JPH09229739A - Gas meter-controlling apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect a leak of gas surely in a short time without cutting the supply of gas, by inputting a pulse signal from a flow rate pulse-detecting means and a flow rate signal from a magnetic flow rate-detecting means and judging the presence/absence of the gas leak. SOLUTION: A flow rate pulse-detecting means consisting of a reed switch 9 and a flow rate pulse-inputting circuit 11 and, a magnetic flow rate-detecting means consisting of a magnetic sensor 12 and an A/D converter 13 are arranged parallel to each other between a measuring device 1 and a microcomputer 4 in the control device 10. In a flow rate range where a gas accident possibly tahes place, the flow rate of gas is monitored by inputs of flow rate pulses from the flow rate pulse-inputting circuit 11, and the presence/absence of gas is detected. In a minute flow rate range where the generation of a gas accident is less feared and which the switch 9 cannot detect, the movement of a magnet in accordance with the flow rate of gas in the measuring device 1 is detected as a string/weak magnetism by the sensor 12, converted to a digital signal at 13 and taken into the computer 4, thereby, the presence/absence of a leak of gas is detected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas meter control device, and more particularly to a gas leak detection function section for detecting gas leak from a gas pipe or the like.

[0002]

2. Description of the Related Art Regarding a gas meter, a control system as shown in FIG. 4 is conventionally known. In the figure,
The metering device 1 creates a mechanical motion according to the flow rate of gas, and operates the display register 2 by the motion. Further, the metering device 1 moves the magnet along a trajectory as shown in FIG. 5 by a mechanical motion according to the flow rate of gas, turns on / off the contact of the reed switch 9, and outputs the contact output of the flow pulse input circuit 11. Is converted into a flow rate pulse (voltage pulse) and transmitted in a non-contact manner to the microcomputer 4 in the control device 30. The microcomputer 4 counts the flow rate pulse and uses it to monitor the gas flow rate. The seismic sensor 5 and the pressure sensor 6 are connected to the control device 30, and the output signals of the sensors 5 and 6 are monitored by the microcomputer 4 as with the flow rate pulse. When an abnormality is found in the gas flow rate and the output signal of each sensor 5, 6, the shutoff valve 7
Is closed and the LED 8 blinks to notify the surroundings of the occurrence of an abnormal situation.

[0003]

One of the gas flow rate monitoring functions in the above control system is a gas leak detection function for detecting gas leaks from indoor piping. This gas leak detection function is realized by the following two methods.
It is judged that there is a gas leak when the flow rate pulse is continuously detected for 30 days. As shown in FIG. 6, the shutoff valve 7 is closed in a state where all the gas cocks 3 in the room are closed, and the pressure sensor 6 measures the degree of decrease in the pressure of the closed space to determine the gas leak. . However,
In this method, it takes a long time to detect a gas leak. In the other method, all the gas cocks in the room are closed, which is a prerequisite for the gas leak inspection. Therefore, it is necessary to witness the customer, and there is a problem that the gas leak inspection cannot be performed in the absence house. there were.

The present invention has been made in view of the above,
An object of the present invention is to provide a gas meter control device capable of surely detecting gas leakage in a short time without stopping gas supply.

[0005]

In order to solve the above-mentioned problems, the present invention according to claim 1 provides a pulse signal for the contact output of a reed switch which is turned on / off by a magnet that mechanically moves according to the flow rate of gas. A flow rate pulse detecting means for converting and outputting the flow rate, a magnetic flow rate detecting means for detecting a magnetic change due to a movement of a magnet according to a flow rate of gas and outputting a flow rate signal, a pulse signal from the flow rate pulse detecting means, The gist of the present invention is to have a control unit for inputting a flow rate signal from the magnetic flow rate detection unit and determining the presence or absence of gas leakage. In this configuration, the control means determines the presence / absence of gas leakage in the flow rate region in which a gas accident may occur by monitoring the flow rate with a pulse signal from the flow rate pulse detection means. In the small flow rate region where the risk of gas accident is low and cannot be detected by the reed switch, flow rate monitoring is performed by the flow rate signal from the magnetic flow rate detecting means to determine the presence or absence of gas leakage.

