JP3044967B2 - Flow measurement device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flow rate measuring device for measuring a flow rate of a fluid, and more particularly to a flow rate measuring device used for a water meter for measuring tap water consumption at home.

[0002]

2. Description of the Related Art In recent years, the amount of tap water used has been increasing with the improvement of daily life. On the other hand, there are many issues such as securing a new water source and maintaining water quality, and it is desired to save tap water, and the amount of water used is managed by water meters provided in each household.

A flow rate measuring device such as a water meter mechanically measures the amount of use by integrating the rotation of an impeller, or converts the rotation of the impeller into an electric signal using a magnetoelectric conversion element, and converts the electric signal. An electronic type that counts and integrates, measures and displays the amount of water used has been put into practical use (for example, see JP-A-56-2).
No. 1017).

Conventionally, as shown in FIG. 5, this type of flow rate measuring device has a rotating means 1 integrally formed with an impeller which rotates in accordance with the flow rate of tap water, and two magnetic members provided on the rotating means 1. 2, a first sensor means 3 comprising a magnetoresistive element for detecting a change in a magnetic field emitted from the magnetic body 2 for measuring the number of rotations of the rotating means 1, and a change in a magnetic field provided for detecting a rotation direction Of a magnetoresistive element for detecting
Sensor means 4, first sensor means 3, and second sensor means 4
The flow rate measuring means 5 for judging the number of rotations and the direction of rotation of the rotating means 1 from the output of the means 1 and integrating the usage fee of tap water used in each household, and supplying power from the first sensor means 3 to the flow rate measuring means 5 A power supply means 6, a connection piece 7 spot-welded to an electrode terminal of the power supply means 6, a printed board 8 for fixing and wiring the connection piece 7 of the power supply means 6 from the first sensor means 3; It is composed of a case 9 and an upper case 10, and the lower case and the upper case are strengthened in waterproofness by ultrasonic welding.

[0005] Then, from the first sensor means 3 to the upper case 1
A flow measurement device is configured with zero.

In the above configuration, the water meter displays the amount of tap water used at home and measures the meter.

[0007]

However, in the above arrangement, a water meter having a diameter of, for example, 13 mm is attached to a home and a child using a magnetic substance such as a magnet when measuring the amount of tap water used at home. There is a problem in that even if a mischief or malicious measurement obstruction for use of unpaid water supply is performed, it can be detected only once a month or every two months on a meter reading day.

[0008] In addition, since the components of the flow rate measuring device are magnetized by the magnetic field of the magnet used for mischief or the like, the rotational torque is increased due to the magnetic effect with the magnetic body 2 installed on the impeller of the water meter. Therefore, there is a problem that the starting flow characteristic that rotates even at a very small flow rate, which is a characteristic of a water meter, is deteriorated, and the very small flow rate cannot be measured.

SUMMARY OF THE INVENTION It is a first object of the present invention to solve the above-mentioned problems and to provide a flow rate measuring device for quickly detecting a metering disturbance for mischief of children or malicious use of unpaid water supply.

A second object of the present invention is to provide a flow rate measuring apparatus in which the constituent means of the flow rate measuring apparatus are magnetized and the deterioration of the starting flow rate characteristic due to the magnetic influence with the magnetic substance provided on the rotating means 1 is improved.

A third object of the present invention is to provide a flow rate measuring device which prevents erroneous measurement of the flow rate when demagnetizing the constituent means of the magnetized flow rate measuring device.

Further, a fourth object is to detect the magnetization of the flow rate measuring device from the change in the magnetic field and to demagnetize when the fluid is not used, thereby automatically deteriorating the starting flow rate characteristic without affecting the flow rate measurement. It is to provide a flow measurement device that is improved.

[0013]

SUMMARY OF THE INVENTION In order to achieve the first object, the present invention provides a sensor means for detecting a magnetic field change caused by a magnetic body provided on a rotating body which rotates according to a flow rate of a fluid; Flow rate measuring means for measuring the fluid flow rate at the output of the means, magnetization monitoring means for outputting a signal when a magnetic field exceeding a preset magnetic flux density is detected, and displaying or notifying an abnormal state by the signal of the magnetization monitoring means Warning means.

According to another aspect of the present invention, there is provided a sensor for detecting a change in a magnetic field caused by a magnetic body provided on a rotating body which rotates in accordance with a fluid flow rate; , A power supply means for supplying power to the sensor means and the flow rate measurement means, and a degaussing means for degaussing the sensor means, the flow rate measurement means and the power supply means.

