JP2002181605A - Gas meter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly reliable gas meter in terms of safety by giving a warning or operating a cutoff valve by instantly sensing it when gas leaks. SOLUTION: In this gas meter for interlocking reciprocating motion of a weighing film 10 with a valve mechanism 15 via a blade shaft 14 and a crank mechanism 15 by reciprocating the weighing film 10 by gas pressure flowing in from a gas inflow port 4, the gas meter is characterized by having a rotary board 27 rotating by crank motion of the crank mechanism 15, plural magnetic substances 28 arranged at an interval along the outer peripheral edge of this rotary board 27, and a reed switch 29 as a magnetic sensor arranged oppositely to the rotary board 27, and generating a pulse signal when opposed to the magnetic substances 28.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas meter capable of monitoring gas flow and detecting gas leakage.

[0002]

2. Description of the Related Art In addition to providing a shut-off valve inside a gas meter body, monitoring a gas flow rate and detecting a gas leak, a gas leak detector, an earthquake sensor detecting an earthquake, a pressure sensor detecting a gas pressure drop, and the like. There is known a microcomputer gas meter which has a built-in microcomputer and operates a shut-off valve to shut off gas flow in an emergency such as a gas leak, an earthquake or a gas pressure drop.

A conventional gas leak detector in a membrane microcomputer gas meter will be described below. That is, the measuring film is reciprocated by the gas pressure flowing from the gas inlet of the gas meter, and the reciprocating motion of the measuring film is linked to the valve mechanism and the integrating mechanism via the blade shaft and the crank mechanism. The crank mechanism includes a large elbow and a small elbow, and is configured to perform a crank motion by a rotational movement of a blade shaft.

[0004] One magnet is attached to the large elbow of the crank mechanism, and a magnetic sensor such as a reed switch is provided on the locus of movement of the magnet. , The magnetic sensor generates a pulse signal, and the microcomputer counts the pulse signal to monitor the gas flow rate. Therefore, when the large elbow of the crank mechanism makes one reciprocation due to the gas flow rate, the magnet once opposes the magnetic sensor and the magnetic sensor generates one pulse, and the gas is circulated by this one pulse. Understand.

[0005]

However, in the prior art, the magnetic sensor does not generate a pulse until the large elbow of the crank mechanism makes one reciprocation and the magnet faces the magnetic sensor. The judgment requires a time for the elbow gold to make one round trip, and even if gas leakage occurs, it cannot be detected instantaneously. In other words, even if a gas leak occurs,
It takes time for the alarm and the shut-off valve to operate, and there is a problem in terms of safety.

The present invention has been made in view of the above circumstances. It is an object of the present invention to instantly detect a gas leak and activate an alarm or a shutoff valve by detecting the gas leak. Another object of the present invention is to provide a highly reliable gas meter in terms of safety.

[0007]

According to the present invention, in order to achieve the above object, a first aspect of the present invention is to reciprocate a measuring membrane by a gas pressure flowing from a gas inlet, and to control the reciprocating motion of the measuring membrane by a blade. In a gas meter linked to a valve mechanism and an integrating mechanism via a shaft and a crank mechanism, a rotating plate provided in conjunction with the crank mechanism and rotated by the crank movement of the crank mechanism, and along a peripheral edge of the rotating plate. It is characterized by comprising a plurality of magnetic members arranged at intervals and a magnetic sensor provided to face the rotating disk and generating a pulse signal each time the magnetic member faces the magnetic member.

According to a second aspect, the plurality of magnetic bodies of the first aspect are arranged at intervals corresponding to the non-uniform reciprocating motion of the measuring film, and the pulse signal generated from the magnetic sensor is corrected to be constant. Features.

A third aspect of the present invention is characterized in that the magnetic sensor of the first aspect is a reed switch.

When the gas is not consumed, the turntable is stopped, so that the magnetic substance does not repeatedly turn on / off by facing / non-facing the magnetic sensor, and the microcomputer senses the gas flow rate. Never.

