JPH11311554A - Multilayer vibrating fluid flowmeter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multilayer vibrating fluid flowmeter which can measure flow rate in various regions from low flow rate to high flow rate and can be fixed easily to low flow rate measuring means and high flow rate measuring means while reducing the cost and time required for development. SOLUTION: A multilayer flow rate measuring section FMa is provided by partitioning a two-dimensional channel horizontally with a baffle plate 11 at a specified thickness position. The flow rate measuring section FMa located at the outermost position is provided with a low flow rate sensor 8 at a position close to the inlet of a nozzle channel 210. A low flow rate measuring means 80 connected with the low flow rate sensor 8 is mounted on one wall part (cover) covering the flow rate measuring section FMa and a high flow rate measuring means 40 is mounted on the other wall part (bottom wall part) covering the flow rate measuring section FMa located at the outermost position while being connected with a pressure introduction hole 4 communicating with the part close to the outlet of the nozzle channel 210 and detecting vibrating fluid in jet flow.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-layer fluid vibration type flow meter having a multi-layer flow rate measuring section for detecting a flow rate based on the 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, for example, FIG.
And FIG. 6 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
0 and the downstream flow path 220 have a constant height (dimension in the direction perpendicular to the plane of FIG. 5 (dimension in the thickness direction)) from the bottom wall 110 constituting the bottom surface of the groove 1a, and the center line C And a two-dimensional flow path symmetrical with respect to the left and right.

The housing 1 has an inlet 1b and an outlet 1c. Further, a screw hole 1e for fixing the cover 5 and a screw hole (not shown) for fixing the nozzle member 2 are formed in the housing 1. The screw hole 1e has a cover 5
A bolt 6 for fixing the screw is screwed. The nozzle member 2 has a through hole 2 a through which the bolt 6 passes, and a through hole 2 b of a bolt 7 for fixing the nozzle member 2 to the housing 1.

[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. Further, the bottom wall 110 of the downstream flow path 220 is formed with a concave portion 1f for holding the setting base 3a of the target 3. When the setting base 3a is fitted in the concave portion 1f, the upper surface thereof has a bottom wall 11
0 is flush with the surface. FIG.
, 51 is a packing.

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). .

[0007] 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.

[0008]

In the meantime, it is important to obtain a fluid vibration type flowmeter FM having a wide measurement range and excellent measurement accuracy. However, the measurement range and the measurement accuracy are, for example, the dimension in the thickness direction of the two-dimensional channel, the width of the nozzle channel 210,
, The position of the target 3, the shape of the downstream channel 220, and the like.

For this reason, for example, even if a device having a wide measurement range in a small flow rate region and excellent measurement accuracy has already been developed, a device for measuring a large flow rate region having a different measurement region, for example, has been developed. For development, it is necessary to find the best two-dimensional flow channel thickness and the width of the nozzle flow channel 210 by repeating the experiment again. Therefore, the fluid vibration type flow meter FM
There was a problem in that development of the device required much cost and time.

As disclosed in Japanese Patent Application Laid-Open No. 6-241850, for example, a flow sensor for detecting a low flow rate by a method different from the fluid vibration is provided in a fluid vibration type flow meter FM, and thereby a measuring range is provided. Some have been improved. However, in this apparatus, a low flow rate measuring means for converting data detected by a flow sensor into a flow rate and a high flow rate measuring means for converting a fluid vibration into a flow rate are the same as the fluid vibration type flow meter. Since these are provided on the side, there is a problem that these low flow rate measuring means and high flow rate measuring means are difficult to attach to the fluid vibration type flow meter.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and can measure the flow rate in various regions from a small flow rate to a large flow rate.
It is an object of the present invention to provide a multilayer fluid vibration type flow meter which can reduce the time and the like and does not hinder the mounting of the low flow rate measuring means and the high flow rate measuring means.

