JPS623620A - Axial-flow impeller type flowmeter - Google Patents

Abstract

PURPOSE:To improve the state of the instrumental error for counterflow without damaging that for normal flow by constituting an impeller storage case and a flow rate display mechanism storage case as bodies independent of each other and providing one of them and the other with ribs and plate-shaped pieces as one body respectively. CONSTITUTION:A liquid A introduced from a flow inlet is rectified by guide blades to become a jet and rotates the impeller to measure the flow rate. Plural ribs 15... are provided on the peripheral part of the upper face of an impeller storage case 2 as one body, and plate-shaped pieces 17... are provided in the peripheral part of the lower face of the flow rate display mechanism storage case as one body. In the normal flow state, the liquid A goes to a flow outlet 7b while being rectified along slopes 15a... formed on one side faces of ribs 15... to improve the instrumental error. In the counterflow state, a liquid A' collides against plate-shaped pieces 17..., and the flow going in the direction of an arrow C by step parts 16... and that in the direction of an arrow B collide with each other and the flow in the direction of an arrow B' turned by plate-shaped pieces 17... and that in the direction of an arrow B'' collide with each other to swirl the liquid, and turning flow of the counterflow liquid A' is prevented to improve the state of the instrumental error.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an axial impeller type flowmeter used, for example, in a water meter, and its purpose is to:
It is possible to improve the condition of instrumental error during reverse flow without impairing the condition of instrumental error during forward flow, and moreover, it is possible to optimally open the instrumental error during reverse flow according to the model, and furthermore, it is compact. An object of the present invention is to provide an axial impeller type flowmeter that can be easily applied to other axial impeller type flowmeters.

To achieve the above object, the axial impeller type flowmeter of the present invention has a plurality of ribs provided at predetermined intervals on the circumference between the upper surface of the impeller housing case and the lower surface of the flow rate display mechanism housing case. The impeller housing case and the flow rate display mechanism housing case are configured separately, and the rib is integrally provided on one of these housing cases, and the rib is integrally provided on the other housing case. A plate-like piece is integrally provided to protrude toward the rib, and this plate-like piece is detachably provided on the outer surface of the rib with a stepped portion on one side.

The present invention will be described below based on an embodiment shown in FIGS. 1 to 5.

FIG. 1 shows a vertical axial flow impeller type flowmeter, which has a central part divided into two upper and lower chambers by a partition file, and an inlet lower chamber connected to the lower chamber at both ends. a and an outflow lower b extending from the upper chamber, a rectifier 1 disposed within the lower case 7, and an impeller 3 disposed within an impeller housing case 2.

The rectifier l is constructed by engaging and fixing a cylindrical frame-shaped case 1b to an opening protruding from the partition wall 7C of the lower case 7.
A boss body IC having a pivot shaft 12 projecting upward is arranged at the center of the case 1b, and a plurality of guide blades 1a (six in this embodiment) are pivoted between the case 1b and the boss body IC. They are arranged radially around the axis 12.

A predetermined distance is ensured between the lower surface of the rectifier 1 and the bottom wall portion 7d of the lower case directly below it, so that the liquid A introduced into the lower case 7 from the inflow lower a is guided below the rectifier 1. After being tilted, the guide vanes ta... can be passed through and raised.

An impeller 3 is rotatably provided directly above the rectifier 1, and as shown in FIG.
The impeller housing case 2 is housed in an impeller housing case 2 that is concentrically attached to the upper surface of the case 1b, with its lower portion rotatably supported by the pivot shaft 12. therefore,
The liquid A introduced under the rectifier 1 and passed through the guide vanes 1a... subsequently passes through the impeller 3 and flows out to the outflow lower b of the lower case 7, and the flow of this liquid A causes the impeller 3 to It is designed to be rotated.

Further, above the impeller housing case 2, a flow rate display mechanism housing case 14 is provided separately from the impeller housing case 2, and the upper part of the impeller 3 is rotatably supported in the housing case 14. At the same time, a flow rate display mechanism is provided that converts the flow rate of the liquid A into the rotation of the impeller 3 and displays the result. This flow rate display mechanism has the same structure as a known one, so the details are omitted, but the rotation of the impeller 3 is transmitted to the pointer 5 via the gear group 4, and the amount of rotation of the pointer 5 is transmitted to the scale plate B. It is constructed so that the flow rate of liquid A can be displayed by reading the flow rate. The scale plate 6 is located facing a window hole opened in the upper surface of the center part of the lower case 7, and is covered with a glass plate 8 of the upper case 10 attached to the opening of the lower case 7. ing. Note that an openable and closable upper lid 11 is attached to the upper case 10, and covers the scale plate 8 and the glass plate 8.

