JPH0972767A - Vibration sensor for fluid and flow detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect flow rate with high accuracy for a long term using a vibration sensor for fluid which can sustain the detection characteristics for a long term without requiring any adjustment. SOLUTION: The flexure detecting section 6 of a flexure detecting means 8 magnetically detects the flexure of a magnetic membrane 5 caused by the pressure P1 of a fluid introduced into a first pressure chamber 3 and the pressure of a fluid introduced into a second pressure chamber 4 and a signal converting section 7 outputs an electric detection signal SD corresponding to the detected flexure of magnetic membrane 5. Since the signal converting section 7 is not exposed directly to the fluid, corrosion of the electric system is retarded and since a magnetic membrane is employed for detecting the flexure, fluctuation in the characteristics is suppressed thus suppressing the aging and providing a sensor suitable for long term use. Furthermore, the flexure detecting section 6 has low electric impedance and insusceptible to electric noise thus ensuring high reliability and a flow detector employing the flexure detecting section 6 can detect the flow rate with high reliability for a long term.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid vibration detection sensor and a flow rate detection device using the fluid vibration detection sensor, and more particularly to a fluidic flow rate sensor for measuring a fluid flow rate by utilizing fluidic vibration. The present invention relates to a fluid vibration detection sensor and a flow rate detection device.

[0002]

2. Description of the Related Art FIG. 7 is a partial cross-sectional perspective view of a conventional fluidic flow sensor when the conventional fluidic flow sensor is configured as a flow rate detecting device. The fluidic flow sensor 80 has an inlet 8 through which a fluid to be measured flows.
A set ring space 83 for rectifying the flow of the fluid into a two-dimensional flow on the flow path connecting 1 and the discharge pipe 82;
A flow path reducing portion 84 for rectifying the flow of the fluid and reducing the flow path diameter of the fluid, a jet nozzle 85 for rectifying the flow of the fluid and converting it into a predetermined jet flow, and the flow path diameter of the fluid is enlarged again. And a flow path expanding portion 86 for

Inside the flow passage expanding portion 86, a pendulum 87 for inducing vibration of the fluid, a side block 88 for forming a flow passage for changing the flow direction of the jet flow, and a side block 88 cooperate with each other. End block 89 that works and changes the flow of the jet flow by the collision of the jet flow
And a discharge space 90 arranged on a surface side of the end block 89 different from the jet flow collision surface.

The end block 89 is the side block 8
A wall 89a extending toward the upstream side of the flow path along 8
A wall 89b, a first pressure detection hole (pressure guide port) 91a, and a second pressure detection hole (pressure guide port) 91b are provided.
Further, the pressure guiding pipe 92a and the pressure guiding pipe 9 are provided in the first pressure detecting hole (pressure guiding port) 91a and the second pressure detecting hole (pressure guiding port) 91b.
A flow rate detection unit 93 incorporating a fluid vibration pressure sensor, which will be described later, is connected via 2b.

FIG. 8A shows a schematic configuration diagram of a fluid vibration pressure sensor. The fluid vibration pressure sensor includes a central chamber 104, a first outer chamber 105, and a second outer chamber 1 in which the pressure chamber 101 is composed of two piezoelectric films, a first piezoelectric film 102 and a second piezoelectric film 103.
As shown in FIG. 7, the central chamber 104 is connected to the first pressure detection hole 91a in the fluidic element of the fluidic flow sensor via the pressure guiding tube 92a, and is divided into two chambers. The chambers 105 and 106 communicate with the second pressure detection hole 91b in the fluidic element via a pressure guiding tube 92b.

FIG. 8 (b) shows a schematic structure of a detection circuit corresponding to the fluid vibration pressure sensor of FIG. 8 (a). Detection circuit 1
Reference numeral 10 denotes a first amplification amplifier 111 that detects and amplifies the output voltage of the first piezoelectric film 102, a second amplification amplifier 112 that detects and amplifies the output voltage of the second piezoelectric film 103, and an output of the first amplification amplifier 111. A differential amplifier 113 that differentially amplifies the signal and the output signal of the second amplification amplifier 112 and outputs an output detection signal.

