JP4540360B2 - Flowmeter - Google Patents

Description

  The present invention relates to a flow meter such as a water meter, and more particularly to a vertical axial flow impeller flow meter represented by a vertical Waltman flow meter.

  In the vertical Waltman-type flow meter, as shown in Patent Document 1, water (fluid to be measured) that flows laterally from the primary (upstream) inlet of the water meter passes through the strainer and falls into the lower case. Then go up and pass through the rectifier and hit the impeller from the direction of the axis. The impeller has a plurality of twisted plate blades having an angle with respect to its own rotation axis, and the impeller rotates by the force of the water flow when water hits the plate blades from substantially the axial direction. The flow rate is measured by mechanically or electrically extracting the number of revolutions, and this is displayed on the weighing display section of the upper case, and the water that has passed through the impeller flows downstream from the outlet.

Japanese Utility Model No. 6-17050

  In the strainer shown in Patent Document 1, the cylindrical side (cylindrical) inlet side opening is held by the inflow port of the lower case, and the water that flows laterally from the inflow port is a flat non-porous bottom surface of the outlet side lid part. It is blocked and flows out from a fluid passage hole provided in the peripheral surface of the cylindrical portion, thereby forming an introduction channel (a lateral channel and an upward channel following the channel). As described above, in the conventional strainer, the fluid once retained at the flat non-porous bottom surface of the outlet side lid part is ejected in the radial direction from the peripheral surface, so the fluid resistance (pressure loss) increases and the flow turbulence occurs. It becomes easy to do. In particular, in vertical Waltman flowmeters, fluctuations in fluid resistance are reflected relatively greatly with respect to instrumental error (measurement tolerance of flowmeters) in the low flow rate region. Flatness) is likely to be impaired, and performance is likely to be unstable.

  The object of the present invention is to reduce the fluctuation of the fluid resistance (pressure loss) of the fluid flowing through the introduction flow path by aligning the direction in which the fluid flows out from the strainer in a predetermined direction, and to improve the flatness (flatness) of the instrumental error. An object of the present invention is to provide a flowmeter that can hold and exhibit stable measurement performance.

Means for Solving the Problems and Effects of the Invention

In order to solve the above problems, the flowmeter of the present invention is:
An impeller having an inflow port and an outflow port, and a rotating shaft of an impeller for measuring a flow rate of the fluid along a longitudinal direction intersecting a direction connecting the inflow port and the outflow port. In a flowmeter of a vertical axial flow impeller type in which an introduction flow path is formed to change the flow of fluid flowing in a lateral direction upward along the axial direction of the impeller and direct it toward the impeller.
A cylindrical portion having an axis along the horizontal flow path and having a fluid passage hole formed on the peripheral surface, an opening formed on the inflow side of the cylindrical portion, and an inside of the outflow side of the cylindrical portion A strainer including a lid having a convex curved surface that is convex toward the inflow side is disposed in the lateral flow path.

  Since the convex curved surface bulges from the strainer lid (bottom) toward the inflow side, the fluid flowing out from the strainer flows out from the fluid passage hole on the peripheral surface along the convex curved surface, It is possible to form an introduction flow path in which the subsequent upward flow path is smoothly connected. As a result, the fluctuation of the fluid resistance (pressure loss) of the fluid flowing through the introduction flow path can be reduced, and the flatness (flatness) of the instrumental error can be maintained and stable measurement performance can be exhibited.

In order to solve the above-mentioned problem, the flow meter of the present invention is
An impeller having an inflow port and an outflow port, and a rotating shaft of an impeller for measuring a flow rate of the fluid along a longitudinal direction intersecting a direction connecting the inflow port and the outflow port. In a flowmeter of a vertical axial flow impeller type in which an introduction flow path is formed to change the flow of fluid flowing in a lateral direction upward along the axial direction of the impeller and direct it toward the impeller.
A cylindrical portion having an axis along the horizontal flow path and having a fluid passage hole formed on the peripheral surface, an opening formed on the inflow side of the cylindrical portion, and an inside of the outflow side of the cylindrical portion A lid portion having a convex curved surface that is convex toward the inflow side, and a strainer disposed in the lateral flow path,
An introduction part arranged in the lateral flow path in the vicinity of the lid part in order to suppress the generation of vortices in the downstream area of the strainer;
It is characterized by providing.

Furthermore, in order to solve the above problems, the flowmeter of the present invention is:
An impeller having an inflow port and an outflow port, and a rotating shaft of an impeller for measuring a flow rate of the fluid along a longitudinal direction intersecting a direction connecting the inflow port and the outflow port. A vertical type in which an inflow channel is formed to change the flow of fluid flowing in in the horizontal direction upward along the axial direction of the impeller and to direct to the impeller, and a rectifier is provided in the upward flow channel to the impeller In the axial flow impeller type flow meter,
A cylindrical portion having an axis along the horizontal flow path and having a fluid passage hole formed on the peripheral surface, an opening formed on the inflow side of the cylindrical portion, and an inside of the outflow side of the cylindrical portion A lid portion having a convex curved surface that is convex toward the inflow side, and a strainer disposed in the lateral flow path,
In order to suppress the occurrence of vortices in the downstream area of the strainer, an introduction part provided in the rectifier in the form facing the lateral flow path and the upward flow path in the vicinity of the lid part of the strainer;
It is characterized by providing.

