JP7570223B2 - Water meter - Google Patents

Description

This disclosure relates to a water meter equipped with an external detector that detects magnetism caused by internal magnetic components.

This type of water meter has been developed to simplify meter reading, and one example has been proposed in which a fixing ring is attached to the outside of the glass plate that covers the flow rate display and is screwed into the base, with a structure for fixing an external detector (see, for example, Patent Document 1).

JP 2012-83298 A (Fig. 1, etc.)

However, for water meters of the above-mentioned type that have a translucent cap instead of the glass plate and that can rotate the translucent cap relative to the base to change the orientation of the flow rate display unit inside the translucent cap, no structure for fixing an external detector has been provided, and there is a demand for such a structure to be developed.

The water meter of claim 1, which has been made to solve the above problem, is a water meter in which the cylindrical upper end of a base part, which is connected to a water pipe and through which tap water passes, is overlapped with the lower end of a translucent cap, and an engagement ring is fitted between them from the outside, and the measurement part inside the translucent cap and the translucent cap can be rotated relative to the base part to change the orientation of the flow rate display part on the top surface of the measurement part, and an external detector that detects magnetic changes caused by magnetic components in the measurement part according to the flow rate of tap water and outputs the detection results to the outside is attached to the outside of the water meter, and the water meter has a detector support part that protrudes upward from the engagement ring and supports the external detector in a state where it is overlapped on the translucent cap.

The water meter of claim 2 is the water meter of claim 1, which has a pair of positioning abutment parts provided on the translucent cap and the detector support part, which come into contact with each other when the translucent cap is rotated relative to the engagement ring, thereby positioning the external detector at a specific position relative to the measurement part.

The invention of claim 3 is the water meter according to claim 2, in which the first positioning projection, which is the positioning abutment of the translucent cap, is formed on the outer circumferential surface of the translucent cap, the second positioning projection, which is the positioning abutment of the detector support part, protrudes toward the outer circumferential surface of the translucent cap, and the detector support part is provided with an auxiliary positioning projection that opposes the first positioning projection between itself and the second positioning projection and restricts the first positioning projection from moving away from the second positioning projection, and an elastic support part that supports the auxiliary positioning projection and elastically deforms in the direction away from the outer circumferential surface of the translucent cap to allow the first positioning projection to overcome the auxiliary positioning projection in the direction approaching the second positioning projection.

The invention of claim 4 is the water meter described in claim 3, in which the second positioning protrusion is disposed away from the elastic support portion.

The invention of claim 5 is the water meter described in claim 3, in which the second positioning projection is supported by the elastic support together with the auxiliary positioning projection.

The invention of claim 6 is a water meter according to any one of claims 1 to 5, in which the engagement ring is rotatable relative to the base portion.

The invention of claim 7 is a water meter according to any one of claims 1 to 6, which has the external detector and an elastic body that is fixed to the surface of the external detector facing the translucent cap and is in close contact with the translucent cap.

According to the configuration of claim 1, an external detector can be attached to a type of water meter in which the orientation of the flow rate display section inside the translucent cap can be changed by rotating the translucent cap relative to the base section. Moreover, because the translucent cap can rotate relative to the engagement ring, after the external detector is attached to the water meter, the external detector can be moved and aligned to a position where it is easy to detect the magnetism from the water meter by rotating the engagement ring and the translucent cap relative to each other. This makes it possible to facilitate the assembly work of the water meter, including the alignment of the external detector.

According to the configuration of claim 2, when the translucent cap is rotated relative to the engagement ring, the positioning abutment parts of the translucent cap and the detector support part come into contact with each other, positioning the external detector at a specific position relative to the measurement part, so that the variation in the position of the external detector relative to the measurement part due to assembly is suppressed, and detection by the external detector is stabilized.

In the configuration of claim 3, the auxiliary positioning projection sandwiches the first positioning projection between itself and the second positioning projection, preventing the first positioning projection from moving away from the second positioning projection. This makes it possible to maintain the external detector in a position relative to the measurement unit.

The second positioning protrusion may be disposed away from the elastic support (configuration of claim 4), or may be supported by the elastic support together with the auxiliary positioning protrusion (configuration of claim 5).

In the configuration of claim 6, the engagement ring is rotatable relative to the base portion, so even if the orientation of the flow rate display portion changes, the external detector can be moved and aligned to a position where it is easy to detect the magnetism from the water meter by rotating the engagement ring relative to the base portion. For example, the external detector can be aligned to a position where it is easy to detect the magnetism from the water meter while keeping the flow rate display portion in an orientation that is easy to see. In addition, by rotating the engagement ring relative to the base portion, for example, the orientation of the cable or the position of the antenna of the external detector can be changed, making it possible to increase the degree of freedom in aligning the external detector.

