JPH11108726A - Gas meter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically and surely perform a test shut-off operation for a shut-off valve so as to prevent the occurrence of the operation failure of the same and to secure safety by performing the test shut-off operation of the shut-off valve when the stop of gas is detected by a gas flow detecting means. SOLUTION: The flowing state of gas 100 is detected for each preset time by a gas flow detecting means 105 and, when the flow stopped state of the gas 100 is detected, control is performed by a shut-off valve control means 104 so as to carry out the test shut-off operation of a shut-off valve 103 (operation of closing the shut-off valve 13 and then opening the same). When the flowing of the gas 100 is detected, while maintaining the open state of the shut-off valve 13, the flowing state of the gas 100 is continuously detected until the stop of the gas 100 is detected. Then, when the flowing stop of the gas 100 is detected, the test shut-off operation of the shut-off valve 13 is performed by the control means 104.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a gas meter,
In particular, the present invention relates to a gas meter having a shutoff valve for preventing a gas leak accident or the like.

[0002]

2. Description of the Related Art In a conventional gas meter, if a gas leak occurs in a gas appliance or the like, there is a danger of an accident. Therefore, a detector for detecting such a gas leak and stopping the gas flow. And a shutoff valve is used.

[0003] Such a shut-off valve 1 (herein referred to as a shut-off valve including not only the valve itself but also an electromagnetic power for moving the same. The same applies hereinafter), for example, as shown in FIG. It is located at the pipe entrance. Here, in FIG. 3, reference numeral 2 denotes an airtight chamber of the membrane gas meter, and 3 denotes a rotation of the mechanism of the membrane flowmeter operating inside the airtight chamber 2 by converting the movement into a rotating action. A gas flow rate detecting means for detecting a pulse corresponding to the gas flow rate; a gas flow rate integrating means for calculating a gas flow rate based on the pulse detected by the gas flow rate detecting means 3; A CPU having an abnormality detecting means for detecting the occurrence of an internal error is internally provided. Reference numeral 5 denotes an interface (I / F) between the CPU 4 and peripheral equipment such as the gas flow rate detecting means 3 outside the CPU 4.
I / F means 6 is a display means such as a liquid crystal display panel for displaying information such as the integrated gas flow rate calculated by the CPU 4.

[0004] When the gas flow abnormality is detected by the CPU 4 in which the abnormality detecting means is constructed as described above, the shut-off valve 1 is controlled based on the detected gas flow, the valve body is closed, and the valve is moved downstream from the gas meter. Stop the gas flow. In this way, even if a gas leak occurs, the safety can be ensured by detecting the gas leak and shutting off the gas flow by the shutoff valve 1. Then, after exiting from the abnormal state, the shut-off valve 1 is returned to the open state by inputting a valve return command to the CPU 4 by, for example, operating the return switch 7 by the user of the gas.

[0005] However, such a conventional shut-off valve 1
In a gas meter using the above, an abnormal condition as described above is generated, or a command input such as a so-called test shut-off operation for operating the shut-off valve 1 for test shut-off is intentionally input from the outside or the like. Except when shutting down, the shut-off valve 1 rarely opens and closes under normal gas use conditions, and the shut-off valve 1 remains open for a long period of time, possibly for several years. . As a result, the oily sludge, dust, moisture, or the like contained in the gas adheres over a long period of time, so that the sliding portion or the contact portion of the mechanical part such as the valve body of the shutoff valve 1 is formed. There is a problem that the shut-off valve 1 does not operate normally due to the sticking or rusting of the respective parts, and as a result, it may not even be possible to ensure safety at the time of gas leakage or the like.

Therefore, in order to solve such a problem,
For example, a technique disclosed in Japanese Patent Application Laid-Open No. 8-28779 filed by the present applicant has been devised. This is because the timer operates at a predetermined time, such as 100 hours, which is set in advance, and if the gas is not used at that time and is stopped, the shutoff valve 1 is once closed and then reopened. The automatic operation is performed to prevent the frictional portion and the contact portion such as the valve body of the shut-off valve 1 from sticking or rusting.

[0007] The so-called test shut-off operation of such an automatic shut-off valve is performed by programming the timer or the like so that the automatic shut-off valve is executed particularly at night when the frequency or probability of using gas is low. Further, the test shutoff operation of the shutoff valve can be automatically performed effectively without adversely affecting the use of ordinary gas.

[0008]

In general, most households who use a gas meter do not use gas at night, as described above. The automatic test shut-off operation of the shut-off valve can be effectively performed, and rust and the like of the shut-off valve can be eliminated.

