JP6756658B2 - Electromagnetic flow meter - Google Patents

Description

The present invention relates to an electromagnetic flow meter that measures the flow rate of water.

In recent years, electromagnetic flowmeters have become remarkably popular in place of impeller type flowmeters (for example, Patent Document 1). In addition, an electromagnetic flowmeter has been developed that transmits the flow rate measurement result by short-range wireless communication.

JP-A-5-99715 (Fig. 1)

However, in order to further popularize electromagnetic flowmeters, it is required to improve the reliability of short-range wireless communication.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an electromagnetic flowmeter having higher reliability of short-range wireless communication than before.

The invention of claim 1 made to achieve the above object is a resin substrate case having an upper surface opening closed by a lid, a translucent portion provided in at least a part of the lid, and the substrate. A control board housed in a case and arranged parallel to the upper surface of the board case, a monitor mounted on the control board at a position visible through the translucent portion and displaying a flow rate measurement result, and the control. The control board has a ring-shaped structure having a wireless circuit for short-range wireless communication mounted on a board and returning a flow rate measurement result in response to a signal received from the outside and a window corresponding to the monitor inside. It is an electromagnetic flow meter including an antenna board arranged facing upward and a loop antenna for short-range wireless communication printed on the antenna board and connected to the wireless circuit.

The invention of claim 2, wherein the monitor, without the Pinguri' de array structure in which a plurality of pins were suspended, in a state where the lower end portion of said plurality of pins floated upward from the control board is soldered to the control board The electromagnetic flowmeter according to claim 1, which is held.

In the invention of claim 3, the control board and the antenna board are provided with through holes or through grooves, stand up from the inner surface of the board case and have a board fixing hole, and the through holes of the control board. Alternatively, the first column that abuts from below on the opening edge of the through groove, the substrate fixing screw that is inserted into the through hole or the through groove of the control board and screwed into the substrate fixing hole, and the substrate case. stands up from the inner surface, through the through-hole or the through groove and the control board and the antenna substrate has a plurality of second struts the upper part is thermally caulked from the antenna substrate, said in the second post The lower side of the antenna board is stepped in diameter so as to abut from below on the through hole or the opening edge of the through groove of the antenna board and penetrate the through hole or the through groove of the control board. The small diameter-expanded portion and the lower side of the second support column below the control board are stepped to be larger than the small-diameter portion, and the through hole or the through groove of the control board is opened. The electromagnetic flowmeter according to claim 1 or 2, which has a large-diameter portion that abuts on the edge from below.

According to the fourth aspect of the present invention, the battery is housed in the substrate case below the control substrate, and a stepped surface is provided on the inner surface of the substrate case in the middle in the vertical direction. The electromagnetic flowmeter according to claim 3, wherein the first support column and the plurality of second columns stand upright.

The invention of claim 5 is a flow path housing having a measurement flow path, a coil that is assembled to the flow path housing to apply a magnetic field to the measurement flow path, and a flow path housing that is assembled to the measurement flow path. A housing having a pair of detection electrodes for detecting a potential difference between two points on the road, and a wire insertion hole provided above the flow path housing through which the coil and the wire group of the pair of detection electrodes are passed. The upper surface wall and the electric wire receiving port formed in the substrate case and overlapping the electric wire insertion hole from above are provided, and the substrate case is fixed to the flow path housing from above by a screw and described as described above. The electromagnetic flow meter according to claim 3 or 4, wherein the electric wire group is passed through the electric wire insertion hole and the electric wire receiving port and connected to the control board.

In the electromagnetic flowmeter of claim 1, a ring-shaped antenna substrate having a window portion facing from above is provided on the monitor, and a loop antenna for short-range wireless communication is printed on the antenna substrate, so that the so-called dead around the monitor is printed. The loop antenna can be enlarged by utilizing the space, and the radio reception sensitivity can be improved while suppressing the enlargement of the board case. Further, since the antenna board is arranged above the control board and separated from the control board, the influence of noise can be suppressed. As a result, in the electromagnetic flowmeter of the present invention, the communication state is more stable than before.

According to the configuration of claim 2, the antenna board is separated from the control board to reduce the influence of noise, the monitor is held in a state of floating upward from the control board, and the monitor is brought closer to the fluoroscopic portion of the lid. be able to.

Further, if the antenna board is simply provided separately from the control board, the labor for assembling work increases and the manufacturing cost increases. However, according to the configuration of claim 3, it is separate from the first support column for screwing the control board. A plurality of second columns are provided, and the antenna substrate is fixed by heat caulking at the upper ends thereof, and the second columns penetrate the control board and the antenna board to make both the control board and the antenna board two-dimensional. Can be positioned to. That is, it is possible to reduce the laborious screwing work and reduce the manufacturing cost.

In the electromagnetic flowmeter of claim 4, since the board case accommodates the battery below the control board, when the first support and the second support stand up from the bottom of the board case, the first support and the like become long and support is not provided. Although it can be stable, in the present invention, a stepped surface is provided in the middle of the inner surface of the substrate case in the vertical direction, and the first strut and the second strut are erected from the stepped surface. Support is stable.

In the electromagnetic flowmeter of claim 5, the fixing of the substrate case to the flow path housing by the screw and the fixing of the control board to the substrate case by the screw can be efficiently performed together.

<Additional notes>
Of the plurality of configurations described in the claims, those in which the names of those configurations and the names of the corresponding parts in the following embodiments are different have the following correspondence.
Housing top wall: Top reinforcing plate 28A
Electric wire inlet: Electric wire insertion hole 65A

Perspective view of the electromagnetic flowmeter according to the first embodiment of the present invention. An exploded perspective view seen from above the case Side view of the meter body Back sectional view of the meter body Perspective view of the flow path housing Planosection of the flow path housing Enlarged side view around the measurement part of the flow path housing Partial fracture perspective view of the flow path housing Partially broken perspective view around the measuring part of the flow path housing Regular cross-sectional view around the measuring part of the flow path housing (A) Enlarged plan sectional view of the tip of the detection electrode and the electrode accommodating hole, (B) Side view of the detection electrode and the electrode accommodating hole as seen from inside the measuring unit. Perspective view of the detection electrode, the electrode fixing member, and the electric wire connecting member Perspective view of the electrode fixing member through which the detection electrode is inserted Perspective view of a pair of yokes Side sectional view of the control unit case Top view of the meter body with the fitting lid and antenna board removed Top view of the meter body with the fitting lid removed Disassembled perspective view from below the case Side sectional view of the case Block diagram showing the electrical configuration of the electromagnetic flowmeter Side view of the outflow port according to another embodiment Side sectional view of the elastic engaging piece according to another embodiment

[First Embodiment]
Hereinafter, the first embodiment of the present invention will be described with reference to FIGS. 1 to 20. The electromagnetic flowmeter 10 of the present embodiment shown in FIG. 1 is used as, for example, a water meter, and a plurality of electromagnetic flowmeters 10 in the middle portion of a flow path housing 20 (see FIG. 5) connected in the middle of a water pipe. It has a meter body 10H in which parts are assembled, and the meter body 10H has a structure housed in a rectangular parallelepiped case 13.

The electromagnetic flowmeter 10 can be used in any posture, but for convenience of explanation, the flow path housing 20 extends horizontally and the lid 16 of the case 13 is arranged on the upper surface as shown in FIG. The positional relationship of each part is specified in this state, and the configuration of each part of the electromagnetic flowmeter 10 will be described below.

First, the single structure of the flow path housing 20 will be described. In FIG. 5, the flow path housing 20 is shown as a single unit. The flow path housing 20 extends in the horizontal direction, and tap water flows from one end to the other end of the measurement flow path 20R penetrating the longitudinal direction thereof. In FIGS. 5 to 7, the direction in which tap water flows is indicated by an arrow A, and a mark 15M (see FIG. 1) indicating the direction in which tap water flows is engraved on the outer surface of the case 13.

As shown in FIG. 6, the measurement flow path 20R has the most narrowed measurement unit 20K at a position where the measurement flow path 20R is gradually narrowed from both ends toward the center and is slightly downstream from the center. As shown in FIG. 9, the measuring unit 20K has a horizontally long rectangular cross-sectional shape with four corners chamfered, and extends over a predetermined length as shown in FIG. Further, both ends of the measurement flow path 20R have a circular cross section, and the cross-sectional shape gradually changes from circular to rectangular from both ends toward the measurement section 20K.

Further, the flow path housing 20 is a resin insert-molded product having metal sleeves 21 and 21 made of metal at both ends. FIG. 6 shows the metal component of the metal sleeve 21 and the other resin component 22 of the flow path housing 20 separately, and FIG. 8 shows one of the resin components 22 of the flow path housing 20. The entire metal sleeve 21 is shown through the section. These metal sleeves 21 and 21 are exposed on the outer surfaces of both end portions of the flow path housing 20, and male screw portions 21N for connecting to the water pipe are formed in the exposed portions.

More specifically, as shown in FIG. 8, the metal sleeve 21 has a cylindrical shape as a whole, and a male screw portion 21N is formed on the outer peripheral surface of the metal sleeve 21 from the tip end to the base end side position. There is. Further, as shown in FIG. 6, the base end side of the metal sleeve 21 from the male screw portion 21N has a large diameter flange portion 21C and a plurality of small diameter flange portions 21D on a base portion 21M having a diameter smaller than that of the male screw portion 21N. It has a structure that is provided at intervals. The large-diameter flange portion 21C has a disk shape having an outer diameter larger than that of the male screw portion 21N. The plurality of small diameter flange portions 21D are arranged on the opposite side of the male screw portion 21N with the large diameter flange portion 21C interposed therebetween, and have a disk shape smaller than that of the large diameter flange portion 21C.

Further, as shown in FIG. 8, at the base end portion of the metal sleeve 21 including one small diameter flange portion 21D, a first square groove 21K that crosses the central portion of the metal sleeve 21 in the radial direction and a first square groove thereof A pair of second angular grooves 21L and 21L orthogonal to 21K are formed. As a result, the base end surface of the metal sleeve 21 has a shape in which irregularities are alternately repeated in the circumferential direction to form the concave-convex engaging portion 21Q.

As shown in FIG. 6, on the inner surface of the metal sleeve 21, the inner large diameter portion 21E is formed by expanding the diameter of the tip portion. Further, the tip surface of the metal sleeve 21 has a flat tip surface 21H whose inner edge portion is orthogonal to the central axis of the metal sleeve 21, and a tapered tip surface 21A whose outer side from the inner edge portion is slightly inclined with respect to the flat tip surface 21H. It has become.

The pair of metal sleeves 21 and 21 are inserted into a pair of work insertion holes provided in a resin molding die (not shown) for molding the flow path housing 20, and the large-diameter flange portion 21C of the metal sleeve 21 is used as a work. It is set in a state where it is fitted to the inner peripheral surface of the insertion hole and the tip tapered surface 21A is in contact with the end surface of the work insertion hole. Then, the resin is injected into the resin molding mold to mold the flow path housing 20. As a result, the range of the metal sleeve 21 from the tip tapered surface 21A to the outer peripheral surface of the large-diameter flange portion 21C is exposed, and the other portion is covered with the resin constituting the flow path housing 20.

Further, the large diameter portion 22E at the tip of the resin component 22 of the flow path housing 20 is fitted to the large diameter portion 21E inside the metal sleeve 21. Then, the large-diameter tip portion 22E projects slightly forward from the tip surface of the metal sleeve 21, and the flat tip surface 21H of the metal sleeve 21 is covered with a cover flange 22F that projects laterally from the protruding portion. Further, the base end side of the metal sleeve 21 with respect to the large diameter flange portion 21C is covered with the tool engaging portion 23 of the resin constituent portion 22 of the flow path housing 20.

