JPH11311553A - Vibrating fluid flowmeter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vibrating fluid flowmeter having two-dimensional channel of high profile in which manufacturing cost can be reduced. SOLUTION: The fluid flowmeter has two-dimensional channels having a constant dimension in the height direction, i.e., a nozzle channel 210 and a downstream side channel 220, and a target standing in the height direction of the two-dimensional channel on the extension of the nozzle channel 210 in the downstream side channel 220 and detects flow rate based on the fluid of a jet flow ejected from the nozzle channel 210 to the downstream side channel 220. The target comprises a first target 31 falling from the lower surface of the two-dimensional channel and a second target 32 having lower end face 32a from the upper surface of the two-dimensional channel and abutting against the upper end face 31a of the first target 31.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid vibration type flow meter for detecting a flow rate based on a fluid vibration of a jet ejected from a nozzle flow path.

[0002]

2. Description of the Related Art As a fluid vibration type flow meter of this type, for example, those shown in FIGS. 3 to 5 are known. In the fluid vibration type flow meter FM shown in these figures, a pair of nozzle members 2 and 2 are provided in a housing 1 closed by a cover 5 to form a nozzle flow path 210 in the housing 1 and the nozzle An upstream channel 200 and a downstream channel 220 are formed on the upstream side and the downstream side of the channel 210, respectively. The target 3 is provided on the downstream flow path 220 on an extension of the nozzle flow path 210 (on the center line C). The gas (fluid) ejected through the nozzle flow path 210 collides with the target 3 to generate fluid vibration, and the principle is to detect the flow rate based on the fluid vibration.

The housing 1 has a box-shaped rectangular groove 1a formed in a concave shape. By covering the surface of the groove 1a with a cover 5, an upstream flow path 200, a nozzle flow path 210, The downstream flow path 220 is configured as a two-dimensional flow path. That is, the upstream flow path 200 and the nozzle flow path 21
The height H (the dimension in the direction perpendicular to the plane of FIG. 3 (the dimension in the thickness direction)) H between the bottom wall portion 110 and the cover 5 constituting the bottom surface of the groove 1a is constant. , A two-dimensional flow path symmetrical with respect to the center line C.

The housing 1 has an inlet 1b and an outlet 1c. Furthermore, a screw hole 1 e for fixing the cover 5 is formed in the housing 1, and a screw hole (not shown) for fixing the nozzle member 2 is formed in the bottom wall 110. Screw hole 1e
, A bolt 6 for fixing the cover 5 is screwed. In addition, a screw hole (not shown) provided in the bottom wall portion 110 is inserted from outside the cover 5,
A bolt 6a passing through the first through hole 2a formed in the nozzle member 2 or a second through hole 2b formed in the nozzle member 2
Bolt 6b passing therethrough is screwed.

[0005] Two pressure extraction holes 4 are formed in the bottom wall portion 110 of the downstream channel 220 at positions symmetrical with respect to the center line C. A pressure sensor is connected to each pressure extraction hole 4. The pressure sensor detects the fluid vibration of the jet by pressure.

Further, a concave portion 1f for holding the setting base 3a of the target 3 is formed in the bottom wall portion 110 of the downstream flow path 220. The upper surface of the setting table 3a is flush with the inner surface of the bottom wall 110 when fitted to the recess 1f. Target 3
Is set so that the height H from the setting base 3a matches the height H of the two-dimensional flow path, as shown in FIGS.

In the fluid vibration type flowmeter FM configured as described above, the flow rate can be measured because the frequency of the fluid vibration is proportional to the flow rate or flow rate of the gas (fluid). .

[0008] The above-mentioned fluid vibration type flow meter FM has an LP
This measures the flow rate of the gas, and measures the fluid vibration of the LP gas. However, in the fluid vibration type flowmeter FM having the above structure, it is also possible to measure the flow rate of a gas other than the LP gas or the flow rate of the liquid.

[0009]

By the way, in the above-mentioned fluid vibration type flow meter FM, the height H of the target 3 is 2
Since it is configured to match the height H of the two-dimensional flow path, a different target 3 must be used for each different height H of the two-dimensional flow path. In this case, as the height H of the target 3 increases, the production becomes more difficult, and the production cost also increases. For this reason, there is a problem that the cost increases for the fluid vibration type flow meter FM having the two-dimensional flow path with a high height H.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problem, and has as its object to provide a fluid vibration type flowmeter which has a two-dimensional high flow path and can reduce the cost. It is an issue.

[0011]

In order to solve the above problems, the present invention provides a nozzle flow path (210) and a downstream flow path (220) as a two-dimensional flow path having a constant height dimension.
And provided on an extension of the nozzle flow path (210) in the downstream flow path (220).
A target erected in the height direction of the two-dimensional flow path, and a downstream flow path (22) extending from the nozzle flow path (210).
0) A fluid vibration type flow meter configured to detect a flow rate based on fluid vibration of a jet ejected at 0), wherein the target is a first target (31) rising from a lower surface of a two-dimensional flow path. A second target (3) having a lower end surface (32a) falling from the upper surface of the two-dimensional flow path and abutting on the upper end surface (31a) of the first target (31);
2).