  In these flow meters, since the introduction part is provided close to the cover part for allowing the fluid to flow out of the strainer without disturbing it, the space in the downstream area of the strainer (that is, the rear side of the cover part) is introduced into the introduction part. By filling with, the generation of vortices in this space can be suppressed. Therefore, the fluctuation of the fluid resistance (pressure loss) of the fluid flowing through the introduction flow path is further reduced, and a flatter and more stable measurement performance (instrument difference) can be obtained.

  In addition, when providing an introducing | transducing part in a rectifier in the form which faces a horizontal flow path and an upward flow path, it is good to form the introducing | transducing part integrally with a rectifier, having the convex curved surface which becomes convex toward an inflow side. In this way, it is possible to easily attach the rectifier to the rectifier with an adhesive, assemble with a fastening member such as a screw, or integrally form with a resin so that the introduction portion does not hinder the flow of the introduction flow path. .

  Further, in these flow meters, when the strainer lid (bottom) is formed with a dome-shaped non-hole curved surface, the fluid flowing in from the opening is prevented from flowing out from the lid, and from the passage hole in the cylindrical portion. It will be leaked. Therefore, the fluid flowing out from the cylindrical part passage hole is guided in the introduction part in a uniform flow, and an introduction flow path with less disturbance is formed.

  By the way, regarding the positional relationship between the strainer and the introduction portion, the introduction portion is arranged so as to overlap at least partially with the strainer lid portion as seen from the flow direction of the lateral flow path, and flows out from the passage hole of the cylindrical portion. It is desirable that the fluid to be guided be guided by the introduction portion to form the introduction flow path. Alternatively, when viewed from the flow direction of the lateral channel, the introduction part is formed in a semicircular shape corresponding to the lower half part of the strainer, and the fluid flowing out from the passage hole of the cylindrical part is guided by the introduction part and introduced It is desirable to arrange so as to form a path.

  By arranging the strainer and the introduction part in this way, the fluid that has flowed out of the cylindrical part passage hole is likely to diffuse evenly radially with respect to its axis, and the flow rate is equalized in the cross section of the introduction flow path. In the state, it is guided by the introduction portion, and an introduction flow path with less disturbance is easily formed.

  Hereinafter, embodiments of the present invention will be described with reference to examples shown in the drawings. The following example is applied to a water meter, for example, and the fluid to be measured in that case is water.

  First, FIG. 1 shows a general structure when a vertical Waltman flow meter (vertical axial flow impeller flow meter) capable of implementing the present invention is used as a water meter. As shown in FIG. 1, in general, this type of water meter 1 includes a casing 2 made of brass or the like connected to a water pipe (not shown), and a casing 2 for collecting and separating foreign matter such as dust. A cylindrical strainer 3 attached to the inlet side of the water and a measuring main body 5 housed and held in the casing 2 for measuring the amount of water flowing through the water pipe.

  Specifically, the casing 2 includes a lower case 21 having an inlet 21F and an outlet 21R that are directly connected to a water pipeline, and an upper case 22 that is screwed into an upper opening of the lower case 21. Become. In the vicinity of the pipeline center line O1 connecting the centers of the inlet 21F and the outlet 21R, an inner flange 21f parallel to the pipeline center line O1 is formed by integral molding so as to bulge to the inner surface side of the lower case 21. Has been. The strainer 3 has an inflow side end (opening 32) inserted and held in the inlet 21F of the lower case 21, while an outflow side end surface (non-hole bottom surface) of the lower case 21 and the inner flange 21f. Are attached and held by an extension wall 21e, and the axis thereof coincides with the pipe center line O1. The cylindrical portion 31 of the strainer 3 is formed in a mesh shape including a large number of passage holes 31a, and the water of the fluid to be measured flowing from the opening 32 flows out through the passage holes 31a of the tubular portion 31. The measuring body 5 includes a housing 50 having an inflow-side measuring chamber 501 and an outflow-side measuring display unit accommodating chamber 502, and a rectifier 51 fixed and held in the housing 50 on the inflow side of the measuring chamber 501. The impeller 52 rotates at a speed corresponding to the amount of water in the measuring chamber 501, and the measuring display unit 53 for taking out and displaying the rotational speed of the impeller 52 mechanically or electrically. Yes.

