JP2003185485A - Gas meter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas meter that outputs a clear pulse signal, and can reliably carry out safety monitoring that can be made in the use of gas. <P>SOLUTION: In the gas meter, the longitudinal direction of a lead switch 2 is arranged nearly in parallel with a tangential line direction in the rotary track of a magnet 1, lead sections 2a and 2b are magnetized to the same pole for opening by repulsion when the line of magnetic force crosses the lead sections 2a and 2b, the lead sections 2a and 2b are magnetized to a different pole for closing by attraction force when the line of magnetic force passes nearly in parallel with the lead sections 2a and 2b, and a pulse signal is outputted corresponding to the opening and closing of the lead switch 2. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas meter having improved output characteristics of pulse signals transmitted for safety monitoring when using gas.

[0002]

2. Description of the Related Art A conventional gas meter typified by a membrane gas meter has a mechanism for changing a moving amount of a diaphragm (membrane) that moves according to a gas passing flow rate into a rotary motion in order to display a gas usage amount. The mechanical counter is rotated by this rotational movement, and the gas usage amount is calculated by performing a count-up (counting) for integrating the gas passage flow rate.

In order to perform safety monitoring when using gas, a safety monitoring controller device, which is an electronic circuit mounted on the gas meter, obtains data on the passing gas flow rate. The principle of this data acquisition will be described with reference to the drawings. FIG. 7: is explanatory drawing explaining the 1st gas passage flow rate data acquisition principle by the gas meter of a prior art. As shown in FIG. 7, the gas meter (not shown) includes a rotating body 100, a magnet 200, and a reed switch 300.

The rotating body 100 is formed in a disc shape and has a rotation driving mechanism (not shown) attached thereto. The rotating body 100 rotates about a rotation center axis by a rotation drive mechanism. The magnet 200 is mounted on the rotating body 100, and when the rotating body 100 rotates, as shown in FIG.
Move while drawing a rotation locus as indicated by the alternate long and short dash line.

The reed switch 300 is arranged in the vicinity of the rotating body 100 and within a predetermined area where the magnetic field of the magnet 200 reaches. The reed switch 3 is rotated by the rotation of the magnet 200.
The strength of the magnetic field that 00 receives is changed. The reed switch 300 closes when the magnetic field becomes strong and closes when the magnetic field becomes weak. As a result, one pulse signal is obtained for one rotation of the rotating body 100. Then, the increase / decrease in the gas passage flow rate can be determined according to the level of the rotation speed. The conventional gas passing flow rate data acquisition principle is as described above.

In addition to the gas meter that outputs one pulse signal per rotation as described above, there is also a gas meter that outputs a plurality of pulse signals per rotation. This gas meter will be described with reference to the drawings. Figure 8
FIG. 4 is an explanatory diagram illustrating a second gas passage flow rate data acquisition principle by a conventional gas meter. As shown in FIG. 8, a plurality of (eight in FIG. 8) magnets 200 are provided in the rotating body 10.
They are arranged on the same circle on 0 and pass on the same rotation locus. When the rotating body 100 makes one rotation,
In the vicinity of the reed switch 300, eight magnets alternately appear, and the magnetic field changes so as to be alternately strong and weak. Then, a plurality of pulse signals (eight when there are eight magnets as shown in FIG. 8) are output in one rotation.

Even in such a conventional gas meter, one or a plurality of pulse signals are taken out in one rotation, but there is a demand to further increase the number of pulses that can be taken out in one rotation. However, if the number of pulses that can be extracted in one rotation is increased, a new problem will occur.

In the above-described conventional gas meter, the reed switch 30 is moved by the movement of the magnet 200 that rotates.
By changing the strength of the magnetic field received by 0, the reed switch 30
Opening and closing operation of 0 is performed. Therefore, it is necessary to further increase the number of magnets 200 and arrange them in order to further increase the number of pulses obtained in one rotation. In this case, two magnets 2 are arranged.
The interval of 00 is shortened, the magnetic fields formed by the plurality of magnets 200 are overlapped with each other, and the change in the strength of the magnetic field is small, and the reed switch 300 cannot detect the change in the strength of the magnetic field and the reed switch 300 is opened and closed. There is a problem that the operation cannot be secured and the pulse signal cannot be generated.

