JP2860126B2 - Fluid flow meter - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates generally to devices for measuring capacitive fluid flow, and more particularly, to its bending motion which operates to allow passage of fluid in a traveling wave. The present invention relates to a fluid flow meter having a flexible thin film.

2. Description of the Related Art Various types of flow meters are known that utilize members that vibrate or wave as a fluid flows therethrough. Fluid flow may be determined from an oscillating frequency or wave rate that is generally proportional to the fluid flow.

A conventional flow meter having a wave spring enclosed within a fluid flow chamber and a mechanical counter for indicating the amount of fluid flowing therethrough is described in U.S. Pat. No. 398,013 (Welker). State-of-the-art traveling wave flowmeters utilizing wave members formed from piezoelectric materials that generate an electrical signal as a function of wave rate are disclosed in U.S. Pat.
Nos. 954 and 4,409,830 (both in Jiong).

[Problems to be solved by the invention]

However, the flow meter described in the above-mentioned Jyoeng patent is limited to use for measuring incompressible fluids, such as water. With a relatively large flow rate,
When used in compressible fluids such as gases, thin films
It is prone to stretching itself across the associated fluid flow path so as to prevent fluid flow along it.

It is an object of the present invention to provide a positive displacement fluid flow meter that overcomes the disadvantages of the prior art for measuring a wide range of compressible or incompressible fluid flows.

[Means for solving the problem]

Therefore, according to the present invention, a housing having a pair of fluid ports and defining a fluid flow path between them, and a front and back surface, wherein both ends of the fluid flow direction in the fluid flow direction are elastic. Attached through a member, and the front and back surfaces respectively cooperate with the housing to simultaneously define a fluid-tight seal at at least two different locations along the fluid flow path; A flexible membrane that bends to allow the passage of fluid in discrete volumes indicated by known volumes with variations as a function of flow rate, and a means for generating an electrical signal in response to the flexing of the membrane; Receiving the electrical signal from the electrical signal generating means over a measurement period, detecting the ratio of the electrical signal, determining the known volume that is the discrete quantity based on the ratio of the electrical signal, and Flow path with known capacity Fluid flow meter is provided for and a flow rate determining means for determining a fluid flow rate along.

The thin film further has a pair of edges lying in respective planes substantially parallel to the flow direction of the fluid, and the cross-sectional shape of the fluid flow path is at least partially in the length direction of the flow path. A uniform, fluid-impervious seal can be defined along the uniform section.

The partial section of the fluid flow path length having a uniform cross-sectional shape is defined by a first and a second pair of parallel walls with a rectangular cross-sectional shape, and the thin film lies on an edge of the thin film. The first and second pairs of parallel walls may be arranged such that respective planes are arranged substantially parallel to the first pair of walls.

The fluid impervious seal has at least three points along the flow path.
Can be defined in one position.

The edge of the membrane may be spaced from the first pair of walls substantially by a fluid boundary layer thickness.

The membrane may have a rectangular shape and its longitudinal axis lies parallel to the flow direction.

The flexible thin film extends longitudinally in the fluid flow direction in the fluid flow path, and both ends in the longitudinal direction are fixed in the housing so as to be capable of wavy bending, and the flowmeter is Further, it may be configured to include at least one guide member adjacent to at least one of the ends to assist the wavy bending of the thin film.

First and second ends of the membrane are partially rotatably mounted, respectively, about first and second axes parallel to and through the first pair of walls. Configuration can be adopted.

The housing may be shaped to permit accumulation of debris from the fluid at a location upstream of the membrane but downstream of an adjacent fluid port.

Each of the walls can define an inward facing surface having antistatic and hydrophobic properties.

The guide member may include a plurality of guide blocks each having a rounded inner surface facing the end of the thin film.

The guide member may have an elongated member.

Each of the guide blocks may further include a fluid permeable extension attached to an inner surface of the guide block.

The thin film may be formed of a piezoelectric material layer.

The thin film may include a pair of metallization layers surrounding the piezoelectric material layer.

The metallization layer may be composed of separate metallization portions provided at predetermined discrete positions on the thin film.