Now, the operation of the detection circuit will be described. The first piezoelectric film 102 will bend due to the difference between the fluid pressure in the central chamber 104 and the fluid pressure in the first outer chamber 105. As a result, an output voltage corresponding to the bending state is generated in the first piezoelectric film 102, and the first amplification amplifier 111 is
The output voltage of the first piezoelectric film 102 is detected, amplified, and output to the differential amplifier 113.

On the other hand, the second piezoelectric film 103 has a central chamber 104.
It will bend due to the difference between the fluid pressure inside and the fluid pressure inside the second outer chamber 106. As a result, an output voltage is generated in the second piezoelectric film 103 according to the bending state, and the second amplification amplifier 112 detects the output voltage of the second piezoelectric film 103, amplifies it, and outputs it to the differential amplifier 113. .

As a result, the differential amplifier 113 has the first
Output signal of amplification amplifier 111 and second amplification amplifier 112
The output detection signal is output by differentially amplifying the output signal of (1), and the flow rate detection unit detects the flow rate of the fluid based on this output detection signal.

FIG. 9 shows a sectional view of the piezoelectric film. Piezoelectric film 12
0 is composed of three layers of electrode part 121 / piezoelectric part 122 / electrode part 123, and the electrode parts 121 and 123 are inside the pressure chamber 101 (in the central chamber 104 or outside chambers 105 and 106).
It is exposed to the inside).

[0011]

In the above-mentioned conventional fluid vibration pressure sensor, since the detection characteristics of the piezoelectric film have individual differences, the auxiliary circuit (filter, Schmidt) is adjusted according to the detection characteristics of the piezoelectric film. There is a problem in that it is necessary to carry out the adjustment and it takes time and effort for adjustment.

Further, there is a problem that it is not suitable for long-term use because the detection characteristic changes with the aging of the piezoelectric film. Further, since the electrode portion of the piezoelectric film is exposed in the pressure chamber (the central chamber or the outer chamber), it comes into direct contact with the gas to be measured, and there is a problem that the detection characteristics are likely to deteriorate due to corrosion or the like. .

Therefore, a first object of the present invention is to provide a fluid vibration detection sensor which requires no adjustment work and can maintain the detection characteristics for a long time and can be used for a long time. A second object of the present invention is to provide a flow rate detecting device that can detect a flow rate with high accuracy over a long period by using a fluid vibration detection sensor.

[0014]

In order to solve the above problems, the invention according to claim 1 is such that the pressure chamber 2 of the fluid vibration pressure sensor 1 is replaced by the first pressure chamber 3 as shown in the basic configuration diagram of FIG.
And the magnetic film 5 which is separated into the second pressure chamber 4 and the pressure P1 of the fluid provided in the pressure chamber 2 and introduced into the first pressure chamber 3.
And a signal conversion unit provided outside the pressure chamber 2 having a bending detection unit 6 for magnetically detecting the bending state of the magnetic film 5 caused by the pressure P2 of the fluid introduced into the second pressure chamber 4. 7
Therefore, the deflection detecting means 8 for outputting the electric detection signal SD according to the deflection state of the magnetic film 5 is provided.

According to the first aspect of the present invention, the flexure detecting portion 6 of the flexure detecting means 8 has the pressure P1 of the fluid introduced into the first pressure chamber 3 and the pressure of the fluid introduced into the second pressure chamber 4. The bending state of the magnetic film 5 caused by P2 is magnetically detected. As a result, the signal converter 7 outputs the electrical detection signal SD according to the detected bending state of the magnetic film 5.

According to a second aspect of the present invention, the first pressure chamber is provided with the second pressure chamber.
A first magnetic film separating the pressure chamber and the third pressure chamber, a second magnetic film separating the fourth pressure chamber into a fifth pressure chamber and a sixth pressure chamber, the second pressure chamber and the sixth pressure film. A first communication passage communicating with the pressure chamber, a second communication passage communicating with the third pressure chamber and the fifth pressure chamber, and a fluid provided in the first pressure chamber and introduced into the second pressure chamber. A flexure first detector for magnetically detecting the flexure state of the first magnetic film caused by the pressure and the pressure of the fluid introduced into the third pressure chamber is provided outside the first pressure chamber. And a first deflection detecting means for outputting a first electric detection signal according to a deflection state of the first magnetic film by the first signal converting section, and a first deflection detecting means provided in the fourth pressure chamber and introduced into the fifth pressure chamber. Fluid pressure and the sixth
A second signal conversion unit provided outside the fourth pressure chamber, which has a second bending unit for magnetically detecting a bending state of the second magnetic film caused by the pressure of the fluid introduced into the pressure chamber. And a second deflection detecting means for outputting a second electrical detection signal having a phase opposite to that of the first electrical detection signal depending on the bending state of the second magnetic film.

