JP5317816B2 - Gas shut-off device - Google Patents

Description

  The present invention relates to an erroneous measurement or error caused by malfunction of electronic components or the like when rainwater or the like is submerged in the gas shutoff device for some reason, or the flow path inside the gas shutoff device is submerged. The present invention relates to a gas shut-off device that prevents shut-off.

  Conventionally, as this type of gas shut-off device, there has been one as shown in FIG. 5, FIG. 6, or FIG. 7 (see, for example, Patent Documents 1 and 2).

  The configuration of the gas cutoff device of Patent Document 1 will be described with reference to FIG. FIG. 5 shows the gas conduit path and gas shut-off device for supplying gas to the home.

  The gas conduit is connected to the gas main pipe 100, the branch pipe 102, the valve tee 103 that connects the branch pipe 102 in communication with the gas main pipe 100, the pipe joint 104, and the branch pipe 102 near the gas supply opening / closing valve 105. The gas shut-off device 106 is included. In the gas conduit, the branch pipe 102 is generally made of a thin material. Therefore, when the flowing water leaked from the water pipe collides in a state containing sand, the pipe wall of the branch pipe 102 erodes the flowing water containing the sand. It may be perforated by the action (sandblast phenomenon).

  The pipe joint 104 is connected so as to externally fit the branch pipe 102 and the branch pipe portion of the valve tee 103. Therefore, the pipe joint 104 forms an enlarged diameter portion on its inner surface. A water-swelling material 107 is disposed in the enlarged diameter portion of the pipe joint 104. The water-swelling material 107 is formed into a spherical shape by mixing a polyurethane part, a polyacrylate high water-absorbing polymer as a highly water-repellent resin, and an aqueous solution of MOCA (methylene-bis-orthochloraniline) as a curing agent. It is a thing.

  In FIG. 5, the water-swelling material 107 that has not yet absorbed water is indicated by a solid-line circle. The water-swelling material 107 that has absorbed water and caused volume expansion and is in close contact with the expanded portion of the pipe joint 104. Is indicated by a broken-line circle. In the state of the broken line, when water enters the gas main pipe 1, the flow path of the gas and the intruding water is blocked by the water swelling material 107. One end of a metal wire 107a that is plastic enough to pass through the bent portion of the branch pipe 102 is inserted into the water swelling material 107, and the other end 107b is connected to the vicinity of the gas opening / closing valve 5. ing.

  On the other hand, the above example is a case where the inside of the gas conduit connected to the gas shut-off device is submerged, but the inside of the gas shut-off device, that is, the outside of the flow rate measuring unit built inside the gas shut-off device is submerged with rainwater, etc. Will be described with reference to FIGS.

  6 shows a front view of the gas shut-off device 108 and the adapter 109, and FIG. 6 is a cross-sectional view seen from the side thereof. The adapter 109 has a control circuit 110 mounted on the gas cutoff device 108 and is detachable from the gas cutoff device 108.

  The gas shut-off device 108 includes a gas inlet 108a and a supply port 108b that supplies gas to an instrument that uses the gas. Measuring means for measuring the gas flow rate is provided inside the gas shut-off device 108, and the gas flow rate that flows in from the inlet 108a and is supplied from the supply port 108b is measured. Display means 108c is provided in front of the gas shut-off device 108, and an integrated value of the gas usage is displayed. In addition, a shut-off valve for shutting off the gas supply at the time of detecting an abnormality is provided, and a return operation unit 108d for returning from the shut-off state in which an abnormality is detected and the gas supply is stopped is provided. When the terminal cover 108e is removed, a connection terminal 108j having a communication terminal to which a communication device can be connected appears. When a control circuit 110 capable of adding a predetermined function is connected to the gas shut-off device 108, various functions, for example, a function of performing wireless communication with a communication device, or a function of storing a gas usage amount at a predetermined time from a predetermined date and time Etc.

  As shown in FIG. 7, the adapter 109 has a box-like shape, and is composed of a case body 109b, an outer lid 109c, and an inner lid 109d. The control circuit 110 is housed in this case, and the adapter unit 109 is configured.

