JP2010243442A - Impeller type water meter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an impeller type water meter for improving instrumental error performance at a large flow rate region and accurately integrating volume. <P>SOLUTION: The impeller type water meter includes: a case body 1 including an inflow-port body 2 and an outflow-port body 3; a lower inner case 4 that is provided inside the case body 1, has an inflow passage 5 communicating with the inflow-port body 2 and an outflow passage 6 communicating with the outflow-port body 3 at an outer periphery, and forms a metering chamber 7 including an impeller 8 at an inner periphery; an inflow nozzle 9 that is provided on a peripheral wall at the inner periphery of the lower inner case 4, communicates with the inflow passage 5, and is open toward the impeller 8 inside the metering chamber 7; and a weir 16 that is provided at a peripheral wall of the inner periphery of the lower inner case 4, and is formed to nearly the same diameter as the outer diameter of the impeller 8 while projecting inside from an outlet 9a of the inflow nozzle 9. One portion of fluid flowing into the metering chamber 7 via the inflow nozzle 9 from the inflow passage 5 is guided to a lower side of the metering chamber 7 by the weir 16. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an impeller-type water meter in which an impeller rotatably supported in a measuring chamber rotates by receiving a fluid force entering the measuring chamber from an inlet body.

  An impeller-type water meter that displays the amount of consumption of tap water in an integrated manner is known from Patent Document 1, for example. This water meter has an inner case in which an inflow passage communicating with the inflow body and an outflow passage communicating with the outflow body are formed in the outer periphery of the case body, and a measuring chamber having an impeller is formed in the inner periphery. Is provided.

  An inflow nozzle communicating with the inflow passage is provided on the peripheral wall of the inner case, and an outflow nozzle communicating with the outflow passage is provided on the upper wall of the inner case. And it is comprised so that the fluid which approached into the measurement chamber via the inflow nozzle from the inflow passage may rise inside the measurement chamber and flow out from the outflow nozzle.

  An upper part of the case body is provided with an indicator mechanism chamber that is isolated from the weighing chamber. The rotation of the impeller is converted into a volume via a magnet coupling and gears, and is integrated and displayed on the indicator mechanism in the indicator mechanism chamber. Has been.

JP 2003-83781 A

  However, the conventional impeller-type water meter described in Patent Document 1 is rotatably supported in a state where the upper end of the main shaft of the impeller is in contact with the bottom surface of the indicating mechanism chamber. Then, after the fluid flowing in from the inflow nozzle on the lower side of the measuring chamber acts on the impeller, it flows out from the outflow nozzle on the upper side of the measuring chamber. For this reason, when the flow velocity is fast (large flow rate), the impeller is pushed up by the fluid, and the pressing force of the upper end of the main shaft against the bottom surface of the indicating mechanism chamber increases. Further, when the flow speed is increased, the rotational speed of the impeller is increased, and the upper end of the main shaft and the bottom surface of the indicating mechanism chamber are worn. For this reason, there is a problem that the contact area between the upper end of the main shaft and the bottom surface of the indicating mechanism chamber becomes large, resulting in rotation resistance of the impeller, and the accuracy of integrating the volume of fluid passing through the water meter is deteriorated.

  The present invention has been made paying attention to the above circumstances, and its object is to provide an impeller-type water meter that can improve the instrumental error performance particularly in a large flow rate region and can accurately calculate the volume. There is.

In order to solve the above-mentioned object, the present invention provides a case body having an inlet body and an outlet body, an inflow passage provided inside the case body and communicating with the inlet body on an outer peripheral portion, and the outlet port. An inner case having an outflow passage communicating with the body and having a measuring chamber having an impeller on an inner peripheral portion thereof, and provided on a peripheral wall of the inner peripheral portion of the inner case, communicated with the inflow passage, and the measuring chamber An inflow nozzle that opens toward the impeller inside the inner case, and a peripheral wall in the inner peripheral portion of the inner case, and protrudes inward from the outlet of the inflow nozzle and is formed to have substantially the same diameter as the outer diameter of the impeller. And weir
The impeller-type water meter is characterized in that a part of the fluid flowing into the measuring chamber from the inflow passage through the inflow nozzle is guided to the lower side of the measuring chamber by the weir.

  A second aspect of the present invention is characterized in that the weir of the first aspect is located below a lower end edge of the impeller blade, and an inner peripheral surface thereof is formed in a cylindrical shape.