However, if gas leaks into a gas pipe, gas appliance, or the like downstream of the gas meter for some reason, the gas flows in from the gas inlet, and the gas flows through the gas passage of the gas meter as in the case of gas consumption. The gas passes through the gas outlet and flows out of the gas outlet, so that the crank mechanism performs a crank motion and the turntable rotates.

Therefore, when a gas leak occurs, the turntable rotates at a rotation speed proportional to the amount of the leak, and the magnetic material repeatedly generates a pulse signal by facing / non-facing the magnetic sensor. The microcomputer senses the gas flow rate (gas leak).

[0013]

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

1 to 4 show a first embodiment, and FIG.
FIG. 2 is a vertical sectional side view of the membrane microcomputer gas meter, and FIG. 2 is a sectional view taken along line AA in FIG. The gas meter main body 1 includes an upper case 2 and a lower case 3. The upper case 2 is provided with a gas inlet 4 and a gas outlet 5.

The upper case 2 is divided by a partition wall 6 into an electrical equipment chamber 7 and a crank chamber 8, and the crank chamber 8 communicates with the gas inlet 4. A pair of measuring chambers 9 are provided in the lower case 3, and a measuring film 10 is provided in these measuring chambers 9 so as to reciprocate so as to divide the measuring chamber 9. The measuring chamber 9 communicates with the crank chamber 8 via the valve mechanism 11 and communicates with the gas outlet 5 via the valve mechanism 11.

A membrane plate 12 is attached to the measuring membrane 10,
The membrane plate 12 is connected to a blade shaft 14 provided on the side of the measuring chamber 9 through a rotating blade 13, so that the reciprocating motion of the measuring film 10 is transmitted to the blade shaft 14 as a rotating motion. ing. The upper end of the blade shaft 14 protrudes into the crank chamber 8, and a crank mechanism 15 is provided at the upper end of the blade shaft 14, and the crank mechanism 15 is interlocked with the valve mechanism 11.

The crank mechanism 15 has a pair of large elbows 16 whose base ends are fixed to the blade shaft 14, and a pair of small elbows whose base ends are rotatably connected to the distal end of the large elbow 16. And an elbow member 17. The distal ends of the pair of small elbows 17 are rotatably connected by connecting pins 18.

The valve mechanism 11 is provided with the valve seat 1.
9 on which a fan-shaped valve 20 is mounted. A pivot shaft 21 is provided at one end of the sector valve 20.
A pivotal support hole 22 is provided at the upper end of the pivotable hole so as to be rotatable. A projecting pin 23 is provided on an upper portion of the sector valve 20.

A rotary shaft 24 is provided in the vicinity of the valve seat 19, and a rotary mechanism 25 that makes a rotary motion about this axis is provided on the rotary shaft 24. The turning mechanism 25 is connected to the connecting pin 18 of the small elbow 17. In addition, the swivel mechanism 25 and the projecting pin 2 of the sector valve 20
3 is connected by a rotating lever 26, and the sector valve 20 on the valve seat 19 reciprocates in a horizontal plane with the pivot 21 as a fulcrum to switch the gas.

Therefore, the connecting pin 18 of the small elbow 17 constituting the crank mechanism 15 is adapted to rotate about the rotating shaft 24, and a disk-shaped rotating disk 27 is connected to the connecting pin 18. The turntable 27 rotates around the rotation shaft 24.

As shown in FIG. 3, a plurality of magnetic members 28 are arranged at equal intervals along the outer peripheral edge of the upper surface of the turntable 27. In the present embodiment, 24 magnetic bodies 28
Is arranged. Further, a reed switch 29 as a magnetic sensor that generates a one-pulse signal when facing the magnetic body 28 is fixed to the partition wall 6 above the rotating disk 27.

The reed switch 29 is electrically connected to a microcomputer 30 provided in the electrical equipment room 7, converts mechanical on / off of the reed switch 29 into a pulse signal, and converts the pulse signal into the microcomputer 30.
Is counted and the gas flow rate is monitored.