In the configuration of claim 7, an elastic body is fixed to the surface of the external detector facing the light-transmitting cap, and this elastic body is in close contact with the light-transmitting cap, so that it is possible to prevent metal pieces or the like from getting between the external detector and the magnetic component, and it is possible to stabilize detection by the external detector.

FIG. 1 is a front view of a water meter according to an embodiment of the present disclosure. Rear view of water meter Cross-sectional view of a water meter Front view of the lower and upper units with the connecting cover removed Plan view of water meter Perspective view of the upper unit A perspective view of the connecting cover Perspective view of external detector 6 is a cross-sectional view of the water meter taken along line B-B in FIG. A cross-sectional plan view of a water meter in a state in which the upper unit can rotate relative to the engagement ring. A cross-sectional plan view of the upper unit rotated rightward relative to the engagement ring A cross-sectional view of the water meter taken along line A-A in FIG. A cross-sectional plan view of the upper unit rotated right together with the engagement ring FIG. 2A is a bottom perspective view of the cover positioning protrusion and the auxiliary positioning protrusion of the connecting cover; FIG. 2B is a partially cutaway top perspective view of the cover positioning protrusion and the auxiliary positioning protrusion of the connecting cover; (A) is a planar cross-sectional view of a cap positioning protrusion approaching the auxiliary positioning protrusion as the light-transmitting cap rotates to the right; (B) is a planar cross-sectional view of a cap positioning protrusion abutting against the auxiliary positioning protrusion as the light-transmitting cap rotates to the right; (A) is a planar cross-sectional view of a cap positioning protrusion in which the light-transmitting cap rotates to the right to elastically deform the elastic support portion; (B) is a planar cross-sectional view of a cap positioning protrusion that has passed over an auxiliary positioning protrusion and is disposed between the auxiliary positioning protrusion and the cover positioning protrusion; FIG. 11 is a cross-sectional plan view of a cover positioning projection and an auxiliary positioning projection of a water meter according to another embodiment;

1 and 2 show a water meter 10 according to an embodiment of the present disclosure. The water meter 10 has a pair of water pipe connectors 21 connected to a water pipe 99, and has an internal flow path R through which tap water from the water pipe 99 passes, as shown in FIG. 3. The flow rate of the tap water passing through the flow path R is measured by a measuring unit 41 inside the water meter 10, and the integrated flow rate of the tap water is displayed on a flow rate display unit 42 (see FIG. 10) provided on the upper surface of the measuring unit 41. In this embodiment, the water meter 10 is a direct-reading water meter that has an impeller 22 that rotates due to the water flow in the flow path R, and the flow rate is displayed on the flow rate display unit 42 by a number wheel 43 that rotates in conjunction with the impeller 22. Note that the pair of water pipe connectors 21 extend in directions that cross each other (see FIG. 5), but in FIG. 3, they are shown as being arranged in a straight line for ease of explanation.

As shown in Figures 1 and 2, the water meter 10 includes a lower unit 20, an upper unit 40, and a connecting cover 50 that connects them. Note that the connecting cover 50 is appropriately illustrated in gray for easy distinction.

The lower unit 20 includes the pair of water pipe connectors 21, and has the flow path R disposed therein. As shown in Figs. 3 and 4, the lower unit 20 has a cylindrical upper end 23 that protrudes upward and constitutes the upper end of the lower unit 20. In this embodiment, the cylindrical upper end 23 is cylindrical, and the opening of the cylindrical upper end 23 is sealed by a lid 24 that fits inside, blocking the flow path R from above (see Fig. 3). A flow path side magnet 25 is fixed to the upper end of the rotating shaft 22J of the impeller 22, and the flow path side magnet 25 can rotate together with the impeller 22.

As shown in Figs. 4 and 6, the upper unit 40 has a mounting cup 44 and a light-transmitting cap 30 fixed thereon. As shown in Fig. 3, the above-mentioned measuring unit 41 is fixed to the mounting cup 44, and the light-transmitting cap 30 is placed over the measuring unit 41.

The measurement section 41 inside the upper unit 40 has a driven rotating shaft 46, the number wheel 43, and an interlocking mechanism that interlocks them. The driven rotating shaft 46 is arranged coaxially above the rotating shaft 22J of the impeller 22, and has a measurement section side magnet 47 fixed to its lower end. The measurement section side magnet 47 is arranged at a position corresponding to the flow path side magnet 25 that rotates integrally with the impeller 22 of the lower unit 20, and rotates in conjunction with the rotation of the impeller 22. This causes the driven rotating shaft 46 to rotate, and the number wheel 43 is interlocked with this rotation by the interlocking mechanism including multiple gears, etc., so that the integrated flow rate can be displayed on the flow rate display section 42.