[0012] In the invention configured as described above, the first target (31) rising from the lower surface of the two-dimensional flow channel and the first target (31) falling from the upper surface of the two-dimensional flow channel. The target is constituted by the second target (32) having the lower end surface (32a) abutting on the upper end surface (31a) of the target device. And a first target (31) and a second target (32), which have low values. Therefore,
For those having a tall two-dimensional flow path, the cost can be reduced.

That is, in the case where a high integral target is formed from a metal by, for example, die casting, it is difficult to form the target unless the draft angle is made large. For this reason, when a target having a high height is formed by die-casting, only a target having a tapered shape along the height direction and having an inferior precision can be obtained. However, when the first target (31) and the second target (32) having a low height are manufactured by die casting as in the present invention, it is easy to obtain a high-precision one having a small draft angle. Can be. Therefore, the accuracy of the target can be improved and the cost can be reduced.

In addition, if one of the first target (31) and the second target (32) is set as a reference target and has a predetermined height, the height of the two-dimensional flow path is reduced. There is an advantage that even if they are different, they can be applied to two-dimensional flow paths of various heights only by exchanging only the other target. That is, since one of the targets can be shared as the reference target, the cost can be further reduced.

Similarly, in the case of manufacturing a target by injection molding using a resin (polymer material), similarly to the case of the above-described die casting, a high-precision one can be easily manufactured. Cost can be reduced. Moreover, the first target (31) and the second target (31)
Since the target (32) need only be low in height, it is possible to obtain a high-accuracy target free from deformation such as sink marks and distortion due to injection molding.

Further, when processing a target by, for example, machining with a milling machine or the like, there is a limit to the height of the target that can be processed, and a target with an extremely high height cannot be processed. That is, when the height of the target is increased, the processing accuracy and the surface roughness are deteriorated. Therefore, it is not possible to process a target having an extremely high height. However, in the present invention, the first target (31) having a low height is provided.
And the second target (32),
By machining such as a milling machine, a target having excellent accuracy and surface roughness can be easily obtained, and the cost can be reduced.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to FIGS. In addition,
FIG. 1 shows a first embodiment, and FIG. 2 shows a second embodiment.

First, a first embodiment will be described with reference to FIG. However, components common to those of the conventional example shown in FIGS. 3 to 5 are denoted by the same reference numerals, and description thereof will be omitted.

Fluid vibration type flow meter FM shown in this embodiment
As shown in FIG. 1, a nozzle channel 210 and a downstream channel 220 are provided as a two-dimensional channel having a constant dimension in the height direction. A target provided on an extension line and erected in the height direction of the two-dimensional flow path;
0 to detect the flow rate based on the fluid vibration of the jet ejected to the downstream flow path 220,
The first target 31 rises from the lower surface of the two-dimensional flow channel, and the target falls from the upper surface of the two-dimensional flow channel.
And a second target 32 having a lower end surface 32a in contact with the upper end surface 31a of the first target 31.

Hereinafter, the above configuration will be described in more detail. That is, the setting base 3a is formed at the base of each of the first target 31 and the second target 32. The first wall 110 of the housing 1
Recess 1 for fitting and holding setting table 3a of target 31
f is formed, and the cover 5 is formed with a concave portion 1f at a position corresponding to the concave portion 1f of the bottom wall portion 110 for fitting and holding the setting base portion 3a of the second target 32. The first and second targets 31 and 32 held in the recesses 1f cover the upper opening of the housing 1 with a cover 5, and the cover 5 is attached to the housing 1 by bolts 6, 6a and 6b. When fixed at (see FIG. 3), the upper end surface 31a and the lower end surface 32a are in close contact with each other.

In this embodiment, when a target is formed by injection molding, die casting, machining, or the like, a height which does not cause any problem in manufacturing is defined as H, and the first target 31 having this height H is defined as H. It is a reference target. Therefore, in this embodiment, two reference targets are provided, and the height of the two-dimensional flow path is 2H.

In the fluid vibration type flow meter FM configured as described above, the first target 31 and the second target 32 constitute a target.
A high target can be configured by a first target 31 and a second target 32 that are low. Therefore, costs can be reduced for those having a tall two-dimensional flow path.

That is, when forming a high integral target from a metal by, for example, die casting, it becomes difficult to form the target unless the draft angle is made large. For this reason, when a target having a high height is formed by die-casting, only a target having a tapered shape along the height direction and having an inferior precision can be obtained. However, when the first target 31 and the second target 32 having a low height are manufactured by die-casting as in this embodiment, a high-precision one having a small draft angle can be easily obtained. Therefore, the accuracy of the target can be improved and the cost can be reduced.

In addition, since one of the first target 31 and the second target 32 (the first target 31) is set as a reference target and has a predetermined height, the two-dimensional flow path is set. Even if the height is different from that of the above embodiment, the other target (the second target 3
There is an advantage that the present invention can be applied to two-dimensional flow paths of various heights only by replacing only 2). That is, since one of the targets can be shared as the reference target, the cost can be further reduced.

