JP2001304925A - Recycling-type flow rate sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve such a problem that a precise instantaneous flow rate cannot be detected when an iron powder or the like is deposited on the surface near the magnetic pole of a magnet inside a flow rate sensor so as to narrow a watercourse, that the life of the sensor is short due to abrasion or the like in the underwater sliding contact of a rotating blade as an injection-molded resin member with a later-stage straightening fixed blade and that the sensor does not have a structure in which respective components or the like are disas sembled simply. SOLUTION: The flow rate sensor is composed of a front-stage straightening fixed blade 10 which supports a rotating-blade support shaft 19. The sensor is composed of the rotating blade 20 which comprises a recessed hole 23 used to insert the support shaft 19, which is axial-flow-rotated by the flow rate of a fluid, which comprises a spherical surface-shaped pressurization protrusion 23 coming into sliding contact with the later-stage straightening fixed blade 30 and which comprises a spiral twist. The sensor is composed of the blade 30 which comrises a curved surface-shaped smooth face 31 coming into sliding contact with the pressurization protrusion 22. The sensor is composed of a rotation detection means 40, a casing 50 and a lid body 60.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an impeller type flow sensor for detecting an instantaneous flow rate of fluid (water) by rotating a rotary blade by combining a magnet and a magnetic detection device. The present invention relates to a recycle type flow sensor that can be easily disassembled into a front-stage rectifying fixed blade, a rotating blade support shaft, a magnet, a rotating blade, a rear-stage rectifying fixed blade, a magnetic detection device, and a casing.

[0002]

2. Description of the Related Art Conventionally, an axial-flow rotary impeller type flow sensor has a helical torsion which has no spiral torsion, has a rear former straightening blade, a rotary blade support shaft, and a magnet, and which rotates axially by a fluid flow rate. The mainstream is a rotating blade having a rotating blade, a post-rectifying blade having no helical twist, a rotation detecting means, and a casing, and both ends of the rotating blade supporting shaft rotating together with the rotating blade are supported. For example, a system disclosed in Japanese Utility Model Publication No. Hei 7-31135 is known, which supports one end of the rotating blade support shaft and attaches the outer peripheral portion of the rotating blade support shaft to the outer periphery. A system in which only the rotating blades rotate is disclosed, for example, in Japanese Patent Application Laid-Open No. 5-99711.

As a reference, a pre-rectifying fixed blade having a helical twist for generating vortex rotation in a fluid, a rotary blade having no helical torsion for axially rotating by a vortex-rotating fluid flow rate, and a helical torsion A post-rectifying fixed blade having no torsion, and a rotary blade supporting shaft (regardless of whether the shaft rotates) supported by the front-stage rectifying fixed blade and the post-rectifying fixed blade.
, A rotation detecting means, and a casing are disclosed in Japanese Patent Publication No. 6-79987 and Japanese Patent Publication No. 7-37.
Japanese Unexamined Patent Publication No. 906 and the like are known.

[0004] Further, a front-stage rectifying fixed blade having a helical twist for generating vortex rotation in a fluid, a rotating blade having a helical torsion for axially rotating by a vortex-rotating fluid flow rate, and a rear-stage rectifying member; A flow sensor comprising a rotating blade supporting shaft (whether or not the shaft rotates) which is supported by the front-stage rectifying fixed blade and the rear-stage rectifying member, a rotation detecting means, and a casing has a real balance. One disclosed in Japanese Patent Application No. 31134 is known.

[0005] A first straightening vane having no spiral torsion, a rotating vane having a spiral torsion that rotates axially by a fluid flow rate, and a rear straightening vane having a spiral torsion,
The flow rate sensor including the rotating blade supporting shaft (whether or not the shaft rotates) supported by the front-stage rectifying fixed blade and the rear-stage rectifying member, the rotation detecting means, and the casing has an actual balance of 7 mm. What is disclosed by -31135 gazette etc. is known.

