JP2007212465A - Flowmeter, and strainer used therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an easily attachable flowmeter with a strainer. <P>SOLUTION: In this flowmeter having a flow-in port and a flow-out port, and having an impeller 15 for measuring a flow rate of a fluid arranged along a longitudinal direction with respect to the flow-in port and the flow-out port, the strainer is arranged to prevent a foreign matter from being passed through a flow passage of the fluid toward the impeller, the strainer has a cylindrical part engaged with an inner wall of the flow passage, a wall part formed to partition the cylindrical part, and a large number of passing-through holes formed penetrated through the wall part, an elastically deformable locking part is formed along a direction approached or separated to/from the inner wall of the flow passage, in the cylindrical part of the strainer, an engaging part is formed to be engaged elastically with the locking part in a strainer side, in the inner wall of the flow passage, and the strainer is attached to the flow passage by a single operation, with the engagement of the locking part with the engaging part. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

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

  In the vertical Waltman type flow meter, as shown in FIG. 17, the water (measuring fluid) flowing in from the primary side (upstream side) of the water meter passes through the supplementary pipe 101, and then flows into the lower case 102. It enters the lower part, then rises, passes through the rectifier 103, and hits the impeller 104 from the axial direction. The impeller 104 or the like has a plurality of twisted plate blades having an angle with respect to its own rotation shaft 105, and water impinges on the plate blades almost from the axial direction. Rotate. The flow rate is measured by mechanically or electrically extracting the number of rotations, and this is displayed on the weighing display unit 107 of the upper case 106. The water that has passed through the impeller 104 flows downstream from the outlet 108.

  Here, in the conventional vertical Waltman type flow meter, a metal plate-like (punching metal) strainer 110 with a number of holes punched is screwed to the inflow side of the supplementary pipe 101 via a sleeve 111. 112 is fixed and installed. The strainer 110 may be installed on the outflow side 113 of the supplementary pipe 101 or the inflow side 104 of the lower case 102. The fluid that enters from the inlet 115 passes through the strainer 110, rotates the impeller 104, and travels toward the outlet 108.

  However, since the conventional strainer 110 is in the form of a punching metal plate, it is difficult to fix it alone, it is necessary to fix it using the sleeve 111 or the screw 112, and it is troublesome to install, so it is not suitable for mass production. there were.

  The subject of this invention is providing the flowmeter provided with the strainer attached easily.

Means for Solving the Problems and Effects of the Invention

  The present invention relates to a flow meter arranged in a vertical direction so that a rotation axis of an impeller for measuring a fluid flow rate intersects with a direction connecting an inflow port and an outflow port, and the flow of the fluid toward the impeller A strainer that prevents passage of foreign matter is disposed in the path, and the strainer includes a cylindrical portion that is fitted to the inner wall of the flow path, a wall portion that is formed to partition the cylindrical portion, and the wall There are a large number of fluid passage holes formed through the part, and the cylindrical part of the strainer is formed with a locking part that can be elastically deformed in the direction approaching and separating from the inner wall of the flow path An engaging portion is formed on the inner wall of the flow path to elastically engage the engaging portion on the strainer side, and the strainer is engaged with the engaging portion by engaging the engaging portion with the engaging portion. It is attached to the inner wall.

  In this way, by adopting a cylindrical strainer, the number of parts, the cost of parts, and the number of assembly steps can be reduced compared to the conventional combination of a plate-shaped strainer, a fixing sleeve and a screw member. Can do. Moreover, even when it is made into a resin, it is possible to prevent a decrease in strength and toughen the thrust load applied in the water flow direction.

  Further, when the tubular portion of the strainer is inserted from the opening of the pipe joint, the engaging portion formed on the strainer is engaged with the engaging portion by the elastic return action after being pushed back by the inner wall with elastic deformation. In combination, the strainer can be attached to the end of the pipe joint in a state of being prevented from coming off.

  In addition, the cylindrical portion of the strainer has a disengagement knob portion for elastically detaching the strainer-side engaging portion from the channel-side engaging portion and detaching the strainer from the channel inner wall with a single touch. Is formed at the end of the cylindrical portion of the strainer, so that the strainer can be easily removed.

  Moreover, this invention can be grasped | ascertained not only as a flow meter but as a strainer in order to attach to a flow meter.

