JPH0257934A - Differential-pressure measuring apparatus - Google Patents

Abstract

PURPOSE:To implement a compact configuration, light weight and cost reduction by communicating one of connecting holes at the normal time; and turning a communicating groove, disconnecting the communication of one connecting hole and communicating the side of one connecting hole on the side of a pressure receiving chamber and the other connecting hole, when a zero point is adjusted. CONSTITUTION:At the normal time, connecting holes 43 and 44 are connected. Therefore, pressures are applied from the right and left sides of a main body. A measuring diaphragm is displaced by the differential pressure of the measured pressures. The electrostatic capacitance between a fixed electrode and the measuring diaphragm is differentially changed by the displacement of the measuring diaphragm. An electric signal output corresponding to the differential pressure is obtained. Then both inputs to be measured of this apparatus are made equal, and the zero point of the apparatus is adjusted. For these purposes, a communicating groove 52 which is provided around a rotary-valve main body 51 is turned. Communication with the connecting hole 44 is disconnected. The connecting hole 44 on the side of pressure receiving chamber is communicated to the connecting hole 43, and the zero point of the apparatus is adjusted. In this way, a compact configuration, light weight and cost reduction can be implemented for the apparatus.

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 the three-way valve I).

<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 mutual piping is required. Further, the device becomes complicated, and it is difficult to reduce the size and weight of the device and reduce the cost.

The present invention solves this problem.

The purpose of the present invention is to reduce costs by reducing size and weight, eliminating the need for parts such as piping, and making it possible to easily switch input circuits, to provide a non-grounded structure for the sensor section, and to simplify electrical circuits. The purpose is to provide a differential pressure measuring device that can be used.

Means for Solving the Problems> In order to achieve this object, the present invention includes a block-shaped body, an internal chamber provided inside the body and made of opposing spherical surfaces, and a system in which measuring pressure is introduced into the internal chamber. a measuring diaphragm functioning as a movable electrode; an insulating film made of a plasma sprayed ceramic film provided on the wall of the internal chamber; a differential pressure sensor section including a fixed electrode provided at the differential pressure sensor section, a pressure impulse tube whose one end is connected to the differential pressure sensor section through an insulator and which guides the measurement pressure, and the other end of the pressure impulse tube is fixed. a pressure receiving block, a seal diaphragm provided on the outer surface of the pressure receiving block and forming a seal chamber communicating with the pressure receiving block and the pressure impulse pipe, and a recess to which the pressure receiving block is attached and forming the seal diaphragm and the pressure receiving chamber. a base block having a base block; two connection holes 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; and two connection holes provided in the base block and connected to the peripheral surface of the rotary valve body. Normally, one of the connection holes is connected through a provided communication groove, and when adjusting the zero point, the communication groove is rotated to disconnect communication between the one connection hole and the pressure receiving chamber side of the one connection hole and the connection with the pressure receiving chamber side. This is a differential pressure measuring device comprising a rotary pressure equalizing valve that communicates with the other hole.

In the above configuration, since the connection holes are usually in communication with each other, measurement pressure is applied to the left and right sides of the main body, and the measurement diaphragm is displaced by the difference in the measurement pressures. 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 remeasurement input of the device and adjust the zero point of the device, rotate the communication groove provided on the circumferential surface of the rotary valve body to disconnect communication from one of the connection holes. The zero point of the device is adjusted after communicating the pressure receiving chamber side with the other side of the connection hole.Hereinafter, a detailed explanation will be given based on an example.

<Embodiment> FIG. 1 is an explanatory diagram of the main part configuration of an embodiment of the present invention, and FIG. 2 is a perspective view of FIG. 1.

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

As shown in FIG. 3, 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 measurement diaphragm which divides the internal chamber 12 into two measurement chambers 14 and 15 and functions as a moving electrode.

Insulating films 131 and 132 are provided on the wall surface of the internal chamber 12 and are made of a plasma sprayed ceramic film. In this case, the thickness is 0.2 to 0.5 mm.

Fixed electrodes 133 and 134 are respectively provided on the surfaces of the insulating films 131 and 132 on the wall of the internal chamber 12 facing the measurement diaphragm 13.

Reference numeral 2 denotes a pressure guide tube whose one end is connected to the differential pressure sensor section 1 via an insulator 21, and which guides the measured pressure. Insulator 2
1, glass is used in this case.

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

A seal diaphragm 31 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 a seal diaphragm 3 to which a pressure receiving block 3 is attached.
1 and a recess 42 forming a pressure receiving chamber 41.

43 and 44 are provided in the base block 4, and one end communicates with the pressure receiving chamber 41, fl! l! These are two connection holes whose ends open to the outside as pressure receiving connection ports.

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

5 is provided in the base block 4 as shown in FIG. 4, and normally communicates with the connection hole 44 through a communication groove 52 provided on the circumferential surface of the rotary valve body 51, and when adjusting the zero point,
The communication groove 52 is rotated to disconnect the connection hole 44 from the connection hole 4.
This is a rotary type pressure equalizing valve that communicates between the pressure receiving chamber 42 side of No. 4 and the connection hole 43.

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 1.01 and 102 are filled liquids sealed in two chambers consisting of a measurement chamber 14, 15, a pressure impulse pipe 2, and a seal chamber 32. In this case, silicone oil is used.

