JPH0886711A - Pressure sensor device and gas meter using this pressure sensor device - Google Patents

Abstract

PURPOSE: To reduce a detecting error to the possible minimum level, reduce cost by reducing the number of part items, and improve productivity. CONSTITUTION: A pressure sensor device is provided with a pressure receiving part to sense pressure of pressure fluid and a reference part composed of an element (a capacitor) having fixed capacity, and is provided with a detecting part 1 which has one and other fixed electrodes 55 and 59 and a movable electrode 57 positioned between these fixed electrodes 55 and 59 so as to move according to pressure sensed by the pressure receiving part and detects capacitance C1 between one fixed electrode 55 and the movable electrode 57 and capacitance C2 between the other fixed electrode 59 and the movable electrode 57 and a signal processing unit C to output a desired signal by processing the capacitance C1 and C2 detected by the detecting part 1 and capacitance CR being a reference detected by the reference part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure sensor device for detecting the pressure of a fluid (gas or the like) and outputting a signal corresponding to the pressure, and a gas meter using this pressure sensor device.

[0002]

2. Description of the Related Art As a conventional pressure sensor device of this type, there is a technique disclosed in Japanese Patent Laid-Open No. 59-171826. This disclosed technology attempts to compensate the temperature by matching the temperature coefficients of the housing, the diaphragm, and the spacer. The diaphragm supporting the movable electrode by soldering is fixed to the housing made of a metal material by soldering. The annular spacer made of a plastic material is fixed to the housing with screws, and the iron plate as a fixed electrode is fixed with screws so as to face the movable electrode.

Also, as a conventional gas meter, Japanese Patent Laid-Open No. 63-63
There is a technique disclosed in Japanese Patent Laid-Open No. 2087718. This disclosed technology mounts a pressure sensor, a vibration absorber, and a determination circuit for controlling gas cutoff by inputting detection signals of these pressure sensor and vibration absorber on the same printed circuit board, and this printed circuit board is mounted on a gas meter. The gas introduction pipe to the pressure sensor is inserted into the metering chamber of the meter body.

[0004]

However, in the case of the technique disclosed in JP-A-59-171826, since the movable electrode is soldered to the diaphragm, the material of the diaphragm is limited, Is limited. In addition, special equipment for soldering is required for production, resulting in poor mass productivity. In terms of performance, since the sensor is composed of a pair of movable and fixed electrodes, deterioration of the sensor linearity due to parasitic capacitance is unavoidable. It is necessary and cannot be used for applications that require a system. In addition, there is a problem that it cannot be used for industrial purposes because the humidity cannot be corrected.

In the above-mentioned conventional gas meter, since the pressure sensor is of the board mounting type, a gas introduction pipe is required for introducing gas into the pressure sensor, and this gas introduction pipe is inserted into the metering chamber of the meter body. Therefore, the insertion portion must be sealed, and the sealing means has a problem of sealing property.

The present invention has been made by paying attention to the above-mentioned problems. The first object of the present invention is that it is excellent in assemblability and that the absolute value of the characteristic can be corrected by circuit processing. Therefore, it is an object of the present invention to provide a pressure sensor device which does not require complicated processing such as origin correction during use, is less susceptible to temperature and humidity, has a small number of parts, and realizes productivity improvement at low cost.

A second object of the present invention is to use a pressure sensor device which has a small number of parts and which can improve productivity at low cost, and is particularly required for introducing gas into the pressure sensor. Unnecessary gas introduction pipe,
An object of the present invention is to provide a gas meter that can avoid the problem of the sealing property of the insertion portion of the gas introduction pipe into the measuring chamber.

[0008]

In order to achieve the above-mentioned first object, a pressure sensor device according to the present invention is a detection unit in which electrostatic capacitances C1 and C2 change in accordance with a predetermined external action. A reference portion whose capacitance CR does not change due to the predetermined action, and a capacitance C detected by the detection portion.
1, C2 and signal processing means for processing the capacitance CR detected by the reference unit and outputting a desired signal.

Further, in order to achieve the above second object, the gas meter according to the present invention comprises a pressure sensor device,
A detection unit in which the electrostatic capacitances C1 and C2 change according to a predetermined action from the outside, and a capacitance C depending on the predetermined action.
Reference part where R does not change and capacitance C detected by the detection part
1, C2 and a signal processing means for processing the electrostatic capacitance CR detected by the reference portion and outputting a desired signal,
A gas pressure introducing passage is formed in a wall portion of the measuring chamber of the meter body, and the pressure sensor device is fixed to the wall portion of the measuring chamber through a sealing means so that the pressure receiving portion of the pressure sensor device is connected to the gas pressure introducing passage. It is characterized by communicating with.

[0010]

In the pressure sensor device according to the present invention, the assembling property is excellent, and since the reference portion is built in and the absolute value of the characteristic can be corrected by the circuit processing, it is possible to correct the origin during use. No complicated processing is required, and the sensor linearity is
Not only is it less susceptible to temperature and humidity, but the number of parts is small, and the productivity is improved at low cost.

Further, in the gas meter according to the present invention, a pressure sensor device which has a small number of parts and realizes an improvement in productivity at a low cost is used, and in particular, a gas required for introducing gas into the pressure sensor is used. No need for an introduction pipe,
It is possible to provide a gas meter which can avoid the problem of the sealing property of the insertion portion of the gas introduction pipe into the measuring chamber.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIG. 1 is a longitudinal sectional view of a pressure sensor device according to a first embodiment of the present invention, FIG. 2 is a perspective view of the pressure sensor device in an exploded state, FIG. 3 is a plan view of a diaphragm, and FIG. Is a side view in which the diaphragm is partially sectioned, and FIG. 5 is a cross-sectional view in which the diaphragm is partially omitted.

The pressure sensor device according to the first embodiment of the present invention includes a base 21, an O-ring 22, and a diaphragm 2.
3, diaphragm retainer 24, electrode holder 47, electric field shield 76, detection unit (differential sensor unit) 1, electric field shield 77, retainer spring 78, electrode retainer 49,
It is composed of a signal processing unit C and a cover 69.

The base 21 has an accommodating portion 25 having a circular shape in a plan view, and a bottom portion 25a of the accommodating portion 25 has a plurality of concentric stopper portions (negative ends) centered on the center of the bottom portion 25a. Pressure stopper) 26a, 26b, 26c
And an O-ring fitting groove 27 which is located outside the stopper portion 26c and is concentric with the stopper portion 26c. In addition, a concave portion 28 is formed in the bottom surface portion 25a in the radial direction from the center thereof.
The recessed portion 28 communicates with the connecting pipe portion 29 formed on the peripheral surface portion of the base 21 so as to project therefrom, and these constitute the inflow port 40.

The diaphragm 23 is made of metal and has a plate-like shape having a mounting portion 23b on the peripheral portion of the surface portion 23a as shown in FIGS. 3 to 5, and the plunger receiving portion 4 is provided at the center thereof.
1 is formed on the surface portion 23a of the diaphragm 23, and the projecting portions 42a, 42b, 42 projecting downward (in FIG. 5) in an annular shape centered on the plunger receiving portion 41.
c and 42d, and a protruding portion 43 that is located outside the protruding portion 42d and is convex upward are formed, and the upper surface side of the surface portion 23a is a flat surface excluding the protruding portion 43.

The diaphragm retainer 24 has a circular shape in a plan view so as to be inserted into the circular accommodating portion 25 of the base 21, and has a stopper portion (positive pressure stopper) 44 having a flat outer bottom surface. A plunger holding hole 45 is formed in the center of the stopper 44.

The O-ring 22 is fitted in the O-ring fitting groove 27 of the accommodating portion 25 of the base 21, and the diaphragm 23 and the diaphragm retainer 24 are accommodated therein. Holds down the mounting portion 23b at the peripheral portion of the diaphragm 23 to fix the diaphragm 23, and the diaphragm 23 is
It is located in a diaphragm chamber 46 defined by the bottom surface portion 25a of the housing portion 25 and the stopper portion 44 of the diaphragm retainer 24, and the pressure receiving side of the diaphragm chamber 46 communicates with the inflow port 40. Then, the diaphragm retainer 2
Numeral 4 movably holds a plunger 51, which is a movable body, in the plunger holding hole portion 45, and these constitute a pressure receiving unit A.

A hole 50 is formed in the center of the electrode holder 47.
, A receiving portion 52 is formed on the bottom of the electrode holder 47, and a plurality of terminal insertion grooves 53 are formed on the inner peripheral surface of the electrode holder 47. The electric field shield 76 is composed of a disk-shaped shield plate 79 and an annular insulating film 80.

Further, the detection unit 1 includes one fixed electrode 55 having a disk shape, one insulating film 56 having a ring shape, a movable electrode 57 having a disk shape, the other insulating film 58 having a ring shape, and the other insulating film 58 having a disk shape. The fixed electrode 5 is provided with the fixed electrode 59.
5, 59 and the movable electrode 57 have terminal portions 55, respectively.
a, 59a, 57a are formed. One fixed electrode 5
5, a hole 55b is formed in the center of the movable electrode 57, and the movable electrode 57 has a pressing portion 57b at its peripheral portion and a movable portion 57c at its central portion. A plurality of slits 57d are formed in the circumferential direction, and the movable portion 57d is formed by the supporting portions 57e between the slits 57d.
c is retained.

The electric field shield 77 comprises a disk-shaped shield plate 83 and an annular insulating film 84. Further, the electrode retainer 49 has a retainer portion 65 at a lower portion thereof and a signal processing unit accommodating portion 66 at an upper portion thereof.
A plurality of terminal holes 67 are formed in the peripheral portion of the signal processing unit accommodating portion 66.