BEST MODE FOR CARRYING OUT THE INVENTION

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

  In FIG. 1, the flow meter 1 includes a supplementary pipe 2, a lower case 11 to which the supplementary pipe 2 is connected, and a metering device 4 provided on the upper part of the lower case 11. The lower case 11 includes a straight tubular inflow pipe portion 3 connected to the supplementary pipe 2 and the joint 5, and an L-shaped curved bent portion bent at a right angle from the straight tubular inflow pipe portion 3 with a predetermined radius of curvature. A curved pipe portion (hereinafter also referred to as an L-shaped pipe) 16 and an L-shaped outflow pipe portion 8 that guides a fluid to be measured through the impeller 15 of the measuring chamber 17 are provided.

  The measuring chamber 17 in the lower case 11 is located at the upper end of the vertical tube portion of the bent portion (L-shaped tube portion) 16, and the impeller 15 is inserted into the measuring chamber 17 by a vertical pivot (rotating support shaft) 14. It is housed rotatably in a horizontal plane. A center hole 6 that opens downward is formed at the center of the impeller 15, and the center hole 6 is loosely fitted to the pivot 14, and the impeller 15 is rotatably supported at the tip of the pivot 14. The impeller 15 includes a plurality of blades 15a spirally twisted around its center line, and is rotated by the fluid to be measured flowing from substantially vertically below.

  The fluid to be measured that has passed through the rotating impeller 15 flows out from the opening on the outer periphery of the measuring chamber 17 outward in the radial direction of the impeller 15, and is horizontally directed from below by the L-shaped outflow pipe portion 8. The direction is changed to a predetermined curvature and is led downstream. The rotation speed of the impeller 15 that is substantially proportional to the flow rate of the fluid to be measured is converted into a flow rate electronically or mechanically and measured by the measuring device 4 to display a predetermined flow rate.

  Near the lower side of the impeller 15, a rectifier 13 is fixed to the lower case 11. The rectifier 13 has an annular shape, and has a plurality of rectifying plates in the radial direction or other predetermined arrangement form in the annular shape, and also has the pivot 14 at the center to serve as a support mechanism for the impeller 15. . The fluid to be measured guided from below passes through the rectifier 13, is rectified by the rectifying plate, and then strikes the impeller 15. In addition to (or replacing) the radial rectifying plate, a rectifying plate 19 for not disturbing the flow of the fluid to be measured can be disposed at the bent portion of the L-shaped tube portion 16. The rectifying plate 19 has a curvature (curved form) with a curvature substantially corresponding to the curvature of the bent portion of the L-shaped tube portion 16, and extends a predetermined length along the bend of the tube wall of the L-shaped tube portion 16. Thus, on the plate surface of the rectifying plate 19 on the concave curved surface side, a rib 18 perpendicular to the rectifying plate 19 is formed so as to extend in a direction parallel to the center line of the L-shaped tube portion 16.

  An appropriate number (for example, 1 to 4 sheets, preferably about 3 sheets) of the current plate 19 can be used. When a plurality of current plates 19 are provided, the plurality of current plates 19 are provided with a predetermined interval and a radius of curvature. An appropriate number (for example, one) of ribs 18 is formed in the middle of the rectifying plate 19 in the width direction so as to intersect each rectifying plate 19 vertically, and the rib 18 connects the rectifying plates 19 to have a certain strength. Secure. Such a rectifying plate 19 is connected to the lower end portion of the rectifier 13 and is supported by the rectifier 13 in a fixed position.

  In this flow meter 1, the supplementary pipe 2 and the straight tubular inflow pipe portion 3 (inlet) are coaxial in the horizontal direction, and the outflow pipe portion 8 (outlet) is also coaxial. In other words, when the side closer to the impeller 15 is the upper side and the side far from the impeller 15 is the lower side with respect to the extension of the center line of the supplementary pipe 2 and the inflow pipe portion 3, the supplementary pipe 2 to the inflow pipe portion 3 The fluid to be weighed introduced through the pipe is introduced straight and horizontally without being lowered downward, and flows as it is in the direction along the axial direction of the impeller 15 (vertically upward) by the L-shaped pipe part (L-shaped pipe) 16 as it is. The configuration is such that the direction of the fluid is changed and the fluid to be measured is applied to the impeller 15 for measurement.

