JP2000146658A - Gas-flow breaking device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To monitor whether the quantity of use of a medium and the state of usage are safe or not by accurately measuring the quantity of flow at the time when apparatus is not used. SOLUTION: While time is counted by a timer means 24, after the lapse of a predetermined time, a channel 1 is periodically closed by a breaking means 26 in a gas apparatus not used state, the flow velocity of a gas medium is measured, and the quantity of flow converted by a flow quantity computing means 21 is stored in a flow quantity correcting means 25 as a new correction value of the quantity of flow. After this, the channel 1 is opened, and the flow velocity is detected by a flow velocity detecting means 17 with the apparatus in a state of being used. Then a flow quantity computing means 21 performs the conversion of the quantity of flow, and a correction value of the quantity of flow is stored in the flow quantity correcting means 25 so that the converted quantity of flow may be corrected by the new correction value of the quantity of flow.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to various media flowing in piping using ultrasonic waves, for example, various city gas or L.
The present invention relates to a gas shut-off device that detects a flow rate of PG gas and the like, accurately measures the amount of medium used, and monitors the amount of medium used and whether or not its use state is safe.

[0002]

2. Description of the Related Art A conventional gas shut-off device of this type has a configuration shown in FIG. 3 as disclosed in, for example, Japanese Patent Application Laid-Open No. 9-21667. FIG. 3 shows a block diagram of a conventional gas shut-off device.

[0003] In FIG. 3, reference numeral 1 denotes a fluid pipeline, and 2 denotes a first vibrator, which transmits and receives ultrasonic waves and is installed on the upstream side of the fluid pipeline 1. Reference numeral 3 denotes a second vibrator, which transmits and receives ultrasonic waves, and
Is installed facing the downstream side of the. Reference numeral 4 denotes a transmission circuit, which transmits an ultrasonic signal to the first transducer 2, and reference numeral 5 denotes an amplification circuit, which amplifies a signal received by the second transducer 3. A comparison circuit 6 compares the amplified signal with a reference signal. Reference numeral 7 denotes a time measuring means for measuring the time from transmission of the ultrasonic wave to reception of the ultrasonic wave by a timer counter. Reference numeral 8 denotes a measuring circuit, which includes the transmitting circuit 4 to the time measuring means 7. Numeral 9 denotes a flow rate calculating means for obtaining a flow rate value in consideration of the size of the pipeline and the state of the flow according to the ultrasonic wave propagation time by the time measuring means 7. Numeral 10 is a cycle variable means for changing the measurement cycle according to the value of the flow rate calculating means 9. 11
Is a measurement start means for adjusting the signal transmission timing to the transmission circuit according to the value of the cycle variable means 10. Numeral 12 denotes a measurement end means for detecting the end of the operation of the flow rate operation means 9. 13
Is a voltage control means, which lowers the voltage of the measurement circuit 11 in synchronization with the measurement end means 12 and restores the voltage of the measurement circuit 8 in synchronization with the start of measurement by the measurement start means 11.

Next, the operation of the conventional configuration will be described. A burst signal is transmitted from the transmission circuit 4 by the measurement start means 11 in the fluid line 1 in which a medium gas such as city gas or LP gas flows, and the ultrasonic signal transmitted from the first vibrator 2 is transmitted through the fluid line 1. , And received by the second oscillator 3, further subjected to signal processing by the amplifier circuit 5 and the comparison circuit 6, and the time from transmission to reception is measured by the timer 7. When the flow rate is large, it is necessary to increase the time sampling and reduce the error. When the flow rate is small or when the flow rate is zero, even if the measurement sampling is slowed down, almost no error occurs.
Therefore, the measurement interval is changed according to the value of the flow rate calculating means 9. When the value of the flow rate calculating means 9 is small, the interval of the measuring time is increased by the variable period variable means 10, and as the value of the flow rate calculating means 9 increases, the measuring time interval is reduced. Further, the voltage of the measurement circuit 8 is reduced between measurements. When the flow rate measurement is completed by the flow rate calculation means 9, the measurement end means 12
And the voltage is reduced by the voltage control means 13 or set to zero. Before the measurement is started by the measurement starting means 11, the voltage of the measuring circuit 8 is restored by the voltage control means 12.