In the electrode holder 47, a shield plate 79 of the electric field shield 76 and an annular insulating film 80 are provided, and one fixed electrode 55 and one insulating film 56 of the detecting section 1 are provided. The movable electrode 57, the other insulating film 58, and the other fixed electrode 59 are housed in this order in a stacked manner, and the movable electrode 57 has its holding portion 57b sandwiched by the insulating films 58 and 56 from above and below. The terminal portions 55 a, 59 a, 57 a are inserted into the terminal insertion groove 53 on the inner peripheral surface portion of the electrode holder 47.

Further, in the electrode holder 47, the shield plate 83 of the electric field shield 77, the insulating film 84, and the pressing spring 78 are housed so as to overlap with the detection unit 1. Then, in the electrode holder 47, the electrode holder 49 is superposed on the detection unit 1 and the electric field shield 77.
The pressing portion 65 is inserted, and the terminal portions 55a, 59a, 57a project from the terminal hole 67 of the electrode pressing portion 49 toward the signal processing unit accommodating portion 66.

The portion extending from the electrode holder 47 to the electrode retainer 49 constitutes a sensor unit B, which is the accommodating portion 2 of the base 21.
5 and one end (lower end) of the plunger 51 has a plunger receiving portion 41 of the diaphragm 23.
And the other end (upper end) of the plunger 51 is in contact with the movable portion 57c of the movable electrode 57 from below.

The signal processing unit C has a substrate 68 having a shape that can be fitted in the signal processing unit accommodating portion 66. The substrate 68 has the reference portion 2 and the capacitance detection circuit shown in FIG. The gate array 3 and the pulse output circuit 4 are incorporated. The reference unit (reference unit) 2 is
The capacitor 2a is composed of an element having a capacitance CR that serves as a reference.

The signal processing unit C is housed in the signal processing unit housing portion 66 of the electrode retainer 49, and the terminal portions 55a, 59a, 57a are connected to the corresponding connecting portions of the substrate 68. is there. Then, the cover 69 is covered over the electrode retainer 49, and the cover 69
Is fixed to the base 21 by inserting and press-fitting the guide pin 90 and the press-fitting pin 91 into the guide pin hole 86 and the pin press-fitting hole 87 provided in the base 21, and the lead wire connected to the substrate 68. 71, 72, 73 are led out of the cover 69. In this case, the lead wire 71,
72 and 73 are sandwiched between the electrode retainer 49 and the projections 74 and 75 provided on the cover 69, and the lead wire 71,
The pull-out strength of 72 and 73 is large.

In the sensor unit B, the detection unit 1 composed of the two fixed electrodes 55 and 59 and the movable electrode 57 has a capacitance C1 of the capacitor 1a composed of one fixed electrode 55 and the movable electrode 57. And the other fixed electrode 5
9 and the electrostatic capacitance C2 of the capacitor 1b constituted by the movable electrode 57. Further, the reference unit 2 has a capacitance CR that serves as a reference for the capacitor 2a.

The inside of the gate array 3 is roughly connected to the detection unit 1 and the reference unit 2 and has a capacitance C.
Oscillation frequency f determined by 1, C2, CR and resistor not shown
There are CR oscillating circuits 31, 32, and 33 that output the signals 1, f2, and fr, respectively, and, in response to these signals, in the first half of one cycle of the reference oscillating signal fr from the CR oscillating circuit 33, the first half Oscillation frequency f1 in cycle, latter half 1 /
There is a frequency measurement circuit 3X that generates a pulse signal according to the frequency difference of f2 in two cycles. The pulse output circuit 4 amplifies the pulse signal output from the gate array 3,
Perform signal processing such as level adjustment.

Next, the operation of the pressure sensor device constructed as described above will be described. The diaphragm chamber 46
When the pressure on the pressure receiving side is zero, the movable electrode 57 in the detection unit 1 is not displaced, so that the electrostatic capacitances C1 and C2 are equal. Therefore, the oscillation frequencies f1 and f
2 becomes equal, and the oscillation frequency f1 in the first half cycle of the reference oscillation signal fr from the CR oscillation circuit 33 and the latter half 1 /
Since the frequency difference between the oscillation frequencies f2 in the two cycles is zero, no pulse signal is output from the gate array 3.

When a pressure fluid (eg, gas) is introduced from the inlet 40 to the pressure receiving side of the diaphragm chamber 46, the diaphragm 23 is displaced upward in FIG. Due to the upward displacement of the diaphragm 23, the movable portion 57c of the movable electrode 57 is pushed through the plunger 51 and displaced upward in FIG. 1, and the electrostatic capacitances C1 and C2 have different values. Therefore, since there is a frequency difference between the oscillation frequency f1 in the first half cycle and the oscillation frequency f2 in the second half cycle of the reference oscillation signal fr from the CR oscillation circuit 33, the frequency difference is generated from the gate array 3. That is, a number of pulse signals proportional to the pressure to be detected is output.

By the way, the capacitances C1 and C2 change depending on the surrounding environment, that is, the temperature, the material composition of the pressure fluid for measuring the pressure, and the like. Therefore, the CR oscillation circuit 31
Although the oscillation frequencies f1 and f2 at 32 and 32 also change, the capacitance CR of the reference unit 2 also changes at the same time, so that a measurement error due to a change in the surrounding environment can be eliminated without providing a correction circuit or the like. it can.

Since the pressure sensor device according to the first embodiment described above is constructed in units, it is excellent in assembling and can be inspected individually, so that the performance yield is good. In addition, each unit A, B, C can be assembled in one direction, which is excellent in mass productivity and can be automated. In addition, no special construction method is required, investment can be suppressed, cost can be reduced, and productivity can be improved.

Further, in the pressure receiving unit A, the diaphragm 23 has a flat surface perpendicular to the displacement direction, and the stopper shape (a stopper for positive pressure of the diaphragm retainer 24) can be accurately set, so that the pressure resistance is high. Performance can be improved. Further, since the output performance can be changed by replacing the diaphragm 23, it can be used for many purposes (pressure specifications).

Since the sensor unit B employs the differential type sensor device (detection section 1), the linearity of the sensor is hardly affected by temperature and humidity. Further, since the performance can be ensured only by the thickness accuracy of the insulating films 56 and 58, no special material is required and the cost can be reduced.

Further, since the signal processing unit C has the built-in elementized reference portion 2 and the absolute value of the characteristic can be corrected by circuit processing, complicated processing such as origin correction during use becomes unnecessary. .

In the first embodiment described above, the negative pressure stopper and the positive pressure stopper for preventing the deformation of the diaphragm 23 due to overload are provided, but only one side may be provided.

In the detection unit 1, fixed electrodes 55, 5
The 9 and the movable electrode 57 have a structure in which only the effective areas face each other as much as possible to reduce the parasitic capacitance. A protrusion made of an insulating material may be provided on a part of the fixed electrode 59 to prevent the fixed electrode 59 and the movable electrode 57 from contacting and electrically short-circuiting when an overload is applied. Instead of this protrusion, the surface of the fixed electrode 59 or the movable electrode 57 may be coated with a film made of an insulator.

Further, by covering the entire housing with an external shield plate made of a metal body, it is possible to eliminate the fluctuation of the output due to the influence of the external electric field.

Further, as shown in FIG. 7, the fixed electrodes 55 and 59 of the detection unit 1 are arranged vertically, and these fixed electrodes 55 and 5 are arranged.
It is also possible to provide a movable electrode 57 so as to be vertically movable between 9 and move the movable electrode 57 by pushing up the plunger 51 to make the detection unit 1 of a variable area type. In this case, the sensor linearity can be improved.

Further, according to the above-described first embodiment, the detecting unit 1 in which the electrostatic capacitances C1 and C2 change in response to a predetermined external action, and the electrostatic capacitance CR depending on the predetermined action.
Is not changed, and the electrostatic capacitance C detected by the detection unit
1, C2 and a signal processing unit C for processing the electrostatic capacitance CR detected by the reference unit 1 and outputting a desired signal, and the reference unit 2 having a fixed capacitance (capacitor 2a).
In addition, the detection unit 1 is configured by the electric field shields 76, 77.
By covering with, the change in output due to the influence of the external electric field is eliminated, it is possible to minimize the detection error, the number of parts is reduced, the cost is reduced, and the productivity is improved. You can

(Second Embodiment) A second embodiment of the pressure sensor device according to the present invention is shown in FIGS. In the pressure sensor device according to the second embodiment, the reference portion 2 is formed into an element to form an element (capacitor 2a) E, and the element E is provided on the substrate 68 of the signal processing unit C, the gate array 3 and the pulse generating circuit 4. The diaphragm retainer 24, the electrode holder 47, and the electrode retainer 4 in the above-described first embodiment are incorporated together.
9, the electric field shields 76 and 77 are omitted.

Therefore, in the pressure sensor device according to the second embodiment, the base 21, the O ring 22, the diaphragm 23, the diaphragm fixing ring 85, the one fixed electrode 55, and the one annular insulating film 56. The movable electrode 57, the other annular insulating film 58, the other fixed electrode 59, the signal processing unit C serving as a signal processing unit, and the cover 69.

The one fixed electrode 55, one annular insulating film 56, the movable electrode 57, the other annular insulating film 58, and the other fixed electrode 59 constitute the detecting section 1. ing.

The base 21 has a circular housing portion 25 in plan view.
The housing 25 has a bottom surface 25a having a concentric O-ring fitting groove 27 centered on the center of the bottom surface 25a. In addition, the bottom surface portion 25a,
A concave portion 28 is formed in the radial direction from the center of this,
The recessed portion 28 communicates with a connecting pipe portion 29 that is formed so as to project on the peripheral surface portion of the base 21, and constitutes an inflow port 40 with these.

