JP2571609Y2 - Fluidic 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 a 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.

In a fluidic flow meter, an ejection nozzle is provided on the inlet side of a flow path. When a fluid is ejected from the ejection nozzle into the flow path, the ejected fluid flows, for example, along the right side wall due to the Coanda effect. A part of the fluid flowing to the right side wall becomes 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, and then flows to the left side wall. A part of the returned fluid becomes a return fluid, and the fluid energy of the return fluid is applied to the jet fluid, and the jet 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.

Incidentally, a conventional fluidic flow meter is configured as shown in FIG. That is, 11
Is the 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 at the lower part of the case body 12.
4 and a gas outlet 15 are arranged side by side, and a fluidic element 17 and a shutoff valve 18 described later are installed inside the case 11.

The fluidic element 17 will be described. Reference numeral 23 denotes a flow passage main body formed by die casting or the like.
The flow path 26 is configured by being closed by the lid 25 through the cover 4.

The flow passage 26 is vertically divided by a partition wall 27, the upstream flow passage 28 communicates with the gas inlet 14, and the downstream flow passage 29 communicates with the gas outlet 15. A partition wall 22 integral with or separate from the flow path main body 23 is provided in the middle of the upstream flow path 28.
Partition on the way.

A valve seat 30 is provided on the partition wall 22, and a valve body 31 of the shut-off valve 18 fixed to the flow path main body 23 is opposed to the valve seat 30. That is, when a pressure switch, a seismic sensor, or the like (not shown) detects an abnormality, a shut-off signal is input to the shut-off valve 18, the shut-off valve 18 is operated, and the valve body 31 is pressed against the valve seat 30, and the upstream side The configuration is such that the flow path 28 can be shut off.

The ejection nozzle 3 is provided on the partition wall 27 of the flow path main body 23.
2 are provided. The jet nozzle 32 is connected to the passage main body 2.
3 has a protruding portion 32a, 32b protruding into the upstream flow path 28 on both side edges in the longitudinal direction, and extends the length of the nozzle passage.

A first target 33 for stabilizing the switching of the flow direction of the fluid is provided in the downstream flow path 29 facing the ejection nozzle 32. Side walls 34a and 34b are provided symmetrically on both sides of the first 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 29 is further provided downstream. Is provided. Return passages 37a, 37b are formed outside the side walls 34a, 34b, and discharge passages 38a,
38b are provided.

Therefore, when the fluid is ejected from the ejection nozzle 32 toward the downstream flow path 29, the ejected fluid flows, for example, along the inside of the right side wall 34a by the Coanda effect.

Most of the fluid flowing to the right side wall 34a goes to the discharge passage 38a, but a part of it becomes return fluid and goes to the return passage 37a. The fluid energy of the return fluid is applied to the ejected fluid, and the ejected fluid is supplied to the left side wall 34.
b, and a part of the fluid that has flowed to the left side wall 34b becomes return fluid, and the fluid energy of this return fluid is applied to the ejected fluid, and the ejected fluid returns to the right side wall 34a. Will flow along the inside of the. That is, the configuration is such that an alternating pressure wave is generated by the vibration phenomenon of the fluid ejected from the ejection nozzle 32 into the downstream flow path 29.

Further, a flow sensor for measuring a minute flow rate region and a piezoelectric film sensor (not shown) for measuring a large flow rate region are provided on the side surface of the flow path main body 23 corresponding to the jet nozzle 32. Is provided.

By the way, conventionally, the shut-off valve 18 is attached to the flow path main body 23 as shown in FIG. 4 (a) or 4 (b). That is, in FIG. 4A, an annular groove 49 is provided in the valve mounting portion 47 of the flow path main body 23 so as to surround the cylindrical portion 48, and the annular groove 49 is provided with an O as a gas seal material.
The ring 50 is housed.

Then, the flange portion 18a of the shutoff valve 18 is joined to the valve mounting portion 47, and the flange portion 18a is fastened to the valve mounting portion 47 with a plurality of bolts 51, thereby fixing the shutoff valve 18 to the flow path main body 23. doing.