[0005]

However, in the above conventional configuration, after the gas shut-off device is installed, the measuring circuit 8
Or when the gas appliance deviates from the flow rate value when the gas appliance is not used, that is, zero flow rate or within a predetermined flow rate range (this range is defined as zero flow rate) due to the time change of the first vibrator 2 or the second vibrator 3. The coping method was not clear.

The present invention has been made to solve the above-mentioned problem, and when the gas shut-off device is installed, when the city gas or the LPG gas is not used, that is, when the gas appliance is not used, the flow rate is accurately measured, and the gas medium is used. It is an object of the present invention to provide a gas shut-off device for monitoring whether a quantity and its use condition are safe.

[0007]

SUMMARY OF THE INVENTION In order to solve this problem, the present invention provides a timer means for counting time to accurately measure a flow rate when a gas appliance is not used after a gas shut-off device is installed. When the determination is made, the flow path of the appliance stopped state is shut off, the flow velocity of the used gas medium is measured and converted into a flow rate value, the flow rate is stored as a flow rate correction value for adjusting the flow rate to zero, and then the flow path is opened to use the gas. When a person uses a gas appliance, the flow rate is detected by the flow rate detecting means, the flow rate is calculated by the flow rate calculating means, and the flow rate correction value is stored in the flow rate correcting means to correct the flow rate converted by the stored flow rate correction value. I have to.

Thus, the gas flow rate when the gas appliance is not used, that is, the zero flow state, can be accurately measured periodically after the gas shut-off device is installed, and it is prevented that the gas appliance is used erroneously and the accumulation is continued. It is possible to accurately measure and monitor the amount of gas used to monitor the usage of gas.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS To achieve the above object, the present invention provides a flow rate detecting means for measuring a signal propagation time in a medium and detecting a flow rate, and a flow rate calculation for converting the flow rate detected by the flow rate detecting means into a flow rate. Means, abnormality determination means for determining whether the flow value obtained by the flow rate calculation means is an abnormal usage amount,
A shutoff means for shutting off the medium flow path when the abnormality judgment means judges an abnormal state; a timer means for counting time; and, when the timer means judges that a predetermined time has elapsed, the shutoff means is driven when the appliance is stopped to close the flow path. And a flow rate correcting means for detecting the flow rate by the flow rate detecting means and using the converted flow rate value as a correction value.

When the timer means for counting the time after the installation of the gas shut-off device has been periodically stopped after the elapse of a predetermined time, the flow rate is detected by the flow speed detecting means while the flow path is closed by the shut-off means, and the flow rate is converted. Is stored in the flow rate correction means as a flow rate correction value, so that the flow rate value obtained by the flow rate calculation means is corrected with the flow rate correction value, so that the flow rate is always zero or within a predetermined flow rate range (when the flow rate is zero) when the appliance is stopped. It is possible to accurately measure the flow rate, to prevent the accumulation of the use flow rate even when the appliance is stopped by mistake, and to monitor the user's gas use state by accurate flow rate measurement.

Further, in order to achieve the above object, the present invention provides a flow rate detecting means for measuring a signal propagation time in a medium and detecting a flow rate, a flow rate calculating means for converting a flow rate detected by the flow rate detecting means into a flow rate, Abnormality determining means for determining whether or not the flow rate value obtained by the flow rate calculating means is an abnormal usage amount; blocking means for blocking the medium flow path when the abnormality determining means determines that the flow rate is abnormal; and timer means for counting time. When the timer means determines that the predetermined time has elapsed, the shut-off means is driven when the appliance is in a stopped state, the flow path is closed, the flow rate is detected by the flow rate detection means and the converted flow value is used as a flow correction value, and the cut-off means is driven to drive the flow path. And a flow rate correction means for correcting the flow rate value obtained by detecting the flow rate by the flow rate detection means with the flow rate correction value and storing the flow rate correction value when the flow rate value is within a predetermined flow rate range.