In order to deal with such a problem, it is necessary to increase the change of the magnetic field by the magnet 200. Therefore, the distance between the two magnets 200 may be increased. However, in order to increase the distance, it is necessary to increase the radius of rotation of the rotation locus. Increasing the size of the gas meter was unavoidable, leading to an increase in the size of the gas meter.

Further, as another prior art relating to a gas meter for generating a pulse signal, Japanese Patent Application Laid-Open No. 9-3041
No. 52 discloses a gas meter. JP-A-9-
The gas meter described in Japanese Patent No. 304152 is intended to improve the transmission pulse characteristic at the time of detecting a flow rate, and includes a rotating magnet magnetized so that a pair of N pole and S pole is formed on a rotating body which is a magnetic body. The gas meter includes an urging magnet arranged to face each other in the radial direction of the rotating magnet, and a reed switch arranged between the rotating magnet and the urging magnet.

In the reed switch of this conventional gas meter, when the magnitude (absolute value) of the supplied magnetic field exceeds a predetermined threshold value, the reed switch is energized, and the magnitude (absolute value) of the magnetic field is increased. When (value) becomes smaller than a predetermined threshold value, the cutoff state is set. Then, only one pulse is emitted when the rotating magnet makes one rotation due to the offsetting / amplifying action of the magnetic fields generated by the rotating magnet and the biasing magnet.

However, in the prior art, no consideration was given to obtaining a plurality of pulse signals per rotation. Further, since an urging magnet is required in addition to the rotating magnet, if an attempt is made to improve so that a plurality of pulses can be obtained per one rotation, the magnetic field formed by the rotating magnet and the urging magnet becomes complicated, and a desired magnetic field is obtained. There is also a problem that it is difficult to determine the magnitude of the magnetic field for obtaining the pulse and the design is difficult.

[0013]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above problems, and an object thereof is to reduce the rotation locus drawn by a magnet to reduce the size of a rotary drive mechanism or a rotating body. It is another object of the present invention to provide a gas meter that can be realized and can output the clear pulse signal with less noise components by surely opening and closing the reed switch to reliably perform safety monitoring when using gas.

[0014]

In order to solve the above-mentioned problems, a gas meter according to a first aspect of the present invention is a gas meter which repeats expansion / contraction operation according to a gas passage flow rate passing through the meter, and an expansion / contraction operation of the film. Rotate and move in tandem with N pole and S pole
A magnet that applies a magnetic field that alternately changes with a pole to a predetermined region; and a reed switch that is arranged on the predetermined region and that performs an opening / closing operation based on a magnetic field change generated by the magnet,
In the gas meter for generating a pulse signal corresponding to the gas passage flow rate according to the opening / closing operation of the reed switch, the longitudinal direction of the pair of reed portions of the reed switch and the tangential direction of the rotation locus of the magnet are substantially parallel. Are arranged in the predetermined area so that when the magnetic force lines pass so as to intersect the pair of lead parts, the pair of lead parts are magnetized to the same pole and opened by the repulsive force, and the magnetic force lines form a pair of lead parts. When passing through substantially parallel, the pair of lead portions are magnetized to different polarities and closed by an attractive force, and a pulse signal is output according to opening / closing of the reed switch.

A gas meter according to a second aspect of the present invention is the gas meter according to the first aspect, wherein the magnet is a disk-shaped magnet and has a fan shape of 2n (n is any natural number of 1 or more). The region is characterized in that N poles and S poles are alternately magnetized.

A gas meter according to a third aspect of the present invention is the gas meter according to the first aspect, wherein the magnet is a magnet having an N pole and an S pole, and 2n (n Is arranged such that N poles and S poles are alternately oriented in the radial direction.

[0017]

DETAILED DESCRIPTION OF THE INVENTION A gas meter according to a first embodiment of the present invention will be described below with reference to the drawings. First, the operation principle will be described.
FIG. 1 is an explanatory view for explaining the operation principle of the reed switch. As shown in FIG. 1, the magnet 1 is arranged in the vicinity of the reed switch 2 to change the magnetic field, which is also common to the prior art, but is different in that the reed switch 2 is closed or opened depending on the direction of the magnetic force line. ing.