As shown in FIG. 5, the tool engaging portion 23 is arranged adjacent to the large-diameter flange portion 21C and projects greatly laterally from the large-diameter flange portion 21C. The tool engaging portion 23 has, for example, a regular hexagon when viewed from the axial direction of the flow path housing 20, and is provided with three sets of six flat surfaces 23B parallel to each other on the outer circumference. Further, a pair of flat surfaces 23B among them are parallel to the vertical direction. Further, a lightening groove 23A is formed at the corner between the adjacent flat surfaces 23B and 23B so as to chamfer the central position of the tool engaging portion 23 in the thickness direction, and shrinkage strain during resin molding is formed. (So-called "sink") can be suppressed. The bottom surface of the lightening groove 23A is an arc surface concentric with the large-diameter flange portion 21C.

As shown in FIG. 6, between the tool engaging portions 23 and 23 of the flow path housing 20, the outer surface faces the central portion in the axial direction of the flow path housing 20 corresponding to the shape of the measurement flow path 20R. A base sleeve 20T that is gradually squeezed is provided. Further, as shown in FIG. 5, a cross sleeve 25 extending in the horizontal direction orthogonal to the base sleeve 20T is provided at the central portion of the flow path housing 20 in the longitudinal direction. The cross-sectional shape of the cross sleeve 25 is an oval shape with the axial direction of the flow path housing 20 as the long axis, and as shown in FIG. 7, the central portion of the base sleeve 20T is arranged in the cross sleeve 25. Further, the cross sleeve 25 has a size of about the outer diameter of the male screw portion 21N in the vertical direction, and a gap 25S is formed between the base sleeve 20T and the upper surface and the lower surface in the cross sleeve 25, and the gap 25S is formed. Is filled with the potting material P described later. The upper gap 25S is larger in the vertical direction than the lower gap 25S.

As shown in FIG. 5, boundary flanges 24, 24 are provided between the tool engaging portions 23, 23 and the cross sleeve 25 in the flow path housing 20. The boundary flange 24 has a shape in which the lower end side of a vertically long rectangle is semicircular, and has an arc portion 24A located below the center of the flow path housing 20 and a quadrangle having the same width as the diameter of the arc portion 24A. It is composed of a square portion 24B located above the center of the flow path housing 20. Further, the distance between the tool engaging portion 23 on one end side of the flow path housing 20 and the boundary flange 24 and the distance between the tool engaging portion 23 on the other end side of the flow path housing 20 and the boundary flange 24 are the same. The cross sleeve 25 is arranged near one end between the pair of boundary flanges 24 and 24 (specifically, near the upstream side of the measurement flow path 20R).

In the flow path housing 20, between each tool engaging portion 23 and the boundary flange 24 is reinforced by a plurality of horizontal ribs 27A and vertical ribs 27B. The horizontal ribs 27A project horizontally from the upper and lower portions of the base sleeve 20T and the intermediate portion in the vertical direction to both sides and communicate between the tool engaging portion 23 and the boundary flange 24. The vertical rib 27B projects upward and downward from the uppermost portion and the lowermost portion of the base sleeve 20T, and communicates between the tool engaging portion 23 and the boundary flange 24. The tips of the horizontal ribs 27A and the vertical ribs 27B and the corners between the outer surfaces of the horizontal ribs 27A and the vertical ribs 27B and the tool engaging portion 23, the boundary flange 24, and the flow path housing 20 are the horizontal ribs 27A and the vertical ribs. A relatively large R chamfer is applied to the thickness of 27B.

The boundary flanges 24, 24 of the flow path housing 20 are reinforced by a plurality of (for example, five) reinforcing plates 28A. The plurality of reinforcing plates 28A have a horizontal plate shape, and are arranged at intervals between the positions near the upper ends and the positions near the lower ends of the boundary flanges 24 and 24. Further, the plurality of reinforcing plates 28A have the same width. Then, as shown in FIG. 7, the central portions in the width direction of a plurality (for example, three) reinforcing plates 28A excluding the uppermost and lowermost reinforcing plates 28A are connected to the base sleeve 20T. Further, between the uppermost reinforcing plate 28A and the reinforcing plate 28A adjacent to the lowermost reinforcing plate 28A, a vertical rib 28B for connecting the central portions in the width direction thereof is provided, and the lowermost reinforcing plate 28A and above the reinforcing plate 28A. A similar vertical rib 28B is provided between the adjacent reinforcing plate 28A.

Further, as shown in FIG. 5, the side surfaces of the reinforcing plates 28A and 28A are flush with each other. Then, the boundary flange 24 protrudes from both side surfaces of the reinforcing plate 28A group to both sides except for the semicircular lower end portion thereof, and only the lowermost reinforcing plate 28A protrudes to both sides from the boundary flange 24.

Further, as shown in FIG. 7, the upper surface of the uppermost reinforcing plate 28A and the upper surface of the cross sleeve 25 are arranged flush with each other, and the lower surface of the lowermost reinforcing plate 28A and the lower surface of the cross sleeve 25 are flush with each other. Arranged in one, the middle portion of all the reinforcing plates 28A is divided within the cross sleeve 25. Further, both ends of the cross sleeve 25 in the axial direction project laterally from both side surfaces of the reinforcing plate 28A group.

As shown in FIG. 6, the inside of the cross sleeve 25 is provided with stepped surfaces 25D and 25D that are substantially flush with both side surfaces of the reinforcing plate 28A, and the wall thickness on the tip side is thinner than those stepped surfaces 25D. ing.

As shown in FIG. 5, mounting holes 28D are formed in the uppermost reinforcing plate 28A at the center in the width direction of the portion upstream of the cross sleeve 25 and near both ends in the width direction of the downstream portion, respectively. There is. Further, although not shown, mounting holes 28D are formed in the lowermost reinforcing plate 28A at both ends in the width direction of the upstream side portion and the downstream side portion of the cross sleeve 25, respectively. As shown in FIGS. 5 and 7, the central mounting hole 28D described above has a larger diameter than the mounting holes 28D near both ends and extends to the vertical rib 28B. Further, on the same axis as the mounting holes 28D near both ends, a pillar portion 28C connecting the reinforcing plates 28A and 28A is provided, and the mounting hole 28D extends into the pillar portion 28C. Further, in the reinforcing plate 28A at the lowermost end, a position determining portion 28T projects downward from between each mounting hole 28D and the boundary flange 24 on the side closer to each mounting hole 28D.

As shown in FIG. 5, the uppermost reinforcing plate 28A is formed with an electric wire insertion hole 28E communicating with the inside of the cross sleeve 25. The electric wire insertion hole 28E is arranged at the uppermost portion of the cross sleeve 25 and at the center of the reinforcing plate 28A in the width direction. Further, from the upper surface of the reinforcing plate 28A, an inner circular rib 28F and an outer circular rib 28G having a concentric circular shape with the electric wire insertion hole 28E project. Further, from the upper surface of the reinforcing plate 28A between the inner circular rib 28F and the electric wire insertion hole 28E, a plurality of (for example, four) protrusions 28H are formed around the electric wire insertion hole 28E to form the inner circular rib 28F. It is one. Then, a mounting hole 28J penetrating each protrusion 28H and the reinforcing plate 28A is drilled. Further, a circular groove 28K is formed between the inner circular rib 28F and the outer circular rib 28G, and a plurality of reinforcing protrusions 28L project from the outer surface of the outer circular rib 28G.

The inner portion of the cross-sleeve 25 of the flow path housing 20 is reinforced by horizontal ribs 29A, cross-linked walls 29B, and vertical ribs 29C. Inside the cross sleeve 25, the outer cross-sectional shape of the base sleeve 20T is an oblong shape as a whole. The horizontal ribs 29A form a horizontal plate and project from the central portion of the base sleeve 20T in the vertical direction to both sides and communicate with each other between the facing portions on the inner surface of the cross sleeve 25. Further, the bridge wall 29B has a horizontal strip shape, is arranged on the upper side and the lower side of the base sleeve 20T, extends parallel to the base sleeve 20T, and communicates between the facing portions on the inner surface of the cross sleeve 25. ing. Further, the upper and lower bridge walls 29B and 29B and the lateral central portion of the base sleeve 20T are connected by a vertical rib 29C. Further, the tip of the horizontal rib 29A is located inside the stepped surface 25D of the cross sleeve 25, and the lateral width of the bridge wall 29B is smaller than the distance between the tips of both horizontal ribs 29A and 29A.

The vertical ribs 29C and 29C are separated from the upper side and the lower side of the measuring unit 20K, and the base sleeve 20T is made thinner than the other parts. As shown in FIG. 7, the base sleeve 20T and the crosslinked wall 29B are formed. , 29B, and parts accommodating spaces 30 and 30 are formed. Further, the portion of the base sleeve 20T located between the cross-linked walls 29B and 29B (that is, the portion having the measuring unit 20K inside) is the measuring tube unit 20P. Horizontal and flat yoke arrangement surfaces 34 and 34 are formed at the positions directly above and directly below the measuring tube portion 20P. Further, in the measuring unit 20K, a pair of columnar electrode support protrusions 31 and 31 project from the axial center of the flow path housing 20 and the vertical center position on both sides. An electrode accommodating hole 35 communicating with the measuring unit 20K is formed in the central portion of each electrode supporting protrusion 31.

As shown in FIG. 5, the fixed protrusion 32 projects laterally from the side of each electrode support protrusion 31. As shown in FIG. 6, the fixed protrusion 32 is arranged next to the upstream side with respect to one electrode support protrusion 31 while being next to the downstream side with respect to the other electrode support protrusion 31. It is arranged and integrated with each electrode support protrusion 31. Further, the tip surface of the fixed protrusion 32 is flush with the tip surface of the electrode support protrusion 31. Further, a mounting hole 32A that does not communicate with the measurement flow path 20R is formed in the central portion of each fixed protrusion 32.

Next to the upstream side of the electrode support protrusion 31 having the fixed protrusion 32 on the downstream side, an arc recess 29D formed by cutting the horizontal rib 29A into an arc shape is formed. Further, as shown in FIG. 5, a pair of ridges 33, 33 extending in parallel with the electrode support protrusion 31 protrudes from the upper surface of the electrode support protrusion 31 having the fixed protrusion 32 on the upstream side. An electric wire accommodating groove 33A is provided between them. Further, as shown in FIGS. 5 and 9, the positioning walls 34W and 34W project from the edge of the yoke arrangement surfaces 34 and 34 on the electrode support protrusion 31 side having the fixed protrusion 32 on the upstream side. There is. Then, as shown in FIG. 5, a pair of ridges 33 and 33 are connected to the upper positioning wall 34W, and the electric wire accommodating groove 33A penetrates the positioning wall 34W, and as shown in FIG. 9, the electric wire accommodating. The bottom surface of the groove 33A is flush with the upper yoke arrangement surface 34.

As shown in FIG. 10, the entire electrode accommodating hole 35 excluding both ends is an intermediate hole portion 35B having a circular cross section, and the end portion on the side of the intermediate hole portion 35B away from the measurement flow path 20R is The base end hole portion 35C having a circular cross section has a stepped diameter with respect to the intermediate hole portion 35B. Further, a gently inclined tapered surface 35D is formed at the end of the intermediate hole 35B on the base end hole 35C side. On the other hand, the opening protrusion 35W projects inward from the end of the electrode accommodating hole 35 on the measurement flow path 20R side, and the inside of the opening protrusion 35W serves as the outflow port 35A.

As shown in FIGS. 11A and 11B, the outflow port 35A has an oval shape that is long in the axial direction of the measurement flow path 20R, and the total length of the outflow port 35A in the long axis direction is the intermediate hole portion. It is smaller than the inner diameter of 35B. Further, the total length of the outflow port 35A in the minor axis direction is 0.7 to 1 times between the curved surfaces 20G and 20G (see FIG. 10) by chamfering the measuring unit 20K (see FIG. 11B). In the present embodiment, the long axis direction of the outflow port 35A is parallel to the axial direction of the measurement flow path 20R. Further, the diameter of the intermediate hole portion 35B is substantially the same as the short side of the measuring portion 20K.

This concludes the description of the structure of the flow path housing 20 as a single unit. Next, each component assembled to the flow path housing 20 will be described.

