JP2022178418A - Flow meter - Google Patents

Abstract

To provide a flow meter having a simple structure and hard to cause a problem such as entanglement of foreign matters, and allowing flow rate measurement even in a case of a pipe line in which a fluid non-periodically inflows and a fluctuation range of the flow rate is large.SOLUTION: A flow meter includes a sensor 10 attached to a top face 51 in a pipe line 50, and converts a load into an electric signal, an electric signal processing device 20 that determines a flow rate from the electric signal obtained by the sensor 10, and a pressing reception part 30 that has one end side coupled to the sensor 10 and transmits dynamic pressure F of a fluid flowing in the pipe line to the sensor 10. The pressing reception part 30 includes a spherical weight part 31 and a coupling line 32 coupling the weight part 31 with the sensor 10. The weight part 31 is coupled with the sensor 10 by the coupling line 32 so as to contact a bottom surface 52 of the pipe line 50, and provides the sensor 10 with a moment load through the coupling line 32 when it flows to move along the flow of the fluid on receiving the dynamic pressure F of the fluid.SELECTED DRAWING: Figure 1

Description

The present invention relates to flow meters.

In recent years, torrential downpours called guerrilla downpours have occurred, causing problems such as flooding of rainwater drainage infrastructure in cities. Therefore, measures are taken to control the amount of rainwater flowing into public sewage pipes by installing facilities for temporarily storing rainwater (hereinafter referred to as "temporary storage facilities") such as infiltration pits and rainwater storage tanks in buildings. ing.

In order to make effective use of these temporary storage facilities, it is necessary to install a flow meter in the pipeline into which rainwater flows.
As flowmeters that are relatively simple in structure and inexpensive, an impeller-type flowmeter that is installed in a pipeline and utilizes the dynamic pressure of a fluid is known. However, the impeller or the like tends to become entangled with foreign matter in the rainwater, thereby hindering its original function as a pipeline. In addition, since the impeller rotates continuously, there is also the problem that the bearings are easily worn.

Non-contact ultrasonic flowmeters are available as flowmeters that can measure the flow without contacting the fluid in the pipe, but they require a straight pipe with a certain length (about 10 times the diameter), It is not easy to install because it needs to be filled with water (liquid) inside and is expensive.
Therefore, Patent Document 1 proposes, as a simple flowmeter, a flowmeter in which a wing on which a lift force acts due to fluid flow is installed in a pipeline, and the force acting on the stay holding the wing is detected by a load cell. .

JP-A-9-26338

However, in the flowmeter of Patent Document 1 as well, the structure of the portion where the wing is held by the stay is complicated, and it is necessary to arrange the rectifying plate on the upstream side. Also, the flow meter of Patent Document 1 cannot measure the flow rate unless the inside of the pipe is full of water (liquid) or in a state close to being full of water (liquid). Therefore, it is unsuitable as a flowmeter installed in a pipeline that flows irregularly like rainwater and has a wide range of flow fluctuations.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a flowmeter that has a simple structure and is less likely to be entangled with foreign matter. Another object of the present invention is to provide a flowmeter capable of measuring the flow rate even in a pipeline into which fluid flows irregularly and whose flow rate fluctuates widely.

In order to achieve the above objects, the present invention employs the following configurations.
[1] A flow meter for measuring the flow rate of a fluid flowing in a pipeline laid substantially horizontally,
A sensor that converts a load into an electrical signal, an electrical signal processing device that determines a flow rate from the electrical signal obtained by the sensor, and a sensor that flows through the pipeline with one end connected to the sensor. a pressure receiving portion that transmits the dynamic pressure of the fluid to the sensor;
The pressure receiving portion has a weight portion and a flexible connecting line that connects the weight portion to the sensor,
The weight section is connected to the sensor by the connection line so as to be able to contact the bottom surface of the pipeline, and has a convex curved surface at least at a portion that can contact the bottom surface of the pipeline. A flow meter that floats when subjected to dynamic pressure of a flowing fluid and tries to move along the flow of the fluid, thereby applying a moment load to the sensor through the connecting line.
[2] The flowmeter according to [1], wherein the weight is spherical.
[3] The flowmeter according to [1] or [2], wherein the fluid is water and the specific gravity of the weight is 7-9.
[4] The flowmeter of [3], wherein the fluid is rainwater.
[5] The flowmeter according to any one of [1] to [4], wherein the weight is made of stainless steel.
[6] Any one of [1] to [5], wherein the sensor has a conversion unit that converts a moment load applied through the connecting line into a uniaxial load, and a load cell that converts the uniaxial load into an electrical signal. flow meter as described above.