When the timer means for counting the time after the installation of the gas shut-off device is at a predetermined time after the elapse of a predetermined time, the flow rate is detected by the flow speed detecting means while the flow path is closed by the shut-off means and the flow rate is converted. Is temporarily stored as a flow correction value, and then the shut-off means is driven to open the flow path, and the flow velocity is detected by the flow velocity detecting means to obtain a flow value, and the flow value is corrected with the temporarily stored flow correction value. If the flow rate is zero or within the predetermined flow rate range, it will be stored in the flow rate correction means as a new flow rate correction value. Alternatively, the flow rate is within the specified flow rate range (zero flow rate) and accurate flow rate measurement can be performed. It can be monitored in such a flow rate measurement.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. In FIGS. 1 and 2, components having the same functions as those in FIG.

(Embodiment 1) FIG. 1 shows a gas shut-off device according to Embodiment 1 of the present invention.
An ultrasonic signal is transmitted from one side to the other side between the upstream side vibrator 2 and the downstream side vibrator 3 opposed to the flow path 1 of the gas medium such as PG, and the flow velocity of the used gas is detected from the propagation time. As an example of the flow velocity detecting means 14, there is the following method. That is, the flow rate detecting means 14 includes the switching means 15 and the transmitting means 16.
, Receiving means 17, repetition means 18, and propagation time measuring means 19. The transmitting means 16 and the receiving means 17 are connected to the switching means 15, and the switching means 15
6 to the upstream oscillator 2 and the receiving means 17 to the downstream oscillator 3
Then, the connection destinations of the transmission means 16 and the reception means 17 are alternately switched such that the transmission means 16 is connected to the downstream transducer 3 and the reception means 17 is connected to the upstream transducer 2.
When the switching means 15 connects the receiving means 17 to the upstream vibrator 2 and the transmitting means 16 to the downstream vibrator 3 by the switching means 15, the ultrasonic signal transmitted from the transmitting means 16 is subjected to the upstream vibration. The signal is received from the transducer 2 via the flow path 1 and from the downstream transducer 3 by the receiving means 17. The transmission and reception of the ultrasonic signal are repeated, and the propagation time measuring means 19 measures the signal propagation time therebetween. Repeat the operation. The propagation time measuring means 19 measures and accumulates the time from transmission to reception of the ultrasonic signal. Next, the receiving means 17 is provided to the downstream vibrator 3 by the switching means 15 and the transmitting means 16 is provided to the upstream vibrator 2.
Are connected, and the above operation is repeated. The propagation time measuring means 19 obtains a propagation time difference from the propagation time initially received and obtained and the signal propagation time measured after switching by the switching means 15.

Numeral 20 denotes a flow velocity calculating means for calculating the flow velocity from the determined propagation time. Numeral 21 denotes a flow rate calculating means, which is obtained by converting a used medium amount, that is, a gas flow rate, from the flow velocity value obtained by the flow velocity calculating means 21. An abnormality determining means 22 determines whether or not the gas is used abnormally based on the gas usage amount obtained by the flow rate calculating means 21. For example, when the hose that supplies gas to the equipment used, such as a stove, is disconnected for any reason, the total flow cutoff value to monitor the abnormal large flow generated, or use much longer than the maximum use time of the equipment normally used The use time cut-off table that defines the use time limit corresponding to the case is stored in the abnormality determination unit 22 and monitors whether there is any corresponding abnormality.

Reference numeral 23 denotes a shut-off means. When an abnormality is judged from the abnormality judging means 22, a shut-off signal is output to shut off the gas flow path 1. Reference numeral 24 denotes timer means for counting the time and outputting a signal for periodically closing the flow path 1 and measuring a new flow rate correction value when a predetermined time has elapsed.

