JPS5836015Y2 - water meter - Google Patents

Description

[Detailed description of the invention] This invention aims to improve the instrumental error (error/positive value) in the measurement range from small flow velocities to large flow velocities in vertical Waltmann type or similar water meters. This was achieved by devising the shape of the impeller's inflow and outflow tips.

Conventional large-diameter impeller-type water meters are broadly divided into tangential-flow impeller types, which are suitable for small flow velocities, and axial-flow impeller types, which are suitable for large flow velocities. Vertical Waltmann type water meters, which allow water to flow from the bottom to the top and extend the measurement range from high flow velocities to very low flow velocities, are increasingly being used to improve durability and instrument error.

However, further improvement is desired.

The present invention addresses this problem, and the shape of the inlet side of the Waltmann type impeller has a small curve in the direction of strengthening the impeller's lead, and the tip is also pointed, and the shape of the outlet side impeller is In this method, a small protrusion, such as a bent flange, is provided on the side surface of the blade that is exposed to the water flow, and it has been found that this significantly improves the instrumental error in the range of not only small flow velocities but also large flow velocities.

The present invention will be described in detail below according to examples.

Generally, a vertical Waltmann water meter is constructed as follows.

In FIG. 1, 1 is an outer case, 2 is an inlet, 3 is an outlet, and 4 is a rectifier to prevent disturbance of water flow, which is equipped with a regulator.

5 is a cylindrical impeller case, and 6 is an indicator mechanism section for displaying the flow rate, which is mainly composed of a gear train.

7 is a glass case containing reinforced glass, which is screwed into the outer case 1.

For example, 8 is a Waltmann-type impeller with 6 and 8 leads and blades extending outward, 9 is a pivot type bearing made of sapphire with a spherical surface, and 9' is a pivot made of ebonite and phosphor bronze. be.

10 is a bearing integral with the impeller, 11 is an impeller shaft, 12 is an upper metal portion, 13 is an impeller gear (pinion), and 14 is a strainer.

To explain this measurement method, the water flow passes through the strainer 14 from the inlet 2, rises vertically from the bottom of the outer case 1, passes through the rectifier 4, and flows into the impeller case, forming spiral blades. Flowing in from the axial direction of the Waltmann type impeller 8,
The blades are rotated and the water flows out from the outlet 3.

The rotation speed of the impeller is proportional to its passing volume,
This rotation is interlocked with an indicating mechanism by a pinion 13 on the upper part of the impeller shaft 11, and is brought to a predetermined reduction ratio by a gear train, and the passing volume is indicated by a needle hole or a visual method.

Here, in order to improve the instrumental error at micro flow speeds, the impeller is made of synthetic resin to reduce weight, and the bearing part is equipped with a pivot bearing 9 to reduce rotational friction and improve rotation at micro flow speeds. .

As shown in Fig. 2, the conventional impeller has a spiral blade 22 with 6 or 8 blades per body 21 of the impeller shaft, and the length is 1/6 or 178 of a pinch. A Waltmann-type vane with the shape of can be used.

As shown in Fig. 3, in order to further improve the measurement at minute flow rates compared to the one shown in Fig. 2, the present invention is designed to change the shape of the tip of each blade on the inflow side (lower side) of the blade 23 as shown in the figure. R radius 10-201R1 in the direction that strengthens the curve (inclination) of the lead
The blade is extended in the shape of a curved line L, and its tip 24
It was made to protrude 2 to 4 mm from the reed crab, and the tip 24' was shaped to be pointed.

The purpose of the present invention cannot be achieved by simply chamfering the tip of an ordinary reed.

Furthermore, on the outflow side (upper side), there is a small 1
A convex portion 25 (a protruding portion from the reed curve) approximately as large as a bolt was provided to improve instrumental error at high flow speeds.

If these are explained using the actually measured instrument difference curve in Figure 4,
The solid line A indicates the conventional performance, and it can be seen that the instrumental error decreases in small areas, and that the large area also has characteristics that tend to decrease compared to the average value.

On the other hand, based on the present invention, the tip portion 24 is located on the inflow side of the impeller.
By configuring the shape with , the measurement range at minute flow velocities was extended as shown by the broken line B, and the instrumental error in the minute flow velocity region was improved.

In addition, by providing the convex portion 25 on the outflow side, the shape becomes as shown by the one-dot broken line C, which eliminates the decrease in instrumental error in the large flow area and improves the instrumental error.

Previous measurements have shown that this idea is effective.

The present invention can also be applied to a turbine-type flow rate type impeller, which has the same shape as the Waltmann type impeller.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view of a vertical Waltmann water meter, Figure 2
Figure A 1 is a plan view and side view of a conventional Waltmann type impeller, Figure 3 A 1 is a plan view and side view of an impeller according to an embodiment of the present invention, and Figure 4 is a plan view and side view of a conventional Waltmann type impeller. It is a comparative explanatory diagram of the instrumental difference between the conventional product and the conventional product. 1...Outer case, 2...Inflow port, 3.
... Outlet, 4 ... Rectifier, 5 ...
... Impeller case, 6... Display mechanism section, 8...
...Waltmann type impeller, 9...Pivot type bearing, 9'...Pivot, 23...
...Blade, 24...Tip bent and extended in a direction that strengthens the curve of the lead of the blade, 25...
·protrusion.

Claims (1)

[Scope of utility model registration request] In the impeller of the vertical Waltmann type water meter or similar type water meters, the shape of the inlet side (lower end) of the impeller has a small curve in the direction of strengthening the lead of the impeller, and the impeller protrudes from the lead curved surface of the impeller. A water meter equipped with a Waltman type impeller or a similar type impeller with a pointed tip and a small protrusion on the side surface of the impeller on the outlet side where the water flow hits.