[0012]

In order to solve the above-mentioned 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 thickness dimension.
And a downstream flow path (2) from the nozzle flow path (210).
20) a flow rate measuring unit (FMa) configured to detect a flow rate based on the fluid vibration of the jet flow jetting out to the partition plate (11) that horizontally partitions the two-dimensional flow path at a predetermined thickness position. ), And the same flow rate measuring section (FMa) is formed in multiple layers by the partition plate (11), and the flow rate measuring section (FMa) arranged at the outermost position of one of the flow rate measuring sections (FMa) is provided. FMa), a low flow sensor (8) is provided near the inlet of the nozzle flow path (210), and one wall (5) covering the flow measurement unit (FMa) has a low flow sensor (8) Is provided on the other wall (110) covering the flow measurement unit (FMa) disposed at the other outermost position, and the nozzle in the flow measurement unit (FMa) is provided on the other wall (110). A pressure that communicates with the vicinity of the outlet of the flow path (210) and detects fluid vibration of the jet. Provided with a guide hole (4), a high flow rate measuring means connected to the pressure introducing hole (4) (4
0) is provided.

The invention configured as described above has the following effects. First, the operation when the flow rate is measured only by the fluid vibration will be described.
That is, the fluid that has flowed from the upstream side flows through each flow rate measuring unit (FMa) and then flows down to the downstream side. For this reason, even if one flow rate measuring unit (FMa) is developed for measuring a small flow rate region, a large flow rate can be measured as a whole. Further, by closing the predetermined flow rate measuring section (FMa), it can be easily changed to a small flow rate type. Therefore, it is possible to measure the flow rate in various regions from a small flow rate to a large flow rate.

In addition, a small flow rate type flow measuring unit (FMa)
It is only necessary to newly develop or to use the already developed small flow rate type flow measuring unit (FMa), so that the cost and time required for development can be reduced. In other words, only by developing one small flow rate type flow rate measuring unit (FMa), it is possible to obtain a flow rate measuring device from a small flow rate to a large flow rate. Therefore, it is not necessary to newly develop each time the measurement area is different, so that the cost and time required for development can be reduced.

Further, since the individual flow rate measuring units (FMa) measure a small flow rate region, they can measure a large flow rate as a whole, but are similar to the small flow rate measuring type. There is an advantage that a high measurement accuracy can be obtained.

Further, since the partition plate (11) for partitioning each of the flow rate measuring sections (FMa) can be made thin, the whole of the partition plate (11) does not increase in size. That is, for example, in the case where a plurality of small flow rate type fluid vibratory flow meters are provided in parallel in order to measure a large flow rate, a plurality of fluid vibratory flow meters can be used to form a large flow meter as a whole. However, the invention can be much smaller.

The required maximum flow rate can be freely designed according to the number of flow rate measuring sections (FMa). In addition, when only a flow rate smaller than the maximum flow rate is measured, the flow rate can be easily changed to a flow rate corresponding to a small flow rate by closing a predetermined flow rate measuring unit (FMa) with, for example, a spacer. Therefore, for example, it can be applied to gas meters of various numbers.

Further, since the pressure on the upstream side of each flow rate measuring section (FMa) acts on each flow rate measuring section (FMa) as the same pressure, the flow rate flowing through each flow rate measuring section (FMa) is extremely uniform. It becomes something. That is, since the flow path is narrowed by the nozzle flow path (210) of each flow rate measurement unit (FMa), the pressure on the upstream side of each flow rate measurement unit (FMa) is applied to each flow rate measurement unit (FMa). To the same pressure. For this reason, since the flow rates flowing through the respective flow rate measuring units (FMa) become equal, only the flow rate is measured in one flow rate measuring unit (FMa), and the total flow rate measuring unit (FMa) is measured.
Can be obtained. Therefore, the pressure extraction hole for extracting the vibration of the fluid need only be provided for one flow measurement unit (FMa), that is, covers the flow measurement unit (FMa) arranged at the other outermost position. It only needs to be installed on the other wall (110), and the electric circuit for detecting the frequency is also one flow measurement unit (FM
There is an advantage that it is only necessary to provide for a).
When a plurality of the same fluid vibration type flowmeters are provided in parallel, the split ratio cannot be kept constant. There is a drawback that the flow rate cannot be obtained accurately, so that a pressure outlet and an electric circuit must be provided for each fluid vibratory flow meter. In contrast, the present invention does not have such a disadvantage.

Next, the operation when the low flow rate sensor (8) is added will be described. That is, since the low flow rate sensor (8) is provided in the flow rate measuring section (FMa) arranged at one of the outermost positions, even the small flow rate that cannot be measured by the fluid vibration is measured by the low flow rate sensor (8). can do.