[0006]

However, since the fluid (water) passing through the casing of the flow sensor contains foreign matter such as iron powder, the fluid near the magnetic pole of the magnet mounted on the flow sensor is not suitable. There has been a problem that the instantaneous flow rate cannot be accurately detected due to the accumulation of iron powder or the like on the surface and a narrow passage of the fluid. When the rotating blades and the post-stage rectifying blades are made of synthetic resin (injection molding resin member) or the like normally used in the atmosphere, etc., for underwater sliding contact, they are described in catalogs, specifications, data books, etc. issued by manufacturers etc. There is a problem that the life due to abrasion or the like is shortened from the characteristic data or the like. In addition, these flow sensors are designed to be recyclable (such as jigs and tools [preferably jigs used for positioning, supporting and guiding components for machining, and general tools such as screwdrivers, etc. Is designed to be easily disassembled and separated without the use of special tools, etc., which are specially manufactured.), So that it can be easily disassembled into each component, etc. There was a problem that was not.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and has as its object to prevent the accumulation and growth of iron powder on the surface near the magnetic pole of a magnet, and to provide an underwater slide. An object of the present invention is to provide a recycle type flow sensor which has good durability in contact and can be easily disassembled into components.

[0008]

In order to achieve the above object, a recycle type flow sensor according to the present invention is configured (hard) in terms of a front-stage rectifying fixed blade for fixing a rotating blade support shaft to an axis, and A rotary blade having a helical torsion having a concave hole into which the blade support shaft is inserted, and having a pressure projection that is axially rotated by the fluid flow rate and slidingly contacts the rear-stage rectifying fixed blade; and that is in sliding contact with the rotary blade pressure projection. It is composed of a post-stage rectifying fixed blade having a smooth surface, a rotation detecting means, a casing, and a lid, and has the following features.

[0009] The pressure projection of the rotary blade during axial rotation by the fluid flow rate presses the smooth surface of the rear-stage rectifying fixed blade spherically. For example, in the case of flat pressing, heat is generated due to the sliding contact resistance and wear and the like are rapid, and in the case of point pressing, the smooth surface of the latter rectifying fixed blade is likely to be dented. In addition to the spherical pressurization, for example, when the front-stage rectifying fixed blade side of the rotary blade is eccentric (deviation, declination, axis shift) due to fluid flow rate fluctuations and the like, the rear-stage rectifying fixed blade slides. Since the sliding contact surface does not always have the same area with respect to the surface, rotation unevenness or the like is likely to occur due to a change in the sliding contact resistance.

The smooth surface of the rear-stage rectifying fixed blade is characterized by a curved surface such that the pressurizing projection of the rotary blade slides substantially at the center during axial rotation by the fluid flow rate.
If the smooth surface of the post-stage rectifying fixed blade is a curved surface, for example,
Even when the rotating blade front-stage rectifying fixed blade side eccentrically swings due to fluctuations in the flow rate of the fluid, the rotating blade rotates like the top of the rotary blade without leaving the pressurizing projection almost at the center of the smooth surface. Can be continued, so that rotation unevenness and the like hardly occur.

[0011] The pressure projection and / or the smooth surface are formed of a synthetic resin containing carbon fibers. When the rotating blades and / or the rear-stage rectifying fixed blades are made of synthetic resin and are slid in water, the hydrolysis and the like of the synthetic resin are accelerated, and the abrasion and the like become ten times or more. It is good to use a resin with a certain property. The rotating blades and / or the post-stage rectifying fixed blades are formed of a commonly used synthetic resin (for example, polyacetal resin) or the like, and carbon fiber-containing synthetic resin (for example, carbon fiber-containing polyacetal resin, carbon fiber-containing polypropylene resin, carbon fiber Nylon resin,
The pressure protrusion and / or the smooth surface formed of carbon fiber-containing polyether ether ketone resin) may be press-fitted (inserted), or the rotating blade and / or the post-stage rectifying fixed blade may be filled with carbon fiber. It may be formed of a synthetic resin.

The rotation detecting means includes a magnet provided on the rotary blade and a magnetism detecting device provided on an outer peripheral portion of the casing, wherein the magnet is exposed so as to be closer to a front rectifying fixed blade of the rotary blade. Characterized by being held between the wings. In consideration of recycling, it cannot be buried (for example, insert molding) in the rotating blade, and in consideration of weight reduction, the entire rotating blade is made of a magnet (for example, plastic, etc.).
Cannot be formed with a magnet), and considering the magnetic sensitivity (detection distance) of the magnetic detection device, the main body (cylinder) of the rotating blade
Since it cannot be fitted into the part (it becomes small), a mounting method that does not make the fluid passage narrow is required.