Next, the function of the gas flow rate monitoring function of the membrane microcomputer gas meter configured as described above will be described.

After the gas flowing from the gas inlet 4 is guided to the crank chamber 8, the gas is alternately distributed to the pair of measuring chambers 9 by the valve mechanism 11. That is, when gas is introduced into one of the measuring chambers 9 defined by the measuring film 10, the gas pressure causes the measuring film 10 and the film plate 12 to be pressed by the other and move in parallel. Therefore, the gas in the other measuring chamber 9 is pushed out by the measuring film 10 and flows out from the gas outlet 5 through the valve mechanism 11.

When the gas is alternately distributed to the pair of measuring chambers 9 as described above, the membrane plate 12 reciprocates in the measuring chamber 9, and when the membrane plate 12 reciprocates, the rotating blade 13 rotates the blade shaft 14. About the axis, and the rotational movement of the blade shaft 14
Is transmitted to

The crank mechanism 15 includes a large elbow 16 and a small elbow 1
The connecting pin 18 turns around the rotation shaft 24 together with the turning mechanism 25 while bending and extending together with the small elbow 16 by the turning movement of the large elbow 16. Accordingly, the turning motion of the turning mechanism 25 is transmitted to the valve mechanism 11 through the turning lever 26 and turns, and the turning mechanism 2 rotates.
7 rotates around the rotation shaft 24.

The rotating disk 27 has 24 magnetic members 2 in the circumferential direction.
8, the reed switch 29 is turned on when the magnetic body 28 faces the reed switch 29 by the rotation of the turntable 27, and turned off when the reed switch 29 is not opposed to the magnetic body 28. That is, since the 24 magnetic bodies 28 are arranged on the rotating disk 27, when the rotating disk 27 makes one rotation, the reed switch 29 repeatedly turns on and off 24 times.

The mechanical ON / OFF of the reed switch 29 is converted into a pulse signal, and the microcomputer 30 counts the pulse signal to monitor the gas flow rate.

Therefore, when gas is consumed, the turntable 27 is rotated and the reed switch 29 is repeatedly turned on and off, but when gas is not consumed,
Since the turntable 27 is stopped, the magnetic body 28 does not repeatedly turn on / off by facing / non-facing the reed switch 29, and the microcomputer 30 does not sense the gas flow rate.

However, when gas leaks into a gas pipe, gas appliance, or the like downstream of the gas meter for some reason, gas flows in from the gas inlet 4 and the gas flows into the gas meter as in the case of gas consumption described above. Since the gas passes through the gas passage and flows out from the gas outlet 5, the crank mechanism 15 performs a crank motion, and the turntable 27 rotates.

Therefore, when gas leakage occurs, the rotating disk 27 rotates at a rotational speed proportional to the amount of leakage, and the magnetic body 28 repeats on / off by repeatedly facing / non-facing the reed switch 29, and the Computer 30 senses the presence or absence of gas flow.

At this time, conventionally, the magnetic body 28 is
6, the reed switch 29 is turned on to generate a one-pulse signal when the rotating shaft 24 makes one rotation and the magnetic body 28 faces the reed switch 29. . For this reason, the time of one rotation cycle of the rotating shaft 24 is required to determine the presence or absence of the gas flow rate. However, according to the present invention, the (1 rotation cycle / magnetic material) Number) time.
That is, gas leakage is determined instantaneously, and a highly reliable microcomputer gas meter can be provided.

However, the measuring film 10 provided in the measuring chamber 9
Repeats reciprocating motion by the gas pressure, but the speed distribution of one reciprocation is not constant, and there are a portion where the measuring film 10 moves fast and a portion where it moves slowly in the measuring chamber 9. The rotation period of the rotating rotating disk 27 is also non-uniform.