However, gas is continuously used for a long time even at night, not to mention during the day, such as a 24-hour restaurant, and gas appliances are often used until midnight even in ordinary households. In such a case, the test valve shut-off operation cannot be performed because the gas continues to be used even when the above-described time for automatically shutting down the shut-off valve 1 is reached.

In the conventional shut-off valve 1 and the gas meter having the function as described above, if the gas is in use at the time of the test shut-off operation, the gas is used from that time to the next test shut-off timing. The specific time is counted again from the beginning. Therefore, in the conventional gas meter as described above, the shut-off valve 1
Will not be able to automatically shut off the test. As a result, the movable body such as the valve body of the shut-off valve 1 and the electromagnet as the power for moving the shut-off valve 1 is fixed or rusted, resulting in a problem that the shut-off valve 1 malfunctions.

The present invention has been made in order to solve such a problem, and it is possible to automatically perform a test shut-off operation of a shut-off valve automatically and to eliminate the occurrence of a malfunction of the shut-off valve. Accordingly, it is an object of the present invention to provide a gas meter that can reliably operate a shut-off valve when required and ensure safety.

[0012]

The gas meter according to the present invention comprises:
In a gas meter having a gas flow rate measuring means for measuring a gas flow rate, a gas flow rate integrating means for integrating the measured gas flow rate, and a shutoff valve for shutting off the gas flow, at every preset time, The gas flow detecting means for detecting the state of the gas flow, and when the gas stopped state is detected by the gas flow detecting means, the shutoff valve is once closed and then reopened. Control, when the gas is detected to flow, while maintaining the shut-off valve open until the gas flow detecting means detects that the gas is stopped, The detection of the state of the gas flow is continued by the gas flow detecting means, and when the gas flow detecting means detects that the flow of the gas has stopped, the shutoff valve is closed once and then again. To control so as to perform the seeking operation,
A shut-off valve control unit is provided.

In other words, according to the present invention, if the gas is in use even after the preset time has elapsed, the shut-off valve control means continues the gas use without resetting the count of the timer. I have been waiting forever
When the gas flow detection means detects that the gas use has stopped, the opportunity is used to immediately close and then reopen the shutoff valve so that the shutoff valve can perform the test shutoff operation. Control the shutoff valve.

Therefore, according to the present invention, even when the gas is used extremely frequently, including at night, a slight time during which the use of the gas is stopped is detected and the time is effectively used. At that time, the test shutoff operation can be automatically and reliably performed, so that the occurrence of malfunction of the shutoff valve can be eliminated, and the safety of the shutoff valve can be ensured when necessary. Can be ensured reliably.

Secondly, in the gas meter according to the first aspect, the shut-off valve control means repeats the operation of once closing and re-opening the shut-off valve a plurality of times. That is, when the automatic test shut-off is performed once, the shut-off valve is repeatedly closed and opened a plurality of times, whereby the shut-off valve can be more securely prevented from sticking and rusting.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a gas meter according to the present invention will be described below in detail with reference to the drawings. FIG. 1 is a diagram showing an outline of the structure of a gas meter according to the present invention. This gas meter is a gas flow rate measuring means that generates an electric pulse corresponding to the flow amount of the gas 100 and outputs this as measurement data of the gas flow rate, such as a membrane capacity meter or a turbine type flow meter. The flow of the gas 100 measured by the gas meter main body 101 and the gas meter main body 101 (here, it is assumed that the gas flow rate detecting means 3 described in the above-mentioned prior art is provided in the gas meter main body 101). Flow rate integrating means 102 for integrating the gas flow rate based on a pulse or the like corresponding to the flow rate (hereinafter referred to as flow rate), and a shutoff valve 1 for shutting off the flow of the gas 100
03 and the function of integrating the gas flow rate therewith, and when an abnormality occurs in the gas pressure or gas flow rate detected by a pressure sensor (not shown) in the gas meter, as described later. The structure and function of the shut-off valve that shuts off the gas flow under the control of the shut-off valve control means 104 also having the function according to the present invention are the same as those of the gas meter described in the above description of the related art. is there. In such a gas meter, the main technology according to the present invention is applied.

That is, the gas meter has a gas flow detecting means 105 for detecting a flow state of the gas 100 at predetermined time intervals, and a state in which the gas 100 is stopped by the gas flow detecting means 105. Is detected, the shutoff valve 103 is controlled to be closed and then reopened, and when the flow of the gas 100 is detected, the gas flow detecting means 105 While the shut-off valve 103 is kept open until it is detected that the gas 100 has stopped, the gas flow detecting means 105
Detection of the gas flow is continued, and the gas flow detecting means 10
When the stop of the flow of the gas 100 is detected by the control unit 5, the shut-off valve control means 104 is provided for controlling the shut-off valve 103 to be closed and then opened again.