  Further, in this flow meter 1, the flow passage cross-sectional area (inlet cross-sectional area) of the inflow pipe portion 3 is S1, and the cross-sectional area of the introduction portion from the lower side with respect to the impeller 15 (the inner diameter of the rectifier 13 or the impeller 15). S2 is a cross-sectional area corresponding to the outer diameter of S1). As a change in the cross-sectional area from S1 to S2, S1 and S2 are almost equal to each other, or the difference between the two is predetermined. It is assumed to be below the value. That is, S2 / S1 is defined in the range of 0.7 to 1.4, for example.

  The fluid to be measured that has passed through the strainer 20 and the supplemental pipe 2 enters the lower case 11. As described above, the inlet portion 3 extends so as to extend the straight pipe continuing from the supplementary pipe 2, and the fluid to be metered hits the impeller 15 on the pivot 14 installed in the rectifier 13 vertically. A straight pipe is bent at a right angle with a predetermined curvature like an L-shaped pipe to form an L-shaped pipe portion 16.

  As described above, the pipe of the fluid to be measured leading from the inlet 3 side to the impeller 15 is bent at a right angle by the L-shaped pipe portion 16 from horizontal to vertical without being lowered downward, and By reducing the cross-sectional change from the inflow side to the impeller 15 (removing the staying part), there are few bent parts in the flow path, there is almost no staying part, and the fluid flow is less disturbed and the pressure loss Decrease. As a result, the capacity of the flow meter can be increased.

  In the flow meter 1 as described above, a resin-made cylindrical strainer 20 is installed at the inflow side end portion (opening portion of the flange 38) of the supplementary pipe 2. The strainer 20 is fitted to the inner wall of the inflow side opening of the supplementary pipe 2, and the inner wall has a circular cross section. Therefore, the outer shell of the strainer 20 is a cylindrical portion 22 (cylindrical portion or cylindrical portion) having a cylindrical shape. It has.

  As shown in FIGS. 2 and 3, the cylindrical portion 22 of the strainer 20 includes a wall portion formed so as to partition the cylindrical portion 22, and the wall portion is convex toward the fluid inflow side. A dome-shaped convex curved surface 24 is formed, and a large number of fluid passage holes 25 are opened in the dome-shaped curved surface 24. More specifically, in the cylindrical portion 22 of the strainer 20, a dome-shaped wall portion (convex curved wall portion) 26 having a predetermined thickness t in the axial direction faces the fluid inflow side (IN). It is formed to be convex. The numerous passage holes 25 described above pass through the dome-shaped wall portion 26 in parallel with the axial direction of the strainer 20. As shown in FIG. 3, an arc-shaped rounded portion 25a having a predetermined curvature is formed on the end surface on the inflow side of the passage hole 25 (lattice), and this rounded portion 25a is contracted (water flow or the like) as described later. To prevent the flow diameter from being narrowed to the center side). Such a rounded portion 25a can also be formed on the outflow side of the passage hole 25 (lattice).

  The passage holes 25 have a polygonal cross section, in particular, a regular hexagonal cross section in this example, and the partition wall portions of adjacent ones of the regular hexagonal passage holes 25 are formed with a substantially constant thickness. ing. In other words, the passage hole 25 of the strainer 20 is formed by the hollow portion of the regular hexagonal honeycomb tubular portion 28, and the fluid inflow side opening of the passage hole 25 has a dome-shaped curved surface that bulges to the inflow side. 24, and the opening on the outflow side opens to the concave dome-shaped concave curved surface 27 of the dome-shaped wall portion 26. Both the openings on the inflow side and the outflow side have a honeycomb shape.

  A flange 29 is formed at one end of the cylindrical portion 22 of the strainer 20 so as to protrude outward in the radial direction. On the outer peripheral surface of the cylindrical portion 22, one or a plurality of (in this example, two) locking portions 30 proximate to the flange 29 project outward and at an angular interval of 180 degrees, the strainer 20 It is formed symmetrically through the center. These locking portions 30 are provided on the flange 29 side (fluid inflow side), a locking surface (stopper surface) 31 substantially perpendicular to the axis of the strainer 20, and gradually from the locking surface 31 toward the outflow side. And a slope 32 having a lower height.

