JP2003302264A - Ultrasonic propagation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive ultrasonic propagation device having an excellent assemblage, manufacturable at a low cost, and providing a high reliability. <P>SOLUTION: This ultrasonic propagation device for measuring the flow or physical amount of measured fluid flowing in a measurement pipe comprises a straight measurement pipe having a same diameter through the overall length thereof, two ultrasonic piezoelectric vibrators installed on the upstream and downstream sides of the measurement pipe at a specified interval with the inner peripheral surface thereof fitted to the outer peripheral surface of the measurement pipe, providing specified measurement sensitivities, and formed in semi-circular or smaller annular shapes, and a calculation circuit for receiving ultrasonic transmitted from one ultrasonic piezoelectric vibrator by the other ultrasonic piezoelectric vibrator and calculating the flow or physical amount of the flow by the signals. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic wave propagation device which is easy to assemble, allows cost reduction, has high reliability, and is inexpensive.

[0002]

2. Description of the Related Art FIG. 9 is a structural explanatory view of a conventional example which has been generally used, for example, Japanese Patent Laid-Open No. 2000-180.
No. 228 (Japanese Patent Application No. 10-359753).

In the figure, reference numeral 11 is a straight tube-shaped measuring tube in which the measuring fluid FL flows and has the same diameter over its entire length. 1
Reference numerals 2 and 13 are an annular first ultrasonic piezoelectric vibrator and a second ultrasonic piezoelectric vibrator which are arranged in the measuring tube 11 at a constant distance L.

Reference numerals 14 and 15 designate one ultrasonic piezoelectric vibrator 1
This is a switching circuit that receives the ultrasonic waves transmitted from the other ultrasonic piezoelectric vibrators 12 and 13 and alternately switches the ultrasonic piezoelectric vibrators 12 and 13 on the transmitting side and the receiving side.

Propagations 16 and 17 measure the propagation time of the ultrasonic wave from the upstream side to the downstream side and the propagation time of the ultrasonic wave from the downstream side to the upstream side, respectively, based on the switching of switching circuits 14 and 15. It is a time measuring circuit.

Reference numeral 18 is an arithmetic circuit for calculating the flow rate or physical quantity of the fluid to be measured by the signals from the propagation time measuring circuits 16 and 17. Reference numeral 19 is a power source.

Reference numerals 21 and 22 denote two ultrasonic piezoelectric vibrators 1.
It is a damping member that is provided in each of the measuring tubes 11 between 2 and 13 and attenuates the ultrasonic waves propagating through the measuring tube 11 between the two ultrasonic piezoelectric vibrators 12 and 13.

In the above configuration, the switching circuits 14 and 15
9 is switched to the side A as shown in FIG. 9, the ultrasonic piezoelectric vibrator 12 is used as an oscillator, and the ultrasonic piezoelectric vibrator 13 is used as a geophone. .

In addition, the switching circuits 14 and 15 are reversed from those of FIG.
By switching to the B side, the propagation time of the reverse flow can be measured by the propagation time measuring circuits 16 and 17 using the ultrasonic piezoelectric vibrator 12 as a geophone and the ultrasonic piezoelectric vibrator 13 as an oscillator.

In the arithmetic circuit 18, the seeding time measuring circuit 16,
From the signal from 17, it is possible to calculate the flow rate or physical quantity of the measurement fluid FL. At this time, the damping member 2
Reference numerals 1 and 22 denote vibration waves propagating in the measuring tube 11 itself, in particular,
It exerts the effect of cutting high frequency waves.

[0011]

In the ultrasonic wave propagation device of the conventional example shown in FIG. 9, annular ultrasonic piezoelectric vibrators 12 and 13 are attached to the entire circumference of a straight measuring tube 11 to transmit and receive ultrasonic waves. The flow rate or physical quantity of the measurement fluid is measured from the propagation time.

As for the damping members 21 and 22 for directly attenuating ultrasonic waves for propagation in the measuring pipe 11, the annular damping members 21 and 22 are attached to the measuring pipe 11 by adhesion or the like.

Conventional annular ultrasonic piezoelectric vibrators 12, 1
When 3 is used, it is necessary to attach a flange larger than the diameter of the measuring pipe 11 or a pipe joint to both ends of the measuring pipe 11 after passing the measuring pipe 11 through the hole of the piezoelectric element and then assembling it at a predetermined position. , Flange fitting measuring pipe 1
It is necessary to attach it to 1 by adhesion or welding.

