JP2999913B2 - Fluid flow velocity measuring 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 rotating body provided with a rotating shaft rotatably provided on a fixed frame, and a blade attached to the rotating shaft, wherein a detection object rotates integrally with the rotating body. And a detecting means for detecting the object to be detected attached to the rotating body and a fluid flow velocity measuring device attached to the fixed frame.

[0002]

2. Description of the Related Art Such a fluid flow velocity measuring device is, for example,
It is installed in a duct through which the drying air flows in the grain drying equipment, and measures the flow rate of the drying air. When the drying air flowing through the duct hits the blades, the rotating body rotates, and the detecting unit detects the object to be detected that rotates integrally with the rotating body, thereby detecting the rotation speed of the rotating body, The flow rate of the drying air is calculated based on the rotation speed.

[0003]

By the way, when the fluid hits the blade, a force (hereinafter, sometimes referred to as a pressing force) which presses the rotating body toward the lower side in the flow direction of the fluid acts on the rotating body. The force changes according to the flow velocity of the fluid. On the other hand, since the rotating shaft has some flexibility in the direction of its axis, for example, if the pressing force acting on the rotating body changes suddenly due to a sudden change in the flow velocity, the rotating body In this case, the rotating body vibrates in the direction of the axis of the rotating shaft. Therefore, when the rotating body vibrates in the direction of the axis of the rotating shaft, the distance between the detected body and the detecting unit fluctuates.
In some cases, the detection means cannot reliably detect the object to be detected, and the detection accuracy of the rotation speed deteriorates. As a result,
There is a problem that the measurement accuracy of the flow velocity is deteriorated.

The present invention has been made in view of such circumstances, and an object of the present invention is to improve the accuracy of flow velocity measurement.

[0005]

According to a first characteristic configuration of the fluid flow rate measuring device according to the present invention, the rotating shaft is rotatably supported by the fixed frame via a bearing, and the bearing is arranged in a flowing direction of the fluid. A receiving portion for preventing movement toward the lower side is provided on the solid frame, and elastic urging means for urging the bearing toward the lower side in the flow direction of the fluid includes the fixed frame and the bearing.
In that it is provided between

A second characteristic configuration is that a cover body for covering a portion of the rotating shaft on the upstream side in the fluid flow direction is attached to the rotating body so as to rotate integrally with the rotating body.

[0007]

According to the first feature, the rotating shaft is fixed to the fixed frame.
The bearing that is rotatably supported by the
The stopper prevents the fluid from moving in the downstream direction.
It is received in a stopped state, and the elastic urging means
Therefore, the fluid is urged downward in the flow direction of the fluid.
In this case, the rotating body is driven by the urging force of the elastic urging means,
Rotatably supported on a fixed frame with no flexibility in the flow direction
Is done. Therefore, with rapid changes in the flow velocity of the fluid,
Pressing force acting on the rolling element on the lower side in the flow direction
Even if changes abruptly, by the urging force of the elastic urging means,
Since the rotating body is prevented from being repelled to the upstream side in the flow direction of the fluid, it is possible to prevent the rotating body from vibrating in the axial direction of the rotating shaft.

By the way, it is conceivable that the provision of the elastic urging means for urging the rotating shaft upward in the flow direction of the fluid prevents the rotating body from vibrating in the axial direction of the rotating shaft. However, in this case, since the rotating shaft is urged in the direction opposite to the direction in which the pressing force acts, the rotating shaft must be urged to the upstream side in the fluid flow direction against the pressing force. It is necessary to increase the urging force of the elastic urging means, and accordingly, it is necessary to make the installation structure of the elastic urging means firm. On the other hand, according to this characteristic configuration, since the bearing is urged in the same direction as the direction in which the pressing force acts, it is not necessary to increase the urging force of the elastic urging means more than necessary. The installation structure of the elastic urging means can be simplified.

The operation of the second characteristic configuration is as follows. If dust or the like contained in the fluid enters a bearing mechanism or the like that rotatably supports the rotating body with respect to the frame, smooth rotation of the rotating body is impaired. Provide a cover body to cover the part,
It is necessary to prevent dust from entering the bearing mechanism. Incidentally, when the cover body is attached to a member (for example, a fixed frame) fixed to a different member from the rotating body, a separation portion is formed between the cover body and the rotating body to allow the rotating body to rotate. There is a need. Therefore, since dust invades from the separated portion, intrusion of dust into the bearing mechanism cannot be reliably prevented.

On the other hand, according to this characteristic configuration, since the cover body is attached to the rotating body so as to rotate integrally with the rotating body, it is not necessary to form the above-mentioned separated portion, and dust can enter the bearing mechanism and the like. Can be reliably prevented.