  According to a third aspect of the present invention, the weir according to the first aspect has an upper surface that is flush with a bottom surface of an inflow nozzle provided in the inner case and an inner peripheral surface that is perpendicular to the upper surface. .

  According to the present invention, even if the flow rate becomes large, a part of the fluid flowing into the measuring chamber via the inflow nozzle can be guided to the lower side of the measuring chamber by the weir, and the rotational resistance of the impeller is reduced. The pressing force upward of the main shaft is reduced. Accordingly, there is an effect that durability is improved, instrumental performance is improved particularly in a large flow rate region, and volume can be accurately integrated.

The longitudinal section side view of the impeller-type water meter which shows the 1st Embodiment of this invention. The longitudinal section side view of the inner case which shows the embodiment. The perspective view of the inner case which showed the same embodiment and was cut along the AA line of FIG. Instrumental difference performance curve diagram. Instrumental difference performance curve diagram.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

1 to 3 show a first embodiment, FIG. 1 is a longitudinal side view of an impeller-type water meter, FIG. 2 is a longitudinal side view of an inner case, and FIG. 3 is taken along line AA in FIG. It is a perspective view of the inner case which carried out the cross section.
As shown in FIGS. 1-3, the inflow body 2 is provided in the one end side of the case main body 1 of an impeller-type water meter, and the outflow body 3 is provided in the other end side. A cylindrical lower inner case 4 is provided inside the case body 1. Inside the case main body 1, an inflow passage 5 through which a fluid such as tap water circulates is provided at the outer peripheral portion of the lower inner case 4 at the lower portion thereof, communicating with the inlet body 2. Inside the case main body 1, an outflow passage 6 communicating with the outflow port body 3 is provided on the outer peripheral portion of the upper portion of the lower inner case 4.

  A measuring chamber 7 is provided inside the lower inner case 4, and an impeller 8 that rotates under the fluid pressure of the fluid is provided in the measuring chamber 7. A plurality of inflow nozzles 9 are provided in a tangential direction from the inflow passage 5 toward the measuring chamber 7 in the lower part of the peripheral wall 4 a of the lower inner case 4. An outflow nozzle 10 that opens from the measuring chamber 7 toward the outflow passage 6 is provided at an upper portion of the peripheral wall 4 a of the lower inner case 4.

  A boss 11 is provided at the center of the bottom of the lower inner case 4, and a pivot shaft 12 that protrudes toward the center of the measuring chamber 7 is fixed to the boss 11. The impeller 8 is rotatably fitted to the pivot shaft 12. The impeller 8 is composed of a main shaft 13 fitted to the pivot shaft 12 and a plurality of blades 14 projecting radially from the main shaft 13, and a driving side magnet 15 constituting a magnetic coupling is provided at the upper end portion of the main shaft 13. It is fixed.

  Note that the drive-side magnet 15 is in contact with the bottom surface 30 a of the upper inner case 30 and is opposed to the driven magnet 31 on the upper surface side of the upper inner case 30 as in the prior art. The driven magnet 31 is interlocked with an integration instruction mechanism 33 including a counter via a gear mechanism 32.

  A weir 16 is integrally provided on the inner peripheral portion of the peripheral wall 4a of the lower inner case 4 so as to protrude from the outlet 9a of the inflow nozzle 9 toward the inner side (center portion of the measuring chamber 7). The upper surface 16 a of the weir 16 is flush with the bottom surface of the inflow nozzle 9 and is located slightly below the blade lower end edge 14 a of the impeller 8. Further, the weir 16 has an inner peripheral surface 16b perpendicular to the upper surface 16a. The inner peripheral surface 16b is formed in a cylindrical shape along the blade lower end edge 14a of the impeller 8. The weir 16 serves to guide a part of the fluid flowing into the measuring chamber 7 from the inflow passage 5 through the inflow nozzle 9 to the lower side of the measuring chamber 7. That is, the fluid that has flowed into the measuring chamber 7 from the inflow passage 5 through the inflow nozzle 9 rises while swirling inside the measuring chamber 7 and flows out from the outflow nozzle 10. A part of the fluid that has flowed into 7 is guided to the lower side of the measuring chamber 7 to reduce the force with which the impeller 8 is pushed up together with the main shaft 13.