  More specifically, the rectifier 51 radiates a boss portion 515 located at the center of the cross section of the flow toward the impeller 52, an annular rim portion 517 located on the outer peripheral portion, and a boss portion 515 and a rim portion 517 radially. And a plurality of arm portions 516 to be connected. An annular flange portion 518 is integrally formed on the outer side of the rim portion 517 of the rectifier 51 so as to be engaged with and held by the inner flange 21 f of the lower case 21. Further, the impeller 52 is configured in an axial flow type in which the axis O2 of the rotation shaft 52a is arranged in a vertical direction intersecting (for example, orthogonal to) the pipe center line O1, and water of the fluid to be measured flows along the rotation shaft 52a. Has been. In order to reduce the resistance due to friction and increase the accuracy of measuring the amount of water, the rotating shaft 52a is received by the pivot bearing 52c, and water of the fluid to be measured is circulated and immersed in these bearing portions.

  Such a water meter 1 is generally set according to the following procedure. First, the housing unit 50 and the rectifier 51 are assembled in a state where the impeller 52 is accommodated in the measurement chamber 501 and the measurement display unit 53 is accommodated in the measurement display unit accommodation chamber 502. Next, the assembled measuring main body 5 is inserted from the upper opening of the lower case 21, and the flange portion 518 of the rectifier 51 is received and held by the inner flange 21 f of the lower case 21. The upper case 22 is screwed into the upper opening. Separately, the strainer 3 is attached to the inlet 21F of the lower case 21 so that the axis thereof coincides with the pipe center line O1.

  The water to be measured flows through the water meter 1 as follows, and the amount of water is measured and displayed. The water flowing in from the inlet 21F of the lower case 21 flows into the lateral flow path 4H flowing toward the outlet 21R along the pipe center line O1, and then the direction of the flow is changed to the direction of the axis O2 of the rotary shaft 52a. It flows through the introduction flow path 4 composed of the upward flow path 4V toward 52. A strainer 3 is disposed in the lateral channel 4H to collect and separate foreign substances such as dust from water, while a flow of water flowing into the measuring chamber 501 (the impeller 52) in the upward channel 4V. Is rectified by a rectifier 51. The water flowing into the measuring chamber 501 from the introduction flow path 4 flows along the rotation shaft 52a, hits the plurality of blades 52b twisted in a spiral shape, and rotates the impeller 52 (rotation shaft 52a). The water that has passed through the measuring chamber 501 flows out from the central portion of the impeller 52 radially along the blade 52 b and flows through the outlet channel 6 that reaches the outlet 21 </ b> R of the lower case 21.

  At this time, the amount of water (volume flow rate) is displayed on the measurement display unit 53 by utilizing the property that the rotational speed of the impeller 52 is proportional to the amount of water passing through the measurement chamber 501. In addition, a part of the water in the measuring chamber 501 is transmitted through the rotary shaft 52a and the like due to a pressure difference between the inlet 21F and the outlet 21R (the inlet 21F side is larger than the outlet 21R side). Into 502, the bearings and the like are immersed and lubricated to reduce the frictional resistance during rotation of the rotating shaft 52a and the like.

  In the following description, as shown in FIG. 1B, the direction of the pipe center line O1 (or a direction parallel thereto) is the front-rear direction, the inlet 21F side is the front side, and the outlet 21R side is the rear side. Call the side. In addition, the direction of the axis O2 (or a direction parallel thereto) is the vertical direction (vertical direction), the side where the weighing display unit 53 is located is called the upper side, and the side where the rectifier 51 is located is called the lower side. Furthermore, as shown to Fig.1 (a), when the water meter 1 is seen from upper side, the direction (or direction parallel to it) orthogonal to the pipe line centerline O1 may be called the left-right direction. And the part which shares a function with FIG. 1 may attach | subject the same code | symbol, and abbreviate | omit description.

  Next, FIG. 2 shows a front sectional view of a water meter embodying the present invention in FIG. In the water meter 1 of FIG. 2, a cylindrical strainer 3 is disposed along the lateral flow path 4 </ b> H of the introduction flow path 4 with its axis line aligned with the pipe center line O <b> 1. The strainer 3 includes a cylindrical portion 31 in which a large number of fluid passage holes 31a are formed in a mesh shape on the peripheral surface, an opening portion 32 formed on the inflow side (inlet side) of the cylindrical portion 31, and a cylindrical portion thereof. A lid portion 33 (bottom portion) having a convex curved surface (convex curved bottom surface) convex toward the inflow side (inlet side) is provided inside the outflow side (outlet side) of the shape portion 32. Further, a bulging portion 511 (introduction portion) having a convex curved surface that is convex toward the inflow side is integrally formed at the front end portion of the rectifier 51 that is positioned behind the strainer 3. The bulging portion 511 faces the lateral flow path 4H and the upward flow path 4V of the introduction flow path 4 in order to suppress the generation of vortices in the downstream area (rear area) of the strainer 3, and It is disposed close to the lid 33.