The signal generating means comprises first and second electrical contacts each mounted on the surface of the membrane and to the flow rate determining means and wherein an electrical signal is generated upon release of a single volume of fluid. Can be.

The flexible thin film may comprise a magnetic material and the generating means may comprise a magnetic head operable to generate an electrical signal when sensing the approach of the thin film thereto.

The flow determining means may include means for identifying an electrical signal generated by bending of the membrane upon release of a single volume of fluid from the membrane.

The fluid flow meter may include a means for sensing a temperature of the fluid.

The flow rate determining means may include means responsive to the temperature sensing means for providing an alarm indication when the temperature of the fluid reaches at least a predetermined temperature.

The fluid flow meter may be provided with means for sensing the pressure of the fluid.

The flow rate determining means may also include means responsive to the pressure sensing means for providing an alarm indication when the pressure of the fluid reaches at least a predetermined pressure.

The fluid flow meter may include remote data collection means and the flow determination means may also include means for supplying fluid flow data thereto.

The remote data collecting means may be constituted by automatic dial calling means linked to a telephone communication system.

Means for storing a predetermined value for one volume of the fluid flow surrounded by one bend of the thin film, and corresponding to a plurality of electrical signals received over a measured time period. Means for calculating an initial fluid flow rate, the volume of the fluid flow surrounded by one bend of the membrane determined based on the flow supply characteristics of the flow meter with respect to the initial fluid flow rate. Means for comparing the reference value with the predetermined value, means for changing the predetermined value to the reference value of the volume based on the flow supply characteristics of the flow meter, and the accuracy of the flow value. In order to further increase the volume, the volume of the fluid flow surrounded by the one bent portion of the thin film may be adjusted by repeating a predetermined value.

〔Example〕

Hereinafter, the present invention will be described with reference to the accompanying drawings so that a sufficient understanding and high evaluation can be obtained.

FIGS. 1 to 3 show a positive displacement fluid flow meter, generally designated by the numeral 10, which comprises a housing 12 defining a fluid flow chamber 14 (FIG. 2). And first and second ends having first and second fluid ports 18 and 22, respectively.
Has 16 and 20.

Although, in the illustrated embodiment, the fluid ports 18 and 22 act as inlets and outlets, respectively, the internal arrangement of the flow meter 10 is such that the fluid flow is provided by the flow meter in any selected direction and in any suitable orientation. It will be appreciated from the following description that this is possible.

According to a preferred embodiment of the present invention, a flow meter is used to meter the flow of a compressible fluid, such as a gas. However, the flow meter of the present invention can also be used for metering incompressible fluids, such as oil or water, so "fluid"
Are described throughout this document, unless applicable.

According to the illustrated embodiment, housing 12 includes a first end receiving chamber 26 for receiving a fluid flow from inlet 18 prior to fluid passing through flow chamber 14. The first receiving chamber 26 allows any debris and, in the case of a gas stream, moisture to be deposited therein before flowing into the flow chamber 14. Also, a second end chamber 27, similar to the first end receiving chamber 26, is provided to receive the accumulation of debris and moisture in the case of flow in a direction opposite to the direction shown.

In accordance with the present invention, a discrete volume of fluid, each having a known volume, is allowed to pass through an area of the membrane 35, and the flow rate can be determined according to the discrete volume. This will be explained in more detail later. The membrane 35 is very close to the side wall 29 at the edge 33 that is not exposed to the flow, so that any leakage of fluid therethrough is prevented. Although positioned to be typically on the order of tens of microns in size, it is preferred that the gap between the thin film edge and the side wall be reduced in flow conditions.

In addition, with reference to FIGS. 4 and 5, the flow chamber 14
Thus, it comprises a pair of preferably rigid first side walls 30 and a pair of non-rigid second side walls 29 made of a flexible elastomer such as rubber.