  The case main body 109b has a part of the side surface as an opening, from which the control circuit 110 is accommodated. The inner lid portion 109d covers the opening of the case main body portion 109b and is detachable. The outer lid portion 109c further covers the inner lid portion 109d and can be removed. As shown in FIG. 6, a concave portion 109e is provided at the lower portion of the case main body portion 109b, and a convex portion 109f corresponding to the lower portion of the inner lid portion 109d is provided and fitted. And it fixes with the fixing member (screw etc.) 109a. A sealing member (O-ring or the like) 109g is sealed between the case main body 109b and the inner lid 109d to prevent rainwater from entering the case main body 109b.

  A wiring hole 109h through which the wiring 108h of the control circuit 110 is drawn out is provided in the inner lid portion 109d. The wiring 108h passes from the control circuit 110 through the wiring hole 109h of the inner lid portion 109d, and further has a wiring hole with a wiring seal member 109j on the upper part of the adapter. It passes through the wiring hole 108k provided in the lower part of the gas cutoff device 108 through 109k, and is further connected to the connection terminal 108j provided in the control circuit 108g for gas cutoff device. The wiring 108h that connects the control circuit 110 and the connection terminal 108j is drawn from the upper part of the adapter 109. By attaching the terminal lid 108e to the gas cutoff device 108 with the fixing member 108f, the wiring 108h is accommodated in the gas cutoff device 108. The structure is not exposed to the outside.

JP-A-9-166263

JP 2005-61864 A

  However, in the above conventional configuration, when the gas main pipe and the water pipe are installed in parallel, a hole on the pinhole is formed in the water pipe for some reason, and the high pressure water is ejected together with the earth and sand around the gas conduit. In this case, there is a case where water enters the gas conduit due to sandblasting phenomenon, etc., but when it enters from the branch pipe, water can easily enter the gas shut-off device side, or water infiltration can be prevented with a water swelling material. Attempts to intrude through the gap due to pressure may result, but if water enters the gas shut-off device as a result, water may accumulate in the measurement channel. In addition, when installing, the construction staff inadvertently connects the wiring from the communication device, alarm device or control device. After opening the terminal cover on the front and connecting it, when fixing the terminal cover with the fixing member, fix the two places. Only one place should be fixed, a gap is created between the terminal cover and the gas shut-off device, rainwater enters, water accumulates in the gas shut-off device body, and rainwater enters the adapter through the wiring hole. The control device may become flooded. If the inside of the gas shut-off device and the inside of the built-in flow path is submerged, the flow rate may be mistakenly measured, or a safety judgment may be made and the gas passage may be shut off. However, there is a problem in terms of safety that security cannot be ensured in case of emergency.

  The present invention solves the above-mentioned problem, and if there is a flood in the gas shut-off device and the flow path built in the gas shut-off device due to some trouble, it is detected at an early stage and sent to the gas company's center. It is intended to provide a highly safe gas shut-off device for reporting or stopping gas supply to ensure safety.

  In order to solve the above-described conventional problems, the gas cutoff device of the present invention includes a flow path, a blocking means for blocking the gas flowing through the flow path, a vibrator pair disposed along the flow path, and the vibration. Comprising a control means for calculating the flow rate of the gas based on the propagation time of the ultrasonic wave between the child pairs and shutting off the gas by the shut-off means at the time of abnormality, the control means includes a flow rate detection means for detecting the flow rate, A flow rate calculation means for converting an instantaneous flow rate value from a detection value of the flow rate detection means, an amplification degree determination means for determining a signal amplification level adjusted by the flow rate detection means, and an upper limit determination of the amplification level adjusted by the flow rate detection means Stable when it is detected that the flow rate obtained by the flow rate calculation means and the amplification time setting means for setting the value and the lower limit judgment value, the propagation time judgment means for judging the propagation time detected by the flow rate detection means, and the flow rate calculation means are changed. Flow rate value obtained A measurement condition setting means for changing the setting to the measurement condition, and a flow that is estimated to be inundated in the flow path when the propagation time determination means determines that the propagation time determination means has an amplification degree that is equal to or lower than the lower limit determination value by the amplification degree determination means. In-road abnormality determination means, time measuring means that is activated when it is determined that the amplification degree determination means is equal to or greater than the upper limit determination value, and a measurement condition that is set to a maximum measurement condition that stabilizes flow rate fluctuations during time measurement by the time measurement means A measurement ratio calculating means for obtaining a ratio; an impedance estimating means for estimating that the impedance between terminals of the flow rate detecting means is abnormal when the amplification ratio determining means is equal to or higher than an upper limit determination value and the measurement ratio is equal to or greater than a predetermined value; Means for calculating an average flow rate from the instantaneous flow rate determined by the means, and an abnormality determination unit for determining presence / absence of abnormality from the obtained average flow rate. Abnormality determination established by the impedance estimating means or the abnormality determining means, in which a structure for interrupting the supply of gas by the blocking means.

