JPH06109499A - Fluidic flowmeter - Google Patents

Abstract

PURPOSE:To detect a uniform flow rate and then to achieve an accurate and sensitive flow rate measurement by setting the width of a settling space to be equal to or more than that of a jet nozzle and then providing a flow sensor in parallel with a fluidic vibration surface. CONSTITUTION:A settling space 10 is formed so that a channel is narrowed as compared with a flow-in pipe 1 by one step and then a jet nozzle 4 where the channel is narrowed further by one step via a flow reduction part 4 continues. Namely, the width of the space 10 is set to be more than that of a nozzle 5. Therefore, the flow of a fluid which is introduced from the flow-in pipe 1 is rectified from three-dimensional flow to two-dimensional flow through the space 10. Further, the speed distribution becomes a stable flow due to the flow into the nozzle 5 via the narrow reduction part 4 and the flow is emitted into the channel expansion part 6 from the nozzle 5. Therefore, since a uniform flow rate from the space 10 toward the reduction part 4 is detected by a flow sensor 11, the flow rate can be measured sensitively and accurately.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluidic flow meter used for measuring the flow rate of gas or liquid.

[0002]

2. Description of the Related Art A fluidic flowmeter utilizing fluidic oscillation, which has been developed as an alternative to a conventional membrane gas meter, is small in size and has no moving parts. The research and improvement are being promoted in the field. Further, it is desired that the conventional gas flow meter requires a rising area for installation and is small in size in view of urban aesthetics, regardless of directionality in installation. From this point of view, there is a demand for a compact and high-performance fluidic flowmeter that takes advantage of its features.

As described in general textbooks, the fluidic flowmeter pays attention to the fact that the flow acts to control itself to generate vibrations, and the frequency is proportional to the flow rate. It was used. Such a fluidic flowmeter is disclosed in, for example, Japanese Patent Laid-Open No. 63-13921.
No. 3, Japanese Patent Laid-Open No. 63-139214, etc., the basic configuration and operation will be described with reference to FIG.

A set ring space 3, a flow path contracting section 4, a jet nozzle 5, and a flow path expanding section 6 are provided in this order on the path connecting the inflow tube 1 and the exhaust tube 2, and are guided into the flow path expanding section 6. The pendulum 7 and the end block 8 are provided. Here, such a fluidic flowmeter has a line-symmetrical shape with respect to a straight line connecting the jet nozzle 5 and the exciter 7. The end block 8 has a wall 8a extending toward the upstream side of the flow path so as to cover the pendulum 7,
8b on both sides. A discharge space 9 is formed behind the end block 8.

First, the tubular flow from the upstream side of the flow passage is rectified into a two-dimensional flow in the set ring space 3 and further rectified by the flow passage contracting portion 4 to smoothly flow toward the jet nozzle 5. Then, the jet flow rectified by the jet nozzle 5 is divided into right and left by hitting the exciter 7. However, when the flow exceeds a certain flow rate in the space of the flow path expanding portion 6 up to the end block 8, the exciter 7 is discharged. Due to the instability of the vortex behind it, a left or right biased flow is formed. Therefore, the flow that hits the end block 8 is
Along the inner surfaces of the walls 8a and 8b, it reaches the outlet of the jet nozzle 5 and hits the jet stream at a right angle. Therefore, the direction of the jet flow is biased in the direction opposite to the initial drift by the flow returning from that side. This again causes the same on the other side, with the result that the flow exiting the jet nozzle 5 changes direction of the flow in a regular and alternating manner. The frequency of this regular directional vibration increases linearly with increasing flow rate.

Regarding such a fluidic flowmeter, for example, JP-A-1-308921 and JP-A-4 are available.
According to Japanese Unexamined Patent Publication No. 128611, Japanese Unexamined Patent Publication No. 4-134219, etc., an introduction passage that reduces toward the jet nozzle is formed, and the flow sensor is provided in the throttle channel immediately upstream of the place where fluidic vibration occurs ( It is shown that it is placed in contact with an upper plate or a bottom plate parallel to a fluidic vibrating surface that vibrates two-dimensionally (in a jet nozzle, etc.).