FIG. 4 shows that 24 magnetic bodies 28 are
Are arranged, the horizontal axis represents the number of pulses, and the vertical axis represents the weight (L / pulse) of one pulse. (A) of FIG.
This is a case where 24 magnetic bodies 28 are arranged at equal intervals in the circumferential direction on the rotating disk 27. As described above, the rotation period of the rotating disk 27 rotated by the reciprocating motion of the measuring film 10 varies. Although the reed switch 29 is turned on in opposition to the magnetic body 28, a deviation occurs between the amount of passing gas and the pulse, and the weight of one pulse is not uniform.

FIGS. 5 and 6 show the second embodiment, in which the disadvantage (unevenness in the weight of one pulse) of the first embodiment is eliminated. FIG. 5 shows a rotary disk 27, in which twelve magnetic bodies 28 are arranged on the outer peripheral edge of the rotary disk 27 in the circumferential direction. , The positions of the magnetic bodies 28 indicated by broken lines are arranged at intervals corresponding to the non-uniform reciprocation of the measuring film 10 (L / p
The pulse signal generated from the reed switch 29 is corrected to be constant by shifting the position of the magnetic body 28 in the circumferential direction.

FIG. 6 is a diagram showing the relationship between the amount of passing gas and the pulse signal. When the magnetic bodies 28 are arranged at equal intervals, a difference occurs between the amount of passing gas and the pulse. When the position is shifted in the circumferential direction and the pulse signal generated from the reed switch 29 is corrected to be constant, a pulse corresponding to the passing gas amount is generated.

Therefore, as shown in FIG. 4B, the position of the magnetic body 28 is shifted in the circumferential direction, and the reed switch 2 is shifted.
By correcting the pulse signal generated from 9 uniformly, the weight of one pulse becomes uniform. However, FIG. 4 shows a case where 24 magnetic bodies 28 are arranged on the turntable 27.

In the above embodiment, the rotating disk 2
Although the case where 12 and 24 magnetic bodies 28 are arranged in 7 has been described, the number of magnetic bodies 28 is not limited as long as it is plural. The invention is not limited to the reed switch, but may be any magnetic sensor that senses magnetism and generates a pulse.

[0039]

As described above, according to the present invention, when a gas leak occurs, it can be instantaneously sensed and the alarm or the shut-off valve can be activated, and the reliability is improved in terms of safety. A high gas meter can be provided.

[Brief description of the drawings]

FIG. 1 shows a first embodiment of the present invention, and is a longitudinal sectional front view of a membrane microcomputer gas meter.

FIG. 2 is a sectional view of the same embodiment, taken along line AA of FIG. 1;

FIG. 3 is a plan view of the turntable of the embodiment.

FIG. 4 is a graph showing pulse generation timing.

FIG. 5 is a plan view of a turntable according to a second embodiment of the present invention.

FIG. 6 is a graph showing a passing gas amount and a pulse generation timing.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 4 ... Gas inlet 5 ... Gas outlet 9 ... Measuring chamber 10 ... Measuring membrane 14 ... Blade shaft 15 ... Crank mechanism 27 ... Rotating disk 28 ... Magnetic body 29 ... Reed switch (magnetic sensor)

Claims (3)

[Claims] 1. A gas meter for reciprocating a measuring membrane by gas pressure flowing from a gas inlet, and interlocking the reciprocating motion of the measuring membrane with a valve mechanism and an integrating mechanism via a blade shaft and a crank mechanism. A rotating disk that is provided in conjunction with the rotating mechanism and that is rotated by the crank motion of the crank mechanism, a plurality of magnetic bodies arranged at intervals along the outer peripheral edge of the rotating disk, And a magnetic sensor for generating a pulse signal each time the magnetic sensor faces the magnetic body. 2. The apparatus according to claim 1, wherein the plurality of magnetic bodies are arranged at intervals corresponding to non-uniform reciprocation of the measuring film, and a pulse signal generated from a magnetic sensor is corrected to be constant. Gas meter. 3. The gas meter according to claim 1, wherein the magnetic sensor is a reed switch.