For example, when the reed switch 2 is closed, as shown in FIG. 1 (a), the longitudinal direction of the lead portions 2a and 2b of the reed switch 2 and the line of magnetic force from the north pole to the south pole of the magnet. Magnet 1 so that the direction is almost parallel
And the reed switch 2 is arranged. In this case, the magnetic field lines from the N pole of the magnet 1 to the S pole cause the reed switch 2 to move.
Of the two lead portions 2a and 2b in which the lead portion 2a is magnetized to the S pole and the lead portion 2b is magnetized to the N pole to be magnetized to different polarities.
Is attracted and reed switch 2 closes the circuit. When the application of this magnetic field is stopped, the reed switch 2 opens the circuit due to the elasticity of the reeds 2a and 2b.

In FIG. 1A, the N pole of the magnet 1 is arranged on the left side of the figure and the S pole of the magnet 1 is arranged on the right side of the figure, but the positions of the N pole and the S pole are interchanged. There may be such cases. In this case as well, the pair of reed portions 2a and 2b magnetized with different polarities are similarly attracted and the reed switch 2 closes the circuit. If the magnet 1 and the reed switch 2 are arranged so that the longitudinal directions of the lead portions 2a and 2b and the direction of the magnetic force lines are substantially parallel to each other, the switches are closed in any case.

When the reed switch 2 is opened, as shown in FIG. 1 (b), the reed portions 2a and 2b of the reed switch 2 and the magnetic lines of force toward the S pole of the magnet are crossed. Due to the magnetic force line toward the S pole of the magnet 1, both the lead portions 2a and 2b of the reed switch 2 are magnetized to the N pole, the pair of lead portions 2a and 2b magnetized to the same pole repel, and the reed switch 2 is connected to the circuit. Open up. Even if the application of the magnetic field is stopped, the elasticity of the lead portions 2a and 2b keeps the circuit open.

Although FIG. 1 (b) does not show the magnetic force lines generated from the N pole of the magnet, the reed portion 2a is also formed when the magnetic force lines generated from the N pole of the magnet intersect the lead portions 2a and 2b of the reed switch 2. , 2b are both magnetized to the S pole, the pair of reed portions 2a and 2b magnetized to the same pole repel, and the reed switch 2 opens the circuit. In any of these cases, the switch is opened.

Next, the gas meter of this embodiment using the above-mentioned principle will be schematically described with reference to FIGS.
FIG. 2 is an explanatory view of a main part of a gas meter using a two-pole circular magnet in the present embodiment, and FIG. 3 is an explanatory view explaining a state of a reed switch of a reed switch which opens and closes depending on a magnetic field direction of the two-pole circular magnet. Is.

The magnet 1 is made of a magnetic material and formed in a disk shape, and is configured to rotate about a rotation center axis as shown in FIG. The disk-shaped magnet 1 is divided into two half moons and is magnetized to the N pole and the S pole. The reed switch 2 includes reed parts 2a and 2b,
The longitudinal directions of the lead portions 2a and 2b and the tangential direction of the rotation trajectory of the magnet 1 are arranged in parallel. This is the same as arranging so that the radial direction by the radius passing through the rotation center axis and the longitudinal direction of the reed switch are approximately 90 °, but they are the same only by changing the expression method.

When the positional relationship between the magnet 1 and the reed switch 2 becomes as shown in FIG. 3 (a) due to the rotation of the magnet 1, the lines of magnetic force from the N pole to the S pole are paired with each other.
Since it passes substantially parallel to a and 2b, as described with reference to FIG. 1A, the pair of lead portions 2a and 2b are magnetized to the different poles of the S pole and the N pole, respectively. The parts 2a and 2b are sucked and the reed switch 2 is closed.

In FIG. 3A, the magnet is 180
Even when the positions of the N pole and the S pole are exchanged by rotating by ゜, the pair of lead portions 2a and 2b are similarly N-shaped.
The different polarities of the pole and the S pole are magnetized, and the reed portions 2a and 2b are attracted to each other and the reed switch 2 is closed.

