JP3272082B2 - Fluid flow meter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid flow meter for detecting a flow rate by detecting an alternating pressure wave generated by a vibration phenomenon of a fluid such as gas ejected from an ejection nozzle into a flow path.

[0002]

2. Description of the Related Art A fluidic flow meter installed in a general household or the like for measuring a gas flow rate is disclosed in, for example,
It is known from JP-A-313018 and JP-A-1-250725.

[0003] In this fluidic flow meter, an ejection nozzle is provided in a partition partitioning an upstream side flow path and a downstream side flow path of the flow path, and a fluidic element provided in the downstream flow path from the ejection nozzle is provided. When the fluid is ejected, the ejected fluid flows, for example, along the right side wall due to the Coanda effect.

[0004] A part of the fluid flowing to the right side wall becomes a return fluid, and the fluid energy of the return fluid is applied to the ejected fluid, so that the ejected fluid flows along the left side wall. A part of the fluid flowing to the side wall becomes a return fluid, and the fluid energy of the return fluid is applied to the ejection fluid, so that the ejection fluid flows again along the right side wall.

That is, an alternating pressure wave is generated by the vibration phenomenon of the fluid ejected from the ejection nozzle into the flow path. The alternating pressure wave is detected by the piezoelectric film sensor, and the flow rate is calculated from the frequency to detect the flow rate of the fluid.

That is, the fluidic flow meter is shown in FIGS.
It is configured as shown in FIG. 11 is a case. The case 11 includes a rectangular box-shaped case body 12 and a lid 13 that closes an opening of the case body 12.

The gas inlet 1 is located above the case body 12.
4 is provided, and a gas outlet body 15 is provided at a lower portion. A fluidic element 17 described below is installed in a lower portion inside the case 11, and a shutoff valve 18 is installed in an upper portion.

Reference numeral 19 denotes a flow passage main body formed by die casting or the like. A side opening 19a is provided on one side surface of the flow passage main body 19, and the side opening 19a is covered by a packing 20 as a sealing material. The channel 21 is closed by the body 21. This flow path 22 is a partition 2
3, the upstream flow path 24 communicates with the gas inlet body 14, and the downstream flow path 25 communicates with the gas outlet body 1.
5 is connected.

A valve seat 26 is provided in the middle of the upstream flow passage 24, and the valve body 27 of the shut-off valve 18 faces the valve seat 26. That is, the flow path 22 can be shut off by the shut-off valve 18 when the seismic sensor or the like detects an abnormality.

A jet nozzle 28 is provided integrally with the partition wall 23 of the flow path main body 19. The jet nozzle 28 has a slit shape that opens over the entire depth direction of the flow path main body 19, and has protrusions 28 a and 28 b that protrude into the upstream flow path 24 on both side edges in the longitudinal direction thereof. The passage length is extended. Further, a side opening 29 that opens in the same direction as the side opening 19 a of the flow path main body 19 is provided on one side surface of the ejection nozzle 28.

Further, a first target 33 for stabilizing the switching of the flow direction of the fluid is provided in the downstream flow path 25 facing the outlet side of the jet nozzle 28. On both sides of the first target 33, the side walls 34a, 3
4b are provided symmetrically.

Further, a second target 35 is provided at a central portion located downstream of the first target 33, and a return wall 36 extending in the width direction of the downstream flow path 25 is provided further downstream. Is provided. Return passages 37a, 37b are formed outside the side walls 34a, 34b, and discharge passages 38a,
38b are provided.

As described above, the side opening 19a of the flow path main body 19 is formed.
And the side opening 29 of the ejection nozzle 28
The cover 21 is closed and fixed to the flow path main body 19 by a plurality of tightening screws 30.

[0014]

By the way, the flow path main body 1
9 and the side opening 2 of the jet nozzle 28
The structure in which 9 is closed and sealed by the lid 21 via the packing 20 cannot be reliably sealed unless it is strongly tightened by the tightening screw 30.

However, when the tightening screw 30 is tightened by a strong tightening force, the packing 20 at the portion facing the side opening 29 of the jet nozzle 28 swells and jets because the packing 20 is formed of an elastic material such as rubber. It will bite into the inside of the nozzle 20. As a result, there is a problem that the opening cross-sectional area of the ejection nozzle 28 is reduced, which affects the pressure loss and causes variation in instrumental performance.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a fluidic flow meter capable of suppressing variations in instrumental performance without deteriorating sealing performance. It is in.