The translucent cap 30 is configured so that the flow rate display unit 42 can be seen from the outside. The translucent cap 30 is made of, for example, transparent glass or transparent resin. As shown in Figures 3 and 5, in this embodiment, the translucent cap 30 is configured such that the upper end of the cylindrical outer wall 31 is closed by the ceiling portion 32. The outer wall 31 widens slightly downward, and an annular flange portion 30F protrudes outward from the lower end of the outer wall 31 (i.e., the opening edge portion of the translucent cap 30). The ceiling portion 32 is in the form of a plate that bulges slightly upward.

As shown in FIG. 3, a circular engagement peripheral wall 44G is erected upward on the outer edge of the mounting cup 44. The upper end of the engagement peripheral wall 44G is bent inward of the engagement peripheral wall 44G. The flange portion 30F of the light-transmitting cap 30 and an O-ring 45 are fitted into the engagement peripheral wall 44G from the inside. The O-ring 45 is sandwiched between the flange portion 30F of the light-transmitting cap 30 and the outer edge of the bottom of the mounting cup 44, sealing the space between the light-transmitting cap 30 and the mounting cup 44. This seals the inside of the upper unit 40.

The upper unit 40 is placed on top of the cylindrical upper end 23 of the lower unit 20 (see FIG. 4). At this time, as shown in FIG. 3, the mounting cup 44 of the upper unit 40 is placed on the lid 24 of the lower unit 20, and the open ends of the translucent cap 30 and the cylindrical upper end 23 of the lower unit 20 are placed together. In detail, a circular flange portion 23F protrudes outward from the open end of the cylindrical upper end 23, and the flange portion 30F of the translucent cap 30 is placed together.

As described above, in the water meter 10 of this embodiment, the lower unit 20 and the upper unit 40 are stacked vertically and connected by the connecting cover 50. The connecting cover 50 is provided with an engagement ring 51. In this embodiment, the engagement ring 51 is annular (see Figures 5 and 7) and is fitted into the cylindrical upper end 23 of the lower unit 20 and the translucent cap 30 of the upper unit 40 (specifically, the engagement peripheral wall 44G of the mounting cup 44). In detail, the flange portion 23F of the cylindrical upper end 23 and the flange portion 30F (engagement peripheral wall 44G) of the translucent cap 30 are pressed into the inside of the engagement ring 51.

As shown in FIG. 7, an engagement groove 52 extending in the circumferential direction is formed on the inner peripheral surface of the engagement ring 51. Specifically, the engagement groove 52 is formed on the inner peripheral surface of the engagement ring 51 between an upper end arc-shaped protruding portion 53 protruding from the upper end and a lower end protruding claw portion 54 protruding from multiple points on the lower end. Then, as shown in FIG. 3, when the flange portions 23F, 30F of the cylindrical upper end 23 and the translucent cap 30 are pressed into the engagement ring 51, the flange portions 23F, 30F (specifically, the engagement peripheral wall 44G and the O-ring 45) fit into the engagement groove portion 52 of the engagement ring 51. This connects the lower unit 20 and the upper unit 40.

As shown in FIG. 1, an external detector 80 is attached to the exterior of the water meter 10 of this embodiment. This external detector 80 outputs a signal corresponding to the flow rate of tap water to the outside, making it possible to perform remote meter reading. Specifically, as shown in FIG. 3, in this embodiment, a magnetic component (detection magnet 48) is fixed to the number wheel 43 of the measuring section 41 in the upper unit 40 so as to be able to rotate integrally with it, and the external detector 80 detects the magnetic change caused by the detection magnet 48 corresponding to the flow rate of tap water using a sensor, and outputs the detection result to the outside. For example, the external detector 80 outputs the detection result as a pulse signal by wire or wirelessly. In this embodiment, the external detector 80 outputs the signal through a cable 89.

1 and 2, the external detector 80 is supported in a state overlapping the translucent cap 30 by the detector support part 60 protruding upward from the engagement ring 51. In this embodiment, the detector support part 60 extends to a position above the translucent cap 30, and the external detector 80 is overlapped on the upper surface of the translucent cap 30. In this embodiment, the detector support part 60 protrudes only partially in the circumferential direction of the engagement ring 51, and the external detector 80 is positioned above a position on the upper surface of the translucent cap 30 near the detector support part 60 (see FIG. 5). In addition, the flow rate display part 42 on the upper surface of the measurement part 41 is positioned toward one half of the measurement part 41 when viewed from above (see FIG. 10).