  According to the above-described invention, when the inside of the gas shut-off device or the inside of the flow passage built in the gas shut-off device is submerged for some reason, first, if the inside of the flow passage is submerged, the propagation time of the ultrasonic signal at the time of detecting the flow rate is shortened. In order to measure the signal of the submerged flow path, if the degree of amplification judged by the amplification degree judging means is detected to be small, it is judged as abnormal in the flow path and a shut-off signal is output. In case of inundation due to, for example, the amplitude of the flow rate detection signal is small, the degree of amplification is high, and if the flow rate value detected by the flow rate detection means is fluctuating, measurement to cope with fluctuations is required to stably measure the flow rate. Although it is changed to the condition, if it is determined that the setting ratio to the measurement condition corresponding to the fluctuation is equal to or greater than the predetermined amplification degree, it is estimated that the impedance between the terminals of the flow rate detecting means is abnormally lowered for some reason, and a cutoff signal is output Ga Internal blocking device, and internal organs can determine the internal flow measurement means and flooded condition, abnormal flow rate measurement state can be prevented that continues, and safety is high.

  The gas shut-off device of the present invention correctly detects the abnormal state when water or the like enters the built-in flow rate measuring unit for any reason, or when rain water or the like enters the gas shut-off device. Since the gas supply to is stopped, it is possible to prevent the gas shut-off device from being continuously monitored even if the gas shut-off device cannot be monitored in a safe and normal state when the gas consumer uses the appliance.

1 is a schematic structural diagram of a gas cutoff device in Embodiment 1 of the present invention. Control block diagram of the gas shutoff device The graph which shows the experimental data 1 in the same gas shut-off device Graph showing experimental data 2 in the gas shutoff device Sectional drawing of the conventional first gas cutoff device Front view of a conventional second gas shut-off device Sectional view of the conventional gas shut-off device

  The present invention relates to a gas flow based on a flow path, a blocking means for blocking gas flowing in the flow path, a transducer pair disposed along the flow path, and an ultrasonic wave propagation time between the transducer pair. And a control means for shutting off the gas by the shut-off means in the event of an abnormality, and the computing unit converts the instantaneous flow rate value from the detected value of the flow rate detecting means and the flow rate detecting means. Flow rate calculation means, amplification degree determination means for determining the signal amplification degree adjusted by the flow rate detection means, amplification degree setting means for setting the upper limit determination value and the lower limit determination value of the amplification degree adjusted by the flow rate detection means, A measurement condition setting for changing the setting to a measurement condition for obtaining a stable flow rate value when a change in the flow rate obtained by the flow rate calculation means is detected and a propagation time determination means for determining the propagation time detected by the flow rate detection means Means and said increase When the degree of amplification is less than the lower limit judgment value by the degree determination means and when the propagation time judgment means determines that the propagation time is abnormally short, the abnormality determination means in the flow path that estimates that the inflow in the flow path is inundated, and the upper limit by the amplification degree determination means Time measuring means that is activated when it is determined that the determination value is equal to or greater than a determination value, a measurement ratio calculating means that obtains a measurement condition ratio that is set to a maximum measurement condition that stabilizes flow rate fluctuation during time measurement by the time measuring means, and the amplification degree determining means When the measurement ratio is equal to or greater than the upper limit determination value, the impedance estimation means for estimating that the impedance between the terminals of the flow rate detection means is abnormal, and the average flow rate calculation for obtaining the average flow rate from the instantaneous flow rate obtained by the flow rate calculation unit Means and an abnormality determining means for determining the presence or absence of abnormality from the obtained average flow rate, the abnormality determining means in the flow path or the impedance estimating means or the abnormality determining means Time in the abnormality determination establishment, in which a structure for interrupting the supply of gas by the blocking means.