According to the flow meter of the present invention, problems such as entanglement of foreign matter with a simple structure are unlikely to occur, and even if a fluid flows irregularly and the fluctuation range of the flow rate is large, the flow rate can be measurement is possible.

1 is a schematic configuration diagram of a flowmeter according to one embodiment of the present invention; FIG.

A flowmeter according to one embodiment of the present invention will be described with reference to FIG.
The flowmeter 1 of the present embodiment is a flowmeter that measures the flow rate of a fluid flowing through a pipe line 50 that is laid substantially horizontally, and is roughly composed of a sensor 10, an electrical signal processing device 20, and a pressure receiving portion 30. there is

The conduit 50 is laid substantially horizontally. Here, the term "substantially horizontal" means that the top surface 51 and the bottom surface of the pipe 50 are located at different vertical positions to such an extent that even if the fluid is flowing toward the bottom surface 52, the fluid does not reach the top surface 51. 52 means a horizontal or near-horizontal state. For example, a degree of tilt that facilitates movement of fluid within conduit 50 is permissible. Rather, it is preferable that there is an inclination (water gradient) that promotes movement of the fluid in the pipeline 50 rather than being completely horizontal. The inclination of the conduit 50 from the horizontal can be, for example, 2 to 3 degrees.
The cross-sectional shape of the conduit 50 is not particularly limited, and may be circular, rectangular, inverted trapezoidal, or the like.

The sensor 10 comprises a mounting plate 11 fixed to the top surface 51 of the inner wall of the pipeline 50, a load cell 12 fixed to the lower surface of the mounting plate 11, and an L-shaped load cell 12 fixed to the mounting plate 11 by a hinge portion 14 at one end. It is configured with a type conversion unit 13 . By rotating the converting portion 13 clockwise around the hinge portion 14 as a rotating shaft, the end portion opposite to the end portion fixed to the hinge portion 14 laterally presses the load cell 12 upward. It has become.

In the present invention, sensor 10 is mounted above conduit 50 . Since it can be kept out of contact with the fluid at all times by being mounted above, maintenance is easy.
In this embodiment, the place where the sensor 10 is fixed is the highest portion (top surface 51) of the inner wall of the conduit 50, which is particularly preferable.

In this embodiment, as the load cell 12, an example using a load cell that converts a uniaxial load into an electric signal (for example, voltage) is shown.
There are no particular restrictions on the type of load cell that converts a uniaxial load into an electrical signal, and compact compression load cells, spring and piezoelectric element types, magnetostrictive load cells, capacitance load cells, gyro load cells, and strain gauge load cells are used. can. Among them, a compact compression load cell is preferable because it is easy to install in a pipe.
The electrical signal processing device 20 is connected to the load cell 12 by a signal line 21, and receives an electrical signal obtained by the load cell 12. FIG.

The pressure-receiving portion 30 is composed of a weight portion 31 and a flexible connecting wire 32 .
The connection line 32 has one end attached to the weight portion 31 and the other end attached to the conversion portion 13 of the sensor 10 , thereby connecting the weight portion 31 to the sensor 10 .
There is no particular limitation on the specific form of the connecting wire 32, and it is sufficient that it has flexibility and strength to connect the weight portion 31 to the sensor 10 against the flow of fluid. For example, it can be string-shaped, band-shaped, chain-shaped, or the like. The material of the connecting line 32 is preferably a material that is resistant to fluid. When the fluid is water, for example, stainless steel (SUS), iron, or the like can be used.

The connecting line 32 is formed longer than the height from the bottom surface 52 to the top surface 51 of the inner surface of the pipeline 50 . As a result, weight 31 is connected to sensor 10 by connecting wire 32 so as to be able to contact bottom surface 52 of conduit 50 . Therefore, when there is no fluid or when there is no fluid flow, the weight 31 is in contact with the bottom surface 52 of the inner surface of the conduit 50, such as by sinking. It floats under pressure, separates from the bottom surface 52, and can move along the flow of fluid within a range permitted by the restraint by the connecting line 32. - 特許庁

In FIG. 1, the weight 31 has a spherical shape, but the portion that can come into contact with the bottom surface 52 may have a convex curved surface. Since the portion that can come into contact with the bottom surface 52 is a convex curved surface, the friction with the bottom surface 52 is reduced, and the dynamic pressure of the fluid allows the body to quickly float from the state of sinking (in contact) with the bottom surface 52 . It has become.