According to a second aspect of the present invention, there is provided a flow rate pulse detecting means for converting a contact output of a reed switch, which is turned on / off by a magnet that mechanically moves according to the flow rate of the gas, into a pulse signal, and outputting the pulse signal. Optical flow rate detecting means for optically detecting a movement of a display register operated by mechanical movement of a gas metering unit according to a flow rate and outputting a flow rate signal, and a pulse signal from the flow rate pulse detecting means and the optical flow rate detecting means. The gist of the present invention is to have a control unit that inputs a flow rate signal from the flow rate detection unit and determines whether or not there is a gas leak. In this configuration, the control means determines the presence / absence of gas leakage in the flow rate region in which a gas accident may occur by monitoring the flow rate with a pulse signal from the flow rate pulse detection means. In the small flow rate region where the risk of gas accident is low and cannot be detected by the reed switch, flow rate monitoring is performed by the flow rate signal from the optical flow rate detecting means to determine the presence or absence of gas leakage.

[0007]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing a first embodiment of the present invention. In FIG. 1 and a diagram showing a second embodiment to be described later, the same or equivalent devices as the devices and the like in FIG. 4 are designated by the same reference numerals as those described above, and the duplicated description will be omitted.

First, the structure of the gas meter control device will be described. In the present embodiment, a reed switch 9 and a flow rate pulse input circuit 11 are provided between the metering device 1 and the microcomputer 4 as the control means in the control device 10. Flow rate pulse detection means, magnetic sensor 12 and A
The magnetic flow rate detecting means composed of the / D converter 13 is arranged in parallel. The magnetic sensor 12 detects the movement of the magnet in the metering device 1 according to the gas flow rate as a magnetic change, and outputs an analog signal. The A / D converter 13 is
This analog signal is converted into a digital flow rate signal and transmitted to the microcomputer 4.

Next, the operation of the present embodiment will be described. With respect to the flow rate range where a gas accident may occur, the microcomputer 4 monitors the gas flow rate by the flow rate pulse input from the side of the flow rate pulse input circuit 11 constituting the flow rate pulse detection means, and determines whether or not there is a gas leak. To be done. In this monitoring process, when the flow rate pulse input, that is, when the contact of the reed switch 9 is turned on for a certain period of time, for example, once for 2 minutes, it is determined that the gas appliance is not used, and the gas flow rate monitoring process is initialized. To be done. When the monitoring process is initialized, the process is switched to a process for detecting a gas leak from a minute flow rate range where the reed switch 9 cannot detect gas leakage, which is less likely to cause a gas accident. In the gas leak detection process in the minute flow rate range, the movement of the magnet in the metering device 1 according to the gas flow rate is detected by the magnetic sensor 12 as the magnetic strength, and the analog level of the magnetic strength is A.
The signal is converted into a digital signal by the / D converter 13 and taken into the microcomputer 4. Then, for example, when the output level of the magnetic sensor 12 continues to change for 24 hours, it is determined that there is a gas leak in the gas pipe or the like. The reason for choosing these 24 hours is that it is considered that gas is not used during sleep at home.

As described above, according to this embodiment,
It is possible to detect a gas leak from a gas pipe or the like in a shorter time than before. In addition, it becomes possible to perform a gas leak inspection from a gas pipe, etc., which was conventionally performed by closing all the gas cocks in the presence of a customer, automatically and reliably without stopping the gas supply. .

2 and 3 show a second embodiment of the present invention. In the present embodiment, a flow rate pulse detecting means composed of a reed switch 9 and a flow rate pulse input circuit 11, an optical sensor 14 and an optical sensor I are provided between the weighing device 1 and the microcomputer 4 in the control device 20.
The optical flow rate detecting means constituted by the / F (current / frequency) circuit 16 is arranged in parallel. Optical sensor 14
Optically detects the movement of the display register 2 operated by the mechanical movement of the measuring device (gas measuring unit) 1 according to the flow rate of gas. That is, as shown in FIG. 3, the character wheel 15 of the display register 2 is provided with a black and white striped pattern, and the movement of the character wheel 15 is optically detected by the optical sensor 14 composed of the LED 14a and the phototransistor 14b. In the black portion of the character wheel 15, light reflection from the LED 14a is weak and the phototransistor 14b is turned off. In white portion, the light reflection from the LED 14a is strong and the phototransistor 14b is turned on. This on / off signal is sent to the optical sensor I / F circuit 1
It is adapted to be taken into the microcomputer 4 via 6 as a flow rate signal.