  When the flow rate signal is detected by the flow rate detection means, it is amplified if the signal is small, and when the flow rate value fluctuates, it is changed to a measurement condition corresponding to fluctuation in order to perform stable measurement. It is estimated that the impedance between the terminals of the terminal has decreased for some reason, and it is determined that the outside of the flow rate detection means has become inundated due to the intrusion of rainwater, etc. If it begins to enter the flow channel with the means, the signal of the flow rate detection means becomes more unstable and the amplification degree becomes higher, and when the amount of inundation increases, it becomes smaller, and the propagation time that is the flow rate measurement signal is normal gas. Unlike the inside, the flow rate detection means starts to detect abnormal flow fluctuations, but if such a change is detected by the flow path abnormality determination means, it is determined that there is an abnormality in the flow path and the gas supply to the gas appliance is stopped. Since stop, it can be prevented from becoming unsafe by stopping an abnormal flow rate measurement state to continue, and reliable.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
1 is a diagram showing a schematic structural diagram of a gas shut-off device according to Embodiment 1 of the present invention, FIG. 2 is a control block diagram of a control device mounted on the gas shut-off device, and FIGS. 3 and 4 are experimental results. .

  In FIG. 1, the gas shut-off device 1 is installed in each home and the like, and after passing through the gas shut-off device 1, is piped to a place where various gas appliances used in each home are installed, and gas is supplied. The internal structure of the gas cutoff device 1 includes a flow path 4 and a control device 5. The flow path 4 is connected to the supply port 1b via the inlet side flow path 4a from the inlet 1a of the gas shut-off device 1, the flow path 4b at the bottom, and the outlet side flow path 4c. An upstream vibrator 6 and a downstream vibrator 7 for transmitting and receiving ultrasonic signals are attached to the flow path 4 so as to oppose the flow direction. Each of the upstream vibrator 6 and the downstream vibrator 7 has terminals 6 a and 7 a connected to the control device 5.

  FIG. 2 is a control block diagram of the control device. The flow rate detecting means 8 comprises an upstream vibrator 6, a downstream vibrator 7, a switching means 9, a transmitting means 10, a receiving means 11, a propagation time measuring means 12, an amplitude determining means 13, and an amplification degree adjusting means 14. The switching means 9 can switch the transmission / reception of the upstream vibrator 6 for transmitting or receiving ultrasonic waves and the downstream vibrator 7 for receiving or transmitting ultrasonic waves. Transmitting means 10 for outputting an ultrasonic signal is connected to the upstream vibrator 6 or the downstream vibrator 7, and the ultrasonic signal is received by the switching means 9 via the upstream vibrator 6 or the downstream vibrator 7. 11 to receive. First, ultrasonic waves are transmitted from upstream to downstream. An ultrasonic signal is transmitted by the transmitting means 10 and received by the downstream vibrator 7, and a propagation time is measured by the propagation time measuring means 12 for the received signal from the receiving means 11.

  Next, an ultrasonic signal is transmitted from the downstream to the upstream by the switching means 9, and the propagation time is measured. Then, the ultrasonic wave propagation time difference between the upstream vibrator 6 and the downstream vibrator 7 is obtained every predetermined period (for example, 2 seconds). The ultrasonic signal received by the receiving unit 11 is determined by the amplitude determining unit 13 as to whether the amplitude level is an appropriate magnitude. When the ultrasonic signal deviates from the appropriate range, the amplification degree adjusting means 14 is set so as to be in an appropriate size range. Adjust with. An ultrasonic signal is transmitted from the transmission means 10 at the time of next measurement with the adjusted amplification degree. The amplification degree adjusting means 14 can control the amplification degree within a gain value range of 1 to 100 so that the peak voltage of the received wave becomes, for example, about 500 mV.

  Then, the propagation time obtained by measuring every predetermined cycle is converted into an instantaneous flow rate value by the flow rate calculation means 15. The measurement condition setting means 16 determines the flow state in the flow path 4 from the obtained fluctuation state of the instantaneous flow rate, and changes the measurement conditions such as the number of times of measurement and the measurement cycle so as to always measure a stable flow rate. To control. For example, the flow rate of gas gas flowing through the flow path changes due to pressure fluctuations, etc., but the flow rate value changes, but there are multiple measurement conditions that can measure the flow rate throughout the flow rate change period, and the flow rate change according to the pressure fluctuation level is stable. The measurement conditions can be changed step by step so that the measurement can be performed in an automated manner. The instantaneous flow rate value is input to the average flow rate calculation means 17, and a predetermined number of instantaneous flow rate values are collected and calculated as an average flow rate value.