Examples of the shape in which the portion in contact with the bottom surface 52 is a convex curved surface include a spherical shape, an elongated sphere shape, an oblate ellipsoidal shape, a teardrop shape, and the like. Among them, a spherical shape is preferable because it is easy to remove dust flowing in the pipe.
When the weight portion 31 is spherical, the diameter is preferably 2 to 3 cm, but when the pipe diameter exceeds 100 mm, it is preferably 3 cm or more. When the diameter of the weight portion 31 is equal to or greater than the lower limit of the preferable range, the dynamic pressure of the fluid can be sufficiently received. Since the diameter of the plummet portion 31 is equal to or less than the upper limit of the preferable range, it can be used for thin pipes.

When the fluid is water, the weight portion 31 preferably has a specific gravity of 7 to 9, more preferably 7.5 to 8.5, and particularly preferably about 8. Since the specific gravity of the weight portion 31 is equal to or higher than the lower limit of the preferable range, it can quickly sink toward the bottom surface 52 and return to the state of contact with the bottom surface 52 when the amount of water becomes small. In addition, it is possible to avoid unstable movements due to water currents.

When the specific gravity of the weight portion 31 is equal to or less than the upper limit of the preferable range, it is easy to float even when the flow rate is small, making it possible to measure the flow rate.
It is preferable that the weight portion 31 is made of a material that has an appropriate specific gravity and is resistant to fluids. When the fluid is water, for example, stainless steel (SUS), iron, or the like can be used.

In the flowmeter 1 of the present embodiment, the plummet 31 is in contact with the bottom surface 52 when the fluid does not exist or does not flow in the conduit 50 . At this time, the connecting wire 32 is loosened between the weight portion 31 and the sensor 10 . That is, the weight portion 31 does not apply tension to the connecting wire 32 and does not apply a moment load to the sensor 10 through the connecting wire 32 .

At this time, the conversion portion 13 of the sensor 10 hangs down below the hinge portion 14, does not laterally press the load cell 12, and the load cell 12 does not detect the load. That is, since the load cell 12 does not output an electrical signal corresponding to the dynamic pressure F along the flow direction to the electrical signal processing device 20, the electrical signal processing device 20 can determine that the flow rate is zero.

On the other hand, when the fluid flows through the conduit 50 , the weight 31 floats away from the bottom surface 52 under the dynamic pressure F of the fluid, and moves along the fluid flow within the range allowed by the restraint by the connecting wire 32 . do. When the limit of the restraint by the connecting line 32 is reached, a moment load is applied to the sensor 10 through the connecting line 32 .

Specifically, the limit of the restraint by the connecting line 32 is that when the weight 31 moves, the conversion section 13 of the sensor 10 rotates clockwise from a state in which it hangs down below the hinge section 14, and the load cell 12 means the point of contact with
After that, the weight portion 31 applies a tension corresponding to the dynamic pressure F to the connecting wire 32 and applies a moment load about the hinge portion 14 to the sensor 10 . A moment load applied to the sensor 10 is converted into a uniaxial load by the conversion unit 13 and applied to the load cell 12 . As a result, the load cell 12 outputs an electrical signal corresponding to the dynamic pressure F to the electrical signal processing device 20 through the signal line 21 .

The electrical signal processing device 20 obtains an approximate flow rate based on the electrical signal input from the load cell 12 .
Specifically, based on a calibration curve showing the relationship between the electrical signal input from the load cell 12 and the flow rate, the flow rate corresponding to the input electrical signal is obtained. The calibration curve is prepared in advance and stored in the electrical signal processing device 20 based on the relationship between the voltage value and the flow rate when the fluid is flowed at several known flow rates.
Then, by integrating the obtained flow rate over the time to be analyzed, an approximate integrated flow rate can be obtained.
A more accurate flow rate can be obtained by installing a water level gauge in the pipeline 50 where the sensor 10 is installed.