On the other hand, when the magnet 1 rotates and changes from the state of FIG. 3 (a) to the state of FIG. 3 (b), the magnetic force lines generated from the N pole cross the pair of lead portions 2a, 2b. After passing through, the pair of lead portions 2a and 2b have the same polarity (Fig. 3 (b)).
Then, it is magnetized to the S pole), and the lead portions 2 of each other are magnetized.
a and 2b repel and can forcefully open the circuit.
In addition, in FIG. 3B, the magnet is rotated 180 ° and
Even when the positions of the pole and the S pole are exchanged, similarly, the pair of reed portions 2a and 2b are magnetized to the same pole and repelled, and the reed switch 2 is opened.

In the conventional gas meter described with reference to FIGS. 7 and 8, even after the pair of reeds are magnetized to have different polarities and the magnet 100 moves away from the reed switch 300, the magnetic force is generated from the reeds 2a and 2b. It will take some time to disappear, so keep closing for a while. For this reason,
The output characteristics were not good when multiple pulses were generated in one rotation.

On the other hand, in the present embodiment, the lead portions 2a, 2b.
Are magnetized to have the same or different polarities to forcibly open and close the pair of lead portions, so that the closing time and the opening time of the reed switch are substantially equal to each other, and the pulse signal can be reliably generated. In addition, as shown in FIG.
When there is a pole and an S pole, two pulse signals can be output, and the number of pulses can be doubled as compared with the conventional technique. Further, even when the magnet 1 rotates faster, it is possible to generate a pulse signal with clear on / off and good output characteristics, and to ensure the safety monitoring operation.

Next, a second embodiment according to claims 1 and 2 will be described. In this embodiment, the disk-shaped magnet 1 that is a magnetic body is divided into a plurality of fan shapes, and the N poles and the S poles are magnetized alternately. Hereinafter, description will be given with reference to the drawings. FIG. 4 is an explanatory view of a main part of a gas meter using a multi-pole (six poles in the figure) circular magnet in the present embodiment, and FIG. 5 opens and closes depending on a magnetic field direction of the multi-pole (six poles in the figure) circular magnet. It is explanatory drawing explaining the state of the reed part of a reed switch.

As shown in FIG. 4, the gas meter of this embodiment includes a reed switch 2 having a magnet 1 and reed portions 2a and 2b. The gas meter of the present embodiment has basically the same configuration as the gas meter of the first embodiment, except that N-poles and S-poles are alternately magnetized in a fan-shaped region having a plurality of magnets (6 in FIG. 4). It's different. Other than this,
The description is omitted because it is the same as in the first embodiment.

Next, the operation will be described. 4 and 5
The second embodiment described by using is almost the same as the first embodiment described by using FIGS. 2 and 3, but in this case,
The difference is that the magnet 1 has a plurality of magnetic poles. Due to the rotation of the magnet 1, the magnetic poles and the lead portions 2a and 2b of the reed switch 2
When the positional relationship with is in the state shown in FIG.
Lines of magnetic force from the pole to the S pole are a pair of lead portions 2a, 2b
As described above with reference to FIG. 3A, the pair of lead portions 2a and 2b are magnetized to different polarities of the S pole and the N pole, respectively. 2a and 2b are sucked and the reed switch 2 is closed.
Such a state also occurs when the N pole and the S pole are exchanged in FIG. 5A.

When the magnet 1 further rotates and changes from the state of FIG. 5 (a) to the state of FIG. 5 (b), the magnetic force lines generated from the N pole run substantially perpendicularly to the pair of lead portions 2a, 2b. , The pair of reed portions 2a and 2b are magnetized to the same pole (S pole in FIG. 5B) to repel them, and the reed switch 2 is forcibly opened. Such a state also occurs when the N pole and the S pole are exchanged in FIG. 5B.

Also in this embodiment, the reed switches 2a and 2b are magnetized to have the same or different polarities to forcibly open and close the pair of reed parts 2a and 2b. By making them substantially equal to each other, it is possible to reliably generate a rectangular wave pulse signal. For example, even when multiple pulses are generated in one rotation, it is possible to generate a pulse signal with a clear rise and fall at the time of opening and closing and good output characteristics, and to ensure safety monitoring operation. it can.