[0013] The magnet is characterized by being coated with fluorine. It is unavoidable that iron powder or the like accumulates on the surface near the magnetic pole of the magnet. However, it is necessary to allow the powder to flow naturally together with the fluid once it accumulates to some extent so as not to narrow the fluid passage. Also, since magnets (rare earths) have the property of cracking when wet with water, even if they are embedded in rotating blades made of synthetic resin, for example, the synthetic resin has water absorption, and eventually the magnet gets wet and breaks. Would. Therefore, it is hydrophilic and has low frictional resistance against fluids and foreign substances (slippery)
Fluorine coating is applied.

[0014] A bead is provided on the surface of the front-stage rectifying fixed blade that is in sliding contact with the magnet. For example,
As disclosed in, for example, Japanese Patent No. 17749, as a technique for improving the adhesion failure, the contact area is reduced as much as possible.
There is a technique of providing a ring-shaped small projection (bead) on a flat surface or the like. This technique is used to protect the fluorine-coated surface of the magnet.

In order to improve the starting flow rate (sensitivity) of the rotary blade, a helical twist of a lead shorter than the lead of the rotary blade for generating vortex rotation in a fluid is provided on the pre-stage rectifying fixed blade. An inclined protrusion is provided on an end face of the spiral torsion facing the flow direction of the fluid of the front-stage rectifying fixed blade. The lead is the distance traveled in the axial direction when making a round around the axis along the vine winding of the screw. The lead angle is defined as the tangent of the vine winding of the screw perpendicular to the axis of the vine winding. The angle between the plane and the plane. For example, if the lead is short, the lead angle becomes small, the flow velocity of the fluid becomes fast, the fluid easily flows on the rotating blade, and the rotation speed of the rotating blade can be increased. Since foreign matter or the like is mixed in the fluid (water) passing through the casing on the end face of the spiral torsion facing the flow direction of the fluid of the first-stage rectifying fixed blades, the scale buildup is unavoidable. However, as the deposition growth progresses, the fluid passage may become narrower, and an accurate instantaneous flow rate may not be detected. When the inclined projections are provided on the end face, some scale buildup is confirmed, but as the deposition growth progresses, the fluid naturally flows under the pressure of the fluid and is not fixed to the end face.

The casing is provided with a catching hole, the lid is provided with a catching claw, and the first lid is inserted into the casing and twisted for locking. The method of inserting the cover into the casing, twisting and hooking the cover can easily fix and disassemble the components.

Further, the recycle type flow sensor according to the present invention comprises:
In terms of configuration (hardware), the front-stage rectifying fixed blade for fixing the rotating blade support shaft, and a concave hole into which the rotary-blade supporting shaft is inserted, axially rotate by the fluid flow rate, and come into sliding contact with the rear-stage rectifying fixed blade. A rotating blade having a helical torsion having a pressure projection, a post-stage rectifying fixed blade having a smooth surface that is in sliding contact with the rotation blade pressure projection, rotation detection means, a casing, and a second casing, It has the following features.

A second casing is provided in the casing, and the front-stage rectifying fixed blade and / or the rotating blade and / or the rear-stage rectifying fixed blade are housed in the second casing. As described above, the method of inserting the lid into the casing and twisting and hooking the lid can easily fix and disassemble each part, but the front-stage rectifying fixed blade, the rotating blade, and the rear-stage rectifying fixed blade May be difficult to take,
If it is stored in the second casing, it can be easily removed.

The casing is provided with a catching hole, the second casing is provided with a catching claw, and the second casing is inserted into the casing and twisted for locking. The method of inserting the second casing into the casing and twisting and hooking is such that each part can be easily fixed and disassembled.