Numeral 25 is a flow rate correcting means. When a signal having passed a predetermined time from the timer means 24 is inputted, the flow path 1 is detected by the flow rate detecting means 14 by closing the flow path 1 by the shutoff means 23 and the flow rate value obtained by the flow rate calculating means 21 is calculated. It is stored as a flow rate correction value when the flow rate is zero. Reference numeral 26 denotes a notification unit. When the use state of the gas is determined to be abnormal by the abnormality determination unit 22 and the shut-off unit 23 is driven, the shut-off state and the details of the shut-down are displayed on a liquid crystal display element and the like, and the safety of the gas is monitored. Report to the center by telephone line.

Next, the operation of the above configuration will be described. When the gas shut-off device is installed and the gas appliance is not used, the flow velocity detecting means 14
The flow rate value converted by the flow rate calculating means 21 from the flow velocity value detected in the step (1) is zero or within a predetermined flow rate range (for example, less than ± 1.5 L / h). The flow rate correction value is measured in advance so that the flow rate becomes zero, stored in the flow rate correction means 25 so that the flow rate becomes zero or within a predetermined flow rate range, and the flow rate value converted by the flow rate calculation means 21 is corrected with the flow rate correction value. .

Here, when the gas is not used, for example, the flow rate calculation means 21 registers the used flow rate when the gas appliance is used.
When there is no registration, it is determined that there is no use of the appliance. However, due to various environmental conditions, temperature and humidity, etc., the flow value when the instrument is not used does not fall to zero flow rate or within the predetermined flow rate range as long as it is used over a long period of time. And deviates from a zero flow rate state or a predetermined flow rate range (for example, less than ± 1.5 L / h). Therefore, the flow rate correction value may be deviated from the previously determined flow rate correction value. Therefore, the timer means 24 counts the time, obtains a new flow rate correction value by the following method, and periodically updates the new flow rate correction value so as to fall within a predetermined flow rate range.

That is, the timer 24 counts the time, and when a predetermined time has elapsed, a signal for measuring a new flow correction value is output to the flow correction means 25. The timer means 24 sets an appropriate time in consideration of a temporal change due to environmental conditions such as temperature. After a lapse of a predetermined time, the flow rate is detected by the flow rate detection means 14 installed in the flow path 1 in the apparatus stopped state, converted into a flow rate value by the flow rate calculation means 21, and detected as a flow rate value within the predetermined flow rate range. More deviating flow values begin to be detected,
Alternatively, there is a case where the flow rate is gradually increased from the initial flow rate correction value when the flow rate is zero due to a temporal change or the like. Then, the blocking means 23 is driven to block the flow path 1. The flow rate correcting means 25 has the flow path 1 blocked by the blocking means 26 and enters a new flow rate correction value measurement state. Since the flow path 1 is closed by the shut-off means 23, the new flow rate correction value is measured in a state where no instrument is used and there is no flow rate. Next, the flow velocity is detected by the flow velocity detecting means 14, and is converted into a flow rate value by the flow rate calculating means 21. Here, the operation of an example of the flow velocity detecting means 14 will be described.

In a flow path (gas pipe) 1, an ultrasonic signal is transmitted and received between an obliquely installed upstream oscillator 2 and a downstream oscillator 3. The transmitting means 16 is connected to the upstream vibrator 2 by the switching means 15, while the downstream vibrator 3 is connected to the receiving means 17, and the signal transmitted from the transmitting means 16 is transmitted from the upstream vibrator 2 to the downstream vibrator. 3 is received. This operation is performed the number of times set by the repetition means 18. A so-called sing-around system is configured. The propagation time until the receiving means 17 receives the ultrasonic signal emitted from the transmitting means 16 is accumulated, and the time is obtained by the propagation time measuring means 19.

Next, the switching means 15 connects the transmitting means 16 to the downstream vibrator 3 and the receiving means 17 to the upstream vibrator 2. An ultrasonic signal is output from the transmitting means 16 and received by the receiving means 17 connected to the upstream transducer 2 via the flow path 1 via the downstream transducer 3. Repeating means 18 as described above
Perform the number of times set in. The propagation time until the receiving means 17 receives the ultrasonic signal emitted from the transmitting means 16 is accumulated by the propagation time measuring means 19, and the propagation time when the ultrasonic signal is emitted from upstream to downstream is further determined. The propagation time difference is obtained from the propagation time when the vehicle is fired upstream from. The flow velocity calculating means 21 converts the propagation time obtained by the propagation time measuring means 19 into a flow velocity value V, and then converts the flow velocity value V into a flow value Q by the flow calculating means 21. In FIG. 1, A indicates the direction in which the gas medium flows.