As shown in FIG. 7, the detector support part 60 is provided with an arc-shaped arc wall 62 extending upward from the engagement ring 51, and a curved upper wall 63 extending upward from the upper end of the arc wall 62 and projecting so as to be offset to the inside of the engagement ring 51. The upper wall 63 constitutes the upper end of the detector support part 60, and a boss 64 is formed to protrude upward from one end of the upper wall 63 in the circumferential direction of the engagement ring 51, and a protruding scaffolding part 65 protrudes from a vertical midpoint of the other end of the upper wall 63 to the inside of the engagement ring 51. In addition, a receiving groove part 66 extending in the vertical direction is formed on the inner surface of the root part of the protruding scaffolding part 65 of the other end of the upper wall 63 (see FIG. 14 (A)). Specifically, the receiving groove part 66 extends from the lower end of the upper wall 63 to a position above the upper surface of the protruding scaffolding part 65 (see FIG. 9 and FIG. 14 (A)).

As shown in FIG. 8, the external detector 80 has a flat shape. The thickness direction of the external detector 80 is arranged so as to face the radial direction of the translucent cap, and the external detector 80 overlaps the outer edge of the upper surface of the translucent cap 30 (see FIG. 5). By arranging in this manner, it is possible to prevent the external detector 80 from getting in the way and making the flow rate display unit 42 difficult to see. In this embodiment, a battery that supplies power to the external detector 80 is housed inside the external detector 80. This battery has a vertically elongated shape (e.g., cylindrical, rectangular, plate-like, etc.) and is arranged so that its longitudinal direction is in the up-down direction. Therefore, it is possible to make the external detector 80 compact when viewed from above while securing space for the magnetic sensor arranged near the detection magnet 48 of the number wheel 43, and it is possible to prevent the external detector 80 from making it difficult to see the flow rate display unit 42.

As shown in FIG. 8, a cable 89 extends from one end of the external detector 80 in the lateral direction perpendicular to the thickness direction. A screw hole 80H is formed in a portion of the external detector 80 near one lateral end. A protruding locking portion 82 is formed on the other lateral end of the external detector 80 (the end opposite the cable 89). The protruding locking portion 82 is disposed near the lower end of the external detector 80 and is formed on the surface of the external detector 80 facing the inside of the engagement ring 51 (see FIG. 5). A protrusion 83 protrudes from a position of the other end of the external detector 80 that is shifted outward from the engagement ring 51 relative to the protruding locking portion 82 (see FIG. 5). The upper surface of the protrusion 83 is disposed at a lower position than the upper surface of the protruding locking portion 82 (see FIG. 9).

The external detector 80 is attached to the detector support part 60 as follows. The overhanging locking part 82 of the external detector 80 is placed on the overhanging scaffolding part 65 of the detector support part 60 from above (see FIG. 2). At this time, as shown in FIG. 9, the protrusion 83 of the external detector 80 is received in the receiving groove part 66 of the detector support part 60 and abuts or is placed close to the inner surface of the receiving groove part 66 from below. As a result, the end of the external detector 80 opposite the cable 89 is fixed to the detector support part 60. In addition, the screw hole 80H of the external detector 80 is overlapped on the screw hole of the boss 64 of the detector support part 60 (see FIG. 1), and the end of the external detector 80 on the cable 89 side is screwed to the boss 64. As a result, the external detector 80 is fixed to the detector support part 60. The external detector 80 may be attached to the connecting cover 50 (detector support portion 60) either before or after the connecting cover 50 is attached to the lower unit 20 and upper unit 40 (see FIG. 4).

As shown in FIG. 1, in this embodiment, when the external detector 80 is assembled and placed on the top surface of the translucent cap 30, the external detector 80 and the translucent cap 30 are arranged with a gap between them. An elastic body 88 is fixed to the surface (lower surface) of the external detector 80 facing the translucent cap 30, and this elastic body 88 is in close contact with the translucent cap 30. The elastic body 88 is made of, for example, a foam such as sponge or rubber.

Here, the upper unit 40 can be rotated relative to the lower unit 20. Specifically, the translucent cap 30 and the measuring unit 41 are fixed to the mounting cup 44, and therefore can be rotated integrally with the lower unit 20 around the central axis of the translucent cap 30. Therefore, by rotating the translucent cap 30 relative to the lower unit 20, the orientation of the flow rate display unit 42 on the upper surface of the measuring unit 41 can be changed (see Figures 10 and 11). This allows the flow rate display unit 42 to be positioned in an easily visible orientation, making meter reading easier.