Further, the base 21 has a signal processing unit accommodating portion 21a on the upper part thereof, and a guide pin hole 86 is provided at one diagonal position of the upper surface (matching surface) 21b of the base 21, and Pin press-fitting holes 87 are formed at the other diagonal positions. Further, a plurality of terminal insertion grooves 21c are formed on the inner peripheral surface of the base 21.

The diaphragm 23 is made of metal, as shown in FIG.
As shown in FIG. 5, it is dish-shaped having a mounting portion 23b on the peripheral portion of the surface portion 23a, and a plunger portion 89 consisting of a protrusion is formed in the center portion thereof.

The one fixed electrode 55, the movable electrode 87, and the other fixed electrode 59 in the detection section 1 have the same structure as that of the first embodiment.

The signal processing unit C includes the base 2
A substrate 68 having a shape that can be fitted into the signal processing unit housing portion 21a of No. 1 is provided, and the substrate 68 has a gate array 3, a pulse output circuit 4, and a reference portion (reference portion) having a reference electrostatic capacitance CR. The element (capacitor 2a) E which is 2 is incorporated. In addition, the cover 69
The guide pin 90 is provided at one diagonal position of the mating surface 69a.
However, press-fitting pins 91 are formed at the other diagonal positions.

The O-ring 22 is fitted in the O-ring fitting groove 27 of the base 21, and the accommodating portion 25
The diaphragm 23 and the diaphragm fixing ring 85 are housed in the housing 23.
Is defined in the diaphragm chamber 46, and the pressure receiving side of the diaphragm chamber 46 communicates with the inflow port 40, and these constitute a pressure receiving portion.

In the accommodating portion 25, one fixed electrode 55, one insulating film 56, movable electrode 57, the other insulating film 58, and the other insulating electrode 55 of the detecting portion 1 are stacked on the diaphragm fixing ring 85. The fixed electrode 59 and the movable electrode 57 are housed in this order, and the movable electrode 57 has its holding portion 57b sandwiched from above and below by insulating films 58 and 56.

The signal processing unit C is accommodated in the signal processing unit accommodating portion 21a of the base 21, and the terminal portions 55a, 57a, 59a are connected to the corresponding connection pattern portions of the substrate 68. is there. And
The cover 69 is covered from above the substrate 68, and the cover 6
9 has its guide pin 90 press-fitted into the guide pin hole 86 and press-fit pin 91 press-fitted into the pin press-fit hole 87, respectively, and fixed to the base 21, and lead wires 71 (72, 73) connected to the substrate 68. Are led out of the cover 69.

In the pressure sensor device assembled as described above, the end portion of the plunger portion 89 formed on the diaphragm 23 penetrates the plunger insertion hole 55b of the one fixed electrode 55 and the movable electrode 57 of the movable electrode 57 is formed. It contacts the movable part 57c from below.

The detecting section 1 composed of the two fixed electrodes 55, 59 and one movable electrode 57 has a first sensor having a capacitance C1 between one fixed electrode 55 and one movable electrode 57. The capacitor 1a, which is a part, constitutes a capacitor 1b, which is a second sensor part having an electrostatic capacitance C2 between the other fixed electrode 59 and the movable electrode 57.

The inside of the gate array 3 is the same as the capacitance detection circuit of the first embodiment described above, and is schematically connected to the detection unit 1 and the reference unit 2 as shown in FIG. There are CR oscillation circuits 31, 32 and 33 which output signals of oscillation frequencies f1, f2 and fr which are determined by capacitances C1, C2 and CR and resistors (not shown), respectively, and CR oscillation is performed by receiving these signals. Reference oscillation signal f from circuit 33
In one cycle of r, the oscillation frequency f in the first half cycle
1, there is a frequency measurement circuit 3X that generates a pulse signal according to the frequency difference of the oscillation frequency f2 in the latter half cycle.
The pulse output circuit 4 subjects the pulse signal output from the gate array 3 to signal processing such as amplification and level adjustment.

Next, the operation of the pressure sensor device of the second embodiment as described above will be explained. The diaphragm chamber 4
When the pressure on the pressure receiving side of 6 is zero, the movable electrode 57 in the detection unit 1 does not displace, so that the electrostatic capacitances C1 and C2 are equal. Therefore, the oscillation frequencies f1 and f2 are also equal, and the oscillation frequency f1 and the second half 1 in the first half cycle of the reference oscillation signal fr from the CR oscillation circuit 33 are the same.
Since the frequency difference between the oscillation frequencies f2 in the / 2 cycle is zero, no pulse signal is output from the gate array 3.

When a pressure fluid (for example, gas) is introduced from the inflow port 40 to the pressure receiving side of the diaphragm chamber 46, the diaphragm 23 is displaced upward. This diaphragm 2
Due to the upward displacement of 3, the movable portion 57c of the movable electrode 57 is pushed through the plunger portion 89 and displaced upward, and the electrostatic capacitances C1 and C2 have different values. Therefore, C
The first half 1 of the reference oscillation signal fr from the R oscillation circuit 103c
Since there is a frequency difference between the oscillation frequency f1 in the / 2 cycle and the oscillation frequency f2 in the latter half cycle, the gate array 3 outputs the number of pulse signals proportional to the frequency difference, that is, the pressure to be detected. It

By the way, the electrostatic capacitances C1 and C2 change depending on the surrounding environment, that is, the temperature and the material composition of the pressure fluid for measuring the pressure. Therefore, the CR oscillation circuit 31
Although the oscillation frequencies f1 and f2 at 32 and 32 also change, the capacitance CR of the reference unit 2 also changes at the same time, so that a measurement error due to a change in the surrounding environment can be eliminated without providing a correction circuit or the like. it can.

In the second embodiment described above, since the differential sensor structure (detection section 1) is adopted, the sensor linearity is hardly affected by temperature and humidity. Further, since the performance can be ensured only by the thickness accuracy of the insulating films 85 and 57, no special material is required and the cost can be reduced. Further, since the reference unit 2 is built-in and the absolute value of the characteristic can be corrected by circuit processing, complicated processing such as origin correction during use becomes unnecessary.

In the detection section 1, fixed electrodes 55, 5
The 9 and the movable electrode 57 have a structure in which only the effective areas face each other as much as possible to reduce the parasitic capacitance. A protrusion made of an insulator is provided on a part of the one fixed electrode 55 to prevent the one fixed electrode 55 and the movable electrode 57 from coming into contact with each other and electrically short-circuited when an overload is applied. Alternatively, instead of the protrusions, the surface of one of the fixed electrodes 55 or the movable electrode 57 may be coated with a film made of an insulator. Further, by covering the entire housing (base 21 and case 69) with an external shield plate made of a metal body, it is possible to eliminate the fluctuation of the output due to the influence of the external electric field.

According to the second embodiment described above, the pressure receiving portion for sensing the pressure of the pressure fluid, the reference portion 2 composed of the element capacitor 2a having a fixed capacitance, and the one and the other fixed electrodes 55, 59 are provided. There is a movable electrode 57 located between these fixed electrodes 55 and 59 and moving according to the pressure sensed by the pressure receiving section, and the electrostatic capacitance C1 between one fixed electrode 55 and the movable electrode 57 and the other. Fixed electrode 59 and movable electrode 5
7 detects the capacitance C2 between the detection unit 1 and the capacitances C1 and C2 detected by the detection unit 1 and the reference capacitance CR detected by the reference unit 2 and processes a desired signal. And the signal processing unit C that outputs the signal, the detection error can be minimized, the number of parts can be reduced, the cost can be reduced, and the productivity can be improved.

(Third Embodiment) A third embodiment of the present invention is shown in FIG.
3 shows. The pressure sensor device according to the third embodiment is
The element (capacitor 1b) is used as the detection portion of the electrostatic capacitance C2 which is the second sensor section in the above-described second embodiment, and this element (capacitor 1b) is provided on the substrate 68 of the signal processing unit C as the gate array 3. The pulse output circuit 4 and the element (capacitor 2a of the reference unit 2) E having the reference electrostatic capacitance CR are incorporated together, and the other fixed electrode 59 in the second embodiment is omitted.

Therefore, in this pressure sensor device, the base 21, the O-ring 22, the diaphragm 23, the diaphragm fixing ring 85, the fixed electrode 55, the one annular insulating film 56, the movable electrode 57, The other insulating film 58 having an annular shape, a signal processing unit C, and a cover 69. And the base 2
1, diaphragm 23, diaphragm fixing ring 85,
Fixed electrode 55, insulating films 56 and 58, movable electrode 57
The cover 69 and the cover 69 have the same structure as that of the third embodiment.

The signal processing unit C includes the base 2
A substrate 68 having a shape that can be fitted into the signal processing unit housing portion 21a of No. 1 is provided. The substrate 68 has the gate array 3, the pulse output circuit 4, and the reference electrostatic capacitance CR as described above. Element (capacitor 2 of the reference unit 2 having
a) Element having E and capacitance C2 (capacitor 1
b) and are incorporated.

The O-ring 22 is fitted in the O-ring fitting groove portion 27 of the base 21, and the accommodation portion 25 accommodates the diaphragm 23 and the diaphragm fixing ring 85. Is the storage unit 25
Is defined in the diaphragm chamber 46, and the pressure receiving side of the diaphragm chamber 46 communicates with the inflow port 40.

In the accommodating portion 25, the fixed electrode 55, one insulating film 56, the movable electrode 57, and the other insulating film 58 are stacked on the diaphragm fixing ring 85.
In this order, the movable electrode 57 has its holding portion 57b vertically sandwiched by insulating films 58 and 56, and the terminal portions 55a and 57a are inserted into the inner peripheral surface portion of the base 21. It is inserted in the groove 21c.