Therefore, according to the configuration of the main part as described above, if the gas 100 is in use (that is, the gas flow continues) even after the preset time has elapsed, the gas flow detecting means 105 (Or the shut-off valve control means 104) continuously waits until the gas use stops without resetting the count of the timer, and the gas flow detection means 105 detects that the gas use has stopped. Taking advantage of the opportunity, the shut-off valve control means 104 controls the shut-off valve 103 so that the shut-off valve 103 immediately closes and then reopens immediately, that is, the test shut-off operation is performed. I do.

A timer function for counting a preset time is formed (or connected) on the gas flow detecting means 105 side, and when the timer completes the counting of the set time, the gas flow is started from that point. The stop detection wait state may be started, and when the gas flow stop is detected, it may be transmitted to the shut-off valve control means 104 to execute the test shut-off operation of the shut-off valve 103 as described above. Alternatively, the timer function is formed (or connected) on the shut-off valve control means 104 side, and when the timer completes counting the set time, the gas flow detection means 105 is started from that point.
When the gas flow stop is detected by the gas flow detecting means 105, the shut-off valve control means 104 controls the shut-off valve 103 to receive the test cut-off. The operation may be executed. In the present embodiment, the former configuration is adopted, but it goes without saying that the latter configuration may be adopted.

However, before the preset time is counted, any abnormality is detected by the above-described abnormality detecting function similar to the conventional one, and the shut-off valve 103 is shut off. But if you are really blocked,
Alternatively, for example, when a test cutoff execution command is input from the outside and the test cutoff is performed, the count of the timer may be reset at the time the cutoff is performed, or It is possible to ignore the shut-off operation due to such a gas leak or an artificial operation from the outside and perform the test shut-off according to the time schedule and method of the automatic test shut-off according to the present invention. Needless to say. From the viewpoint of preventing malfunction of the shut-off valve 103, which can be said to be a main part of the technology of the present invention, it is preferable that the number of times of opening and closing of the shut-off valve 103 is large. In consideration of complication, etc., it is preferable to perform the test interruption according to the time schedule and method of the automatic test interruption according to the present invention. In this case, the number of times of opening / closing operation of the shut-off valve 103 is larger than that in the case of resetting, and the power consumption of the power supply system, that is, the gas meter built-in battery at the time of performing the operation increases. However, since the number of times of increase (that is, gas leakage and artificial test interruption) is at most once every few months, this point is also substantially smaller than in the case of resetting. There is no problem. Therefore, in the gas meter according to the present embodiment, the test shutoff is performed according to the time schedule and method of the automatic test shutoff according to the present invention, ignoring the shutoff operation caused by a gas leak or an artificial operation from the outside. I made it.

The gas flow integrating means 102, the shut-off valve control means 104, and the gas flow detecting means 105 are connected to the shut-off valve 103, the measuring means of the gas meter body 101, and the like via an I / F (interface) 106. It may be constructed inside a CPU 107 called a so-called one-chip microcomputer (microcomputer). Alternatively, it goes without saying that each of these means may be constructed by a combination of individual (discrete) circuits or circuit elements. However, as for the structure of the circuit system and the hardware resources such as the one-chip microcomputer used for the same, considering the manufacturing and cost advantages that almost the same as the conventional one can be applied effectively, It is preferable to construct the main part of the configuration of the present invention inside a one-chip microcomputer. Therefore, in this embodiment, a circuit structure using such a one-chip microcomputer is adopted.

Next, the outline of the main operation of the gas meter according to the present invention having the main parts described above will be described with reference to the flowchart of FIG. In addition, since the same operation as the conventional operation such as the operation of integrating the normal gas flow rate is the same as the conventional operation, the detailed description is omitted for the sake of simplicity of the description, and the present invention is not described. The following description focuses on the test interruption operation.

The gas flow detecting means 105 detects whether or not the flow of the gas 100 is stopped at predetermined time intervals, for example, 30 hours. That is, based on a timer function (not shown) attached to the gas flow detecting means 105, the time T from the previous automatic test shut-off execution time
Is started (s1), and the count is continued until the count time T becomes equal to or longer than the preset time Tth (here, Tth = 30 hours) (s2).
N), and when it becomes longer (Y in s2), the counting of T is temporarily stopped (s3). Then, it is detected whether or not the flow of the gas 100 is stopped (s4).