  Further, as shown in FIG. 4, elastic deformation portions 33 are formed in the cylindrical portion 22 of the strainer 20 corresponding to these locking portions 30. The elastic deformation portion 33 has two slits 34 formed in parallel to the axial direction from the end on the flange 29 side with respect to the cylindrical portion 22, so that the belt-shaped elastic deformation portion 33 is the main body of the cylindrical portion 22. Each elastically deformable portion 33 is partly separated from the portion, and can be elastically deformed in the radial direction of the strainer 20 within the range of the elastic performance of the resin material, and each locking portion 30 is formed at an intermediate portion of these elastically deformable portions 33. Therefore, each of the locking portions 30 can be elastically displaced in the direction of approaching / separating from the axis of the strainer 20.

  The free end portion 33a of each elastically deformable portion 33 is positioned substantially flush with the outer end surface of the flange 29, but the flange 29 has a predetermined shape (on the outer side of the free end portion 33a of the elastically deformable portion 33). For example, rectangular notches 35 are formed, and the free ends 33a of the elastically deformable portion 33 are allowed to approach and separate from each other by the notches 35, and both free ends are inserted by inserting fingers from the notches 35. If the portion 33a is made to approach, the locking (stopper) action by the locking portion 30 can be released as will be described later. Here, the free end 33a in the notch 35 functions as an engagement release knob.

  The strainer 20 as described above is disposed at the fluid inflow side end portion 37 of the supplementary pipe 2 of FIG. 1, and in this example, a flange 38 is formed at the end portion 37. As shown in FIG. 6, a large-diameter inner peripheral portion 40 having a larger inner diameter than the inner peripheral portion (fluid passage inner wall) 39 of the supplementary pipe 2 is formed on the inner wall of the inflow side end portion 37 corresponding to the strainer 20. The large-diameter inner peripheral portion 40 is larger than the normal hole diameter (passage diameter) 39 of the supplementary pipe 2 by a dimension corresponding to approximately twice the thickness of the cylindrical portion 22 of the strainer 20 and the axial length of the strainer 20. The length corresponds to the length, and opens to the flange 37 side. The cylindrical portion 22 of the strainer 20 is fitted to the large-diameter inner peripheral portion 40.

  In the vicinity of the opening end of the large-diameter inner peripheral portion 40 (the end face of the flange 37), an annular (or partial formed with a predetermined phase) continuous in the circumferential direction of the large-diameter inner peripheral portion 40 is provided. A mating groove 41 is formed, and the two locking portions 30 of the strainer 20 are engaged with the engaging groove 41. Further, a counterbore portion having an inner diameter corresponding to the outer diameter of the flange 35 of the strainer 20 and a depth corresponding to the thickness of the flange 35 is provided on the end face on the inflow side of the supplementary pipe 2 (in this example, the end face of the flange 37). 42 is formed, and the flange 29 of the strainer 20 is seated on the counterbore 42.

  The boundary between the counterbore part 42 and the engagement groove 41 has an inner diameter that is substantially the same as that of the large-diameter inner peripheral part 40, but the inner diameter slightly increases toward the inflow side end face (the counterbore part 42). A tapered inner peripheral portion 43 or a rounded or chamfered inner peripheral surface 43 is used. This inner peripheral portion 43 is over the here, and when the engaging portion 30 of the strainer 20 enters the engaging groove 41, the inner peripheral portion 43 is reduced in diameter (advanced) of the engaging portion 30, and as a result is an elastically deforming portion that supports the engaging portion 30. This contributes to smooth elastic deformation of 33.

  As shown in FIG. 6, the strainer 20 is oriented so that the dome-shaped convex curved surface 24 is convex toward the inflow side with respect to the inflow side end portion 37 of the supplementary pipe 2 (the end opposite to the flange 29). Is inserted (fitted) into the large-diameter inner peripheral portion 40 of the supplemental tube 2. At the end of the insertion, the locking portion 30 of the strainer 20 hits the inner wall (in this example, the inner peripheral portion 43) of the supplementary tube 2 and is elastically pushed back inward. At this time, the leading inclined surface 32 of the locking portion 30 rides on the inner peripheral portion 43, whereby the elastically deforming portion 33 of the strainer 20 having the locking portion 30 in the middle is elastically deformed inward (center side), and thereafter When the locking portion 30 reaches the engaging groove 41 and elastically returns, the locking portion 30 engages with the engaging groove 41, and the attachment of the strainer 20 to the supplementary tube 2 is completed with one touch.