There is also an assembly in which the ultrasonic piezoelectric vibrator is cut in half and assembled (Japanese Patent Laid-Open No. 11-264).
No. 750), and finally, two of them are combined and assembled into an annular shape for use. However, in a semicircular shape,
This is not a problem for the type that combines two ultrasonic piezoelectric vibrators cut in half.

Next, the case in which the ultrasonic piezoelectric vibrators 12 and 13 are housed is the same as the ultrasonic piezoelectric vibrators 12 and 13,
The measurement tube 11 needs to be provided so as to sandwich it. In general, this is to prevent corrosion of the electrodes of the ultrasonic piezoelectric vibrators 12 and 13 using silver-baked electrodes, protect lead wires, or withstand external stress from pipes contacting both ends of the measuring tube 11. This is to ensure that

The ultrasonic waves propagating in the measuring tube 11 itself between the transmitter and the receiver become noise, and the damping members 21 and 22 for reducing the noise are provided in the ultrasonic piezoelectric vibrators 12 and 13.
In order to attach it in the same manner as above, it is necessary to carry out adhesion or the like.

Further, it is general that the conversion portion for performing the signal processing is formed separately from the detection portion, but it is expensive in cost.

An object of the present invention is to solve the above problems, and the present invention provides an ultrasonic wave propagation device which is easy to assemble, enables cost reduction, is highly reliable, and is inexpensive. is there.

[0019]

In order to achieve such an object, according to the present invention, in the ultrasonic wave propagation device according to claim 1, ultrasonic waves are used as the flow rate or physical quantity of the measuring fluid flowing in the measuring pipe. In the ultrasonic wave propagating device for measuring by a straight tube measuring tube having the same diameter over the entire length,
Two ultrasonic piezoelectric vibrators having an inner peripheral surface attached to the outer peripheral surface of the measuring tube at a predetermined interval upstream and downstream of the measuring tube to obtain a predetermined measurement sensitivity and having a shape of a semi-circular ring or less, A switching circuit that receives ultrasonic waves transmitted from one of the ultrasonic piezoelectric vibrators by the other ultrasonic piezoelectric vibrator and switches the ultrasonic piezoelectric vibrators on the transmitting side and the receiving side alternately, and switching of this switching circuit A propagation time measuring circuit that measures the propagation time of the ultrasonic wave from the upstream side to the downstream side and the propagation time of the ultrasonic wave from the downstream side to the upstream side, respectively, based on And a calculation circuit for calculating the flow rate or physical quantity of.

In the ultrasonic wave propagating device according to the second aspect of the present invention, in the ultrasonic wave propagating device for measuring the flow rate or physical quantity of the measuring fluid flowing in the measuring pipe by using ultrasonic waves, a straight line having the same diameter over the entire length. A tubular measuring tube, and two superstructures having an inner peripheral surface attached to the outer peripheral surface of the measuring tube at predetermined intervals upstream and downstream of the measuring tube to obtain a predetermined measurement sensitivity and having a shape of a semicircular ring or less. A piezoelectric acoustic wave oscillator and an arithmetic circuit that receives an ultrasonic wave transmitted from one ultrasonic piezoelectric oscillator at the other ultrasonic piezoelectric oscillator and calculates a physical quantity from the magnitude of the reception level. And

According to a third aspect of the present invention, in the ultrasonic wave propagation device according to the first or second aspect, the measuring tube, the joint portion, and the protective case for the ultrasonic piezoelectric vibrator are integrally formed from the beginning. It is characterized by being formed.

According to a fourth aspect of the present invention, in the ultrasonic wave propagation device according to the third aspect, the two ultrasonic transducers provided in the measuring tubes between the two semi-annular ultrasonic piezoelectric vibrators are provided. An attenuating member for attenuating ultrasonic noise propagating in the measuring tube between the sonic piezoelectric vibrators, the measuring tube, a joint portion, and a protective case of the ultrasonic piezoelectric vibrator are integrally formed from the beginning. And

According to a fifth aspect of the present invention, in the ultrasonic wave propagation device according to the third or fourth aspect, the storage case for storing the conversion circuit is formed integrally with the protective case from the beginning. And

According to a sixth aspect of the present invention, in the ultrasonic wave propagation device according to any one of the third to fifth aspects,
It is characterized by being integrally formed from the beginning with resin.

[0025]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in detail below with reference to the drawings. FIG. 1 is an explanatory view of the main configuration of an embodiment of the present invention,
2 is a plan view of FIG. 1, FIG. 3 is a side view of FIG. 1, and FIG.
FIG. In the figure, the same symbols as those in FIG. 9 represent the same functions. Only the parts different from FIG. 9 will be described below.