Next, a third embodiment according to claims 1 and 3 will be described. In this embodiment, the first and second
Instead of the disk-shaped magnet of the embodiment, a plurality of magnets 1 having N and S poles are attached to the rotating body 3 to form a magnetic field. Specifically, a magnetic field is formed by using a plurality of line-shaped or bar-shaped magnets 1 each having an N pole and an S pole. FIG. 6 is an explanatory diagram illustrating the state of the reed portion of the reed switch that opens and closes according to the direction of the magnetic field of the multi-pole circular magnet according to this embodiment.

As shown in FIGS. 6 (a) and 6 (b), a plurality of (in FIG. 6, in FIG. 6) N and S poles are alternately arranged in the radial direction on the rotating body 3 which draws a rotation locus. 4 magnets 1 are arranged. The reed switch 2 is the same as that described in the first embodiment, and the description thereof is omitted. The rotating body 3 is a non-magnetic body and is designed so as not to be magnetized by the magnetic force from the magnet 1.

The magnetic field formed by the plurality of magnets 1 is the same as the magnetic field described in the second embodiment.
The magnet 1 is rotated by the rotation of the rotating body 3, and the positional relationship between the magnetic poles and the reeds 2a and 2b of the reed switch 2 is such that the magnetic field lines from the N pole to the S pole are paired as shown in FIG. 6A. When passing through the lead portions 2a and 2b substantially in parallel, as described with reference to FIG. 5A, the pair of lead portions 2a and 2b are magnetized to the different poles of the S pole and the N pole, respectively. This means that the reed parts 2a and 2b are attracted to each other and the reed switch 2 is closed. Such a state similarly occurs when the N pole and the S pole are exchanged in FIG. 6A.

Further, when the magnet 1 is rotated by the rotation of the rotating body 3 and the state of FIG. 6 (a) is changed to the state of FIG. 6 (b), the lines of magnetic force generated from the N pole are a pair of lead portions 2.
The pair of reed parts 2a and 2b are magnetized to have the same pole (S pole in FIG. 6B) to repel by running a and 2b substantially vertically, and the reed switch 2 is forcibly opened. Such a state also occurs when the N pole and the S pole are exchanged in FIG. 6B.

In the present embodiment, the lead portions 2a and 2b are magnetized to have the same or different polarities so that the pair of lead portions 2a and 2b are forcibly opened and closed. Therefore, the closing time and the opening time of the reed switch 2 are set. By making them substantially equal to each other, it is possible to reliably generate a rectangular wave pulse signal. For example, even when multiple pulses are generated in one rotation, it is possible to generate a pulse signal with a clear rise and fall at the time of opening and closing and good output characteristics, and to ensure safety monitoring operation. it can. Even in the case where the small and even number of magnets 1 are arranged on the disc-shaped rotating body so that the S poles and the N poles are alternately oriented in the radial direction of the circle, the same effect as that described in the second embodiment is obtained. The effect can be obtained.

The first to third embodiments have been described above. In addition, 2 poles in the first embodiment, 6 poles in the second embodiment,
Although the case of using a 4-pole magnet has been described in the third embodiment, the number of poles is not limited to these, and if the number of poles satisfies 2n, the number of poles may be 8 or 10. . Therefore, in the second embodiment, the circular magnet 1 is divided into 2n fan-shaped regions so that the N poles and the S poles are magnetized alternately, or in the third embodiment, 2
N magnets are arranged so that the N poles and the S poles alternately face outward,
You may arrange. These are appropriately designed and selected.

[0040]

As described above, according to the present invention, a pair of reed portions of a reed switch are made to have different polarities to be closed by a suction force,
Further, since the electrodes are made to have the same polarity and are opened by the repulsive force, it is possible to improve the responsiveness of opening and closing the contacts and improve the pulse output characteristics.

