JPH07103841A - Differential pressure transmitter - Google Patents

Abstract

PURPOSE:To enhance the workability and manufacturability by employing a metal flow junction as means for fitting members airtightly each other. CONSTITUTION:A pressure receiving section for measuring fluid comprises a unit component of the seal diaphragm fixing hole part of a pressure receiving member 20 and plugs 35, 36. Seal diaphragms 6, 7 comprise a center diaphragm fixed in parallel with the opposite ends of the pressure receiving section. A seal metal 2 is disposed perpendicularly to the seal diaphragms 6, 7 and a first pressure receiving chamber 201 is communicated with an isolation chamber 203 and a semiconductor sensor 44 through conduction paths 24, 61, 63. Similarly, a second pressure receiving chamber 202 is communicated with a second isolation chamber 204 and the semiconductor sensor 44 through conduction paths 25, 26, 60, 62. A metal flow junction is employed entirely in the constitution. Consequently, a differential manometer can be manufactured using a machine of only one type thus realizing a line production through a conveyor.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a differential pressure transmitter, and more particularly to a differential pressure transmitter with improved manufacturability.

[0002]

2. Description of the Related Art A conventional pressure receiving portion structure of a differential pressure transmitter is disclosed in Japanese Patent Laid-Open No. 60-185131 (see FIG. 2).
The pressure receiving member is composed of two parts, a main body H and a main body L, and a seal diaphragm is fixed to one surface of the main body H, and a sensor portion and a center diaphragm are fixed to the other surface.

The seal diaphragm is fixed to one surface of the body L, and the other surface is welded on the outer periphery of the body H and the body L so that the center diaphragm of the body H is pressed against the seal diaphragm. Further, on both sides of the main body composed of the main bodies H and L, first and second pressure receiving chambers formed by seal diaphragms for receiving the first and second fluids are formed, and the main body H, the sensor assembly, A center diaphragm and a main body L provide first and second isolation chambers, and a pressure guiding path that connects the first pressure receiving chamber and the first isolation chamber, and a pressure guiding path that connects the first isolation chamber and the semiconductor differential pressure sensor. , A pressure guiding path connecting the second pressure receiving chamber and the second isolation chamber, and a pressure guiding path connecting the second isolation chamber and the semiconductor differential pressure sensor.

Filling liquid is filled in the first pressure receiving chamber, the first isolation chamber, the semiconductor differential pressure sensor, and the pressure guide path connecting these. Similarly, the second pressure receiving chamber, the second isolation chamber, the semiconductor pressure differential pressure sensor, and the pressure guiding path connecting these are filled with the filled liquid, and the pressure is transmitted to the semiconductor differential pressure sensor.

In the conventional differential pressure transmitter, a flange is attached at a position facing the seal diaphragm, and the main body H,
By tightening and fixing L and the flange with bolts and nuts, the pressure from the process fluid is transmitted to each pressure receiving chamber.

[0006]

In the pressure receiving portion of the conventional differential pressure transmitter, welding is the mainstream of welding, and in particular, the welding of the seal fitting, the sensor diaphragm, the seal diaphragm, etc., is all. Such welding work requires several kinds of welding machines such as TIG, laser, and electron beam welding, and is difficult to manufacture.

[0007]

In order to solve the above problems, in the differential pressure transmitter according to the present invention, a metal flow is used as a means for combining members with each other to make airtight. Further, a triangular groove is provided at a portion fixed by metal flow, and a metal having a low hardness is poured into the triangular groove, so that the degree of airtightness can be further increased. Then, it is possible to give strength by the shearing force of the metal that has flowed into the triangular groove, and to give a sealing property at the corners. If copper or brass having a lower hardness is used, metal flow can be achieved even if the number of grooves is reduced or eliminated. As a result, since it is possible to easily perform joining by changing the pressure using a press machine, it is possible to shorten the process of making the transmitter airtight without performing many manufacturing processes.

[0008]

The operation of the differential pressure transmitter according to the present invention will be described below in comparison with the conventional differential pressure transmitter.