  The amplitude level of the ultrasonic signal detected by the receiving means 11 of the flow rate detecting means 8 is adjusted by the amplification degree adjusting means 14, and the adjusted amplification degree is monitored by the amplification degree judging means 18. The amplification degree determination means 18 is determined based on the upper limit determination value and the lower limit determination value of the amplification degree set by the amplification degree setting means 19. For example, when the flow rate is increased, the ultrasonic signal reception sensitivity is decreased and the amplitude level is decreased, so that the amplification degree tends to be largely controlled. In a state where the flow rate is low, the amplification degree may be smaller than that of the large flow rate. However, when the amplification degree of the amplification degree determination means 18 is a predetermined value or more at a low flow rate, the abnormality detection of the flow rate detection means 8 is performed.

  The propagation time measured by the propagation time measuring means 12 of the flow rate detecting means 8 is determined by the propagation time determining means 20. The upper limit value or lower limit value of the propagation time obtained from the propagation velocity in the fluid to be used is set in advance in the propagation time monitoring value setting means 21, and the propagation time value measured by the propagation time measuring means 12 is used. It is determined whether or not the measured value is medium. Further, the amplification degree of the amplification degree determination means 18 and the propagation time value of the propagation time determination means 20 are determined by the in-flow path abnormality determination means 22.

  For some reason, for example, a water pipe or the like is provided near the gas pipe in the pipe flow path (not shown) of the gas shut-off device 1, and water leakage such as a joint hits the gas pipe, so-called sandblast phenomenon occurs and enters the gas pipe. There is a case. When the intrusion water enters the flow path in which the upstream vibrator 6 and the downstream vibrator 7 of the flow rate detecting means 8 of the gas cutoff device 1 are installed facing each other, the ultrasonic signal is reflected on the water surface or the like. Reception sensitivity changes, and the detection signal level of the flow rate detection means 8 fluctuates.

  For example, when the flow path is gradually submerged, a route through the water and a route through the gas is created, and the propagation speed of the ultrasonic signal is different, and reaches the upstream transducer 6 or the downstream transducer 7 on the receiving side. The time varies and the received signal level decreases, and as a result, the amplification level adjusting means 14 increases the amplification level in an attempt to increase the signal level. Also, if the flow path is largely submerged, it can be detected at the received signal level due to underwater propagation, and if the upstream vibrator 6 or the downstream vibrator 7 of the flow rate detecting means 8 is under water, the reception sensitivity is increased. The signal amplitude level is increased, and the amplification degree adjusting means 14 controls the amplification degree to be smaller. As a result, it is determined that the amplification degree determining means 18 is smaller than the amplification lower limit determination value. Estimate that the channel is flooded and output a shutoff signal.

  Next, when the flow path 4 in which the upstream side vibrator 6 or the downstream side vibrator 7 of the control device 5 or the flow rate detecting means 8 inside the gas shut-off device 1 is installed, particularly the outside of the flow path 4b at the bottom, is submerged, Since the upstream vibrator 6 and the downstream vibrator are submerged, the impedance between the terminals is lowered, the reception detection signal level of the receiving means 11 is reduced, and the amplification degree is largely controlled by the amplification degree adjusting means 14. When the amplification degree determination means 18 exceeds the amplification degree upper limit determination value set by the amplification degree setting means 19, the timing means 23 starts to start. When the impedance between the terminals of the upstream vibrator 6 and the downstream vibrator 7 is lowered, the received signal level is likely to be affected by noise, and as a result, the instantaneous flow rate is fluctuated. The measurement condition setting means 16 changes the setting of a plurality of measurement conditions according to the flow rate fluctuation level. GHP (gas heat pump type air conditioner) that causes so-called pressure fluctuation is used to measure the entire fluctuation cycle of the flow velocity signal by changing the measurement conditions such as the number of measurements and the measurement cycle, and so that the flow rate can always be measured stably at the flow velocity. As a result, the measurement conditions change. While measuring the predetermined time by the time measuring means 23, the measurement ratio calculating means 24 counts the number of times the measurement condition setting means 16 measures with the maximum set value and the number of times with the other set values, and sets the maximum set value. Calculate the ratio of the number of measurements at. When the impedance estimation means 25 detects that this ratio is greater than or equal to a predetermined value, the flow path 4 is submerged for some reason, determines that it is in an abnormal state (impedance is abnormal), and outputs a cutoff signal.

