JPH01295129A - Differential pressure measuring instrument - Google Patents

Abstract

PURPOSE:To reduce the size and weight of the differential measuring instrument by constituting a differential pressure measuring instrument main body part and a changeover valve in one body and omitting a piping. CONSTITUTION:A connection hole 43 is connected to the high-pressure side of liquid to be measured and a connection hole 44 is connected to the low- pressure side. Then the connection holes 43 and 44 are normally linked respectively, so pressure to be measured is applied from the right and left sides of the main body 11 and a measurement diaphragm 13 is displaced according to differential pressure to be measured. The electrostatic capacity between fixed electrodes 133 and 134 and measurement diaphragm 13 varies differentially by the displacement of the measurement diaphragm 13 to obtain an electric signal corresponding to the differential pressure. Further, the zero point of the device is adjusted by moving a valve shaft 52 in the axial direction of the valve shaft 52, cutting off the communicating of the connection hole 44, and communicating the connection hole 43 with the pressure receiving chamber side of the connection hole 44.

Description

[Detailed description of the invention] <Industrial application field> The present invention relates to a differential pressure measuring device.

More specifically, the present invention relates to an input circuit of a differential pressure measuring device.

<Prior Art> FIG. 6 is a diagram illustrating the configuration of a conventional example of a flow rate measurement system using an orifice that has been commonly used.

In the figure, A is a conduit through which the measurement fluid flows.

B is an orifice provided in conduit A.

C is a conduit attached to conduit A upstream or downstream of orifice B. C1 is a main valve that opens and closes the conduit.

D is a three-way valve connected to conduit C. Dl is a stop valve provided on the three-way valve, and D2 is a pressure equalization valve.

E is a differential pressure measuring device connected to a three-way valve.

<Problems to be Solved by the Invention> However, in such a device, the three-way valve and the differential pressure measuring device E are separate bodies, and require mutual piping. Furthermore, the device becomes complicated, making it impossible to reduce the size, weight, and cost of the device.

The present invention solves this problem.

An object of the present invention is to provide a differential pressure measuring device that can reduce costs by reducing size and weight and eliminating the need for parts such as piping, and allows easy and reliable switching of input circuits.

Means for Solving the Problems> In order to achieve this object, the present invention provides a differential pressure sensor section having a different overpressure protection mechanism, and a differential pressure sensor section connected at one end to the differential pressure sensor section for guiding measurement pressure. a pressure-receiving block to which the other end of the pressure-receiving pipe is fixed, a seal tyre flamm that is provided on the outer surface of the pressure-receiving block and constitutes a seal chamber that communicates with the pressure-receiving block and the pressure pipe; a base block having a concave portion to which a pressure receiving block is attached and forming a pressure receiving chamber with the seal tire phragm; and a base block provided in the base block with one end communicating with the pressure receiving chamber and the other end opening to the outside as a pressure receiving connection port. connection holes,
A pressure equalization hole provided in the base block and communicating the two connection holes, a rod-shaped valve shaft provided in the middle of the pressure equalization hole, two valve bodies provided in the valve shaft, and the valve body. and a valve seat provided in the middle of the pressure equalizing hole opposite to the pressure equalizing hole. Normally, one of the connecting holes is communicated, and when adjusting the zero point, the valve shaft is moved in the axial direction of the valve shaft. A differential pressure measuring device is constructed, which includes a two-bow valve 1 which disconnects communication between the connecting holes and communicates the pressure receiving chamber side of one of the connecting holes with the other connecting hole.

In the above configuration, since the connecting holes are usually in communication with each other, measurement pressure is applied from the left and right sides of the main body, and the measurement diaphragm is displaced by the difference in the measurement pressure. The displacement of the measurement diaphragm differentially changes the capacitance between the fixed electrode and the measurement diaphragm, resulting in an electrical signal output corresponding to the differential pressure.

To equalize the constant inputs on both sides of the device and adjust the zero point of the device, move the valve shaft in the axial direction of the shaft and disconnect the connection hole on one side by bringing the valve body into contact with and separating from the valve seat. , after communicating the pressure receiving chamber side of one connection hole with the other connection hole,
Adjusting the zero point of the device will be described in detail below based on an example.

<Example> FIG. 1 is an explanatory diagram of the main part of an embodiment of the present invention.

In the figure, 1 is a differential pressure sensor section.

As shown in FIG. 2, 11 is a block-shaped main body made of metal.

12 is an internal chamber provided in the main body 11.