As shown in FIG. 10, each electrode accommodating hole 35 accommodates a detection electrode 40. The detection electrode 40 is made of a conductive metal having high corrosion resistance (for example, stainless steel) and has a circular cross section as a whole. As shown in FIG. 12, the detection electrode 40 has a small diameter tip portion 40A, a medium diameter body portion 40B, and a large diameter in order from one end side. It includes a flange portion 40C and a thin rod portion 40D. Then, as shown in FIG. 10, the detection electrode 40 has an O-ring 36 mounted on the small-diameter tip portion 40A and is inserted into the electrode accommodating hole 35 from the small-diameter tip portion 40A side. Further, the detection electrode 40 is positioned in the axial direction with respect to the electrode accommodating hole 35 by abutting the large diameter flange portion 40C against the back surface 35E of the base end hole portion 35C, and the tip surface of the medium diameter body portion 40B is in the middle. It is arranged at a position closer to the tip of the hole 35B, and the tip surface of the small diameter tip 40A is arranged flush with the inner surface of the measurement flow path 20R. Further, as shown in FIGS. 11A and 11B, the small diameter tip 40A is located at the center of the outflow port 35A. As shown in FIG. 11B, the diameter of the small diameter tip 40A is 0.6 to 0.9 times the total length of the outflow port 35A in the minor axis direction, and the small diameter tip 40A and the outflow port A gap is formed between the 35A and the inner surface.

As shown in FIG. 11A, the O-ring 36 is in contact with the tip surface of the medium-diameter body portion 40B and is in a state of being separated from the opening protrusion 35W. Then, the measurement flow path 20R side of the electrode accommodating hole 35 from the O-ring 36 becomes a submerged room 35H in which water enters from the measurement flow path 20R side, and the measurement flow path 20R side of the detection electrode 40 from the O-ring 36 is submerged. It is a submerged tip 40H that comes into contact with water in the room 35H.

As shown in FIG. 10, the pair of detection electrodes 40, 40 are prevented from coming off into the electrode accommodating holes 35, 35 by the pair of resin electrode fixing members 42, 42. As shown in FIG. 12, the electrode fixing member 42 has a member base portion 43 having an L-shape in a plan view, and a thin rod insertion hole 43A penetrates the L-shaped corner portion thereof, and the L-shaped short side portion 43X. The screw insertion hole 43B penetrates the tip end portion of the wire, and the electric wire insertion hole 44A penetrates the middle portion of the L-shaped long side portion 43Y.

From the front surface of the member base portion 43, a contact rib 43T concentric with the thin rod insertion hole 43A projects. Further, a tapered surface 43V is formed at the tip of the thin rod insertion hole 43A. Then, the thin rod portion 40D of the detection electrode 40 is inserted into the thin rod insertion hole 43A, and the contact rib 43T abuts on the large diameter flange portion 40C.

The tip of the L-shaped short side portion 43X of the member base portion 43 has an arc shape concentric with the screw insertion hole 43B, and a semicircular arc-shaped fitting rib 43S protrudes forward from the tip edge thereof. Further, as shown in FIG. 13, a circular rib 43U concentric with the screw insertion hole 43B protrudes from the rear surface of the member base portion 43. Then, the fitting rib 43S is fitted to the outside of the above-mentioned fixed protrusion 32 (see FIG. 7) so that the mounting hole 32A and the screw insertion hole 43B face each other, and the screw B passed through the screw insertion hole 43B is mounted. The electrode fixing member 42 is fixed to the flow path housing 20 by screwing into the hole 32A. Further, as a result, the detection electrode 40 is pushed toward the back side of the electrode accommodating hole 35 by the electrode fixing member 42 and is positioned as described above. The head portion of the screw B fits inside the circular rib 43U (see FIG. 13).

As shown in FIG. 12, the electric wire insertion hole 44A has an oval shape extending in the longitudinal direction of the long side portion 43Y of the L shape, and tapered surfaces 44T are formed on both opening edges of the electric wire insertion hole 44A. .. Further, as shown in FIG. 10, with the pair of electrode fixing members 42, 42 fixed to the flow path housing 20, the long side portions 43Y, 43Y of the electrode fixing members 42, 42 are the respective electrode support protrusions. Standing upward from the tips of 31 and 31, the wire insertion holes 44A and 44A of the electrode fixing members 42 and 42 face each other with the component housing space 30 in between. The lower end of the inner surface of the electric wire insertion hole 44A is arranged flush with the lower surface of the upper yoke arrangement surface 34 and the electric wire accommodating groove 33A.

As shown in FIG. 13, a pair of facing protrusions 45, 45 project from the rear surface of the tip end portion of the long side portion 43Y and face each other in the width direction of the long side portion 43Y, and a wire receiving groove 45M is between them. It has become. The opposite tip corners of the pair of facing protrusions 45, 45 are C-chamfered, and as shown in FIG. 10, the corners between the bottom surface of the wire receiving groove 45M and the tip surface of the long side 43Y are R. It is chamfered.

As shown in FIG. 13, a wire connecting member 46 for connecting the wire 90 is fixed to the tip of the thin rod portion 40D of the detection electrode 40 that penetrates the electrode fixing member 42. The electric wire connecting member 46 has a columnar shape as a whole, and an electric wire receiving groove 46M extending in the radial direction is formed on one end surface thereof, and a through hole 46A is formed in the central portion thereof. Then, the thin rod portion 40D is press-fitted into the through hole 46A from the opposite side of the electric wire receiving groove 46M, so that the bottom surface of the electric wire receiving groove 46M and the tip surface of the thin rod portion 40D are flush with each other.

The electric wire 90 is formed by covering, for example, a copper core wire 90B with an insulating coating 90A. Then, the end portion of the core wire 90B exposed from the insulating coating 90A is soldered or brazed so as to be arranged in the electric wire receiving groove 46M. Here, the detection electrode 40 is made of, for example, stainless steel, which has high corrosion resistance as described above, whereas the electric wire connecting member 46 is made of a conductive member (for example, copper), which has high wettability to solder or wax. ing. As a result, the connection reliability between the detection electrode 40 and the electric wire 90 is improved while ensuring the corrosion resistance of the detection electrode 40. Further, since the electric wire connecting member 46 is fixed to the tip of the thin rod portion 40D and separated from the resin electrode fixing member 42, deformation of the electrode fixing member 42 due to heat such as soldering can be prevented.

As shown in FIG. 9, a coil unit 53 is arranged next to one of the electrode support protrusions 31. As shown in FIG. 14, the coil unit 53 has a structure in which the coil 53C is wound around the resin bobbin 53A and the core shaft 51J penetrates the central portion of the bobbin 53A. Further, the central axis of the bobbin 53A faces in the vertical direction, and the projecting pieces 53E and 53E extend horizontally from the flange portions 53F and 53F at both upper and lower ends of the bobbin 53A. The side of the coil 53C opposite to the protruding side of the projecting pieces 53E and 53E is received by the arc recess 29D shown in FIG.

As shown in FIG. 14, a terminal support wall 53H projects downward from the tip of the lower projecting piece 53E, and a pair of terminals 53G and 53G penetrate the terminal support wall 53H. Both terminals of the coil 53C are connected to the base ends of the pair of terminals 53G and 53G (not shown). On the other hand, the tips of the pair of terminals 53G and 53G protrude forward from the tip surface of the projecting piece 53E and are folded in half, and soldered or brazed with the core wire of an electric wire (not shown) sandwiched between them. ing.

On the other hand, electric wire insertion holes 53J and 53J penetrate vertically through the tip of the upper projecting piece 53E, and a part of the electric wire insertion holes 53J and 53J is open to the tip surface of the projecting piece 53E. Then, the terminals 53G and 53G are bent upward at right angles from the state shown in FIG. 14, and a pair of electric wires connected to the terminals 53G and 53G are passed through the electric wire insertion holes 53J and 53J and extend upward. It has been skipped.

Both ends of the core shaft 51J project from the outer surfaces of the flanges 53F and 53F, and the surrounding walls 53K and 53K project from the flanges 53F and 53F so as to surround both ends of the core shaft 51J. The surrounding wall 53K has a circular shape centered on the core shaft 51J, and a part of the flow path housing 20 facing the yoke arrangement surfaces 34 and 34 is cut out. The base end plate portions 51A and 51A of the pair of yokes 51 and 51 described below are housed in the surrounding walls 53K and 53K.

The yoke 51 is formed by punching, for example, a ferritic metal sheet metal, and has a disk-shaped base end plate portion 51A, a rectangular tip plate portion 51C, and a strip-shaped intermediate plate portion 51B connecting between them. It is composed of. A through hole 51F is formed in the central portion of the base end plate portion 51A. Further, the intermediate plate portion 51B extends diagonally from a corner portion of the tip plate portion 51C. Then, as shown in FIG. 9, the base end plate portions 51A and 51A of the pair of yokes 51 and 51 are housed in the upper and lower surrounding walls 53K and 53K of the coil unit 53, and both ends of the core shaft 51J are respectively accommodated. It is fitted in the through hole 51F of the base end plate portion 51A. Further, the intermediate plate portions 51B and 51B of the pair of yokes 51 and 51 are pulled out from the cutout portions of the surrounding walls 53K and 53K, and the magnetic flux penetration surfaces 51Z and 51Z (one surface of the front and back surfaces of the tip plate portions 51C and 51C) ( (See FIG. 14) is superimposed on the yoke arrangement surfaces 34, 34.

The tip plate portion 51C is positioned from three sides by the positioning wall 34W of the flow path housing 20 and the wall portions (see FIG. 7) on both sides of the positioning wall 34W, and the long side direction of the tip plate portion 51C is 1. The pair of detection electrodes 40, 40 are oriented in the opposite direction, and the central portion of the tip plate portion 51C in the short side direction is arranged directly above the coaxial center line of the pair of detection electrodes 40, 40. A yoke retainer 52 is fitted in the electrode support protrusion 31 adjacent to the coil unit 53, and each tip plate portion 51C is sandwiched between the yoke retainer 52 and the positioning wall 34W. Further, a wedge piece (not shown) protruding from the yoke retainer 52 is pushed between each tip plate portion 51C and the bridge wall 29B, and each tip plate portion 51C is pressed against the yoke arrangement surface 34.

As shown in FIG. 14, the tip plate portion 51C of the yoke 51 arranged on the upper side has a groove-shaped ridge 51D in which the central portion in the short side direction is bulged in a semicircular shape on the opposite side of the magnetic flux penetration surface 51Z. It is formed. The electric wire receiving groove 51E inside the groove-shaped ridge 51D is arranged on the extension line of the electric wire accommodating groove 33A described above. Further, as shown in FIG. 9, the yoke holding 52 also has the electric wire receiving groove 52E formed on the extension line of the electric wire receiving groove 51E.

As shown in FIG. 9, the electric wire 90 of one of the detection electrodes 40 on the side away from the coil unit 53 is bent above the detection electrode 40, and the electric wire insertion hole 44A of the one electrode fixing member 42 and the electric wire accommodating. It is passed through the groove 33A, the electric wire receiving grooves 51E and 52E, and the electric wire insertion hole 44A of the other electrode fixing member 42 (that is, on the coil unit 53 side). Then, after being passed through the electric wire insertion hole 44A of the other electrode fixing member 42, it is bent upward. Further, the electric wire 90 of the detection electrode 40 on the coil unit 53 side extends upward from the detection electrode 40. Then, the intermediate portions of the electric wires 90 and 90 of both detection electrodes 40 and 40 are received side by side in the electric wire receiving groove 45M of the electrode fixing member 42 in the depth direction, and further bent above the electric wire receiving groove 45M of the flow path housing 20. It is extended to the center side in the lateral direction, is further led out from the electric wire insertion hole 28E above the flow path housing 20, and is connected to the control board 73 described later. Further, a pair of electric wires (not shown) extending from the coil unit 53 are also led out upward from the electric wire insertion hole 28E and connected to the control board 73.