In the conventional differential pressure transmitter, the members are welded by means of generating high heat such as TIG, laser, electron beam, etc., so that the members are deformed in the manufacturing process, and The pressure transmission state of the silicone oil may change, which requires a lot of time other than production such as setup inspection. On the other hand, in the differential pressure transmitter of the present invention, all the work can be performed only by changing the pressing method and the pressure state at the time of metal flow, and the manufacturing process can be facilitated. Further, according to the metal flow method, the plugs and the seal fittings can be directly fixed by the triangular groove, so that the number of parts can be reduced.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The differential pressure transmitter of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of a differential pressure transmitter according to the present invention. The differential pressure transmitter mainly comprises a pressure receiving member 20, a seal fitting part group 2, seal diaphragms 6, 7 ,.
Overload protection diaphragm 4, first and second pressure chamber 20
1, 202, first and second isolation chambers 203 and 204.

FIG. 3 is a detailed view of the pressure receiving member 20 shown in FIG. The pressure receiving member 20 is composed of a single member,
At both ends of the pressure receiving member 20, there are symmetrically provided holes 21, 22 for attaching the seal diaphragms 6, 7, triangular grooves 90, 91 for attachment are provided therein, and the bottom surface is the same as the seal diaphragms 6, 7. The shape is processed and the hole 2
The inlets of 1, 22 have a larger diameter than the sealing diaphragms 6, 7 for fixing the stoppers 35, 36, and have triangular grooves 78, 7
9 is provided.

Further, on the central axis of the pressure receiving member 20,
Triangular grooves 80, 8 for fixing the seal fitting part set 2 in a direction perpendicular to the seal diaphragms 6, 7 in the stepped hole part 23 for housing the overload protection diaphragm 4 and the seal fitting part set 2.
1, a triangular groove 82 for fixing the overload protection diaphragm 4 is provided. A triangular groove 83 for mounting an amplifier is provided on the small diameter side of the stepped hole 23, and a triangular groove 84 for mounting the fixing metal fitting 10 for fixing the overload protection diaphragm 4 is provided on the large diameter side. .

A conduction path 2 is formed between the seal diaphragms 6 and 7, the overload protection diaphragm 4, and the sensor unit set 2.
4, 25, 26 and 27 are connected.

The structure of the first pressure receiving chamber 201, the second pressure receiving chamber 202, the first isolation chamber 203, and the second isolation chamber 204 in the differential pressure transmitter of one embodiment of the present invention will be described with reference to FIG. explain.

In the differential pressure transmitter of the present embodiment, the seal diaphragms 6 and 7 are incorporated from the holes 21 and 22 of the pressure receiving member 20 so that the surfaces of the seal diaphragms 6 and 7 are parallel to each other. The first and second pressure receiving chambers 201 and 202 are formed by performing metal flow bonding using the metals 11 and 12 having lower hardness as the contact plates.
Next, the stoppers 35 and 36 are assembled into the stepped holes 37 and 38, and the stopper 3
Metal flow joining of 5, 36 to the triangular grooves 78, 79 is performed to form measurement fluid pressure receiving chambers 17, 18.

In the central stepped hole portion 23 of the pressure receiving member 20, the seal fitting portion set 2 is inserted from the direction of the larger diameter, and the passage 60 of the sealing fitting portion set 2 and the passage 27 of the pressure receiving member 20 are formed. It is assembled so as to be electrically connected, and both ends of the seal fitting part assembly 2 are metal-flowed.

After that, the center metal fitting 5 is placed at a position where the conduction path 61 of the center metal fitting 5 and the conduction portion 24 of the pressure receiving member 20 are electrically connected, and the surface of the overload protection diaphragm 4 which has been processed into the same wavy shape is overpassed. The first isolation chamber 203 is formed by mounting the load protection diaphragm 4 toward the overload protection diaphragm 4 and further metal-flow joining the overload protection diaphragm 4 with a metal 66 having a hardness lower than that of the pressure receiving member 20 as a contact plate.

At the center of the center metal fitting 5, there is provided a conducting path 63 for transmitting pressure from the overload protection diaphragm 4 to the semiconductor sensor 44. The fixing metal fitting 8 is installed in the fixing metal fitting mounting hole 10 and the pressure passage member 20 and the passage 62 of the fixing metal fitting 8 are connected.
Of the overload protection diaphragm 4 is attached to the triangular groove 84 of the pressure receiving member 20 such that the surface of the overload protection diaphragm 4 processed in the same shape as the corrugated shape of the overload protection diaphragm 4 faces toward the overload protection diaphragm 4 side. Metal flow bonding is performed to form the second isolation chamber 204.