Further, the rotation locus for the pulse signal transmission of the gas meter represented by the membrane gas meter can be made small, and the space in the gas meter can be easily secured. In particular, in order to improve accuracy by obtaining multiple transmissions per rotation, conventionally, it was necessary to increase the distance between magnets to be arranged, so it was necessary to increase the rotating body or rotation locus. According to the method of the present invention, the opening / closing operation of the reed switch, particularly the opening operation, can be reliably performed even with a small rotation locus of the magnet.

In general, the rotation locus drawn by the magnet is made small to realize the miniaturization of the rotary drive mechanism and the rotary body, and the reed switch is surely opened / closed to output a clear pulse signal with a small noise component. It is possible to provide a gas meter that can reliably perform safety monitoring when using gas.

[Brief description of drawings]

FIG. 1 is an explanatory diagram illustrating an operation principle of a reed switch.

FIG. 2 is an explanatory view of a main part of a gas meter using a two-pole circular magnet according to the first embodiment of the present invention.

FIG. 3 is an explanatory view illustrating a state of a reed portion of a reed switch that opens and closes depending on a magnetic field direction of a two-pole circular magnet.

FIG. 4 is an explanatory view of a main part of a gas meter using a multi-pole circular magnet according to the second embodiment of the present invention.

FIG. 5 is an explanatory diagram illustrating a state of a lead portion of a reed switch that opens and closes according to a magnetic field direction of a multi-pole circular magnet.

FIG. 6 is an explanatory diagram illustrating a state of a reed portion of a reed switch that opens and closes according to a magnetic field direction of a multi-pole circular magnet according to a third embodiment of the present invention.

FIG. 7 is an explanatory diagram illustrating a first gas passage flow rate data acquisition principle by a conventional gas meter.

FIG. 8 is an explanatory diagram illustrating a second gas passage flow rate data acquisition principle by a conventional gas meter.

[Explanation of symbols]

1 magnet 2 reed switch 2a, 2b lead part 3 rotating bodies

Continued front page    (72) Inventor Mitsuhiro Nakamura             1-5-20 Kaigan, Minato-ku, Tokyo Tokyo Gas             Within the corporation (72) Inventor Eiichi Oshima             7-8-36 Nobe, East Road, Kamagaya City, Chiba Prefecture (72) Inventor Hideki Akai             5-15-30 Higashi Narashino, Narashino City, Chiba Prefecture (72) Inventor Takeshi Numagami             1-1 Tanabe Nitta, Kawasaki-ku, Kawasaki-shi, Kanagawa             Within Fuji Electric Co., Ltd. F-term (reference) 2F030 CA01 CC13 CD06 CE03 CE05

Claims (3)

[Claims] 1. A membrane that repeats expansion and contraction operations in accordance with the flow rate of gas passing through the inside of a meter, and a magnetic field that rotates and moves in conjunction with the expansion and contraction operations of the film, and that alternates between N and S poles. A magnet applied to a predetermined area, and a reed switch arranged on the predetermined area and performing an opening / closing operation based on a magnetic field change generated by the magnet are provided, and a pulse signal corresponding to a gas passage flow rate is provided to open / close the reed switch. In a gas meter generated according to an operation, the reed switch is arranged in the predetermined region such that a longitudinal direction of a pair of reed portions and a tangential direction of a rotation locus of the magnet are substantially parallel to each other, and a line of magnetic force is formed between the pair of reeds. When a pair of lead parts are magnetized to the same pole when passing so as to intersect with each other and opened by repulsive force, a pair of leads when magnetic field lines pass substantially parallel to a pair of lead parts It was closed by the suction force by magnetizing the different poles, characterized in that for outputting a pulse signal in response to the opening and closing of reed switch gas meter. 2. The gas meter according to claim 1, wherein the magnet is a disk-shaped magnet, and N poles and S poles are alternately arranged in a fan-shaped region of 2n (n is an arbitrary natural number of 1 or more). A gas meter characterized by being magnetized. 3. The gas meter according to claim 1, wherein the magnet is a magnet having an N pole and an S pole, and 2n (n is an arbitrary natural number of 1 or more) magnets are formed on a rotation mechanism that draws a rotation locus. A gas meter, wherein magnets are arranged such that north poles and south poles are alternately oriented in a radial direction.