As shown in FIG. 4, both ends of the cross sleeve 25 in the flow path housing 20 are closed by a pair of side caps 37, 37. The side cap 37 has an oval cap shape, the opening end side thereof is fitted inside the cross sleeve 25, and the flange 37F protruding laterally from the peripheral surface of the cross sleeve 25 is the tip surface of the cross sleeve 25. Is in contact with. Further, the tip of the outer surface of the side cap 37 is narrowed in a stepped shape to form a seal fitting portion 37A, and the O-ring 38 fitted to the outside of the seal fitting portion 37A is the seal fitting portion 37A. It is sandwiched between the stepped surface 37D on the base end side of the cross sleeve 25 and the stepped surface 25D of the cross sleeve 25. Further, from the outer surface of each side cap 37, a projecting piece 37B projects in the axial direction of the cross sleeve 25 and is abutted against the inner surface of the main shield member 47 described below, whereby each side cap 37 is attached to the cross sleeve 25. It is stuck.

As shown in FIG. 4, the central portion of the flow path housing 20 is surrounded by a magnetic shield 47U from the side. The magnetic shield 47U is composed of a main shield member 47 and a sub shield member 48, and the main shield member 47 and the sub shield member 48 are formed by bending a magnetic sheet metal into a square U shape. Then, the bottom portion 47A of the main shield member 47 is overlapped with the lower surface of the flow path housing 20, and is just fitted between the position determination portions 28T and 28T of the flow path housing 20 as shown in FIG. Further, a plurality of screw insertion holes (not shown) corresponding to the mounting holes 28D (see FIG. 7) of the flow path housing 20 are formed in the bottom portion 47A of the main shield member 47, and the screws B passed through them are inserted into the mounting holes 28D. The main shield member 47 is fixed to the flow path housing 20 by tightening. The pair of vertical side portions 47B and 47B of the main shield member 47 extend above the upper surface of the flow path housing 20.

On the other hand, the bottom portion 48A of the sub-shield member 48 is overlapped with the upper surface of the flow path housing 20. A through hole 48C for receiving the outer circular rib 28G on the upper surface of the flow path housing 20 and a plurality of screws (not shown) corresponding to the upper mounting hole 28D (see FIG. 7) of the flow path housing 20 are inserted into the bottom portion 48A. The sub-shield member 48 is fixed to the flow path housing 20 by being provided with holes and tightening the screws B passed through the screw insertion holes into the mounting holes 28D. Further, the pair of vertical side portions 48B and 48B of the sub shield member 48 are overlapped on the inner surfaces of the vertical side portions 47B and 47B of the main shield member 47, and the upper surfaces of the vertical side portions 47B and the vertical side portions 48B face each other. It is one.

Further, as shown in FIG. 3, the right vertical side portions 47B and 48B in FIG. 4 have a first notch 47E for avoiding interference with the hood portion 66 protruding from the substrate case 60 described later, and a hood. A second notch 47F for passing the external connection cable 93 which is led out downward from the portion 66 and folded upward is formed.

A control unit 10U is assembled from above the sub-shield member 48 in the central portion of the flow path housing 20. The control unit 10U includes a battery 72, a control board 73, a monitor 74, an antenna board 75, and the like in a rectangular parallelepiped resin board case 60.

As shown in FIG. 15, the substrate case 60 includes an upper accommodating portion 60A and a lower accommodating portion 60B. The upper accommodating portion 60A has a rectangular parallelepiped structure having a rectangular planar shape, and has an upper surface opening 60W closed by a lid 70. On the other hand, the lower accommodating portion 60B has a rectangular parallelepiped shape in which a pair of short side portions and one long side portion are narrowed stepwise from the upper accommodating portion 60A. As a result, a stepped surface 60D extending horizontally along the three sides of the rectangular shape of the upper accommodating portion 60A is formed between the upper accommodating portion 60A and the lower accommodating portion 60B (FIG. 4). And FIG. 15). Further, the lower accommodating portion 60B accommodates the cylindrical battery 72 with its axial direction directed toward the long side of the rectangular accommodating portion 60A. The lower end of one side wall of the lower accommodating portion 60B is curved in an arc shape corresponding to the shape of the battery 72. The upper part of the battery 72 is located in the upper accommodating portion 60A.

As shown in FIG. 4, the hood portion 66 projects from one outer surface of the substrate case 60, which corresponds to one short side of the plan shape of the upper accommodating portion 60A. As shown in FIG. 3, the hood portion 66 has an L-shape, extends laterally at the lateral position of the upper accommodating portion 60A, and extends from one end thereof to the lower end position of the lower accommodating portion 60B. .. Further, the entire tip surface of the hood portion 66 is parallel to the vertical direction. Further, the L-shaped horizontal side portion and the vertical side portion of the hood portion 66 are partitioned by a partition wall 66E extending in the lateral direction, and the tip surface of the partition wall 66E is from the tip surface of the entire hood portion 66. It is located on the back side of the hood portion 66. Further, a circular through hole 66F that penetrates vertically is formed at the lower end portion of the hood portion 66. Further, in the L-shaped vertical side portion of the hood portion 66, a pair of guide protrusions 66G protruding from the outer surface of the substrate case 60 and a pair of cable insertion holes 66H penetrating the side wall of the substrate case 60 And are formed. The pair of guide protrusions 66G is located above the through hole 66F, and the pair of cable insertion holes 66H is located further above the through hole 66F.

As shown in FIG. 4, a cylindrical wall 64 projects from the lower surface of the substrate case 60, and a circular bottom wall 65S is provided at a position near the lower end in the cylindrical wall 64. Further, an electric wire insertion hole 65A is formed in the central portion of the circular bottom wall 65S, and a plurality of screw insertion holes 65B are formed around the electric wire insertion hole 65A. Further, the cylindrical wall 64 is formed with a plurality of notches 64A (see FIG. 15) corresponding to the reinforcing protrusions 28L (see FIG. 5) on the upper surface of the flow path housing 20 at a plurality of locations. Then, the cylindrical wall 64 is fitted to the outside of the outer circular rib 28G on the upper surface of the flow path housing 20, and the screw B inserted into the screw insertion hole 65B is tightened into the mounting hole 28J of the flow path housing 20 to tighten the substrate case 60. Is fixed to the flow path housing 20. Further, an O-ring 39 is housed between the inner circular rib 28F and the outer circular rib 28G of the flow path housing 20, and is crushed between the flow path housing 20 and the substrate case 60.

The lid 70 has a rectangular cap shape, and the open end side thereof is fitted inside the substrate case 60. The upper surfaces of the lid 70 and the substrate case 60 are flush with each other. A ring groove 70M is formed on the outer peripheral surface of the lid 70 at a position near the lower end. The O-ring 71 is housed in the ring groove 70M and is crushed between the lid 70 and the substrate case 60. The lid 70 is entirely made of a transparent material (for example, resin, glass, etc.), and the lid 70 is provided with a rectangular translucent portion 70A corresponding to the window portion 75M of the antenna substrate 75, which will be described later. Has been done. The light transmitting portion 70A slightly protrudes from the upper surface of the lid 70 in a stepped manner. Further, on the lower surface of the lid 70, the outer edge portion is bordered by the frame-shaped ridge 70B as shown in FIG. A frame-shaped groove 70C is formed on the outside of the frame-shaped ridge 70B by slightly recessing the lower surface of the lid 70. The outer surface of the lower surface of the lid 70 from the frame-shaped ridge 70B is painted or colored in black, for example, so that the inside of the substrate case 60 can be visually recognized only through the translucent portion 70A.

As shown in FIG. 15, the first column 63, the second column 62, and the third column 61 stand up from the stepped surface 60D of the substrate case 60. The first support column 63 is arranged at a position slightly deviated from the center of the stepped surface 60D along one long side of the upper accommodating portion 60A to the one short side side, and has a cylindrical cross section. Further, a substrate fixing hole 63N is formed in the central portion of the first support column 63 from the upper surface to an intermediate position in the vertical direction.

The second support column 62 has an end portion on the stepped surface 60D along one short side of the upper accommodating portion 60A on the side away from the first support column 63 and the first support column 63 in the substrate case 60 along the other short side. It is located at the end near the side. The second support column 62 includes a small diameter portion 62A, a small diameter expansion portion 62B, and a large diameter expansion portion 62C in this order from the upper side, and the outer diameter is gradually increased downward. Further, the stepped surface 62Y between the small diameter-expanded portion 62B and the large-diameter portion 62C in both the second columns 62 and 62 is flush with the upper end surface of the first column 63. The outer diameter of the large diameter enlarged portion 62C is larger than that of the third support column 61.

The third support column 61 is arranged at an end portion of the stepped surface 60D along one short side of the upper accommodating portion 60A on the side close to the first support column 63. The third support column 61 is provided with a step surface 61X at a position near the upper end, and the step surface 61X is flush with the step surface 62X of the second support column 62. Further, the small diameter portion 61A at the upper end of the third support column 61 and the small diameter portion 62A at the upper end of the second support column 62 have the same outer diameter. Further, the large-diameter portion 61B below the small-diameter portion 61A of the third support column 61 is thinner than the large-diameter portion 62C of the second support column 62 and thicker than the small-diameter portion 62B. A part of the second and third columns 61 and 62 is located on the stepped surface 60D, and the rest is located on the rib 60C protruding from the inner surface of the lower accommodating portion 60B. The lower ends of the second and third columns 61 and 62 are reinforced by the reinforcing ribs 61L and 62L.

FIG. 16 shows the planar shape of the control board 73. As shown in the figure, the control board 73 has a shape in which the four corners of a rectangle having a size that fits in the upper accommodating portion 60A are cut out in a quadrangle. The control board 73 is arranged parallel to the upper surface of the board case 60. Further, the control board 73 is provided with a pair of through holes 73A and 73A penetrating to the lower ends of the small diameter-expanded portions 62B and 62B of the pair of second columns 62 and 62 described above, and the pair of through holes 73A and 73A are provided. The stepped surfaces 62Y and 62Y of the pair of second columns 62 and 62 are in contact with the opening edges of the holes 73A and 73A. Further, the control board 73 is provided with a through hole 73B corresponding to the board fixing hole 63N of the first support column 63, and the board fixing screw 99 passed through the through hole 73B is screwed into the board fixing hole 63N. As a result, the control board 73 is positioned at a substantially central position in the vertical direction of the upper accommodating portion 60A and is fixed to the board case 60. The third support column 61 passes through a notch at one corner of the control board 73 and extends above the control board 73.

FIG. 17 shows the planar shape of the antenna substrate 75. As shown in the figure, the antenna substrate 75 has a rectangular ring-shaped structure (that is, a frame-shaped structure), and has a rectangular window portion 75M inside. Then, the loop antenna 75T is printed on the antenna substrate 75 so as to wind around the window portion 75M, and a pair of pinholes 75P and 75P to which both terminals of the loop antenna 75T are connected are provided. .. Further, the antenna substrate 75 has a pair of through holes 75A and 75A through which the small diameter portions 62A and 62A of the pair of second columns 62 and 62 have penetrated, and a penetration through which the small diameter portions 61A of the third column 61 penetrate. A groove 75B is provided, and the stepped surface 62X of the second support column 62 and the stepped surface 61X of the third support column 61 are in contact with the opening edges of the through hole 75A and the through groove 75B. Then, the portions of the small diameter portion 61A and the small diameter portion 62A that protrude upward from the antenna substrate 75 are heat-pressed to form the head portion 62T shown in FIG. As a result, the antenna substrate 75 is positioned at the upper end of the upper accommodating portion 60A in the vertical direction and fixed to the substrate case 60.

Further, a pair of pins (not shown) penetrating the pinholes 75P and 75P also penetrate the pinholes (not shown) of the control board 73, and both ends of the pins are soldered to the pinholes. As a result, the control board 73 and the antenna board 75 are electrically connected.

A monitor 74 is mounted on a portion of the control board 73 that is covered by the antenna board 75. Monitor 74, for example, at an Pinguri' de array structure in which a plurality of pins extending downward from the outer edge downward, their lower end portions of the plurality of pins, is soldered to the control board 73, upwardly from the control board 73 It is held in a floating state. Further, the entire upper surface of the monitor 74 except for a pair of opposite outer edges is a liquid crystal screen, on which the integrated flow rate and the flow rate per unit time are displayed. Then, as shown in FIG. 17, the entire monitor 74 except for the above-mentioned pair of outer edge portions can be visually recognized through the window portion 75M of the antenna substrate 75.