Then, the seal diaphragm 6, the overload protection diaphragm 4, the seal fitting part set 2, the conductive paths 24, 6
1, 63, the space surrounded by the seal pin 51 of the liquid sealing port is filled with the filled liquid 15, and similarly, the seal diaphragm 7, the overload protection diaphragm 4, the seal fitting part set 2, the conductive paths 25, 26, The enclosed liquid 16 is also filled in the space surrounded by 27, 60, 62 and the seal pin 52 of the liquid sealing port.

In order to increase the strength of the sealing method of the seal pins 51 and 52, the triangular grooves 85 and 86 are provided and formed by metal flow.

The amplifier case 47 is inserted into the amplifier mounting hole 9, and the amplifier case 47 is fixed to the pressure receiving member 20 by metal flow bonding with a triangular groove.

The differential pressure detecting operation of the differential pressure transmitter having such a configuration will be described with reference to FIG. When the first pressure from the process fluid is applied to the seal diaphragm 6, the first pressure of the measurement fluid is transmitted to the sealed liquid 15 in the first pressure receiving chamber 201 on the back side of the seal diaphragm 6 through the seal diaphragm 6. Further, this first pressure is applied to the conduit 24,
61 overload protection diaphragm 4 and center metal fitting 5
Is transmitted to the first isolation chamber 203 formed between the semiconductor sensor 44 and the center metal fitting 4 through the conducting path 63.
Be transmitted to. Also, when the second pressure from the process fluid is applied to the seal diaphragm 7, the second pressure of the measurement fluid is similarly transmitted to the enclosed liquid 16 in the second pressure receiving chamber 202 via the seal diaphragm 7, and this second pressure is transmitted. The second pressure is the second isolation chamber 204 formed between the overload protection diaphragm 4 and the fixing member 8 by the communication passages 25, 26 and 27.
Is transmitted to the back surface of the sensor through the conduction path 60. In this way, the semiconductor sensor 44 has a center diaphragm table,
The first and second pressures of the measurement fluid transmitted to the back are detected, and the output of the semiconductor sensor 44 is taken out to the atmosphere open side from the hermetic seal pin 45 and is transmitted to the amplifier via the FPC 46. Further, the overload protection diaphragm 4 is a diaphragm for protecting the semiconductor sensor 44, and serves to protect the sensor when an excessive pressure is applied to the seal diaphragm 6 or 7. When an excessive pressure is applied, the seal diaphragm 6 or 7 is seated on the pressure receiving member 20 processed into the same waveform as the shape of the seal diaphragms 6 and 7 to prevent the internal pressure of the filled liquids 15 and 16 from rising. The overload protection diaphragm 4 absorbs the amount of the moving liquid until the seal diaphragms 6 and 7 are seated in the first and second isolation chambers 203 and 204, and suppresses the internal pressure rise below the breakdown voltage of the semiconductor sensor 44. Protect the sensor 44.

FIG. 6 is a sectional view showing an embodiment of the multi-function type sensor used in the present invention, FIG. 8 is a plan view of only the sensor of FIG. 6, and FIG. 7 is a circuit diagram thereof.

In FIG. 6, reference numeral 44 denotes a composite function type sensor chip made of single crystal silicon. The multifunctional sensor chip 44 is attached to the housing 2 via a hollow first fixing base 302 and a hollow second fixing base 303. First
The fixing base 302 of is made of borosilicate glass having a linear expansion coefficient close to that of silicon in consideration of electrical insulation from the housing 2 of the multi-function sensor chip 44 and reduction of thermal strain due to a difference in linear expansion coefficient from the housing 2. Silicon having an oxide film only on its bonding surface is preferable. Further, the second fixing base 303, like the fixing base 302, takes into consideration the linear expansion coefficient and attachment to the housing 2 by welding or the like, and in consideration of the linear expansion coefficient, a Fe—Ni alloy or Fe which has a linear expansion coefficient close to that of silicon.
-Ni-Co alloy is preferred. The first fixing table 302 is made of borosilicate liquid glass, or silicon having an oxide film on the bonding surface,
The second fixed base 303 is made of Fe-Ni alloy or Fe-Ni-
If a Co alloy is used, the multi-functional sensor chip 44 and the first
The fixing base 302 and the second fixing base 303 can be easily joined by the anodic bonding method. Further, the second fixing base 3 and the housing 4 are easily joined by ordinary welding joining (for example, TIG welding 2 is plasma welding).