When the flow rate is measured by the low flow rate sensor (8), as described above, since the flow rate flowing through each flow rate measuring section (FMa) is equal, one flow rate measuring section (FM) is used.
By measuring the flow rate with the low flow rate sensor (8) provided only in (a), the total minute flow rate flowing through all the flow rate measuring units (FMa) can be accurately obtained. Then, by closing the other predetermined flow measurement unit (FMa) while leaving the flow measurement unit (FMa) at one outermost position, the smallest flow rate can be measured.

In addition, the low flow rate sensor (8) is provided in one of the outermost flow rate measuring sections (FMa), and the pressure introducing hole (4) is provided in the other outermost flow rate measuring section (FMa). Therefore, the fluid vibration detected by the pressure introducing hole (4) is never disturbed by the low flow rate sensor (8). Therefore, even if the low flow sensor (8) is provided, the flow measurement by the fluid vibration can be accurately performed.

Further, the low flow rate measuring means (80) is provided on one wall (5) and the high flow rate measuring means (40) is provided on the other wall (110). The problem that the measuring means (80) and the high flow rate measuring means (40) interfere with each other and cannot be mounted can be solved. Therefore, even if the surface area of one wall (5) and the other wall (110) is small,
The mounting of the low flow rate measuring means (80) and the high flow rate measuring means (40) is not hindered. In addition, regardless of the size of one wall (5) or the other wall (110), it is possible to use a low flow rate measuring means (80) and a high flow rate measuring means (40) of the same size in common. There is also the advantage that you can.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to FIGS. 1 to 3 show a first embodiment, and FIG. 4 shows a second embodiment.

First, a first embodiment will be described with reference to FIGS. However, the same components as those of the conventional example shown in FIGS. 5 and 6 are denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIGS. 1 to 3, a multilayer fluid vibration type flow meter MFM shown in this embodiment has a nozzle flow path 210 as a two-dimensional flow path having a constant thickness dimension and a downstream flow path. A flow measuring unit FMa configured to detect a flow rate based on fluid vibration of a jet ejected from the nozzle flow path 210 to the downstream flow path 220, Partitioning plate 11 that partitions horizontally at the thickness position
And the same flow rate measuring unit FM
a is formed in a multilayer structure, and one of the flow rate measuring units (FMa), which is located at the outermost position, has a low flow rate sensor 8 near the inlet of the nozzle flow path 210.
And the flow rate measuring unit FMa disposed at the other outermost position
The bottom wall portion (the other wall portion) 110 that covers the nozzle is provided with a pressure introduction hole 4 that communicates with the vicinity of the outlet of the nozzle flow path 210 in the flow rate measurement unit FMa and detects fluid vibration of a jet flow. .

The partition plate 11 is formed in the shape of a thin plate from the same metal as the housing 1 such as aluminum or the like, and extends from the upstream end of the upstream flow path 200 to the downstream flow path 2.
The groove 1a reaching the downstream end of the groove 20 is completely partitioned up and down. That is, in a range from the upstream end of the upstream flow passage 200 provided with the partition plate 11 to the downstream end of the downstream flow passage 220, the LP gas flowing into the flow measurement unit FMa on the bottom wall 110 side is covered by the cover 5. Side flow measurement unit F
It does not flow into Ma or flow in the opposite direction. Further, the upstream end of the partition plate 11 protrudes in a semicircular curved surface, and evenly divides the LP gas flowing from the upstream into the respective flow rate measuring units FMa,
The flow is not disturbed by the partition plate 11.

In this embodiment, one partition plate 11 is used.
Thereby, the two flow rate measurement units FMa are configured in a layered manner. The height of the nozzle member 2 and the height of the target 3 in each flow rate measurement unit FMa are the same. The target 3 on the bottom wall 110 side (the other side) has the setting base 3a fitted and fixed in the recess 1f. On the other hand, for the target 3 on the cover 5 side (one side), the setting base 3a is
Is fitted and fixed to the recessed portion 1f provided in the recess.

The partition plate 11 has through holes (not shown) formed at the same positions as the through holes 2a and 2b of the nozzle member 2 shown in FIGS. 2 and 3. Are fixed to the housing 1 together with the nozzle members 2 arranged in two layers.

The flow measuring unit F arranged at one of the outermost positions
As shown in FIGS. 1 and 2, a low flow rate sensor 8 is provided at a position near the inlet of the nozzle flow path 210 in Ma, that is, in the flow rate measurement unit FMa on the cover 5 side. Nozzle channel 2
As shown in FIG. 2, the nozzle 10 has a predetermined width W by making nozzle forming surfaces of the nozzle member 2 face each other in parallel. Further, the inlet portion of the nozzle flow path 210 is formed so as to gradually approach the width W by an R portion formed at the upstream end of the nozzle forming surface.