  In this attached state, as shown in FIG. 7, the distal end of the strainer 20 is in contact with or very close to the stepped portion 44 at the distal end of the large-diameter inner peripheral portion 40, and the inner peripheral portion 39 of the supplementary tube 2 and the strainer 20 There is almost no difference in inner diameter with the inner peripheral surface of the cylindrical portion 22, and both inner peripheral surfaces are substantially flush with each other (or the inner diameter of the cylindrical portion 22 is not smaller than the inner diameter of the inner peripheral portion 39 of the supplemental tube 20. ) Thereby, even if the strainer 20 is fitted to the supplementary pipe 2, the maximum diameter of the water flow passage is not reduced thereby, and the contracted flow (throttle) is hardly generated.

  Further, the flange 29 of the strainer 20 is seated on a counterbore 42 on the opening end surface of the supplementary pipe 2, and the fitting amount of the strainer 20 is defined, and the end face of the flange 29 and thus the strainer 20 is the end face of the supplemental pipe 2. And is not flush with the end face of the supplemental tube 2. Thereby, when the supplementary pipe 2 is connected to another pipe member via the flange 37, the flange 29 of the strainer 20 does not interfere with the connection, and the flange 29 is different from the supplementary pipe 2 and the pipe member. If the strainer 20 is in a state of being in close contact with each other, the attachment state of the strainer 20 to the pipe line is stabilized, and vibration and sound due to the passage of the water flow can be suppressed.

  Further, when the strainer 20 is attached to the supplementary pipe 2, even if a pulling force acts on the strainer 20 or a situation where the strainer 20 is easily detached from the supplementary pipe 2 due to vibration or the like occurs, The locking surface 31 of the portion 30 comes into contact with the opening-side groove surface of the engaging groove 41 in the supplementary tube 2 and the strainer is prevented from coming off. Thus, the strainer 20 is not attached to the supplementary pipe 2 at the time of installation of the flow meter (although of course it is possible), but the strainer 20 is attached to the supplementary pipe 2 in advance at the time of shipment in a factory or a warehouse and transported in that state. It is possible to reduce the labor of on-site construction.

  Further, when it becomes necessary to remove the strainer 20 from the supplementary pipe 2 for some reason (for example, removal of dust from the strainer or replacement of the strainer), the strainer elastic deformation portion located at the inflow side opening of the supplementary pipe 2 When the two free ends 33a (see also FIG. 5) of 33 are pulled into the notch 35 and the free ends are elastically pulled toward the center side of the strainer 20, each of the free ends 33a (see FIG. 5) is attached. Since the locking portion 30 is disengaged from the engagement groove 41 of the supplementary tube 2, the strainer 20 can be detached from the supplementary tube 2 with one touch if a pulling force is applied to the strainer 20 in this state.

  As shown in FIG. 4, one or a plurality of low protrusions (for example, strip-shaped protrusions) are formed on the outer peripheral surface of the cylindrical portion 22 of the strainer 20 with a predetermined length from the end portion on the fluid inflow side toward the distal end. Part) 45 can be formed. A plurality of the belt-like convex portions 45 can be formed on the portion of the cylindrical portion 22 excluding the elastic deformation portion 33, preferably at a predetermined interval (for example, about four at equal angular intervals). Such a low convex portion 45 is in a state in which the strainer 20 is fitted to the supplementary pipe 2, and comes into contact with the inner wall (for example, the large-diameter inner peripheral portion 40) of the supplementary pipe 2 to cause play between the strainer 20 and the supplementary pipe 2. Can be used to eliminate. Thereby, the vibration of the strainer 20 due to the water flow is suppressed.

  In the flow meter of FIG. 1 to which the strainer 20 as described above is attached, fluid (typically water) flows from the inlet 37 of the supplemental pipe 2 so as to hit the dome-shaped convex curved surface 24 of the strainer 20, and there After flowing through the supplementary pipe 2 through a large number of passage holes 25 and reaching the lower case 11, the L-shaped bent portion 16 is lifted by changing its direction almost 90 degrees, and hits the impeller 15 to rotate it. Then, it descends and flows out from the outlet 7 of the lower case 11.