According to the second aspect of the invention, since the first communication passage connects the second pressure chamber and the sixth pressure chamber, the pressure of the fluid in the second pressure chamber and the pressure of the fluid in the sixth pressure chamber are Will be equal. Similarly, since the second communication passage connects the third pressure chamber and the fifth pressure chamber, the pressure of the fluid inside the third pressure chamber and the pressure of the fluid inside the fifth pressure chamber become equal.

In parallel with these, the first detecting portion of the first deflection detecting means is caused by the pressure of the fluid introduced into the second pressure chamber and the pressure of the fluid introduced into the third pressure chamber. The bending state of the first magnetic film is magnetically detected, and the first signal conversion unit outputs a first electrical detection signal according to the bending state of the first magnetic film.

The second detecting portion of the second deflection detecting means is
The bending state of the second magnetic film caused by the pressure of the fluid introduced into the fifth pressure chamber and the pressure of the fluid introduced into the sixth pressure chamber is magnetically detected, and the second signal conversion unit 2 The second electric detection signal is output according to the bending state of the magnetic film and in the opposite phase to the first electric detection signal.

According to the second aspect of the present invention, since the first communication passage connects the second pressure chamber and the fifth pressure chamber, the pressure of the fluid in the second pressure chamber and the pressure of the fluid in the fifth pressure chamber are Will be equal. Similarly, since the second communication passage connects the third pressure chamber and the fifth pressure chamber, the pressure of the fluid inside the third pressure chamber and the pressure of the fluid inside the fifth pressure chamber become equal.

In parallel with these, the first detecting section of the first deflection detecting means is caused by the pressure of the fluid introduced into the second pressure chamber and the pressure of the fluid introduced into the third pressure chamber. The bending state of the first magnetic film is magnetically detected, and the first signal conversion unit outputs a first electrical detection signal according to the bending state of the first magnetic film.

The second detector of the second deflection detecting means is
The bending state of the second magnetic film caused by the pressure of the fluid introduced into the fifth pressure chamber and the pressure of the fluid introduced into the sixth pressure chamber is magnetically detected, and the second signal conversion unit 2 The second electric detection signal is output according to the bending state of the magnetic film and in the opposite phase to the first electric detection signal.

The invention according to claim 3 has the fluid vibration detection sensor according to claim 1, and as shown in the basic configuration diagram of FIG. 1, the flow rate of the fluid is determined based on the fluid vibration in the fluidic element 10. A flow rate detecting device 20 for detecting, which is a first pressure introducing port 11 and a second pressure introducing port 12 provided at predetermined symmetrical positions in the fluidic element with respect to the flow direction of the fluid G in the fluidic element 10. The first pressure chamber 3 communicates with one of the pressure guide ports (the first pressure guide port 11 in the figure) and the second pressure chamber with the other pressure guide port (the second pressure guide port 12 in FIG. 1). Four
And a flow rate calculating means 13 for calculating the flow rate of the fluid G based on the electricity detection signal SD.

According to the third aspect of the present invention, the first pressure introducing port 11 and the second pressure introducing port 11 provided at the predetermined symmetrical positions in the fluidic element 10 with respect to the flow direction of the fluid G in the fluidic element 10. One of the pressure guide ports 12 communicates with the first pressure chamber 3 of the fluid vibration detection sensor 1, and the other pressure guide port 12 communicates with the second pressure chamber 4. SD is the pressure of the fluid G on the first pressure guide port 11 side and the second
The signal corresponding to the fluidic vibration is generated based on the relative relationship of the pressure of the fluid G on the pressure guide port 12 side, and the flow rate calculation means 13 determines the fluid G based on the frequency of this electrical detection signal SD.
Calculate the flow rate of.