  As shown in the perspective sectional view of FIG. 3, the lid portion 33 of the strainer 3 is formed by a dome-shaped non-porous curved surface (dome-shaped non-porous curved bottom surface). The maximum protrusion height H of the dome-shaped non-porous curved surface (dome-shaped non-porous curved bottom surface) is set to be larger than the axis orthogonal cross-sectional radius R of the cylindrical portion 31. Therefore, the water flowing in from the opening portion 32 on the inlet side is prevented from flowing out from the lid portion 33 and is guided along the dome-shaped curved surface (curved bottom surface), and smoothly from the passage hole 31a of the cylindrical portion 31. leak. Thereby, the fluctuation of the fluid resistance (pressure loss) in the introduction flow path 4 is reduced, and the instrumental error is flattened. A plurality of reinforcing ribs 33a are provided on the back side (rear side) of the dome-shaped curved surface (curved bottom surface) of the lid portion 33 along the direction of the axis (pipeline center line O1). This prevents the strainer 3 from being crushed (buckled and deformed) in the axial direction when sandwiched and held between the inlet 21F and the extension wall 21e of the lower case 21.

Returning to FIG. 2, the strainer 3 and the bulging portion 51 are arranged so as to have the following positional relationship.
(1) The bulging portion 51 is disposed so as to be substantially overlapped with the lid portion 33 of the strainer 3 when viewed from the flow direction of the lateral flow path 4H, and the water flowing out from the passage hole 31a of the cylindrical portion 31 swells. The introduction channel 4 is formed by being guided by the outlet 51.
(2) The bulging part 51 is formed in a semicircular shape corresponding to the lower half part of the strainer 3 (lid part 33) when viewed from the flow direction of the lateral flow path 4H, and the passage hole 31a of the cylindrical part 31 Water flowing out from the water is guided by the bulging portion 51 to form the introduction flow path 4.
(3) The dome-shaped curved surface (curved bottom surface) of the lid portion 33 protrudes symmetrically with respect to the axis (pipeline center line O1), and has no directivity with respect to the circumferential direction in the relations (1) and (2).

  By arranging the strainer 3 and the bulging portion 51 in this manner, the water flowing out from the passage hole 31a of the tubular portion 31 is likely to diffuse evenly radially with respect to its axis (the pipeline center line O1). Thus, it is guided by the bulging portion 51 in a state where the flow rate is equalized in the cross section of the introduction flow path 4. Therefore, the introduction flow path 4 with less disturbance is easily formed. In addition, since the curved surface (curved bottom surface) of the lid portion 33 has no circumferential directionality, when setting the strainer 3 to the lower case 21, it is necessary to specify the circumferential mounting angle position around the axis. The design and manufacturing burden is reduced.

  As shown in FIG. 4 (and FIG. 5), the lower part of the boss portion 515 of the rectifier 51 is bent from the lateral flow path 4H to the upward flow path 4V in order to bisect the introduction flow path 4 to the impeller 52. Correspondingly, a base portion of a flow dividing plate 512 (a flow dividing portion) having a curved shape over the entire width in the left-right direction of the introduction flow path 4 is installed. This flow dividing plate 512 bisects the introduction flow path 4 into the upper side and the lower side in the horizontal flow path 4H and the front side and the rear side in the upward flow path 4V, and flows into the measuring chamber 501. The amount of water in the introduction flow path 4 is divided into two equal parts, rectified symmetrically with respect to the rotating shaft 52 a, and has a function of uniformly applying water to the blades 52 b of the impeller 52. Thus, by providing the flow dividing plate 512, generation of unbalanced rotational force at the impeller 52 is prevented, and the peak of instrumental error is reduced (or eliminated).

  Furthermore, in FIG. 2, in order to be able to adjust the space | interval S (gap) between the front-end | tip (lower end) of the flow dividing plate 512 and the inner surface (upper edge) of the lower case 21, the flow dividing plate 512 is impeller 52 (rotating shaft 52a). ) In the direction of the axis O2. Specifically, the vertical position adjustment of the flow dividing plate 512 is performed by a fastening member 512 a such as a screw provided in the boss portion 515. Therefore, if the vertical position of the flow dividing plate 512 is adjusted according to the cross-sectional shape of the casing 2 (lower case 21) which is different for each city and the interval S is adjusted, the peak of the instrumental error can be almost eliminated and the stable measurement performance is long-term. Maintained over time.

  As shown in FIG. 4, when the rotation axis O2 of the impeller 52 passes through the center of the rectifier 51 and passes through the base of the flow dividing plate 512 (preferably, the attachment with the lower portion of the boss 515), Since the adjustment amount of the fastening member 512a can be set to the change amount of the interval S, the adjustment of the interval S is easy, and the fluctuation of the rectifying action of the rectifier 51 accompanying the change of the interval S can be minimized. At that time, if both the front and back surfaces of the flow dividing plate 512 are formed on a smooth surface along the horizontal flow path 4H and the upward flow path 4V, the flow dividing plate 512 maximizes the rectification function of the divided flow path 4 divided into two. it can.