The differential pressure or pressure difference signal, the static pressure signal, and the temperature signal from the composite function type sensor chip 1 are connected to the lead wire 3.
It is taken out through the terminal 17 of the hermetic seal portion 341 provided in the housing 2 through the wiring board 17 and the wiring board 305.

The composite function type sensor chip 44 is (100)
The surface is n-type single crystal silicon, and has a substantially circular or annular thin-walled portion 311 at approximately the center of one surface thereof. on the other hand,
On the other surface of the chip 44, a recess 313 is formed by the first fixing base 302 having a hole in the center. This recess 313
One of the pressures to be detected is introduced from the second fixing base 303 having a hole in the center. As a result, the thin portion 311 becomes a strain-generating body sensitive to the differential pressure or the pressure difference, and operates as a differential pressure sensitive diaphragm.

On the upper surface of the differential pressure sensitive diaphragm 311,
The piezoresistive coefficient in the (100) plane becomes maximum <1
10> p-type gauge resistors 611 to 614, 65 in the axial direction
Four differential pressures 1 to 654 or pressure differential resistances are formed in parallel or at right angles by the diffusion method or the ion implantation method. The positions of the resistors 611 to 614 and 651 to 654 are the differential pressure sensitive diaphragm 3 when the differential pressure or the pressure difference is applied.
It is formed in the vicinity of the fixed portion where the stress in the radial direction and the circumferential direction generated on 11 is maximized. The directions of the resistances are 611 and 613 in the radial direction and 612 and 614 in the tangential direction. These resistance groups are connected to a bridge as shown in FIG. Differential pressure sensitive diaphragm 31
The shape and wall thickness of No. 1 are set to a desired shape and wall thickness depending on the differential pressure or pressure difference that is sensitive.

Resistor group 6 on differential pressure sensitive diaphragm 311
11 to 614 are subjected to stress generated by the pressure difference between the upper surface of the diaphragm and the concave portion 13, and their resistance values change due to the piezoresistive effect, so that the terminals 504 to 507 in the circuit of FIG. You can take it out. However, this output is sensitive even when the pressure on both sides of the differential pressure sensitive diaphragm 311 is equal, or even when the temperature changes. The first of these is that the resistance values of 611 to 614 change as a function of temperature. Secondly, the multi-function sensor chip 44 exerts its function as a continuous structure having joints made of different materials as shown in FIG.
It means that some kind of stress is inevitably generated when pressure is applied.

For this reason, in one embodiment of the present invention, the auxiliary sensor sensitive to pressure and temperature is used as the composite function type sensor chip 4.
4 and the signals are used to correct the differential pressure or the pressure difference signal with high accuracy.

14 and 16, at least one temperature-sensitive resistor 655 is formed in the thick portion 312 of the multi-function sensor chip 44 other than the differential pressure-sensitive diaphragm 311. This temperature-sensitive resistance is a p-type temperature-sensitive resistance arranged in the <100> axis direction showing the minimum sensitivity of the piezoresistive coefficient in the (100) plane, and is insensitive to pressure. Similar to the differential pressure resistance groups 611 to 614, this resistance is formed with a resistance value by which a predetermined output can be obtained by the diffusion or ion implantation method.

On the other hand, the static pressure sensor, which is another auxiliary sensor, is similar to the temperature-sensitive resistor 655 in that the sensor chip 4
Four static pressure resistance groups 6 are provided in the thick portion 312 of 4 in the same crystal axis direction as the differential pressure resistance group, in parallel or at right angles.
51-654 are formed. Static pressure resistance group 651-654
Of these, 651 and 654 are thick portions 312 of the tip 44.
Is formed on a surface having a thin portion 315 in a part thereof. The other surface of the thin portion 315 is the first fixing base 302.
One surface and the concave portion 321 are formed. Since the recess 321 is completely enclosed at the time of joining, it is completely separated from the static pressure and operates as a reference pressure chamber having a predetermined pressure. Generally, the pressure of the reference pressure chamber is maintained at a predetermined pressure between vacuum and atmospheric pressure. As a result, the thick portion 312
The upper thin portion 315 serves as a flexure element sensitive to static pressure, and operates as a static pressure sensitive diaphragm sensitive to the pressure difference between the pressure of the reference pressure chamber and the static pressure. This static pressure sensitive diaphragm 31
5 is required to withstand a pressure difference several hundred times higher than that of the differential pressure sensitive diaphragm 311. Therefore, it is necessary to pay sufficient attention to setting the shape of the recess 321.