FIG. 4B shows that a cork seat packing 52 as a gas seal material is joined to the valve mounting portion 47 of the flow path main body 23, and the flange portion 18 a of the shut-off valve 18 is connected via the cork seat packing 52. The shutoff valve 18 is fixed to the flow path main body 23 by being joined to the valve mounting portion 47 and tightening the flange portion 18a to the valve mounting portion 47 with a plurality of bolts 51.

[0019]

As described above, the shut-off valve 18 is fixed to the flow path main body 23 through the O-ring 50 or the cork seat packing 52, and is fixed in a gas-sealed state. Has little impact damping effect,
For example, when an external impact is applied to the case 11 of the flow meter, the impact force is transmitted to the shutoff valve 18 via the flow path main body 23.

The shut-off valve 18 is constituted by a self-holding solenoid, and a movable iron core is magnetically attracted to a permanent magnet, and a valve element 31 provided integrally with the movable iron core is held in an open state. When a pressure switch, a seismic sensor, or the like (not shown) detects an abnormality, a shut-off signal (reverse magnetic field) flows through the exciting coil, and the exciting coil separates the movable iron core from the permanent magnet. To shut off the upstream flow path 28. Therefore, when an impact is applied to the shutoff valve 18 from the outside, the movable iron core separates from the permanent magnet, and the valve body 31 may malfunction in the valve closing direction.

The present invention has been made in view of the above circumstances. The purpose of the invention is to absorb the impact force even if an external impact is applied to the case of the flowmeter, and the shut-off valve malfunctions. It is an object of the present invention to provide a highly reliable fluidic flow meter.

[0022]

According to the present invention, in order to achieve the above object, a partition is provided in a flow path main body constituting a flow path and divided into an upstream flow path and a downstream flow path, The flow path main body is provided with a shutoff valve for opening and closing the middle of the upstream flow path, and the partition wall is provided with a jet nozzle for jetting fluid of the upstream flow path to the downstream flow path, and a fluidic is provided in the downstream flow path. In the fluidic flow meter provided with the element, the shut-off valve is attached to a valve attaching portion of the flow path main body via a high impact absorbing elastic body.

When an external impact is applied to the flow path main body through the case or the like, the impact force is absorbed by the high impact absorbing elastic body, so that malfunction of the shutoff valve in the valve closing direction can be prevented.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described hereinafter with reference to the drawings. FIG. 1 shows a first embodiment. Channel body 2
The annular groove 5 is formed in the valve mounting portion 47 so as to surround the cylindrical portion 48.
The annular groove 53 accommodates a high shock absorbing elastic body 54 such as high elastic rubber having a gas sealing function. The high-impact-absorbing elastic body 54 is a ring having a rectangular cross section, and its height is formed such that about half of the height in the non-compressed state protrudes from the end face of the valve mounting portion 47. Have been. Further, a screw hole 55 is formed in the valve mounting portion 47 located outside the annular groove 53.

On the other hand, a bolt insertion hole 56 is formed in the flange portion 18a of the shut-off valve 18 in correspondence with the screw hole 55, and a bolt 57 is inserted in the bolt insertion hole 56.
The bolt 57 is fitted with an elastic washer 58 and a washer 59 made of a high-impact absorbing elastic body.

The flange portion 18a of the shut-off valve 18 is joined to the valve mounting portion 47 via the high impact absorbing elastic body 54, and the bolt 57 is inserted into the bolt insertion hole 56 of the flange portion 18a.
Into the screw hole 5 of the valve mounting portion 47.
5, the shut-off valve 18 is connected to the flow path main body 23.
It is fixed to.

In FIG. 1, (a) shows the state before bolt tightening.
(B) shows the state after the bolt is tightened, and the high impact absorbing elastic body 54 is compressed by the tightening force of the bolt 57, but the valve mounting portion 47 and the flange 1 are also compressed against the maximum tightening force.
It is desirable that a gap 60 be formed between the first and second members 8a. Also,
Since the elastic washer 58 is pressed against the flange portion 18a via the washer 59 at the head of the bolt 57 by tightening the bolt 57, metal contact between the flange portion 18a and the washer 59 is avoided.