In the above configuration, since the connecting 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 diaphragm 13 is displaced by the difference in the measurement pressures. As the measurement diaphragm 13 is displaced, the capacitance between the fixed electrode 133134 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, as shown in FIG. The communication is cut off and the pressure receiving chamber 42 side of the connection hole 44 communicates with the connection hole 43, and then the zero point of the device is adjusted.As a result, (1) the main body of the differential pressure measuring device and the switching valve were integrated; , bolts, body flanges, brackets, etc. are not required for installation, making it compact, lightweight, and cost-effective.

(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 base block 4 by the impulse pipe 2 and supported in the air, it is not 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 the input circuit can be done by simply rotating the main body 51 of the rotary valve.

(5) The impulse tube 2 has one end connected to the differential pressure sensor section 1 with an insulator 21.
Since they are connected to each other via the sensor section 1, the sensor section 1 can be made into a non-grounded structure, and the electric circuit can be simplified.

(6) Since the insulating films 131 and 132 are sprayed ceramics, they can be made extremely thin, there is no need to sandwich 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. I can do it.

In the above-mentioned embodiment, the rotary type pressure equalizing valve 5 was described as being manually operated, but it goes without saying that it may be a remote type valve using a solenoid valve or the like.

<Effects of the Invention> As explained above, the present invention has a block-shaped main body,
an internal chamber provided inside the main body and consisting of opposing spherical surfaces;
The internal chamber is divided into two measurement chambers into which measurement pressure is introduced, and includes a 1+11 constant diaphragm that functions as a moving electrode, an insulating film made of a plasma sprayed ceramic film provided on the wall of the internal chamber, and an insulating film made of a plasma sprayed ceramic film. a differential pressure sensor section including a fixed electrode provided on a surface facing the measurement diaphragm; a pressure impulse tube whose one end is connected to the differential pressure sensor section via an insulator and which guides the measurement pressure; a pressure-receiving block to which the other ends of the pressure-receiving tubes are respectively fixed; a seal diaphragm provided on the outer surface of the pressure-receiving block and forming a seal chamber communicating with the pressure-receiving block and the pressure-receiving tube; and a seal to which the pressure-receiving block is attached. a base block having a concave portion constituting a diaphragm and a pressure receiving chamber; two connection holes 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; A communication groove provided on the circumferential surface of the rotary valve body normally connects one of the connection holes, and when adjusting the zero point, the communication groove is rotated to disconnect the one connection hole and connect the one connection. A differential pressure measuring device was constructed which included a rotary pressure equalizing valve that communicates the pressure receiving chamber side of the hole with the other side of the connection hole.

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, body flanges, brackets, etc. for installation, resulting in a smaller size, lighter weight, and cost reduction6 (2) Differential pressure No need for piping between the main body of the measuring device and the switching valve.

(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 device is obtained.

(4) Switching the input circuit can be done with one touch, as all you have to do is turn the rotary valve body.

(5) Since one end of each pressure impulse pipe is connected to the differential pressure sensor section through an insulator, the sensor section can be made into a non-grounded structure, and the electric circuit can be simplified.

(6) Since a sprayed ceramic film is used as the insulating film, it can be made extremely thin, there is no need to hold the main body large, the strength of the main body can be increased, and the main body can be made smaller.

Therefore, according to the present invention, it is possible to reduce costs by reducing size and weight, eliminating the need for parts such as piping, and making it possible to make the sensor part a non-grounded structure that allows easy switching of input circuits.
It is possible to realize a differential pressure measuring device whose electric circuit can be simplified.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the main part of an embodiment of the present invention, FIG. 2 is a perspective view of FIG. 1, and FIGS. 3, 4, and 5 are explanatory diagrams of the main part of FIG. FIG. 6 is a diagram illustrating the configuration of a conventional example that has been commonly used. ■... 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, 14.15...Measurement chamber, 2.
... Impulse tube, 21... Insulator, 3... Pressure receiving block, 31... Seal diaphragm, 32... Seal chamber, 4... Base block, 41... Pressure receiving chamber, 42...
... Recessed portion, 43.44... Connection hole, 5... Rotary pressure equalizing valve, 51... Rotary valve body, 52... Communication groove, 6... Cover, 61... Printed board unit. Figure 3 Figure 3

Claims (1)

[Claims] A block-shaped main body, an internal chamber formed inside the main body and made of opposing spherical surfaces, and a chamber into which measurement pressure is introduced.
a measuring diaphragm that functions as a movable electrode divided into two measuring chambers; an insulating film made of a ceramic plasma sprayed film provided on the wall of the internal chamber; and a measuring diaphragm provided on the surface of the insulating film opposite to the measuring diaphragm a differential pressure sensor section including a fixed electrode; a pressure impulse tube whose one end is connected to the differential pressure sensor section via an insulator and which guides the measured pressure;
a pressure receiving block to which the other ends of the impulse pipes are respectively fixed;
a seal diaphragm provided on the outer surface of the pressure receiving 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 the seal diaphragm and the pressure receiving chamber; two connection holes provided in the base block, one end communicating with the pressure receiving chamber and the other end opening to the outside as a pressure receiving connection port; and a communication groove provided in the base block and provided on the circumferential surface of the rotary valve body. Normally, one of the connection holes is connected, and when adjusting the zero point, the communication groove is rotated to disconnect the one connection hole and connect the pressure receiving chamber side of the one connection hole and the other connection hole. A differential pressure measuring device comprising a rotary type pressure equalizing valve that communicates with the valve.