The signal processing unit C is accommodated in the signal processing unit accommodating portion 21a of the base 21, and the terminal portions 55a and 57a are provided in the corresponding substrate 6.
8 are connected to the connection pattern portion. And the substrate 68
The cover 69 is covered from above, and the cover 69 is fixed to the base 21 by press-fitting the guide pin 90 into the guide pin hole 86 and the press-fit pin 91 into the pin press-fit hole 87, respectively. A lead wire (not shown) connected to is led out of the cover 69.

In the pressure sensor device assembled as described above, the end portion of the plunger portion 89 formed on the diaphragm 23 penetrates the plunger insertion hole 55b of the fixed electrode 55 and the movable electrode 57 is movable. Part 5
It touches 7c from below. The fixed electrode 55 and the movable electrode 57 form a first sensor section (capacitor 1a) having a capacitance C1 between these electrodes. The first sensor unit and the elementized second sensor unit (capacitor 1b) constitute the detection unit 1.

The inside of the gate array 3 has the same structure as the capacitance detection circuit of the first embodiment described above, and is schematically connected to the detection unit 1 and the reference unit 2 as shown in FIG. C, which outputs the signals of the oscillation frequencies f1, f2, fr determined by the capacitances C1, C2, CR and resistors (not shown), respectively.
There are R oscillating circuits 31, 32 and 33, and when these signals are received, one of the reference oscillating signals from the CR oscillating circuit 33 is received.
In the cycle, there is a frequency measurement circuit 3X that generates a pulse signal according to the frequency difference between the oscillation frequency f1 in the first half cycle and the oscillation frequency f2 in the second half cycle. The pulse output circuit 4 subjects the pulse signal output from the gate array 3 to signal processing such as amplification and level adjustment.

Next, the operation of the pressure sensor device according to the third embodiment constructed as described above will be described. When the pressure on the pressure receiving side of the diaphragm chamber 46 is zero, the movable electrode 57 is not displaced, so that the electrostatic capacitances C1 and C
2 is equal. Therefore, the oscillation frequencies f1 and f2 are also equal, and the frequency difference between the oscillation frequency f1 in the first half cycle and the oscillation frequency f2 in the second half cycle of the reference oscillation signal fr from the CR oscillation circuit 33 is zero. Therefore, no pulse signal is output from the gate array 3.

When a pressure fluid (for example, gas) is introduced from the inlet 40 to the pressure receiving side of the diaphragm chamber 46, the diaphragm 23 is displaced upward. This diaphragm 2
Due to the upward displacement of 3, the movable portion 57c of the movable electrode 57 is pushed through the plunger portion 89 and displaced upward, and the electrostatic capacitances C1 and C2 have different values. Therefore, C
The first half of the reference oscillation signal fr from the R oscillation circuit 33
Since there is a frequency difference between the oscillation frequency f1 in the cycle and the oscillation frequency f2 in the latter half cycle, the gate array 3 outputs the number of pulse signals proportional to the frequency difference, that is, the pressure to be detected.

According to the third embodiment described above, the pressure receiving portion for sensing the pressure of the pressure fluid, the reference portion 2 constituted by the element (capacitor 2a) having the fixed capacitance, the fixed electrode 55,
59 and a movable electrode 57 that moves according to the pressure sensed by the pressure receiving portion, and a first sensor portion that detects the electrostatic capacitance C1 between the fixed electrode 55 and the movable electrode 57, and a capacitance. Capacitance C composed of an element (capacitor 1b)
2nd sensor part which detects 2, the electrostatic capacitance C1 which the 1st sensor part detected, the electrostatic capacitance C2 which the 2nd sensor part detected, and the electrostatic capacitance used as the reference which the reference part 2 detected. CR
And a signal processing unit C for processing a desired signal to output a desired signal, the detection error can be minimized, the number of parts is small, the cost is low, and the productivity is improved. You can

(Embodiment 4) A fourth embodiment of the present invention is shown in FIG.
Shown in In the pressure sensor device according to the fourth embodiment, the detection portion of the electrostatic capacitance C1 which is the first sensor portion in the above-described third embodiment is an element (capacitor 1a), and this element (capacitor 1a) is used as a signal. In the substrate 68 of the processing unit C, the gate array 3, the pulse output circuit 4, and the element (capacitor 2a of the reference portion 2) E having the reference electrostatic capacitance CR are incorporated, and one of the above-described third embodiment is used. This is a configuration in which the fixed electrode 85 is omitted.

Therefore, in this pressure sensor device, the base 21, the O-ring 22, the diaphragm 23, the diaphragm fixing ring 85, the movable electrode 57, the ring-shaped insulating film 58, the fixed electrode 59, and the signal processing. It is composed of a unit C and a cover 69. Then, the base 21, the diaphragm 23, the insulating film 58,
The movable electrode 57 and the cover 69 have the same structure as that of the above-described fourth embodiment.

The signal processing unit C includes the base 2
A substrate 68 having a shape that can be fitted into the signal processing unit housing portion 21a of No. 1 is provided. The substrate 68 has the gate array 3, the pulse output circuit 4, and the reference electrostatic capacitance CR as described above. Element (capacitor 2 of the reference unit 2 having
a) Element having E and capacitance C1 (capacitor 1
a) and are incorporated.

The O-ring 22 is fitted in the O-ring fitting groove 274 of the base 21, and the housing 25
Includes a diaphragm 23 and a diaphragm fixing ring 85.
And the diaphragm 23 are housed in the housing section 2.
5 is defined in the diaphragm chamber 46, and the pressure receiving side of the diaphragm chamber 46 communicates with the inflow port 40. Then, in the accommodating portion 25, the movable electrode 57 and the insulating film 5 are stacked on the diaphragm fixing ring 85.
8 and a fixed electrode 59 are housed in this order, and the movable electrode 57 has a holding portion 57b sandwiched from above and below by an insulating film 58 and a diaphragm fixing ring 85.

The signal processing unit C is accommodated in the signal processing unit accommodating portion 21a of the base 21, and the terminal portions 57a and 59a are provided in the corresponding substrate 6.
8 are connected to the connection pattern portion. And the substrate 68
The cover 69 is covered from above, and the guide pin 90 of the cover 69 is press-fitted into the guide pin hole 86 and the press-fit pin 91 is press-fitted into the pin press-fit hole 87, respectively, similarly to the fourth embodiment. Lead wires 71 (72, 73) fixed to the base 21 and connected to the substrate 68 are led out of the cover 69.

In the pressure sensor device assembled as described above, the end of the plunger portion 89 formed on the diaphragm 23 is in contact with the movable portion 57c of the movable electrode 57 from below. The fixed electrode 59 and the movable electrode 57 constitute a second sensor section (capacitor 1b) having a capacitance C2 between these electrodes. And this second
The sensor unit and the first sensor unit (capacitor 1a) which is made into an element constitute the detection unit 1.

The inside of the gate array 3 has the same structure as the electrostatic capacitance detection circuit (FIG. 6) of the first embodiment described above, and is roughly connected to the detection unit 1 and the reference unit 2. There are CR oscillating circuits 31, 32, and 33 that output signals of oscillating frequencies f1, f2, and fr determined by capacitances C1, C2, and CR and resistors (not shown), respectively, and a CR oscillating circuit that receives these signals. In one cycle of the reference oscillation signal from 33, the oscillation frequency f1 in the first half cycle and the second half 1 /
There is a frequency measuring circuit 3X that generates a pulse signal according to the frequency difference of the oscillation frequency f2 in two cycles. The pulse output circuit 4 subjects the pulse signal output from the gate array 3 to signal processing such as amplification and level adjustment.

Next, the operation of the pressure sensor device according to the fourth embodiment constructed as described above will be described.

When the pressure on the pressure receiving side of the diaphragm chamber 46 is zero, the movable electrode 57 is not displaced, so that the electrostatic capacitances C1 and C2 are equal. Therefore,
The oscillation frequencies f1 and f2 are also equal, and the difference between the oscillation frequency f1 in the first half cycle and the oscillation frequency f2 in the second half cycle of the reference oscillation signal fr from the CR oscillation circuit 33 becomes zero. No pulse signal is output from the gate array 3.

When a pressure fluid (eg, gas) is introduced from the inflow port 40 to the pressure receiving side of the diaphragm chamber 46, the diaphragm 23 is displaced upward. This diaphragm 2
Due to the upward displacement of 3, the movable portion 57c of the movable electrode 57 is pushed through the plunger portion 89 and displaced upward, and the electrostatic capacitances C1 and C2 have different values. Therefore, C
The first half of the reference oscillation signal fr from the R oscillation circuit 33
Since there is a frequency difference between the oscillation frequency f1 in the cycle and the oscillation frequency f2 in the latter half cycle, the gate array 3 outputs the number of pulse signals proportional to the frequency difference, that is, the pressure to be detected.

According to the fourth embodiment described above, the pressure receiving portion for sensing the pressure of the pressure fluid, the reference portion 2 including the element (capacitor 2a) having a fixed capacitance, and the element (capacitor 1a) are included. The fixed electrode 59 has a first sensor section for detecting the electrostatic capacitance C1 and a fixed electrode 59 and a movable electrode 57 that moves according to the pressure sensed by the pressure receiving section.
And a capacitance C1 detected by the first sensor unit, which detects a capacitance C2 between the movable electrode 57 and the movable electrode 57.
And a signal processing unit C that processes the electrostatic capacitance C2 detected by the second sensor unit and the reference electrostatic capacitance CR detected by the reference unit 2 and outputs a desired signal, thereby providing a detection error. Can be made as small as possible, the number of parts is small, and the cost can be reduced to improve the productivity.