According to a fourth aspect of the present invention, there is provided a fluid flow detection device having the fluid vibration detection sensor according to the second aspect, wherein the flow rate detection device detects the flow rate of the fluid based on the fluid vibration in the fluidic element. One of the first pressure guide port and the second pressure guide port provided at a symmetrical predetermined position in the fluidic device with respect to the flow direction of the fluid in the device has the second pressure chamber and the second pressure chamber. The sixth pressure chamber communicates with the other pressure guide port, the third pressure chamber communicates with the fifth pressure chamber, and a difference signal corresponding to the difference between the first electric detection signal and the second electric detection signal. And a flow rate detecting means for calculating the flow rate of the fluid based on the difference signal.

According to the fourth aspect of the present invention, the first pressure guiding port and the second pressure guiding port provided at symmetrical predetermined positions in the fluidic element with respect to the flow direction of the fluid in the fluidic element. Since the second pressure chamber and the sixth pressure chamber are communicated with one of the pressure guide ports and the third pressure chamber and the fifth pressure chamber are communicated with the other pressure guide port, the first electric detection signal and The second electric detection signal becomes a signal corresponding to fluidic vibration based on the relative relationship between the pressure of the fluid on the first pressure guide side and the pressure of the fluid on the second pressure guide side, and the phase of the second electric detection signal Becomes opposite to the phase of the first electrical detection signal.

Thus, the differential means outputs the difference between the first electric detection signal and the second electric detection signal, that is, the difference signal which is a signal obtained by amplifying the amplitude of one electric detection signal. Thereby, the flow rate detection means calculates the flow rate of the fluid based on the difference signal.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a preferred embodiment of the present invention will be described with reference to the drawings. FIG. 2 shows a schematic configuration diagram when the fluid vibration detection sensor is connected to the fluidic element of FIG.

The fluid vibration detection sensor 30 includes the first pressure chamber 3
1 for separating 1 into a second pressure chamber 32 and a third pressure chamber 33
The magnetic film 34, the fourth pressure chamber 35, and the fifth pressure chamber 36
A second magnetic film 38 which separates into the pressure chamber 37, a first communication passage 39 which connects the second pressure chamber 33 and the sixth pressure chamber 37, and a first communication passage 39 which connects the third pressure chamber 33 and the fifth pressure chamber 36. 2 passages 4
0, and the first magnetic film formed due to the pressure P1 of the fluid introduced into the second pressure chamber 32 provided in the first pressure chamber 31 and the pressure P2 of the fluid introduced into the third pressure chamber 33. 34
The first signal converter 42 provided outside the first pressure chamber 31 has a bending first detector 41 that magnetically detects the bending state of the first pressure chamber 31.
The first deflection detection circuit 43 that outputs the first electrical detection signal SD1 according to the deflection state of the first magnetic film 34 and the fluid that is provided in the fourth pressure chamber 35 and is introduced into the fifth pressure chamber 36 The second pressure detecting portion 44 magnetically detects the bending state of the second magnetic film 38 caused by the pressure P2 and the pressure P1 of the fluid introduced into the sixth pressure chamber 37. A second deflection detection circuit 46 that outputs a second electrical detection signal SD2 according to the deflection state of the second magnetic film 38 by a second signal conversion unit 45 provided outside the circuit 35.

Further, the first communication passage 39 is communicated with the first pressure detection hole 91a of the fluidic flow sensor 80, and the second communication passage 40 is the second pressure passage of the fluidic flow sensor 80.
It communicates with the pressure detection hole 91b. FIG. 3 shows a schematic block diagram of a flow rate detection display device as a flow rate detection device of the present invention.

The flow rate detection display device 50 amplifies the first electric detection signal SD1 which is the output signal of the fluid vibration detection sensor 30 and outputs it as the first amplified detection signal ASD1 and the fluid vibration detection sensor 30. Second output signal of
A second amplifier 52 that amplifies the electrical detection signal SD2 and outputs it as a second amplification detection signal ASD2; and a first amplification detection signal AS
A differential amplifier 53 that differentially amplifies D1 and the second amplified detection signal AS D2 and outputs as a differential signal SDEL, and a differential signal S
A filter circuit 54 for removing and outputting a predetermined frequency band component in order to remove a noise component of DEL, and a filter circuit 5.
The Schmitt trigger circuit 55 that performs the waveform shaping based on the output signal of 4 and outputs the rectangular wave output signal, and the operation based on the rectangular wave output signal of the Schmitt trigger circuit to obtain the flow rate of the fluid and the operation result. Is provided with a processor 56 for outputting a display control signal SCD for displaying on a monitor, which will be described later, and a monitor 57 such as a liquid crystal monitor for performing various displays.