In the figure, reference numeral 31 denotes an attenuating member 311 for attenuating ultrasonic noise propagating in a measuring pipe 312 between two ultrasonic piezoelectric vibrators 33 and 34, which will be described later, and a measuring pipe 312.
The joint body 313, the protective case 314 for the ultrasonic piezoelectric vibrators 33 and 34, and the housing case 315 for housing the arithmetic circuit 18 are integrally formed from the beginning.

Further, the damping member 311 is the measuring pipe 312.
In addition, it also serves as a structural member that doubles as a support for the converter and a reinforcing material for the pipe. In this case, the resin is integrally molded. A cover 32 covers the storage case 315.

33 and 34 are provided on the upstream and downstream sides of the measuring pipe 312,
These are two ultrasonic piezoelectric vibrators whose inner peripheral surface is attached to the outer peripheral surface of the measuring tube 312 at a predetermined interval L, has a predetermined measurement sensitivity, and has a shape of a semi-circular ring or smaller. In this case, the ultrasonic piezoelectric vibrators 33 and 34 have a semi-annular shape.

In the above structure, two semi-annular ultrasonic piezoelectric vibrators 33, 3 attached to the measuring tube 312.
The ultrasonic waves propagating through the fluid in the pipe are detected by alternately transmitting and receiving ultrasonic waves from 4, and the arithmetic circuit 18 converts the ultrasonic waves into a flow rate signal.

Here, according to the experiments conducted by the inventor, even if the ultrasonic piezoelectric vibrators 33 and 34 are not annular, but semi-annular, they are sufficient for signal processing at the ultrasonic transmission / reception level. It was found that sensitivity was obtained.

As a result, (1) the semi-annular ultrasonic piezoelectric vibrator may be directly attached to the outer circumference of the measuring tube, and the ultrasonic piezoelectric vibrator needs to be passed from the end of the measuring tube to a predetermined position. When using a flange or pipe joint larger than the diameter of the measuring pipe, it is not necessary to assemble the flange or pipe joint to the measuring pipe after assembling the ultrasonic piezoelectric vibrator to the measuring pipe, and the ease of assembly is good and the cost can be reduced. Therefore, a highly reliable and inexpensive ultrasonic wave propagation device can be obtained.

(2) If the measuring tube, the joint, and the protective case for the ultrasonic piezoelectric vibrator are integrally formed from the beginning, the assembling property is further improved, the cost can be reduced, and the reliability can be improved. A high and inexpensive ultrasonic wave propagation device can be obtained. This is possible because a semi-annular ultrasonic piezoelectric vibrator can be adopted.

(3) An ultrasonic wave propagating through the measuring pipe between the two semi-annular ultrasonic piezoelectric vibrators is provided in each of the measuring pipes between the two semi-annular ultrasonic piezoelectric vibrators. The damping member and the measuring tube were integrally formed from the beginning.

Therefore, it is not necessary to perform adhesion, and further,
Assembleability is good, cost reduction is possible, and because it is acoustically integrated, the damping effect is large, the reliability is high,
An inexpensive ultrasonic wave propagation device can be obtained. This is possible because a semi-annular ultrasonic piezoelectric vibrator can be adopted.

(4) The storage case for storing the conversion circuit is
As it was formed by integral molding from the beginning with the protective case,
It is not a separate body, the cost is low, the assemblability is good, the cost can be reduced, the reliability is high, and the inexpensive ultrasonic wave propagation device can be obtained.

Further, since the detecting portion and the protective case can be constituted by only two resin parts, the ultrasonic flowmeter which is easy to assemble, inexpensive and excellent in reliability can be obtained.

(5) Since the resin is integrally formed from the beginning, the assembling property is good, the cost can be reduced, the reliability is high, and the ultrasonic wave transmitting device is inexpensive.

FIG. 5 is an explanatory view of the essential structure of another embodiment of the present invention, and FIG. 6 is a side view of FIG. In this embodiment,
The mounting angles of the ultrasonic piezoelectric vibrators 33 and 34 to the measuring tube 312 are different from each other by 90 degrees.

FIG. 7 is an explanatory view of the essential structure of another embodiment of the present invention, and FIG. 8 is a side view of FIG. In this embodiment,
The attachment angles of the ultrasonic piezoelectric vibrators 33 and 34 to the measuring tube 312 are different from each other by 180 degrees.