As the fluid passes through the membrane 35, the pressure in the flow chamber 14 drops and the flexible second side wall 29 is therefore thickened by the fluid boundary layer (a thin fluid layer with a large flow velocity gradient near the wall). In the transverse direction, tending to move slightly inward to reduce the gap between the edge 33 of the membrane and the second side wall 29. Due to the high resistance to flow along the gap, leakage is thus substantially prevented. The inward movement of the second side wall 29 is further facilitated by the space 31 provided adjacent the edge of the membrane 35.

Referring briefly to FIG. 6, when the second side wall 29 is not made from a flexible material, fluid leakage is substantially prevented by providing a rough surface (also shown in FIG. 3) on the second side wall. It was recognized that it could be done.

With particular reference to FIGS. 2 and 14, the first side wall 30 is shown.
Is preferably coated with a thin layer 34 of antistatic and hydrophobic material such as carbonized polyethylene. The thin layer 34 prevents the formation of static electricity in the flow chamber 14 and the condensation of moisture on the first side wall 30 that may otherwise interfere with the bending of the membrane 35. As will be understood from the following description, it is important that the thin film 35 be maintained so that the bending action is not hindered. According to another embodiment of the present invention, the first side wall 30 is made entirely of an antistatic and hydrophobic material.

With particular reference to FIG. 7, a cross section of a portion of the thin film 35 is shown. According to the illustrated embodiment, the thin film 35 is piezoelectric and comprises a thin layer 36 of piezoelectric material, such as polyvinylidene fluoride, and a metallized surrounding layer, labeled 38 and 40.

According to the embodiment shown in FIG. 24, the thin film 35 is piezoelectric, but unlike the embodiment shown in FIG. 7, the layer 36 made of piezoelectric material is placed on one or both of its surfaces. Are superimposed by separate metallized strips 44 each having an electrical connection 45 to a pulse detector unit 66 (FIG. 17). The membrane flexes, as will be described below in connection with FIGS. 15A-15C, thus allowing the microcontroller 70 to further "correct" the calculated volume of each fluid volume.
(FIG. 17) it is possible to determine the speed of wave propagation along the flow chamber which can be used.

According to a preferred embodiment of the present invention, membrane 35 has a substantially vertical position within flow chamber 14. This avoids possible asymmetric effects of the film due to the effect of gravity.

As shown in FIG. 2, the membrane 35 is preferably longer than the length of the flow chamber 14 in which it is located. This is a thin film
35 assumes a wavy position and the flat side 42 of the membrane preferably has a first side of the flow chamber 14 in at least three positions.
Ensures a stable engagement with the side wall 30.

Referring to FIGS. 2 and 13, it can be seen that the membrane 35 is secured around a rod 52 at its end 51 according to a preferred embodiment. Each rod 52 is sequentially fixed to a fixed rod 54 by a spring 53 housed in a housing 56. This type of mounting, as will be appreciated, allows for limited longitudinal movement of the membrane within the flow chamber.

Referring to FIGS. 2 and 8, a rounded guide block 48 is provided to increase the weakness of the membrane 35 so that as each fluid volume passes through it, an emergency Quick change of position is required. Providing the guide block 48 is an important feature because the guide block 48 assists in switching the membrane from one position to the other under very low input of kinetic energy generated in the gas stream. The range of positions taken by the flexure membrane 35 will be described in detail below with reference to FIGS. 15A-15C.

Referring briefly to FIG. 9, an alternative embodiment of the guide block 48, where each guide block also has an additional layer of rubber, is shown. The guide block 48 has inner surfaces 49, 50 which are rounded in facing relation.

Referring to FIG. 10, a fluid permeable guide extension 60 is provided which is attached to the guide block 48 and forms an extension of the rounded inner or bent surface 49 thereof.

In addition, with reference to FIGS.15A-15C, although the membrane 35 generally does not move along the length of the flow chamber 14, the membrane 35 waves when a separate fluid volume passes through the flow meter, causing the membrane 35 to wave. The point of contact between the fluid and the wall of the flow chamber 14 "runs" through the thin film 35 which bends and moves from a first position just before releasing the fluid flow to a second position just after releasing the fluid flow in the direction of the fluid flow. can do. The guide extension 60 is made of, for example, a wire mesh. Therefore, without interfering with the fluid, the guide extension has the same shape as the membrane 35 in either of its two respective positions taken immediately before and immediately after the release of the fluid volume. Thin film 35
The point of contact with the wall of the flow chamber 14, which coincides with the point of maximum inflection of the membrane 35, flows toward its end and moves along the flow chamber 14, so that the point of contact exits the first side wall 30 and is guided Move on the road extension 60. The guide extension 60 includes a weak constraint under relatively low kinetic energy input, thereby causing a relatively fast change in membrane position between positions taken immediately before and immediately after the release of fluid flow.