Next, the operations of the fluid vibration detection sensor 30 and the flow rate detection display device 50 will be described with reference to FIGS. 1 A) In the case of P1> P2 FIG. 4 shows an operation explanatory diagram in the case of P1> P2.

In the case of P1> P2, that is, the fluid pressure is high on the side of the first pressure detecting hole 91a and the second pressure detecting hole 91b.
When the fluid pressure on the side is low, as shown in FIG.
Since the fluid pressure on the second pressure chamber 32 side is low and the fluid pressure on the third pressure chamber 33 side is high on the first pressure chamber 31 side, the first magnetic film 34 is disposed on the second pressure chamber 32 side (drawing, upper side). ) Will be bent to be convex.

As a result, the deflection first detection section 41 of the first deflection detection circuit 43 magnetically detects the deflection state of the first magnetic film 34, and the first signal conversion section 42 causes the deflection of the first magnetic film 34. The first electrical detection signal SD1 (FIG. 4 (b) (i) according to the state
Is output to the first amplification amplifier 51.

The first amplification amplifier 51 amplifies the first electric detection signal SD1 and outputs it as the first amplification detection signal ASD1 to the non-inverting input terminal of the differential amplifier 53. On the other hand, on the fourth pressure chamber 35 side, the fluid pressure on the fifth pressure chamber 36 side is high, and
Since the fluid pressure on the pressure chamber 37 side is low, the second magnetic film 38
Is bent so as to be convex toward the sixth pressure chamber 37 side (the lower side in the drawing).

As a result, the second bending detecting section 44 of the second bending detecting circuit 46 magnetically detects the bending state of the second magnetic film 38, and the second signal converting section 45 bends the second magnetic film 38. The second electrical detection signal SD2 (FIG. 4 (b) (i
i)) is output to the second amplification amplifier 52.

The second amplification amplifier 52 amplifies the second electric detection signal SD2 and outputs it as the second amplification detection signal ASD2 to the inverting input terminal of the differential amplifier 53. As a result, the differential amplifier 53 differentially amplifies the first amplification detection signal AS D1 and the second amplification detection signal AS D2 to generate the difference signal SDEL (see FIG. 4).
(B) (see (iii)), and outputs to the filter circuit 54.

As described above, the first detection signal SD1 (substantially the first amplification detection signal ASD1) and the second electric detection signal SD2
(Substantially, the second amplification detection signal AS D1) is differentially amplified, so that a minute change in the flow rate can be easily detected, and the in-phase noise component included in both signals can be removed. Therefore, the flow rate can be detected with higher accuracy.

Next, the filter circuit 54 removes a predetermined frequency band component in order to remove the noise component of the difference signal SDEL and outputs it to the Schmitt trigger circuit 55. The Schmitt trigger circuit is based on the output signal of the filter circuit 54. Waveform shaping is performed and a rectangular wave output signal is output to the processor 56.

As a result, the processor 56 calculates based on the rectangular wave output signal of the Schmitt trigger circuit to obtain the flow rate of the fluid and outputs the display control signal SCD for displaying the calculation result on the monitor. ,
The flow rate as the calculation result is displayed on the monitor. B) In the case of P1 <P2 FIG. 5 shows the operation explanatory diagram in the case of P1 <P2.

When P1 <P2, that is, the first pressure detecting hole 91a side has a low fluid pressure, and the second pressure detecting hole 91b
When the fluid pressure on the side is high, as shown in FIG.
On the first pressure chamber 31 side, the fluid pressure on the second pressure chamber 32 side is high and the fluid pressure on the third pressure chamber 33 side is low. It will bend so that it is convex to the side).

As a result, the flexure first detecting section 41 of the first flexure detecting circuit 43 magnetically detects the flexing state of the first magnetic film 34, and the first signal converting section 42 flexes the first magnetic film 34. The first electric detection signal SD1 according to the state (FIG. 5 (b) (i)
Is output to the first amplification amplifier 51.