FIG. 9 shows an embodiment of the metal flow working process used in the present invention. In the differential pressure transmitter of the present invention, it is possible to use a metal flow at the place where the members are joined, but for the sake of explanation, the metal flow between the pressure receiving member 20 and the plug 36 will be taken as an example. Take and explain.

First, as the first working step, the groove portion 698 is formed in the stepped hole 38 into which the plug of the pressure receiving member 20 is inserted. As a method of forming the groove portion 698, it can be appropriately created by a lathe or other processing method. Next, the stopper 36 is incorporated into the stepped hole 38, and the push blade 699 is fixed to the stopper 36. Then, a pressing pressure of 700 (about ten tons) is applied to this pushing blade to remove the plug material 36.
The portion in contact with the groove portion 698 is deformed and metal flow joining is performed.

As a result, as shown in FIG. 10, in the groove portion 698, a sealing property is generated between the member 20 and the member 36 in the triangular portion of the groove portion, and further, the portion of the plug 36 that has entered the groove portion is sheared. It becomes possible to give strength between members.

Further, when performing metal flow bonding, the strength relationship between two members becomes a problem. For example, if stainless steel (SUS316) is used for the pressure receiving member,
If a relatively soft member such as copper is used as the plug 36, the metal flow can be performed relatively easily.
However, a fundamentally soft member is insufficient in strength as a plug material, and thus a problem remains.

Therefore, in one embodiment of the present invention, when a material having the same difference as the pressure receiving member is used as the plug material, the portion of the plug material that enters the groove is made relatively softer than the peripheral portion by the solution treatment or the like. It is possible to facilitate the metal flow work by performing the processing.

Table 1 below shows the pressure receiving member 20.
When SUS316 is used, the hardness change before and after the solution treatment performed on the plug material made of each material is shown to facilitate the metal flow.

The solution treatment temperature is about 1000 ° C.

[0040]

[Table 1]

By thus softening the circumference of the plug material, it is possible to facilitate the metalloflow bonding.

Next, modified examples of mounting the plug are shown in FIGS.

FIG. 4 shows a method in which the overload protection diaphragm 4 and the fixing metal fitting 8 are joined at the same time. A projection is provided on the circumference of the surface of the fixing metal fitting 8 that contacts the overload protection diaphragm 4, and the overload protection diaphragm is attached by the projection. Hold down. As a result, there is an advantage that the metal 66 is not needed when the overload protection diaphragm 4 is metal-flowed, and the number of operations is only one.

Similarly in FIG. 5, by providing protrusions on the plugs 35 and 36, the seal diaphragms 6 and 7 and the plugs 35 and 3 are formed.
6 can be joined at the same time, the metal 11 and 12 at the time of metal-flowing the seal diaphragms 6 and 7 are unnecessary, and the number of times of work is only one.

In the above-described embodiment of the present invention, when joining members to each other by metal flow, there is shown an example in which two groove portions are provided and the members are pushed in. By using, it becomes possible to perform a complete metal flow joining even if there is only one groove.

Further, as one embodiment of the present invention, an example is shown in which all the members in the differential pressure transmitter and the parts for joining the members are subjected to the metal flow. However, if there is a part where the metal flow is not necessary, It is also possible to adopt a method of joining these members by a conventional method, for example, the stopper 35 and the stopper 3
It is also possible to carry out only 6 or only the fixing member 8 and further only these three members.

Further, in order to facilitate the production and suppress the deformation of the pressure receiving member 20, the members in the opposite directions, for example, the plug 36 and the plug 35, the amplifier case 47 and the fixing member 8 are pressed by the press pressure from the respective directions. This makes it possible to suppress deformation and facilitate manufacturing.

In this embodiment, the pressure receiving member 20 and the respective members are constituted by a single member. However, it is of course possible to obtain the same effect by combining a plurality of members. it can.