[0007]

However, the provision of the flow sensor in the throttle channel immediately upstream of the place where fluidic vibration occurs disturbs the flow of the ejected fluid and results in stable fluidic vibration. There is a problem that does not occur. Further, a boundary layer is developed at a place called the upper plate or the bottom plate in the throttle channel, and it is not sensitive to disposing the flow sensor in the boundary layer, and the velocity distribution in the boundary layer is There is a problem that an accurate flow rate cannot be measured because it is affected by the velocity of a uniform flow.

[0008]

[MEANS FOR SOLVING THE PROBLEMS] A set ring space for rectifying a flow flowing from an inflow pipe into a two-dimensional flow,
A flow reducing portion for rectification, a jet nozzle, and a flow passage enlarging portion are sequentially provided on the same line, and a pendulum that causes a biased flow is provided at a position facing the jet nozzle in the flow passage enlarging portion. In the fluidic flowmeter in which a return end block is provided at a position behind the exciter in the section and up to the discharge pipe, in the invention according to claim 1, the width of the set ring space is set to the width of the jet nozzle. The flow sensor was set to have a width or more, and a flow sensor was arranged in the center of the flow path of the set ring space in parallel or perpendicular to a fluidic vibrating surface that vibrates two-dimensionally.

On the other hand, according to the second aspect of the present invention, the width of the set ring space is set to be equal to or larger than the width of the jet nozzle, and a fluidic vibrating surface which two-dimensionally vibrates in the center of the flow path of the set ring space. A dividing plate that divides the flow path into two parallel to each other is arranged, and a flow sensor is arranged in the set ring space on the upper plate, the bottom plate, or the upper surface or the lower surface of the dividing plate that is parallel to the fluidic vibration surface. did.

[0010]

According to the present invention, a flow sensor disposed in the center of the flow path of the set ring space in parallel or perpendicular to the fluidic vibration surface detects a uniform flow velocity of the fluid. Therefore, the flow rate can be accurately measured with high sensitivity. Further, since the pressure loss is not increased by installing the flow sensor, the flow rate measurement range can be widened from the low flow rate range to the high flow rate range.

In the invention described in claim 2, claim 1
In addition to the actions of the invention described above, the flow sensor is arranged on the upper surface or the lower surface of the upper plate, the bottom plate or the dividing plate, so that the workability of arranging the sensor is excellent and it is durable even against a high flow rate flow. As a result, the flow meter can be used well and the usage period of the flow meter can be sufficiently satisfied. Furthermore, since the flow path in the settling space is divided into two by the dividing plate, the dividing plate has a rectifying action against the uneven flow of the fluid, and the flow velocity can be increased by devising the thickness of the dividing plate to improve the flow sensor. You can also increase the sensitivity.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the invention described in claim 1 will be described with reference to FIGS. The same parts as those shown in FIG. 7 are designated by the same reference numerals (the same applies to the following embodiments). First, the set ring space 10 of the present embodiment is formed in a shape that narrows a one-step flow path from the inflow pipe 1, and further, in the set ring space 10, the flow path reduction section 4 is formed.
The jet nozzle 5 whose flow path is narrowed by one step is continuous through the. That is, as shown in FIG. 3, when the width of the set ring space 10 (flow passage width) is b and the width of the jet nozzle 5 (flow passage width) is a, b ≧ a. .

As a result, the flow of the fluid introduced from the inflow pipe 1 first passes through the settling space 10 so that the three-dimensional flow is rectified into the two-dimensional flow.
Then, by flowing into the jet nozzle 5 through the narrower flow passage contracting portion 4, the velocity distribution becomes a stable flow and is ejected from the jet nozzle 5 into the flow passage expanding portion 6. Become. After that, the operation described in FIG. 7 is performed.

