JP4568970B2 - Gas security device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a gas safety device that secures safety in using a gas by measuring a gas flow rate and periodically checking an abnormal flow rate.
[0002]
[Prior art]
In recent years, if a gas meter that measures the amount of gas used has been measured for a large flow rate or if it has been used for a long period of time that is not normal, it is judged as abnormal and the gas passage is shut off. The one with a built-in security device to ensure the safety is widespread.
[0003]
In this type of gas safety device flow rate measurement method, a membrane meter that measures the flow rate from the volume that has passed through the meter within a predetermined time is generally used. A conventional gas security device will be described with reference to FIG. Normally, when gas is used, the gas flows into the membrane flow rate measuring unit 13 of the meter, and a signal is transmitted to the control circuit 6 every time a certain volume flows. Based on this signal, the integrated gas flow rate is calculated to determine whether the gas flow pattern is abnormal. If it is determined that the gas flow is abnormal, a cutoff signal is sent to the cutoff valve drive circuit 4 and the cutoff valve 3 is shut off. Stop the gas. Furthermore, as a safety function, when an earthquake of a predetermined seismic intensity or higher occurs, the seismic device 15 detects a shake and shuts off the shut-off valve 3, and a gas sensor abnormality is detected by the pressure sensor 14 to give a warning. It has a function of taking out or shutting off the shut-off valve 3.
[0004]
[Problems to be solved by the invention]
However, with a conventional gas safety device that uses a membrane-type measuring unit, when performing a leak check on a pipe at the time of installing the gas safety device or at the start of gas use, a pressure gauge for leak check is required, and it takes time to check for leaks. There was a problem that it took.
[0005]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the gas safety device of the present invention can automatically and highly check pipe leakage by enabling instantaneous flow rate measurement using ultrasonic waves to measure minute flow rates instantaneously. A gas security device can be realized.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
The gas security device according to the first means of the present invention comprises an ultrasonic sensor and a measurement flow path, and determines whether or not the gas usage state is normal, and an ultrasonic measurement unit for measuring the gas usage amount. It has a control circuit, a shut-off valve that shuts off gas when an abnormality occurs, and a pipe leak checker that measures the flow rate when the gas passage is shut off and opened to check for pipe leaks. A method of measuring the propagation time of ultrasonic waves is adopted as a method, and a high-accuracy measurement mode with a higher clock frequency and improved measurement accuracy is provided as a measurement mode for pipe leak checking. By providing the timer means to be performed at the same time , the accuracy of the pipe leak check is improved.
[0007]
【Example】
Embodiments of the present invention will be described below with reference to the drawings.
[0008]
Example 1
FIG. 1 is a block diagram showing a gas security device according to the first means of the present invention. In this embodiment, an ultrasonic flow rate measuring unit including the ultrasonic sensor 1, the measurement flow path 2, and the ultrasonic sensor driving circuit 5 is used as the flow rate measuring unit. Utilizing the fact that the instantaneous flow rate can be measured by this ultrasonic flow measuring unit, in this embodiment, the instantaneous flow rate when the shutoff valve 3 is shut off and opened when the gas safety device is installed by the pipe leak check means 7 is compared. By this, the presence or absence of pipe leakage can be confirmed in a short time. Further, in the timer means 8, it is possible to periodically check the pipe leakage due to the time change after the gas safety device is installed using the pipe leak check means 7. The term “periodic” as used herein refers to, for example, about once a month, but can be changed depending on the installation conditions and frequency of use of the gas security device.
[0009]
(Example 2)
Figure 2 is a diagram showing the switching of the measurement timing and regular measurement mode of the onset Ming Gas Safety device. In this embodiment, the instantaneous flow rate is measured in a high-precision measurement mode having a measurement interval shorter than that in the normal measurement mode as shown in the figure at the time of pipe leakage check. By shortening the measurement interval, it is possible to follow minute changes in the flow rate, so that pipe leakage can be confirmed more accurately.
[0010]
In addition, by periodically performing the high-accuracy measurement mode, it is possible to check for pipe leaks due to time changes.
[0011]
( Reference Example 1 )
FIG. 3 is a diagram showing a measurement flow of the gas safety device according to Reference Example 1 of the present invention. The difference from the measurement flow based on the conventional sing-around method is that the number of sing-around times (S times) can be changed between high-precision measurement and normal measurement. Here, A> B, and in the case of high-precision measurement, the number of times of single-around can be set, and the resolution of the flow rate measurement becomes higher. Therefore, the pipe leak can be confirmed more accurately by measuring in the high-accuracy measurement mode at the time of the pipe leak check. In addition, by periodically switching the setting of the number of times of sing around with a timer, it is possible to check for pipe leaks due to changes in timekeeping.