  Therefore, when the fluid flows into the strainer 20 of the supplemental pipe 2, the passing water simply flows into the passage hole 25 by the dome-shaped convex curved surface (R-shaped portion) 24 of the strainer 20, as shown in FIG. In addition, since the guide is smoothly guided by the rounded portion 25a on the inflow side of the passage hole 25 and guided to the inside of the passage hole 25, the contracted flow in which the water flow is rapidly and forcibly restricted at the end face of the inlet portion of the passage hole 25 is generated. Hard to occur. In addition, the function of inducing a water flow from the top of the dome-shaped convex curved surface 24 to the skirt (in the direction of diameter expansion away from the center) is also likely to occur, which also contributes to suppressing the contraction that restricts the water flow to the center side. . When the contraction occurs, the pressure loss and flow velocity may fluctuate due to the throttling action, which may have an unfavorable effect on the metering action. However, according to the strainer 20, since such contraction is suppressed, a stable flow rate is achieved. Easy to measure. In addition, when water flow loss is sufficient so that contraction may occur to some extent, as shown in the lower column of the right column in FIG. The inflow side inner surface and the inflow side end surface of the hole 25 may form a substantially right-angled corner.

  Further, the passage hole 25 of the strainer 20 is formed in a dome-shaped wall portion 26 having a predetermined thickness (axial width) (also can be said to be a rib having a predetermined width in the cylindrical portion) and has a predetermined axial length. Since the fluid led here passes through the strainer 20 while being rectified by the wall surface (hole wall surface) of the dome-shaped wall portion 26, there is also an effect that the disturbance of the water flow hardly occurs.

  In addition to the dome-shaped convex curved surface 24 of the strainer 20 being formed on the inflow side end surface of the passage hole 25, in this example, the end surface on the outflow side of the passage hole 25 is also formed with a dome-shaped concave curved surface 25. Since the inside is a dome-shaped wall portion 26 as a whole, the water flow is not restricted on the outflow side, and the lengths of the individual passage holes 25 are substantially uniform. The effect is greater.

  Further, the strainer 20 is made of a resin, and its strength may be reduced as compared with a metal one. However, the portion of the strainer 20 that faces the flow of fluid is a dome-shaped convex curved surface 24 (as a dome shape as a whole). The wall 26), in other words, a three-dimensional arch shape, can improve the strength in the water flow direction. Furthermore, the strainer 20 can be attached by one touch as described above, and does not require screwing, thereby reducing the number of assembly steps. And by using the strainer 20 of a resin molded product, the cost reduction as a mass-produced product can be further achieved.

  In addition, by making the cross-sectional shape of the passage hole of the strainer 20 not a circle but a polygonal shape, it is possible to effectively ensure a fluid passage area without forming a useless thick portion. Here, in order to suppress the passage of foreign substances as much as possible, a regular hexagonal hole shape is adopted as a shape that secures an effective passage area while reducing the diagonal length of the hole cross section and also provides strength, and a honeycomb shape as a whole is adopted. ing. Of course, when a sufficient opening area and strength can be ensured, a circular shape, a triangular shape, a quadrangular shape, an octagonal shape, or the like can also be adopted.

  In the above embodiment, the strainer 20 has the flange 29. However, the strainer 20 may have a cylindrical shape having no flange like the strainer 47 shown in FIG. The other parts are the same as those shown in FIGS. 2 and 3, etc., but when the flange is omitted, the counterbore part 42 on the end face of the supplementary pipe 2 in FIG. 6 is also omitted.

  Further, in the above embodiment, the strainer 20 is attached to the inflow side end portion 37 of the supplementary pipe 2 in FIG. 1, but the strainer may be the outflow side end portion 48 of the supplementary pipe 2 or the inflow side of the lower case 11. It can also be attached to the end 49. As the strainer attached to the inflow side end portion 49 of the lower case 11, the strainer 20 similar to that shown in FIGS. 2 and 3 can be used, or the strainer 47 having no flange as shown in FIG. 8 is used. You can also On the other hand, the strainer to be attached to the outflow side end portion 48 of the supplementary pipe 2 in FIG. 1 is the same in that the attachment direction (insertion direction) to the supplementary pipe 2 and the fluid flow direction are reversed. Different from the embodiment of FIG.

