JPH0313691Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] This invention relates to an axial flow impeller type water meter equipped with a rectifier.

[Technical background of the invention and its problems]

The basic configuration of a conventional axial impeller water meter is as shown in FIG. 5, for example. That is, in the figure, 1 is a main body, and the main body 1 is provided with an inlet body 2 at one end and an outlet body 3 at the other end. A partition wall 4 that partitions an inflow side and an outflow side is integrally provided in the main body 1, and a communication port 5 is bored in the partition wall 4. A rectifier 7 integrated with the impeller case 6 is provided in the communication port 5. That is, a flange portion 9 is provided on the vessel body 8 of the rectifier 7, and the flange portion 9 is engaged and fixed to the rim of the communication port 5. Further, a rectifying boss 10 is provided concentrically with the axis of the vessel body 8 on the lower side, that is, upstream side of the vertically substantially intermediate portion of the rectifying device 7, and a plurality of rectifying bosses 10 are arranged radially around the outer periphery of the rectifying boss 10. Ribs 11... are integrally provided. Furthermore, a pivot shaft 13 projects perpendicularly from the axis of the rectifying boss 10 with a bush 12 interposed therebetween. And this pivot axis 13
An impeller shaft 14 is rotatably supported on the impeller shaft 14, and an impeller 15 having a plurality of inclined blades is integrally fitted onto the impeller shaft 14. The impeller 15 is adapted to rotate within the impeller case 6. Furthermore, a casing 16 is fitted around the outer periphery of the impeller case 6, and this casing 16 is provided with a plurality of outflow ports 17. Furthermore, a gear case 18 is integrally provided on the upper part of the casing 16, and this gear case 1
8 houses an integration indicating mechanism 19 that is interlocked with the impeller shaft 14. Further, this integration instruction mechanism 19 is connected to a transparent glass 2 provided at the top of the main body 1.
0. Covered by cover 21.

Further, a vessel body 8 of the rectifier 7 and a rectifier boss 10
The flow path 22... between the flow passages 22... is formed to gradually become narrower from the inflow side to the outflow side.
As shown in FIG. 7A, the outer circumferential surface of the rectifying rib 11 is formed to be smooth, and both side surfaces of the rectifying rib 11 are also formed to be smooth as shown in FIG. 7B.

Therefore, the fluid flowing in from the inlet body 2 enters the impeller case through each flow passage 22 of the rectifier 7, and the impeller 15 is rotated by the fluid pressure. The rotation of the impeller 15 is then transmitted to the integration instruction mechanism 19 via the impeller shaft 14, and the fluid flow rate is instructed to integrate. Further, the fluid that has exited the impeller case 6 flows out from the outlet 17 of the casing 16 toward the outlet body 3 .

However, in the conventional axial impeller type water meter, the rectifying boss 10 and the rectifying rib 11 facing the flow path 22 of the rectifier 7 are formed smoothly. Therefore, the fluid flowing through the flow path 22 becomes a uniform flow and flows toward the impeller 15. When the fluid flowing through the flow path 22 becomes a uniform flow, the flow velocity and the rotational angular velocity of the impeller 15 are in a proportional relationship when the flow is large, and accurate measurement is possible, but when the flow becomes minute, the impeller 15 cannot follow the flow velocity. , the measurement will be negative than the actual flow rate and cannot be measured accurately. According to experiments by the creator of this device, as shown by curve A in the instrumental error characteristic diagram in Figure 6, the instrumental error becomes -4% at 50 l/h, and as the flow rate becomes even smaller, the minus instrumental error decreases. To increase.

[Purpose of invention]

This invention was made with attention to the above-mentioned circumstances, and its purpose is to allow the fluid to act effectively on the impeller even at a minute flow rate, and to maintain a proportional relationship between the flow velocity and the rotational angular velocity of the impeller as much as possible. The present invention aims to provide an axial flow impeller type water meter that can maintain even a minute flow rate and improve the performance of the device.

[Summary of the idea]

In order to achieve the above-mentioned object, this invention provides a vortex generation part that protrudes into the flow path of the rectifier on the rectifier boss and rectifier rib provided on the inflow side of the impeller case, and creates a vortex in the fluid flowing through the flow path. The present invention is configured to generate the following effects and to effectively act on the impeller within the impeller case.