Here, by changing the position of the measuring unit 41 in this way, the position of the detection magnet 48 of the measuring unit 41 changes. In this embodiment, since the upper unit 40 (i.e., the light-transmitting cap 30) is rotatable relative to the connecting cover 50 (i.e., the engagement ring 51), if the position of the external detector 80 does not change, the relative position between the external detector 80 and the measuring unit 41 changes, as shown in the change from FIG. 10 to FIG. 11. As a result, it may become difficult for the external detector 80 to detect changes in the magnetism of the detection magnet 48, and there is a risk of a decrease in detection accuracy. In response to this, the water meter 10 of this embodiment is provided with a positioning mechanism 70 that positions the rotational position of the external detector 80 relative to the measuring unit 41 (see FIG. 16B). In this embodiment, the positioning mechanism 70 is provided with positioning abutment parts that come into contact with each other when the light-transmitting cap 30 rotates relative to the engagement ring 51 and is positioned at a specific rotational position, and these are provided integrally with the light-transmitting cap 30 and the detector support part 60, respectively.

Specifically, as shown in FIG. 6, a cap positioning protrusion 35 is formed on the outer peripheral surface of the translucent cap 30 as the positioning abutment on the translucent cap 30 side. In this embodiment, the cap positioning protrusion 35 is disposed at one location in the circumferential direction of the translucent cap 30, and is a protrusion extending from the lower end of the outer peripheral wall 31 to the boundary between the outer peripheral wall 31 and the ceiling portion 32. When viewed from the axial direction of the translucent cap 30, both side surfaces of the cap positioning protrusion 35 extend in the radial direction of the translucent cap 30. The protruding amount of the cap positioning protrusion 35 is smaller than the protruding amount of the flange portion 30F.

As shown in Figure 7, a cover positioning projection 71 protruding toward the outer peripheral surface of the translucent cap 30 is formed as the positioning abutment portion on the detector support portion 60 side. In addition, an auxiliary positioning projection 72 protruding toward the outer peripheral surface of the translucent cap is also formed at a position aligned side by side with the cover positioning projection 71. As shown in Figures 14(B) and 15(A), the cover positioning projection 71 and the auxiliary positioning projection 72 are aligned so as to face each other in the circumferential direction of the engagement ring 51 (i.e., the circumferential direction of the translucent cap 30). The cover positioning projection 71 and the auxiliary positioning projection 72 have a tapered triangular shape in a plan view, and their opposing surfaces are locking surfaces 71T, 72T extending in the radial direction of the translucent cap 30. In addition, the surfaces of the cover positioning projection 71 and the auxiliary positioning projection 72 that face opposite each other in the opposing direction are inclined surfaces 71K and 72K that taper the projections 71 and 72. It is preferable that the inclined surfaces 71K and 72K are more inclined toward the radial direction of the light-transmitting cap 30 than the locking surfaces 71T and 72T. The cover positioning projection 71 and the auxiliary positioning projection 72 are located at a height closer to the upper end of the arc wall 62 of the detector support part 60.

The cover positioning protrusion 71 is connected to the arc wall 62 of the detector support part 60 by a fixed support part 73. The fixed support part 73 extends along the opposing direction of the arc wall 62 and the light-transmitting cap 30, and in this embodiment, is shorter and thicker than the elastic support part 74 (described below) that supports the auxiliary positioning protrusion 72. The fixed support part 73 also becomes thicker as it moves toward the detector support part 60.

The auxiliary positioning projection 72 is connected to the arc wall 62 of the detector support 60 by an elastic support 74. The elastic support 74 is an elastic piece that extends along the inner circumferential surface of the arc wall 62 (i.e., along the outer circumferential surface of the light-transmitting cap 30). It is preferable that the inclined surface 72K of the auxiliary positioning projection 72 is more inclined than the locking surface 72T with respect to the extension direction of the elastic support 74.

15A shows the positioning mechanism 70 in a state in which the upper unit 40 can rotate relative to the connecting cover 50 as in FIG. 11. In this state, the cap positioning projection 35 is not disposed between the cover positioning projection 71 and the auxiliary positioning projection 72. Here, in the positioning mechanism 70, the upper unit 40 (i.e., the light-transmitting cap 30) is rotated relative to the cover member 50 (i.e., the engagement ring 51) clockwise as viewed from above (hereinafter, appropriately referred to as "right relative rotation"), so that the cap positioning projection 35 is disposed between the cover positioning projection 71 and the auxiliary positioning projection 72 (see FIG. 16B) and can be abutted against the cover positioning projection 71. This allows the light-transmitting cap 30 to be positioned at a specific rotational position relative to the engagement ring 51, and the outer detector 80 to be positioned at a specific position relative to the measurement unit 41 (see FIGS. 12 and 13). By setting the specific position thus determined to a position suitable for the external detector 80 to detect changes in the magnetic field of the detection magnet 48, detection by the external detector 80 can be stabilized.

