliance 10 with a governor is used, there exists a tendency which shows a high amplitude in the frequency component of 20 Hz or more. On the other hand, as shown in FIG. 9B, when the governorless gas appliance 10 is used, there is a tendency that a high amplitude is not shown in a frequency component of 20 Hz or more. Therefore, the microcomputer 44 determines whether or not the amplitude value of the high frequency component is equal to or greater than the first predetermined amplitude value, as shown in step S12 of FIG.

  When it is determined that the amplitude value of the high frequency component (specifically, the component of 20 Hz or more) is equal to or greater than the first predetermined amplitude value (S12: YES), the microcomputer 44 determines that the gas appliance 10 with the governor is used. (S13). Thereafter, the process shown in FIG. 8 ends. On the other hand, when it is determined that the amplitude value of the high-frequency component is not equal to or greater than the first predetermined amplitude value (S12: NO), the microcomputer 44 determines that the governorless gas appliance 10 is used (S14). Thereafter, the process shown in FIG. 8 ends.

  FIG. 10 is a flowchart showing details of the second determination process (S6) shown in FIG. As shown in FIG. 10, in the second determination process, the microcomputer 44 performs a Fourier transform on the flow rate waveform (S21). As a result, the microcomputer 44 generates spectrum data indicating the correlation between the frequency and the amplitude. Then, the microcomputer 44 determines whether or not the amplitude value of the medium frequency component in the spectrum data is greater than or equal to the second predetermined amplitude value (S22).

  FIG.9 (c) is a graph which shows an example of the spectrum data at the time of gas leak generation | occurrence | production. As shown in FIG. 9C, when a gas leak occurs, not only does the frequency component of 20 Hz or higher not show high amplitude, but the frequency component of about 10 Hz tends not to show high amplitude. On the other hand, as shown in FIG. 9 (b), when the governorless gas appliance 10 is used, it is the same in that it does not show a high amplitude in a frequency component of 20 Hz or higher, but in the frequency component in the vicinity of about 10 Hz There is a tendency to show a higher amplitude than when the leak occurred. Therefore, the microcomputer 44 determines whether or not the amplitude value of the medium frequency component is equal to or greater than the second predetermined amplitude value, as shown in step S22 of FIG.

  When it is determined that the amplitude value of the medium frequency component (specifically, a component of about 10 Hz) is equal to or greater than the second predetermined amplitude value (S22: YES), the microcomputer 44 determines that the gas appliance 10 without governor is used. (S23). Thereafter, the process shown in FIG. 10 ends. On the other hand, if it is determined that the amplitude value of the medium frequency component is not equal to or greater than the second predetermined amplitude value (S22: NO), the microcomputer 44 determines that there is a gas leak (S24). Thereafter, the process shown in FIG. 10 ends.

  In step S12 of FIG. 8, it is determined whether the amplitude value of the high frequency component is equal to or greater than the first predetermined amplitude value. In step S22 of FIG. 10, the amplitude value of the medium frequency component is equal to or greater than the second predetermined amplitude value. It was judged whether or not. However, the determination is not limited to this, and other methods may be used. For example, the spectrum data when using the gas appliance 10 with governor and the spectrum data when using the gas appliance 10 without governor are stored in the microcomputer 44 in advance. Then, in step S12 of FIG. 8, the microcomputer 44 reads the stored spectrum data, determines which spectrum data is high in similarity between the spectrum data obtained in step S11, and the gas appliance with governor. 10 or the use of the governorless gas appliance 10 may be determined. The same applies to step S22 in FIG.

  As described above, according to the gas meter 40 and the determination method according to the present embodiment, when the electric signal from the flow sensor 41 exceeds a predetermined output change, the first trigger signal is output and the electric signal from the flow sensor 41 is output. When the signal is integrated and the integrated amount reaches a predetermined amount, the second trigger signal is output, and the gas appliance 10 with the governor is not used depending on the input status of the first trigger signal and the second trigger signal. Or whether a gas leak has occurred. Here, for example, when the governor-equipped gas appliance 10 is not used, a high-frequency component tends to be not included in the flow rate waveform. On the other hand, when there is no gas leakage, the flow waveform tends to contain a lot of high frequency components. Further, since the first trigger signal is output when a predetermined output change occurs, the first trigger signal is output relatively early when the flow waveform includes many high frequency components. On the other hand, the second trigger signal is output when an overall flow rate increase occurs. Therefore, the gas usage status can be determined from the output status of the first trigger signal and the second trigger signal, and the power consumption can be reduced.