  Therefore, the amount of force that the driving magnet 15 provided at the upper end of the main shaft 13 of the impeller 8 presses against the bottom surface 30a of the upper inner case 30 is reduced, and the rotational resistance of the impeller 8 is reduced. As a result, particularly in a large flow rate region, even if the rotational speed of the impeller 8 increases, the rotational resistance decreases and the instrumental error performance can be improved.

  The impeller-type water meter thus configured has an upstream side connected to a water main or the like, and a downstream side connected to a faucet or the like via a water pipe. When the tap is opened and tap water flows out of the tap, tap water flows from the inlet body 2 into the measuring chamber 7 of the lower inner case 4 through the inflow passage 5 in the case body 1. The impeller 8 and the main shaft 13 in the measuring chamber 7 rotate around the pivot shaft 12 by the fluid pressure of the tap water. The rotation of the main shaft 13 is transmitted from the drive-side magnet 15 to the driven-side magnet 31, and the rotation of the driven-side magnet 31 is transmitted to the integrating instruction mechanism 33 via the gear mechanism 32, and the fluid flow rate is instructed to the integrating instruction mechanism 33. .

  At this time, the fluid flowing into the measuring chamber 7 from the inflow passage 5 via the inflow nozzle 9 rises while swirling inside the measuring chamber 7 and flows out from the outflow nozzle 10. A part of the fluid flowing into the chamber 7 can be guided to the lower side of the measuring chamber 7.

  Therefore, the amount of force that the driving magnet 15 provided at the upper end of the main shaft 13 of the impeller 8 presses against the bottom surface 30a of the upper inner case 30 is reduced, and the rotational resistance of the impeller 8 is reduced. As a result, particularly in a large flow rate region, even if the rotational speed of the impeller 8 increases, the rotational resistance decreases and the instrumental error performance can be improved.

Table 1 shows the initial performance and instrument performance after durability in a conventional impeller-type water meter that does not have the weir 16 in the lower inner case 4, and No1 to No3 are impeller-type waterworks for testing. It is a meter.

  FIG. 4 shows an instrumental difference performance curve in which Table 1 is graphed. The curve (solid line) shows the instrumental difference curve of the initial performance, and the curve (broken line) shows the instrumental difference curve after endurance. As is apparent from FIG. 4, the instrumental difference is large and the durability performance is poor.

Table 2 shows the initial performance and instrumental performance after endurance of the impeller water meter of the present invention in which the lower inner case 4 is provided with the weir 16. No1 to No3 are impeller water meters for testing. It is.

  FIG. 5 shows an instrumental difference performance curve in which Table 2 is graphed. The curve (solid line) shows the instrumental difference curve of the initial performance, and the curve (broken line) shows the instrumental difference curve after endurance. As is apparent from FIG. 5, it can be seen that the instrumental difference is small, the durability performance is greatly improved, and the volume conversion accuracy is improved.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. Moreover, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, the constituent elements over different embodiments may be combined.

DESCRIPTION OF SYMBOLS 1 ... Case main body, 2 ... Inlet body, 3 ... Outlet body, 4 ... Lower inner case, 5 ... Inflow passage, 6 ... Outflow passage, 7 ... Measuring chamber, 8 ... Impeller, 9 ... Inflow nozzle, 10 ... Outflow nozzle, 16 ... weir

Claims (3)

A case body having an inlet body and an outlet body;
An inner case that is provided inside the case body and has an inflow passage that communicates with the inflow body and an outflow passage that communicates with the outflow body at the outer periphery, and a measuring chamber that has an impeller at the inner periphery. When,
An inflow nozzle that is provided on a peripheral wall of the inner peripheral portion of the inner case, communicates with the inflow passage, and opens toward an impeller inside the measuring chamber;
It is provided on the peripheral wall of the inner peripheral portion of the inner case, and includes a weir that protrudes inward from the outlet of the inflow nozzle and is formed to have substantially the same diameter as the outer diameter of the impeller.
An impeller-type water meter characterized in that a part of the fluid flowing into the measuring chamber from the inflow passage through the inflow nozzle is guided to the lower side of the measuring chamber by the weir.   The impeller-type water meter according to claim 1, wherein the weir is located below the lower edge of the blade of the impeller, and an inner peripheral surface thereof is formed in a cylindrical shape.   The impeller-type water supply according to claim 1, wherein the weir has an upper surface that is flush with a bottom surface of an inflow nozzle provided in the inner case and an inner peripheral surface that is perpendicular to the upper surface. Meter.

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