JP2001021394A - Flow sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily build a flow sensor in a compact water purifier for home use, and to detect and inform flow rate without the help of a commercial power supply and a battery. SOLUTION: In a flow sensor, the inside of a housing 1 is divided into measurement and power generation parts 30 and 31 by a partition 10, the measurement part 30 is provided with inlet and outlet 2 and 3 of fluid that are provided in the housing 1, a turbine 15 that is rotatably supported by the housing 1 so that the turbine can be rotated by the pressure of the fluid flowing from the inlet 2 to the outlet 3, and a magnetic pole plate 17 that is mounted to the back-surface side of the turbine 15 for rotating in one piece with the turbine 15, and the power generation part 31 has a coil 20 that is fixed to the housing 1 while the coil opposes the magnetic pole plate 17 by sandwiching the partition 10. By the rotation of the magnetic pole plate 17 due to the rotation of the turbine 15, an induced voltage is generated in the coil 20 according to speed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a flow rate sensor for detecting a flow rate of a fluid.

[0002]

2. Description of the Related Art In recent years, water purifiers have been widely used in ordinary households due to, for example, deterioration of tap water quality (such as bad smell, turbidity, and bad smell of smell) around a large city and improvement of hygiene philosophy. Most water purifiers use some kind of filter to improve the water quality.However, since the filter has a limited service life due to clogging or deterioration of the filter, it is recommended to replace the filter with an instruction manual. And it is described that the battery should be replaced after an approximate period from the start of use.

[0003]

However, the total flow rate can be accurately detected and detected, such as when the amount of filtered water has reached a limit.
Even though the function to notify is provided in large-scale industrial water purifiers, it is not provided in small and inexpensive home water purifiers, so it continues to use filters without knowing the filter whose filtration capacity has reached its limit. Is easy to occur.

A water purifier is not only a device for handling water, but also a household water purifier is usually installed in a kitchen sink, so that an AC100V power supply is used for detection and notification of the total flow rate. It is not preferable to use it in order to prevent an electric shock or a leakage accident. Even if dry batteries are used instead of commercial power, it is not possible to know when the usage limit will be reached during a certain long period of use.Therefore, when the usage limit is reached, the dry batteries are likely to be lost due to natural discharge. I also want to avoid this in terms of running costs.

The present invention has been made in view of such a problem, and can be easily incorporated into a small household water purifier, and can detect and detect a flow rate without the aid of a commercial power supply or a battery.
It is an object of the present invention to provide a flow sensor capable of performing notification.

[0006]

According to a first aspect of the present invention, there is provided a flow sensor having a fluid flow path having a fluid inlet and a fluid outlet, and a fluid flowing from the fluid inlet to the fluid outlet. A rotating body rotatably supported in the fluid flow path so as to rotate by the fluid pressure of the fluid, a magnetic pole plate connected to the rotating body and rotating integrally with the rotating body and having at least one pair of magnetic poles, and the magnetic pole At least one coil arranged so that magnetic fluxes from the magnetic poles of the plate interlink with each other, and electric power generated in proportion to the flow rate of fluid from the coil is used as a sensor output.

In this flow sensor, when the rotating body rotates due to the flow pressure of the fluid flowing from the inlet to the outlet in the fluid flow path, the magnetic pole plate rotates integrally with the rotating body, and the coil rotates the magnetic field from the magnetic pole plate. And an induced voltage is generated in the coil in accordance with the rotation speed of the magnetic pole plate, and the flow rate is measured by the magnitude of the voltage / current and the level of the frequency. The electric power (voltage, current, frequency) obtained from the coil in proportion to the flow rate of the fluid is used as the sensor output.

In a flow sensor according to a second aspect of the present invention, the fluid flow path, the rotating body, the magnetic pole plate, and the coil are provided inside a housing, and the inside of the housing is separated from a measuring unit by a partition. A rotation unit which is partitioned by a power generation unit, and wherein the measurement unit is rotatably supported by the housing so as to rotate by an inflow port and an outflow port of the fluid provided in the housing and a flow pressure of the fluid flowing from the inflow port to the outflow port. And a magnetic pole plate connected to the rotating body and integrally rotating with the rotating body and having at least a pair of magnetic poles,
The power generation unit includes at least one coil fixed to a housing so as to face the magnetic pole plate with a partition wall interposed therebetween, and an electric power generated by the power generation unit in proportion to a fluid flow rate is used as a sensor output. It is characterized by.

In this flow sensor, when the rotating body rotates by the flow pressure of the fluid flowing from the inlet to the outlet of the housing, the magnetic pole plate rotates integrally with the rotating body, and the coil facing the magnetic pole plate with the partition wall interposed therebetween. Interaction with the rotating magnetic field from the magnetic pole plate generates an induced voltage in the coil, and the flow rate is measured based on the magnitude of the voltage / current or the frequency. Further, electric power obtained from the power generation unit in proportion to the flow rate of the fluid is used as the sensor output.

That is, since the flow rate sensor of the present invention has a function of generating power by the fluid measured by itself, the flow rate can be measured by a commercial power supply (AC 100 V) or a battery (primary / secondary battery).
Is unnecessary. Therefore, if this flow rate sensor is incorporated into a household water purifier, the total water amount can be detected and notified without using a separate power supply, and the structure can be made compact, so that it can be easily incorporated into the water purifier.