Normally, when the instrument is used, a difference in propagation time occurs, and the flow rate is obtained as follows. Flow velocity V, flow path cross-sectional area S, signal propagation distance L, angle θ between signal propagation direction and gas flow direction, ultrasonic signal propagation time t1 from upstream transducer 2 to downstream transducer 3, upstream from downstream transducer 3 Assuming that the signal propagation time to the vibrator 2 is t2, the flow value Q (L / h) is given by the following equation.

Q = V × S = (L / (2COSθ)) ×
(1 / t1-1 / t2) × S The flow rate value obtained by the above equation should be such that the propagation time difference at the time of stoppage of the appliance should be zero and the flow rate should be zero, or a flow rate within a predetermined flow rate range (for example, ± 1. Should be less than 5L / h)
It shifts due to environmental factors such as temperature. Then, the flow rate deviates from the original zero flow rate or a predetermined flow rate range. Then, the flow velocity is obtained by the flow velocity detecting means 14 in a state where the shut-off means 23 is driven and the flow path 1 is closed, and the flow velocity is converted into a flow value by the above equation. This flow rate value is stored in the flow rate correction means 25 as a new flow rate correction value. Thereafter, the flow rate calculating means 21 corrects the flow rate conversion using the stored flow rate correction value. That is, the flow rate was detected by the flow rate detecting means 14 and the flow rate value converted by the flow rate calculating means 21 was stored in the flow rate correcting means 25 in a state where the shutoff means 23 was driven to open the flow path 1 and the gas appliance was used as usual. Correct with the new flow rate correction value (the sign of the correction value is ± and there is addition correction or subtraction correction).

As a result, the flow rate value when the appliance is stopped is zero or within a predetermined flow range (defined as a zero flow range), and the flow rate can be measured accurately even when the appliance is used. The flow rate correction value is updated as a zero point correction value (zero point offset value) when the flow rate is zero, and is adjusted so that the flow rate always becomes zero. When a gas appliance is not used, a very small flow rate that is detected as a deviation is measured as if the appliance is being used. Accuracy is improved, and safety and usability are improved.

In this manner, the flow rate correction value can be obtained and updated and set so that the flow rate is adjusted to the zero flow state periodically by the timer means 27 after the gas shut-off device is installed. The flow rate is determined later and the total flow rate is cut off. Also, the gas flow rate is incorrectly measured when determining the time limit for shutting down the use time, and the gas is correctly used by the abnormality determination means 24 without setting a different time limit. You can monitor the status.

(Embodiment 2) FIG. 2 shows a gas shut-off device according to Embodiment 2 of the present invention. 2, components having the same functions as those in FIGS. 1 and 3 are denoted by the same reference numerals, and description thereof will be omitted.

In FIG. 2, reference numeral 27 denotes a flow rate correction temporary storage means.
When a predetermined time elapses from the timer means 24, a signal for calculating the flow value when the appliance is stopped is output, the shutoff means 23 is driven to close the flow path 1, the flow velocity is detected by the flow velocity detecting means 14, and the flow rate is calculated by the flow calculating means 21. The flow rate value thus temporarily stored is temporarily stored as a temporary flow rate correction value, and thereafter, the shut-off means 23 is driven and the flow path 1
The flow rate is detected by the flow rate detecting means 14 and the flow rate calculating means 2 is opened.
The flow rate is converted in step 1, and the converted flow rate value is corrected with a temporarily stored flow rate correction value. When it is confirmed that the flow rate is zero or within a predetermined flow rate range, the flow rate is output to the flow rate correction means 25 and stored as a new flow rate correction value.