(Fifth Embodiment) FIG. 1 shows a fifth embodiment of the present invention.
5 shows. The pressure sensor device according to the fifth embodiment is
An element (capacitor 1a) is used as the detection portion of the electrostatic capacitance C1 in the third embodiment described above, and this element (capacitor 1a) is connected to the substrate 68 of the signal processing unit C on the gate array 3 and the pulse output circuit 4. , The reference capacitance C
The movable electrode 57 is incorporated together with the element having R (the capacitor 2a of the reference portion 2) E, and the movable electrode 57 in the fourth embodiment described above is also used as the diaphragm 23.
7 and the insulating rings 56 and 58 are omitted.

Therefore, the pressure sensor device is based on the base 2
1, the O-ring 22, the diaphragm 23 also serving as the movable electrode, the diaphragm fixing ring 85, and the fixed electrode 59.
And a signal processing unit C and a cover 69. Then, the base 21, the diaphragm 23,
The fixed electrode 59 and the cover 69 have the same structure as that of the fourth embodiment described above.

The signal processing unit C includes the base 2
A substrate 68 having a shape that can be fitted into the signal processing unit housing portion 21a of No. 1 is provided. The substrate 68 has the gate array 3, the pulse output circuit 4, and the reference electrostatic capacitance CR as described above. Element (capacitor 2 of the reference unit 2 having
a) Element having E and capacitance C1 (capacitor 1
a) and are incorporated.

The O-ring 22 is fitted in the O-ring fitting groove 27 of the base 21, and the diaphragm 23 and the diaphragm fixing ring 85 are housed in the housing 46. Is the storage unit 25
Is defined in the diaphragm chamber 46, and the pressure receiving side of the diaphragm chamber 46 communicates with the inflow port 40. A fixed electrode 59 is accommodated in the accommodating portion 25 so as to be superposed on the diaphragm fixing ring 85, and the terminal portion 59a is a terminal insertion groove 2 in the inner peripheral surface portion of the base 21.
1c is inserted.

The signal processing unit C is housed in the signal processing unit housing portion 21a of the base 21, and the terminal portion 59a is connected to the corresponding connection pattern portion of the substrate 68. A cover 69 is covered over the substrate 68, and the cover 69 is fixed to the base 21 by pressing the guide pin 90 into the guide pin hole 86 and the press-fitting pin 91 into the pin press-fitting hole 87, respectively. A lead wire (not shown) connected to the substrate 68 is led out of the cover 69.

In the pressure sensor device assembled as described above, the end of the plunger portion 89 formed on the diaphragm 23 penetrates the plunger insertion hole 59b of the fixed electrode 59. The fixed electrode 59 and the diaphragm 23 that also serves as the movable electrode are connected to the second sensor unit (capacitor 1) that detects the electrostatic capacitance C2 between these electrodes.
b). The second sensor section and the elementized first sensor section (capacitor 1a) constitute the detection section 1.

The inside of the gate array 3 has the same structure as that of the electrostatic capacitance detection circuit (FIGS. 6 and 8) of the first embodiment described above, and schematically, as shown in FIG. 1. CR oscillation circuits 31, 32, 33 connected to the reference unit 2 and outputting signals of oscillation frequencies f1, f2, fr determined by capacitances C1, C2, CR and resistors not shown, respectively,
In addition, in response to these signals, in one cycle of the reference oscillation signal fr from the CR oscillation circuit 33, the oscillation frequency f1 in the first half cycle and the oscillation frequency f2 in the second half cycle are obtained.
There is a frequency measurement circuit 103 that generates a pulse signal according to the frequency difference of The pulse output circuit 4 subjects the pulse signal output from the gate array 3 to signal processing such as amplification and level adjustment.

Next, the operation of the pressure sensor device constructed as described above will be described. The diaphragm chamber 46
When the pressure on the pressure receiving side is zero, the diaphragm 23 also serving as the movable electrode does not displace, so that the electrostatic capacitances C1 and C2 are equal. Therefore, the oscillation frequency f1
And f2 also become equal, and the oscillation frequency f1 in the first half cycle of the reference oscillation signal fr from the CR oscillation circuit 33,
Since the frequency difference of the oscillation frequency f2 in the latter half cycle is zero, no pulse signal is output from the gate array 3.

When a pressure fluid (for example, gas) is introduced from the inlet 40 to the pressure receiving side of the diaphragm 23, the diaphragm 23 is displaced upward. Due to the upward displacement of the diaphragm (movable electrode) 23, the electrostatic capacitances C1 and C2 have different values. Therefore, the CR oscillation circuit 3
Since there is a frequency difference between the oscillation frequency f1 in the first half cycle and the oscillation frequency f2 in the second half cycle of the reference oscillation signal fr from FIG. 3, the frequency difference from the gate array 3, that is, should be detected. A number of pulse signals proportional to the pressure are output.

According to the fifth embodiment described above, the pressure receiving portion that senses the pressure of the pressure fluid and also serves as the movable electrode 57, the reference portion 2 including the element (capacitor 2a) having a fixed capacitance, and the element A first sensor portion composed of (capacitor 1a) for detecting the electrostatic capacitance C1, and a fixed electrode 5
A second sensor portion having a fixed electrode 59 and detecting a capacitance C2 between the fixed electrode 59 and the pressure receiving portion that moves according to the sensed pressure; and a capacitance detected by the first sensor portion. C
1 and the signal processing unit C that processes the electrostatic capacitance C2 detected by the second sensor unit and the reference electrostatic capacitance CR detected by the reference unit 2 and outputs a desired signal. Can be made as small as possible, the number of parts is small, and the cost can be reduced to improve the productivity.

(Sixth Embodiment) In the sixth embodiment, the movable electrode 57 is not omitted and
As shown in FIG. 16, it is fixed to the upper surface (plunger portion 89) of the diaphragm 23, and the other structure is the same as that of the fifth embodiment.

Therefore, when the pressure on the pressure receiving side of the diaphragm chamber 46 is zero, the diaphragm 23 does not displace, so the movable electrode 57 does not displace and the electrostatic capacitances C1 and C are generated.
2 is equal. Therefore, the oscillation frequencies f1 and f2 are also equal, and the frequency difference between the oscillation frequency f1 in the first half cycle and the frequency f2 in the second half cycle of the reference oscillation signal fr from the CR oscillation circuit 33 becomes zero. No pulse signal is output from the gate array 3.

When a pressure fluid (eg, gas) is introduced from the inflow port 40 to the pressure receiving side of the diaphragm chamber 46, the diaphragm 23 is displaced upward, the movable electrode 57 is displaced upward, and the electrostatic capacitances C1 and C2. Have different values. Therefore, the reference oscillation signal fr from the CR oscillation circuit 33 is generated.
Since there is a frequency difference between the oscillation frequency f1 in the first half cycle and the oscillation frequency f2 in the second half cycle, the number of pulse signals proportional to the frequency difference from the gate array 3, that is, the pressure to be detected. Is output.

According to the sixth embodiment described above, the pressure receiving portion for sensing the pressure of the pressure fluid, the reference portion 2 including the element (capacitor 2a) having a fixed capacitance, and the element (capacitor 1a) are used. Between the first sensor unit that detects the electrostatic capacitance C1 and the movable electrode 57 that is provided in the pressure receiving unit that has the fixed electrode 59 and that moves according to the sensed pressure. A second sensor section for detecting the capacitance C2, an electrostatic capacity C1 detected by the first sensor section,
The signal processing unit C that processes the electrostatic capacitance C2 detected by the second sensor unit and the reference electrostatic capacitance CR detected by the reference unit 2 and outputs a desired signal is provided. It is possible to reduce the size, the number of parts is small, the cost is low, and the productivity can be improved.

(Seventh Embodiment) A seventh embodiment of the present invention is shown in FIG.
7 to 20. In the pressure sensor device according to the seventh embodiment, the capacitor 1b having the electrostatic capacitance C2 in the fifth embodiment and the diaphragm 23 are integrated to form a microsensor 120, and the microsensor 120 is subjected to signal processing. On the substrate 68 of the unit C, the gate array 3, the pulse output circuit 4, and the reference capacitance C
This is a configuration that is incorporated together with an element having R (capacitor 2a of the reference unit 2) E.

Therefore, the pressure sensor device is based on the base 2
1, a O-ring 121, a micro sensor 120, a signal processing unit C, and a cover 69. The base 21 has a circular accommodating portion 25 in a plan view,
A fitting hole 122 communicating with the connecting pipe portion 96 and an O-ring fitting groove 123 concentric with the fitting hole 122 are formed in the bottom surface 25 a of the housing portion 25. It communicates with the connecting pipe portion 96, and these constitute the inflow port 97. Further, the base 21 has a signal processing unit accommodating portion 21a on its upper portion, and a guide pin hole 86 is provided at one diagonal position of an upper surface (a mating surface) 21b of the base 21, and a pair of the other is provided. Pin press-fitting holes 87 are formed at the respective angular positions.

As shown in FIG. 20, the microsensor 120 includes a silicon element 124, a glass element 125, and a glass element 125.
A sensor element 127 is formed by stacking these elements 124 and 125 so as to form a space 126 between them.
This sensor element 127 is attached to the stem 12 as shown in FIG.
8a through the pedestal 128b to attach the housing 12
8 and the voltage is applied between the elements 124 and 125. The conduit portion 1 is provided on the lower surface of the stem 128a.
29 is provided, and this conduit portion 129 communicates with the pressure receiving portion 124 b of the silicon element 124. In addition, the electrode 1 connected to the silicon element 124 and the glass element 125
The terminal portion 130 from 24a and 125a is the stem 12
It projects outside from the lower surface of 8a. An air hole 131 is formed on the upper surface of the housing 128.