  Further, the differentiation circuit 42 and the integration circuit 43 are constituted by peripheral analog circuits outside the microcomputer 44. For this reason, when the first and second trigger signals are output, there is no need for calculation, and the amount of calculation can be further reduced to reduce power consumption. In the first embodiment, the differentiation circuit 42 and the integration circuit 43 are configured by a peripheral analog circuit outside the microcomputer 44, but at least one may be configured by a peripheral analog circuit. This is also because the amount of calculation can be reduced and the power consumption can be reduced on the side constituted by the peripheral analog circuits.

  If the second trigger signal is input after the first trigger signal is input, it is determined that no gas leak has occurred. Here, when there is no gas leakage, the waveform tends to include many relatively high frequency components. For this reason, a predetermined output change occurs due to a relatively high frequency component, and the first trigger signal tends to be output before the second trigger signal. Therefore, in the above case, it can be determined that no gas leak has occurred, the possibility of gas leak can be eliminated, the amount of calculation can be reduced, and the power consumption can be reduced.

  When the first trigger signal is not input and the second trigger signal is input, it is determined that the gas appliance 10 with the governor is not used. Here, when the gas appliance 10 with the governor is not used, there is a tendency that the waveform does not include a lot of high frequency components. For this reason, a predetermined output change does not occur, the first trigger signal is not output, and the integrated value tends to reach a predetermined amount due to the overall flow rate increase, and only the second trigger signal tends to be output. Therefore, in the above case, by determining that the gas appliance with governor 10 is not used, the possibility of using the gas appliance with governor 10 can be eliminated, and the amount of calculation can be reduced to reduce power consumption.

  Further, if the first trigger signal is not input, the second trigger signal is input, and the average gas flow rate within a specified time after the second trigger signal is input is equal to or greater than a specified amount, it is determined that there is a gas leak. To do. Here, when a gas leak occurs (especially when a large amount of gas leaks), the waveform tends not to contain many high-frequency components. Further, the governorless gas appliance 10 tends to have a flow rate not greater than a specific flow rate. For this reason, the first trigger signal is not output, the integrated value reaches a predetermined amount due to the overall flow rate increase, and only the second trigger signal is output, and the average gas flow rate within the specified time is equal to or greater than the specified amount. In some cases, it will no longer be a gas leak. Therefore, in the above case, it is possible to eliminate the possibility of using other governor-equipped gas appliances, etc., by determining that the gas is leaking, thereby reducing the amount of calculation and reducing power consumption. Furthermore, the security process can be executed quickly when a large amount of gas leaks.

  Next, a second embodiment of the present invention will be described. FIG. 11 is a configuration diagram of a gas meter 40 according to the second embodiment of the present invention. In FIG. 11, the same or similar components as those in the gas meter 40 shown in FIG. As shown in FIG. 11, the gas meter 40 includes a pressure sensor 45. The pressure sensor 45 outputs an electrical signal corresponding to the gas pressure in the flow path.

  In the second embodiment, the differentiating circuit 42 receives an electric signal from the pressure sensor 45. Here, there is a certain correlation between the flow rate waveform and the pressure waveform. In particular, the pressure waveform tends to contain a lot of high-frequency components when using the gas appliance 10 with governor, as well as the flow rate, and tends to contain many medium frequency components when using the gas appliance 10 without governor. When gas leaks, medium frequency components tend to be hardly included. For this reason, the differentiating circuit 42 according to the second embodiment inputs an electric signal from the pressure sensor 45 and outputs a first trigger signal as in the first embodiment.

  On the other hand, with respect to the integrating circuit 43, the electric signal from the flow sensor 41 is input as in the first embodiment. If the electric signal from the pressure sensor 45 is input to the integration circuit 43, the pressure rises when the pipe is cooled at night and then warmed in the daytime, and the integration amount reaches the predetermined amount in the integration circuit 43. End up. For this reason, when the electric signal from the pressure sensor 45 is input to the integration circuit 43, the second trigger signal cannot be appropriately output. Therefore, regarding the integrating circuit 43, an electric signal from the flow sensor 41 is input.