Therefore, even if an external impact is applied to the flow path main body 23 through the case 11 or the like, the impact is absorbed by the high impact absorbing elastic body 54 and the elastic washer 58, and the impact is directly cut off. The signal is not transmitted to the valve 18 and the malfunction of the shutoff valve 18 in the valve closing direction can be prevented. Note that the elastic washer 58 is not necessarily provided, and the high-impact-absorbing elastic body 54 alone can sufficiently absorb the impact.

FIG. 2 shows a second embodiment. Channel body 23
A high-impact elastic body 61 having an annular shape and a large thickness is joined to the valve mounting portion 47 so as to surround the cylindrical portion 48, and an outer peripheral portion thereof is fastened to the valve mounting portion 47 by a plurality of bolts 62. Fixed. A plurality of screw holes 63 are formed in the inner peripheral edge of the high impact absorbing elastic body 61.

On the other hand, a bolt insertion hole 64 is formed in the flange portion 18a of the shutoff valve 18 in correspondence with the screw hole 63, and a bolt 65 is inserted in the bolt insertion hole 64.
The flange portion 18a is provided with a high shock absorbing elastic body 61.
And the bolt 65 is fastened and fixed to the screw hole 63 of the high shock absorbing elastic body 61, and the flange portion 18 a of the shutoff valve 18 is fixed to the valve mounting portion 47 via the high shock absorbing elastic body 61. .

Therefore, even if an external impact is applied to the flow path main body 23 via the case 11 or the like, the impact is absorbed by the high impact absorbing elastic body 61 and the impact is directly transmitted to the shutoff valve 18. The shut-off valve 18 can be prevented from malfunctioning in the valve closing direction.

[0032]

As described above, according to the present invention, the shut-off valve is attached to the valve mounting portion of the flow path main body via the high shock absorbing elastic body, so that the shut-off valve is externally mounted on the case of the flow meter. Even if a shock is applied, a highly reliable fluidic flowmeter can be provided in which a high shock absorbing elastic body absorbs a shock force and the shut-off valve does not malfunction.

[Brief description of the drawings]

FIG. 1 is a vertical sectional side view showing a mounting structure of a shut-off valve of a fluidic flow meter according to a first embodiment of the present invention.

FIG. 2 is a vertical sectional side view showing a shut-off valve mounting structure of a fluidic flow meter according to a second embodiment of the present invention.

FIG. 3 is a partially cutaway front view of a conventional fluidic flow meter.

FIG. 4 is a vertical sectional side view showing a conventional fluidic flowmeter shutoff valve mounting structure.

[Description of Signs] 17: Fluidic element, 18: Shutoff valve, 22: Partition wall, 23: Flow path main body, 26: Flow path, 27: Partition wall, 28
... Upstream channel, 29 ... Downstream channel, 31 ... Valve, 32 ...
Spout nozzle, 47: Valve mounting part, 54, 61: High impact absorbing elastic body.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hideyuki Oike 1-3-2 Shimura, Itabashi-ku, Tokyo Inside Kinmon Manufacturing Co., Ltd. (56) References JP-A-4-50724 (JP, A) JP-A-Hei 4-134219 (JP, A) JP-A-4-145327 (JP, A)

Claims (1)

(57) [Scope of request for utility model registration] 1. A flow path main body constituting a flow path is provided with a partition wall to divide the flow path into an upstream flow path and a downstream flow path, and the flow path main body is provided with a shut-off valve for opening and closing the middle of the upstream flow path. In a fluid flow meter provided with an ejection nozzle for ejecting a fluid in an upstream flow path to a downstream flow path in the partition wall, and a fluid flow element provided in the downstream flow path, A fluidic flowmeter, wherein the fluidic flowmeter is mounted on a valve mounting portion of the above through a high impact absorbing elastic body.