Therefore, in this embodiment, the flow sensor 11 is arranged in the set ring space 10. However, as shown in FIG. 1, the thickness (upper and lower) of the upper plate 12 and the bottom plate 13 is increased.
It is arranged at the center position in the direction and parallel to the fluidic vibration surface that vibrates two-dimensionally.

According to this structure, since the flow sensor 11 detects the uniform flow velocity of the fluid flowing from the set ring space 10 toward the flow path reducing portion 4, the flow rate is very sensitive and accurate. Can be measured. Further, since the flow sensor 11 is installed, the flow of the fluid ejected from the jet nozzle 5 is not disturbed and the pressure loss is not increased, so that the flow rate measurement range is wide from low flow rate to high flow rate.

Next, a second embodiment of the invention according to claim 1 will be described with reference to FIG. In the present embodiment, the flow sensor 11 is also arranged in the set ring space 10, but at the center position in the flow channel width direction and perpendicular to the fluidic vibrating surface that vibrates two-dimensionally ( Therefore, it is arranged over the upper plate 12 and the bottom plate 13).

Also in the case of the configuration of this embodiment, the same effect as that of the above embodiment can be obtained.

Further, an embodiment of the invention described in claim 2 will be described with reference to FIGS. 5 and 6. In this embodiment, first, the dividing plate 14 is provided in the set ring space 10. The dividing plate 14 is at the center position of the channel width and thickness of the set ring space 10 (the center position in the direction perpendicular to the fluidic vibrating surface), and with respect to the fluidic vibrating surface that vibrates two-dimensionally. They are arranged in parallel and divide the flow path in the set ring space 10 into upper and lower parts, and have a streamline cross section in shape. A flow sensor 15 is provided at the position of the upper plate 12 corresponding to such a dividing plate 14.
Are embedded.

Also in the case of the structure of this embodiment, the flow sensor 15 detects the uniform flow velocity of the fluid.
The flow rate can be measured accurately. In particular, the flow velocity of the fluid flowing through the flow sensor 15 portion can be increased by not only rectifying the uneven flow of the fluid by the dividing plate 14 itself but also changing the thickness thereof, so that the sensitivity of the flow sensor 15 is improved. It is also easy to raise. Furthermore, the flow sensor 1
By disposing 5 in the upper plate 12, the disposition workability is excellent and the durability is high even for a high flow rate flow, and the period of use as a flow meter is sufficiently satisfied. You will get it.

The flow sensor 16 may be provided on the bottom plate 13 side as shown in FIG. 6, or may be provided on the upper surface or the lower surface of the dividing plate 14.

Further, in these embodiments, the flow path is reduced in two stages by the set ring space 10 and the flow path reduction section 4 in the process of ejecting the fluid introduced from the inflow pipe 1 from the jet nozzle 5. However, the present invention is not limited to this, and the width of the flow passage may be narrowed in multiple stages.

[0022]

Since the present invention is configured as described above, according to the invention of claim 1, the width of the set ring space is set to be not less than the width of the jet nozzle, and
Since the flow sensor is arranged parallel or perpendicular to the fluidic vibrating surface that vibrates two-dimensionally in the center of the flow path of the settling space, the flow sensor can detect a uniform flow velocity of the fluid. Therefore, the flow rate can be accurately measured with high sensitivity, and the pressure loss is not increased by installing the flow sensor. Therefore, the flow rate measurement range can be widened from the low flow rate range to the high flow rate range.

According to the second aspect of the invention, in addition to the effect of the first aspect of the invention, the flow sensor is arranged on the upper surface or the lower surface of the upper plate, the bottom plate or the dividing plate. The workability is excellent and the durability is high even for high flow rate flow, and the flow meter can be used for a sufficient period of time. Since the path is divided into two, the dividing plate has a rectifying action against the uneven flow of the fluid, and the flow velocity can be increased by increasing the thickness of the dividing plate to increase the sensitivity of the flow sensor.