  The microcomputer 44 determines that it is not the use of the gas appliance 10 with the governor and determines that it is not a gas leak as in the first embodiment. Similarly to the first embodiment, the microcomputer 44 may determine the use of the gas appliance 10 with the governor by setting the multiplier of the differentiating circuit 42, or may use the gas appliance 10 with the governor and the gas without the governor. It may be determined that either the instrument 10 is used. Further, the microcomputer 44 may determine that the gas leak is caused by setting the multiplier of the differentiation circuit 42, or may determine that the gas leak or the use of the gas appliance 10 without governor is used. .

  Thus, according to the gas meter 40 and the determination method according to the second embodiment, when the electrical signal from the pressure sensor 45 exceeds a predetermined output change, the first trigger signal is output and the flow sensor 41 When the electrical signal is integrated and the integrated amount reaches a predetermined amount, the second trigger signal is output, and the gas appliance 10 with the governor is used according to the input status of the first trigger signal and the second trigger signal. It is judged whether there is any gas leak. Here, for example, when the governor-equipped gas appliance 10 is not used, the pressure waveform and the flow waveform tend not to include a high-frequency component. On the other hand, when no gas leak occurs, the pressure waveform and the flow rate waveform tend to contain many high frequency components. Further, since the first trigger signal is output when a predetermined output change occurs, the first trigger signal is output relatively early when the pressure waveform includes many high frequency components. On the other hand, the second trigger signal is output when an overall flow rate increase occurs. Therefore, the gas usage status can be determined from the output status of the first trigger signal and the second trigger signal, and the power consumption can be reduced.

  Moreover, similarly to 1st Embodiment, possibility that it is use of the gas appliance 10 with a governor and the possibility of being a gas leak can be excluded, and calculation amount can be reduced and power consumption can be reduced. Furthermore, by configuring the differentiation circuit 42 and the integration circuit 43 as an external analog circuit of the microcomputer 44, it is possible to further reduce the amount of calculation and reduce power consumption.

  Next, a third embodiment of the present invention will be described. FIG. 12 is a configuration diagram of a gas meter 40 according to the third embodiment of the present invention. In FIG. 12, the same or similar components as those of the gas meter 40 shown in FIG.

  The pressure switch 46 outputs a first trigger signal in accordance with a change in pressure of the gas present in the flow path in the gas meter 40. In the present embodiment, the pressure switch 46 is provided in the flow path in the gas meter 40. However, the pressure switch 46 is not limited to this, and if possible, the first that exists outside the gas meter 40 without departing from the configuration of the present invention. You may install in the piping 31 side or the 2nd piping 32 side.

  The pressure switch 46 includes a displacement part 46a, a branch pipe 46b, a bypass flow path 46c, a pressure suppression part 46d, and the like.

  First, the branch pipe 46b is a pipe branched from the gas flow path, and forms branch spaces 47a and 47b branched from the gas flow path. Moreover, the displacement part 46a is formed by the diaphragm of a thin film member, and has the structure which divides the branched spaces 47a and 47b into the one side A and the other side B. Here, the one side A is a directly facing side facing the pressure fluctuation and is also called a facing side facing the gas flow path. That is, this one side A is the side that makes the space the same as the gas channel without passing through the bypass channel 46c. Moreover, since this displacement part 46a is formed with the thin film diaphragm, it can be displaced to the one side A and the other side B according to the pressure fluctuation of a gas flow path.

  The bypass flow path 46c is a flow path that connects the one side A and the other side B. The pressure suppression unit 46d is, for example, an orifice. The orifice is a member having a hole having a diameter smaller than that of the bypass channel 46c. This orifice suppresses the occurrence of pressure change on the other side B based on the pressure change on one side A. That is, when the pressure in the gas flow path decreases relatively rapidly, such as when the gas appliance 10 is used, the pressure decreases on the one side A, but on the other side B, the pressure is reduced by the pressure suppressing portion 46d. It becomes difficult to do. For this reason, the displacement part 46a will be displaced to the one side A. On the other hand, when the pressure gradually decreases, such as when a small amount of gas leaks, the pressure decreases on one side A and also on the other side B. For this reason, the displacement part 46a is not displaced, or is displaced only slightly.