[0011]

According to the first characteristic configuration, the distance between the object to be detected and the detecting means can always be kept constant, and the object to be detected can be reliably detected by the detecting means. The detection accuracy of the rotation speed has been improved, and as a result, the measurement accuracy of the flow velocity can be improved.

Further, according to the second characteristic configuration, it is possible to reliably prevent dust and the like from entering the bearing mechanism and the like, so that the durability can be improved.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a flow rate measuring device for drying air in a grain drying facility will be described below with reference to the drawings.

First, an overall configuration of a grain drying facility will be described with reference to FIG. Reference numeral 1 in the figure denotes a storage chamber for pre-drying and storing harvested cereals. A cereal input port 2 is formed at the upper part of the storage chamber 1, and a cereal input port 2 is provided below the cereal input port 2. There is provided an equalizer 3 for dispersing the cereal fed from the plant. The grains sequentially fed into the receiving hopper 18 are lifted and conveyed by the bucket elevator 4, conveyed horizontally by the conveyor 5, thrown into the storage room 1 from the grain input port 2, and accumulated in the storage room 1. It is configured to store. In addition, the weighing device 6 measures the weight of the grain loaded into the receiving hopper 18 for each receiving.

An air supply duct 7 to which drying air is supplied from an air conditioner (not shown) is connected to an upper portion of the storage chamber 1, and an outside air inlet 8 is formed. The floor 9 is configured to be freely ventilated, and an exhaust chamber 10 is provided on the entire lower surface of the floor 9. The outside air inlet 8 is provided with a damper 11 for adjusting the opening.

At the lower part of the storage chamber 1, a rotary valve 12 is provided for discharging stored grains down to the exhaust chamber 10, and the exhaust chamber 10 receives the grains flowing down from the rotary valve 12, An unloading conveyor 13 for unloading the room is provided.

An exhaust duct 15 in which an exhaust fan 14 is interposed is connected to the exhaust chamber 10. Then, by operating the blower 14, the normal-temperature and low-humidity drying air dehumidified and temperature-controlled by the air conditioner is introduced into the storage chamber 1 from above through the air supply duct 7, and passes through the accumulated grains. After that, it is drawn out of the exhaust chamber 10. Thereby, the grains stored in the storage room 1 are pre-dried until the water content becomes, for example, about 18 to 19%. The damper 11 adjusts the opening of the outside air inlet 8 so that outside air can be introduced from the outside air inlet 8 as drying air.

The exhaust duct 15 is provided with a detector 20A of a flow rate measuring device 20 for measuring the flow rate of the drying air flowing through the exhaust duct 15. Then, based on the detection information of the detection unit 20A of the flow velocity measurement device 20, the calculation unit 20 of the flow velocity measurement device 20 installed outside the exhaust duct 15 is used.
B, the flow rate of the drying air is calculated, and based on the calculated flow rate, the control device C controls the rotation speed of the electric motor 16 that drives the blower 14 so as to control the flow rate of the drying air. It is composed. The control device C is configured using a microcomputer, and the calculation unit 20B of the flow velocity measuring device 20 is configured using the control device C.
Hereinafter, the control operation of the control device C will be described.

The control device C calculates the cumulative receiving weight for each day of receiving over a one-day period based on the information from the weighing device 6, and adds the predetermined receiving air volume ratio (for example, 0.25 to 0) to the cumulative receiving weight. .3m ³ / (t · sec)) to calculate the set airflow, calculate the set flow velocity from the set airflow, and set the blower 14 so that the flow velocity measured by the flow velocity measuring device 20 becomes the set flow velocity. The number of rotations of the electric motor 16 is controlled. Then, when the receiving of the day is completed, the blower 14 is operated for a predetermined time according to the set flow rate set based on the final cumulative receiving weight of the day, and the grains received on the day and put into the storage room 1 are stored. Is pre-dried. On the next day, after clearing the accumulated weight of the previous day,
The ventilation amount control as described above is executed, and the preliminarily dried cereal is put on the cereal that has been put in the previous day and is preliminarily dried and stored.

Next, the flow rate measuring device 20 will be described with reference to FIGS. First, the detection unit 20A of the flow velocity measuring device 20 will be described.

It is substantially cylindrical and has a large diameter portion at one end.
Frame body portion 22 and end of large diameter portion in frame body portion 22
The rear cover 32, which is airtightly connected to the
A fixed frame K is formed, and the fixed frame K is formed into a cylindrical casing.
21 is provided in a state supported by a support 23.
You. The rotating shaft 2 is provided inside the frame body 22 of the fixed frame K.
6 is rotatably provided via a bearing J , a bottomed cylindrical front cover 27 is attached to a rotating shaft 26 via a boss 28, and eight blades 29 are provided on the side surface of the front cover 27. A rotating body R that is rotatable around the axis P of the rotating shaft 26 is attached at regular intervals.