  In FIG. 4, in the rectifier 51, a regulating plate 513 (regulating portion) is disposed at the end position of the lateral channel 4H so as to correspond to the bending from the lateral channel 4H to the upward channel 4V. The restricting plate 513 has a function of restricting and guiding the flow direction of water from the lateral flow path 4H to the upward flow path 4V, and between the staying region R and the introduction flow path 4 located behind (the rear side) the lateral flow path 4H. And the function of suppressing the generation of vortices between them. Here, the staying area R refers to a stagnation area that is formed along the lower case 21 (casing 2) behind the lateral flow path 4H and that does not generate a water flow. By providing such a restriction plate 513, inflow from the introduction flow path 4 (particularly the lateral flow path 4H) to the stay region R is suppressed, and accordingly, the generation of vortices between the two is reduced. The fluctuation of the fluid resistance (pressure loss) of the water flowing through the passage 4 is reduced, and the flatness of the instrumental difference is maintained.

  As shown in FIG. 5, the restriction plate 513 is integrally attached to the lower part of the rim portion 517 (see FIG. 4) of the rectifier 51 over the rear side half circumference (180 °), and is behind the lateral channel 4 </ b> H (rear side). ) Is formed as a convex curved surface (semi-cylindrical surface). A partition between the introduction flow path 4 (lateral flow path 4H) and the staying region R can be set in a wide range, and the staying region R is kept in a state of being isolated from the introduction flow channel 4, so that vortices are less likely to be generated. Further, the restriction plate 513 is formed with a notch 513a corresponding to the reinforcing rib 21r (see FIG. 9) protruding from the inner surface of the lower case 21 (casing 2). Accordingly, it can be used for the lower case 21 having the reinforcing rib 21r, and can be applied to more specifications.

  As shown in FIG. 2, for the purpose of providing the regulating plate 513, the interval S ′ (gap) between the tip (lower end) of the regulating plate 513 and the inner surface (upper edge) of the lower case 21 is set to 0. Is most desirable. However, as described above, in order to match the cross-sectional shape of the casing 2 (lower case 21) that is different for each city and to correspond to the dimensional accuracy of the casing 2 made of casting, it is realistic to set an appropriate interval in advance. It is.

  In FIG. 2, the rectifier 51 is integrally attached with a flow dividing plate 512 (a flow dividing portion), a boss portion 515, and a flow rectifying plate 514 (a flow rectifying portion). Of these, as described above, the flow dividing plate 512 is introduced into the impeller 52 (the measuring chamber 501) on the upper side and the lower side in the lateral flow path 4H and on the front side and the rear side in the upward flow path 4V. Each of the flow paths 4 is divided into two. The boss is located at the center of the cross section of the upward flow path 4V to the impeller 52.

  As shown in FIG. 4, the rectifying plates 514 </ b> F and 514 </ b> R are provided radially outward from the boss portion 515 for each of the two upward flow paths 4 </ b> VF and 4 </ b> VR divided by the flow dividing plate 512. The lengths LF and LR of the both rectifying plates 514F and 514R along the direction of the axis O2 of the impeller 52 (rotating shaft 52a) are formed to be shorter as the fluid pressure in the upward flow paths 4VF and 4VR is higher. ing.

  Specifically, the lengths LF and LR of the rectifying plates 514F and 514R along the direction of the axis O2 of the impeller 52 (rotating shaft 52a) are long on the front side of the upward flow paths 4VF and 4VR and are short on the rear side. In addition, they are formed in two stages. That is, in the forward upward flow path 4VF, the fluid pressure is low on the front side and high on the rear side, so the length of the front side (front half) of the rectifying plate 514F is LF1, and the length of the rear side (second half) of the rectifying plate 514F is When the length is LF2, LF1> LF2. In the rear upward channel 4VR, the fluid pressure is similarly low on the front side and high on the rear side. Therefore, the length of the front side (front half) of the rectifying plate 514R is LR1, and the rear side (second half) of the rectifying plate 514R. Part) is represented by LR1> LR2.

  On the front side (front half) where the fluid pressure is relatively high in each upward flow path 4VF, 4VR, the flow velocity is relatively fast, so even if the length of the rectifying plates 514F, 514R along the direction of the axis O2 is shortened, The flow direction (vector) is less likely to fluctuate (not easily disturbed). On the other hand, on the rear side (second half) where the fluid pressure is relatively low in the upward flow paths 4VF and 4VR, the flow velocity is relatively slow, so unless the length of the rectifying plates 514F and 514R along the direction of the axis O2 is increased, The flow direction (vector) is likely to fluctuate (prone to disturbance). Therefore, as described above, the lengths of the rectifying plates 514F and 514R along the direction of the axis O2 are adjusted according to the level of the fluid pressure in the upward flow paths 4VF and 4VR.