The signal processing unit C includes the base 2
A substrate 68 having a shape that can be fitted into the signal processing unit housing portion 21a of No. 1 is provided. The substrate 68 has the gate array 3, the pulse output circuit 4, and the reference electrostatic capacitance CR as described above. Element (capacitor 2 of the reference unit 2 having
a) Element having E and capacitance C1 (capacitor 1
a) and are incorporated. A hole 135 and a plurality of through holes 136 located around the hole 135 are formed in the substrate 68.

Then, the hole portion 13 is formed in the substrate 68.
5, the conduit portion 129 is inserted, the terminal portion 130 is inserted into the through hole 136 and soldered to mount the microsensor 120, and the O-ring fitting groove portion 123 of the housing portion 25 of the base 21 is mounted. The O-ring 121 is attached, the conduit portion 129 of the microsensor 120 is fitted into the hole 122 of the housing portion 25, and the microsensor 120 and the substrate 68 of the signal processing unit C are housed in the housing portion 2.
5, and the cover 69 is covered from above the substrate 68 so that the cover 69 inserts the guide pin 90 into the guide pin hole 86.
In addition, the press-fitting pins 91 are press-fitted into the pin press-fitting holes 87 and fixed to the base 21. In this case, the substrate 6
The lead wire 71 (72, 73) connected to 8 is the cover 6
9 out of the.

In the pressure sensor device assembled as described above, the silicon element 124 and the glass element 125 of the microsensor 120 are the electrodes 124 of these.
The change in the voltage between a and 125a is detected and converted into the electrostatic capacitance C1. The microsensor 120 and the element (capacitor 1a) form a pressure receiving section and a detecting section 1.

Inside the gate array 3, there is a circuit section having the same configuration as the electrostatic capacitance detection circuit (FIG. 6) of the first embodiment described above, and is roughly connected to the detection section 1 and the reference section 2. CR which outputs signals of oscillation frequencies f1, f2, fr determined by the capacitances C1, C2, CR and resistors (not shown), respectively.
There are oscillating circuits 31, 32 and 33, and in response to these signals, in one cycle of the reference oscillating signal fr from the CR oscillating circuit 33, the oscillating frequency f1 in the first half cycle is
There is a frequency measurement circuit 3X that generates a pulse signal according to the frequency difference of the oscillation frequency f2 in the latter half cycle. The pulse output circuit 4 subjects the pulse signal output from the gate array 3 to signal processing such as amplification and level adjustment.

Next, the operation of the pressure sensor device constructed as above will be described. The micro sensor 12
When the pressure on the pressure receiving portion 124b side of the silicon element 124 of 0 is zero, the silicon element 124 is not displaced,
The electrostatic capacitances C1 and C2 are equal. Therefore, the oscillation frequencies f1 and f2 are also equal, and the oscillation frequency f1 in the first half cycle and the oscillation frequency f2 in the second half cycle of the reference oscillation signal fr from the CR oscillation circuit 33.
Since the frequency difference is zero, no pulse signal is output from the gate array 3.

When a pressure fluid (for example, gas) is introduced from the inlet port 97 to the pressure receiving portion 124b side of the silicon element 124 via the conduit portion 129 of the microsensor 120, the silicon element 124 is displaced and The voltage between the silicon element 124 and the glass element 125 changes.
By converting this voltage into the electrostatic capacitance C1, the electrostatic capacitances C1 and C2 have different values. Therefore, C
The first half of the reference oscillation signal fr from the R oscillation circuit 33
Since there is a frequency difference between the oscillation frequency f1 in the cycle and the oscillation frequency f2 in the latter half cycle, the gate array 3 outputs the number of pulse signals proportional to the frequency difference, that is, the pressure to be detected.

According to the seventh embodiment described above, the reference portion 2 composed of the element (capacitor 2a) having a fixed capacitance.
And the capacitance (C1)
, A micro sensor 120 that detects the pressure of the pressure fluid and converts this pressure change into a capacitance change of the electrostatic capacitance C2, the electrostatic capacitance C1 detected by the sensor unit, and the micro sensor 120. The microsensor 120 of the signal processing unit C is provided with a signal processing unit C that processes the electrostatic capacitance C2 detected by the sensor 120 and the reference electrostatic capacitance CR detected by the reference unit 2 and outputs a desired signal. Since it is mounted on the substrate 68, the detection error can be minimized, the number of parts is small, the cost can be reduced, and the productivity can be improved.

(Embodiment 8) Embodiment 8 of the present invention is shown in FIG. In the pressure sensor device according to the eighth embodiment, the microsensor 120 according to the seventh embodiment is not directly mounted on the substrate 68 of the signal processing unit C but is mounted via the flexible substrate 122. On the substrate 68 of the signal processing unit C, the flexible substrate 122 on which the microsensor 120 is mounted, the gate array 3, the pulse output circuit 4, and the reference electrostatic capacitance C.
An element (capacitor 2a of the reference unit 2) E having R and an element (capacitor 1a) are incorporated.

Therefore, the pressure sensor device is based on the base 2
1, an O-ring 121, a flexible substrate 122,
It is composed of a micro sensor 120, a signal processing unit C, and a cover 69.

The base 21 has a circular accommodating portion 25 in a plan view.
And a fitting hole 122 communicating with the connecting pipe portion 96 and an O-ring fitting groove 123 concentric with the fitting hole 122 are formed in the bottom surface 25a of the housing portion 25. The joint hole 122 communicates with the connecting pipe portion 96, and the inlet port 9
Make up 7. Further, the base 21 has a signal processing unit accommodating portion 21a on its upper part, and a guide pin hole 86 is provided at one diagonal position of an upper surface (a mating surface) 21b of the base 21, and a pair of the other is provided. Pin press-fitting holes 87 are formed at the respective angular positions.

The microsensor 120 is the same as that of the seventh embodiment. And the flexible substrate 1
21 has a hole 132 and a hole 13 at one end thereof.
It has a plurality of through holes 133 formed around it, and a connecting portion 134 having a pattern connected to the through holes 133 is formed at the other end.

The signal processing unit C includes the base 2
A substrate 68 having a shape that can be fitted into the signal processing unit housing portion 21a of No. 1 is provided. The substrate 68 has the gate array 3, the pulse output circuit 4, and the reference electrostatic capacitance CR as described above. Capacitance detection element (reference unit 2)
E and an element for detecting the electrostatic capacitance C1 (capacitor 1a)
And are included.

Then, at one end of the flexible substrate 122, the conduit portion 129 is inserted into the hole 132 of the flexible substrate 122, and the terminal portion 130 is inserted into the through hole 133 and soldered to mount the microsensor 120. After mounting, the O-ring fitting groove portion 1 of the housing portion 25 of the base 21
The O-ring 121 is attached to the housing 22a, and the conduit portion 129 of the microsensor 120 is inserted into the hole 122 of the housing portion 25.
And connect the connecting portion 134 of the flexible substrate 122 to the connecting portion of the substrate 68 of the signal processing unit C,
The microsensor 120, the flexible substrate 122, and the substrate 68 of the signal processing unit C are accommodated in the accommodating portion 25, and the cover 69 is put over the substrate 68 to cover the cover 69.
The guide pin 90 into the guide pin hole 86 and the press-fit pin 91 into the pin press-fit hole 87, respectively.
It is fixed at 1. In this case, lead wires (not shown) connected to the substrate 68 are led out of the cover 69.

In the pressure sensor device assembled as described above, the silicon element 124 and the glass element 125 of the microsensor 120 are the electrodes 124.
The change in the voltage between a and 125a is detected and converted into the electrostatic capacitance C1. The microsensor 120 and the capacitor 1a form a pressure receiving section and a detecting section 1.

Inside the gate array 3, there is a circuit section having the same structure as the capacitance detecting circuit of the first embodiment described above, and as shown schematically in FIG. 6, the detecting section 1 and the reference section 2 are provided. There are CR oscillating circuits 31, 32 and 33, which are connected to each other and output signals of oscillating frequencies f1, f2 and fr which are determined by capacitances C1, C2 and CR and resistors (not shown), respectively, and which receive these signals. In one cycle of the reference oscillation signal fr from the CR oscillation circuit 33, a frequency for generating a pulse signal according to the frequency difference between the oscillation frequency f1 in the first half cycle and the oscillation frequency f2 in the second half cycle. Measuring circuit 103
There is. The pulse output circuit 4 subjects the pulse signal output from the gate array 3 to signal processing such as amplification and level adjustment.

Next, the operation of the pressure sensor device configured as described above will be described. The micro sensor 12
When the pressure on the pressure receiving portion 124b side of the silicon element 124 of 0 is zero, the silicon element 124 is not displaced,
The electrostatic capacitances C1 and C2 are equal. Therefore, the oscillation frequencies f1 and f2 are also equal, and the oscillation frequency f1 in the first half cycle and the oscillation frequency f2 in the second half cycle of the reference oscillation signal fr from the CR oscillation circuit 33.
Since the frequency difference is zero, no pulse signal is output from the gate array 3.

When a pressure fluid (for example, gas) is introduced from the inlet port 97 to the pressure receiving portion 124b side of the silicon element 124 via the conduit portion 129 of the microsensor 120, the silicon element 124 is displaced and The voltage between the silicon element 124 and the glass element 125 changes.
By converting this voltage into the electrostatic capacitance C1, the electrostatic capacitances C1 and C2 have different values. Therefore, C
The first half of the reference oscillation signal fr from the R oscillation circuit 33
Since there is a frequency difference between the oscillation frequency f1 in the cycle and the oscillation frequency f2 in the latter half cycle, the gate array 3 outputs the number of pulse signals proportional to the frequency difference, that is, the pressure to be detected.