As noted, the membrane 35 generally does not move along the flow chamber 14, but a certain amount of relative movement
This occurs between the first side wall 30 and the first side wall 30. Therefore, the first side wall
It is important that the 30 inward faces 37 be very smooth.

According to one embodiment of the present invention, as described,
Is made from a piezoelectric material. However, according to an alternative embodiment, as shown in FIG. 10, the membrane 35 is not made of piezoelectric material, but instead has a pair of electrical contacts 61 attached thereto, each electrical contact 61 being attached to a guide extension 60. The contact is made alternately with the corresponding contact of the pair of attached electrical contacts 63.

It is understood that when each fluid volume passes through the flow chamber 14 and the membrane 35 switches from one position to the other,
That is, the contact between the corresponding contact 63 and one of the contacts 61 generates an electric pulse.

This embodiment has particular advantages with respect to piezoelectric thin films, since a separate pulse is generated each time the thin film 35 moves to release the fluid volume. Therefore, when a piezoelectric thin film is used,
Each movement produces an electrical signal, and a change in the position of the membrane is simply indicated by an increase in signal strength.

According to an alternative embodiment of the invention, only one of each electrical contact 61 and 63 is provided, and a single pulse is thus generated when alternating fluid volumes are passed. It will also be appreciated that the contacts 61 and 63 can be incorporated into other embodiments of the present invention, such as the embodiment shown in FIGS. Further, in another alternative embodiment of the present invention, the electrical contacts 63 may be provided independently of the guide block 48.

FIG. 22 shows an alternative embodiment of the present invention in which the thin film 35 comprises a magnetic tape. Incorporated into the first side wall 30 is preferably a pair of magnetic heads 39. Thin film
The point of contact between one of the first side walls 30 and the membrane 35 is adjacent because the point of contact between the first side wall 30 and the first side wall 30 travels along the flow chamber 14 so that the amount of fluid is typically released. It moves across the head 39, thereby generating an electrical pulse. According to the illustrated embodiment, a signal is generated each time a fluid volume is released, while according to an alternative embodiment, a single magnetic head can be provided to indicate alternating fluid volume releases. .

Referring to FIG. 23, in the illustrated embodiment, as in the embodiment of FIG. 22, the thin film 35 is made of a magnetic tape. However, according to the illustrated embodiment, the magnetic head 39 is embedded in the first side wall 30 of the flow chamber 14 and is operative to engage the surface 41 of the membrane 35 when making contact therewith.

According to the illustrated embodiment, the thin film 35 includes a plurality of magnetic bands provided thereon at a known frequency, such as 5 KHz. When the surface 41 contacts the head 39, the associated processing device 43 senses not only the passage of a portion of the thin film across the head 39, but also the frequency at which the magnetic band passes and measures the speed at which the fluid is passing. Works as follows.

In FIG. 11, the thin film 35 has an additional layer 65 of piezoelectric material.
A thick end 46 is shown which can include The thick end
46 and the additional material layer 65 help reduce the likelihood of failure of the thin film 35 due to fatigue strain. According to an alternative embodiment, the membrane 35 may have a different cross-sectional thickness along its entire length or along its selected part.

As shown in FIGS. 12 and 13, the guide block
48 is not rigidly positioned but is preferably fixed to the first side wall 30 of the flow chamber 14 by a spring 58.