The low flow rate sensor 8 is constituted by, for example, a thermal sensor, and is inserted into the nozzle flow path 210 at a position on the center line C from the cover 5 side. On the outer surface of the cover 5, a low flow rate measuring means 8 electrically connected to the low flow rate sensor 8 and holding the low flow rate sensor 8 is provided.
0 is attached.

The low flow rate measuring means 80 is mainly constituted by an electric circuit housed in a predetermined box. The low flow rate measuring means 80 detects the flow rate of the LP gas by, for example, the resistance of the heat wire in the low flow rate sensor 8 and detects the flow rate of the LP gas. And nozzle channel 210
The flow rate is measured from the cross-sectional area and the like.

That is, in this embodiment, since the number of the flow rate measuring units FMa is 2, for example, by setting the dip switch to 2, the flow rate measurement result on one side is doubled, Low flow rate measuring means 8
The output is provided to a display unit provided at 0 or to another computer, a printer, or the like. Also,
When the flow measurement unit FMa on the side without the low flow sensor 8, that is, the flow measurement unit FMa on the bottom wall 110 side is closed with a spacer or the like, the dip switch is set to 1 so that the LP gas passing through only one of the flow measurement units FMa is set. The measurement result is output. Also, set the dip switch to 1,
By measuring the relationship between the total flow rate and the output of the low flow rate sensor, flow rate measurement can also be performed.

The pressure introducing hole 4 is provided only in the bottom wall 110 of the housing 1 as shown in FIG. That is, the pressure introducing hole 4 is provided at the flow rate measuring unit FM on the bottom wall 110 side.
a, and as shown in FIG. 3, they are arranged at symmetrical positions with respect to the center line C of the nozzle flow path 210. In addition, on the outer surface of the bottom wall portion 110, the high flow rate measuring means 40 connected to each pressure introducing hole 4 is provided.
Is attached.

The high flow rate measuring means 40 is provided with a pressure sensor (not shown) for detecting a pressure difference between the LP gas introduced from the left and right pressure introducing holes 4, and this pressure sensor is used for the nozzle flow path. Detecting the fluid vibration at the outlet side of 210,
The flow velocity and flow rate of the LP gas passing through the nozzle flow path 210 are measured from the frequency.

Also in this high flow rate measuring means 40, by setting the dip switch to 2, for example, the flow rate measurement result on the other side is doubled, and the high flow rate measuring means 40 is set as a normal flow rate. The data is output to a built-in display unit or output to another computer or printer. Further, when the flow measurement unit FMa on the side without the pressure introduction hole 4, that is, the cover 5 side is closed with a spacer or the like, the dip switch is set to 1 to allow only the flow measurement unit FMa on the other side to pass.
The measurement result of the flow rate of the P gas is output.
Further, by setting the dip switch to 1 and obtaining the relationship between the normal total flow rate and the output frequency of the high flow rate sensor, the flow rate can be measured by performing calibration.

The multi-layer fluid vibration type flow meter MFM configured as described above has the following operational effects. First, the operation and effect of measuring the flow rate using only the fluid vibration will be described. That is, the LP gas (fluid) flowing from the upstream side through the inflow port 1b passes through each flow rate measurement unit FMa, further flows through the outflow port 1c, and flows down to the downstream side. Therefore, one flow measurement unit F
Even if Ma is developed for measuring a small flow rate region, a large flow rate can be measured as a whole. In addition, by closing the predetermined flow rate measuring unit FMa, it can be easily changed to a small flow rate type. Therefore, it is possible to measure the flow rate in various regions from a small flow rate to a large flow rate.

In addition, it is only necessary to newly develop a small flow rate type flow rate measuring unit FMa or to use a small flow rate type flow rate measuring unit FMa which has already been developed, so that the cost and time required for development can be reduced. Can be planned. In other words, only by developing one small flow rate type flow measuring unit FMa,
What can be measured from a small flow rate to a large flow rate can be obtained. Therefore, it is not necessary to newly develop each time the measurement area is different, so that the cost and time required for development can be reduced.