Specifically, as shown in FIG. 15(A), when the translucent cap 30 is not between the cover positioning projection 71 and the auxiliary positioning projection 72, when the translucent cap 30 is rotated relative to the engagement ring 51 to the right, the cap positioning projection 35 comes into contact with the inclined surface 72K of the auxiliary positioning projection 72, as shown in FIG. 15(B).

Here, when the translucent cap 30 is further rotated to the right, the elastic support 74 elastically deforms so as to move away from the outer peripheral surface of the translucent cap, due to the inclination of the inclined surface 72K relative to the movement direction of the cap positioning projection 35 (see FIG. 16(A)). This allows the cap positioning projection 35 to overcome the auxiliary positioning projection 72 on the side approaching the cover positioning projection 71, and is positioned between the cover positioning projection 71 and the auxiliary positioning projection 72 (see FIG. 16(B)), and abuts against the locking surface 71T of the cover positioning projection 71. In this way, the translucent cap 30 is positioned at a specific rotational position relative to the engagement ring 51, and the external detector 80 is positioned at a specific position relative to the measurement unit 41 (see FIGS. 12 and 13).

In addition, in this position, even if the translucent cap 30 is rotated relatively to the engagement ring 51 counterclockwise when viewed from above (hereinafter referred to as "left relative rotation"), the cap positioning projection 35 abuts against the locking surface 72T of the auxiliary positioning projection 72, so that the cap positioning projection 35 is restricted from moving away from the cover positioning projection 71. Specifically, when the translucent cap 30 is rotated relatively to the left from the specific rotation position to the engagement ring 51, the elastic support portion 74 is less likely to elastically deform, so that the cap positioning projection 35 is less likely to overcome the auxiliary positioning projection 72. In detail, at this time, the locking surface 72T of the auxiliary positioning projection 72 is disposed so as to directly face the side surface of the cap positioning projection 35, and the elastic support portion 74 is in a braced state, so that the elastic support portion 74 is less likely to elastically deform. In this embodiment, the external detector 80 can be held in the above-mentioned specific position (see Figures 12 and 13) relative to the measurement unit 41 in this way. In this state, when the light-transmitting cap 30 is rotated relative to the lower unit 20, the light-transmitting cap 30 and the connecting cover 50 (i.e., the external detector 80) can rotate together (see Figures 12 and 13).

The locking surface 72T of the auxiliary positioning protrusion 72 may be inclined with respect to the radial direction of the translucent cap 30, for example, may be inclined at an angle of 10 degrees or less with respect to the radial direction of the translucent cap 30. In this case, if the locking surface 72T is inclined so as to face the radial inside of the translucent cap 30, even if the cap positioning protrusion 35 abuts against the locking surface 72T and the elastic support portion 74 is elastically deformed so as to move away from the translucent cap 30, it is possible to make the locking surface 72T and the side surface of the cap positioning protrusion 35 directly face each other, and it is possible to make it difficult for the cap positioning protrusion 35 to overcome the auxiliary positioning protrusion 72 when the translucent cap 30 is rotated relatively to the left.

This concludes the explanation of the configuration of the water meter 10 of this embodiment. In this embodiment, the lower unit 20 corresponds to the "base" described in the claims. The cap positioning projection 35 and the cover positioning projection 71 correspond to the "first positioning projection" and "second positioning projection" described in the claims, respectively.

Next, the effects of the water meter 10 of this embodiment will be described. According to the configuration of this embodiment, the external detector 80 can be attached to a type of water meter in which the orientation of the flow rate display unit 42 inside the translucent cap 30 can be changed by rotating the translucent cap 30 relative to the lower unit 20. Furthermore, since the translucent cap 30 can rotate relative to the engagement ring 51, after the external detector 80 is attached to the water meter 10, the external detector 80 can be moved and aligned to a position where it is easy to detect magnetism from the water meter 20 by the relative rotation of the engagement ring 51 and the translucent cap 30. This makes it possible to facilitate the assembly work of the water meter 20, including the alignment of the external detector 80.