  Furthermore, the abnormality determination means 26 monitors the equipment used at the obtained average flow rate. The abnormality determination means 26 stores a time limit value for use time corresponding to each flow rate region, a monitor determination value for the maximum use flow rate, or the like. For example, when the hose that supplies gas to a stove or the like is disconnected for some reason, an abnormally large flow rate is generated, but the total flow cutoff value for monitoring such a condition and the maximum use time of the appliance normally Stored is a time limit for safety duration cut-off that defines a time limit for use time corresponding to the case of using for a much longer time. By comparing and determining the set value and the average flow rate value by the abnormality determining means 26, the flow rate value does not exceed the maximum use flow rate value, or the use time of the appliance is set to the continuous use time limit corresponding to the registered flow rate. Monitor whether it has exceeded.

  When the abnormality determining means 26 determines that an abnormality is established, or when the abnormality determining means 22 in the flow path is determined to be abnormal, or when the impedance estimating means 25 determines that the flow rate detecting means 8 is abnormal due to water for some reason, shut off. A cutoff signal is sent to the means 27 to stop the gas supply. Further, the notification means 28 displays the shut-off state and shut-off content on a liquid crystal display element or the like, and notifies the center of the gas company that is monitoring the safety of the gas by communication such as a telephone line.

  Next, operation | movement of the structure of the above gas cutoff apparatus 1 is demonstrated. The gas company installs the gas shut-off device 1 at the gas customer's home, opens the terminal lid 1e, connects the communication device, alarm device (not shown), etc., and then attaches the terminal lid 1e to the fixing member 1f (screw etc.) It is fixed with. In addition, a gas pipe (not shown) to the gas shut-off device 1 may be provided near the water pipe or the like. For some reason, a high-pressure water leak from a joint or the like hits the gas pipe in the ground together with the surrounding earth and sand for a long period of time, so-called sand blasting phenomenon may occur, causing a hole in the gas pipe and water intrusion into the gas pipe. When the intruded water enters the flow path where the upstream vibrator 6 and the downstream vibrator 7 of the flow rate detecting means 8 of the gas shut-off device 1 are opposed to each other, the flow rate is detected in the flooded state. To detect.

  Alternatively, after connecting the wiring or communication line of the alarm device, the terminal lid 1e is fixed and a gap is generated. After that, rainwater enters the gas shut-off device from the gap, and the flow path 4, particularly the flow path 4b at the bottom is formed. May be submerged.

  When water in the pipe reaches the gas shut-off device 1 due to repeated evaporation and condensation due to sandblasting or the like, and accumulates in the flow path 4 at the bottom and enters a water-impregnated state, it is between the upstream vibrator 6 and the downstream vibrator 7. When the flow path is submerged to some extent, there can be a route through which the ultrasonic signal during flow measurement passes through water or a gas. When the amount of water is small, the signal level is disturbed due to reflection or the like when the ultrasonic wave propagates, the signal level detected by the receiving unit 11 is reduced, the signal level is determined by the amplitude determining unit 13, and the amplitude level is set to the optimum level. Therefore, the amplification degree adjusting means 14 increases the amplification degree in the direction of increasing the signal level. If the state exceeding the upper limit value of the amplification degree setting means 19 continues, the abnormality determination means 22 in the flow path determines an abnormality, outputs a blocking signal to the blocking means 27, and displays an abnormality in the notification means 28. However, if the state exceeding the upper limit value does not continue or continues with an amplification degree less than the upper limit value, and the amount of inundation gradually increases during that time, the flow rate is detected with an ultrasonic signal due to underwater propagation in the flow path 4. The detection value of the propagation time of the ultrasonic signal measured by the flow rate detection means 8 differs depending on the route taken. The propagation speed of the ultrasonic signal is about 1500 m / s faster in water than in gas, so it is received earlier and the propagation time is shorter than in gas propagation. When the ultrasonic wave is received through the underwater route of the flow path 4, the reception sensitivity of the upstream transducer 6 or the downstream transducer 7 on the reception side is increased and the signal amplitude is increased. The degree of amplification is controlled to decrease. Further, since the propagation time measured by the propagation time measuring means 12 passes underwater, it is lower than the lower limit value of the propagation time monitoring value setting means 21, that is, becomes shorter. Therefore, it is determined that the flow path has become flooded for some reason, and a blocking signal is output to the blocking means 26. The flow rate measurement experiment was performed by injecting water into the flow path. The change data of the propagation time at that time is shown in FIG. 3, and the change data of the amplification degree (gain) is shown in FIG. ).