FIG. 11 shows an embodiment of the signal processing circuit of the differential pressure transmitter of the present invention. The composite sensor 44 outputs a change in gauge resistance due to differential pressure, static pressure and temperature as an electric signal, and is selectively taken into the multiplexer (MPX) 731.

Various signals taken in by the multiplexer 731 are programmable gain amplifier (PGA) 73.
3 and then converted into a digital signal by the A / D converter 734, and the microprocessor (MPU) 730
Sent to. Memory 739 (EPROM) has a differential pressure,
Each characteristic of the static pressure and temperature sensors (in the case of a pressure transmitter, each characteristic of the pressure and the same degree sensor) is stored in advance, and by using these data, the microprocessor 730 corrects and calculates Precision differential pressure signal type, static pressure,
Calculate the temperature signal value. The calculation result is converted into a normal analog signal through the D / A converter 737 and the V / I converter 738, and becomes a signal of DC 4 to 20 mA, which is applied to the computer 740, which is a higher-level control device, by differential pressure and static. It is configured to send out pressure and temperature signals.

In the apparatus of this embodiment, the information about the process state obtained from the multi-function sensor 44 is converted into a direct current (for example, DC 4 to 20 mA) and provided near the signal processing circuit (shown in the figure). It is difficult to output process information by sending a digital signal directly from the signal processing circuit (not shown in the figure). .

Further, the digital I / O circuit 740 superimposes a digital signal on the direct current signal to communicate with an external monitoring control device, and this device displays information on the process state, and this device. Can set and change parameters such as measurement range, output adjustment, input / output monitor, and self-diagnosis.

FIG. 18 shows an embodiment of a process control system when the differential pressure transmitter of the present invention is connected to a host device for monitoring and controlling the process state.

The signal that has detected the process state of the differential pressure transmitters 930 and 940 connected to the two-wire type transmitter 950 is connected to the operator console 740 via the signal comparator 910, so that the signal can be transmitted from a location remote from the process site. But you will be able to know. In addition to the operator's console 740, the handle-held type communication device 920 connected to the two-wire transmission line can detect the path change state of the process state detector.

[0055]

According to the differential pressure transmitter of the present invention, the metal fitting is used to join the seal fitting, the center diaphragm, the fixing fitting, the seal diaphragm, the measurement fluid pressure receiving chamber forming plug, the seal pin and the amplifier to the pressure receiving body. Therefore, it can be manufactured by one type of machine. In addition, line production by a conveyor is also possible, which has the effect of manufacturing a differential pressure transmitter that has extremely high productivity and is inexpensive.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of a differential pressure transmitter of the present invention.

FIG. 2 is a vertical sectional view of a conventional differential pressure transmitter.

3 is a longitudinal sectional view of the pressure receiving member of FIG.

FIG. 4 is a cross-sectional view of another embodiment of overload protection diaphragm bonding.

FIG. 5 is a cross-sectional view of another embodiment of sealing diaphragm bonding.

FIG. 6 is a multifunctional sensor used in an embodiment of the present invention.

FIG. 7 is a circuit diagram of the sensor of FIG.

FIG. 8 is a plan view of the sensor of FIG.

FIG. 9 is an example of a manufacturing process of the differential pressure transmitter of the present invention.

FIG. 10 is an explanatory view of a groove portion of the differential pressure transmitter of the present invention.

FIG. 11 is an embodiment of the detection circuit of the differential pressure transmitter of the present invention.

FIG. 12 is a diagram showing how the differential pressure transmitter of the present invention is attached to a transmission line.

[Explanation of symbols]

2 ... Seal metal part assembly, 4 ... Overload protection diaphragm, 5
... Center metal fittings, 6,7 ... Seal diaphragm, 8 ... Fixing metal fittings, 9 ... Amplifier mounting hole, 10 ... Fixing metal fitting mounting hole, 1
1, 12, 13, 14, 66 ... Metal, 15, 16 ... Filled liquid, 17, 18 ... Measuring fluid pressure receiving chamber, 20 ... Pressure receiving member 21, 22 ... Seal diaphragm mounting hole portion, 23
... Sensor assembly storage holes, 24, 25, 26, 27, 6
0, 61, 62, 63 ... Conducting path, 35, 36 ... Stopper, 3
7, 38 ... Stepped hole, 44 ... Semiconductor differential pressure sensor, 45 ... Hermetic seal pin, 46 ... FPC, 47 ... Amplifier case, 51, 52 ... Seal pin, 53, 54 ... Liquid sealing port,
201 ... First pressure receiving chamber, 202 ... Second pressure receiving chamber, 203
... first isolation chamber, 204 ... second isolation chamber, 699 ... push blade.