According to a third aspect of the present invention, there is provided a sensor for detecting a change in a magnetic field caused by a magnetic material provided on a rotating body which rotates in accordance with a fluid flow rate; Flow rate measuring means for measuring the flow rate, power supply means for supplying power to the sensor means and the flow rate measuring means, degaussing means for degaussing the sensor means, the flow rate measuring means and the power supply means, the power supply means The degaussing means stops power supply to the sensor means during degaussing.

According to a fourth aspect of the present invention, there is provided a sensor for detecting a change in a magnetic field caused by a magnetic body provided on a rotating body which rotates in accordance with a fluid flow rate; Flow measurement means for measuring the flow rate, zero flow rate determination means that outputs a signal when the flow rate measured by the flow rate measurement means is zero, and magnetization monitoring means that outputs a signal when a magnetic field exceeding a preset magnetic flux density is detected Power supply means for supplying power to the sensor means, the flow rate measurement means, the flow rate zero determination means, the magnetization monitoring means, and degaussing means for degaussing, wherein the degaussing means detects a signal from the magnetization monitoring means. And when the signal of the flow rate zero determining means is detected, the constituent means of the flow meter device are demagnetized.

[0017]

According to the present invention, when the magnetization monitoring means detects a magnetic field exceeding a preset magnetic flux density, it outputs a signal,
It works to detect children's mischief using magnetic material, weighing disturbance using magnetic material for malicious use of unpaid water supply, and adverse effects on the components of the flow rate measurement device due to welding work and warning. The means notifies the center of the abnormal state by the signal of the magnetization monitoring means.

Further, the demagnetizing means demagnetizes the constituent means of the flow rate measuring device, so that the constituent means of the flow rate measuring device and the magnetic substance installed on the rotating body act so as to eliminate the magnetic influence. Degradation is improved.

The power supply means stops the power supply to the sensor means during degaussing by the degaussing means, thereby acting so that the sensor means does not detect a change in the magnetic field at the time of degaussing, thereby preventing erroneous measurement of the flow rate.

Further, the degaussing means automatically detects when the fluid is not used by detecting the signal of the magnetization monitoring means and degaussing the constituent means of the flow measuring device when detecting the signal of the zero flow determining means. It acts to demagnetize and automatically improves the degradation of the starting flow characteristics without affecting the flow measurement.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIG. The same parts as those in the conventional example are denoted by the same reference numerals. In FIG. 1, reference numeral 1 denotes a rotating means integrally formed with an impeller which rotates in accordance with the flow rate of tap water, and 2 denotes a center located at a position of 5 mm with respect to the center of the rotating shaft of the rotating means 1 and different from each other in the direction of the rotating axis. There are two magnetic bodies installed to be poles. Reference numeral 3 denotes first sensor means comprising a magnetoresistive element for detecting a change in a magnetic field generated by the magnetic body 2 for measuring the number of rotations of the rotation means 1, and 4 denotes a change in a magnetic field provided for detecting a rotation direction. The second sensor means 5 comprising a magnetoresistive element for detecting the use of tap water used in each household by judging the number of rotations and the direction of rotation of the rotating means 1 from the outputs of the first sensor means 3 and the second sensor means 4 It is a flow rate measuring means 5 for integrating charges. Numeral 11 denotes a magnetic field detecting means comprising three search coils installed for measuring a three-dimensional magnetic flux density component and an operational amplifier for amplifying a voltage induced in the search coil, and 12 outputs a signal every second. A / D conversion means for converting an analog voltage value from the magnetic field detection means 11 into a digital value based on an output signal of the one-second counting means 12 and a 14-second counting means for controlling a magnetic field intensity which affects a water meter in advance. Threshold storage means 15 for storing the converted induced voltage value, 15 is an induced voltage value obtained by converting the induced voltage value digitized by the A / D conversion means 13 and the magnetic field intensity stored in the threshold value storage means 14 and affecting the water meter. This is a magnetization monitoring unit that compares a value (threshold value) and outputs a signal that a water meter abnormality has occurred when the value is larger than the value. 16
Reference numeral denotes warning means for notifying the waterworks center device 18 that an abnormality has occurred in the water meter based on the output signal of the magnetization monitoring means 15. In the present embodiment, it is also possible to set the induced voltage value (threshold value) obtained by converting the magnetic field intensity affecting the water meter into the threshold value storage means 14 using the communication port of the warning means 16. Reference numeral 17 denotes a signal from the one-second counting means 12 for updating and storing the tap water usage accumulated and stored by the flow rate measuring means 5 and a signal from the magnetizing monitoring means 15 for notifying the water meter abnormality of the tap water usage. Backup memory means for stopping the update storage, storing the integrated value immediately before the abnormality, and outputting the stored integrated value to the warning means 16. In the present embodiment, a memory that retains the stored contents even during a power failure is used as the backup memory unit 17. Then, the first sensor means 3, the second sensor means 4, the flow rate measuring means 5, the magnetic field detecting means 11, the 1 second counting means 12, the A / D converting means 1
3, threshold storage means 14, magnetization monitoring means 15, warning means 1
6. The flow rate measuring device is constituted by the backup memory means 17.