  That is, for example, as in the strainer 50 shown in FIG. 9, the flange 52, elastic deformation at the end of the cylindrical portion 22 opposite to the strainer 20 shown in FIG. 3 or the like (in the opposite direction in the axial direction). A free end portion 33a of the portion 33 and a locking portion 51 are formed, and a dome-like wall portion 26 similar to the strainer 20 in FIG. It is formed so that the end face of the cylindrical part protrudes further toward the inflow side, not in the cylindrical part 22, and both ends of the single passage hole 25 penetrating the dome-like wall part 26 are formed so as to bulge out. The dome-shaped convex curved surface 24 and the dome-shaped concave curved surface 27 are opened. This strainer 50 is inserted in the direction opposite to the flow direction of the water flow from the opening of the outflow side end portion 48 of the supplementary pipe 2 in FIG. 1, and is not shown in FIG. 1, but the position (41) in FIG. The engagement portion 51 shown in FIG. 9 is engaged with an engagement groove formed on the opposite tube end, so that one-touch mounting can be performed.

  Further, instead of the dome-shaped wall portion 26 of FIG. 9, a conical wall portion 54 (or a polygonal pyramid-shaped wall portion such as a triangular pyramid) as shown in FIG. It is also possible to employ a strainer 55 that is provided so as to protrude opposite the inflow side. The through holes 25 penetrating the conical (polygonal pyramid) wall portion 54 open into conical (or polygonal conical) convex portions 56 and concave portions 57 of the wall portion 54, respectively. In this example, the locking portions 51 are formed at four equal positions in the circumferential direction of the cylindrical portion 22, and the elastic deformation portions 33 are provided at four locations correspondingly.

  FIG. 11 is a strainer 56 provided with a conical wall portion 54 (or a polygonal pyramid-like wall portion such as a triangular pyramid) in the middle of the cylindrical portion 22 in the same direction as the fluid flow direction. It is the same type as FIG. 3 inserted in an inflow side edge part. In other words, the strainer is a strainer in which the dome-shaped wall portion 26 in FIG. 3 is replaced with a conical wall portion 54 (or a polygonal pyramid-shaped wall portion such as a triangular pyramid). The flange 29 may or may not be present.

  Furthermore, like the strainer 57 of FIG. 12, a truncated cone shape (or a truncated polygonal frustum shape) wall portion 58 that protrudes in the fluid inflow direction may be provided. The frustoconical wall portion (rib) 58 can also be referred to as a tapered wall portion that narrows in the inflow direction, and a large number of passage holes 25 penetrating through the frustoconical wall portion 58 are: Opening is made on the convex frustoconical shape (or the frustoconical frustum shape) convex curved surface and concave curved surface which are the front and rear surfaces of the frustoconical wall portion 58, respectively. Even in the case of a strainer having a large number of passage holes 25 in such a tapered wall portion, substantially the same effect as that of a dome shape, a truncated cone or a truncated cone shape can be obtained.

  Further, like the strainer 60 shown in FIG. 13, a dome-shaped convex curved surface (R-shaped portion) 24 is formed on the inflow side end face of the end face of the strainer hole where the passage hole 25 opens, and the outflow is also carried out as shown in FIG. A dome-shaped concave curved surface (R-shaped portion) 27 can also be provided on the side hole end surface, but a dome-shaped portion is not formed on the outflow side as shown in FIG. It can also be the hole end face 61. Similarly, FIG. 14 shows a strainer 62 having a conical (or a polygonal pyramid shape such as a triangular pyramid) convex curved surface 63 on the inflow side hole end surface, while the outflow side hole end surface 61 is flat. FIG. 15 shows a strainer 65 having a frustoconical (or frustoconical frustum) convex curved surface 66 (tapered portion) on the inflow side hole end surface while the outflow side hole end surface 61 is flat. .

  Further, as in the strainer 68 shown in FIG. 16, it is not a convex curved surface (R-shaped portion) that protrudes facing the inflow side, but a convex portion (such as a dome-shaped wall portion 69 that protrudes toward the outflow side). It is also possible to form a concave curved surface portion 70 and a convex curved surface 70 ′ on the outflow side. Even in this case, the strength of the strainer 68 is high due to the dome-shaped wall portion 69, and there is an advantage that the strainer 68 can be attached to the tube member by one-touch as described above by the locking portion 30 of the cylindrical portion 22.

  In addition, although the modification of the wall part (rib) of the cylindrical part in which the passage hole was formed was shown in the simplified diagrams of FIGS. 11 to 16, the flange, the locking part, etc. Ignore it and focus only on the shape of the wall, and if the above-mentioned basic wall shape is attached with the above-mentioned flange, locking part, etc., all examples not included are also included. .