As shown in FIG. 20, in addition to the monitor 74, a microcomputer 91, a wireless circuit 94, an A / D converter 92, a coil drive circuit 96, and a power supply circuit 97 are mounted on the control board 73. Then, the microcomputer 91 controls the excitation of the coil 53C by the coil drive circuit 96, and takes in the detection result of the detection electrode 40 through the A / D converter 92 to calculate the flow rate. Then, the flow rate is wirelessly transmitted by short-range wireless communication using the wireless circuit 94 and the antenna 75.

Further, an external connection cable 93 is connected to the microcomputer 91 via the interface 98. The external connection cables 93 are pulled into a pair of elastomeric tubular bushes 66K mounted in the through holes 66F of the hood portion 66. The external connection cable 93 is sandwiched between a pair of guide protrusions 66G and 66G in the hood portion 66, is bent above the sandwiched portion, and is passed through the cable insertion hole 66H from inside the hood portion 66 to the substrate. It is pulled into the case 60. Further, a metal cord clip 66D is fixed between the through hole 66F and the guide protrusion 66G of the external connection cable 93. Further, in the external connection cable 93, a permeation water blocking portion 93D from which the insulating coating has been stripped is provided between the guide protrusion 66G and the cable insertion hole 66H.

As shown in FIG. 3, the portion of the external connection cable 93 extending downward from the hood portion 66 is accommodated in the magnetic shield 47U through the cable insertion hole 48D provided in the magnetic shield 47U, and then folded upward and separately. It is discharged to the outside from the cable insertion hole 48D of the above, and is bent outward so as to pass through the second notch 47F. A binding band 80 is wound around the position in front of the second notch 47F in the external connection cable 93 and is locked to the edge of the second notch 47F.

By the way, the cross sleeve 25 closed with the pair of side caps 37, 37 described above with respect to the substrate case 60 is an electrode case 25X for accommodating the detection electrode 40 and the like. Further, the electrode case 25X and the substrate case 60 are communicated with each other to form one electric component case 69. Then, when the area inside the case, which is the entire inside of the electric component case 69, is distinguished for each contained item, the inside of the electrode case 25X forms the lower area A1 for accommodating the coil 53C and the pair of detection electrodes 40, 40, and the substrate case 60. It is said that the entire lower accommodating portion 60B and the lower portion of the upper accommodating portion 60A form the central area A2 accommodating the battery 72, and the entire upper side thereof forms the upper area A3 accommodating the control board 73 and the monitor 74. be able to. Then, in consideration of the characteristics of the contents and the like, the entire inside of the electric component case 69 is filled with a plurality of types of potting materials separately, and the hood portion 66 is used to isolate the inside and the outside of the electric component case 69. The potting material is also separately filled in the inner hood area A4.

Specifically, in the present embodiment, the potting material P filled in the electronic component case 69 is composed of three types of potting materials, the first to third potting materials P1 to P3.

The first potting material P1 is filled in the upper part of the upper area A3 and the upper part of the middle area A2 (that is, in the upper accommodating portion 60A). The first potting material P1 is made of a silicon-based resin. Since the first potting material P1 is transparent, the monitor 74 can be visually recognized through the lid 70 and the first potting material P1. Further, the first potting material P1 covers the upper part of the battery 72.

The second potting material P2 is filled in the hood portion area A4 and is made of an epoxy resin. The second potting material P2 is in close contact with the seepage water blocking portion 93D of the external connection cable 93, whereby the fixation of the external connection cable 93 is stabilized. Further, the second potting material P2 is also in close contact with the cord clip 66D fixed to the external connection cable 93, which also stabilizes the fixing of the external connection cable 93.

The third potting material P3 is filled in the lower portion of the lower area A1 and the middle area A2 (that is, in the electrode case 25X and in the lower accommodating portion 60B). The third potting material P3 and the first potting material P1 are vertically adjacent to each other, and the third potting material P3 covers the lower portion of the battery 72. In the present embodiment, the third potting material P3 is composed of an epoxy resin of a different type from the second potting material P2.

In the electromagnetic flow meter 10 of the present embodiment, the entire inside of the electric component case 69 and the first to third potting materials P1 to P3 filled in the hood portion area A4 are housed in the electric component case 69 and the hood section area A4. It is possible to stabilize the fixing of electrical components (boards such as control board 73, monitor 74, antenna board 75, electric wires connected to these boards, yoke 51, etc.) and improve waterproof performance. ..

The details of the first to third potting materials P1 to P3 are as follows. For example, an ultraviolet absorber or the like is added to the first potting material P1 to suppress discoloration due to ultraviolet rays. Further, the first potting material P1 has a higher needle insertion degree (based on JIS K-2235) than the second potting material P2 and the third potting material P3. As a result, the possibility that the substrates such as the control substrate 73, the monitor 74, and the antenna substrate 75 are cracked is suppressed.

Further, in the present embodiment, the second potting material P2 and the third potting material P3 are easier to adhere to the metal than the first potting material P1. As a result, the second potting material P2 can be easily adhered to the seepage water blocking portion 93D formed of the metal core portion of the external connection cable 93 and the metal cord clip 66D, and the third potting material P3 can be attached to the yoke. 51, it is easy to adhere to the detection electrode 40 and the like.

Further, in the present embodiment, the curing temperature of the first potting material and the third potting material P3 is lower than that of the second potting material P2. Therefore, as compared with the case where the second potting material P2 is used for filling the portion in contact with the battery 72, the deterioration of the battery 72 due to the heat for curing the potting material is suppressed. The first potting material P1 and the third potting material P3 are preferably curable at 100 ° C. or lower, and more preferably 80 ° C. or lower. Further, the first potting material P1 and the third potting material P3 are less likely to generate heat during curing than the second potting material P2. In this respect as well, deterioration of the battery 72 is suppressed.

In the present embodiment, the second potting material P2 and the third potting material P3 are both made of an epoxy resin, but have different physical properties in the following points as well. The third potting material P3 has a lower viscosity before curing than the second potting material P2. Therefore, as shown in FIG. 4, it becomes easy to pour the potting material into the cable insertion hole 28E, which is a constricted portion, and the intricate portion in the cross sleeve 25, inside the electric component case 69. Further, in the present embodiment, the third potting material P3 is easier to adhere to the resin constituting the hood portion 66 (in this embodiment, the ABS resin) than the second potting material P2. Therefore, the infiltration of water from the hood portion 66 can be further suppressed.

As described above, in the electromagnetic flowmeter 10 of the present embodiment, the electric component case 69 and the hood portion area R2 are filled with a potting material of a type suitable for each part.

In the present embodiment, the first to third potting materials P1 to P3 are filled as follows, for example. First, the flow path housing 20 includes members (side cap 37, substrate case 60, and hood 66) constituting the electric component case 69, and electrical components (detection electrode 40, yoke 51, control) housed in the electrical component case 69. The substrate 73, the monitor 74, the electric wire 90, etc.) are assembled. Next, in the posture in which the substrate case 60 is arranged on the upper side (the posture shown in FIG. 4), the third potting material P3 extends from the hood portion 66 to the middle of the substrate case 60 (specifically, the lower accommodating portion 60B). It is injected (up to the top) and cured. After that, the electric component case 69 is laid on its side so that the opening of the hood portion 66 faces upward. Then, in the sideways posture, the first potting material P1 is injected from the hood portion 66 into the substrate case 60 (that is, into the upper accommodating portion 60A) and cured. Next, the second potting material P2 is injected into the hood portion 66 while maintaining its sideways posture, and is cured. As described above, the first to third potting materials P1 to P3 are filled in the internal region R. The lid 70 may be attached to the substrate case 60 before the second potting material P2 is injected, and may not be attached when the first potting material P1 is injected and cured. In this case, the first potting material P1 may be injected from the upper surface opening 60W of the substrate case 60.

As described above, the potting material is filled in the electric component case 69 and the hood 66 to complete the meter body 10H of the electromagnetic flow meter 10. Then, the electromagnetic flowmeter 10 is housed in the case 13 as described at the beginning. The case 13 will be described below.

As shown in FIG. 18, the case 13 includes an upper case 15 and a lower case 14. The upper case 15 and the lower case 14 have a box shape in which the surfaces facing each other are open. Then, in the meter body 10H, the control unit 10B composed of the board case 60 and the parts housed therein is housed in the upper case 15, while the lower part of the meter body 10H below the board case 60, that is, the flow. A detection unit 10A including an intermediate portion of the road housing 20 (that is, a portion sandwiched between the pair of boundary flanges 24 and 24) and parts assembled therein is housed in the lower case 14.

As shown in FIG. 2, the upper case 15 and the lower case 14 have a horizontally long rectangular shape, and the upper case 15 is slightly larger in the vertical direction than the lower case 14. Further, on the inner surface of the lower case 14, a stepped surface is formed at the entire position near the upper end, and the upper side of the stepped surface is a case fitting portion 14T whose wall thickness is slightly thinner. On the other hand, on the outer surface of the upper case 15, a stepped surface is formed at the entire position near the lower end, and the inner fitting portion 15T having a slightly thinner wall thickness below the stepped surface is formed. Then, as shown in FIG. 19, the inner fitting portion 15T of the upper case 15 is fitted inside the case fitting portion 14T of the lower case 14.

A pair of side wall grooves 14A and 14A are formed in the lateral center of the pair of long side wall surfaces 14X and 14X of the lower case 14. The side wall groove 14A has a uniform width from the upper end to the lower end position and has a semicircular lower end portion corresponding to the boundary flange 24 of the flow path housing 20. Further, a pair of first vertical ribs 78 and 78 are provided at both side positions of the side wall groove 14A on the inner side surface of the long side side wall 14X. The first vertical rib 78 extends from the upper end to the entire lower end of the long side side wall 14X, has a gap between the first vertical rib 78 and the case fitting portion 14T, and further chamfers the upper end corner portion on the case fitting portion 14T side. Has been done.

A square groove-shaped inner cover portion 77 is formed on the inner opening edge of the side wall groove 14A on the inner surface of the long side side wall 14X. Both side portions of the inner cover portion 77 are integrally formed with a pair of first vertical ribs 78 and 78, extend from the lower end of the long side side wall 14X to the front position of the case fitting portion 14T, and extend from the side wall groove 14A. It projects from both sides to the inside of the side wall groove 14A. Further, the bottom portion of the inner cover portion 77 extends so as to communicate between the lower ends of the pair of first vertical ribs 78 and 78, and the intermediate portion thereof extends from the lower end portion of the side wall groove 14A to the inside of the side wall groove 14A. Overhanging.

A pair of second vertical ribs 14L and 14L are provided at positions near both ends of the pair of short side wall surfaces 14Y and 14Y of the lower case 14 in the lateral direction. Like the first vertical rib 78, the second vertical rib 14L extends from the upper end to the entire lower end of the short side side wall 14Y, has a gap between the second vertical rib 14L and the case fitting portion 14T, and chamfers the upper end corner portion. Has been done. Further, between the pair of short side wall surfaces 14Y and 14Y, the lower ends of the pair of second vertical ribs 14L and 14L facing each other are connected by the horizontal ribs 14M protruding from the bottom wall 14Z.

On the bottom wall 14Z of the lower case 14, two pairs of elastic holding pieces 19 and 19 facing each other with a pair of lateral ribs 14M and 14M in the lateral direction of the bottom wall 14Z are provided on the short side side walls 14Y and 14Y. It is provided in a closer position. Further, a locking protrusion 19T is provided at the upper end of each elastic holding piece 19 on the facing surface side.

A cable guide 76 is provided between one end of one short side wall 14Y and the second vertical rib 14L, and projects upward from the short side wall 14Y, and a cable groove 76M is provided in the projecting portion.