[0012]
(Example 3 )
Figure 4 is a diagram showing the switching state and periodic clock frequency of the time measuring clock of the onset Ming Gas Safety device. By increasing the clock frequency from the figure, the resolution of measurement increases, and reception can be confirmed closer to the true reception timing of ultrasonic waves. For this reason, pipe leak can be more accurately confirmed by measuring in the high-accuracy measurement mode at the time of pipe leak check.
[0013]
Further, by periodically increasing the clock frequency, it is possible to check for pipe leaks due to time changes.
[0014]
(Example 4 )
Figure 5 is a block diagram showing a gas safety device of the present onset bright. In this embodiment, an ultrasonic flow rate measuring unit including the ultrasonic sensor 1, the measurement flow path 2, and the ultrasonic sensor driving circuit 5 is used as the flow rate measuring unit. In this embodiment, the instantaneous flow rate when the shutoff valve 3 is shut off and opened when the gas safety device is installed is compared by the pipe leak check means 7 by utilizing the fact that the ultrasonic flow rate measuring unit can measure the instantaneous flow rate. Thus, the presence or absence of pipe leakage can be confirmed in a short time. Further, in the timer means 8, it is possible to periodically check the pipe leakage due to the time change after the gas safety device is installed using the pipe leak check means 7.
[0015]
The timer start means 9 can also determine the leakage of the gas combustion appliance by performing the pipe leak tick means 7 periodically performed by the timer means 8 after the operation of the gas combustion appliance not shown.
[0016]
(Example 5 )
6 is a block diagram showing a gas safety device of the present onset bright. In this embodiment, an ultrasonic flow rate measuring unit including the ultrasonic sensor 1, the measurement flow path 2, and the ultrasonic sensor driving circuit 5 is used as the flow rate measuring unit. In this embodiment, the instantaneous flow rate when the shutoff valve 3 is shut off and opened when the gas safety device is installed is compared by the pipe leak check means 7 by utilizing the fact that the ultrasonic flow rate measuring unit can measure the instantaneous flow rate. Thus, the presence or absence of pipe leakage can be confirmed in a short time. Further, in the timer means 8, it is possible to periodically check the pipe leakage due to the time change after the gas safety device is installed using the pipe leak check means 7.
[0017]
The operation storage means 11 can store an operation pattern of a gas combustion appliance (not shown). The timer start confirming means 10 can perform the pipe leak tick means 7 periodically performed by the timer means 8 in a time zone in which the gas combustion appliance confirmed by the operation storage means 11 is not operating.
[0018]
【The invention's effect】
As described above, according to the gas safety device according to the first means of the present invention, since a minute flow rate can be regularly confirmed in a short time, a pipe leakage can be automatically confirmed in a short time by using only the gas safety device. Since the measurement accuracy at the time of leak check is improved, it is possible to check the presence or absence of pipe leak more accurately and automatically.
[Brief description of the drawings]
Gas Safety in Reference Example 1 in FIG. 1 is a diagram showing the measurement timing of the gas safety device according to the second embodiment of the block diagram Figure 2 the present invention of a gas safety device according to the first embodiment of the present invention [3] The present invention FIG. 4 is a flowchart showing the state of a clock for measuring the time of the gas safety device according to the third embodiment of the present invention. FIG. 5 is a diagram showing a state of periodic clock switching of the apparatus. FIG. 6 is a block diagram of a gas safety device according to a fourth embodiment of the present invention. FIG. 6 is a block diagram of a conventional gas security device according to a fifth embodiment of the present invention.
DESCRIPTION OF SYMBOLS 1 Ultrasonic sensor 2 Flow path 3 Shut-off valve 4 Shut-off valve drive circuit 5 Ultrasonic sensor drive circuit 6 Control circuit 7 Pipe leak check means 8 Timer means 9 Timer start means 10 Timer start confirmation means 11 Operation memory means

Claims (1)

Consists of an ultrasonic sensor and a measurement channel, an ultrasonic measurement unit that measures the amount of gas used, a control circuit that determines whether the gas is in normal use, and shuts off the gas when an abnormality occurs And a pipe leak checker that measures the flow rate when the gas passage is shut off and opened, and checks for pipe leaks, and measures the ultrasonic propagation time as an ultrasonic flow rate measurement method. and use, as the measurement mode when the piping leakage check, the high-precision measurement mode with improved high measure accuracy clock frequency provided, comprising a timer means to perform the high-precision measurement mode periodically gas Security equipment.

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