Reference numeral 13 denotes a measuring diaphragm which divides the internal chamber 12 into two measuring chambers 14 and 15 and functions as a moving electrode.

Reference numeral 131.1.32 is a ceramic plasma-sprayed film provided on the wall of the internal chamber 12. In this case, the thickness is 02 to 0.5 mm.

Fixed electrodes 13'3 and 134 are respectively provided on the surfaces of the insulating films 13], 132 and on the walls of the internal chamber 12, facing the measurement tyrephragm 13.

Reference numeral 2 denotes a pressure guiding pipe which is connected at one end to the differential pressure sensor section 1 and guides the measured pressure.

Reference numeral 3 designates pressure receiving blocks to which the other ends of the pressure guiding pipes 2 are respectively fixed.

Reference numeral 31 denotes a seal tyrephragm that is provided on the outer surface of the pressure receiving block 3 and constitutes a seal chamber 32 that communicates with the pressure receiving block 3 and the pressure guiding pipe 2.

4 is the seal tire phragm 3 to which the pressure receiving block 3 is attached.
1 and a recess 42 forming a pressure receiving chamber 41.

Reference numerals 43 and 44 designate two connection holes provided in the base block 4, one end communicating with the pressure receiving chamber 41 and the other end opening to the outside as a connection port.

In this case, the connection hole 43 is connected to the high pressure side of the fluid to be measured, and the connection hole 44 is connected to the low pressure side.

Reference numeral 5 designates a two-port valve, as shown in FIGS. 3 and 4, which includes a pressure equalizing hole 51 provided in the base block 4 and communicating between the connecting hole 43 and the connecting hole 44, and a pressure equalizing hole 51 provided in the middle of the pressure equalizing hole 51. a rod-shaped valve shaft 52 and a valve shaft 52 provided on the valve shaft 52;
valve body 53, and a base block 4 facing the valve body 53.
A valve seat 54 provided in the valve seat 54 is provided.

The 2-port valve 5 normally communicates the connection hole 44 with the pressure receiving chamber side of the connection hole 44 and the connection hole 43 by moving the valve shaft 52 in the axial direction of the valve shaft 52 to disconnect the connection hole 44 during zero point adjustment. Communicate.

6 is a cover attached to the base block 4, covering the differential pressure sensor section 1, as shown in FIG.

Reference numeral 61 denotes a printed board unit attached to the cover 6 and having electronic components attached thereto.

Reference numerals 101 and 102 are filled liquids sealed in two chambers consisting of the measurement chambers 14 and 15, the impulse tube 2, and the seal chamber 32. In this case, silicone oil is used.

In the above configuration, since the connection holes 43 and 44 are normally in communication with each other, measurement pressure is applied from the left and right sides of the main body 11, and the measurement tire flammable 13 is displaced by the difference between the measurement pressures. As the measurement diaphragm 13 is displaced, the capacitance between the fixed electrodes 133 and 134 and the measurement diaphragm 13 changes differentially, and an electrical signal output corresponding to the differential pressure is obtained.

To equalize the constant inputs on both sides of the device and adjust the zero point of the device, move the valve shaft 52 in the axial direction of the valve shaft 52 to disconnect the connection hole 44, as shown in FIG.
The zero point of the device is adjusted after communicating the pressure receiving chamber side of the connection hole 44 with the connection hole 43. As a result, (1) The main body of the differential pressure measuring device and the switching valve were integrated, so the bolts and main body There is no need for a flange or bracket for installation, making it compact, lightweight, and can be installed anywhere.

(2) Piping between the main body of the differential pressure measuring device and the switching valve becomes unnecessary.

(3) Since the differential pressure sensor section 1 is separated from the Hayes block 4 by the impulse tube 2 and supported in the air, it is not easily affected by the temperature of the measured fluid even if the measured fluid is at a high temperature. , a device with a wide measurable temperature range can be obtained.

(4) Switching of the input circuit can be done with a single touch, since it is enough to move the valve shaft 52.

(5) Since the switching of the input circuit is performed by the valve body 53 and the valve seat 54, the input circuit can be switched easily and reliably.

(6) Insulation r! Since A131.132 uses a ceramic sprayed film, it can be made extremely thin, so there is no need to hold the main body 11 large, and the strength of the main body 11 can be increased, so the main body 11 can be made smaller, and the device can be made smaller. The whole can be made smaller.

In the above-mentioned embodiment, the two-port valve was described as being manually operated, but it goes without saying that a remote-type valve using a solenoid valve or the like may also be used.