Claims (10)

[Claims] 1. A first pressure receiving chamber formed by a first diaphragm and containing a first detection fluid, and a second pressure receiving chamber formed by a second diaphragm and containing a second detection fluid. A pressure-receiving chamber, the pressure of the first measurement fluid is applied to the first diaphragm, the pressure of the second measurement fluid is applied to the second diaphragm, and the difference between the two pressures is detected by a differential pressure detection sensor. In the differential pressure transmitter, a first isolation chamber conducting to the first pressure receiving chamber and a second isolation chamber conducting to the second pressure receiving chamber are provided in different directions from the first and second diaphragms. A differential pressure transmitter having a structure configured to apply the first and second detection fluids that are electrically connected to the first and second isolation chambers to the differential pressure detection sensor, A differential pressure transmitter characterized by coupling with a metal flow. 2. The differential pressure transmitter according to claim 1, wherein the first diaphragm is disposed on a first end face of a pressure receiving member main body of the differential pressure transmitter, and the second diaphragm is the first diaphragm. A differential pressure transmitter characterized in that the first and second diaphragms of the differential pressure transmitter arranged on the second end face of the pressure receiving member main body facing the end face of are connected by a metal flow. 3. The differential pressure transmitter according to claim 1, wherein the pressure receiving direction of the first diaphragm and the pressure receiving direction of the third diaphragm are positioned at right angles to each other. A differential pressure in which three diaphragms are arranged and the second and third diaphragms are arranged so that the pressure receiving direction of the second diaphragm and the pressure receiving direction of the third diaphragm are positioned at right angles. A differential pressure transmitter characterized in that the transmitter is coupled with a metal flow. 4. The differential pressure transmitter according to claim 1, wherein one side of the third diaphragm is joined to a pressure receiving member constituting the differential pressure transmitter to form the first isolation chamber. A differential pressure transmitter characterized in that a metal flow is used for joining. 5. The differential pressure transmitter according to claim 4, wherein a metal member is used for joining when a sealing member is joined to one surface of the third diaphragm to form the second isolation chamber. Differential pressure transmitter characterized by being joined together. 6. The differential pressure transmitter according to claim 1, further comprising a semiconductor differential pressure sensor having a pressure detection diaphragm as the differential pressure detection sensor, the pressure receiving direction of the pressure detection diaphragm and the third diaphragm. A differential pressure transmitter characterized in that the differential pressure transmitters whose pressure receiving directions are the same direction are connected by a metal flow. 7. The differential pressure transmitter according to claim 6, wherein the semiconductor differential pressure sensor is held by a seal fitting, and a metal flow is used for joining the pressure receiving member constituting the differential pressure transmitter and the seal fitting. A differential pressure transmitter characterized by using. 8. The differential pressure transmitter according to claim 7, wherein a hole is formed in a pressure receiving member constituting the differential pressure transmitter so as to be coaxial with the seal fitting, and an output signal from the differential pressure detection sensor is provided. A differential pressure transmitter characterized in that a metal flow is used for joining the amplifier for amplification and the hole. 9. The differential pressure transmitter according to claim 1, wherein the pressure receiving member of the differential pressure transmitter to which the first, second and third diaphragms are joined is formed of a single member. The differential pressure transmitter is characterized in that the coupling is performed by a metal flow. 10. The differential pressure transmitter according to claim 1, wherein a pressure receiving member of the differential pressure transmitter which forms the first pressure receiving chamber controls the pressure of the first measurement fluid to the first diaphragm. The pressure of the second measurement fluid is guided to the second diaphragm by the pressure receiving member of the differential pressure transmitter that constitutes the first measurement fluid pressure receiving chamber that guides the pressure to the second diaphragm. A differential pressure transmitter characterized in that a metal flow is used as a method of joining and sealing members when forming the second measurement fluid pressure receiving chamber to be pressed.