Reference is now made to FIGS. 15A to 15C, which illustrate successive stages of fluid flow through the flow meter of the present invention. Initially, a force is exerted on the membrane 35 until the first fluid volume passes through the flow chamber 14 and the membrane 35 is forced to change position. At this stage, a first quantity of fluid, labeled 62 a, enters between the walls of the flow chamber 14, the membrane 35 and the two contact points between the membrane 35 labeled 67 and the wall of the flow chamber 14.

Since the point of contact closest to the entrance 69 has been established,
A second fluid quantity, labeled 62b, enters the flow chamber 14 and also
Work on 5 and run downstream until it eventually re-enters.

A third fluid quantity, labeled 62c, enters the flow chamber 14 and also exerts a force on the membrane 35. The point of contact continues to travel downstream until the membrane moves from one position to the other by bending, thereby releasing the first fluid volume and generating an electrical pulse.

When the membrane 35 engages the walls of the flow chamber 14 in at least three locations, possible distortion of the membrane 35 and the resulting blockage of the flow chamber 14 that may otherwise occur due to the high velocity flow. Is blocked.

FIG. 16 shows a flow chamber 14 constructed according to an alternative embodiment of the present invention. The flow chamber 14 has a pair of curved walls 64.
Consists of a and 64b. The curvature of the flow chamber 14 results in a desired weak constraint at the location taken by the membrane 35, as described above. Although the amount of fluid flowing along the outer wall 64a is greater than the amount of fluid flowing along the inner wall 64b, the amount of fluid may be determined by averaging two different sized quantities.

Referring to FIGS. 3 and 17, an electrical connection is made to a metallization layer comprising a piezoelectric thin film 35 for carrying an electrical signal generated by the movement of the thin film 35 to a pulse detector unit 66 (FIG. 17). 47 is shown. According to an embodiment of the invention in which the membrane 35 is not piezoelectric and instead uses electrical contacts, the electrical connection 47 is connected to the electrical contact.

When a piezoelectric membrane 35 is used, the pulse detector unit should preferably recognize a special shape of a pulse or electrical signal that corresponds to flexing of the membrane upon release of fluid volume from the outlet 22 of the fluid flow meter. Includes operative signal processing electronics. It is understood that it is important to be able to distinguish such pulses from the background noise signal that is constantly being generated by the membrane 35.

The volume value of the volume of fluid enclosed by one bend of the membrane is preset or predetermined as an initial value, such that each signal received indicates the flow of the reference fluid volume through the flow meter, and the microprocessor 70 is stored in the memory 68. Microprocessor 70 also preferably has a display 72 and a serial communication port 74.

According to a preferred embodiment of the present invention, microprocessor 70 calculates the flow rate by using a preset value for the capacity and by means of the received electrical signal.
Next, using the typical flow supply characteristic data stored in the lookup table for the flow meter 10, the calculated flow rate is compared with the value of the capacity corresponding to the flow rate in the table and the value of the preset amount. Is done. If the values differ in this comparison,
Microprocessor 70 operates to change the value of the preset amount to a different value. And by repeating these steps of the calculation and comparison, in an iterative manner, the microprocessor 70 provides a "real" quantity value and, therefore,
Operate to reach actual flow value.

According to a preferred embodiment of the present invention,
Pressure and temperature sensors (sensing means), labeled 108 and 110 (FIG. 17), are attached to the flow chamber 14 and the microprocessor 70 also provides, according to the received pressure and temperature data, the amount of each fluid volume. The required adjustment of the preset value of the value can be calculated.

Pressure and temperature readings may also be taken when the temperature rises to dangerously high levels that may cause a fire, or below a predetermined threshold that the pressure may serve as an indication of a leak in the equipment. Can be used by microprocessor 70 to provide an alarm indication when descending.

According to an alternative embodiment of the present invention, multiple flow meters are provided to accommodate very large fluid flows, and the flow pulse signals are directed to a central microcontroller for determination of overall fluid flow.