Further, since the individual flow rate measuring units FMa measure a small flow rate region, they can measure a large flow rate as a whole, but have the same high flow rate as the small flow rate measuring type. There is an advantage that measurement accuracy can be obtained.

Furthermore, since the partition plate 11 for partitioning each flow rate measuring unit FMa may be thin, the multilayer plate 11 does not increase the size of the multilayer fluid vibration type flow meter MFM. That is, for example, in the case where a plurality of small flow rate type fluid vibratory flow meters are provided in parallel in order to measure a large flow rate, a plurality of fluid vibratory flow meters can be used to form a large flow meter as a whole. However, the invention can be much smaller.

Further, the required maximum flow rate can be freely designed according to the size of the housing 1 and the number of the flow rate measuring parts FMa. In addition, when a flow rate smaller than the maximum flow rate is measured, the flow rate can be easily changed to a flow rate corresponding to a small flow rate by closing the predetermined flow rate measuring portion FMa with a blocking member such as a spacer. In other words, in the case of this embodiment, the pair of left and right nozzle members 2
Instead of this, by providing a plate-shaped closing member that fills the portion where the nozzle member 2 exists, one flow rate measuring unit FMa can be easily closed, and a small flow rate type can be obtained. Therefore, it can be applied to gas meters of various numbers.

Further, since the pressure on the upstream side of each flow rate measuring section FMa acts on each flow rate measuring section FMa as the same pressure, the flow rate flowing through the flow rate measuring section FMa becomes very uniform. That is, since the flow path is narrowed by the nozzle flow path 210 of each flow measurement unit FMa, the pressure on the upstream side of each flow measurement unit FMa becomes the same pressure with respect to each flow measurement unit FMa.

For this reason, since the flow rates flowing through the respective flow rate measuring sections FMa become equal, the flow rate flowing through the entire flow rate measuring section FMa can be obtained only by measuring the flow rate in one flow rate measuring section FMa. That is, in this embodiment, since the detected flow rate is doubled because it is composed of two layers, the actual flow rate can be accurately obtained. Therefore, the pressure extraction hole 1 for extracting the vibration of the fluid is:
It only needs to be provided for one flow measurement unit FMa,
In addition, there is an advantage that an electric circuit for detecting the frequency only needs to be provided for only one flow rate measuring unit FMa.

Further, by simply inputting the number of the flow rate measuring units FMa to be measured by, for example, a dip switch, the total flow rate of the LP gas can be calculated and output by a calculation circuit (calculation program) on a computer. However, in this embodiment, since there are two flow rate measuring units FMa, the numerical value input by the dip switch is 1 or 2. Also, the flow rate can be measured by performing calibration for obtaining the relationship between the total flow rate and the sensor output.

When a plurality of the same fluid vibration type flow meters are simply provided in parallel to measure a large flow rate, the ratio of the flow to each fluid vibration type flow meter cannot be kept constant. It is not possible to accurately obtain the total flow rate only by measuring the flow rate with one of the fluid vibration type flowmeters. For this reason,
There is a drawback in that each of the fluid vibration type flow meters must be provided with a pressure outlet 4 and an electric circuit for detecting fluid vibration. In contrast, the present embodiment does not have such a disadvantage.

Next, the operation and effect of having the low flow sensor 8 will be described. That is, since the low flow rate sensor 8 is provided in the flow rate measuring unit FMa disposed at one of the outermost positions, a small flow rate that cannot be measured by fluid vibration can be measured by the low flow rate sensor 8.

When measuring the flow rate with the low flow rate sensor 8,
As described above, since the flow rates flowing through the respective flow rate measuring units FMa are equal to each other, the flow rate is measured by the low flow rate sensor 8 provided only in one flow rate measuring unit FMa, thereby flowing through all the flow rate measuring units FMa. The total micro flow rate can be determined accurately. Then, by closing one of the flow measurement units FMa while leaving the flow measurement unit FMa at one outermost position, the smallest flow rate can be measured.

Further, since the low flow rate sensor 8 is provided in the flow measuring section FMa at one outermost position and the pressure introducing hole 4 is provided in the flow measuring section FMa at the other outermost position, Is not disturbed by the low flow rate sensor 8 at all. Therefore, even if the low flow rate sensor 8 is provided, the flow rate measurement by the fluid vibration can be accurately performed.