When the meter body 10H is housed in the lower case 14, the pair of boundary flanges 24, 24 of the flow path housing 20 fits in the side wall grooves 14A, 14A of the lower case 14, and the main shield member 47 of the magnetic shield 47U is paired. It is supported from below by the lateral ribs 14M and 14M. Further, the main shield member 47 is positioned in the longitudinal direction of the lower case 14 by the two pairs of the second vertical ribs 14L, and the bottom portion 47A of the main shield member 47 is sandwiched by the two pairs of elastic holding pieces 19 in the lower case. Positioning is performed in the lateral direction of 14, and further, the locking protrusion 19T of the elastic holding piece 19 is locked to the bottom portion 47A from the upper surface side, and the main shield member 47 is prevented from coming off by the lower case 14. Further, the inner cover portion 77 overlaps the outer edge portion of the boundary flange 24 from the inside, and the gap between the boundary flange 24 and the lower case 14 is closed. Further, the outer surface of the boundary flange 24 and the outer surface of the long side wall 14X are arranged flush with each other.

Further, the external connection cable 93 of the meter body 10H fits in the cable groove 76M of the cable guide 76 and is pulled out to the outside of the lower case 14.

By simply pushing the meter body 10H into the lower case 14 from above, the bottom portion 47A of the main shield member 47 is in sliding contact with the inclined surface 19A of the locking protrusion 19T, and the elastic holding pieces 19 group are elastically deformed, resulting in an electromagnetic flow rate. When the total 10 is pushed all the way into the lower case 14, the elastic holding pieces 19 group elastically returns, and the locking surface 19B of the locking protrusion 19T is locked to the bottom portion 47A of the main shield member 47, which is the above-mentioned state. become.

Elastic engagement pieces 17 are provided at both ends of the long side wall 14X in the lower case 14 in the lateral direction and at the center of the short side wall 14Y in the lateral direction. The elastic engaging piece 17 of the long side side wall 14X has a strip shape, overlaps the inner surface of the long side side wall 14X, extends in the vertical direction, and protrudes upward from the long side side wall 14X, and is between the long side side wall 14X and the case fitting portion 14T. Has a gap. Further, a quadrangular through hole is formed in a portion of the elastic engaging piece 17 that protrudes upward from the long side side wall 14X, and the inside thereof is the engaging portion 17A. Further, the elastic engaging piece 17 of the short side wall 14Y has a structure in which the entire lower portion of the elastic engaging piece 17 of the long side wall 14X is removed from the quadrangular through hole.

As shown in FIG. 18, an engaging protrusion 18 is provided on the inner surface of the upper case 15 corresponding to the elastic engaging piece 17. The engaging protrusion 18 has an inclined surface 18A inclined in the vertical direction and an engaging surface 18B horizontal at the upper end. Then, when the upper case 15 is fitted to the lower case 14 in the state where the detection unit 10A of the meter body 10H is housed from above, 17 groups of elastic engaging pieces are simultaneously assembled into 18 groups of engaging protrusions in the process. When the case fitting portion 14T and the inner fitting portion 15T are fitted to each other by sliding contact with the inclined surface 18A and elastically deforming inward, 17 groups of elastic engaging pieces all get over the engaging protrusion 18 groups all at once. After elastic recovery, as shown in FIG. 19, the engaging protrusion 18 engages with the engaging portion 17A of the elastic engaging piece 17, and the upper case 15 and the lower case 14 cannot be separated (that is, in a fitted and killed state). ) Is connected.

The detailed structure other than the above in Case 13 is as follows. That is, one short side wall surface 15Y of the upper case 15 is provided with a notch portion 15B corresponding to the cable groove 76M, and the upper case 15 receives an intermediate portion of the external connection cable 93. The long side wall 15X of the upper case 15 is provided with two pairs of third vertical ribs 15L and 15L to reinforce the upper case 15. When the control unit 10B is housed in the upper case 15, the third vertical ribs 15L and 15L come into contact with the main body case 10H. Further, on the upper surface of the upper case 15, a rectangular upper window portion 15W corresponding to the translucent portion 70A of the lid 70 is provided. Then, as shown in FIG. 1, a lid portion 16 is rotatably attached to the upper portion of the upper case 15 to close the upper surface window portion 15W. A hinge portion 16H of the lid portion 16 is provided at the center of the long side side wall 15X on the downstream side of the upper case 15 in the lateral direction, and the lid portion 16 rotates and opens around the hinge portion 16H. A recess 15A is provided at the upper end of the lateral center of the long side wall 15X on the upstream side so that the lid 16 can be easily opened. Further, as shown in FIG. 3, an engaging protrusion 15D protruding downward from the upper surface of the upper case 15 is provided. The engaging protrusion 15D engages with the engaging recess 26 provided on the upper surface of the lid 70. As a result, the upper case 15 and the substrate case 60 are integrated, and the upper case 15 is strengthened. Further, depending on the position where the engaging protrusion 15D and the engaging recess 26 are arranged, it is possible to prevent the upper case 15 from being assembled with the lower case 14 in the direction opposite to the original orientation.

Further, as shown in FIG. 2, a wire stopper 79 is provided at the upper end of the long side side wall 14X of the lower case 14 at a position closer to the side wall groove 14A. The wire stopper 79 has a through hole 79A, a wire (not shown) is wound around the water pipe through the through hole 79A, and the lower case 14 is fixed to the water pipe.

The description of the configuration of the electromagnetic flow meter 10 of the present embodiment has been described above. Next, the action and effect of the electromagnetic flowmeter 10 will be described. The electromagnetic flow meter 10 is connected to the middle of the water pipe and operates to measure the flow rate of water flowing through the water pipe. Therefore, the control board 73 energizes the coil 53C with an alternating current. Then, a magnetic circuit is formed from the core shaft 51J, a pair of yokes 51, 51, and the measuring tube portion 20P between the magnetic flux penetrating surfaces 51Z, 51Z of the yokes 51, 51, and the water flowing in the measuring tube portion 20P is formed. , Magnetic flux (magnetic field) is applied from the direction intersecting the flow direction. Further, a closed circuit 89 (see FIG. 20, hereinafter referred to as “measurement closed circuit 89”) is formed by the water between the detection electrodes 40 and 40, the detection electrodes 40 and 40, their electric wires 90, and the control board 73. To. Then, when water flows in the measuring tube portion 20P, a potential difference according to the flow velocity of the water in the measuring tube portion 20P between the tip surfaces of the pair of detection electrodes 40, 40 in the closed circuit 89 for measurement by electromagnetic induction. Occurs. The control board 73 calculates the flow rate of water per unit time based on the potential difference and the cross-sectional area of the measurement flow path 20R (that is, the measurement unit 20K) in the measurement tube unit 20P, and integrates the flow rates. Calculate the integrated flow rate. Then, the calculation results are displayed on the monitor 74.

By the way, when the intensity of the magnetic flux penetrating the closed circuit 89 for measurement changes, it becomes noise and causes a decrease in measurement accuracy. On the other hand, in the present embodiment, as shown in FIG. 9, a wire receiving groove 51E is formed in one yoke 51, and the wire 90 of one detection electrode 40 is received therein and the wire of the other detection electrode 40 is received. By supporting the detection electrode 40 so as to extend to the 90 side, the electric wire 90 of one of the detection electrodes 40 and the electric circuit 89W by water between the detection electrodes 40 and 40 are arranged in the direction in which the magnetic flux extends (the vertical direction in FIG. 9). , It becomes difficult for the magnetic flux to penetrate through the closed circuit 89 for measurement.

More specifically, the electric wire receiving groove 51E is arranged together with the detection electrodes 40 and 40 in the reference surface S (cut surface shown in FIGS. 8 and 9) orthogonal to the yoke arrangement surfaces 34 and 34. The electric wire 90 of one of the detection electrodes 40 and the electric path 89W due to water between the detection electrodes 40 and 40 overlap in the magnetic flux direction, and it is possible to prevent the magnetic flux from penetrating into the closed circuit 89 for measurement. Further, both detection electrodes 40 and 40 form a rod shape arranged on the same straight line, and the electric wire 90 of one of the detection electrodes 40 is received by the electric wire accommodating groove 33A and the electric wire receiving groove 52E extending on the extension line of the electric wire receiving groove 51E. As a result, it is possible to prevent the magnetic flux from penetrating the inside of the closed circuit 89 for measurement even on the side of the magnetic flux penetrating surfaces 51Z and 51Z of the yokes 51 and 51.

Further, the electric wires 90 and 90 of the detection electrodes 40 and 40 both pass by the sides of the yokes 51 and 51 and extend to the control substrate 73, and the electric wires 90 and 90 are held so as to be side by side in the reference plane S. As a result, it is possible to prevent the magnetic flux leaking laterally from the magnetic flux penetrating surfaces 51Z and 51Z from penetrating the inside of the measurement closed circuit 89.

Further, since the pair of yokes 51 and 51 are provided so as to face each other with the measuring tube portion 20P in between, and the yoke arrangement surfaces 34 and 34 and the magnetic flux penetration surfaces 51Z and 51Z are flat, these are used. The spread of the magnetic flux to the side is suppressed, and at this point as well, it becomes difficult for the magnetic flux to penetrate the inside of the closed circuit 89 for measurement. As a result, it is possible to suppress the generation of noise in the closed circuit 89 for measurement and improve the measurement accuracy of the flow rate.

Since the portions near the bent portions on both sides of the electric wire 90 passing through the electric wire accommodating groove 33A and the electric wire receiving groove 52E are passed through the electric wire insertion holes 44A and 44A and supported, the arrangement of the electric wire 90 is stable. Further, the electric wire receiving groove 51E may be formed on the yoke arrangement surface 34 of the measuring tube portion 20P, but if it is formed on the magnetic flux penetrating surface 51Z (that is, if it is formed on the yoke 51), the strength of the measuring tube portion 20P. It will be easier to secure.

Further, before the electromagnetic flow meter 10 is attached to the water pipe, there is no water in the measurement flow path 20R. In addition, water may escape from the measurement flow path 20R due to a water outage. Here, when water flows into the measurement flow path 20R, there is a concern that air may stay in the gap between the detection electrode 40 and the electrode accommodating hole 35. Specifically, in the conventional electromagnetic flowmeter, the gap is made small in order to reduce the capacity of air entering the gap as much as possible, so that it becomes difficult for water to enter the gap, and once air collects in the gap, it becomes difficult. It may not be excluded, which is considered to have been the cause of the decrease in measurement accuracy.

On the other hand, in the electromagnetic flowmeter 10 of the present embodiment, as shown in FIG. 11A, a submerged chamber 35H for accommodating the submerged tip portion 40H of the detection electrode 40 is provided at the end of each electrode accommodating hole 35. Each of these submerged chambers 35H is provided with an outflow port 35A through which water enters and exits depending on the presence or absence of water in the measurement flow path 20R. As a result, even if air enters the submerged room 35H, the air can be easily eliminated.

Specifically, when the supply of tap water is started or restarted and water flows into the measurement flow path 20R, water flows into the submerged room 35H from one end of the oval outflow port 35A, and the air in the submerged room 35H is oval. Extrude from the other end of the outflow port 35A. Here, the outflow port 35A is extended so that the total length in the minor axis direction is 0.7 to 1 times the distance between the R chamfered curved surfaces 20G and 20G on the inner surface of the measurement flow path 20R. Water can be reliably taken into the submerged room 35H. Further, in the submerged room 35H, the opening protrusion 35W protrudes inward from the edge on the measurement flow path 20R side, and the inside of the opening protrusion 35W is the outflow port 35A. Therefore, by any chance, the O-ring 36 is the measurement flow. Even if it is sucked to the road 20R side, it does not separate from the measurement flow path 20R side. Further, by providing the O-ring 36 away from the opening protrusion 35W, the inside of the submerged room 35H becomes wider, the water can easily flow into the submerged room 35H, and even if a small amount of air remains in the submerged room 35H. The air can be separated from the submerged tip 40H of the detection electrode 40, and the entire submerged tip 40H can be submerged. Moreover, since the long axis direction of the oval outflow port 35A and the axial direction of the measurement flow path 20R, that is, the direction in which water flows are parallel, the flow of water in the measurement flow path 20R is used. Water is easily taken into the submerged room 35H.