Then, by the microcomputer 4,
As for the flow rate region in which a gas accident may occur, the gas flow rate monitoring process is performed by the flow rate pulse input from the flow rate pulse detecting means side, as in the case of the first embodiment. When the monitoring process is initialized, the process is switched to a process for detecting a gas leak in the minute flow rate range, that is, a process for monitoring the movement of the character wheel 15. After that, when the movement of the character wheel 15 is detected for 24 hours, it is determined that there is a gas leak in the gas pipe or the like.

According to the present embodiment, the same effect as that of the first embodiment can be obtained.

[0015]

As described above, according to the first aspect of the present invention, the contact output of the reed switch that is turned on / off by the magnet that mechanically moves according to the flow rate of gas is converted into a pulse signal. Flow rate pulse detecting means for outputting, magnetic flow rate detecting means for detecting a magnetic change due to movement of a magnet according to gas flow rate and outputting a flow rate signal, pulse signal from the flow rate pulse detecting means and the magnetic flow rate Since the control means is provided with the flow rate signal from the detection means to judge the presence or absence of gas leakage, the control means determines the flow rate by the pulse signal from the flow rate pulse detection means for the flow rate range in which a gas accident may occur. The flow rate signal from the magnetic flow rate detection means is used for the minute flow rate range that cannot be detected by the reed switch because there is little risk of gas accidents by monitoring the gas leakage. By performing amount monitoring to determine the presence or absence of gas leakage, short time, and can be reliably gas leakage inspection without stopping the gas supply.

According to the second aspect of the present invention, flow rate pulse detecting means for converting the contact output of the reed switch, which is turned on / off by the magnet that mechanically moves according to the flow rate of the gas, into a pulse signal for output. Optical flow rate detecting means for optically detecting a movement of a display register operated by mechanical movement of a gas metering unit according to a gas flow rate and outputting a flow rate signal, a pulse signal from the flow rate pulse detecting means and the Since the control means for inputting the flow rate signal from the optical flow rate detecting means to judge the presence / absence of gas leakage is provided, the control means determines a pulse from the flow rate pulse detecting means for a flow rate range where a gas accident may occur. The signal is used to monitor the flow rate to determine whether or not there is a gas leak, and there is little risk of a gas accident. Performing flow monitoring by determining the presence or absence of gas leakage at a flow rate signal, the same effect as the effect of the invention according to the first aspect is obtained.

[Brief description of drawings]

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

FIG. 2 is a block diagram showing a second embodiment of the present invention.

FIG. 3 is a perspective view showing a configuration of a display register and an optical sensor portion in the second embodiment.

FIG. 4 is a block diagram showing a conventional gas meter control device.

FIG. 5 is a diagram for explaining movement of a magnet by the weighing device.

FIG. 6 is a diagram for explaining a gas leak inspection from indoor piping by a conventional gas meter control device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Measuring device (gas measuring part) 2 Display register 4 Microcomputer (control means) 9 Reed switch 10, 20 Control device 11 Flow pulse input circuit which constitutes a flow pulse detection means with a reed switch 12 Magnetic sensor 13 Magnetic with magnetic sensor A / D converter constituting optical flow detecting means 14 Optical sensor 15 Character wheel 16 Optical sensor I / F circuit constituting optical flow detecting means together with optical sensor

Claims (2)

[Claims] 1. A flow rate pulse detecting means for converting a contact output of a reed switch, which is turned on / off by a magnet that mechanically moves according to a gas flow rate, into a pulse signal and outputs the pulse signal, and a magnet for the magnet according to the gas flow rate. The presence or absence of gas leakage is determined by inputting a magnetic flow rate detection means for detecting a magnetic change due to movement and outputting a flow rate signal, and a pulse signal from the flow rate pulse detection means and a flow rate signal from the magnetic flow rate detection means. And a control unit that controls the gas meter. 2. A flow rate pulse detecting means for converting a contact output of a reed switch which is turned on and off by a magnet that performs a mechanical motion according to the flow rate of gas into a pulse signal and outputs the pulse signal, and a gas metering according to the flow rate of gas. Optical flow rate detecting means for optically detecting the movement of the display register operated by the mechanical movement of the section and outputting a flow rate signal, a pulse signal from the flow rate pulse detecting means and a flow rate from the optical flow rate detecting means. A gas meter control device, comprising: a control unit that inputs a signal and determines whether or not there is a gas leak.