Next, the magnetic body 2 will be described in detail. In this embodiment, the shape of the magnetic body 2 is 3.0 mm in width and 2.8 m in height.
m, length 7.0 mm, magnetization in 2.8 mm direction. Also,
The material is a rare earth cobalt magnet with a residual magnetic flux density of 9.6.
A magnetic material having a magnetic characteristic of kGauss and a coercive force of 8.5 kOe was used. In addition, this material has a linear demagnetization curve (BH curve) and is optimal as a permanent magnet.

Next, the first sensor means 3 and the second sensor means 4 are installed at a distance of 8.5 mm from the magnetic body 2 installed on the rotating means 1 and at a distance of 5 mm from the rotating axis and perpendicular to the rotating axis. . And the rotation of the magnetic material from 0 Gauss to 4
The magnetic flux density of 5 Gauss is detected, and rotation is detected based on a preset magnetic flux density threshold value. Second sensor means 4
Is rotated 135 degrees with respect to the first sensor means 3 and is disposed at a position 5 mm away from the center of the rotation axis.

Next, the water meter abnormality detection of this embodiment will be described in detail. In this embodiment, the magnetic field detecting means 11 is installed in parallel with the first sensor means 3 and the second sensor means 4 and at a distance of 20 mm from the rotation axis, and detects the maximum magnetic flux density of 1 Gauss or less by rotating the magnetic body 2. can do. In addition, the threshold value storage means 14 stores an induced voltage conversion value of a magnetic flux density of 5 Gauss which adversely affects the water meter. Then, the magnetization monitoring means 15 outputs a signal indicating that the water meter is adversely affected when the magnetic flux density at the position where the magnetic field detection means 11 is installed is 5 Gauss or more.

In the above flow rate measuring device, when the magnetization monitoring means 15 detects a magnetic field exceeding the magnetic flux density set in the threshold value storage means 14 in advance, a signal is output, so that the child using the magnetic material can be tampered with or maliciously used. It works to detect weighing disturbances using magnetic material for the purpose of using uneasy water supplies, and adverse effects on the components of the flow rate measurement device due to welding work, etc. Weighing disturbance can be detected immediately.

Although the magnetic field detecting means 11 of this embodiment detects the magnetic flux density by the induced voltage by the search coil, the same effect can be obtained by the MR sensor using the magnetoresistive element and the Hall IC using the Hall element. it can.