The first target 31 as a reference target can be applied to a two-dimensional flow path having a height H as shown in the conventional example as it is, and two first targets 31 can be used as in the above embodiment. The present invention can be applied to a two-dimensional flow path having a height of 2H. Therefore, there is also an advantage that the applicable range of the target is widened. Further, the target 3 used conventionally can be reused as the reference target (first target 31).

Similarly, in the case of manufacturing a target by injection molding using a resin (polymer material), similarly to the case of the above-mentioned die casting, a high-precision one can be easily manufactured, and Cost can be reduced. Moreover, since the first target 31 and the second target 32 need only be low in height,
It is possible to obtain a high-accuracy target without deformation or distortion such as sink due to injection molding.

When a target is machined by, for example, machining with a milling machine or the like, there is a limit to the height of the target that can be machined, and a target that is too high cannot be machined. That is, when the height of the target is increased, the processing accuracy and the surface roughness are deteriorated. Therefore, it is not possible to process a target having an extremely high height. However, in the present invention, since the target is divided into the first target 31 and the second target 32 having a low height, it is possible to cope with a target having a high height even by machining such as a milling machine. it can. That is, a target having excellent accuracy and surface roughness can be easily obtained by machining such as a milling machine, and the cost can be reduced.

Next, a second embodiment of the present invention will be described with reference to FIG. The second embodiment is different from the first embodiment in that a second target 32 having a height of 0.5H is used. As described above, by changing the height of the second target 32, the second target 32 can be applied to two-dimensional flow paths having various heights.

Although the fluid vibration type flow meter FM shown in each of the above embodiments measures the flow rate of LP gas as a fluid, it measures the flow rate of a gas other than LP gas or a liquid. Is also possible.

[0030]

According to the first aspect of the present invention,
A first target rising from the lower surface of the two-dimensional flow path;
Since the target is constituted by the second target having the lower end surface falling from the upper surface of the two-dimensional flow path and abutting on the upper end surface of the first target, even when a high target is required, This target can be constituted by a first target and a second target having a low height. Therefore, costs can be reduced for those having a tall two-dimensional flow path.

That is, when a high integrated target is formed from a metal by, for example, die casting, it is difficult to form the target unless the draft angle is made large. For this reason, when a target having a high height is formed by die-casting, only a target having a tapered shape along the height direction and having an inferior precision can be obtained. However, when the first target or the second target having a low height is manufactured by die casting as in the present invention,
A high-precision product with a small draft angle can be easily obtained. Therefore, the accuracy of the target can be improved and the cost can be reduced.

Moreover, if one of the first target and the second target is set as a reference target and has a predetermined height, the other target is set even if the height of the two-dimensional flow path is different. There is an advantage that the present invention can be applied to two-dimensional flow paths of various heights only by replacing only the same. That is, since one of the targets can be shared as the reference target, the cost can be further reduced.

Similarly, in the case of manufacturing a target by injection molding using a resin (polymer material), similarly to the case of the above-described die casting, a high-precision one can be easily manufactured. Cost can be reduced. In addition, since the first target and the second target need only be low in height, it is possible to obtain a high-accuracy target free from deformation such as sink marks and distortion due to injection molding.

In the case of processing a target by, for example, machining with a milling machine or the like, there is a limit to the height of the target that can be processed, and a target that is too high cannot be processed. That is, when the height of the target is increased, the processing accuracy and the surface roughness are deteriorated. Therefore, it is not possible to process a target having an extremely high height. However, in the present invention, since the target is divided into a first target and a second target having a low height, a target having excellent precision and surface roughness can be easily obtained even by machining such as a milling machine. Not only can be obtained, but also the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a fluid vibration type flowmeter shown as a first embodiment of the present invention, and is a cross-sectional view at a position corresponding to line IV-IV in FIG.

FIG. 2 is a sectional view of a fluid vibration type flow meter shown as a second embodiment of the present invention, and is a sectional view at a position corresponding to line IV-IV in FIG.

FIG. 3 is a fragmentary plan view of a main part of a fluid vibration type flow meter shown as a conventional example.

FIG. 4 is a cross-sectional view showing the fluid vibration type flow meter, and is a cross-sectional view taken along the line IV-IV in FIG.

FIG. 5 is a perspective view showing a target used in the fluid vibration type flow meter.

[Explanation of symbols]

 2 Nozzle member 31 First target 32 Second target 210 Nozzle flow path 220 Downstream flow path FM Fluid vibration type flow meter

Claims (1)

[Claims] 1. A method according to claim 1, further comprising a nozzle flow path and a downstream flow path as a two-dimensional flow path having a constant dimension in the height direction, and provided on an extension of the nozzle flow path in the downstream flow path. A fluid vibration type comprising a target set upright in the height direction of the two-dimensional flow path, and configured to detect a flow rate based on fluid vibration of a jet ejected from the nozzle flow path to the downstream flow path. A flow meter, wherein the target rises from a lower surface of a two-dimensional flow path, and a first target falls from an upper surface of the two-dimensional flow path;
A second target having a lower end surface in contact with an upper end surface of the first target.