The rotator R will be further described. The center of the bottom of the front cover 27 is fixed to the boss 28 in a state where the center of the bottom of the front cover 27 is airtightly fitted to the boss 28.
Is fixed in a state of being externally fitted to the tip of the airtight. Thereby, the flow direction F of the drying air on the rotating shaft 26 is
Front cover 27 corresponding to a cover body covering the upper side portion of
Is attached to the rotating body R so as to rotate integrally with the rotating body R. Further, as shown in FIGS. 2 and 4, the blade 29
Standing on the side surface of the front cover 27 with its longitudinal direction L along the radial direction of the front cover 27 and with its width direction W and the axis P intersecting at 45 °. is there.

Further, the protective cover 30 having a truncated cone shape is fixed to the tip of the rotating shaft 26 so as to cover the bottom of the front cover 27, and is attached to the rotating body R so as to rotate integrally with the rotating body R. is there.

A disk-shaped detection plate 31 is attached to the rear end of the rotating shaft 26 so as to rotate integrally with the rotating body R in a state of being fitted to the outside. The detection target plate 31 is formed of a material capable of reflecting light, and as shown in FIG. 5, four notches 31a are formed at equal intervals in a peripheral portion thereof. is there.

Rear part having a bottomed cylindrical shape and a flange portion
The cover portion 32, by connecting the flange portion while interposing the ring-like packing 33 on the end surface of the large diameter portion of the frame body 22 in an airtight state, is attached to the frame body portion 22. An optical proximity sensor 34 configured so that the distal end surface functions as a detection unit is mounted on a fixed frame K.
It is attached to the fixed frame K by being inserted from the bottom of the rear cover part 32 in an airtight state. Also, the proximity sensor 3
4 has a predetermined interval between its tip end surface and the plate surface of the detection target plate 31, and is located at a position alternately facing the plate surface of the rotating detection target plate 31 and the notch 31a. is there. When the detected plate 31 rotates integrally with the rotating body R,
A pulse-like detection signal is output from the proximity sensor 34. Therefore, the detected plate 31 corresponds to a detected object, and the proximity sensor 34 corresponds to a detecting unit that detects the detected plate 31.

Next, the rotary shaft 26 is fixed based on FIG.
The configuration for rotatably providing the frame body 22 of the frame K will be described.

The bearing J is composed of a pair of bearings 24 and 25.
And the outer ring 24a of the bearing 24 and the outer ring 25a of the bearing 25
The rotating shaft 26 is fitted inside the frame main body 22, and the rotating shaft 26 is fitted inside the inner ring 24 b of the bearing 24 and the inner ring 25 b of the bearing 25.
Through a pair of bearings 24 and 25 , ie, the frame body 22,
It is rotatably supported on a fixed frame K. In the fixed frame K
The lower end surface of the outer ring 25a of the bearing 25 on the lower side of the flow direction F is applied to the abutting surface 22a formed on the frame main body 22, and the flow of the inner ring 25b of the bearing 25 on the inner ring 25b of the bearing 25 is applied. On the end face on the better side of direction F,
An abutment surface 26a formed on the rotating shaft 26 is abutted, and an abutment surface 26b formed on the rotating shaft 26 is abutted against the abutment surface 26b on the inner ring 24b of the bearing 24 on the upstream side in the flow direction F. by abutted end surfaces, solid
The contact surface 22 formed on the frame body 22 in the fixed frame K
This prevents the pair of bearings 24 and 25 from moving downward in the flow direction F. Therefore, the contact surface 22a corresponds to the receiving portion. In addition, 24c in FIG.
And 25c are balls as rolling elements of the bearing 24 and the bearing 25, respectively.

Further, a ring-shaped washer 35 is applied to the upper end surface of the outer ring 24a of the bearing 24 on the upper side of the flow direction F, and the C-shaped ring body 36 is fixed to the fixed frame. K is fixed by fitting it into a groove formed on the inner surface of the frame main body portion 22 at K , and by disposing the disc spring 37 between the washer 35 and the ring body 36, the urging force of the disc spring 37 Bearing 2
4, 25 are urged to the lower side in the flow direction F. Thus, the rotating body R is rotatably provided on the frame main body 22, that is, the fixed frame K , without play in the flow direction F. Therefore, the disc spring 37 corresponds to an elastic biasing means.
Then, a disc spring 37 is provided between the fixed frame K and the bearing J.
You.

As described above, the rotating body R is moved in the flow direction F
Is provided on the fixed frame K without play.
The gap provided between the opening end of the front cover 27 and the outer peripheral surface of the fixed frame K can be made as small as possible. Therefore, rice husks, straw debris, dust and the like contained in the drying air are not covered by the front cover 2.
7 can be suppressed as much as possible.