In addition, according to the water meter 10 of this embodiment, when the translucent cap 30 is rotated in one direction relative to the engagement ring 51 (right relative rotation), the external detector 80 is positioned at a specific position relative to the measurement unit 41 by the abutment of the positioning abutment parts (cap positioning protrusion 35, cover positioning protrusion 71) of the translucent cap 30 and the detector support part 60, so that the variation in the position of the external detector 80 relative to the measurement unit 41 due to assembly is suppressed, and detection by the external detector 80 is stabilized. In addition, since the above positioning can be achieved by rotating the translucent cap 30 relative to the engagement ring 51 in this way, when the engagement ring 51 is fitted to the translucent cap 30 and the cylindrical upper end 23, it is not necessary to align the translucent cap 30 with a specific rotational position relative to the engagement ring 51, and the fitting operation of the engagement ring 51 is facilitated. In addition, by shifting the light-transmitting cap 30 to a rotational position away from the specific rotational position relative to the engagement ring 51 during this fitting, it is possible to prevent the cap positioning projection 35 and the cover positioning projection 71 or auxiliary positioning projection 72 from interfering with each other and becoming damaged during the above fitting (particularly when press-fitting).

In addition, by providing a positioning abutment in this manner, even if the orientation of the flow rate display unit 42 is changed to an easier-to-see orientation by rotating the light-transmitting cap 30 when checking the flow rate display unit 42, the light-transmitting cap 30 can be easily returned to the specific rotation position thereafter. Here, if a position that makes it easier for the external detector 80 to detect is set as this specific rotation position, it becomes easier to return the light-transmitting cap 30 to the specific rotation position, making it easier to stabilize detection by the external detector 80.

In addition, in this embodiment, the auxiliary positioning projection 72 sandwiches the cap positioning projection 35 between the cover positioning projection 71 and the auxiliary positioning projection 72, preventing the cap positioning projection 35 from moving away from the cover positioning projection 71. This makes it possible to maintain the external detector 80 in a state where it is positioned at a specific position relative to the measurement unit 41.

In addition, the cap positioning projection 35 is sandwiched between the cover positioning projection 71 and the auxiliary positioning projection 72 in the circumferential direction of the light-transmitting cap, so that the light-transmitting cap 30 can be rotated integrally with the engagement ring 51 regardless of the direction of rotation. As a result, even if the light-transmitting cap 30 is rotated to change the position of the measuring unit 41, the external detector 80 can also be moved accordingly to a position suitable for detecting the change in magnetism caused by the detection magnet 48.

In addition, in this embodiment, since the engagement ring 51 is rotatable relative to the lower unit 20, even if the orientation of the flow rate display unit 42 changes, the external detector 80 can be moved and aligned to a position where it is easy to detect the magnetism from the water meter 10 by rotating the engagement ring 51 relative to the lower unit 20. For example, the external detector 80 can be aligned to a position where it is easy to detect the magnetism from the water meter 10 while keeping the flow rate display unit 42 in an orientation where it is easy to see. In addition, by rotating the engagement ring 51 relative to the lower unit 20, for example, the orientation of the cable 89 or the position of the antenna of the external detector 80 can be changed, which increases the freedom of positioning of the external detector 80.

Here, for example, even if the external detector 80 and the light-transmitting cap 30 are designed to be in close contact with each other, a gap may occur between the external detector 80 and the light-transmitting cap 30 due to variations in the shape of the light-transmitting cap 30. In this case, if metal pieces or the like get between the external detector 80 and the light-transmitting cap 30, errors are likely to occur in the detection of magnetic changes by the magnetic component (detection magnet 48). In contrast, in this embodiment, an elastic body 88 is fixed to the surface of the external detector 80 facing the light-transmitting cap 30, and this elastic body 88 is in close contact with the light-transmitting cap 30, so that it is possible to prevent metal pieces or the like from getting between the external detector and the magnetic component, and to stabilize detection by the external detector 80.

In addition, by using the water meter 10 of this embodiment, for example, the signals from each external detector 80 attached to multiple water meters 10 installed in an apartment building, commercial facility, etc. are received by a receiving device, and each flow rate is displayed on a monitor, making it possible to check the flow rate of each water meter 10 in one place without having to go to the installation location of each water meter 10.

[Other embodiments]
(1) In the above embodiment, the engaging ring 51 is rotatable relative to the lower unit 20, but it may be fixed so as not to rotate. Even in this case, by providing a positioning mechanism 70 that positions the rotational positions of the light-transmitting cap 30 and the measuring unit 41 relative to the engaging ring 51, it is possible to position the external detector 80 relative to the measuring unit 41. For example, when a meter reader of the water meter 10 directly checks the flow rate display unit 42, the meter reader can rotate the light-transmitting cap 30 to change the orientation of the flow rate display unit 42 so that it is easy to see, and after checking, return the light-transmitting cap 30 to the specific rotation position, thereby stabilizing the detection accuracy of the flow rate checked by remote meter reading.