The flowmeter 1 of this embodiment includes a sensor that converts a load into an electrical signal, an electrical signal processing device that determines the flow rate from the electrical signal obtained by the sensor, and one end of the sensor. a pressure receiving portion that is connected and transmits a dynamic pressure of a fluid flowing in the pipeline to the sensor; It is configured to impart a moment load to the sensor by attempting to move along.

That is, the configuration is such that a moment load corresponding to the flow rate is generated with a simple configuration, and the flow rate is obtained by detecting this.
Therefore, it is possible to obtain a flowmeter that has a simple structure and is less prone to problems such as entanglement with foreign matter.

For example, when the pressure receiving portion 30 is a rod-shaped body or plate-shaped body that reaches near the bottom surface 52 from the sensor 10 side, when the pressure receiving portion 30 receives the dynamic pressure of the fluid flowing in the conduit 50, A clearance is required between the bearing 30 and the bottom surface 52 to move along with the fluid flow. In this case, when the flow rate is very small, the dynamic pressure F of the fluid cannot be received by the pressure receiving portion 30, and the flow rate cannot be measured.

Therefore, in the flow meter 1 of the present embodiment, the pressure receiving portion 30 is further composed of a weight portion 31 and a connecting wire 32, and the weight portion 31 is connected to the bottom surface 52 of the pipe line 50 by the connecting wire 32. 10. Therefore, even if the flow rate is very small, the weight portion 31 of the pressure receiving portion 30 can receive the dynamic pressure F of the fluid, and the flow rate can be measured.

Further, in the present embodiment, the portion of the weight 31 that can come into contact with the bottom surface 52 has a convex curved surface. As a result, the friction with the bottom surface 52 is reduced, and when receiving the dynamic pressure of the fluid flowing in the conduit 50, the sensor 10 can quickly float and move along the flow of the fluid. A moment load can be applied to

In this embodiment, the sensor 10 is also composed of the conversion unit 13 that converts the moment load applied through the connecting line 32 into a uniaxial load, and the load cell 12 that converts the uniaxial load into an electric signal. Therefore, the sensor 10 can be configured with an inexpensive load cell.
Note that the sensor of the present invention may be a sensor that directly converts a moment load into an electrical signal.

It is preferable that the fluid targeted by the flowmeter 1 of the present embodiment is a liquid. The liquid is not limited to water and may be oil, for example.
The flowmeter 1 of the present embodiment can be suitably used particularly when the fluid is water. Rainwater is particularly preferred.
If the weather is fine, no rainwater will flow through the pipes through which rainwater flows, and the inside of the pipes will be dry. Also, in rainy weather, there are cases where the amount of rainfall is extremely small, while there are cases where the amount of flow is very large, such as so-called guerrilla rainfall.
According to the flowmeter 1 of the present embodiment, it is also possible to measure the flow rate of a pipeline having such a large fluctuation width of the flow rate.

1 Flow meter 10 Sensor 11 Mounting plate 12 Load cell 13 Converting part 14 Hinge part 20 Electric signal processing device 21 Signal line 30 Pressure receiving part 31 Weight part 32 Connecting wire 50 Pipe line 51 Top surface 52 Bottom surface

Claims (6)

A flow meter for measuring the flow rate of a fluid flowing in a pipeline laid substantially horizontally,
A sensor that converts a load into an electrical signal, an electrical signal processing device that determines a flow rate from the electrical signal obtained by the sensor, and a sensor that flows through the pipeline with one end connected to the sensor. a pressure receiving portion that transmits the dynamic pressure of the fluid to the sensor;
The pressure receiving portion has a weight portion and a flexible connecting line that connects the weight portion to the sensor,
The weight section is connected to the sensor by the connection line so as to be able to contact the bottom surface of the pipeline, and has a convex curved surface at least at a portion that can contact the bottom surface of the pipeline. A flow meter that floats when subjected to dynamic pressure of a flowing fluid and tries to move along the flow of the fluid, thereby applying a moment load to the sensor through the connecting line. 2. The flowmeter of claim 1, wherein said weight is spherical. 3. The flowmeter according to claim 1, wherein said fluid is water, and said weight portion has a specific gravity of 7-9. 4. The flow meter of claim 3, wherein said fluid is rainwater. The flowmeter according to any one of claims 1 to 4, wherein the weight is made of stainless steel. The flow rate according to any one of claims 1 to 5, wherein the sensor has a conversion unit that converts a moment load applied through the connecting line into a uniaxial load, and a load cell that converts the uniaxial load into an electrical signal. Total.

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