[0020]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a plan view of a flow sensor 90 according to a first embodiment of the present invention, and FIG. 2 is a right side sectional view of the flow sensor 90 when a magnet part (41) is cut.
Is a front sectional view (partially transparent view) of the flow sensor 90. The flow rate sensor 90 according to the first embodiment of the present invention has a front-stage rectifying fixed blade 10 for fixing the rotary blade support shaft 19 and a concave hole 23 into which the rotary blade support shaft 19 is inserted. Rotating blade 20 having a helical twist and having a spherical pressurizing projection 22 which rotates and slides on a post-stage rectifying fixed blade 30
And a curved smooth surface 3 slidably contacting the rotating blade pressing projection 22.
1, a rotation detecting means 40 comprising a magnet 41 and a magnetic detecting device 42, and a locking hole 54.
(Not shown) and a casing 50 having a printed wiring board cover 51, and a lid 60 having a locking claw 63 (not shown).
And Since the lid 60 is merely inserted into the casing 50 and twisted and hung, the casing 50
The cover 60 can be easily disassembled by twisting it off. Then, it is preferable to separate the parts into metal parts, resin-formed parts, and the like, and further separate them into those that can be recycled and those that cannot.

The front-stage rectifying fixed blade 10 is formed of a synthetic resin (for example, an injection-molded resin member such as an ABS resin), and has a single annular bead 12 on a sliding contact surface 11 with the magnet 41.
Is provided. A plurality of the beads 12 may be provided. The rotating blade support shaft 19 is formed of a stainless steel rod,
Although it is fixed to the front straightening fixed blade 10 by insert molding, it can be easily pulled out with a tool such as pliers. The rotating blade support shaft 19 is
The front-stage rectifying fixed blade 10 may be press-fitted (inserted) and fixed to the shaft.

The rotating blade 20 is integrally formed of carbon fiber-containing polyacetal resin. However, the rotating blade 20 body is formed of polyacetal resin or the like, and the spherical pressing protrusion 22 is formed of carbon fiber-containing polyacetal resin. The pressurizing protrusion 22 may be press-fitted into the main body of the rotary blade 20.

The rear-stage rectifying fixed blade 30 is formed integrally with a polyacetal resin containing carbon fibers. However, the main body of the rear-stage rectifying fixed blade 30 is formed of polyacetal resin or the like, and the curved smooth surface 31 is formed of polyacetal resin containing carbon fibers. And
The curved smooth surface 31 may be press-fitted into the rear-stage rectifying fixed blade 30 body. Thus, it has been confirmed that the life of the rotating blade 20 and the rear-stage rectifying blade 30 due to abrasion in sliding contact with water is 100 times or more as long as that of a general synthetic resin (injection molded resin member) or the like.

The rotation detecting means 40 according to the first embodiment of the present invention.
Is implemented in combination with a rare-earth magnet 41 and a magnetic detection device 42 capable of outputting an electrical signal.
An oval shape, a D-shape, or the like that can be sandwiched was coated with fluorine, and was sandwiched between the blades 21 (claw shape) of the rotary blade 20 so as to be exposed near the front straightening fixed blade 10 of the rotary blade 20. The outer periphery of the casing 50 is provided with a magnetism detecting device 42 (magnetic sensing element). It has been confirmed that the surface near the magnetic pole of the fluorine-coated magnet 41 does not cause accumulation of iron powder and does not cause an obstacle such that a water passage becomes narrow and an accurate instantaneous flow rate cannot be detected. The magnetic detection device 42 includes, for example, a reed switch, a Hall IC, a magnetic resistance, a coil, and the like. Usually, a normally open contact (a
Also called a contact or a make contact. ) Is frequently used. In terms of cost, a Hall IC (single pole detection type of S pole or N pole, both pole detection type of S pole and N pole, energy saving standby type at the time of no detection) may be advantageous in some cases. The magnetic detection device 4
2 is soldered to the printed wiring board 43 or the like (electrical connection and / or
Alternatively, it may be designed so as to be easily disposed (attached) to the outer peripheral portion of the casing 50 by mechanical fixing). In the present embodiment, the Hall IC 44 is provided on the printed wiring board 43 with the wiring member 45.
And is fixed by soldering and put into the printed wiring board cover portion 51, and the potting material 46 (for example, an electric insulating material such as urethane resin, polyester resin, epoxy resin, silicone resin, an adhesive sealing material, or another material is used. (Including those for waterproofing, moistureproofing, and dew condensation).) However, if the wiring member 45 is pulled slightly stronger, it can be easily pulled out from the inside of the printed wiring board cover portion 51, and the wiring member 45, the potting material 46,
It can be easily disassembled into the printed wiring board 43 and the Hall IC 44.

