JPH0210128A - Differential pressure measuring instrument - Google Patents

Abstract

PURPOSE:To eliminate the need of a bolt, a body flange, a fitting bracket, etc. and to make the title instrument small in size and light in weight, and reduce its cost by constituting as one body a differential pressure measuring instrument and a changeover valve. CONSTITUTION:Usually connecting holes 43, 44 are allowed to communicate with each other, respectively, therefore, a measuring diaphragm 13 is displaced by differential pressure of measuring pressure from the right and the left of a body 11. When the measuring diaphragm 13 is displaced, the capacitance of fixed electrodes 133, 134 and the measuring diaphragm 13 is varied, and an output of an electric signal corresponding to the differential pressure is obtained. At the time of equalizing both measuring inputs of the instrument and adjusting the zero point, a pressure receiving chamber 41 side of the connecting hole 43 and a pressure receiving chamber 41 side of the connecting hole 44 are allowed to communicate with each other by rotating a rotary equalizing valve 5, and also, a pressure receiving connecting port 45 side of the connecting hole 43 and a pressure receiving connecting port 45 side of the connecting hole 44 are allowed to communicate with each other.

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.

<Problem 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. In addition, the device becomes complicated, making it difficult to reduce the size and weight of the device and reduce costs.

The present invention solves this problem.

The purpose of the present invention is to provide a differential pressure measuring device that can reduce costs by being smaller and lighter and eliminates the need for parts such as piping, has easy input circuit switching, and can stably and accurately adjust the zero point. It is in.

Means for Solving the Problems> In order to achieve this object, the present invention provides a differential pressure sensor section equipped with an excessive protection mechanism, and a conductor whose one end is connected to the differential pressure sensor section and which guides the measured pressure. A pressure pipe, a pressure receiving block to which the other ends of the pressure receiving pipe are respectively fixed, a seal diaphragm provided on an outer surface of the pressure receiving block and forming a seal chamber communicating with the pressure receiving block and the pressure pipe, and the pressure receiving block a base block having a recess that is attached and forms a pressure receiving chamber with the seal diaphragm; and two connecting 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 I. , two communication grooves provided in the base block facing the circumferential surface of the rotary valve body normally communicate each of the connection holes, and the communication grooves are rotated when adjusting the seven-point point. The communication between the two connection holes is then cut, and one communication groove connects the pressure receiving chamber side of the one connection hole with the pressure reception chamber side of the other connection hole, and the other communication groove connects the pressure receiving chamber side of the other connection hole. A differential pressure measuring device is constructed, comprising a rotary type pressure equalizing valve that communicates the pressure receiving connection port side of the connection hole with the pressure receiving connection port side of the other connection hole.

In the above configuration, since the connection 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 tire flammable is displaced by the difference between the measurement pressures. The capacitance between the fixed electrode and the measuring tyre-phragm changes differentially depending on the displacement of the measuring tyre-phragm, and an electrical signal output corresponding to the differential pressure is obtained.

In order to equalize the constant input pressure on both sides of the device and adjust the zero point of the device, rotate the two communication grooves provided on the circumferential surface of the rotary valve body, and adjust the communication between the two connection holes. one communication groove connects the pressure receiving chamber side of one connection hole with the pressure receiving chamber side of the other connection hole, and the other communication groove connects the pressure receiving connection port side of one connection hole with the pressure receiving chamber side of the other connection hole. Adjusting the zero point of the device after communicating with the pressure receiving connection port side will be described below in detail 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 measuring diaphragm which divides the internal chamber 12 into two measuring chambers 1, 4 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 guiding pipe whose one end is connected to the differential pressure sensor section 1 and which 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.

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 four parts 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 pressure receiving connection port 45.

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.

As shown in FIG.
．． The second communication grooves 52 and 53 normally allow the connection hole 43.
44, and when adjusting the zero point, the rotary valve main body 51 is rotated to connect the first. Second communication groove 52.5
3 to disconnect each of the connection holes 43 and 44, the first communication groove 52 connects the pressure receiving chamber 41 side of the connection hole 43 and the pressure receiving chamber 41 side of the connection hole 44, and the second Communication groove 5
3 is a rotary type pressure equalizing valve that communicates the pressure receiving connection port 45 side of the connection hole 43 with the pressure receiving connection port 45 side of the connection hole 44.