In the present invention, the fluid may be a liquid such as water (water supply), a gas such as air, or fluid fine particles (for example, powder). In addition, as a rotating body, a water turbine (wind turbine) is generally used, and the types thereof include a spiral turbine type, a Belton type, a Francis type, a paddle type, a savory type, an axial flow propeller type, and the like. The optimum efficiency may be selected according to the type of the fluid, and the magnitude of the flow rate / velocity.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on embodiments. FIG. 1A is a partially cutaway top view of the flow sensor according to the embodiment, and FIG.
FIG. 2 shows a partially cutaway bottom view. This flow sensor is
It measures the flow rate of water as a fluid, and the inside of a cylindrical housing 1 as shown in FIG.
And a power generation unit 31.

The measuring unit 30 is provided on the housing 1 such that the housing 1 is rotated by the pressure of water flowing from the inlet 2 to the outlet 3 and the inlet 2 and the outlet 3 of the fluid (here, water) provided in the housing 1. A turbine 15 as a rotating body rotatably supported, and a magnetic pole plate 1 having a magnetic pole attached to the back side of the turbine 15 and rotating integrally with the turbine 15
7 is provided. The power generation unit 31 includes a coil 20 fixed to the housing 1 so as to face the magnetic pole plate 17 with the partition wall 10 interposed therebetween.

The housing 1 includes an upper lid 5, a bottom lid 7, and a partition 1.
The two lids 5 and 7 are detachably attached to the housing 1, and the partition 10 is provided integrally with the housing 1. The housing 1 including the top cover 5, the bottom cover 7 and the partition 10 is made of a non-magnetic material (for example, resin). When the top cover 5 is removed, the coil 20 of the power generation unit 31 appears, and when the bottom cover 7 is removed,
The turbine 15 of the measuring unit 30 appears. The measuring unit 30 and the power generating unit 31 are completely separated by the partition 10. The measuring unit 30 has a watertight structure when the bottom cover 7 is attached to the housing 1, and the power generating unit 31 has an airtight structure when the top cover 5 is attached to the housing 1. The water in the section 30 does not enter the power generation section 31. The inflow port 2 and the outflow port 3 provided in the housing 1 are arranged at symmetrical positions so that water flows smoothly (see FIG. 2).

A partition 10 provided integrally with the housing 1
Has a shaft portion 10a at the center of the housing 1. The turbine 15 includes a bearing 19 fixed to the shaft 10a of the partition 10.
Are supported rotatably. The portion of the partition wall 10, particularly between the coil 20 and the side plate 17 a of the pole plate 17, is thin enough to allow the magnetic field lines from the side plate 17 a to sufficiently penetrate while functioning as a partition wall.

As shown in FIG. 3, the magnetic pole plate 17 has a ring-shaped side plate 17a. The side plate 17a is poled, and faces the end face of the coil 20 with the partition wall 10 interposed therebetween.
Here, the side plate 17a is magnetized to four poles (two pairs of magnetic poles S and N). Of course, the number of magnetic poles may be one or three or more. The number of coils 20 is four in this case, and four coils 2
0 is arranged at equal angular intervals from the center, and one conductor is continuously wound around a cross-shaped yoke. That is, as shown in FIG. 4, one conductive wire is wound at four places to form coils 20 (a to d).
The winding start end and winding end of (a to d) are connected in series (polarity). Winding start end of coil 20a and coil 20d
End terminals are output terminals A and B, which are insulated from the housing 1 and pulled out.

In the flow sensor constructed as described above, when water flows into the measuring section 30 of the housing 1 from the inflow port 2 connected to the flowing water path and flows out from the outflow port 3, the turbine is rotated at a rotational speed corresponding to the amount of water. 15 rotates. Water volume (L /
min) and the rotation speed (rpm / min) of the turbine 15 are linear as shown in the graph of FIG.

When the turbine 15 rotates, the pole plate 17 on the back side also rotates at the same rotation speed. Accordingly, a rotating magnetic field is generated around the side plate 17a of the pole plate 17, and the rotating magnetic field penetrates the partition wall 10 and reaches the coil 20. Since the coil 20 cuts off the alternating magnetic field, an induced voltage is generated in the coil 20, and as a result, an AC voltage output is obtained between the output terminals A and B of the coil 20.

Since the AC voltage output is proportional to the flow rate, that is, if the flow rate is small, the rotation speed of the turbine 15 is low and the pressure is low (the current is small and the frequency is low). Since the number is high and the pressure is high (the current is large, the frequency is high), the voltage / current output value or the output frequency can be adopted as the output value of the flow rate.

FIG. 5A is a block diagram showing the overall system configuration in which the above-mentioned flow sensor is incorporated in a household water purifier. In this case, the flow sensor is disposed in the path of the filtered water, and the path is connected to the inlet 2 and the outlet 3 of the housing 1 by, for example, a hose. The power generation unit 3 of the flow sensor
1, a rectifier circuit rectifies an AC voltage output obtained between the output terminals A and B of the coil 20 to DC with a rectifier element, and further reduces the DC voltage with an appropriate constant voltage circuit element. I do. The DC low voltage obtained by the rectifier circuit can be used as an electronic circuit power supply of the control unit 32.