  As a result, a rectifying action is applied symmetrically to the rotation shaft 52a of the impeller 52 on the cross section of the upward flow path 4V, and an unbalanced rotational force is not generated in the impeller 52, thereby suppressing the instrumental error peak. . In addition, since the rectifier 51 is provided with such rectifying plates 514F and 514R and the flow dividing plate 512 arranged to bisect the introduction flow path 4 to the impeller 52 (metering chamber 501), It is also possible to almost eliminate the peak. The lengths of the rectifying plates 514F and 514R along the direction of the axis O2 may be continuously changed according to the level of the fluid pressure in the upward flow paths 4VF and 4VR.

  Further, as seen from the flow direction of the upward flow path 4V as shown in FIG. 5, the flow dividing plate 512 and the rectifying plate 514 are arranged orthogonally. In other words, the flow dividing plate 512 is arranged in a shape that vertically cuts the upward flow path 4V in the left-right direction, and the two rectifying plates 514F and 514R are straight in a shape that crosses the two upward flow paths 4VF and 4VR in the front-rear direction. Is arranged. In this way, the upward flow path 4V is divided into two in the front-rear direction by the flow dividing plate 512, and each of the divided upward flow paths 4VF, 4VR is subdivided (equally divided) in the left-right direction by the two rectifying plates 514F, 514R. Therefore, the rectifying action can be exerted symmetrically with respect to the rotation shaft 52a of the impeller 52 at intervals of 90 degrees.

  Further, as shown in FIG. 4, the flow dividing plate 512 is attached to the boss portion 515 so as to be movable in the direction of the axis O2, as described above. On the other hand, the two rectifying plates 514F and 514R are attached to the boss portion 515 so as not to move. Therefore, even when the flow dividing plate 512 is moved and adjusted in accordance with the shape of the lower case 21 (casing 2) that is different for each city, the positional relationship between the 514F and 514R and the impeller 52 does not change, so the rectification function varies. Absent.

  Actually, the two rectifying plates 514F and 514R are straight in the front-rear direction among a plurality of (for example, four) arm portions 516, 516, ..., 516 that radially connect the boss portion 515 and the rim portion 517. It is formed by extending only the two arm portions 516 and 516 having a shape in the direction of the axis O2. Thus, by combining the two arm portions 516 and 516 and the two rectifying plates 514F and 514R, the strength of the rectifier 51 is prevented from being reduced, and the rectifier plates 514F and 514R and the rectifier 51 can be easily formed integrally. .

  Next, as shown in FIG. 4, the housing part 50 has a partition 503 in which a measurement display part storage chamber 502 for storing the measurement display part 53 is formed in the upper part and a lead-out flow path 6 is formed in the lower part. . The partition wall 503 is formed with a through-hole 503 a that communicates the measurement display portion accommodation chamber 502 and the outlet channel 6. As a result, as the water flowing in from the inflow port 21F flows out of the outflow port 21R, a pressure difference is generated between the outflow port 21R side and the inflow port 21F side so that the outflow port 21R side has a negative pressure. Then, the water flowing from the introduction flow path 4 into the measurement display unit accommodation chamber 502 is discharged to the discharge flow path 6 through the through hole 503a.

  Therefore, by discharging the water staying in the measurement display unit accommodation chamber 502 to the outlet 21R side (outflow passage 6) through the through hole 503a, the bearing portion ( The rotational friction resistance of the rotating shaft 52a and the pivot bearing 52c) can be reduced. In particular, it is possible to prevent a sudden drop in the instrumental difference in a region where the flow rate is small, and to maintain stable measurement performance over a wide range.

  At this time, a part of the air staying in the weighing display unit accommodation chamber 502 is also sucked and discharged together with the water discharged to the outlet channel 6 through the through hole 503a. As a result, the generation of a water / air boundary layer at the bearing portion (rotary shaft 52a / pivot bearing 52c) of the impeller 52 and the increase in rotational frictional resistance associated therewith are prevented.

  Further, as shown in FIG. 4 (and FIG. 5), the outlet channel 6 has a plurality of (for example, 16) outlets for uniformly discharging water radially from the center of the impeller 52 in the circumferential direction. A side rectifying plate 504 (exit side rectifying unit) is provided. As a result, the water after rotating the impeller 52 can be uniformly discharged (discharged) in the circumferential direction, and the generation of vortices in the outlet channel 6 can be suppressed. In particular, the instrumental error peak due to circumferential imbalance, which tends to appear in a small flow rate region, is reduced (or eliminated).