According to the eighth embodiment described above, the reference portion 2 composed of the element (capacitor 2a) having a fixed capacitance.
And the capacitance (C1)
, A microsensor 120 that detects the pressure of the pressure fluid and converts this pressure change into a capacitance change of the capacitance C2, and the capacitance C1 detected by the sensor unit.
And capacitance C2 detected by the microsensor 120
And a signal processing unit C that processes the reference electrostatic capacitance CR detected by the reference unit 2 and outputs a desired signal, and mounts the microsensor 120 on a flexible substrate 122 and through the flexible substrate 122. Since the microsensor 129 is connected to the substrate 68 of the signal processing unit C, the detection error can be minimized, and the number of parts is small and the cost can be reduced to improve the productivity.

FIG. 22 is a schematic view of a gas meter using the pressure sensor device according to the present invention (Embodiments 1 to 8). In the meter main body 150 of the gas meter G, a measuring chamber 151, a gas introducing path 152 for introducing gas into the measuring chamber 151, a gas outlet path 153 for discharging gas from the measuring chamber 151 to the outside, and a pressure sensor housing portion 154. The metering chamber 151 is provided with a metering device (not shown), and the gas outlet passage 153 is provided with a shutoff valve 155A. Further, a gas pressure introducing passage 155 and a seal ring seat 157 are formed so as to surround the gas pressure introducing passage 155 in the ceiling portion 151a of the measuring chamber 151.

The meter body 150 of the gas meter G
The pressure sensor device S is housed and fixed in the pressure sensor housing part 154 of the above. In this case, in the pressure sensor device S of the first to ninth embodiments, the seal ring mounting part 158 is provided on the lower surface part thereof. Also, the mounting seats 1 on both sides
The base 21 is provided with a gas passage 156 for communicating with the diaphragm chamber 46 or the pressure receiving portion 124b of the silicon element 124 of the microsensor 129.

Then, the O-ring 160 is attached to the seal ring attaching portion 158 of the base 21, and the base 2
The mounting seats 159 on both sides of 1 are fixed to the bottom of the pressure sensor housing 154 by mounting screws 161, and the O-ring 160 is pressed against the seal ring seat 157, and the pressure guide hole 155 is It communicates with the gas passage 156. Then, the seal ring mounting portion 158 and the 0 ring 1
60 and the seal ring seat portion 157 constitute a sealing means. The driver (not shown) of the shutoff valve 155A is connected to the output side of the determination circuit formed on the substrate 68 of the signal processing unit C.

Next, the operation of the gas meter G of the above embodiment will be described. In the gas meter G, the gas is introduced into the measuring chamber 151 from the gas introduction path 152, measured by a metering device, and led out from the gas discharge path 153. The gas pressure in the measuring chamber 151 is transmitted through the gas passage 156 of the pressure sensor device S to the diaphragm 83 or the pressure receiving portion 12 of the silicon element 124 of the microsensor 120.
Always acting on 4b.

Therefore, when the gas pressure drops, the pressure sensor device S outputs a gas pressure drop signal, and when this gas pressure drop signal is input to the determination circuit, this determination circuit causes the shutoff valve 155A to drive the driver. Is controlled to operate the shutoff valve 155A to shut off the gas supply.

Further, the pressure sensor device S may be provided with a vibration sensor (not shown). In this case, the vibration absorber outputs a signal according to the level (seismic intensity) of the earthquake, and when the level of the earthquake reaches a predetermined value, the determination circuit controls the driver of the shutoff valve 155A to shut it off. Valve 155A
To shut off the gas supply.

As described above, in the gas meter G according to the present invention, the gas pressure introducing passage 155 is formed in the wall portion of the metering chamber 154 of the meter main body 150, and the pressure is applied to the wall portion of the metering chamber 154 via the sealing means. Since the sensor device S is fixed and the pressure receiving portion of the pressure sensor device S is communicated with the gas pressure introducing passage 155, the gas introducing pipe necessary for introducing gas into the pressure sensor device S becomes unnecessary. Pipe measuring room 15
It is possible to avoid the problem of the sealing property of the insertion portion into the connector 6.

Further, in the gas meter G according to the present invention, the pressure sensor device S is provided with a vibration absorber for detecting the vibration of the earthquake, and the signal processing unit C of the pressure sensor device S is provided.
In addition, since a control function for controlling the flow rate of gas when a predetermined seismic intensity is reached by inputting the detection signal of the vibration absorber is added, it is possible to provide a gas meter that controls the flow rate of gas when the predetermined seismic intensity is reached. it can.

[0125]

As described above, in the pressure sensor device according to the present invention, the electrostatic capacitances C1 and C2 change according to a predetermined action from the outside, and the electrostatic sensor is used depending on the predetermined action. Since the reference unit in which the capacitance CR does not change and the electrostatic capacitances C1 and C2 detected by the detection unit and the electrostatic capacitance CR detected by the reference unit are processed to output a desired signal, the assembling property is improved. Excellent, and because it has the reference part built-in and can correct the absolute value of the characteristic by circuit processing, complicated processing such as origin correction during use is unnecessary,
The linearity of the sensor is not only less affected by temperature and humidity, but also the number of parts is small and the productivity is improved at low cost.

Further, the pressure sensor device according to the present invention is
By configuring the reference portion with an element having a fixed capacitance and by covering the detection portion with an electric field shield, there is no change in the output due to the influence of the external electric field, and the detection error can be minimized. Moreover, the number of parts is reduced, the cost is reduced, and the productivity can be improved.

Further, the pressure sensor device according to the present invention is
A pressure receiving portion for detecting the pressure of the pressure fluid, a reference portion formed of an element having a fixed capacitance, one and the other fixed electrodes and located between these fixed electrodes according to the pressure detected by the pressure receiving portion. A detection unit having a movable electrode that moves and detecting an electrostatic capacitance C1 between one fixed electrode and the movable electrode and an electrostatic capacitance C2 between the other fixed electrode and the movable electrode; Since it has a signal processing means for processing the detected capacitances C1 and C2 and the reference capacitance CR detected by the reference unit and outputting a desired signal, it is possible to minimize the detection error. Further, the number of parts is reduced, the cost is reduced, and the productivity can be improved.

Further, the pressure sensor device according to the present invention is
A pressure receiving part for sensing the pressure of the pressure fluid, a reference part composed of an element having a fixed capacitance, a fixed electrode and a movable electrode movable according to the pressure sensed by the pressure receiving part, and movable with the fixed electrode. A first sensor unit that detects the electrostatic capacitance C1 between the electrodes, a second sensor unit that is composed of elements to detect the electrostatic capacitance C2, and an electrostatic capacitance C1 that is detected by the first sensor unit. And a signal processing means for processing the electrostatic capacitance C2 detected by the second sensor unit and the reference electrostatic capacitance CR detected by the reference unit and outputting a desired signal, thereby reducing the detection error as much as possible. It is possible to reduce the size, the number of parts is small, the cost is low, and the productivity can be improved.

Further, the pressure sensor device according to the present invention is
The pressure receiving portion for detecting the pressure of the pressure fluid, the reference portion formed of an element having a fixed capacitance, the first sensor portion formed of the element for detecting the electrostatic capacitance C1, the fixed electrode and the pressure receiving portion. A second sensor unit having a movable electrode that moves according to the sensed pressure and detecting an electrostatic capacitance C2 between the fixed electrode and the movable electrode; and an electrostatic capacitance C1 detected by the first sensor unit. And a signal processing means for processing the electrostatic capacitance C2 detected by the second sensor unit and the reference electrostatic capacitance CR detected by the reference unit and outputting a desired signal, thereby reducing the detection error as much as possible. It is possible to reduce the size, the number of parts is small, the cost is low, and the productivity can be improved.

Further, the pressure sensor device according to the present invention is
A pressure receiving unit that senses the pressure of the pressure fluid and also serves as a movable electrode, and a reference unit configured by an element having a fixed capacitance,
Detects an electrostatic capacitance C2 between a first sensor portion configured by an element for detecting an electrostatic capacitance C1 and a fixed electrode and having the fixed electrode and the pressure receiving portion that moves according to the sensed pressure. The second sensor unit, the capacitance C1 detected by the first sensor unit, and the capacitance C2 detected by the second sensor unit.
Further, the detection error can be minimized by including the signal processing means for processing the reference electrostatic capacitance CR detected by the reference portion and outputting a desired signal, and the number of parts can be reduced. The cost can be reduced, and the productivity can be improved.

Further, the pressure sensor device according to the present invention is
A diaphragm is used as the pressure receiving member of the pressure receiving section, and the diaphragm is provided with a plunger section for displacing the movable electrode when the diaphragm is displaced, so that the number of parts is reduced and the cost is reduced, thereby improving productivity. be able to.

Further, the pressure sensor device according to the present invention is
A pressure receiving portion for sensing the pressure of the pressure fluid, a reference portion formed of an element having a fixed capacitance, a first sensor portion formed of the element for detecting the electrostatic capacitance C1, and a fixed electrode A second sensor unit that detects an electrostatic capacitance C2 between the fixed electrode and a movable electrode that is provided in the pressure receiving unit that moves according to the sensed pressure, and an electrostatic capacitance C1 that is detected by the first sensor unit. And the signal processing means for processing the electrostatic capacitance C2 detected by the second sensor unit and the reference electrostatic capacitance CR detected by the reference unit and outputting a desired signal, the detection error is minimized. In addition, the number of parts is small, the cost is low, and the productivity can be improved.