Further, in this embodiment, the guide vanes 1a...
An appropriate number of them (three in this example) are divided into upper and lower halves as shown in Fig. 1, and the upper body blade part 1 is
a'... in case 1 in the same way as the other guide vanes 1a...
b and the boss body IC, and the lower movable blades 1a'' are supported by the case tb and the boss body 1c so as to be rotatable by a predetermined amount around the pivot shaft 12.

That is, each rotary blade portion 1a'' is positioned circumferentially offset from the position where it overlaps the main body blade portion 1a' (the position in FIG. 2) with respect to the main body blade portion la° (for example, the position in FIG. 3). The movable blade portion 1a'' is configured so that it can be rotated to a certain position), and can be fixed at any position within a certain rotation range.Therefore, the movable blade portion 1a''... is shown in FIG. By shifting the guide blades 1a' to a position where they do not overlap with the main body blades 1a', the guide blades 1a...
・The direction of the liquid flow to the impeller 3 can be changed by changing the torque (rotation speed) of the impeller 3.
can be changed to perform instrumental adjustment.

Therefore, from the inflow lower a of the lower case 7 to the strainer 13
The liquid A introduced below the rectifier 1 through the guide vanes of the rectifier l! The flow is rectified by rising along the direction a..., hits the impeller 3 in the impeller storage case 2 as a jet, and rotates the impeller 3 so that the amount of rotation corresponds to the flow rate of liquid A. let The rotation of the impeller 3 rotates the pointer 5 via the gear group 4, and the flow rate of the liquid A is measured by reading the position of the pointer 5 on the scale plate 8.

Incidentally, in such a flowmeter, a plurality of ribs 15 are integrally provided at predetermined intervals on the upper circumference of the impeller housing case 2, as shown in FIGS. 4 and 5. ing. This rib 15... is an inclined surface 15 whose side surface is inclined at an acute angle from the inner tip to improve instrumental error during normal flow.
a, and the other side surface is also inclined at an acute angle to form an inclined surface 15b. On the other hand, as shown in the figure, a triangular plate-shaped piece (
Embodiment) Alternatively, although not shown in the drawings, a rectangular, semicircular, etc. plate-like piece 17 is provided integrally. and,
The plate-shaped pieces 17 are removably provided by press-fitting their inner surfaces into the outer surfaces of the ribs 15, as shown in FIG. In addition, the plate-like piece 17...
is provided on the outer surface of the rib 15..., a stepped portion IB... is formed on the -blade side thereof.

With this configuration, when the liquid A is in a normal flow state from the inflow 07a of the lower case 7 to the outflow lower b of the lower case 7, the liquid A that has passed through the impeller 3 will be.

As shown in FIG. 5, the water flows toward the outflow lower b of the lower case 7 while being rectified in one direction along the inclined surfaces 15a formed on the negative sides of each rib 15. Therefore, due to the rectification effect of the inclined painters 5a, the instrumental error in the normal flow state can be flattened, and the measurement error can be effectively improved.

On the other hand, if the instrumental error during normal flow is improved in this way, the inflow port of the lower case 7 will be changed from the outflow lower b of the lower case 7 to the inflow port of the lower case 7. In the case of a backflow state toward a, the backflow liquid A' is on the contrary
If too much turning force is applied in the direction along the flow direction, the impeller 3 will be rotated more than necessary, which will worsen the condition of instrumental error during backflow. However, in this case, Junryo division
Since the plate-like piece 17 and the stepped portion 1B... are provided,
The backflow liquid A' in the upper part of the figure collides with the plate-shaped pieces 17 and then moves in the direction of arrow C by the steps 16, and the flow in the direction of arrow C and the flow in the direction of arrow B are separated. collide with each other to form a vortex state, and it is possible to prevent the flow of the backflow liquid A' from exerting too much swirling force.