  Moreover, the pressure switch 46 has the 1st contact 46e in the displacement part 46a. The first contact 46e is connected to the ground. The pressure switch 46 includes a second contact 46f. For this reason, when the gas pressure in the gas flow path suddenly decreases and the displacement portion 46a is displaced by a predetermined amount to the one side A, the first contact 46e and the second contact 46f come into contact with each other. As a result, a first trigger signal indicating that the displacement portion 46a has been displaced to the one side A by a predetermined amount is output to the microcomputer 44. That is, the pressure switch 46 does not generate a first trigger signal when the gas pressure decreases below a predetermined value, but generates a first trigger signal when the gas pressure decreases above a predetermined value. Therefore, the pressure switch 46 exhibits the same behavior as the differentiating circuit 42 shown in the first embodiment and the second embodiment, and generates the first trigger signal.

  The pressure switch 46 generates the first trigger signal when the gas pressure decreases by a predetermined value or more. However, the present invention is not limited to this, and the pressure switch 46 may generate a trigger signal when the gas pressure increases by a predetermined value or more. Good. The pressure switch 46 is not limited to the flow path in the gas meter 40, but may be installed on the first pipe 31 side or the second pipe 32 side. In this case, the branch pipe 46b, the pressure suppression unit 46d, etc. Needless to say, it is installed on the first pipe 31 side or the second pipe 32 side.

  As for the integrating circuit 43, an electric signal from the flow sensor 41 is input as in the above embodiment. Similarly to the above embodiment, the microcomputer 44 determines that the gas appliance 10 with the governor is not used and determines that it is not a gas leak.

  For the pressure switch 46, the first trigger signal of the first trigger signal can be adjusted by adjusting the material of the displacement portion 46a, the diameter of the bypass flow path 46c, the diameter of the orifice, and the like, similarly to setting the multiplier of the differentiation circuit 42. The occurrence can be adjusted.

  As described above, according to the gas meter 40 and the determination method according to the third embodiment, the pressure switch 46 outputs the first trigger signal and the electric signal from the flow sensor 41 is output when the gas pressure changes by a predetermined value or more. When the integrated amount reaches a predetermined amount, the second trigger signal is output, and the gas usage status is determined according to the input status of the first trigger signal and the second trigger signal. Here, for example, when the governor-equipped gas appliance 10 is not used, the pressure waveform and the flow waveform tend not to include a high-frequency component. On the other hand, when no gas leak occurs, the pressure waveform and the flow rate waveform tend to contain many high frequency components. Further, since the first trigger signal is output when a predetermined output change occurs, the first trigger signal is output relatively early when the pressure waveform includes many high frequency components. On the other hand, the second trigger signal is output when an overall flow rate increase occurs. Therefore, the gas usage status can be determined from the output status of the first trigger signal and the second trigger signal, and the power consumption can be reduced.

  Moreover, similarly to 1st Embodiment, possibility that it is use of the gas appliance 10 with a governor and the possibility of being a gas leak can be excluded, and calculation amount can be reduced and power consumption can be reduced. Furthermore, by configuring the integrating circuit 43 as an external analog circuit of the microcomputer 44, the amount of calculation can be further reduced and the power consumption can be reduced.

  As described above, the present invention has been described based on the embodiment, but the present invention is not limited to the above embodiment, and may be modified without departing from the gist of the present invention. For example, in the present embodiment, the determination device exists as an internal configuration of the gas meter 40. However, the determination device is not limited thereto, and the determination device may be extracted from the gas meter 40.

  In the present embodiment, the flowchart shown in FIG. 7 is executed when the flow rate is zero, but may be executed when a predetermined flow rate value is generated. In this case, the microcomputer 44 inputs the first trigger signal from the differentiation circuit 42 or the pressure switch 46 and does not input the second trigger signal from the integration circuit 43, and the integration circuit 43 starts from the predetermined flow rate value. When there is a flow rate change corresponding to outputting two trigger signals, the second trigger signal is generated internally.

  Further, the microcomputer 44 is not limited to the example shown in FIG. 7, and may determine that there is no gas leakage by another method. For example, when the second trigger signal is input before the first trigger signal, the microcomputer 44 determines that there is no gas leak. The high frequency component and medium frequency component of the flow rate waveform and pressure waveform may be observed with a delay due to differences in piping and the like in each home. In such a case, the gas appliance 10 is used. Since the possibility is high, it is determined that there is no gas leak.