Reference is now made to FIG. 18, which illustrates, in block diagram form, a central data collection device utilizing the flowmeter of the present invention. According to a preferred embodiment of the present invention, a dialer 78 that allows communication between the flow meter (gas meter) 10 and the home telephone line 81 automatically dials the data center 106 and sends it to the flow meter 10.
Operable to transmit information pertaining to the fluid stream as measured by

Timer 76 may be provided to trigger dialer 78 at a given interval, such as once a month and preferably when the telephone line is not in use. The dialer 78 or, preferably, is operable to continue dialing from when triggered by the timer 76 until it has passed through the data center 106 and processed to pass predetermined information. If the connection is interrupted while information is being passed, dialer 78 will operate repeatedly to dial again, if necessary, until the information is passed continuously.

Next, in FIG. 19, the communication between the flow meter (gas meter) 10 and the mini-terminal 86 is performed by the first receiver / transmitter 82 connected to the flow meter 10 and the second transmitter associated with the mini-terminal 86. /
It can be provided by a receiver 84. Mini terminal 86
Can also include a memory bank 88 and a display panel 90. A local network of optical isolation units 92 may be provided on the mini-terminal 96 via a connector 94, as shown in FIG.

In FIG. 21, a flow meter 10, which is a gas flow meter, according to a preferred embodiment has a modem 104 and a remote data center 1.
06 can be connected. This not only allows for the regular transmission of flow information from the flow meter (gas meter) 10 to the data center 106, but also allows the data center 106 to initially scan the flow meter 10.

〔The invention's effect〕

As described above, according to the present invention, a configuration is employed in which a flexible thin film is used and both ends of the thin film are held by the elastic members so as to swing in the fluid flow direction. And when used in a compressible fluid such as a gas, the discrete volume at the bend of the membrane changes with the fluid flow rate, but this fluid flow rate is approximately proportional to the wave rate or vibration frequency of the membrane. Is based on the knowledge of That is, the discrete capacity at the bent portion of the thin film, which is stored in advance in accordance with the count number of the electric signal (ie, a function of the wave rate) obtained by measuring the wave of the flexible thin film, is output as an initial value. A provisional flow value is calculated from the initial value and the count number of the electric signal. This provisional flow rate is then compared to a look-up table (hereinafter referred to as LUT), which derives a separate capacity at the bend of the thin film from the flow rate, which indicates the flow supply characteristics of the flow meter of the present invention. By inputting a value, a separate capacitance at the bent portion is output again, and the initial value of the separate capacitance is compared with the output value of the LUT. In this comparison, if there is no difference, the flow rate is such that there is almost no change in the discrete capacity at the bent portion of the thin film, and the provisional flow rate value can be considered as a correct value. On the other hand, in this comparison, when the initial value and the output value of the LUT are different, first, the initial value of the separate capacitance at the bent portion of the thin film is replaced with the output value of the LUT, and the same processing is repeated. And derive the correct flow value.

In this way, it is used not only for measuring incompressible fluid flow where the characteristics and operation of the flexible thin film does not change, but also for measuring compressible fluid flow where the characteristics and operation of the flexible thin film change due to a change in flow rate. It is possible to provide a fluid flow meter that performs accurate measurement over a wide range irrespective of the magnitude of the flow rate by the correction capability.