<Effects of the Invention> As explained above, the present invention includes a differential pressure sensor section equipped with an overpressure protection device, a pressure impulse pipe whose one end is connected to the differential pressure sensor section and which guides the measured pressure, and the guide tube. a pressure receiving block to which the other ends of the pressure pipes are each fixed; a seal tyre phragm provided on the outer surface of the pressure receiving block and forming a seal chamber communicating with the pressure receiving block and the pressure guiding pipe; and a seal to which the pressure receiving block is attached. a base block having a concave portion constituting a tire phragm and a pressure receiving chamber; two # reading tags provided on the base block with one end communicating with the pressure receiving chamber and the other end opening to the outside as a pressure receiving connection port; and the base A pressure equalizing hole provided in the block that communicates the two connecting holes, a rod-shaped valve shaft provided in the middle of the pressure equalizing hole, two valve bodies provided on the valve shaft, and opposing to the valve bodies. and a valve seat provided in the middle of the pressure equalizing hole. Normally, one of the connecting holes is communicated with the other connecting hole, and when adjusting the zero point, the valve shaft is moved in the axial direction of the valve shaft to connect the one connecting hole. and a two-port valve that disconnects communication between the pressure receiving chamber side of one of the connection holes and the other of the connection holes.

As a result, (1) Since the main body of the differential pressure measuring device and the switching valve can be integrated, there is no need for bolts, main body flanges, brackets, etc. for installation, resulting in a smaller size, lighter weight, and lower cost.

(2) Piping between the main body of the differential pressure measuring device and the switching valve becomes unnecessary.

(3) The differential pressure sensor part is separated from the base block by a pressure impulse tube and is supported in the air, so even if the fluid to be measured is at high temperature, it is not affected by the temperature of the fluid to be measured and is within the measurable temperature range. A wide range of equipment is available.

(4) Switching of the input circuit can be done with one touch because all you have to do is slide the screws 1 to 1.

(5) Switching of input circuit is done by valve body and valve seat-11
= Switching can be done reliably and reliably.

Therefore, according to the present invention, it is possible to reduce costs by reducing the size and weight and eliminating the need for parts such as piping, and it is possible to realize a differential pressure measuring device in which input circuits can be switched easily and reliably.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the main part configuration of an embodiment of the present invention, FIG.
FIGS. 3, 4, and 5 are explanatory diagrams of the main part configuration of FIG. 1, and FIG. 6 is an explanatory diagram of the configuration of a conventional example that has been generally used. 1... Differential pressure sensor section, 101. ．． 102. ... Filled liquid, 11 ... Main body, 12 ... Internal chamber, 13 ... Measurement diaphragm, 131, 132 ... Insulating film, 133
, 134... Fixed electrode, 14, 1.5... Measurement chamber,
2... Impulse pipe, 3... Pressure receiving block, 31... Seal tyre phragm, 32... Seal chamber, 4... Base block, 41... Pressure receiving chamber, 42... Recess, 43
．． 44... Connection hole, 5... 2 port valve, 51...
Equalizing hole, 52... Valve shaft, 53... Valve body, 54
... Valve seat, 6... Cover, 61... Pulley 12
= board unit. Fig. 3 Fig. 6 - θ (- to Heron'''' 31 ≧ 11 hardness ゛6, #

Claims (1)

[Claims] A differential pressure sensor section equipped with an overpressure protection mechanism, a pressure impulse tube whose one end is connected to the differential pressure sensor section and which guides the measured pressure, a pressure receiving block to which the other end of the impulse tube is fixed, and the pressure receiving block. a seal diaphragm provided on the outer surface of the block and forming a seal chamber communicating with the pressure receiving block and the pressure impulse pipe; a base block having a recess to which the pressure receiving block is attached and forming a pressure receiving chamber with the seal diaphragm; two connection holes provided in the block, one end communicating with the pressure receiving chamber and the other end opening to the outside as a pressure receiving connection port; a pressure equalization hole provided in the base block communicating the two connection holes; Usually comprises a rod-shaped valve shaft provided in the middle of the pressure equalizing hole, two valve bodies provided on the valve shaft, and a valve seat provided in the middle of the pressure equalizing hole opposite to the valve body. connects one of the connection holes, and when adjusting the zero point, moves the valve shaft in the axial direction of the valve shaft to disconnect the one connection hole and connect the pressure receiving chamber side of the one connection hole with the connection hole. A differential pressure measuring device comprising a two-port valve communicating with the other.