  Further, in the present embodiment, it is determined that the gas appliance 10 with the governor is not used, but not limited thereto, the use of the gas appliance 10 having an electronic control function, or the gas appliance 10 having an electronic control function. You may make it judge that it is not use. Here, the electronic control function refers to a function of controlling the gas combustion amount by finely adjusting the gas amount by automatic control such as PID. For this reason, when the gas appliance 10 having the electronic control function is used, a higher frequency (for example, 50 Hz or more) is superimposed on the pressure waveform or the flow waveform, and a high-frequency amplitude signal is superimposed and measured on the waveform. Even in this case, the determination can be made by adjusting the multiplier of the differentiating circuit 42.

  In addition, in this embodiment, by adjusting the multiplier of the differentiation circuit 42, it may be determined that neither the use of the gas appliance 10 with the governor nor the use of the gas appliance 10 without the governor is used, or the gas without the governor. It may be determined that neither the use of the instrument 10 nor a gas leak is present.

  Furthermore, although the user of the gas appliance 10 ignited once in the present embodiment, an ignition error may be determined when ignition is not successful. FIG. 13 is a graph showing the flow rate and pressure waveforms when an ignition error occurs.

  As shown in FIG. 13, as shown in FIG. 13, the flow waveform tends to show a relatively high frequency component at the time of ignition mistake. However, since the ignition has failed in the end, the user has to reignite the ignition. As a result, the flow rate does not show an increase, and the waveform does not show an increase in the flow rate as a whole while including a relatively high frequency component. Therefore, in the first embodiment, the first trigger signal is output from the differentiating circuit 42, but the second trigger signal is not output from the integrating circuit 43. As described above, the microcomputer 44 can determine that an ignition error has occurred when the second trigger signal is not input within a predetermined time after the one trigger signal is input.

  Further, as shown in FIG. 13, the pressure waveform tends to show a relatively high frequency component at the time of ignition mistake. Therefore, in the second and third embodiments, the first trigger signal is output, but the second trigger signal is not output. As described above, the microcomputer 44 can determine that an ignition error has occurred when the second trigger signal is not input within a predetermined time after the one trigger signal is input.

  In addition, when a large crack is generated in the thick pipe or the thick pipe is cut, a large amount of gas flows. Then, there is a possibility that the first trigger signal is output due to a large amount of gas flowing. Further, since the second trigger signal is output when a gas leak occurs, the second trigger signal may be input after the first trigger signal is input when a large amount of gas leak occurs. Therefore, when the second trigger signal is input after the first trigger signal is input, the microcomputer 44 determines that a small amount of gas leakage has not occurred, and a large amount of gas leakage is processed later (for example, You may make it judge by the 2nd judgment process of step S8. Further, the multiplier of the differentiation circuit 42 may be adjusted, or each configuration of the pressure switch 46 may be adjusted so that the first trigger signal is not output even if a large amount of gas leaks. Thereby, the microcomputer 44 can determine that not only a small amount of gas leakage but also a large amount of gas leakage has not occurred.

  Further, in the present embodiment, the differentiating circuit 42 and the integrating circuit 43 are configured by peripheral analog circuits of the microcomputer 44, but are not limited to this, and may be a function of the microcomputer 44. This is because even if only one function of the microcomputer 44 is used, the overall calculation amount is reduced, which can lead to a reduction in power consumption. Furthermore, at least one of the differentiation circuit 42 and the integration circuit 43 may be an external small microcomputer.

DESCRIPTION OF SYMBOLS 1 ... Gas supply system 10 ... Gas appliance 12 ... Shut-off valve 13 ... Governor 13a ... Governor inner valve 13b ... Nozzle 13c ... Outer wall 13d ... Governor cap 13e ... Diaphragm 13f ... Adjustment spring 13g ... Adjustment screw 13h ... Air hole 14 ... Burner 20 ... Adjuster 31 ... First pipe 32 ... Second pipe 40 ... Gas meter (judgment device)
41 ... Flow sensor 42 ... Differentiation circuit (differentiation means)
43. Integration circuit (integration means)
44 ... Microcomputer (judgment means)
45 ... Pressure sensor 46 ... Pressure switch 46a ... Displacement part 46b ... Branch pipe 46c ... Bypass flow path 46d ... Pressure suppression part 46e ... First contact 46f ... Second contact