At this time, if the gas flow detecting means 105 detects that the gas flow has stopped (s4
(Y), the detection information is transmitted to the gas flow detecting means 105, and the gas flow detecting means 105 controls the shut-off valve 103 so that the shut-off valve 103 is once closed and then reopened, that is, the test shut-off is performed (s6). ).

However, if the gas flow detecting means 105 detects that the gas is being used and the gas flow is not stopped at the time of the completion of the counting (N in s4), the gas flow detecting means 105 (S5), and when the gas flow detecting means 105 detects that the flow of the gas 100 has stopped (Y in s4), the shut-off valve control means 104 receives the signal to stop the flow. 10
3 to control the shutoff valve 103 to perform an automatic test shutoff operation (s6).

After the automatic test shut-off operation is executed, the count of the timer is reset to T = 0 (s7). Then, the operation of the above s1 is started again until the start timing of the next automatic test cutoff, and the subsequent steps repeat the above steps s2 and subsequent steps (s2 to s7). In this manner, the operation of the gas meter according to the present invention, in particular, the automatic test shutoff operation is performed.

The method of determining the stop state of the gas flow in the gas flow detecting means 105 is described in more detail below.
In general, the flow rate of the gas flow or the change in volume per unit time is sampled at a predetermined time interval Δt, and is measured based on a change in a value measured at each of the plurality of samplings. It is a target. Therefore, it is theoretically impossible to detect instantaneously that the gas flow has stopped without relying on such multiple samplings. Then, as a result of sampling n times at every sampling time interval Δt, Δt × n =
If the change in the gas flow rate is 0 continuously over the sampling time Ts, which is Ts, it can be determined that the gas flow at that time has stopped. Such a sampling time Ts must be set. However, if the sampling time Ts is too short, an error due to disturbance or the like may be picked up. A malfunction such as detection may occur. Further, if the sampling time Ts is too long, even if the gas is stopped such that the automatic test can be cut off, the gas will be used again after a long time without being detected. In the end, you miss out on the opportunity to shut off the automatic test.

Therefore, it is desirable to set the sampling time Ts to an appropriate time so as to avoid such a problem. Such a sampling time Ts may be set, for example, to several seconds to several tens of seconds. However, it is needless to say that the shorter the sampling time Ts is, the better the immediacy of the gas flow stop detection becomes, as long as the error does not occur.

The opening / closing operation of the shut-off valve 103 as the above-mentioned automatic test shut-off may be performed such that only one closing / opening is performed per execution of one test shut-off. In the case of a shut-off valve of a type such as a two-way shut-off valve that does not require a target return operation, a plurality of closing / opening operations may be repeated for each execution of the test shut-off. In particular, by repeating the closing and opening operations a plurality of times at a time, the sticking and rusting of the shutoff valve 103 can be more reliably prevented, and the time required for one closing and opening operation is at most 1 second or less. Therefore, it is more preferable to repeat the closing and opening operations a plurality of times at one time.

[0030]

As described above, according to the present invention, the test shut-off operation of the shut-off valve can be reliably performed automatically, and the occurrence of the malfunction of the shut-off valve can be eliminated. Thus, it is possible to provide a gas meter capable of reliably operating when the shut-off valve is required and ensuring safety.

[Brief description of the drawings]

FIG. 1 is a diagram showing an outline of a main part of a configuration of a gas meter according to the present invention.

FIG. 2 is a flowchart showing an outline of a main operation of the gas meter according to the present invention.

FIG. 3 is a diagram showing an outline of a main part of a configuration of a conventional gas meter having a shutoff valve and the like.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 100 ... Gas 101 ... Gas meter main body 102 ... Gas flow integrating means 103 ... Shutoff valve 104 ... Shutoff valve control means 105 ... Gas flow detection means 105 106 ... I / F 107 ... CPU

Claims (2)

[Claims] 1. A gas meter comprising: gas flow rate measuring means for measuring a gas flow rate; gas flow rate integrating means for integrating the measured gas flow rate; and a shutoff valve for shutting off the gas flow. Every time the gas flow detecting means detects the state of the gas flow, and when a state in which the gas is stopped is detected by the gas flow detecting means, the shutoff valve is temporarily operated at that time. It controls to perform the operation of closing and reopening, and when it is detected that the gas is flowing, the shut-off valve until the gas flow detecting means detects that the gas is stopped. When the gas flow detection means continues to detect the state of the gas flow while maintaining the open state, and when the gas flow detection means detects that the gas flow has stopped, Controls to perform an operation close and re-open the serial shutoff valve once, and further comprising a shut-off valve control means gas meter. 2. The gas meter according to claim 1, wherein the shut-off valve control means repeats the operation of once closing and re-opening the shut-off valve a plurality of times.