Next, the operation of the above configuration will be described. When the gas shut-off device is installed and the gas appliance is not used, the flow velocity detecting means 14
The flow rate value converted by the flow rate calculating means 21 from the flow velocity value detected in the step (1) is zero or within a predetermined flow rate range (for example, less than ± 1.5 L / h). The flow rate correction value is measured in advance so that the flow rate becomes zero, stored in the flow rate correction means 25 so that the flow rate becomes zero or within a predetermined flow rate range, and the flow rate value converted into the flow rate calculation means 21 is corrected by the flow rate correction value. Here, when the gas is not used, for example, the flow rate calculating means 21 registers the used flow rate when the gas appliance is used, but when no gas is used, it is determined that the appliance is not used.

However, due to various environmental conditions, temperature, humidity, and the like, the flow rate value when the instrument is not used does not fall to zero flow rate or within a predetermined flow rate range as long as it is used over a long period of time. Indicates the flow rate value, zero flow rate or predetermined flow rate range (for example, less than ± 1.5 L / h)
Deviate more. Therefore, the flow rate correction value may be deviated from the previously determined flow rate correction value. Therefore, the timer means 24 counts the time, obtains a new flow rate correction value by the following method, and periodically updates the new flow rate correction value so as to fall within a predetermined flow rate range.

That is, when the time is counted by the timer means 24 and a predetermined time has elapsed, a signal for measuring the new flow rate correction value is outputted to the flow rate correction means 25 and the flow rate correction temporary storage means 27. The timer means 24 sets an appropriate time in consideration of a temporal change due to environmental conditions such as temperature. After a lapse of a predetermined time, the flow rate is detected by the flow rate detection means 14 installed in the flow path 1 in the apparatus stopped state, converted into a flow rate value by the flow rate calculation means 21, and detected as a flow rate value within the predetermined flow rate range. In some cases, a flow value that deviates from the initial value may be detected, or may gradually increase from the initial flow correction value at zero flow due to a change with time, for example, from the deviation width. Then, the blocking means 23 is driven to block and close the flow path 1. The flow rate correction means 25 and the flow rate correction temporary storage means 27 enter a new flow rate correction value measurement state when the timer means 24 counts the time and a predetermined time elapses. At the time of measuring the new flow rate correction value, the flow rate is detected by the flow rate detecting means 14 in a state where the flow path 1 is closed by the shut-off means 23 and the instrument is not used, and there is no flow rate completely. A flow correction value is measured. Here, the operation of an example of the flow velocity detecting means 14 will be described.

In a flow path (gas pipe) 1, an ultrasonic signal is transmitted and received between an upstream oscillator 2 and a downstream oscillator 3 installed obliquely. The transmitting means 16 is connected to the upstream vibrator 2 by the switching means 15, while the downstream vibrator 3 is connected to the receiving means 17, and the signal transmitted from the transmitting means 16 is transmitted from the upstream vibrator 2 to the downstream vibrator. 3 is received. This operation is performed the number of times set by the repetition means 18. A so-called sing-around system is configured. The propagation time until the receiving means 17 receives the ultrasonic signal emitted from the transmitting means 16 is accumulated, and the time is obtained by the propagation time measuring means 19.

Next, the switching means 15 connects the transmitting means 16 to the downstream vibrator 3 and the receiving means 17 to the upstream vibrator 2. An ultrasonic signal is output from the transmitting means 16 and received by the receiving means 17 connected to the upstream transducer 2 via the flow path 1 via the downstream transducer 3. Repeating means 18 as described above
Perform the number of times set in. The propagation time until the receiving means 17 receives the ultrasonic signal emitted from the transmitting means 16 is accumulated by the propagation time measuring means 19, and the propagation time when the ultrasonic signal is emitted from upstream to downstream is further determined. The propagation time difference is obtained from the propagation time when the vehicle is fired upstream from. The flow velocity calculating means 21 converts the propagation time obtained by the propagation time measuring means 19 into a flow velocity value V, and then converts the flow velocity value V into a flow value Q by the flow calculating means 21. In FIG. 2, A indicates the direction in which the gas medium flows.