[0017]

According to the present invention, in order to achieve the above object, a first aspect of the present invention has a side opening on one side, and the side opening is closed by a lid via a sealing material. A flow path main body constituting a flow path, a partition provided in the flow path main body and dividing the flow path into an upstream flow path and a downstream flow path, and detachably provided on the partition. An ejection nozzle having a side opening closed on one side by a lid via the sealing material, and a fluidic flow meter including a fluidic element provided in the downstream flow path, wherein the ejection nozzle has The invention is characterized in that a cover plate having rigidity for closing the side opening is provided integrally, and the sealing material is joined to a side surface of the cover plate.

A second aspect of the present invention resides in that the side opening of the ejection nozzle provided integrally with the partition is closed by a separate rigid covering plate, and the sealing material is joined to the side surface of the covering plate.

According to a third aspect of the present invention, in the fluidic flow meter having the ejection nozzle provided integrally with the fluidic element, a separate rigid cover plate for closing at least a side opening of the ejection nozzle is provided in the flow path main body. The sealing material is joined to the side surface of the cover plate.

[0020]

The side opening of the ejection nozzle provided on the partition or the fluidic element is closed by a rigid cover plate, so that the packing does not bite into the ejection nozzle, and the opening cross-sectional area of the ejection nozzle is maintained constant. It can eliminate variations in instrumental differences.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described hereinafter with reference to the drawings.

FIGS. 1 and 2 show the first embodiment, in which a jet nozzle 41 is provided separately from the partition wall 23 of the flow path main body 19. An upstream flow path 24 is provided in a part of the partition 23.
And a notch portion 42 that communicates with the downstream flow path 25,
The ejection nozzle 41 is detachably fitted in the notch 42.

The jet nozzle 41 is formed by die-casting or synthetic resin, and has a slit-shaped nozzle hole 44 which is long in the depth direction of the flow path main body 19 in the nozzle main body 43. Cover plates 45a and 45 for closing the side opening 41a of the nozzle hole 44 are provided at the upper and lower portions.
b is provided integrally.

By fitting the ejection nozzle 41 into the notch 42 of the partition wall 23, the lower cover plate 45b is joined to the bottom surface of the notch 42, and the upper cover plate 45a closes the opening of the notch 42. It is designed to be flush with the partition wall 23.

When the side opening 19a of the flow path main body 19 is closed by the lid 21 via the packing 20,
The packing 20 is joined to the upper surface of the cover plate 45a, and the flow path 22 of the flow path main body 19 is sealed. Therefore, the packing 20 does not bite into the ejection nozzle 41,
By maintaining the opening cross-sectional area of the ejection nozzle 41 constant, it is possible to eliminate variations in instrumental differences.

FIGS. 3 and 4 show a second embodiment, in which a partition wall 2 of a flow path main body 19 formed by die casting or the like.
3 is provided with an ejection nozzle 46 integrally. The ejection nozzle 46 has a slit-shaped nozzle hole 47 that opens long in the depth direction of the flow path main body 19.
Is provided with a side opening 48 that opens in the same direction as the side opening 19 a of the flow path main body 19.

Recesses 49 are formed at both side edges of the side opening 48 of the ejection nozzle 46.
A cover plate 50 closing the cover 8 is fitted. The cover plate 50 is made of a rigid material such as a metal plate, for example, and has a thickness equal to the depth of the recess 49, and is designed such that the cover plate 50 is flush with the partition wall 23.

When the side opening 19a of the channel body 19 is closed by the lid 21 via the packing 20,
The packing 20 is joined to the upper surface of the cover plate 50, and the flow path 22 of the flow path main body 19 is sealed. Therefore, the packing 20 does not bite into the ejection nozzle 46, and the opening cross-sectional area of the ejection nozzle 46 is kept constant, so that the variation in instrumental difference can be eliminated.

FIGS. 5 and 6 show a third embodiment, in which a fluidic element 51 separate from the flow path main body 19 is incorporated in the flow path main body 19. Fluidic element 51
Is formed integrally by die casting or synthetic resin, etc., and a base 52 incorporated in the downstream flow path 25 is provided with a first target 33 for stabilizing the switching of the flow direction of the fluid in the same manner as in the prior art. Side walls 34a and 34b are provided symmetrically on both sides of one target 33.

Further, a second target 35 is provided at a central portion located downstream of the first target 33, and a return wall 36 extending in the width direction of the downstream flow path 25 is provided further downstream. Have been. Return passages 37a and 37b are formed outside the side walls 34a and 34b, and discharge passages 38a and 3b are formed outside both ends of the return wall 36.
8b are provided.

An ejection nozzle 53 is provided integrally with the base 52 of the fluidic element 51, and the ejection nozzle 53 is fitted in a notch 54 provided in a part of the partition wall 23. The ejection nozzle 53 has a slit-shaped nozzle hole 55 that opens long in the depth direction of the flow path main body 19, and has a side opening that opens in the same direction as the side opening 19 a of the flow path main body 19. 56 are provided.