The first amplification amplifier 51 amplifies the first electric detection signal SD1 and outputs it as the first amplification detection signal ASD1 to the non-inverting input terminal of the differential amplifier 53. On the other hand, on the fourth pressure chamber 35 side, the fluid pressure on the fifth pressure chamber 36 side is low,
Since the fluid pressure on the pressure chamber 37 side is high, the second magnetic film 38
Is bent so as to be convex toward the fifth pressure chamber 37 side (upper side in the drawing).

As a result, the deflection second detection section 44 of the second deflection detection circuit 46 magnetically detects the deflection state of the second magnetic film 38, and the second signal conversion section 45 causes the deflection of the second magnetic film 38. The second electrical detection signal SD2 (FIG. 5 (b) (i
i)) is output to the second amplification amplifier 52.

The second amplification amplifier 52 amplifies the second electric detection signal SD2 and outputs it as the second amplification detection signal ASD2 to the inverting input terminal of the differential amplifier 53. As a result, the differential amplifier 53 differentially amplifies the first amplification detection signal AS D1 and the second amplification detection signal AS D2 to generate the difference signal SDEL (see FIG. 5).
(B) (see (iii)), and outputs to the filter circuit 54.

As described above, the first detection signal SD1 (substantially the first amplification detection signal ASD1) and the second electric detection signal SD2
(Substantially, the second amplification detection signal AS D1) is differentially amplified, so that a minute change in the flow rate can be easily detected, and the in-phase noise component included in both signals can be removed. Therefore, the flow rate can be detected with higher accuracy.

Next, the filter circuit 54 removes a predetermined frequency band component in order to remove the noise component of the difference signal SDEL and outputs it to the Schmitt trigger circuit 55. The Schmitt trigger circuit is based on the output signal of the filter circuit 54. Waveform shaping is performed and a rectangular wave output signal is output to the processor 56.

As a result, the processor 56 calculates based on the rectangular wave output signal of the Schmitt trigger circuit to obtain the flow rate of the fluid, and outputs the display control signal SCD for displaying the calculation result to the monitor. ,
The flow rate as the calculation result is displayed on the monitor. C) In case of noise such as external vibration Fig. 6 shows an operation explanatory diagram when noise such as external vibration occurs.

When noise such as an external vibration occurs (it is easy to understand if a case of P1 = P2 is typically assumed), that is, the fluid pressure on the first pressure detecting hole 91a side and the second pressure detecting hole 91b side. Irrespective of the fluid pressure, the first magnetic film 34 and the second magnetic film 38 are bent in the same direction due to external vibration or the like.

As a result, the deflection first detection section 41 of the first deflection detection circuit 43 magnetically detects the deflection state of the first magnetic film 34, and the first signal conversion section 42 deflects the first magnetic film 34. The first electric detection signal SD1 according to the state (FIG. 6 (b) (i)
Output) to the first amplification amplifier 51, and the 1 amplification amplifier 5
1 amplifies the first electric detection signal SD1 and outputs it to the non-inverting input terminal of the differential amplifier 53 as the first amplification detection signal ASD1.

Similarly, the deflection second detection section 44 of the second deflection detection circuit 46 magnetically detects the deflection state of the second magnetic film 38, and the second signal conversion section 45 causes the deflection of the second magnetic film 38. The second electric detection signal SD2 (see FIG. 6 (b) (ii)) corresponding to the state is output to the second amplification amplifier 52, and the second amplification amplifier 5
2 amplifies the second electric detection signal SD2 and outputs it to the inverting input terminal of the differential amplifier 53 as the second amplification detection signal ASD2.

As a result, the differential amplifier 53 differentially amplifies the first amplified detection signal AS D1 and the second amplified detection signal AS D2 to obtain a difference signal SDEL (see FIG. 6B (iii)). To 54. Figure 6 (b)
As shown in (iii), the first detection signal SD1 (substantially the first amplified detection signal ASD1) and the second electrical detection signal SD2
(Substantially, the second amplified detection signal AS D1) is canceled by the differential amplification, and the deflection due to noise is detected.

Therefore, it is understood that the flow rate can be detected with high accuracy without being affected by such a disturbance.