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 diaphragm 13 is displaced by the difference in the measurement pressures. Due to the displacement of the measurement diaphragm 13, the electrostatic charge 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 surface measurement input of the device and adjust the zero point of the device, rotate the rotary valve body 51 as shown in FIG. The second communication groove 5253 is rotated to disconnect communication between the connection holes 43 and 44, and the first communication groove 5253 is rotated.
2 communicates the pressure receiving chamber 41 side of the connection hole 43 with the pressure receiving chamber 41 side of the connection hole 44 , and the second communication groove 53 connects the connection hole 4 with the pressure receiving chamber 41 side of the connection hole 44 .
The zero point of the device is adjusted after communicating the pressure receiving connection port 45 side of No. 3 with the pressure receiving connection port 45 side of the connection hole 44. As a result, (1) the main body of the differential pressure measuring device and the switching valve can be integrated. This eliminates the need for bolts, body flanges, brackets, etc. for installation, resulting in smaller size, lighter weight, and lower costs.

(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 of the input circuit can be done with one touch, since it is only necessary to rotate the main body 51 of the rotary valve.

(5) When adjusting the zero point of the device, the first communication groove 52 connects the pressure receiving chamber 41 side of the connecting hole 43 and the pressure receiving chamber 4 side of the connecting hole 44.
1 side, and the pressure receiving connection L145 side of the connection hole 43 and the pressure receiving connection port 45 side of the connection hole 44 are communicated through the second communication groove 53, and then the zero point of the device is adjusted. The zero point can be adjusted easily and accurately without being affected by fluctuations.

(6) If ceramic sprayed films are used as the insulating films 131 and 132, they can be made extremely thin, so there is no need to sandwich the main body 11 large, and the strength of the main body 1 can be increased, so the main body 11 can be made smaller. I can do it.

In the above embodiments, the rotary 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 comprises: a differential pressure sensor section equipped with an overpressure protection mechanism; a guide pipe 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 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, 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. Normally, each of the connecting holes is connected by two communicating grooves provided facing each other on the circumferential surface of the rotary valve body, and when adjusting the zero point, the communicating groove is rotated to connect the two connecting holes. The pressure receiving chamber side of the one connection hole and the pressure receiving chamber side of the other connection hole are connected through one communication groove, and the pressure reception connection of the one connection hole is connected through the other communication groove. A differential pressure measuring device was constructed, comprising a rotary pressure equalizing valve ν that communicates the port side with the pressure receiving connection port side of the other connection hole.

As a result, (1) Since the main body part of the differential pressure measuring device and the switching valve can be integrated, bolts, main body flanges, brackets, etc. are not required for installation, and the device is small, lightweight, and cost-effective.

(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 supported in the air, so it is less susceptible to the influence of the temperature of the measuring fluid even if the measuring fluid is high temperature. A wide range of equipment is available.

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

(5) When adjusting the zero point of the device, rotate the two communication grooves to cut off communication between the two connection holes, and use one communication groove to connect the pressure receiving chamber side of one connection hole to the pressure receiving chamber side of the other connection hole. The zero point of the device is adjusted after communicating the pressure receiving chamber side of the connection hole and communicating the pressure receiving connection port side of one connection hole and the pressure receiving connection port side of the other connection hole through the other communication groove. The zero point can be adjusted easily and accurately without being affected by fluctuations in measurement pressure.

Therefore, according to the present invention, by reducing the size and weight and eliminating the need for parts such as piping, loss 1 to town can be achieved, input circuits can be easily switched, and zero point adjustment can be made stably and accurately in differential pressure measurement. Is it possible to realize the device?

[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 tire phragm, 131, 132 ... Insulating film, 133
, 1.34... Fixed electrode, 1.4.15... Measurement chamber,
2... Impulse pipe, 3... Pressure receiving block, 31... Seal diaphragm, 32... Seal chamber, 4... Base block, 41... Pressure receiving chamber, 42... Recess, 43
．． 44... Connection hole, 45... Pressure receiving connection port, 5...
Rotary pressure equalization valve, 51...Rotary valve body, 52
...First communication groove, 53...Second communication groove, 6...
Cover, 61...Printed board unit.

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; 2, which is provided in the block and has one end communicating with the pressure receiving chamber and the other end opening to the outside as a pressure receiving connection port.
Normally, the connecting holes are connected to each other by two connecting holes provided in the base block and facing the circumferential surface of the rotary valve body, and the communicating grooves are connected to each other during zero point adjustment. to disconnect the communication between the two connection holes and connect the pressure receiving chamber side of the one connection hole and the pressure receiving chamber side of the other connection hole through one of the communication grooves. A differential pressure measuring device comprising a rotary pressure equalizing valve that communicates the pressure receiving connection port side of the one connection hole with the pressure receiving connection port side of the other connection hole through a groove.