Concave portions 57 are formed on both side edges of the side opening 56 of the ejection nozzle 53, and the side opening 5 is formed in the concave portion 57.
A cover plate 58 closing the cover 6 is fitted. The cover plate 58 is made of a rigid material such as a metal plate, for example, and has the same thickness as the depth of the concave portion 57, and is designed so that the cover plate 58 is flush with the partition wall 23.

When the side opening 19a of the flow path main body 19 is closed by the lid 21 via the packing 20,
The packing 20 is joined to the upper surface of the cover plate 58, and the flow path 22 of the flow path main body 19 is sealed. Therefore, the packing 20 does not bite into the ejection nozzle 53, and the opening cross-sectional area of the ejection nozzle 53 can be maintained constant, so that variations in instrumental differences can be eliminated.

In the third embodiment, the cover plate 58
Is not limited to closing only the side opening 56 of the ejection nozzle 53, and may be a structure that covers the entire fluidic element 51.

[0035]

As described above, according to the present invention, the side opening of the ejection nozzle provided in the flow path main body or the fluidic element is closed by the cover plate. There is an effect that the bite is eliminated, the cross-sectional area of the opening of the ejection nozzle can be kept constant, the variation in instrumental difference can be eliminated, and the performance of the fluidic element can be further improved.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a jet nozzle of a fluid flow meter according to a first embodiment of the present invention.

FIG. 2 is a vertical side view of the ejection nozzle of the embodiment.

FIG. 3 is an exploded perspective view showing a jet nozzle of a fluid flow meter according to a second embodiment of the present invention.

FIG. 4 is a vertical sectional side view of the ejection nozzle of the embodiment.

FIG. 5 is a longitudinal sectional front view showing the internal structure of a fluidic flow meter according to a third embodiment of the present invention.

FIG. 6 is a partially cutaway side view of the fluidic flow meter of the embodiment.

FIG. 7 is a front view showing the internal structure of a conventional fluidic flow meter.

FIG. 8 is a partially cutaway side view of the fluidic flow meter.

FIG. 9 is a sectional view of an ejection nozzle portion of the fluidic flow meter.

[Explanation of symbols]

17, 51 ... fluidic element, 19 ... flow path body, 2
0: Packing, 21: Lid, 22: Channel, 23: Partition, 24: Upstream channel, 25: Downstream channel, 41, 4
6, 53 ... ejection nozzle, 41a, 48, 56 ... side opening, 45a, 50, 58 ... cover plate.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Naoshi Isshiki 1-2-3 Shimura, Itabashi-ku, Tokyo Kinmon Seisakusho Co., Ltd. (56) References Patent 2709203 (JP, B2) Patent 2854352 (JP, B2) ( 58) Field surveyed (Int. Cl. ⁷ , DB name) G01F 1/20

Claims (3)

(57) [Claims] 1. A flow path main body having a side opening on one side and closing the side opening with a lid via a sealing material to form a flow path, and a flow path provided in the flow path main body. An ejection nozzle having a partition partitioning into an upstream flow path and a downstream flow path, and a side face opening detachably provided to the partition and separately closed on one side by a lid via the sealing material. And a fluidic flow meter comprising a fluidic element provided in the downstream flow path, wherein the ejection nozzle is provided with a cover plate having rigidity for closing the side opening integrally therewith, and a side surface of the cover plate. A fluid meter, wherein the sealing material is joined to the fluid meter. 2. A flow path body having a side surface opening on one side surface, the side surface opening being closed by a lid via a sealing material to form a flow path, and the flow path provided in the flow path main body. A partition partitioning into an upstream flow path and a downstream flow path, an ejection nozzle provided integrally with the partition and having a side opening closed on one side by a lid via the sealing material, In a fluidic flow meter comprising a fluidic element provided in a passage, a cover plate having a separate rigidity for closing a side opening of a jet nozzle is provided on the partition, and the sealing material is joined to a side surface of the cover plate. Fluid flow meter characterized by the following. 3. A flow path body having a side surface opening on one side surface, the side surface opening being closed by a lid via a sealing material to form a flow path, and the flow path provided in the flow path main body. A partition partitioning into an upstream flow path and a downstream flow path, a fluidic element provided in the downstream flow path, and a lid body provided integrally with the fluidic element and having one side surface provided with the sealing material therebetween. In the fluidic flow meter comprising an ejection nozzle having a side opening closed by, a cover plate having a separate rigidity for closing at least the side opening of the ejection nozzle is provided in the flow path main body, and a side surface of the cover plate is provided. A fluidic flowmeter, wherein the sealing material is joined.