[Embodiment of the invention] Hereinafter, this invention will be explained based on an embodiment shown in Figs. 1 to 4. The same components as the conventional axial flow impeller type water meter shown in Fig. 7 will be explained below. are given the same number and the explanation will be omitted. That is, numeral 31 in the figure is a first vortex generating portion provided at the upper edge of the rectifying boss 10, that is, on the downstream side of the flow path 22. The first vortex generating portion 31 is formed by an annular protrusion provided integrally with the rectifying boss 10, and protrudes into the flow passages 22. In addition, the rectifying rib 11
On one side of the upper edge, that is, on the rotational direction side of the impeller 15, a second vortex generating section 32 consisting of a convex strip extending in the longitudinal direction of the rectifying rib 11 and protruding into the flow path 22 is integrally provided. There is. Then, the first,
The second vortex generating portions 31 and 32 are configured to generate a vortex. Therefore, the fluid flowing in from the inlet body 2 enters the impeller case 6 through each flow passage 22 of the rectifier 7, and the impeller 15 is rotated by the fluid pressure. At this time, a part of the fluid passing through the flow passages 22 of the rectifier 7 is transferred to the first and second vortex generating parts 31 and 32.
collides with and generates a vortex. In other words, the laminar flow of the fluid in the passageway 22 turns into a vortex flow, and the impeller 15
It will affect. Therefore, even if the fluid flow rate is minute, it effectively acts on the impeller 15,
The rotational angular velocity of the impeller 15 approaches the flow velocity.

Here, to describe the experimental results of the inventor of this invention, firstly, when the second vortex generating portion 32 is provided only on the rectifying rib 11 of the rectifier 7, the curve B becomes as shown in FIG. At around 200/h, the peak of instrumental error appears as high as about 7%. And 40l/
At h, the instrumental error becomes -4%, indicating an improvement in the instrumental error performance. Furthermore, if the first eddy current generating section 31 is also provided in the rectifying boss 10, a curve C in the same figure is obtained. That is, the instrumental error peaks at 5% around 80 to 150 l/h, and -4% at 35 l/h. Therefore,
Compared to a conventional axial flow impeller type water meter in which the rectifier 7 does not have a vortex generating section, the instrumental error performance can be significantly improved.

[Effect of idea]

As explained above, according to this invention, the flow rate of fluid flowing through the flow path is increased because the vortex generation portions that protrude into the flow path of the flow straightener are provided in the flow straightening boss and the flow straightening rib of the flow straightener provided on the inflow side of the impeller case. Even if the vortex is minute, it can be generated and act on the impeller. As a result, the proportional relationship between the flow velocity and the rotational angular velocity of the impeller can be maintained down to the minute flow rate range.
As shown by curve C in FIG. 5, the instrumental error performance can be greatly improved.

[Brief explanation of the drawing]

Figures 1 to 4 show an embodiment of this invention. Figure 1 is a plan view of the rectifier, Figure 2 is a longitudinal sectional front view of the rectifier, and Figure 3 is a cross section taken along the - line in Figure 1. Figure 4 is a sectional view taken along the - line in Figure 1, Figure 5 is a longitudinal sectional front view of a conventional axial impeller type water meter, Figure 6 is an instrumental characteristic diagram, and Figures 7 A and B. is an enlarged cross-sectional view of the same straightening boss and straightening rib. 1... Main body, 2... Inlet body, 3... Outlet body,
4... Partition wall, 5... Communication port, 7... Rectifier, 8...
... vessel body, 10 ... rectification boss, 11 ... rectification rib,
15... Impeller, 22... Distribution path, 31... First
A vortex generating section, 32... a second vortex generating section.

Claims (1)

[Scope of utility model registration request] A communication port is provided in the partition wall that separates the inflow side and the outflow side of the water meter main body, and a rectifier that rectifies the fluid that flows into the communication port and rotates in response to the fluid pressure of the fluid rectified by the rectifier. In an axial flow impeller water meter equipped with an impeller, the rectifier is comprised of a vessel body, a rectification boss provided at the axis of the vessel body, and a plurality of rectification ribs connecting the rectification boss and the vessel body. A first vortex generating portion having a convex shape protruding into the flow path on the downstream side of the straightening boss is provided integrally with the straightening boss and protruding in the rotation direction of the impeller on the downstream side of the straightening rib. An axial flow impeller type water meter characterized in that a second vortex generating section consisting of a convex strip is provided integrally with a rectifying rib.