FIG. 4 shows a flow sensor 9 according to a second embodiment of the present invention.
1 is a front sectional view (partially transparent view) of FIG. In the flow sensor 91 according to the second embodiment of the present invention, in order to improve the starting flow rate (sensitivity) of the rotary blade 20, the rotary blade 20 is replaced with a rotary blade 24 having a helical reverse twist that generates vortex rotation in a fluid. The front-stage rectifying fixed blade 10 is connected to a lead (for example, 19 mm) shorter than a lead (for example, 30 mm) of the rotary blade 24.
mm) of the front-stage rectifying fixed blade 13 provided with a helical twist, and an inclined projection 15 is provided on an end surface 14 of the helical torsion facing the fluid flow direction of the front-stage rectifying fixed blade 13. When the rotary blade 20 is used as it is, a blade provided with a spiral reverse twist on the front-stage rectifying fixed blade 13 may be formed. Alternatively, the front-stage rectifying fixed blade 13 may be employed as it is.

FIG. 5 shows a flow sensor 9 according to a third embodiment of the present invention.
2 is a plan view, FIG. 6 is a left side view of the flow sensor 92, and FIG. 7 is a front sectional view (partially transparent view) of the flow sensor 92. Flow sensor 92 according to a third embodiment of the present invention
Is a front-stage rectifying fixed blade 1 for stopping the rotating blade support shaft 19.
0, a rotary blade having a helical torsion having a concave hole 23 into which the rotary blade support shaft 19 is inserted, and having a spherical pressurizing projection 22 axially rotated by a fluid flow and slidingly contacting the rear-stage rectifying fixed blade 30. 20, a post-stage rectifying fixed blade 30 having a curved smooth surface 31 which is in sliding contact with the rotary blade pressing projection 22, and a magnet 4
1 and a rotation detecting means 40 comprising a magnetic detecting device 42;
A casing 52 having a retaining hole 54 and a printed wiring board cover 53; the rotary blade 20 and the rear-stage rectifying fixed blade 3;
0 and a second casing 62 having a locking claw 63
And Since the second casing 62 is simply inserted into the casing 52 and twisted and hung, it can be easily disassembled by twisting and removing the second casing 62 from the casing 52. Then, it is preferable to separate the parts into metal parts, resin-formed parts, and the like, and further separate them into those that can be recycled and those that cannot be recycled.

As described above, various combinations and the like of the preferred embodiments of the present invention have been described. However, the present invention is not limited to the above-described embodiments, and a number of combinations are possible without departing from the spirit of the invention. Needless to say, combinations, modifications and the like can be made.

For example, if water and air are mixed in the flow sensor, since the flow sensor alone does not have a water / water separation function, an obstacle such as the impeller that should rotate at low flow does not rotate occurs. If this is the case, a trap may be provided at least in the outlet-side pipe of the flow rate sensor to enable air-water separation.

[0029]

According to the recycle type flow sensor of the present invention, iron powder does not grow on the surface near the magnetic pole of the magnet, has good durability in sliding contact with water, and can be easily disassembled into various components. It works.

[Brief description of the drawings]

FIG. 1 is a plan view of a flow sensor according to a first embodiment of the present invention.

FIG. 2 is a right side sectional view of the flow sensor according to the first embodiment of the present invention when a magnet portion is cut.

FIG. 3 is a front sectional view (partially transparent view) of the flow sensor according to the first embodiment of the present invention.

FIG. 4 is a front sectional view (partially transparent view) of a flow sensor according to a second embodiment of the present invention.

FIG. 5 is a plan view of a flow sensor according to a third embodiment of the present invention.

FIG. 6 is a left side view of a flow sensor according to a third embodiment of the present invention.