A second embodiment will be described with reference to FIG. The same parts as those in the conventional example are denoted by the same reference numerals. In FIG. 2, reference numeral 1 denotes a rotating means integrally formed with an impeller which rotates according to the flow rate of tap water, and 2 denotes a center located at a position of 5 mm with respect to the center of the rotation axis of the rotation means 1 and different from each other in the direction of the rotation axis. There are two magnetic bodies installed to be poles. Reference numeral 3 denotes a magnetic body 2 for measuring the number of rotations of the rotating means 1.
The first sensor means 4 comprises a magnetoresistive element for detecting a change in the magnetic field generated by the sensor. The second sensor means 4 comprises a magnetoresistive element for detecting a change in a magnetic field provided for detecting the direction of rotation. A flow rate measuring means 5 for judging the number of rotations and the direction of rotation of the rotating means 1 from the outputs of the sensor means 3 and the second sensor means 4 and integrating the usage fee of tap water used in each household. Numeral 11 denotes a magnetic field detecting means comprising three search coils installed for measuring a three-dimensional magnetic flux density component and an operational amplifier for amplifying a voltage induced in the search coil, and 12 outputs a signal every second. A / D conversion means for converting an analog voltage value from the magnetic field detection means 11 into a digital value based on an output signal of the one-second counting means 12 and a 14-second counting means for controlling a magnetic field intensity which affects a water meter in advance. Threshold storage means 15 for storing the converted induced voltage value, 15 is an induced voltage value obtained by converting the induced voltage value digitized by the A / D conversion means 13 and the magnetic field intensity stored in the threshold value storage means 14 and affecting the water meter. This is a magnetization monitoring unit that compares a value (threshold) and outputs a signal that a water meter abnormality has occurred when the value is larger than the threshold. Numeral 16 denotes a warning unit for notifying the water station central unit 18 that an abnormality has occurred in the water meter based on an output signal of the magnetization monitoring unit 15. In the present embodiment, it is also possible to set the induced voltage value (threshold value) obtained by converting the magnetic field intensity affecting the water meter into the threshold value storage means 14 using the communication port of the warning means 16. Reference numeral 17 denotes a signal from the one-second counting means 12 for updating and storing the tap water usage accumulated and stored by the flow rate measuring means 5 and a signal from the magnetizing monitoring means 15 for notifying the water meter abnormality of the tap water usage. The update storage is stopped, the integrated value immediately before the time of the abnormality is stored, and the stored integrated value is indicated by the warning means 16.
Backup memory means for outputting to In the present embodiment, a memory that retains the stored contents even during a power failure is used as the backup memory unit 17. Reference numeral 19 denotes a power supply unit that supplies power to the flow rate measuring device according to the present embodiment. Reference numeral 20 denotes when the magnetization monitoring means 15 detects a water meter abnormality due to magnetic influence and outputs a signal, and applies an AC voltage of 60 Hz to a degaussing coil previously installed so as to surround the entire flow rate measuring device to gradually reduce the amplitude. Degaussing means (AC degaussing method). Reference numeral 21 denotes an external terminal for supplying an AC power necessary for the degaussing means 20 to perform the AC degaussing method. Then, the first sensor means 3, the second sensor means 4, the flow rate measuring means 5, the magnetic field detecting means 11, the 1 second counting means 12, the A /
D conversion means 13, threshold storage means 14, magnetization monitoring means 1
5, a warning unit 16, a backup memory unit 17, a power supply unit 19, a demagnetizing unit 20, and an external terminal unit 21 constitute a flow rate measuring device.

Next, the magnetic body 2 will be described in detail. In this embodiment, the shape of the magnetic body 2 is 3.0 mm in width and 2.8 m in height.
m, length 7.0 mm, magnetization in 2.8 mm direction. Also,
The material is a rare earth cobalt magnet with a residual magnetic flux density of 9.6.
A magnetic material having a magnetic characteristic of kGauss and a coercive force of 8.5 kOe was used. In addition, this material has a linear demagnetization curve (BH curve) and is optimal as a permanent magnet.

Next, the first sensor means 3 and the second sensor means 4 are installed at a distance of 8.5 mm from the magnetic body 2 installed on the rotating means 1 and at a distance of 5 mm from the rotating axis and perpendicular to the rotating axis. . And the rotation of the magnetic material from 0 Gauss to 4
The magnetic flux density of 5 Gauss is detected, and rotation is detected based on a preset magnetic flux density threshold value. Second sensor means 4
Is rotated 135 degrees with respect to the first sensor means 3 and is disposed at a position 5 mm away from the center of the rotation axis.

Next, the abnormality detection of the water meter and the operation of the demagnetizing means 21 in this embodiment will be described in detail. In this embodiment, the magnetic field detecting means 11 is installed in parallel with the first sensor means 3 and the second sensor means 4 and at a distance of 20 mm from the rotation axis, and detects the maximum magnetic flux density of 1 Gauss or less by rotating the magnetic body 2. can do. In addition, the threshold value storage means 14 stores an induced voltage conversion value of a magnetic flux density of 5 Gauss which adversely affects the water meter. When the magnetic flux density at the position where the magnetic field detecting means 11 is installed is 5 Gauss or more, the magnetization monitoring means 15 outputs a signal indicating that the water meter is adversely affected, and the warning means 16 notifies the water station center apparatus of the abnormality. The dewatering means 20 supplies the AC voltage necessary for degaussing the external terminals 21 after the water bureau staff inspects the corresponding water meter and removes the magnetic field generation material, so that the degaussing means 20 constitutes a flow rate measuring device. Is demagnetized.