  At that time, as shown in FIG. 6, the outlet-side rectifying plates 504 are a plurality of (for example, four) main rectifying plates 504 a formed as a continuous (overall) radial partition wall from the center to the outer peripheral edge. (Main rectification unit). Between the main rectifying plates 504a, a plurality (for example, four) of sub rectifying plates 503b (sub rectifying units) and a plurality (for example, eight) of auxiliary rectifying plates 503c (auxiliary rectifying units) from the partition wall 503 side of the housing unit 50 are provided. Projectingly formed. Specifically, the sub-rectifying plate 503b is formed as a continuous (overall) radial partition wall from the central portion to the outer peripheral edge, like the main rectifying plate 504a, while the auxiliary rectifying plate 503c The outer peripheral edge is formed as a partial radial partition wall. As a result, the main rectifying plate 504a (or the auxiliary rectifying plate 503b) and the auxiliary rectifying plate 503c are alternately arranged in the circumferential direction on the partition wall 503 of the housing portion 50. The auxiliary rectifying plate 503c formed between the main rectifying plates 504a (or the sub rectifying plates 503b) is gradually and circumferentially changed without suddenly changing (rapidly expanding) the cross-sectional area through which water passes from the center side to the outer peripheral edge side. Can be expanded evenly. As a result, the disturbance of the flow in the circumferential direction on the outlet 21R (outflow channel 6) side is suppressed, the generation of vortices is suppressed, and the peak of the instrumental error is reduced (or eliminated).

  Next, FIG. 7 shows another example of moving and adjusting the flow dividing plate, and FIGS. 8 and 9 show modified examples thereof. In the water meter 200 of FIG. 8, the flow dividing plate 512 (flow dividing portion) and the restriction plate 513 (restricting portion) described in FIG. 2 can be moved and adjusted simultaneously in the direction of the axis O2 of the impeller 52 (rotating shaft 52a). It has changed. Specifically, an adjustment plate 519b (interval adjustment member) is interposed between the flange portion 518 of the rectifier 251 and the flow dividing plate 512 and the restriction plate 513, so that the flow dividing plate 512 and the restriction plate 513 are impeller 52 ( The movement is adjusted in the direction of the axis O2 of the rotary shaft 52a). Thereby, the distance between the tips (lower ends) of the flow dividing plate 512 and the regulating plate 513 and the inner surface (upper edge) of the lower case 221 (casing 202) can be adjusted. By allowing the flow dividing plate 512 and the regulating plate 513 to move simultaneously in the direction of the axis O2, the peak of the instrumental error is reduced (or eliminated) and the flatness of the instrumental error is maintained.

  As shown in the water meters 100, 200, and 300 of FIGS. 7 to 9, the base of the flow dividing plate 512 is integrated with the horizontal connecting plate 519a spreading in a semicircular shape around the axis O2 in the rear side. The base of the restriction plate 513 is integrally attached along the rear edge. The connecting plate 519a is fixed to the flange portion 518 of the rectifiers 151, 251 and 351 by a fastening member 519c such as a screw at the rear end portion. The vertical position adjustment of the flow dividing plate 512 and the regulating plate 513 is performed by sandwiching and fixing a predetermined number or thickness of adjusting plates 519b between the flange portion 518 and the connecting plate 519a.

  Here, the number of adjustment plates 519b is adjusted according to the lower cases 121, 221 and 321 (casings 102, 202 and 302) having different cross-sectional shapes (for example, 0 in FIG. 7, 1 in FIG. 8, 1 in FIG. 9). The vertical position adjustment of the flow dividing plate 512 and the regulating plate 513 is performed. By changing the number and / or thickness of the adjusting plates 519b to be sandwiched, the distances between the tips (lower ends) of the flow dividing plate 512 and the regulating plate 513 and the inner surfaces (upper edges) of the lower cases 121, 221 and 321 can be easily adjusted. Therefore, it is possible to quickly cope with different casing shapes for each city. In addition, it respond | corresponds by fitting the notch 513a (refer FIG. 5) of the control board 513 to the reinforcement rib 21r protrudingly provided by the inner surface of the lower case 321 like FIG.

  7 to 9, parts having the same functions as those in FIG. 2 are denoted by the same reference numerals and description thereof is omitted.

  FIG. 10 shows a performance comparison between the water meter 1 embodying the present invention and a conventional one. As shown in FIG. 2, “the meter of the present invention” in FIG. 10 means “a strainer 3 having a cylindrical portion 31, an opening portion 32, and a convex-curved lid portion 33, and a rectifier 51 positioned behind the strainer 3. It is a water meter 1 "provided with the bulging part 511 integrally formed in the front-end part. As is clear from FIG. 10, the meter of the present invention shows a stable measurement performance with greatly improved flatness of instrumental error. This is because the fluctuation of the fluid resistance (pressure loss) of the water flowing through the introduction flow path 4 is reduced by the lid portion 33 (strainer 3) having a convex curved surface and the bulging portion 511 formed integrally with the rectifier 51. Conceivable.

  In the above description, the embodiment of the vertical Waltman type flow meter has been described on the assumption that the pipe center line O1 is horizontally disposed and the axis O2 of the impeller 52 (rotating shaft 52a) is vertically disposed. Of course, the flow meter is generally installed and fixed in the arrangement of FIG. 2, but in the water meter 1 (vertical Waltman flow meter) shown in FIG. In some cases, it is installed and fixed in an upside-down posture within an angle range of 90 degrees or the like so as to be arranged vertically. The same applies to FIGS. Expressions such as top / bottom / vertical / horizontal / front / rear or horizontal / vertical in the above description are for convenience of description and do not limit the essence of the invention.