Claims (12)

A flow rate sensor that outputs an electrical signal corresponding to the gas flow rate in the flow path;
Differential means for outputting a first trigger signal when the electrical signal from the flow sensor exceeds a predetermined output change;
Integrating means for outputting a second trigger signal when the electrical signal from the flow sensor is integrated and the integrated amount reaches a predetermined amount;
Determining means for determining a gas usage state in accordance with input states of the first trigger signal from the differentiating means and the second trigger signal from the integrating means;
A judgment device comprising: A pressure sensor that outputs an electrical signal corresponding to the gas pressure in the flow path;
A flow rate sensor that outputs an electrical signal corresponding to the gas flow rate in the flow path;
Differential means for outputting a first trigger signal when the electrical signal from the pressure sensor exceeds a predetermined output change;
Integrating means for outputting a second trigger signal when the electrical signal from the flow sensor is integrated and the integrated amount reaches a predetermined amount;
Determining means for determining a gas usage state in accordance with input states of the first trigger signal from the differentiating means and the second trigger signal from the integrating means;
A judgment device comprising: The determination means is configured as one function of the microcomputer,
The determination apparatus according to claim 1, wherein at least one of the differentiating unit and the integrating unit is configured by a peripheral analog circuit outside the microcomputer. A pressure switch that does not generate a first trigger signal when the gas pressure changes below a predetermined value and outputs a first trigger signal when the gas pressure changes above a predetermined value;
A flow rate sensor that outputs an electrical signal corresponding to the gas flow rate in the flow path;
Integrating means for outputting a second trigger signal when the electrical signal from the flow sensor is integrated and the integrated amount reaches a predetermined amount;
Determining means for determining a gas usage status in accordance with the input status of the first trigger signal from the pressure switch and the second trigger signal from the integrating means;
A judgment device comprising: The determination means is configured as one function of the microcomputer,
The determination device according to claim 4, wherein the integration unit is configured by a peripheral analog circuit outside the microcomputer. 6. The determination unit according to claim 1, wherein when the second trigger signal is input after the first trigger signal is input, it is determined that no gas leak has occurred. The judgment device according to item 1. The determination unit determines that the gas appliance with a governor is not used when the second trigger signal is input without inputting the first trigger signal. The judging device according to claim 1. When the determination means does not input the first trigger signal, inputs the second trigger signal, and an average gas flow rate within a specified time after the input of the second trigger signal is equal to or more than a specified amount, It is judged that it is a gas leak. The judgment device according to any one of claims 1 to 7 characterized by things. 9. The determination unit according to claim 1, wherein if the second trigger signal is not input within a predetermined time after the input of the first trigger signal, the determination unit determines that an ignition error has occurred. The judging device according to claim 1. A differential step of outputting a first trigger signal when an electrical signal from a flow sensor that outputs an electrical signal corresponding to a gas flow rate in the flow path exceeds a predetermined output change;
An integration step of outputting a second trigger signal when the electrical signal from the flow sensor is integrated and the integrated amount reaches a predetermined amount;
A determination step of determining a gas usage state according to input states of the first trigger signal output in the differentiation step and the second trigger signal output in the integration step;
The judgment method characterized by comprising. A differentiation step of outputting a first trigger signal when an electrical signal from a pressure sensor that outputs an electrical signal corresponding to a gas pressure in the flow path exceeds a predetermined output change;
An integration step of outputting a second trigger signal when the integration amount reaches a predetermined amount by integrating the electrical signals from the flow rate sensor that outputs an electrical signal corresponding to the gas flow rate in the flow path;
A determination step of determining a gas usage state according to input states of the first trigger signal output in the differentiation step and the second trigger signal output in the integration step;
The judgment method characterized by comprising. This is a method for determining a gas usage status in a determination apparatus having a pressure switch that does not generate a first trigger signal when the gas pressure changes below a predetermined value but outputs a first trigger signal when the gas pressure changes above a predetermined value. And
An integration step of outputting a second trigger signal when the integration amount reaches a predetermined amount by integrating the electrical signals from the flow rate sensor that outputs an electrical signal corresponding to the gas flow rate in the flow path;
A determination step of determining a gas usage status according to the input status of the first trigger signal from the pressure switch and the second trigger signal from the integrating means;
The judgment method characterized by comprising.

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