The detector 20A of the flow velocity measuring device 20 configured as described above is arranged in a state where the axis P of the rotating shaft 26 is aligned with the flow direction F and at the center of the exhaust duct 15.
It is suspended by a suspending tool 38 inside the exhaust duct 15.

[0031] The addition of explanation, the detection unit 20A of the flow rate measuring device 20 has an inner diameter and a length L ₁ is provided within the inner diameter D equal coupling portion 15A of the exhaust duct 15, the connecting portion 15
A is connected in the middle of the exhaust duct 15. Further, FIG.
As shown in, the exhaust duct 15, the length L ₂ of the straight pipe portion located upstream side of the flow direction F of the connecting portion 15A (the flow path straight portion) than 7 times the inner diameter D also long, and the length L ₃ of the straight pipe portion located downstream side of the flow direction F of the connecting portion 15a are set to be longer than 3 times the internal diameter D. Therefore, by increasing the length of the straight pipe portion, the drying air flows in the straight pipe portion in a laminar flow state, and the variation in the flow velocity in the plane direction orthogonal to the flow direction F is reduced. Measurement accuracy increases.

Next, the operation unit 20B of the flow velocity measuring device 20 will be described. When the drying air hits the blade 29, the rotating body R rotates, and accordingly, the proximity sensor 34
Outputs a detection signal corresponding to the rotation speed N of the rotating body R. Then, based on the output signal from the proximity sensor 34, the calculating unit 20B of the flow rate measuring device 20 calculates the rotation speed N, and based on the calculated rotation speed N, calculates the flow speed v of the drying air into the following equation. To calculate. v = 2π × N × G where G is the distance from the axis P of the rotating shaft 26 to the center of gravity of the blade 29.

[Another Embodiment] Next, another embodiment will be described. The proximity sensor 34 has a predetermined distance between its tip end surface and the end surface of the detection target plate 31, and is located at a position alternately facing the end surface of the rotating detection target plate 31 and the notch 31a. Is also good.

In the above-described embodiment, the case where the detecting means is constituted by the optical proximity sensor 34 has been described.
Instead, a magnetic proximity sensor may be used. In this case, the object to be detected is formed of a magnetic material.

In the above-described embodiment, the case where the arithmetic unit 20B of the flow velocity measuring device 20 is configured by using the control device C has been exemplified.
May be configured separately from the control device C.

The specific configuration of the elastic urging means is not limited to the disc spring 37 shown in the above embodiment. Further, the structure for supporting the elastic urging means is not limited to the case where the structure is constituted by the washer 35 and the ring body 36 as shown in the above-described embodiment, and can be variously changed.

In the above embodiment, the case where the present invention is applied to the measurement of the flow velocity of the drying air in the grain drying equipment is illustrated. However, the present invention may be applied to the measurement of the flow velocity of various fluids. Can be. For example, the present invention can be applied to measurement of the flow rate of air-conditioning air in an air-conditioning facility.

Incidentally, reference numerals are written in the claims for convenience of comparison with the drawings, but the present invention is not limited to the configuration of the attached drawings by the entry.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a grain drying facility.

FIG. 2 is a longitudinal sectional side view of a fluid flow velocity measuring device.

FIG. 3 is a longitudinal sectional side view showing a support structure of a rotating shaft in a fluid flow velocity measuring device.

FIG. 4 is a partially cutaway side view of the fluid flow velocity measuring device.

FIG. 5 is a rear view showing an object to be detected in the fluid flow velocity measuring device.

[Description of Signs ] 22a Receiving part 26 Rotating shaft 27 Cover body 29 Blade 31 Detected body 34 Detecting means 37 Elastic urging means J Bearing K Fixed frame R Rotating body

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G01P 5/06 F26B 17/14 F26B 21/12

Claims (2)

(57) [Claims] A rotating shaft (26) is rotatably provided on a fixed frame (K) , and a blade (2) is attached to the rotating shaft (26).
9) is attached to form a rotating body (R), and the detected object (31) is attached to the rotating body (R) so as to rotate integrally with the rotating body (R). )
Detecting means (34) for detecting the flow rate of the fluid is a fluid flow rate measuring device attached to the fixed frame (K) , wherein the rotating shaft (26) is mounted on the fixed frame via a bearing (J)
(K) rotatably supported by the receiving portion (2) for preventing the bearing (J) from moving downward in the fluid flow direction.
2a) is provided on the solid frame (K) , and the bearing (J)
Resilient urging means (37) for urging the fluid downward in the flow direction of the fluid is provided between the fixed frame (K) and the bearing (J).
Flow rate measurement apparatus of the fluid provided in the. 2. A cover (27) for covering a portion of the rotating shaft (26) on the upstream side in the fluid flow direction is attached to the rotating body (R) so as to rotate integrally with the rotating body (R). The fluid flow velocity measuring device according to claim 1.