Also, the pressure sensor device according to the present invention is
A reference portion formed of an element having a fixed capacitance, a sensor portion formed of an element for detecting the electrostatic capacitance C1, a pressure of the pressure fluid is detected, and this pressure change is converted into a capacitance change of the electrostatic capacitance C2. Signal processing for processing the microsensor, the electrostatic capacitance C1 detected by the sensor unit, the electrostatic capacitance C2 detected by the microsensor, and the reference electrostatic capacitance CR detected by the reference unit, and outputting a desired signal. Since it is provided with the means, the detection error can be minimized, the number of parts is small, the cost is low, and the productivity can be improved.

In the gas meter according to the present invention, the pressure sensor device is provided with a detecting portion in which the electrostatic capacitances C1 and C2 change in accordance with a predetermined action from the outside, and an electrostatic capacitance CR depending on the predetermined action. The reference unit which does not change, and the capacitances C1 and C2 detected by the detection unit and the capacitance CR detected by the reference unit, and a signal processing means for outputting a desired signal are provided, and the meter main body is weighed. Since the gas pressure introducing passage is formed in the wall portion of the chamber, the pressure sensor device is fixed to the wall portion of the measuring chamber through the sealing means, and the pressure receiving portion of the pressure sensor device is communicated with the gas pressure introducing passage. The gas introduction pipe necessary for introducing the gas into the pressure sensor device becomes unnecessary, and the problem of the sealing property of the insertion portion of the gas introduction pipe into the measuring chamber can be avoided.

Further, in the gas meter according to the present invention, the pressure sensor device is provided with a vibration absorber for detecting vibration of an earthquake, and the signal processing unit of the pressure sensor device inputs the detection signal of the vibration absorber. Since a control function for controlling the gas flow rate when the predetermined seismic intensity is reached is added, a gas meter that controls the gas flow rate when the predetermined seismic intensity is reached can be provided.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a first embodiment of a pressure sensor device according to the present invention.

FIG. 2 is a perspective view of the pressure sensor device in an exploded state.

FIG. 3 is a plan view of a diaphragm.

FIG. 4 is a partial cross-sectional side view of the diaphragm.

FIG. 5 is a cross-sectional view of the diaphragm with a part thereof omitted.

FIG. 6 is a schematic block diagram of a capacitance detection circuit of the pressure sensor device according to the present invention.

FIG. 7 is a perspective view showing another embodiment of the differential type detection unit.

FIG. 8 is a vertical sectional view of a second embodiment of the pressure sensor device according to the present invention.

FIG. 9 is a perspective view of the pressure sensor device in an exploded state.

FIG. 10 is a plan view of a diaphragm.

FIG. 11 is a side view showing a partial cross section of the diaphragm.

FIG. 12 is a cross-sectional view of the diaphragm with a part thereof omitted.

FIG. 13 is an exploded perspective view of a third embodiment of the pressure sensor device according to the present invention.

FIG. 14 is a vertical sectional view of a fourth embodiment of the pressure sensor device according to the present invention.

FIG. 15 is an exploded perspective view of a fifth embodiment of the pressure sensor device according to the present invention.

FIG. 16 is a sectional view of a movable electrode and a diaphragm portion in a sixth embodiment of the pressure sensor device according to the present invention.

FIG. 17 is a vertical sectional view of a seventh embodiment of the pressure sensor device according to the present invention.

FIG. 18 is a perspective view of the pressure sensor device in an exploded state.

FIG. 19 is an exploded view of the microsensor.

FIG. 20 is a diagram illustrating the configuration of a sensor element of a micro sensor.

FIG. 21 is an exploded perspective view of an eighth embodiment of the pressure sensor device according to the present invention.

FIG. 22 is a schematic view of a gas meter using the pressure sensor device according to the present invention.

FIG. 23 is a cross-sectional view of a mounting portion of the pressure sensor device in the gas meter.

[Explanation of symbols]

 1 Detection Section 2 Reference Section 2a Element (Capacitor) 55 One Fixed Electrode 57 Movable Electrode 59 Other Fixed Electrode C Signal Processing Unit (Signal Processing Means)

Front page continuation (72) Inventor Tomonori Morimura 10 Odoron-cho, Hanazono, Ukyo-ku, Kyoto City Kyoto Prefecture OMRON Corporation

Claims (14)

[Claims] 1. A detection unit in which electrostatic capacitances C1 and C2 change in response to a predetermined external action, a reference unit in which electrostatic capacitance CR does not change due to the predetermined action, and a static electricity detected by the detection unit. A pressure sensor device, comprising: a signal processing unit that processes the capacitances C1 and C2 and the capacitance CR detected by the reference unit and outputs a desired signal. 2. The pressure sensor device according to claim 1, wherein the reference portion is composed of an element having a fixed capacitance. 3. The pressure sensor device according to claim 1, wherein the reference portion is composed of an element having a fixed capacitance, and the detection portion is covered with an electric field shield. 4. A pressure receiving portion for detecting the pressure of a pressure fluid, a reference portion formed of an element having a fixed capacitance, one and the other fixed electrodes, and the pressure receiving portion located between these fixed electrodes. A movable electrode that moves according to the applied pressure, and a detection unit that detects an electrostatic capacitance C1 between one fixed electrode and the movable electrode and an electrostatic capacitance C2 between the other fixed electrode and the movable electrode. And a signal processing unit for processing the electrostatic capacitances C1 and C2 detected by the detection unit and the reference electrostatic capacitance CR detected by the reference unit and outputting a desired signal. . 5. A pressure receiving part for detecting the pressure of the pressure fluid, a reference part composed of an element having a fixed capacitance, a fixed electrode and a movable electrode which moves according to the pressure sensed by the pressure receiving part. The first sensor unit that detects the electrostatic capacitance C1 between the fixed electrode and the movable electrode, the second sensor unit that is configured by an element to detect the electrostatic capacitance C2, and the first sensor unit detect The electrostatic capacitance C1, the electrostatic capacitance C2 detected by the second sensor unit, and the reference electrostatic capacitance CR detected by the reference unit.
And a signal processing means for processing a desired signal and outputting a desired signal. 6. A pressure receiving part for sensing the pressure of a pressure fluid, a reference part composed of an element having a fixed capacitance, a first sensor part composed of the element for detecting an electrostatic capacitance C1, and a fixed electrode. A second sensor unit having a movable electrode that moves according to the pressure sensed by the pressure receiving unit and detecting a capacitance C2 between the fixed electrode and the movable electrode; and a first sensor unit detecting the electrostatic capacitance C2. The electrostatic capacitance C1, the electrostatic capacitance C2 detected by the second sensor unit, and the reference electrostatic capacitance CR detected by the reference unit.
And a signal processing means for processing a desired signal and outputting a desired signal. 7. A first portion configured to sense the pressure of a pressure fluid and also serve as a movable electrode, a reference portion configured by an element having a fixed capacitance, and a capacitance C1 configured by the element. The first sensor unit detects a second sensor unit that detects a capacitance C2 between the sensor unit and the fixed electrode that has the fixed electrode and moves according to the sensed pressure. And a signal processing means for processing the electrostatic capacitance C2 detected by the second sensor unit and the reference electrostatic capacitance CR detected by the reference unit unit and outputting a desired signal. A pressure sensor device characterized by. 8. A diaphragm is used as a pressure-receiving member of the pressure-receiving portion, and the diaphragm is provided with a plunger portion for displacing the movable electrode when the diaphragm is displaced. 7. The pressure sensor device according to 7. 9. A pressure receiving part for sensing the pressure of a pressure fluid, a reference part composed of an element having a fixed capacitance, a first sensor part composed of the element for detecting an electrostatic capacitance C1, and a fixed electrode. And a second sensor section for detecting an electrostatic capacitance C2 between the fixed electrode and a movable electrode provided in the pressure receiving section that moves according to the sensed pressure, and a first sensor section detects The electrostatic capacitance C1, the electrostatic capacitance C2 detected by the second sensor unit, and the electrostatic capacitance C serving as the reference detected by the reference unit.
A pressure sensor device, comprising: a signal processing unit that processes R and outputs a desired signal. 10. A reference portion formed of an element having a fixed capacitance, a sensor portion formed of an element for detecting an electrostatic capacitance C1, a pressure of a fluid under pressure is detected, and this pressure change is detected by an electrostatic capacitance C2. A microsensor for converting into a capacitance change, a capacitance C1 detected by the sensor unit, a capacitance C2 detected by the microsensor, and a reference capacitance CR detected by the reference unit, and a desired signal is processed. And a signal processing unit that outputs the pressure sensor device. 11. The pressure sensor device according to claim 10, wherein the microsensor is mounted on a substrate of a signal processing means. 12. The pressure sensor device according to claim 10, wherein the microsensor is mounted on a flexible substrate, and the microsensor is connected to the signal processing means via the flexible substrate. 13. A pressure sensor device comprising: a detection part in which electrostatic capacitances C1 and C2 change in response to a predetermined external action;
A signal processing unit that processes a reference unit in which the capacitance CR does not change due to the predetermined action, the capacitances C1 and C2 detected by the detection unit, and the capacitance CR detected by the reference unit, and outputs a desired signal. And a gas pressure introducing passage is formed in the wall of the metering chamber of the meter main body, and the pressure sensor device is fixed to the wall of the metering chamber via a sealing means to receive the pressure of the pressure sensor device. A gas meter, wherein a part is communicated with the gas pressure introduction path. 14. The pressure sensor device is provided with a vibration absorber for detecting vibration of an earthquake, and the detection signal of the vibration absorber is input to the signal processing means of the pressure sensor device to reach a predetermined seismic intensity. The gas meter according to claim 13, further comprising a control function for controlling the flow rate of gas.