The top view and front sectional view which show the general structure of the water meter which can implement this invention. Front sectional drawing of the water meter which implemented this invention. The perspective sectional view of a strainer. Front sectional drawing of a measurement main-body part. The perspective view of FIG. Explanatory drawing which shows arrangement | positioning of an exit side baffle plate. Front sectional drawing which shows the other example which moves and adjusts a shunt plate. Front sectional drawing which shows the 1st modification of FIG. Front sectional drawing which shows the 2nd modification of FIG. The graph which shows the effect by implementation of this invention.

Explanation of symbols

1 Water meter (vertical Waltman flow meter; vertical axial impeller flow meter; flow meter)
2 Casing 21 Lower case 21F Inlet 21R Outlet 3 Strainer 31 Cylindrical part 32 Opening part 33 Cover part (bottom part)
4 Introducing flow path 4H Horizontal flow path 4V Upward flow path 5 Weighing body section 50 Housing section 501 Weighing chamber 502 Weighing display section receiving chamber 503 Partition 503a Through hole 504 Outlet side rectifying plate (outlet side rectifying section)
51 Rectifier 511 Swelling part (introduction part)
512 Dividing plate (dividing part)
513 Restriction plate (regulation part)
514 Current plate (rectifier)
515 Boss part 52 Impeller 53 Measurement display part 6 Lead-out flow path

Claims (7)

An impeller having an inflow port and an outflow port, and a rotating shaft of an impeller for measuring a flow rate of the fluid along a longitudinal direction intersecting a direction connecting the inflow port and the outflow port. In a flowmeter of a vertical axial flow impeller type in which an introduction flow path is formed to change the flow of fluid flowing in a lateral direction upward along the axial direction of the impeller and direct it toward the impeller.
A cylindrical portion having an axis along the horizontal flow path and having a fluid passage hole formed on the peripheral surface, an opening formed on the inflow side of the cylindrical portion, and an inside of the outflow side of the cylindrical portion A strainer including a lid having a convex curved surface that is convex toward the inflow side, is disposed in the lateral flow path. An impeller having an inflow port and an outflow port, and a rotating shaft of an impeller for measuring a flow rate of the fluid along a longitudinal direction intersecting a direction connecting the inflow port and the outflow port. In a flowmeter of a vertical axial flow impeller type in which an introduction flow path is formed to change the flow of fluid flowing in laterally upward along the axial direction of the impeller and direct it toward the impeller.
A cylindrical portion having an axis along the horizontal flow path and having a fluid passage hole formed on the peripheral surface, an opening formed on the inflow side of the cylindrical portion, and an inside of the outflow side of the cylindrical portion A lid portion having a convex curved surface that is convex toward the inflow side, and a strainer disposed in the lateral flow path,
An introduction part arranged in the lateral flow path in the vicinity of the lid part in order to suppress the generation of vortices in the downstream area of the strainer;
A flow meter comprising: An impeller having an inflow port and an outflow port, and a rotating shaft of an impeller for measuring a flow rate of the fluid along a longitudinal direction intersecting a direction connecting the inflow port and the outflow port. A vertical type in which an inflow channel is formed to change the flow of fluid flowing in in the horizontal direction upward along the axial direction of the impeller and to direct to the impeller, and a rectifier is provided in the upward flow channel to the impeller In the axial flow impeller type flow meter,
A cylindrical portion having an axis along the horizontal flow path and having a fluid passage hole formed on the peripheral surface, an opening formed on the inflow side of the cylindrical portion, and an inside of the outflow side of the cylindrical portion A lid portion having a convex curved surface that is convex toward the inflow side, and a strainer disposed in the lateral flow path,
In order to suppress the occurrence of vortices in the downstream area of the strainer, an introduction portion provided in the rectifier in the form facing the lateral flow path and the upward flow path in the vicinity of the lid portion of the strainer;
A flow meter comprising:   The flowmeter according to claim 3, wherein the introduction portion has a convex curved surface that is convex toward the inflow side, and is integrally formed with the rectifier. The strainer lid is formed of a dome-shaped non-porous curved surface,
The flowmeter according to any one of claims 1 to 4, wherein the fluid flowing in from the opening is prevented from flowing out from the lid and flows out from the passage hole of the cylindrical portion. The introduction portion is disposed so as to at least partially overlap with the lid portion of the strainer when viewed from the flow direction of the lateral flow path,
The flow meter according to any one of claims 2 to 5, wherein a fluid flowing out from a passage hole of the cylindrical portion is guided by the introduction portion to form the introduction flow path. The introduction part is formed in a semicircular shape corresponding to the lower half part of the strainer as seen from the flow direction of the lateral flow path,
The flowmeter according to any one of claims 2 to 6, wherein a fluid flowing out from a passage hole of the cylindrical portion is guided by the introduction portion to form the introduction flow path.

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