  Next, since the terminal lid 1e is not sufficiently fixed at the time of construction, a gap is generated and rainwater enters the inside of the gas shut-off device 1, and the flow path 4, in particular, the bottom flow path 4b is submerged. When the terminals of the upstream vibrator 6 and the downstream vibrator 7 are submerged, the impedance between the terminals decreases. As a result, the received signal level of the ultrasonic wave is reduced, and the amplification level adjusting means 14 increases the amplification level to increase the signal level. When the amplification degree determining means 18 detects that the amplification degree has increased and has reached the upper limit value, the time measuring means 23 starts to time. When the impedance between the terminals of the upstream vibrator 6 and the downstream vibrator 7 of the flow rate detection means 8 decreases due to water immersion, the received signal level is likely to be affected by noise and the like, and the instantaneous flow rate obtained by the flow rate calculation means 15 is obtained. Therefore, the measurement condition setting means 16 changes the measurement condition so as to obtain a stable flow rate value corresponding to the flow rate fluctuation. The measurement condition setting means 16 changes the measurement conditions (measurement interval, etc.) so that the measurement conditions such as the number of times of measurement and the measurement cycle are changed according to the change in the instantaneous flow rate, that is, the flow rate change period can be measured finely over a wide area. . Then, the measurement conditions are changed so that the flow rate is always stable regardless of changes in flow velocity. For example, the flow rate detection means 8 normally starts measurement every 2 seconds, but further transmits ultrasonic waves in a short time (several ms) during that time and measures the propagation time to measure all the parts such as large part, small part, middle part where the flow rate fluctuation is large. So that the number of times of measurement is increased so as to measure at many points so as to cover, and even if there is a fluctuation in flow velocity, the flow rate is measured to be a constant flow value. If the stable flow rate state continues for a certain period of time, the measurement condition set value is changed to the original condition.

  However, when rainwater or the like enters the outside of the flow path 4 inside the gas shut-off device 1, the flow rate always continues to fluctuate, and the measurement conditions set by the measurement condition setting means 16 for the flow rate measurement during the period that the time measuring means 23 keeps timing. Is measured under the measurement condition corresponding to the maximum change in flow velocity, and the time measuring means 23 obtains the set ratio of the maximum measurement condition by the measurement end time measurement ratio calculating means 24. When the timing means 23 finishes timing, the obtained measurement ratio is determined by the impedance estimation means 25, but the amplification degree determination means 18 determines whether the measurement ratio calculated by the measurement ratio calculation means 24 is equal to or greater than a predetermined ratio. If it is determined that the ratio is equal to or greater than the predetermined ratio, the flow rate detection means 8 of the flow path 4 estimates that the impedance between the terminals due to submergence or the like is in a lowered state and outputs a cutoff signal to the cutoff means 27. Call communication in the abnormal state to the center of the person.

  Further, in parallel, the average flow rate obtained by the average flow rate detection means 17 is monitored by the abnormality determination means 26, whether the flow rate has been used for a long time, or whether the obtained flow rate has reached an abnormal flow rate higher than the appliance flow rate, etc. Always monitor to determine whether there is an abnormality. The abnormality determination means 26 stores a time limit value for use time corresponding to each flow rate region, a monitor determination value for the maximum use flow rate, or the like. For example, when the hose that supplies gas to a stove or the like is disconnected for some reason, an abnormally large flow rate is generated, but the total flow cutoff value for monitoring such a condition and the maximum use time of the appliance normally Stored is a time limit for safety duration cut-off that defines a time limit for safe continuous use time corresponding to the case of use for a much longer time. By comparing and determining the set value and the average flow rate value by the abnormality determining means 26, the flow rate value does not exceed the maximum use flow rate value, or the use time of the appliance is set to the continuous use time limit corresponding to the registered flow rate. Monitors whether it exceeds the limit, and outputs a cut-off signal if exceeded. Further, the notification means 28 displays the shut-off state and shut-off content on a liquid crystal display element or the like, and notifies the center of the gas company that is monitoring the safety of the gas by communication such as a telephone line. The gas company can immediately take countermeasures such as exchanging the gas shut-off device 1, and can quickly avoid an abnormal state.