With the above configuration, even if the constituent means of the flow rate measuring device is magnetized by an artificially forced magnetic field, the demagnetizing means 20
Demagnetizes the constituent means of the flow rate measuring device so as to eliminate the magnetic influence between the constituent means of the flow rate measuring device and the magnetic body 2 provided on the rotating means 1, thereby improving the deterioration of the starting flow rate characteristic. be able to.

In this embodiment, the necessary power is supplied from the external terminal portion 21 when the degaussing means 20 is degaussed. However, the same effect can be obtained by supplying the power using the communication port of the warning means 16. .

In this embodiment, a degaussing coil is incorporated in the flow rate measuring device. However, when an abnormality due to magnetic influence is found, a waterworks bureau staff removes magnetic debris at the site and covers the meter with the degaussing coil. A similar effect can be obtained by demagnetizing the means.

A third embodiment will be described with reference to FIG. The same parts as those in the conventional example are denoted by the same reference numerals. In FIG. 3, reference numeral 1 denotes a rotating means integrally formed with an impeller which rotates according to the flow rate of tap water, and 2 denotes a center located at a position of 5 mm with respect to the center of the rotating shaft of the rotating means 1 and is different from each other in the direction of the rotating axis. There are two magnetic bodies installed to be poles. Reference numeral 3 denotes a magnetic body 2 for measuring the number of rotations of the rotating means 1.
The first sensor means 4 comprises a magnetoresistive element for detecting a change in the magnetic field generated by the sensor. The second sensor means 4 comprises a magnetoresistive element for detecting a change in a magnetic field provided for detecting the direction of rotation. A flow rate measuring means 5 for judging the number of rotations and the direction of rotation of the rotating means 1 from the outputs of the sensor means 3 and the second sensor means 4 and integrating the usage fee of tap water used in each household. Numeral 11 denotes a magnetic field detecting means comprising three search coils installed for measuring a three-dimensional magnetic flux density component and an operational amplifier for amplifying a voltage induced in the search coil, and 12 outputs a signal every second. A / D conversion means for converting an analog voltage value from the magnetic field detection means 11 into a digital value based on an output signal of the one-second counting means 12 and a 14-second counting means for controlling a magnetic field intensity which affects a water meter in advance. Threshold storage means 15 for storing the converted induced voltage value, 15 is an induced voltage value obtained by converting the induced voltage value digitized by the A / D conversion means 13 and the magnetic field intensity stored in the threshold value storage means 14 and affecting the water meter. This is a magnetization monitoring unit that compares a value (threshold) and outputs a signal that a water meter abnormality has occurred when the value is larger than the threshold. Numeral 16 denotes a warning unit for notifying the water station central unit 18 that an abnormality has occurred in the water meter based on an output signal of the magnetization monitoring unit 15. In the present embodiment, it is also possible to set the induced voltage value (threshold value) obtained by converting the magnetic field intensity affecting the water meter into the threshold value storage means 14 using the communication port of the warning means 16. Reference numeral 17 denotes a signal from the one-second counting means 12 for updating and storing the tap water usage accumulated and stored by the flow rate measuring means 5 and a signal from the magnetizing monitoring means 15 for notifying the water meter abnormality of the tap water usage. The update storage is stopped, the integrated value immediately before the time of the abnormality is stored, and the stored integrated value is indicated by the warning means 16.
Backup memory means for outputting to In the present embodiment, a memory that retains the stored contents even during a power failure is used as the backup memory unit 17. Reference numeral 19 denotes power supply means for supplying power to the flow rate measuring device. 20 is the magnetization monitoring means 15
Is a degaussing means that applies a 60 Hz AC voltage to a degaussing coil previously installed so as to surround the entire flow rate measuring device and gradually reduces the amplitude when a water meter abnormality due to magnetic influence is detected and a signal is output. . 21 is demagnetizing means 20
Is an external terminal for supplying an AC power necessary for performing the AC demagnetization method. The power supply 19 is a first sensor 3
Power supply unit 23 for supplying power to the second sensor means 4
And a first power supply unit 22 for supplying power to the units constituting the flow rate measuring device other than the first sensor unit 3 and the second sensor unit 4
And a switching unit 24 for stopping the power supply of the second power supply unit 23 when the degaussing means 20 is degaussed. Then, the first sensor means 3, the second sensor means 4, the flow rate measuring means 5, the magnetic field detecting means 11, the 1 second counting means 12, the A /
D conversion means 13, threshold storage means 14, magnetization monitoring means 1
5, a warning unit 16, a backup memory unit 17, a power supply unit 19, a demagnetizing unit 20, and an external terminal unit 21 constitute a flow rate measuring device.