The control section 32 uses the electric power from the flow sensor as a power source, and the display section 33 displays the total flow rate and various alarms (requests for filter replacement, etc.) based on the output of the control section 32. However, in addition to the display of the alarm, the indicator light (for example, LED)
May be turned on, an electronic buzzer sounds, or the like. According to the above-mentioned water purifier, electric power for operations such as display, lighting, and sound generation can be supplied by its own power generation, so that a commercial power supply or a battery is unnecessary, and an electric shock, an electric leakage accident, and a natural discharge of the battery do not occur. In addition, since the flow sensor has a simple structure and can be made compact, it can be easily incorporated into a water purifier, and does not require much installation space.

FIG. 5B shows the system configuration of another apparatus incorporating the above-mentioned flow sensor. Here, an operation unit 34 is provided instead of the display unit 33. Operation unit 3
4 is for opening and closing an electromagnetic valve, for example. That is, when supplying water to a water storage tank or a bath, for example, this device detects that a predetermined amount of water has been reached, and switches the electromagnetic valve from the open state to the closed state by the operation unit 34 to stop water supply. is there. In this case, the power obtained by the flow rate sensor is used for the output of the control signal for opening and closing the electromagnetic valve.

As a similar application, a flushing device for a flush toilet using an infrared proximity sensor, which has been widely used recently, mostly relies on a built-in dry cell power supply for its operation. With the device shown in (1), a maintenance-free flush water device for flush toilets can be realized.

[0024]

As described above, according to the flow rate sensor of the present invention, the following effects can be obtained because the flow rate sensor has the function of generating power by the fluid measured by itself. (1) No commercial power supply (100V AC) or batteries (primary / secondary batteries) are required to measure the flow rate, which can prevent electric shock and electric leakage accidents when using a commercial power supply and prevent natural discharge when using a battery it can. (2) If incorporated into a household water purifier, it will be possible to detect and notify the total amount of water without using a separate power supply, and it will be compact in structure. Can be. (3) It is maintenance-free because battery replacement / charging is not required.

[Brief description of the drawings]

FIG. 1 is a partially cutaway top view (a) and a partially cutaway side view (b) of a flow sensor according to an embodiment.

FIG. 2 is a partially cutaway bottom view of the flow sensor.

FIG. 3 is a top view and a sectional view of a magnetic pole plate in the flow rate sensor.

FIG. 4 is a diagram illustrating a winding form of a coil in the flow rate sensor.

FIG. 5A is a block diagram showing a system configuration of a household water purifier using the flow rate sensor, and FIG. 5B is a block diagram showing a system configuration of another apparatus using the flow rate sensor.

FIG. 6 is a graph showing the relationship between the amount of water and the number of rotations of a turbine in the same flow sensor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Housing 2 Inflow port 3 Outflow port 10 Partition wall 15 Turbine (rotating body) 17 Magnetic pole plate 17a Side plate 20 Coil 30 Measurement part 31 Power generation part

Claims (6)

[Claims] A fluid passage having a fluid inlet and a fluid outlet, a rotating body rotatably supported by the fluid passage so as to rotate by the flow pressure of the fluid flowing from the fluid inlet to the fluid outlet, A magnetic pole plate connected to the rotating body and rotating integrally with the rotating body and having at least one pair of magnetic poles, and at least one magnetic pole arranged at a magnetic flux from the magnetic poles of the magnetic pole plate;
A flow sensor comprising: a plurality of coils; and electric power generated in proportion to the flow rate of fluid from the coils as a sensor output. 2. The fluid flow path, the rotating body, the magnetic pole plate, and the coil are provided inside a housing, and the inside of the housing is partitioned by a partition into a measuring unit and a power generating unit. The measuring unit includes a fluid provided in the housing. And a rotating body rotatably supported by the housing so as to rotate by the flow pressure of the fluid flowing from the inlet to the outflow port. The rotating body is connected to the rotating body and rotates integrally with the rotating body. And a magnetic pole plate having at least a pair of magnetic poles. The power generation unit includes at least one coil fixed to a housing so as to face the magnetic pole plate with a partition wall interposed therebetween, and a flow rate of fluid from the power generation unit. 2. The flow sensor according to claim 1, wherein electric power generated in proportion to the sensor output is used as a sensor output. 3. The flow rate sensor according to claim 2, wherein the fluid is water, and the measurement unit has a watertight structure and the power generation unit has an airtight structure by the housing and the partition. 4. The magnetic pole plate according to claim 2, wherein the magnetic pole plate has a ring-shaped side plate, and the side plate is magnetized and faces the end face of the coil with a partition wall interposed therebetween. Flow sensor. 5. The flow sensor according to claim 2, wherein the power generation unit includes a rectifier circuit for converting an AC voltage obtained by a coil into a DC voltage. 6. A flow sensor according to claim 1, wherein said flow output is also used as a power supply voltage of a signal processing circuit.