In the above-mentioned embodiments, the semi-annular ultrasonic piezoelectric vibrators 33 and 34 have been described, but the present invention is not limited to this, and may be smaller than the semi-annular, for example. , The inner peripheral surface is attached to the outer peripheral surface of the measuring pipe 312 at a predetermined interval upstream and downstream of the measuring pipe 312,
Has a predetermined measurement sensitivity and has a shape of a semi-ring or less 2
Any number of ultrasonic piezoelectric vibrators may be used.

Further, in the above-mentioned embodiments, the mounting angles of the ultrasonic piezoelectric vibrators 33 and 34 to the measuring tube 312 are described as being offset from each other by 0 °, 90 ° and 180 °. It is not limited to the above, and it goes without saying that they may be displaced from each other any number of times.

The present invention is not limited to the ultrasonic flowmeter,
It is also applicable to a densitometer, a component analyzer, a bubble detector, etc. by measuring the speed of sound from the propagation time of sound or ultrasonic waves in a fluid, or by observing the reception level of ultrasonic waves.

The above description merely shows specific preferred embodiments for the purpose of explaining and exemplifying the present invention. Therefore, the present invention is not limited to the above-mentioned embodiment, and many modifications are made without departing from the essence thereof.
It also includes deformation.

[0044]

As described above, according to the first aspect of the present invention.
Alternatively, according to claim 2, there is the following effect. A straight tubular measuring tube having the same diameter over its entire length, and an inner peripheral surface attached to the outer peripheral surface of the measuring tube at a predetermined interval upstream and downstream of the measuring tube to obtain a predetermined measurement sensitivity and a semi-circular ring or less. Two ultrasonic piezoelectric vibrators having a shape, and ultrasonic waves transmitted from one of the ultrasonic piezoelectric vibrators are received by the other ultrasonic piezoelectric vibrator, and the ultrasonic wave of the measurement fluid is measured based on the propagation time or the size of the reception level. An arithmetic circuit for calculating a flow rate or a physical quantity is provided.

Therefore, it suffices to mount the ultrasonic piezoelectric vibrator directly on the outer circumference of the measuring pipe, and it is not necessary to pass the ultrasonic piezoelectric vibrator from the end of the measuring pipe to a predetermined position, and the ultrasonic piezoelectric vibrator is larger than the diameter of the measuring pipe. When using a flange or pipe joint, it is not necessary to assemble the flange or pipe joint on the measuring pipe after assembling the ultrasonic piezoelectric vibrator to the measuring pipe, and the assemblability is good, the cost can be reduced, and the reliability is high.
An inexpensive ultrasonic wave propagation device can be obtained.

According to claim 3 of the present invention, there are the following effects. Since the measuring tube, the joint and the protective case for the ultrasonic piezoelectric vibrator are integrally formed from the beginning, the assemblability is good, the cost can be reduced, the reliability is high, and the ultrasonic wave is inexpensive. A propagation device is obtained.

This is because the inner peripheral surface is attached to the outer peripheral surface of the measuring tube at a predetermined interval in the upstream and downstream of the measuring tube so that a predetermined measuring sensitivity can be obtained and the shape of the semi-circular ring or less is two. This is possible because a piezoelectric acoustic wave oscillator can be adopted.

According to claim 4 of the present invention, the following effects can be obtained. An attenuating member that is provided in each of the measuring tubes between the two ultrasonic piezoelectric vibrators and that attenuates the ultrasonic waves propagating through the measuring tubes between the two ultrasonic piezoelectric vibrators and the measuring tube are integrally molded from the beginning. Been formed.

Therefore, it is not necessary to perform adhesion or the like, and further,
Assembleability is good, cost reduction is possible, and because it is acoustically integrated, the damping effect is large, the reliability is high,
An inexpensive ultrasonic wave propagation device can be obtained.

This is because two superstructures having an inner peripheral surface attached to the outer peripheral surface of the measuring pipe at a predetermined interval upstream and downstream of the measuring pipe to obtain a predetermined measuring sensitivity and having a shape of a semi-circular ring or less. This is possible because a piezoelectric acoustic wave oscillator can be adopted.

According to claim 5 of the present invention, the following effects can be obtained. Since the storage case that houses the conversion circuit was formed integrally with the protective case from the beginning, it is not a separate body, it is cheaper in terms of cost, it is easy to assemble, cost can be reduced, and reliability is high. An inexpensive ultrasonic wave propagation device can be obtained.