[0054]

According to the invention as set forth in claim 1, the flexure detecting portion 6 of the flexure detecting means 8 has the pressure P1 of the fluid introduced into the first pressure chamber 3 and the fluid introduced into the second pressure chamber 4. The bending state of the magnetic film 5 caused by the pressure is magnetically detected, and the signal conversion unit 7 outputs the electric detection signal SD corresponding to the detected bending state of the magnetic film 5. Therefore, the signal conversion unit 7
Is not directly exposed to the fluid, and corrosion of the electric system can be suppressed. Further, since the magnetic film is used for the deflection detection, the variation in characteristics can be suppressed as compared with the case where the piezoelectric film is used, and the change over time is small, which is suitable for long-term use. Further, the deflection detection unit 6 can lower the electrical impedance, resist electrical noise, and obtain high reliability.

According to the second aspect of the present invention, since the first communication passage connects the second pressure chamber and the fifth pressure chamber, the pressure of the fluid in the second pressure chamber and the pressure of the fluid in the fifth pressure chamber are Similarly, since the second communication passage connects the third pressure chamber and the sixth pressure chamber, the pressure of the fluid in the third pressure chamber becomes equal to the pressure of the fluid in the sixth pressure chamber, and the first deflection First of detection means
The detection unit magnetically detects the bending state of the first magnetic film caused by the pressure of the fluid introduced into the second pressure chamber and the pressure of the fluid introduced into the third pressure chamber, and performs the first signal conversion. The section outputs a first electric detection signal according to the bending state of the first magnetic film, and the second detecting section of the second bending detecting means is configured to detect the pressure of the fluid introduced into the fifth pressure chamber and the sixth pressure chamber. The bending state of the second magnetic film caused by the pressure of the fluid introduced into the magnetic field is magnetically detected, and the second signal conversion unit is responsive to the bending state of the second magnetic film and detects the first electrical detection signal. Since the second electric detection signal having a phase opposite to that of is output, it is possible to easily remove the common-mode noise component included in both the first electric detection signal and the second electric detection signal by performing differential amplification. As a result, disturbance noise such as external vibration is included as in-phase noise in both the first electrical detection signal and the second electrical detection signal, and these effects can be reduced.

According to the third aspect of the present invention, the first pressure guide port and the second pressure guide port are provided at predetermined symmetrical positions in the fluidic element with respect to the fluid flow direction in the fluidic element.
One of the pressure guide ports is connected to the first pressure chamber 3 of the fluid vibration detection sensor 1, the other pressure guide port is connected to the second pressure chamber 4, and the electrical detection signal is the first pressure guide port. Is a signal corresponding to fluidic vibration based on the relative relationship between the pressure of the fluid on the side and the pressure of the fluid on the side of the second pressure guide, and the flow rate calculation means calculates the flow rate of the fluid based on the frequency of this electrical detection signal. Therefore, the signal converter 7 is not directly exposed to the fluid, corrosion of the electric system is suppressed, and the magnetic film is used for the deflection detection, so that there is variation in characteristics as compared with the case of using the piezoelectric film. It is suitable for long-term use because it can be suppressed to a small value, has little change over time, and can stably detect the fluid flow rate over a long period of time. Further, the deflection detection unit 6 can lower the electric impedance,
It becomes resistant to electrical noise and highly reliable flow rate data can be obtained.

According to the fourth aspect of the present invention, the first pressure guiding port and the second pressure guiding port provided at symmetrical predetermined positions in the fluidic element with respect to the flow direction of the fluid in the fluidic element. Since the second pressure chamber and the fifth pressure chamber are communicated with one of the pressure guide ports and the third pressure chamber and the sixth pressure chamber are communicated with the other pressure guide port, the first electric detection signal and The second electric detection signal becomes a signal corresponding to fluidic vibration based on the relative relationship between the pressure of the fluid on the first pressure guide side and the pressure of the fluid on the second pressure guide side, and the phase of the second electric detection signal Is a phase opposite to the phase of the first electric detection signal, and the differential means is a difference between the first electric detection signal and the second electric detection signal,
That is, the difference signal, which is a signal obtained by amplifying the amplitude of one of the electric detection signals, is output, and the flow rate detecting means calculates the flow rate of the fluid based on the difference signal. Therefore, the first electric detection is performed by performing differential amplification. The in-phase noise component included in both the signal and the second electrical detection signal can be easily removed. As a result, disturbance noise such as external vibration is included as in-phase noise in both the first electric detection signal and the second electric detection signal, and the influence can be reduced to obtain the flow rate.