FIG. 7 is a front sectional view (partially transparent view) of a flow sensor according to a third embodiment of the present invention.

[Explanation of symbols]

Reference numeral 10: Pre-rectifying fixed blade, 11: Sliding contact surface, 12: Bead, 13: Pre-rectifying fixed blade having helical twist, 14
... End face, 15 ... Incline projection, 19 ... Rotating blade support shaft, 20
… Rotating blades, 21… blades (claw shape), 22… spherical pressing projections, 23… recessed holes, 24… rotating blades with helical reverse twist, 30… rear-stage rectifying fixed blades, 31… curved surface smooth Face, 4
0: rotation detection means, 41: magnet, 42: magnetic detection device,
43: printed wiring board, 44: hall IC, 45: wiring material, 46: potting material, 47: connecting connectors, 5
0 ... casing, 51 ... printed wiring board cover, 52 ...
Casing of the third embodiment, 53: printed wiring board cover portion of the third embodiment, 54: locking hole, 60: lid, 61: watertight packing (O-ring), 62: second casing of the third embodiment , 63: engaging claw, 90: fluid sensor, 91: fluid sensor of the second embodiment, 92: fluid sensor of the third embodiment

Claims (10)

[Claims] 1. A front-stage rectifying fixed blade for fixing a rotary blade support shaft to a shaft, and a pressurizing projection having a concave hole into which the rotary blade supporting shaft is inserted, axially rotating by a fluid flow rate and slidingly contacting the rear-stage rectifying fixed blade. Rotating blade having a spiral torsion, and a post-stage rectifying fixed blade having a smooth surface that comes into sliding contact with the rotating blade pressing projection,
A flow sensor comprising: a rotation detecting means; and a casing, wherein a pressure projection of the rotating blade when performing axial flow rotation by a fluid flow rate presses a smooth surface of the post-stage rectifying fixed blade spherically. Recycle type flow sensor. 2. A front-stage rectifying fixed blade for fixing the rotating blade support shaft to a shaft, and a pressurizing projection having a concave hole into which the rotary blade supporting shaft is inserted, and axially rotating by a fluid flow rate and slidingly contacting the rear-stage rectifying fixed blade. Rotating blade having a spiral torsion, and a post-stage rectifying fixed blade having a smooth surface that comes into sliding contact with the rotating blade pressing projection,
A rotation detecting means and a casing, the flow sensor comprising: a post-flow rectifying fixed blade such that a pressurizing projection of the rotating blade slides substantially at a central portion when the blade is axially rotated by a fluid flow rate. A recycle type flow sensor having a smooth smooth surface. 3. A front-stage rectifying fixed blade for fixing the rotating blade support shaft to a shaft, and a pressurizing protrusion having a concave hole into which the rotary blade supporting shaft is inserted, axially rotating by a fluid flow rate and slidingly contacting the rear-stage rectifying fixed blade. Rotating blade having a spiral torsion, and a post-stage rectifying fixed blade having a smooth surface that comes into sliding contact with the rotating blade pressing projection,
A recycle type flow sensor, comprising: a rotation detection unit; and a casing, wherein the pressure protrusion and / or the smooth surface are formed of a synthetic resin containing carbon fibers. 4. A front-stage rectifying fixed blade for fixing the rotating blade support shaft to a shaft, and a pressurizing projection having a concave hole into which the rotary blade supporting shaft is inserted, and axially rotating by a fluid flow and slidingly contacting the rear-stage rectifying fixed blade. Rotating blade having a spiral torsion, and a post-stage rectifying fixed blade having a smooth surface that comes into sliding contact with the rotating blade pressing projection,
A rotation sensor comprising a rotation detector and a casing, wherein the rotation detector is provided with a magnet on the rotating blade and a magnetic detection device is provided on an outer periphery of the casing. A recycle type flow sensor characterized by being held between the blades of the rotating blade so as to be exposed near the front-stage rectifying fixed blade. 5. A front-stage rectifying fixed blade for fixing the rotating blade support shaft to a shaft, and a pressurizing projection having a concave hole into which the rotary blade supporting shaft is inserted, axially rotating by a fluid flow rate and slidingly contacting the rear-stage rectifying fixed blade. Rotating blade having a spiral torsion, and a post-stage rectifying fixed blade having a smooth surface that comes into sliding contact with the rotating blade pressing projection,