[Brief description of drawings]

FIG. 1 is a vertical sectional front view of a main part showing a first embodiment of the invention according to claim 1.

FIG. 2 is a horizontal sectional view showing the overall structure of a fluidic flow meter.

FIG. 3 is a horizontal sectional view of a main part.

FIG. 4 is a vertical sectional front view showing a second embodiment of the invention according to claim 1;

FIG. 5 is a horizontal sectional view showing an embodiment of the invention described in claim 2.

FIG. 6 is a vertical sectional front view thereof.

FIG. 7 is a horizontal sectional view showing a general fluidic flow meter structure.

[Explanation of symbols]

 1 Inflow pipe 2 Discharge pipe 4 Flow reduction part 5 Jet nozzle 6 Flow expansion part 7 Pendulum 8 End block 10 Set ring space 11 Flow sensor 12 Upper plate 13 Bottom plate 14 Dividing plate 15, 16 Flow sensor

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Yuko Oshima Inc. 1-3-6 Nakamagome, Ota-ku, Tokyo Within Ricoh Co., Ltd. (72) Inventor Hiroyuki Horiguchi 1-3-3 Nakamagome, Ota-ku, Tokyo Stocks Inside Ricoh Company (72) Zenichi Akiyama 1-3-6 Nakamagome, Ota-ku, Tokyo Within Ricoh Co., Ltd. (72) Inventor Makoto Tanabe 1-3-6 Nakamagome, Ota-ku, Tokyo Within Ricoh Company (72) Inventor Yoshio Ishii 1-3-6 Nakamagome, Ota-ku, Tokyo, Ricoh Co., Ltd. (72) Inventor Tatsuo Miyaji 1-3-6 Nakamagome, Ota-ku, Tokyo (72) Invention Toshiyuki Takamiya 6-16-10 Minamioi, Shinagawa-ku, Tokyo Ricoh Seiki Co., Ltd. (72) Inventor, Hiroshi Onda 2-28-24 Izumi 2-chome, Higashi-ku, Nagoya, Aichi Prefecture Ricoh Elementary School Box in the Corporation

Claims (2)

[Claims] 1. A set ring space for rectifying a flow flowing from an inflow pipe into a two-dimensional flow, a rectifying flow passage reducing portion, a jet nozzle, and a flow passage expanding portion are sequentially provided on the same line, An exciter for causing a non-uniform flow is provided at a position facing the jet nozzle in the enlarged flow passage, and an end block for return is provided at a position behind the exciter in the enlarged flow passage to reach the discharge pipe. In the fluidic flow meter, the width of the set ring space is set to be equal to or larger than the width of the jet nozzle, and the fluid is set parallel or perpendicular to a fluidic vibrating surface that two-dimensionally vibrates in the center of the flow path of the set ring space. A fluidic flowmeter characterized by having a flow sensor. 2. A set ring space for rectifying a flow that flows in from an inflow pipe into a two-dimensional flow, a flow reduction portion for rectification, a jet nozzle, and a flow passage expansion portion are sequentially provided on the same line, An exciter for causing a non-uniform flow is provided at a position facing the jet nozzle in the enlarged flow passage, and an end block for return is provided at a position behind the exciter in the enlarged flow passage to reach the discharge pipe. In the fluidic flow meter, the width of the set ring space is set to be equal to or larger than the width of the jet nozzle, and the flow is parallel to the fluidic vibrating surface that two-dimensionally vibrates in the center of the flow path of the set ring space. A dividing plate that divides the path into two is provided, and a flow sensor is provided on the upper plate, the bottom plate, or the upper surface or the lower surface of the dividing plate that is parallel to the fluidic vibration surface in the set ring space. A fluidic flowmeter characterized by being installed.