It will be understood by those skilled in the art that the present invention is not limited to what has been described above. The scope of the present invention is limited only by the claims.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a revolutionary fluid flow meter constructed according to the present invention, FIG. 2 is a cross section of the fluid flow meter of FIG. 1 along line 2-2 of FIG. 1, and FIG. FIG. 4 is a sectional view taken along line 3-3 of FIG. 2, FIG. 4 is a sectional view taken along line 4-4 of FIG. 3, FIG. 5 is an enlarged detailed view showing a part of the section shown in FIG. FIG. 6 is an enlarged detail view showing a portion of the cross-section shown in FIG. 4, constructed in accordance with an alternative embodiment of the present invention; FIG. 7 is a piezoelectric member useful in the flow meter of FIG. FIG. 8 is an enlarged sectional view taken along line 8-8 of FIG. 3; FIG. 9 is a sectional view showing a structure according to an alternative embodiment of the present invention;
FIG. 10 is an enlarged sectional view similar to FIG. 8, showing the structure according to another embodiment of the present invention, and FIG. 11 is similar to FIG. 7, which has a thicker end. FIG. 12 is a partial cross-sectional view showing the attachment of the guide block spring shown in FIGS. 8 to 10, and FIG. 13 is an end portion of the piezoelectric member shown in FIG. FIG. 14 is a cutaway view showing a part of the side wall of the housing of the flow meter shown in FIG. 1, and FIGS. 15A, 15B and 15C show the flow meter of FIG. FIG. 16 is an illustration showing three successive stages of the transfer of discrete fluid volumes through it; FIG. 16 is a schematic diagram showing a fluid flow meter similar to that shown in FIG. 1 with an arcuate wall; FIG. FIG. 18 is a block diagram illustrating an electronic device associated with the flow meter. FIG. 18 is a block diagram illustrating a telemetry device useful in connection with the fluid flow meter of the present invention. FIG. 19 is a block diagram showing an optional telemetry device useful in connection with the fluid flow meter of the present invention. FIG. 20 is another remote control device useful in connection with the fluid flow meter of the present invention. FIG. 21 is a block diagram showing a measuring device, FIG. 21 is a block diagram showing a multiple telemetry device useful in connection with the fluid flow meter of the present invention, and FIG. 22 is a portion showing a fluid flow meter constructed and operating according to the present invention. FIG. 23 is a partial side sectional view showing a fluid flow meter constructed and operative in accordance with another alternative embodiment of the present invention; FIG. 24 is a view in accordance with an alternative embodiment of the present invention; FIG. 3 is a plan view showing a configured and operating piezoelectric member. In the figure, reference numeral 10 is a fluid flow meter (gas meter), 12 is a housing,
16, 20 are first and second ends, 18, 22 are first and second fluid ports, 30 is first side wall, 35 is thin film, 38, 40 is metallized surrounding layer, 39 is head, 44 is metal Chemical strips, 48 are guiding means (guiding blocks), 49 and 50 are rounded inner surfaces, 60 is a fluid guideway extension, 70 is a microcontroller (microprocessor), 82 is a receiver / transmitter, 84 is Transmitter / receiver,
86 is a mini terminal, 88 is a memory bank, 106 is a data collection center, 108 is a temperature sensing means (temperature sensor), and 110 is a pressure sensing means (pressure sensor).

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-59-40118 (JP, A) JP-A-59-5920 (JP, A) JP-A-59-5917 (JP, A) 114816 (JP, A) JP-A-62-251620 (JP, A)

Claims (26)