Normally, when the instrument is used, a difference in propagation time occurs, and the flow rate is obtained as follows. Flow velocity V, flow path cross-sectional area S, signal propagation distance L, angle θ between signal propagation direction and gas flow direction, ultrasonic signal propagation time t1 from upstream transducer 2 to downstream transducer 3, upstream from downstream transducer 3 Assuming that the signal propagation time to the vibrator 2 is t2, the flow value Q (L / h) is given by the following equation.

Q = V × S = (L / (2COSθ)) ×
(1 / t1-1 / t2) × S The flow rate value obtained by the above equation should be such that the propagation time difference at the time of stoppage of the appliance should be zero and the flow rate should be zero, or a flow rate within a predetermined flow rate range (for example, ± 1. Should be less than 5L / h)
It shifts due to environmental factors such as temperature. Then, the flow rate deviates from the original zero flow rate or a predetermined flow rate range. Then, the flow velocity is obtained by the flow velocity detecting means 14 in a state where the shut-off means 23 is driven and the flow path 1 is closed, and the flow velocity is converted into a flow value by the above equation. This flow value is stored in the flow correction temporary storage means 27 as a temporary flow correction value. Next, the blocking means 23 is driven to open the flow path 1. The flow velocity is detected by the flow velocity detecting means 14 and the flow rate calculating means 2 is detected.
The flow rate is converted to a flow rate value in step 1 and further corrected with the temporary flow rate correction value stored in the flow rate correction temporary storage means 27 to check whether the flow rate is zero or falls within a predetermined flow rate range. That is, in order to obtain a new flow rate correction value, the flow rate and the flow rate were obtained in a state where the shut-off means 23 was driven and the flow path 1 was closed, but when the gas appliance was used by mistake during this time, an incorrect flow rate value was obtained. In order to prevent the flow rate from being measured and stored as a flow rate correction value, the flow rate is once stored as a temporary flow rate correction value, the flow path 1 is opened again, the flow rate is detected by the flow rate detecting means 14, and the flow rate value is obtained. Correct and confirm that the flow rate is exactly zero.

After confirming that the flow rate is in the zero flow state or within a predetermined flow rate range (for example, less than ± 1.5 L / h), the flow rate calculating means 21 corrects the flow rate conversion using the stored flow rate correction value. That is, in a state where the gas appliance can be used as usual, the flow velocity is detected by the flow velocity detecting means 14 and the flow rate value converted by the flow rate calculating means 21 is confirmed to be within a predetermined flow rate range, and stored in the flow rate correction temporary storage means 27. The flow rate correction value is stored in the flow rate correction means 25 as a new flow rate correction value (the sign of the correction value is ±, there is addition correction or subtraction correction), and this correction value is used thereafter.

As a result, the flow value when the appliance is stopped is zero flow or within a predetermined flow range (defined as the zero flow range), and the flow can be accurately measured even when the appliance is used. The flow rate correction value is updated as a zero point correction value (zero point offset value) when the flow rate is zero, and is adjusted so that the flow rate always becomes zero. When a gas appliance is not used, a very small flow rate that is detected as a deviation is measured as if the appliance is being used. Accuracy is improved, and safety and usability are improved.

In this way, after the gas shut-off device is installed, the flow rate correction value can be obtained and updated and set so that the flow rate is adjusted to the zero flow state by the timer means 27 at regular intervals. The flow rate is incorrectly determined as the flow rate and the total flow rate is cut off. Also, the gas flow rate is erroneously measured when determining the time limit for shutting off the use time, and the gas is correctly used by the abnormality determination means 24 without setting a different time limit. You can monitor the status.

[0039]

As is apparent from the above description, according to the first aspect of the present invention, the time is counted by the timer means, and the shut-off means is driven with the equipment stopped periodically at predetermined time intervals to close the flow path. Calculates the flow rate by driving the flow rate detecting means, further converts it into a flow rate value by the flow rate calculating means, stores the value in the flow rate correcting means, and thereafter opens the shut-off means to measure the flow rate in a normal gas appliance use state. The flow rate is detected by the flow rate calculation means, the flow rate value is converted, and the flow rate is corrected by the new flow rate correction value of the flow rate correction means, so that the flow rate detected when the gas appliance is not used is as if the appliance is used. There is no mistaken accumulation of gas usage, and no false warning is displayed as gas is leaking. Usage time The gas flow rate is incorrectly measured when determining the cutoff time limit, and the gas use condition can be monitored accurately by the abnormality determination means without setting a different time limit.The flow rate measurement accuracy is greatly improved, and safety and usability are improved. The effect is improved.