Next, the magnetic body 2 will be described in detail. In this embodiment, the shape of the magnetic body 2 is 3.0 mm in width and 2.8 m in height.
m, length 7.0 mm, magnetization in 2.8 mm direction. Also,
The material is a rare earth cobalt magnet with a residual magnetic flux density of 9.6.
A magnetic material having a magnetic characteristic of kGauss and a coercive force of 8.5 kOe was used. In addition, this material has a linear demagnetization curve (BH curve) and is optimal as a permanent magnet.

Next, the first sensor means 3 and the second sensor means 4 are installed at a distance of 8.5 mm from the magnetic body 2 installed on the rotating means 1 and at a distance of 5 mm from the rotating axis and perpendicular to the rotating axis. . When the magnetic body 2 rotates, the magnetic flux density from 0 Gauss to 45 Gauss is detected, and the rotation is detected based on a preset magnetic flux density threshold value. Second sensor means 4
Is rotated 135 degrees with respect to the first sensor means 3 and is disposed at a position 5 mm away from the center of the rotation axis.

Next, the operation of stopping the power supply to the first sensor means 3 and the second sensor means 4 when the abnormality of the water meter is detected and the demagnetizing means 20 operates in this embodiment will be described in detail. In this embodiment, the magnetic field detecting means 11 is installed in parallel with the first sensor means 3 and the second sensor means 4 and at a distance of 20 mm from the rotation axis, and when the magnetic body 2 rotates, 1 Ga
The maximum magnetic flux density below uss can be detected. In addition, the threshold value storage means 14 stores an induced voltage conversion value of a magnetic flux density of 5 Gauss which adversely affects the water meter. When the magnetic flux density at the position where the magnetic field detecting means 11 is installed is 5 Gauss or more, the magnetization monitoring means 15 outputs a signal indicating that the water meter is adversely affected, and the warning means 16 notifies the water station center apparatus of the abnormality. Water terminal bureau staff inspects the applicable water meter and removes the magnetic field generated.
The demagnetizing means 20 demagnetizes the means constituting the flow rate measuring device by supplying an AC voltage necessary for demagnetizing to 1. At this time, the switching unit 24 is configured to stop the power supply to the first sensor unit 3 and the second sensor unit 4 supplied by the second power supply unit 23.

With the above configuration, the power supply means 19 stops the power supply to the first sensor means 3 and the second sensor means 4 while the degaussing means 20 is degaussing, so that the first sensor means 3 and the second sensor means are demagnetized. This prevents the change in the 60 Hz AC magnetic field at the time of detection, prevents erroneous measurement of the flow rate, and enables accurate flow rate measurement even in the event of abnormality due to magnetic influence.