According to claim 6 of the present invention, there are the following effects. Since the resin is integrally formed from the beginning, the assembling property is further improved, the cost can be reduced, the reliability is high, and the ultrasonic wave transmitting device is inexpensive.

Further, since the detecting portion and the protective case can be constituted by only two resin parts, the ultrasonic flowmeter which is easy to assemble, inexpensive and excellent in reliability can be obtained.

Therefore, according to the present invention, it is possible to realize an ultrasonic wave propagation device which has a good assembling property, enables cost reduction, has high reliability, and is inexpensive.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a main part configuration of an embodiment of the present invention.

FIG. 2 is a plan view of FIG.

FIG. 3 is a side view of FIG.

FIG. 4 is a cross-sectional view taken along the line AA of FIG.

FIG. 5 is an explanatory diagram of a main part configuration of another embodiment of the present invention.

FIG. 6 is a side view of FIG.

FIG. 7 is an explanatory diagram of a main part configuration of another embodiment of the present invention.

FIG. 8 is a side view of FIG. 7.

FIG. 9 is an explanatory diagram of a main part configuration of a conventional example that is generally used in the past.

[Explanation of symbols]

11 measuring tubes 12 First ultrasonic piezoelectric vibrator 13 Second ultrasonic piezoelectric vibrator 14 Switching circuit 15 Switching circuit 16 Propagation time measurement circuit 17 Propagation time measurement circuit 18 Arithmetic circuit 19 power supply 21 Damping member 22 Damping member 31 Case body 311 Damping member 312 measuring tube 313 Joint part 314 protective case 315 storage case 32 covers 33 Ultrasonic piezoelectric vibrator 34 Ultrasonic Piezoelectric Transducer FL measuring fluid

Claims (6)

[Claims] 1. An ultrasonic wave propagation device for measuring the flow rate or physical quantity of a measuring fluid flowing in a measuring tube using ultrasonic waves, wherein a straight tube measuring tube having the same diameter over its entire length and upstream and downstream of this measuring tube. Two ultrasonic piezoelectric vibrators having an inner peripheral surface attached to the outer peripheral surface of the measuring tube at a predetermined interval to obtain a predetermined measurement sensitivity and having a shape of a semi-circular ring or less, and one of the ultrasonic piezoelectric vibrations. A switching circuit that receives the ultrasonic wave transmitted from the child by the other ultrasonic piezoelectric vibrator and alternately switches the ultrasonic piezoelectric vibrators on the transmitting side and the receiving side, and from the upstream side to the downstream side based on the switching of this switching circuit. Side propagation time measurement circuit that measures the propagation time of the ultrasonic wave to the side and the propagation time of the ultrasonic wave from the downstream side to the upstream side respectively, and the flow rate or physical quantity of the measured fluid is calculated by the signal from this seeding time measurement circuit. Calculation Ultrasonic propagation apparatus characterized by comprising a road. 2. An ultrasonic wave propagation device for measuring the flow rate or physical quantity of a measuring fluid flowing in a measuring tube by using ultrasonic waves, wherein a straight tube measuring tube having the same diameter over its entire length and upstream and downstream of this measuring tube. Two ultrasonic piezoelectric vibrators having an inner peripheral surface attached to the outer peripheral surface of the measuring tube at a predetermined interval to obtain a predetermined measurement sensitivity and having a shape of a semi-circular ring or less, and one of the ultrasonic piezoelectric vibrations. An ultrasonic wave propagation device, comprising: an arithmetic circuit that receives an ultrasonic wave transmitted from a child by the other ultrasonic piezoelectric vibrator and calculates a physical quantity from the magnitude of the reception level. 3. The ultrasonic wave propagation device according to claim 1, wherein the measuring tube, the joint portion, and the protective case for the ultrasonic piezoelectric vibrator are integrally formed from the beginning. 4. An attenuating member, which is provided in each of the measuring pipes between the two ultrasonic piezoelectric vibrators and attenuates ultrasonic noise propagating in the measuring pipes between the two ultrasonic piezoelectric vibrators, and 4. The ultrasonic wave propagation device according to claim 3, wherein the measuring tube, the joint portion, and the protective case for the ultrasonic piezoelectric vibrator are integrally formed from the beginning. 5. The ultrasonic wave propagation device according to claim 3, wherein a housing case for housing the conversion circuit is formed integrally with the protective case from the beginning. 6. The ultrasonic wave propagation device according to claim 3, wherein the ultrasonic wave propagation device is integrally formed from resin from the beginning.