According to the second aspect of the present invention, the time is counted by the timer means, and the appliance is periodically stopped every predetermined time.
In the state where the shut-off means is driven and the flow path is closed, the flow velocity detecting means is driven to obtain the flow velocity, further converted to a flow rate value by the flow rate calculation means, the value is temporarily stored as a flow rate correction value, and the shut-off means is driven again to drive the flow path. The flow rate is detected by the flow rate detecting means, the flow rate value is obtained by the flow rate calculating means, and the flow rate is corrected by the temporarily stored flow rate correction value.
Then, as a result, it is confirmed that the flow rate value is in the zero flow state or within the predetermined flow rate range, and stored and updated as a new flow rate correction value in the flow rate correction means as a new flow rate correction value. It is possible to prevent a gas appliance from being used by mistake while the correction value is being calculated and storing an abnormal flow rate correction value. Then, when measuring the flow rate while the gas appliance is in use, the flow rate is detected by the flow rate detection means, the flow rate value is converted by the flow rate calculation means, and the flow rate is corrected by the flow rate correction value of the flow rate correction means. Incorrect monitoring of gas equipment usage status is possible without incorrectly accumulating the gas usage as if the equipment is being used, or incorrectly displaying a warning that gas is leaking as if the equipment was used. It is possible to determine the total flow shutoff by erroneously determining that the flow rate is abnormal and to determine the total flow cutoff. Can monitor the usage of gas,
There is an effect that the flow rate measurement accuracy is extremely improved and safety and usability are improved.

[Brief description of the drawings]

FIG. 1 is a control block diagram of a gas shutoff device according to a first embodiment of the present invention.

FIG. 2 is a control block diagram of a gas cutoff device according to a second embodiment of the present invention.

FIG. 3 is a control block diagram of a conventional gas shut-off device.

[Explanation of symbols]

 14 Flow rate detecting means 21 Flow rate calculating means 22 Abnormality judging means 23 Interrupting means 24 Timer means 25 Flow rate correcting means 27 Flow rate correcting temporary storage means

Claims (2)

[Claims] 1. Flow rate detecting means for measuring a signal propagation time in a medium to detect a flow rate, flow rate calculating means for converting a flow rate detected by the flow rate detecting means into a flow rate, and a flow rate value obtained by the flow rate calculating means. Abnormality determination means for determining whether or not is an abnormal use amount, a disconnection means for disconnecting the medium flow path when the abnormality determination means determines that there is an abnormality, a timer means for counting time, and the timer means determines whether a predetermined time has elapsed. And a flow rate correction means for driving the shutoff means when the appliance is stopped, closing the flow path, detecting the flow velocity by the flow velocity detection means, and using a converted flow value as a correction value. 2. A flow rate detecting means for measuring a signal propagation time in a medium and detecting a flow rate, a flow rate calculating means for converting a flow rate detected by the flow rate detecting means into a flow rate, and a flow rate value obtained by the flow rate calculating means. Abnormality determination means for determining whether or not is an abnormal use amount, a disconnection means for disconnecting the medium flow path when the abnormality determination means determines that there is an abnormality, a timer means for counting time, and the timer means determines whether a predetermined time has elapsed. When the instrument is stopped, the shutoff means is driven to close the flow path, the flow rate is detected by the flow rate detection means, and the converted flow rate is used as a flow rate correction value.The shutoff means is driven to open the flow path, and the flow rate is detected by the flow rate detection means. A gas shut-off device comprising: a flow rate correction unit that corrects a detected and obtained flow rate value with the flow rate correction value and stores the flow rate correction value when the flow rate value is within a predetermined flow rate range.