A fourth embodiment will be described with reference to FIG. The same parts as those in the conventional example are denoted by the same reference numerals. In FIG. 4, reference numeral 1 denotes a rotating means in which an impeller which rotates according to the flow rate of tap water is integrally formed. There are two magnetic bodies installed to be poles. Reference numeral 3 denotes a magnetic body 2 for measuring the number of rotations of the rotating means 1.
The first sensor means 4 comprises a magnetoresistive element for detecting a change in the magnetic field generated by the sensor. The second sensor means 4 comprises a magnetoresistive element for detecting a change in a magnetic field provided for detecting the direction of rotation. A flow rate measuring means 5 for judging the number of rotations and the rotating direction of the rotating means 1 from the outputs of the sensor means 3 and the second sensor means 4, accumulating the usage fee of tap water used in each household, and calculating the instantaneous flow rate. . Numeral 11 denotes a magnetic field detecting means comprising three search coils installed for measuring a three-dimensional magnetic flux density component and an operational amplifier for amplifying a voltage induced in the search coil, and 12 outputs a signal every second. 1 second counting means, 25 is a signal of the 1 second counting means 12, a flow rate zero determining means for outputting a signal when the instantaneous flow rate of the flow measuring means 5 is zero, and 13 is a magnetic field detecting means by an output signal of the 1 second counting means 12. A / D conversion means for converting an analog voltage value from 11 into a digital value, 14 a threshold value storage means for storing an induced voltage value converted in advance from a magnetic field intensity affecting a water meter, and 15 an A / D conversion means 1
3 compares the digitized induced voltage value with the induced voltage value (threshold value) converted from the magnetic field intensity affecting the water meter stored in the threshold value storage means 14, and when the value is larger than the threshold value, a water meter abnormality has occurred. , And outputs a signal when the signal of the flow rate zero determination means 25 and the demagnetization permission signal are output. Reference numeral 16 denotes an output signal of the magnetization monitoring means 15 which notifies the water station center apparatus 18 that an abnormality has occurred in the water meter, and a water station clerk inspects the water meter from the water station center apparatus to remove the magnetic field generated product. This is a warning means for notifying the water meter of the demagnetization permission signal from the water station center device 28 after the countermeasure is implemented. In the present embodiment, it is also possible to set the induced voltage value (threshold value) obtained by converting the magnetic field intensity affecting the water meter into the threshold value storage means 14 using the communication port of the warning means 16. 1
Reference numeral 7 denotes a signal from the one-second counting means 12 for updating and storing the amount of tap water used by the flow rate measuring means 5 and storing the accumulated amount of tap water. Backup memory means for stopping the update storage, storing the integrated value immediately before the abnormality, and outputting the stored integrated value to the warning means 16. In the present embodiment, a memory that retains the stored contents even during a power failure is used as the backup memory unit 17. Reference numeral 19 denotes power supply means for supplying power to the flow rate measuring device. Reference numeral 20 indicates that when the magnetization monitoring means 15 detects a water meter abnormality due to magnetic influence and outputs a signal, an AC voltage of 60 Hz is applied to a degaussing coil previously installed so as to surround the entire flow rate measuring device to gradually reduce the amplitude. This is a degaussing means for degaussing. In this embodiment, the power supply unit 1
9 supplies AC power to the demagnetizing means 20. Then, the first sensor means 3, the second sensor means 4, the flow rate measuring means 5,
Magnetic field detecting means 11, 1 second counting means 12, A / D converting means 13, threshold storage means 14, magnetization monitoring means 15, warning means 16, backup memory means 17, power supply means 1,
The demagnetizing means 20 and the zero flow rate determining means 25 constitute a flow rate measuring device.

Next, the magnetic body 2 will be described in detail. In this embodiment, the shape of the magnetic body 2 is 3.0 mm in width and 2.8 m in height.
m, length 7.0 mm, magnetization in 2.8 mm direction. Also,
The material is a rare earth cobalt magnet with a residual magnetic flux density of 9.6.
A magnetic material having a magnetic characteristic of kGauss and a coercive force of 8.5 kOe was used. In addition, this material has a linear demagnetization curve (BH curve) and is optimal as a permanent magnet.

Next, the first sensor means 3 and the second sensor means 4 are installed at a distance of 8.5 mm from the magnetic substance 2 installed on the rotating means 1 and at a distance of 5 mm from the rotating axis and perpendicular to the rotating axis. . When the magnetic body 2 rotates, the magnetic flux density from 0 Gauss to 45 Gauss is detected, and the rotation is detected based on a preset magnetic flux density threshold value. Second sensor means 4
Is rotated 135 degrees with respect to the first sensor means 3 and is disposed at a position 5 mm away from the center of the rotation axis.

Next, the abnormality detection of the water meter and the operation of the demagnetizing means 21 in this embodiment will be described in detail. In this embodiment, the magnetic field detecting means 11 is installed in parallel with the first sensor means 3 and the second sensor means 4 and at a distance of 20 mm from the rotation axis, and detects the maximum magnetic flux density of 1 Gauss or less by rotating the magnetic body 2. can do. In addition, the threshold value storage means 14 stores an induced voltage conversion value of a magnetic flux density of 5 Gauss which adversely affects the water meter. When the magnetic flux density at the position where the magnetic field detecting means 11 is installed is 5 Gauss or more, the magnetization monitoring means 15 determines that the water meter will be adversely affected, and notifies the water station center apparatus 18 via the warning means 16 of an abnormality. Then, after the Water Bureau staff inspects the water meter concerned and implements measures such as removal of magnetic field generated substances, the Water Bureau center equipment 18
Sends a demagnetization permission signal to the warning means 16 of the flow rate measuring device, and the arrival monitoring means 15 is configured to cause the degaussing means 20 to perform degaussing based on the demagnetization permission signal from the warning means 16 and the signal of the flow rate zero determination means 25. .