[Brief description of drawings]

FIG. 1 is a basic configuration diagram of the present invention.

FIG. 2 is a schematic configuration diagram when a fluid vibration detection sensor is connected to a fluidic element.

FIG. 3 is a schematic block diagram of a flow rate detection display device.

FIG. 4 is an operation explanatory view in the case of fluid pressure P1> fluid pressure P2.

FIG. 5 is an operation explanatory diagram in the case of fluid pressure P1 <fluid pressure P2.

FIG. 6 is an operation explanatory diagram when noise such as an external vibration occurs.

FIG. 7 is a schematic configuration diagram of a flow rate detection device using a fluidic element.

FIG. 8 is a schematic configuration and operation explanatory diagram of a fluid vibration pressure sensor.

FIG. 9 is a cross-sectional view of a piezoelectric film.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fluid vibration pressure sensor 2 Pressure chamber 3 1st pressure chamber 4 2nd pressure chamber 5 Magnetic film 6 Deflection detection part 7 Signal conversion part 8 Deflection detection means 10 Fluidic element 11 First pressure port 12 Second pressure port 13 Flow rate calculation means 20 Flow rate detector G Fluid P1, P2 Fluid pressure SD Electric detection signal

Claims (4)

[Claims] 1. A magnetic film for separating a pressure chamber into a first pressure chamber and a second pressure chamber, a pressure of a fluid provided in the pressure chamber and introduced into the first pressure chamber, and a second pressure chamber. It has a flexure detecting section for magnetically detecting the flexing state of the magnetic film caused by the pressure of the introduced fluid, and responds to the flexing state of the magnetic film by a signal converting section provided outside the pressure chamber. A fluid vibration detection sensor, comprising: a deflection detection unit that outputs an electrical detection signal; 2. A first magnetic film separating the first pressure chamber into a second pressure chamber and a third pressure chamber, and a second magnetic film separating the fourth pressure chamber into a fifth pressure chamber and a sixth pressure chamber.
A magnetic film, a first communication passage that communicates the second pressure chamber and the sixth pressure chamber, a second communication passage that communicates the third pressure chamber and the fifth pressure chamber, and the first pressure chamber Deflection first detection for magnetically detecting a deflection state of the first magnetic film, which is caused by the pressure of the fluid introduced into the second pressure chamber and the pressure of the fluid introduced into the third pressure chamber. A first deflection detecting unit that has a portion and outputs a first electric detection signal according to a deflection state of the first magnetic film by a first signal conversion unit provided outside the first pressure chamber; and the fourth pressure. A flexure magnetically detecting a flexure state of the second magnetic film caused by the pressure of the fluid introduced into the fifth pressure chamber and the pressure of the fluid introduced into the sixth pressure chamber, which is provided inside the chamber; The second signal conversion unit provided outside the fourth pressure chamber has two detection units. Fluid vibration detection, comprising: a second deflection detection means that outputs a second electrical detection signal that is in phase with the first electrical detection signal and that is in phase with the first electrical detection signal. Sensor. 3. A flow rate detection device comprising the fluid vibration detection sensor according to claim 1, wherein the flow rate detection device detects the flow rate of the fluid based on the fluid vibration in the fluidic element. The first pressure chamber is communicated with one pressure guide port of the first pressure guide port and the second pressure guide port provided at a predetermined symmetrical position in the fluidic element with respect to the flow direction, and the other pressure guide port is connected. The second pressure chamber is communicated with a pressure port, and a flow rate calculating device that calculates a flow rate of the fluid based on the electrical detection signal is provided. 4. A flow rate detection device comprising the fluid vibration detection sensor according to claim 2, wherein the flow rate detection device detects the flow rate of the fluid based on the fluid vibration in the fluidic element. The second pressure chamber and the fifth pressure chamber are provided in one pressure guide port of the first pressure guide port and the second pressure guide port provided at a predetermined symmetrical position in the fluidic element with respect to the flow direction. A differential means that communicates with each other and that the third pressure chamber and the sixth pressure chamber communicate with the other pressure guide port and that outputs a difference signal corresponding to the difference between the first electric detection signal and the second electric detection signal. And a flow rate detecting means for calculating a flow rate of the fluid based on the difference signal.