As described above, in the electromagnetic flowmeter 10 of the present embodiment, the entire submerged tip portions 40H and 40H of the pair of detection electrodes 40 and 40 are surely submerged, and the variation in the contact area between the detection electrodes 40 and 40 and water is suppressed. The measurement accuracy is improved.

Further, the electromagnetic flow meter 10 returns the measurement result of the flow rate of tap water as a wireless signal from the outside in response to a predetermined wireless signal by short-range wireless communication (Near field radio communication).

Here, in the electromagnetic flow meter 10, since the antenna substrate 75 having a ring structure is provided and the loop antenna 75T for short-range wireless communication is printed on the antenna substrate 75, the loop antenna 75T is used by utilizing the so-called dead space around the monitor 74. It is possible to improve the radio reception sensitivity while suppressing the increase in size of the substrate case 60. Further, since the control board 73 is separated from the antenna board 75, the influence of noise from the control board 73 to the antenna board 75 can be suppressed. Nevertheless, since the monitor 74 is held in a floating state with respect to the control board 73 and is brought close to the translucent portion 70A of the lid 70, the monitor 74 can be visually recognized satisfactorily.

Further, if the antenna board 75 is simply provided separately from the control board 73, the labor for assembling work increases and the manufacturing cost increases. However, in the electromagnetic flow meter 10 of the present embodiment, the control board 73 is screwed into the first position. A plurality of second columns 62 and third columns 61 are provided separately from the columns 63, and the antenna board 75 is fixed by heat caulking at the upper ends thereof, and the second columns 62 penetrate the control board 73 and the antenna board 75. Since positioning is performed by this, the laborious screwing work can be reduced and the manufacturing cost can be suppressed.

Further, since the board case 60 accommodates the battery 72 below the control board 73, when the first support column 63 and the second support column 62 stand up from the bottom of the board case 60, the first support column 63 and the like become long and support is not provided. Although it can be stable, in the electromagnetic flow meter 10 of the present embodiment, a stepped surface 60D is provided in the middle of the inner surface of the substrate case 60 in the vertical direction, and the stepped surface 60D to the first to third columns 63, Since 62 and 61 are erected, the support of the control board 73 and the antenna board 75 is stable.

Further, the electromagnetic flowmeter 10 combines the upper case 15 and the lower case 14 (hereinafter, appropriately referred to as "upper and lower cases 14, 15") except for both ends of the flow path housing 20 connected to the water pipe. It is housed in the case 13. When the upper and lower cases 14 and 15 are combined, they become inseparable, so that unauthorized operation can be effectively prevented as compared with the conventional case. Further, in order to make the upper and lower cases 14 and 15 inseparable, the elastic engaging piece 17 provided in the lower case 14 is inserted inside the upper case 15 with elastic deformation, and elastically returns in the case united state. Since the structure is such that it engages with the engaging protrusion 18 on the inner surface of the upper case 15 (so-called “fitting and killing” structure), the assembly work of the electromagnetic flowmeter 10 can be easily performed.

The elastic engaging piece 17 stands up from a position away from the tip portion of the inner surface of the lower case 14, and as shown in FIG. 19, the inner fitting portion 15T of the upper case 15 fits the case of the lower case 14. Since it fits between the joint portion 14T and the elastic engaging piece 17, even if the side wall of the upper case 15 is pushed and pulled, the elastic engaging piece 17 also moves together with the side wall of the upper case 15 and is elastically engaged. It is possible to surely prevent the unit 17 from being disengaged. Further, since the plurality of first and second vertical ribs 14L and 78 for reinforcing the long side side wall 14X and the short side side wall 14Y of the lower case 14 are inserted inside the upper case 15, the upper and lower cases 14 and 15 It is possible to firmly prevent lateral slippage. Further, since the second vertical ribs 14L and 14L are connected to each other by the horizontal ribs 14M, the entire lower case 14 is effectively reinforced by the continuous second vertical ribs 14L and 14L and the horizontal ribs 14M. be able to.

Further, since the lower case 14 and the upper case 15 have a quadrangular flat cross section, and the elastic engaging pieces 17 are arranged on all sides of the quadrangular surface of the lower case 14, the upper and lower cases 14, 15 Occurrence of a gap is suppressed between any of the side walls, and unauthorized operation can be reliably prevented. Moreover, since the elastic engaging pieces 17 are arranged in pairs on both sides of each side wall groove 14A in the lower case 14 where there is a concern about a decrease in strength, the reduced strength is due to the engagement of the elastic engaging pieces 17. Can be supplemented.

Further, since the boundary flanges 24, 24 projecting laterally from the flow path housing 20 fit into the side wall grooves 14A, 14A of the lower case 14 and become flush with the outer surface and the upper surface of the lower case 14, the flow path housing The sense of unity between the 20 and the lower case 14 is enhanced, and the aesthetics are improved. Since the lower ends of the boundary flanges 24 and 24 and the side wall groove 14A are arcuate, stress concentration can be prevented and the strength can be increased. Further, since the inner cover portion 77 of the lower case 14 overlaps the edge portions of the boundary flanges 24 and 24 from the inside, it is possible to prevent the occurrence of a gap into which a tool or the like is illegally inserted.

Further, the detection unit 10A is surrounded by the main shield member 47 and the sub shield member 48 from all sides and magnetically shielded, so that an unauthorized operation can be prevented in which a magnetic field is applied from the outside to cause the electromagnetic flow meter 10 to malfunction. Further, both ends of the bottom portion of the main shield member 47 are sandwiched by two pairs of elastic holding pieces 19 standing up from the bottom surface of the lower case 14, and the locking protrusions 19T of each elastic holding piece 19 are the main shield member. By locking to the bottom of 47 from above, the lower case 14 and the main shield member 47 are integrated, and the lower case 14 is strengthened.

In the electromagnetic flowmeter 10 of the present embodiment, the metal sleeve 21 is fixed to the flow path housing 20 by insert molding of the flow path housing 20, and the metal sleeve 21 is provided with a male screw portion 21N for connecting to the pipe. Both weight reduction and high strength can be achieved.

Here, when the electromagnetic flowmeter 10 is attached to the pipe, if the case 13 of the electromagnetic flowmeter 10 is gripped and the screwed parts are tightened to the male screw portion 21N, a large twisting load is applied to the electromagnetic flowmeter 10. However, in the present embodiment, since the tool engaging portions 23 are provided at positions near both ends of the flow path housing 20, the electromagnetic flowmeter is provided by engaging the tools there to prevent the flow path housing 20 from rotating. It is possible to prevent a large twisting load from being applied to 10. Further, since the tool engaging portion 23 is integrally molded with the flow path housing 20, the increase in manufacturing cost and weight due to the provision of the tool engaging portion 23 can be suppressed. Further, when the tool engaging portion 23 has a polygonal flange shape as in the present embodiment, the flow path housing 20 is provided with a lightening groove 23A that crosses the intermediate portion of the ridgeline of each corner of the polygon. It is possible to suppress molding distortion due to "sink" during resin molding.

In the present embodiment, since the cover flange 22F covering the tip surface of the metal sleeve 21 is integrally molded with the flow path housing 20, peeling of the flow path housing 20 from the inner surface of the metal sleeve 21 is prevented, and the durability is improved. improves. Further, according to the present embodiment, the outer edge portion of the tip surface of the metal sleeve 21 is pressed against the mold for insert molding the flow path housing 20, and the molten resin of the metal sleeve 21 is pressed toward the male screw portion 21N side. It is possible to prevent the inflow. Further, since the outer edge portion of the tip surface of the metal sleeve 21 has a tapered shape, the metal sleeve 21 can be easily centered on the mold.

According to the present embodiment, the outer peripheral surface of the large-diameter flange portion 21C of the metal sleeve 21 is fitted into a mold for insert molding the flow path housing 20, and the metal sleeve 21 is moved to the male screw portion 21N side. The inflow of molten resin can be prevented. Moreover, since the outer edge of the tip surface of the metal sleeve 21 has a tapered shape, the metal sleeve 21 can be easily centered on the mold.

Further, since the small diameter flange portion 21D and the inner large diameter portion 21E are provided on the metal sleeve 21 and covered with the resin of the flow path housing 20, the metal sleeve 21 is prevented from coming off from the flow path housing 20. Further, since the metal sleeve 21 is provided with the uneven engagement portion 21Q having a shape in which the unevenness repeats in the circumferential direction, the rotation prevention of the metal sleeve 21 with respect to the flow path housing 20 is strengthened.

In the present embodiment, the cross sleeve 25 reinforces the intermediate portion of the flow path housing 20, and the cross sleeve 25 is reinforced at both ends by a pair of side caps 37, 37. Further, the coil 53C and the detection electrode 40 are protected by being housed in the cross sleeve 25.

Further, in the present embodiment, the portion of the flow path housing 20 sandwiched between the pair of yokes 51 and 51 is reinforced by the pair of cross-linking walls 29B and 29B. As a result, the portion of the flow path housing 20 sandwiched between the pair of yokes 51 and 51 can be thinned to increase the magnetic field strength to the measurement flow path 20R inside the flow path housing 20, and the measurement accuracy can be improved. .. Further, if a plurality of horizontal ribs 29A projecting laterally from the flow path housing 20 are provided inside the cross sleeve 25 to increase reinforcement, a portion of the flow path housing 20 sandwiched between a pair of yokes 51 and 51 is further provided. Can be thinned.

In the present embodiment, the upper end and lower end reinforcing plates 28A and 28A are delivered between the pair of boundary flanges 24 and 24 that project laterally from two locations of the flow path housing 20 sandwiching the cross sleeve 25 in between. At the same time, a plurality of reinforcing plates 28A are passed between the pair of boundary flanges 24 and 24 and the cross sleeve 25, so that the entire intermediate portion of the flow path housing 20 including the cross sleeve 25 is reinforced. In addition to this, the entire flow path housing 20 is reinforced by a plurality of horizontal ribs 27A projecting from the side surface on the end side of the pair of boundary flanges 24, 24 of the flow path housing 20.

Further, in the present embodiment, the portion of the measurement flow path 20R that receives the magnetic field from the coil 53C is magnetically shielded by being surrounded from three sides by the main shield member 47 formed by bending the sheet metal into a U shape, so that the magnetic field is magnetically shielded from the outside. It is possible to prevent an unauthorized operation that causes the electromagnetic flow meter 10 to malfunction. The cross sleeve 25 is also reinforced by the main shield member 47. The magnetic shield and reinforcement are strengthened by adding the sub-shield member 48 whose both ends are overlapped to the pair of side sides of the main shield member 47.

Here, the detection electrode that requires corrosion resistance to come into contact with water has low wettability to solder or wax due to its corrosion resistance. Therefore, when the pair of electric wires 90, 90 extending from the control board 73 is soldered to the pair of detection electrodes 40, 40, the reliability of the conduction connection is lowered. Further, when the caulking structure is applied to the connecting portion between the electric wire 90 and the detection electrode 40, it is difficult to secure the contact area of the connecting portion. On the other hand, the electromagnetic flow meter 10 of the present embodiment includes a pair of electric wire connecting members 46, 46 made of a conductive member having a higher wettability to solder or wax than the detection electrode 40, and the pair of electric wires are connected. The members 46, 46 and the pair of detection electrodes 40, 40 are press-fitted, and the core wires of the pair of electric wires 90, 90 extending from the control board 73 with respect to the pair of detection electrodes 40, 40 are connected to the pair of electric wires. Since the connecting members 46 and 46 are soldered or soldered, both the reliability and the corrosion resistance of the conductive connection can be improved.

Further, in the electromagnetic flowmeter 10 of the present embodiment, the electrode case 25 that surrounds at least a part of the flow path housing 20 and houses the electric wire connecting members 46, 46 is filled with the potting material P, so that the electrode connecting member 46 The surrounding area is waterproof. Moreover, since the electrode connecting member 46 and the detection electrode 40 are connected by press fitting, the potting material P does not enter into the gap between them, and the potting material P does not enter and a contact failure occurs.