With the above arrangement, the demagnetizing means 20 detects the signal of the magnetization monitoring means 15 and, when detecting the demagnetizing permission signal from the water station center apparatus 18 and the signal of the zero flow rate determining means 25, changes the constituent means of the flow rate measuring device. By degaussing, when the fluid is not used, it acts so as to be degaussed automatically, and it is possible to automatically improve the starting flow characteristic deterioration without affecting the flow measurement.

[0044]

As described above, the flow rate measuring device according to the present invention outputs a signal when the magnetization monitoring means detects a magnetic field exceeding a preset magnetic flux density, so that children's mischief using a magnetic substance can be achieved. Detects and reports or displays adverse effects on the components of the flow rate measurement device due to the use of magnetic materials intended for malicious use of unpaid water supply, or welding work, etc., and measures or reports the flow rate due to magnetic effects. An abnormality of the device can be found at an early stage.

Further, the demagnetizing means demagnetizes the constituent means of the flow rate measuring device, so that the constituent means of the flow rate measuring device and the magnetic substance installed on the rotating body are prevented from being magnetically affected, and the water meter is operated. The starting flow rate can be improved without replacement.

Further, the power supply means prevents the sensor means from detecting a magnetic field change at the time of degaussing by stopping the power supply to the sensor means while the degaussing means is being degaussed, thereby preventing erroneous flow rate measurement during degaussing. Can be.

Further, the degaussing means automatically detects when the fluid is not used by detecting the signal of the magnetization monitoring means and degaussing the constituent means of the flow rate measuring device when detecting the signal of the zero flow rate determining means. It acts so as to demagnetize and can automatically improve the deterioration of the starting flow characteristic without affecting the flow measurement.

[Brief description of the drawings]

FIG. 1 is a block diagram of a flow measurement device according to a first embodiment of the present invention.

FIG. 2 is a block diagram of a flow measurement device according to a second embodiment of the present invention.

FIG. 3 is a block diagram of a flow rate measuring device according to a third embodiment of the present invention.

FIG. 4 is a block diagram of a flow rate measuring device according to a fourth embodiment of the present invention.

FIG. 5 is a configuration diagram of a conventional flow measurement device.

[Explanation of symbols]

 3 First sensor means 4 Second sensor means 5 Flow rate measuring means 11 Magnetic field detecting means 15 Abnormality monitoring means 16 Warning means 19 Power supply means 20 Degaussing means 25 Flow rate zero determination means

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-318426 (JP, A) Patent 2865833 (JP, B2) Patent 2579834 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , (DB name) G01F 15/075 G01F 1/00 G01F 1/075 G01F 1/115

Claims (4)

(57) [Claims] 1. A sensor means for detecting a magnetic field change by a magnetic body provided on a rotating body which rotates according to a fluid flow rate; a flow rate measuring means for measuring a fluid flow rate by an output of the sensor means; A flow rate measuring device comprising: a magnetization monitoring means for outputting a signal when a magnetic field exceeding a density is detected; and a warning means for displaying or notifying an abnormal state based on a signal from the magnetization monitoring means. 2. A sensor means for detecting a magnetic field change caused by a magnetic body provided on a rotating body which rotates according to a fluid flow rate, a flow rate measuring means for measuring a fluid flow rate by an output of the sensor means, and the sensor means. A flow rate measuring device comprising a power supply means for supplying power to the flow rate measuring means, and a demagnetizing means for degaussing the sensor means, the flow rate measuring means and the power supply means. 3. The flow rate measuring device according to claim 2, wherein the power supply means stops power supply to the sensor means while the degaussing means is degaussing. 4. A sensor for detecting a change in magnetic field due to a magnetic body provided on a rotating body which rotates according to a fluid flow rate, a flow rate measuring means for measuring a fluid flow rate by an output of the sensor means, and the flow rate measuring means. Zero flow rate determination means that outputs a signal when the measured flow rate is zero, magnetization monitoring means that outputs a signal when a magnetic field exceeding a preset magnetic flux density is detected, the sensor means, the flow rate measurement means, and a zero flow rate A power supply unit for supplying power to the determination unit and the magnetization monitoring unit; and a degaussing unit for performing degaussing, wherein the degaussing unit detects a signal from the magnetization monitoring unit and detects a signal from the zero flow rate determining unit. A flow rate measuring device, wherein each of the means is demagnetized.