Further, since the low flow rate measuring means 80 is provided on the cover 5 as one wall and the high flow rate measuring means 40 is provided on the bottom wall 110 as the other wall, the low flow rate The problem that the measuring means 80 and the high flow rate measuring means 40 cannot be attached because they interfere with each other can be solved. Therefore, even if the surface area of one wall and the other wall is small, the low flow rate measuring means 8
The installation of the zero and high flow rate measuring means 40 is not hindered. There is also an advantage that the low flow rate measuring means 80 and the high flow rate measuring means 40 having the same size can be commonly used regardless of the size of one wall portion or the other wall portion.

Next, a second embodiment of the present invention will be described with reference to FIG. However, components common to those of the first embodiment shown in FIGS. 1 to 3 are denoted by the same reference numerals, and description thereof will be omitted. The second embodiment is different from the first embodiment in that the number of the partition plates 11 is two and the same flow rate measuring unit FMa is used.
In three layers.

That is, the flow rate measuring unit FMa can be configured to have a three-layer structure or a multilayer structure having more layers through the partition plate 11. Therefore, there is an advantage that almost the entire flow rate range of the LP gas that can be actually measured can be covered.

In each of the above embodiments, an example in which the flow rate of LP gas as a fluid is measured has been described, but it is also possible to measure the flow rate of a gas other than LP gas or a liquid. Not even.

The flow rate measuring unit FMa has two layers or three layers.
Although a single-layer structure is shown, a multi-layer structure may be employed. For example, when the flow rate is measured by the fluid flow, or when the flow rate is measured by the low flow rate sensor 8, when the flow rate is measured by one flow rate measuring unit FMa, when the flow rate is measured by the fluid vibration, the flow rate is measured by only n times. Thus, the actual flow rate can be accurately obtained. The maximum flow rate that can be measured also depends on each flow rate measurement unit F
It becomes n times the maximum flow rate of Ma.

[0053]

According to the present invention, the following effects can be obtained. First, the effect when the flow rate is measured only by the fluid vibration will be described. That is, the fluid flowing from the upstream side passes through each flow rate measuring unit and flows off to the downstream side. For this reason, as one flow measurement unit, even if it is developed for measuring a small flow area,
As a whole, a large flow rate can be measured. Further, by closing the predetermined flow rate measuring unit, it can be easily changed to a small flow rate type. Therefore, it is possible to measure the flow rate in various regions from a small flow rate to a large flow rate.

Moreover, it is only necessary to newly develop a small flow type flow measuring unit or to use a small flow type flow measuring unit which has already been developed, so that the cost and time required for development can be reduced. Can be. That is, it is possible to obtain a device capable of measuring from a small flow rate to a large flow rate only by developing one small flow rate type flow measurement unit. Therefore, it is not necessary to newly develop each time the measurement area is different, so that the cost and time required for development can be reduced.

Further, since the individual flow rate measuring units measure a small flow rate region, a large flow rate can be measured as a whole. There is an advantage that accuracy can be obtained.

Further, since only a thin partition plate is required for partitioning each of the flow rate measuring sections, the partition plate does not increase the overall size. That is, for example, in the case where a plurality of small flow rate type fluid vibratory flow meters are provided in parallel in order to measure a large flow rate, a plurality of fluid vibratory flow meters can be used to form a large flow meter as a whole. However, the invention can be much smaller.

Further, the required maximum flow rate can be freely designed according to the number of flow rate measuring units. In addition, when only a flow rate smaller than the maximum flow rate is measured, the flow rate can be easily changed to a flow rate corresponding to a small flow rate by closing a predetermined flow rate measurement unit with, for example, a spacer. Therefore, for example, it can be applied to gas meters of various numbers.

Further, since the pressure on the upstream side of each flow rate measuring section acts on each flow rate measuring section as the same pressure, the flow rate flowing through each flow rate measuring section becomes extremely uniform. That is, since the flow path is narrowed by the nozzle flow path of each flow measurement unit, the pressure on the upstream side of each flow measurement unit becomes the same pressure for each flow measurement unit. For this reason, since the flow rates flowing through the respective flow rate measuring units become equal, the flow rate flowing through all the flow rate measuring sections can be obtained by measuring the flow rate in one flow rate measuring section. Therefore, the pressure extraction hole for extracting the vibration of the fluid need only be provided for one flow measurement unit, that is, provided on the other wall portion covering the flow measurement unit arranged at the other outermost position. There is an advantage that only an electric circuit for detecting the frequency need be provided for only one flow rate measuring unit. When a plurality of the same fluid vibration type flowmeters are provided in parallel, the split ratio cannot be kept constant. There is a drawback that the flow rate cannot be obtained accurately, so that a pressure outlet and an electric circuit must be provided for each fluid vibratory flow meter. In contrast, the present invention does not have such a disadvantage.