On the other hand, the backflow liquid A° at the bottom of the figure is the plate-shaped piece 17...
The flow in the direction of the force of arrow B° whose direction has been changed by the direction of arrow B'' collides with the flow in the direction of arrow B'', creating a vortex state, which can also suppress the swirling flow of the backflow liquid A°.Therefore, 1 No more rotational force than necessary is applied to the impeller 3,
This makes it possible to effectively improve the state of instrumental error during backflow.

In addition, a comparison experiment was conducted between the vertical impeller type flowmeter having the configuration of the above embodiment and the conventionally used vertical impeller type flowmeter having the inclined rib 100 shown in the WIIG diagram, that is, a comparison experiment of instrumental error characteristics. When I tried this, I got results like the graph shown in Figure 7. According to this, with the conventional system, as the flow rate increased, the instrumental error during reverse flow moved toward the positive side, and there was a large gap between the instrumental error during forward flow, but in the case of the system to which the present invention is applied, It was confirmed that even when the flow rate increased, there was no large gap between the reverse flow and the forward flow, and good instrumental error characteristics were obtained both during the reverse flow and the forward flow.

As described above, although the present invention has a very simple configuration, its effects are outstanding and it can fully meet the international standards for instrumental differences between forward and reverse flows that have recently been required.

Moreover, with the configuration of the present invention, since the plate-like piece is removable from the outer surface of the rib, the attachment of the plate-like piece to the outer surface of the rib can be done by appropriately setting the position to maintain the instrumental error during backflow. It is extremely convenient because it can be set to the optimal instrument error condition for other models with different types, and it can also be easily applied to small vertical axial flow impeller type flowmeters that have space constraints. can.

It should be noted that the present invention is not limited to the configuration of the above-mentioned embodiment. For example, as shown in FIG. 8, four ribs 15 are arranged in the circumferential direction, and on both sides of each rib It can also be applied to objects without sloped surfaces. Even with ribs like this,
This is because if there is a structural change in the structure of the impeller housing case, the structure of the lower case, or any other part, a case may occur if too much rotational force is applied to the impeller during backflow. Furthermore, in the above embodiment, the rib was integrally provided in the impeller housing case, and the plate-like piece was integrally provided in the flow rate display mechanism housing case, but
Of course, the ribs and the plate-shaped piece may be provided integrally in the reverse state, but in any case, the present invention is applicable to all axial flow impeller type flowmeters having ribs.

[Brief explanation of drawings]

Figures 1 to 4 show an embodiment of the present invention. Figure 1 is a vertical cross-sectional view of a vertical axial impeller flowmeter. Figure 2 is a bottom view of a rectifier. Figure 3 is a bottom view of the rectifier. FIG. 4 is a front view showing the impeller storage case and the flow rate display mechanism storage case, and FIG. 5 is a sectional view of the main parts along the v-v line in FIG. 1. , Fig. 6 is a sectional view of the main part corresponding to Fig. 5 showing a conventional rib, and Fig. 7 shows the results of a comparative test between the rib to which the present invention is applied and the conventional rib, using measured values and a diagram. , FIG. 8 is a sectional view of a main part corresponding to FIG. 5, showing another embodiment of the present invention. 2... Impeller housing case 14... Flow rate display mechanism housing case 15... Rib 1B... Step portion 17... Plate-shaped piece Patent applicant Toko Seiki Co., Ltd. Agent Patent attorney Takashi Suzue Figure 4 (Figure 8) Flag for writing amendments to procedures) October 11, 1985 Commissioner of the Japan Patent Office Academic Award Resignation Mr. 2 Name of the invention Axial flow impeller type flow meter 3 Person making the amendment Relationship to the case Patent applicant Toko Seiki Co., Ltd. 4, Agent

Claims (1)

[Claims] In an axial impeller type flowmeter in which a plurality of ribs are provided at predetermined intervals on the circumference between the upper surface of the impeller storage case and the lower surface of the flow rate display mechanism storage case, the impeller storage case and the flow rate display mechanism are provided. The storage case is configured separately, one of these storage cases is integrally provided with the rib, and the other is integrally provided with a plate-like piece that projects outward from the outer surface of the rib, and An axial impeller type flowmeter characterized in that the plate-like piece is removably provided on the outer surface of the rib with a stepped portion on one side.