(2) In the above embodiment, the cover positioning protrusion 71 was positioned away from the elastic support portion 74, but as shown in FIG. 17, it may be supported by the elastic support portion 74 together with the auxiliary positioning protrusion 72. In the example shown in the figure, whether the translucent cap 30 is rotated relative to the engagement ring 51 to the right or to the left, it is possible to elastically move the elastic support portion 74 away from the translucent cap 30, and it is possible to position the cap positioning protrusion 35 between the cover positioning protrusion 71 and the auxiliary positioning protrusion 72.

(3) The positioning mechanism 70 that positions the external detector 80 relative to the measurement unit 41 may be configured so that the translucent cap 30 and the detector support unit 60 are frictionally fixed at a specific rotational position.

(4) The external detector 80 may be fixed so as to be overlapped on the peripheral surface of the light-transmitting cap 30.

(5) In the above embodiment, the flow rate display unit 42 of the measuring unit 41 was a direct-reading type, but it may be a circular-reading type.

(6) In the above embodiment, only one of the cover positioning projection 71 and the auxiliary positioning projection 72 may be provided. Also, none of the cap positioning projection 35, the cover positioning projection 71, and the auxiliary positioning projection 72 may be provided.

(7) In the above embodiment, the magnetic component that detects the magnetic change according to the flow rate of tap water by the external detector 80 may be, for example, the measurement unit side magnet 47. In this case, for example, the detection magnet 48 may not be provided.

(8) In the above embodiment, when positioning the external detector 80 at a specific position relative to the measurement unit 41, the light-transmitting cap 30 is rotated clockwise relative to the engagement ring 51, but it may be rotated counterclockwise. In this case, for example, the arrangement of the cover positioning protrusion 71 and the auxiliary positioning protrusion 72 in FIG. 15 may be reversed left to right.

Note that although specific examples of the technology included in the scope of the claims are disclosed in this specification and drawings, the technology described in the claims is not limited to these specific examples, but includes various modifications and variations of the specific examples, as well as parts of the specific examples taken separately.

REFERENCE SIGNS LIST 10 Water meter 20 Lower unit 23 Cylindrical upper end 30 Light-transmitting cap 35 Cap positioning projection 41 Measuring section 42 Flow rate display section 51 Engagement ring 60 Detector support section 71 Cover positioning projection 72 Auxiliary positioning projection 74 Elastic support section 80 External detector

Claims (7)

A water meter in which a cylindrical upper end of a base part, which is connected to a water pipe and through which tap water passes, and a lower end of a light-transmitting cap are overlapped with each other and an engagement ring is fitted between them from the outside, and the orientation of a flow rate display part on the upper surface of the measurement part can be changed by rotating the measurement part inside the light-transmitting cap together with the base part,
A water meter having an external detector attached to an external surface thereof for detecting a change in magnetism caused by a magnetic component in the measuring unit in response to a flow rate of tap water and outputting the detection result to an external device,
The water meter includes a detector support portion that protrudes upward from the engaging ring and supports the external detector in a state overlapping the light-transmitting cap. The water meter according to claim 1, which has a pair of positioning abutments provided on the translucent cap and the detector support part, which come into contact with each other when the translucent cap is rotated relative to the engagement ring, thereby positioning the external detector at a specific position relative to the measurement part. The first positioning protrusion, which is the positioning contact portion of the light-transmitting cap, is formed on an outer circumferential surface of the light-transmitting cap,
the second positioning protrusion, which is the positioning contact portion of the detector support portion, protrudes toward an outer circumferential surface of the light-transmitting cap,
The detector support portion includes:
an auxiliary positioning protrusion that faces the second positioning protrusion with the first positioning protrusion sandwiched therebetween and restricts the first positioning protrusion from moving away from the second positioning protrusion;
3. The water meter as described in claim 2, further comprising an elastic support portion that supports the auxiliary positioning protrusion and elastically deforms away from the outer peripheral surface of the translucent cap to allow the first positioning protrusion to overcome the auxiliary positioning protrusion on the side approaching the second positioning protrusion. The water meter according to claim 3, wherein the second positioning protrusion is disposed away from the elastic support. The water meter according to claim 3, wherein the second positioning projection is supported by the elastic support together with the auxiliary positioning projection. The water meter according to any one of claims 1 to 5, wherein the engagement ring is rotatable relative to the base portion. The external detector;
7. The water meter according to claim 1, further comprising: an elastic body fixed to a surface of said external detector facing said light-transmitting cap and in close contact with said light-transmitting cap.

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