A flow sensor comprising a rotation detection unit and a casing, wherein the rotation detection unit is provided with a magnet on the rotary blade near a front-stage rectifying fixed blade of the rotary blade, and a magnetic detection device on an outer peripheral portion of the casing. A recycle type flow sensor, wherein the magnet is coated with fluorine. 6. A front-stage rectifying fixed blade for fixing the rotary blade support shaft to a shaft, and a pressurizing projection having a concave hole into which the rotary blade supporting shaft is inserted, axially rotating by a fluid flow rate and slidingly contacting the rear-stage rectifying fixed blade. Rotating blade having a spiral torsion, and a post-stage rectifying fixed blade having a smooth surface that comes into sliding contact with the rotating blade pressing projection,
A flow sensor comprising: a rotation detecting unit; and a casing, wherein the rotation detecting unit is provided with a magnet coated with fluorine on the rotating blade near a front-stage rectifying fixed blade of the rotating blade, and a magnetic detecting device is provided on an outer peripheral portion of the casing. Wherein a bead is provided on a surface of the pre-rectifying fixed blade that is in sliding contact with the magnet. 7. A rectifying fixed vane having a bead for fixing a rotary blade support shaft to a shaft and slidingly contacting a magnet, and a concave hole for sandwiching the magnet and inserting the rotary blade support shaft, and an axial flow by a fluid flow rate. A rotating blade having a helical torsion having a pressure protrusion that rotates and slidingly contacts the rear-stage rectifying fixed blade, a rear-stage rectifying fixed blade having a smooth surface that slides on the rotating blade pressing protrusion, and a casing having a magnetic detection device. And a helical torsion of a lead shorter than the lead of the rotary blade for generating a vortex rotation in the fluid to improve the starting flow rate (sensitivity) of the rotary blade. The recycle type flow sensor according to claim 1, wherein an inclined projection is provided on an end face of the spiral torsion facing the flow direction of the fluid of the pre-stage rectifying fixed blade. 8. A front-stage rectifying fixed blade for fixing the rotating blade support shaft to a shaft, and a pressurizing protrusion having a concave hole into which the rotary blade supporting shaft is inserted, axially rotating by a fluid flow rate, and slidingly contacting the rear-stage rectifying fixed blade. Rotating blade having a spiral torsion, and a post-stage rectifying fixed blade having a smooth surface that comes into sliding contact with the rotating blade pressing projection,
A flow sensor comprising a rotation detecting means, a casing, and a lid, wherein the casing has a retaining hole, the lid has a retaining claw, and the lid is inserted into the casing. A recycling type flow sensor characterized by being twisted and hooked. 9. A front-stage rectifying fixed blade for fixing the rotating blade support shaft to a shaft, and a pressurizing projection having a concave hole into which the rotary blade supporting shaft is inserted, rotating axially by a fluid flow rate and slidingly contacting the rear-stage rectifying fixed blade. Rotating blade having a spiral torsion, and a post-stage rectifying fixed blade having a smooth surface that comes into sliding contact with the rotating blade pressing projection,
A flow sensor comprising a rotation detecting means and a casing, wherein a second casing is provided in the casing, and the front-stage rectifying fixed blade and / or the rotating blade and / or the rear-stage rectifying fixed blade are provided in the second casing. A recycle type flow sensor characterized by storing therein. 10. A front-stage rectifying fixed blade for axially fixing a rotary blade support shaft, and a pressurizing projection having a concave hole into which the rotary blade supporting shaft is inserted, axially rotating by a fluid flow rate and slidingly contacting the rear-stage rectified fixed blade. A flow sensor comprising: a rotary blade having a helical twist; a rear-stage rectifying fixed blade having a smooth surface in sliding contact with the rotary blade pressing projection; rotation detection means; a casing; and a second casing. A recycle type flow sensor, wherein a hook hole is provided in the casing, a hook claw is provided in the second casing, and the second casing is inserted into the casing and twisted and hooked.