Examples of the member constituting the detection electrode 40 include stainless steel, and examples of the member constituting the electric wire connecting member 46 include copper and the like. As the detection electrode 40, one whose surface has been subjected to corrosion resistance treatment by plating or the like may be used. Further, the detection electrode 40 is preferably a non-magnetic or low austenitic metal.

In the present embodiment, since the electric wire receiving groove 46M for receiving the core wire of the electric wire 90 is formed in the electric wire connecting member 46, the molten solder or wax can be poured into the electric wire receiving groove 46M to easily perform soldering or brazing. it can. Further, since the end surface of the thin rod portion 40D is flush with the bottom surface of the electric wire receiving groove 46M, it is difficult to create a gap between the bottom surface of the electric wire receiving groove 46M and the core wire, and the reliability of the connection is improved. .. Moreover, in the electromagnetic flow meter 10 of the present embodiment, before the detection electrode 40 is inserted into the electrode accommodating hole 35, the thin rod portion 40D of the detection electrode 40 is passed through the electrode fixing member 42, and the thin rod portion 40D is formed. By press-fitting the electric wire connecting member 46 into the end portion, the detection electrode 40, the electric wire connecting member 46, and the electrode fixing member 42 can be made into one assembly, and the subsequent assembly becomes easy.

Further, in the present embodiment, since the resin wire fixing member 42 that prevents the detection electrode 40 from coming off and the wire connecting member 46 are separated from each other, the electrode fixing member 42 is affected by the heat generated during soldering or brazing. Deformation is prevented. Moreover, in the electromagnetic flowmeter 10 of the present embodiment, the electric wire 90 can be easily routed by using the electric wire receiving groove 45M or the electric wire insertion hole 44A.

[Other Embodiments]
The present invention is not limited to the above-described embodiment, and for example, embodiments as described below are also included in the technical scope of the present invention, and various other than the following, as long as the gist is not deviated. It can be changed and implemented.

(1) The outflow port 35A of the first embodiment is oval, but it may be oval or circular as shown in FIG. 21 (A). Further, the outflow port 35A may have a polygonal shape elongated in the axial direction of the flow path housing 20, such as a rectangle shown in FIG. 21 (C) or a rhombus shown in FIG. 21 (D). It may have a polygonal shape. Further, as shown in FIG. 21B, the outflow port 35A has notches 35Y and 35Y having a semicircular shape formed at the upstream and downstream ends of the circular opening 35X coaxial with the detection electrode 40. It may have a shaped shape. In this case, the circular opening 35X may be fitted with the small-diameter tip 40A of the detection electrode 40, and in this configuration, water flows into the submerged chamber 35H from the notch 35Y.

(2) In the first embodiment, the protrusion that prevents the O-ring 36 from coming off is composed of the opening protrusion 35W, but is separate from the opening protrusion 35W (for example, the opening protrusion 35W and the O-ring 36). It may be provided (between).

(3) In the above embodiment, the control board 73 is fixed to the board case 60 by the board fixing screw 99, but the control board 73 is attached to the upper end of the first support 63 like the third support 61. A small-diameter portion penetrating the through hole 73B of the above may be provided, and the small-diameter portion may be heated.

(4) In the above embodiment, the control board 73 and the antenna board 75 are projected from the inner surface of the upper accommodating portion 60A of the board case 60 instead of being supported by the first to third columns 63, 62, 61. It may be supported by a portion, or may be supported by a stepped surface provided on the inner surface of the upper accommodating portion 60A of the substrate case 60 and facing upward.

(5) In the above embodiment, a plurality of first columns 63 and third columns 61 may be provided. In addition, one or three or more second columns 62 may be provided.

(6) In the above embodiment, the elastic engaging piece 17 is provided only in the lower case 14 and the engaging protrusion 18 is provided only in the upper case 15, but in the reverse configuration, the elastic engaging piece 17 is provided. It may be provided only in the upper case 15 and the engaging protrusion 18 may be provided only in the lower case 14. Further, both the elastic engaging piece 17 and the engaging protrusion 18 may be provided in the lower case 14 and the upper case 15, respectively.

(7) In the above embodiment, the elastic engagement piece 17 is provided on both the long side side wall 14X and the short side side wall 14Y of the lower case 14, but may be provided only on the long side side wall 14X. , May be provided only on the short side side wall 14Y.

(8) In the above embodiment, as shown in FIG. 22 (A), the elastic engaging piece 17 may be provided with a recess instead of the through hole, and the inside of the recess may be the engaging portion 17A. Further, as shown in FIG. 22B, the elastic engaging piece 17 may be provided with a protrusion instead of the through hole, and the lower surface of the protrusion may be the engaging portion 17A. In this case, the engaging portion may be provided. As a portion to be engaged with 17A, an engaging protrusion 18 may be provided on the inner surface of the upper case 15, or a recess may be provided as shown in FIG. 22 (C).

(9) In the above embodiment, the boundary between the first potting material P1 and the third potting material P3 is provided in the middle portion of the central area A2, but is provided in the boundary portion between the upper area A3 and the central area A2. It may be provided at a boundary portion between the central area A2 and the lower area A1, or may be provided at an intermediate portion of the lower area A1.

(10) In the above embodiment, the epoxy resins constituting the second potting material P1 and the third potting material P3 are of different types, but may be of the same type.

(11) In the above embodiment, instead of the third potting material P3, a potting material made of a resin other than the epoxy resin (for example, a silicon resin) may be filled. In this case, for example, the entire inside of the electric component case 69 may be filled with the first potting material P1.

(12) In the above embodiment, the potting material to be filled in the electric component case 69 may be divided into three or more types in the vertical direction. In this case, for example, the upper area A3 is filled with the first potting material P1, the lower area A1 is filled with the third potting material P3, and the middle area A2 is different from the first potting material P1 and the third potting material P3. It may be filled with a potting material.

(13) In the above embodiment, the electromagnetic flow meter 10 may be configured such that the electric component case 69 is not filled with the potting material P.

(14) In the above embodiment, the tool engaging portion 23 of the flow path housing 20 is made of resin, but may be made of metal. In this case, the tool engaging portion 23 may be assembled by fitting to the resin constituent portion 22, or may be integrated with the resin constituent portion 22 by insert molding.

(15) In the above embodiment, the tool engaging portion 23 of the flow path housing 20 has a hexagonal cross section, but the present invention is not limited to this, and a tool for connecting the flow path housing 20 to the water pipe is engaged. If so, it may have another shape. Such a shape may be, for example, a shape provided with a recess or a protrusion that engages with the tool.

(16) In the above embodiment, in the electric wire connecting member 46, the portion where the detection electrode 40 (specifically, the thin rod portion 40D of the detection electrode 40) is press-fitted is the through hole 46A, but it is a recess. May be good.

(17) In the above embodiment, the electric wire connecting member 46 and the detection electrode 40 are fixed by press-fitting the detection electrode 40 into the electric wire connecting member 46, but the electric wire connecting member 46 is press-fitted into the detection electrode 40. It may be done by being done. In this case, the detection electrode 40 is formed with a hole or a recess into which the electric wire connecting member 46 is press-fitted.

(18) In the above embodiment, the electric wire receiving groove 46M communicates with the through hole 46A of the electric wire connecting member 46, but it does not have to communicate with the through hole 46A. Further, the electric wire receiving groove 46M may be provided on the outer peripheral surface of the electric wire connecting member 46.

(19) In the above embodiment, the electric wire connecting member 46 is provided with the electric wire receiving groove 46M, but the electric wire connecting member 46 is not provided with the electric wire receiving groove 46M, and one end surface of the electric wire connecting member 46 becomes a flat surface. You may.

(20) In the above embodiment, the electrode fixing member 42 is made of resin, but it may be made of metal. In this case, the electrode fixing member 42 and the electric wire connecting member 46 may be adjacent to each other.

(21) In the above embodiment, one pair of yokes 51 is provided, but only one yoke 51 on the wire receiving groove 51E side may be provided.

(22) In the above embodiment, the electric wire receiving groove 51E is provided in the yoke 51, but it may be provided in the measuring tube portion 20P. In this case, the electric wire receiving groove 52E may be provided on the extension line of the electric wire receiving groove 51E in the portion of the flow path housing 20 facing the yoke retainer 52.

(23) In the above embodiment, the magnetic flux penetration surface 51Z is flat, but may be curved.

(24) In the above embodiment, the electric wire receiving groove 51E of the yoke 51 is arranged in the reference surface S, but it may not be arranged in the reference surface S. In this case, it is preferable that the electric wire receiving groove 51E of the yoke 51 is arranged along the reference surface S.

(25) In the above embodiment, the control board 73 is arranged on the upper side of the yoke 51, but may be arranged on the side of the yoke 51.

10 Electromagnetic flow meter 13 Case 14 Lower case 15 Upper case 17 Elastic engagement piece 18 Engagement protrusion 20 Flow path housing 20R Measurement flow path 35 Electrode accommodating hole 35A Outflow port 35H Submerged room 35W Opening protrusion 36 O-ring 40 Detection electrode 40H Submerged tip 51 York 60 Board case 70A Transmissive part 73 Control board 74 Monitor 75 Antenna board 75M Window part 75T Loop antenna P1 1st potting material P2 2nd potting material P3 3rd potting material

Claims (5)

A resin substrate case with a top opening closed by a lid,
A translucent portion provided in at least a part of the lid,
A control board housed in the board case and arranged parallel to the upper surface of the board case.
A monitor mounted on the control board at a position visible through the translucent portion and displaying the measurement result of the flow rate.
A wireless circuit for short-range wireless communication mounted on the control board and returning the measurement result of the flow rate according to a signal received from the outside,
An antenna substrate having a ring-shaped structure having a window portion corresponding to the monitor inside and arranged to face the control substrate above the control substrate.
An electromagnetic flowmeter including a loop antenna for short-range wireless communication printed on the antenna board and connected to the wireless circuit. The monitor of claim plurality of pins forms the Pinguri' de array structure hanging down, is held to a lower end portion of the plurality of pins floated upward from the control board is soldered to the control board 1 The electromagnetic flowmeter described in. The control board and the antenna board are provided with through holes or through grooves.
A first column that stands up from the inner surface of the substrate case, has a substrate fixing hole, and comes into contact with the through hole or the opening edge of the through groove of the control substrate from below.
A substrate fixing screw that is inserted into the through hole or the through groove of the control board and screwed into the board fixing hole.
Stands up from the inner surface of the substrate case and the through-hole or the through groove and a through, the antenna plurality of second struts the upper part is thermally caulked than the substrate and the control substrate and the antenna substrate has,
The diameter of the second support column below the antenna substrate is expanded in a stepped manner so as to abut from below on the through hole of the antenna substrate or the opening edge of the through groove, and the through hole of the control substrate. Or, with a small diameter-expanded portion that penetrates the through groove,
Of the second support column, the lower side of the control board is stepped and has a larger diameter than the small diameter-enlarged portion, and is in contact with the through hole or the opening edge of the through groove of the control board from below. The electromagnetic flowmeter according to claim 1 or 2, which has an enlarged diameter portion. The battery is housed in the board case below the control board.
A stepped surface is provided on the inner surface of the substrate case in the middle in the vertical direction.
The electromagnetic flowmeter according to claim 3, wherein the first support column and the plurality of second columns stand up from the stepped surface. A flow path housing with a measurement flow path and
A coil that is assembled to the flow path housing and applies a magnetic field to the measurement flow path,
A pair of detection electrodes, which are assembled to the flow path housing and detect a potential difference between two points of the measurement flow path,
A housing upper surface wall provided on the upper part of the flow path housing and having an electric wire insertion hole through which the electric wire group of the coil and the pair of detection electrodes is passed.
An electric wire receiving port formed in the substrate case and overlapping the electric wire insertion hole from above is provided.
Claim 3 or 4 in which the substrate case is fixed to the flow path housing from above with a screw, and the electric wire group is passed through the electric wire insertion hole and the electric wire receiving port and connected to the control board. The electromagnetic flowmeter described in.

Images