(57) [Claims] 1. A housing having a pair of fluid ports and defining a fluid channel between them, and has front and rear surfaces, and both ends of the fluid channel in a fluid path direction have elastic members. And the front and back surfaces each cooperate with the housing to simultaneously define a fluid-tight seal at at least two different locations along the fluid flow path. A flexible membrane that bends to allow the passage of fluid in discrete volumes indicated by known volumes having a variation as a function of: a means for generating an electrical signal in response to the flexion of the membrane; Receiving the electrical signal from the signal generating means over a measurement period, detecting a ratio of the electrical signal, determining the known volume that is the discrete quantity based on the ratio of the electrical signal, and Flow along the flow path with known volume Fluid flow meter characterized by comprising a flow determining means for determining the flow rate. 2. The thin film further comprises a pair of edges lying in respective planes substantially parallel to a flow direction of the fluid, wherein a cross-sectional shape of the fluid flow path is in a length direction of the flow path. The fluid flow meter of claim 1, wherein the fluid flow meter is uniform at least in some sections and the fluid impermeable seal is defined along the uniform section. 3. The first and second sections of the fluid flow path having a uniform cross-sectional shape having a rectangular cross-sectional shape.
The first and second pairs of the thin films are defined by a pair of parallel walls such that the respective planes on which the edges of the thin films lie are arranged substantially parallel to the first pair of walls. 3. The fluid flow meter according to claim 2, wherein the fluid flow meter is disposed between the parallel walls. 4. The fluid flow meter according to claim 3, wherein said fluid impermeable seal is defined at at least three locations along said flow path. 5. The fluid flow meter of claim 4, wherein the edge of the membrane is spaced from the first pair of walls by substantially the fluid boundary layer thickness. 6. A fluid flow meter according to claim 5, wherein said membrane has a rectangular shape and its longitudinal axis lies parallel to the flow direction. 7. The flexible thin film extends longitudinally in the fluid flow direction in the fluid flow path, and has both ends in the longitudinal direction fixed in the housing so as to be capable of wavy bending, and The fluid flow meter of claim 6, wherein the flow meter further comprises at least one guide member adjacent at least one of the ends to assist in wavy bending of the membrane. 8. The thin film according to claim 1, wherein said first and second ends are connected to said second end.
8. The method of claim 7, wherein the first and second walls are partially rotatably mounted about first and second axes, respectively, parallel to and through the first pair of walls. Fluid flow meter. 9. The fluid according to claim 8, wherein said housing is configured to permit accumulation of debris from said fluid at a location upstream of said membrane but downstream of an adjacent fluid port. Flowmeter. 10. The fluid flow meter of claim 9, wherein each of said walls defines an inward facing surface having antistatic and hydrophobic properties. 11. The fluid flow meter according to claim 7, wherein said guide member has a plurality of guide blocks having a rounded inner surface facing the end of said thin film. 12. The fluid flow meter according to claim 7, wherein said guide member has an elongated member. 13. The fluid flow meter according to claim 11, wherein each of said guide blocks further comprises a fluid permeable extension mounted on an inner surface of said guide block. 14. The fluid flow meter according to claim 1, wherein said thin film is made of a piezoelectric material layer. 15. The fluid flow meter according to claim 14, wherein the thin film has a pair of metallization layers surrounding the piezoelectric material layer. 16. The fluid flow meter according to claim 15, wherein said metallized layer comprises a separate metallized portion provided at a predetermined discrete position on said thin film. 17. A method according to claim 1, wherein said signal generating means are respectively mounted on said surface of said membrane and to said flow rate determining means, and wherein said first and second electrical contacts are such that an electrical signal is generated upon release of a single quantity of fluid. The fluid flow meter according to claim 1, wherein 18. The flexible thin film comprises a magnetic material and said generating means comprises a magnetic head operable to generate an electrical signal when sensing the approach of said thin film thereto. Item 7. A fluid flow meter according to Item 1. 19. The apparatus according to claim 1, wherein said flow rate determining means includes means for identifying an electrical signal generated by bending of said membrane upon release of a single volume of fluid from said membrane. Fluid flow meter. 20. The fluid flow meter according to claim 1, wherein the fluid flow meter includes a means for sensing a temperature of the fluid. 21. The apparatus according to claim 20, wherein said flow rate determining means includes means responsive to said temperature sensing means for providing an alarm indication when the temperature of the fluid reaches at least a predetermined temperature. Fluid flow meter. 22. A fluid flow meter according to claim 1, wherein said fluid flow meter is provided with means for sensing the pressure of said fluid. 23. The apparatus of claim 22, wherein said flow determining means also includes means responsive to said pressure sensing means for providing an alarm indication when the pressure of the fluid reaches at least a predetermined pressure. Fluid flow meter. 24. The fluid flow meter of claim 1, wherein said fluid flow meter includes remote data collection means and said flow rate determining means also includes means for supplying fluid flow data thereto. 25. The fluid flow meter according to claim 24, wherein said remote data collection means comprises an automatic dialing means linked to a telephone communication system. 26. The flow rate determining means for storing a predetermined value for one volume of a fluid flow surrounded by one bend of the thin film, and a plurality of values received over a measured time period. Means for calculating an initial fluid flow rate corresponding to the electrical signal of the fluid, and further comprising a fluid surrounded by one bend of the thin film determined based on a flow supply characteristic of the flow meter with respect to the initial fluid flow rate. Means for comparing a reference value of one volume of the flow with the predetermined value; means for changing the predetermined value to the reference value of the volume based on a flow supply characteristic of the flow meter; And means for adjusting a volume of the fluid flow surrounded by one bend of the thin film by repeating a predetermined value so as to further increase the accuracy of the value. To (25). Body flow meter.