  Further, in the description so far, as a one-touch mounting (fitting) structure of the strainer, the elastic deformation portion 33 is provided at one or several places of the cylindrical portion 22 by the slit 35, and the locking portion 30 is formed there. However, instead of this, a ring portion is integrally provided in the circumferential direction (for example, in the circumferential direction) on the outer peripheral surface of the cylindrical portion, and the ring portion is a groove on the inner wall side of the tube. It may be a ring push-in type fitting structure that is forcibly fitted and fixed to the engaged portion. The ring portion can be attached to the entire circumference of the cylindrical portion or can be formed by dividing it into fixed intervals.

  As described above, all the strainers described above are selectively attached to the inflow side end 37, the outflow side end 48 and the inflow side end 49 of the lower case 11 in FIG. In addition to this type of flow meter 1, the flow meter 100 shown in FIG. 17 is selectively provided with an inflow side end 115, an outflow side end 113 of the supplementary pipe 101, and an inflow side end 114 of the lower case 102. It can also be attached. In addition to this, the strainer of the present invention is only required to be incorporated in the pipe line upstream of the impeller 15 or 104. The above example is an illustration of the mounting position, and furthermore, the meter equipped with the impeller. Of course, even if it is provided downstream of the section, it has an effect of capturing garbage.

  Furthermore, in the description of FIG. 1, the embodiment of the vertical Waltman type flow meter has been described on the assumption that the supplementary tube 2 is arranged horizontally and the impeller 15 is arranged vertically. Of course, the flow meter is generally installed and fixed in the arrangement shown in FIG. 1, but in the vertical Waltman flow meter 1 shown in FIG. 1, the supplementary tube 2 is arranged vertically such as vertical. May be installed and fixed in an inverted posture within an angle range of 90 degrees. The same applies to FIG. Expressions such as “upper and lower”, “horizontal” and “vertical” in the above description are for convenience of explanation, and do not limit the essence of the invention.

1 is a cross-sectional view of an entire flow meter that is an embodiment of the present invention. The front view of a strainer. Side surface sectional drawing of a strainer. The side view of the strainer. Simplified front view of the strainer (internal omitted). Sectional drawing which shows the process of attaching the strainer of FIG. 3 to a supplementary pipe. Sectional drawing which shows the attachment completion state of FIG. Sectional drawing which shows the modification 1 of a strainer. Sectional drawing which shows the modification 2 of a strainer. Sectional drawing which shows the modification 3 of a strainer. Sectional drawing which shows the modification 4 of a strainer. Sectional drawing which shows the modification 5 of a strainer. Sectional drawing which shows the modification 6 of a strainer. Sectional drawing which shows the modification 7 of a strainer. Sectional drawing which shows the modification 8 of a strainer. Sectional drawing which shows the modification 9 of a strainer. The whole sectional view which shows the strainer of the conventional example, and the flow meter in which the strainer was incorporated.

Explanation of symbols

1,100 Flow meter
2, 101 Supplementary tube 11, 102 Lower case
15, 104 Impeller 20, 47, 50, 55, 56, 57, 60, 62, 65, 68 Strainer 22 Tubular part 25 Passing hole 26 Domed wall part (wall part)
30 Locking part 33a Free end part (engagement release knob part)
41 engagement groove (engagement part)

Claims (3)

In the flowmeter arranged in the vertical direction so that the rotation axis of the impeller that measures the flow rate of the fluid intersects the direction connecting the inflow port and the outflow port,
A strainer for preventing the passage of foreign substances is disposed in the fluid flow path toward the impeller, and the strainer is formed so as to partition the cylindrical portion from the inner wall of the flow path and the cylindrical portion. And a fluid passage hole formed through the wall portion, and the cylindrical portion of the strainer is elastic in a direction approaching and separating from the inner wall of the flow path. A deformable locking portion is formed, and an engaging portion is formed on the inner wall of the flow path to elastically engage the locking portion on the strainer side, and the engaging portion and the engaging portion are engaged with each other. The flowmeter is characterized in that the strainer is attached to the inner wall of the flow path with a single touch.   The cylindrical portion of the strainer has an engagement release knob for elastically releasing the strainer-side engaging portion from the flow-path-side engaging portion and removing the strainer from the flow-path inner wall with a single touch. The flow meter according to claim 1, wherein the flow meter is formed at an end portion of the cylindrical portion of the strainer.   The strainer according to claim 1 or 2.

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