  Note that the configuration used in the present embodiment is an example, and the usage pattern is not limited to the present embodiment.

  As described above, when water that has entered the gas pipe for some reason enters the flow path 4 located at the lower part of the gas shut-off device 1 and becomes inundated, that is, the upstream vibrator 6 of the flow rate detection means 8. Or when the downstream side vibrator 7 has entered the inside of the flow path, or when the space between the housing of the gas shut-off device 1 and the outside of the flow path 4 at the bottom of the housing has been submerged, the detection from the flow rate detection means 8 A change in the flow rate value and the amplification level of the amplification level adjusting means 14 for controlling the signal level and the detected propagation time value are monitored to check whether the flow rate detection means 8 is abnormal or not. Abnormalities such as flooding can be detected at an early stage in the gas shut-off device 1 by detecting a state in which the amplification degree is increased, and the measurement condition is changed to stabilize by causing fluctuations in instantaneous flow rate. The flow rate is not used at all By using a gas appliance, it is possible to prevent abnormal operations such as integrating abnormal gas usage by erroneous detection and erroneous measurement, or malfunctioning of the safety shut-off function when abnormal flow rate is detected. Since it is determined and notified at an early stage that the gas shutoff device for safely monitoring the gas consumer is abnormal, there is an effect that the safety and reliability are extremely high and the usability is high.

  It should be noted that the present invention is not limited to those shown in the above-described embodiments, and those skilled in the art can also make changes and applications based on the description in the specification and well-known techniques. Yes, included in the scope of protection.

  As described above, the gas shutoff device according to the present invention secures high reliability by detecting an abnormal state when the inside and outside of the flow channel are submerged for some reason, and determining that it is difficult to continue monitoring and flow measurement. It can be applied to all measurement and monitoring devices such as a water meter of a gas mixture produced by mistake.

4 flow path 5 control device (control means)
DESCRIPTION OF SYMBOLS 8 Flow rate detection means 15 Flow rate calculation means 16 Measurement condition setting means 17 Average flow rate calculation means 18 Amplification degree determination means 19 Amplification degree setting means 20 Propagation time determination means 22 In-channel abnormality determination means 23 Timing means 24 Measurement ratio calculation means 25 Impedance Estimating means 26 Abnormality determining means 27 Blocking means

Claims (1)

The flow rate of the gas is calculated based on the flow path, the blocking means for blocking the gas flowing in the flow path, the vibrator pair arranged along the flow path, and the ultrasonic wave propagation time between the vibrator pair. And control means for shutting off the gas by the shut-off means at the time of abnormality,
The control means includes a flow rate detection means for detecting a flow rate, a flow rate calculation means for converting an instantaneous flow rate value from a detection value of the flow rate detection means, and an amplification degree determination means for determining a signal amplification degree adjusted by the flow rate detection means. Amplification level setting means for setting an upper limit determination value and a lower limit determination value of the amplification level adjusted by the flow rate detection means, a propagation time determination means for determining the propagation time detected by the flow rate detection means, and the flow rate calculation means A measurement condition setting means for changing the setting to a measurement condition for obtaining a stable flow value when it detects that the flow rate determined in step fluctuates, and the propagation time determination means with an amplification degree equal to or lower than a lower limit judgment value in the amplification degree judgment means If it is determined that the propagation time is abnormally short, the in-channel abnormality determining means for estimating the inundation in the flow path, the time measuring means that is activated when the amplification degree determining means determines that the upper limit determination value is exceeded, and the time measuring means A measurement ratio calculation means for obtaining a measurement condition ratio set to a maximum measurement condition that stabilizes the flow rate fluctuation during timing, and the flow rate when the amplification ratio determination means is equal to or greater than an upper limit determination value and the measurement ratio is equal to or greater than a predetermined value. Impedance estimating means for estimating that the impedance between the terminals of the detecting means is abnormal, an average flow calculating means for obtaining an average flow rate from the instantaneous flow obtained by the flow rate calculating means, and an abnormality determining means for determining the presence or absence of abnormality from the obtained average flow rate And a gas shut-off device configured to shut off the gas supply by the shut-off means when an abnormality judgment is established by the in-flow path abnormality judging means, the impedance estimating means or the abnormality judging means.

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