Next, the effect when the low flow rate sensor is added will be described. In other words, since the low flow rate sensor is provided in the flow rate measuring unit disposed at one of the outermost positions, a small flow rate that cannot be measured by fluid vibration can be measured by the low flow rate sensor.

When measuring the flow rate with the low flow rate sensor, as described above, the flow rates flowing through the respective flow rate measuring sections are equal, so the flow rate is measured with the low flow rate sensor provided only in one flow rate measuring section. Thus, the total minute flow rate flowing through all the flow rate measurement units can be accurately obtained. Then, by closing the other predetermined flow measurement unit while leaving the flow measurement unit at one outermost position, the smallest flow rate can be measured.

Further, since the low flow rate sensor is provided in the flow measuring section at one outermost position and the pressure introducing hole is provided in the flow measuring section at the other outermost position, the fluid vibration detected by the pressure introducing hole is reduced. Is not disturbed by the low flow sensor at all. Therefore, even if the low flow sensor is provided, the flow measurement by the fluid vibration can be accurately performed.

Further, since the low flow rate measuring means is provided on one wall and the high flow rate measuring means is provided on the other wall, the low flow rate measuring means and the high flow rate measuring means interfere with each other. Can be eliminated. Therefore, even if the surface areas of the one wall portion and the other wall portion are small, it does not hinder the attachment of the low flow rate measuring means and the high flow rate measuring means. Another advantage is that the low flow rate measuring means and the high flow rate measuring means having the same size can be commonly used regardless of the size of one wall portion or the other wall portion. In addition, increasing the thickness of the two-dimensional flow path prevents the flow state from changing from a two-dimensional flow to a three-dimensional flow, and has an effect of improving measurement accuracy by maintaining the two-dimensional flow.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a multi-layer fluid vibration type flow meter shown as a first embodiment of the present invention, which is a cross-sectional view taken along line II of FIG.

FIG. 2 is a fragmentary front view of the essential part showing the multilayer fluid vibration type flowmeter.

FIG. 3 is a diagram showing the multi-layer fluid vibration type flow meter,
FIG. 3 is a cross-sectional view along the line III-III in FIG. 1.

FIG. 4 is a cross-sectional view of a multi-layer fluid vibration type flow meter shown as a second embodiment of the present invention, and is a cross-sectional view at a position corresponding to line II in FIG. 2;

FIG. 5 is a fragmentary front view of a main part of a fluid vibration type flow meter shown as a conventional example.

FIG. 6 is a view showing the fluid vibration type flow meter,
It is sectional drawing which follows the VI-VI line.

[Explanation of symbols]

 Reference Signs List 4 pressure introduction hole 40 high flow rate measuring means 5 one wall (cover) 8 low flow rate sensor 80 low flow rate measuring means 11 partition plate 110 the other wall (bottom wall) 210 nozzle flow path 220 downstream flow path FMa flow rate Measuring unit MFM Multi-layer fluid vibration type flow meter

Claims (1)

[Claims] 1. A method according to claim 1, further comprising a nozzle flow path as a two-dimensional flow path having a constant thickness dimension and a downstream flow path, wherein a flow rate is determined based on a fluid vibration of a jet jet from the nozzle flow path to the downstream flow path. Having a flow rate measuring unit configured to detect the flow rate, a partition plate that horizontally partitions the two-dimensional flow path at a predetermined thickness position is provided, and the same flow rate measuring unit is configured in multiple layers by the partition plate. In the flow rate measurement unit, a flow rate measurement unit arranged at one outermost position is provided with a low flow rate sensor at a position near the inlet of the nozzle flow path, and one wall portion covering the flow rate measurement unit is A low flow rate measuring means connected to the low flow rate sensor is provided, and the other wall portion covering the flow rate measuring section arranged at the other outermost position communicates with the vicinity of the outlet of the nozzle flow path in the same flow rate measuring section, A pressure introduction hole for detecting the fluid vibration of the jet is provided, Multilayer fluidic oscillator flowmeter, characterized in that a high flow rate measuring means connected to the hole.